X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=avahi-core%2Fdns.c;h=41ccc8f3503c689e93ae6e612d22100f3656b3b5;hb=a4572037763c65ec34ac921a6e15b936c6525b5d;hp=8c8b42bcbb56317ef0cefd4ee36bfd9f379afdab;hpb=3073103812f0ea376582eb0ff1479945a847b361;p=catta diff --git a/avahi-core/dns.c b/avahi-core/dns.c index 8c8b42b..41ccc8f 100644 --- a/avahi-core/dns.c +++ b/avahi-core/dns.c @@ -23,13 +23,15 @@ #include #endif -#include - #include #include #include #include +#include +#include + +#include #include #include @@ -56,6 +58,7 @@ AvahiDnsPacket* avahi_dns_packet_new(unsigned mtu) { 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; @@ -150,6 +153,19 @@ void avahi_dns_packet_inc_field(AvahiDnsPacket *p, unsigned idx) { avahi_dns_packet_set_field(p, idx, avahi_dns_packet_get_field(p, idx) + 1); } + +static void name_table_cleanup(void *key, void *value, void *user_data) { + AvahiDnsPacket *p = user_data; + + if ((uint8_t*) value >= AVAHI_DNS_PACKET_DATA(p) + p->size) + avahi_hashmap_remove(p->name_table, key); +} + +void avahi_dns_packet_cleanup_name_table(AvahiDnsPacket *p) { + if (p->name_table) + avahi_hashmap_foreach(p->name_table, name_table_cleanup, p); +} + uint8_t* avahi_dns_packet_append_name(AvahiDnsPacket *p, const char *name) { uint8_t *d, *saved_ptr = NULL; size_t saved_size; @@ -213,6 +229,8 @@ uint8_t* avahi_dns_packet_append_name(AvahiDnsPacket *p, const char *name) { fail: p->size = saved_size; + avahi_dns_packet_cleanup_name_table(p); + return NULL; } @@ -320,7 +338,6 @@ int avahi_dns_packet_check_valid_multicast(AvahiDnsPacket *p) { return 0; } - int avahi_dns_packet_is_query(AvahiDnsPacket *p) { assert(p); @@ -331,9 +348,11 @@ static int consume_labels(AvahiDnsPacket *p, unsigned idx, char *ret_name, size_ int ret = 0; int compressed = 0; int first_label = 1; + unsigned label_ptr; + int i; assert(p && ret_name && l); - for (;;) { + for (i = 0; i < AVAHI_DNS_LABELS_MAX; i++) { uint8_t n; if (idx+1 > p->size) @@ -383,7 +402,12 @@ static int consume_labels(AvahiDnsPacket *p, unsigned idx, char *ret_name, size_ if (idx+2 > p->size) return -1; - idx = ((unsigned) (AVAHI_DNS_PACKET_DATA(p)[idx] & ~0xC0)) << 8 | AVAHI_DNS_PACKET_DATA(p)[idx+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; @@ -392,6 +416,8 @@ static int consume_labels(AvahiDnsPacket *p, unsigned idx, char *ret_name, size_ } else return -1; } + + return -1; } int avahi_dns_packet_consume_name(AvahiDnsPacket *p, char *ret_name, size_t l) { @@ -495,88 +521,59 @@ int avahi_dns_packet_skip(AvahiDnsPacket *p, size_t length) { return 0; } -AvahiRecord* avahi_dns_packet_consume_record(AvahiDnsPacket *p, int *ret_cache_flush) { - char name[257], buf[257]; - uint16_t type, class; - uint32_t ttl; - uint16_t rdlength; - AvahiRecord *r = NULL; +static int parse_rdata(AvahiDnsPacket *p, AvahiRecord *r, uint16_t rdlength) { + char buf[AVAHI_DOMAIN_NAME_MAX]; const void* start; - + assert(p); + assert(r); -/* avahi_log_debug("consume_record()"); */ - - 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; - -/* avahi_log_debug("name = %s, rdlength = %u", name, rdlength); */ - - if (ret_cache_flush) - *ret_cache_flush = !!(class & AVAHI_DNS_CACHE_FLUSH); - class &= ~AVAHI_DNS_CACHE_FLUSH; - start = avahi_dns_packet_get_rptr(p); - - if (!(r = avahi_record_new_full(name, class, type, ttl))) - return NULL; - - switch (type) { + + switch (r->key->type) { case AVAHI_DNS_TYPE_PTR: case AVAHI_DNS_TYPE_CNAME: case AVAHI_DNS_TYPE_NS: - -/* avahi_log_debug("ptr"); */ if (avahi_dns_packet_consume_name(p, buf, sizeof(buf)) < 0) - goto fail; + return -1; r->data.ptr.name = avahi_strdup(buf); break; case AVAHI_DNS_TYPE_SRV: - -/* avahi_log_debug("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) - goto fail; + return -1; r->data.srv.name = avahi_strdup(buf); break; case AVAHI_DNS_TYPE_HINFO: - -/* avahi_log_debug("hinfo"); */ if (avahi_dns_packet_consume_string(p, buf, sizeof(buf)) < 0) - goto fail; - + return -1; + r->data.hinfo.cpu = avahi_strdup(buf); - + if (avahi_dns_packet_consume_string(p, buf, sizeof(buf)) < 0) - goto fail; - + return -1; + r->data.hinfo.os = avahi_strdup(buf); break; case AVAHI_DNS_TYPE_TXT: -/* avahi_log_debug("txt"); */ - if (rdlength > 0) { - r->data.txt.string_list = avahi_string_list_parse(avahi_dns_packet_get_rptr(p), rdlength); + 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) - goto fail; + return -1; } else r->data.txt.string_list = NULL; @@ -587,7 +584,7 @@ AvahiRecord* avahi_dns_packet_consume_record(AvahiDnsPacket *p, int *ret_cache_f /* avahi_log_debug("A"); */ if (avahi_dns_packet_consume_bytes(p, &r->data.a.address, sizeof(AvahiIPv4Address)) < 0) - goto fail; + return -1; break; @@ -596,7 +593,7 @@ AvahiRecord* avahi_dns_packet_consume_record(AvahiDnsPacket *p, int *ret_cache_f /* avahi_log_debug("aaaa"); */ if (avahi_dns_packet_consume_bytes(p, &r->data.aaaa.address, sizeof(AvahiIPv6Address)) < 0) - goto fail; + return -1; break; @@ -607,20 +604,52 @@ AvahiRecord* avahi_dns_packet_consume_record(AvahiDnsPacket *p, int *ret_cache_f if (rdlength > 0) { r->data.generic.data = avahi_memdup(avahi_dns_packet_get_rptr(p), rdlength); + r->data.generic.size = rdlength; if (avahi_dns_packet_skip(p, rdlength) < 0) - goto fail; + return -1; } break; } -/* avahi_log_debug("%i == %u ?", (uint8_t*) avahi_dns_packet_get_rptr(p) - (uint8_t*) start, rdlength); */ - /* 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: @@ -633,6 +662,7 @@ fail: AvahiKey* avahi_dns_packet_consume_key(AvahiDnsPacket *p, int *ret_unicast_response) { char name[256]; uint16_t type, class; + AvahiKey *k; assert(p); @@ -646,7 +676,15 @@ AvahiKey* avahi_dns_packet_consume_key(AvahiDnsPacket *p, int *ret_unicast_respo class &= ~AVAHI_DNS_UNICAST_RESPONSE; - return avahi_key_new(name, class, type); + 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) { @@ -662,30 +700,18 @@ uint8_t* avahi_dns_packet_append_key(AvahiDnsPacket *p, AvahiKey *k, int unicast !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; + avahi_dns_packet_cleanup_name_table(p); + return NULL; } return t; } -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; - +static int append_rdata(AvahiDnsPacket *p, AvahiRecord *r) { 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); - + switch (r->key->type) { case AVAHI_DNS_TYPE_PTR: @@ -693,7 +719,7 @@ uint8_t* avahi_dns_packet_append_record(AvahiDnsPacket *p, AvahiRecord *r, int c case AVAHI_DNS_TYPE_NS: if (!(avahi_dns_packet_append_name(p, r->data.ptr.name))) - goto fail; + return -1; break; @@ -703,14 +729,14 @@ uint8_t* avahi_dns_packet_append_record(AvahiDnsPacket *p, AvahiRecord *r, int c !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)) - goto fail; + 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)) - goto fail; + return -1; break; @@ -721,10 +747,8 @@ uint8_t* avahi_dns_packet_append_record(AvahiDnsPacket *p, AvahiRecord *r, int c n = avahi_string_list_serialize(r->data.txt.string_list, NULL, 0); -/* avahi_log_debug("appending string: %u %p", n, r->data.txt.string_list); */ - if (!(data = avahi_dns_packet_extend(p, n))) - goto fail; + return -1; avahi_string_list_serialize(r->data.txt.string_list, data, n); break; @@ -734,31 +758,53 @@ uint8_t* avahi_dns_packet_append_record(AvahiDnsPacket *p, AvahiRecord *r, int c case AVAHI_DNS_TYPE_A: if (!avahi_dns_packet_append_bytes(p, &r->data.a.address, sizeof(r->data.a.address))) - goto fail; + return -1; break; case AVAHI_DNS_TYPE_AAAA: if (!avahi_dns_packet_append_bytes(p, &r->data.aaaa.address, sizeof(r->data.aaaa.address))) - goto fail; + return -1; break; default: - if (r->data.generic.size && - avahi_dns_packet_append_bytes(p, r->data.generic.data, r->data.generic.size)) - goto fail; + 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); + assert(size <= AVAHI_DNS_RDATA_MAX); /* avahi_log_debug("appended %u", size); */ @@ -770,6 +816,8 @@ uint8_t* avahi_dns_packet_append_record(AvahiDnsPacket *p, AvahiRecord *r, int c fail: p->size = size; + avahi_dns_packet_cleanup_name_table(p); + return NULL; } @@ -786,3 +834,46 @@ size_t avahi_dns_packet_space(AvahiDnsPacket *p) { 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; +}