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

/* SPDX-License-Identifier: LGPL-2.1+ */

#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

#define WRITE_TLS_DATA 1

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;
        else if (!ordered_set_isempty(s->write_queue)) {
                dns_packet_unref(s->write_packet);
                s->write_packet = ordered_set_steal_first(s->write_queue);
                s->write_size = htobe16(s->write_packet->size);
                s->n_written = 0;
                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);

#if HAVE_GNUTLS
        if (s->tls_session && IN_SET(error, ETIMEDOUT, 0)) {
                int r;

                r = gnutls_bye(s->tls_session, GNUTLS_SHUT_RDWR);
                if (r == GNUTLS_E_AGAIN && !s->tls_bye) {
                        dns_stream_ref(s); /* keep reference for closing TLS session */
                        s->tls_bye = true;
                } else
                        dns_stream_stop(s);
        } else
#endif
                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 ssize_t dns_stream_writev(DnsStream *s, const struct iovec *iov, size_t iovcnt, int flags) {
        ssize_t r;

        assert(s);
        assert(iov);

#if HAVE_GNUTLS
        if (s->tls_session && !(flags & WRITE_TLS_DATA)) {
                ssize_t ss;
                size_t i;

                r = 0;
                for (i = 0; i < iovcnt; i++) {
                        ss = gnutls_record_send(s->tls_session, iov[i].iov_base, iov[i].iov_len);
                        if (ss < 0) {
                                switch(ss) {

                                case GNUTLS_E_INTERRUPTED:
                                        return -EINTR;
                                case GNUTLS_E_AGAIN:
                                        return -EAGAIN;
                                default:
                                        log_debug("Failed to invoke gnutls_record_send: %s", gnutls_strerror(ss));
                                        return -EIO;
                                }
                        }

                        r += ss;
                        if (ss != (ssize_t) iov[i].iov_len)
                                continue;
                }
        } else
#endif
        if (s->tfo_salen > 0) {
                struct msghdr hdr = {
                        .msg_iov = (struct iovec*) iov,
                        .msg_iovlen = iovcnt,
                        .msg_name = &s->tfo_address.sa,
                        .msg_namelen = s->tfo_salen
                };

                r = sendmsg(s->fd, &hdr, MSG_FASTOPEN);
                if (r < 0) {
                        if (errno == EOPNOTSUPP) {
                                s->tfo_salen = 0;
                                r = connect(s->fd, &s->tfo_address.sa, s->tfo_salen);
                                if (r < 0)
                                        return -errno;

                                r = -EAGAIN;
                        } else if (errno == EINPROGRESS)
                                r = -EAGAIN;
                } else
                        s->tfo_salen = 0; /* connection is made */
        } else {
                r = writev(s->fd, iov, iovcnt);
                if (r < 0)
                        r = -errno;
        }

        return r;
}

static ssize_t dns_stream_read(DnsStream *s, void *buf, size_t count) {
        ssize_t ss;

#if HAVE_GNUTLS
        if (s->tls_session) {
                ss = gnutls_record_recv(s->tls_session, buf, count);
                if (ss < 0) {
                        switch(ss) {

                        case GNUTLS_E_INTERRUPTED:
                                return -EINTR;
                        case GNUTLS_E_AGAIN:
                                return -EAGAIN;
                        default:
                                log_debug("Failed to invoke gnutls_record_send: %s", gnutls_strerror(ss));
                                return -EIO;
                        }
                } else if (s->on_connection) {
                        int r;

                        r = s->on_connection(s);
                        s->on_connection = NULL; /* only call once */
                        if (r < 0)
                                return r;
                }
        } else
#endif
        {
                ss = read(s->fd, buf, count);
                if (ss < 0)
                        ss = -errno;
        }

        return ss;
}

#if HAVE_GNUTLS
static ssize_t dns_stream_tls_writev(gnutls_transport_ptr_t p, const giovec_t * iov, int iovcnt) {
        int r;

        assert(p);

        r = dns_stream_writev((DnsStream*) p, (struct iovec*) iov, iovcnt, WRITE_TLS_DATA);
        if (r < 0) {
                errno = -r;
                return -1;
        }

        return r;
}
#endif

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);

#if HAVE_GNUTLS
        if (s->tls_bye) {
                assert(s->tls_session);

                r = gnutls_bye(s->tls_session, GNUTLS_SHUT_RDWR);
                if (r != GNUTLS_E_AGAIN) {
                        s->tls_bye = false;
                        dns_stream_unref(s);
                }

                return 0;
        }

        if (s->tls_handshake < 0) {
                assert(s->tls_session);

                s->tls_handshake = gnutls_handshake(s->tls_session);
                if (s->tls_handshake >= 0) {
                        if (s->on_connection && !(gnutls_session_get_flags(s->tls_session) & GNUTLS_SFLAGS_FALSE_START)) {
                                r = s->on_connection(s);
                                s->on_connection = NULL; /* only call once */
                                if (r < 0)
                                        return r;
                        }
                } else {
                        if (gnutls_error_is_fatal(s->tls_handshake))
                                return dns_stream_complete(s, ECONNREFUSED);
                        else
                                return 0;
                }

        }
#endif

        /* only identify after connecting */
        if (s->tfo_salen == 0) {
                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 = dns_stream_writev(s, iov, 2, 0);
                if (ss < 0) {
                        if (!IN_SET(-ss, EINTR, EAGAIN))
                                return dns_stream_complete(s, -ss);
                } 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 = dns_stream_read(s, (uint8_t*) &s->read_size + s->n_read, sizeof(s->read_size) - s->n_read);
                        if (ss < 0) {
                                if (!IN_SET(-ss, EINTR, EAGAIN))
                                        return dns_stream_complete(s, -ss);
                        } 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), DNS_PACKET_SIZE_MAX);
                                        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 = dns_stream_read(s,
                                          (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 (!IN_SET(errno, EINTR, 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)) {
                                /* If there's a packet handler
                                 * installed, call that. Note that
                                 * this is optional... */
                                if (s->on_packet) {
                                        r = s->on_packet(s);
                                        if (r < 0)
                                                return r;
                                }

                                r = dns_stream_update_io(s);
                                if (r < 0)
                                        return dns_stream_complete(s, -r);
                        }
                }
        }

        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) {
        DnsPacket *p;
        Iterator i;

        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->server && s->server->stream == s)
                s->server->stream = NULL;

        if (s->manager) {
                LIST_REMOVE(streams, s->manager->dns_streams, s);
                s->manager->n_dns_streams--;
        }

#if HAVE_GNUTLS
        if (s->tls_session)
                gnutls_deinit(s->tls_session);
#endif

        ORDERED_SET_FOREACH(p, s->write_queue, i)
                dns_packet_unref(ordered_set_remove(s->write_queue, p));

        dns_packet_unref(s->write_packet);
        dns_packet_unref(s->read_packet);
        dns_server_unref(s->server);

        ordered_set_free(s->write_queue);

        return mfree(s);
}

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, const union sockaddr_union *tfo_address) {
        _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;

        r = ordered_set_ensure_allocated(&s->write_queue, &dns_packet_hash_ops);
        if (r < 0)
                return r;

        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;
        if (tfo_address) {
                s->tfo_address = *tfo_address;
                s->tfo_salen = tfo_address->sa.sa_family == AF_INET6 ? sizeof(tfo_address->in6) : sizeof(tfo_address->in);
        }

        m->n_dns_streams++;

        *ret = TAKE_PTR(s);

        return 0;
}

#if HAVE_GNUTLS
int dns_stream_connect_tls(DnsStream *s, gnutls_session_t tls_session) {
        gnutls_transport_set_ptr2(tls_session, (gnutls_transport_ptr_t) (long) s->fd, s);
        gnutls_transport_set_vec_push_function(tls_session, &dns_stream_tls_writev);

        s->encrypted = true;
        s->tls_session = tls_session;
        s->tls_handshake = gnutls_handshake(tls_session);
        if (s->tls_handshake < 0 && gnutls_error_is_fatal(s->tls_handshake))
                return -ECONNREFUSED;

        return 0;
}
#endif

int dns_stream_write_packet(DnsStream *s, DnsPacket *p) {
        int r;

        assert(s);

        r = ordered_set_put(s->write_queue, p);
        if (r < 0)
                return r;

        dns_packet_ref(p);

        return dns_stream_update_io(s);
}
Commit	Line	Data
53e1b683	1	/* SPDX-License-Identifier: LGPL-2.1+ */
623a4c97 LP	2
	3	#include <netinet/tcp.h>
	4
b5efdb8a	5	#include "alloc-util.h"
3ffd4af2	6	#include "fd-util.h"
afc5dbf3	7	#include "io-util.h"
623a4c97 LP	8	#include "missing.h"
	9	#include "resolved-dns-stream.h"
	10
	11	#define DNS_STREAM_TIMEOUT_USEC (10 * USEC_PER_SEC)
	12	#define DNS_STREAMS_MAX 128
	13
5d67a7ae IT	14	#define WRITE_TLS_DATA 1
5d67a7ae IT	15
623a4c97 LP	16	static void dns_stream_stop(DnsStream *s) {
	17	assert(s);
	18
	19	s->io_event_source = sd_event_source_unref(s->io_event_source);
	20	s->timeout_event_source = sd_event_source_unref(s->timeout_event_source);
	21	s->fd = safe_close(s->fd);
	22	}
	23
	24	static int dns_stream_update_io(DnsStream *s) {
	25	int f = 0;
	26
	27	assert(s);
	28
	29	if (s->write_packet && s->n_written < sizeof(s->write_size) + s->write_packet->size)
	30	f \|= EPOLLOUT;
98767d75 IT	31	else if (!ordered_set_isempty(s->write_queue)) {
	32	dns_packet_unref(s->write_packet);
	33	s->write_packet = ordered_set_steal_first(s->write_queue);
	34	s->write_size = htobe16(s->write_packet->size);
	35	s->n_written = 0;
	36	f \|= EPOLLOUT;
	37	}
623a4c97 LP	38	if (!s->read_packet \|\| s->n_read < sizeof(s->read_size) + s->read_packet->size)
	39	f \|= EPOLLIN;
	40
	41	return sd_event_source_set_io_events(s->io_event_source, f);
	42	}
	43
b914e211	44	static int dns_stream_complete(DnsStream *s, int error) {
623a4c97 LP	45	assert(s);
623a4c97 LP	46
5d67a7ae IT	47	#if HAVE_GNUTLS
	48	if (s->tls_session && IN_SET(error, ETIMEDOUT, 0)) {
	49	int r;
	50
	51	r = gnutls_bye(s->tls_session, GNUTLS_SHUT_RDWR);
	52	if (r == GNUTLS_E_AGAIN && !s->tls_bye) {
	53	dns_stream_ref(s); /* keep reference for closing TLS session */
	54	s->tls_bye = true;
	55	} else
	56	dns_stream_stop(s);
	57	} else
	58	#endif
	59	dns_stream_stop(s);
623a4c97 LP	60
	61	if (s->complete)
	62	s->complete(s, error);
b30bf55d LP	63	else /* the default action if no completion function is set is to close the stream */
b30bf55d LP	64	dns_stream_unref(s);
623a4c97 LP	65
	66	return 0;
	67	}
	68
b914e211 LP	69	static int dns_stream_identify(DnsStream *s) {
	70	union {
	71	struct cmsghdr header; /* For alignment */
40a1eebd	72	uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo))
b914e211 LP	73	+ EXTRA_CMSG_SPACE /* kernel appears to require extra space */];
	74	} control;
	75	struct msghdr mh = {};
	76	struct cmsghdr *cmsg;
	77	socklen_t sl;
	78	int r;
	79
	80	assert(s);
	81
	82	if (s->identified)
	83	return 0;
	84
	85	/* Query the local side */
	86	s->local_salen = sizeof(s->local);
	87	r = getsockname(s->fd, &s->local.sa, &s->local_salen);
	88	if (r < 0)
	89	return -errno;
	90	if (s->local.sa.sa_family == AF_INET6 && s->ifindex <= 0)
	91	s->ifindex = s->local.in6.sin6_scope_id;
	92
	93	/* Query the remote side */
	94	s->peer_salen = sizeof(s->peer);
	95	r = getpeername(s->fd, &s->peer.sa, &s->peer_salen);
	96	if (r < 0)
	97	return -errno;
	98	if (s->peer.sa.sa_family == AF_INET6 && s->ifindex <= 0)
	99	s->ifindex = s->peer.in6.sin6_scope_id;
	100
	101	/* Check consistency */
	102	assert(s->peer.sa.sa_family == s->local.sa.sa_family);
	103	assert(IN_SET(s->peer.sa.sa_family, AF_INET, AF_INET6));
	104
	105	/* Query connection meta information */
	106	sl = sizeof(control);
	107	if (s->peer.sa.sa_family == AF_INET) {
	108	r = getsockopt(s->fd, IPPROTO_IP, IP_PKTOPTIONS, &control, &sl);
	109	if (r < 0)
	110	return -errno;
	111	} else if (s->peer.sa.sa_family == AF_INET6) {
	112
	113	r = getsockopt(s->fd, IPPROTO_IPV6, IPV6_2292PKTOPTIONS, &control, &sl);
	114	if (r < 0)
	115	return -errno;
	116	} else
	117	return -EAFNOSUPPORT;
	118
	119	mh.msg_control = &control;
	120	mh.msg_controllen = sl;
2a1288ff LP	121
2a1288ff LP	122	CMSG_FOREACH(cmsg, &mh) {
b914e211 LP	123
	124	if (cmsg->cmsg_level == IPPROTO_IPV6) {
	125	assert(s->peer.sa.sa_family == AF_INET6);
	126
	127	switch (cmsg->cmsg_type) {
	128
	129	case IPV6_PKTINFO: {
	130	struct in6_pktinfo i = (struct in6_pktinfo) CMSG_DATA(cmsg);
	131
	132	if (s->ifindex <= 0)
	133	s->ifindex = i->ipi6_ifindex;
	134	break;
	135	}
	136
	137	case IPV6_HOPLIMIT:
	138	s->ttl = (int ) CMSG_DATA(cmsg);
	139	break;
	140	}
	141
	142	} else if (cmsg->cmsg_level == IPPROTO_IP) {
	143	assert(s->peer.sa.sa_family == AF_INET);
	144
	145	switch (cmsg->cmsg_type) {
	146
	147	case IP_PKTINFO: {
	148	struct in_pktinfo i = (struct in_pktinfo) CMSG_DATA(cmsg);
	149
	150	if (s->ifindex <= 0)
	151	s->ifindex = i->ipi_ifindex;
	152	break;
	153	}
	154
	155	case IP_TTL:
	156	s->ttl = (int ) CMSG_DATA(cmsg);
	157	break;
	158	}
	159	}
	160	}
	161
	162	/* The Linux kernel sets the interface index to the loopback
	163	* device if the connection came from the local host since it
	164	* avoids the routing table in such a case. Let's unset the
	165	* interface index in such a case. */
a5f03596	166	if (s->ifindex == LOOPBACK_IFINDEX)
b914e211 LP	167	s->ifindex = 0;
	168
	169	/* If we don't know the interface index still, we look for the
	170	* first local interface with a matching address. Yuck! */
	171	if (s->ifindex <= 0)
	172	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);
	173
	174	if (s->protocol == DNS_PROTOCOL_LLMNR && s->ifindex > 0) {
	175	uint32_t ifindex = htobe32(s->ifindex);
	176
	177	/* Make sure all packets for this connection are sent on the same interface */
	178	if (s->local.sa.sa_family == AF_INET) {
	179	r = setsockopt(s->fd, IPPROTO_IP, IP_UNICAST_IF, &ifindex, sizeof(ifindex));
	180	if (r < 0)
56f64d95	181	log_debug_errno(errno, "Failed to invoke IP_UNICAST_IF: %m");
b914e211 LP	182	} else if (s->local.sa.sa_family == AF_INET6) {
	183	r = setsockopt(s->fd, IPPROTO_IPV6, IPV6_UNICAST_IF, &ifindex, sizeof(ifindex));
	184	if (r < 0)
56f64d95	185	log_debug_errno(errno, "Failed to invoke IPV6_UNICAST_IF: %m");
b914e211 LP	186	}
	187	}
	188
	189	s->identified = true;
	190
	191	return 0;
	192	}
	193
5d67a7ae	194	static ssize_t dns_stream_writev(DnsStream s, const struct iovec iov, size_t iovcnt, int flags) {
91ccab1e IT	195	ssize_t r;
	196
	197	assert(s);
	198	assert(iov);
	199
5d67a7ae IT	200	#if HAVE_GNUTLS
	201	if (s->tls_session && !(flags & WRITE_TLS_DATA)) {
	202	ssize_t ss;
	203	size_t i;
	204
	205	r = 0;
	206	for (i = 0; i < iovcnt; i++) {
	207	ss = gnutls_record_send(s->tls_session, iov[i].iov_base, iov[i].iov_len);
	208	if (ss < 0) {
	209	switch(ss) {
	210
	211	case GNUTLS_E_INTERRUPTED:
	212	return -EINTR;
	213	case GNUTLS_E_AGAIN:
	214	return -EAGAIN;
	215	default:
	216	log_debug("Failed to invoke gnutls_record_send: %s", gnutls_strerror(ss));
	217	return -EIO;
	218	}
	219	}
	220
	221	r += ss;
	222	if (ss != (ssize_t) iov[i].iov_len)
	223	continue;
	224	}
	225	} else
	226	#endif
91ccab1e IT	227	if (s->tfo_salen > 0) {
	228	struct msghdr hdr = {
	229	.msg_iov = (struct iovec*) iov,
	230	.msg_iovlen = iovcnt,
	231	.msg_name = &s->tfo_address.sa,
	232	.msg_namelen = s->tfo_salen
	233	};
	234
	235	r = sendmsg(s->fd, &hdr, MSG_FASTOPEN);
	236	if (r < 0) {
	237	if (errno == EOPNOTSUPP) {
	238	s->tfo_salen = 0;
	239	r = connect(s->fd, &s->tfo_address.sa, s->tfo_salen);
	240	if (r < 0)
	241	return -errno;
	242
	243	r = -EAGAIN;
	244	} else if (errno == EINPROGRESS)
	245	r = -EAGAIN;
	246	} else
	247	s->tfo_salen = 0; /* connection is made */
f6c9c5f8	248	} else {
91ccab1e	249	r = writev(s->fd, iov, iovcnt);
f6c9c5f8 IT	250	if (r < 0)
	251	r = -errno;
	252	}
91ccab1e IT	253
	254	return r;
	255	}
	256
5d67a7ae IT	257	static ssize_t dns_stream_read(DnsStream s, void buf, size_t count) {
	258	ssize_t ss;
	259
	260	#if HAVE_GNUTLS
	261	if (s->tls_session) {
	262	ss = gnutls_record_recv(s->tls_session, buf, count);
	263	if (ss < 0) {
	264	switch(ss) {
	265
	266	case GNUTLS_E_INTERRUPTED:
	267	return -EINTR;
	268	case GNUTLS_E_AGAIN:
	269	return -EAGAIN;
	270	default:
	271	log_debug("Failed to invoke gnutls_record_send: %s", gnutls_strerror(ss));
	272	return -EIO;
	273	}
	274	} else if (s->on_connection) {
	275	int r;
	276
	277	r = s->on_connection(s);
	278	s->on_connection = NULL; /* only call once */
	279	if (r < 0)
	280	return r;
	281	}
	282	} else
	283	#endif
f6c9c5f8	284	{
5d67a7ae	285	ss = read(s->fd, buf, count);
f6c9c5f8 IT	286	if (ss < 0)
	287	ss = -errno;
	288	}
5d67a7ae IT	289
	290	return ss;
	291	}
	292
	293	#if HAVE_GNUTLS
	294	static ssize_t dns_stream_tls_writev(gnutls_transport_ptr_t p, const giovec_t * iov, int iovcnt) {
	295	int r;
	296
	297	assert(p);
	298
	299	r = dns_stream_writev((DnsStream) p, (struct iovec) iov, iovcnt, WRITE_TLS_DATA);
	300	if (r < 0) {
	301	errno = -r;
	302	return -1;
	303	}
	304
	305	return r;
	306	}
	307	#endif
	308
623a4c97 LP	309	static int on_stream_timeout(sd_event_source es, usec_t usec, void userdata) {
	310	DnsStream *s = userdata;
	311
	312	assert(s);
	313
b914e211	314	return dns_stream_complete(s, ETIMEDOUT);
623a4c97 LP	315	}
	316
	317	static int on_stream_io(sd_event_source es, int fd, uint32_t revents, void userdata) {
	318	DnsStream *s = userdata;
	319	int r;
	320
	321	assert(s);
	322
5d67a7ae IT	323	#if HAVE_GNUTLS
	324	if (s->tls_bye) {
	325	assert(s->tls_session);
	326
	327	r = gnutls_bye(s->tls_session, GNUTLS_SHUT_RDWR);
	328	if (r != GNUTLS_E_AGAIN) {
	329	s->tls_bye = false;
	330	dns_stream_unref(s);
	331	}
	332
	333	return 0;
	334	}
	335
	336	if (s->tls_handshake < 0) {
	337	assert(s->tls_session);
	338
	339	s->tls_handshake = gnutls_handshake(s->tls_session);
	340	if (s->tls_handshake >= 0) {
	341	if (s->on_connection && !(gnutls_session_get_flags(s->tls_session) & GNUTLS_SFLAGS_FALSE_START)) {
	342	r = s->on_connection(s);
	343	s->on_connection = NULL; /* only call once */
	344	if (r < 0)
	345	return r;
	346	}
	347	} else {
	348	if (gnutls_error_is_fatal(s->tls_handshake))
	349	return dns_stream_complete(s, ECONNREFUSED);
	350	else
	351	return 0;
	352	}
	353
	354	}
	355	#endif
	356
91ccab1e IT	357	/* only identify after connecting */
	358	if (s->tfo_salen == 0) {
	359	r = dns_stream_identify(s);
	360	if (r < 0)
	361	return dns_stream_complete(s, -r);
	362	}
b914e211	363
623a4c97 LP	364	if ((revents & EPOLLOUT) &&
	365	s->write_packet &&
	366	s->n_written < sizeof(s->write_size) + s->write_packet->size) {
	367
	368	struct iovec iov[2];
	369	ssize_t ss;
	370
	371	iov[0].iov_base = &s->write_size;
	372	iov[0].iov_len = sizeof(s->write_size);
	373	iov[1].iov_base = DNS_PACKET_DATA(s->write_packet);
	374	iov[1].iov_len = s->write_packet->size;
	375
	376	IOVEC_INCREMENT(iov, 2, s->n_written);
	377
5d67a7ae	378	ss = dns_stream_writev(s, iov, 2, 0);
623a4c97	379	if (ss < 0) {
f6c9c5f8 IT	380	if (!IN_SET(-ss, EINTR, EAGAIN))
f6c9c5f8 IT	381	return dns_stream_complete(s, -ss);
623a4c97 LP	382	} else
	383	s->n_written += ss;
	384
	385	/* Are we done? If so, disable the event source for EPOLLOUT */
	386	if (s->n_written >= sizeof(s->write_size) + s->write_packet->size) {
	387	r = dns_stream_update_io(s);
	388	if (r < 0)
b914e211	389	return dns_stream_complete(s, -r);
623a4c97 LP	390	}
	391	}
	392
	393	if ((revents & (EPOLLIN\|EPOLLHUP\|EPOLLRDHUP)) &&
	394	(!s->read_packet \|\|
	395	s->n_read < sizeof(s->read_size) + s->read_packet->size)) {
	396
	397	if (s->n_read < sizeof(s->read_size)) {
	398	ssize_t ss;
	399
5d67a7ae	400	ss = dns_stream_read(s, (uint8_t*) &s->read_size + s->n_read, sizeof(s->read_size) - s->n_read);
623a4c97	401	if (ss < 0) {
f6c9c5f8 IT	402	if (!IN_SET(-ss, EINTR, EAGAIN))
f6c9c5f8 IT	403	return dns_stream_complete(s, -ss);
623a4c97	404	} else if (ss == 0)
b914e211	405	return dns_stream_complete(s, ECONNRESET);
623a4c97 LP	406	else
	407	s->n_read += ss;
	408	}
	409
	410	if (s->n_read >= sizeof(s->read_size)) {
	411
	412	if (be16toh(s->read_size) < DNS_PACKET_HEADER_SIZE)
b914e211	413	return dns_stream_complete(s, EBADMSG);
623a4c97 LP	414
	415	if (s->n_read < sizeof(s->read_size) + be16toh(s->read_size)) {
	416	ssize_t ss;
	417
	418	if (!s->read_packet) {
51027656	419	r = dns_packet_new(&s->read_packet, s->protocol, be16toh(s->read_size), DNS_PACKET_SIZE_MAX);
623a4c97	420	if (r < 0)
b914e211	421	return dns_stream_complete(s, -r);
623a4c97 LP	422
	423	s->read_packet->size = be16toh(s->read_size);
	424	s->read_packet->ipproto = IPPROTO_TCP;
	425	s->read_packet->family = s->peer.sa.sa_family;
	426	s->read_packet->ttl = s->ttl;
	427	s->read_packet->ifindex = s->ifindex;
	428
	429	if (s->read_packet->family == AF_INET) {
	430	s->read_packet->sender.in = s->peer.in.sin_addr;
	431	s->read_packet->sender_port = be16toh(s->peer.in.sin_port);
	432	s->read_packet->destination.in = s->local.in.sin_addr;
	433	s->read_packet->destination_port = be16toh(s->local.in.sin_port);
	434	} else {
	435	assert(s->read_packet->family == AF_INET6);
	436	s->read_packet->sender.in6 = s->peer.in6.sin6_addr;
	437	s->read_packet->sender_port = be16toh(s->peer.in6.sin6_port);
	438	s->read_packet->destination.in6 = s->local.in6.sin6_addr;
	439	s->read_packet->destination_port = be16toh(s->local.in6.sin6_port);
	440
	441	if (s->read_packet->ifindex == 0)
	442	s->read_packet->ifindex = s->peer.in6.sin6_scope_id;
	443	if (s->read_packet->ifindex == 0)
	444	s->read_packet->ifindex = s->local.in6.sin6_scope_id;
	445	}
	446	}
	447
5d67a7ae	448	ss = dns_stream_read(s,
623a4c97 LP	449	(uint8_t*) DNS_PACKET_DATA(s->read_packet) + s->n_read - sizeof(s->read_size),
	450	sizeof(s->read_size) + be16toh(s->read_size) - s->n_read);
	451	if (ss < 0) {
ec2ce0c5	452	if (!IN_SET(errno, EINTR, EAGAIN))
b914e211	453	return dns_stream_complete(s, errno);
623a4c97	454	} else if (ss == 0)
b914e211	455	return dns_stream_complete(s, ECONNRESET);
623a4c97 LP	456	else
	457	s->n_read += ss;
	458	}
	459
	460	/* Are we done? If so, disable the event source for EPOLLIN */
	461	if (s->n_read >= sizeof(s->read_size) + be16toh(s->read_size)) {
623a4c97 LP	462	/* If there's a packet handler
	463	* installed, call that. Note that
	464	* this is optional... */
98767d75 IT	465	if (s->on_packet) {
	466	r = s->on_packet(s);
	467	if (r < 0)
	468	return r;
	469	}
	470
	471	r = dns_stream_update_io(s);
	472	if (r < 0)
	473	return dns_stream_complete(s, -r);
623a4c97 LP	474	}
	475	}
	476	}
	477
	478	if ((s->write_packet && s->n_written >= sizeof(s->write_size) + s->write_packet->size) &&
	479	(s->read_packet && s->n_read >= sizeof(s->read_size) + s->read_packet->size))
b914e211	480	return dns_stream_complete(s, 0);
623a4c97 LP	481
	482	return 0;
	483	}
	484
b30bf55d	485	DnsStream dns_stream_unref(DnsStream s) {
98767d75 IT	486	DnsPacket *p;
	487	Iterator i;
	488
623a4c97 LP	489	if (!s)
	490	return NULL;
	491
b30bf55d LP	492	assert(s->n_ref > 0);
	493	s->n_ref--;
	494
	495	if (s->n_ref > 0)
	496	return NULL;
	497
623a4c97 LP	498	dns_stream_stop(s);
623a4c97 LP	499
98767d75 IT	500	if (s->server && s->server->stream == s)
	501	s->server->stream = NULL;
	502
623a4c97 LP	503	if (s->manager) {
	504	LIST_REMOVE(streams, s->manager->dns_streams, s);
	505	s->manager->n_dns_streams--;
	506	}
	507
5d67a7ae IT	508	#if HAVE_GNUTLS
	509	if (s->tls_session)
	510	gnutls_deinit(s->tls_session);
	511	#endif
	512
98767d75 IT	513	ORDERED_SET_FOREACH(p, s->write_queue, i)
	514	dns_packet_unref(ordered_set_remove(s->write_queue, p));
	515
623a4c97 LP	516	dns_packet_unref(s->write_packet);
623a4c97 LP	517	dns_packet_unref(s->read_packet);
98767d75 IT	518	dns_server_unref(s->server);
	519
	520	ordered_set_free(s->write_queue);
623a4c97	521
6b430fdb	522	return mfree(s);
623a4c97 LP	523	}
623a4c97 LP	524
b30bf55d LP	525	DnsStream dns_stream_ref(DnsStream s) {
	526	if (!s)
	527	return NULL;
	528
	529	assert(s->n_ref > 0);
	530	s->n_ref++;
	531
	532	return s;
	533	}
623a4c97	534
91ccab1e	535	int dns_stream_new(Manager m, DnsStream ret, DnsProtocol protocol, int fd, const union sockaddr_union tfo_address) {
b30bf55d	536	_cleanup_(dns_stream_unrefp) DnsStream *s = NULL;
623a4c97 LP	537	int r;
	538
	539	assert(m);
	540	assert(fd >= 0);
	541
	542	if (m->n_dns_streams > DNS_STREAMS_MAX)
	543	return -EBUSY;
	544
	545	s = new0(DnsStream, 1);
	546	if (!s)
	547	return -ENOMEM;
	548
98767d75 IT	549	r = ordered_set_ensure_allocated(&s->write_queue, &dns_packet_hash_ops);
	550	if (r < 0)
	551	return r;
	552
b30bf55d	553	s->n_ref = 1;
623a4c97 LP	554	s->fd = -1;
	555	s->protocol = protocol;
	556
623a4c97 LP	557	r = sd_event_add_io(m->event, &s->io_event_source, fd, EPOLLIN, on_stream_io, s);
	558	if (r < 0)
	559	return r;
	560
aa4a9deb LP	561	(void) sd_event_source_set_description(s->io_event_source, "dns-stream-io");
aa4a9deb LP	562
9a015429 LP	563	r = sd_event_add_time(
	564	m->event,
	565	&s->timeout_event_source,
	566	clock_boottime_or_monotonic(),
	567	now(clock_boottime_or_monotonic()) + DNS_STREAM_TIMEOUT_USEC, 0,
	568	on_stream_timeout, s);
623a4c97 LP	569	if (r < 0)
	570	return r;
	571
aa4a9deb LP	572	(void) sd_event_source_set_description(s->timeout_event_source, "dns-stream-timeout");
aa4a9deb LP	573
623a4c97 LP	574	LIST_PREPEND(streams, m->dns_streams, s);
	575	s->manager = m;
	576	s->fd = fd;
91ccab1e IT	577	if (tfo_address) {
	578	s->tfo_address = *tfo_address;
	579	s->tfo_salen = tfo_address->sa.sa_family == AF_INET6 ? sizeof(tfo_address->in6) : sizeof(tfo_address->in);
	580	}
	581
623a4c97 LP	582	m->n_dns_streams++;
623a4c97 LP	583
1cc6c93a	584	*ret = TAKE_PTR(s);
623a4c97 LP	585
	586	return 0;
	587	}
	588
5d67a7ae IT	589	#if HAVE_GNUTLS
	590	int dns_stream_connect_tls(DnsStream *s, gnutls_session_t tls_session) {
	591	gnutls_transport_set_ptr2(tls_session, (gnutls_transport_ptr_t) (long) s->fd, s);
	592	gnutls_transport_set_vec_push_function(tls_session, &dns_stream_tls_writev);
	593
	594	s->encrypted = true;
	595	s->tls_session = tls_session;
	596	s->tls_handshake = gnutls_handshake(tls_session);
	597	if (s->tls_handshake < 0 && gnutls_error_is_fatal(s->tls_handshake))
	598	return -ECONNREFUSED;
	599
	600	return 0;
	601	}
	602	#endif
	603
623a4c97	604	int dns_stream_write_packet(DnsStream s, DnsPacket p) {
98767d75 IT	605	int r;
98767d75 IT	606
623a4c97 LP	607	assert(s);
623a4c97 LP	608
98767d75 IT	609	r = ordered_set_put(s->write_queue, p);
	610	if (r < 0)
	611	return r;
623a4c97	612
98767d75	613	dns_packet_ref(p);
623a4c97 LP	614
	615	return dns_stream_update_io(s);
	616	}