X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=avahi-core%2Fdns.c;h=7a99192b0e56b667e697e87f7c8a9cd1c537106c;hb=8d8c0255f0f0242a067b577747740bab1b1021ea;hp=cc1463a729b15ea66702bedd2e1134ccfeb4ba9e;hpb=c58379bde376cb2298fca14f83a86626f1b76f2f;p=catta diff --git a/avahi-core/dns.c b/avahi-core/dns.c index cc1463a..7a99192 100644 --- a/avahi-core/dns.c +++ b/avahi-core/dns.c @@ -32,12 +32,18 @@ #include "dns.h" #include "util.h" -AvahiDnsPacket* avahi_dns_packet_new(guint max_size) { +AvahiDnsPacket* avahi_dns_packet_new(guint mtu) { AvahiDnsPacket *p; + guint max_size; - if (max_size <= 0) + if (mtu <= 0) max_size = AVAHI_DNS_PACKET_MAX_SIZE; - else if (max_size < AVAHI_DNS_PACKET_HEADER_SIZE) + else if (mtu >= 48) + max_size = mtu - 48; + else + max_size = 0; + + if (max_size < AVAHI_DNS_PACKET_HEADER_SIZE) max_size = AVAHI_DNS_PACKET_HEADER_SIZE; p = g_malloc(sizeof(AvahiDnsPacket) + max_size); @@ -49,22 +55,59 @@ AvahiDnsPacket* avahi_dns_packet_new(guint max_size) { return p; } -AvahiDnsPacket* avahi_dns_packet_new_query(guint max_size) { +AvahiDnsPacket* avahi_dns_packet_new_query(guint mtu) { AvahiDnsPacket *p; - p = avahi_dns_packet_new(max_size); + p = avahi_dns_packet_new(mtu); 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(guint max_size) { +AvahiDnsPacket* avahi_dns_packet_new_response(guint mtu, gboolean aa) { AvahiDnsPacket *p; - p = avahi_dns_packet_new(max_size); - avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_FLAGS, AVAHI_DNS_FLAGS(1, 0, 0, 0, 0, 0, 0, 0, 0, 0)); + p = avahi_dns_packet_new(mtu); + 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, guint mtu, gboolean copy_queries, gboolean aa) { + AvahiDnsPacket *r; + g_assert(p); + + r = avahi_dns_packet_new_response(mtu, aa); + + if (copy_queries) { + guint n, saved_rindex; + + 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; + gboolean 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) { g_assert(p); @@ -654,7 +697,7 @@ guint8* avahi_dns_packet_append_key(AvahiDnsPacket *p, AvahiKey *k, gboolean uni return t; } -guint8* avahi_dns_packet_append_record(AvahiDnsPacket *p, AvahiRecord *r, gboolean cache_flush) { +guint8* avahi_dns_packet_append_record(AvahiDnsPacket *p, AvahiRecord *r, gboolean cache_flush, guint max_ttl) { guint8 *t, *l, *start; guint size; @@ -666,7 +709,7 @@ guint8* avahi_dns_packet_append_record(AvahiDnsPacket *p, AvahiRecord *r, gboole 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->class | AVAHI_DNS_CACHE_FLUSH) : (r->key->class &~ AVAHI_DNS_CACHE_FLUSH)) || - !avahi_dns_packet_append_uint32(p, r->ttl) || + !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;