| /* $Id$ */ |
| |
| /* Copyright 1998 by the Massachusetts Institute of Technology. |
| * |
| * Permission to use, copy, modify, and distribute this |
| * software and its documentation for any purpose and without |
| * fee is hereby granted, provided that the above copyright |
| * notice appear in all copies and that both that copyright |
| * notice and this permission notice appear in supporting |
| * documentation, and that the name of M.I.T. not be used in |
| * advertising or publicity pertaining to distribution of the |
| * software without specific, written prior permission. |
| * M.I.T. makes no representations about the suitability of |
| * this software for any purpose. It is provided "as is" |
| * without express or implied warranty. |
| */ |
| |
| #include "setup.h" |
| |
| #if defined(WIN32) && !defined(WATT32) |
| #include "nameser.h" |
| |
| #else |
| #include <sys/socket.h> |
| #ifdef HAVE_SYS_UIO_H |
| #include <sys/uio.h> |
| #endif |
| #include <netinet/in.h> |
| #include <netdb.h> |
| #include <arpa/nameser.h> |
| #ifdef HAVE_ARPA_NAMESER_COMPAT_H |
| #include <arpa/nameser_compat.h> |
| #endif |
| #endif /* WIN32 && !WATT32 */ |
| |
| #ifdef HAVE_UNISTD_H |
| #include <unistd.h> |
| #endif |
| #ifdef HAVE_SYS_IOCTL_H |
| #include <sys/ioctl.h> |
| #endif |
| #ifdef NETWARE |
| #include <sys/filio.h> |
| #endif |
| |
| #include <string.h> |
| #include <stdlib.h> |
| #include <fcntl.h> |
| #include <time.h> |
| #include <errno.h> |
| |
| #include "ares.h" |
| #include "ares_dns.h" |
| #include "ares_private.h" |
| |
| |
| static int try_again(int errnum); |
| static void write_tcp_data(ares_channel channel, fd_set *write_fds, |
| ares_socket_t write_fd, time_t now); |
| static void read_tcp_data(ares_channel channel, fd_set *read_fds, |
| ares_socket_t read_fd, time_t now); |
| static void read_udp_packets(ares_channel channel, fd_set *read_fds, |
| ares_socket_t read_fd, time_t now); |
| static void process_timeouts(ares_channel channel, time_t now); |
| static void process_answer(ares_channel channel, unsigned char *abuf, |
| int alen, int whichserver, int tcp, time_t now); |
| static void handle_error(ares_channel channel, int whichserver, time_t now); |
| static struct query *next_server(ares_channel channel, struct query *query, time_t now); |
| static int open_tcp_socket(ares_channel channel, struct server_state *server); |
| static int open_udp_socket(ares_channel channel, struct server_state *server); |
| static int same_questions(const unsigned char *qbuf, int qlen, |
| const unsigned char *abuf, int alen); |
| static struct query *end_query(ares_channel channel, struct query *query, int status, |
| unsigned char *abuf, int alen); |
| |
| /* Something interesting happened on the wire, or there was a timeout. |
| * See what's up and respond accordingly. |
| */ |
| void ares_process(ares_channel channel, fd_set *read_fds, fd_set *write_fds) |
| { |
| time_t now; |
| |
| time(&now); |
| write_tcp_data(channel, write_fds, ARES_SOCKET_BAD, now); |
| read_tcp_data(channel, read_fds, ARES_SOCKET_BAD, now); |
| read_udp_packets(channel, read_fds, ARES_SOCKET_BAD, now); |
| process_timeouts(channel, now); |
| } |
| |
| /* Something interesting happened on the wire, or there was a timeout. |
| * See what's up and respond accordingly. |
| */ |
| void ares_process_fd(ares_channel channel, |
| ares_socket_t read_fd, /* use ARES_SOCKET_BAD or valid |
| file descriptors */ |
| ares_socket_t write_fd) |
| { |
| time_t now; |
| |
| time(&now); |
| write_tcp_data(channel, NULL, write_fd, now); |
| read_tcp_data(channel, NULL, read_fd, now); |
| read_udp_packets(channel, NULL, read_fd, now); |
| process_timeouts(channel, now); |
| } |
| |
| |
| /* Return 1 if the specified error number describes a readiness error, or 0 |
| * otherwise. This is mostly for HP-UX, which could return EAGAIN or |
| * EWOULDBLOCK. See this man page |
| * |
| * http://devrsrc1.external.hp.com/STKS/cgi-bin/man2html?manpage=/usr/share/man/man2.Z/send.2 |
| */ |
| static int try_again(int errnum) |
| { |
| #if !defined EWOULDBLOCK && !defined EAGAIN |
| #error "Neither EWOULDBLOCK nor EAGAIN defined" |
| #endif |
| switch (errnum) |
| { |
| #ifdef EWOULDBLOCK |
| case EWOULDBLOCK: |
| return 1; |
| #endif |
| #if defined EAGAIN && EAGAIN != EWOULDBLOCK |
| case EAGAIN: |
| return 1; |
| #endif |
| } |
| return 0; |
| } |
| |
| /* If any TCP sockets select true for writing, write out queued data |
| * we have for them. |
| */ |
| static void write_tcp_data(ares_channel channel, |
| fd_set *write_fds, |
| ares_socket_t write_fd, |
| time_t now) |
| { |
| struct server_state *server; |
| struct send_request *sendreq; |
| struct iovec *vec; |
| int i; |
| ssize_t scount; |
| ssize_t wcount; |
| size_t n; |
| |
| if(!write_fds && (write_fd == ARES_SOCKET_BAD)) |
| /* no possible action */ |
| return; |
| |
| for (i = 0; i < channel->nservers; i++) |
| { |
| /* Make sure server has data to send and is selected in write_fds or |
| write_fd. */ |
| server = &channel->servers[i]; |
| if (!server->qhead || server->tcp_socket == ARES_SOCKET_BAD) |
| continue; |
| |
| if(write_fds) { |
| if(!FD_ISSET(server->tcp_socket, write_fds)) |
| continue; |
| } |
| else { |
| if(server->tcp_socket != write_fd) |
| continue; |
| } |
| |
| /* Count the number of send queue items. */ |
| n = 0; |
| for (sendreq = server->qhead; sendreq; sendreq = sendreq->next) |
| n++; |
| |
| /* Allocate iovecs so we can send all our data at once. */ |
| vec = malloc(n * sizeof(struct iovec)); |
| if (vec) |
| { |
| /* Fill in the iovecs and send. */ |
| n = 0; |
| for (sendreq = server->qhead; sendreq; sendreq = sendreq->next) |
| { |
| vec[n].iov_base = (char *) sendreq->data; |
| vec[n].iov_len = sendreq->len; |
| n++; |
| } |
| wcount = (ssize_t)writev(server->tcp_socket, vec, (int)n); |
| free(vec); |
| if (wcount < 0) |
| { |
| if (!try_again(SOCKERRNO)) |
| handle_error(channel, i, now); |
| continue; |
| } |
| |
| /* Advance the send queue by as many bytes as we sent. */ |
| while (wcount) |
| { |
| sendreq = server->qhead; |
| if ((size_t)wcount >= sendreq->len) |
| { |
| wcount -= sendreq->len; |
| server->qhead = sendreq->next; |
| if (server->qhead == NULL) |
| { |
| SOCK_STATE_CALLBACK(channel, server->tcp_socket, 1, 0); |
| server->qtail = NULL; |
| } |
| free(sendreq); |
| } |
| else |
| { |
| sendreq->data += wcount; |
| sendreq->len -= wcount; |
| break; |
| } |
| } |
| } |
| else |
| { |
| /* Can't allocate iovecs; just send the first request. */ |
| sendreq = server->qhead; |
| |
| scount = swrite(server->tcp_socket, sendreq->data, sendreq->len); |
| if (scount < 0) |
| { |
| if (!try_again(SOCKERRNO)) |
| handle_error(channel, i, now); |
| continue; |
| } |
| |
| /* Advance the send queue by as many bytes as we sent. */ |
| if ((size_t)scount == sendreq->len) |
| { |
| server->qhead = sendreq->next; |
| if (server->qhead == NULL) |
| { |
| SOCK_STATE_CALLBACK(channel, server->tcp_socket, 1, 0); |
| server->qtail = NULL; |
| } |
| free(sendreq); |
| } |
| else |
| { |
| sendreq->data += scount; |
| sendreq->len -= scount; |
| } |
| } |
| } |
| } |
| |
| /* If any TCP socket selects true for reading, read some data, |
| * allocate a buffer if we finish reading the length word, and process |
| * a packet if we finish reading one. |
| */ |
| static void read_tcp_data(ares_channel channel, fd_set *read_fds, |
| ares_socket_t read_fd, time_t now) |
| { |
| struct server_state *server; |
| int i; |
| ssize_t count; |
| |
| if(!read_fds && (read_fd == ARES_SOCKET_BAD)) |
| /* no possible action */ |
| return; |
| |
| for (i = 0; i < channel->nservers; i++) |
| { |
| /* Make sure the server has a socket and is selected in read_fds. */ |
| server = &channel->servers[i]; |
| if (server->tcp_socket == ARES_SOCKET_BAD) |
| continue; |
| |
| if(read_fds) { |
| if(!FD_ISSET(server->tcp_socket, read_fds)) |
| continue; |
| } |
| else { |
| if(server->tcp_socket != read_fd) |
| continue; |
| } |
| |
| if (server->tcp_lenbuf_pos != 2) |
| { |
| /* We haven't yet read a length word, so read that (or |
| * what's left to read of it). |
| */ |
| count = sread(server->tcp_socket, |
| server->tcp_lenbuf + server->tcp_lenbuf_pos, |
| 2 - server->tcp_lenbuf_pos); |
| if (count <= 0) |
| { |
| if (!(count == -1 && try_again(SOCKERRNO))) |
| handle_error(channel, i, now); |
| continue; |
| } |
| |
| server->tcp_lenbuf_pos += (int)count; |
| if (server->tcp_lenbuf_pos == 2) |
| { |
| /* We finished reading the length word. Decode the |
| * length and allocate a buffer for the data. |
| */ |
| server->tcp_length = server->tcp_lenbuf[0] << 8 |
| | server->tcp_lenbuf[1]; |
| server->tcp_buffer = malloc(server->tcp_length); |
| if (!server->tcp_buffer) |
| handle_error(channel, i, now); |
| server->tcp_buffer_pos = 0; |
| } |
| } |
| else |
| { |
| /* Read data into the allocated buffer. */ |
| count = sread(server->tcp_socket, |
| server->tcp_buffer + server->tcp_buffer_pos, |
| server->tcp_length - server->tcp_buffer_pos); |
| if (count <= 0) |
| { |
| if (!(count == -1 && try_again(SOCKERRNO))) |
| handle_error(channel, i, now); |
| continue; |
| } |
| |
| server->tcp_buffer_pos += (int)count; |
| if (server->tcp_buffer_pos == server->tcp_length) |
| { |
| /* We finished reading this answer; process it and |
| * prepare to read another length word. |
| */ |
| process_answer(channel, server->tcp_buffer, server->tcp_length, |
| i, 1, now); |
| if (server->tcp_buffer) |
| free(server->tcp_buffer); |
| server->tcp_buffer = NULL; |
| server->tcp_lenbuf_pos = 0; |
| server->tcp_buffer_pos = 0; |
| } |
| } |
| } |
| } |
| |
| /* If any UDP sockets select true for reading, process them. */ |
| static void read_udp_packets(ares_channel channel, fd_set *read_fds, |
| ares_socket_t read_fd, time_t now) |
| { |
| struct server_state *server; |
| int i; |
| ssize_t count; |
| unsigned char buf[PACKETSZ + 1]; |
| |
| if(!read_fds && (read_fd == ARES_SOCKET_BAD)) |
| /* no possible action */ |
| return; |
| |
| for (i = 0; i < channel->nservers; i++) |
| { |
| /* Make sure the server has a socket and is selected in read_fds. */ |
| server = &channel->servers[i]; |
| |
| if (server->udp_socket == ARES_SOCKET_BAD) |
| continue; |
| |
| if(read_fds) { |
| if(!FD_ISSET(server->udp_socket, read_fds)) |
| continue; |
| } |
| else { |
| if(server->udp_socket != read_fd) |
| continue; |
| } |
| |
| count = sread(server->udp_socket, buf, sizeof(buf)); |
| if (count == -1 && try_again(SOCKERRNO)) |
| continue; |
| else if (count <= 0) |
| handle_error(channel, i, now); |
| |
| process_answer(channel, buf, (int)count, i, 0, now); |
| } |
| } |
| |
| /* If any queries have timed out, note the timeout and move them on. */ |
| static void process_timeouts(ares_channel channel, time_t now) |
| { |
| struct query *query, *next; |
| |
| for (query = channel->queries; query; query = next) |
| { |
| next = query->next; |
| if (query->timeout != 0 && now >= query->timeout) |
| { |
| query->error_status = ARES_ETIMEOUT; |
| next = next_server(channel, query, now); |
| } |
| } |
| } |
| |
| /* Handle an answer from a server. */ |
| static void process_answer(ares_channel channel, unsigned char *abuf, |
| int alen, int whichserver, int tcp, time_t now) |
| { |
| int id, tc, rcode; |
| struct query *query; |
| |
| /* If there's no room in the answer for a header, we can't do much |
| * with it. */ |
| if (alen < HFIXEDSZ) |
| return; |
| |
| /* Grab the query ID, truncate bit, and response code from the packet. */ |
| id = DNS_HEADER_QID(abuf); |
| tc = DNS_HEADER_TC(abuf); |
| rcode = DNS_HEADER_RCODE(abuf); |
| |
| /* Find the query corresponding to this packet. */ |
| for (query = channel->queries; query; query = query->next) |
| { |
| if (query->qid == id) |
| break; |
| } |
| if (!query) |
| return; |
| |
| /* If we got a truncated UDP packet and are not ignoring truncation, |
| * don't accept the packet, and switch the query to TCP if we hadn't |
| * done so already. |
| */ |
| if ((tc || alen > PACKETSZ) && !tcp && !(channel->flags & ARES_FLAG_IGNTC)) |
| { |
| if (!query->using_tcp) |
| { |
| query->using_tcp = 1; |
| ares__send_query(channel, query, now); |
| } |
| return; |
| } |
| |
| /* Limit alen to PACKETSZ if we aren't using TCP (only relevant if we |
| * are ignoring truncation. |
| */ |
| if (alen > PACKETSZ && !tcp) |
| alen = PACKETSZ; |
| |
| /* If we aren't passing through all error packets, discard packets |
| * with SERVFAIL, NOTIMP, or REFUSED response codes. |
| */ |
| if (!(channel->flags & ARES_FLAG_NOCHECKRESP)) |
| { |
| if (rcode == SERVFAIL || rcode == NOTIMP || rcode == REFUSED) |
| { |
| query->skip_server[whichserver] = 1; |
| if (query->server == whichserver) |
| next_server(channel, query, now); |
| return; |
| } |
| if (!same_questions(query->qbuf, query->qlen, abuf, alen)) |
| { |
| if (query->server == whichserver) |
| next_server(channel, query, now); |
| return; |
| } |
| } |
| |
| end_query(channel, query, ARES_SUCCESS, abuf, alen); |
| } |
| |
| static void handle_error(ares_channel channel, int whichserver, time_t now) |
| { |
| struct query *query, *next; |
| |
| /* Reset communications with this server. */ |
| ares__close_sockets(channel, &channel->servers[whichserver]); |
| |
| /* Tell all queries talking to this server to move on and not try |
| * this server again. |
| */ |
| |
| for (query = channel->queries; query; query = next) |
| { |
| next = query->next; |
| if (query->server == whichserver) |
| { |
| query->skip_server[whichserver] = 1; |
| next = next_server(channel, query, now); |
| } |
| } |
| } |
| |
| static struct query *next_server(ares_channel channel, struct query *query, time_t now) |
| { |
| /* Advance to the next server or try. */ |
| query->server++; |
| for (; query->try < channel->tries; query->try++) |
| { |
| for (; query->server < channel->nservers; query->server++) |
| { |
| if (!query->skip_server[query->server]) |
| { |
| ares__send_query(channel, query, now); |
| return (query->next); |
| } |
| } |
| query->server = 0; |
| |
| /* Only one try if we're using TCP. */ |
| if (query->using_tcp) |
| break; |
| } |
| return end_query(channel, query, query->error_status, NULL, 0); |
| } |
| |
| void ares__send_query(ares_channel channel, struct query *query, time_t now) |
| { |
| struct send_request *sendreq; |
| struct server_state *server; |
| |
| server = &channel->servers[query->server]; |
| if (query->using_tcp) |
| { |
| /* Make sure the TCP socket for this server is set up and queue |
| * a send request. |
| */ |
| if (server->tcp_socket == ARES_SOCKET_BAD) |
| { |
| if (open_tcp_socket(channel, server) == -1) |
| { |
| query->skip_server[query->server] = 1; |
| next_server(channel, query, now); |
| return; |
| } |
| } |
| sendreq = calloc(sizeof(struct send_request), 1); |
| if (!sendreq) |
| { |
| end_query(channel, query, ARES_ENOMEM, NULL, 0); |
| return; |
| } |
| sendreq->data = query->tcpbuf; |
| sendreq->len = query->tcplen; |
| sendreq->next = NULL; |
| if (server->qtail) |
| server->qtail->next = sendreq; |
| else |
| { |
| SOCK_STATE_CALLBACK(channel, server->tcp_socket, 1, 1); |
| server->qhead = sendreq; |
| } |
| server->qtail = sendreq; |
| query->timeout = 0; |
| } |
| else |
| { |
| if (server->udp_socket == ARES_SOCKET_BAD) |
| { |
| if (open_udp_socket(channel, server) == -1) |
| { |
| query->skip_server[query->server] = 1; |
| next_server(channel, query, now); |
| return; |
| } |
| } |
| if (swrite(server->udp_socket, query->qbuf, query->qlen) == -1) |
| { |
| /* FIXME: Handle EAGAIN here since it likely can happen. */ |
| query->skip_server[query->server] = 1; |
| next_server(channel, query, now); |
| return; |
| } |
| query->timeout = now |
| + ((query->try == 0) ? channel->timeout |
| : channel->timeout << query->try / channel->nservers); |
| } |
| } |
| |
| /* |
| * nonblock() set the given socket to either blocking or non-blocking mode |
| * based on the 'nonblock' boolean argument. This function is highly portable. |
| */ |
| static int nonblock(ares_socket_t sockfd, /* operate on this */ |
| int nonblock /* TRUE or FALSE */) |
| { |
| #undef SETBLOCK |
| #define SETBLOCK 0 |
| #ifdef HAVE_O_NONBLOCK |
| /* most recent unix versions */ |
| int flags; |
| |
| flags = fcntl(sockfd, F_GETFL, 0); |
| if (FALSE != nonblock) |
| return fcntl(sockfd, F_SETFL, flags | O_NONBLOCK); |
| else |
| return fcntl(sockfd, F_SETFL, flags & (~O_NONBLOCK)); |
| #undef SETBLOCK |
| #define SETBLOCK 1 |
| #endif |
| |
| #if defined(HAVE_FIONBIO) && (SETBLOCK == 0) |
| /* older unix versions */ |
| int flags; |
| |
| flags = nonblock; |
| return ioctl(sockfd, FIONBIO, &flags); |
| #undef SETBLOCK |
| #define SETBLOCK 2 |
| #endif |
| |
| #if defined(HAVE_IOCTLSOCKET) && (SETBLOCK == 0) |
| #ifdef WATT32 |
| char flags; |
| #else |
| /* Windows? */ |
| unsigned long flags; |
| #endif |
| flags = nonblock; |
| |
| return ioctlsocket(sockfd, FIONBIO, &flags); |
| #undef SETBLOCK |
| #define SETBLOCK 3 |
| #endif |
| |
| #if defined(HAVE_IOCTLSOCKET_CASE) && (SETBLOCK == 0) |
| /* presumably for Amiga */ |
| return IoctlSocket(sockfd, FIONBIO, (long)nonblock); |
| #undef SETBLOCK |
| #define SETBLOCK 4 |
| #endif |
| |
| #if defined(HAVE_SO_NONBLOCK) && (SETBLOCK == 0) |
| /* BeOS */ |
| long b = nonblock ? 1 : 0; |
| return setsockopt(sockfd, SOL_SOCKET, SO_NONBLOCK, &b, sizeof(b)); |
| #undef SETBLOCK |
| #define SETBLOCK 5 |
| #endif |
| |
| #ifdef HAVE_DISABLED_NONBLOCKING |
| return 0; /* returns success */ |
| #undef SETBLOCK |
| #define SETBLOCK 6 |
| #endif |
| |
| #if (SETBLOCK == 0) |
| #error "no non-blocking method was found/used/set" |
| #endif |
| } |
| |
| static int open_tcp_socket(ares_channel channel, struct server_state *server) |
| { |
| ares_socket_t s; |
| struct sockaddr_in sockin; |
| |
| /* Acquire a socket. */ |
| s = socket(AF_INET, SOCK_STREAM, 0); |
| if (s == ARES_SOCKET_BAD) |
| return -1; |
| |
| /* Set the socket non-blocking. */ |
| nonblock(s, TRUE); |
| |
| /* Connect to the server. */ |
| memset(&sockin, 0, sizeof(sockin)); |
| sockin.sin_family = AF_INET; |
| sockin.sin_addr = server->addr; |
| sockin.sin_port = (unsigned short)(channel->tcp_port & 0xffff); |
| if (connect(s, (struct sockaddr *) &sockin, sizeof(sockin)) == -1) { |
| int err = SOCKERRNO; |
| |
| if (err != EINPROGRESS && err != EWOULDBLOCK) { |
| closesocket(s); |
| return -1; |
| } |
| } |
| |
| SOCK_STATE_CALLBACK(channel, s, 1, 0); |
| server->tcp_buffer_pos = 0; |
| server->tcp_socket = s; |
| return 0; |
| } |
| |
| static int open_udp_socket(ares_channel channel, struct server_state *server) |
| { |
| ares_socket_t s; |
| struct sockaddr_in sockin; |
| |
| /* Acquire a socket. */ |
| s = socket(AF_INET, SOCK_DGRAM, 0); |
| if (s == ARES_SOCKET_BAD) |
| return -1; |
| |
| /* Set the socket non-blocking. */ |
| nonblock(s, TRUE); |
| |
| /* Connect to the server. */ |
| memset(&sockin, 0, sizeof(sockin)); |
| sockin.sin_family = AF_INET; |
| sockin.sin_addr = server->addr; |
| sockin.sin_port = (unsigned short)(channel->udp_port & 0xffff); |
| if (connect(s, (struct sockaddr *) &sockin, sizeof(sockin)) == -1) |
| { |
| closesocket(s); |
| return -1; |
| } |
| |
| SOCK_STATE_CALLBACK(channel, s, 1, 0); |
| |
| server->udp_socket = s; |
| return 0; |
| } |
| |
| static int same_questions(const unsigned char *qbuf, int qlen, |
| const unsigned char *abuf, int alen) |
| { |
| struct { |
| const unsigned char *p; |
| int qdcount; |
| char *name; |
| long namelen; |
| int type; |
| int dnsclass; |
| } q, a; |
| int i, j; |
| |
| if (qlen < HFIXEDSZ || alen < HFIXEDSZ) |
| return 0; |
| |
| /* Extract qdcount from the request and reply buffers and compare them. */ |
| q.qdcount = DNS_HEADER_QDCOUNT(qbuf); |
| a.qdcount = DNS_HEADER_QDCOUNT(abuf); |
| if (q.qdcount != a.qdcount) |
| return 0; |
| |
| /* For each question in qbuf, find it in abuf. */ |
| q.p = qbuf + HFIXEDSZ; |
| for (i = 0; i < q.qdcount; i++) |
| { |
| /* Decode the question in the query. */ |
| if (ares_expand_name(q.p, qbuf, qlen, &q.name, &q.namelen) |
| != ARES_SUCCESS) |
| return 0; |
| q.p += q.namelen; |
| if (q.p + QFIXEDSZ > qbuf + qlen) |
| { |
| free(q.name); |
| return 0; |
| } |
| q.type = DNS_QUESTION_TYPE(q.p); |
| q.dnsclass = DNS_QUESTION_CLASS(q.p); |
| q.p += QFIXEDSZ; |
| |
| /* Search for this question in the answer. */ |
| a.p = abuf + HFIXEDSZ; |
| for (j = 0; j < a.qdcount; j++) |
| { |
| /* Decode the question in the answer. */ |
| if (ares_expand_name(a.p, abuf, alen, &a.name, &a.namelen) |
| != ARES_SUCCESS) |
| { |
| free(q.name); |
| return 0; |
| } |
| a.p += a.namelen; |
| if (a.p + QFIXEDSZ > abuf + alen) |
| { |
| free(q.name); |
| free(a.name); |
| return 0; |
| } |
| a.type = DNS_QUESTION_TYPE(a.p); |
| a.dnsclass = DNS_QUESTION_CLASS(a.p); |
| a.p += QFIXEDSZ; |
| |
| /* Compare the decoded questions. */ |
| if (strcasecmp(q.name, a.name) == 0 && q.type == a.type |
| && q.dnsclass == a.dnsclass) |
| { |
| free(a.name); |
| break; |
| } |
| free(a.name); |
| } |
| |
| free(q.name); |
| if (j == a.qdcount) |
| return 0; |
| } |
| return 1; |
| } |
| |
| static struct query *end_query (ares_channel channel, struct query *query, int status, |
| unsigned char *abuf, int alen) |
| { |
| struct query **q, *next; |
| int i; |
| |
| query->callback(query->arg, status, abuf, alen); |
| for (q = &channel->queries; *q; q = &(*q)->next) |
| { |
| if (*q == query) |
| break; |
| } |
| *q = query->next; |
| if (*q) |
| next = (*q)->next; |
| else |
| next = NULL; |
| free(query->tcpbuf); |
| free(query->skip_server); |
| free(query); |
| |
| /* Simple cleanup policy: if no queries are remaining, close all |
| * network sockets unless STAYOPEN is set. |
| */ |
| if (!channel->queries && !(channel->flags & ARES_FLAG_STAYOPEN)) |
| { |
| for (i = 0; i < channel->nservers; i++) |
| ares__close_sockets(channel, &channel->servers[i]); |
| } |
| return (next); |
| } |