[thirdparty/systemd.git] / src / resolve / resolved-dns-stream.c

/***
  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 "alloc-util.h"
#include "fd-util.h"
#include "io-util.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 /* the default action if no completion function is set is to close the stream */
                dns_stream_unref(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;

        CMSG_FOREACH(cmsg, &mh) {

                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_unref(DnsStream *s) {
        if (!s)
                return NULL;

        assert(s->n_ref > 0);
        s->n_ref--;

        if (s->n_ref > 0)
                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);

        return mfree(s);
}

DEFINE_TRIVIAL_CLEANUP_FUNC(DnsStream*, dns_stream_unref);

DnsStream *dns_stream_ref(DnsStream *s) {
        if (!s)
                return NULL;

        assert(s->n_ref > 0);
        s->n_ref++;

        return s;
}

int dns_stream_new(Manager *m, DnsStream **ret, DnsProtocol protocol, int fd) {
        _cleanup_(dns_stream_unrefp) 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->n_ref = 1;
        s->fd = -1;
        s->protocol = protocol;

        r = sd_event_add_io(m->event, &s->io_event_source, fd, EPOLLIN, on_stream_io, s);
        if (r < 0)
                return r;

        (void) sd_event_source_set_description(s->io_event_source, "dns-stream-io");

        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;

        (void) sd_event_source_set_description(s->timeout_event_source, "dns-stream-timeout");

        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);
}
Commit	Line	Data
623a4c97 LP	1	/***
	2	This file is part of systemd.
	3
	4	Copyright 2014 Lennart Poettering
	5
	6	systemd is free software; you can redistribute it and/or modify it
	7	under the terms of the GNU Lesser General Public License as published by
	8	the Free Software Foundation; either version 2.1 of the License, or
	9	(at your option) any later version.
	10
	11	systemd is distributed in the hope that it will be useful, but
	12	WITHOUT ANY WARRANTY; without even the implied warranty of
	13	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	14	Lesser General Public License for more details.
	15
	16	You should have received a copy of the GNU Lesser General Public License
	17	along with systemd; If not, see <http://www.gnu.org/licenses/>.
	18	***/
	19
	20	#include <netinet/tcp.h>
	21
b5efdb8a	22	#include "alloc-util.h"
3ffd4af2	23	#include "fd-util.h"
afc5dbf3	24	#include "io-util.h"
623a4c97 LP	25	#include "missing.h"
	26	#include "resolved-dns-stream.h"
	27
	28	#define DNS_STREAM_TIMEOUT_USEC (10 * USEC_PER_SEC)
	29	#define DNS_STREAMS_MAX 128
	30
	31	static void dns_stream_stop(DnsStream *s) {
	32	assert(s);
	33
	34	s->io_event_source = sd_event_source_unref(s->io_event_source);
	35	s->timeout_event_source = sd_event_source_unref(s->timeout_event_source);
	36	s->fd = safe_close(s->fd);
	37	}
	38
	39	static int dns_stream_update_io(DnsStream *s) {
	40	int f = 0;
	41
	42	assert(s);
	43
	44	if (s->write_packet && s->n_written < sizeof(s->write_size) + s->write_packet->size)
	45	f \|= EPOLLOUT;
	46	if (!s->read_packet \|\| s->n_read < sizeof(s->read_size) + s->read_packet->size)
	47	f \|= EPOLLIN;
	48
	49	return sd_event_source_set_io_events(s->io_event_source, f);
	50	}
	51
b914e211	52	static int dns_stream_complete(DnsStream *s, int error) {
623a4c97 LP	53	assert(s);
	54
	55	dns_stream_stop(s);
	56
	57	if (s->complete)
	58	s->complete(s, error);
b30bf55d LP	59	else /* the default action if no completion function is set is to close the stream */
b30bf55d LP	60	dns_stream_unref(s);
623a4c97 LP	61
	62	return 0;
	63	}
	64
b914e211 LP	65	static int dns_stream_identify(DnsStream *s) {
	66	union {
	67	struct cmsghdr header; /* For alignment */
40a1eebd	68	uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo))
b914e211 LP	69	+ EXTRA_CMSG_SPACE /* kernel appears to require extra space */];
	70	} control;
	71	struct msghdr mh = {};
	72	struct cmsghdr *cmsg;
	73	socklen_t sl;
	74	int r;
	75
	76	assert(s);
	77
	78	if (s->identified)
	79	return 0;
	80
	81	/* Query the local side */
	82	s->local_salen = sizeof(s->local);
	83	r = getsockname(s->fd, &s->local.sa, &s->local_salen);
	84	if (r < 0)
	85	return -errno;
	86	if (s->local.sa.sa_family == AF_INET6 && s->ifindex <= 0)
	87	s->ifindex = s->local.in6.sin6_scope_id;
	88
	89	/* Query the remote side */
	90	s->peer_salen = sizeof(s->peer);
	91	r = getpeername(s->fd, &s->peer.sa, &s->peer_salen);
	92	if (r < 0)
	93	return -errno;
	94	if (s->peer.sa.sa_family == AF_INET6 && s->ifindex <= 0)
	95	s->ifindex = s->peer.in6.sin6_scope_id;
	96
	97	/* Check consistency */
	98	assert(s->peer.sa.sa_family == s->local.sa.sa_family);
	99	assert(IN_SET(s->peer.sa.sa_family, AF_INET, AF_INET6));
	100
	101	/* Query connection meta information */
	102	sl = sizeof(control);
	103	if (s->peer.sa.sa_family == AF_INET) {
	104	r = getsockopt(s->fd, IPPROTO_IP, IP_PKTOPTIONS, &control, &sl);
	105	if (r < 0)
	106	return -errno;
	107	} else if (s->peer.sa.sa_family == AF_INET6) {
	108
	109	r = getsockopt(s->fd, IPPROTO_IPV6, IPV6_2292PKTOPTIONS, &control, &sl);
	110	if (r < 0)
	111	return -errno;
	112	} else
	113	return -EAFNOSUPPORT;
	114
	115	mh.msg_control = &control;
	116	mh.msg_controllen = sl;
2a1288ff LP	117
2a1288ff LP	118	CMSG_FOREACH(cmsg, &mh) {
b914e211 LP	119
	120	if (cmsg->cmsg_level == IPPROTO_IPV6) {
	121	assert(s->peer.sa.sa_family == AF_INET6);
	122
	123	switch (cmsg->cmsg_type) {
	124
	125	case IPV6_PKTINFO: {
	126	struct in6_pktinfo i = (struct in6_pktinfo) CMSG_DATA(cmsg);
	127
	128	if (s->ifindex <= 0)
	129	s->ifindex = i->ipi6_ifindex;
	130	break;
	131	}
	132
	133	case IPV6_HOPLIMIT:
	134	s->ttl = (int ) CMSG_DATA(cmsg);
	135	break;
	136	}
	137
	138	} else if (cmsg->cmsg_level == IPPROTO_IP) {
	139	assert(s->peer.sa.sa_family == AF_INET);
	140
	141	switch (cmsg->cmsg_type) {
	142
	143	case IP_PKTINFO: {
	144	struct in_pktinfo i = (struct in_pktinfo) CMSG_DATA(cmsg);
	145
	146	if (s->ifindex <= 0)
	147	s->ifindex = i->ipi_ifindex;
	148	break;
	149	}
	150
	151	case IP_TTL:
	152	s->ttl = (int ) CMSG_DATA(cmsg);
	153	break;
	154	}
	155	}
	156	}
	157
	158	/* The Linux kernel sets the interface index to the loopback
	159	* device if the connection came from the local host since it
	160	* avoids the routing table in such a case. Let's unset the
	161	* interface index in such a case. */
a5f03596	162	if (s->ifindex == LOOPBACK_IFINDEX)
b914e211 LP	163	s->ifindex = 0;
	164
	165	/* If we don't know the interface index still, we look for the
	166	* first local interface with a matching address. Yuck! */
	167	if (s->ifindex <= 0)
	168	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);
	169
	170	if (s->protocol == DNS_PROTOCOL_LLMNR && s->ifindex > 0) {
	171	uint32_t ifindex = htobe32(s->ifindex);
	172
	173	/* Make sure all packets for this connection are sent on the same interface */
	174	if (s->local.sa.sa_family == AF_INET) {
	175	r = setsockopt(s->fd, IPPROTO_IP, IP_UNICAST_IF, &ifindex, sizeof(ifindex));
	176	if (r < 0)
56f64d95	177	log_debug_errno(errno, "Failed to invoke IP_UNICAST_IF: %m");
b914e211 LP	178	} else if (s->local.sa.sa_family == AF_INET6) {
	179	r = setsockopt(s->fd, IPPROTO_IPV6, IPV6_UNICAST_IF, &ifindex, sizeof(ifindex));
	180	if (r < 0)
56f64d95	181	log_debug_errno(errno, "Failed to invoke IPV6_UNICAST_IF: %m");
b914e211 LP	182	}
	183	}
	184
	185	s->identified = true;
	186
	187	return 0;
	188	}
	189
623a4c97 LP	190	static int on_stream_timeout(sd_event_source es, usec_t usec, void userdata) {
	191	DnsStream *s = userdata;
	192
	193	assert(s);
	194
b914e211	195	return dns_stream_complete(s, ETIMEDOUT);
623a4c97 LP	196	}
	197
	198	static int on_stream_io(sd_event_source es, int fd, uint32_t revents, void userdata) {
	199	DnsStream *s = userdata;
	200	int r;
	201
	202	assert(s);
	203
b914e211 LP	204	r = dns_stream_identify(s);
	205	if (r < 0)
	206	return dns_stream_complete(s, -r);
	207
623a4c97 LP	208	if ((revents & EPOLLOUT) &&
	209	s->write_packet &&
	210	s->n_written < sizeof(s->write_size) + s->write_packet->size) {
	211
	212	struct iovec iov[2];
	213	ssize_t ss;
	214
	215	iov[0].iov_base = &s->write_size;
	216	iov[0].iov_len = sizeof(s->write_size);
	217	iov[1].iov_base = DNS_PACKET_DATA(s->write_packet);
	218	iov[1].iov_len = s->write_packet->size;
	219
	220	IOVEC_INCREMENT(iov, 2, s->n_written);
	221
	222	ss = writev(fd, iov, 2);
	223	if (ss < 0) {
	224	if (errno != EINTR && errno != EAGAIN)
b914e211	225	return dns_stream_complete(s, errno);
623a4c97 LP	226	} else
	227	s->n_written += ss;
	228
	229	/* Are we done? If so, disable the event source for EPOLLOUT */
	230	if (s->n_written >= sizeof(s->write_size) + s->write_packet->size) {
	231	r = dns_stream_update_io(s);
	232	if (r < 0)
b914e211	233	return dns_stream_complete(s, -r);
623a4c97 LP	234	}
	235	}
	236
	237	if ((revents & (EPOLLIN\|EPOLLHUP\|EPOLLRDHUP)) &&
	238	(!s->read_packet \|\|
	239	s->n_read < sizeof(s->read_size) + s->read_packet->size)) {
	240
	241	if (s->n_read < sizeof(s->read_size)) {
	242	ssize_t ss;
	243
	244	ss = read(fd, (uint8_t*) &s->read_size + s->n_read, sizeof(s->read_size) - s->n_read);
	245	if (ss < 0) {
	246	if (errno != EINTR && errno != EAGAIN)
b914e211	247	return dns_stream_complete(s, errno);
623a4c97	248	} else if (ss == 0)
b914e211	249	return dns_stream_complete(s, ECONNRESET);
623a4c97 LP	250	else
	251	s->n_read += ss;
	252	}
	253
	254	if (s->n_read >= sizeof(s->read_size)) {
	255
	256	if (be16toh(s->read_size) < DNS_PACKET_HEADER_SIZE)
b914e211	257	return dns_stream_complete(s, EBADMSG);
623a4c97 LP	258
	259	if (s->n_read < sizeof(s->read_size) + be16toh(s->read_size)) {
	260	ssize_t ss;
	261
	262	if (!s->read_packet) {
	263	r = dns_packet_new(&s->read_packet, s->protocol, be16toh(s->read_size));
	264	if (r < 0)
b914e211	265	return dns_stream_complete(s, -r);
623a4c97 LP	266
	267	s->read_packet->size = be16toh(s->read_size);
	268	s->read_packet->ipproto = IPPROTO_TCP;
	269	s->read_packet->family = s->peer.sa.sa_family;
	270	s->read_packet->ttl = s->ttl;
	271	s->read_packet->ifindex = s->ifindex;
	272
	273	if (s->read_packet->family == AF_INET) {
	274	s->read_packet->sender.in = s->peer.in.sin_addr;
	275	s->read_packet->sender_port = be16toh(s->peer.in.sin_port);
	276	s->read_packet->destination.in = s->local.in.sin_addr;
	277	s->read_packet->destination_port = be16toh(s->local.in.sin_port);
	278	} else {
	279	assert(s->read_packet->family == AF_INET6);
	280	s->read_packet->sender.in6 = s->peer.in6.sin6_addr;
	281	s->read_packet->sender_port = be16toh(s->peer.in6.sin6_port);
	282	s->read_packet->destination.in6 = s->local.in6.sin6_addr;
	283	s->read_packet->destination_port = be16toh(s->local.in6.sin6_port);
	284
	285	if (s->read_packet->ifindex == 0)
	286	s->read_packet->ifindex = s->peer.in6.sin6_scope_id;
	287	if (s->read_packet->ifindex == 0)
	288	s->read_packet->ifindex = s->local.in6.sin6_scope_id;
	289	}
	290	}
	291
	292	ss = read(fd,
	293	(uint8_t*) DNS_PACKET_DATA(s->read_packet) + s->n_read - sizeof(s->read_size),
	294	sizeof(s->read_size) + be16toh(s->read_size) - s->n_read);
	295	if (ss < 0) {
	296	if (errno != EINTR && errno != EAGAIN)
b914e211	297	return dns_stream_complete(s, errno);
623a4c97	298	} else if (ss == 0)
b914e211	299	return dns_stream_complete(s, ECONNRESET);
623a4c97 LP	300	else
	301	s->n_read += ss;
	302	}
	303
	304	/* Are we done? If so, disable the event source for EPOLLIN */
	305	if (s->n_read >= sizeof(s->read_size) + be16toh(s->read_size)) {
	306	r = dns_stream_update_io(s);
	307	if (r < 0)
b914e211	308	return dns_stream_complete(s, -r);
623a4c97 LP	309
	310	/* If there's a packet handler
	311	* installed, call that. Note that
	312	* this is optional... */
	313	if (s->on_packet)
	314	return s->on_packet(s);
	315	}
	316	}
	317	}
	318
	319	if ((s->write_packet && s->n_written >= sizeof(s->write_size) + s->write_packet->size) &&
	320	(s->read_packet && s->n_read >= sizeof(s->read_size) + s->read_packet->size))
b914e211	321	return dns_stream_complete(s, 0);
623a4c97 LP	322
	323	return 0;
	324	}
	325
b30bf55d	326	DnsStream dns_stream_unref(DnsStream s) {
623a4c97 LP	327	if (!s)
	328	return NULL;
	329
b30bf55d LP	330	assert(s->n_ref > 0);
	331	s->n_ref--;
	332
	333	if (s->n_ref > 0)
	334	return NULL;
	335
623a4c97 LP	336	dns_stream_stop(s);
	337
	338	if (s->manager) {
	339	LIST_REMOVE(streams, s->manager->dns_streams, s);
	340	s->manager->n_dns_streams--;
	341	}
	342
	343	dns_packet_unref(s->write_packet);
	344	dns_packet_unref(s->read_packet);
	345
6b430fdb	346	return mfree(s);
623a4c97 LP	347	}
623a4c97 LP	348
b30bf55d LP	349	DEFINE_TRIVIAL_CLEANUP_FUNC(DnsStream*, dns_stream_unref);
	350
	351	DnsStream dns_stream_ref(DnsStream s) {
	352	if (!s)
	353	return NULL;
	354
	355	assert(s->n_ref > 0);
	356	s->n_ref++;
	357
	358	return s;
	359	}
623a4c97 LP	360
623a4c97 LP	361	int dns_stream_new(Manager m, DnsStream *ret, DnsProtocol protocol, int fd) {
b30bf55d	362	_cleanup_(dns_stream_unrefp) DnsStream *s = NULL;
623a4c97 LP	363	int r;
	364
	365	assert(m);
	366	assert(fd >= 0);
	367
	368	if (m->n_dns_streams > DNS_STREAMS_MAX)
	369	return -EBUSY;
	370
	371	s = new0(DnsStream, 1);
	372	if (!s)
	373	return -ENOMEM;
	374
b30bf55d	375	s->n_ref = 1;
623a4c97 LP	376	s->fd = -1;
	377	s->protocol = protocol;
	378
623a4c97 LP	379	r = sd_event_add_io(m->event, &s->io_event_source, fd, EPOLLIN, on_stream_io, s);
	380	if (r < 0)
	381	return r;
	382
aa4a9deb LP	383	(void) sd_event_source_set_description(s->io_event_source, "dns-stream-io");
aa4a9deb LP	384
9a015429 LP	385	r = sd_event_add_time(
	386	m->event,
	387	&s->timeout_event_source,
	388	clock_boottime_or_monotonic(),
	389	now(clock_boottime_or_monotonic()) + DNS_STREAM_TIMEOUT_USEC, 0,
	390	on_stream_timeout, s);
623a4c97 LP	391	if (r < 0)
	392	return r;
	393
aa4a9deb LP	394	(void) sd_event_source_set_description(s->timeout_event_source, "dns-stream-timeout");
aa4a9deb LP	395
623a4c97 LP	396	LIST_PREPEND(streams, m->dns_streams, s);
	397	s->manager = m;
	398	s->fd = fd;
	399	m->n_dns_streams++;
	400
	401	*ret = s;
	402	s = NULL;
	403
	404	return 0;
	405	}
	406
	407	int dns_stream_write_packet(DnsStream s, DnsPacket p) {
	408	assert(s);
	409
	410	if (s->write_packet)
	411	return -EBUSY;
	412
	413	s->write_packet = dns_packet_ref(p);
	414	s->write_size = htobe16(p->size);
	415	s->n_written = 0;
	416
	417	return dns_stream_update_io(s);
	418	}