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http://thekelleys.org.uk/git/dnsmasq.git
synced 2026-11-04 13:48:30 +00:00
Compare commits
| Author | SHA1 | Date | |
|---|---|---|---|
 Helge Deller
|
368ceff6e0 | ||
|
Simon Kelley
|
77c4e95d4a | ||
|
Simon Kelley
|
e44165c0f7 |
No files matched your search
@@ -116,6 +116,14 @@ version 2.91
|
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will be logged. If this coincides with DNS not functioning, it
|
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is necessary to disable bit 0x20 encoding with --no-0x20-encode.
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|
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Fix a long-standing problem when two queries which are identical
|
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in every repect _except_ case, get combined by dnsmasq. If
|
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dnsmasq gets eg, two queries for example.com and Example.com
|
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in quick succession it will get the answer for example.com from
|
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upstream and send that answer to both requestors. This means that
|
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the query for Example.com will get an answer for example.com, and
|
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in the modern DNS, that answer may not be accepted.
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|
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version 2.90
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Fix reversion in --rev-server introduced in 2.88 which
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+2
-2
@@ -775,12 +775,13 @@ struct dyndir {
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#define FREC_DO_QUESTION 64
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#define FREC_HAS_PHEADER 128
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#define FREC_GONE_TO_TCP 256
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#define FREC_ANSWER 512
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|
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struct frec {
|
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struct frec_src {
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union mysockaddr source;
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union all_addr dest;
|
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unsigned int iface, log_id;
|
||||
unsigned int iface, log_id, encode_bitmap, *encode_bigmap;
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int fd;
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unsigned short orig_id, udp_pkt_size;
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struct frec_src *next;
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@@ -791,7 +792,6 @@ struct frec {
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int forwardall, flags;
|
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time_t time;
|
||||
u32 forward_timestamp;
|
||||
unsigned int encode_bitmap;
|
||||
int forward_delay;
|
||||
struct blockdata *stash; /* saved query or saved reply, whilst we validate */
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||||
size_t stash_len;
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||||
|
||||
+156
-23
@@ -197,6 +197,9 @@ static void forward_query(int udpfd, union mysockaddr *udpaddr,
|
||||
FREC_HAS_PHEADER | FREC_DNSKEY_QUERY | FREC_DS_QUERY | FREC_NO_CACHE)))
|
||||
{
|
||||
struct frec_src *src;
|
||||
struct dns_header *saved_header;
|
||||
unsigned int casediff = 0;
|
||||
unsigned int *bitvector = NULL;
|
||||
|
||||
for (src = &forward->frec_src; src; src = src->next)
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if (src->orig_id == ntohs(header->id) &&
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@@ -221,6 +224,7 @@ static void forward_query(int udpfd, union mysockaddr *udpaddr,
|
||||
{
|
||||
daemon->frec_src_count++;
|
||||
daemon->free_frec_src->next = NULL;
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||||
daemon->free_frec_src->encode_bigmap = NULL;
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||||
}
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||||
|
||||
/* If we've been spammed with many duplicates, return REFUSED. */
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||||
@@ -237,6 +241,54 @@ static void forward_query(int udpfd, union mysockaddr *udpaddr,
|
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free_frec(forward);
|
||||
goto reply;
|
||||
}
|
||||
|
||||
/* Find a bitmap of case differences between the query send upstream and this one,
|
||||
so we can reply to each query with the correct case pattern.
|
||||
Since we need this to get back the exact case pattern of each query when doing
|
||||
query combining, we have to handle the (rare) case that there are case differences
|
||||
beyond the first 32 letters.
|
||||
If that happens we have to allocate memory to save it, and the casediff variable
|
||||
holds the length of that array.
|
||||
Mismatches beyond 32 letters are rare because most queries are all lowercase and
|
||||
we only scramble the first 32 letters for security reasons.
|
||||
|
||||
Note the two names are guaranteed to be the same length and differ only in the case
|
||||
of letters. */
|
||||
if ((saved_header = blockdata_retrieve(forward->stash, forward->stash_len, NULL)) &&
|
||||
extract_request(saved_header, forward->stash_len, daemon->workspacename, NULL))
|
||||
{
|
||||
unsigned int i, gobig = 0;
|
||||
char *s1, *s2;
|
||||
|
||||
#define BITS_IN_INT (sizeof(unsigned int) * 8)
|
||||
|
||||
big_redo:
|
||||
for (s1 = daemon->namebuff, s2 = daemon->workspacename, i = 0; *s1; s1++, s2++)
|
||||
{
|
||||
char c1 = *s1, c2 = *s2;
|
||||
|
||||
if ((c1 >= 'a' && c1 <= 'z') || (c1 >= 'A' && c1 <= 'Z'))
|
||||
{
|
||||
if ((c1 & 0x20) ^ (c2 & 0x20))
|
||||
{
|
||||
if (bitvector)
|
||||
bitvector[i/BITS_IN_INT] |= 1<<(i%BITS_IN_INT);
|
||||
else if (i >= BITS_IN_INT)
|
||||
gobig = 1; /* More than 32 */
|
||||
else
|
||||
casediff |= 1<<i;
|
||||
}
|
||||
i++;
|
||||
}
|
||||
}
|
||||
|
||||
if (gobig && !bitvector)
|
||||
{
|
||||
casediff = (i/BITS_IN_INT) + 1; /* length of array */
|
||||
if ((bitvector = whine_malloc(casediff)))
|
||||
goto big_redo;
|
||||
}
|
||||
}
|
||||
|
||||
src = daemon->free_frec_src;
|
||||
daemon->free_frec_src = src->next;
|
||||
@@ -248,6 +300,9 @@ static void forward_query(int udpfd, union mysockaddr *udpaddr,
|
||||
src->log_id = daemon->log_id;
|
||||
src->iface = dst_iface;
|
||||
src->fd = udpfd;
|
||||
src->encode_bitmap = casediff;
|
||||
src->encode_bigmap = bitvector;
|
||||
|
||||
src->udp_pkt_size = (unsigned short)replylimit;
|
||||
|
||||
/* closely spaced identical queries cannot be a try and a retry, so
|
||||
@@ -326,9 +381,9 @@ static void forward_query(int udpfd, union mysockaddr *udpaddr,
|
||||
forward->new_id = get_id();
|
||||
header->id = ntohs(forward->new_id);
|
||||
|
||||
forward->encode_bitmap = option_bool(OPT_NO_0x20) ? 0 : rand32();
|
||||
forward->frec_src.encode_bitmap = option_bool(OPT_NO_0x20) ? 0 : rand32();
|
||||
p = (unsigned char *)(header+1);
|
||||
if (!extract_name(header, plen, &p, NULL, EXTR_NAME_FLIP, forward->encode_bitmap))
|
||||
if (!extract_name(header, plen, &p, (char *)&forward->frec_src.encode_bitmap, EXTR_NAME_FLIP, 1))
|
||||
goto reply;
|
||||
|
||||
/* Keep copy of query for retries and move to TCP */
|
||||
@@ -975,7 +1030,7 @@ static void dnssec_validate(struct frec *forward, struct dns_header *header,
|
||||
new->flags &= ~(FREC_DNSKEY_QUERY | FREC_DS_QUERY);
|
||||
new->flags |= flags;
|
||||
new->forwardall = 0;
|
||||
new->encode_bitmap = 0;
|
||||
new->frec_src.encode_bitmap = 0;
|
||||
|
||||
forward->next_dependent = NULL;
|
||||
new->dependent = forward; /* to find query awaiting new one. */
|
||||
@@ -1098,7 +1153,7 @@ void reply_query(int fd, time_t now)
|
||||
GETSHORT(rrtype, p);
|
||||
GETSHORT(class, p);
|
||||
|
||||
if (!(forward = lookup_frec(daemon->namebuff, class, rrtype, ntohs(header->id), 0, 0)))
|
||||
if (!(forward = lookup_frec(daemon->namebuff, class, rrtype, ntohs(header->id), FREC_ANSWER, 0)))
|
||||
return;
|
||||
|
||||
filter_servers(forward->sentto->arrayposn, F_SERVER, &first, &last);
|
||||
@@ -1205,7 +1260,7 @@ void reply_query(int fd, time_t now)
|
||||
|
||||
/* Flip the bits back in the query name. */
|
||||
p = (unsigned char *)(header+1);
|
||||
if (!extract_name(header, n, &p, NULL, EXTR_NAME_FLIP, forward->encode_bitmap))
|
||||
if (!extract_name(header, n, &p, (char *)&forward->frec_src.encode_bitmap, EXTR_NAME_FLIP, 1))
|
||||
return;
|
||||
|
||||
#ifdef HAVE_DNSSEC
|
||||
@@ -1227,6 +1282,51 @@ void reply_query(int fd, time_t now)
|
||||
return_reply(now, forward, header, n, STAT_OK);
|
||||
}
|
||||
|
||||
static void xor_array(unsigned int *arg1, unsigned int *arg2, unsigned int len)
|
||||
{
|
||||
unsigned int i;
|
||||
|
||||
for (i = 0; i < len; i++)
|
||||
arg1[i] ^= arg2[i];
|
||||
}
|
||||
|
||||
/* Call extract_name() to flip case of query in packet according to the XOR of the bit maps help in arg1 and arg2 */
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static void flip_queryname(struct dns_header *header, ssize_t len, struct frec_src *arg1, struct frec_src *arg2)
|
||||
{
|
||||
unsigned char *p = (unsigned char *)(header+1);
|
||||
unsigned int *arg1p, *arg2p, arg1len, arg2len, *swapp, swap;
|
||||
|
||||
/* Two cases: bitmap is single 32 bit int, or it's arbitrary-length array of 32bit ints.
|
||||
The two args may be different and of different lengths.
|
||||
The shorter gets notionally extended with zeros. */
|
||||
|
||||
if (arg1->encode_bigmap)
|
||||
arg1p = arg1->encode_bigmap, arg1len = arg1->encode_bitmap;
|
||||
else
|
||||
arg1p = &arg1->encode_bitmap, arg1len = 1;
|
||||
|
||||
if (arg2->encode_bigmap)
|
||||
arg2p = arg2->encode_bigmap, arg2len = arg2->encode_bitmap;
|
||||
else
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||||
arg2p = &arg2->encode_bitmap, arg2len = 1;
|
||||
|
||||
/* make arg1 the longer, if they differ. */
|
||||
if (arg2len > arg1len)
|
||||
{
|
||||
swap = arg1len;
|
||||
swapp = arg1p;
|
||||
arg1len = arg2len;
|
||||
arg1p = arg2p;
|
||||
arg2len = swap;
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||||
arg2p = swapp;
|
||||
}
|
||||
|
||||
/* XOR on shorter length, flip on longer, operate on longer */
|
||||
xor_array(arg1p, arg2p, arg2len);
|
||||
extract_name(header, len, &p, (char *)arg1p, EXTR_NAME_FLIP, arg1len);
|
||||
xor_array(arg1p, arg2p, arg2len); /* restore */
|
||||
}
|
||||
|
||||
void return_reply(time_t now, struct frec *forward, struct dns_header *header, ssize_t n, int status)
|
||||
{
|
||||
int check_rebind = 0, no_cache_dnssec = 0, cache_secure = 0, bogusanswer = 0;
|
||||
@@ -1316,10 +1416,10 @@ void return_reply(time_t now, struct frec *forward, struct dns_header *header, s
|
||||
!(forward->flags & FREC_HAS_PHEADER), &forward->frec_src.source,
|
||||
((unsigned char *)header) + daemon->edns_pktsz, ede)))
|
||||
{
|
||||
struct frec_src *src;
|
||||
struct frec_src *src, *prev;
|
||||
int do_trunc;
|
||||
|
||||
for (do_trunc = 0, src = &forward->frec_src; src; src = src->next)
|
||||
|
||||
for (do_trunc = 0, prev = NULL, src = &forward->frec_src; src; prev = src, src = src->next)
|
||||
{
|
||||
header->id = htons(src->orig_id);
|
||||
|
||||
@@ -1333,6 +1433,13 @@ void return_reply(time_t now, struct frec *forward, struct dns_header *header, s
|
||||
}
|
||||
#endif
|
||||
|
||||
/* You will have to draw diagrams and scratch your head to convince yourself
|
||||
that this works. Bear in mind that the flip to upstream state has already been undone,
|
||||
for the original query so nothing needs to be done, but subsequent queries' flips
|
||||
were recorded relative to the flipped name sent upstream. */
|
||||
if (prev)
|
||||
flip_queryname(header, nn, prev, src);
|
||||
|
||||
if (src->fd != -1)
|
||||
{
|
||||
/* Only send packets that fit what the requestor allows.
|
||||
@@ -1356,7 +1463,7 @@ void return_reply(time_t now, struct frec *forward, struct dns_header *header, s
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
/* The packet is too big for one or more requestors, send them a truncated answer. */
|
||||
if (do_trunc)
|
||||
{
|
||||
@@ -1368,22 +1475,31 @@ void return_reply(time_t now, struct frec *forward, struct dns_header *header, s
|
||||
header->arcount = htons(0);
|
||||
header->hb3 |= HB3_TC;
|
||||
new = resize_packet(header, nn, pheader, hlen);
|
||||
|
||||
|
||||
daemon->log_display_id = forward->frec_src.log_id;
|
||||
daemon->log_source_addr = &forward->frec_src.source;
|
||||
log_query(F_UPSTREAM, NULL, NULL, "truncated", 0);
|
||||
|
||||
for (src = &forward->frec_src; src; src = src->next)
|
||||
if (src->fd != -1 && nn > src->udp_pkt_size)
|
||||
{
|
||||
header->id = htons(src->orig_id);
|
||||
send_from(src->fd, option_bool(OPT_NOWILD) || option_bool (OPT_CLEVERBIND), daemon->packet, new,
|
||||
&src->source, &src->dest, src->iface);
|
||||
|
||||
/* This gets the name back to the state it was in when we started. */
|
||||
flip_queryname(header, nn, prev, &forward->frec_src);
|
||||
|
||||
for (src = &forward->frec_src, prev = NULL; src; prev = src, src = src->next)
|
||||
{
|
||||
/* If you didn't undertand this above, you won't understand it here either. */
|
||||
if (prev)
|
||||
flip_queryname(header, nn, prev, src);
|
||||
|
||||
if (src->fd != -1 && nn > src->udp_pkt_size)
|
||||
{
|
||||
header->id = htons(src->orig_id);
|
||||
send_from(src->fd, option_bool(OPT_NOWILD) || option_bool (OPT_CLEVERBIND), daemon->packet, new,
|
||||
&src->source, &src->dest, src->iface);
|
||||
|
||||
#ifdef HAVE_DUMPFILE
|
||||
dump_packet_udp(DUMP_REPLY, daemon->packet, (size_t)new, NULL, &src->source, src->fd);
|
||||
dump_packet_udp(DUMP_REPLY, daemon->packet, (size_t)new, NULL, &src->source, src->fd);
|
||||
#endif
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
@@ -2916,8 +3032,15 @@ static void free_frec(struct frec *f)
|
||||
{
|
||||
struct frec_src *last;
|
||||
|
||||
/* add back to freelist if not the record builtin to every frec. */
|
||||
for (last = f->frec_src.next; last && last->next; last = last->next) ;
|
||||
/* add back to freelist if not the record builtin to every frec,
|
||||
also free any bigmaps they's been decorated with. */
|
||||
for (last = f->frec_src.next; last && last->next; last = last->next)
|
||||
if (last->encode_bigmap)
|
||||
{
|
||||
free(last->encode_bigmap);
|
||||
last->encode_bigmap = NULL;
|
||||
}
|
||||
|
||||
if (last)
|
||||
{
|
||||
last->next = daemon->free_frec_src;
|
||||
@@ -2934,7 +3057,7 @@ static void free_frec(struct frec *f)
|
||||
blockdata_free(f->stash);
|
||||
f->stash = NULL;
|
||||
}
|
||||
|
||||
|
||||
#ifdef HAVE_DNSSEC
|
||||
/* Anything we're waiting on is pointless now, too */
|
||||
if (f->blocking_query)
|
||||
@@ -3057,6 +3180,16 @@ static struct frec *lookup_frec(char *target, int class, int rrtype, int id, int
|
||||
{
|
||||
struct frec *f;
|
||||
struct dns_header *header;
|
||||
int compare_mode = EXTR_NAME_COMPARE;
|
||||
|
||||
/* Only compare case-sensitive when matching frec to a recieved answer,
|
||||
NOT when looking for a duplicated question. */
|
||||
if (flags & FREC_ANSWER)
|
||||
{
|
||||
flags &= ~FREC_ANSWER;
|
||||
if (!option_bool(OPT_NO_0x20))
|
||||
compare_mode = EXTR_NAME_NOCASE;
|
||||
}
|
||||
|
||||
for (f = daemon->frec_list; f; f = f->next)
|
||||
if (f->sentto &&
|
||||
@@ -3068,7 +3201,7 @@ static struct frec *lookup_frec(char *target, int class, int rrtype, int id, int
|
||||
int hclass, hrrtype, rc;
|
||||
|
||||
/* Case sensitive compare for DNS-0x20 encoding. */
|
||||
if ((rc = extract_name(header, f->stash_len, &p, target, option_bool(OPT_NO_0x20) ? EXTR_NAME_COMPARE : EXTR_NAME_NOCASE, 4)))
|
||||
if ((rc = extract_name(header, f->stash_len, &p, target, compare_mode, 4)))
|
||||
{
|
||||
GETSHORT(hrrtype, p);
|
||||
GETSHORT(hclass, p);
|
||||
|
||||
+23
-6
@@ -19,7 +19,11 @@
|
||||
/* EXTR_NAME_EXTRACT -> extract name
|
||||
EXTR_NAME_COMPARE -> compare name, case insensitive
|
||||
EXTR_NAME_NOCASE -> compare name, case sensitive
|
||||
EXTR_NAME_FLIP -> flip 0x20 bits in packet, controlled by bitmap in parm. name may be NULL
|
||||
EXTR_NAME_FLIP -> flip 0x20 bits in packet.
|
||||
|
||||
For flip, name is an array of ints, whose size
|
||||
is given in parm, which forms the bitmap. Bits beyond the size
|
||||
are assumed to be zero.
|
||||
|
||||
return = 0 -> error
|
||||
return = 1 -> extract OK, compare OK, flip OK
|
||||
@@ -31,14 +35,21 @@ int extract_name(struct dns_header *header, size_t plen, unsigned char **pp,
|
||||
{
|
||||
unsigned char *cp = (unsigned char *)name, *p = *pp, *p1 = NULL;
|
||||
unsigned int j, l, namelen = 0, hops = 0;
|
||||
unsigned int bigmap_counter = 0, bigmap_posn = 0, bigmap_size, bitmap;
|
||||
int retvalue = 1, case_insens = 1, isExtract = 0, flip = 0, extrabytes = (int)parm;
|
||||
|
||||
unsigned int *bigmap;
|
||||
|
||||
if (func == EXTR_NAME_EXTRACT)
|
||||
isExtract = 1, *cp = 0;
|
||||
else if (func == EXTR_NAME_NOCASE)
|
||||
case_insens = 0;
|
||||
else if (func == EXTR_NAME_FLIP)
|
||||
flip = 1, extrabytes = 0;
|
||||
{
|
||||
flip = 1, extrabytes = 0;
|
||||
bigmap = (unsigned int *)name;
|
||||
name = NULL;
|
||||
bigmap_size = parm;
|
||||
}
|
||||
|
||||
while (1)
|
||||
{
|
||||
@@ -116,12 +127,18 @@ int extract_name(struct dns_header *header, size_t plen, unsigned char **pp,
|
||||
{
|
||||
unsigned char c = *p;
|
||||
|
||||
/* parm is unsigned. We only flip up to the first 32 alpha-chars. */
|
||||
if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))
|
||||
{
|
||||
if (parm & 1)
|
||||
/* Get the next int of the bitmap */
|
||||
if (bigmap_posn < bigmap_size && bigmap_counter-- == 0)
|
||||
{
|
||||
bitmap = bigmap[bigmap_posn++];
|
||||
bigmap_counter = (sizeof(unsigned int) * 8) - 1;
|
||||
}
|
||||
|
||||
if (bitmap & 1)
|
||||
*p ^= 0x20;
|
||||
parm >>= 1;
|
||||
bitmap >>= 1;
|
||||
}
|
||||
}
|
||||
else
|
||||
|
||||
+1
-1
@@ -360,7 +360,7 @@ void tftp_request(struct listener *listen, time_t now)
|
||||
}
|
||||
|
||||
p = packet + 2;
|
||||
end = packet + len;
|
||||
end = packet + 2 + len;
|
||||
|
||||
if (ntohs(*((unsigned short *)packet)) != OP_RRQ ||
|
||||
!(filename = next(&p, end)) ||
|
||||
|
||||
Reference in new issue
Block a user