X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fresolve%2Fresolved-dns-scope.c;h=5141a8d8047920a37c8e071848c8c0c6002f700b;hp=1fa8401ed50f738388c4d9bc89fc2374a0135163;hb=2d4c5cbc0ed3ccb09dc086a040088b454c22c644;hpb=b45d9e86e41c453e0b57f2f8316bef06dee42e5a

diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c
index 1fa8401ed..5141a8d80 100644
--- a/src/resolve/resolved-dns-scope.c
+++ b/src/resolve/resolved-dns-scope.c
@@ -21,14 +21,16 @@
 
 #include <netinet/tcp.h>
 
+#include "missing.h"
 #include "strv.h"
 #include "socket-util.h"
+#include "af-list.h"
 #include "resolved-dns-domain.h"
 #include "resolved-dns-scope.h"
 
 #define SEND_TIMEOUT_USEC (2*USEC_PER_SEC)
 
-int dns_scope_new(Manager *m, DnsScope **ret, DnsScopeType t) {
+int dns_scope_new(Manager *m, DnsScope **ret, Link *l, DnsProtocol protocol, int family) {
         DnsScope *s;
 
         assert(m);
@@ -39,27 +41,45 @@ int dns_scope_new(Manager *m, DnsScope **ret, DnsScopeType t) {
                 return -ENOMEM;
 
         s->manager = m;
-        s->type = t;
+        s->link = l;
+        s->protocol = protocol;
+        s->family = family;
 
         LIST_PREPEND(scopes, m->dns_scopes, s);
 
+        dns_scope_llmnr_membership(s, true);
+
+        log_debug("New scope on link %s, protocol %s, family %s", l ? l->name : "*", dns_protocol_to_string(protocol), family == AF_UNSPEC ? "*" : af_to_name(family));
+
         *ret = s;
         return 0;
 }
 
 DnsScope* dns_scope_free(DnsScope *s) {
+        DnsQueryTransaction *t;
+
         if (!s)
                 return NULL;
 
-        while (s->transactions) {
-                DnsQuery *q;
+        log_debug("Removing scope on link %s, protocol %s, family %s", s->link ? s->link->name : "*", dns_protocol_to_string(s->protocol), s->family == AF_UNSPEC ? "*" : af_to_name(s->family));
+
+        dns_scope_llmnr_membership(s, false);
+
+        while ((t = s->transactions)) {
 
-                q = s->transactions->query;
-                dns_query_transaction_free(s->transactions);
+                /* Abort the transaction, but make sure it is not
+                 * freed while we still look at it */
 
-                dns_query_finish(q);
+                t->block_gc++;
+                dns_query_transaction_complete(t, DNS_QUERY_ABORTED);
+                t->block_gc--;
+
+                dns_query_transaction_free(t);
         }
 
+        dns_cache_flush(&s->cache);
+        dns_zone_flush(&s->zone);
+
         LIST_REMOVE(scopes, s->manager->dns_scopes, s);
         strv_free(s->domains);
         free(s);
@@ -70,6 +90,9 @@ DnsScope* dns_scope_free(DnsScope *s) {
 DnsServer *dns_scope_get_server(DnsScope *s) {
         assert(s);
 
+        if (s->protocol != DNS_PROTOCOL_DNS)
+                return NULL;
+
         if (s->link)
                 return link_get_dns_server(s->link);
         else
@@ -79,6 +102,9 @@ DnsServer *dns_scope_get_server(DnsScope *s) {
 void dns_scope_next_dns_server(DnsScope *s) {
         assert(s);
 
+        if (s->protocol != DNS_PROTOCOL_DNS)
+                return;
+
         if (s->link)
                 link_next_dns_server(s->link);
         else
@@ -86,84 +112,160 @@ void dns_scope_next_dns_server(DnsScope *s) {
 }
 
 int dns_scope_send(DnsScope *s, DnsPacket *p) {
-        int ifindex = 0;
-        DnsServer *srv;
-        int r;
+        union in_addr_union addr;
+        int ifindex = 0, r;
+        int family;
+        uint16_t port;
+        uint32_t mtu;
+        int fd;
 
         assert(s);
         assert(p);
-
-        srv = dns_scope_get_server(s);
-        if (!srv)
-                return -ESRCH;
+        assert(p->protocol == s->protocol);
 
         if (s->link) {
-                if (p->size > s->link->mtu)
-                        return -EMSGSIZE;
-
+                mtu = s->link->mtu;
                 ifindex = s->link->ifindex;
-        } else {
-                uint32_t mtu;
-
+        } else
                 mtu = manager_find_mtu(s->manager);
-                if (mtu > 0) {
-                        if (p->size > mtu)
-                                return -EMSGSIZE;
-                }
-        }
 
-        if (p->size > DNS_PACKET_UNICAST_SIZE_MAX)
-                return -EMSGSIZE;
+        if (s->protocol == DNS_PROTOCOL_DNS) {
+                DnsServer *srv;
 
-        if (srv->family == AF_INET)
-                r = manager_dns_ipv4_send(s->manager, srv, ifindex, p);
-        else if (srv->family == AF_INET6)
-                r = manager_dns_ipv6_send(s->manager, srv, ifindex, p);
-        else
+                if (DNS_PACKET_QDCOUNT(p) > 1)
+                        return -ENOTSUP;
+
+                srv = dns_scope_get_server(s);
+                if (!srv)
+                        return -ESRCH;
+
+                family = srv->family;
+                addr = srv->address;
+                port = 53;
+
+                if (p->size > DNS_PACKET_UNICAST_SIZE_MAX)
+                        return -EMSGSIZE;
+
+                if (p->size > mtu)
+                        return -EMSGSIZE;
+
+                if (family == AF_INET)
+                        fd = manager_dns_ipv4_fd(s->manager);
+                else if (family == AF_INET6)
+                        fd = manager_dns_ipv6_fd(s->manager);
+                else
+                        return -EAFNOSUPPORT;
+                if (fd < 0)
+                        return fd;
+
+        } else if (s->protocol == DNS_PROTOCOL_LLMNR) {
+
+                if (DNS_PACKET_QDCOUNT(p) > 1)
+                        return -ENOTSUP;
+
+                family = s->family;
+                port = 5355;
+
+                if (family == AF_INET) {
+                        addr.in = LLMNR_MULTICAST_IPV4_ADDRESS;
+                        fd = manager_llmnr_ipv4_udp_fd(s->manager);
+                } else if (family == AF_INET6) {
+                        addr.in6 = LLMNR_MULTICAST_IPV6_ADDRESS;
+                        fd = manager_llmnr_ipv6_udp_fd(s->manager);
+                } else
+                        return -EAFNOSUPPORT;
+                if (fd < 0)
+                        return fd;
+        } else
                 return -EAFNOSUPPORT;
 
+        r = manager_send(s->manager, fd, ifindex, family, &addr, port, p);
         if (r < 0)
                 return r;
 
         return 1;
 }
 
-int dns_scope_tcp_socket(DnsScope *s) {
+int dns_scope_tcp_socket(DnsScope *s, int family, const union in_addr_union *address, uint16_t port) {
         _cleanup_close_ int fd = -1;
         union sockaddr_union sa = {};
         socklen_t salen;
-        int one, ifindex, ret;
-        DnsServer *srv;
-        int r;
+        static const int one = 1;
+        int ret, r;
 
         assert(s);
+        assert((family == AF_UNSPEC) == !address);
+
+        if (family == AF_UNSPEC) {
+                DnsServer *srv;
+
+                srv = dns_scope_get_server(s);
+                if (!srv)
+                        return -ESRCH;
+
+                sa.sa.sa_family = srv->family;
+                if (srv->family == AF_INET) {
+                        sa.in.sin_port = htobe16(port);
+                        sa.in.sin_addr = srv->address.in;
+                        salen = sizeof(sa.in);
+                } else if (srv->family == AF_INET6) {
+                        sa.in6.sin6_port = htobe16(port);
+                        sa.in6.sin6_addr = srv->address.in6;
+                        sa.in6.sin6_scope_id = s->link ? s->link->ifindex : 0;
+                        salen = sizeof(sa.in6);
+                } else
+                        return -EAFNOSUPPORT;
+        } else {
+                sa.sa.sa_family = family;
+
+                if (family == AF_INET) {
+                        sa.in.sin_port = htobe16(port);
+                        sa.in.sin_addr = address->in;
+                        salen = sizeof(sa.in);
+                } else if (family == AF_INET6) {
+                        sa.in6.sin6_port = htobe16(port);
+                        sa.in6.sin6_addr = address->in6;
+                        sa.in6.sin6_scope_id = s->link ? s->link->ifindex : 0;
+                        salen = sizeof(sa.in6);
+                } else
+                        return -EAFNOSUPPORT;
+        }
 
-        srv = dns_scope_get_server(s);
-        if (!srv)
-                return -ESRCH;
-
-        if (s->link)
-                ifindex = s->link->ifindex;
-
-        sa.sa.sa_family = srv->family;
-        if (srv->family == AF_INET) {
-                sa.in.sin_port = htobe16(53);
-                sa.in.sin_addr = srv->address.in;
-                salen = sizeof(sa.in);
-        } else if (srv->family == AF_INET6) {
-                sa.in6.sin6_port = htobe16(53);
-                sa.in6.sin6_addr = srv->address.in6;
-                sa.in6.sin6_scope_id = ifindex;
-                salen = sizeof(sa.in6);
-        } else
-                return -EAFNOSUPPORT;
-
-        fd = socket(srv->family, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+        fd = socket(sa.sa.sa_family, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
         if (fd < 0)
                 return -errno;
 
-        one = 1;
-        setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one));
+        r = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one));
+        if (r < 0)
+                return -errno;
+
+        if (s->link) {
+                uint32_t ifindex = htobe32(s->link->ifindex);
+
+                if (sa.sa.sa_family == AF_INET) {
+                        r = setsockopt(fd, IPPROTO_IP, IP_UNICAST_IF, &ifindex, sizeof(ifindex));
+                        if (r < 0)
+                                return -errno;
+                } else if (sa.sa.sa_family == AF_INET6) {
+                        r = setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_IF, &ifindex, sizeof(ifindex));
+                        if (r < 0)
+                                return -errno;
+                }
+        }
+
+        if (s->protocol == DNS_PROTOCOL_LLMNR) {
+                /* RFC 4795, section 2.5 requires the TTL to be set to 1 */
+
+                if (sa.sa.sa_family == AF_INET) {
+                        r = setsockopt(fd, IPPROTO_IP, IP_TTL, &one, sizeof(one));
+                        if (r < 0)
+                                return -errno;
+                } else if (sa.sa.sa_family == AF_INET6) {
+                        r = setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &one, sizeof(one));
+                        if (r < 0)
+                                return -errno;
+                }
+        }
 
         r = connect(fd, &sa.sa, salen);
         if (r < 0 && errno != EINPROGRESS)
@@ -171,44 +273,255 @@ int dns_scope_tcp_socket(DnsScope *s) {
 
         ret = fd;
         fd = -1;
+
         return ret;
 }
 
-DnsScopeMatch dns_scope_test(DnsScope *s, const char *domain) {
+DnsScopeMatch dns_scope_good_domain(DnsScope *s, const char *domain) {
         char **i;
 
         assert(s);
         assert(domain);
 
         STRV_FOREACH(i, s->domains)
-                if (dns_name_endswith(domain, *i))
+                if (dns_name_endswith(domain, *i) > 0)
                         return DNS_SCOPE_YES;
 
-        if (dns_name_root(domain))
+        if (dns_name_root(domain) != 0)
                 return DNS_SCOPE_NO;
 
         if (is_localhost(domain))
                 return DNS_SCOPE_NO;
 
-        if (s->type == DNS_SCOPE_MDNS) {
-                if (dns_name_endswith(domain, "254.169.in-addr.arpa") ||
-                    dns_name_endswith(domain, "0.8.e.f.ip6.arpa"))
-                        return DNS_SCOPE_YES;
-                else if (dns_name_endswith(domain, "local") &&
-                         !dns_name_single_label(domain))
+        if (s->protocol == DNS_PROTOCOL_DNS) {
+                if (dns_name_endswith(domain, "254.169.in-addr.arpa") == 0 &&
+                    dns_name_endswith(domain, "0.8.e.f.ip6.arpa") == 0 &&
+                    dns_name_single_label(domain) == 0)
                         return DNS_SCOPE_MAYBE;
 
                 return DNS_SCOPE_NO;
         }
 
-        if (s->type == DNS_SCOPE_DNS) {
-                if (dns_name_endswith(domain, "254.169.in-addr.arpa") ||
-                    dns_name_endswith(domain, "0.8.e.f.ip6.arpa") ||
-                    dns_name_single_label(domain))
-                        return DNS_SCOPE_NO;
+        if (s->protocol == DNS_PROTOCOL_MDNS) {
+                if (dns_name_endswith(domain, "254.169.in-addr.arpa") > 0 ||
+                    dns_name_endswith(domain, "0.8.e.f.ip6.arpa") > 0 ||
+                    (dns_name_endswith(domain, "local") > 0 && dns_name_equal(domain, "local") == 0))
+                        return DNS_SCOPE_MAYBE;
 
-                return DNS_SCOPE_MAYBE;
+                return DNS_SCOPE_NO;
         }
 
-        assert_not_reached("Unknown scope type");
+        if (s->protocol == DNS_PROTOCOL_LLMNR) {
+                if (dns_name_endswith(domain, "in-addr.arpa") > 0 ||
+                    dns_name_endswith(domain, "ip6.arpa") > 0 ||
+                    dns_name_single_label(domain) > 0)
+                        return DNS_SCOPE_MAYBE;
+
+                return DNS_SCOPE_NO;
+        }
+
+        assert_not_reached("Unknown scope protocol");
+}
+
+int dns_scope_good_key(DnsScope *s, DnsResourceKey *key) {
+        assert(s);
+        assert(key);
+
+        if (s->protocol == DNS_PROTOCOL_DNS)
+                return true;
+
+        /* On mDNS and LLMNR, send A and AAAA queries only on the
+         * respective scopes */
+
+        if (s->family == AF_INET && key->class == DNS_CLASS_IN && key->type == DNS_TYPE_AAAA)
+                return false;
+
+        if (s->family == AF_INET6 && key->class == DNS_CLASS_IN && key->type == DNS_TYPE_A)
+                return false;
+
+        return true;
+}
+
+int dns_scope_llmnr_membership(DnsScope *s, bool b) {
+        int fd;
+
+        if (s->family == AF_INET) {
+                struct ip_mreqn mreqn = {
+                        .imr_multiaddr = LLMNR_MULTICAST_IPV4_ADDRESS,
+                        .imr_ifindex = s->link->ifindex,
+                };
+
+                fd = manager_llmnr_ipv4_udp_fd(s->manager);
+                if (fd < 0)
+                        return fd;
+
+                if (setsockopt(fd, IPPROTO_IP, b ? IP_ADD_MEMBERSHIP : IP_DROP_MEMBERSHIP, &mreqn, sizeof(mreqn)) < 0)
+                        return -errno;
+
+        } else if (s->family == AF_INET6) {
+                struct ipv6_mreq mreq = {
+                        .ipv6mr_multiaddr = LLMNR_MULTICAST_IPV6_ADDRESS,
+                        .ipv6mr_interface = s->link->ifindex,
+                };
+
+                fd = manager_llmnr_ipv6_udp_fd(s->manager);
+                if (fd < 0)
+                        return fd;
+
+                if (setsockopt(fd, IPPROTO_IPV6, b ? IPV6_ADD_MEMBERSHIP : IPV6_DROP_MEMBERSHIP, &mreq, sizeof(mreq)) < 0)
+                        return -errno;
+        } else
+                return -EAFNOSUPPORT;
+
+        return 0;
+}
+
+int dns_scope_good_dns_server(DnsScope *s, int family, const union in_addr_union *address) {
+        assert(s);
+        assert(address);
+
+        if (s->protocol != DNS_PROTOCOL_DNS)
+                return 1;
+
+        if (s->link)
+                return !!link_find_dns_server(s->link,  family, address);
+        else
+                return !!manager_find_dns_server(s->manager, family, address);
+}
+
+static int dns_scope_make_reply_packet(DnsScope *s, uint16_t id, int rcode, DnsQuestion *q, DnsAnswer *answer, DnsAnswer *soa, DnsPacket **ret) {
+        _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
+        unsigned i;
+        int r;
+
+        assert(s);
+
+        if (q->n_keys <= 0 && answer->n_rrs <= 0 && soa->n_rrs <= 0)
+                return -EINVAL;
+
+        r = dns_packet_new(&p, s->protocol, 0);
+        if (r < 0)
+                return r;
+
+        DNS_PACKET_HEADER(p)->id = id;
+        DNS_PACKET_HEADER(p)->flags = htobe16(DNS_PACKET_MAKE_FLAGS(
+                                                              1 /* qr */,
+                                                              0 /* opcode */,
+                                                              0 /* c */,
+                                                              0 /* tc */,
+                                                              0 /* t */,
+                                                              0 /* (ra) */,
+                                                              0 /* (ad) */,
+                                                              0 /* (cd) */,
+                                                              rcode));
+
+        if (q) {
+                for (i = 0; i < q->n_keys; i++) {
+                        r = dns_packet_append_key(p, q->keys[i], NULL);
+                        if (r < 0)
+                                return r;
+                }
+
+                DNS_PACKET_HEADER(p)->qdcount = htobe16(q->n_keys);
+        }
+
+        if (answer) {
+                for (i = 0; i < answer->n_rrs; i++) {
+                        r = dns_packet_append_rr(p, answer->rrs[i], NULL);
+                        if (r < 0)
+                                return r;
+                }
+
+                DNS_PACKET_HEADER(p)->ancount = htobe16(answer->n_rrs);
+        }
+
+        if (soa) {
+                for (i = 0; i < soa->n_rrs; i++) {
+                        r = dns_packet_append_rr(p, soa->rrs[i], NULL);
+                        if (r < 0)
+                                return r;
+                }
+
+                DNS_PACKET_HEADER(p)->arcount = htobe16(soa->n_rrs);
+        }
+
+        *ret = p;
+        p = NULL;
+
+        return 0;
+}
+
+void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p) {
+        _cleanup_(dns_packet_unrefp) DnsPacket *reply = NULL;
+        _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL, *soa = NULL;
+        int r, fd;
+
+        assert(s);
+        assert(p);
+
+        if (p->protocol != DNS_PROTOCOL_LLMNR)
+                return;
+
+        if (p->ipproto == IPPROTO_UDP) {
+                /* Don't accept UDP queries directed to anything but
+                 * the LLMNR multicast addresses. See RFC 4795,
+                 * section 2.5.*/
+
+                if (p->family == AF_INET && !in_addr_equal(AF_INET, &p->destination, (union in_addr_union*) &LLMNR_MULTICAST_IPV4_ADDRESS))
+                        return;
+
+                if (p->family == AF_INET6 && !in_addr_equal(AF_INET6, &p->destination, (union in_addr_union*) &LLMNR_MULTICAST_IPV6_ADDRESS))
+                        return;
+        }
+
+        r = dns_packet_extract(p);
+        if (r < 0) {
+                log_debug("Failed to extract resources from incoming packet: %s", strerror(-r));
+                return;
+        }
+
+        if (DNS_PACKET_C(p)) {
+                /* FIXME: Somebody notified us about a likely conflict */
+                return;
+        }
+
+        r = dns_zone_lookup(&s->zone, p->question, &answer, &soa);
+        if (r < 0) {
+                log_debug("Failed to lookup key: %s", strerror(-r));
+                return;
+        }
+        if (r == 0)
+                return;
+
+        dns_answer_order_by_scope(answer, in_addr_is_link_local(p->family, &p->sender) > 0);
+
+        r = dns_scope_make_reply_packet(s, DNS_PACKET_ID(p), DNS_RCODE_SUCCESS, p->question, answer, soa, &reply);
+        if (r < 0) {
+                log_debug("Failed to build reply packet: %s", strerror(-r));
+                return;
+        }
+
+        if (stream)
+                r = dns_stream_write_packet(stream, reply);
+        else {
+                if (p->family == AF_INET)
+                        fd = manager_llmnr_ipv4_udp_fd(s->manager);
+                else if (p->family == AF_INET6)
+                        fd = manager_llmnr_ipv6_udp_fd(s->manager);
+                else {
+                        log_debug("Unknown protocol");
+                        return;
+                }
+                if (fd < 0) {
+                        log_debug("Failed to get reply socket: %s", strerror(-fd));
+                        return;
+                }
+
+                r = manager_send(s->manager, fd, p->ifindex, p->family, &p->sender, p->sender_port, reply);
+        }
+
+        if (r < 0) {
+                log_debug("Failed to send reply packet: %s", strerror(-r));
+                return;
+        }
 }