diff options
Diffstat (limited to 'trunk/avahi-core/dns.c')
| -rw-r--r-- | trunk/avahi-core/dns.c | 856 |
1 files changed, 0 insertions, 856 deletions
diff --git a/trunk/avahi-core/dns.c b/trunk/avahi-core/dns.c deleted file mode 100644 index b31aa20..0000000 --- a/trunk/avahi-core/dns.c +++ /dev/null @@ -1,856 +0,0 @@ -/* $Id$ */ - -/*** - This file is part of avahi. - - avahi 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. - - avahi 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 avahi; if not, write to the Free Software - Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 - USA. -***/ - -#ifdef HAVE_CONFIG_H -#include <config.h> -#endif - -#include <stdlib.h> -#include <string.h> -#include <stdio.h> -#include <assert.h> - -#include <netinet/in.h> - -#include <avahi-common/defs.h> -#include <avahi-common/domain.h> -#include <avahi-common/malloc.h> - -#include "dns.h" -#include "log.h" - -AvahiDnsPacket* avahi_dns_packet_new(unsigned mtu) { - AvahiDnsPacket *p; - size_t max_size; - - if (mtu <= 0) - max_size = AVAHI_DNS_PACKET_SIZE_MAX; - else if (mtu >= AVAHI_DNS_PACKET_EXTRA_SIZE) - max_size = mtu - AVAHI_DNS_PACKET_EXTRA_SIZE; - else - max_size = 0; - - if (max_size < AVAHI_DNS_PACKET_HEADER_SIZE) - max_size = AVAHI_DNS_PACKET_HEADER_SIZE; - - if (!(p = avahi_malloc(sizeof(AvahiDnsPacket) + max_size))) - return p; - - p->size = p->rindex = AVAHI_DNS_PACKET_HEADER_SIZE; - p->max_size = max_size; - p->name_table = NULL; - p->data = NULL; - - memset(AVAHI_DNS_PACKET_DATA(p), 0, p->size); - return p; -} - -AvahiDnsPacket* avahi_dns_packet_new_query(unsigned mtu) { - AvahiDnsPacket *p; - - if (!(p = avahi_dns_packet_new(mtu))) - return NULL; - - avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_FLAGS, AVAHI_DNS_FLAGS(0, 0, 0, 0, 0, 0, 0, 0, 0, 0)); - return p; -} - -AvahiDnsPacket* avahi_dns_packet_new_response(unsigned mtu, int aa) { - AvahiDnsPacket *p; - - if (!(p = avahi_dns_packet_new(mtu))) - return NULL; - - avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_FLAGS, AVAHI_DNS_FLAGS(1, 0, aa, 0, 0, 0, 0, 0, 0, 0)); - return p; -} - -AvahiDnsPacket* avahi_dns_packet_new_reply(AvahiDnsPacket* p, unsigned mtu, int copy_queries, int aa) { - AvahiDnsPacket *r; - assert(p); - - if (!(r = avahi_dns_packet_new_response(mtu, aa))) - return NULL; - - if (copy_queries) { - unsigned saved_rindex; - uint32_t n; - - saved_rindex = p->rindex; - p->rindex = AVAHI_DNS_PACKET_HEADER_SIZE; - - for (n = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_QDCOUNT); n > 0; n--) { - AvahiKey *k; - int unicast_response; - - if ((k = avahi_dns_packet_consume_key(p, &unicast_response))) { - avahi_dns_packet_append_key(r, k, unicast_response); - avahi_key_unref(k); - } - } - - p->rindex = saved_rindex; - - avahi_dns_packet_set_field(r, AVAHI_DNS_FIELD_QDCOUNT, avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_QDCOUNT)); - } - - avahi_dns_packet_set_field(r, AVAHI_DNS_FIELD_ID, avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ID)); - - avahi_dns_packet_set_field(r, AVAHI_DNS_FIELD_FLAGS, - (avahi_dns_packet_get_field(r, AVAHI_DNS_FIELD_FLAGS) & ~AVAHI_DNS_FLAG_OPCODE) | - (avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_FLAGS) & AVAHI_DNS_FLAG_OPCODE)); - - return r; -} - - -void avahi_dns_packet_free(AvahiDnsPacket *p) { - assert(p); - - if (p->name_table) - avahi_hashmap_free(p->name_table); - - avahi_free(p); -} - -void avahi_dns_packet_set_field(AvahiDnsPacket *p, unsigned idx, uint16_t v) { - assert(p); - assert(idx < AVAHI_DNS_PACKET_HEADER_SIZE); - - ((uint16_t*) AVAHI_DNS_PACKET_DATA(p))[idx] = htons(v); -} - -uint16_t avahi_dns_packet_get_field(AvahiDnsPacket *p, unsigned idx) { - assert(p); - assert(idx < AVAHI_DNS_PACKET_HEADER_SIZE); - - return ntohs(((uint16_t*) AVAHI_DNS_PACKET_DATA(p))[idx]); -} - -void avahi_dns_packet_inc_field(AvahiDnsPacket *p, unsigned idx) { - assert(p); - assert(idx < AVAHI_DNS_PACKET_HEADER_SIZE); - - avahi_dns_packet_set_field(p, idx, avahi_dns_packet_get_field(p, idx) + 1); -} - -uint8_t* avahi_dns_packet_append_name(AvahiDnsPacket *p, const char *name) { - uint8_t *d, *saved_ptr = NULL; - size_t saved_size; - - assert(p); - assert(name); - - saved_size = p->size; - saved_ptr = avahi_dns_packet_extend(p, 0); - - while (*name) { - uint8_t* prev; - const char *pname; - char label[64], *u; - - /* Check whether we can compress this name. */ - - if (p->name_table && (prev = avahi_hashmap_lookup(p->name_table, name))) { - unsigned idx; - - assert(prev >= AVAHI_DNS_PACKET_DATA(p)); - idx = (unsigned) (prev - AVAHI_DNS_PACKET_DATA(p)); - - assert(idx < p->size); - - if (idx < 0x4000) { - uint8_t *t; - if (!(t = (uint8_t*) avahi_dns_packet_extend(p, sizeof(uint16_t)))) - return NULL; - - t[0] = (uint8_t) ((0xC000 | idx) >> 8); - t[1] = (uint8_t) idx; - return saved_ptr; - } - } - - pname = name; - - if (!(avahi_unescape_label(&name, label, sizeof(label)))) - goto fail; - - if (!(d = avahi_dns_packet_append_string(p, label))) - goto fail; - - if (!p->name_table) - /* This works only for normalized domain names */ - p->name_table = avahi_hashmap_new(avahi_string_hash, avahi_string_equal, avahi_free, NULL); - - if (!(u = avahi_strdup(pname))) - avahi_log_error("avahi_strdup() failed."); - else - avahi_hashmap_insert(p->name_table, u, d); - } - - if (!(d = avahi_dns_packet_extend(p, 1))) - goto fail; - - *d = 0; - - return saved_ptr; - -fail: - p->size = saved_size; - return NULL; -} - -uint8_t* avahi_dns_packet_append_uint16(AvahiDnsPacket *p, uint16_t v) { - uint8_t *d; - assert(p); - - if (!(d = avahi_dns_packet_extend(p, sizeof(uint16_t)))) - return NULL; - - d[0] = (uint8_t) (v >> 8); - d[1] = (uint8_t) v; - return d; -} - -uint8_t *avahi_dns_packet_append_uint32(AvahiDnsPacket *p, uint32_t v) { - uint8_t *d; - assert(p); - - if (!(d = avahi_dns_packet_extend(p, sizeof(uint32_t)))) - return NULL; - - d[0] = (uint8_t) (v >> 24); - d[1] = (uint8_t) (v >> 16); - d[2] = (uint8_t) (v >> 8); - d[3] = (uint8_t) v; - - return d; -} - -uint8_t *avahi_dns_packet_append_bytes(AvahiDnsPacket *p, const void *b, size_t l) { - uint8_t* d; - - assert(p); - assert(b); - assert(l); - - if (!(d = avahi_dns_packet_extend(p, l))) - return NULL; - - memcpy(d, b, l); - return d; -} - -uint8_t* avahi_dns_packet_append_string(AvahiDnsPacket *p, const char *s) { - uint8_t* d; - size_t k; - - assert(p); - assert(s); - - if ((k = strlen(s)) >= 255) - k = 255; - - if (!(d = avahi_dns_packet_extend(p, k+1))) - return NULL; - - *d = (uint8_t) k; - memcpy(d+1, s, k); - - return d; -} - -uint8_t *avahi_dns_packet_extend(AvahiDnsPacket *p, size_t l) { - uint8_t *d; - - assert(p); - - if (p->size+l > p->max_size) - return NULL; - - d = AVAHI_DNS_PACKET_DATA(p) + p->size; - p->size += l; - - return d; -} - -int avahi_dns_packet_check_valid(AvahiDnsPacket *p) { - uint16_t flags; - assert(p); - - if (p->size < AVAHI_DNS_PACKET_HEADER_SIZE) - return -1; - - flags = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_FLAGS); - - if (flags & AVAHI_DNS_FLAG_OPCODE) - return -1; - - return 0; -} - -int avahi_dns_packet_check_valid_multicast(AvahiDnsPacket *p) { - uint16_t flags; - assert(p); - - if (avahi_dns_packet_check_valid(p) < 0) - return -1; - - flags = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_FLAGS); - - if (flags & AVAHI_DNS_FLAG_RCODE) - return -1; - - return 0; -} - -int avahi_dns_packet_is_query(AvahiDnsPacket *p) { - assert(p); - - return !(avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_FLAGS) & AVAHI_DNS_FLAG_QR); -} - -static int consume_labels(AvahiDnsPacket *p, unsigned idx, char *ret_name, size_t l) { - int ret = 0; - int compressed = 0; - int first_label = 1; - unsigned label_ptr; - int i; - assert(p && ret_name && l); - - for (i = 0; i < AVAHI_DNS_LABELS_MAX; i++) { - uint8_t n; - - if (idx+1 > p->size) - return -1; - - n = AVAHI_DNS_PACKET_DATA(p)[idx]; - - if (!n) { - idx++; - if (!compressed) - ret++; - - if (l < 1) - return -1; - *ret_name = 0; - - return ret; - - } else if (n <= 63) { - /* Uncompressed label */ - idx++; - if (!compressed) - ret++; - - if (idx + n > p->size) - return -1; - - if ((size_t) n + 1 > l) - return -1; - - if (!first_label) { - *(ret_name++) = '.'; - l--; - } else - first_label = 0; - - if (!(avahi_escape_label((char*) AVAHI_DNS_PACKET_DATA(p) + idx, n, &ret_name, &l))) - return -1; - - idx += n; - - if (!compressed) - ret += n; - } else if ((n & 0xC0) == 0xC0) { - /* Compressed label */ - - if (idx+2 > p->size) - return -1; - - label_ptr = ((unsigned) (AVAHI_DNS_PACKET_DATA(p)[idx] & ~0xC0)) << 8 | AVAHI_DNS_PACKET_DATA(p)[idx+1]; - - if ((label_ptr < AVAHI_DNS_PACKET_HEADER_SIZE) || (label_ptr >= idx)) - return -1; - - idx = label_ptr; - - if (!compressed) - ret += 2; - - compressed = 1; - } else - return -1; - } -} - -int avahi_dns_packet_consume_name(AvahiDnsPacket *p, char *ret_name, size_t l) { - int r; - - if ((r = consume_labels(p, p->rindex, ret_name, l)) < 0) - return -1; - - p->rindex += r; - return 0; -} - -int avahi_dns_packet_consume_uint16(AvahiDnsPacket *p, uint16_t *ret_v) { - uint8_t *d; - - assert(p); - assert(ret_v); - - if (p->rindex + sizeof(uint16_t) > p->size) - return -1; - - d = (uint8_t*) (AVAHI_DNS_PACKET_DATA(p) + p->rindex); - *ret_v = (d[0] << 8) | d[1]; - p->rindex += sizeof(uint16_t); - - return 0; -} - -int avahi_dns_packet_consume_uint32(AvahiDnsPacket *p, uint32_t *ret_v) { - uint8_t* d; - - assert(p); - assert(ret_v); - - if (p->rindex + sizeof(uint32_t) > p->size) - return -1; - - d = (uint8_t*) (AVAHI_DNS_PACKET_DATA(p) + p->rindex); - *ret_v = (d[0] << 24) | (d[1] << 16) | (d[2] << 8) | d[3]; - p->rindex += sizeof(uint32_t); - - return 0; -} - -int avahi_dns_packet_consume_bytes(AvahiDnsPacket *p, void * ret_data, size_t l) { - assert(p); - assert(ret_data); - assert(l > 0); - - if (p->rindex + l > p->size) - return -1; - - memcpy(ret_data, AVAHI_DNS_PACKET_DATA(p) + p->rindex, l); - p->rindex += l; - - return 0; -} - -int avahi_dns_packet_consume_string(AvahiDnsPacket *p, char *ret_string, size_t l) { - size_t k; - - assert(p); - assert(ret_string); - assert(l > 0); - - if (p->rindex >= p->size) - return -1; - - k = AVAHI_DNS_PACKET_DATA(p)[p->rindex]; - - if (p->rindex+1+k > p->size) - return -1; - - if (l > k+1) - l = k+1; - - memcpy(ret_string, AVAHI_DNS_PACKET_DATA(p)+p->rindex+1, l-1); - ret_string[l-1] = 0; - - p->rindex += 1+k; - - return 0; -} - -const void* avahi_dns_packet_get_rptr(AvahiDnsPacket *p) { - assert(p); - - if (p->rindex > p->size) - return NULL; - - return AVAHI_DNS_PACKET_DATA(p) + p->rindex; -} - -int avahi_dns_packet_skip(AvahiDnsPacket *p, size_t length) { - assert(p); - - if (p->rindex + length > p->size) - return -1; - - p->rindex += length; - return 0; -} - -static int parse_rdata(AvahiDnsPacket *p, AvahiRecord *r, uint16_t rdlength) { - char buf[AVAHI_DOMAIN_NAME_MAX]; - const void* start; - - assert(p); - assert(r); - - start = avahi_dns_packet_get_rptr(p); - - switch (r->key->type) { - case AVAHI_DNS_TYPE_PTR: - case AVAHI_DNS_TYPE_CNAME: - case AVAHI_DNS_TYPE_NS: - - if (avahi_dns_packet_consume_name(p, buf, sizeof(buf)) < 0) - return -1; - - r->data.ptr.name = avahi_strdup(buf); - break; - - - case AVAHI_DNS_TYPE_SRV: - - if (avahi_dns_packet_consume_uint16(p, &r->data.srv.priority) < 0 || - avahi_dns_packet_consume_uint16(p, &r->data.srv.weight) < 0 || - avahi_dns_packet_consume_uint16(p, &r->data.srv.port) < 0 || - avahi_dns_packet_consume_name(p, buf, sizeof(buf)) < 0) - return -1; - - r->data.srv.name = avahi_strdup(buf); - break; - - case AVAHI_DNS_TYPE_HINFO: - - if (avahi_dns_packet_consume_string(p, buf, sizeof(buf)) < 0) - return -1; - - r->data.hinfo.cpu = avahi_strdup(buf); - - if (avahi_dns_packet_consume_string(p, buf, sizeof(buf)) < 0) - return -1; - - r->data.hinfo.os = avahi_strdup(buf); - break; - - case AVAHI_DNS_TYPE_TXT: - - if (rdlength > 0) { - if (avahi_string_list_parse(avahi_dns_packet_get_rptr(p), rdlength, &r->data.txt.string_list) < 0) - return -1; - - if (avahi_dns_packet_skip(p, rdlength) < 0) - return -1; - } else - r->data.txt.string_list = NULL; - - break; - - case AVAHI_DNS_TYPE_A: - -/* avahi_log_debug("A"); */ - - if (avahi_dns_packet_consume_bytes(p, &r->data.a.address, sizeof(AvahiIPv4Address)) < 0) - return -1; - - break; - - case AVAHI_DNS_TYPE_AAAA: - -/* avahi_log_debug("aaaa"); */ - - if (avahi_dns_packet_consume_bytes(p, &r->data.aaaa.address, sizeof(AvahiIPv6Address)) < 0) - return -1; - - break; - - default: - -/* avahi_log_debug("generic"); */ - - if (rdlength > 0) { - - r->data.generic.data = avahi_memdup(avahi_dns_packet_get_rptr(p), rdlength); - - if (avahi_dns_packet_skip(p, rdlength) < 0) - return -1; - } - - break; - } - - /* Check if we read enough data */ - if ((const uint8_t*) avahi_dns_packet_get_rptr(p) - (const uint8_t*) start != rdlength) - return -1; - - return 0; -} - -AvahiRecord* avahi_dns_packet_consume_record(AvahiDnsPacket *p, int *ret_cache_flush) { - char name[AVAHI_DOMAIN_NAME_MAX]; - uint16_t type, class; - uint32_t ttl; - uint16_t rdlength; - AvahiRecord *r = NULL; - - assert(p); - - if (avahi_dns_packet_consume_name(p, name, sizeof(name)) < 0 || - avahi_dns_packet_consume_uint16(p, &type) < 0 || - avahi_dns_packet_consume_uint16(p, &class) < 0 || - avahi_dns_packet_consume_uint32(p, &ttl) < 0 || - avahi_dns_packet_consume_uint16(p, &rdlength) < 0 || - p->rindex + rdlength > p->size) - goto fail; - - if (ret_cache_flush) - *ret_cache_flush = !!(class & AVAHI_DNS_CACHE_FLUSH); - class &= ~AVAHI_DNS_CACHE_FLUSH; - - if (!(r = avahi_record_new_full(name, class, type, ttl))) - goto fail; - - if (parse_rdata(p, r, rdlength) < 0) - goto fail; - - if (!avahi_record_is_valid(r)) - goto fail; - - return r; - -fail: - if (r) - avahi_record_unref(r); - - return NULL; -} - -AvahiKey* avahi_dns_packet_consume_key(AvahiDnsPacket *p, int *ret_unicast_response) { - char name[256]; - uint16_t type, class; - AvahiKey *k; - - assert(p); - - if (avahi_dns_packet_consume_name(p, name, sizeof(name)) < 0 || - avahi_dns_packet_consume_uint16(p, &type) < 0 || - avahi_dns_packet_consume_uint16(p, &class) < 0) - return NULL; - - if (ret_unicast_response) - *ret_unicast_response = !!(class & AVAHI_DNS_UNICAST_RESPONSE); - - class &= ~AVAHI_DNS_UNICAST_RESPONSE; - - if (!(k = avahi_key_new(name, class, type))) - return NULL; - - if (!avahi_key_is_valid(k)) { - avahi_key_unref(k); - return NULL; - } - - return k; -} - -uint8_t* avahi_dns_packet_append_key(AvahiDnsPacket *p, AvahiKey *k, int unicast_response) { - uint8_t *t; - size_t size; - - assert(p); - assert(k); - - size = p->size; - - if (!(t = avahi_dns_packet_append_name(p, k->name)) || - !avahi_dns_packet_append_uint16(p, k->type) || - !avahi_dns_packet_append_uint16(p, k->clazz | (unicast_response ? AVAHI_DNS_UNICAST_RESPONSE : 0))) { - p->size = size; - return NULL; - } - - return t; -} - -static int append_rdata(AvahiDnsPacket *p, AvahiRecord *r) { - assert(p); - assert(r); - - switch (r->key->type) { - - case AVAHI_DNS_TYPE_PTR: - case AVAHI_DNS_TYPE_CNAME: - case AVAHI_DNS_TYPE_NS: - - if (!(avahi_dns_packet_append_name(p, r->data.ptr.name))) - return -1; - - break; - - case AVAHI_DNS_TYPE_SRV: - - if (!avahi_dns_packet_append_uint16(p, r->data.srv.priority) || - !avahi_dns_packet_append_uint16(p, r->data.srv.weight) || - !avahi_dns_packet_append_uint16(p, r->data.srv.port) || - !avahi_dns_packet_append_name(p, r->data.srv.name)) - return -1; - - break; - - case AVAHI_DNS_TYPE_HINFO: - if (!avahi_dns_packet_append_string(p, r->data.hinfo.cpu) || - !avahi_dns_packet_append_string(p, r->data.hinfo.os)) - return -1; - - break; - - case AVAHI_DNS_TYPE_TXT: { - - uint8_t *data; - size_t n; - - n = avahi_string_list_serialize(r->data.txt.string_list, NULL, 0); - - if (!(data = avahi_dns_packet_extend(p, n))) - return -1; - - avahi_string_list_serialize(r->data.txt.string_list, data, n); - break; - } - - - case AVAHI_DNS_TYPE_A: - - if (!avahi_dns_packet_append_bytes(p, &r->data.a.address, sizeof(r->data.a.address))) - return -1; - - break; - - case AVAHI_DNS_TYPE_AAAA: - - if (!avahi_dns_packet_append_bytes(p, &r->data.aaaa.address, sizeof(r->data.aaaa.address))) - return -1; - - break; - - default: - - if (r->data.generic.size) - if (avahi_dns_packet_append_bytes(p, r->data.generic.data, r->data.generic.size)) - return -1; - - break; - } - - return 0; -} - - -uint8_t* avahi_dns_packet_append_record(AvahiDnsPacket *p, AvahiRecord *r, int cache_flush, unsigned max_ttl) { - uint8_t *t, *l, *start; - size_t size; - - assert(p); - assert(r); - - size = p->size; - - if (!(t = avahi_dns_packet_append_name(p, r->key->name)) || - !avahi_dns_packet_append_uint16(p, r->key->type) || - !avahi_dns_packet_append_uint16(p, cache_flush ? (r->key->clazz | AVAHI_DNS_CACHE_FLUSH) : (r->key->clazz &~ AVAHI_DNS_CACHE_FLUSH)) || - !avahi_dns_packet_append_uint32(p, (max_ttl && r->ttl > max_ttl) ? max_ttl : r->ttl) || - !(l = avahi_dns_packet_append_uint16(p, 0))) - goto fail; - - start = avahi_dns_packet_extend(p, 0); - - if (append_rdata(p, r) < 0) - goto fail; - - size = avahi_dns_packet_extend(p, 0) - start; - assert(size <= 0xFFFF); - -/* avahi_log_debug("appended %u", size); */ - - l[0] = (uint8_t) ((uint16_t) size >> 8); - l[1] = (uint8_t) ((uint16_t) size); - - return t; - - -fail: - p->size = size; - return NULL; -} - -int avahi_dns_packet_is_empty(AvahiDnsPacket *p) { - assert(p); - - return p->size <= AVAHI_DNS_PACKET_HEADER_SIZE; -} - -size_t avahi_dns_packet_space(AvahiDnsPacket *p) { - assert(p); - - assert(p->size <= p->max_size); - - return p->max_size - p->size; -} - -int avahi_rdata_parse(AvahiRecord *record, const void* rdata, size_t size) { - int ret; - AvahiDnsPacket p; - - assert(record); - assert(rdata); - - p.data = (void*) rdata; - p.max_size = p.size = size; - p.rindex = 0; - p.name_table = NULL; - - ret = parse_rdata(&p, record, size); - - assert(!p.name_table); - - return ret; -} - -size_t avahi_rdata_serialize(AvahiRecord *record, void *rdata, size_t max_size) { - int ret; - AvahiDnsPacket p; - - assert(record); - assert(rdata); - assert(max_size > 0); - - p.data = (void*) rdata; - p.max_size = max_size; - p.size = p.rindex = 0; - p.name_table = NULL; - - ret = append_rdata(&p, record); - - if (p.name_table) - avahi_hashmap_free(p.name_table); - - if (ret < 0) - return (size_t) -1; - - return p.size; -} |