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-rw-r--r--src/resolve/resolved-dns-packet.c422
1 files changed, 178 insertions, 244 deletions
diff --git a/src/resolve/resolved-dns-packet.c b/src/resolve/resolved-dns-packet.c
index abb9725b73..6a9a1f732d 100644
--- a/src/resolve/resolved-dns-packet.c
+++ b/src/resolve/resolved-dns-packet.c
@@ -30,6 +30,19 @@
#define EDNS0_OPT_DO (1<<15)
+typedef struct DnsPacketRewinder {
+ DnsPacket *packet;
+ size_t saved_rindex;
+} DnsPacketRewinder;
+
+static void rewind_dns_packet(DnsPacketRewinder *rewinder) {
+ if (rewinder->packet)
+ dns_packet_rewind(rewinder->packet, rewinder->saved_rindex);
+}
+
+#define INIT_REWINDER(rewinder, p) do { rewinder.packet = p; rewinder.saved_rindex = p->rindex; } while(0)
+#define CANCEL_REWINDER(rewinder) do { rewinder.packet = NULL; } while(0)
+
int dns_packet_new(DnsPacket **ret, DnsProtocol protocol, size_t mtu) {
DnsPacket *p;
size_t a;
@@ -1231,80 +1244,67 @@ int dns_packet_read_uint32(DnsPacket *p, uint32_t *ret, size_t *start) {
}
int dns_packet_read_string(DnsPacket *p, char **ret, size_t *start) {
- size_t saved_rindex;
+ _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder;
const void *d;
char *t;
uint8_t c;
int r;
assert(p);
-
- saved_rindex = p->rindex;
+ INIT_REWINDER(rewinder, p);
r = dns_packet_read_uint8(p, &c, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read(p, c, &d, NULL);
if (r < 0)
- goto fail;
+ return r;
- if (memchr(d, 0, c)) {
- r = -EBADMSG;
- goto fail;
- }
+ if (memchr(d, 0, c))
+ return -EBADMSG;
t = strndup(d, c);
- if (!t) {
- r = -ENOMEM;
- goto fail;
- }
+ if (!t)
+ return -ENOMEM;
if (!utf8_is_valid(t)) {
free(t);
- r = -EBADMSG;
- goto fail;
+ return -EBADMSG;
}
*ret = t;
if (start)
- *start = saved_rindex;
+ *start = rewinder.saved_rindex;
+ CANCEL_REWINDER(rewinder);
return 0;
-
-fail:
- dns_packet_rewind(p, saved_rindex);
- return r;
}
int dns_packet_read_raw_string(DnsPacket *p, const void **ret, size_t *size, size_t *start) {
- size_t saved_rindex;
+ _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder;
uint8_t c;
int r;
assert(p);
-
- saved_rindex = p->rindex;
+ INIT_REWINDER(rewinder, p);
r = dns_packet_read_uint8(p, &c, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read(p, c, ret, NULL);
if (r < 0)
- goto fail;
+ return r;
if (size)
*size = c;
if (start)
- *start = saved_rindex;
+ *start = rewinder.saved_rindex;
+ CANCEL_REWINDER(rewinder);
return 0;
-
-fail:
- dns_packet_rewind(p, saved_rindex);
- return r;
}
int dns_packet_read_name(
@@ -1313,7 +1313,8 @@ int dns_packet_read_name(
bool allow_compression,
size_t *start) {
- size_t saved_rindex, after_rindex = 0, jump_barrier;
+ _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder;
+ size_t after_rindex = 0, jump_barrier;
_cleanup_free_ char *ret = NULL;
size_t n = 0, allocated = 0;
bool first = true;
@@ -1321,19 +1322,18 @@ int dns_packet_read_name(
assert(p);
assert(_ret);
+ INIT_REWINDER(rewinder, p);
+ jump_barrier = p->rindex;
if (p->refuse_compression)
allow_compression = false;
- saved_rindex = p->rindex;
- jump_barrier = p->rindex;
-
for (;;) {
uint8_t c, d;
r = dns_packet_read_uint8(p, &c, NULL);
if (r < 0)
- goto fail;
+ return r;
if (c == 0)
/* End of name */
@@ -1344,12 +1344,10 @@ int dns_packet_read_name(
/* Literal label */
r = dns_packet_read(p, c, (const void**) &label, NULL);
if (r < 0)
- goto fail;
+ return r;
- if (!GREEDY_REALLOC(ret, allocated, n + !first + DNS_LABEL_ESCAPED_MAX)) {
- r = -ENOMEM;
- goto fail;
- }
+ if (!GREEDY_REALLOC(ret, allocated, n + !first + DNS_LABEL_ESCAPED_MAX))
+ return -ENOMEM;
if (first)
first = false;
@@ -1358,7 +1356,7 @@ int dns_packet_read_name(
r = dns_label_escape(label, c, ret + n, DNS_LABEL_ESCAPED_MAX);
if (r < 0)
- goto fail;
+ return r;
n += r;
continue;
@@ -1368,13 +1366,11 @@ int dns_packet_read_name(
/* Pointer */
r = dns_packet_read_uint8(p, &d, NULL);
if (r < 0)
- goto fail;
+ return r;
ptr = (uint16_t) (c & ~0xc0) << 8 | (uint16_t) d;
- if (ptr < DNS_PACKET_HEADER_SIZE || ptr >= jump_barrier) {
- r = -EBADMSG;
- goto fail;
- }
+ if (ptr < DNS_PACKET_HEADER_SIZE || ptr >= jump_barrier)
+ return -EBADMSG;
if (after_rindex == 0)
after_rindex = p->rindex;
@@ -1382,16 +1378,12 @@ int dns_packet_read_name(
/* Jumps are limited to a "prior occurrence" (RFC-1035 4.1.4) */
jump_barrier = ptr;
p->rindex = ptr;
- } else {
- r = -EBADMSG;
- goto fail;
- }
+ } else
+ return -EBADMSG;
}
- if (!GREEDY_REALLOC(ret, allocated, n + 1)) {
- r = -ENOMEM;
- goto fail;
- }
+ if (!GREEDY_REALLOC(ret, allocated, n + 1))
+ return -ENOMEM;
ret[n] = 0;
@@ -1402,13 +1394,10 @@ int dns_packet_read_name(
ret = NULL;
if (start)
- *start = saved_rindex;
+ *start = rewinder.saved_rindex;
+ CANCEL_REWINDER(rewinder);
return 0;
-
-fail:
- dns_packet_rewind(p, saved_rindex);
- return r;
}
static int dns_packet_read_type_window(DnsPacket *p, Bitmap **types, size_t *start) {
@@ -1418,32 +1407,31 @@ static int dns_packet_read_type_window(DnsPacket *p, Bitmap **types, size_t *sta
uint8_t bit = 0;
unsigned i;
bool found = false;
- size_t saved_rindex;
+ _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder;
int r;
assert(p);
assert(types);
-
- saved_rindex = p->rindex;
+ INIT_REWINDER(rewinder, p);
r = bitmap_ensure_allocated(types);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint8(p, &window, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint8(p, &length, NULL);
if (r < 0)
- goto fail;
+ return r;
if (length == 0 || length > 32)
return -EBADMSG;
r = dns_packet_read(p, length, (const void **)&bitmap, NULL);
if (r < 0)
- goto fail;
+ return r;
for (i = 0; i < length; i++) {
uint8_t bitmask = 1 << 7;
@@ -1468,7 +1456,7 @@ static int dns_packet_read_type_window(DnsPacket *p, Bitmap **types, size_t *sta
r = bitmap_set(*types, n);
if (r < 0)
- goto fail;
+ return r;
}
bit ++;
@@ -1480,70 +1468,61 @@ static int dns_packet_read_type_window(DnsPacket *p, Bitmap **types, size_t *sta
return -EBADMSG;
if (start)
- *start = saved_rindex;
+ *start = rewinder.saved_rindex;
+ CANCEL_REWINDER(rewinder);
return 0;
-fail:
- dns_packet_rewind(p, saved_rindex);
- return r;
}
static int dns_packet_read_type_windows(DnsPacket *p, Bitmap **types, size_t size, size_t *start) {
- size_t saved_rindex;
+ _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder;
int r;
- saved_rindex = p->rindex;
+ INIT_REWINDER(rewinder, p);
- while (p->rindex < saved_rindex + size) {
+ while (p->rindex < rewinder.saved_rindex + size) {
r = dns_packet_read_type_window(p, types, NULL);
if (r < 0)
- goto fail;
+ return r;
/* don't read past end of current RR */
- if (p->rindex > saved_rindex + size) {
- r = -EBADMSG;
- goto fail;
- }
+ if (p->rindex > rewinder.saved_rindex + size)
+ return -EBADMSG;
}
- if (p->rindex != saved_rindex + size) {
- r = -EBADMSG;
- goto fail;
- }
+ if (p->rindex != rewinder.saved_rindex + size)
+ return -EBADMSG;
if (start)
- *start = saved_rindex;
+ *start = rewinder.saved_rindex;
+ CANCEL_REWINDER(rewinder);
return 0;
-fail:
- dns_packet_rewind(p, saved_rindex);
- return r;
}
int dns_packet_read_key(DnsPacket *p, DnsResourceKey **ret, bool *ret_cache_flush, size_t *start) {
+ _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder;
_cleanup_free_ char *name = NULL;
bool cache_flush = false;
uint16_t class, type;
DnsResourceKey *key;
- size_t saved_rindex;
int r;
assert(p);
assert(ret);
-
- saved_rindex = p->rindex;
+ INIT_REWINDER(rewinder, p);
r = dns_packet_read_name(p, &name, true, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint16(p, &type, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint16(p, &class, NULL);
if (r < 0)
- goto fail;
+ return r;
if (p->protocol == DNS_PROTOCOL_MDNS) {
/* See RFC6762, Section 10.2 */
@@ -1555,10 +1534,8 @@ int dns_packet_read_key(DnsPacket *p, DnsResourceKey **ret, bool *ret_cache_flus
}
key = dns_resource_key_new_consume(class, type, name);
- if (!key) {
- r = -ENOMEM;
- goto fail;
- }
+ if (!key)
+ return -ENOMEM;
name = NULL;
*ret = key;
@@ -1566,12 +1543,10 @@ int dns_packet_read_key(DnsPacket *p, DnsResourceKey **ret, bool *ret_cache_flus
if (ret_cache_flush)
*ret_cache_flush = cache_flush;
if (start)
- *start = saved_rindex;
+ *start = rewinder.saved_rindex;
+ CANCEL_REWINDER(rewinder);
return 0;
-fail:
- dns_packet_rewind(p, saved_rindex);
- return r;
}
static bool loc_size_ok(uint8_t size) {
@@ -1583,7 +1558,8 @@ static bool loc_size_ok(uint8_t size) {
int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, bool *ret_cache_flush, size_t *start) {
_cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
_cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
- size_t saved_rindex, offset;
+ _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder;
+ size_t offset;
uint16_t rdlength;
bool cache_flush;
int r;
@@ -1591,27 +1567,22 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, bool *ret_cache_fl
assert(p);
assert(ret);
- saved_rindex = p->rindex;
+ INIT_REWINDER(rewinder, p);
r = dns_packet_read_key(p, &key, &cache_flush, NULL);
if (r < 0)
- goto fail;
+ return r;
- if (!dns_class_is_valid_rr(key->class)||
- !dns_type_is_valid_rr(key->type)) {
- r = -EBADMSG;
- goto fail;
- }
+ if (!dns_class_is_valid_rr(key->class) || !dns_type_is_valid_rr(key->type))
+ return -EBADMSG;
rr = dns_resource_record_new(key);
- if (!rr) {
- r = -ENOMEM;
- goto fail;
- }
+ if (!rr)
+ return -ENOMEM;
r = dns_packet_read_uint32(p, &rr->ttl, NULL);
if (r < 0)
- goto fail;
+ return r;
/* RFC 2181, Section 8, suggests to
* treat a TTL with the MSB set as a zero TTL. */
@@ -1620,12 +1591,10 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, bool *ret_cache_fl
r = dns_packet_read_uint16(p, &rdlength, NULL);
if (r < 0)
- goto fail;
+ return r;
- if (p->rindex + rdlength > p->size) {
- r = -EBADMSG;
- goto fail;
- }
+ if (p->rindex + rdlength > p->size)
+ return -EBADMSG;
offset = p->rindex;
@@ -1634,13 +1603,13 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, bool *ret_cache_fl
case DNS_TYPE_SRV:
r = dns_packet_read_uint16(p, &rr->srv.priority, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint16(p, &rr->srv.weight, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint16(p, &rr->srv.port, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_name(p, &rr->srv.name, true, NULL);
break;
@@ -1654,7 +1623,7 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, bool *ret_cache_fl
case DNS_TYPE_HINFO:
r = dns_packet_read_string(p, &rr->hinfo.cpu, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_string(p, &rr->hinfo.os, NULL);
break;
@@ -1710,27 +1679,27 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, bool *ret_cache_fl
case DNS_TYPE_SOA:
r = dns_packet_read_name(p, &rr->soa.mname, true, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_name(p, &rr->soa.rname, true, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint32(p, &rr->soa.serial, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint32(p, &rr->soa.refresh, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint32(p, &rr->soa.retry, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint32(p, &rr->soa.expire, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint32(p, &rr->soa.minimum, NULL);
break;
@@ -1738,7 +1707,7 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, bool *ret_cache_fl
case DNS_TYPE_MX:
r = dns_packet_read_uint16(p, &rr->mx.priority, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_name(p, &rr->mx.exchange, true, NULL);
break;
@@ -1749,49 +1718,43 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, bool *ret_cache_fl
r = dns_packet_read_uint8(p, &t, &pos);
if (r < 0)
- goto fail;
+ return r;
if (t == 0) {
rr->loc.version = t;
r = dns_packet_read_uint8(p, &rr->loc.size, NULL);
if (r < 0)
- goto fail;
+ return r;
- if (!loc_size_ok(rr->loc.size)) {
- r = -EBADMSG;
- goto fail;
- }
+ if (!loc_size_ok(rr->loc.size))
+ return -EBADMSG;
r = dns_packet_read_uint8(p, &rr->loc.horiz_pre, NULL);
if (r < 0)
- goto fail;
+ return r;
- if (!loc_size_ok(rr->loc.horiz_pre)) {
- r = -EBADMSG;
- goto fail;
- }
+ if (!loc_size_ok(rr->loc.horiz_pre))
+ return -EBADMSG;
r = dns_packet_read_uint8(p, &rr->loc.vert_pre, NULL);
if (r < 0)
- goto fail;
+ return r;
- if (!loc_size_ok(rr->loc.vert_pre)) {
- r = -EBADMSG;
- goto fail;
- }
+ if (!loc_size_ok(rr->loc.vert_pre))
+ return -EBADMSG;
r = dns_packet_read_uint32(p, &rr->loc.latitude, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint32(p, &rr->loc.longitude, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint32(p, &rr->loc.altitude, NULL);
if (r < 0)
- goto fail;
+ return r;
break;
} else {
@@ -1804,122 +1767,114 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, bool *ret_cache_fl
case DNS_TYPE_DS:
r = dns_packet_read_uint16(p, &rr->ds.key_tag, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint8(p, &rr->ds.algorithm, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint8(p, &rr->ds.digest_type, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_memdup(p, rdlength - 4,
&rr->ds.digest, &rr->ds.digest_size,
NULL);
if (r < 0)
- goto fail;
+ return r;
- if (rr->ds.digest_size <= 0) {
+ if (rr->ds.digest_size <= 0)
/* the accepted size depends on the algorithm, but for now
just ensure that the value is greater than zero */
- r = -EBADMSG;
- goto fail;
- }
+ return -EBADMSG;
break;
case DNS_TYPE_SSHFP:
r = dns_packet_read_uint8(p, &rr->sshfp.algorithm, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint8(p, &rr->sshfp.fptype, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_memdup(p, rdlength - 2,
&rr->sshfp.fingerprint, &rr->sshfp.fingerprint_size,
NULL);
- if (rr->sshfp.fingerprint_size <= 0) {
+ if (rr->sshfp.fingerprint_size <= 0)
/* the accepted size depends on the algorithm, but for now
just ensure that the value is greater than zero */
- r = -EBADMSG;
- goto fail;
- }
+ return -EBADMSG;
break;
case DNS_TYPE_DNSKEY:
r = dns_packet_read_uint16(p, &rr->dnskey.flags, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint8(p, &rr->dnskey.protocol, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint8(p, &rr->dnskey.algorithm, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_memdup(p, rdlength - 4,
&rr->dnskey.key, &rr->dnskey.key_size,
NULL);
- if (rr->dnskey.key_size <= 0) {
+ if (rr->dnskey.key_size <= 0)
/* the accepted size depends on the algorithm, but for now
just ensure that the value is greater than zero */
- r = -EBADMSG;
- goto fail;
- }
+ return -EBADMSG;
break;
case DNS_TYPE_RRSIG:
r = dns_packet_read_uint16(p, &rr->rrsig.type_covered, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint8(p, &rr->rrsig.algorithm, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint8(p, &rr->rrsig.labels, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint32(p, &rr->rrsig.original_ttl, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint32(p, &rr->rrsig.expiration, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint32(p, &rr->rrsig.inception, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint16(p, &rr->rrsig.key_tag, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_name(p, &rr->rrsig.signer, false, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_memdup(p, offset + rdlength - p->rindex,
&rr->rrsig.signature, &rr->rrsig.signature_size,
NULL);
- if (rr->rrsig.signature_size <= 0) {
+ if (rr->rrsig.signature_size <= 0)
/* the accepted size depends on the algorithm, but for now
just ensure that the value is greater than zero */
- r = -EBADMSG;
- goto fail;
- }
+ return -EBADMSG;
break;
@@ -1934,11 +1889,9 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, bool *ret_cache_fl
r = dns_packet_read_name(p, &rr->nsec.next_domain_name, allow_compressed, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_type_windows(p, &rr->nsec.types, offset + rdlength - p->rindex, NULL);
- if (r < 0)
- goto fail;
/* We accept empty NSEC bitmaps. The bit indicating the presence of the NSEC record itself
* is redundant and in e.g., RFC4956 this fact is used to define a use for NSEC records
@@ -1951,41 +1904,39 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, bool *ret_cache_fl
r = dns_packet_read_uint8(p, &rr->nsec3.algorithm, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint8(p, &rr->nsec3.flags, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint16(p, &rr->nsec3.iterations, NULL);
if (r < 0)
- goto fail;
+ return r;
/* this may be zero */
r = dns_packet_read_uint8(p, &size, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_memdup(p, size, &rr->nsec3.salt, &rr->nsec3.salt_size, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint8(p, &size, NULL);
if (r < 0)
- goto fail;
+ return r;
- if (size <= 0) {
- r = -EBADMSG;
- goto fail;
- }
+ if (size <= 0)
+ return -EBADMSG;
- r = dns_packet_read_memdup(p, size, &rr->nsec3.next_hashed_name, &rr->nsec3.next_hashed_name_size, NULL);
+ r = dns_packet_read_memdup(p, size,
+ &rr->nsec3.next_hashed_name, &rr->nsec3.next_hashed_name_size,
+ NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_type_windows(p, &rr->nsec3.types, offset + rdlength - p->rindex, NULL);
- if (r < 0)
- goto fail;
/* empty non-terminals can have NSEC3 records, so empty bitmaps are allowed */
@@ -1995,25 +1946,24 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, bool *ret_cache_fl
case DNS_TYPE_TLSA:
r = dns_packet_read_uint8(p, &rr->tlsa.cert_usage, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint8(p, &rr->tlsa.selector, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_uint8(p, &rr->tlsa.matching_type, NULL);
if (r < 0)
- goto fail;
+ return r;
r = dns_packet_read_memdup(p, rdlength - 3,
&rr->tlsa.data, &rr->tlsa.data_size,
NULL);
- if (rr->tlsa.data_size <= 0) {
+
+ if (rr->tlsa.data_size <= 0)
/* the accepted size depends on the algorithm, but for now
just ensure that the value is greater than zero */
- r = -EBADMSG;
- goto fail;
- }
+ return -EBADMSG;
break;
@@ -2022,16 +1972,13 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, bool *ret_cache_fl
default:
unparseable:
r = dns_packet_read_memdup(p, rdlength, &rr->generic.data, &rr->generic.data_size, NULL);
- if (r < 0)
- goto fail;
+
break;
}
if (r < 0)
- goto fail;
- if (p->rindex != offset + rdlength) {
- r = -EBADMSG;
- goto fail;
- }
+ return r;
+ if (p->rindex != offset + rdlength)
+ return -EBADMSG;
*ret = rr;
rr = NULL;
@@ -2039,12 +1986,10 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, bool *ret_cache_fl
if (ret_cache_flush)
*ret_cache_flush = cache_flush;
if (start)
- *start = saved_rindex;
+ *start = rewinder.saved_rindex;
+ CANCEL_REWINDER(rewinder);
return 0;
-fail:
- dns_packet_rewind(p, saved_rindex);
- return r;
}
static bool opt_is_good(DnsResourceRecord *rr, bool *rfc6975) {
@@ -2092,23 +2037,21 @@ static bool opt_is_good(DnsResourceRecord *rr, bool *rfc6975) {
int dns_packet_extract(DnsPacket *p) {
_cleanup_(dns_question_unrefp) DnsQuestion *question = NULL;
_cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
- size_t saved_rindex;
+ _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder = {};
unsigned n, i;
int r;
if (p->extracted)
return 0;
- saved_rindex = p->rindex;
+ INIT_REWINDER(rewinder, p);
dns_packet_rewind(p, DNS_PACKET_HEADER_SIZE);
n = DNS_PACKET_QDCOUNT(p);
if (n > 0) {
question = dns_question_new(n);
- if (!question) {
- r = -ENOMEM;
- goto finish;
- }
+ if (!question)
+ return -ENOMEM;
for (i = 0; i < n; i++) {
_cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
@@ -2116,21 +2059,17 @@ int dns_packet_extract(DnsPacket *p) {
r = dns_packet_read_key(p, &key, &cache_flush, NULL);
if (r < 0)
- goto finish;
+ return r;
- if (cache_flush) {
- r = -EBADMSG;
- goto finish;
- }
+ if (cache_flush)
+ return -EBADMSG;
- if (!dns_type_is_valid_query(key->type)) {
- r = -EBADMSG;
- goto finish;
- }
+ if (!dns_type_is_valid_query(key->type))
+ return -EBADMSG;
r = dns_question_add(question, key);
if (r < 0)
- goto finish;
+ return r;
}
}
@@ -2140,10 +2079,8 @@ int dns_packet_extract(DnsPacket *p) {
bool bad_opt = false;
answer = dns_answer_new(n);
- if (!answer) {
- r = -ENOMEM;
- goto finish;
- }
+ if (!answer)
+ return -ENOMEM;
for (i = 0; i < n; i++) {
_cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
@@ -2151,7 +2088,7 @@ int dns_packet_extract(DnsPacket *p) {
r = dns_packet_read_rr(p, &rr, &cache_flush, NULL);
if (r < 0)
- goto finish;
+ return r;
/* Try to reduce memory usage a bit */
if (previous)
@@ -2214,7 +2151,7 @@ int dns_packet_extract(DnsPacket *p) {
(i < DNS_PACKET_ANCOUNT(p) ? DNS_ANSWER_CACHEABLE : 0) |
(p->protocol == DNS_PROTOCOL_MDNS && !cache_flush ? DNS_ANSWER_SHARED_OWNER : 0));
if (r < 0)
- goto finish;
+ return r;
}
/* Remember this RR, so that we potentically can merge it's ->key object with the next RR. Note
@@ -2235,11 +2172,8 @@ int dns_packet_extract(DnsPacket *p) {
p->extracted = true;
- r = 0;
-
-finish:
- p->rindex = saved_rindex;
- return r;
+ /* no CANCEL, always rewind */
+ return 0;
}
int dns_packet_is_reply_for(DnsPacket *p, const DnsResourceKey *key) {
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-27 13:53:16 +0000