int avahi_send_dns_packet_ipv6(
int fd,
AvahiIfIndex interface,
AvahiDnsPacket *p,
const AvahiIPv6Address *src_address,
const AvahiIPv6Address *dst_address,
uint16_t dst_port) {
struct sockaddr_in6 sa;
struct msghdr msg;
struct iovec io;
struct cmsghdr *cmsg;
size_t cmsg_data[(CMSG_SPACE(sizeof(struct in6_pktinfo))/sizeof(size_t)) + 1];
assert(fd >= 0);
assert(p);
assert(avahi_dns_packet_check_valid(p) >= 0);
assert(!dst_address || dst_port > 0);
if (!dst_address)
mdns_mcast_group_ipv6(&sa);
else
ipv6_address_to_sockaddr(&sa, dst_address, dst_port);
memset(&io, 0, sizeof(io));
io.iov_base = AVAHI_DNS_PACKET_DATA(p);
io.iov_len = p->size;
memset(&msg, 0, sizeof(msg));
msg.msg_name = &sa;
msg.msg_namelen = sizeof(sa);
msg.msg_iov = &io;
msg.msg_iovlen = 1;
msg.msg_flags = 0;
if (interface > 0 || src_address) {
struct in6_pktinfo *pkti;
memset(cmsg_data, 0, sizeof(cmsg_data));
msg.msg_control = cmsg_data;
msg.msg_controllen = CMSG_LEN(sizeof(struct in6_pktinfo));
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_len = msg.msg_controllen;
cmsg->cmsg_level = IPPROTO_IPV6;
cmsg->cmsg_type = IPV6_PKTINFO;
pkti = (struct in6_pktinfo*) CMSG_DATA(cmsg);
if (interface > 0)
pkti->ipi6_ifindex = interface;
if (src_address)
memcpy(&pkti->ipi6_addr, src_address->address, sizeof(src_address->address));
} else {
msg.msg_control = NULL;
msg.msg_controllen = 0;
}
return sendmsg_loop(fd, &msg, 0);
}
static void handle_packet(AvahiWideAreaLookupEngine *e, AvahiDnsPacket *p) {
AvahiWideAreaLookup *l = NULL;
int i, r;
AvahiBrowserEvent final_event = AVAHI_BROWSER_ALL_FOR_NOW;
assert(e);
assert(p);
/* Some superficial validity tests */
if (avahi_dns_packet_check_valid(p) < 0 || avahi_dns_packet_is_query(p)) {
avahi_log_warn(__FILE__": Ignoring invalid response for wide area datagram.");
goto finish;
}
/* Look for the lookup that issued this query */
if (!(l = find_lookup(e, avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ID))) || l->dead)
goto finish;
/* Check whether this a packet indicating a failure */
if ((r = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_FLAGS) & 15) != 0 ||
avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ANCOUNT) == 0) {
avahi_server_set_errno(e->server, r == 0 ? AVAHI_ERR_NOT_FOUND : map_dns_error(r));
/* Tell the user about the failure */
final_event = AVAHI_BROWSER_FAILURE;
/* We go on here, since some of the records contained in the
reply might be interesting in some way */
}
/* Skip over the question */
for (i = (int) avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_QDCOUNT); i > 0; i--) {
AvahiKey *k;
if (!(k = avahi_dns_packet_consume_key(p, NULL))) {
avahi_log_warn(__FILE__": Wide area response packet too short or invalid while reading question key. (Maybe a UTF-8 problem?)");
avahi_server_set_errno(e->server, AVAHI_ERR_INVALID_PACKET);
final_event = AVAHI_BROWSER_FAILURE;
goto finish;
}
avahi_key_unref(k);
}
/* Process responses */
for (i = (int) avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ANCOUNT) +
(int) avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_NSCOUNT) +
(int) avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ARCOUNT); i > 0; i--) {
AvahiRecord *rr;
if (!(rr = avahi_dns_packet_consume_record(p, NULL))) {
avahi_log_warn(__FILE__": Wide area response packet too short or invalid while reading response record. (Maybe a UTF-8 problem?)");
avahi_server_set_errno(e->server, AVAHI_ERR_INVALID_PACKET);
final_event = AVAHI_BROWSER_FAILURE;
goto finish;
}
add_to_cache(e, rr);
avahi_record_unref(rr);
}
finish:
if (l && !l->dead) {
if (l->callback)
l->callback(e, final_event, AVAHI_LOOKUP_RESULT_WIDE_AREA, NULL, l->userdata);
lookup_stop(l);
}
}
int avahi_send_dns_packet_ipv4(
int fd,
AvahiIfIndex interface,
AvahiDnsPacket *p,
const AvahiIPv4Address *src_address,
const AvahiIPv4Address *dst_address,
uint16_t dst_port) {
struct sockaddr_in sa;
struct msghdr msg;
struct iovec io;
#ifdef IP_PKTINFO
struct cmsghdr *cmsg;
size_t cmsg_data[( CMSG_SPACE(sizeof(struct in_pktinfo)) / sizeof(size_t)) + 1];
#elif !defined(IP_MULTICAST_IF) && defined(IP_SENDSRCADDR)
struct cmsghdr *cmsg;
size_t cmsg_data[( CMSG_SPACE(sizeof(struct in_addr)) / sizeof(size_t)) + 1];
#endif
assert(fd >= 0);
assert(p);
assert(avahi_dns_packet_check_valid(p) >= 0);
assert(!dst_address || dst_port > 0);
if (!dst_address)
mdns_mcast_group_ipv4(&sa);
else
ipv4_address_to_sockaddr(&sa, dst_address, dst_port);
memset(&io, 0, sizeof(io));
io.iov_base = AVAHI_DNS_PACKET_DATA(p);
io.iov_len = p->size;
memset(&msg, 0, sizeof(msg));
msg.msg_name = &sa;
msg.msg_namelen = sizeof(sa);
msg.msg_iov = &io;
msg.msg_iovlen = 1;
msg.msg_flags = 0;
msg.msg_control = NULL;
msg.msg_controllen = 0;
#ifdef IP_PKTINFO
if (interface > 0 || src_address) {
struct in_pktinfo *pkti;
memset(cmsg_data, 0, sizeof(cmsg_data));
msg.msg_control = cmsg_data;
msg.msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo));
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_len = msg.msg_controllen;
cmsg->cmsg_level = IPPROTO_IP;
cmsg->cmsg_type = IP_PKTINFO;
pkti = (struct in_pktinfo*) CMSG_DATA(cmsg);
if (interface > 0)
pkti->ipi_ifindex = interface;
if (src_address)
pkti->ipi_spec_dst.s_addr = src_address->address;
}
#elif defined(IP_MULTICAST_IF)
if (src_address) {
struct in_addr any = { INADDR_ANY };
if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF, src_address ? &src_address->address : &any, sizeof(struct in_addr)) < 0) {
avahi_log_warn("IP_MULTICAST_IF failed: %s", strerror(errno));
return -1;
}
}
#elif defined(IP_SENDSRCADDR)
if (src_address) {
struct in_addr *addr;
memset(cmsg_data, 0, sizeof(cmsg_data));
msg.msg_control = cmsg_data;
msg.msg_controllen = CMSG_LEN(sizeof(struct in_addr));
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_len = msg.msg_controllen;
cmsg->cmsg_level = IPPROTO_IP;
cmsg->cmsg_type = IP_SENDSRCADDR;
addr = (struct in_addr *)CMSG_DATA(cmsg);
addr->s_addr = src_address->address;
}
#elif defined(__GNUC__)
#warning "FIXME: We need some code to set the outgoing interface/local address here if IP_PKTINFO/IP_MULTICAST_IF is not available"
#endif
return sendmsg_loop(fd, &msg, 0);
}
