From: Lennart Poettering Date: Tue, 29 Jul 2014 12:24:02 +0000 (+0200) Subject: resolve: add llmnr responder side for UDP and TCP X-Git-Tag: v216~398 X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=623a4c97b9175f95c4b1c6fc34e36c56f1e4ddbf;hp=359017c1aec9596e9d3c4c19bd62d34a6f3366b8;ds=sidebyside resolve: add llmnr responder side for UDP and TCP Name defending is still missing. --- diff --git a/Makefile.am b/Makefile.am index d02a8ca42..9a3913b9c 100644 --- a/Makefile.am +++ b/Makefile.am @@ -4754,7 +4754,11 @@ systemd_resolved_SOURCES = \ src/resolve/resolved-dns-server.h \ src/resolve/resolved-dns-server.c \ src/resolve/resolved-dns-cache.h \ - src/resolve/resolved-dns-cache.c + src/resolve/resolved-dns-cache.c \ + src/resolve/resolved-dns-zone.h \ + src/resolve/resolved-dns-zone.c \ + src/resolve/resolved-dns-stream.h \ + src/resolve/resolved-dns-stream.c nodist_systemd_resolved_SOURCES = \ src/resolve/resolved-gperf.c diff --git a/src/resolve/resolved-dns-cache.c b/src/resolve/resolved-dns-cache.c index 6ea5d49fc..8c859d19b 100644 --- a/src/resolve/resolved-dns-cache.c +++ b/src/resolve/resolved-dns-cache.c @@ -28,6 +28,24 @@ /* We never keep any item longer than 10min in our cache */ #define CACHE_TTL_MAX_USEC (10 * USEC_PER_MINUTE) +typedef enum DnsCacheItemType DnsCacheItemType; +typedef struct DnsCacheItem DnsCacheItem; + +enum DnsCacheItemType { + DNS_CACHE_POSITIVE, + DNS_CACHE_NODATA, + DNS_CACHE_NXDOMAIN, +}; + +struct DnsCacheItem { + DnsResourceKey *key; + DnsResourceRecord *rr; + usec_t until; + DnsCacheItemType type; + unsigned prioq_idx; + LIST_FIELDS(DnsCacheItem, by_key); +}; + static void dns_cache_item_free(DnsCacheItem *i) { if (!i) return; @@ -157,9 +175,11 @@ static int dns_cache_item_prioq_compare_func(const void *a, const void *b) { return 0; } -static int init_cache(DnsCache *c) { +static int dns_cache_init(DnsCache *c) { int r; + assert(c); + r = prioq_ensure_allocated(&c->by_expiry, dns_cache_item_prioq_compare_func); if (r < 0) return r; @@ -258,7 +278,7 @@ static int dns_cache_put_positive(DnsCache *c, DnsResourceRecord *rr, usec_t tim } /* Otherwise, add the new RR */ - r = init_cache(c); + r = dns_cache_init(c); if (r < 0) return r; @@ -294,7 +314,7 @@ static int dns_cache_put_negative(DnsCache *c, DnsResourceKey *key, int rcode, u if (!IN_SET(rcode, DNS_RCODE_SUCCESS, DNS_RCODE_NXDOMAIN)) return 0; - r = init_cache(c); + r = dns_cache_init(c); if (r < 0) return r; @@ -394,6 +414,7 @@ int dns_cache_lookup(DnsCache *c, DnsQuestion *q, int *rcode, DnsAnswer **ret) { assert(c); assert(q); + assert(rcode); assert(ret); if (q->n_keys <= 0) { diff --git a/src/resolve/resolved-dns-cache.h b/src/resolve/resolved-dns-cache.h index 6f5bf45a3..590cf691b 100644 --- a/src/resolve/resolved-dns-cache.h +++ b/src/resolve/resolved-dns-cache.h @@ -28,8 +28,6 @@ #include "time-util.h" #include "list.h" -typedef struct DnsCacheItem DnsCacheItem; - typedef struct DnsCache { Hashmap *by_key; Prioq *by_expiry; @@ -39,21 +37,6 @@ typedef struct DnsCache { #include "resolved-dns-question.h" #include "resolved-dns-answer.h" -typedef enum DnsCacheItemType { - DNS_CACHE_POSITIVE, - DNS_CACHE_NODATA, - DNS_CACHE_NXDOMAIN, -} DnsCacheItemType; - -typedef struct DnsCacheItem { - DnsResourceKey *key; - DnsResourceRecord *rr; - usec_t until; - DnsCacheItemType type; - unsigned prioq_idx; - LIST_FIELDS(DnsCacheItem, by_key); -} DnsCacheItem; - void dns_cache_flush(DnsCache *c); void dns_cache_prune(DnsCache *c); diff --git a/src/resolve/resolved-dns-packet.c b/src/resolve/resolved-dns-packet.c index e5a4a4034..1ff56875e 100644 --- a/src/resolve/resolved-dns-packet.c +++ b/src/resolve/resolved-dns-packet.c @@ -130,7 +130,7 @@ int dns_packet_validate(DnsPacket *p) { if (p->size > DNS_PACKET_SIZE_MAX) return -EBADMSG; - return 0; + return 1; } int dns_packet_validate_reply(DnsPacket *p) { @@ -142,13 +142,44 @@ int dns_packet_validate_reply(DnsPacket *p) { if (r < 0) return r; - if (DNS_PACKET_QR(p) == 0) + if (DNS_PACKET_QR(p) != 1) + return 0; + + if (DNS_PACKET_OPCODE(p) != 0) return -EBADMSG; + return 1; +} + +int dns_packet_validate_query(DnsPacket *p) { + int r; + + assert(p); + + r = dns_packet_validate(p); + if (r < 0) + return r; + + if (DNS_PACKET_QR(p) != 0) + return 0; + if (DNS_PACKET_OPCODE(p) != 0) return -EBADMSG; - return 0; + if (DNS_PACKET_TC(p)) + return -EBADMSG; + + if (p->protocol == DNS_PROTOCOL_LLMNR && + DNS_PACKET_QDCOUNT(p) != 1) + return -EBADMSG; + + if (DNS_PACKET_ANCOUNT(p) > 0) + return -EBADMSG; + + if (DNS_PACKET_NSCOUNT(p) > 0) + return -EBADMSG; + + return 1; } static int dns_packet_extend(DnsPacket *p, size_t add, void **ret, size_t *start) { @@ -216,6 +247,20 @@ static void dns_packet_truncate(DnsPacket *p, size_t sz) { p->size = sz; } +int dns_packet_append_blob(DnsPacket *p, const void *d, size_t l, size_t *start) { + void *q; + int r; + + assert(p); + + r = dns_packet_extend(p, l, &q, start); + if (r < 0) + return r; + + memcpy(q, d, l); + return 0; +} + int dns_packet_append_uint8(DnsPacket *p, uint8_t v, size_t *start) { void *d; int r; @@ -242,7 +287,25 @@ int dns_packet_append_uint16(DnsPacket *p, uint16_t v, size_t *start) { return r; ((uint8_t*) d)[0] = (uint8_t) (v >> 8); - ((uint8_t*) d)[1] = (uint8_t) (v & 255); + ((uint8_t*) d)[1] = (uint8_t) v; + + return 0; +} + +int dns_packet_append_uint32(DnsPacket *p, uint32_t v, size_t *start) { + void *d; + int r; + + assert(p); + + r = dns_packet_extend(p, sizeof(uint32_t), &d, start); + if (r < 0) + return r; + + ((uint8_t*) d)[0] = (uint8_t) (v >> 24); + ((uint8_t*) d)[1] = (uint8_t) (v >> 16); + ((uint8_t*) d)[2] = (uint8_t) (v >> 8); + ((uint8_t*) d)[3] = (uint8_t) v; return 0; } @@ -387,6 +450,114 @@ fail: return r; } +int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *start) { + size_t saved_size, rdlength_offset, end, rdlength; + int r; + + assert(p); + assert(rr); + + saved_size = p->size; + + r = dns_packet_append_key(p, rr->key, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint32(p, rr->ttl, NULL); + if (r < 0) + goto fail; + + /* Initially we write 0 here */ + r = dns_packet_append_uint16(p, 0, &rdlength_offset); + if (r < 0) + goto fail; + + switch (rr->key->type) { + + case DNS_TYPE_PTR: + case DNS_TYPE_NS: + case DNS_TYPE_CNAME: + r = dns_packet_append_name(p, rr->ptr.name, NULL); + break; + + case DNS_TYPE_HINFO: + r = dns_packet_append_string(p, rr->hinfo.cpu, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_string(p, rr->hinfo.os, NULL); + break; + + case DNS_TYPE_A: + r = dns_packet_append_blob(p, &rr->a.in_addr, sizeof(struct in_addr), NULL); + break; + + case DNS_TYPE_AAAA: + r = dns_packet_append_blob(p, &rr->aaaa.in6_addr, sizeof(struct in6_addr), NULL); + break; + + case DNS_TYPE_SOA: + r = dns_packet_append_name(p, rr->soa.mname, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_name(p, rr->soa.rname, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint32(p, rr->soa.serial, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint32(p, rr->soa.refresh, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint32(p, rr->soa.retry, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint32(p, rr->soa.expire, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint32(p, rr->soa.minimum, NULL); + break; + + case DNS_TYPE_MX: + case DNS_TYPE_TXT: + case DNS_TYPE_SRV: + case DNS_TYPE_DNAME: + case DNS_TYPE_SSHFP: + default: + r = dns_packet_append_blob(p, rr->generic.data, rr->generic.size, NULL); + break; + } + if (r < 0) + goto fail; + + /* Let's calculate the actual data size and update the field */ + rdlength = p->size - rdlength_offset - sizeof(uint16_t); + if (rdlength > 0xFFFF) { + r = ENOSPC; + goto fail; + } + + end = p->size; + p->size = rdlength_offset; + r = dns_packet_append_uint16(p, rdlength, NULL); + if (r < 0) + goto fail; + p->size = end; + + return 0; + +fail: + dns_packet_truncate(p, saved_size); + return r; +} + + int dns_packet_read(DnsPacket *p, size_t sz, const void **ret, size_t *start) { assert(p); @@ -411,6 +582,21 @@ void dns_packet_rewind(DnsPacket *p, size_t idx) { p->rindex = idx; } +int dns_packet_read_blob(DnsPacket *p, void *d, size_t sz, size_t *start) { + const void *q; + int r; + + assert(p); + assert(d); + + r = dns_packet_read(p, sz, &q, start); + if (r < 0) + return r; + + memcpy(d, q, sz); + return 0; +} + int dns_packet_read_uint8(DnsPacket *p, uint8_t *ret, size_t *start) { const void *d; int r; @@ -696,19 +882,11 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) { break; case DNS_TYPE_A: - r = dns_packet_read(p, sizeof(struct in_addr), &d, NULL); - if (r < 0) - goto fail; - - memcpy(&rr->a.in_addr, d, sizeof(struct in_addr)); + r = dns_packet_read_blob(p, &rr->a.in_addr, sizeof(struct in_addr), NULL); break; case DNS_TYPE_AAAA: - r = dns_packet_read(p, sizeof(struct in6_addr), &d, NULL); - if (r < 0) - goto fail; - - memcpy(&rr->aaaa.in6_addr, d, sizeof(struct in6_addr)); + r = dns_packet_read_blob(p, &rr->aaaa.in6_addr, sizeof(struct in6_addr), NULL); break; case DNS_TYPE_SOA: @@ -739,6 +917,11 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) { r = dns_packet_read_uint32(p, &rr->soa.minimum, NULL); break; + case DNS_TYPE_MX: + case DNS_TYPE_TXT: + case DNS_TYPE_SRV: + case DNS_TYPE_DNAME: + case DNS_TYPE_SSHFP: default: r = dns_packet_read(p, rdlength, &d, NULL); if (r < 0) diff --git a/src/resolve/resolved-dns-packet.h b/src/resolve/resolved-dns-packet.h index b8370def3..ad4a38e6e 100644 --- a/src/resolve/resolved-dns-packet.h +++ b/src/resolve/resolved-dns-packet.h @@ -77,8 +77,9 @@ struct DnsPacket { /* Packet reception meta data */ int ifindex; - int family; + int family, ipproto; union in_addr_union sender, destination; + uint16_t sender_port, destination_port; uint32_t ttl; }; @@ -131,15 +132,20 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(DnsPacket*, dns_packet_unref); int dns_packet_validate(DnsPacket *p); int dns_packet_validate_reply(DnsPacket *p); +int dns_packet_validate_query(DnsPacket *p); +int dns_packet_append_blob(DnsPacket *p, const void *d, size_t sz, size_t *start); int dns_packet_append_uint8(DnsPacket *p, uint8_t v, size_t *start); int dns_packet_append_uint16(DnsPacket *p, uint16_t v, size_t *start); +int dns_packet_append_uint32(DnsPacket *p, uint32_t v, size_t *start); int dns_packet_append_string(DnsPacket *p, const char *s, size_t *start); int dns_packet_append_label(DnsPacket *p, const char *s, size_t l, size_t *start); int dns_packet_append_name(DnsPacket *p, const char *name, size_t *start); -int dns_packet_append_key(DnsPacket *p, const DnsResourceKey *k, size_t *start); +int dns_packet_append_key(DnsPacket *p, const DnsResourceKey *key, size_t *start); +int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *start); int dns_packet_read(DnsPacket *p, size_t sz, const void **ret, size_t *start); +int dns_packet_read_blob(DnsPacket *p, void *d, size_t sz, size_t *start); int dns_packet_read_uint8(DnsPacket *p, uint8_t *ret, size_t *start); int dns_packet_read_uint16(DnsPacket *p, uint16_t *ret, size_t *start); int dns_packet_read_uint32(DnsPacket *p, uint32_t *ret, size_t *start); diff --git a/src/resolve/resolved-dns-query.c b/src/resolve/resolved-dns-query.c index 8b4aa3bfd..32448c582 100644 --- a/src/resolve/resolved-dns-query.c +++ b/src/resolve/resolved-dns-query.c @@ -43,8 +43,7 @@ DnsQueryTransaction* dns_query_transaction_free(DnsQueryTransaction *t) { dns_packet_unref(t->received); dns_answer_unref(t->cached); - sd_event_source_unref(t->tcp_event_source); - safe_close(t->tcp_fd); + dns_stream_free(t->stream); if (t->scope) { LIST_REMOVE(transactions_by_scope, t->scope->transactions, t); @@ -90,7 +89,6 @@ static int dns_query_transaction_new(DnsQueryTransaction **ret, DnsScope *s, Dns if (!t) return -ENOMEM; - t->tcp_fd = -1; t->question = dns_question_ref(q); do @@ -119,8 +117,7 @@ static void dns_query_transaction_stop(DnsQueryTransaction *t) { assert(t); t->timeout_event_source = sd_event_source_unref(t->timeout_event_source); - t->tcp_event_source = sd_event_source_unref(t->tcp_event_source); - t->tcp_fd = safe_close(t->tcp_fd); + t->stream = dns_stream_free(t->stream); } void dns_query_transaction_complete(DnsQueryTransaction *t, DnsQueryState state) { @@ -149,132 +146,66 @@ void dns_query_transaction_complete(DnsQueryTransaction *t, DnsQueryState state) dns_query_transaction_gc(t); } -static int on_tcp_ready(sd_event_source *s, int fd, uint32_t revents, void *userdata) { - DnsQueryTransaction *t = userdata; - int r; - - assert(t); - - if (revents & EPOLLOUT) { - struct iovec iov[2]; - be16_t sz; - ssize_t ss; - - sz = htobe16(t->sent->size); - - iov[0].iov_base = &sz; - iov[0].iov_len = sizeof(sz); - iov[1].iov_base = DNS_PACKET_DATA(t->sent); - iov[1].iov_len = t->sent->size; - - IOVEC_INCREMENT(iov, 2, t->tcp_written); - - ss = writev(fd, iov, 2); - if (ss < 0) { - if (errno != EINTR && errno != EAGAIN) { - dns_query_transaction_complete(t, DNS_QUERY_RESOURCES); - return -errno; - } - } else - t->tcp_written += ss; - - /* Are we done? If so, disable the event source for EPOLLOUT */ - if (t->tcp_written >= sizeof(sz) + t->sent->size) { - r = sd_event_source_set_io_events(s, EPOLLIN); - if (r < 0) { - dns_query_transaction_complete(t, DNS_QUERY_RESOURCES); - return r; - } - } - } - - if (revents & (EPOLLIN|EPOLLHUP|EPOLLRDHUP)) { - - if (t->tcp_read < sizeof(t->tcp_read_size)) { - ssize_t ss; - - ss = read(fd, (uint8_t*) &t->tcp_read_size + t->tcp_read, sizeof(t->tcp_read_size) - t->tcp_read); - if (ss < 0) { - if (errno != EINTR && errno != EAGAIN) { - dns_query_transaction_complete(t, DNS_QUERY_RESOURCES); - return -errno; - } - } else if (ss == 0) { - dns_query_transaction_complete(t, DNS_QUERY_RESOURCES); - return -EIO; - } else - t->tcp_read += ss; - } - - if (t->tcp_read >= sizeof(t->tcp_read_size)) { - - if (be16toh(t->tcp_read_size) < DNS_PACKET_HEADER_SIZE) { - dns_query_transaction_complete(t, DNS_QUERY_INVALID_REPLY); - return -EBADMSG; - } +static int on_stream_complete(DnsStream *s, int error) { + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + DnsQueryTransaction *t; - if (t->tcp_read < sizeof(t->tcp_read_size) + be16toh(t->tcp_read_size)) { - ssize_t ss; + assert(s); + assert(s->transaction); - if (!t->received) { - r = dns_packet_new(&t->received, t->scope->protocol, be16toh(t->tcp_read_size)); - if (r < 0) { - dns_query_transaction_complete(t, DNS_QUERY_RESOURCES); - return r; - } - } + /* Copy the data we care about out of the stream before we + * destroy it. */ + t = s->transaction; + p = dns_packet_ref(s->read_packet); - ss = read(fd, - (uint8_t*) DNS_PACKET_DATA(t->received) + t->tcp_read - sizeof(t->tcp_read_size), - sizeof(t->tcp_read_size) + be16toh(t->tcp_read_size) - t->tcp_read); - if (ss < 0) { - if (errno != EINTR && errno != EAGAIN) { - dns_query_transaction_complete(t, DNS_QUERY_RESOURCES); - return -errno; - } - } else if (ss == 0) { - dns_query_transaction_complete(t, DNS_QUERY_RESOURCES); - return -EIO; - } else - t->tcp_read += ss; - } + t->stream = dns_stream_free(t->stream); - if (t->tcp_read >= sizeof(t->tcp_read_size) + be16toh(t->tcp_read_size)) { - t->received->size = be16toh(t->tcp_read_size); - dns_query_transaction_process_reply(t, t->received); - return 0; - } - } + if (error != 0) { + dns_query_transaction_complete(t, DNS_QUERY_RESOURCES); + return 0; } + dns_query_transaction_process_reply(t, p); 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) - return -ENOTSUP; + fd = dns_scope_tcp_socket(t->scope, AF_UNSPEC, NULL, 53); + else if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { + if (!t->received) + return -EINVAL; - if (t->tcp_fd >= 0) - return 0; + fd = dns_scope_tcp_socket(t->scope, t->received->family, &t->received->sender, t->received->sender_port); + } else + return -EAFNOSUPPORT; - t->tcp_written = 0; - t->tcp_read = 0; - t->received = dns_packet_unref(t->received); + if (fd < 0) + return fd; + + r = dns_stream_new(t->scope->manager, &t->stream, t->scope->protocol, fd); + if (r < 0) + return r; - t->tcp_fd = dns_scope_tcp_socket(t->scope); - if (t->tcp_fd < 0) - return t->tcp_fd; + fd = -1; - r = sd_event_add_io(t->scope->manager->event, &t->tcp_event_source, t->tcp_fd, EPOLLIN|EPOLLOUT, on_tcp_ready, t); + r = dns_stream_write_packet(t->stream, t->sent); if (r < 0) { - t->tcp_fd = safe_close(t->tcp_fd); + t->stream = dns_stream_free(t->stream); return r; } + t->received = dns_packet_unref(t->received); + t->stream->complete = on_stream_complete; + return 0; } @@ -289,12 +220,46 @@ void dns_query_transaction_process_reply(DnsQueryTransaction *t, DnsPacket *p) { * 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; + + if (p->ipproto == IPPROTO_UDP) { + if (p->family == AF_INET && !in_addr_equal(AF_INET, &p->destination, (union in_addr_union*) &LLMNR_MULTICAST_IPV4_ADDRESS)) + return; + + if (p->family == AF_INET6 && !in_addr_equal(AF_INET6, &p->destination, (union in_addr_union*) &LLMNR_MULTICAST_IPV6_ADDRESS)) + return; + } + } + + 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 (t->tcp_fd >= 0) { + 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); @@ -317,7 +282,14 @@ void dns_query_transaction_process_reply(DnsQueryTransaction *t, DnsPacket *p) { return; } if (r < 0) { - /* Couldn't send? Try immediately again, with a new server */ + /* 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); diff --git a/src/resolve/resolved-dns-query.h b/src/resolve/resolved-dns-query.h index 0b7656489..37f50b67c 100644 --- a/src/resolve/resolved-dns-query.h +++ b/src/resolve/resolved-dns-query.h @@ -36,6 +36,7 @@ typedef struct DnsQueryTransaction DnsQueryTransaction; #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, @@ -65,11 +66,8 @@ struct DnsQueryTransaction { sd_event_source *timeout_event_source; unsigned n_attempts; - /* TCP connection logic */ - int tcp_fd; - sd_event_source *tcp_event_source; - size_t tcp_written, tcp_read; - be16_t tcp_read_size; + /* 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. */ diff --git a/src/resolve/resolved-dns-rr.c b/src/resolve/resolved-dns-rr.c index f68eb1842..5097eff08 100644 --- a/src/resolve/resolved-dns-rr.c +++ b/src/resolve/resolved-dns-rr.c @@ -213,6 +213,40 @@ DnsResourceRecord* dns_resource_record_unref(DnsResourceRecord *rr) { return NULL; } +int dns_resource_record_new_reverse(DnsResourceRecord **ret, int family, const union in_addr_union *address, const char *hostname) { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; + _cleanup_free_ char *ptr = NULL; + int r; + + assert(ret); + assert(address); + assert(hostname); + + r = dns_name_reverse(family, address, &ptr); + if (r < 0) + return r; + + key = dns_resource_key_new_consume(DNS_CLASS_IN, DNS_TYPE_PTR, ptr); + if (!key) + return -ENOMEM; + + ptr = NULL; + + rr = dns_resource_record_new(key); + if (!rr) + return -ENOMEM; + + rr->ptr.name = strdup(hostname); + if (!rr->ptr.name) + return -ENOMEM; + + *ret = rr; + rr = NULL; + + return 0; +} + int dns_resource_record_equal(const DnsResourceRecord *a, const DnsResourceRecord *b) { int r; diff --git a/src/resolve/resolved-dns-rr.h b/src/resolve/resolved-dns-rr.h index 418bbede6..a9d14fc22 100644 --- a/src/resolve/resolved-dns-rr.h +++ b/src/resolve/resolved-dns-rr.h @@ -26,6 +26,7 @@ #include "util.h" #include "hashmap.h" +#include "in-addr-util.h" typedef struct DnsResourceKey DnsResourceKey; typedef struct DnsResourceRecord DnsResourceRecord; @@ -49,8 +50,8 @@ enum { DNS_TYPE_TXT = 0x10, DNS_TYPE_AAAA = 0x1C, DNS_TYPE_SRV = 0x21, - DNS_TYPE_SSHFP = 0x2C, DNS_TYPE_DNAME = 0x27, + DNS_TYPE_SSHFP = 0x2C, /* Special records */ DNS_TYPE_ANY = 0xFF, @@ -141,6 +142,7 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(DnsResourceKey*, dns_resource_key_unref); DnsResourceRecord* dns_resource_record_new(DnsResourceKey *key); DnsResourceRecord* dns_resource_record_ref(DnsResourceRecord *rr); DnsResourceRecord* dns_resource_record_unref(DnsResourceRecord *rr); +int dns_resource_record_new_reverse(DnsResourceRecord **ret, int family, const union in_addr_union *address, const char *name); int dns_resource_record_equal(const DnsResourceRecord *a, const DnsResourceRecord *b); DEFINE_TRIVIAL_CLEANUP_FUNC(DnsResourceRecord*, dns_resource_record_unref); diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c index 96a2ff7fa..9a636b179 100644 --- a/src/resolve/resolved-dns-scope.c +++ b/src/resolve/resolved-dns-scope.c @@ -21,6 +21,7 @@ #include +#include "missing.h" #include "strv.h" #include "socket-util.h" #include "af-list.h" @@ -77,6 +78,7 @@ DnsScope* dns_scope_free(DnsScope *s) { } dns_cache_flush(&s->cache); + dns_zone_flush(&s->zone); LIST_REMOVE(scopes, s->manager->dns_scopes, s); strv_free(s->domains); @@ -130,6 +132,9 @@ int dns_scope_send(DnsScope *s, DnsPacket *p) { if (s->protocol == DNS_PROTOCOL_DNS) { DnsServer *srv; + if (DNS_PACKET_QDCOUNT(p) > 1) + return -ENOTSUP; + srv = dns_scope_get_server(s); if (!srv) return -ESRCH; @@ -163,12 +168,10 @@ int dns_scope_send(DnsScope *s, DnsPacket *p) { if (family == AF_INET) { addr.in = LLMNR_MULTICAST_IPV4_ADDRESS; - /* fd = manager_dns_ipv4_fd(s->manager); */ fd = manager_llmnr_ipv4_udp_fd(s->manager); } else if (family == AF_INET6) { addr.in6 = LLMNR_MULTICAST_IPV6_ADDRESS; fd = manager_llmnr_ipv6_udp_fd(s->manager); - /* fd = manager_dns_ipv6_fd(s->manager); */ } else return -EAFNOSUPPORT; if (fd < 0) @@ -183,39 +186,86 @@ int dns_scope_send(DnsScope *s, DnsPacket *p) { return 1; } -int dns_scope_tcp_socket(DnsScope *s) { +int dns_scope_tcp_socket(DnsScope *s, int family, const union in_addr_union *address, uint16_t port) { _cleanup_close_ int fd = -1; union sockaddr_union sa = {}; socklen_t salen; - int one, ret; - DnsServer *srv; - int r; + static const int one = 1; + int ret, r; assert(s); + assert((family == AF_UNSPEC) == !address); - srv = dns_scope_get_server(s); - if (!srv) - return -ESRCH; - - sa.sa.sa_family = srv->family; - if (srv->family == AF_INET) { - sa.in.sin_port = htobe16(53); - sa.in.sin_addr = srv->address.in; - salen = sizeof(sa.in); - } else if (srv->family == AF_INET6) { - sa.in6.sin6_port = htobe16(53); - sa.in6.sin6_addr = srv->address.in6; - sa.in6.sin6_scope_id = s->link ? s->link->ifindex : 0; - salen = sizeof(sa.in6); - } else - return -EAFNOSUPPORT; + if (family == AF_UNSPEC) { + DnsServer *srv; + + srv = dns_scope_get_server(s); + if (!srv) + return -ESRCH; + + sa.sa.sa_family = srv->family; + if (srv->family == AF_INET) { + sa.in.sin_port = htobe16(port); + sa.in.sin_addr = srv->address.in; + salen = sizeof(sa.in); + } else if (srv->family == AF_INET6) { + sa.in6.sin6_port = htobe16(port); + sa.in6.sin6_addr = srv->address.in6; + sa.in6.sin6_scope_id = s->link ? s->link->ifindex : 0; + salen = sizeof(sa.in6); + } else + return -EAFNOSUPPORT; + } else { + sa.sa.sa_family = family; + + if (family == AF_INET) { + sa.in.sin_port = htobe16(port); + sa.in.sin_addr = address->in; + salen = sizeof(sa.in); + } else if (family == AF_INET6) { + sa.in6.sin6_port = htobe16(port); + sa.in6.sin6_addr = address->in6; + sa.in6.sin6_scope_id = s->link ? s->link->ifindex : 0; + salen = sizeof(sa.in6); + } else + return -EAFNOSUPPORT; + } - fd = socket(srv->family, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + fd = socket(sa.sa.sa_family, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); if (fd < 0) return -errno; - one = 1; - setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one)); + r = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one)); + if (r < 0) + return -errno; + + if (s->link) { + uint32_t ifindex = htobe32(s->link->ifindex); + + if (sa.sa.sa_family == AF_INET) { + r = setsockopt(fd, IPPROTO_IP, IP_UNICAST_IF, &ifindex, sizeof(ifindex)); + if (r < 0) + return -errno; + } else if (sa.sa.sa_family == AF_INET6) { + r = setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_IF, &ifindex, sizeof(ifindex)); + if (r < 0) + return -errno; + } + } + + if (s->protocol == DNS_PROTOCOL_LLMNR) { + /* RFC 4795, section 2.5 suggests the TTL to be set to 1 */ + + if (sa.sa.sa_family == AF_INET) { + r = setsockopt(fd, IPPROTO_IP, IP_TTL, &one, sizeof(one)); + if (r < 0) + return -errno; + } else if (sa.sa.sa_family == AF_INET6) { + r = setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &one, sizeof(one)); + if (r < 0) + return -errno; + } + } r = connect(fd, &sa.sa, salen); if (r < 0 && errno != EINPROGRESS) @@ -223,6 +273,7 @@ int dns_scope_tcp_socket(DnsScope *s) { ret = fd; fd = -1; + return ret; } @@ -324,3 +375,115 @@ int dns_scope_llmnr_membership(DnsScope *s, bool b) { return 0; } + +int dns_scope_good_dns_server(DnsScope *s, int family, const union in_addr_union *address) { + assert(s); + assert(address); + + if (s->protocol != DNS_PROTOCOL_DNS) + return 1; + + if (s->link) + return !!link_find_dns_server(s->link, family, address); + else + return !!manager_find_dns_server(s->manager, family, address); +} + +static int dns_scope_make_reply_packet(DnsScope *s, uint16_t id, int rcode, DnsQuestion *q, DnsAnswer *a, DnsPacket **ret) { + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + unsigned i; + int r; + + assert(s); + + if (q->n_keys <= 0 && a->n_rrs <= 0) + return -EINVAL; + + r = dns_packet_new(&p, s->protocol, 0); + if (r < 0) + return r; + + DNS_PACKET_HEADER(p)->id = id; + DNS_PACKET_HEADER(p)->flags = htobe16(DNS_PACKET_MAKE_FLAGS(1, 0, 0, 0, 0, 0, 0, 0, rcode)); + + if (q) { + for (i = 0; i < q->n_keys; i++) { + r = dns_packet_append_key(p, q->keys[i], NULL); + if (r < 0) + return r; + } + + DNS_PACKET_HEADER(p)->qdcount = htobe16(q->n_keys); + } + + if (a) { + for (i = 0; i < a->n_rrs; i++) { + r = dns_packet_append_rr(p, a->rrs[i], NULL); + if (r < 0) + return r; + } + + DNS_PACKET_HEADER(p)->ancount = htobe16(a->n_rrs); + } + + *ret = p; + p = NULL; + + return 0; +} + +void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p) { + _cleanup_(dns_packet_unrefp) DnsPacket *reply = NULL; + _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; + int r, fd; + + assert(s); + assert(p); + + if (p->protocol != DNS_PROTOCOL_LLMNR) + return; + + r = dns_packet_extract(p); + if (r < 0) { + log_debug("Failed to extract resources from incoming packet: %s", strerror(-r)); + return; + } + + r = dns_zone_lookup(&s->zone, p->question, &answer); + if (r < 0) { + log_debug("Failed to lookup key: %s", strerror(-r)); + return; + } + if (r == 0) + return; + + r = dns_scope_make_reply_packet(s, DNS_PACKET_ID(p), DNS_RCODE_SUCCESS, p->question, answer, &reply); + if (r < 0) { + log_debug("Failed to build reply packet: %s", strerror(-r)); + return; + } + + if (stream) + r = dns_stream_write_packet(stream, reply); + else { + if (p->family == AF_INET) + fd = manager_llmnr_ipv4_udp_fd(s->manager); + else if (p->family == AF_INET6) + fd = manager_llmnr_ipv6_udp_fd(s->manager); + else { + log_debug("Unknown protocol"); + return; + } + if (fd < 0) { + log_debug("Failed to get reply socket: %s", strerror(-fd)); + return; + } + + r = manager_send(s->manager, fd, p->ifindex, p->family, &p->sender, p->sender_port, reply); + } + + if (r < 0) { + log_debug("Failed to send reply packet: %s", strerror(-r)); + return; + } +} diff --git a/src/resolve/resolved-dns-scope.h b/src/resolve/resolved-dns-scope.h index 6c93fa80b..639c4b4e8 100644 --- a/src/resolve/resolved-dns-scope.h +++ b/src/resolve/resolved-dns-scope.h @@ -31,6 +31,8 @@ typedef struct DnsScope DnsScope; #include "resolved-dns-packet.h" #include "resolved-dns-query.h" #include "resolved-dns-cache.h" +#include "resolved-dns-zone.h" +#include "resolved-dns-stream.h" typedef enum DnsScopeMatch { DNS_SCOPE_NO, @@ -51,6 +53,7 @@ struct DnsScope { char **domains; DnsCache cache; + DnsZone zone; LIST_HEAD(DnsQueryTransaction, transactions); @@ -61,12 +64,15 @@ int dns_scope_new(Manager *m, DnsScope **ret, Link *l, DnsProtocol p, int family DnsScope* dns_scope_free(DnsScope *s); int dns_scope_send(DnsScope *s, DnsPacket *p); -int dns_scope_tcp_socket(DnsScope *s); +int dns_scope_tcp_socket(DnsScope *s, int family, const union in_addr_union *address, uint16_t port); DnsScopeMatch dns_scope_good_domain(DnsScope *s, const char *domain); int dns_scope_good_key(DnsScope *s, DnsResourceKey *key); +int dns_scope_good_dns_server(DnsScope *s, int family, const union in_addr_union *address); DnsServer *dns_scope_get_server(DnsScope *s); 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); diff --git a/src/resolve/resolved-dns-server.h b/src/resolve/resolved-dns-server.h index 45a7c4ff3..2736032ea 100644 --- a/src/resolve/resolved-dns-server.h +++ b/src/resolve/resolved-dns-server.h @@ -31,6 +31,7 @@ typedef enum DnsServerSource DnsServerSource; #include "resolved-dns-server.h" enum DnsServerSource { + DNS_SERVER_ANY, DNS_SERVER_SYSTEM, DNS_SERVER_LINK, _DNS_SERVER_SOURCE_MAX diff --git a/src/resolve/resolved-dns-stream.c b/src/resolve/resolved-dns-stream.c new file mode 100644 index 000000000..24a228842 --- /dev/null +++ b/src/resolve/resolved-dns-stream.c @@ -0,0 +1,380 @@ +/*-*- 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 + +#include "missing.h" +#include "resolved-dns-stream.h" + +#define DNS_STREAM_TIMEOUT_USEC (10 * USEC_PER_SEC) +#define DNS_STREAMS_MAX 128 + +static void dns_stream_stop(DnsStream *s) { + assert(s); + + s->io_event_source = sd_event_source_unref(s->io_event_source); + s->timeout_event_source = sd_event_source_unref(s->timeout_event_source); + s->fd = safe_close(s->fd); +} + +static int dns_stream_update_io(DnsStream *s) { + int f = 0; + + assert(s); + + if (s->write_packet && s->n_written < sizeof(s->write_size) + s->write_packet->size) + f |= EPOLLOUT; + if (!s->read_packet || s->n_read < sizeof(s->read_size) + s->read_packet->size) + f |= EPOLLIN; + + return sd_event_source_set_io_events(s->io_event_source, f); +} + +static int stream_complete(DnsStream *s, int error) { + assert(s); + + dns_stream_stop(s); + + if (s->complete) + s->complete(s, error); + else + dns_stream_free(s); + + return 0; +} + +static int on_stream_timeout(sd_event_source *es, usec_t usec, void *userdata) { + DnsStream *s = userdata; + + assert(s); + + return stream_complete(s, ETIMEDOUT); +} + +static int on_stream_io(sd_event_source *es, int fd, uint32_t revents, void *userdata) { + DnsStream *s = userdata; + int r; + + assert(s); + + if ((revents & EPOLLOUT) && + s->write_packet && + s->n_written < sizeof(s->write_size) + s->write_packet->size) { + + struct iovec iov[2]; + ssize_t ss; + + iov[0].iov_base = &s->write_size; + iov[0].iov_len = sizeof(s->write_size); + iov[1].iov_base = DNS_PACKET_DATA(s->write_packet); + iov[1].iov_len = s->write_packet->size; + + IOVEC_INCREMENT(iov, 2, s->n_written); + + ss = writev(fd, iov, 2); + if (ss < 0) { + if (errno != EINTR && errno != EAGAIN) + return stream_complete(s, errno); + } else + s->n_written += ss; + + /* Are we done? If so, disable the event source for EPOLLOUT */ + if (s->n_written >= sizeof(s->write_size) + s->write_packet->size) { + r = dns_stream_update_io(s); + if (r < 0) + return stream_complete(s, -r); + } + } + + if ((revents & (EPOLLIN|EPOLLHUP|EPOLLRDHUP)) && + (!s->read_packet || + s->n_read < sizeof(s->read_size) + s->read_packet->size)) { + + if (s->n_read < sizeof(s->read_size)) { + ssize_t ss; + + ss = read(fd, (uint8_t*) &s->read_size + s->n_read, sizeof(s->read_size) - s->n_read); + if (ss < 0) { + if (errno != EINTR && errno != EAGAIN) + return stream_complete(s, errno); + } else if (ss == 0) + return stream_complete(s, ECONNRESET); + else + s->n_read += ss; + } + + if (s->n_read >= sizeof(s->read_size)) { + + if (be16toh(s->read_size) < DNS_PACKET_HEADER_SIZE) + return stream_complete(s, EBADMSG); + + if (s->n_read < sizeof(s->read_size) + be16toh(s->read_size)) { + ssize_t ss; + + if (!s->read_packet) { + r = dns_packet_new(&s->read_packet, s->protocol, be16toh(s->read_size)); + if (r < 0) + return stream_complete(s, -r); + + s->read_packet->size = be16toh(s->read_size); + s->read_packet->ipproto = IPPROTO_TCP; + s->read_packet->family = s->peer.sa.sa_family; + s->read_packet->ttl = s->ttl; + s->read_packet->ifindex = s->ifindex; + + if (s->read_packet->family == AF_INET) { + s->read_packet->sender.in = s->peer.in.sin_addr; + s->read_packet->sender_port = be16toh(s->peer.in.sin_port); + s->read_packet->destination.in = s->local.in.sin_addr; + s->read_packet->destination_port = be16toh(s->local.in.sin_port); + } else { + assert(s->read_packet->family == AF_INET6); + s->read_packet->sender.in6 = s->peer.in6.sin6_addr; + s->read_packet->sender_port = be16toh(s->peer.in6.sin6_port); + s->read_packet->destination.in6 = s->local.in6.sin6_addr; + s->read_packet->destination_port = be16toh(s->local.in6.sin6_port); + + if (s->read_packet->ifindex == 0) + s->read_packet->ifindex = s->peer.in6.sin6_scope_id; + if (s->read_packet->ifindex == 0) + s->read_packet->ifindex = s->local.in6.sin6_scope_id; + } + } + + ss = read(fd, + (uint8_t*) DNS_PACKET_DATA(s->read_packet) + s->n_read - sizeof(s->read_size), + sizeof(s->read_size) + be16toh(s->read_size) - s->n_read); + if (ss < 0) { + if (errno != EINTR && errno != EAGAIN) + return stream_complete(s, errno); + } else if (ss == 0) + return stream_complete(s, ECONNRESET); + else + s->n_read += ss; + } + + /* Are we done? If so, disable the event source for EPOLLIN */ + if (s->n_read >= sizeof(s->read_size) + be16toh(s->read_size)) { + r = dns_stream_update_io(s); + if (r < 0) + return stream_complete(s, -r); + + /* If there's a packet handler + * installed, call that. Note that + * this is optional... */ + if (s->on_packet) + return s->on_packet(s); + } + } + } + + if ((s->write_packet && s->n_written >= sizeof(s->write_size) + s->write_packet->size) && + (s->read_packet && s->n_read >= sizeof(s->read_size) + s->read_packet->size)) + return stream_complete(s, 0); + + return 0; +} + +DnsStream *dns_stream_free(DnsStream *s) { + if (!s) + return NULL; + + dns_stream_stop(s); + + if (s->manager) { + LIST_REMOVE(streams, s->manager->dns_streams, s); + s->manager->n_dns_streams--; + } + + dns_packet_unref(s->write_packet); + dns_packet_unref(s->read_packet); + + free(s); + + return 0; +} + +DEFINE_TRIVIAL_CLEANUP_FUNC(DnsStream*, dns_stream_free); + +int dns_stream_new(Manager *m, DnsStream **ret, DnsProtocol protocol, int fd) { + static const int one = 1; + union { + struct cmsghdr header; /* For alignment */ + uint8_t buffer[CMSG_SPACE(MAX(sizeof(struct in_pktinfo), sizeof(struct in6_pktinfo))) + + EXTRA_CMSG_SPACE /* kernel appears to require extra space */]; + } control; + struct msghdr mh = {}; + struct cmsghdr *cmsg; + _cleanup_(dns_stream_freep) DnsStream *s = NULL; + socklen_t sl; + int r; + + assert(m); + assert(fd >= 0); + + if (m->n_dns_streams > DNS_STREAMS_MAX) + return -EBUSY; + + s = new0(DnsStream, 1); + if (!s) + return -ENOMEM; + + s->fd = -1; + s->protocol = protocol; + + /* Query the remote side */ + s->peer_salen = sizeof(s->peer); + r = getpeername(fd, &s->peer.sa, &s->peer_salen); + if (r < 0) + return -errno; + if (s->peer.sa.sa_family == AF_INET6) + s->ifindex = s->peer.in6.sin6_scope_id; + + /* Query the local side */ + s->local_salen = sizeof(s->local); + r = getsockname(fd, &s->local.sa, &s->local_salen); + if (r < 0) + return -errno; + if (s->local.sa.sa_family == AF_INET6 && s->ifindex <= 0) + s->ifindex = s->local.in6.sin6_scope_id; + + /* Check consistency */ + assert(s->peer.sa.sa_family == s->local.sa.sa_family); + assert(IN_SET(s->peer.sa.sa_family, AF_INET, AF_INET6)); + + /* Query connection meta information */ + sl = sizeof(control); + if (s->peer.sa.sa_family == AF_INET) { + r = getsockopt(fd, IPPROTO_IP, IP_PKTOPTIONS, &control, &sl); + if (r < 0) + return -errno; + } else { + assert(s->peer.sa.sa_family == AF_INET6); + + r = getsockopt(fd, IPPROTO_IPV6, IPV6_2292PKTOPTIONS, &control, &sl); + if (r < 0) + return -errno; + } + + mh.msg_control = &control; + mh.msg_controllen = sl; + for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) { + + if (cmsg->cmsg_level == IPPROTO_IPV6) { + assert(s->peer.sa.sa_family == AF_INET6); + + switch (cmsg->cmsg_type) { + + case IPV6_PKTINFO: { + struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg); + + if (s->ifindex <= 0) + s->ifindex = i->ipi6_ifindex; + break; + } + + case IPV6_HOPLIMIT: + s->ttl = *(int *) CMSG_DATA(cmsg); + break; + } + + } else if (cmsg->cmsg_level == IPPROTO_IP) { + assert(s->peer.sa.sa_family == AF_INET); + + switch (cmsg->cmsg_type) { + + case IP_PKTINFO: { + struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg); + + if (s->ifindex <= 0) + s->ifindex = i->ipi_ifindex; + break; + } + + case IP_TTL: + s->ttl = *(int *) CMSG_DATA(cmsg); + break; + } + } + } + + /* The Linux kernel sets the interface index to the loopback + * device if the connection came from the local host since it + * avoids the routing table in such a case. Let's unset the + * interface index in such a case. */ + if (s->ifindex > 0 && manager_ifindex_is_loopback(m, s->ifindex) != 0) + s->ifindex = 0; + + /* If we don't know the interface index still, we look for the + * first local interface with a matching address. Yuck! */ + if (s->ifindex <= 0) + s->ifindex = manager_find_ifindex(m, s->local.sa.sa_family, s->local.sa.sa_family == AF_INET ? (union in_addr_union*) &s->local.in.sin_addr : (union in_addr_union*) &s->local.in6.sin6_addr); + + r = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one)); + if (r < 0) + return -errno; + + if (s->protocol == DNS_PROTOCOL_LLMNR && s->ifindex > 0) { + uint32_t ifindex = htobe32(s->ifindex); + + /* Make sure all packets for this connection are sent on the same interface */ + if (s->local.sa.sa_family == AF_INET) { + r = setsockopt(fd, IPPROTO_IP, IP_UNICAST_IF, &ifindex, sizeof(ifindex)); + if (r < 0) + return -errno; + } else if (s->local.sa.sa_family == AF_INET6) { + r = setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_IF, &ifindex, sizeof(ifindex)); + if (r < 0) + return -errno; + } + } + + r = sd_event_add_io(m->event, &s->io_event_source, fd, EPOLLIN, on_stream_io, s); + if (r < 0) + return r; + + r = sd_event_add_time(m->event, &s->timeout_event_source, CLOCK_MONOTONIC, now(CLOCK_MONOTONIC) + DNS_STREAM_TIMEOUT_USEC, 0, on_stream_timeout, s); + if (r < 0) + return r; + + LIST_PREPEND(streams, m->dns_streams, s); + s->manager = m; + s->fd = fd; + m->n_dns_streams++; + + *ret = s; + s = NULL; + + return 0; +} + +int dns_stream_write_packet(DnsStream *s, DnsPacket *p) { + assert(s); + + if (s->write_packet) + return -EBUSY; + + s->write_packet = dns_packet_ref(p); + s->write_size = htobe16(p->size); + s->n_written = 0; + + return dns_stream_update_io(s); +} diff --git a/src/resolve/resolved-dns-stream.h b/src/resolve/resolved-dns-stream.h new file mode 100644 index 000000000..db456580c --- /dev/null +++ b/src/resolve/resolved-dns-stream.h @@ -0,0 +1,61 @@ +/*-*- 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 . +***/ + +#include "socket-util.h" + +typedef struct DnsStream DnsStream; + +#include "resolved.h" + +struct DnsStream { + Manager *manager; + + DnsProtocol protocol; + + int fd; + union sockaddr_union peer; + socklen_t peer_salen; + union sockaddr_union local; + socklen_t local_salen; + int ifindex; + uint32_t ttl; + + sd_event_source *io_event_source; + sd_event_source *timeout_event_source; + + be16_t write_size, read_size; + DnsPacket *write_packet, *read_packet; + size_t n_written, n_read; + + int (*on_packet)(DnsStream *s); + int (*complete)(DnsStream *s, int error); + + DnsQueryTransaction *transaction; + + LIST_FIELDS(DnsStream, streams); +}; + +int dns_stream_new(Manager *m, DnsStream **s, DnsProtocol protocol, int fd); +DnsStream *dns_stream_free(DnsStream *s); + +int dns_stream_write_packet(DnsStream *s, DnsPacket *p); diff --git a/src/resolve/resolved-dns-zone.c b/src/resolve/resolved-dns-zone.c new file mode 100644 index 000000000..2325ddfe7 --- /dev/null +++ b/src/resolve/resolved-dns-zone.c @@ -0,0 +1,244 @@ +/*-*- 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 "list.h" + +#include "resolved-dns-zone.h" +#include "resolved-dns-domain.h" +#include "resolved-dns-packet.h" + +/* Never allow more than 1K entries */ +#define ZONE_MAX 1024 + +typedef struct DnsZoneItem DnsZoneItem; + +struct DnsZoneItem { + DnsResourceRecord *rr; + bool verified; + LIST_FIELDS(DnsZoneItem, by_key); + LIST_FIELDS(DnsZoneItem, by_name); +}; + +static void dns_zone_item_free(DnsZoneItem *i) { + if (!i) + return; + + dns_resource_record_unref(i->rr); + free(i); +} + +DEFINE_TRIVIAL_CLEANUP_FUNC(DnsZoneItem*, dns_zone_item_free); + +static void dns_zone_item_remove_and_free(DnsZone *z, DnsZoneItem *i) { + DnsZoneItem *first; + + assert(z); + + if (!i) + return; + + first = hashmap_get(z->by_key, i->rr->key); + LIST_REMOVE(by_key, first, i); + if (first) + assert_se(hashmap_replace(z->by_key, first->rr->key, first) >= 0); + else + hashmap_remove(z->by_key, i->rr->key); + + first = hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(i->rr->key)); + LIST_REMOVE(by_name, first, i); + if (first) + assert_se(hashmap_replace(z->by_name, DNS_RESOURCE_KEY_NAME(first->rr->key), first) >= 0); + else + hashmap_remove(z->by_name, DNS_RESOURCE_KEY_NAME(i->rr->key)); + + dns_zone_item_free(i); +} + +void dns_zone_flush(DnsZone *z) { + DnsZoneItem *i; + + assert(z); + + while ((i = hashmap_first(z->by_key))) + dns_zone_item_remove_and_free(z, i); + + assert(hashmap_size(z->by_key) == 0); + assert(hashmap_size(z->by_name) == 0); + + hashmap_free(z->by_key); + z->by_key = NULL; + + hashmap_free(z->by_name); + z->by_name = NULL; +} + +static DnsZoneItem* dns_zone_get(DnsZone *z, DnsResourceRecord *rr) { + DnsZoneItem *i; + + assert(z); + assert(rr); + + LIST_FOREACH(by_key, i, hashmap_get(z->by_key, rr->key)) + if (dns_resource_record_equal(i->rr, rr)) + return i; + + return NULL; +} + +void dns_zone_remove_rr(DnsZone *z, DnsResourceRecord *rr) { + DnsZoneItem *i; + + assert(z); + assert(rr); + + i = dns_zone_get(z, rr); + if (i) + dns_zone_item_remove_and_free(z, i); +} + +static int dns_zone_init(DnsZone *z) { + int r; + + assert(z); + + r = hashmap_ensure_allocated(&z->by_key, dns_resource_key_hash_func, dns_resource_key_compare_func); + if (r < 0) + return r; + + r = hashmap_ensure_allocated(&z->by_name, dns_name_hash_func, dns_name_compare_func); + if (r < 0) + return r; + + return 0; +} + +static int dns_zone_link_item(DnsZone *z, DnsZoneItem *i) { + DnsZoneItem *first; + int r; + + first = hashmap_get(z->by_key, i->rr->key); + if (first) { + LIST_PREPEND(by_key, first, i); + assert_se(hashmap_replace(z->by_key, first->rr->key, first) >= 0); + } else { + r = hashmap_put(z->by_key, i->rr->key, i); + if (r < 0) + return r; + } + + first = hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(i->rr->key)); + if (first) { + LIST_PREPEND(by_name, first, i); + assert_se(hashmap_replace(z->by_name, DNS_RESOURCE_KEY_NAME(first->rr->key), first) >= 0); + } else { + r = hashmap_put(z->by_name, DNS_RESOURCE_KEY_NAME(i->rr->key), i); + if (r < 0) + return r; + } + + return 0; +} + +int dns_zone_put(DnsZone *z, DnsResourceRecord *rr) { + _cleanup_(dns_zone_item_freep) DnsZoneItem *i = NULL; + DnsZoneItem *existing; + int r; + + assert(z); + assert(rr); + + existing = dns_zone_get(z, rr); + if (existing) + return 0; + + r = dns_zone_init(z); + if (r < 0) + return r; + + i = new0(DnsZoneItem, 1); + if (!i) + return -ENOMEM; + + i->rr = dns_resource_record_ref(rr); + + r = dns_zone_link_item(z, i); + if (r < 0) + return r; + + i = NULL; + return 0; +} + +int dns_zone_lookup(DnsZone *z, DnsQuestion *q, DnsAnswer **ret) { + _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; + int r; + unsigned i, n = 0; + bool has_other_rrs = false; + + assert(z); + assert(q); + assert(ret); + + if (q->n_keys <= 0) { + *ret = NULL; + return 0; + } + + for (i = 0; i < q->n_keys; i++) { + DnsZoneItem *j; + + j = hashmap_get(z->by_key, q->keys[i]); + if (!j) { + if (hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(q->keys[i]))) + has_other_rrs = true; + + continue; + } + + LIST_FOREACH(by_name, j, j) + n++; + } + + if (n <= 0) { + *ret = NULL; + return has_other_rrs; + } + + answer = dns_answer_new(n); + if (!answer) + return -ENOMEM; + + for (i = 0; i < q->n_keys; i++) { + DnsZoneItem *j; + + j = hashmap_get(z->by_key, q->keys[i]); + LIST_FOREACH(by_key, j, j) { + r = dns_answer_add(answer, j->rr); + if (r < 0) + return r; + } + } + + *ret = answer; + answer = NULL; + + return 1; +} diff --git a/src/resolve/resolved-dns-zone.h b/src/resolve/resolved-dns-zone.h new file mode 100644 index 000000000..89d0bbe35 --- /dev/null +++ b/src/resolve/resolved-dns-zone.h @@ -0,0 +1,40 @@ +/*-*- 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 . +***/ + +#include "hashmap.h" + +typedef struct DnsZone { + Hashmap *by_key; + Hashmap *by_name; +} DnsZone; + +#include "resolved-dns-rr.h" +#include "resolved-dns-question.h" +#include "resolved-dns-answer.h" + +void dns_zone_flush(DnsZone *z); + +int dns_zone_put(DnsZone *z, DnsResourceRecord *rr); +void dns_zone_remove_rr(DnsZone *z, DnsResourceRecord *rr); + +int dns_zone_lookup(DnsZone *z, DnsQuestion *q, DnsAnswer **answer); diff --git a/src/resolve/resolved-link.c b/src/resolve/resolved-link.c index 3c6c75772..6ac7c5be9 100644 --- a/src/resolve/resolved-link.c +++ b/src/resolve/resolved-link.c @@ -25,6 +25,10 @@ #include "strv.h" #include "resolved-link.h" +#define DEFAULT_TTL (10) + +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; @@ -110,6 +114,13 @@ 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) { + LinkAddress *a; + + LIST_FOREACH(addresses, a, l->addresses) + link_address_add_rrs(a); +} + int link_update_rtnl(Link *l, sd_rtnl_message *m) { const char *n = NULL; int r; @@ -129,6 +140,8 @@ int link_update_rtnl(Link *l, sd_rtnl_message *m) { } link_allocate_scopes(l); + link_add_rrs(l); + return 0; } @@ -183,6 +196,7 @@ int link_update_monitor(Link *l) { link_update_dns_servers(l); link_allocate_scopes(l); + link_add_rrs(l); return 0; } @@ -210,7 +224,7 @@ bool link_relevant(Link *l, int family) { return false; } -LinkAddress *link_find_address(Link *l, int family, union in_addr_union *in_addr) { +LinkAddress *link_find_address(Link *l, int family, const union in_addr_union *in_addr) { LinkAddress *a; assert(l); @@ -222,7 +236,7 @@ LinkAddress *link_find_address(Link *l, int family, union in_addr_union *in_addr return NULL; } -DnsServer* link_find_dns_server(Link *l, int family, union in_addr_union *in_addr) { +DnsServer* link_find_dns_server(Link *l, int family, const union in_addr_union *in_addr) { DnsServer *s; assert(l); @@ -230,7 +244,6 @@ DnsServer* link_find_dns_server(Link *l, int family, union in_addr_union *in_add LIST_FOREACH(servers, s, l->dns_servers) if (s->family == family && in_addr_equal(family, &s->address, in_addr)) return s; - return NULL; } @@ -265,7 +278,7 @@ void link_next_dns_server(Link *l) { l->current_dns_server = l->dns_servers; } -int link_address_new(Link *l, LinkAddress **ret, int family, union in_addr_union *in_addr) { +int link_address_new(Link *l, LinkAddress **ret, int family, const union in_addr_union *in_addr) { LinkAddress *a; assert(l); @@ -291,13 +304,130 @@ LinkAddress *link_address_free(LinkAddress *a) { if (!a) return NULL; - if (a->link) + if (a->link) { 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) { + if (a->family == AF_INET && a->link->llmnr_ipv4_scope) + 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); + } + } + free(a); return NULL; } +static void link_address_add_rrs(LinkAddress *a) { + int r; + + assert(a); + + if (a->family == AF_INET && a->link->llmnr_ipv4_scope) { + + 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 (!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->a.in_addr = a->in_addr.in; + a->llmnr_address_rr->ttl = 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; + + a->llmnr_ptr_rr->ttl = DEFAULT_TTL; + } + + if (link_address_relevant(a)) { + r = dns_zone_put(&a->link->llmnr_ipv4_scope->zone, a->llmnr_address_rr); + if (r < 0) + goto fail; + + r = dns_zone_put(&a->link->llmnr_ipv4_scope->zone, a->llmnr_ptr_rr); + if (r < 0) + goto fail; + } 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->family == AF_INET6 && a->link->llmnr_ipv6_scope) { + + 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 (!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->aaaa.in6_addr = a->in_addr.in6; + a->llmnr_address_rr->ttl = 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; + + a->llmnr_ptr_rr->ttl = DEFAULT_TTL; + } + + if (link_address_relevant(a)) { + r = dns_zone_put(&a->link->llmnr_ipv6_scope->zone, a->llmnr_address_rr); + if (r < 0) + goto fail; + + r = dns_zone_put(&a->link->llmnr_ipv6_scope->zone, a->llmnr_ptr_rr); + if (r < 0) + goto fail; + } 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); + } + } + + return; + +fail: + log_debug("Failed to update address RRs: %s", strerror(-r)); +} + int link_address_update_rtnl(LinkAddress *a, sd_rtnl_message *m) { int r; assert(a); @@ -310,6 +440,8 @@ 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); + return 0; } diff --git a/src/resolve/resolved-link.h b/src/resolve/resolved-link.h index cef0400b2..f58bd5420 100644 --- a/src/resolve/resolved-link.h +++ b/src/resolve/resolved-link.h @@ -32,6 +32,7 @@ typedef struct LinkAddress LinkAddress; #include "resolved.h" #include "resolved-dns-server.h" #include "resolved-dns-scope.h" +#include "resolved-dns-rr.h" struct LinkAddress { Link *link; @@ -41,6 +42,9 @@ struct LinkAddress { unsigned char flags, scope; + DnsResourceRecord *llmnr_address_rr; + DnsResourceRecord *llmnr_ptr_rr; + LIST_FIELDS(LinkAddress, addresses); }; @@ -71,13 +75,13 @@ Link *link_free(Link *l); 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, union in_addr_union *in_addr); +LinkAddress* link_find_address(Link *l, int family, const union in_addr_union *in_addr); -DnsServer* link_find_dns_server(Link *l, int family, union in_addr_union *in_addr); +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); -int link_address_new(Link *l, LinkAddress **ret, int family, union in_addr_union *in_addr); +int link_address_new(Link *l, LinkAddress **ret, int family, const union in_addr_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); diff --git a/src/resolve/resolved-manager.c b/src/resolve/resolved-manager.c index f4fa197d4..a8715bd5b 100644 --- a/src/resolve/resolved-manager.c +++ b/src/resolve/resolved-manager.c @@ -390,6 +390,7 @@ int manager_new(Manager **ret) { m->dns_ipv4_fd = m->dns_ipv6_fd = -1; m->llmnr_ipv4_udp_fd = m->llmnr_ipv6_udp_fd = -1; + m->llmnr_ipv4_tcp_fd = m->llmnr_ipv6_tcp_fd = -1; m->use_llmnr = true; @@ -397,6 +398,10 @@ int manager_new(Manager **ret) { if (r < 0) return r; + m->hostname = gethostname_malloc(); + if (!m->hostname) + return -ENOMEM; + r = sd_event_default(&m->event); if (r < 0) return r; @@ -422,6 +427,19 @@ int manager_new(Manager **ret) { if (r < 0) return r; + r = manager_llmnr_ipv4_udp_fd(m); + if (r < 0) + return r; + r = manager_llmnr_ipv6_udp_fd(m); + if (r < 0) + return r; + r = manager_llmnr_ipv4_tcp_fd(m); + if (r < 0) + return r; + r = manager_llmnr_ipv6_tcp_fd(m); + if (r < 0) + return r; + *ret = m; m = NULL; @@ -461,10 +479,19 @@ Manager *manager_free(Manager *m) { safe_close(m->llmnr_ipv4_udp_fd); safe_close(m->llmnr_ipv6_udp_fd); + sd_event_source_unref(m->llmnr_ipv4_tcp_event_source); + sd_event_source_unref(m->llmnr_ipv6_tcp_event_source); + safe_close(m->llmnr_ipv4_tcp_fd); + safe_close(m->llmnr_ipv6_tcp_fd); + sd_event_source_unref(m->bus_retry_event_source); sd_bus_unref(m->bus); sd_event_unref(m->event); + + dns_resource_key_unref(m->host_ipv4_key); + dns_resource_key_unref(m->host_ipv6_key); + free(m->hostname); free(m); return NULL; @@ -545,7 +572,7 @@ int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) { struct cmsghdr header; /* For alignment */ uint8_t buffer[CMSG_SPACE(MAX(sizeof(struct in_pktinfo), sizeof(struct in6_pktinfo))) + CMSG_SPACE(int) /* ttl/hoplimit */ - + 1024 /* kernel appears to require extra buffer space */]; + + EXTRA_CMSG_SPACE /* kernel appears to require extra buffer space */]; } control; union sockaddr_union sa; struct msghdr mh = {}; @@ -595,11 +622,15 @@ int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) { p->size = (size_t) l; p->family = sa.sa.sa_family; - if (p->family == AF_INET) + p->ipproto = IPPROTO_UDP; + if (p->family == AF_INET) { p->sender.in = sa.in.sin_addr; - else if (p->family == AF_INET6) + p->sender_port = be16toh(sa.in.sin_port); + } else if (p->family == AF_INET6) { p->sender.in6 = sa.in6.sin6_addr; - else + p->sender_port = be16toh(sa.in6.sin6_port); + p->ifindex = sa.in6.sin6_scope_id; + } else return -EAFNOSUPPORT; for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) { @@ -612,7 +643,9 @@ int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) { case IPV6_PKTINFO: { struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg); - p->ifindex = i->ipi6_ifindex; + if (p->ifindex <= 0) + p->ifindex = i->ipi6_ifindex; + p->destination.in6 = i->ipi6_addr; break; } @@ -630,18 +663,32 @@ int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) { case IP_PKTINFO: { struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg); - p->ifindex = i->ipi_ifindex; + if (p->ifindex <= 0) + p->ifindex = i->ipi_ifindex; + p->destination.in = i->ipi_addr; break; } - case IP_RECVTTL: + case IP_TTL: p->ttl = *(int *) CMSG_DATA(cmsg); break; } } } + /* The Linux kernel sets the interface index to the loopback + * device if the packet came from the local host since it + * avoids the routing table in such a case. Let's unset the + * interface index in such a case. */ + if (p->ifindex > 0 && manager_ifindex_is_loopback(m, p->ifindex) != 0) + p->ifindex = 0; + + /* If we don't know the interface index still, we look for the + * first local interface with a matching address. Yuck! */ + if (p->ifindex <= 0) + p->ifindex = manager_find_ifindex(m, p->family, &p->destination); + *ret = p; p = NULL; @@ -658,14 +705,15 @@ static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *use if (r <= 0) return r; - if (dns_packet_validate_reply(p) >= 0) { + if (dns_packet_validate_reply(p) > 0) { t = hashmap_get(m->dns_query_transactions, UINT_TO_PTR(DNS_PACKET_ID(p))); if (!t) return 0; dns_query_transaction_process_reply(t, p); + } else - log_debug("Invalid reply packet."); + log_debug("Invalid DNS packet."); return 0; } @@ -754,7 +802,7 @@ static int sendmsg_loop(int fd, struct msghdr *mh, int flags) { } } -static int manager_ipv4_send(Manager *m, int fd, int ifindex, struct in_addr *addr, uint16_t port, DnsPacket *p) { +static int manager_ipv4_send(Manager *m, int fd, int ifindex, const struct in_addr *addr, uint16_t port, DnsPacket *p) { union sockaddr_union sa = { .in.sin_family = AF_INET, }; @@ -803,7 +851,7 @@ static int manager_ipv4_send(Manager *m, int fd, int ifindex, struct in_addr *ad return sendmsg_loop(fd, &mh, 0); } -static int manager_ipv6_send(Manager *m, int fd, int ifindex, struct in6_addr *addr, uint16_t port, DnsPacket *p) { +static int manager_ipv6_send(Manager *m, int fd, int ifindex, const struct in6_addr *addr, uint16_t port, DnsPacket *p) { union sockaddr_union sa = { .in6.sin6_family = AF_INET6, }; @@ -853,7 +901,7 @@ static int manager_ipv6_send(Manager *m, int fd, int ifindex, struct in6_addr *a return sendmsg_loop(fd, &mh, 0); } -int manager_send(Manager *m, int fd, int ifindex, int family, union in_addr_union *addr, uint16_t port, DnsPacket *p) { +int manager_send(Manager *m, int fd, int ifindex, int family, const union in_addr_union *addr, uint16_t port, DnsPacket *p) { assert(m); assert(fd >= 0); assert(addr); @@ -869,7 +917,7 @@ int manager_send(Manager *m, int fd, int ifindex, int family, union in_addr_unio } -DnsServer* manager_find_dns_server(Manager *m, int family, union in_addr_union *in_addr) { +DnsServer* manager_find_dns_server(Manager *m, int family, const union in_addr_union *in_addr) { DnsServer *s; assert(m); @@ -943,13 +991,30 @@ static int on_llmnr_packet(sd_event_source *s, int fd, uint32_t revents, void *u if (r <= 0) return r; - if (dns_packet_validate_reply(p) >= 0) { + if (dns_packet_validate_reply(p) > 0) { t = hashmap_get(m->dns_query_transactions, UINT_TO_PTR(DNS_PACKET_ID(p))); if (!t) return 0; dns_query_transaction_process_reply(t, p); - } + + } else if (dns_packet_validate_query(p) > 0) { + Link *l; + + l = hashmap_get(m->links, INT_TO_PTR(p->ifindex)); + if (l) { + DnsScope *scope = NULL; + + if (p->family == AF_INET) + scope = l->llmnr_ipv4_scope; + else if (p->family == AF_INET6) + scope = l->llmnr_ipv6_scope; + + if (scope) + dns_scope_process_query(scope, NULL, p); + } + } else + log_debug("Invalid LLMNR packet."); return 0; } @@ -1108,3 +1173,225 @@ fail: m->llmnr_ipv6_udp_fd = safe_close(m->llmnr_ipv6_udp_fd); return r; } + +static int on_llmnr_stream_packet(DnsStream *s) { + assert(s); + + if (dns_packet_validate_query(s->read_packet) > 0) { + Link *l; + + l = hashmap_get(s->manager->links, INT_TO_PTR(s->read_packet->ifindex)); + if (l) { + DnsScope *scope = NULL; + + if (s->read_packet->family == AF_INET) + scope = l->llmnr_ipv4_scope; + else if (s->read_packet->family == AF_INET6) + scope = l->llmnr_ipv6_scope; + + if (scope) { + dns_scope_process_query(scope, s, s->read_packet); + + /* If no reply packet was set, we free the stream */ + if (s->write_packet) + return 0; + } + } + } + + dns_stream_free(s); + return 0; +} + +static int on_llmnr_stream(sd_event_source *s, int fd, uint32_t revents, void *userdata) { + DnsStream *stream; + Manager *m = userdata; + int cfd, r; + + cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC); + if (cfd < 0) { + if (errno == EAGAIN || errno == EINTR) + return 0; + + return -errno; + } + + r = dns_stream_new(m, &stream, DNS_PROTOCOL_LLMNR, cfd); + if (r < 0) { + safe_close(cfd); + return r; + } + + stream->on_packet = on_llmnr_stream_packet; + return 0; +} + +int manager_llmnr_ipv4_tcp_fd(Manager *m) { + union sockaddr_union sa = { + .in.sin_family = AF_INET, + .in.sin_port = htobe16(5355), + }; + static const int one = 1, pmtu = IP_PMTUDISC_DONT; + int r; + + assert(m); + + if (m->llmnr_ipv4_tcp_fd >= 0) + return m->llmnr_ipv4_tcp_fd; + + m->llmnr_ipv4_tcp_fd = socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (m->llmnr_ipv4_tcp_fd < 0) + return -errno; + + r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_TTL, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv4_tcp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + /* Disable Don't-Fragment bit in the IP header */ + r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_MTU_DISCOVER, &pmtu, sizeof(pmtu)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = bind(m->llmnr_ipv4_tcp_fd, &sa.sa, sizeof(sa.in)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = listen(m->llmnr_ipv4_tcp_fd, SOMAXCONN); + if (r < 0) { + r = -errno; + goto fail; + } + + r = sd_event_add_io(m->event, &m->llmnr_ipv4_tcp_event_source, m->llmnr_ipv4_tcp_fd, EPOLLIN, on_llmnr_stream, m); + if (r < 0) + goto fail; + + return m->llmnr_ipv4_tcp_fd; + +fail: + m->llmnr_ipv4_tcp_fd = safe_close(m->llmnr_ipv4_tcp_fd); + return r; +} + +int manager_llmnr_ipv6_tcp_fd(Manager *m) { + union sockaddr_union sa = { + .in6.sin6_family = AF_INET6, + .in6.sin6_port = htobe16(5355), + }; + static const int one = 1; + int r; + + assert(m); + + if (m->llmnr_ipv6_tcp_fd >= 0) + return m->llmnr_ipv6_tcp_fd; + + m->llmnr_ipv6_tcp_fd = socket(AF_INET6, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (m->llmnr_ipv6_tcp_fd < 0) + return -errno; + + r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv6_tcp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = bind(m->llmnr_ipv6_tcp_fd, &sa.sa, sizeof(sa.in6)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = listen(m->llmnr_ipv6_tcp_fd, SOMAXCONN); + if (r < 0) { + r = -errno; + goto fail; + } + + r = sd_event_add_io(m->event, &m->llmnr_ipv6_tcp_event_source, m->llmnr_ipv6_tcp_fd, EPOLLIN, on_llmnr_stream, m); + if (r < 0) { + r = -errno; + goto fail; + } + + return m->llmnr_ipv6_tcp_fd; + +fail: + m->llmnr_ipv6_tcp_fd = safe_close(m->llmnr_ipv6_tcp_fd); + return r; +} + +int manager_ifindex_is_loopback(Manager *m, int ifindex) { + Link *l; + assert(m); + + if (ifindex <= 0) + return -EINVAL; + + l = hashmap_get(m->links, INT_TO_PTR(ifindex)); + if (l->flags & IFF_LOOPBACK) + return 1; + + return 0; +} + +int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr) { + Link *l; + Iterator i; + + assert(m); + + HASHMAP_FOREACH(l, m->links, i) + if (link_find_address(l, family, in_addr)) + return l->ifindex; + + return 0; +} diff --git a/src/resolve/resolved.h b/src/resolve/resolved.h index 35ef8bdea..6aa0fc9e5 100644 --- a/src/resolve/resolved.h +++ b/src/resolve/resolved.h @@ -34,6 +34,7 @@ typedef struct Manager Manager; #include "resolved-dns-query.h" #include "resolved-dns-server.h" #include "resolved-dns-scope.h" +#include "resolved-dns-stream.h" struct Manager { sd_event *event; @@ -54,6 +55,9 @@ struct Manager { LIST_HEAD(DnsQuery, dns_queries); unsigned n_dns_queries; + LIST_HEAD(DnsStream, dns_streams); + unsigned n_dns_streams; + /* Unicast dns */ int dns_ipv4_fd; int dns_ipv6_fd; @@ -70,15 +74,22 @@ struct Manager { /* LLMNR */ int llmnr_ipv4_udp_fd; int llmnr_ipv6_udp_fd; - /* int llmnr_ipv4_tcp_fd; */ - /* int llmnr_ipv6_tcp_fd; */ + int llmnr_ipv4_tcp_fd; + int llmnr_ipv6_tcp_fd; sd_event_source *llmnr_ipv4_udp_event_source; sd_event_source *llmnr_ipv6_udp_event_source; + sd_event_source *llmnr_ipv4_tcp_event_source; + sd_event_source *llmnr_ipv6_tcp_event_source; /* dbus */ sd_bus *bus; sd_event_source *bus_retry_event_source; + + /* The hostname we publish on LLMNR and mDNS */ + char *hostname; + DnsResourceKey *host_ipv4_key; + DnsResourceKey *host_ipv6_key; }; /* Manager */ @@ -89,18 +100,23 @@ Manager* manager_free(Manager *m); int manager_parse_config_file(Manager *m); int manager_write_resolv_conf(Manager *m); -DnsServer* manager_find_dns_server(Manager *m, int family, union in_addr_union *in_addr); +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, union in_addr_union *addr, uint16_t port, DnsPacket *p); +int manager_send(Manager *m, int fd, int ifindex, int family, const union in_addr_union *addr, uint16_t port, DnsPacket *p); int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret); int manager_dns_ipv4_fd(Manager *m); int manager_dns_ipv6_fd(Manager *m); int manager_llmnr_ipv4_udp_fd(Manager *m); int manager_llmnr_ipv6_udp_fd(Manager *m); +int manager_llmnr_ipv4_tcp_fd(Manager *m); +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); int manager_connect_bus(Manager *m); @@ -108,3 +124,5 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(Manager*, manager_free); const struct ConfigPerfItem* resolved_gperf_lookup(const char *key, unsigned length); int config_parse_dnsv(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata); + +#define EXTRA_CMSG_SPACE 1024 diff --git a/src/shared/in-addr-util.c b/src/shared/in-addr-util.c index ff008bd26..e9a99177f 100644 --- a/src/shared/in-addr-util.c +++ b/src/shared/in-addr-util.c @@ -23,7 +23,7 @@ #include "in-addr-util.h" -int in_addr_null(int family, union in_addr_union *u) { +int in_addr_null(int family, const union in_addr_union *u) { assert(u); if (family == AF_INET) @@ -40,7 +40,7 @@ int in_addr_null(int family, union in_addr_union *u) { } -int in_addr_equal(int family, union in_addr_union *a, union in_addr_union *b) { +int in_addr_equal(int family, const union in_addr_union *a, const union in_addr_union *b) { assert(a); assert(b); diff --git a/src/shared/in-addr-util.h b/src/shared/in-addr-util.h index 98de032d9..cff2c321e 100644 --- a/src/shared/in-addr-util.h +++ b/src/shared/in-addr-util.h @@ -31,8 +31,8 @@ union in_addr_union { struct in6_addr in6; }; -int in_addr_null(int family, union in_addr_union *u); -int in_addr_equal(int family, union in_addr_union *a, union in_addr_union *b); +int in_addr_null(int family, const union in_addr_union *u); +int in_addr_equal(int family, const union in_addr_union *a, const union in_addr_union *b); int in_addr_prefix_intersect(int family, const union in_addr_union *a, unsigned aprefixlen, const union in_addr_union *b, unsigned bprefixlen); int in_addr_prefix_next(int family, union in_addr_union *u, unsigned prefixlen); int in_addr_to_string(int family, const union in_addr_union *u, char **ret); diff --git a/src/shared/missing.h b/src/shared/missing.h index 298528540..f4378a36b 100644 --- a/src/shared/missing.h +++ b/src/shared/missing.h @@ -499,3 +499,7 @@ static inline int setns(int fd, int nstype) { #define IFLA_BRIDGE_MAX (__IFLA_BRIDGE_MAX - 1) #endif + +#ifndef IPV6_UNICAST_IF +#define IPV6_UNICAST_IF 76 +#endif