From ec2c5e4398f9d65e5dfe61530f2556224733d1e6 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Thu, 31 Jul 2014 17:46:40 +0200 Subject: [PATCH] resolved: implement LLMNR uniqueness verification --- Makefile.am | 2 + src/resolve/resolved-bus.c | 24 +- src/resolve/resolved-dns-query.c | 609 +++---------------------- src/resolve/resolved-dns-query.h | 55 +-- src/resolve/resolved-dns-scope.c | 42 +- src/resolve/resolved-dns-scope.h | 4 +- src/resolve/resolved-dns-stream.h | 4 +- src/resolve/resolved-dns-transaction.c | 538 ++++++++++++++++++++++ src/resolve/resolved-dns-transaction.h | 108 +++++ src/resolve/resolved-dns-zone.c | 270 +++++++++-- src/resolve/resolved-dns-zone.h | 38 +- src/resolve/resolved-link.c | 163 ++++--- src/resolve/resolved-link.h | 3 +- src/resolve/resolved-manager.c | 88 +++- src/resolve/resolved.h | 7 +- src/shared/missing.h | 8 + 16 files changed, 1204 insertions(+), 759 deletions(-) create mode 100644 src/resolve/resolved-dns-transaction.c create mode 100644 src/resolve/resolved-dns-transaction.h diff --git a/Makefile.am b/Makefile.am index 94eeb114ab0..2d7f76d97d9 100644 --- a/Makefile.am +++ b/Makefile.am @@ -4750,6 +4750,8 @@ systemd_resolved_SOURCES = \ src/resolve/resolved-dns-packet.c \ src/resolve/resolved-dns-query.h \ src/resolve/resolved-dns-query.c \ + src/resolve/resolved-dns-transaction.h \ + src/resolve/resolved-dns-transaction.c \ src/resolve/resolved-dns-scope.h \ src/resolve/resolved-dns-scope.c \ src/resolve/resolved-dns-server.h \ diff --git a/src/resolve/resolved-bus.c b/src/resolve/resolved-bus.c index 0b8ecf1b82f..bfb060d86bc 100644 --- a/src/resolve/resolved-bus.c +++ b/src/resolve/resolved-bus.c @@ -42,22 +42,22 @@ static int reply_query_state(DnsQuery *q) { switch (q->state) { - case DNS_QUERY_NO_SERVERS: + case DNS_TRANSACTION_NO_SERVERS: return sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_NAME_SERVERS, "No appropriate name servers or networks for name found"); - case DNS_QUERY_TIMEOUT: + case DNS_TRANSACTION_TIMEOUT: return sd_bus_reply_method_errorf(q->request, SD_BUS_ERROR_TIMEOUT, "Query timed out"); - case DNS_QUERY_ATTEMPTS_MAX: + case DNS_TRANSACTION_ATTEMPTS_MAX_REACHED: return sd_bus_reply_method_errorf(q->request, SD_BUS_ERROR_TIMEOUT, "All attempts to contact name servers or networks failed"); - case DNS_QUERY_RESOURCES: + case DNS_TRANSACTION_RESOURCES: return sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_RESOURCES, "Not enough resources"); - case DNS_QUERY_INVALID_REPLY: + case DNS_TRANSACTION_INVALID_REPLY: return sd_bus_reply_method_errorf(q->request, BUS_ERROR_INVALID_REPLY, "Received invalid reply"); - case DNS_QUERY_FAILURE: { + case DNS_TRANSACTION_FAILURE: { _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL; if (q->answer_rcode == DNS_RCODE_NXDOMAIN) @@ -79,9 +79,9 @@ static int reply_query_state(DnsQuery *q) { return sd_bus_reply_method_error(q->request, &error); } - case DNS_QUERY_NULL: - case DNS_QUERY_PENDING: - case DNS_QUERY_SUCCESS: + case DNS_TRANSACTION_NULL: + case DNS_TRANSACTION_PENDING: + case DNS_TRANSACTION_SUCCESS: default: assert_not_reached("Impossible state"); } @@ -136,7 +136,7 @@ static void bus_method_resolve_hostname_complete(DnsQuery *q) { assert(q); - if (q->state != DNS_QUERY_SUCCESS) { + if (q->state != DNS_TRANSACTION_SUCCESS) { r = reply_query_state(q); goto finish; } @@ -336,7 +336,7 @@ static void bus_method_resolve_address_complete(DnsQuery *q) { assert(q); - if (q->state != DNS_QUERY_SUCCESS) { + if (q->state != DNS_TRANSACTION_SUCCESS) { r = reply_query_state(q); goto finish; } @@ -474,7 +474,7 @@ static void bus_method_resolve_record_complete(DnsQuery *q) { assert(q); - if (q->state != DNS_QUERY_SUCCESS) { + if (q->state != DNS_TRANSACTION_SUCCESS) { r = reply_query_state(q); goto finish; } diff --git a/src/resolve/resolved-dns-query.c b/src/resolve/resolved-dns-query.c index 22770023047..57f7467667d 100644 --- a/src/resolve/resolved-dns-query.c +++ b/src/resolve/resolved-dns-query.c @@ -24,516 +24,36 @@ #include "resolved-dns-query.h" #include "resolved-dns-domain.h" -/* After how much time to repeat classic DNS requests */ -#define DNS_TRANSACTION_TIMEOUT_USEC (5 * USEC_PER_SEC) - -/* After how much time to repeat LLMNR requests, see RFC 4795 Section 7 */ -#define LLMNR_TRANSACTION_TIMEOUT_USEC (1 * USEC_PER_SEC) - /* How long to wait for the query in total */ #define QUERY_TIMEOUT_USEC (30 * USEC_PER_SEC) -/* Maximum attempts to send DNS requests, across all DNS servers */ -#define DNS_TRANSACTION_ATTEMPTS_MAX 8 - -/* Maximum attempts to send LLMNR requests, see RFC 4795 Section 2.7 */ -#define LLMNR_TRANSACTION_ATTEMPTS_MAX 3 - #define CNAME_MAX 8 #define QUERIES_MAX 2048 -#define TRANSACTION_TIMEOUT_USEC(p) ((t)->scope->protocol == DNS_PROTOCOL_LLMNR ? LLMNR_TRANSACTION_TIMEOUT_USEC : DNS_TRANSACTION_TIMEOUT_USEC) -#define TRANSACTION_ATTEMPTS_MAX(p) ((t)->scope->protocol == DNS_PROTOCOL_LLMNR ? LLMNR_TRANSACTION_ATTEMPTS_MAX : DNS_TRANSACTION_ATTEMPTS_MAX) - -static int dns_query_transaction_go(DnsQueryTransaction *t); - -DnsQueryTransaction* dns_query_transaction_free(DnsQueryTransaction *t) { - DnsQuery *q; - - if (!t) - return NULL; - - sd_event_source_unref(t->timeout_event_source); - - dns_question_unref(t->question); - dns_packet_unref(t->sent); - dns_packet_unref(t->received); - dns_answer_unref(t->cached); - - dns_stream_free(t->stream); - - if (t->scope) { - LIST_REMOVE(transactions_by_scope, t->scope->transactions, t); - - if (t->id != 0) - hashmap_remove(t->scope->manager->dns_query_transactions, UINT_TO_PTR(t->id)); - } - - while ((q = set_steal_first(t->queries))) - set_remove(q->transactions, t); - - set_free(t->queries); - - free(t); - return NULL; -} - -DEFINE_TRIVIAL_CLEANUP_FUNC(DnsQueryTransaction*, dns_query_transaction_free); - -static void dns_query_transaction_gc(DnsQueryTransaction *t) { - assert(t); - - if (t->block_gc > 0) - return; - - if (set_isempty(t->queries)) - dns_query_transaction_free(t); -} - -static int dns_query_transaction_new(DnsQueryTransaction **ret, DnsScope *s, DnsQuestion *q) { - _cleanup_(dns_query_transaction_freep) DnsQueryTransaction *t = NULL; - int r; +static void dns_query_stop(DnsQuery *q) { + DnsTransaction *t; - assert(ret); - assert(s); assert(q); - r = hashmap_ensure_allocated(&s->manager->dns_query_transactions, NULL, NULL); - if (r < 0) - return r; - - t = new0(DnsQueryTransaction, 1); - if (!t) - return -ENOMEM; - - t->question = dns_question_ref(q); - - do - random_bytes(&t->id, sizeof(t->id)); - while (t->id == 0 || - hashmap_get(s->manager->dns_query_transactions, UINT_TO_PTR(t->id))); - - r = hashmap_put(s->manager->dns_query_transactions, UINT_TO_PTR(t->id), t); - if (r < 0) { - t->id = 0; - return r; - } - - LIST_PREPEND(transactions_by_scope, s->transactions, t); - t->scope = s; - - if (ret) - *ret = t; - - t = NULL; - - return 0; -} - -static void dns_query_transaction_stop(DnsQueryTransaction *t) { - assert(t); - - t->timeout_event_source = sd_event_source_unref(t->timeout_event_source); - t->stream = dns_stream_free(t->stream); -} - -void dns_query_transaction_complete(DnsQueryTransaction *t, DnsQueryState state) { - DnsQuery *q; - Iterator i; - - assert(t); - assert(!IN_SET(state, DNS_QUERY_NULL, DNS_QUERY_PENDING)); - assert(IN_SET(t->state, DNS_QUERY_NULL, DNS_QUERY_PENDING)); - - /* Note that this call might invalidate the query. Callers - * should hence not attempt to access the query or transaction - * after calling this function. */ - - log_debug("Transaction on scope %s on %s/%s now complete with %s", - dns_protocol_to_string(t->scope->protocol), - t->scope->link ? t->scope->link->name : "*", - t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family), - dns_query_state_to_string(state)); - - t->state = state; - - dns_query_transaction_stop(t); - - /* Notify all queries that are interested, but make sure the - * transaction isn't freed while we are still looking at it */ - t->block_gc++; - SET_FOREACH(q, t->queries, i) - dns_query_ready(q); - t->block_gc--; - - dns_query_transaction_gc(t); -} - -static int on_stream_complete(DnsStream *s, int error) { - _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; - DnsQueryTransaction *t; - - assert(s); - assert(s->transaction); - - /* Copy the data we care about out of the stream before we - * destroy it. */ - t = s->transaction; - p = dns_packet_ref(s->read_packet); - - t->stream = dns_stream_free(t->stream); - - if (error != 0) { - dns_query_transaction_complete(t, DNS_QUERY_RESOURCES); - return 0; - } - - t->block_gc++; - dns_query_transaction_process_reply(t, p); - t->block_gc--; - - /* If the response wasn't useful, then complete the transition now */ - if (t->state == DNS_QUERY_PENDING) - dns_query_transaction_complete(t, DNS_QUERY_INVALID_REPLY); - - return 0; -} - -static int dns_query_transaction_open_tcp(DnsQueryTransaction *t) { - _cleanup_close_ int fd = -1; - int r; - - assert(t); - - if (t->stream) - return 0; - - if (t->scope->protocol == DNS_PROTOCOL_DNS) - fd = dns_scope_tcp_socket(t->scope, AF_UNSPEC, NULL, 53); - else if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { - - /* When we already received a query to this (but it was truncated), send to its sender address */ - if (t->received) - fd = dns_scope_tcp_socket(t->scope, t->received->family, &t->received->sender, t->received->sender_port); - else { - union in_addr_union address; - int family; - - /* Otherwise, try to talk to the owner of a - * the IP address, in case this is a reverse - * PTR lookup */ - r = dns_question_extract_reverse_address(t->question, &family, &address); - if (r < 0) - return r; - if (r == 0) - return -EINVAL; - - fd = dns_scope_tcp_socket(t->scope, family, &address, 5355); - } - } else - return -EAFNOSUPPORT; - - if (fd < 0) - return fd; - - r = dns_stream_new(t->scope->manager, &t->stream, t->scope->protocol, fd); - if (r < 0) - return r; - - fd = -1; - - r = dns_stream_write_packet(t->stream, t->sent); - if (r < 0) { - t->stream = dns_stream_free(t->stream); - return r; - } - - t->received = dns_packet_unref(t->received); - t->stream->complete = on_stream_complete; - t->stream->transaction = t; - - /* The interface index is difficult to determine if we are - * connecting to the local host, hence fill this in right away - * instead of determining it from the socket */ - if (t->scope->link) - t->stream->ifindex = t->scope->link->ifindex; - - return 0; -} - -void dns_query_transaction_process_reply(DnsQueryTransaction *t, DnsPacket *p) { - int r; - - assert(t); - assert(p); - assert(t->state == DNS_QUERY_PENDING); - - /* Note that this call might invalidate the query. Callers - * should hence not attempt to access the query or transaction - * after calling this function. */ - - if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { - assert(t->scope->link); - - /* For LLMNR we will not accept any packets from other - * interfaces */ - - if (p->ifindex != t->scope->link->ifindex) - return; - - if (p->family != t->scope->family) - return; - - /* Tentative replies shall be discarded, see RFC 4795, - * 2.1.1 */ - - if (DNS_PACKET_T(p)) - return; - } - - 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 one of - * a valid DNS server */ - - if (!dns_scope_good_dns_server(t->scope, p->family, &p->sender)) - return; - - if (p->sender_port != 53) - return; - } - - if (t->received != p) { - dns_packet_unref(t->received); - t->received = dns_packet_ref(p); - } - - if (p->ipproto == IPPROTO_TCP) { - if (DNS_PACKET_TC(p)) { - /* Truncated via TCP? Somebody must be fucking with us */ - dns_query_transaction_complete(t, DNS_QUERY_INVALID_REPLY); - return; - } - - if (DNS_PACKET_ID(p) != t->id) { - /* Not the reply to our query? Somebody must be fucking with us */ - dns_query_transaction_complete(t, DNS_QUERY_INVALID_REPLY); - return; - } - } - - if (DNS_PACKET_TC(p)) { - /* Response was truncated, let's try again with good old TCP */ - r = dns_query_transaction_open_tcp(t); - if (r == -ESRCH) { - /* No servers found? Damn! */ - dns_query_transaction_complete(t, DNS_QUERY_NO_SERVERS); - return; - } - if (r < 0) { - /* On LLMNR, if we cannot connect to the host, - * we immediately give up */ - if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { - dns_query_transaction_complete(t, DNS_QUERY_RESOURCES); - return; - } - - /* On DNS, couldn't send? Try immediately again, with a new server */ - dns_scope_next_dns_server(t->scope); - - r = dns_query_transaction_go(t); - if (r < 0) { - dns_query_transaction_complete(t, DNS_QUERY_RESOURCES); - return; - } - - return; - } - } - - /* Parse and update the cache */ - r = dns_packet_extract(p); - if (r < 0) { - dns_query_transaction_complete(t, DNS_QUERY_INVALID_REPLY); - return; - } - - /* According to RFC 4795, section 2.9. only the RRs from the answer section shall be cached */ - dns_cache_put(&t->scope->cache, p->question, DNS_PACKET_RCODE(p), p->answer, DNS_PACKET_ANCOUNT(p), 0); - - if (DNS_PACKET_RCODE(p) == DNS_RCODE_SUCCESS) - dns_query_transaction_complete(t, DNS_QUERY_SUCCESS); - else - dns_query_transaction_complete(t, DNS_QUERY_FAILURE); -} - -static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) { - DnsQueryTransaction *t = userdata; - int r; - - assert(s); - assert(t); - - /* Timeout reached? Try again, with a new server */ - dns_scope_next_dns_server(t->scope); - - r = dns_query_transaction_go(t); - if (r < 0) - dns_query_transaction_complete(t, DNS_QUERY_RESOURCES); - - return 0; -} - -static int dns_query_make_packet(DnsQueryTransaction *t) { - _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; - unsigned n, added = 0; - int r; - - assert(t); - - if (t->sent) - return 0; - - r = dns_packet_new_query(&p, t->scope->protocol, 0); - if (r < 0) - return r; - - for (n = 0; n < t->question->n_keys; n++) { - r = dns_scope_good_key(t->scope, t->question->keys[n]); - if (r < 0) - return r; - if (r == 0) - continue; - - r = dns_packet_append_key(p, t->question->keys[n], NULL); - if (r < 0) - return r; - - added++; - } - - if (added <= 0) - return -EDOM; - - DNS_PACKET_HEADER(p)->qdcount = htobe16(added); - DNS_PACKET_HEADER(p)->id = t->id; - - t->sent = p; - p = NULL; - - return 0; -} - -static int dns_query_transaction_go(DnsQueryTransaction *t) { - bool had_stream; - int r; - - assert(t); - - had_stream = !!t->stream; - - dns_query_transaction_stop(t); - - log_debug("Beginning transaction on scope %s on %s/%s", - dns_protocol_to_string(t->scope->protocol), - t->scope->link ? t->scope->link->name : "*", - t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family)); - - if (t->n_attempts >= TRANSACTION_ATTEMPTS_MAX(t)) { - dns_query_transaction_complete(t, DNS_QUERY_ATTEMPTS_MAX); - return 0; - } - - if (t->scope->protocol == DNS_PROTOCOL_LLMNR && had_stream) { - /* If we already tried via a stream, then we don't - * retry on LLMNR. See RFC 4795, Section 2.7. */ - dns_query_transaction_complete(t, DNS_QUERY_ATTEMPTS_MAX); - return 0; - } - - t->n_attempts++; - t->received = dns_packet_unref(t->received); - t->cached = dns_answer_unref(t->cached); - t->cached_rcode = 0; - - /* First, let's try the cache */ - dns_cache_prune(&t->scope->cache); - r = dns_cache_lookup(&t->scope->cache, t->question, &t->cached_rcode, &t->cached); - if (r < 0) - return r; - if (r > 0) { - if (t->cached_rcode == DNS_RCODE_SUCCESS) - dns_query_transaction_complete(t, DNS_QUERY_SUCCESS); - else - dns_query_transaction_complete(t, DNS_QUERY_FAILURE); - return 0; - } - - /* Otherwise, we need to ask the network */ - r = dns_query_make_packet(t); - if (r == -EDOM) { - /* Not the right request to make on this network? - * (i.e. an A request made on IPv6 or an AAAA request - * made on IPv4, on LLMNR or mDNS.) */ - dns_query_transaction_complete(t, DNS_QUERY_NO_SERVERS); - return 0; - } - if (r < 0) - return r; - - if (t->scope->protocol == DNS_PROTOCOL_LLMNR && - (dns_question_endswith(t->question, "in-addr.arpa") > 0 || - dns_question_endswith(t->question, "ip6.arpa") > 0)) { - - /* RFC 4795, Section 2.4. says reverse lookups shall - * always be made via TCP on LLMNR */ - r = dns_query_transaction_open_tcp(t); - } else { - /* Try via UDP, and if that fails due to large size try via TCP */ - r = dns_scope_send(t->scope, t->sent); - if (r == -EMSGSIZE) - r = dns_query_transaction_open_tcp(t); - } - if (r == -ESRCH) { - /* No servers to send this to? */ - dns_query_transaction_complete(t, DNS_QUERY_NO_SERVERS); - return 0; - } - if (r < 0) { - /* Couldn't send? Try immediately again, with a new server */ - dns_scope_next_dns_server(t->scope); + q->timeout_event_source = sd_event_source_unref(q->timeout_event_source); - return dns_query_transaction_go(t); + while ((t = set_steal_first(q->transactions))) { + set_remove(t->queries, q); + dns_transaction_gc(t); } - - r = sd_event_add_time(t->scope->manager->event, &t->timeout_event_source, CLOCK_MONOTONIC, now(CLOCK_MONOTONIC) + TRANSACTION_TIMEOUT_USEC(t), 0, on_transaction_timeout, t); - if (r < 0) - return r; - - t->state = DNS_QUERY_PENDING; - return 1; } DnsQuery *dns_query_free(DnsQuery *q) { - DnsQueryTransaction *t; - if (!q) return NULL; - sd_bus_message_unref(q->request); + dns_query_stop(q); + set_free(q->transactions); dns_question_unref(q->question); dns_answer_unref(q->answer); - sd_event_source_unref(q->timeout_event_source); - - while ((t = set_steal_first(q->transactions))) { - set_remove(t->queries, q); - dns_query_transaction_gc(t); - } - - set_free(q->transactions); + sd_bus_message_unref(q->request); if (q->manager) { LIST_REMOVE(queries, q->manager->dns_queries, q); @@ -587,23 +107,10 @@ int dns_query_new(Manager *m, DnsQuery **ret, DnsQuestion *question) { return 0; } -static void dns_query_stop(DnsQuery *q) { - DnsQueryTransaction *t; - - assert(q); - - q->timeout_event_source = sd_event_source_unref(q->timeout_event_source); - - while ((t = set_steal_first(q->transactions))) { - set_remove(t->queries, q); - dns_query_transaction_gc(t); - } -} - -static void dns_query_complete(DnsQuery *q, DnsQueryState state) { +static void dns_query_complete(DnsQuery *q, DnsTransactionState state) { assert(q); - assert(!IN_SET(state, DNS_QUERY_NULL, DNS_QUERY_PENDING)); - assert(IN_SET(q->state, DNS_QUERY_NULL, DNS_QUERY_PENDING)); + assert(!IN_SET(state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING)); + assert(IN_SET(q->state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING)); /* Note that this call might invalidate the query. Callers * should hence not attempt to access the query or transaction @@ -622,16 +129,17 @@ static int on_query_timeout(sd_event_source *s, usec_t usec, void *userdata) { assert(s); assert(q); - dns_query_complete(q, DNS_QUERY_TIMEOUT); + dns_query_complete(q, DNS_TRANSACTION_TIMEOUT); return 0; } static int dns_query_add_transaction(DnsQuery *q, DnsScope *s, DnsResourceKey *key) { _cleanup_(dns_question_unrefp) DnsQuestion *question = NULL; - DnsQueryTransaction *t; + DnsTransaction *t; int r; assert(q); + assert(s); r = set_ensure_allocated(&q->transactions, NULL, NULL); if (r < 0) @@ -648,34 +156,31 @@ static int dns_query_add_transaction(DnsQuery *q, DnsScope *s, DnsResourceKey *k } else question = dns_question_ref(q->question); - LIST_FOREACH(transactions_by_scope, t, s->transactions) - if (dns_question_is_superset(t->question, question)) - break; - + t = dns_scope_find_transaction(s, question); if (!t) { - r = dns_query_transaction_new(&t, s, question); + r = dns_transaction_new(&t, s, question); if (r < 0) return r; } r = set_ensure_allocated(&t->queries, NULL, NULL); if (r < 0) - goto fail; + goto gc; r = set_put(t->queries, q); if (r < 0) - goto fail; + goto gc; r = set_put(q->transactions, t); if (r < 0) { set_remove(t->queries, q); - goto fail; + goto gc; } return 0; -fail: - dns_query_transaction_gc(t); +gc: + dns_transaction_gc(t); return r; } @@ -709,14 +214,14 @@ static int dns_query_add_transaction_split(DnsQuery *q, DnsScope *s) { int dns_query_go(DnsQuery *q) { DnsScopeMatch found = DNS_SCOPE_NO; DnsScope *s, *first = NULL; - DnsQueryTransaction *t; + DnsTransaction *t; const char *name; Iterator i; int r; assert(q); - if (q->state != DNS_QUERY_NULL) + if (q->state != DNS_TRANSACTION_NULL) return 0; assert(q->question); @@ -752,21 +257,21 @@ int dns_query_go(DnsQuery *q) { r = dns_query_add_transaction_split(q, first); if (r < 0) - return r; + goto fail; LIST_FOREACH(scopes, s, first->scopes_next) { DnsScopeMatch match; match = dns_scope_good_domain(s, name); if (match < 0) - return match; + goto fail; if (match != found) continue; r = dns_query_add_transaction_split(q, s); if (r < 0) - return r; + goto fail; } q->answer = dns_answer_unref(q->answer); @@ -777,15 +282,17 @@ int dns_query_go(DnsQuery *q) { if (r < 0) goto fail; - q->state = DNS_QUERY_PENDING; + q->state = DNS_TRANSACTION_PENDING; q->block_ready++; + /* Start the transactions that are not started yet */ SET_FOREACH(t, q->transactions, i) { - if (t->state == DNS_QUERY_NULL) { - r = dns_query_transaction_go(t); - if (r < 0) - goto fail; - } + if (t->state != DNS_TRANSACTION_NULL) + continue; + + r = dns_transaction_go(t); + if (r < 0) + goto fail; } q->block_ready--; @@ -799,8 +306,8 @@ fail: } void dns_query_ready(DnsQuery *q) { - DnsQueryTransaction *t; - DnsQueryState state = DNS_QUERY_NO_SERVERS; + DnsTransaction *t; + DnsTransactionState state = DNS_TRANSACTION_NO_SERVERS; _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; int rcode = 0; DnsScope *scope = NULL; @@ -808,7 +315,7 @@ void dns_query_ready(DnsQuery *q) { Iterator i; assert(q); - assert(IN_SET(q->state, DNS_QUERY_NULL, DNS_QUERY_PENDING)); + assert(IN_SET(q->state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING)); /* Note that this call might invalidate the query. Callers * should hence not attempt to access the query or transaction @@ -821,18 +328,18 @@ void dns_query_ready(DnsQuery *q) { SET_FOREACH(t, q->transactions, i) { /* If we found a successful answer, ignore all answers from other scopes */ - if (state == DNS_QUERY_SUCCESS && t->scope != scope) + if (state == DNS_TRANSACTION_SUCCESS && t->scope != scope) continue; /* One of the transactions is still going on, let's maybe wait for it */ - if (IN_SET(t->state, DNS_QUERY_PENDING, DNS_QUERY_NULL)) { + if (IN_SET(t->state, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_NULL)) { pending = true; continue; } /* One of the transactions is successful, let's use * it, and copy its data out */ - if (t->state == DNS_QUERY_SUCCESS) { + if (t->state == DNS_TRANSACTION_SUCCESS) { DnsAnswer *a; if (t->received) { @@ -843,12 +350,12 @@ void dns_query_ready(DnsQuery *q) { a = t->cached; } - if (state == DNS_QUERY_SUCCESS) { + if (state == DNS_TRANSACTION_SUCCESS) { DnsAnswer *merged; merged = dns_answer_merge(answer, a); if (!merged) { - dns_query_complete(q, DNS_QUERY_RESOURCES); + dns_query_complete(q, DNS_TRANSACTION_RESOURCES); return; } @@ -860,14 +367,14 @@ void dns_query_ready(DnsQuery *q) { } scope = t->scope; - state = DNS_QUERY_SUCCESS; + state = DNS_TRANSACTION_SUCCESS; continue; } /* One of the transactions has failed, let's see * whether we find anything better, but if not, return * its response data */ - if (state != DNS_QUERY_SUCCESS && t->state == DNS_QUERY_FAILURE) { + if (state != DNS_TRANSACTION_SUCCESS && t->state == DNS_TRANSACTION_FAILURE) { DnsAnswer *a; if (t->received) { @@ -882,11 +389,11 @@ void dns_query_ready(DnsQuery *q) { answer = dns_answer_ref(a); scope = t->scope; - state = DNS_QUERY_FAILURE; + state = DNS_TRANSACTION_FAILURE; continue; } - if (state == DNS_QUERY_NO_SERVERS && t->state != DNS_QUERY_NO_SERVERS) + if (state == DNS_TRANSACTION_NO_SERVERS && t->state != DNS_TRANSACTION_NO_SERVERS) state = t->state; } @@ -894,18 +401,18 @@ void dns_query_ready(DnsQuery *q) { /* If so far we weren't successful, and there's * something still pending, then wait for it */ - if (state != DNS_QUERY_SUCCESS) + if (state != DNS_TRANSACTION_SUCCESS) return; /* If we already were successful, then only wait for * other transactions on the same scope to finish. */ SET_FOREACH(t, q->transactions, i) { - if (t->scope == scope && IN_SET(t->state, DNS_QUERY_PENDING, DNS_QUERY_NULL)) + if (t->scope == scope && IN_SET(t->state, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_NULL)) return; } } - if (IN_SET(state, DNS_QUERY_SUCCESS, DNS_QUERY_FAILURE)) { + if (IN_SET(state, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_FAILURE)) { q->answer = dns_answer_ref(answer); q->answer_rcode = rcode; q->answer_ifindex = (scope && scope->link) ? scope->link->ifindex : 0; @@ -934,21 +441,7 @@ int dns_query_cname_redirect(DnsQuery *q, const char *name) { q->n_cname_redirects++; dns_query_stop(q); - q->state = DNS_QUERY_NULL; + q->state = DNS_TRANSACTION_NULL; return 0; } - -static const char* const dns_query_state_table[_DNS_QUERY_STATE_MAX] = { - [DNS_QUERY_NULL] = "null", - [DNS_QUERY_PENDING] = "pending", - [DNS_QUERY_FAILURE] = "failure", - [DNS_QUERY_SUCCESS] = "success", - [DNS_QUERY_NO_SERVERS] = "no-servers", - [DNS_QUERY_TIMEOUT] = "timeout", - [DNS_QUERY_ATTEMPTS_MAX] = "attempts-max", - [DNS_QUERY_INVALID_REPLY] = "invalid-reply", - [DNS_QUERY_RESOURCES] = "resources", - [DNS_QUERY_ABORTED] = "aborted", -}; -DEFINE_STRING_TABLE_LOOKUP(dns_query_state, DnsQueryState); diff --git a/src/resolve/resolved-dns-query.h b/src/resolve/resolved-dns-query.h index 67fe7f6e8f5..7fc11dfbf45 100644 --- a/src/resolve/resolved-dns-query.h +++ b/src/resolve/resolved-dns-query.h @@ -28,63 +28,20 @@ #include "set.h" typedef struct DnsQuery DnsQuery; -typedef struct DnsQueryTransaction DnsQueryTransaction; #include "resolved.h" #include "resolved-dns-scope.h" #include "resolved-dns-rr.h" -#include "resolved-dns-packet.h" #include "resolved-dns-question.h" #include "resolved-dns-answer.h" #include "resolved-dns-stream.h" - -typedef enum DnsQueryState { - DNS_QUERY_NULL, - DNS_QUERY_PENDING, - DNS_QUERY_FAILURE, - DNS_QUERY_SUCCESS, - DNS_QUERY_NO_SERVERS, - DNS_QUERY_TIMEOUT, - DNS_QUERY_ATTEMPTS_MAX, - DNS_QUERY_INVALID_REPLY, - DNS_QUERY_RESOURCES, - DNS_QUERY_ABORTED, - _DNS_QUERY_STATE_MAX, - _DNS_QUERY_STATE_INVALID = -1 -} DnsQueryState; - -struct DnsQueryTransaction { - DnsScope *scope; - - DnsQuestion *question; - - DnsQueryState state; - uint16_t id; - - DnsPacket *sent, *received; - DnsAnswer *cached; - int cached_rcode; - - sd_event_source *timeout_event_source; - unsigned n_attempts; - - /* TCP connection logic, if we need it */ - DnsStream *stream; - - /* Queries this transaction is referenced by and that shall by - * notified about this specific transaction completing. */ - Set *queries; - - unsigned block_gc; - - LIST_FIELDS(DnsQueryTransaction, transactions_by_scope); -}; +#include "resolved-dns-transaction.h" struct DnsQuery { Manager *manager; DnsQuestion *question; - DnsQueryState state; + DnsTransactionState state; unsigned n_cname_redirects; sd_event_source *timeout_event_source; @@ -109,11 +66,6 @@ struct DnsQuery { LIST_FIELDS(DnsQuery, queries); }; -DnsQueryTransaction* dns_query_transaction_free(DnsQueryTransaction *t); -void dns_query_transaction_complete(DnsQueryTransaction *t, DnsQueryState state); - -void dns_query_transaction_process_reply(DnsQueryTransaction *t, DnsPacket *p); - int dns_query_new(Manager *m, DnsQuery **q, DnsQuestion *question); DnsQuery *dns_query_free(DnsQuery *q); @@ -122,7 +74,4 @@ void dns_query_ready(DnsQuery *q); int dns_query_cname_redirect(DnsQuery *q, const char *name); -const char* dns_query_state_to_string(DnsQueryState p) _const_; -DnsQueryState dns_query_state_from_string(const char *s) _pure_; - DEFINE_TRIVIAL_CLEANUP_FUNC(DnsQuery*, dns_query_free); diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c index 4c53edb5a03..60617617233 100644 --- a/src/resolve/resolved-dns-scope.c +++ b/src/resolve/resolved-dns-scope.c @@ -28,8 +28,6 @@ #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, Link *l, DnsProtocol protocol, int family) { DnsScope *s; @@ -56,7 +54,7 @@ int dns_scope_new(Manager *m, DnsScope **ret, Link *l, DnsProtocol protocol, int } DnsScope* dns_scope_free(DnsScope *s) { - DnsQueryTransaction *t; + DnsTransaction *t; if (!s) return NULL; @@ -71,10 +69,10 @@ DnsScope* dns_scope_free(DnsScope *s) { * freed while we still look at it */ t->block_gc++; - dns_query_transaction_complete(t, DNS_QUERY_ABORTED); + dns_transaction_complete(t, DNS_TRANSACTION_ABORTED); t->block_gc--; - dns_query_transaction_free(t); + dns_transaction_free(t); } dns_cache_flush(&s->cache); @@ -389,7 +387,16 @@ int dns_scope_good_dns_server(DnsScope *s, int family, const union in_addr_union 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) { +static int dns_scope_make_reply_packet( + DnsScope *s, + uint16_t id, + int rcode, + DnsQuestion *q, + DnsAnswer *answer, + DnsAnswer *soa, + bool tentative, + DnsPacket **ret) { + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; unsigned i; int r; @@ -409,7 +416,7 @@ static int dns_scope_make_reply_packet(DnsScope *s, uint16_t id, int rcode, DnsQ 0 /* opcode */, 0 /* c */, 0 /* tc */, - 0 /* t */, + tentative, 0 /* (ra) */, 0 /* (ad) */, 0 /* (cd) */, @@ -454,6 +461,7 @@ static int dns_scope_make_reply_packet(DnsScope *s, uint16_t id, int rcode, DnsQ 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; + bool tentative = false; int r, fd; assert(s); @@ -485,7 +493,7 @@ void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p) { return; } - r = dns_zone_lookup(&s->zone, p->question, &answer, &soa); + r = dns_zone_lookup(&s->zone, p->question, &answer, &soa, &tentative); if (r < 0) { log_debug("Failed to lookup key: %s", strerror(-r)); return; @@ -496,7 +504,7 @@ void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p) { if (answer) 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); + r = dns_scope_make_reply_packet(s, DNS_PACKET_ID(p), DNS_RCODE_SUCCESS, p->question, answer, soa, tentative, &reply); if (r < 0) { log_debug("Failed to build reply packet: %s", strerror(-r)); return; @@ -526,3 +534,19 @@ void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p) { return; } } + +DnsTransaction *dns_scope_find_transaction(DnsScope *scope, DnsQuestion *question) { + DnsTransaction *t; + + assert(scope); + assert(question); + + /* Try to find an ongoing transaction that is a equal or a + * superset of the specified question */ + + LIST_FOREACH(transactions_by_scope, t, scope->transactions) + if (dns_question_is_superset(t->question, question) > 0) + return t; + + return NULL; +} diff --git a/src/resolve/resolved-dns-scope.h b/src/resolve/resolved-dns-scope.h index 639c4b4e86c..67a6ba29011 100644 --- a/src/resolve/resolved-dns-scope.h +++ b/src/resolve/resolved-dns-scope.h @@ -55,7 +55,7 @@ struct DnsScope { DnsCache cache; DnsZone zone; - LIST_HEAD(DnsQueryTransaction, transactions); + LIST_HEAD(DnsTransaction, transactions); LIST_FIELDS(DnsScope, scopes); }; @@ -76,3 +76,5 @@ void dns_scope_next_dns_server(DnsScope *s); int dns_scope_llmnr_membership(DnsScope *s, bool b); void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p); + +DnsTransaction *dns_scope_find_transaction(DnsScope *scope, DnsQuestion *question); diff --git a/src/resolve/resolved-dns-stream.h b/src/resolve/resolved-dns-stream.h index 5509f7528b1..fc24bb670ea 100644 --- a/src/resolve/resolved-dns-stream.h +++ b/src/resolve/resolved-dns-stream.h @@ -26,6 +26,8 @@ typedef struct DnsStream DnsStream; #include "resolved.h" +#include "resolved-dns-packet.h" +#include "resolved-dns-transaction.h" struct DnsStream { Manager *manager; @@ -51,7 +53,7 @@ struct DnsStream { int (*on_packet)(DnsStream *s); int (*complete)(DnsStream *s, int error); - DnsQueryTransaction *transaction; + DnsTransaction *transaction; LIST_FIELDS(DnsStream, streams); }; diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c new file mode 100644 index 00000000000..92f7e4c5b1f --- /dev/null +++ b/src/resolve/resolved-dns-transaction.c @@ -0,0 +1,538 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + 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 . +***/ + +#include "af-list.h" + +#include "resolved-dns-transaction.h" + +DnsTransaction* dns_transaction_free(DnsTransaction *t) { + DnsQuery *q; + DnsZoneItem *i; + + if (!t) + return NULL; + + sd_event_source_unref(t->timeout_event_source); + + dns_question_unref(t->question); + dns_packet_unref(t->sent); + dns_packet_unref(t->received); + dns_answer_unref(t->cached); + + dns_stream_free(t->stream); + + if (t->scope) { + LIST_REMOVE(transactions_by_scope, t->scope->transactions, t); + + if (t->id != 0) + hashmap_remove(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id)); + } + + while ((q = set_steal_first(t->queries))) + set_remove(q->transactions, t); + set_free(t->queries); + + while ((i = set_steal_first(t->zone_items))) + i->probe_transaction = NULL; + set_free(t->zone_items); + + free(t); + return NULL; +} + +DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction*, dns_transaction_free); + +void dns_transaction_gc(DnsTransaction *t) { + assert(t); + + if (t->block_gc > 0) + return; + + if (set_isempty(t->queries) && set_isempty(t->zone_items)) + dns_transaction_free(t); +} + +int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsQuestion *q) { + _cleanup_(dns_transaction_freep) DnsTransaction *t = NULL; + int r; + + assert(ret); + assert(s); + assert(q); + + r = hashmap_ensure_allocated(&s->manager->dns_transactions, NULL, NULL); + if (r < 0) + return r; + + t = new0(DnsTransaction, 1); + if (!t) + return -ENOMEM; + + t->question = dns_question_ref(q); + + do + random_bytes(&t->id, sizeof(t->id)); + while (t->id == 0 || + hashmap_get(s->manager->dns_transactions, UINT_TO_PTR(t->id))); + + r = hashmap_put(s->manager->dns_transactions, UINT_TO_PTR(t->id), t); + if (r < 0) { + t->id = 0; + return r; + } + + LIST_PREPEND(transactions_by_scope, s->transactions, t); + t->scope = s; + + if (ret) + *ret = t; + + t = NULL; + + return 0; +} + +static void dns_transaction_stop(DnsTransaction *t) { + assert(t); + + t->timeout_event_source = sd_event_source_unref(t->timeout_event_source); + t->stream = dns_stream_free(t->stream); +} + +static void dns_transaction_tentative(DnsTransaction *t, DnsPacket *p) { + DnsZoneItem *z; + Iterator i; + + assert(t); + assert(p); + + if (manager_our_packet(t->scope->manager, p) != 0) + return; + + log_debug("Transaction on scope %s on %s/%s got tentative packet", + dns_protocol_to_string(t->scope->protocol), + t->scope->link ? t->scope->link->name : "*", + t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family)); + + t->block_gc++; + SET_FOREACH(z, t->zone_items, i) + dns_zone_item_conflict(z); + t->block_gc--; + + dns_transaction_gc(t); +} + +void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state) { + DnsQuery *q; + DnsZoneItem *z; + Iterator i; + + assert(t); + assert(!IN_SET(state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING)); + assert(IN_SET(t->state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING)); + + /* Note that this call might invalidate the query. Callers + * should hence not attempt to access the query or transaction + * after calling this function. */ + + log_debug("Transaction on scope %s on %s/%s now complete with <%s>", + dns_protocol_to_string(t->scope->protocol), + t->scope->link ? t->scope->link->name : "*", + t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family), + dns_transaction_state_to_string(state)); + + t->state = state; + + dns_transaction_stop(t); + + /* Notify all queries that are interested, but make sure the + * transaction isn't freed while we are still looking at it */ + t->block_gc++; + SET_FOREACH(q, t->queries, i) + dns_query_ready(q); + SET_FOREACH(z, t->zone_items, i) + dns_zone_item_ready(z); + t->block_gc--; + + dns_transaction_gc(t); +} + +static int on_stream_complete(DnsStream *s, int error) { + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + DnsTransaction *t; + + assert(s); + assert(s->transaction); + + /* Copy the data we care about out of the stream before we + * destroy it. */ + t = s->transaction; + p = dns_packet_ref(s->read_packet); + + t->stream = dns_stream_free(t->stream); + + if (error != 0) { + dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); + return 0; + } + + t->block_gc++; + dns_transaction_process_reply(t, p); + t->block_gc--; + + /* If the response wasn't useful, then complete the transition now */ + if (t->state == DNS_TRANSACTION_PENDING) + dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); + + return 0; +} + +static int dns_transaction_open_tcp(DnsTransaction *t) { + _cleanup_close_ int fd = -1; + int r; + + assert(t); + + if (t->stream) + return 0; + + if (t->scope->protocol == DNS_PROTOCOL_DNS) + fd = dns_scope_tcp_socket(t->scope, AF_UNSPEC, NULL, 53); + else if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { + + /* When we already received a query to this (but it was truncated), send to its sender address */ + if (t->received) + fd = dns_scope_tcp_socket(t->scope, t->received->family, &t->received->sender, t->received->sender_port); + else { + union in_addr_union address; + int family; + + /* Otherwise, try to talk to the owner of a + * the IP address, in case this is a reverse + * PTR lookup */ + r = dns_question_extract_reverse_address(t->question, &family, &address); + if (r < 0) + return r; + if (r == 0) + return -EINVAL; + + fd = dns_scope_tcp_socket(t->scope, family, &address, 5355); + } + } else + return -EAFNOSUPPORT; + + if (fd < 0) + return fd; + + r = dns_stream_new(t->scope->manager, &t->stream, t->scope->protocol, fd); + if (r < 0) + return r; + + fd = -1; + + r = dns_stream_write_packet(t->stream, t->sent); + if (r < 0) { + t->stream = dns_stream_free(t->stream); + return r; + } + + t->received = dns_packet_unref(t->received); + t->stream->complete = on_stream_complete; + t->stream->transaction = t; + + /* The interface index is difficult to determine if we are + * connecting to the local host, hence fill this in right away + * instead of determining it from the socket */ + if (t->scope->link) + t->stream->ifindex = t->scope->link->ifindex; + + return 0; +} + +void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { + int r; + + assert(t); + assert(p); + assert(t->state == DNS_TRANSACTION_PENDING); + + /* Note that this call might invalidate the query. Callers + * should hence not attempt to access the query or transaction + * after calling this function. */ + + if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { + assert(t->scope->link); + + /* For LLMNR we will not accept any packets from other + * interfaces */ + + if (p->ifindex != t->scope->link->ifindex) + return; + + if (p->family != t->scope->family) + return; + + /* Tentative packets are not full responses but still + * useful for identifying uniqueness conflicts during + * probing. */ + if (DNS_PACKET_T(p)) { + dns_transaction_tentative(t, p); + return; + } + } + + 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 one of + * a valid DNS server */ + + if (!dns_scope_good_dns_server(t->scope, p->family, &p->sender)) + return; + + if (p->sender_port != 53) + return; + } + + if (t->received != p) { + dns_packet_unref(t->received); + t->received = dns_packet_ref(p); + } + + if (p->ipproto == IPPROTO_TCP) { + if (DNS_PACKET_TC(p)) { + /* Truncated via TCP? Somebody must be fucking with us */ + dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); + return; + } + + if (DNS_PACKET_ID(p) != t->id) { + /* Not the reply to our query? Somebody must be fucking with us */ + dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); + return; + } + } + + if (DNS_PACKET_TC(p)) { + /* Response was truncated, let's try again with good old TCP */ + r = dns_transaction_open_tcp(t); + if (r == -ESRCH) { + /* No servers found? Damn! */ + dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); + return; + } + if (r < 0) { + /* On LLMNR, if we cannot connect to the host, + * we immediately give up */ + if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { + dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); + return; + } + + /* On DNS, couldn't send? Try immediately again, with a new server */ + dns_scope_next_dns_server(t->scope); + + r = dns_transaction_go(t); + if (r < 0) { + dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); + return; + } + + return; + } + } + + /* Parse and update the cache */ + r = dns_packet_extract(p); + if (r < 0) { + dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); + return; + } + + /* According to RFC 4795, section 2.9. only the RRs from the answer section shall be cached */ + dns_cache_put(&t->scope->cache, p->question, DNS_PACKET_RCODE(p), p->answer, DNS_PACKET_ANCOUNT(p), 0); + + if (DNS_PACKET_RCODE(p) == DNS_RCODE_SUCCESS) + dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); + else + dns_transaction_complete(t, DNS_TRANSACTION_FAILURE); +} + +static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) { + DnsTransaction *t = userdata; + int r; + + assert(s); + assert(t); + + /* Timeout reached? Try again, with a new server */ + dns_scope_next_dns_server(t->scope); + + r = dns_transaction_go(t); + if (r < 0) + dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); + + return 0; +} + +static int dns_transaction_make_packet(DnsTransaction *t) { + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + unsigned n, added = 0; + int r; + + assert(t); + + if (t->sent) + return 0; + + r = dns_packet_new_query(&p, t->scope->protocol, 0); + if (r < 0) + return r; + + for (n = 0; n < t->question->n_keys; n++) { + r = dns_scope_good_key(t->scope, t->question->keys[n]); + if (r < 0) + return r; + if (r == 0) + continue; + + r = dns_packet_append_key(p, t->question->keys[n], NULL); + if (r < 0) + return r; + + added++; + } + + if (added <= 0) + return -EDOM; + + DNS_PACKET_HEADER(p)->qdcount = htobe16(added); + DNS_PACKET_HEADER(p)->id = t->id; + + t->sent = p; + p = NULL; + + return 0; +} + +int dns_transaction_go(DnsTransaction *t) { + bool had_stream; + int r; + + assert(t); + + had_stream = !!t->stream; + + dns_transaction_stop(t); + + log_debug("Beginning transaction on scope %s on %s/%s", + dns_protocol_to_string(t->scope->protocol), + t->scope->link ? t->scope->link->name : "*", + t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family)); + + if (t->n_attempts >= TRANSACTION_ATTEMPTS_MAX(t->scope->protocol)) { + dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); + return 0; + } + + if (t->scope->protocol == DNS_PROTOCOL_LLMNR && had_stream) { + /* If we already tried via a stream, then we don't + * retry on LLMNR. See RFC 4795, Section 2.7. */ + dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); + return 0; + } + + t->n_attempts++; + t->received = dns_packet_unref(t->received); + t->cached = dns_answer_unref(t->cached); + t->cached_rcode = 0; + + /* First, let's try the cache */ + dns_cache_prune(&t->scope->cache); + r = dns_cache_lookup(&t->scope->cache, t->question, &t->cached_rcode, &t->cached); + if (r < 0) + return r; + if (r > 0) { + if (t->cached_rcode == DNS_RCODE_SUCCESS) + dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); + else + dns_transaction_complete(t, DNS_TRANSACTION_FAILURE); + return 0; + } + + /* Otherwise, we need to ask the network */ + r = dns_transaction_make_packet(t); + if (r == -EDOM) { + /* Not the right request to make on this network? + * (i.e. an A request made on IPv6 or an AAAA request + * made on IPv4, on LLMNR or mDNS.) */ + dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); + return 0; + } + if (r < 0) + return r; + + if (t->scope->protocol == DNS_PROTOCOL_LLMNR && + (dns_question_endswith(t->question, "in-addr.arpa") > 0 || + dns_question_endswith(t->question, "ip6.arpa") > 0)) { + + /* RFC 4795, Section 2.4. says reverse lookups shall + * always be made via TCP on LLMNR */ + r = dns_transaction_open_tcp(t); + } else { + /* Try via UDP, and if that fails due to large size try via TCP */ + r = dns_scope_send(t->scope, t->sent); + if (r == -EMSGSIZE) + r = dns_transaction_open_tcp(t); + } + if (r == -ESRCH) { + /* No servers to send this to? */ + dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); + return 0; + } + if (r < 0) { + /* Couldn't send? Try immediately again, with a new server */ + dns_scope_next_dns_server(t->scope); + + return dns_transaction_go(t); + } + + r = sd_event_add_time(t->scope->manager->event, &t->timeout_event_source, CLOCK_MONOTONIC, now(CLOCK_MONOTONIC) + TRANSACTION_TIMEOUT_USEC(t->scope->protocol), 0, on_transaction_timeout, t); + if (r < 0) + return r; + + t->state = DNS_TRANSACTION_PENDING; + return 1; +} + +static const char* const dns_transaction_state_table[_DNS_TRANSACTION_STATE_MAX] = { + [DNS_TRANSACTION_NULL] = "null", + [DNS_TRANSACTION_PENDING] = "pending", + [DNS_TRANSACTION_FAILURE] = "failure", + [DNS_TRANSACTION_SUCCESS] = "success", + [DNS_TRANSACTION_NO_SERVERS] = "no-servers", + [DNS_TRANSACTION_TIMEOUT] = "timeout", + [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED] = "attempts-max-reached", + [DNS_TRANSACTION_INVALID_REPLY] = "invalid-reply", + [DNS_TRANSACTION_RESOURCES] = "resources", + [DNS_TRANSACTION_ABORTED] = "aborted", +}; +DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state, DnsTransactionState); diff --git a/src/resolve/resolved-dns-transaction.h b/src/resolve/resolved-dns-transaction.h new file mode 100644 index 00000000000..d825b3ec859 --- /dev/null +++ b/src/resolve/resolved-dns-transaction.h @@ -0,0 +1,108 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +#pragma once + +/*** + 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 . +***/ + +typedef struct DnsTransaction DnsTransaction; +typedef enum DnsTransactionState DnsTransactionState; + +enum DnsTransactionState { + DNS_TRANSACTION_NULL, + DNS_TRANSACTION_PENDING, + DNS_TRANSACTION_FAILURE, + DNS_TRANSACTION_SUCCESS, + DNS_TRANSACTION_NO_SERVERS, + DNS_TRANSACTION_TIMEOUT, + DNS_TRANSACTION_ATTEMPTS_MAX_REACHED, + DNS_TRANSACTION_INVALID_REPLY, + DNS_TRANSACTION_RESOURCES, + DNS_TRANSACTION_ABORTED, + _DNS_TRANSACTION_STATE_MAX, + _DNS_TRANSACTION_STATE_INVALID = -1 +}; + +#include "resolved-dns-scope.h" +#include "resolved-dns-rr.h" +#include "resolved-dns-packet.h" +#include "resolved-dns-question.h" +#include "resolved-dns-answer.h" +#include "resolved-dns-stream.h" + +struct DnsTransaction { + DnsScope *scope; + + DnsQuestion *question; + + DnsTransactionState state; + uint16_t id; + + DnsPacket *sent, *received; + DnsAnswer *cached; + int cached_rcode; + + sd_event_source *timeout_event_source; + unsigned n_attempts; + + /* TCP connection logic, if we need it */ + DnsStream *stream; + + /* Queries this transaction is referenced by and that shall be + * notified about this specific transaction completing. */ + Set *queries; + + /* Zone items this transaction is referenced by and that shall + * be notified about completion. */ + Set *zone_items; + + unsigned block_gc; + + LIST_FIELDS(DnsTransaction, transactions_by_scope); +}; + +int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsQuestion *q); +DnsTransaction* dns_transaction_free(DnsTransaction *t); + +void dns_transaction_gc(DnsTransaction *t); +int dns_transaction_go(DnsTransaction *t); + +void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p); +void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state); + +const char* dns_transaction_state_to_string(DnsTransactionState p) _const_; +DnsTransactionState dns_transaction_state_from_string(const char *s) _pure_; + +/* After how much time to repeat classic DNS requests */ +#define DNS_TRANSACTION_TIMEOUT_USEC (5 * USEC_PER_SEC) + +/* After how much time to repeat LLMNR requests, see RFC 4795 Section 7 */ +#define LLMNR_TRANSACTION_TIMEOUT_USEC (1 * USEC_PER_SEC) + +/* LLMNR Jitter interval, see RFC 4795 Section 7 */ +#define LLMNR_TRANSACTION_JITTER_INTERVAL_USEC (100 * USEC_PER_MSEC) + +/* Maximum attempts to send DNS requests, across all DNS servers */ +#define DNS_TRANSACTION_ATTEMPTS_MAX 8 + +/* Maximum attempts to send LLMNR requests, see RFC 4795 Section 2.7 */ +#define LLMNR_TRANSACTION_ATTEMPTS_MAX 3 + +#define TRANSACTION_TIMEOUT_USEC(p) (p == DNS_PROTOCOL_LLMNR ? LLMNR_TRANSACTION_TIMEOUT_USEC : DNS_TRANSACTION_TIMEOUT_USEC) +#define TRANSACTION_ATTEMPTS_MAX(p) (p == DNS_PROTOCOL_LLMNR ? LLMNR_TRANSACTION_ATTEMPTS_MAX : DNS_TRANSACTION_ATTEMPTS_MAX) diff --git a/src/resolve/resolved-dns-zone.c b/src/resolve/resolved-dns-zone.c index 99ea420ff4e..b577fd6cc68 100644 --- a/src/resolve/resolved-dns-zone.c +++ b/src/resolve/resolved-dns-zone.c @@ -28,20 +28,27 @@ /* Never allow more than 1K entries */ #define ZONE_MAX 1024 -typedef struct DnsZoneItem DnsZoneItem; +static void dns_zone_item_probe_stop(DnsZoneItem *i) { + DnsTransaction *t; + assert(i); -struct DnsZoneItem { - DnsResourceRecord *rr; - bool verified; - LIST_FIELDS(DnsZoneItem, by_key); - LIST_FIELDS(DnsZoneItem, by_name); -}; + if (!i->probe_transaction) + return; + + t = i->probe_transaction; + i->probe_transaction = NULL; + + set_remove(t->zone_items, i); + dns_transaction_gc(t); +} static void dns_zone_item_free(DnsZoneItem *i) { if (!i) return; + dns_zone_item_probe_stop(i); dns_resource_record_unref(i->rr); + free(i); } @@ -157,12 +164,74 @@ static int dns_zone_link_item(DnsZone *z, DnsZoneItem *i) { return 0; } -int dns_zone_put(DnsZone *z, DnsResourceRecord *rr) { +static int dns_zone_item_probe_start(DnsZoneItem *i) { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; + _cleanup_(dns_question_unrefp) DnsQuestion *question = NULL; + DnsTransaction *t; + int r; + + assert(i); + + if (i->probe_transaction) + return 0; + + key = dns_resource_key_new(i->rr->key->class, DNS_TYPE_ANY, DNS_RESOURCE_KEY_NAME(i->rr->key)); + if (!key) + return -ENOMEM; + + question = dns_question_new(1); + if (!question) + return -ENOMEM; + + r = dns_question_add(question, key); + if (r < 0) + return r; + + t = dns_scope_find_transaction(i->scope, question); + if (!t) { + r = dns_transaction_new(&t, i->scope, question); + if (r < 0) + return r; + } + + r = set_ensure_allocated(&t->zone_items, NULL, NULL); + if (r < 0) + goto gc; + + r = set_put(t->zone_items, i); + if (r < 0) + goto gc; + + i->probe_transaction = t; + + if (t->state == DNS_TRANSACTION_NULL) { + + i->block_ready++; + r = dns_transaction_go(t); + i->block_ready--; + + if (r < 0) { + dns_zone_item_probe_stop(i); + return r; + } + } + + dns_zone_item_ready(i); + + return 0; + +gc: + dns_transaction_gc(t); + return r; +} + +int dns_zone_put(DnsZone *z, DnsScope *s, DnsResourceRecord *rr, bool probe) { _cleanup_(dns_zone_item_freep) DnsZoneItem *i = NULL; DnsZoneItem *existing; int r; assert(z); + assert(s); assert(rr); if (rr->key->class == DNS_CLASS_ANY) @@ -182,19 +251,34 @@ int dns_zone_put(DnsZone *z, DnsResourceRecord *rr) { if (!i) return -ENOMEM; + i->scope = s; i->rr = dns_resource_record_ref(rr); + i->probing_enabled = probe; r = dns_zone_link_item(z, i); if (r < 0) return r; + if (probe) { + r = dns_zone_item_probe_start(i); + if (r < 0) { + dns_zone_item_remove_and_free(z, i); + i = NULL; + return r; + } + + i->state = DNS_ZONE_ITEM_PROBING; + } else + i->state = DNS_ZONE_ITEM_ESTABLISHED; + i = NULL; return 0; } -int dns_zone_lookup(DnsZone *z, DnsQuestion *q, DnsAnswer **ret_answer, DnsAnswer **ret_soa) { +int dns_zone_lookup(DnsZone *z, DnsQuestion *q, DnsAnswer **ret_answer, DnsAnswer **ret_soa, bool *ret_tentative) { _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL, *soa = NULL; unsigned i, n_answer = 0, n_soa = 0; + bool tentative = true; int r; assert(z); @@ -205,40 +289,70 @@ int dns_zone_lookup(DnsZone *z, DnsQuestion *q, DnsAnswer **ret_answer, DnsAnswe if (q->n_keys <= 0) { *ret_answer = NULL; *ret_soa = NULL; + + if (ret_tentative) + *ret_tentative = false; + return 0; } /* First iteration, count what we have */ for (i = 0; i < q->n_keys; i++) { - DnsZoneItem *j; + DnsZoneItem *j, *first; if (q->keys[i]->type == DNS_TYPE_ANY || q->keys[i]->class == DNS_CLASS_ANY) { + bool found = false, added = false; int k; /* If this is a generic match, then we have to * go through the list by the name and look * for everything manually */ - j = hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(q->keys[i])); - LIST_FOREACH(by_name, j, j) { + first = hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(q->keys[i])); + LIST_FOREACH(by_name, j, first) { + if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) + continue; + + found = true; + k = dns_resource_key_match_rr(q->keys[i], j->rr); if (k < 0) return k; - if (k == 0) - n_soa++; - else + if (k > 0) { n_answer++; + added = true; + } + } + if (found && !added) + n_soa++; + } else { - j = hashmap_get(z->by_key, q->keys[i]); - if (j) { - LIST_FOREACH(by_key, j, j) - n_answer++; - } else { - if (hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(q->keys[i]))) - n_soa ++; + bool found = false; + + /* If this is a specific match, then look for + * the right key immediately */ + + first = hashmap_get(z->by_key, q->keys[i]); + LIST_FOREACH(by_key, j, first) { + if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) + continue; + + found = true; + n_answer++; + } + + if (!found) { + first = hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(q->keys[i])); + LIST_FOREACH(by_name, j, first) { + if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) + continue; + + n_soa++; + break; + } } } } @@ -246,6 +360,10 @@ int dns_zone_lookup(DnsZone *z, DnsQuestion *q, DnsAnswer **ret_answer, DnsAnswe if (n_answer <= 0 && n_soa <= 0) { *ret_answer = NULL; *ret_soa = NULL; + + if (ret_tentative) + *ret_tentative = false; + return 0; } @@ -263,35 +381,73 @@ int dns_zone_lookup(DnsZone *z, DnsQuestion *q, DnsAnswer **ret_answer, DnsAnswe /* Second iteration, actually add the RRs to the answers */ for (i = 0; i < q->n_keys; i++) { - DnsZoneItem *j; + DnsZoneItem *j, *first; if (q->keys[i]->type == DNS_TYPE_ANY || q->keys[i]->class == DNS_CLASS_ANY) { + bool found = false, added = false; int k; - j = hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(q->keys[i])); - LIST_FOREACH(by_name, j, j) { + first = hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(q->keys[i])); + LIST_FOREACH(by_name, j, first) { + if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) + continue; + + found = true; + + if (j->state != DNS_ZONE_ITEM_PROBING) + tentative = false; + k = dns_resource_key_match_rr(q->keys[i], j->rr); if (k < 0) return k; - if (k == 0) - r = dns_answer_add_soa(soa, DNS_RESOURCE_KEY_NAME(q->keys[i]), LLMNR_DEFAULT_TTL); - else + if (k > 0) { r = dns_answer_add(answer, j->rr); + if (r < 0) + return r; + + added = true; + } + } + + if (found && !added) { + r = dns_answer_add_soa(soa, DNS_RESOURCE_KEY_NAME(q->keys[i]), LLMNR_DEFAULT_TTL); if (r < 0) return r; } } else { + bool found = false; - j = hashmap_get(z->by_key, q->keys[i]); - if (j) { - LIST_FOREACH(by_key, j, j) { - r = dns_answer_add(answer, j->rr); - if (r < 0) - return r; + first = hashmap_get(z->by_key, q->keys[i]); + LIST_FOREACH(by_key, j, first) { + if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) + continue; + + found = true; + + if (j->state != DNS_ZONE_ITEM_PROBING) + tentative = false; + + r = dns_answer_add(answer, j->rr); + if (r < 0) + return r; + } + + if (!found) { + bool add_soa = false; + + first = hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(q->keys[i])); + LIST_FOREACH(by_name, j, first) { + if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) + continue; + + if (j->state != DNS_ZONE_ITEM_PROBING) + tentative = false; + + add_soa = true; } - } else { - if (hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(q->keys[i]))) { + + if (add_soa) { r = dns_answer_add_soa(soa, DNS_RESOURCE_KEY_NAME(q->keys[i]), LLMNR_DEFAULT_TTL); if (r < 0) return r; @@ -306,5 +462,47 @@ int dns_zone_lookup(DnsZone *z, DnsQuestion *q, DnsAnswer **ret_answer, DnsAnswe *ret_soa = soa; soa = NULL; + if (ret_tentative) + *ret_tentative = tentative; + return 1; } + +void dns_zone_item_conflict(DnsZoneItem *i) { + _cleanup_free_ char *pretty = NULL; + + assert(i); + + dns_resource_record_to_string(i->rr, &pretty); + log_info("Detected conflict on %s", strna(pretty)); + + /* Withdraw the conflict item */ + i->state = DNS_ZONE_ITEM_WITHDRAWN; + + /* Maybe change the hostname */ + if (dns_name_equal(i->scope->manager->hostname, DNS_RESOURCE_KEY_NAME(i->rr->key)) > 0) + manager_next_hostname(i->scope->manager); +} + +void dns_zone_item_ready(DnsZoneItem *i) { + assert(i); + assert(i->probe_transaction); + + if (i->block_ready > 0) + return; + + if (IN_SET(i->probe_transaction->state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING)) + return; + + if (i->probe_transaction->state != DNS_TRANSACTION_SUCCESS) { + _cleanup_free_ char *pretty = NULL; + + dns_resource_record_to_string(i->rr, &pretty); + log_debug("Record %s successfully probed.", strna(pretty)); + + dns_zone_item_probe_stop(i); + i->state = DNS_ZONE_ITEM_ESTABLISHED; + + } else + dns_zone_item_conflict(i); +} diff --git a/src/resolve/resolved-dns-zone.h b/src/resolve/resolved-dns-zone.h index b2af028cfc2..bf93ab43fb2 100644 --- a/src/resolve/resolved-dns-zone.h +++ b/src/resolve/resolved-dns-zone.h @@ -28,16 +28,46 @@ typedef struct DnsZone { Hashmap *by_name; } DnsZone; +typedef struct DnsZoneItem DnsZoneItem; +typedef enum DnsZoneItemState DnsZoneItemState; + #include "resolved-dns-rr.h" #include "resolved-dns-question.h" #include "resolved-dns-answer.h" +#include "resolved-dns-transaction.h" + +/* RFC 4795 Section 2.8. suggests a TTL of 30s by default */ +#define LLMNR_DEFAULT_TTL (30) + +enum DnsZoneItemState { + DNS_ZONE_ITEM_PROBING, + DNS_ZONE_ITEM_ESTABLISHED, + DNS_ZONE_ITEM_VERIFYING, + DNS_ZONE_ITEM_WITHDRAWN, +}; + +struct DnsZoneItem { + DnsScope *scope; + DnsResourceRecord *rr; + + DnsZoneItemState state; + + unsigned block_ready; + + bool probing_enabled; + + LIST_FIELDS(DnsZoneItem, by_key); + LIST_FIELDS(DnsZoneItem, by_name); + + DnsTransaction *probe_transaction; +}; void dns_zone_flush(DnsZone *z); -int dns_zone_put(DnsZone *z, DnsResourceRecord *rr); +int dns_zone_put(DnsZone *z, DnsScope *s, DnsResourceRecord *rr, bool probe); void dns_zone_remove_rr(DnsZone *z, DnsResourceRecord *rr); -int dns_zone_lookup(DnsZone *z, DnsQuestion *q, DnsAnswer **answer, DnsAnswer **soa); +int dns_zone_lookup(DnsZone *z, DnsQuestion *q, DnsAnswer **answer, DnsAnswer **soa, bool *tentative); -/* RFC 4795 Section 2.8. suggests a TTL of 30s by default */ -#define LLMNR_DEFAULT_TTL (30) +void dns_zone_item_conflict(DnsZoneItem *i); +void dns_zone_item_ready(DnsZoneItem *i); diff --git a/src/resolve/resolved-link.c b/src/resolve/resolved-link.c index a4c23bab06a..5355eab042c 100644 --- a/src/resolve/resolved-link.c +++ b/src/resolve/resolved-link.c @@ -23,10 +23,9 @@ #include "sd-network.h" #include "strv.h" +#include "missing.h" #include "resolved-link.h" -static void link_address_add_rrs(LinkAddress *a); - int link_new(Manager *m, Link **ret, int ifindex) { _cleanup_(link_freep) Link *l = NULL; int r; @@ -93,7 +92,7 @@ static void link_allocate_scopes(Link *l) { } else l->unicast_scope = dns_scope_free(l->unicast_scope); - if (link_relevant(l, AF_INET) && (l->flags & IFF_MULTICAST) && l->manager->use_llmnr) { + if (link_relevant(l, AF_INET) && l->manager->use_llmnr) { if (!l->llmnr_ipv4_scope) { r = dns_scope_new(l->manager, &l->llmnr_ipv4_scope, l, DNS_PROTOCOL_LLMNR, AF_INET); if (r < 0) @@ -102,7 +101,7 @@ static void link_allocate_scopes(Link *l) { } else l->llmnr_ipv4_scope = dns_scope_free(l->llmnr_ipv4_scope); - if (link_relevant(l, AF_INET6) && (l->flags & IFF_MULTICAST) && l->manager->use_llmnr) { + if (link_relevant(l, AF_INET6) && l->manager->use_llmnr) { if (!l->llmnr_ipv6_scope) { r = dns_scope_new(l->manager, &l->llmnr_ipv6_scope, l, DNS_PROTOCOL_LLMNR, AF_INET6); if (r < 0) @@ -112,11 +111,11 @@ static void link_allocate_scopes(Link *l) { l->llmnr_ipv6_scope = dns_scope_free(l->llmnr_ipv6_scope); } -static void link_add_rrs(Link *l) { +void link_add_rrs(Link *l, bool force_remove) { LinkAddress *a; LIST_FOREACH(addresses, a, l->addresses) - link_address_add_rrs(a); + link_address_add_rrs(a, force_remove); } int link_update_rtnl(Link *l, sd_rtnl_message *m) { @@ -138,7 +137,7 @@ int link_update_rtnl(Link *l, sd_rtnl_message *m) { } link_allocate_scopes(l); - link_add_rrs(l); + link_add_rrs(l, false); return 0; } @@ -194,7 +193,7 @@ int link_update_monitor(Link *l) { link_update_dns_servers(l); link_allocate_scopes(l); - link_add_rrs(l); + link_add_rrs(l, false); return 0; } @@ -205,10 +204,14 @@ bool link_relevant(Link *l, int family) { assert(l); - /* A link is relevant if it isn't a loopback device and has at - * least one relevant IP address */ + /* A link is relevant if it isn't a loopback or pointopoint + * device, has a link beat, can do multicast and has at least + * one relevant IP address */ + + if (l->flags & (IFF_LOOPBACK|IFF_POINTOPOINT|IFF_DORMANT)) + return false; - if (l->flags & IFF_LOOPBACK) + if ((l->flags & (IFF_UP|IFF_LOWER_UP|IFF_MULTICAST)) != (IFF_UP|IFF_LOWER_UP|IFF_MULTICAST)) return false; sd_network_get_link_operational_state(l->ifindex, &state); @@ -306,13 +309,10 @@ LinkAddress *link_address_free(LinkAddress *a) { LIST_REMOVE(addresses, a->link->addresses, a); if (a->llmnr_address_rr) { - if (a->family == AF_INET && a->link->llmnr_ipv4_scope) dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_address_rr); else if (a->family == AF_INET6 && a->link->llmnr_ipv6_scope) dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_address_rr); - - dns_resource_record_unref(a->llmnr_address_rr); } if (a->llmnr_ptr_rr) { @@ -320,103 +320,122 @@ LinkAddress *link_address_free(LinkAddress *a) { dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_ptr_rr); else if (a->family == AF_INET6 && a->link->llmnr_ipv6_scope) dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_ptr_rr); - - dns_resource_record_unref(a->llmnr_ptr_rr); } } + dns_resource_record_unref(a->llmnr_address_rr); + dns_resource_record_unref(a->llmnr_ptr_rr); + free(a); return NULL; } -static void link_address_add_rrs(LinkAddress *a) { +void link_address_add_rrs(LinkAddress *a, bool force_remove) { int r; assert(a); - if (a->family == AF_INET && a->link->llmnr_ipv4_scope) { + if (a->family == AF_INET) { - if (!a->link->manager->host_ipv4_key) { - a->link->manager->host_ipv4_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_A, a->link->manager->hostname); + if (!force_remove && link_address_relevant(a) && a->link->llmnr_ipv4_scope) { if (!a->link->manager->host_ipv4_key) { - r = -ENOMEM; - goto fail; + a->link->manager->host_ipv4_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_A, a->link->manager->hostname); + if (!a->link->manager->host_ipv4_key) { + r = -ENOMEM; + goto fail; + } } - } - if (!a->llmnr_address_rr) { - a->llmnr_address_rr = dns_resource_record_new(a->link->manager->host_ipv4_key); if (!a->llmnr_address_rr) { - r = -ENOMEM; - goto fail; + a->llmnr_address_rr = dns_resource_record_new(a->link->manager->host_ipv4_key); + if (!a->llmnr_address_rr) { + r = -ENOMEM; + goto fail; + } + + a->llmnr_address_rr->a.in_addr = a->in_addr.in; + a->llmnr_address_rr->ttl = LLMNR_DEFAULT_TTL; } - a->llmnr_address_rr->a.in_addr = a->in_addr.in; - a->llmnr_address_rr->ttl = LLMNR_DEFAULT_TTL; - } - - if (!a->llmnr_ptr_rr) { - r = dns_resource_record_new_reverse(&a->llmnr_ptr_rr, a->family, &a->in_addr, a->link->manager->hostname); - if (r < 0) - goto fail; + if (!a->llmnr_ptr_rr) { + r = dns_resource_record_new_reverse(&a->llmnr_ptr_rr, a->family, &a->in_addr, a->link->manager->hostname); + if (r < 0) + goto fail; - a->llmnr_ptr_rr->ttl = LLMNR_DEFAULT_TTL; - } + a->llmnr_ptr_rr->ttl = LLMNR_DEFAULT_TTL; + } - if (link_address_relevant(a)) { - r = dns_zone_put(&a->link->llmnr_ipv4_scope->zone, a->llmnr_address_rr); + r = dns_zone_put(&a->link->llmnr_ipv4_scope->zone, a->link->llmnr_ipv4_scope, a->llmnr_address_rr, true); if (r < 0) - goto fail; + log_warning("Failed tp add A record to LLMNR zone: %s", strerror(-r)); - r = dns_zone_put(&a->link->llmnr_ipv4_scope->zone, a->llmnr_ptr_rr); + r = dns_zone_put(&a->link->llmnr_ipv4_scope->zone, a->link->llmnr_ipv4_scope, a->llmnr_ptr_rr, false); if (r < 0) - goto fail; + log_warning("Failed tp add IPv6 PTR record to LLMNR zone: %s", strerror(-r)); } else { - dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_address_rr); - dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_ptr_rr); + if (a->llmnr_address_rr) { + if (a->link->llmnr_ipv4_scope) + dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_address_rr); + a->llmnr_address_rr = dns_resource_record_unref(a->llmnr_address_rr); + } + + if (a->llmnr_ptr_rr) { + if (a->link->llmnr_ipv4_scope) + dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_ptr_rr); + a->llmnr_ptr_rr = dns_resource_record_unref(a->llmnr_ptr_rr); + } } } - if (a->family == AF_INET6 && a->link->llmnr_ipv6_scope) { + if (a->family == AF_INET6) { - if (!a->link->manager->host_ipv6_key) { - a->link->manager->host_ipv6_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_AAAA, a->link->manager->hostname); + if (!force_remove && link_address_relevant(a) && a->link->llmnr_ipv6_scope) { if (!a->link->manager->host_ipv6_key) { - r = -ENOMEM; - goto fail; + a->link->manager->host_ipv6_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_AAAA, a->link->manager->hostname); + if (!a->link->manager->host_ipv6_key) { + r = -ENOMEM; + goto fail; + } } - } - if (!a->llmnr_address_rr) { - a->llmnr_address_rr = dns_resource_record_new(a->link->manager->host_ipv6_key); if (!a->llmnr_address_rr) { - r = -ENOMEM; - goto fail; + a->llmnr_address_rr = dns_resource_record_new(a->link->manager->host_ipv6_key); + if (!a->llmnr_address_rr) { + r = -ENOMEM; + goto fail; + } + + a->llmnr_address_rr->aaaa.in6_addr = a->in_addr.in6; + a->llmnr_address_rr->ttl = LLMNR_DEFAULT_TTL; } - a->llmnr_address_rr->aaaa.in6_addr = a->in_addr.in6; - a->llmnr_address_rr->ttl = LLMNR_DEFAULT_TTL; - } - - if (!a->llmnr_ptr_rr) { - r = dns_resource_record_new_reverse(&a->llmnr_ptr_rr, a->family, &a->in_addr, a->link->manager->hostname); - if (r < 0) - goto fail; + if (!a->llmnr_ptr_rr) { + r = dns_resource_record_new_reverse(&a->llmnr_ptr_rr, a->family, &a->in_addr, a->link->manager->hostname); + if (r < 0) + goto fail; - a->llmnr_ptr_rr->ttl = LLMNR_DEFAULT_TTL; - } + a->llmnr_ptr_rr->ttl = LLMNR_DEFAULT_TTL; + } - if (link_address_relevant(a)) { - r = dns_zone_put(&a->link->llmnr_ipv6_scope->zone, a->llmnr_address_rr); + r = dns_zone_put(&a->link->llmnr_ipv6_scope->zone, a->link->llmnr_ipv6_scope, a->llmnr_address_rr, true); if (r < 0) - goto fail; + log_warning("Failed to add AAAA record to LLMNR zone: %s", strerror(-r)); - r = dns_zone_put(&a->link->llmnr_ipv6_scope->zone, a->llmnr_ptr_rr); + r = dns_zone_put(&a->link->llmnr_ipv6_scope->zone, a->link->llmnr_ipv6_scope, a->llmnr_ptr_rr, false); if (r < 0) - goto fail; + log_warning("Failed to add IPv6 PTR record to LLMNR zone: %s", strerror(-r)); } else { - dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_address_rr); - dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_ptr_rr); + if (a->llmnr_address_rr) { + if (a->link->llmnr_ipv6_scope) + dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_address_rr); + a->llmnr_address_rr = dns_resource_record_unref(a->llmnr_address_rr); + } + + if (a->llmnr_ptr_rr) { + if (a->link->llmnr_ipv6_scope) + dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_ptr_rr); + a->llmnr_ptr_rr = dns_resource_record_unref(a->llmnr_ptr_rr); + } } } @@ -438,7 +457,7 @@ int link_address_update_rtnl(LinkAddress *a, sd_rtnl_message *m) { sd_rtnl_message_addr_get_scope(m, &a->scope); link_allocate_scopes(a->link); - link_add_rrs(a->link); + link_add_rrs(a->link, false); return 0; } diff --git a/src/resolve/resolved-link.h b/src/resolve/resolved-link.h index f58bd542034..3cafaab26c4 100644 --- a/src/resolve/resolved-link.h +++ b/src/resolve/resolved-link.h @@ -76,7 +76,7 @@ int link_update_rtnl(Link *l, sd_rtnl_message *m); int link_update_monitor(Link *l); bool link_relevant(Link *l, int family); LinkAddress* link_find_address(Link *l, int family, const union in_addr_union *in_addr); - +void link_add_rrs(Link *l, bool force_remove); DnsServer* link_find_dns_server(Link *l, int family, const union in_addr_union *in_addr); DnsServer* link_get_dns_server(Link *l); void link_next_dns_server(Link *l); @@ -85,5 +85,6 @@ int link_address_new(Link *l, LinkAddress **ret, int family, const union in_addr LinkAddress *link_address_free(LinkAddress *a); int link_address_update_rtnl(LinkAddress *a, sd_rtnl_message *m); bool link_address_relevant(LinkAddress *l); +void link_address_add_rrs(LinkAddress *a, bool force_remove); DEFINE_TRIVIAL_CLEANUP_FUNC(Link*, link_free); diff --git a/src/resolve/resolved-manager.c b/src/resolve/resolved-manager.c index fecd7ea0c61..72034c1f487 100644 --- a/src/resolve/resolved-manager.c +++ b/src/resolve/resolved-manager.c @@ -461,7 +461,7 @@ Manager *manager_free(Manager *m) { while (m->dns_queries) dns_query_free(m->dns_queries); - hashmap_free(m->dns_query_transactions); + hashmap_free(m->dns_transactions); while ((l = hashmap_first(m->links))) link_free(l); @@ -703,7 +703,7 @@ int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) { static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; - DnsQueryTransaction *t = NULL; + DnsTransaction *t = NULL; Manager *m = userdata; int r; @@ -712,11 +712,11 @@ static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *use return r; if (dns_packet_validate_reply(p) > 0) { - t = hashmap_get(m->dns_query_transactions, UINT_TO_PTR(DNS_PACKET_ID(p))); + t = hashmap_get(m->dns_transactions, UINT_TO_PTR(DNS_PACKET_ID(p))); if (!t) return 0; - dns_query_transaction_process_reply(t, p); + dns_transaction_process_reply(t, p); } else log_debug("Invalid DNS packet."); @@ -990,7 +990,7 @@ uint32_t manager_find_mtu(Manager *m) { static int on_llmnr_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; - DnsQueryTransaction *t = NULL; + DnsTransaction *t = NULL; Manager *m = userdata; int r; @@ -1001,11 +1001,11 @@ static int on_llmnr_packet(sd_event_source *s, int fd, uint32_t revents, void *u if (dns_packet_validate_reply(p) > 0) { log_debug("Got reply packet for id %u", DNS_PACKET_ID(p)); - t = hashmap_get(m->dns_query_transactions, UINT_TO_PTR(DNS_PACKET_ID(p))); + t = hashmap_get(m->dns_transactions, UINT_TO_PTR(DNS_PACKET_ID(p))); if (!t) return 0; - dns_query_transaction_process_reply(t, p); + dns_transaction_process_reply(t, p); } else if (dns_packet_validate_query(p) > 0) { Link *l; @@ -1397,14 +1397,80 @@ int manager_ifindex_is_loopback(Manager *m, int ifindex) { } int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr) { - Link *l; + LinkAddress *a; + + assert(m); + + a = manager_find_address(m, family, in_addr); + if (a) + return a->link->ifindex; + + return 0; +} + +int manager_next_hostname(Manager *m) { + const char *p; Iterator i; + uint64_t u; + char *h; + Link *l; assert(m); - HASHMAP_FOREACH(l, m->links, i) - if (link_find_address(l, family, in_addr)) - return l->ifindex; + p = strchr(m->hostname, 0); + assert(p); + + while (p > m->hostname) { + if (!strchr("0123456789", p[-1])) + break; + + p--; + } + + if (*p == 0 || safe_atou64(p, &u) < 0 || u <= 0) + u = 1; + + u++; + + if (asprintf(&h, "%.*s%" PRIu64, (int) (p - m->hostname), m->hostname, u) < 0) + return -ENOMEM; + + log_info("Hostname conflict, changing local hostname from '%s' to '%s'.", m->hostname, h); + + free(m->hostname); + m->hostname = h; + + m->host_ipv4_key = dns_resource_key_unref(m->host_ipv4_key); + m->host_ipv6_key = dns_resource_key_unref(m->host_ipv6_key); + + HASHMAP_FOREACH(l, m->links, i) { + link_add_rrs(l, true); + link_add_rrs(l, false); + } return 0; } + +LinkAddress* manager_find_address(Manager *m, int family, const union in_addr_union *in_addr) { + Iterator i; + Link *l; + + assert(m); + + HASHMAP_FOREACH(l, m->links, i) { + LinkAddress *a; + + a = link_find_address(l, family, in_addr); + if (a) + return a; + } + + return NULL; +} + +int manager_our_packet(Manager *m, DnsPacket *p) { + assert(m); + assert(p); + + return !!manager_find_address(m, p->family, &p->sender); +} diff --git a/src/resolve/resolved.h b/src/resolve/resolved.h index 6aa0fc9e56d..07560553b98 100644 --- a/src/resolve/resolved.h +++ b/src/resolve/resolved.h @@ -51,7 +51,7 @@ struct Manager { sd_event_source *network_event_source; /* DNS query management */ - Hashmap *dns_query_transactions; + Hashmap *dns_transactions; LIST_HEAD(DnsQuery, dns_queries); unsigned n_dns_queries; @@ -103,6 +103,7 @@ int manager_write_resolv_conf(Manager *m); DnsServer* manager_find_dns_server(Manager *m, int family, const union in_addr_union *in_addr); DnsServer *manager_get_dns_server(Manager *m); void manager_next_dns_server(Manager *m); + uint32_t manager_find_mtu(Manager *m); int manager_send(Manager *m, int fd, int ifindex, int family, const union in_addr_union *addr, uint16_t port, DnsPacket *p); @@ -117,7 +118,11 @@ int manager_llmnr_ipv6_tcp_fd(Manager *m); int manager_ifindex_is_loopback(Manager *m, int ifindex); int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr); +LinkAddress* manager_find_address(Manager *m, int family, const union in_addr_union *in_addr); + +int manager_next_hostname(Manager *m); +int manager_our_packet(Manager *m, DnsPacket *p); int manager_connect_bus(Manager *m); DEFINE_TRIVIAL_CLEANUP_FUNC(Manager*, manager_free); diff --git a/src/shared/missing.h b/src/shared/missing.h index f4378a36b11..083b85a26cb 100644 --- a/src/shared/missing.h +++ b/src/shared/missing.h @@ -503,3 +503,11 @@ static inline int setns(int fd, int nstype) { #ifndef IPV6_UNICAST_IF #define IPV6_UNICAST_IF 76 #endif + +#ifndef IFF_LOWER_UP +#define IFF_LOWER_UP 0x10000 +#endif + +#ifndef IFF_DORMANT +#define IFF_DORMANT 0x20000 +#endif -- 2.39.2