+++ /dev/null
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
-/***
- This file is part of systemd.
-
- Copyright 2014 Lennart Poettering
-
- systemd 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.
-
- systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#include <netinet/tcp.h>
-
-#include "missing.h"
-#include "resolved-dns-stream.h"
-
-#define DNS_STREAM_TIMEOUT_USEC (10 * USEC_PER_SEC)
-#define DNS_STREAMS_MAX 128
-
-static void dns_stream_stop(DnsStream *s) {
- assert(s);
-
- s->io_event_source = sd_event_source_unref(s->io_event_source);
- s->timeout_event_source = sd_event_source_unref(s->timeout_event_source);
- s->fd = safe_close(s->fd);
-}
-
-static int dns_stream_update_io(DnsStream *s) {
- int f = 0;
-
- assert(s);
-
- if (s->write_packet && s->n_written < sizeof(s->write_size) + s->write_packet->size)
- f |= EPOLLOUT;
- if (!s->read_packet || s->n_read < sizeof(s->read_size) + s->read_packet->size)
- f |= EPOLLIN;
-
- return sd_event_source_set_io_events(s->io_event_source, f);
-}
-
-static int dns_stream_complete(DnsStream *s, int error) {
- assert(s);
-
- dns_stream_stop(s);
-
- if (s->complete)
- s->complete(s, error);
- else
- dns_stream_free(s);
-
- return 0;
-}
-
-static int dns_stream_identify(DnsStream *s) {
- union {
- struct cmsghdr header; /* For alignment */
- uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo))
- + EXTRA_CMSG_SPACE /* kernel appears to require extra space */];
- } control;
- struct msghdr mh = {};
- struct cmsghdr *cmsg;
- socklen_t sl;
- int r;
-
- assert(s);
-
- if (s->identified)
- return 0;
-
- /* Query the local side */
- s->local_salen = sizeof(s->local);
- r = getsockname(s->fd, &s->local.sa, &s->local_salen);
- if (r < 0)
- return -errno;
- if (s->local.sa.sa_family == AF_INET6 && s->ifindex <= 0)
- s->ifindex = s->local.in6.sin6_scope_id;
-
- /* Query the remote side */
- s->peer_salen = sizeof(s->peer);
- r = getpeername(s->fd, &s->peer.sa, &s->peer_salen);
- if (r < 0)
- return -errno;
- if (s->peer.sa.sa_family == AF_INET6 && s->ifindex <= 0)
- s->ifindex = s->peer.in6.sin6_scope_id;
-
- /* Check consistency */
- assert(s->peer.sa.sa_family == s->local.sa.sa_family);
- assert(IN_SET(s->peer.sa.sa_family, AF_INET, AF_INET6));
-
- /* Query connection meta information */
- sl = sizeof(control);
- if (s->peer.sa.sa_family == AF_INET) {
- r = getsockopt(s->fd, IPPROTO_IP, IP_PKTOPTIONS, &control, &sl);
- if (r < 0)
- return -errno;
- } else if (s->peer.sa.sa_family == AF_INET6) {
-
- r = getsockopt(s->fd, IPPROTO_IPV6, IPV6_2292PKTOPTIONS, &control, &sl);
- if (r < 0)
- return -errno;
- } else
- return -EAFNOSUPPORT;
-
- mh.msg_control = &control;
- mh.msg_controllen = sl;
- for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) {
-
- if (cmsg->cmsg_level == IPPROTO_IPV6) {
- assert(s->peer.sa.sa_family == AF_INET6);
-
- switch (cmsg->cmsg_type) {
-
- case IPV6_PKTINFO: {
- struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg);
-
- if (s->ifindex <= 0)
- s->ifindex = i->ipi6_ifindex;
- break;
- }
-
- case IPV6_HOPLIMIT:
- s->ttl = *(int *) CMSG_DATA(cmsg);
- break;
- }
-
- } else if (cmsg->cmsg_level == IPPROTO_IP) {
- assert(s->peer.sa.sa_family == AF_INET);
-
- switch (cmsg->cmsg_type) {
-
- case IP_PKTINFO: {
- struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg);
-
- if (s->ifindex <= 0)
- s->ifindex = i->ipi_ifindex;
- break;
- }
-
- case IP_TTL:
- s->ttl = *(int *) CMSG_DATA(cmsg);
- break;
- }
- }
- }
-
- /* The Linux kernel sets the interface index to the loopback
- * device if the connection came from the local host since it
- * avoids the routing table in such a case. Let's unset the
- * interface index in such a case. */
- if (s->ifindex == LOOPBACK_IFINDEX)
- s->ifindex = 0;
-
- /* If we don't know the interface index still, we look for the
- * first local interface with a matching address. Yuck! */
- if (s->ifindex <= 0)
- s->ifindex = manager_find_ifindex(s->manager, s->local.sa.sa_family, s->local.sa.sa_family == AF_INET ? (union in_addr_union*) &s->local.in.sin_addr : (union in_addr_union*) &s->local.in6.sin6_addr);
-
- if (s->protocol == DNS_PROTOCOL_LLMNR && s->ifindex > 0) {
- uint32_t ifindex = htobe32(s->ifindex);
-
- /* Make sure all packets for this connection are sent on the same interface */
- if (s->local.sa.sa_family == AF_INET) {
- r = setsockopt(s->fd, IPPROTO_IP, IP_UNICAST_IF, &ifindex, sizeof(ifindex));
- if (r < 0)
- log_debug_errno(errno, "Failed to invoke IP_UNICAST_IF: %m");
- } else if (s->local.sa.sa_family == AF_INET6) {
- r = setsockopt(s->fd, IPPROTO_IPV6, IPV6_UNICAST_IF, &ifindex, sizeof(ifindex));
- if (r < 0)
- log_debug_errno(errno, "Failed to invoke IPV6_UNICAST_IF: %m");
- }
- }
-
- s->identified = true;
-
- return 0;
-}
-
-static int on_stream_timeout(sd_event_source *es, usec_t usec, void *userdata) {
- DnsStream *s = userdata;
-
- assert(s);
-
- return dns_stream_complete(s, ETIMEDOUT);
-}
-
-static int on_stream_io(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
- DnsStream *s = userdata;
- int r;
-
- assert(s);
-
- r = dns_stream_identify(s);
- if (r < 0)
- return dns_stream_complete(s, -r);
-
- if ((revents & EPOLLOUT) &&
- s->write_packet &&
- s->n_written < sizeof(s->write_size) + s->write_packet->size) {
-
- struct iovec iov[2];
- ssize_t ss;
-
- iov[0].iov_base = &s->write_size;
- iov[0].iov_len = sizeof(s->write_size);
- iov[1].iov_base = DNS_PACKET_DATA(s->write_packet);
- iov[1].iov_len = s->write_packet->size;
-
- IOVEC_INCREMENT(iov, 2, s->n_written);
-
- ss = writev(fd, iov, 2);
- if (ss < 0) {
- if (errno != EINTR && errno != EAGAIN)
- return dns_stream_complete(s, errno);
- } else
- s->n_written += ss;
-
- /* Are we done? If so, disable the event source for EPOLLOUT */
- if (s->n_written >= sizeof(s->write_size) + s->write_packet->size) {
- r = dns_stream_update_io(s);
- if (r < 0)
- return dns_stream_complete(s, -r);
- }
- }
-
- if ((revents & (EPOLLIN|EPOLLHUP|EPOLLRDHUP)) &&
- (!s->read_packet ||
- s->n_read < sizeof(s->read_size) + s->read_packet->size)) {
-
- if (s->n_read < sizeof(s->read_size)) {
- ssize_t ss;
-
- ss = read(fd, (uint8_t*) &s->read_size + s->n_read, sizeof(s->read_size) - s->n_read);
- if (ss < 0) {
- if (errno != EINTR && errno != EAGAIN)
- return dns_stream_complete(s, errno);
- } else if (ss == 0)
- return dns_stream_complete(s, ECONNRESET);
- else
- s->n_read += ss;
- }
-
- if (s->n_read >= sizeof(s->read_size)) {
-
- if (be16toh(s->read_size) < DNS_PACKET_HEADER_SIZE)
- return dns_stream_complete(s, EBADMSG);
-
- if (s->n_read < sizeof(s->read_size) + be16toh(s->read_size)) {
- ssize_t ss;
-
- if (!s->read_packet) {
- r = dns_packet_new(&s->read_packet, s->protocol, be16toh(s->read_size));
- if (r < 0)
- return dns_stream_complete(s, -r);
-
- s->read_packet->size = be16toh(s->read_size);
- s->read_packet->ipproto = IPPROTO_TCP;
- s->read_packet->family = s->peer.sa.sa_family;
- s->read_packet->ttl = s->ttl;
- s->read_packet->ifindex = s->ifindex;
-
- if (s->read_packet->family == AF_INET) {
- s->read_packet->sender.in = s->peer.in.sin_addr;
- s->read_packet->sender_port = be16toh(s->peer.in.sin_port);
- s->read_packet->destination.in = s->local.in.sin_addr;
- s->read_packet->destination_port = be16toh(s->local.in.sin_port);
- } else {
- assert(s->read_packet->family == AF_INET6);
- s->read_packet->sender.in6 = s->peer.in6.sin6_addr;
- s->read_packet->sender_port = be16toh(s->peer.in6.sin6_port);
- s->read_packet->destination.in6 = s->local.in6.sin6_addr;
- s->read_packet->destination_port = be16toh(s->local.in6.sin6_port);
-
- if (s->read_packet->ifindex == 0)
- s->read_packet->ifindex = s->peer.in6.sin6_scope_id;
- if (s->read_packet->ifindex == 0)
- s->read_packet->ifindex = s->local.in6.sin6_scope_id;
- }
- }
-
- ss = read(fd,
- (uint8_t*) DNS_PACKET_DATA(s->read_packet) + s->n_read - sizeof(s->read_size),
- sizeof(s->read_size) + be16toh(s->read_size) - s->n_read);
- if (ss < 0) {
- if (errno != EINTR && errno != EAGAIN)
- return dns_stream_complete(s, errno);
- } else if (ss == 0)
- return dns_stream_complete(s, ECONNRESET);
- else
- s->n_read += ss;
- }
-
- /* Are we done? If so, disable the event source for EPOLLIN */
- if (s->n_read >= sizeof(s->read_size) + be16toh(s->read_size)) {
- r = dns_stream_update_io(s);
- if (r < 0)
- return dns_stream_complete(s, -r);
-
- /* If there's a packet handler
- * installed, call that. Note that
- * this is optional... */
- if (s->on_packet)
- return s->on_packet(s);
- }
- }
- }
-
- if ((s->write_packet && s->n_written >= sizeof(s->write_size) + s->write_packet->size) &&
- (s->read_packet && s->n_read >= sizeof(s->read_size) + s->read_packet->size))
- return dns_stream_complete(s, 0);
-
- return 0;
-}
-
-DnsStream *dns_stream_free(DnsStream *s) {
- if (!s)
- return NULL;
-
- dns_stream_stop(s);
-
- if (s->manager) {
- LIST_REMOVE(streams, s->manager->dns_streams, s);
- s->manager->n_dns_streams--;
- }
-
- dns_packet_unref(s->write_packet);
- dns_packet_unref(s->read_packet);
-
- free(s);
-
- return 0;
-}
-
-DEFINE_TRIVIAL_CLEANUP_FUNC(DnsStream*, dns_stream_free);
-
-int dns_stream_new(Manager *m, DnsStream **ret, DnsProtocol protocol, int fd) {
- static const int one = 1;
- _cleanup_(dns_stream_freep) DnsStream *s = NULL;
- int r;
-
- assert(m);
- assert(fd >= 0);
-
- if (m->n_dns_streams > DNS_STREAMS_MAX)
- return -EBUSY;
-
- s = new0(DnsStream, 1);
- if (!s)
- return -ENOMEM;
-
- s->fd = -1;
- s->protocol = protocol;
-
- r = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one));
- if (r < 0)
- return -errno;
-
- r = sd_event_add_io(m->event, &s->io_event_source, fd, EPOLLIN, on_stream_io, s);
- if (r < 0)
- return r;
-
- r = sd_event_add_time(
- m->event,
- &s->timeout_event_source,
- clock_boottime_or_monotonic(),
- now(clock_boottime_or_monotonic()) + DNS_STREAM_TIMEOUT_USEC, 0,
- on_stream_timeout, s);
- if (r < 0)
- return r;
-
- LIST_PREPEND(streams, m->dns_streams, s);
- s->manager = m;
- s->fd = fd;
- m->n_dns_streams++;
-
- *ret = s;
- s = NULL;
-
- return 0;
-}
-
-int dns_stream_write_packet(DnsStream *s, DnsPacket *p) {
- assert(s);
-
- if (s->write_packet)
- return -EBUSY;
-
- s->write_packet = dns_packet_ref(p);
- s->write_size = htobe16(p->size);
- s->n_written = 0;
-
- return dns_stream_update_io(s);
-}
~ianmdlvl / elogind.git / blobdiff