static void idnsRetryTcp(idns_query * q) { struct in_addr addr; int ns = (q->nsends - 1) % nns; idnsTcpCleanup(q); if (Config.Addrs.udp_outgoing.s_addr != no_addr.s_addr) addr = Config.Addrs.udp_outgoing; else addr = Config.Addrs.udp_incoming; q->tcp_socket = comm_open(SOCK_STREAM, IPPROTO_TCP, addr, 0, COMM_NONBLOCKING, "DNS TCP Socket"); #ifdef CC_FRAMEWORK if(q->tcp_socket < 0) { idnsTcpCleanup(q); cbdataFree(q); return; } #endif q->queue_t = q->sent_t = current_time; dlinkAdd(q, &q->lru, &lru_list); commConnectStart(q->tcp_socket, inet_ntoa(nameservers[ns].S.sin_addr), ntohs(nameservers[ns].S.sin_port), idnsSendTcpQuery, q ); }
static void idnsReadTcp(int fd, void *data) { ssize_t n; idns_query *q = data; int ns = (q->nsends - 1) % nns; if (!q->tcp_buffer) q->tcp_buffer = memAllocBuf(1024, &q->tcp_buffer_size); statCounter.syscalls.sock.reads++; n = FD_READ_METHOD(q->tcp_socket, q->tcp_buffer + q->tcp_buffer_offset, q->tcp_buffer_size - q->tcp_buffer_offset); if (n < 0 && ignoreErrno(errno)) { commSetSelect(q->tcp_socket, COMM_SELECT_READ, idnsReadTcp, q, 0); return; } if (n <= 0) { debug(78, 1) ("idnsReadTcp: Short response from nameserver %d for %s.\n", ns + 1, q->name); idnsTcpCleanup(q); return; } fd_bytes(fd, n, FD_READ); q->tcp_buffer_offset += n; if (q->tcp_buffer_offset > 2) { unsigned short response_size = ntohs(*(short *) q->tcp_buffer); if (q->tcp_buffer_offset >= response_size + 2) { nameservers[ns].nreplies++; idnsGrokReply(q->tcp_buffer + 2, response_size); return; } if (q->tcp_buffer_size < response_size + 2) q->tcp_buffer = memReallocBuf(q->tcp_buffer, response_size + 2, &q->tcp_buffer_size); } commSetSelect(q->tcp_socket, COMM_SELECT_READ, idnsReadTcp, q, 0); }
static void idnsSendTcpQueryDone(int fd, char *bufnotused, size_t size, int errflag, void *data) { idns_query *q = data; if (size > 0) fd_bytes(fd, size, FD_WRITE); if (errflag == COMM_ERR_CLOSING) return; if (errflag) { idnsTcpCleanup(q); return; } commSetSelect(q->tcp_socket, COMM_SELECT_READ, idnsReadTcp, q, 0); }
static void idnsCheckQueue(void *unused) { dlink_node *n; dlink_node *p = NULL; idns_query *q; event_queued = 0; if (0 == nns) /* name servers went away; reconfiguring or shutting down */ return; for (n = lru_list.tail; n; n = p) { p = n->prev; q = n->data; /* Anything to process in the queue? */ if (tvSubDsec(q->queue_t, current_time) < Config.Timeout.idns_retransmit) break; /* Query timer expired? */ if (tvSubDsec(q->sent_t, current_time) < Config.Timeout.idns_retransmit * 1 << ((q->nsends - 1) / nns)) { dlinkDelete(&q->lru, &lru_list); q->queue_t = current_time; dlinkAdd(q, &q->lru, &lru_list); continue; } debug(78, 3) ("idnsCheckQueue: ID %#04x timeout\n", q->id); dlinkDelete(&q->lru, &lru_list); if (tvSubDsec(q->start_t, current_time) < Config.Timeout.idns_query) { idnsSendQuery(q); } else { debug(78, 2) ("idnsCheckQueue: ID %x: giving up after %d tries and %5.1f seconds\n", (int) q->id, q->nsends, tvSubDsec(q->start_t, current_time)); if (q->rcode != 0) idnsCallback(q, NULL, -q->rcode, q->error); else idnsCallback(q, NULL, -16, "Timeout"); idnsTcpCleanup(q); cbdataFree(q); } } idnsTickleQueue(); }
static void idnsSendTcpQuery(int fd, int status, void *data) { MemBuf buf; idns_query *q = data; short nsz; if (status != COMM_OK) { int ns = (q->nsends - 1) % nns; debug(78, 1) ("idnsSendTcpQuery: Failed to connect to DNS server %d using TCP\n", ns + 1); idnsTcpCleanup(q); return; } memBufInit(&buf, q->sz + 2, q->sz + 2); nsz = htons(q->sz); memBufAppend(&buf, &nsz, 2); memBufAppend(&buf, q->buf, q->sz); comm_write_mbuf(q->tcp_socket, buf, idnsSendTcpQueryDone, q); }
static void idnsSendQuery(idns_query * q) { int x; int ns; if (DnsSocket < 0) { debug(78, 1) ("idnsSendQuery: Can't send query, no DNS socket!\n"); return; } /* XXX Select nameserver */ assert(nns > 0); assert(q->lru.next == NULL); assert(q->lru.prev == NULL); idnsTcpCleanup(q); try_again: ns = q->nsends % nns; x = comm_udp_sendto(DnsSocket, &nameservers[ns].S, sizeof(nameservers[ns].S), q->buf, q->sz); q->nsends++; q->queue_t = q->sent_t = current_time; if (x < 0) { debug(50, 1) ("idnsSendQuery: FD %d: sendto: %s\n", DnsSocket, xstrerror()); if (q->nsends % nns != 0) goto try_again; } else { fd_bytes(DnsSocket, x, FD_WRITE); commSetSelect(DnsSocket, COMM_SELECT_READ, idnsRead, NULL, 0); } nameservers[ns].nqueries++; dlinkAdd(q, &q->lru, &lru_list); idnsTickleQueue(); }
static void idnsGrokReply(const char *buf, size_t sz) { int n; rfc1035_message *message = NULL; idns_query *q; n = rfc1035MessageUnpack(buf, sz, &message); if (message == NULL) { debug(78, 2) ("idnsGrokReply: Malformed DNS response\n"); return; } debug(78, 3) ("idnsGrokReply: ID %#hx, %d answers\n", message->id, n); q = idnsFindQuery(message->id); if (q == NULL) { debug(78, 3) ("idnsGrokReply: Late response\n"); rfc1035MessageDestroy(message); return; } if (rfc1035QueryCompare(&q->query, message->query) != 0) { debug(78, 3) ("idnsGrokReply: Query mismatch (%s != %s)\n", q->query.name, message->query->name); rfc1035MessageDestroy(message); return; } dlinkDelete(&q->lru, &lru_list); if (message->tc && q->tcp_socket == -1) { debug(78, 2) ("idnsGrokReply: Response for %s truncated. Retrying using TCP\n", message->query->name); rfc1035MessageDestroy(message); idnsRetryTcp(q); return; } idnsRcodeCount(n, q->attempt); q->error = NULL; if (n < 0) { debug(78, 3) ("idnsGrokReply: error %s (%d)\n", rfc1035_error_message, rfc1035_errno); q->error = rfc1035_error_message; q->rcode = -n; if (q->rcode == 2 && ++q->attempt < MAX_ATTEMPT) { /* * RCODE 2 is "Server failure - The name server was * unable to process this query due to a problem with * the name server." */ rfc1035MessageDestroy(message); q->start_t = current_time; q->id = idnsQueryID(); rfc1035SetQueryID(q->buf, q->id); idnsSendQuery(q); return; } if (q->rcode == 3 && q->do_searchpath && q->attempt < MAX_ATTEMPT) { strcpy(q->name, q->orig); if (q->domain < npc) { strcat(q->name, "."); strcat(q->name, searchpath[q->domain].domain); debug(78, 3) ("idnsGrokReply: searchpath used for %s\n", q->name); q->domain++; } else { q->attempt++; } rfc1035MessageDestroy(message); if (q->hash.key) { hash_remove_link(idns_lookup_hash, &q->hash); q->hash.key = NULL; } q->start_t = current_time; q->id = idnsQueryID(); rfc1035SetQueryID(q->buf, q->id); q->sz = rfc1035BuildAQuery(q->name, q->buf, sizeof(q->buf), q->id, &q->query); idnsCacheQuery(q); idnsSendQuery(q); return; } } idnsCallback(q, message->answer, n, q->error); rfc1035MessageDestroy(message); idnsTcpCleanup(q); cbdataFree(q); }