+++ /dev/null
-/*-*- 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);
~ianmdlvl / elogind.git / blobdiff