diff options
Diffstat (limited to 'src/resolve/resolved-dns-transaction.c')
-rw-r--r-- | src/resolve/resolved-dns-transaction.c | 188 |
1 files changed, 69 insertions, 119 deletions
diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c index 3d46c99df8..b235fda3d2 100644 --- a/src/resolve/resolved-dns-transaction.c +++ b/src/resolve/resolved-dns-transaction.c @@ -39,10 +39,8 @@ DnsTransaction* dns_transaction_free(DnsTransaction *t) { dns_packet_unref(t->received); dns_answer_unref(t->cached); - sd_event_source_unref(t->dns_ipv4_event_source); - sd_event_source_unref(t->dns_ipv6_event_source); - safe_close(t->dns_ipv4_fd); - safe_close(t->dns_ipv6_fd); + sd_event_source_unref(t->dns_event_source); + safe_close(t->dns_fd); dns_server_unref(t->server); dns_stream_free(t->stream); @@ -94,7 +92,7 @@ int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsQuestion *q) { if (!t) return -ENOMEM; - t->dns_ipv4_fd = t->dns_ipv6_fd = -1; + t->dns_fd = -1; t->question = dns_question_ref(q); @@ -245,7 +243,7 @@ static int on_stream_complete(DnsStream *s, int error) { } static int dns_transaction_open_tcp(DnsTransaction *t) { - _cleanup_(dns_server_unrefp) DnsServer *server = NULL; + DnsServer *server = NULL; _cleanup_close_ int fd = -1; int r; @@ -310,6 +308,16 @@ static int dns_transaction_open_tcp(DnsTransaction *t) { return 0; } +static void dns_transaction_next_dns_server(DnsTransaction *t) { + assert(t); + + t->server = dns_server_unref(t->server); + t->dns_event_source = sd_event_source_unref(t->dns_event_source); + t->dns_fd = safe_close(t->dns_fd); + + dns_scope_next_dns_server(t->scope); +} + void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { int r; @@ -342,24 +350,6 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { } } - if (t->scope->protocol == DNS_PROTOCOL_DNS) { - - /* For DNS we are fine with accepting packets on any - * interface, but the source IP address must be the - * one of the DNS server we queried */ - - assert(t->server); - - if (t->server->family != p->family) - return; - - if (!in_addr_equal(p->family, &p->sender, &t->server->address)) - return; - - if (p->sender_port != 53) - return; - } - if (t->received != p) { dns_packet_unref(t->received); t->received = dns_packet_ref(p); @@ -396,7 +386,7 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { } /* On DNS, couldn't send? Try immediately again, with a new server */ - dns_scope_next_dns_server(t->scope); + dns_transaction_next_dns_server(t); r = dns_transaction_go(t); if (r < 0) { @@ -431,6 +421,56 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { dns_transaction_complete(t, DNS_TRANSACTION_FAILURE); } +static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + DnsTransaction *t = userdata; + int r; + + assert(t); + assert(t->scope); + + r = manager_recv(t->scope->manager, fd, DNS_PROTOCOL_DNS, &p); + if (r <= 0) + return r; + + if (dns_packet_validate_reply(p) > 0 && + DNS_PACKET_ID(p) == t->id) { + dns_transaction_process_reply(t, p); + } else + log_debug("Invalid DNS packet."); + + return 0; +} + +static int dns_transaction_emit(DnsTransaction *t) { + int r; + + assert(t); + + if (t->scope->protocol == DNS_PROTOCOL_DNS && !t->server) { + DnsServer *server = NULL; + _cleanup_close_ int fd = -1; + + fd = dns_scope_udp_dns_socket(t->scope, &server); + if (fd < 0) + return fd; + + r = sd_event_add_io(t->scope->manager->event, &t->dns_event_source, fd, EPOLLIN, on_dns_packet, t); + if (r < 0) + return r; + + t->dns_fd = fd; + fd = -1; + t->server = dns_server_ref(server); + } + + r = dns_scope_emit(t->scope, t->dns_fd, t->sent); + if (r < 0) + return r; + + return 0; +} + static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) { DnsTransaction *t = userdata; int r; @@ -439,7 +479,7 @@ static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdat assert(t); /* Timeout reached? Try again, with a new server */ - dns_scope_next_dns_server(t->scope); + dns_transaction_next_dns_server(t); r = dns_transaction_go(t); if (r < 0) @@ -516,7 +556,6 @@ int dns_transaction_go(DnsTransaction *t) { } t->n_attempts++; - t->server = dns_server_unref(t->server); t->received = dns_packet_unref(t->received); t->cached = dns_answer_unref(t->cached); t->cached_rcode = 0; @@ -596,13 +635,9 @@ int dns_transaction_go(DnsTransaction *t) { * always be made via TCP on LLMNR */ r = dns_transaction_open_tcp(t); } else { - DnsServer *server; - /* Try via UDP, and if that fails due to large size try via TCP */ - r = dns_scope_emit(t->scope, t, t->sent, &server); - if (r >= 0) - t->server = dns_server_ref(server); - else if (r == -EMSGSIZE) + r = dns_transaction_emit(t); + if (r == -EMSGSIZE) r = dns_transaction_open_tcp(t); } if (r == -ESRCH) { @@ -616,7 +651,7 @@ int dns_transaction_go(DnsTransaction *t) { } /* Couldn't send? Try immediately again, with a new server */ - dns_scope_next_dns_server(t->scope); + dns_transaction_next_dns_server(t); return dns_transaction_go(t); } @@ -634,91 +669,6 @@ int dns_transaction_go(DnsTransaction *t) { return 1; } -static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { - _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; - DnsTransaction *t = userdata; - int r; - - assert(t); - assert(t->scope); - - r = manager_recv(t->scope->manager, fd, DNS_PROTOCOL_DNS, &p); - if (r <= 0) - return r; - - if (dns_packet_validate_reply(p) > 0 && - DNS_PACKET_ID(p) == t->id) { - dns_transaction_process_reply(t, p); - } else - log_debug("Invalid DNS packet."); - - return 0; -} - -int transaction_dns_ipv4_fd(DnsTransaction *t) { - const int one = 1; - int r; - - assert(t); - assert(t->scope); - assert(t->scope->manager); - - if (t->dns_ipv4_fd >= 0) - return t->dns_ipv4_fd; - - t->dns_ipv4_fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); - if (t->dns_ipv4_fd < 0) - return -errno; - - r = setsockopt(t->dns_ipv4_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one)); - if (r < 0) { - r = -errno; - goto fail; - } - - r = sd_event_add_io(t->scope->manager->event, &t->dns_ipv4_event_source, t->dns_ipv4_fd, EPOLLIN, on_dns_packet, t); - if (r < 0) - goto fail; - - return t->dns_ipv4_fd; - -fail: - t->dns_ipv4_fd = safe_close(t->dns_ipv4_fd); - return r; -} - -int transaction_dns_ipv6_fd(DnsTransaction *t) { - const int one = 1; - int r; - - assert(t); - assert(t->scope); - assert(t->scope->manager); - - if (t->dns_ipv6_fd >= 0) - return t->dns_ipv6_fd; - - t->dns_ipv6_fd = socket(AF_INET6, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); - if (t->dns_ipv6_fd < 0) - return -errno; - - r = setsockopt(t->dns_ipv6_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one)); - if (r < 0) { - r = -errno; - goto fail; - } - - r = sd_event_add_io(t->scope->manager->event, &t->dns_ipv6_event_source, t->dns_ipv6_fd, EPOLLIN, on_dns_packet, t); - if (r < 0) - goto fail; - - return t->dns_ipv6_fd; - -fail: - t->dns_ipv6_fd = safe_close(t->dns_ipv6_fd); - return r; -} - static const char* const dns_transaction_state_table[_DNS_TRANSACTION_STATE_MAX] = { [DNS_TRANSACTION_NULL] = "null", [DNS_TRANSACTION_PENDING] = "pending", |