diff options
author | Andy Wingo <wingo@pobox.com> | 2015-04-19 13:28:46 +0200 |
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committer | Andy Wingo <wingo@pobox.com> | 2015-04-19 13:32:26 +0200 |
commit | 2dd57213e1114c1e034e52b7ff8eaeaee752d9f3 (patch) | |
tree | 524803384d8065fd99a70fdbc1dff6ede6dce3f4 /src/resolve/resolved-dns-packet.c | |
parent | 1dcca8e5fe679b21a7203d6e35d58aa7aa83bbe1 (diff) |
Remove src/resolve
Diffstat (limited to 'src/resolve/resolved-dns-packet.c')
-rw-r--r-- | src/resolve/resolved-dns-packet.c | 1478 |
1 files changed, 0 insertions, 1478 deletions
diff --git a/src/resolve/resolved-dns-packet.c b/src/resolve/resolved-dns-packet.c deleted file mode 100644 index 21756f566f..0000000000 --- a/src/resolve/resolved-dns-packet.c +++ /dev/null @@ -1,1478 +0,0 @@ -/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ - -/*** - This file is part of systemd. - - Copyright 2014 Lennart Poettering - - systemd is free software; you can redistribute it and/or modify it - under the terms of the GNU Lesser General Public License as published by - the Free Software Foundation; either version 2.1 of the License, or - (at your option) any later version. - - systemd 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 - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public License - along with systemd; If not, see <http://www.gnu.org/licenses/>. - ***/ - -#include "utf8.h" -#include "util.h" -#include "strv.h" -#include "unaligned.h" -#include "resolved-dns-domain.h" -#include "resolved-dns-packet.h" - -int dns_packet_new(DnsPacket **ret, DnsProtocol protocol, size_t mtu) { - DnsPacket *p; - size_t a; - - assert(ret); - - if (mtu <= 0) - a = DNS_PACKET_SIZE_START; - else - a = mtu; - - if (a < DNS_PACKET_HEADER_SIZE) - a = DNS_PACKET_HEADER_SIZE; - - /* round up to next page size */ - a = PAGE_ALIGN(ALIGN(sizeof(DnsPacket)) + a) - ALIGN(sizeof(DnsPacket)); - - /* make sure we never allocate more than useful */ - if (a > DNS_PACKET_SIZE_MAX) - a = DNS_PACKET_SIZE_MAX; - - p = malloc0(ALIGN(sizeof(DnsPacket)) + a); - if (!p) - return -ENOMEM; - - p->size = p->rindex = DNS_PACKET_HEADER_SIZE; - p->allocated = a; - p->protocol = protocol; - p->n_ref = 1; - - *ret = p; - - return 0; -} - -int dns_packet_new_query(DnsPacket **ret, DnsProtocol protocol, size_t mtu) { - DnsPacket *p; - DnsPacketHeader *h; - int r; - - assert(ret); - - r = dns_packet_new(&p, protocol, mtu); - if (r < 0) - return r; - - h = DNS_PACKET_HEADER(p); - - if (protocol == DNS_PROTOCOL_LLMNR) - h->flags = htobe16(DNS_PACKET_MAKE_FLAGS(0 /* qr */, - 0 /* opcode */, - 0 /* c */, - 0 /* tc */, - 0 /* t */, - 0 /* ra */, - 0 /* ad */, - 0 /* cd */, - 0 /* rcode */)); - else - h->flags = htobe16(DNS_PACKET_MAKE_FLAGS(0 /* qr */, - 0 /* opcode */, - 0 /* aa */, - 0 /* tc */, - 1 /* rd (ask for recursion) */, - 0 /* ra */, - 0 /* ad */, - 0 /* cd */, - 0 /* rcode */)); - - *ret = p; - return 0; -} - -DnsPacket *dns_packet_ref(DnsPacket *p) { - - if (!p) - return NULL; - - assert(p->n_ref > 0); - p->n_ref++; - return p; -} - -static void dns_packet_free(DnsPacket *p) { - char *s; - - assert(p); - - dns_question_unref(p->question); - dns_answer_unref(p->answer); - - while ((s = hashmap_steal_first_key(p->names))) - free(s); - hashmap_free(p->names); - - free(p->_data); - free(p); -} - -DnsPacket *dns_packet_unref(DnsPacket *p) { - if (!p) - return NULL; - - assert(p->n_ref > 0); - - if (p->n_ref == 1) - dns_packet_free(p); - else - p->n_ref--; - - return NULL; -} - -int dns_packet_validate(DnsPacket *p) { - assert(p); - - if (p->size < DNS_PACKET_HEADER_SIZE) - return -EBADMSG; - - if (p->size > DNS_PACKET_SIZE_MAX) - return -EBADMSG; - - return 1; -} - -int dns_packet_validate_reply(DnsPacket *p) { - int r; - - assert(p); - - r = dns_packet_validate(p); - if (r < 0) - return r; - - if (DNS_PACKET_QR(p) != 1) - return 0; - - if (DNS_PACKET_OPCODE(p) != 0) - return -EBADMSG; - - /* RFC 4795, Section 2.1.1. says to discard all replies with QDCOUNT != 1 */ - if (p->protocol == DNS_PROTOCOL_LLMNR && - DNS_PACKET_QDCOUNT(p) != 1) - return -EBADMSG; - - return 1; -} - -int dns_packet_validate_query(DnsPacket *p) { - int r; - - assert(p); - - r = dns_packet_validate(p); - if (r < 0) - return r; - - if (DNS_PACKET_QR(p) != 0) - return 0; - - if (DNS_PACKET_OPCODE(p) != 0) - return -EBADMSG; - - if (DNS_PACKET_TC(p)) - return -EBADMSG; - - /* RFC 4795, Section 2.1.1. says to discard all queries with QDCOUNT != 1 */ - if (p->protocol == DNS_PROTOCOL_LLMNR && - DNS_PACKET_QDCOUNT(p) != 1) - return -EBADMSG; - - /* RFC 4795, Section 2.1.1. says to discard all queries with ANCOUNT != 0 */ - if (DNS_PACKET_ANCOUNT(p) > 0) - return -EBADMSG; - - /* RFC 4795, Section 2.1.1. says to discard all queries with NSCOUNT != 0 */ - if (DNS_PACKET_NSCOUNT(p) > 0) - return -EBADMSG; - - return 1; -} - -static int dns_packet_extend(DnsPacket *p, size_t add, void **ret, size_t *start) { - assert(p); - - if (p->size + add > p->allocated) { - size_t a; - - a = PAGE_ALIGN((p->size + add) * 2); - if (a > DNS_PACKET_SIZE_MAX) - a = DNS_PACKET_SIZE_MAX; - - if (p->size + add > a) - return -EMSGSIZE; - - if (p->_data) { - void *d; - - d = realloc(p->_data, a); - if (!d) - return -ENOMEM; - - p->_data = d; - } else { - p->_data = malloc(a); - if (!p->_data) - return -ENOMEM; - - memcpy(p->_data, (uint8_t*) p + ALIGN(sizeof(DnsPacket)), p->size); - memzero((uint8_t*) p->_data + p->size, a - p->size); - } - - p->allocated = a; - } - - if (start) - *start = p->size; - - if (ret) - *ret = (uint8_t*) DNS_PACKET_DATA(p) + p->size; - - p->size += add; - return 0; -} - -static void dns_packet_truncate(DnsPacket *p, size_t sz) { - Iterator i; - char *s; - void *n; - - assert(p); - - if (p->size <= sz) - return; - - HASHMAP_FOREACH_KEY(s, n, p->names, i) { - - if (PTR_TO_SIZE(n) < sz) - continue; - - hashmap_remove(p->names, s); - free(s); - } - - p->size = sz; -} - -int dns_packet_append_blob(DnsPacket *p, const void *d, size_t l, size_t *start) { - void *q; - int r; - - assert(p); - - r = dns_packet_extend(p, l, &q, start); - if (r < 0) - return r; - - memcpy(q, d, l); - return 0; -} - -int dns_packet_append_uint8(DnsPacket *p, uint8_t v, size_t *start) { - void *d; - int r; - - assert(p); - - r = dns_packet_extend(p, sizeof(uint8_t), &d, start); - if (r < 0) - return r; - - ((uint8_t*) d)[0] = v; - - return 0; -} - -int dns_packet_append_uint16(DnsPacket *p, uint16_t v, size_t *start) { - void *d; - int r; - - assert(p); - - r = dns_packet_extend(p, sizeof(uint16_t), &d, start); - if (r < 0) - return r; - - unaligned_write_be16(d, v); - - return 0; -} - -int dns_packet_append_uint32(DnsPacket *p, uint32_t v, size_t *start) { - void *d; - int r; - - assert(p); - - r = dns_packet_extend(p, sizeof(uint32_t), &d, start); - if (r < 0) - return r; - - unaligned_write_be32(d, v); - - return 0; -} - -int dns_packet_append_string(DnsPacket *p, const char *s, size_t *start) { - void *d; - size_t l; - int r; - - assert(p); - assert(s); - - l = strlen(s); - if (l > 255) - return -E2BIG; - - r = dns_packet_extend(p, 1 + l, &d, start); - if (r < 0) - return r; - - ((uint8_t*) d)[0] = (uint8_t) l; - memcpy(((uint8_t*) d) + 1, s, l); - - return 0; -} - -int dns_packet_append_label(DnsPacket *p, const char *d, size_t l, size_t *start) { - void *w; - int r; - - assert(p); - assert(d); - - if (l > DNS_LABEL_MAX) - return -E2BIG; - - r = dns_packet_extend(p, 1 + l, &w, start); - if (r < 0) - return r; - - ((uint8_t*) w)[0] = (uint8_t) l; - memcpy(((uint8_t*) w) + 1, d, l); - - return 0; -} - -int dns_packet_append_name(DnsPacket *p, const char *name, - bool allow_compression, size_t *start) { - size_t saved_size; - int r; - - assert(p); - assert(name); - - saved_size = p->size; - - while (*name) { - _cleanup_free_ char *s = NULL; - char label[DNS_LABEL_MAX]; - size_t n = 0; - int k; - - if (allow_compression) - n = PTR_TO_SIZE(hashmap_get(p->names, name)); - if (n > 0) { - assert(n < p->size); - - if (n < 0x4000) { - r = dns_packet_append_uint16(p, 0xC000 | n, NULL); - if (r < 0) - goto fail; - - goto done; - } - } - - s = strdup(name); - if (!s) { - r = -ENOMEM; - goto fail; - } - - r = dns_label_unescape(&name, label, sizeof(label)); - if (r < 0) - goto fail; - - if (p->protocol == DNS_PROTOCOL_DNS) - k = dns_label_apply_idna(label, r, label, sizeof(label)); - else - k = dns_label_undo_idna(label, r, label, sizeof(label)); - if (k < 0) { - r = k; - goto fail; - } - if (k > 0) - r = k; - - r = dns_packet_append_label(p, label, r, &n); - 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; - - s = NULL; - } - } - - r = dns_packet_append_uint8(p, 0, NULL); - if (r < 0) - return r; - -done: - if (start) - *start = saved_size; - - return 0; - -fail: - dns_packet_truncate(p, saved_size); - return r; -} - -int dns_packet_append_key(DnsPacket *p, const DnsResourceKey *k, size_t *start) { - size_t saved_size; - int r; - - assert(p); - assert(k); - - saved_size = p->size; - - r = dns_packet_append_name(p, DNS_RESOURCE_KEY_NAME(k), true, NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_uint16(p, k->type, NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_uint16(p, k->class, NULL); - if (r < 0) - goto fail; - - if (start) - *start = saved_size; - - return 0; - -fail: - dns_packet_truncate(p, saved_size); - return r; -} - -int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *start) { - size_t saved_size, rdlength_offset, end, rdlength; - int r; - - assert(p); - assert(rr); - - saved_size = p->size; - - r = dns_packet_append_key(p, rr->key, NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_uint32(p, rr->ttl, NULL); - if (r < 0) - goto fail; - - /* Initially we write 0 here */ - r = dns_packet_append_uint16(p, 0, &rdlength_offset); - if (r < 0) - goto fail; - - switch (rr->unparseable ? _DNS_TYPE_INVALID : rr->key->type) { - - case DNS_TYPE_SRV: - r = dns_packet_append_uint16(p, rr->srv.priority, NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_uint16(p, rr->srv.weight, NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_uint16(p, rr->srv.port, NULL); - if (r < 0) - goto fail; - - 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, true, NULL); - break; - - case DNS_TYPE_HINFO: - r = dns_packet_append_string(p, rr->hinfo.cpu, NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_string(p, rr->hinfo.os, NULL); - break; - - case DNS_TYPE_SPF: /* exactly the same as TXT */ - case DNS_TYPE_TXT: { - char **s; - - if (strv_isempty(rr->txt.strings)) { - /* RFC 6763, section 6.1 suggests to generate - * single empty string for an empty array. */ - - r = dns_packet_append_string(p, "", NULL); - if (r < 0) - goto fail; - } else { - STRV_FOREACH(s, rr->txt.strings) { - r = dns_packet_append_string(p, *s, NULL); - if (r < 0) - goto fail; - } - } - - r = 0; - break; - } - - case DNS_TYPE_A: - r = dns_packet_append_blob(p, &rr->a.in_addr, sizeof(struct in_addr), NULL); - break; - - case DNS_TYPE_AAAA: - r = dns_packet_append_blob(p, &rr->aaaa.in6_addr, sizeof(struct in6_addr), NULL); - break; - - case DNS_TYPE_SOA: - 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, true, NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_uint32(p, rr->soa.serial, NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_uint32(p, rr->soa.refresh, NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_uint32(p, rr->soa.retry, NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_uint32(p, rr->soa.expire, NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_uint32(p, rr->soa.minimum, NULL); - break; - - case DNS_TYPE_MX: - r = dns_packet_append_uint16(p, rr->mx.priority, NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_name(p, rr->mx.exchange, true, NULL); - break; - - case DNS_TYPE_LOC: - r = dns_packet_append_uint8(p, rr->loc.version, NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_uint8(p, rr->loc.size, NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_uint8(p, rr->loc.horiz_pre, NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_uint8(p, rr->loc.vert_pre, NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_uint32(p, rr->loc.latitude, NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_uint32(p, rr->loc.longitude, NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_uint32(p, rr->loc.altitude, NULL); - break; - - case DNS_TYPE_SSHFP: - r = dns_packet_append_uint8(p, rr->sshfp.algorithm, NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_uint8(p, rr->sshfp.fptype, NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_blob(p, rr->sshfp.key, rr->sshfp.key_size, NULL); - break; - - case DNS_TYPE_DNSKEY: - r = dns_packet_append_uint16(p, dnskey_to_flags(rr), NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_uint8(p, 3u, NULL); - if (r < 0) - goto fail; - - r = dns_packet_append_uint8(p, rr->dnskey.algorithm, NULL); - if (r < 0) - goto fail; - - 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: - - r = dns_packet_append_blob(p, rr->generic.data, rr->generic.size, NULL); - break; - } - if (r < 0) - goto fail; - - /* Let's calculate the actual data size and update the field */ - rdlength = p->size - rdlength_offset - sizeof(uint16_t); - if (rdlength > 0xFFFF) { - r = ENOSPC; - goto fail; - } - - end = p->size; - p->size = rdlength_offset; - r = dns_packet_append_uint16(p, rdlength, NULL); - if (r < 0) - goto fail; - p->size = end; - - if (start) - *start = saved_size; - - return 0; - -fail: - dns_packet_truncate(p, saved_size); - return r; -} - - -int dns_packet_read(DnsPacket *p, size_t sz, const void **ret, size_t *start) { - assert(p); - - if (p->rindex + sz > p->size) - return -EMSGSIZE; - - if (ret) - *ret = (uint8_t*) DNS_PACKET_DATA(p) + p->rindex; - - if (start) - *start = p->rindex; - - p->rindex += sz; - return 0; -} - -void dns_packet_rewind(DnsPacket *p, size_t idx) { - assert(p); - assert(idx <= p->size); - assert(idx >= DNS_PACKET_HEADER_SIZE); - - p->rindex = idx; -} - -int dns_packet_read_blob(DnsPacket *p, void *d, size_t sz, size_t *start) { - const void *q; - int r; - - assert(p); - assert(d); - - r = dns_packet_read(p, sz, &q, start); - if (r < 0) - return r; - - memcpy(d, q, sz); - return 0; -} - -int dns_packet_read_uint8(DnsPacket *p, uint8_t *ret, size_t *start) { - const void *d; - int r; - - assert(p); - - r = dns_packet_read(p, sizeof(uint8_t), &d, start); - if (r < 0) - return r; - - *ret = ((uint8_t*) d)[0]; - return 0; -} - -int dns_packet_read_uint16(DnsPacket *p, uint16_t *ret, size_t *start) { - const void *d; - int r; - - assert(p); - - r = dns_packet_read(p, sizeof(uint16_t), &d, start); - if (r < 0) - return r; - - *ret = unaligned_read_be16(d); - - return 0; -} - -int dns_packet_read_uint32(DnsPacket *p, uint32_t *ret, size_t *start) { - const void *d; - int r; - - assert(p); - - r = dns_packet_read(p, sizeof(uint32_t), &d, start); - if (r < 0) - return r; - - *ret = unaligned_read_be32(d); - - return 0; -} - -int dns_packet_read_string(DnsPacket *p, char **ret, size_t *start) { - size_t saved_rindex; - const void *d; - char *t; - uint8_t c; - int r; - - assert(p); - - saved_rindex = p->rindex; - - r = dns_packet_read_uint8(p, &c, NULL); - if (r < 0) - goto fail; - - r = dns_packet_read(p, c, &d, NULL); - if (r < 0) - goto fail; - - if (memchr(d, 0, c)) { - r = -EBADMSG; - goto fail; - } - - t = strndup(d, c); - if (!t) { - r = -ENOMEM; - goto fail; - } - - if (!utf8_is_valid(t)) { - free(t); - r = -EBADMSG; - goto fail; - } - - *ret = t; - - if (start) - *start = saved_rindex; - - return 0; - -fail: - dns_packet_rewind(p, saved_rindex); - return r; -} - -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; - int r; - - assert(p); - assert(_ret); - - 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; - - if (c == 0) - /* End of name */ - break; - else if (c <= 63) { - _cleanup_free_ char *t = NULL; - const char *label; - - /* Literal label */ - r = dns_packet_read(p, c, (const void**) &label, NULL); - if (r < 0) - goto fail; - - r = dns_label_escape(label, c, &t); - if (r < 0) - goto fail; - - if (!GREEDY_REALLOC(ret, allocated, n + !first + strlen(t) + 1)) { - r = -ENOMEM; - goto fail; - } - - if (!first) - ret[n++] = '.'; - else - first = false; - - memcpy(ret + n, t, r); - n += r; - continue; - } else if (allow_compression && (c & 0xc0) == 0xc0) { - uint16_t ptr; - - /* Pointer */ - r = dns_packet_read_uint8(p, &d, NULL); - if (r < 0) - goto fail; - - ptr = (uint16_t) (c & ~0xc0) << 8 | (uint16_t) d; - if (ptr < DNS_PACKET_HEADER_SIZE || ptr >= jump_barrier) { - r = -EBADMSG; - goto fail; - } - - if (after_rindex == 0) - after_rindex = p->rindex; - - /* Jumps are limited to a "prior occurrence" (RFC-1035 4.1.4) */ - jump_barrier = ptr; - p->rindex = ptr; - } else { - r = -EBADMSG; - goto fail; - } - } - - if (!GREEDY_REALLOC(ret, allocated, n + 1)) { - r = -ENOMEM; - goto fail; - } - - ret[n] = 0; - - if (after_rindex != 0) - p->rindex= after_rindex; - - *_ret = ret; - ret = NULL; - - if (start) - *start = saved_rindex; - - return 0; - -fail: - dns_packet_rewind(p, saved_rindex); - return r; -} - -int dns_packet_read_key(DnsPacket *p, DnsResourceKey **ret, size_t *start) { - _cleanup_free_ char *name = NULL; - uint16_t class, type; - DnsResourceKey *key; - size_t saved_rindex; - int r; - - assert(p); - assert(ret); - - saved_rindex = p->rindex; - - r = dns_packet_read_name(p, &name, true, NULL); - if (r < 0) - goto fail; - - r = dns_packet_read_uint16(p, &type, NULL); - if (r < 0) - goto fail; - - r = dns_packet_read_uint16(p, &class, NULL); - if (r < 0) - goto fail; - - key = dns_resource_key_new_consume(class, type, name); - if (!key) { - r = -ENOMEM; - goto fail; - } - - name = NULL; - *ret = key; - - if (start) - *start = saved_rindex; - - return 0; -fail: - dns_packet_rewind(p, saved_rindex); - return r; -} - -static int dns_packet_read_public_key(DnsPacket *p, size_t length, - void **dp, size_t *lengthp, - size_t *start) { - int r; - const void *d; - void *d2; - - r = dns_packet_read(p, length, &d, NULL); - if (r < 0) - return r; - - d2 = memdup(d, length); - if (!d2) - return -ENOMEM; - - *dp = d2; - *lengthp = length; - return 0; -} - -static bool loc_size_ok(uint8_t size) { - uint8_t m = size >> 4, e = size & 0xF; - - return m <= 9 && e <= 9 && (m > 0 || e == 0); -} - -static int dnskey_parse_flags(DnsResourceRecord *rr, uint16_t flags) { - assert(rr); - - if (flags & ~(DNSKEY_FLAG_SEP | DNSKEY_FLAG_ZONE_KEY)) - return -EBADMSG; - - rr->dnskey.zone_key_flag = flags & DNSKEY_FLAG_ZONE_KEY; - rr->dnskey.sep_flag = flags & DNSKEY_FLAG_SEP; - return 0; -} - -int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) { - _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; - _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; - size_t saved_rindex, offset; - uint16_t rdlength; - const void *d; - int r; - - assert(p); - assert(ret); - - saved_rindex = p->rindex; - - r = dns_packet_read_key(p, &key, NULL); - if (r < 0) - goto fail; - - if (key->class == DNS_CLASS_ANY || - key->type == DNS_TYPE_ANY) { - r = -EBADMSG; - goto fail; - } - - rr = dns_resource_record_new(key); - if (!rr) { - r = -ENOMEM; - goto fail; - } - - r = dns_packet_read_uint32(p, &rr->ttl, NULL); - if (r < 0) - goto fail; - - r = dns_packet_read_uint16(p, &rdlength, NULL); - if (r < 0) - goto fail; - - if (p->rindex + rdlength > p->size) { - r = -EBADMSG; - goto fail; - } - - offset = p->rindex; - - switch (rr->key->type) { - - case DNS_TYPE_SRV: - r = dns_packet_read_uint16(p, &rr->srv.priority, NULL); - if (r < 0) - goto fail; - r = dns_packet_read_uint16(p, &rr->srv.weight, NULL); - if (r < 0) - goto fail; - r = dns_packet_read_uint16(p, &rr->srv.port, NULL); - if (r < 0) - goto fail; - 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, true, NULL); - break; - - case DNS_TYPE_HINFO: - r = dns_packet_read_string(p, &rr->hinfo.cpu, NULL); - if (r < 0) - goto fail; - - r = dns_packet_read_string(p, &rr->hinfo.os, NULL); - break; - - case DNS_TYPE_SPF: /* exactly the same as TXT */ - case DNS_TYPE_TXT: - if (rdlength <= 0) { - /* RFC 6763, section 6.1 suggests to treat - * empty TXT RRs as equivalent to a TXT record - * with a single empty string. */ - - r = strv_extend(&rr->txt.strings, ""); - if (r < 0) - goto fail; - } else { - while (p->rindex < offset + rdlength) { - char *s; - - r = dns_packet_read_string(p, &s, NULL); - if (r < 0) - goto fail; - - r = strv_consume(&rr->txt.strings, s); - if (r < 0) - goto fail; - } - } - - r = 0; - break; - - case DNS_TYPE_A: - r = dns_packet_read_blob(p, &rr->a.in_addr, sizeof(struct in_addr), NULL); - break; - - case DNS_TYPE_AAAA: - r = dns_packet_read_blob(p, &rr->aaaa.in6_addr, sizeof(struct in6_addr), NULL); - break; - - case DNS_TYPE_SOA: - 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, true, NULL); - if (r < 0) - goto fail; - - r = dns_packet_read_uint32(p, &rr->soa.serial, NULL); - if (r < 0) - goto fail; - - r = dns_packet_read_uint32(p, &rr->soa.refresh, NULL); - if (r < 0) - goto fail; - - r = dns_packet_read_uint32(p, &rr->soa.retry, NULL); - if (r < 0) - goto fail; - - r = dns_packet_read_uint32(p, &rr->soa.expire, NULL); - if (r < 0) - goto fail; - - r = dns_packet_read_uint32(p, &rr->soa.minimum, NULL); - break; - - case DNS_TYPE_MX: - r = dns_packet_read_uint16(p, &rr->mx.priority, NULL); - if (r < 0) - goto fail; - - r = dns_packet_read_name(p, &rr->mx.exchange, true, NULL); - break; - - case DNS_TYPE_LOC: { - uint8_t t; - size_t pos; - - r = dns_packet_read_uint8(p, &t, &pos); - if (r < 0) - goto fail; - - if (t == 0) { - rr->loc.version = t; - - r = dns_packet_read_uint8(p, &rr->loc.size, NULL); - if (r < 0) - goto fail; - - if (!loc_size_ok(rr->loc.size)) { - r = -EBADMSG; - goto fail; - } - - r = dns_packet_read_uint8(p, &rr->loc.horiz_pre, NULL); - if (r < 0) - goto fail; - - if (!loc_size_ok(rr->loc.horiz_pre)) { - r = -EBADMSG; - goto fail; - } - - r = dns_packet_read_uint8(p, &rr->loc.vert_pre, NULL); - if (r < 0) - goto fail; - - if (!loc_size_ok(rr->loc.vert_pre)) { - r = -EBADMSG; - goto fail; - } - - r = dns_packet_read_uint32(p, &rr->loc.latitude, NULL); - if (r < 0) - goto fail; - - r = dns_packet_read_uint32(p, &rr->loc.longitude, NULL); - if (r < 0) - goto fail; - - r = dns_packet_read_uint32(p, &rr->loc.altitude, NULL); - if (r < 0) - goto fail; - - break; - } else { - dns_packet_rewind(p, pos); - rr->unparseable = true; - goto unparseable; - } - } - - case DNS_TYPE_SSHFP: - r = dns_packet_read_uint8(p, &rr->sshfp.algorithm, NULL); - if (r < 0) - goto fail; - - r = dns_packet_read_uint8(p, &rr->sshfp.fptype, NULL); - if (r < 0) - goto fail; - - r = dns_packet_read_public_key(p, rdlength - 2, - &rr->sshfp.key, &rr->sshfp.key_size, - NULL); - break; - - case DNS_TYPE_DNSKEY: { - uint16_t flags; - uint8_t proto; - - r = dns_packet_read_uint16(p, &flags, NULL); - if (r < 0) - goto fail; - - r = dnskey_parse_flags(rr, flags); - if (r < 0) - goto fail; - - r = dns_packet_read_uint8(p, &proto, NULL); - if (r < 0) - goto fail; - - /* protocol is required to be always 3 */ - if (proto != 3) { - r = -EBADMSG; - goto fail; - } - - r = dns_packet_read_uint8(p, &rr->dnskey.algorithm, NULL); - if (r < 0) - goto fail; - - r = dns_packet_read_public_key(p, rdlength - 4, - &rr->dnskey.key, &rr->dnskey.key_size, - NULL); - 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); - if (r < 0) - goto fail; - - rr->generic.data = memdup(d, rdlength); - if (!rr->generic.data) { - r = -ENOMEM; - goto fail; - } - - rr->generic.size = rdlength; - break; - } - if (r < 0) - goto fail; - if (p->rindex != offset + rdlength) { - r = -EBADMSG; - goto fail; - } - - *ret = rr; - rr = NULL; - - if (start) - *start = saved_rindex; - - return 0; -fail: - dns_packet_rewind(p, saved_rindex); - return r; -} - -int dns_packet_extract(DnsPacket *p) { - _cleanup_(dns_question_unrefp) DnsQuestion *question = NULL; - _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; - size_t saved_rindex; - unsigned n, i; - int r; - - if (p->extracted) - return 0; - - saved_rindex = p->rindex; - 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; - } - - for (i = 0; i < n; i++) { - _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; - - r = dns_packet_read_key(p, &key, NULL); - if (r < 0) - goto finish; - - r = dns_question_add(question, key); - if (r < 0) - goto finish; - } - } - - n = DNS_PACKET_RRCOUNT(p); - if (n > 0) { - answer = dns_answer_new(n); - if (!answer) { - r = -ENOMEM; - goto finish; - } - - for (i = 0; i < n; i++) { - _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; - - r = dns_packet_read_rr(p, &rr, NULL); - if (r < 0) - goto finish; - - r = dns_answer_add(answer, rr); - if (r < 0) - goto finish; - } - } - - p->question = question; - question = NULL; - - p->answer = answer; - answer = NULL; - - p->extracted = true; - - r = 0; - -finish: - p->rindex = saved_rindex; - return r; -} - -static const char* const dns_rcode_table[_DNS_RCODE_MAX_DEFINED] = { - [DNS_RCODE_SUCCESS] = "SUCCESS", - [DNS_RCODE_FORMERR] = "FORMERR", - [DNS_RCODE_SERVFAIL] = "SERVFAIL", - [DNS_RCODE_NXDOMAIN] = "NXDOMAIN", - [DNS_RCODE_NOTIMP] = "NOTIMP", - [DNS_RCODE_REFUSED] = "REFUSED", - [DNS_RCODE_YXDOMAIN] = "YXDOMAIN", - [DNS_RCODE_YXRRSET] = "YRRSET", - [DNS_RCODE_NXRRSET] = "NXRRSET", - [DNS_RCODE_NOTAUTH] = "NOTAUTH", - [DNS_RCODE_NOTZONE] = "NOTZONE", - [DNS_RCODE_BADVERS] = "BADVERS", - [DNS_RCODE_BADKEY] = "BADKEY", - [DNS_RCODE_BADTIME] = "BADTIME", - [DNS_RCODE_BADMODE] = "BADMODE", - [DNS_RCODE_BADNAME] = "BADNAME", - [DNS_RCODE_BADALG] = "BADALG", - [DNS_RCODE_BADTRUNC] = "BADTRUNC", -}; -DEFINE_STRING_TABLE_LOOKUP(dns_rcode, int); - -static const char* const dns_protocol_table[_DNS_PROTOCOL_MAX] = { - [DNS_PROTOCOL_DNS] = "dns", - [DNS_PROTOCOL_MDNS] = "mdns", - [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); |