diff options
Diffstat (limited to 'src/resolve/resolved-dns-transaction.c')
| -rw-r--r-- | src/resolve/resolved-dns-transaction.c | 244 |
1 files changed, 121 insertions, 123 deletions
diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c index 3d46c99df8..53779f3372 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; @@ -310,12 +308,25 @@ 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) { + usec_t ts; int r; assert(t); assert(p); assert(t->state == DNS_TRANSACTION_PENDING); + assert(t->scope); + assert(t->scope->manager); /* Note that this call might invalidate the query. Callers * should hence not attempt to access the query or transaction @@ -342,24 +353,6 @@ 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); @@ -379,6 +372,24 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { } } + assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); + + switch (t->scope->protocol) { + case DNS_PROTOCOL_DNS: + assert(t->server); + + dns_server_packet_received(t->server, ts - t->start_usec); + + break; + case DNS_PROTOCOL_LLMNR: + case DNS_PROTOCOL_MDNS: + dns_scope_packet_received(t->scope, ts - t->start_usec); + + break; + default: + assert_not_reached("Invalid DNS protocol."); + } + if (DNS_PACKET_TC(p)) { /* Response was truncated, let's try again with good old TCP */ r = dns_transaction_open_tcp(t); @@ -396,7 +407,7 @@ 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) { @@ -416,8 +427,8 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { } /* Only consider responses with equivalent query section to the request */ - if (!dns_question_is_superset(p->question, t->question) || - !dns_question_is_superset(t->question, p->question)) { + r = dns_question_is_equal(p->question, t->question); + if (r <= 0) { dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); return; } @@ -431,6 +442,56 @@ 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 +500,13 @@ 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); + + /* ... and possibly increased timeout */ + if (t->server) + dns_server_packet_lost(t->server, usec - t->start_usec); + else + dns_scope_packet_lost(t->scope, usec - t->start_usec); r = dns_transaction_go(t); if (r < 0) @@ -488,8 +555,26 @@ static int dns_transaction_make_packet(DnsTransaction *t) { return 0; } +static usec_t transaction_get_resend_timeout(DnsTransaction *t) { + assert(t); + assert(t->scope); + + switch (t->scope->protocol) { + case DNS_PROTOCOL_DNS: + assert(t->server); + + return t->server->resend_timeout; + case DNS_PROTOCOL_LLMNR: + case DNS_PROTOCOL_MDNS: + return t->scope->resend_timeout; + default: + assert_not_reached("Invalid DNS protocol."); + } +} + int dns_transaction_go(DnsTransaction *t) { bool had_stream; + usec_t ts; int r; assert(t); @@ -515,8 +600,10 @@ int dns_transaction_go(DnsTransaction *t) { return 0; } + assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); + t->n_attempts++; - t->server = dns_server_unref(t->server); + t->start_usec = ts; t->received = dns_packet_unref(t->received); t->cached = dns_answer_unref(t->cached); t->cached_rcode = 0; @@ -561,7 +648,7 @@ int dns_transaction_go(DnsTransaction *t) { t->scope->manager->event, &t->timeout_event_source, clock_boottime_or_monotonic(), - now(clock_boottime_or_monotonic()) + jitter, + ts + jitter, LLMNR_JITTER_INTERVAL_USEC, on_transaction_timeout, t); if (r < 0) @@ -596,13 +683,9 @@ 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 +699,7 @@ 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); } @@ -625,7 +708,7 @@ int dns_transaction_go(DnsTransaction *t) { t->scope->manager->event, &t->timeout_event_source, clock_boottime_or_monotonic(), - now(clock_boottime_or_monotonic()) + TRANSACTION_TIMEOUT_USEC(t->scope->protocol), 0, + ts + transaction_get_resend_timeout(t), 0, on_transaction_timeout, t); if (r < 0) return r; @@ -634,91 +717,6 @@ 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", |