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treewide: use log_*_errno whenever %m is in the format string
[elogind.git] / src / resolve / resolved-dns-packet.c
diff --git a/src/resolve/resolved-dns-packet.c b/src/resolve/resolved-dns-packet.c
index 951c7980872f032962d0ba3aecb95441624795bd..a9bd8b13988dc31d6e5641921097be38fc3d6e08 100644 (file)
--- a/src/resolve/resolved-dns-packet.c
+++ b/src/resolve/resolved-dns-packet.c
@@ -22,6 +22,7 @@
 #include "utf8.h"
 #include "util.h"
 #include "strv.h"
+#include "unaligned.h"
 #include "resolved-dns-domain.h"
 #include "resolved-dns-packet.h"
 
@@ -311,8 +312,7 @@ int dns_packet_append_uint16(DnsPacket *p, uint16_t v, size_t *start) {
         if (r < 0)
                 return r;
 
-        ((uint8_t*) d)[0] = (uint8_t) (v >> 8);
-        ((uint8_t*) d)[1] = (uint8_t) v;
+        unaligned_write_be16(d, v);
 
         return 0;
 }
@@ -327,10 +327,7 @@ int dns_packet_append_uint32(DnsPacket *p, uint32_t v, size_t *start) {
         if (r < 0)
                 return r;
 
-        ((uint8_t*) d)[0] = (uint8_t) (v >> 24);
-        ((uint8_t*) d)[1] = (uint8_t) (v >> 16);
-        ((uint8_t*) d)[2] = (uint8_t) (v >> 8);
-        ((uint8_t*) d)[3] = (uint8_t) v;
+        unaligned_write_be32(d, v);
 
         return 0;
 }
@@ -377,7 +374,8 @@ int dns_packet_append_label(DnsPacket *p, const char *d, size_t l, size_t *start
         return 0;
 }
 
-int dns_packet_append_name(DnsPacket *p, const char *name, size_t *start) {
+int dns_packet_append_name(DnsPacket *p, const char *name,
+                           bool allow_compression, size_t *start) {
         size_t saved_size;
         int r;
 
@@ -389,10 +387,11 @@ int dns_packet_append_name(DnsPacket *p, const char *name, size_t *start) {
         while (*name) {
                 _cleanup_free_ char *s = NULL;
                 char label[DNS_LABEL_MAX];
-                size_t n;
+                size_t n = 0;
                 int k;
 
-                n = PTR_TO_SIZE(hashmap_get(p->names, name));
+                if (allow_compression)
+                        n = PTR_TO_SIZE(hashmap_get(p->names, name));
                 if (n > 0) {
                         assert(n < p->size);
 
@@ -430,15 +429,17 @@ int dns_packet_append_name(DnsPacket *p, const char *name, size_t *start) {
                 if (r < 0)
                         goto fail;
 
-                r = hashmap_ensure_allocated(&p->names, dns_name_hash_func, dns_name_compare_func);
-                if (r < 0)
-                        goto fail;
+                if (allow_compression) {
+                        r = hashmap_ensure_allocated(&p->names, &dns_name_hash_ops);
+                        if (r < 0)
+                                goto fail;
 
-                r = hashmap_put(p->names, s, SIZE_TO_PTR(n));
-                if (r < 0)
-                        goto fail;
+                        r = hashmap_put(p->names, s, SIZE_TO_PTR(n));
+                        if (r < 0)
+                                goto fail;
 
-                s = NULL;
+                        s = NULL;
+                }
         }
 
         r = dns_packet_append_uint8(p, 0, NULL);
@@ -465,7 +466,7 @@ int dns_packet_append_key(DnsPacket *p, const DnsResourceKey *k, size_t *start)
 
         saved_size = p->size;
 
-        r = dns_packet_append_name(p, DNS_RESOURCE_KEY_NAME(k), NULL);
+        r = dns_packet_append_name(p, DNS_RESOURCE_KEY_NAME(k), true, NULL);
         if (r < 0)
                 goto fail;
 
@@ -524,14 +525,14 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star
                 if (r < 0)
                         goto fail;
 
-                r = dns_packet_append_name(p, rr->srv.name, NULL);
+                r = dns_packet_append_name(p, rr->srv.name, true, NULL);
                 break;
 
         case DNS_TYPE_PTR:
         case DNS_TYPE_NS:
         case DNS_TYPE_CNAME:
         case DNS_TYPE_DNAME:
-                r = dns_packet_append_name(p, rr->ptr.name, NULL);
+                r = dns_packet_append_name(p, rr->ptr.name, true, NULL);
                 break;
 
         case DNS_TYPE_HINFO:
@@ -565,11 +566,11 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star
                 break;
 
         case DNS_TYPE_SOA:
-                r = dns_packet_append_name(p, rr->soa.mname, NULL);
+                r = dns_packet_append_name(p, rr->soa.mname, true, NULL);
                 if (r < 0)
                         goto fail;
 
-                r = dns_packet_append_name(p, rr->soa.rname, NULL);
+                r = dns_packet_append_name(p, rr->soa.rname, true, NULL);
                 if (r < 0)
                         goto fail;
 
@@ -597,7 +598,7 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star
                 if (r < 0)
                         goto fail;
 
-                r = dns_packet_append_name(p, rr->mx.exchange, NULL);
+                r = dns_packet_append_name(p, rr->mx.exchange, true, NULL);
                 break;
 
         case DNS_TYPE_LOC:
@@ -656,6 +657,42 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star
                 r = dns_packet_append_blob(p, rr->dnskey.key, rr->dnskey.key_size, NULL);
                 break;
 
+        case DNS_TYPE_RRSIG:
+                r = dns_packet_append_uint16(p, rr->rrsig.type_covered, NULL);
+                if (r < 0)
+                        goto fail;
+
+                r = dns_packet_append_uint8(p, rr->rrsig.algorithm, NULL);
+                if (r < 0)
+                        goto fail;
+
+                r = dns_packet_append_uint8(p, rr->rrsig.labels, NULL);
+                if (r < 0)
+                        goto fail;
+
+                r = dns_packet_append_uint32(p, rr->rrsig.original_ttl, NULL);
+                if (r < 0)
+                        goto fail;
+
+                r = dns_packet_append_uint32(p, rr->rrsig.expiration, NULL);
+                if (r < 0)
+                        goto fail;
+
+                r = dns_packet_append_uint32(p, rr->rrsig.inception, NULL);
+                if (r < 0)
+                        goto fail;
+
+                r = dns_packet_append_uint8(p, rr->rrsig.key_tag, NULL);
+                if (r < 0)
+                        goto fail;
+
+                r = dns_packet_append_name(p, rr->rrsig.signer, false, NULL);
+                if (r < 0)
+                        goto fail;
+
+                r = dns_packet_append_blob(p, rr->rrsig.signature, rr->rrsig.signature_size, NULL);
+                break;
+
         case _DNS_TYPE_INVALID: /* unparseable */
         default:
 
@@ -753,8 +790,8 @@ int dns_packet_read_uint16(DnsPacket *p, uint16_t *ret, size_t *start) {
         if (r < 0)
                 return r;
 
-        *ret = (((uint16_t) ((uint8_t*) d)[0]) << 8) |
-                ((uint16_t) ((uint8_t*) d)[1]);
+        *ret = unaligned_read_be16(d);
+
         return 0;
 }
 
@@ -768,10 +805,7 @@ int dns_packet_read_uint32(DnsPacket *p, uint32_t *ret, size_t *start) {
         if (r < 0)
                 return r;
 
-        *ret = (((uint32_t) ((uint8_t*) d)[0]) << 24) |
-               (((uint32_t) ((uint8_t*) d)[1]) << 16) |
-               (((uint32_t) ((uint8_t*) d)[2]) << 8) |
-                ((uint32_t) ((uint8_t*) d)[3]);
+        *ret = unaligned_read_be32(d);
 
         return 0;
 }
@@ -824,8 +858,9 @@ fail:
         return r;
 }
 
-int dns_packet_read_name(DnsPacket *p, char **_ret, size_t *start) {
-        size_t saved_rindex, after_rindex = 0;
+int dns_packet_read_name(DnsPacket *p, char **_ret,
+                         bool allow_compression, size_t *start) {
+        size_t saved_rindex, after_rindex = 0, jump_barrier;
         _cleanup_free_ char *ret = NULL;
         size_t n = 0, allocated = 0;
         bool first = true;
@@ -835,6 +870,7 @@ int dns_packet_read_name(DnsPacket *p, char **_ret, size_t *start) {
         assert(_ret);
 
         saved_rindex = p->rindex;
+        jump_barrier = p->rindex;
 
         for (;;) {
                 uint8_t c, d;
@@ -872,7 +908,7 @@ int dns_packet_read_name(DnsPacket *p, char **_ret, size_t *start) {
                         memcpy(ret + n, t, r);
                         n += r;
                         continue;
-                } else if ((c & 0xc0) == 0xc0) {
+                } else if (allow_compression && (c & 0xc0) == 0xc0) {
                         uint16_t ptr;
 
                         /* Pointer */
@@ -881,7 +917,7 @@ int dns_packet_read_name(DnsPacket *p, char **_ret, size_t *start) {
                                 goto fail;
 
                         ptr = (uint16_t) (c & ~0xc0) << 8 | (uint16_t) d;
-                        if (ptr < DNS_PACKET_HEADER_SIZE || ptr >= saved_rindex) {
+                        if (ptr < DNS_PACKET_HEADER_SIZE || ptr >= jump_barrier) {
                                 r = -EBADMSG;
                                 goto fail;
                         }
@@ -889,9 +925,13 @@ int dns_packet_read_name(DnsPacket *p, char **_ret, size_t *start) {
                         if (after_rindex == 0)
                                 after_rindex = p->rindex;
 
+                        /* Jumps are limited to a "prior occurence" (RFC-1035 4.1.4) */
+                        jump_barrier = ptr;
                         p->rindex = ptr;
-                } else
+                } else {
+                        r = -EBADMSG;
                         goto fail;
+                }
         }
 
         if (!GREEDY_REALLOC(ret, allocated, n + 1)) {
@@ -929,7 +969,7 @@ int dns_packet_read_key(DnsPacket *p, DnsResourceKey **ret, size_t *start) {
 
         saved_rindex = p->rindex;
 
-        r = dns_packet_read_name(p, &name, NULL);
+        r = dns_packet_read_name(p, &name, true, NULL);
         if (r < 0)
                 goto fail;
 
@@ -986,6 +1026,8 @@ static bool loc_size_ok(uint8_t size) {
 }
 
 static int dnskey_parse_flags(DnsResourceRecord *rr, uint16_t flags) {
+        assert(rr);
+
         if (flags & ~(DNSKEY_FLAG_SEP | DNSKEY_FLAG_ZONE_KEY))
                 return -EBADMSG;
 
@@ -1050,14 +1092,14 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) {
                 r = dns_packet_read_uint16(p, &rr->srv.port, NULL);
                 if (r < 0)
                         goto fail;
-                r = dns_packet_read_name(p, &rr->srv.name, NULL);
+                r = dns_packet_read_name(p, &rr->srv.name, true, NULL);
                 break;
 
         case DNS_TYPE_PTR:
         case DNS_TYPE_NS:
         case DNS_TYPE_CNAME:
         case DNS_TYPE_DNAME:
-                r = dns_packet_read_name(p, &rr->ptr.name, NULL);
+                r = dns_packet_read_name(p, &rr->ptr.name, true, NULL);
                 break;
 
         case DNS_TYPE_HINFO:
@@ -1072,6 +1114,13 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) {
         case DNS_TYPE_TXT: {
                 char *s;
 
+                /* RFC 1035 says that TXT must be at least one
+                   string. Reject empty records. */
+                if (!rdlength) {
+                        r = -EBADMSG;
+                        goto fail;
+                }
+
                 while (p->rindex < offset + rdlength) {
                         r = dns_packet_read_string(p, &s, NULL);
                         if (r < 0)
@@ -1095,11 +1144,11 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) {
                 break;
 
         case DNS_TYPE_SOA:
-                r = dns_packet_read_name(p, &rr->soa.mname, NULL);
+                r = dns_packet_read_name(p, &rr->soa.mname, true, NULL);
                 if (r < 0)
                         goto fail;
 
-                r = dns_packet_read_name(p, &rr->soa.rname, NULL);
+                r = dns_packet_read_name(p, &rr->soa.rname, true, NULL);
                 if (r < 0)
                         goto fail;
 
@@ -1127,7 +1176,7 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) {
                 if (r < 0)
                         goto fail;
 
-                r = dns_packet_read_name(p, &rr->mx.exchange, NULL);
+                r = dns_packet_read_name(p, &rr->mx.exchange, true, NULL);
                 break;
 
         case DNS_TYPE_LOC: {
@@ -1234,6 +1283,44 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) {
                 break;
         }
 
+        case DNS_TYPE_RRSIG:
+                r = dns_packet_read_uint16(p, &rr->rrsig.type_covered, NULL);
+                if (r < 0)
+                        goto fail;
+
+                r = dns_packet_read_uint8(p, &rr->rrsig.algorithm, NULL);
+                if (r < 0)
+                        goto fail;
+
+                r = dns_packet_read_uint8(p, &rr->rrsig.labels, NULL);
+                if (r < 0)
+                        goto fail;
+
+                r = dns_packet_read_uint32(p, &rr->rrsig.original_ttl, NULL);
+                if (r < 0)
+                        goto fail;
+
+                r = dns_packet_read_uint32(p, &rr->rrsig.expiration, NULL);
+                if (r < 0)
+                        goto fail;
+
+                r = dns_packet_read_uint32(p, &rr->rrsig.inception, NULL);
+                if (r < 0)
+                        goto fail;
+
+                r = dns_packet_read_uint16(p, &rr->rrsig.key_tag, NULL);
+                if (r < 0)
+                        goto fail;
+
+                r = dns_packet_read_name(p, &rr->rrsig.signer, false, NULL);
+                if (r < 0)
+                        goto fail;
+
+                r = dns_packet_read_public_key(p, offset + rdlength - p->rindex,
+                                               &rr->rrsig.signature, &rr->rrsig.signature_size,
+                                               NULL);
+                break;
+
         default:
         unparseable:
                 r = dns_packet_read(p, rdlength, &d, NULL);
@@ -1275,6 +1362,9 @@ int dns_packet_extract(DnsPacket *p) {
         unsigned n, i;
         int r;
 
+        if (p->extracted)
+                return 0;
+
         saved_rindex = p->rindex;
         dns_packet_rewind(p, DNS_PACKET_HEADER_SIZE);
 
@@ -1326,6 +1416,8 @@ int dns_packet_extract(DnsPacket *p) {
         p->answer = answer;
         answer = NULL;
 
+        p->extracted = true;
+
         r = 0;
 
 finish:
@@ -1361,3 +1453,15 @@ static const char* const dns_protocol_table[_DNS_PROTOCOL_MAX] = {
         [DNS_PROTOCOL_LLMNR] = "llmnr",
 };
 DEFINE_STRING_TABLE_LOOKUP(dns_protocol, DnsProtocol);
+
+static const char* const dnssec_algorithm_table[_DNSSEC_ALGORITHM_MAX_DEFINED] = {
+        [DNSSEC_ALGORITHM_RSAMD5]     = "RSAMD5",
+        [DNSSEC_ALGORITHM_DH]         = "DH",
+        [DNSSEC_ALGORITHM_DSA]        = "DSA",
+        [DNSSEC_ALGORITHM_ECC]        = "ECC",
+        [DNSSEC_ALGORITHM_RSASHA1]    = "RSASHA1",
+        [DNSSEC_ALGORITHM_INDIRECT]   = "INDIRECT",
+        [DNSSEC_ALGORITHM_PRIVATEDNS] = "PRIVATEDNS",
+        [DNSSEC_ALGORITHM_PRIVATEOID] = "PRIVATEOID",
+};
+DEFINE_STRING_TABLE_LOOKUP(dnssec_algorithm, int);
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