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QtZeroConf/avahi-core/socket.c
Jonathan Bagg d91e9e5b81 updates from avahi project
2018-05-18 13:16:17 -04:00

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/***
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 <inttypes.h>
#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#ifdef HAVE_SYS_FILIO_H
#include <sys/filio.h>
#endif
#include <assert.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <sys/uio.h>
#ifdef IP_RECVIF
#include <net/if_dl.h>
#endif
#include "dns.h"
#include "fdutil.h"
#include "socket.h"
#include "log.h"
#include "addr-util.h"
/* this is a portability hack */
#ifndef IPV6_ADD_MEMBERSHIP
#ifdef IPV6_JOIN_GROUP
#define IPV6_ADD_MEMBERSHIP IPV6_JOIN_GROUP
#endif
#endif
#ifndef IPV6_DROP_MEMBERSHIP
#ifdef IPV6_LEAVE_GROUP
#define IPV6_DROP_MEMBERSHIP IPV6_LEAVE_GROUP
#endif
#endif
static void mdns_mcast_group_ipv4(struct sockaddr_in *ret_sa) {
assert(ret_sa);
memset(ret_sa, 0, sizeof(struct sockaddr_in));
ret_sa->sin_family = AF_INET;
ret_sa->sin_port = htons(AVAHI_MDNS_PORT);
inet_pton(AF_INET, AVAHI_IPV4_MCAST_GROUP, &ret_sa->sin_addr);
}
static void mdns_mcast_group_ipv6(struct sockaddr_in6 *ret_sa) {
assert(ret_sa);
memset(ret_sa, 0, sizeof(struct sockaddr_in6));
ret_sa->sin6_family = AF_INET6;
ret_sa->sin6_port = htons(AVAHI_MDNS_PORT);
inet_pton(AF_INET6, AVAHI_IPV6_MCAST_GROUP, &ret_sa->sin6_addr);
}
static void ipv4_address_to_sockaddr(struct sockaddr_in *ret_sa, const AvahiIPv4Address *a, uint16_t port) {
assert(ret_sa);
assert(a);
assert(port > 0);
memset(ret_sa, 0, sizeof(struct sockaddr_in));
ret_sa->sin_family = AF_INET;
ret_sa->sin_port = htons(port);
memcpy(&ret_sa->sin_addr, a, sizeof(AvahiIPv4Address));
}
static void ipv6_address_to_sockaddr(struct sockaddr_in6 *ret_sa, const AvahiIPv6Address *a, uint16_t port) {
assert(ret_sa);
assert(a);
assert(port > 0);
memset(ret_sa, 0, sizeof(struct sockaddr_in6));
ret_sa->sin6_family = AF_INET6;
ret_sa->sin6_port = htons(port);
memcpy(&ret_sa->sin6_addr, a, sizeof(AvahiIPv6Address));
}
int avahi_mdns_mcast_join_ipv4(int fd, const AvahiIPv4Address *a, int idx, int join) {
#ifdef HAVE_STRUCT_IP_MREQN
struct ip_mreqn mreq;
#else
struct ip_mreq mreq;
#endif
struct sockaddr_in sa;
assert(fd >= 0);
assert(idx >= 0);
assert(a);
memset(&mreq, 0, sizeof(mreq));
#ifdef HAVE_STRUCT_IP_MREQN
mreq.imr_ifindex = idx;
mreq.imr_address.s_addr = a->address;
#else
mreq.imr_interface.s_addr = a->address;
#endif
mdns_mcast_group_ipv4(&sa);
mreq.imr_multiaddr = sa.sin_addr;
/* Some network drivers have issues with dropping membership of
* mcast groups when the iface is down, but don't allow rejoining
* when it comes back up. This is an ugly workaround */
if (join)
setsockopt(fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq));
if (setsockopt(fd, IPPROTO_IP, join ? IP_ADD_MEMBERSHIP : IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
avahi_log_warn("%s failed: %s", join ? "IP_ADD_MEMBERSHIP" : "IP_DROP_MEMBERSHIP", strerror(errno));
return -1;
}
return 0;
}
int avahi_mdns_mcast_join_ipv6(int fd, const AvahiIPv6Address *a, int idx, int join) {
struct ipv6_mreq mreq6;
struct sockaddr_in6 sa6;
assert(fd >= 0);
assert(idx >= 0);
assert(a);
memset(&mreq6, 0, sizeof(mreq6));
mdns_mcast_group_ipv6 (&sa6);
mreq6.ipv6mr_multiaddr = sa6.sin6_addr;
mreq6.ipv6mr_interface = idx;
if (join)
setsockopt(fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6));
if (setsockopt(fd, IPPROTO_IPV6, join ? IPV6_ADD_MEMBERSHIP : IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) {
avahi_log_warn("%s failed: %s", join ? "IPV6_ADD_MEMBERSHIP" : "IPV6_DROP_MEMBERSHIP", strerror(errno));
return -1;
}
return 0;
}
static int reuseaddr(int fd) {
int yes;
yes = 1;
if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
avahi_log_warn("SO_REUSEADDR failed: %s", strerror(errno));
return -1;
}
#ifdef SO_REUSEPORT
yes = 1;
if (setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &yes, sizeof(yes)) < 0) {
avahi_log_warn("SO_REUSEPORT failed: %s", strerror(errno));
if (errno != ENOPROTOOPT)
return -1;
}
#endif
return 0;
}
static int bind_with_warn(int fd, const struct sockaddr *sa, socklen_t l) {
assert(fd >= 0);
assert(sa);
assert(l > 0);
if (bind(fd, sa, l) < 0) {
if (errno != EADDRINUSE) {
avahi_log_warn("bind() failed: %s", strerror(errno));
return -1;
}
avahi_log_warn("*** WARNING: Detected another %s mDNS stack running on this host. This makes mDNS unreliable and is thus not recommended. ***",
sa->sa_family == AF_INET ? "IPv4" : "IPv6");
/* Try again, this time with SO_REUSEADDR set */
if (reuseaddr(fd) < 0)
return -1;
if (bind(fd, sa, l) < 0) {
avahi_log_warn("bind() failed: %s", strerror(errno));
return -1;
}
} else {
/* We enable SO_REUSEADDR afterwards, to make sure that the
* user may run other mDNS implementations if he really
* wants. */
if (reuseaddr(fd) < 0)
return -1;
}
return 0;
}
static int ipv4_pktinfo(int fd) {
int yes;
#ifdef IP_PKTINFO
yes = 1;
if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &yes, sizeof(yes)) < 0) {
avahi_log_warn("IP_PKTINFO failed: %s", strerror(errno));
return -1;
}
#else
#ifdef IP_RECVINTERFACE
yes = 1;
if (setsockopt (fd, IPPROTO_IP, IP_RECVINTERFACE, &yes, sizeof(yes)) < 0) {
avahi_log_warn("IP_RECVINTERFACE failed: %s", strerror(errno));
return -1;
}
#elif defined(IP_RECVIF)
yes = 1;
if (setsockopt (fd, IPPROTO_IP, IP_RECVIF, &yes, sizeof(yes)) < 0) {
avahi_log_warn("IP_RECVIF failed: %s", strerror(errno));
return -1;
}
#endif
#ifdef IP_RECVDSTADDR
yes = 1;
if (setsockopt (fd, IPPROTO_IP, IP_RECVDSTADDR, &yes, sizeof(yes)) < 0) {
avahi_log_warn("IP_RECVDSTADDR failed: %s", strerror(errno));
return -1;
}
#endif
#endif /* IP_PKTINFO */
#ifdef IP_RECVTTL
yes = 1;
if (setsockopt(fd, IPPROTO_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0) {
avahi_log_warn("IP_RECVTTL failed: %s", strerror(errno));
return -1;
}
#endif
return 0;
}
static int ipv6_pktinfo(int fd) {
int yes;
#ifdef IPV6_RECVPKTINFO
yes = 1;
if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &yes, sizeof(yes)) < 0) {
avahi_log_warn("IPV6_RECVPKTINFO failed: %s", strerror(errno));
return -1;
}
#elif defined(IPV6_PKTINFO)
yes = 1;
if (setsockopt(fd, IPPROTO_IPV6, IPV6_PKTINFO, &yes, sizeof(yes)) < 0) {
avahi_log_warn("IPV6_PKTINFO failed: %s", strerror(errno));
return -1;
}
#endif
#ifdef IPV6_RECVHOPS
yes = 1;
if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVHOPS, &yes, sizeof(yes)) < 0) {
avahi_log_warn("IPV6_RECVHOPS failed: %s", strerror(errno));
return -1;
}
#elif defined(IPV6_RECVHOPLIMIT)
yes = 1;
if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &yes, sizeof(yes)) < 0) {
avahi_log_warn("IPV6_RECVHOPLIMIT failed: %s", strerror(errno));
return -1;
}
#elif defined(IPV6_HOPLIMIT)
yes = 1;
if (setsockopt(fd, IPPROTO_IPV6, IPV6_HOPLIMIT, &yes, sizeof(yes)) < 0) {
avahi_log_warn("IPV6_HOPLIMIT failed: %s", strerror(errno));
return -1;
}
#endif
return 0;
}
int avahi_open_socket_ipv4(int no_reuse) {
struct sockaddr_in local;
int fd = -1, r, ittl;
uint8_t ttl, cyes;
if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
avahi_log_warn("socket() failed: %s", strerror(errno));
goto fail;
}
ttl = 255;
if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0) {
avahi_log_warn("IP_MULTICAST_TTL failed: %s", strerror(errno));
goto fail;
}
ittl = 255;
if (setsockopt(fd, IPPROTO_IP, IP_TTL, &ittl, sizeof(ittl)) < 0) {
avahi_log_warn("IP_TTL failed: %s", strerror(errno));
goto fail;
}
cyes = 1;
if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &cyes, sizeof(cyes)) < 0) {
avahi_log_warn("IP_MULTICAST_LOOP failed: %s", strerror(errno));
goto fail;
}
memset(&local, 0, sizeof(local));
local.sin_family = AF_INET;
local.sin_port = htons(AVAHI_MDNS_PORT);
if (no_reuse)
r = bind(fd, (struct sockaddr*) &local, sizeof(local));
else
r = bind_with_warn(fd, (struct sockaddr*) &local, sizeof(local));
if (r < 0)
goto fail;
if (ipv4_pktinfo (fd) < 0)
goto fail;
if (avahi_set_cloexec(fd) < 0) {
avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
goto fail;
}
if (avahi_set_nonblock(fd) < 0) {
avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));
goto fail;
}
return fd;
fail:
if (fd >= 0)
close(fd);
return -1;
}
int avahi_open_socket_ipv6(int no_reuse) {
struct sockaddr_in6 sa, local;
int fd = -1, yes, r;
int ttl;
mdns_mcast_group_ipv6(&sa);
if ((fd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
avahi_log_warn("socket() failed: %s", strerror(errno));
goto fail;
}
ttl = 255;
if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0) {
avahi_log_warn("IPV6_MULTICAST_HOPS failed: %s", strerror(errno));
goto fail;
}
ttl = 255;
if (setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)) < 0) {
avahi_log_warn("IPV6_UNICAST_HOPS failed: %s", strerror(errno));
goto fail;
}
yes = 1;
if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &yes, sizeof(yes)) < 0) {
avahi_log_warn("IPV6_V6ONLY failed: %s", strerror(errno));
goto fail;
}
yes = 1;
if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) {
avahi_log_warn("IPV6_MULTICAST_LOOP failed: %s", strerror(errno));
goto fail;
}
memset(&local, 0, sizeof(local));
local.sin6_family = AF_INET6;
local.sin6_port = htons(AVAHI_MDNS_PORT);
if (no_reuse)
r = bind(fd, (struct sockaddr*) &local, sizeof(local));
else
r = bind_with_warn(fd, (struct sockaddr*) &local, sizeof(local));
if (r < 0)
goto fail;
if (ipv6_pktinfo(fd) < 0)
goto fail;
if (avahi_set_cloexec(fd) < 0) {
avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
goto fail;
}
if (avahi_set_nonblock(fd) < 0) {
avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));
goto fail;
}
return fd;
fail:
if (fd >= 0)
close(fd);
return -1;
}
static int sendmsg_loop(int fd, struct msghdr *msg, int flags) {
assert(fd >= 0);
assert(msg);
for (;;) {
if (sendmsg(fd, msg, flags) >= 0)
break;
if (errno == EINTR)
continue;
if (errno != EAGAIN) {
char where[64];
struct sockaddr_in *sin = msg->msg_name;
inet_ntop(sin->sin_family, &sin->sin_addr, where, sizeof(where));
avahi_log_debug("sendmsg() to %s failed: %s", where, strerror(errno));
return -1;
}
if (avahi_wait_for_write(fd) < 0)
return -1;
}
return 0;
}
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);
}
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);
}
AvahiDnsPacket *avahi_recv_dns_packet_ipv4(
int fd,
AvahiIPv4Address *ret_src_address,
uint16_t *ret_src_port,
AvahiIPv4Address *ret_dst_address,
AvahiIfIndex *ret_iface,
uint8_t *ret_ttl) {
AvahiDnsPacket *p= NULL;
struct msghdr msg;
struct iovec io;
size_t aux[1024 / sizeof(size_t)]; /* for alignment on ia64 ! */
ssize_t l;
struct cmsghdr *cmsg;
int found_addr = 0;
int ms;
struct sockaddr_in sa;
assert(fd >= 0);
if (ioctl(fd, FIONREAD, &ms) < 0) {
avahi_log_warn("ioctl(): %s", strerror(errno));
goto fail;
}
if (ms < 0) {
avahi_log_warn("FIONREAD returned negative value.");
goto fail;
}
p = avahi_dns_packet_new(ms + AVAHI_DNS_PACKET_EXTRA_SIZE);
io.iov_base = AVAHI_DNS_PACKET_DATA(p);
io.iov_len = p->max_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_control = aux;
msg.msg_controllen = sizeof(aux);
msg.msg_flags = 0;
if ((l = recvmsg(fd, &msg, 0)) < 0) {
/* Linux returns EAGAIN when an invalid IP packet has been
received. We suppress warnings in this case because this might
create quite a bit of log traffic on machines with unstable
links. (See #60) */
if (errno != EAGAIN)
avahi_log_warn("recvmsg(): %s", strerror(errno));
goto fail;
}
/* For corrupt packets FIONREAD returns zero size (See rhbz #607297). So
* fail after having read them. */
if (!ms)
goto fail;
if (sa.sin_addr.s_addr == INADDR_ANY)
/* Linux 2.4 behaves very strangely sometimes! */
goto fail;
assert(!(msg.msg_flags & MSG_CTRUNC));
assert(!(msg.msg_flags & MSG_TRUNC));
p->size = (size_t) l;
if (ret_src_port)
*ret_src_port = avahi_port_from_sockaddr((struct sockaddr*) &sa);
if (ret_src_address) {
AvahiAddress a;
avahi_address_from_sockaddr((struct sockaddr*) &sa, &a);
*ret_src_address = a.data.ipv4;
}
if (ret_ttl)
*ret_ttl = 255;
if (ret_iface)
*ret_iface = AVAHI_IF_UNSPEC;
for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
if (cmsg->cmsg_level == IPPROTO_IP) {
switch (cmsg->cmsg_type) {
#ifdef IP_RECVTTL
case IP_RECVTTL:
#endif
case IP_TTL:
if (ret_ttl)
*ret_ttl = (uint8_t) (*(int *) CMSG_DATA(cmsg));
break;
#ifdef IP_PKTINFO
case IP_PKTINFO: {
struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg);
if (ret_iface && i->ipi_ifindex > 0)
*ret_iface = (int) i->ipi_ifindex;
if (ret_dst_address)
ret_dst_address->address = i->ipi_addr.s_addr;
found_addr = 1;
break;
}
#endif
#ifdef IP_RECVIF
case IP_RECVIF: {
struct sockaddr_dl *sdl = (struct sockaddr_dl *) CMSG_DATA (cmsg);
if (ret_iface) {
#ifdef __sun
if (*(uint_t*) sdl > 0)
*ret_iface = *(uint_t*) sdl;
#else
if (sdl->sdl_index > 0)
*ret_iface = (int) sdl->sdl_index;
#endif
}
break;
}
#endif
#ifdef IP_RECVDSTADDR
case IP_RECVDSTADDR:
if (ret_dst_address)
memcpy(&ret_dst_address->address, CMSG_DATA (cmsg), 4);
found_addr = 1;
break;
#endif
default:
avahi_log_warn("Unhandled cmsg_type: %d", cmsg->cmsg_type);
break;
}
}
}
assert(found_addr);
return p;
fail:
if (p)
avahi_dns_packet_free(p);
return NULL;
}
AvahiDnsPacket *avahi_recv_dns_packet_ipv6(
int fd,
AvahiIPv6Address *ret_src_address,
uint16_t *ret_src_port,
AvahiIPv6Address *ret_dst_address,
AvahiIfIndex *ret_iface,
uint8_t *ret_ttl) {
AvahiDnsPacket *p = NULL;
struct msghdr msg;
struct iovec io;
size_t aux[1024 / sizeof(size_t)];
ssize_t l;
int ms;
struct cmsghdr *cmsg;
int found_ttl = 0, found_iface = 0;
struct sockaddr_in6 sa;
assert(fd >= 0);
if (ioctl(fd, FIONREAD, &ms) < 0) {
avahi_log_warn("ioctl(): %s", strerror(errno));
goto fail;
}
if (ms < 0) {
avahi_log_warn("FIONREAD returned negative value.");
goto fail;
}
p = avahi_dns_packet_new(ms + AVAHI_DNS_PACKET_EXTRA_SIZE);
io.iov_base = AVAHI_DNS_PACKET_DATA(p);
io.iov_len = p->max_size;
memset(&msg, 0, sizeof(msg));
msg.msg_name = (struct sockaddr*) &sa;
msg.msg_namelen = sizeof(sa);
msg.msg_iov = &io;
msg.msg_iovlen = 1;
msg.msg_control = aux;
msg.msg_controllen = sizeof(aux);
msg.msg_flags = 0;
if ((l = recvmsg(fd, &msg, 0)) < 0) {
/* Linux returns EAGAIN when an invalid IP packet has been
received. We suppress warnings in this case because this might
create quite a bit of log traffic on machines with unstable
links. (See #60) */
if (errno != EAGAIN)
avahi_log_warn("recvmsg(): %s", strerror(errno));
goto fail;
}
/* For corrupt packets FIONREAD returns zero size (See rhbz #607297). So
* fail after having read them. */
if (!ms)
goto fail;
assert(!(msg.msg_flags & MSG_CTRUNC));
assert(!(msg.msg_flags & MSG_TRUNC));
p->size = (size_t) l;
if (ret_src_port)
*ret_src_port = avahi_port_from_sockaddr((struct sockaddr*) &sa);
if (ret_src_address) {
AvahiAddress a;
avahi_address_from_sockaddr((struct sockaddr*) &sa, &a);
*ret_src_address = a.data.ipv6;
}
for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
if (cmsg->cmsg_level == IPPROTO_IPV6) {
switch (cmsg->cmsg_type) {
case IPV6_HOPLIMIT:
if (ret_ttl)
*ret_ttl = (uint8_t) (*(int *) CMSG_DATA(cmsg));
found_ttl = 1;
break;
case IPV6_PKTINFO: {
struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg);
if (ret_iface && i->ipi6_ifindex > 0)
*ret_iface = i->ipi6_ifindex;
if (ret_dst_address)
memcpy(ret_dst_address->address, i->ipi6_addr.s6_addr, 16);
found_iface = 1;
break;
}
default:
avahi_log_warn("Unhandled cmsg_type: %d", cmsg->cmsg_type);
break;
}
}
}
assert(found_iface);
assert(found_ttl);
return p;
fail:
if (p)
avahi_dns_packet_free(p);
return NULL;
}
int avahi_open_unicast_socket_ipv4(void) {
struct sockaddr_in local;
int fd = -1;
if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
avahi_log_warn("socket() failed: %s", strerror(errno));
goto fail;
}
memset(&local, 0, sizeof(local));
local.sin_family = AF_INET;
if (bind(fd, (struct sockaddr*) &local, sizeof(local)) < 0) {
avahi_log_warn("bind() failed: %s", strerror(errno));
goto fail;
}
if (ipv4_pktinfo(fd) < 0) {
goto fail;
}
if (avahi_set_cloexec(fd) < 0) {
avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
goto fail;
}
if (avahi_set_nonblock(fd) < 0) {
avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));
goto fail;
}
return fd;
fail:
if (fd >= 0)
close(fd);
return -1;
}
int avahi_open_unicast_socket_ipv6(void) {
struct sockaddr_in6 local;
int fd = -1, yes;
if ((fd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
avahi_log_warn("socket() failed: %s", strerror(errno));
goto fail;
}
yes = 1;
if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &yes, sizeof(yes)) < 0) {
avahi_log_warn("IPV6_V6ONLY failed: %s", strerror(errno));
goto fail;
}
memset(&local, 0, sizeof(local));
local.sin6_family = AF_INET6;
if (bind(fd, (struct sockaddr*) &local, sizeof(local)) < 0) {
avahi_log_warn("bind() failed: %s", strerror(errno));
goto fail;
}
if (ipv6_pktinfo(fd) < 0)
goto fail;
if (avahi_set_cloexec(fd) < 0) {
avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
goto fail;
}
if (avahi_set_nonblock(fd) < 0) {
avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));
goto fail;
}
return fd;
fail:
if (fd >= 0)
close(fd);
return -1;
}
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