Scale the DNS random scket pool on the value of dns-forward-max.

Previously, without min-port or max-port configured, dnsmasq would
default to the compiled in defaults for those, which are 1024 and
65535. Now, when neither are configured, it defaults instead to
the kernel's ephemeral port range, which is typically
32768 to 60999 on Linux systems. This change eliminates the
possibility that dnsmasq may be using a registered port > 1024
when a long-running daemon starts up and wishes to claim it.

This change does likely slighly reduce the number of random ports
and therefore the protection from reply spoofing. The older
behaviour can be restored using the min-port and max-port config
switches should that be a concern.

CHANGELOG

@@ -1,7 +1,114 @@
+version 2.85
+        Fix problem with DNS retries in 2.83/2.84.
+        The new logic in 2.83/2.84 which merges distinct requests
+	for the same domain causes problems with clients which do
+	retries as distinct requests (differing IDs and/or source ports.)
+	The retries just get piggy-backed on the first, failed, request.
+        The logic is now changed so that distinct requests for repeated
+        queries still get merged into a single ID/source port, but
+	they now always trigger a re-try upstream.
+        Thanks to Nicholas Mu for his analysis.
+
+	Tweak sort order of tags in get-version. v2.84 sorts
+	before v2.83, but v2.83 sorts before v2.83rc1 and 2.83rc1
+	sorts before v2.83test1. This fixes the problem which lead
+	to 2.84 announcing itself as 2.84rc2.
+
+ 	Avoid treating a --dhcp-host which has an IPv6 address
+	as eligable for use with DHCPv4 on the grounds that it has
+	no address, and vice-versa. Thanks to Viktor Papp for
+	spotting the problem. (This bug was fixed was back in 2.67, and
+	then regessed in 2.81).
+
+	Add --dynamic-host option: A and AAAA records which take their
+	network part from the network of a local interface. Useful
+	for routers with dynamically prefixes. Thanks
+	to Fred F for the suggestion.
+
+	Teach --bogus-nxdomain and --ignore-address to take an IPv4 subnet.
+
+	Use random source ports where possible if source
+	addresses/interfaces in use.
+	CVE-2021-3448 applies. Thanks to Petr Menšík for spotting this.
+	It's possible to specify the source address or interface to be
+	used when contacting upstream nameservers: server=8.8.8.8@1.2.3.4
+	or server=8.8.8.8@1.2.3.4#66 or server=8.8.8.8@eth0, and all of
+	these have, until now, used a single socket, bound to a fixed
+	port. This was originally done to allow an error (non-existent
+	interface, or non-local address) to be detected at start-up. This
+	means that any upstream servers specified in such a way don't use
+	random source ports, and are more susceptible to cache-poisoning
+	attacks.
+	We now use random ports where possible, even when the
+	source is specified, so server=8.8.8.8@1.2.3.4 or
+	server=8.8.8.8@eth0 will use random source
+	ports. server=8.8.8.8@1.2.3.4#66 or any use of --query-port will
+	use the explicitly configured port, and should only be done with
+	understanding of the security implications.
+	Note that this change changes non-existing interface, or non-local
+	source address errors from fatal to run-time. The error will be
+	logged and communiction with the server not possible.
+
+	Change the method of allocation of random source ports for DNS.
+	Previously, without min-port or max-port configured, dnsmasq would
+	default to the compiled in defaults for those, which are 1024 and
+	65535. Now, when neither are configured, it defaults instead to
+	the kernel's ephemeral port range, which is typically
+	32768 to 60999 on Linux systems. This change eliminates the
+	possibility that dnsmasq may be using a registered port > 1024
+	when a long-running daemon starts up and wishes to claim it.
+	This change does likely slighly reduce the number of random ports
+	and therefore the protection from reply spoofing. The older
+	behaviour can be restored using the min-port and max-port config
+	switches should that be a concern.
+
+	Scale the size of the DNS random-port pool based on the
+	value of the --dns-forward-max configuration.
+
+	
+version 2.84
+	Fix a problem, introduced in 2.83, which could see DNS replies
+	being sent via the wrong socket. On machines running both
+	IPv4 and IPv6 this could result in sporadic messages of
+	the form "failed to send packet: Network is unreachable" and
+	the lost of the query. Since the error is sporadic and of
+	low probability, the client retry would normally succeed.
+
+	Change HAVE_NETTLEHASH compile-time to HAVE_CRYPTOHASH.
+
+
 version 2.83
+	Use the values of --min-port and --max-port in outgoing
+	TCP connections to upstream DNS servers.
+
 	Fix a remote buffer overflow problem in the DNSSEC code. Any
 	dnsmasq with DNSSEC compiled in and enabled is vulnerable to this,
-	referenced by CERT VU#434904.
+	referenced by CVE-2020-25681, CVE-2020-25682, CVE-2020-25683
+	CVE-2020-25687.
+
+	Be sure to only accept UDP DNS query replies at the address
+	from which the query was originated. This keeps as much entropy
+	in the {query-ID, random-port} tuple as possible, to help defeat
+	cache poisoning attacks. Refer: CVE-2020-25684.
+
+	Use the SHA-256 hash function to verify that DNS answers
+	received are for the questions originally asked. This replaces
+	the slightly insecure SHA-1 (when compiled with DNSSEC) or
+	the very insecure CRC32 (otherwise). Refer: CVE-2020-25685.
+
+	Handle multiple identical near simultaneous DNS queries better.
+	Previously, such queries would all be forwarded
+	independently. This is, in theory, inefficent but in practise
+	not a problem, _except_ that is means that an answer for any
+	of the forwarded queries will be accepted and cached.
+	An attacker can send a query multiple times, and for each repeat,
+	another {port, ID} becomes capable of accepting the answer he is
+	sending in the blind, to random IDs and ports. The chance of a
+	succesful attack is therefore multiplied by the number of repeats
+	of the query. The new behaviour detects repeated queries and
+	merely stores the clients sending repeats so that when the
+	first query completes, the answer can be sent to all the
+	clients who asked. Refer: CVE-2020-25686.
 	
 
 version 2.82

Makefile

@@ -1,4 +1,4 @@
-# dnsmasq is Copyright (c) 2000-2016 Simon Kelley
+# dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 #
 #  This program is free software; you can redistribute it and/or modify
 #  it under the terms of the GNU General Public License as published by
@@ -53,7 +53,7 @@ top?=$(CURDIR)
 
 dbus_cflags =   `echo $(COPTS) | $(top)/bld/pkg-wrapper HAVE_DBUS $(PKG_CONFIG) --cflags dbus-1` 
 dbus_libs =     `echo $(COPTS) | $(top)/bld/pkg-wrapper HAVE_DBUS $(PKG_CONFIG) --libs dbus-1` 
-ubus_libs =     `echo $(COPTS) | $(top)/bld/pkg-wrapper HAVE_UBUS "" --copy -lubox -lubus`
+ubus_libs =     `echo $(COPTS) | $(top)/bld/pkg-wrapper HAVE_UBUS "" --copy '-lubox -lubus'`
 idn_cflags =    `echo $(COPTS) | $(top)/bld/pkg-wrapper HAVE_IDN $(PKG_CONFIG) --cflags libidn` 
 idn_libs =      `echo $(COPTS) | $(top)/bld/pkg-wrapper HAVE_IDN $(PKG_CONFIG) --libs libidn` 
 idn2_cflags =   `echo $(COPTS) | $(top)/bld/pkg-wrapper HAVE_LIBIDN2 $(PKG_CONFIG) --cflags libidn2`
@@ -62,8 +62,12 @@ ct_cflags =     `echo $(COPTS) | $(top)/bld/pkg-wrapper HAVE_CONNTRACK $(PKG_CON
 ct_libs =       `echo $(COPTS) | $(top)/bld/pkg-wrapper HAVE_CONNTRACK $(PKG_CONFIG) --libs libnetfilter_conntrack`
 lua_cflags =    `echo $(COPTS) | $(top)/bld/pkg-wrapper HAVE_LUASCRIPT $(PKG_CONFIG) --cflags lua5.2` 
 lua_libs =      `echo $(COPTS) | $(top)/bld/pkg-wrapper HAVE_LUASCRIPT $(PKG_CONFIG) --libs lua5.2` 
-nettle_cflags = `echo $(COPTS) | $(top)/bld/pkg-wrapper HAVE_DNSSEC $(PKG_CONFIG) --cflags nettle hogweed`
-nettle_libs =   `echo $(COPTS) | $(top)/bld/pkg-wrapper HAVE_DNSSEC $(PKG_CONFIG) --libs nettle hogweed`
+nettle_cflags = `echo $(COPTS) | $(top)/bld/pkg-wrapper HAVE_DNSSEC     $(PKG_CONFIG) --cflags 'nettle hogweed' \
+                                                        HAVE_CRYPTOHASH $(PKG_CONFIG) --cflags nettle \
+                                                        HAVE_NETTLEHASH $(PKG_CONFIG) --cflags nettle`
+nettle_libs =   `echo $(COPTS) | $(top)/bld/pkg-wrapper HAVE_DNSSEC     $(PKG_CONFIG) --libs 'nettle hogweed' \
+                                                        HAVE_CRYPTOHASH $(PKG_CONFIG) --libs nettle \
+                                                        HAVE_NETTLEHASH $(PKG_CONFIG) --libs nettle`
 gmp_libs =      `echo $(COPTS) | $(top)/bld/pkg-wrapper HAVE_DNSSEC NO_GMP --copy -lgmp`
 sunos_libs =    `if uname | grep SunOS >/dev/null 2>&1; then echo -lsocket -lnsl -lposix4; fi`
 version =     -DVERSION='\"`$(top)/bld/get-version $(top)`\"'
@@ -77,7 +81,8 @@ objs = cache.o rfc1035.o util.o option.o forward.o network.o \
        helper.o tftp.o log.o conntrack.o dhcp6.o rfc3315.o \
        dhcp-common.o outpacket.o radv.o slaac.o auth.o ipset.o \
        domain.o dnssec.o blockdata.o tables.o loop.o inotify.o \
-       poll.o rrfilter.o edns0.o arp.o crypto.o dump.o ubus.o metrics.o
+       poll.o rrfilter.o edns0.o arp.o crypto.o dump.o ubus.o \
+       metrics.o hash_questions.o
 
 hdrs = dnsmasq.h config.h dhcp-protocol.h dhcp6-protocol.h \
        dns-protocol.h radv-protocol.h ip6addr.h metrics.h

bld/Android.mk

@@ -11,7 +11,7 @@ LOCAL_SRC_FILES :=  bpf.c cache.c dbus.c dhcp.c dnsmasq.c \
 		    radv.c slaac.c auth.c ipset.c domain.c \
 	            dnssec.c dnssec-openssl.c blockdata.c tables.c \
 		    loop.c inotify.c poll.c rrfilter.c edns0.c arp.c \
-		    crypto.c dump.c ubus.c
+		    crypto.c dump.c ubus.c metrics.c hash_questions.c
 
 LOCAL_MODULE := dnsmasq
 

bld/get-version

@@ -9,7 +9,10 @@
 # If we can find one which matches $v[0-9].* then we assume it's
 # a version-number tag, else we just use the whole string.
 # If there is more than one v[0-9].* tag, sort them and use the
-# first. This favours, eg v2.63 over 2.63rc6.
+# first. The insane arguments to the sort command are to ensure
+# that, eg v2.64 comes before v2.63, but v2.63 comes before v2.63rc1
+# and v2.63rc1 comes before v2.63test1
+
 
 # Change directory to the toplevel source directory.
 if test -z "$1" || ! test -d "$1" || ! cd "$1"; then
@@ -28,7 +31,7 @@ else
      vers=`cat $1/VERSION | sed 's/[(), ]/,/ g' | tr ',' '\n' | grep ^v[0-9]`
 
      if [ $? -eq 0 ]; then
-         echo "${vers}" | sort -r | head -n 1 | sed 's/^v//'
+         echo "${vers}" | sort -k1.2,1.5Vr -k1.6,1.6 -k1.8,1.9Vr -k1.10,1.11Vr | head -n 1 | sed 's/^v//'
      else
          cat $1/VERSION
      fi

bld/pkg-wrapper

@@ -1,35 +1,37 @@
 #!/bin/sh
 
-search=$1
-shift
-pkg=$1
-shift
-op=$1
-shift
-
 in=`cat`
 
-if grep "^\#[[:space:]]*define[[:space:]]*$search" config.h >/dev/null 2>&1 || \
-    echo $in | grep $search >/dev/null 2>&1; then
+search()
+{
+    grep "^\#[[:space:]]*define[[:space:]]*$1" config.h >/dev/null 2>&1 || \
+    echo $in | grep $1 >/dev/null 2>&1
+}
+
+while [ "$#" -gt 0 ]; do
+    search=$1
+    pkg=$2
+    op=$3
+    lib=$4
+    shift 4
+if search "$search"; then
+
 # Nasty, nasty, in --copy, arg 2 (if non-empty) is another config to search for, used with NO_GMP
     if [ $op = "--copy" ]; then
 	if [ -z "$pkg" ]; then
-	    pkg="$*"
-	elif grep "^\#[[:space:]]*define[[:space:]]*$pkg" config.h >/dev/null 2>&1 || \
-		 echo $in | grep $pkg >/dev/null 2>&1; then
+	    pkg="$lib"
+	elif search "$pkg"; then
 	    pkg=""
 	else 
-	    pkg="$*"
+	    pkg="$lib"
 	fi
-    elif grep "^\#[[:space:]]*define[[:space:]]*${search}_STATIC" config.h >/dev/null 2>&1 || \
-	     echo $in | grep ${search}_STATIC >/dev/null 2>&1; then
-	pkg=`$pkg  --static $op $*`
+    elif search "${search}_STATIC"; then
+	pkg=`$pkg  --static $op $lib`
     else
-	pkg=`$pkg $op $*`
+	pkg=`$pkg $op $lib`
     fi
     
-    if grep "^\#[[:space:]]*define[[:space:]]*${search}_STATIC" config.h >/dev/null 2>&1 || \
-	   echo $in | grep ${search}_STATIC >/dev/null 2>&1; then
+    if search "${search}_STATIC"; then
 	if [ $op = "--libs" ] || [ $op = "--copy" ]; then
 	    echo "-Wl,-Bstatic $pkg -Wl,-Bdynamic"
 	else
@@ -40,3 +42,4 @@ if grep "^\#[[:space:]]*define[[:space:]]*$search" config.h >/dev/null 2>&1 || \
     fi
 fi
 
+done

debian/changelog

@@ -1,3 +1,22 @@
+dnsmasq (2.85-1) unstable; urgency=low
+
+   * New upstream.
+
+ -- Simon Kelley <simon@thekelleys.org.uk>  Tue, 2 Mar 2021 21:40:23 +0000
+
+dnsmasq (2.84-1) unstable; urgency=low
+
+   * New upstream.
+
+ -- Simon Kelley <simon@thekelleys.org.uk>  Sun, 24 Jan 2021 22:02:01 +0000
+
+dnsmasq (2.83-1) unstable; urgency=high
+
+   * New upstream.
+   * Includes fixes to CVE-2020-25681 - CVE-2020-25687 inclusive.
+
+ -- Simon Kelley <simon@thekelleys.org.uk>  Fri, 15 Jan 2021 22:22:41 +0000
+
 dnsmasq (2.82-1) unstable; urgency=low
 
    * New upstream.

debian/copyright

@@ -1,4 +1,4 @@
-dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
 It was downloaded from: http://www.thekelleys.org.uk/dnsmasq/
 

man/dnsmasq.8

@@ -135,6 +135,9 @@ running, will go exclusively to the file.) When logging to a file,
 dnsmasq will close and reopen the file when it receives SIGUSR2. This 
 allows the log file to be rotated without stopping dnsmasq.
 .TP
+.B --log-debug
+Enable extra logging intended for debugging rather than information.
+.TP
 .B --log-async[=<lines>]
 Enable asynchronous logging and optionally set the limit on the
 number of lines
@@ -296,7 +299,7 @@ option requires non-standard networking APIs and it is only available
 under Linux. On other platforms it falls-back to \fB--bind-interfaces\fP mode.
 .TP
 .B \-y, --localise-queries
-Return answers to DNS queries from /etc/hosts and \fB--interface-name\fP which depend on the interface over which the query was
+Return answers to DNS queries from /etc/hosts and \fB--interface-name\fP and \fB--dynamic-host\fP which depend on the interface over which the query was
 received. If a name has more than one address associated with
 it, and at least one of those addresses is on the same subnet as the
 interface to which the query was sent, then return only the
@@ -323,8 +326,8 @@ are re-written. So
 .B --alias=192.168.0.10-192.168.0.40,10.0.0.0,255.255.255.0
 maps 192.168.0.10->192.168.0.40 to 10.0.0.10->10.0.0.40
 .TP 
-.B \-B, --bogus-nxdomain=<ipaddr>
-Transform replies which contain the IP address given into "No such
+.B \-B, --bogus-nxdomain=<ipaddr>[/prefix]
+Transform replies which contain the IP specified address or subnet into "No such
 domain" replies. This is intended to counteract a devious move made by
 Verisign in September 2003 when they started returning the address of
 an advertising web page in response to queries for unregistered names,
@@ -332,8 +335,8 @@ instead of the correct NXDOMAIN response. This option tells dnsmasq to
 fake the correct response when it sees this behaviour. As at Sept 2003
 the IP address being returned by Verisign is 64.94.110.11
 .TP 
-.B --ignore-address=<ipaddr>
-Ignore replies to A-record queries which include the specified address. 
+.B --ignore-address=<ipaddr>[/prefix]
+Ignore replies to A-record queries which include the specified address or subnet. 
 No error is generated, dnsmasq simply continues to listen for another reply. 
 This is useful to defeat blocking strategies which rely on quickly supplying a
 forged answer to a DNS request for certain domain, before the correct answer can arrive.
@@ -428,7 +431,7 @@ Tells dnsmasq to never forward A or AAAA queries for plain names, without dots
 or domain parts, to upstream nameservers. If the name is not known
 from /etc/hosts or DHCP then a "not found" answer is returned.
 .TP
-.B \-S, --local, --server=[/[<domain>]/[domain/]][<ipaddr>[#<port>]][@<source-ip>|<interface>[#<port>]]
+.B \-S, --local, --server=[/[<domain>]/[domain/]][<ipaddr>[#<port>]][@<interface>][@<source-ip>[#<port>]]
 Specify IP address of upstream servers directly. Setting this flag does
 not suppress reading of /etc/resolv.conf, use \fB--no-resolv\fP to do that. If one or more
 optional domains are given, that server is used only for those domains
@@ -489,7 +492,7 @@ source address specified but the port may be specified directly as
 part of the source address. Forcing queries to an interface is not
 implemented on all platforms supported by dnsmasq.
 .TP
-.B --rev-server=<ip-address>/<prefix-len>[,<ipaddr>][#<port>][@<source-ip>|<interface>[#<port>]]
+.B --rev-server=<ip-address>/<prefix-len>[,<ipaddr>][#<port>][@<interface>][@<source-ip>[#<port>]]
 This is functionally the same as 
 .B --server, 
 but provides some syntactic sugar to make specifying address-to-name queries easier. For example
@@ -591,6 +594,12 @@ If the time-to-live is given, it overrides the default, which is zero
 or the value of \fB--local-ttl\fP. The value is a positive integer and gives
 the time-to-live in seconds.
 .TP
+.B --dynamic-host=<name>,[IPv4-address],[IPv6-address],<interface>
+Add A, AAAA and PTR records to the DNS in the same subnet as the specified interface. The address is derived from the network part of each address associated with the interface, and the host part from the specified address. For example
+.B --dynamic-host=example.com,0.0.0.8,eth0
+will, when eth0 has the address 192.168.78.x and netmask 255.255.255.0 give the
+name example.com an A record for 192.168.78.8. The same principle applies to IPv6 addresses. Note that if an interface has more than one address, more than one A or AAAA record will be created. The TTL of the records is always zero, and any changes to interface addresses will be immediately reflected in them.
+.TP
 .B \-Y, --txt-record=<name>[[,<text>],<text>]
 Return a TXT DNS record. The value of TXT record is a set of strings,
 so  any number may be included, delimited by commas; use quotes to put
@@ -692,8 +701,8 @@ still marks the request so that no upstream nameserver will add client
 address information either. The default is zero for both IPv4 and
 IPv6. Note that upstream nameservers may be configured to return
 different results based on this information, but the dnsmasq cache
-does not take account. If a dnsmasq instance is configured such that
-different results may be encountered, caching should be disabled.
+does not take account. Caching is therefore disabled for such replies,
+unless the subnet address being added is constant.
 
 For example,
 .B --add-subnet=24,96
@@ -1045,6 +1054,19 @@ option, but aliases are possible by using CNAMEs. (See
 .B --cname
 ).
 
+More than one
+.B --dhcp-host
+can be associated (by name, hardware address or UID) with a host. Which one is used
+(and therefore which address is allocated by DHCP and appears in the DNS) depends
+on the subnet on which the host last obtained a DHCP lease:
+the
+.B --dhcp-host
+with an address within the subnet is used. If more than one address is within the subnet,
+the result is undefined. A corollary to this is that the name associated with a host using
+.B --dhcp-host
+does not appear in the DNS until the host obtains a DHCP lease.
+
+
 The special keyword "ignore"
 tells dnsmasq to never offer a DHCP lease to a machine. The machine
 can be specified by hardware address, client ID or hostname, for
@@ -1436,7 +1458,7 @@ functions when supported by a suitable DHCP server.
 This specifies a boot option which may appear in a PXE boot menu. <CSA> is
 client system type, only services of the correct type will appear in a
 menu. The known types are x86PC, PC98, IA64_EFI, Alpha, Arc_x86,
-Intel_Lean_Client, IA32_EFI,  X86-64_EFI, Xscale_EFI, BC_EFI, ARM32_EFI and ARM64_EFI; an
+Intel_Lean_Client, IA32_EFI,  x86-64_EFI, Xscale_EFI, BC_EFI, ARM32_EFI and ARM64_EFI; an
 integer may be used for other types. The
 parameter after the menu text may be a file name, in which case dnsmasq acts as a
 boot server and directs the PXE client to download the file by TFTP,
@@ -1480,6 +1502,22 @@ to allow netbooting. This mode is enabled using the
 .B proxy
 keyword in
 .B --dhcp-range.
+.TP
+.B --dhcp-pxe-vendor=<vendor>[,...]
+According to UEFI and PXE specifications, DHCP packets between PXE clients and
+proxy PXE servers should have 
+.I PXEClient 
+in their vendor-class field. However, the firmware of computers from a few
+vendors is customized to carry a different identifier in that field. This option
+is used to consider such identifiers valid for identifying PXE clients. For 
+instance
+
+.B --dhcp-pxe-vendor=PXEClient,HW-Client
+
+will enable dnsmasq to also provide proxy PXE service to those PXE clients with
+.I HW-Client
+in as their identifier.
+>>>>>>> 907def3... pxe: support pxe clients with custom vendor-class
 .TP  
 .B \-X, --dhcp-lease-max=<number>
 Limits dnsmasq to the specified maximum number of DHCP leases. The
@@ -2351,6 +2389,8 @@ IPv4 and IPv6 addresses from /etc/hosts (and
 .B --host-record
 and 
 .B --interface-name
+and
+.B ---dynamic-host
 provided the address falls into one of the subnets specified in the
 .B --auth-zone.
 .PP

src/arp.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/auth.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/blockdata.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/bpf.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/cache.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/config.h

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -29,7 +29,6 @@
 #define UDP_TEST_TIME 60 /* How often to reset our idea of max packet size. */
 #define SERVERS_LOGGED 30 /* Only log this many servers when logging state */
 #define LOCALS_LOGGED 8 /* Only log this many local addresses when logging state */
-#define RANDOM_SOCKS 64 /* max simultaneous random ports */
 #define LEASE_RETRY 60 /* on error, retry writing leasefile after LEASE_RETRY seconds */
 #define CACHESIZ 150 /* default cache size */
 #define TTL_FLOOR_LIMIT 3600 /* don't allow --min-cache-ttl to raise TTL above this under any circumstances */
@@ -120,6 +119,9 @@ HAVE_AUTH
    define this to include the facility to act as an authoritative DNS
    server for one or more zones.
 
+HAVE_CRYPTOHASH
+   include just hash function from crypto library, but no DNSSEC.
+
 HAVE_DNSSEC
    include DNSSEC validator.
 
@@ -187,6 +189,7 @@ RESOLVFILE
 /* #define HAVE_IDN */
 /* #define HAVE_LIBIDN2 */
 /* #define HAVE_CONNTRACK */
+/* #define HAVE_CRYPTOHASH */
 /* #define HAVE_DNSSEC */
 
 
@@ -420,6 +423,10 @@ static char *compile_opts =
 "no-"
 #endif
 "auth "
+#if !defined(HAVE_CRYPTOHASH) && !defined(HAVE_DNSSEC)
+"no-"
+#endif
+"cryptohash "
 #ifndef HAVE_DNSSEC
 "no-"
 #endif

src/conntrack.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/crypto.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -25,6 +25,9 @@
 #if NETTLE_VERSION_MAJOR == 3 && NETTLE_VERSION_MINOR >= 6
 #  include <nettle/gostdsa.h>
 #endif
+#endif
+
+#if defined(HAVE_DNSSEC) || defined(HAVE_CRYPTOHASH)
 #include <nettle/nettle-meta.h>
 #include <nettle/bignum.h>
 
@@ -167,6 +170,10 @@ int hash_init(const struct nettle_hash *hash, void **ctxp, unsigned char **diges
 
   return 1;
 }
+
+#endif
+
+#ifdef HAVE_DNSSEC
   
 static int dnsmasq_rsa_verify(struct blockdata *key_data, unsigned int key_len, unsigned char *sig, size_t sig_len,
 			      unsigned char *digest, size_t digest_len, int algo)

src/dbus.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/dhcp-common.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -280,31 +280,29 @@ static int is_config_in_context(struct dhcp_context *context, struct dhcp_config
 {
   if (!context) /* called via find_config() from lease_update_from_configs() */
     return 1; 
+
+  if (!(config->flags & (CONFIG_ADDR | CONFIG_ADDR6)))
+    return 1;
   
 #ifdef HAVE_DHCP6
   if (context->flags & CONTEXT_V6)
     {
        struct addrlist *addr_list;
 
-       if (!(config->flags & CONFIG_ADDR6))
-	 return 1;
-       
-        for (; context; context = context->current)
-	  for (addr_list = config->addr6; addr_list; addr_list = addr_list->next)
-	    {
-	      if ((addr_list->flags & ADDRLIST_WILDCARD) && context->prefix == 64)
-		return 1;
-	      
-	      if (is_same_net6(&addr_list->addr.addr6, &context->start6, context->prefix))
-		return 1;
-	    }
+       if (config->flags & CONFIG_ADDR6)
+	 for (; context; context = context->current)
+	   for (addr_list = config->addr6; addr_list; addr_list = addr_list->next)
+	     {
+	       if ((addr_list->flags & ADDRLIST_WILDCARD) && context->prefix == 64)
+		 return 1;
+	       
+	       if (is_same_net6(&addr_list->addr.addr6, &context->start6, context->prefix))
+		 return 1;
+	     }
     }
   else
 #endif
     {
-      if (!(config->flags & CONFIG_ADDR))
-	return 1;
-      
       for (; context; context = context->current)
 	if ((config->flags & CONFIG_ADDR) && is_same_net(config->addr, context->start, context->netmask))
 	  return 1;

src/dhcp-protocol.h

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/dhcp.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/dhcp6-protocol.h

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/dhcp6.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/dns-protocol.h

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/dnsmasq.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -237,9 +237,16 @@ int main (int argc, char **argv)
     die(_("Ubus not available: set HAVE_UBUS in src/config.h"), NULL, EC_BADCONF);
 #endif
   
+  /* Handle only one of min_port/max_port being set. */
+  if (daemon->min_port != 0 && daemon->max_port == 0)
+    daemon->max_port = MAX_PORT;
+  
+  if (daemon->max_port != 0 && daemon->min_port == 0)
+    daemon->min_port = MIN_PORT;
+   
   if (daemon->max_port < daemon->min_port)
     die(_("max_port cannot be smaller than min_port"), NULL, EC_BADCONF);
-
+  
   now = dnsmasq_time();
 
   if (daemon->auth_zones)
@@ -390,8 +397,16 @@ int main (int argc, char **argv)
   if (daemon->port != 0)
     {
       cache_init();
-
       blockdata_init();
+      hash_questions_init();
+
+      /* Scale random socket pool by ftabsize, but
+	 limit it based on available fds. */
+      daemon->numrrand = daemon->ftabsize/2;
+      if (daemon->numrrand > max_fd/3)
+	daemon->numrrand = max_fd/3;
+      /* safe_malloc returns zero'd memory */
+      daemon->randomsocks = safe_malloc(daemon->numrrand * sizeof(struct randfd));
     }
 
 #ifdef HAVE_INOTIFY
@@ -980,7 +995,7 @@ int main (int argc, char **argv)
 	 a single file will be sent to may clients (the file only needs
 	 one fd). */
 
-      max_fd -= 30; /* use other than TFTP */
+      max_fd -= 30 + daemon->numrrand; /* use other than TFTP */
       
       if (max_fd < 0)
 	max_fd = 5;
@@ -1672,6 +1687,7 @@ static int set_dns_listeners(time_t now)
 {
   struct serverfd *serverfdp;
   struct listener *listener;
+  struct randfd_list *rfl;
   int wait = 0, i;
   
 #ifdef HAVE_TFTP
@@ -1692,11 +1708,14 @@ static int set_dns_listeners(time_t now)
   for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next)
     poll_listen(serverfdp->fd, POLLIN);
     
-  if (daemon->port != 0 && !daemon->osport)
-    for (i = 0; i < RANDOM_SOCKS; i++)
-      if (daemon->randomsocks[i].refcount != 0)
-	poll_listen(daemon->randomsocks[i].fd, POLLIN);
-	  
+  for (i = 0; i < daemon->numrrand; i++)
+    if (daemon->randomsocks[i].refcount != 0)
+      poll_listen(daemon->randomsocks[i].fd, POLLIN);
+
+  /* Check overflow random sockets too. */
+  for (rfl = daemon->rfl_poll; rfl; rfl = rfl->next)
+    poll_listen(rfl->rfd->fd, POLLIN);
+  
   for (listener = daemon->listeners; listener; listener = listener->next)
     {
       /* only listen for queries if we have resources */
@@ -1733,18 +1752,23 @@ static void check_dns_listeners(time_t now)
 {
   struct serverfd *serverfdp;
   struct listener *listener;
+  struct randfd_list *rfl;
   int i;
   int pipefd[2];
   
   for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next)
     if (poll_check(serverfdp->fd, POLLIN))
-      reply_query(serverfdp->fd, serverfdp->source_addr.sa.sa_family, now);
+      reply_query(serverfdp->fd, now);
   
-  if (daemon->port != 0 && !daemon->osport)
-    for (i = 0; i < RANDOM_SOCKS; i++)
-      if (daemon->randomsocks[i].refcount != 0 && 
-	  poll_check(daemon->randomsocks[i].fd, POLLIN))
-	reply_query(daemon->randomsocks[i].fd, daemon->randomsocks[i].family, now);
+  for (i = 0; i < daemon->numrrand; i++)
+    if (daemon->randomsocks[i].refcount != 0 && 
+	poll_check(daemon->randomsocks[i].fd, POLLIN))
+      reply_query(daemon->randomsocks[i].fd, now);
+
+  /* Check overflow random sockets too. */
+  for (rfl = daemon->rfl_poll; rfl; rfl = rfl->next)
+    if (poll_check(rfl->rfd->fd, POLLIN))
+      reply_query(rfl->rfd->fd, now);
 
   /* Races. The child process can die before we read all of the data from the
      pipe, or vice versa. Therefore send tcp_pids to zero when we wait() the 

src/dnsmasq.h

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
  
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -14,7 +14,7 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#define COPYRIGHT "Copyright (c) 2000-2020 Simon Kelley"
+#define COPYRIGHT "Copyright (c) 2000-2021 Simon Kelley"
 
 /* We do defines that influence behavior of stdio.h, so complain
    if included too early. */
@@ -95,11 +95,7 @@ typedef unsigned long long u64;
 #if defined(HAVE_SOLARIS_NETWORK)
 #  include <sys/sockio.h>
 #endif
-#if defined(HAVE_POLL_H)
-#  include <poll.h>
-#else
-#  include <sys/poll.h>
-#endif
+#include <poll.h>
 #include <sys/wait.h>
 #include <sys/time.h>
 #include <sys/un.h>
@@ -157,7 +153,11 @@ extern int capget(cap_user_header_t header, cap_user_data_t data);
 #include <priv.h>
 #endif
 
-#ifdef HAVE_DNSSEC
+/* Backwards compat with 2.83 */
+#if defined(HAVE_NETTLEHASH)
+#  define HAVE_CRYPTOHASH
+#endif
+#if defined(HAVE_DNSSEC) || defined(HAVE_CRYPTOHASH)
 #  include <nettle/nettle-meta.h>
 #endif
 
@@ -269,7 +269,8 @@ struct event_desc {
 #define OPT_IGNORE_CLID    59
 #define OPT_SINGLE_PORT    60
 #define OPT_LEASE_RENEW    61
-#define OPT_LAST           62
+#define OPT_LOG_DEBUG      62
+#define OPT_LAST           63
 
 #define OPTION_BITS (sizeof(unsigned int)*8)
 #define OPTION_SIZE ( (OPT_LAST/OPTION_BITS)+((OPT_LAST%OPTION_BITS)!=0) )
@@ -277,11 +278,13 @@ struct event_desc {
 #define option_val(x) ((1u) << ((x) % OPTION_BITS))
 #define option_bool(x) (option_var(x) & option_val(x))
 
-/* extra flags for my_syslog, we use a couple of facilities since they are known 
-   not to occupy the same bits as priorities, no matter how syslog.h is set up. */
+/* extra flags for my_syslog, we use facilities since they are known 
+   not to occupy the same bits as priorities, no matter how syslog.h is set up. 
+   MS_DEBUG messages are suppressed unless --log-debug is set. */
 #define MS_TFTP   LOG_USER
 #define MS_DHCP   LOG_DAEMON
 #define MS_SCRIPT LOG_MAIL
+#define MS_DEBUG  LOG_NEWS
 
 /* Note that this is used widely as a container for IPv4/IPv6 addresses,
    so for that reason, was well as to avoid wasting memory in almost every
@@ -322,7 +325,7 @@ union all_addr {
 
 
 struct bogus_addr {
-  struct in_addr addr;
+  struct in_addr addr, mask;
   struct bogus_addr *next;
 };
 
@@ -423,10 +426,17 @@ struct host_record {
   struct host_record *next;
 };
 
+#define IN4  1
+#define IN6  2
+#define INP4 4
+#define INP6 8
+
 struct interface_name {
   char *name; /* domain name */
   char *intr; /* interface name */
-  int family; /* AF_INET, AF_INET6 or zero for both */
+  int flags;
+  struct in_addr proto4;
+  struct in6_addr proto6;
   struct addrlist *addr;
   struct interface_name *next;
 };
@@ -539,13 +549,20 @@ struct serverfd {
 };
 
 struct randfd {
+  struct server *serv;
   int fd;
-  unsigned short refcount, family;
+  unsigned short refcount; /* refcount == 0xffff means overflow record. */
 };
-  
+
+struct randfd_list {
+  struct randfd *rfd;
+  struct randfd_list *next;
+};
+
 struct server {
   union mysockaddr addr, source_addr;
   char interface[IF_NAMESIZE+1];
+  unsigned int ifindex; /* corresponding to interface, above */
   struct serverfd *sfd; 
   char *domain; /* set if this server only handles a domain. */ 
   int flags, tcpfd, edns_pktsz;
@@ -653,23 +670,25 @@ struct hostsfile {
 #define FREC_DO_QUESTION       64
 #define FREC_ADDED_PHEADER    128
 #define FREC_TEST_PKTSZ       256
-#define FREC_HAS_EXTRADATA    512        
+#define FREC_HAS_EXTRADATA    512
+#define FREC_HAS_PHEADER     1024
+#define FREC_NO_CACHE        2048
 
-#ifdef HAVE_DNSSEC
-#define HASH_SIZE 20 /* SHA-1 digest size */
-#else
-#define HASH_SIZE sizeof(int)
-#endif
+#define HASH_SIZE 32 /* SHA-256 digest size */
 
 struct frec {
-  union mysockaddr source;
-  union all_addr dest;
+  struct frec_src {
+    union mysockaddr source;
+    union all_addr dest;
+    unsigned int iface, log_id;
+    int fd;
+    unsigned short orig_id;
+    struct frec_src *next;
+  } frec_src;
   struct server *sentto; /* NULL means free */
-  struct randfd *rfd4;
-  struct randfd *rfd6;
-  unsigned int iface;
-  unsigned short orig_id, new_id;
-  int log_id, fd, forwardall, flags;
+  struct randfd_list *rfds;
+  unsigned short new_id;
+  int forwardall, flags;
   time_t time;
   unsigned char *hash[HASH_SIZE];
 #ifdef HAVE_DNSSEC 
@@ -829,6 +848,7 @@ struct dhcp_opt {
 #define DHOPT_RFC3925         2048
 #define DHOPT_TAGOK           4096
 #define DHOPT_ADDR6           8192
+#define DHOPT_VENDOR_PXE     16384
 
 struct dhcp_boot {
   char *file, *sname, *tftp_sname;
@@ -852,6 +872,8 @@ struct pxe_service {
   struct pxe_service *next;
 };
 
+#define DHCP_PXE_DEF_VENDOR      "PXEClient"
+
 #define MATCH_VENDOR     1
 #define MATCH_USER       2
 #define MATCH_CIRCUIT    3
@@ -867,6 +889,11 @@ struct dhcp_vendor {
   struct dhcp_vendor *next;
 };
 
+struct dhcp_pxe_vendor {
+  char *data;
+  struct dhcp_pxe_vendor *next;
+};
+
 struct dhcp_mac {
   unsigned int mask;
   int hwaddr_len, hwaddr_type;
@@ -1040,6 +1067,7 @@ extern struct daemon {
   struct dhcp_config *dhcp_conf;
   struct dhcp_opt *dhcp_opts, *dhcp_match, *dhcp_opts6, *dhcp_match6;
   struct dhcp_match_name *dhcp_name_match;
+  struct dhcp_pxe_vendor *dhcp_pxe_vendors;
   struct dhcp_vendor *dhcp_vendors;
   struct dhcp_mac *dhcp_macs;
   struct dhcp_boot *boot_config;
@@ -1088,6 +1116,8 @@ extern struct daemon {
   int back_to_the_future;
 #endif
   struct frec *frec_list;
+  struct frec_src *free_frec_src;
+  int frec_src_count;
   struct serverfd *sfds;
   struct irec *interfaces;
   struct listener *listeners;
@@ -1096,11 +1126,13 @@ extern struct daemon {
   int forwardcount;
   struct server *srv_save; /* Used for resend on DoD */
   size_t packet_len;       /*      "        "        */
-  struct randfd *rfd_save; /*      "        "        */
+  int    fd_save;          /*      "        "        */
   pid_t tcp_pids[MAX_PROCS];
   int tcp_pipes[MAX_PROCS];
   int pipe_to_parent;
-  struct randfd randomsocks[RANDOM_SOCKS];
+  int numrrand;
+  struct randfd *randomsocks;
+  struct randfd_list *rfl_spare, *rfl_poll;
   int v6pktinfo; 
   struct addrlist *interface_addrs; /* list of all addresses/prefix lengths associated with all local interfaces */
   int log_id, log_display_id; /* ids of transactions for logging */
@@ -1217,10 +1249,9 @@ size_t answer_request(struct dns_header *header, char *limit, size_t qlen,
 		      struct in_addr local_addr, struct in_addr local_netmask, 
 		      time_t now, int ad_reqd, int do_bit, int have_pseudoheader);
 int check_for_bogus_wildcard(struct dns_header *header, size_t qlen, char *name, 
-			     struct bogus_addr *baddr, time_t now);
-int check_for_ignored_address(struct dns_header *header, size_t qlen, struct bogus_addr *baddr);
+			     time_t now);
+int check_for_ignored_address(struct dns_header *header, size_t qlen);
 int check_for_local_domain(char *name, time_t now);
-unsigned int questions_crc(struct dns_header *header, size_t plen, char *name);
 size_t resize_packet(struct dns_header *header, size_t plen, 
 		  unsigned char *pheader, size_t hlen);
 int add_resource_record(struct dns_header *header, char *limit, int *truncp,
@@ -1245,9 +1276,12 @@ int dnssec_validate_reply(time_t now, struct dns_header *header, size_t plen, ch
 			  int check_unsigned, int *neganswer, int *nons, int *nsec_ttl);
 int dnskey_keytag(int alg, int flags, unsigned char *key, int keylen);
 size_t filter_rrsigs(struct dns_header *header, size_t plen);
-unsigned char* hash_questions(struct dns_header *header, size_t plen, char *name);
 int setup_timestamp(void);
 
+/* hash_questions.c */
+void hash_questions_init(void);
+unsigned char *hash_questions(struct dns_header *header, size_t plen, char *name);
+
 /* crypto.c */
 const struct nettle_hash *hash_find(char *name);
 int hash_init(const struct nettle_hash *hash, void **ctxp, unsigned char **digestp);
@@ -1270,7 +1304,7 @@ void safe_strncpy(char *dest, const char *src, size_t size);
 void safe_pipe(int *fd, int read_noblock);
 void *whine_malloc(size_t size);
 int sa_len(union mysockaddr *addr);
-int sockaddr_isequal(union mysockaddr *s1, union mysockaddr *s2);
+int sockaddr_isequal(const union mysockaddr *s1, const union mysockaddr *s2);
 int hostname_isequal(const char *a, const char *b);
 int hostname_issubdomain(char *a, char *b);
 time_t dnsmasq_time(void);
@@ -1321,7 +1355,7 @@ char *parse_server(char *arg, union mysockaddr *addr,
 int option_read_dynfile(char *file, int flags);
 
 /* forward.c */
-void reply_query(int fd, int family, time_t now);
+void reply_query(int fd, time_t now);
 void receive_query(struct listener *listen, time_t now);
 unsigned char *tcp_request(int confd, time_t now,
 			   union mysockaddr *local_addr, struct in_addr netmask, int auth_dns);
@@ -1331,13 +1365,12 @@ int send_from(int fd, int nowild, char *packet, size_t len,
 	       union mysockaddr *to, union all_addr *source,
 	       unsigned int iface);
 void resend_query(void);
-struct randfd *allocate_rfd(int family);
-void free_rfd(struct randfd *rfd);
+int allocate_rfd(struct randfd_list **fdlp, struct server *serv);
+void free_rfds(struct randfd_list **fdlp);
 
 /* network.c */
 int indextoname(int fd, int index, char *name);
 int local_bind(int fd, union mysockaddr *addr, char *intname, unsigned int ifindex, int is_tcp);
-int random_sock(int family);
 void pre_allocate_sfds(void);
 int reload_servers(char *fname);
 void mark_servers(int flag);
@@ -1645,7 +1678,7 @@ size_t add_pseudoheader(struct dns_header *header, size_t plen, unsigned char *l
 			unsigned short udp_sz, int optno, unsigned char *opt, size_t optlen, int set_do, int replace);
 size_t add_do_bit(struct dns_header *header, size_t plen, unsigned char *limit);
 size_t add_edns0_config(struct dns_header *header, size_t plen, unsigned char *limit, 
-			union mysockaddr *source, time_t now, int *check_subnet);
+			union mysockaddr *source, time_t now, int *check_subnet, int *cacheable);
 int check_source(struct dns_header *header, size_t plen, unsigned char *pseudoheader, union mysockaddr *peer);
 
 /* arp.c */

src/dnssec.c

@@ -334,37 +334,64 @@ static int sort_rrset(struct dns_header *header, size_t plen, u16 *rr_desc, int
 	  if (!CHECK_LEN(header, state2.ip, plen, rdlen2))
 	    return rrsetidx; /* short packet */
 	  state2.end = state2.ip + rdlen2; 
-	  	  
-	  while (1)
-	    {
-	      int ok1, ok2;
-	      
-	      ok1 = get_rdata(header, plen, &state1);
-	      ok2 = get_rdata(header, plen, &state2);
 
-	      if (!ok1 && !ok2)
+	  /* If the RR has no names in it then canonicalisation
+	     is the identity function and we can compare
+	     the RRs directly. If not we compare the 
+	     canonicalised RRs one byte at a time. */
+	  if (*rr_desc == (u16)-1)	  
+	    {
+	      int rdmin = rdlen1 > rdlen2 ? rdlen2 : rdlen1;
+	      int cmp = memcmp(state1.ip, state2.ip, rdmin);
+	      
+	      if (cmp > 0 || (cmp == 0 && rdlen1 > rdmin))
+		{
+		  unsigned char *tmp = rrset[i+1];
+		  rrset[i+1] = rrset[i];
+		  rrset[i] = tmp;
+		  swap = 1;
+		}
+	      else if (cmp == 0 && (rdlen1 == rdlen2))
 		{
 		  /* Two RRs are equal, remove one copy. RFC 4034, para 6.3 */
 		  for (j = i+1; j < rrsetidx-1; j++)
 		    rrset[j] = rrset[j+1];
 		  rrsetidx--;
 		  i--;
-		  break;
 		}
-	      else if (ok1 && (!ok2 || *state1.op > *state2.op)) 
-		{
-		  unsigned char *tmp = rrset[i+1];
-		  rrset[i+1] = rrset[i];
-		  rrset[i] = tmp;
-		  swap = 1;
-		  break;
-		}
-	      else if (ok2 && (!ok1 || *state2.op > *state1.op))
-		break;
-	      
-	      /* arrive here when bytes are equal, go round the loop again
-		 and compare the next ones. */
 	    }
+	  else
+	    /* Comparing canonicalised RRs, byte-at-a-time. */
+	    while (1)
+	      {
+		int ok1, ok2;
+		
+		ok1 = get_rdata(header, plen, &state1);
+		ok2 = get_rdata(header, plen, &state2);
+		
+		if (!ok1 && !ok2)
+		  {
+		    /* Two RRs are equal, remove one copy. RFC 4034, para 6.3 */
+		    for (j = i+1; j < rrsetidx-1; j++)
+		      rrset[j] = rrset[j+1];
+		    rrsetidx--;
+		    i--;
+		    break;
+		  }
+		else if (ok1 && (!ok2 || *state1.op > *state2.op)) 
+		  {
+		    unsigned char *tmp = rrset[i+1];
+		    rrset[i+1] = rrset[i];
+		    rrset[i] = tmp;
+		    swap = 1;
+		    break;
+		  }
+		else if (ok2 && (!ok1 || *state2.op > *state1.op))
+		  break;
+		
+		/* arrive here when bytes are equal, go round the loop again
+		   and compare the next ones. */
+	      }
 	}
     } while (swap);
 
@@ -579,7 +606,7 @@ static int validate_rrset(time_t now, struct dns_header *header, size_t plen, in
       hash->update(ctx, (unsigned int)wire_len, (unsigned char*)keyname);
       from_wire(keyname);
 
-#define RRBUFLEN 300 /* Most RRs are smaller than this. */
+#define RRBUFLEN 128 /* Most RRs are smaller than this. */
       
       for (i = 0; i < rrsetidx; ++i)
 	{
@@ -617,50 +644,66 @@ static int validate_rrset(time_t now, struct dns_header *header, size_t plen, in
 	  hash->update(ctx, (unsigned int)wire_len, (unsigned char *)name_start);
 	  hash->update(ctx, 4, p); /* class and type */
 	  hash->update(ctx, 4, (unsigned char *)&nsigttl);
-	  
-	  p += 8; /* skip class, type, ttl */
+
+	  p += 8; /* skip type, class, ttl */
 	  GETSHORT(rdlen, p);
 	  if (!CHECK_LEN(header, p, plen, rdlen))
 	    return STAT_BOGUS; 
-	  
-	  /* canonicalise rdata and calculate length of same, use 
-	     name buffer as workspace for get_rdata. */
-	  state.ip = p;
-	  state.op = NULL;
-	  state.desc = rr_desc;
-	  state.buff = name;
-	  state.end = p + rdlen;
-	  
-	  for (j = 0; get_rdata(header, plen, &state); j++)
-	    if (j < RRBUFLEN)
-	      rrbuf[j] = *state.op;
 
-	  len = htons((u16)j);
-	  hash->update(ctx, 2, (unsigned char *)&len); 
-
-	  /* If the RR is shorter than RRBUFLEN (most of them, in practice)
-	     then we can just digest it now. If it exceeds RRBUFLEN we have to
-	     go back to the start and do it in chunks. */
-	  if (j >= RRBUFLEN)
+	  /* Optimisation for RR types which need no cannonicalisation.
+	     This includes DNSKEY DS NSEC and NSEC3, which are also long, so
+	     it saves lots of calls to get_rdata, and avoids the pessimal
+	     segmented insertion, even with a small rrbuf[].
+	     
+	     If canonicalisation is not needed, a simple insertion into the hash works.
+	  */
+	  if (*rr_desc == (u16)-1)
 	    {
+	      len = htons(rdlen);
+	      hash->update(ctx, 2, (unsigned char *)&len);
+	      hash->update(ctx, rdlen, p);
+	    }
+	  else
+	    {
+	      /* canonicalise rdata and calculate length of same, use 
+		 name buffer as workspace for get_rdata. */
 	      state.ip = p;
 	      state.op = NULL;
 	      state.desc = rr_desc;
-
+	      state.buff = name;
+	      state.end = p + rdlen;
+	      
 	      for (j = 0; get_rdata(header, plen, &state); j++)
+		if (j < RRBUFLEN)
+		  rrbuf[j] = *state.op;
+	      
+	      len = htons((u16)j);
+	      hash->update(ctx, 2, (unsigned char *)&len); 
+	      
+	      /* If the RR is shorter than RRBUFLEN (most of them, in practice)
+		 then we can just digest it now. If it exceeds RRBUFLEN we have to
+		 go back to the start and do it in chunks. */
+	      if (j >= RRBUFLEN)
 		{
-		   rrbuf[j] = *state.op;
-
-		   if (j == RRBUFLEN - 1)
-		     {
-		       hash->update(ctx, RRBUFLEN, rrbuf);
-		       j = -1;
-		     }
+		  state.ip = p;
+		  state.op = NULL;
+		  state.desc = rr_desc;
+		  
+		  for (j = 0; get_rdata(header, plen, &state); j++)
+		    {
+		      rrbuf[j] = *state.op;
+		      
+		      if (j == RRBUFLEN - 1)
+			{
+			  hash->update(ctx, RRBUFLEN, rrbuf);
+			  j = -1;
+			}
+		    }
 		}
+	      
+	      if (j != 0)
+		hash->update(ctx, j, rrbuf);
 	    }
-	  
-	  if (j != 0)
-	    hash->update(ctx, j, rrbuf);
 	}
      
       hash->digest(ctx, hash->digest_size, digest);
@@ -2087,35 +2130,4 @@ size_t dnssec_generate_query(struct dns_header *header, unsigned char *end, char
   return ret;
 }
 
-unsigned char* hash_questions(struct dns_header *header, size_t plen, char *name)
-{
-  int q;
-  unsigned int len;
-  unsigned char *p = (unsigned char *)(header+1);
-  const struct nettle_hash *hash;
-  void *ctx;
-  unsigned char *digest;
-  
-  if (!(hash = hash_find("sha1")) || !hash_init(hash, &ctx, &digest))
-    return NULL;
-  
-  for (q = ntohs(header->qdcount); q != 0; q--) 
-    {
-      if (!extract_name(header, plen, &p, name, 1, 4))
-	break; /* bad packet */
-      
-      len = to_wire(name);
-      hash->update(ctx, len, (unsigned char *)name);
-      /* CRC the class and type as well */
-      hash->update(ctx, 4, p);
-
-      p += 4;
-      if (!CHECK_LEN(header, p, plen, 0))
-	break; /* bad packet */
-    }
-  
-  hash->digest(ctx, hash->digest_size, digest);
-  return digest;
-}
-
 #endif /* HAVE_DNSSEC */

src/domain.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/dump.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/edns0.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -264,7 +264,8 @@ static void encoder(unsigned char *in, char *out)
   out[3] = char64(in[2]);
 }
 
-static size_t add_dns_client(struct dns_header *header, size_t plen, unsigned char *limit, union mysockaddr *l3, time_t now)
+static size_t add_dns_client(struct dns_header *header, size_t plen, unsigned char *limit,
+			     union mysockaddr *l3, time_t now, int *cacheablep)
 {
   int maclen, replace = 2; /* can't get mac address, just delete any incoming. */
   unsigned char mac[DHCP_CHADDR_MAX];
@@ -273,6 +274,7 @@ static size_t add_dns_client(struct dns_header *header, size_t plen, unsigned ch
   if ((maclen = find_mac(l3, mac, 1, now)) == 6)
     {
       replace = 1;
+      *cacheablep = 0;
 
       if (option_bool(OPT_MAC_HEX))
 	print_mac(encode, mac, maclen);
@@ -288,14 +290,18 @@ static size_t add_dns_client(struct dns_header *header, size_t plen, unsigned ch
 }
 
 
-static size_t add_mac(struct dns_header *header, size_t plen, unsigned char *limit, union mysockaddr *l3, time_t now)
+static size_t add_mac(struct dns_header *header, size_t plen, unsigned char *limit,
+		      union mysockaddr *l3, time_t now, int *cacheablep)
 {
   int maclen;
   unsigned char mac[DHCP_CHADDR_MAX];
 
   if ((maclen = find_mac(l3, mac, 1, now)) != 0)
-    plen = add_pseudoheader(header, plen, limit, PACKETSZ, EDNS0_OPTION_MAC, mac, maclen, 0, 0); 
-    
+    {
+      *cacheablep = 0;
+      plen = add_pseudoheader(header, plen, limit, PACKETSZ, EDNS0_OPTION_MAC, mac, maclen, 0, 0); 
+    }
+  
   return plen; 
 }
 
@@ -313,17 +319,18 @@ static void *get_addrp(union mysockaddr *addr, const short family)
   return &addr->in.sin_addr;
 }
 
-static size_t calc_subnet_opt(struct subnet_opt *opt, union mysockaddr *source)
+static size_t calc_subnet_opt(struct subnet_opt *opt, union mysockaddr *source, int *cacheablep)
 {
   /* http://tools.ietf.org/html/draft-vandergaast-edns-client-subnet-02 */
   
   int len;
   void *addrp = NULL;
   int sa_family = source->sa.sa_family;
-
+  int cacheable = 0;
+  
   opt->source_netmask = 0;
   opt->scope_netmask = 0;
-
+    
   if (source->sa.sa_family == AF_INET6 && daemon->add_subnet6)
     {
       opt->source_netmask = daemon->add_subnet6->mask;
@@ -331,6 +338,7 @@ static size_t calc_subnet_opt(struct subnet_opt *opt, union mysockaddr *source)
 	{
 	  sa_family = daemon->add_subnet6->addr.sa.sa_family;
 	  addrp = get_addrp(&daemon->add_subnet6->addr, sa_family);
+	  cacheable = 1;
 	} 
       else 
 	addrp = &source->in6.sin6_addr;
@@ -343,6 +351,7 @@ static size_t calc_subnet_opt(struct subnet_opt *opt, union mysockaddr *source)
 	{
 	  sa_family = daemon->add_subnet4->addr.sa.sa_family;
 	  addrp = get_addrp(&daemon->add_subnet4->addr, sa_family);
+	  cacheable = 1; /* Address is constant */
 	} 
 	else 
 	  addrp = &source->in.sin_addr;
@@ -350,8 +359,6 @@ static size_t calc_subnet_opt(struct subnet_opt *opt, union mysockaddr *source)
   
   opt->family = htons(sa_family == AF_INET6 ? 2 : 1);
   
-  len = 0;
-  
   if (addrp && opt->source_netmask != 0)
     {
       len = ((opt->source_netmask - 1) >> 3) + 1;
@@ -359,18 +366,26 @@ static size_t calc_subnet_opt(struct subnet_opt *opt, union mysockaddr *source)
       if (opt->source_netmask & 7)
 	opt->addr[len-1] &= 0xff << (8 - (opt->source_netmask & 7));
     }
+  else
+    {
+      cacheable = 1; /* No address ever supplied. */
+      len = 0;
+    }
+
+  if (cacheablep)
+    *cacheablep = cacheable;
   
   return len + 4;
 }
  
-static size_t add_source_addr(struct dns_header *header, size_t plen, unsigned char *limit, union mysockaddr *source)
+static size_t add_source_addr(struct dns_header *header, size_t plen, unsigned char *limit, union mysockaddr *source, int *cacheable)
 {
   /* http://tools.ietf.org/html/draft-vandergaast-edns-client-subnet-02 */
   
   int len;
   struct subnet_opt opt;
   
-  len = calc_subnet_opt(&opt, source);
+  len = calc_subnet_opt(&opt, source, cacheable);
   return add_pseudoheader(header, plen, (unsigned char *)limit, PACKETSZ, EDNS0_OPTION_CLIENT_SUBNET, (unsigned char *)&opt, len, 0, 0);
 }
 
@@ -383,18 +398,18 @@ int check_source(struct dns_header *header, size_t plen, unsigned char *pseudohe
   unsigned char *p;
   int code, i, rdlen;
   
-   calc_len = calc_subnet_opt(&opt, peer);
+  calc_len = calc_subnet_opt(&opt, peer, NULL);
    
-   if (!(p = skip_name(pseudoheader, header, plen, 10)))
-     return 1;
-   
-   p += 8; /* skip UDP length and RCODE */
-   
-   GETSHORT(rdlen, p);
-   if (!CHECK_LEN(header, p, plen, rdlen))
-     return 1; /* bad packet */
-   
-   /* check if option there */
+  if (!(p = skip_name(pseudoheader, header, plen, 10)))
+    return 1;
+  
+  p += 8; /* skip UDP length and RCODE */
+  
+  GETSHORT(rdlen, p);
+  if (!CHECK_LEN(header, p, plen, rdlen))
+    return 1; /* bad packet */
+  
+  /* check if option there */
    for (i = 0; i + 4 < rdlen; i += len + 4)
      {
        GETSHORT(code, p);
@@ -412,24 +427,28 @@ int check_source(struct dns_header *header, size_t plen, unsigned char *pseudohe
    return 1;
 }
 
+/* Set *check_subnet if we add a client subnet option, which needs to checked 
+   in the reply. Set *cacheable to zero if we add an option which the answer
+   may depend on. */
 size_t add_edns0_config(struct dns_header *header, size_t plen, unsigned char *limit, 
-			union mysockaddr *source, time_t now, int *check_subnet)    
+			union mysockaddr *source, time_t now, int *check_subnet, int *cacheable)    
 {
   *check_subnet = 0;
-
+  *cacheable = 1;
+  
   if (option_bool(OPT_ADD_MAC))
-    plen  = add_mac(header, plen, limit, source, now);
+    plen  = add_mac(header, plen, limit, source, now, cacheable);
   
   if (option_bool(OPT_MAC_B64) || option_bool(OPT_MAC_HEX))
-    plen = add_dns_client(header, plen, limit, source, now);
-
+    plen = add_dns_client(header, plen, limit, source, now, cacheable);
+  
   if (daemon->dns_client_id)
     plen = add_pseudoheader(header, plen, limit, PACKETSZ, EDNS0_OPTION_NOMCPEID, 
 			    (unsigned char *)daemon->dns_client_id, strlen(daemon->dns_client_id), 0, 1);
   
   if (option_bool(OPT_CLIENT_SUBNET))
     {
-      plen = add_source_addr(header, plen, limit, source); 
+      plen = add_source_addr(header, plen, limit, source, cacheable); 
       *check_subnet = 1;
     }
 	  

src/hash_questions.c

@@ -0,0 +1,284 @@
+/* Copyright (c) 2012-2020 Simon Kelley
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 dated June, 1991, or
+   (at your option) version 3 dated 29 June, 2007.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+
+/* Hash the question section. This is used to safely detect query 
+   retransmission and to detect answers to questions we didn't ask, which 
+   might be poisoning attacks. Note that we decode the name rather 
+   than CRC the raw bytes, since replies might be compressed differently. 
+   We ignore case in the names for the same reason. 
+
+   The hash used is SHA-256. If we're building with DNSSEC support,
+   we use the Nettle cypto library. If not, we prefer not to
+   add a dependency on Nettle, and use a stand-alone implementaion. 
+*/
+
+#include "dnsmasq.h"
+
+#if defined(HAVE_DNSSEC) || defined(HAVE_CRYPTOHASH)
+
+static const struct nettle_hash *hash;
+static void *ctx;
+static unsigned char *digest;
+
+void hash_questions_init(void)
+{
+  if (!(hash = hash_find("sha256")))
+    die(_("Failed to create SHA-256 hash object"), NULL, EC_MISC);
+
+  ctx = safe_malloc(hash->context_size);
+  digest = safe_malloc(hash->digest_size);
+}
+
+unsigned char *hash_questions(struct dns_header *header, size_t plen, char *name)
+{
+  int q;
+  unsigned char *p = (unsigned char *)(header+1);
+
+  hash->init(ctx);
+
+  for (q = ntohs(header->qdcount); q != 0; q--) 
+    {
+      char *cp, c;
+
+      if (!extract_name(header, plen, &p, name, 1, 4))
+	break; /* bad packet */
+
+      for (cp = name; (c = *cp); cp++)
+	 if (c >= 'A' && c <= 'Z')
+	   *cp += 'a' - 'A';
+
+      hash->update(ctx, cp - name, (unsigned char *)name);
+      /* CRC the class and type as well */
+      hash->update(ctx, 4, p);
+
+      p += 4;
+      if (!CHECK_LEN(header, p, plen, 0))
+	break; /* bad packet */
+    }
+  
+  hash->digest(ctx, hash->digest_size, digest);
+  return digest;
+}
+
+#else /* HAVE_DNSSEC  || HAVE_CRYPTOHASH */
+
+#define SHA256_BLOCK_SIZE 32            // SHA256 outputs a 32 byte digest
+typedef unsigned char BYTE;             // 8-bit byte
+typedef unsigned int  WORD;             // 32-bit word, change to "long" for 16-bit machines
+
+typedef struct {
+  BYTE data[64];
+  WORD datalen;
+  unsigned long long bitlen;
+  WORD state[8];
+} SHA256_CTX;
+
+static void sha256_init(SHA256_CTX *ctx);
+static void sha256_update(SHA256_CTX *ctx, const BYTE data[], size_t len);
+static void sha256_final(SHA256_CTX *ctx, BYTE hash[]);
+
+void hash_questions_init(void)
+{
+}
+
+unsigned char *hash_questions(struct dns_header *header, size_t plen, char *name)
+{
+  int q;
+  unsigned char *p = (unsigned char *)(header+1);
+  SHA256_CTX ctx;
+  static BYTE digest[SHA256_BLOCK_SIZE];
+  
+  sha256_init(&ctx);
+    
+  for (q = ntohs(header->qdcount); q != 0; q--) 
+    {
+      char *cp, c;
+
+      if (!extract_name(header, plen, &p, name, 1, 4))
+	break; /* bad packet */
+
+      for (cp = name; (c = *cp); cp++)
+	 if (c >= 'A' && c <= 'Z')
+	   *cp += 'a' - 'A';
+
+      sha256_update(&ctx, (BYTE *)name, cp - name);
+      /* CRC the class and type as well */
+      sha256_update(&ctx, (BYTE *)p, 4);
+
+      p += 4;
+      if (!CHECK_LEN(header, p, plen, 0))
+	break; /* bad packet */
+    }
+  
+  sha256_final(&ctx, digest);
+  return (unsigned char *)digest;
+}
+
+/* Code from here onwards comes from https://github.com/B-Con/crypto-algorithms
+   and was written by Brad Conte (brad@bradconte.com), to whom all credit is given.
+
+   This code is in the public domain, and the copyright notice at the head of this 
+   file does not apply to it.
+*/
+
+
+/****************************** MACROS ******************************/
+#define ROTLEFT(a,b) (((a) << (b)) | ((a) >> (32-(b))))
+#define ROTRIGHT(a,b) (((a) >> (b)) | ((a) << (32-(b))))
+
+#define CH(x,y,z) (((x) & (y)) ^ (~(x) & (z)))
+#define MAJ(x,y,z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
+#define EP0(x) (ROTRIGHT(x,2) ^ ROTRIGHT(x,13) ^ ROTRIGHT(x,22))
+#define EP1(x) (ROTRIGHT(x,6) ^ ROTRIGHT(x,11) ^ ROTRIGHT(x,25))
+#define SIG0(x) (ROTRIGHT(x,7) ^ ROTRIGHT(x,18) ^ ((x) >> 3))
+#define SIG1(x) (ROTRIGHT(x,17) ^ ROTRIGHT(x,19) ^ ((x) >> 10))
+
+/**************************** VARIABLES *****************************/
+static const WORD k[64] = {
+			   0x428a2f98,0x71374491,0xb5c0fbcf,0xe9b5dba5,0x3956c25b,0x59f111f1,0x923f82a4,0xab1c5ed5,
+			   0xd807aa98,0x12835b01,0x243185be,0x550c7dc3,0x72be5d74,0x80deb1fe,0x9bdc06a7,0xc19bf174,
+			   0xe49b69c1,0xefbe4786,0x0fc19dc6,0x240ca1cc,0x2de92c6f,0x4a7484aa,0x5cb0a9dc,0x76f988da,
+			   0x983e5152,0xa831c66d,0xb00327c8,0xbf597fc7,0xc6e00bf3,0xd5a79147,0x06ca6351,0x14292967,
+			   0x27b70a85,0x2e1b2138,0x4d2c6dfc,0x53380d13,0x650a7354,0x766a0abb,0x81c2c92e,0x92722c85,
+			   0xa2bfe8a1,0xa81a664b,0xc24b8b70,0xc76c51a3,0xd192e819,0xd6990624,0xf40e3585,0x106aa070,
+			   0x19a4c116,0x1e376c08,0x2748774c,0x34b0bcb5,0x391c0cb3,0x4ed8aa4a,0x5b9cca4f,0x682e6ff3,
+			   0x748f82ee,0x78a5636f,0x84c87814,0x8cc70208,0x90befffa,0xa4506ceb,0xbef9a3f7,0xc67178f2
+};
+
+/*********************** FUNCTION DEFINITIONS ***********************/
+static void sha256_transform(SHA256_CTX *ctx, const BYTE data[])
+{
+  WORD a, b, c, d, e, f, g, h, i, j, t1, t2, m[64];
+  
+  for (i = 0, j = 0; i < 16; ++i, j += 4)
+    m[i] = (data[j] << 24) | (data[j + 1] << 16) | (data[j + 2] << 8) | (data[j + 3]);
+  for ( ; i < 64; ++i)
+    m[i] = SIG1(m[i - 2]) + m[i - 7] + SIG0(m[i - 15]) + m[i - 16];
+
+  a = ctx->state[0];
+  b = ctx->state[1];
+  c = ctx->state[2];
+  d = ctx->state[3];
+  e = ctx->state[4];
+  f = ctx->state[5];
+  g = ctx->state[6];
+  h = ctx->state[7];
+
+  for (i = 0; i < 64; ++i)
+    {
+      t1 = h + EP1(e) + CH(e,f,g) + k[i] + m[i];
+      t2 = EP0(a) + MAJ(a,b,c);
+      h = g;
+      g = f;
+      f = e;
+      e = d + t1;
+      d = c;
+      c = b;
+      b = a;
+      a = t1 + t2;
+    }
+  
+  ctx->state[0] += a;
+  ctx->state[1] += b;
+  ctx->state[2] += c;
+  ctx->state[3] += d;
+  ctx->state[4] += e;
+  ctx->state[5] += f;
+  ctx->state[6] += g;
+  ctx->state[7] += h;
+}
+
+static void sha256_init(SHA256_CTX *ctx)
+{
+  ctx->datalen = 0;
+  ctx->bitlen = 0;
+  ctx->state[0] = 0x6a09e667;
+  ctx->state[1] = 0xbb67ae85;
+  ctx->state[2] = 0x3c6ef372;
+  ctx->state[3] = 0xa54ff53a;
+  ctx->state[4] = 0x510e527f;
+  ctx->state[5] = 0x9b05688c;
+  ctx->state[6] = 0x1f83d9ab;
+  ctx->state[7] = 0x5be0cd19;
+}
+
+static void sha256_update(SHA256_CTX *ctx, const BYTE data[], size_t len)
+{
+  WORD i;
+  
+  for (i = 0; i < len; ++i)
+    {
+      ctx->data[ctx->datalen] = data[i];
+      ctx->datalen++;
+      if (ctx->datalen == 64) {
+	sha256_transform(ctx, ctx->data);
+	ctx->bitlen += 512;
+	ctx->datalen = 0;
+      }
+    }
+}
+
+static void sha256_final(SHA256_CTX *ctx, BYTE hash[])
+{
+  WORD i;
+  
+  i = ctx->datalen;
+
+  // Pad whatever data is left in the buffer.
+  if (ctx->datalen < 56)
+    {
+      ctx->data[i++] = 0x80;
+      while (i < 56)
+	ctx->data[i++] = 0x00;
+    }
+  else
+    {
+      ctx->data[i++] = 0x80;
+      while (i < 64)
+	ctx->data[i++] = 0x00;
+      sha256_transform(ctx, ctx->data);
+      memset(ctx->data, 0, 56);
+    }
+  
+  // Append to the padding the total message's length in bits and transform.
+  ctx->bitlen += ctx->datalen * 8;
+  ctx->data[63] = ctx->bitlen;
+  ctx->data[62] = ctx->bitlen >> 8;
+  ctx->data[61] = ctx->bitlen >> 16;
+  ctx->data[60] = ctx->bitlen >> 24;
+  ctx->data[59] = ctx->bitlen >> 32;
+  ctx->data[58] = ctx->bitlen >> 40;
+  ctx->data[57] = ctx->bitlen >> 48;
+  ctx->data[56] = ctx->bitlen >> 56;
+  sha256_transform(ctx, ctx->data);
+  
+  // Since this implementation uses little endian byte ordering and SHA uses big endian,
+  // reverse all the bytes when copying the final state to the output hash.
+  for (i = 0; i < 4; ++i)
+    {
+      hash[i]      = (ctx->state[0] >> (24 - i * 8)) & 0x000000ff;
+      hash[i + 4]  = (ctx->state[1] >> (24 - i * 8)) & 0x000000ff;
+      hash[i + 8]  = (ctx->state[2] >> (24 - i * 8)) & 0x000000ff;
+      hash[i + 12] = (ctx->state[3] >> (24 - i * 8)) & 0x000000ff;
+      hash[i + 16] = (ctx->state[4] >> (24 - i * 8)) & 0x000000ff;
+      hash[i + 20] = (ctx->state[5] >> (24 - i * 8)) & 0x000000ff;
+      hash[i + 24] = (ctx->state[6] >> (24 - i * 8)) & 0x000000ff;
+      hash[i + 28] = (ctx->state[7] >> (24 - i * 8)) & 0x000000ff;
+    }
+}
+
+#endif

src/helper.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/inotify.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
  
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/ip6addr.h

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/lease.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/log.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -273,7 +273,7 @@ static void log_write(void)
 /* priority is one of LOG_DEBUG, LOG_INFO, LOG_NOTICE, etc. See sys/syslog.h.
    OR'd to priority can be MS_TFTP, MS_DHCP, ... to be able to do log separation between
    DNS, DHCP and TFTP services.
-*/
+   If OR'd with MS_DEBUG, the messages are suppressed unless --log-debug is set. */
 void my_syslog(int priority, const char *format, ...)
 {
   va_list ap;
@@ -290,7 +290,13 @@ void my_syslog(int priority, const char *format, ...)
     func = "-dhcp";
   else if ((LOG_FACMASK & priority) == MS_SCRIPT)
     func = "-script";
-	    
+  else if ((LOG_FACMASK & priority) == MS_DEBUG)
+    {
+      if (!option_bool(OPT_LOG_DEBUG))
+	return;
+      func = "-debug";
+    }
+  
 #ifdef LOG_PRI
   priority = LOG_PRI(priority);
 #else

src/loop.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -22,6 +22,7 @@ static ssize_t loop_make_probe(u32 uid);
 void loop_send_probes()
 {
    struct server *serv;
+   struct randfd_list *rfds = NULL;
    
    if (!option_bool(OPT_LOOP_DETECT))
      return;
@@ -34,29 +35,22 @@ void loop_send_probes()
        {
 	 ssize_t len = loop_make_probe(serv->uid);
 	 int fd;
-	 struct randfd *rfd = NULL;
 	 
-	 if (serv->sfd)
-	   fd = serv->sfd->fd;
-	 else 
-	   {
-	     if (!(rfd = allocate_rfd(serv->addr.sa.sa_family)))
-	       continue;
-	     fd = rfd->fd;
-	   }
-
+	 if ((fd = allocate_rfd(&rfds, serv)) == -1)
+	   continue;
+	 
 	 while (retry_send(sendto(fd, daemon->packet, len, 0, 
 				  &serv->addr.sa, sa_len(&serv->addr))));
-	 
-	 free_rfd(rfd);
        }
+
+   free_rfds(&rfds);
 }
   
 static ssize_t loop_make_probe(u32 uid)
 {
   struct dns_header *header = (struct dns_header *)daemon->packet;
   unsigned char *p = (unsigned char *)(header+1);
-
+  
   /* packet buffer overwritten */
   daemon->srv_save = NULL;
   

src/metrics.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/metrics.h

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
    
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/netlink.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -41,19 +41,26 @@
 
 #ifndef NDA_RTA
 #  define NDA_RTA(r) ((struct rtattr*)(((char*)(r)) + NLMSG_ALIGN(sizeof(struct ndmsg)))) 
-#endif 
+#endif
+
+/* Used to request refresh of addresses or routes just once,
+ * when multiple changes might be announced. */
+enum async_states {
+  STATE_NEWADDR = (1 << 0),
+  STATE_NEWROUTE = (1 << 1),
+};
 
 
 static struct iovec iov;
 static u32 netlink_pid;
 
-static void nl_async(struct nlmsghdr *h);
+static unsigned nl_async(struct nlmsghdr *h, unsigned state);
+static void nl_multicast_state(unsigned state);
 
 char *netlink_init(void)
 {
   struct sockaddr_nl addr;
   socklen_t slen = sizeof(addr);
-  int opt = 1;
 
   addr.nl_family = AF_NETLINK;
   addr.nl_pad = 0;
@@ -92,14 +99,10 @@ char *netlink_init(void)
   iov.iov_len = 100;
   iov.iov_base = safe_malloc(iov.iov_len);
   
-  if (daemon->kernel_version >= KERNEL_VERSION(2,6,30) &&
-      setsockopt(daemon->netlinkfd, SOL_NETLINK, NETLINK_NO_ENOBUFS, &opt, sizeof(opt)) == -1)
-    return _("warning: failed to set NETLINK_NO_ENOBUFS on netlink socket");
-  
   return NULL;
 }
 
-static ssize_t netlink_recv(void)
+static ssize_t netlink_recv(int flags)
 {
   struct msghdr msg;
   struct sockaddr_nl nladdr;
@@ -115,7 +118,8 @@ static ssize_t netlink_recv(void)
       msg.msg_iovlen = 1;
       msg.msg_flags = 0;
       
-      while ((rc = recvmsg(daemon->netlinkfd, &msg, MSG_PEEK | MSG_TRUNC)) == -1 && errno == EINTR);
+      while ((rc = recvmsg(daemon->netlinkfd, &msg, flags | MSG_PEEK | MSG_TRUNC)) == -1 &&
+	     errno == EINTR);
       
       /* make buffer big enough */
       if (rc != -1 && (msg.msg_flags & MSG_TRUNC))
@@ -132,7 +136,7 @@ static ssize_t netlink_recv(void)
 
       /* read it for real */
       msg.msg_flags = 0;
-      while ((rc = recvmsg(daemon->netlinkfd, &msg, 0)) == -1 && errno == EINTR);
+      while ((rc = recvmsg(daemon->netlinkfd, &msg, flags)) == -1 && errno == EINTR);
       
       /* Make sure this is from the kernel */
       if (rc == -1 || nladdr.nl_pid == 0)
@@ -151,7 +155,9 @@ static ssize_t netlink_recv(void)
   
 
 /* family = AF_UNSPEC finds ARP table entries.
-   family = AF_LOCAL finds MAC addresses. */
+   family = AF_LOCAL finds MAC addresses.
+   returns 0 on failure, 1 on success, -1 when restart is required
+*/
 int iface_enumerate(int family, void *parm, int (*callback)())
 {
   struct sockaddr_nl addr;
@@ -159,6 +165,7 @@ int iface_enumerate(int family, void *parm, int (*callback)())
   ssize_t len;
   static unsigned int seq = 0;
   int callback_ok = 1;
+  unsigned state = 0;
 
   struct {
     struct nlmsghdr nlh;
@@ -170,7 +177,6 @@ int iface_enumerate(int family, void *parm, int (*callback)())
 
   addr.nl_family = AF_NETLINK;
  
- again: 
   if (family == AF_UNSPEC)
     req.nlh.nlmsg_type = RTM_GETNEIGH;
   else if (family == AF_LOCAL)
@@ -193,12 +199,12 @@ int iface_enumerate(int family, void *parm, int (*callback)())
     
   while (1)
     {
-      if ((len = netlink_recv()) == -1)
+      if ((len = netlink_recv(0)) == -1)
 	{
 	  if (errno == ENOBUFS)
 	    {
-	      sleep(1);
-	      goto again;
+	      nl_multicast_state(state);
+	      return -1;
 	    }
 	  return 0;
 	}
@@ -207,7 +213,7 @@ int iface_enumerate(int family, void *parm, int (*callback)())
 	if (h->nlmsg_pid != netlink_pid || h->nlmsg_type == NLMSG_ERROR)
 	  {
 	    /* May be multicast arriving async */
-	    nl_async(h);
+	    state = nl_async(h, state);
 	  }
 	else if (h->nlmsg_seq != seq)
 	  {
@@ -341,26 +347,28 @@ int iface_enumerate(int family, void *parm, int (*callback)())
     }
 }
 
-void netlink_multicast(void)
+static void nl_multicast_state(unsigned state)
 {
   ssize_t len;
   struct nlmsghdr *h;
-  int flags;
+
+  do {
+    /* don't risk blocking reading netlink messages here. */
+    while ((len = netlink_recv(MSG_DONTWAIT)) != -1)
   
-  /* don't risk blocking reading netlink messages here. */
-  if ((flags = fcntl(daemon->netlinkfd, F_GETFL)) == -1 ||
-      fcntl(daemon->netlinkfd, F_SETFL, flags | O_NONBLOCK) == -1) 
-    return;
-  
-  if ((len = netlink_recv()) != -1)
-    for (h = (struct nlmsghdr *)iov.iov_base; NLMSG_OK(h, (size_t)len); h = NLMSG_NEXT(h, len))
-      nl_async(h);
-  
-  /* restore non-blocking status */
-  fcntl(daemon->netlinkfd, F_SETFL, flags);
+      for (h = (struct nlmsghdr *)iov.iov_base; NLMSG_OK(h, (size_t)len); h = NLMSG_NEXT(h, len))
+	state = nl_async(h, state);
+  } while (errno == ENOBUFS);
 }
 
-static void nl_async(struct nlmsghdr *h)
+void netlink_multicast(void)
+{
+  unsigned state = 0;
+  nl_multicast_state(state);
+}
+
+
+static unsigned nl_async(struct nlmsghdr *h, unsigned state)
 {
   if (h->nlmsg_type == NLMSG_ERROR)
     {
@@ -368,7 +376,8 @@ static void nl_async(struct nlmsghdr *h)
       if (err->error != 0)
 	my_syslog(LOG_ERR, _("netlink returns error: %s"), strerror(-(err->error)));
     }
-  else if (h->nlmsg_pid == 0 && h->nlmsg_type == RTM_NEWROUTE) 
+  else if (h->nlmsg_pid == 0 && h->nlmsg_type == RTM_NEWROUTE &&
+	   (state & STATE_NEWROUTE)==0)
     {
       /* We arrange to receive netlink multicast messages whenever the network route is added.
 	 If this happens and we still have a DNS packet in the buffer, we re-send it.
@@ -380,10 +389,18 @@ static void nl_async(struct nlmsghdr *h)
       if (rtm->rtm_type == RTN_UNICAST && rtm->rtm_scope == RT_SCOPE_LINK &&
 	  (rtm->rtm_table == RT_TABLE_MAIN ||
 	   rtm->rtm_table == RT_TABLE_LOCAL))
-	queue_event(EVENT_NEWROUTE);
+	{
+	  queue_event(EVENT_NEWROUTE);
+	  state |= STATE_NEWROUTE;
+	}
     }
-  else if (h->nlmsg_type == RTM_NEWADDR || h->nlmsg_type == RTM_DELADDR) 
-    queue_event(EVENT_NEWADDR);
+  else if ((h->nlmsg_type == RTM_NEWADDR || h->nlmsg_type == RTM_DELADDR) &&
+	   (state & STATE_NEWADDR)==0)
+    {
+      queue_event(EVENT_NEWADDR);
+      state |= STATE_NEWADDR;
+    }
+  return state;
 }
 #endif
 

src/network.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -232,7 +232,7 @@ static int iface_allowed(struct iface_param *param, int if_index, char *label,
 			 union mysockaddr *addr, struct in_addr netmask, int prefixlen, int iface_flags) 
 {
   struct irec *iface;
-  int mtu = 0, loopback;
+  int loopback;
   struct ifreq ifr;
   int tftp_ok = !!option_bool(OPT_TFTP);
   int dhcp_ok = 1;
@@ -253,9 +253,6 @@ static int iface_allowed(struct iface_param *param, int if_index, char *label,
   if (loopback)
     dhcp_ok = 0;
   
-  if (ioctl(param->fd, SIOCGIFMTU, &ifr) != -1)
-    mtu = ifr.ifr_mtu;
-  
   if (!label)
     label = ifr.ifr_name;
   else
@@ -351,36 +348,109 @@ static int iface_allowed(struct iface_param *param, int if_index, char *label,
       /* Update addresses from interface_names. These are a set independent
 	 of the set we're listening on. */  
       for (int_name = daemon->int_names; int_name; int_name = int_name->next)
-	if (strncmp(label, int_name->intr, IF_NAMESIZE) == 0 && 
-	    (addr->sa.sa_family == int_name->family || int_name->family == 0))
+	if (strncmp(label, int_name->intr, IF_NAMESIZE) == 0)
 	  {
-	    if (param->spare)
+	    struct addrlist *lp;
+
+	    al = NULL;
+	    
+	    if (addr->sa.sa_family == AF_INET && (int_name->flags & (IN4 | INP4)))
 	      {
-		al = param->spare;
-		param->spare = al->next;
+		struct in_addr newaddr = addr->in.sin_addr;
+		
+		if (int_name->flags & INP4)
+		  {
+		    if (netmask.s_addr == 0xffff)
+		      continue;
+
+		    newaddr.s_addr = (addr->in.sin_addr.s_addr & netmask.s_addr) |
+		      (int_name->proto4.s_addr & ~netmask.s_addr);
+		  }
+		
+		/* check for duplicates. */
+		for (lp = int_name->addr; lp; lp = lp->next)
+		  if (lp->flags == 0 && lp->addr.addr4.s_addr == newaddr.s_addr)
+		    break;
+		
+		if (!lp)
+		  {
+		    if (param->spare)
+		      {
+			al = param->spare;
+			param->spare = al->next;
+		      }
+		    else
+		      al = whine_malloc(sizeof(struct addrlist));
+
+		    if (al)
+		      {
+			al->flags = 0;
+			al->addr.addr4 = newaddr;
+		      }
+		  }
+	      }
+
+	    if (addr->sa.sa_family == AF_INET6 && (int_name->flags & (IN6 | INP6)))
+	      {
+		struct in6_addr newaddr = addr->in6.sin6_addr;
+		
+		if (int_name->flags & INP6)
+		  {
+		    int i;
+
+		    /* No sense in doing /128. */
+		    if (prefixlen == 128)
+		      continue;
+		    
+		    for (i = 0; i < 16; i++)
+		      {
+			int bits = ((i+1)*8) - prefixlen;
+		       
+			if (bits >= 8)
+			  newaddr.s6_addr[i] = int_name->proto6.s6_addr[i];
+			else if (bits >= 0)
+			  {
+			    unsigned char mask = 0xff << bits;
+			    newaddr.s6_addr[i] =
+			      (addr->in6.sin6_addr.s6_addr[i] & mask) |
+			      (int_name->proto6.s6_addr[i] & ~mask);
+			  }
+		      }
+		  }
+		
+		/* check for duplicates. */
+		for (lp = int_name->addr; lp; lp = lp->next)
+		  if ((lp->flags & ADDRLIST_IPV6) &&
+		      IN6_ARE_ADDR_EQUAL(&lp->addr.addr6, &newaddr))
+		    break;
+					
+		if (!lp)
+		  {
+		    if (param->spare)
+		      {
+			al = param->spare;
+			param->spare = al->next;
+		      }
+		    else
+		      al = whine_malloc(sizeof(struct addrlist));
+		    
+		    if (al)
+		      {
+			al->flags = ADDRLIST_IPV6;
+			al->addr.addr6 = newaddr;
+
+			/* Privacy addresses and addresses still undergoing DAD and deprecated addresses
+			   don't appear in forward queries, but will in reverse ones. */
+			if (!(iface_flags & IFACE_PERMANENT) || (iface_flags & (IFACE_DEPRECATED | IFACE_TENTATIVE)))
+			  al->flags |= ADDRLIST_REVONLY;
+		      }
+		  }
 	      }
-	    else
-	      al = whine_malloc(sizeof(struct addrlist));
 	    
 	    if (al)
 	      {
 		al->next = int_name->addr;
 		int_name->addr = al;
-		
-		if (addr->sa.sa_family == AF_INET)
-		  {
-		    al->addr.addr4 = addr->in.sin_addr;
-		    al->flags = 0;
-		  }
-		else
-		 {
-		    al->addr.addr6 = addr->in6.sin6_addr;
-		    al->flags = ADDRLIST_IPV6;
-		    /* Privacy addresses and addresses still undergoing DAD and deprecated addresses
-		       don't appear in forward queries, but will in reverse ones. */
-		    if (!(iface_flags & IFACE_PERMANENT) || (iface_flags & (IFACE_DEPRECATED | IFACE_TENTATIVE)))
-		      al->flags |= ADDRLIST_REVONLY;
-		 } 
 	      }
 	  }
     }
@@ -458,6 +528,11 @@ static int iface_allowed(struct iface_param *param, int if_index, char *label,
   /* add to list */
   if ((iface = whine_malloc(sizeof(struct irec))))
     {
+      int mtu = 0;
+
+      if (ioctl(param->fd, SIOCGIFMTU, &ifr) != -1)
+	mtu = ifr.ifr_mtu;
+
       iface->addr = *addr;
       iface->netmask = netmask;
       iface->tftp_ok = tftp_ok;
@@ -592,7 +667,7 @@ static int release_listener(struct listener *l)
       int port;
 
       port = prettyprint_addr(&l->iface->addr, daemon->addrbuff);
-      my_syslog(LOG_DEBUG, _("stopped listening on %s(#%d): %s port %d"),
+      my_syslog(LOG_DEBUG|MS_DEBUG, _("stopped listening on %s(#%d): %s port %d"),
 		l->iface->name, l->iface->index, daemon->addrbuff, port);
       /* In case it ever returns */
       l->iface->done = 0;
@@ -621,7 +696,8 @@ int enumerate_interfaces(int reset)
 #ifdef HAVE_AUTH
   struct auth_zone *zone;
 #endif
-
+  struct server *serv;
+  
   /* Do this max once per select cycle  - also inhibits netlink socket use
    in TCP child processes. */
 
@@ -638,7 +714,26 @@ int enumerate_interfaces(int reset)
 
   if ((param.fd = socket(PF_INET, SOCK_DGRAM, 0)) == -1)
     return 0;
- 
+
+  /* iface indexes can change when interfaces are created/destroyed. 
+     We use them in the main forwarding control path, when the path
+     to a server is specified by an interface, so cache them.
+     Update the cache here. */
+  for (serv = daemon->servers; serv; serv = serv->next)
+    if (serv->interface[0] != 0)
+      {
+#ifdef HAVE_LINUX_NETWORK
+	struct ifreq ifr;
+	
+	safe_strncpy(ifr.ifr_name, serv->interface, IF_NAMESIZE);
+	if (ioctl(param.fd, SIOCGIFINDEX, &ifr) != -1) 
+	  serv->ifindex = ifr.ifr_ifindex;
+#else
+	serv->ifindex = if_nametoindex(serv->interface);
+#endif
+      }
+    
+again:
   /* Mark interfaces for garbage collection */
   for (iface = daemon->interfaces; iface; iface = iface->next) 
     iface->found = 0;
@@ -690,9 +785,14 @@ int enumerate_interfaces(int reset)
   param.spare = spare;
   
   ret = iface_enumerate(AF_INET6, &param, iface_allowed_v6);
-
-  if (ret)
-    ret = iface_enumerate(AF_INET, &param, iface_allowed_v4); 
+  if (ret < 0)
+    goto again;
+  else if (ret)
+    {
+      ret = iface_enumerate(AF_INET, &param, iface_allowed_v4);
+      if (ret < 0)
+	goto again;
+    }
  
   errsave = errno;
   close(param.fd);
@@ -727,7 +827,7 @@ int enumerate_interfaces(int reset)
 
   errno = errsave;
   spare = param.spare;
-    
+  
   return ret;
 }
 
@@ -867,10 +967,10 @@ int tcp_interface(int fd, int af)
   /* use mshdr so that the CMSDG_* macros are available */
   msg.msg_control = daemon->packet;
   msg.msg_controllen = len = daemon->packet_buff_sz;
-  
+
   /* we overwrote the buffer... */
-  daemon->srv_save = NULL;
-  
+  daemon->srv_save = NULL; 
+
   if (af == AF_INET)
     {
       if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &opt, sizeof(opt)) != -1 &&
@@ -1045,7 +1145,7 @@ void create_bound_listeners(int dienow)
             if (!dienow)
               {
 		int port = prettyprint_addr(&iface->addr, daemon->addrbuff);
-		my_syslog(LOG_DEBUG, _("listening on %s(#%d): %s port %d"),
+		my_syslog(LOG_DEBUG|MS_DEBUG, _("listening on %s(#%d): %s port %d"),
 			  iface->name, iface->index, daemon->addrbuff, port);
 	      }
 	  }
@@ -1072,7 +1172,7 @@ void create_bound_listeners(int dienow)
 	if (!dienow)
 	  {
 	    int port = prettyprint_addr(&if_tmp->addr, daemon->addrbuff);
-	    my_syslog(LOG_DEBUG, _("listening on %s port %d"), daemon->addrbuff, port);
+	    my_syslog(LOG_DEBUG|MS_DEBUG, _("listening on %s port %d"), daemon->addrbuff, port);
 	  }
       }
 }
@@ -1206,74 +1306,58 @@ void join_multicast(int dienow)
 }
 #endif
 
-/* return a UDP socket bound to a random port, have to cope with straying into
-   occupied port nos and reserved ones. */
-int random_sock(int family)
-{
-  int fd;
-
-  if ((fd = socket(family, SOCK_DGRAM, 0)) != -1)
-    {
-      union mysockaddr addr;
-      unsigned int ports_avail = ((unsigned short)daemon->max_port - (unsigned short)daemon->min_port) + 1;
-      int tries = ports_avail < 30 ? 3 * ports_avail : 100;
-
-      memset(&addr, 0, sizeof(addr));
-      addr.sa.sa_family = family;
-
-      /* don't loop forever if all ports in use. */
-
-      if (fix_fd(fd))
-	while(tries--)
-	  {
-	    unsigned short port = htons(daemon->min_port + (rand16() % ((unsigned short)ports_avail)));
-	    
-	    if (family == AF_INET) 
-	      {
-		addr.in.sin_addr.s_addr = INADDR_ANY;
-		addr.in.sin_port = port;
-#ifdef HAVE_SOCKADDR_SA_LEN
-		addr.in.sin_len = sizeof(struct sockaddr_in);
-#endif
-	      }
-	    else
-	      {
-		addr.in6.sin6_addr = in6addr_any; 
-		addr.in6.sin6_port = port;
-#ifdef HAVE_SOCKADDR_SA_LEN
-		addr.in6.sin6_len = sizeof(struct sockaddr_in6);
-#endif
-	      }
-	    
-	    if (bind(fd, (struct sockaddr *)&addr, sa_len(&addr)) == 0)
-	      return fd;
-	    
-	    if (errno != EADDRINUSE && errno != EACCES)
-	      break;
-	  }
-
-      close(fd);
-    }
-
-  return -1; 
-}
-  
-
 int local_bind(int fd, union mysockaddr *addr, char *intname, unsigned int ifindex, int is_tcp)
 {
   union mysockaddr addr_copy = *addr;
+  unsigned short port;
+  int tries = 1;
+  unsigned short ports_avail = 1;
+
+  if (addr_copy.sa.sa_family == AF_INET)
+    port = addr_copy.in.sin_port;
+  else
+    port = addr_copy.in6.sin6_port;
 
   /* cannot set source _port_ for TCP connections. */
   if (is_tcp)
+    port = 0;
+  else if (port == 0 && daemon->max_port != 0)
     {
-      if (addr_copy.sa.sa_family == AF_INET)
-	addr_copy.in.sin_port = 0;
-      else
-	addr_copy.in6.sin6_port = 0;
+      /* Bind a random port within the range given by min-port and max-port if either
+	 or both are set. Otherwise use the OS's random ephemeral port allocation by
+	 leaving port == 0 and tries == 1 */
+      ports_avail = daemon->max_port - daemon->min_port + 1;
+      tries = ports_avail < 30 ? 3 * ports_avail : 100;
+      port = htons(daemon->min_port + (rand16() % ports_avail));
     }
   
-  if (bind(fd, (struct sockaddr *)&addr_copy, sa_len(&addr_copy)) == -1)
-    return 0;
+  while (1)
+    {
+      /* elide bind() call if it's to port 0, address 0 */
+      if (addr_copy.sa.sa_family == AF_INET)
+	{
+	  if (port == 0 && addr_copy.in.sin_addr.s_addr == 0)
+	    break;
+	  addr_copy.in.sin_port = port;
+	}
+      else
+	{
+	  if (port == 0 && IN6_IS_ADDR_UNSPECIFIED(&addr_copy.in6.sin6_addr))
+	    break;
+	  addr_copy.in6.sin6_port = port;
+	}
+      
+      if (bind(fd, (struct sockaddr *)&addr_copy, sa_len(&addr_copy)) != -1)
+	break;
+      
+       if (errno != EADDRINUSE && errno != EACCES) 
+	 return 0;
+
+      if (--tries == 0)
+	return 0;
+
+      port = htons(daemon->min_port + (rand16() % ports_avail));
+    }
 
   if (!is_tcp && ifindex > 0)
     {
@@ -1303,38 +1387,33 @@ int local_bind(int fd, union mysockaddr *addr, char *intname, unsigned int ifind
   return 1;
 }
 
-static struct serverfd *allocate_sfd(union mysockaddr *addr, char *intname)
+static struct serverfd *allocate_sfd(union mysockaddr *addr, char *intname, unsigned int ifindex)
 {
   struct serverfd *sfd;
-  unsigned int ifindex = 0;
   int errsave;
   int opt = 1;
   
   /* when using random ports, servers which would otherwise use
-     the INADDR_ANY/port0 socket have sfd set to NULL */
-  if (!daemon->osport && intname[0] == 0)
+     the INADDR_ANY/port0 socket have sfd set to NULL, this is 
+     anything without an explictly set source port. */
+  if (!daemon->osport)
     {
       errno = 0;
       
       if (addr->sa.sa_family == AF_INET &&
-	  addr->in.sin_addr.s_addr == INADDR_ANY &&
 	  addr->in.sin_port == htons(0)) 
 	return NULL;
 
       if (addr->sa.sa_family == AF_INET6 &&
-	  memcmp(&addr->in6.sin6_addr, &in6addr_any, sizeof(in6addr_any)) == 0 &&
 	  addr->in6.sin6_port == htons(0)) 
 	return NULL;
     }
 
-  if (intname && strlen(intname) != 0)
-    ifindex = if_nametoindex(intname); /* index == 0 when not binding to an interface */
-      
   /* may have a suitable one already */
   for (sfd = daemon->sfds; sfd; sfd = sfd->next )
-    if (sockaddr_isequal(&sfd->source_addr, addr) &&
-	strcmp(intname, sfd->interface) == 0 &&
-	ifindex == sfd->ifindex) 
+    if (ifindex == sfd->ifindex &&
+	sockaddr_isequal(&sfd->source_addr, addr) &&
+	strcmp(intname, sfd->interface) == 0)
       return sfd;
   
   /* need to make a new one. */
@@ -1385,7 +1464,7 @@ void pre_allocate_sfds(void)
 #ifdef HAVE_SOCKADDR_SA_LEN
       addr.in.sin_len = sizeof(struct sockaddr_in);
 #endif
-      if ((sfd = allocate_sfd(&addr, "")))
+      if ((sfd = allocate_sfd(&addr, "", 0)))
 	sfd->preallocated = 1;
 
       memset(&addr, 0, sizeof(addr));
@@ -1395,13 +1474,13 @@ void pre_allocate_sfds(void)
 #ifdef HAVE_SOCKADDR_SA_LEN
       addr.in6.sin6_len = sizeof(struct sockaddr_in6);
 #endif
-      if ((sfd = allocate_sfd(&addr, "")))
+      if ((sfd = allocate_sfd(&addr, "", 0)))
 	sfd->preallocated = 1;
     }
   
   for (srv = daemon->servers; srv; srv = srv->next)
     if (!(srv->flags & (SERV_LITERAL_ADDRESS | SERV_NO_ADDR | SERV_USE_RESOLV | SERV_NO_REBIND)) &&
-	!allocate_sfd(&srv->source_addr, srv->interface) &&
+	!allocate_sfd(&srv->source_addr, srv->interface, srv->ifindex) &&
 	errno != 0 &&
 	option_bool(OPT_NOWILD))
       {
@@ -1610,7 +1689,7 @@ void check_servers(void)
 	  
 	  /* Do we need a socket set? */
 	  if (!serv->sfd && 
-	      !(serv->sfd = allocate_sfd(&serv->source_addr, serv->interface)) &&
+	      !(serv->sfd = allocate_sfd(&serv->source_addr, serv->interface, serv->ifindex)) &&
 	      errno != 0)
 	    {
 	      my_syslog(LOG_WARNING, 

src/option.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -167,6 +167,9 @@ struct myoption {
 #define LOPT_IGNORE_CLID   358
 #define LOPT_SINGLE_PORT   359
 #define LOPT_SCRIPT_TIME   360
+#define LOPT_PXE_VENDOR    361
+#define LOPT_DYNHOST       362
+#define LOPT_LOG_DEBUG     363
  
 #ifdef HAVE_GETOPT_LONG
 static const struct option opts[] =  
@@ -270,6 +273,7 @@ static const struct myoption opts[] =
     { "dhcp-circuitid", 1, 0, LOPT_CIRCUIT },
     { "dhcp-remoteid", 1, 0, LOPT_REMOTE },
     { "dhcp-subscrid", 1, 0, LOPT_SUBSCR },
+    { "dhcp-pxe-vendor", 1, 0, LOPT_PXE_VENDOR },
     { "interface-name", 1, 0, LOPT_INTNAME },
     { "dhcp-hostsfile", 1, 0, LOPT_DHCP_HOST },
     { "dhcp-optsfile", 1, 0, LOPT_DHCP_OPTS },
@@ -339,6 +343,8 @@ static const struct myoption opts[] =
     { "dumpfile", 1, 0, LOPT_DUMPFILE },
     { "dumpmask", 1, 0, LOPT_DUMPMASK },
     { "dhcp-ignore-clid", 0, 0,  LOPT_IGNORE_CLID },
+    { "dynamic-host", 1, 0, LOPT_DYNHOST },
+    { "log-debug", 0, 0, LOPT_LOG_DEBUG },
     { NULL, 0, 0, 0 }
   };
 
@@ -383,6 +389,7 @@ static struct {
   { LOPT_CIRCUIT, ARG_DUP, "set:<tag>,<circuit>", gettext_noop("Map RFC3046 circuit-id to tag."), NULL },
   { LOPT_REMOTE, ARG_DUP, "set:<tag>,<remote>", gettext_noop("Map RFC3046 remote-id to tag."), NULL },
   { LOPT_SUBSCR, ARG_DUP, "set:<tag>,<remote>", gettext_noop("Map RFC3993 subscriber-id to tag."), NULL },
+  { LOPT_PXE_VENDOR, ARG_DUP, "<vendor>[,...]", gettext_noop("Specify vendor class to match for PXE requests."), NULL },
   { 'J', ARG_DUP, "tag:<tag>...", gettext_noop("Don't do DHCP for hosts with tag set."), NULL },
   { LOPT_BROADCAST, ARG_DUP, "[=tag:<tag>...]", gettext_noop("Force broadcast replies for hosts with tag set."), NULL }, 
   { 'k', OPT_NO_FORK, NULL, gettext_noop("Do NOT fork into the background, do NOT run in debug mode."), NULL },
@@ -488,6 +495,7 @@ static struct {
   { LOPT_RA, OPT_RA, NULL, gettext_noop("Send router-advertisements for interfaces doing DHCPv6"), NULL },
   { LOPT_DUID, ARG_ONE, "<enterprise>,<duid>", gettext_noop("Specify DUID_EN-type DHCPv6 server DUID"), NULL },
   { LOPT_HOST_REC, ARG_DUP, "<name>,<address>[,<ttl>]", gettext_noop("Specify host (A/AAAA and PTR) records"), NULL },
+  { LOPT_DYNHOST, ARG_DUP, "<name>,[<IPv4>][,<IPv6>],<interface-name>", gettext_noop("Specify host record in interface subnet"), NULL },
   { LOPT_CAA, ARG_DUP, "<name>,<flags>,<tag>,<value>", gettext_noop("Specify certification authority authorization record"), NULL },  
   { LOPT_RR, ARG_DUP, "<name>,<RR-number>,[<data>]", gettext_noop("Specify arbitrary DNS resource record"), NULL },
   { LOPT_CLVERBIND, OPT_CLEVERBIND, NULL, gettext_noop("Bind to interfaces in use - check for new interfaces"), NULL },
@@ -509,6 +517,7 @@ static struct {
   { LOPT_QUIET_DHCP, OPT_QUIET_DHCP, NULL, gettext_noop("Do not log routine DHCP."), NULL },
   { LOPT_QUIET_DHCP6, OPT_QUIET_DHCP6, NULL, gettext_noop("Do not log routine DHCPv6."), NULL },
   { LOPT_QUIET_RA, OPT_QUIET_RA, NULL, gettext_noop("Do not log RA."), NULL },
+  { LOPT_LOG_DEBUG, OPT_LOG_DEBUG, NULL, gettext_noop("Log debugging information."), NULL }, 
   { LOPT_LOCAL_SERVICE, OPT_LOCAL_SERVICE, NULL, gettext_noop("Accept queries only from directly-connected networks."), NULL },
   { LOPT_LOOP_DETECT, OPT_LOOP_DETECT, NULL, gettext_noop("Detect and remove DNS forwarding loops."), NULL },
   { LOPT_IGNORE_ADDR, ARG_DUP, "<ipaddr>", gettext_noop("Ignore DNS responses containing ipaddr."), NULL }, 
@@ -810,7 +819,8 @@ char *parse_server(char *arg, union mysockaddr *addr, union mysockaddr *source_a
     if (interface_opt)
       {
 #if defined(SO_BINDTODEVICE)
-	safe_strncpy(interface, interface_opt, IF_NAMESIZE);
+	safe_strncpy(interface, source, IF_NAMESIZE);
+	source = interface_opt;
 #else
 	return _("interface binding not supported");
 #endif
@@ -2478,8 +2488,14 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
     case LOPT_IGNORE_ADDR: /* --ignore-address */
      {
 	struct in_addr addr;
+	int prefix = 32;
 	unhide_metas(arg);
-	if (arg && (inet_pton(AF_INET, arg, &addr) > 0))
+
+	if (!arg ||
+	    ((comma = split_chr(arg, '/')) && !atoi_check(comma, &prefix)) ||
+	    (inet_pton(AF_INET, arg, &addr) != 1))
+	  ret_err(gen_err); /* error */
+	else
 	  {
 	    struct bogus_addr *baddr = opt_malloc(sizeof(struct bogus_addr));
 	    if (option == 'B')
@@ -2492,12 +2508,11 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 		baddr->next = daemon->ignore_addr;
 		daemon->ignore_addr = baddr;
 	      }
-	    baddr->addr = addr;
+	    baddr->mask.s_addr = htonl(~((1 << (32 - prefix)) - 1));
+	    baddr->addr.s_addr = addr.s_addr & baddr->mask.s_addr;
 	  }
-	else
-	  ret_err(gen_err); /* error */
-	break;	
-      }
+	break;
+     }
       
     case 'a':  /* --listen-address */
     case LOPT_AUTHPEER: /* --auth-peer */
@@ -3672,8 +3687,8 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 	     new->val = opt_malloc(new->len);
 	     memcpy(new->val + 1, arg, new->len - 1);
 	     
-	     new->u.vendor_class = (unsigned char *)"PXEClient";
-	     new->flags = DHOPT_VENDOR;
+	     new->u.vendor_class = NULL;
+	     new->flags = DHOPT_VENDOR | DHOPT_VENDOR_PXE;
 	     
 	     if (comma && atoi_check(comma, &timeout))
 	       *(new->val) = timeout;
@@ -3935,6 +3950,19 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 	new->next = daemon->override_relays;
 	daemon->override_relays = new;
 	arg = comma;
+	}
+	  break;
+
+    case LOPT_PXE_VENDOR: /* --dhcp-pxe-vendor */
+      {
+        while (arg) {
+	  struct dhcp_pxe_vendor *new = opt_malloc(sizeof(struct dhcp_pxe_vendor));
+	  comma = split(arg);
+          new->data = opt_string_alloc(arg);
+	  new->next = daemon->dhcp_pxe_vendors;
+	  daemon->dhcp_pxe_vendors = new;
+	  arg = comma;
+	}
       }
       break;
 
@@ -4059,36 +4087,66 @@ err:
       }
       
     case LOPT_INTNAME:  /* --interface-name */
+    case LOPT_DYNHOST:  /* --dynamic-host */
       {
 	struct interface_name *new, **up;
-	char *domain = NULL;
-
-	comma = split(arg);
+	char *domain = arg;
 	
-	if (!comma || !(domain = canonicalise_opt(arg)))
-	  ret_err(_("bad interface name"));
+	arg = split(arg);
 	
 	new = opt_malloc(sizeof(struct interface_name));
-	new->next = NULL;
-	new->addr = NULL;
+	memset(new, 0, sizeof(struct interface_name));
+	new->flags = IN4 | IN6;
 	
 	/* Add to the end of the list, so that first name
 	   of an interface is used for PTR lookups. */
 	for (up = &daemon->int_names; *up; up = &((*up)->next));
 	*up = new;
-	new->name = domain;
-	new->family = 0;
-	arg = split_chr(comma, '/');
-	if (arg)
+	
+	while ((comma = split(arg)))
 	  {
-	    if (strcmp(arg, "4") == 0)
-	      new->family = AF_INET;
-	    else if (strcmp(arg, "6") == 0)
-	      new->family = AF_INET6;
+	    if (inet_pton(AF_INET, arg, &new->proto4))
+	      new->flags |= INP4;
+	    else if (inet_pton(AF_INET6, arg, &new->proto6))
+	      new->flags |= INP6;
+	    else
+	      break;
+	    
+	    arg = comma;
+	  }
+
+	if ((comma = split_chr(arg, '/')))
+	  {
+	    if (strcmp(comma, "4") == 0)
+	      new->flags &= ~IN6;
+	    else if (strcmp(comma, "6") == 0)
+	      new->flags &= ~IN4;
 	    else
 	      ret_err_free(gen_err, new);
-	  } 
-	new->intr = opt_string_alloc(comma);
+	  }
+
+	new->intr = opt_string_alloc(arg);
+
+	if (option == LOPT_DYNHOST)
+	  {
+	    if (!(new->flags & (INP4 | INP6)))
+	      ret_err(_("missing address in dynamic host"));
+
+	    if (!(new->flags & IN4) || !(new->flags & IN6))
+	      arg = NULL; /* provoke error below */
+
+	    new->flags &= ~(IN4 | IN6);
+	  }
+	else
+	  {
+	    if (new->flags & (INP4 | INP6))
+	      arg = NULL; /* provoke error below */
+	  }
+	
+	if (!domain || !arg || !(new->name = canonicalise_opt(domain)))
+	  ret_err(option == LOPT_DYNHOST ?
+		  _("bad dynamic host") : _("bad interface name"));
+	
 	break;
       }
       
@@ -5018,9 +5076,7 @@ void read_opts(int argc, char **argv, char *compile_opts)
   daemon->soa_refresh = SOA_REFRESH;
   daemon->soa_retry = SOA_RETRY;
   daemon->soa_expiry = SOA_EXPIRY;
-  daemon->max_port = MAX_PORT;
-  daemon->min_port = MIN_PORT;
-
+  
 #ifndef NO_ID
   add_txt("version.bind", "dnsmasq-" VERSION, 0 );
   add_txt("authors.bind", "Simon Kelley", 0);
@@ -5212,6 +5268,13 @@ void read_opts(int argc, char **argv, char *compile_opts)
       strcat(buff, daemon->authserver);
       daemon->hostmaster = opt_string_alloc(buff);
     }
+
+  if (!daemon->dhcp_pxe_vendors)
+    {
+      daemon->dhcp_pxe_vendors = opt_malloc(sizeof(struct dhcp_pxe_vendor));
+      daemon->dhcp_pxe_vendors->data = opt_string_alloc(DHCP_PXE_DEF_VENDOR);
+      daemon->dhcp_pxe_vendors->next = NULL;
+    }
   
   /* only one of these need be specified: the other defaults to the host-name */
   if (option_bool(OPT_LOCALMX) || daemon->mxnames || daemon->mxtarget)

src/outpacket.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/poll.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/radv-protocol.h

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/radv.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/rfc1035.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -333,55 +333,6 @@ unsigned char *skip_section(unsigned char *ansp, int count, struct dns_header *h
   return ansp;
 }
 
-/* CRC the question section. This is used to safely detect query 
-   retransmission and to detect answers to questions we didn't ask, which 
-   might be poisoning attacks. Note that we decode the name rather 
-   than CRC the raw bytes, since replies might be compressed differently. 
-   We ignore case in the names for the same reason. Return all-ones
-   if there is not question section. */
-#ifndef HAVE_DNSSEC
-unsigned int questions_crc(struct dns_header *header, size_t plen, char *name)
-{
-  int q;
-  unsigned int crc = 0xffffffff;
-  unsigned char *p1, *p = (unsigned char *)(header+1);
-
-  for (q = ntohs(header->qdcount); q != 0; q--) 
-    {
-      if (!extract_name(header, plen, &p, name, 1, 4))
-	return crc; /* bad packet */
-      
-      for (p1 = (unsigned char *)name; *p1; p1++)
-	{
-	  int i = 8;
-	  char c = *p1;
-
-	  if (c >= 'A' && c <= 'Z')
-	    c += 'a' - 'A';
-
-	  crc ^= c << 24;
-	  while (i--)
-	    crc = crc & 0x80000000 ? (crc << 1) ^ 0x04c11db7 : crc << 1;
-	}
-      
-      /* CRC the class and type as well */
-      for (p1 = p; p1 < p+4; p1++)
-	{
-	  int i = 8;
-	  crc ^= *p1 << 24;
-	  while (i--)
-	    crc = crc & 0x80000000 ? (crc << 1) ^ 0x04c11db7 : crc << 1;
-	}
-
-      p += 4;
-      if (!CHECK_LEN(header, p, plen, 0))
-	return crc; /* bad packet */
-    }
-
-  return crc;
-}
-#endif
-
 size_t resize_packet(struct dns_header *header, size_t plen, unsigned char *pheader, size_t hlen)
 {
   unsigned char *ansp = skip_questions(header, plen);
@@ -1066,30 +1017,33 @@ int check_for_local_domain(char *name, time_t now)
   return 0;
 }
 
-/* Is the packet a reply with the answer address equal to addr?
-   If so mung is into an NXDOMAIN reply and also put that information
-   in the cache. */
-int check_for_bogus_wildcard(struct dns_header *header, size_t qlen, char *name, 
-			     struct bogus_addr *baddr, time_t now)
+static int check_bad_address(struct dns_header *header, size_t qlen, struct bogus_addr *baddr, char *name, unsigned long *ttlp)
 {
   unsigned char *p;
   int i, qtype, qclass, rdlen;
   unsigned long ttl;
   struct bogus_addr *baddrp;
-
+  struct in_addr addr;
+  
   /* skip over questions */
   if (!(p = skip_questions(header, qlen)))
     return 0; /* bad packet */
 
   for (i = ntohs(header->ancount); i != 0; i--)
     {
-      if (!extract_name(header, qlen, &p, name, 1, 10))
+      if (name && !extract_name(header, qlen, &p, name, 1, 10))
 	return 0; /* bad packet */
-  
+
+      if (!name && !(p = skip_name(p, header, qlen, 10)))
+	return 0;
+      
       GETSHORT(qtype, p); 
       GETSHORT(qclass, p);
       GETLONG(ttl, p);
       GETSHORT(rdlen, p);
+
+      if (ttlp)
+	*ttlp = ttl;
       
       if (qclass == C_IN && qtype == T_A)
 	{
@@ -1097,16 +1051,12 @@ int check_for_bogus_wildcard(struct dns_header *header, size_t qlen, char *name,
 	    return 0;
 	  
 	  for (baddrp = baddr; baddrp; baddrp = baddrp->next)
-	    if (memcmp(&baddrp->addr, p, INADDRSZ) == 0)
-	      {
-		/* Found a bogus address. Insert that info here, since there no SOA record
-		   to get the ttl from in the normal processing */
-		cache_start_insert();
-		cache_insert(name, NULL, C_IN, now, ttl, F_IPV4 | F_FORWARD | F_NEG | F_NXDOMAIN);
-		cache_end_insert();
-		
+	    {
+	      memcpy(&addr, p, INADDRSZ);
+	      
+	      if ((addr.s_addr & baddrp->mask.s_addr) == baddrp->addr.s_addr)
 		return 1;
-	      }
+	    }
 	}
       
       if (!ADD_RDLEN(header, p, qlen, rdlen))
@@ -1116,43 +1066,31 @@ int check_for_bogus_wildcard(struct dns_header *header, size_t qlen, char *name,
   return 0;
 }
 
-int check_for_ignored_address(struct dns_header *header, size_t qlen, struct bogus_addr *baddr)
+/* Is the packet a reply with the answer address equal to addr?
+   If so mung is into an NXDOMAIN reply and also put that information
+   in the cache. */
+int check_for_bogus_wildcard(struct dns_header *header, size_t qlen, char *name, time_t now)
 {
-  unsigned char *p;
-  int i, qtype, qclass, rdlen;
-  struct bogus_addr *baddrp;
+  unsigned long ttl;
 
-  /* skip over questions */
-  if (!(p = skip_questions(header, qlen)))
-    return 0; /* bad packet */
-
-  for (i = ntohs(header->ancount); i != 0; i--)
+  if (check_bad_address(header, qlen, daemon->bogus_addr, name, &ttl))
     {
-      if (!(p = skip_name(p, header, qlen, 10)))
-	return 0; /* bad packet */
-      
-      GETSHORT(qtype, p); 
-      GETSHORT(qclass, p);
-      p += 4; /* TTL */
-      GETSHORT(rdlen, p);
-      
-      if (qclass == C_IN && qtype == T_A)
-	{
-	  if (!CHECK_LEN(header, p, qlen, INADDRSZ))
-	    return 0;
-	  
-	  for (baddrp = baddr; baddrp; baddrp = baddrp->next)
-	    if (memcmp(&baddrp->addr, p, INADDRSZ) == 0)
-	      return 1;
-	}
-      
-      if (!ADD_RDLEN(header, p, qlen, rdlen))
-	return 0;
+      /* Found a bogus address. Insert that info here, since there no SOA record
+	 to get the ttl from in the normal processing */
+      cache_start_insert();
+      cache_insert(name, NULL, C_IN, now, ttl, F_IPV4 | F_FORWARD | F_NEG | F_NXDOMAIN);
+      cache_end_insert();
+
+      return 1;
     }
-  
+
   return 0;
 }
 
+int check_for_ignored_address(struct dns_header *header, size_t qlen)
+{
+  return check_bad_address(header, qlen, daemon->ignore_addr, NULL, NULL);
+}
 
 int add_resource_record(struct dns_header *header, char *limit, int *truncp, int nameoffset, unsigned char **pp, 
 			unsigned long ttl, int *offset, unsigned short type, unsigned short class, char *format, ...)
@@ -1408,6 +1346,8 @@ size_t answer_request(struct dns_header *header, char *limit, size_t qlen,
 		}
 
 	    }
+	  else
+	    return 0; /* give up if any cached CNAME in chain can't be used for DNSSEC reasons. */
 
 	  strcpy(name, cname_target);
 	}

src/rfc2131.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -30,7 +30,7 @@ static struct in_addr server_id(struct dhcp_context *context, struct in_addr ove
 static unsigned int calc_time(struct dhcp_context *context, struct dhcp_config *config, unsigned char *opt);
 static void option_put(struct dhcp_packet *mess, unsigned char *end, int opt, int len, unsigned int val);
 static void option_put_string(struct dhcp_packet *mess, unsigned char *end, 
-			      int opt, char *string, int null_term);
+			      int opt, const char *string, int null_term);
 static struct in_addr option_addr(unsigned char *opt);
 static unsigned int option_uint(unsigned char *opt, int offset, int size);
 static void log_packet(char *type, void *addr, unsigned char *ext_mac, 
@@ -54,17 +54,19 @@ static void do_options(struct dhcp_context *context,
 		       int vendor_class_len,
 		       time_t now,
 		       unsigned int lease_time,
-		       unsigned short fuzz);
+		       unsigned short fuzz,
+		       const char *pxevendor);
 
 
 static void match_vendor_opts(unsigned char *opt, struct dhcp_opt *dopt); 
 static int do_encap_opts(struct dhcp_opt *opt, int encap, int flag, struct dhcp_packet *mess, unsigned char *end, int null_term);
-static void pxe_misc(struct dhcp_packet *mess, unsigned char *end, unsigned char *uuid);
+static void pxe_misc(struct dhcp_packet *mess, unsigned char *end, unsigned char *uuid, const char *pxevendor);
 static int prune_vendor_opts(struct dhcp_netid *netid);
 static struct dhcp_opt *pxe_opts(int pxe_arch, struct dhcp_netid *netid, struct in_addr local, time_t now);
 struct dhcp_boot *find_boot(struct dhcp_netid *netid);
 static int pxe_uefi_workaround(int pxe_arch, struct dhcp_netid *netid, struct dhcp_packet *mess, struct in_addr local, time_t now, int pxe);
 static void apply_delay(u32 xid, time_t recvtime, struct dhcp_netid *netid);
+static int is_pxe_client(struct dhcp_packet *mess, size_t sz, const char **pxe_vendor);
 
 size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
 		  size_t sz, time_t now, int unicast_dest, int loopback,
@@ -76,6 +78,7 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
   struct dhcp_mac *mac;
   struct dhcp_netid_list *id_list;
   int clid_len = 0, ignore = 0, do_classes = 0, rapid_commit = 0, selecting = 0, pxearch = -1;
+  const char *pxevendor = NULL;
   struct dhcp_packet *mess = (struct dhcp_packet *)daemon->dhcp_packet.iov_base;
   unsigned char *end = (unsigned char *)(mess + 1); 
   unsigned char *real_end = (unsigned char *)(mess + 1); 
@@ -647,7 +650,7 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
 	      
 	      clear_packet(mess, end);
 	      do_options(context, mess, end, NULL, hostname, get_domain(mess->yiaddr), 
-			 netid, subnet_addr, 0, 0, -1, NULL, vendor_class_len, now, 0xffffffff, 0);
+			 netid, subnet_addr, 0, 0, -1, NULL, vendor_class_len, now, 0xffffffff, 0, NULL);
 	    }
 	}
       
@@ -835,9 +838,8 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
     clid = NULL;
           
   /* Check if client is PXE client. */
-  if (daemon->enable_pxe && 
-      (opt = option_find(mess, sz, OPTION_VENDOR_ID, 9)) && 
-      strncmp(option_ptr(opt, 0), "PXEClient", 9) == 0)
+  if (daemon->enable_pxe &&
+      is_pxe_client(mess, sz, &pxevendor))
     {
       if ((opt = option_find(mess, sz, OPTION_PXE_UUID, 17)))
 	{
@@ -899,7 +901,7 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
 	  
 	  option_put(mess, end, OPTION_MESSAGE_TYPE, 1, DHCPACK);
 	  option_put(mess, end, OPTION_SERVER_IDENTIFIER, INADDRSZ, htonl(context->local.s_addr));
-	  pxe_misc(mess, end, uuid);
+	  pxe_misc(mess, end, uuid, pxevendor);
 	  
 	  prune_vendor_opts(tagif_netid);
 	  opt71.val = save71;
@@ -979,7 +981,7 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
 		  option_put(mess, end, OPTION_MESSAGE_TYPE, 1, 
 			     mess_type == DHCPDISCOVER ? DHCPOFFER : DHCPACK);
 		  option_put(mess, end, OPTION_SERVER_IDENTIFIER, INADDRSZ, htonl(tmp->local.s_addr));
-		  pxe_misc(mess, end, uuid);
+		  pxe_misc(mess, end, uuid, pxevendor);
 		  prune_vendor_opts(tagif_netid);
 		  if ((pxe && !workaround) || !redirect4011)
 		    do_encap_opts(pxe_opts(pxearch, tagif_netid, tmp->local, now), OPTION_VENDOR_CLASS_OPT, DHOPT_VENDOR_MATCH, mess, end, 0);
@@ -1150,7 +1152,7 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
       option_put(mess, end, OPTION_LEASE_TIME, 4, time);
       /* T1 and T2 are required in DHCPOFFER by HP's wacky Jetdirect client. */
       do_options(context, mess, end, req_options, offer_hostname, get_domain(mess->yiaddr), 
-		 netid, subnet_addr, fqdn_flags, borken_opt, pxearch, uuid, vendor_class_len, now, time, fuzz);
+		 netid, subnet_addr, fqdn_flags, borken_opt, pxearch, uuid, vendor_class_len, now, time, fuzz, pxevendor);
       
       return dhcp_packet_size(mess, agent_id, real_end);
 	
@@ -1499,7 +1501,7 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
 	  if (rapid_commit)
 	     option_put(mess, end, OPTION_RAPID_COMMIT, 0, 0);
 	   do_options(context, mess, end, req_options, hostname, get_domain(mess->yiaddr), 
-		     netid, subnet_addr, fqdn_flags, borken_opt, pxearch, uuid, vendor_class_len, now, time, fuzz);
+		     netid, subnet_addr, fqdn_flags, borken_opt, pxearch, uuid, vendor_class_len, now, time, fuzz, pxevendor);
 	}
 
       return dhcp_packet_size(mess, agent_id, real_end); 
@@ -1566,7 +1568,7 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
 	}
 
       do_options(context, mess, end, req_options, hostname, get_domain(mess->ciaddr),
-		 netid, subnet_addr, fqdn_flags, borken_opt, pxearch, uuid, vendor_class_len, now, 0xffffffff, 0);
+		 netid, subnet_addr, fqdn_flags, borken_opt, pxearch, uuid, vendor_class_len, now, 0xffffffff, 0, pxevendor);
       
       *is_inform = 1; /* handle reply differently */
       return dhcp_packet_size(mess, agent_id, real_end); 
@@ -1948,7 +1950,7 @@ static void option_put(struct dhcp_packet *mess, unsigned char *end, int opt, in
 }
 
 static void option_put_string(struct dhcp_packet *mess, unsigned char *end, int opt, 
-			      char *string, int null_term)
+			      const char *string, int null_term)
 {
   unsigned char *p;
   size_t len = strlen(string);
@@ -2026,15 +2028,32 @@ static void match_vendor_opts(unsigned char *opt, struct dhcp_opt *dopt)
       dopt->flags &= ~DHOPT_VENDOR_MATCH;
       if (opt && (dopt->flags & DHOPT_VENDOR))
 	{
-	  int i, len = 0;
-	  if (dopt->u.vendor_class)
-	    len = strlen((char *)dopt->u.vendor_class);
-	  for (i = 0; i <= (option_len(opt) - len); i++)
-	    if (len == 0 || memcmp(dopt->u.vendor_class, option_ptr(opt, i), len) == 0)
-	      {
-		dopt->flags |= DHOPT_VENDOR_MATCH;
-		break;
-	      }
+	  const struct dhcp_pxe_vendor *pv;
+	  struct dhcp_pxe_vendor dummy_vendor = {
+	    .data = (char *)dopt->u.vendor_class,
+	    .next = NULL,
+	  };
+	  if (dopt->flags & DHOPT_VENDOR_PXE)
+	    pv = daemon->dhcp_pxe_vendors;
+	  else
+	    pv = &dummy_vendor;
+	  for (; pv; pv = pv->next)
+	    {
+	      int i, len = 0, matched = 0;
+	      if (pv->data)
+	        len = strlen(pv->data);
+	      for (i = 0; i <= (option_len(opt) - len); i++)
+	        if (len == 0 || memcmp(pv->data, option_ptr(opt, i), len) == 0)
+	          {
+		    matched = 1;
+	            break;
+	          }
+	      if (matched)
+		{
+	          dopt->flags |= DHOPT_VENDOR_MATCH;
+		  break;
+		}
+	    }
 	}
     }
 }
@@ -2087,11 +2106,13 @@ static int do_encap_opts(struct dhcp_opt *opt, int encap, int flag,
   return ret;
 }
 
-static void pxe_misc(struct dhcp_packet *mess, unsigned char *end, unsigned char *uuid)
+static void pxe_misc(struct dhcp_packet *mess, unsigned char *end, unsigned char *uuid, const char *pxevendor)
 {
   unsigned char *p;
 
-  option_put_string(mess, end, OPTION_VENDOR_ID, "PXEClient", 0);
+  if (!pxevendor)
+    pxevendor="PXEClient";
+  option_put_string(mess, end, OPTION_VENDOR_ID, pxevendor, 0);
   if (uuid && (p = free_space(mess, end, OPTION_PXE_UUID, 17)))
     memcpy(p, uuid, 17);
 }
@@ -2308,6 +2329,29 @@ struct dhcp_boot *find_boot(struct dhcp_netid *netid)
   return boot;
 }
 
+static int is_pxe_client(struct dhcp_packet *mess, size_t sz, const char **pxe_vendor)
+{
+  const unsigned char *opt = NULL;
+  ssize_t conf_len = 0;
+  const struct dhcp_pxe_vendor *conf = daemon->dhcp_pxe_vendors;
+  opt = option_find(mess, sz, OPTION_VENDOR_ID, 0);
+  if (!opt) 
+    return 0;
+  for (; conf; conf = conf->next)
+    {
+      conf_len = strlen(conf->data);
+      if (option_len(opt) < conf_len)
+        continue;
+      if (strncmp(option_ptr(opt, 0), conf->data, conf_len) == 0)
+        {
+          if (pxe_vendor)
+            *pxe_vendor = conf->data;
+          return 1;
+        }
+    }
+  return 0;
+}
+
 static void do_options(struct dhcp_context *context,
 		       struct dhcp_packet *mess,
 		       unsigned char *end, 
@@ -2322,7 +2366,8 @@ static void do_options(struct dhcp_context *context,
 		       int vendor_class_len,
 		       time_t now,
 		       unsigned int lease_time,
-		       unsigned short fuzz)
+		       unsigned short fuzz,
+		       const char *pxevendor)
 {
   struct dhcp_opt *opt, *config_opts = daemon->dhcp_opts;
   struct dhcp_boot *boot;
@@ -2696,7 +2741,7 @@ static void do_options(struct dhcp_context *context,
   
   if (context && pxe_arch != -1)
     {
-      pxe_misc(mess, end, uuid);
+      pxe_misc(mess, end, uuid, pxevendor);
       if (!pxe_uefi_workaround(pxe_arch, tagif, mess, context->local, now, 0))
 	config_opts = pxe_opts(pxe_arch, tagif, context->local, now);
     }

src/rfc3315.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/rrfilter.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/slaac.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/tftp.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -22,7 +22,7 @@ static void handle_tftp(time_t now, struct tftp_transfer *transfer, ssize_t len)
 static struct tftp_file *check_tftp_fileperm(ssize_t *len, char *prefix);
 static void free_transfer(struct tftp_transfer *transfer);
 static ssize_t tftp_err(int err, char *packet, char *message, char *file);
-static ssize_t tftp_err_oops(char *packet, char *file);
+static ssize_t tftp_err_oops(char *packet, const char *file);
 static ssize_t get_block(char *packet, struct tftp_transfer *transfer);
 static char *next(char **p, char *end);
 static void sanitise(char *buf);
@@ -94,7 +94,7 @@ void tftp_request(struct listener *listen, time_t now)
 
   if ((len = recvmsg(listen->tftpfd, &msg, 0)) < 2)
     return;
-
+  
   /* Can always get recvd interface for IPv6 */
   if (!check_dest)
     {
@@ -587,7 +587,7 @@ void check_tftp_listeners(time_t now)
 	  daemon->srv_save = NULL;
 	  handle_tftp(now, transfer, recv(transfer->sockfd, daemon->packet, daemon->packet_buff_sz, 0));
 	}
-
+  
   for (transfer = daemon->tftp_trans, up = &daemon->tftp_trans; transfer; transfer = tmp)
     {
       tmp = transfer->next;
@@ -602,7 +602,7 @@ void check_tftp_listeners(time_t now)
 	  	  
 	  /* we overwrote the buffer... */
 	  daemon->srv_save = NULL;
-	 
+
 	  if ((len = get_block(daemon->packet, transfer)) == -1)
 	    {
 	      len = tftp_err_oops(daemon->packet, transfer->file->filename);
@@ -748,10 +748,11 @@ static ssize_t tftp_err(int err, char *packet, char *message, char *file)
   return  ret;
 }
 
-static ssize_t tftp_err_oops(char *packet, char *file)
+static ssize_t tftp_err_oops(char *packet, const char *file)
 {
   /* May have >1 refs to file, so potentially mangle a copy of the name */
-  strcpy(daemon->namebuff, file);
+  if (file != daemon->namebuff)
+    strcpy(daemon->namebuff, file);
   return tftp_err(ERR_NOTDEF, packet, _("cannot read %s: %s"), daemon->namebuff);
 }
 

src/ubus.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by

src/util.c

@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2020 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -316,7 +316,7 @@ void *whine_malloc(size_t size)
   return ret;
 }
 
-int sockaddr_isequal(union mysockaddr *s1, union mysockaddr *s2)
+int sockaddr_isequal(const union mysockaddr *s1, const union mysockaddr *s2)
 {
   if (s1->sa.sa_family == s2->sa.sa_family)
     {