Fix diff link

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

ChangeLog.md

@@ -4,6 +4,31 @@ Change Log
 All relevant changes are documented in this file.
 
 
+[4.1][UNRELEASED]
+-----------------
+
+Bug fix release.
+
+### Changes
+* Change behavior on SIGUSR1 to be compatible with sysvinit and systemd.
+  Previously SIGUSR1 caused Finit to halt, like BusyBox init.  This had
+  "interesting" side effects on Debian systems when coexisting with
+  sysvinit (upgrading/reinstalling causes scripts to `kill -USR1 1`)
+* Change how `contrib/debian/install.sh` sets up a Grub boot entry for
+  finit.  We now modify the $SUPPORTED_INITS variable in `10_linux`
+
+### Fixes
+* Stricter interface name validation in netlink plugin, modeled after
+  the kernel.  Suggested by Coverity Scan
+* The `contrib/*/install.sh` scripts failed to run from tarball
+* Fix #170: detect loss of default route when interfaces go down.  This
+  emulates the missing kernel netlink message to remove the condition
+  net/default/route to allow stopping dependent services
+* Fix #171: restore automatic mount of `/dev/shm`, `/dev/pts`, `/run`
+  and `/tmp`, unless mounted already by `/etc/fstab`.  This is what most
+  desktop systems expect PID 1 to do
+
+
 [4.0][] - 2021-04-26
 --------------------
 
@@ -875,7 +900,7 @@ Major bug fix release.
 
 * Initial release
 
-[UNRELEASED]: https://github.com/troglobit/finit/compare/3.1...HEAD
+[UNRELEASED]: https://github.com/troglobit/finit/compare/4.0...HEAD
 [4.0]: https://github.com/troglobit/finit/compare/3.1...4.0
 [3.1]: https://github.com/troglobit/finit/compare/3.0...3.1
 [3.0]: https://github.com/troglobit/finit/compare/2.4...3.0
@@ -907,9 +932,3 @@ Major bug fix release.
 [0.2]: https://github.com/troglobit/finit/compare/0.1...0.2
 [libuEv]: https://github.com/troglobit/libuev
 [dea3ae8]: https://github.com/troglobit/finit/commit/dea3ae8
-
-<!--
-  -- Local Variables:
-  -- mode: markdown
-  -- End:
-  -->

configure.ac

@@ -1,4 +1,4 @@
-AC_INIT(Finit, 4.0, https://github.com/troglobit/finit/issues, finit, https://troglobit.com/finit.html)
+AC_INIT(Finit, 4.1-rc1, https://github.com/troglobit/finit/issues, finit, https://troglobit.com/finit.html)
 AC_CONFIG_AUX_DIR(aux)
 AM_INIT_AUTOMAKE([1.11 foreign dist-xz subdir-objects])
 AM_SILENT_RULES([yes])
@@ -8,7 +8,7 @@ AC_CONFIG_HEADER([config.h])
 AC_CONFIG_FILES([Makefile
 	contrib/Makefile
 	contrib/alpine/Makefile contrib/alpine/finit.d/Makefile contrib/alpine/finit.d/available/Makefile
-	contrib/debian/Makefile contrib/debian/finit.d/Makefile contrib/debian/finit.d/available/Makefile contrib/debian/grub.d/Makefile
+	contrib/debian/Makefile contrib/debian/finit.d/Makefile contrib/debian/finit.d/available/Makefile
 	contrib/void/Makefile   contrib/void/finit.d/Makefile   contrib/void/finit.d/available/Makefile
 	doc/Makefile
 	plugins/Makefile

contrib/alpine/install.sh

@@ -10,7 +10,7 @@ fi
 # Adjust base directory
 if [ -e alpine-release ]; then
     cd ../..
-elif [ ! -e autogen.sh ]; then
+elif [ ! -e configure.ac ]; then
     echo "*** Please run this script from the Finit base directory."
     exit 1
 fi

contrib/debian/Makefile.am

@@ -1,4 +1,4 @@
-SUBDIRS    = finit.d grub.d
+SUBDIRS    = finit.d
 docsdir   := @docdir@/contrib/debian
 docs_DATA  = README.md finit.conf os-release build.sh install.sh
 EXTRA_DIST = $(docs_DATA)

contrib/debian/README.md

@@ -29,10 +29,10 @@ set up your system to run Finit:
     user@debian:~/finit$ contrib/debian/build.sh
 
 However, since `/sbin/init` already exists on your system, the script
-creates another entry in your GRUB config, in `/etc/grub.d/40_custom`,
-where `init=/sbin/finit` is added to your kernel line.  It is of course
-also possible to change the default init to Finit, if you do you can
-remove the custom Grub entry:
+creates another entry in your GRUB config by updating `$SUPPORTED_INITS`
+in `/etc/grub.d/10_inux` and run `update-grub`.  On reboot you will find
+a (finit) entry in the "Advanced options for Debian GNU/Linux" section.
+It is of course also possible to change the default init to Finit:
 
     user@debian:~/finit# cd /sbin
     user@debian:/sbin# sudo mv init oldinit
@@ -51,7 +51,8 @@ If you want to use the X Window system, `sudo apt install elogind`
 (Bullseye and later).  Followed by `initctl reload` (enabled by default)
 and logout/login again.  The elogind daemon ensures a regular non-root
 user can start and interact with an X session, otherwise keyboard and
-mouse won't work.
+mouse won't work.  When you're happy, you can enable the lightdm.conf,
+change the default runlevel to 3, and presto! you have a desktop again.
 
 
 Have fun!  

contrib/debian/grub.d/40_custom

@@ -1,14 +0,0 @@
-#!/bin/sh
-exec tail -n +3 $0
-# This file provides an easy way to add custom menu entries.  Simply type the
-# menu entries you want to add after this comment.  Be careful not to change
-# the 'exec tail' line above.
-
-menuentry '$MENU with Finit' --class $TYPE --class gnu-linux --class gnu --class os --user {
-	insmod gzio
-	insmod part_msdos
-	insmod ext2
-	search --no-floppy --fs-uuid --set=root $BOOT
-	linux	/vmlinuz root=UUID=$ROOT ro quiet init=/sbin/finit
-	initrd	/initrd.img
-}

contrib/debian/grub.d/Makefile.am

@@ -1,3 +0,0 @@
-docsdir   := @docdir@/contrib/debian/grub.d
-docs_DATA  = 40_custom
-EXTRA_DIST = $(docs_DATA)

contrib/debian/install.sh

@@ -11,7 +11,7 @@ fi
 grep -q Debian os-release 2>/dev/null
 if [ $? -eq 0 ]; then
     cd ../..
-elif [ ! -e autogen.sh ]; then
+elif [ ! -e configure.ac ]; then
     echo "*** Please run this script from the Finit base directory."
     exit 1
 fi
@@ -23,7 +23,7 @@ echo "/sbin/finit           - PID 1"
 echo "/lib/finit/plugins/*  - All enabled Finit plugins"
 echo "/etc/finit.conf       - Finit configuration file"
 echo "/etc/finit.d/         - Finit services"
-echo "/etc/grub.d/40_custom - Add menu entry to the Grub boot loader"
+echo "/etc/grub.d/10_linux  - Add Finit to Grub's SUPPORTED_INITS"
 echo
 read -p "Do you want to continue (y/N)? " yorn
 echo
@@ -38,12 +38,18 @@ if [ "x$yorn" = "xy" -o "x$yorn" = "xY" ]; then
     cp -va finit.d /etc/
 
     echo "*** Setting up a GRUB boot entry ..."
-    MENU=`grep gnu-linux /boot/grub/grub.cfg |head -1 |sed "s/menuentry '\([^']*\).*/\1/"`
-    TYPE=`grep gnu-linux /boot/grub/grub.cfg |head -1 |sed "s/.*' --class \([a-z]*\).*/\1/"`
-    BOOT=`grep set=root /boot/grub/grub.cfg |head -1 |sed 's/.* \([a-f0-9]*-[a-f0-9]*-[a-f0-9]*-[a-f0-9]*-[a-f0-9]*\).*/\1/'`
-    ROOT=`grep root=UUID /boot/grub/grub.cfg |head -1 |sed 's/.*UUID=\([a-f0-9]*-[a-f0-9]*-[a-f0-9]*-[a-f0-9]*-[a-f0-9]*\).*/\1/'`
-    cat grub.d/40_custom | sed "s,\$BOOT,$BOOT,;s,\$ROOT,$ROOT,;s,\$TYPE,$TYPE,;s,\$MENU,$MENU," >/etc/grub.d/40_custom
-    update-grub
+    fn=/etc/grub.d/10_linux
+    if [ -e $fn ]; then
+	if `grep SUPPORTED_INITS $fn |head -1 |grep -q finit`; then
+	    echo "Already installed, done."
+	else
+	    echo "Adding Finit to list of SUPPORTED_INITS ..."
+	    sed -i 's/SUPPORTED_INITS="[^"]*/& finit:\/sbin\/finit/' $fn
+	    update-grub
+	fi
+    else
+	echo "Cannot find $fn, you'll have to set up your bootloader on your own."
+    fi
 
     echo
     echo "*** Done"

contrib/void/install.sh

@@ -10,7 +10,7 @@ fi
 # Adjust base directory
 if [ -e xbps ]; then
     cd ../..
-elif [ ! -e autogen.sh ]; then
+elif [ ! -e configure.ac ]; then
     echo "*** Please run this script from the Finit base directory."
     exit 1
 fi

doc/signals.md

@@ -12,28 +12,36 @@ have been adopted:
 Same effect as `finit q`, `init q`, or `initctl reload`, reloads all
 *.conf files in `/etc/finit.d/`
 
+This also restarts the API (initctl) socket, like SysV init and systemd
+does on USR1 with their FIFO/D-Bus.
+
+
 `SIGUSR1`
 ---------
 
-Calls shutdown hooks, including `HOOK_SHUTDOWN`, stopping all running
-processes, and unmounts all file systems.  Then tells kernel to halt.
-Most people these days want `SIGUSR2` though.
+Since Finit 4.1 this signal causes Finit to restart its API (initctl)
+socket, like SysV init and systemd does on USR1 with their FIFO/D-Bus.
+
+Finit <= 4.0 performed a system halt (like USR2 without power-off), but
+this caused compatibility problems with systemd and sysvinit on desktop
+systems.  Hence, since Finit 4.1 it is no longer possible to halt a
+system with a signal.
 
-SysV init and systemd use this to re-open their FIFO/D-Bus.
 
 `SIGUSR2`
 ---------
 
-Like SIGUSR1, but tell kernel to power-off the system, if ACPI or
-similar exists to actually do this.  If the kernel fails power-off,
-Finit falls back to halt.
- 
+Calls shutdown hooks, including `HOOK_SHUTDOWN`, stopping all running
+processes, and unmounts all file systems.  Then tells kernel to power
+off the system, if ACPI or similar exists to actually do this.  If the
+kernel fails power-off, Finit falls back to halt.
+
 SysV init N/A, systemd dumps its internal state to log.
 
 `SIGTERM`
 ---------
 
-Like `SIGUSR1`, but tell kernel to reboot the system when done.
+Like `SIGUSR2`, but tell kernel to reboot the system when done.
  
 SysV init N/A, systemd rexecutes itself.
 

plugins/netlink.c

@@ -31,6 +31,9 @@
 #include "helpers.h"
 #include "plugin.h"
 
+static int ifdown = 0;
+
+
 static int nlmsg_validate(struct nlmsghdr *nh, size_t len)
 {
 	if (!NLMSG_OK(nh, len))
@@ -51,10 +54,16 @@ static int nlmsg_validate(struct nlmsghdr *nh, size_t len)
 
 static void nl_route(struct nlmsghdr *nlmsg, ssize_t len)
 {
+	char daddr[INET_ADDRSTRLEN];
+	char gaddr[INET_ADDRSTRLEN];
+	struct in_addr ind, ing;
 	struct rtmsg *r;
 	struct rtattr *a;
+	int plen = 0;
+	int dst = 0;
+	int idx = 0;
+	int gw = 0;
 	int la;
-	int gw = 0, dst = 0, mask = 0, idx = 0;
 
 	if (nlmsg->nlmsg_len < NLMSG_LENGTH(sizeof(struct rtmsg))) {
 		_e("Packet too small or truncated!");
@@ -80,8 +89,8 @@ static void nl_route(struct nlmsghdr *nlmsg, ssize_t len)
 
 		case RTA_DST:
 			dst = *((int *)data);
-			mask = r->rtm_dst_len;
-			//_d("MASK: 0x%04x", mask);
+			plen = r->rtm_dst_len;
+			//_d("Prefix LEN: 0x%04x", plen);
 			break;
 
 		case RTA_OIF:
@@ -93,7 +102,13 @@ static void nl_route(struct nlmsghdr *nlmsg, ssize_t len)
 		a = RTA_NEXT(a, la);
 	}
 
-	if ((!dst && !mask) && (gw || idx)) {
+	ind.s_addr = dst;
+	ing.s_addr = gw;
+	inet_ntop(AF_INET, &ind, daddr, sizeof(daddr));
+	inet_ntop(AF_INET, &ing, gaddr, sizeof(gaddr));
+	_d("Got gw %s dst/len %s/%d ifindex %d", gaddr, daddr, plen, idx);
+
+	if ((!dst && !plen) && (gw || idx)) {
 		if (nlmsg->nlmsg_type == RTM_DELROUTE)
 			cond_clear("net/route/default");
 		else
@@ -101,6 +116,36 @@ static void nl_route(struct nlmsghdr *nlmsg, ssize_t len)
 	}
 }
 
+static int nl_default(struct nlmsghdr *nlh, struct in_addr *dst, struct in_addr *gw)
+{
+	struct in_addr nil = { 0 };
+	struct rtattr *a;
+	struct rtmsg *r;
+	int len;
+
+	r = (struct rtmsg *)NLMSG_DATA(nlh);
+	if ((r->rtm_family != AF_INET) || (r->rtm_table != RT_TABLE_MAIN))
+		return -1;
+
+	len = RTM_PAYLOAD(nlh);
+	for (a = RTM_RTA(r); RTA_OK(a, len); a = RTA_NEXT(a, len)) {
+		switch (a->rta_type) {
+		case RTA_GATEWAY:
+			memcpy(gw, RTA_DATA(a), sizeof(*gw));
+			break;
+
+		case RTA_DST:
+			memcpy(dst, RTA_DATA(a), sizeof(*dst));
+			break;
+		}
+	}
+
+	if (!memcmp(dst, &nil, sizeof(nil)) && memcmp(gw, &nil, sizeof(nil)))
+		return 0;
+
+	return 1;
+}
+
 static void net_cond_set(char *ifname, char *cond, int set)
 {
 	char msg[MAX_ARG_LEN];
@@ -117,14 +162,14 @@ static int validate_ifname(const char *ifname)
 	if (!ifname || !ifname[0])
 		return 1;
 
-	if (strlen(ifname) >= IFNAMSIZ)
+	if (strnlen(ifname, IFNAMSIZ) == IFNAMSIZ)
 		return 1;
 
-	if (strstr(ifname, ".."))
+	if (!strcmp(ifname, ".") || !strcmp(ifname, ".."))
 		return 1;
 
 	while (*ifname) {
-		if (*ifname == '/' || isspace(*ifname))
+		if (*ifname == '/' || *ifname == ':' || isspace(*ifname))
 			return 1;
 		ifname++;
 	}
@@ -134,10 +179,10 @@ static int validate_ifname(const char *ifname)
 
 static void nl_link(struct nlmsghdr *nlmsg, ssize_t len)
 {
-	int la;
 	char ifname[IFNAMSIZ + 1];
-	struct rtattr *a;
 	struct ifinfomsg *i;
+	struct rtattr *a;
+	int la;
 
 	if (nlmsg->nlmsg_len < NLMSG_LENGTH(sizeof(struct ifinfomsg))) {
 		_e("Packet too small or truncated!");
@@ -172,6 +217,8 @@ static void nl_link(struct nlmsghdr *nlmsg, ssize_t len)
 			net_cond_set(ifname, "exist",   1);
 			net_cond_set(ifname, "up",      i->ifi_flags & IFF_UP);
 			net_cond_set(ifname, "running", i->ifi_flags & IFF_RUNNING);
+			if (!(i->ifi_flags & IFF_UP) || !(i->ifi_flags & IFF_RUNNING))
+				ifdown = 1;
 			break;
 
 		case RTM_DELLINK:
@@ -180,6 +227,7 @@ static void nl_link(struct nlmsghdr *nlmsg, ssize_t len)
 			net_cond_set(ifname, "exist",   0);
 			net_cond_set(ifname, "up",      0);
 			net_cond_set(ifname, "running", 0);
+			ifdown = 1;
 			break;
 
 		case RTM_NEWADDR:
@@ -211,6 +259,9 @@ static void nl_callback(void *arg, int sd, int events)
 		return;
 	}
 
+	/* check for interface changes -> loss of default route */
+	ifdown = 0;
+
 	for (nh = (struct nlmsghdr *)buf; !nlmsg_validate(nh, len); nh = NLMSG_NEXT(nh, len)) {
 		//_d("Well formed netlink message received. type %d ...", nh->nlmsg_type);
 		if (nh->nlmsg_type == RTM_NEWROUTE || nh->nlmsg_type == RTM_DELROUTE)
@@ -218,6 +269,53 @@ static void nl_callback(void *arg, int sd, int events)
 		else
 			nl_link(nh, len);
 	}
+
+	/*
+	 * Linux doesn't send route changes, when interfaces go down, so
+	 * we need to check ourselves, e.g. for loss of default route.
+	 */
+	if (ifdown) {
+		unsigned int seq = 0;
+		int found = 0;
+
+		sd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
+		if (sd < 0) {
+			_pe("netlink socket");
+			return;
+		}
+
+		memset(buf, 0, sizeof(buf));
+		nh = (struct nlmsghdr *)buf;
+		nh->nlmsg_len   = NLMSG_LENGTH(sizeof(struct rtmsg));
+		nh->nlmsg_type  = RTM_GETROUTE;
+		nh->nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST;
+		nh->nlmsg_seq   = seq++;
+		nh->nlmsg_pid   = 1;
+
+		if (send(sd, nh, nh->nlmsg_len, 0) < 0) {
+			_pe("Failed netlink route request");
+			close(sd);
+			return;
+		}
+
+		len = recv(sd, buf, sizeof(buf), 0);
+		close(sd);
+
+		for (; NLMSG_OK(nh, len); nh = NLMSG_NEXT(nh, len)) {
+			struct in_addr dst = { 0 };
+			struct in_addr gw = { 0 };
+
+			if (nl_default(nh, &dst, &gw))
+				continue;
+
+			_d("default via %s\n", inet_ntoa(gw));
+			found = 1;
+		}
+
+		/* We already get notification when adding default rt */
+		if (!found)
+			cond_clear("net/route/default");
+	}
 }
 
 static void nl_reconf(void *arg)
@@ -236,8 +334,8 @@ static plugin_t plugin = {
 
 PLUGIN_INIT(plugin_init)
 {
-	int sd;
 	struct sockaddr_nl sa;
+	int sd;
 
 	sd = socket(AF_NETLINK, SOCK_RAW | SOCK_NONBLOCK | SOCK_CLOEXEC, NETLINK_ROUTE);
 	if (sd < 0) {

src/finit.c

@@ -186,6 +186,44 @@ static void fs_remount_root(int fsckerr)
 }
 #endif	/* SYSROOT */
 
+/*
+ * Opinionated file system setup.  Checks for critical mount points and
+ * mounts them as most users expect.  All file systems are checked with
+ * /proc/mounts before mounting.
+ *
+ * Embedded systems, and other people who want full control, can set up
+ * their system with /etc/fstab, which is handled before this function
+ * is called.  For systems like Debian/Ubuntu, who only have / and swap
+ * in their /etc/fstab, this function does all the magic necessary.
+ */
+static void fs_finalize(void)
+{
+	/*
+	 * Some systems rely on us to both create /dev/shm and, to mount
+	 * a tmpfs there.  Any system with dbus needs shared memory, so
+	 * mount it, unless its already mounted, but not if listed in
+	 * the /etc/fstab file already.
+	 */
+	if (!fismnt("/dev/shm")) {
+		makedir("/dev/shm", 0777);
+		mount("shm", "/dev/shm", "tmpfs", 0, "mode=0777");
+	}
+
+	/* Modern systems use /dev/pts */
+	if (!fismnt("/dev/pts")) {
+		makedir("/dev/pts", 0755);
+		mount("devpts", "/dev/pts", "devpts", 0, "gid=5,mode=620,ptmxmode=0666");
+	}
+
+	/* Modern systems use tmpfs for /run */
+	if (!fismnt("/run"))
+		mount("tmpfs", "/run", "tmpfs", 0, "mode=0755,nosuid,nodev,noexec,relatime");
+
+	/* Modern systems use tmpfs for /tmp */
+	if (!fismnt("/tmp"))
+		mount("tmpfs", "/tmp", "tmpfs", 0, "mode=0755,nosuid,nodev");
+}
+
 static void fs_mount(void)
 {
 	if (!rescue)
@@ -201,6 +239,9 @@ static void fs_mount(void)
 	plugin_run_hooks(HOOK_MOUNT_POST);
 
 	run("swapon -ea");
+
+	_d("Finalize, ensure common file systems are available ...");
+	fs_finalize();
 }
 
 /*

src/reboot.c

@@ -206,7 +206,7 @@ int reboot_main(int argc, char *argv[])
 
 	case CMD_HALT:
 		if (do_halt(NULL))
-			do_kill(SIGUSR1, msg);
+			do_kill(SIGUSR2, msg);
 		break;
 
 	case CMD_POWEROFF:

src/sig.c

@@ -31,21 +31,24 @@
  *      does on USR1 with their FIFO/D-Bus.
  *
  * SIGUSR1
- *      Calls shutdown hooks, including HOOK_SHUTDOWN, stops all running
- *      processes, and unmounts all file systems.  Then tells kernel to
- *      halt.  Most people these days want SIGUSR2 though.
+ *      Restarts API (initctl) socket, like SysV init and systemd does
+ *      on USR1 with their FIFO/D-Bus.
  *
- *      (SysV init and systemd use this to re-open their FIFO/D-Bus.)
+ *      Finit <= 4.0 used to perform a system halt on USR1.  This caused
+ *      some quite nasty problems on systems with both systemd/sysvinit
+ *      installed alongside finit.  For compatibility reasons Finit 4.1
+ *      changed to partial SIGHUP (api_exit/init).
  *
  * SIGUSR2
- *      Like SIGUSR1, but tell kernel to power-off the system, if ACPI
- *      or similar exists to actually do this.  If the kernel fails
- *      power-off, Finit falls back to halt.
+ *      Calls shutdown hooks, including HOOK_SHUTDOWN, stops all running
+ *      processes, and unmounts all file systems.  Then tells kernel to
+ *      power-off the system, if ACPI or similar exists to actually do
+ *      this.  If the kernel fails power-off, Finit falls back to halt.
  *
  *      (SysV init N/A, systemd dumps its internal state to log.)
  *
  * SIGTERM
- *      Like SIGUSR1, but tell kernel to reboot the system when done.
+ *      Like SIGUSR2, but tell kernel to reboot the system when done.
  *
  *      (SysV init N/A, systemd rexecutes itself.)
  *
@@ -323,7 +326,7 @@ static void sigint_cb(uev_t *w, void *arg, int events)
 }
 
 /*
- * SIGUSR1: BusyBox style halt
+ * SIGUSR1: SysV init/systemd API socket restart
  */
 static void sigusr1_cb(uev_t *w, void *arg, int events)
 {
@@ -333,8 +336,9 @@ static void sigusr1_cb(uev_t *w, void *arg, int events)
 		return;
 	}
 
-	halt = SHUT_HALT;
-	service_runlevel(0);
+	/* Restart initctl API domain socket, similar to systemd/SysV init */
+	api_exit();
+	api_init(w->ctx);
 }
 
 /*
@@ -520,7 +524,7 @@ void sig_setup(uev_ctx_t *ctx)
 	/* Standard SysV init calls ctrl-alt-delete handler */
 	uev_signal_init(ctx, &sigint_watcher, sigint_cb, NULL, SIGINT);
 
-	/* BusyBox init style signals for halt, power-off and reboot. */
+	/* BusyBox/SysV init style signals for halt, power-off and reboot. */
 	uev_signal_init(ctx, &sigusr1_watcher, sigusr1_cb, NULL, SIGUSR1);
 	uev_signal_init(ctx, &sigusr2_watcher, sigusr2_cb, NULL, SIGUSR2);
 	uev_signal_init(ctx, &sigpwr_watcher, sigusr2_cb, NULL, SIGPWR);