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authorDaniel Buch <boogiewasthere@gmail.com>2014-01-06 13:41:59 +0100
committerTom Gundersen <teg@jklm.no>2014-01-11 15:03:25 +0000
commite963e3ada17e7592ad499b9d7fbb3355287a05ca (patch)
tree7de6383df371c81f17500f0dd338fa6d534e5c3d /src
parente0d4a0ac06afb856c9370c5c256f0f7bb7efdc8e (diff)
sd-dns: initial commit
Origin: <http://0pointer.de/lennart/projects/libasyncns/> [tomegun: renamed some more files asyncns -> sd-dns and moved to libsystemd-bus as requested by Lennart]
Diffstat (limited to 'src')
-rw-r--r--src/libsystemd-bus/dns-util.h8
-rw-r--r--src/libsystemd-bus/sd-dns.c1158
-rw-r--r--src/libsystemd-bus/test-dns.c164
-rw-r--r--src/systemd/sd-dns.h156
4 files changed, 1486 insertions, 0 deletions
diff --git a/src/libsystemd-bus/dns-util.h b/src/libsystemd-bus/dns-util.h
new file mode 100644
index 0000000000..31d19bd95a
--- /dev/null
+++ b/src/libsystemd-bus/dns-util.h
@@ -0,0 +1,8 @@
+#pragma once
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(asyncns_t*, asyncns_free);
+DEFINE_TRIVIAL_CLEANUP_FUNC(unsigned char *, asyncns_freeanswer);
+DEFINE_TRIVIAL_CLEANUP_FUNC(struct addrinfo*, asyncns_freeaddrinfo);
+#define _cleanup_asyncns_free_ _cleanup_(asyncns_freep)
+#define _cleanup_asyncns_answer_free_ _cleanup_(asyncns_freeanswerp)
+#define _cleanup_asyncns_addrinfo_free_ _cleanup_(asyncns_freeaddrinfop)
diff --git a/src/libsystemd-bus/sd-dns.c b/src/libsystemd-bus/sd-dns.c
new file mode 100644
index 0000000000..508f6b0945
--- /dev/null
+++ b/src/libsystemd-bus/sd-dns.c
@@ -0,0 +1,1158 @@
+/***
+ This file is part of libasyncns.
+
+ Copyright 2005-2008 Lennart Poettering
+
+ libasyncns 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.
+
+ libasyncns 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 libasyncns. If not, see
+ <http://www.gnu.org/licenses/>.
+ ***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <assert.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <unistd.h>
+#include <sys/select.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/wait.h>
+#include <sys/types.h>
+#include <pwd.h>
+#include <netinet/in.h>
+#include <arpa/nameser.h>
+#include <resolv.h>
+#include <dirent.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <stdint.h>
+#include <pthread.h>
+
+#ifdef HAVE_SYS_PRCTL_H
+#include <sys/prctl.h>
+#endif
+
+#include "sd-dns.h"
+#include "util.h"
+
+#define MAX_WORKERS 16
+#define MAX_QUERIES 256
+#define BUFSIZE (10240)
+
+typedef enum {
+ REQUEST_ADDRINFO,
+ RESPONSE_ADDRINFO,
+ REQUEST_NAMEINFO,
+ RESPONSE_NAMEINFO,
+ REQUEST_RES_QUERY,
+ REQUEST_RES_SEARCH,
+ RESPONSE_RES,
+ REQUEST_TERMINATE,
+ RESPONSE_DIED
+} query_type_t;
+
+enum {
+ REQUEST_RECV_FD = 0,
+ REQUEST_SEND_FD = 1,
+ RESPONSE_RECV_FD = 2,
+ RESPONSE_SEND_FD = 3,
+ MESSAGE_FD_MAX = 4
+};
+
+struct asyncns {
+ int fds[MESSAGE_FD_MAX];
+
+ pthread_t workers[MAX_WORKERS];
+ unsigned valid_workers;
+
+ unsigned current_id, current_index;
+ asyncns_query_t* queries[MAX_QUERIES];
+
+ asyncns_query_t *done_head, *done_tail;
+
+ int n_queries;
+ int dead;
+};
+
+struct asyncns_query {
+ asyncns_t *asyncns;
+ int done;
+ unsigned id;
+ query_type_t type;
+ asyncns_query_t *done_next, *done_prev;
+ int ret;
+ int _errno;
+ int _h_errno;
+ struct addrinfo *addrinfo;
+ char *serv, *host;
+ void *userdata;
+};
+
+typedef struct rheader {
+ query_type_t type;
+ unsigned id;
+ size_t length;
+} rheader_t;
+
+typedef struct addrinfo_request {
+ struct rheader header;
+ int hints_is_null;
+ int ai_flags;
+ int ai_family;
+ int ai_socktype;
+ int ai_protocol;
+ size_t node_len, service_len;
+} addrinfo_request_t;
+
+typedef struct addrinfo_response {
+ struct rheader header;
+ int ret;
+ int _errno;
+ int _h_errno;
+ /* followed by addrinfo_serialization[] */
+} addrinfo_response_t;
+
+typedef struct addrinfo_serialization {
+ int ai_flags;
+ int ai_family;
+ int ai_socktype;
+ int ai_protocol;
+ size_t ai_addrlen;
+ size_t canonname_len;
+ /* Followed by ai_addr amd ai_canonname with variable lengths */
+} addrinfo_serialization_t;
+
+typedef struct nameinfo_request {
+ struct rheader header;
+ int flags;
+ socklen_t sockaddr_len;
+ int gethost, getserv;
+} nameinfo_request_t;
+
+typedef struct nameinfo_response {
+ struct rheader header;
+ size_t hostlen, servlen;
+ int ret;
+ int _errno;
+ int _h_errno;
+} nameinfo_response_t;
+
+typedef struct res_request {
+ struct rheader header;
+ int class;
+ int type;
+ size_t dname_len;
+} res_request_t;
+
+typedef struct res_response {
+ struct rheader header;
+ int ret;
+ int _errno;
+ int _h_errno;
+} res_response_t;
+
+typedef union packet {
+ rheader_t rheader;
+ addrinfo_request_t addrinfo_request;
+ addrinfo_response_t addrinfo_response;
+ nameinfo_request_t nameinfo_request;
+ nameinfo_response_t nameinfo_response;
+ res_request_t res_request;
+ res_response_t res_response;
+} packet_t;
+
+static int send_died(int out_fd) {
+ rheader_t rh = {};
+ assert(out_fd > 0);
+
+ rh.type = RESPONSE_DIED;
+ rh.id = 0;
+ rh.length = sizeof(rh);
+
+ return send(out_fd, &rh, rh.length, MSG_NOSIGNAL);
+}
+
+static void *serialize_addrinfo(void *p, const struct addrinfo *ai, size_t *length, size_t maxlength) {
+ addrinfo_serialization_t s;
+ size_t cnl, l;
+ assert(p);
+ assert(ai);
+ assert(length);
+ assert(*length <= maxlength);
+
+ cnl = (ai->ai_canonname ? strlen(ai->ai_canonname)+1 : 0);
+ l = sizeof(addrinfo_serialization_t) + ai->ai_addrlen + cnl;
+
+ if (*length + l > maxlength)
+ return NULL;
+
+ s.ai_flags = ai->ai_flags;
+ s.ai_family = ai->ai_family;
+ s.ai_socktype = ai->ai_socktype;
+ s.ai_protocol = ai->ai_protocol;
+ s.ai_addrlen = ai->ai_addrlen;
+ s.canonname_len = cnl;
+
+ memcpy((uint8_t*) p, &s, sizeof(addrinfo_serialization_t));
+ memcpy((uint8_t*) p + sizeof(addrinfo_serialization_t), ai->ai_addr, ai->ai_addrlen);
+
+ if (ai->ai_canonname)
+ strcpy((char*) p + sizeof(addrinfo_serialization_t) + ai->ai_addrlen, ai->ai_canonname);
+
+ *length += l;
+ return (uint8_t*) p + l;
+}
+
+static int send_addrinfo_reply(int out_fd, unsigned id, int ret, struct addrinfo *ai, int _errno, int _h_errno) {
+ addrinfo_response_t data[BUFSIZE/sizeof(addrinfo_response_t) + 1] = {};
+ addrinfo_response_t *resp = data;
+ assert(out_fd >= 0);
+
+ resp->header.type = RESPONSE_ADDRINFO;
+ resp->header.id = id;
+ resp->header.length = sizeof(addrinfo_response_t);
+ resp->ret = ret;
+ resp->_errno = _errno;
+ resp->_h_errno = _h_errno;
+
+ if (ret == 0 && ai) {
+ void *p = data + 1;
+ struct addrinfo *k;
+
+ for (k = ai; k; k = k->ai_next) {
+ if (!(p = serialize_addrinfo(p, k, &resp->header.length, (char*) data + BUFSIZE - (char*) p))) {
+ resp->ret = EAI_MEMORY;
+ break;
+ }
+ }
+ }
+
+ if (ai)
+ freeaddrinfo(ai);
+
+ return send(out_fd, resp, resp->header.length, MSG_NOSIGNAL);
+}
+
+static int send_nameinfo_reply(int out_fd, unsigned id, int ret, const char *host, const char *serv, int _errno, int _h_errno) {
+ nameinfo_response_t data[BUFSIZE/sizeof(nameinfo_response_t) + 1] = {};
+ size_t hl, sl;
+ nameinfo_response_t *resp = data;
+
+ assert(out_fd >= 0);
+
+ sl = serv ? strlen(serv)+1 : 0;
+ hl = host ? strlen(host)+1 : 0;
+
+ resp->header.type = RESPONSE_NAMEINFO;
+ resp->header.id = id;
+ resp->header.length = sizeof(nameinfo_response_t) + hl + sl;
+ resp->ret = ret;
+ resp->_errno = _errno;
+ resp->_h_errno = _h_errno;
+ resp->hostlen = hl;
+ resp->servlen = sl;
+
+ assert(sizeof(data) >= resp->header.length);
+
+ if (host)
+ memcpy((uint8_t *)data + sizeof(nameinfo_response_t), host, hl);
+
+ if (serv)
+ memcpy((uint8_t *)data + sizeof(nameinfo_response_t) + hl, serv, sl);
+
+ return send(out_fd, resp, resp->header.length, MSG_NOSIGNAL);
+}
+
+static int send_res_reply(int out_fd, unsigned id, const unsigned char *answer, int ret, int _errno, int _h_errno) {
+ res_response_t data[BUFSIZE/sizeof(res_response_t) + 1] = {};
+ res_response_t *resp = data;
+
+ assert(out_fd >= 0);
+
+ resp->header.type = RESPONSE_RES;
+ resp->header.id = id;
+ resp->header.length = sizeof(res_response_t) + (ret < 0 ? 0 : ret);
+ resp->ret = ret;
+ resp->_errno = _errno;
+ resp->_h_errno = _h_errno;
+
+ assert(sizeof(data) >= resp->header.length);
+
+ if (ret > 0)
+ memcpy((uint8_t *)data + sizeof(res_response_t), answer, ret);
+
+ return send(out_fd, resp, resp->header.length, MSG_NOSIGNAL);
+}
+
+static int handle_request(int out_fd, const packet_t *packet, size_t length) {
+ const rheader_t *req;
+ assert(out_fd >= 0);
+
+ req = &packet->rheader;
+ assert(req);
+ assert(length >= sizeof(rheader_t));
+ assert(length == req->length);
+
+ switch (req->type) {
+ case REQUEST_ADDRINFO: {
+ struct addrinfo ai = {}, *result = NULL;
+ const addrinfo_request_t *ai_req = &packet->addrinfo_request;
+ const char *node, *service;
+ int ret;
+
+ assert(length >= sizeof(addrinfo_request_t));
+ assert(length == sizeof(addrinfo_request_t) + ai_req->node_len + ai_req->service_len);
+
+ ai.ai_flags = ai_req->ai_flags;
+ ai.ai_family = ai_req->ai_family;
+ ai.ai_socktype = ai_req->ai_socktype;
+ ai.ai_protocol = ai_req->ai_protocol;
+
+ node = ai_req->node_len ? (const char*) ai_req + sizeof(addrinfo_request_t) : NULL;
+ service = ai_req->service_len ? (const char*) ai_req + sizeof(addrinfo_request_t) + ai_req->node_len : NULL;
+
+ ret = getaddrinfo(node, service,
+ ai_req->hints_is_null ? NULL : &ai,
+ &result);
+
+ /* send_addrinfo_reply() frees result */
+ return send_addrinfo_reply(out_fd, req->id, ret, result, errno, h_errno);
+ }
+
+ case REQUEST_NAMEINFO: {
+ int ret;
+ const nameinfo_request_t *ni_req = &packet->nameinfo_request;
+ char hostbuf[NI_MAXHOST], servbuf[NI_MAXSERV];
+ struct sockaddr_storage sa;
+
+ assert(length >= sizeof(nameinfo_request_t));
+ assert(length == sizeof(nameinfo_request_t) + ni_req->sockaddr_len);
+
+ memcpy(&sa, (const uint8_t *) ni_req + sizeof(nameinfo_request_t), ni_req->sockaddr_len);
+
+ ret = getnameinfo((struct sockaddr *)&sa, ni_req->sockaddr_len,
+ ni_req->gethost ? hostbuf : NULL, ni_req->gethost ? sizeof(hostbuf) : 0,
+ ni_req->getserv ? servbuf : NULL, ni_req->getserv ? sizeof(servbuf) : 0,
+ ni_req->flags);
+
+ return send_nameinfo_reply(out_fd, req->id, ret,
+ ret == 0 && ni_req->gethost ? hostbuf : NULL,
+ ret == 0 && ni_req->getserv ? servbuf : NULL,
+ errno, h_errno);
+ }
+
+ case REQUEST_RES_QUERY:
+ case REQUEST_RES_SEARCH: {
+ int ret;
+ HEADER answer[BUFSIZE/sizeof(HEADER) + 1];
+ const res_request_t *res_req = &packet->res_request;
+ const char *dname;
+
+ assert(length >= sizeof(res_request_t));
+ assert(length == sizeof(res_request_t) + res_req->dname_len);
+
+ dname = (const char *) req + sizeof(res_request_t);
+
+ if (req->type == REQUEST_RES_QUERY)
+ ret = res_query(dname, res_req->class, res_req->type, (unsigned char *) answer, BUFSIZE);
+ else
+ ret = res_search(dname, res_req->class, res_req->type, (unsigned char *) answer, BUFSIZE);
+
+ return send_res_reply(out_fd, req->id, (unsigned char *) answer, ret, errno, h_errno);
+ }
+
+ case REQUEST_TERMINATE:
+ /* Quit */
+ return -1;
+
+ default:
+ ;
+ }
+
+ return 0;
+}
+
+static void* thread_worker(void *p) {
+ asyncns_t *asyncns = p;
+ sigset_t fullset;
+
+ /* No signals in this thread please */
+ sigfillset(&fullset);
+ pthread_sigmask(SIG_BLOCK, &fullset, NULL);
+
+ while (!asyncns->dead) {
+ packet_t buf[BUFSIZE/sizeof(packet_t) + 1];
+ ssize_t length;
+
+ length = recv(asyncns->fds[REQUEST_RECV_FD], buf, sizeof(buf), 0);
+
+ if (length <= 0) {
+ if (length < 0 && (errno == EAGAIN || errno == EINTR))
+ continue;
+ break;
+ }
+
+ if (asyncns->dead)
+ break;
+
+ if (handle_request(asyncns->fds[RESPONSE_SEND_FD], buf, (size_t) length) < 0)
+ break;
+ }
+
+ send_died(asyncns->fds[RESPONSE_SEND_FD]);
+
+ return NULL;
+}
+
+asyncns_t* asyncns_new(unsigned n_proc) {
+ int i;
+ asyncns_t *asyncns = NULL;
+
+ assert(n_proc >= 1);
+
+ if (n_proc > MAX_WORKERS)
+ n_proc = MAX_WORKERS;
+
+ asyncns = malloc(sizeof(asyncns_t));
+ if (!asyncns) {
+ errno = ENOMEM;
+ goto fail;
+ }
+
+ asyncns->dead = 0;
+ asyncns->valid_workers = 0;
+
+ for (i = 0; i < MESSAGE_FD_MAX; i++)
+ asyncns->fds[i] = -1;
+
+ memset(asyncns->queries, 0, sizeof(asyncns->queries));
+
+#ifdef SOCK_CLOEXEC
+ if (socketpair(PF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, asyncns->fds) < 0 ||
+ socketpair(PF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, asyncns->fds+2) < 0) {
+
+ /* Try again, without SOCK_CLOEXEC */
+ if (errno == EINVAL) {
+#endif
+ if (socketpair(PF_UNIX, SOCK_DGRAM, 0, asyncns->fds) < 0 ||
+ socketpair(PF_UNIX, SOCK_DGRAM, 0, asyncns->fds+2) < 0)
+ goto fail;
+#ifdef SOCK_CLOEXEC
+ } else
+ goto fail;
+ }
+#endif
+
+ for (i = 0; i < MESSAGE_FD_MAX; i++)
+ fd_cloexec(asyncns->fds[i], true);
+
+ for (asyncns->valid_workers = 0; asyncns->valid_workers < n_proc; asyncns->valid_workers++) {
+ int r;
+
+ if ((r = pthread_create(&asyncns->workers[asyncns->valid_workers], NULL, thread_worker, asyncns)) != 0) {
+ errno = r;
+ goto fail;
+ }
+ }
+
+ asyncns->current_index = asyncns->current_id = 0;
+ asyncns->done_head = asyncns->done_tail = NULL;
+ asyncns->n_queries = 0;
+
+ fd_nonblock(asyncns->fds[RESPONSE_RECV_FD], true);
+
+ return asyncns;
+
+fail:
+ if (asyncns)
+ asyncns_free(asyncns);
+
+ return NULL;
+}
+
+void asyncns_free(asyncns_t *asyncns) {
+ int i;
+ int saved_errno = errno;
+ unsigned p;
+
+ assert(asyncns);
+
+ asyncns->dead = 1;
+
+ if (asyncns->fds[REQUEST_SEND_FD] >= 0) {
+ rheader_t req = {};
+
+ req.type = REQUEST_TERMINATE;
+ req.length = sizeof(req);
+ req.id = 0;
+
+ /* Send one termination packet for each worker */
+ for (p = 0; p < asyncns->valid_workers; p++)
+ send(asyncns->fds[REQUEST_SEND_FD], &req, req.length, MSG_NOSIGNAL);
+ }
+
+ /* Now terminate them and wait until they are gone. */
+ for (p = 0; p < asyncns->valid_workers; p++) {
+ for (;;) {
+ if (pthread_join(asyncns->workers[p], NULL) != EINTR)
+ break;
+ }
+ }
+
+ /* Close all communication channels */
+ for (i = 0; i < MESSAGE_FD_MAX; i++)
+ if (asyncns->fds[i] >= 0)
+ close(asyncns->fds[i]);
+
+ for (p = 0; p < MAX_QUERIES; p++)
+ if (asyncns->queries[p])
+ asyncns_cancel(asyncns, asyncns->queries[p]);
+
+ free(asyncns);
+
+ errno = saved_errno;
+}
+
+int asyncns_fd(asyncns_t *asyncns) {
+ assert(asyncns);
+
+ return asyncns->fds[RESPONSE_RECV_FD];
+}
+
+static asyncns_query_t *lookup_query(asyncns_t *asyncns, unsigned id) {
+ asyncns_query_t *q;
+ assert(asyncns);
+
+ if ((q = asyncns->queries[id % MAX_QUERIES]))
+ if (q->id == id)
+ return q;
+
+ return NULL;
+}
+
+static void complete_query(asyncns_t *asyncns, asyncns_query_t *q) {
+ assert(asyncns);
+ assert(q);
+ assert(!q->done);
+
+ q->done = 1;
+
+ if ((q->done_prev = asyncns->done_tail))
+ asyncns->done_tail->done_next = q;
+ else
+ asyncns->done_head = q;
+
+ asyncns->done_tail = q;
+ q->done_next = NULL;
+}
+
+static const void *unserialize_addrinfo(const void *p, struct addrinfo **ret_ai, size_t *length) {
+ addrinfo_serialization_t s;
+ size_t l;
+ struct addrinfo *ai;
+ assert(p);
+ assert(ret_ai);
+ assert(length);
+
+ if (*length < sizeof(addrinfo_serialization_t))
+ return NULL;
+
+ memcpy(&s, p, sizeof(s));
+
+ l = sizeof(addrinfo_serialization_t) + s.ai_addrlen + s.canonname_len;
+ if (*length < l)
+ return NULL;
+
+ if (!(ai = malloc(sizeof(struct addrinfo))))
+ goto fail;
+
+ ai->ai_addr = NULL;
+ ai->ai_canonname = NULL;
+ ai->ai_next = NULL;
+
+ if (s.ai_addrlen && !(ai->ai_addr = malloc(s.ai_addrlen)))
+ goto fail;
+
+ if (s.canonname_len && !(ai->ai_canonname = malloc(s.canonname_len)))
+ goto fail;
+
+ ai->ai_flags = s.ai_flags;
+ ai->ai_family = s.ai_family;
+ ai->ai_socktype = s.ai_socktype;
+ ai->ai_protocol = s.ai_protocol;
+ ai->ai_addrlen = s.ai_addrlen;
+
+ if (ai->ai_addr)
+ memcpy(ai->ai_addr, (const uint8_t*) p + sizeof(addrinfo_serialization_t), s.ai_addrlen);
+
+ if (ai->ai_canonname)
+ memcpy(ai->ai_canonname, (const uint8_t*) p + sizeof(addrinfo_serialization_t) + s.ai_addrlen, s.canonname_len);
+
+ *length -= l;
+ *ret_ai = ai;
+
+ return (const uint8_t*) p + l;
+
+
+fail:
+ if (ai)
+ asyncns_freeaddrinfo(ai);
+
+ return NULL;
+}
+
+static int handle_response(asyncns_t *asyncns, const packet_t *packet, size_t length) {
+ const rheader_t *resp;
+ asyncns_query_t *q;
+
+ assert(asyncns);
+
+ resp = &packet->rheader;
+ assert(resp);
+ assert(length >= sizeof(rheader_t));
+ assert(length == resp->length);
+
+ if (resp->type == RESPONSE_DIED) {
+ asyncns->dead = 1;
+ return 0;
+ }
+
+ if (!(q = lookup_query(asyncns, resp->id)))
+ return 0;
+
+ switch (resp->type) {
+ case RESPONSE_ADDRINFO: {
+ const addrinfo_response_t *ai_resp = &packet->addrinfo_response;
+ const void *p;
+ size_t l;
+ struct addrinfo *prev = NULL;
+
+ assert(length >= sizeof(addrinfo_response_t));
+ assert(q->type == REQUEST_ADDRINFO);
+
+ q->ret = ai_resp->ret;
+ q->_errno = ai_resp->_errno;
+ q->_h_errno = ai_resp->_h_errno;
+ l = length - sizeof(addrinfo_response_t);
+ p = (const uint8_t*) resp + sizeof(addrinfo_response_t);
+
+ while (l > 0 && p) {
+ struct addrinfo *ai = NULL;
+ p = unserialize_addrinfo(p, &ai, &l);
+
+ if (!p || !ai) {
+ q->ret = EAI_MEMORY;
+ break;
+ }
+
+ if (prev)
+ prev->ai_next = ai;
+ else
+ q->addrinfo = ai;
+
+ prev = ai;
+ }
+
+ complete_query(asyncns, q);
+ break;
+ }
+
+ case RESPONSE_NAMEINFO: {
+ const nameinfo_response_t *ni_resp = &packet->nameinfo_response;
+
+ assert(length >= sizeof(nameinfo_response_t));
+ assert(q->type == REQUEST_NAMEINFO);
+
+ q->ret = ni_resp->ret;
+ q->_errno = ni_resp->_errno;
+ q->_h_errno = ni_resp->_h_errno;
+
+ if (ni_resp->hostlen)
+ if (!(q->host = strndup((const char*) ni_resp + sizeof(nameinfo_response_t), ni_resp->hostlen-1)))
+ q->ret = EAI_MEMORY;
+
+ if (ni_resp->servlen)
+ if (!(q->serv = strndup((const char*) ni_resp + sizeof(nameinfo_response_t) + ni_resp->hostlen, ni_resp->servlen-1)))
+ q->ret = EAI_MEMORY;
+
+ complete_query(asyncns, q);
+ break;
+ }
+
+ case RESPONSE_RES: {
+ const res_response_t *res_resp = &packet->res_response;
+
+ assert(length >= sizeof(res_response_t));
+ assert(q->type == REQUEST_RES_QUERY || q->type == REQUEST_RES_SEARCH);
+
+ q->ret = res_resp->ret;
+ q->_errno = res_resp->_errno;
+ q->_h_errno = res_resp->_h_errno;
+
+ if (res_resp->ret >= 0) {
+ if (!(q->serv = malloc(res_resp->ret))) {
+ q->ret = -1;
+ q->_errno = ENOMEM;
+ } else
+ memcpy(q->serv, (const char *)resp + sizeof(res_response_t), res_resp->ret);
+ }
+
+ complete_query(asyncns, q);
+ break;
+ }
+
+ default:
+ ;
+ }
+
+ return 0;
+}
+
+int asyncns_wait(asyncns_t *asyncns, int block) {
+ int handled = 0;
+ assert(asyncns);
+
+ for (;;) {
+ packet_t buf[BUFSIZE/sizeof(packet_t) + 1];
+ ssize_t l;
+
+ if (asyncns->dead) {
+ errno = ECHILD;
+ return -1;
+ }
+
+ if (((l = recv(asyncns->fds[RESPONSE_RECV_FD], buf, sizeof(buf), 0)) < 0)) {
+ fd_set fds;
+
+ if (errno != EAGAIN)
+ return -1;
+
+ if (!block || handled)
+ return 0;
+
+ FD_ZERO(&fds);
+ FD_SET(asyncns->fds[RESPONSE_RECV_FD], &fds);
+
+ if (select(asyncns->fds[RESPONSE_RECV_FD]+1, &fds, NULL, NULL, NULL) < 0)
+ return -1;
+
+ continue;
+ }
+
+ if (handle_response(asyncns, buf, (size_t) l) < 0)
+ return -1;
+
+ handled = 1;
+ }
+}
+
+static asyncns_query_t *alloc_query(asyncns_t *asyncns) {
+ asyncns_query_t *q;
+ assert(asyncns);
+
+ if (asyncns->n_queries >= MAX_QUERIES) {
+ errno = ENOMEM;
+ return NULL;
+ }
+
+ while (asyncns->queries[asyncns->current_index]) {
+
+ asyncns->current_index++;
+ asyncns->current_id++;
+
+ while (asyncns->current_index >= MAX_QUERIES)
+ asyncns->current_index -= MAX_QUERIES;
+ }
+
+ if (!(q = asyncns->queries[asyncns->current_index] = malloc(sizeof(asyncns_query_t)))) {
+ errno = ENOMEM;
+ return NULL;
+ }
+
+ asyncns->n_queries++;
+
+ q->asyncns = asyncns;
+ q->done = 0;
+ q->id = asyncns->current_id;
+ q->done_next = q->done_prev = NULL;
+ q->ret = 0;
+ q->_errno = 0;
+ q->_h_errno = 0;
+ q->addrinfo = NULL;
+ q->userdata = NULL;
+ q->host = q->serv = NULL;
+
+ return q;
+}
+
+asyncns_query_t* asyncns_getaddrinfo(asyncns_t *asyncns, const char *node, const char *service, const struct addrinfo *hints) {
+ addrinfo_request_t data[BUFSIZE/sizeof(addrinfo_request_t) + 1] = {};
+ addrinfo_request_t *req = data;
+ asyncns_query_t *q;
+ assert(asyncns);
+ assert(node || service);
+
+ if (asyncns->dead) {
+ errno = ECHILD;
+ return NULL;
+ }
+
+ if (!(q = alloc_query(asyncns)))
+ return NULL;
+
+
+ req->node_len = node ? strlen(node)+1 : 0;
+ req->service_len = service ? strlen(service)+1 : 0;
+
+ req->header.id = q->id;
+ req->header.type = q->type = REQUEST_ADDRINFO;
+ req->header.length = sizeof(addrinfo_request_t) + req->node_len + req->service_len;
+
+ if (req->header.length > BUFSIZE) {
+ errno = ENOMEM;
+ goto fail;
+ }
+
+ if (!(req->hints_is_null = !hints)) {
+ req->ai_flags = hints->ai_flags;
+ req->ai_family = hints->ai_family;
+ req->ai_socktype = hints->ai_socktype;
+ req->ai_protocol = hints->ai_protocol;
+ }
+
+ if (node)
+ strcpy((char*) req + sizeof(addrinfo_request_t), node);
+
+ if (service)
+ strcpy((char*) req + sizeof(addrinfo_request_t) + req->node_len, service);
+
+ if (send(asyncns->fds[REQUEST_SEND_FD], req, req->header.length, MSG_NOSIGNAL) < 0)
+ goto fail;
+
+ return q;
+
+fail:
+ if (q)
+ asyncns_cancel(asyncns, q);
+
+ return NULL;
+}
+
+int asyncns_getaddrinfo_done(asyncns_t *asyncns, asyncns_query_t* q, struct addrinfo **ret_res) {
+ int ret;
+ assert(asyncns);
+ assert(q);
+ assert(q->asyncns == asyncns);
+ assert(q->type == REQUEST_ADDRINFO);
+
+ if (asyncns->dead) {
+ errno = ECHILD;
+ return EAI_SYSTEM;
+ }
+
+ if (!q->done)
+ return EAI_AGAIN;
+
+ *ret_res = q->addrinfo;
+ q->addrinfo = NULL;
+
+ ret = q->ret;
+
+ if (ret == EAI_SYSTEM)
+ errno = q->_errno;
+
+ if (ret != 0)
+ h_errno = q->_h_errno;
+
+ asyncns_cancel(asyncns, q);
+
+ return ret;
+}
+
+asyncns_query_t* asyncns_getnameinfo(asyncns_t *asyncns, const struct sockaddr *sa, socklen_t salen, int flags, int gethost, int getserv) {
+ nameinfo_request_t data[BUFSIZE/sizeof(nameinfo_request_t) + 1] = {};
+ nameinfo_request_t *req = data;
+ asyncns_query_t *q;
+
+ assert(asyncns);
+ assert(sa);
+ assert(salen > 0);
+
+ if (asyncns->dead) {
+ errno = ECHILD;
+ return NULL;
+ }
+
+ if (!(q = alloc_query(asyncns)))
+ return NULL;
+
+
+ req->header.id = q->id;
+ req->header.type = q->type = REQUEST_NAMEINFO;
+ req->header.length = sizeof(nameinfo_request_t) + salen;
+
+ if (req->header.length > BUFSIZE) {
+ errno = ENOMEM;
+ goto fail;
+ }
+
+ req->flags = flags;
+ req->sockaddr_len = salen;
+ req->gethost = gethost;
+ req->getserv = getserv;
+
+ memcpy((uint8_t*) req + sizeof(nameinfo_request_t), sa, salen);
+
+ if (send(asyncns->fds[REQUEST_SEND_FD], req, req->header.length, MSG_NOSIGNAL) < 0)
+ goto fail;
+
+ return q;
+
+fail:
+ if (q)
+ asyncns_cancel(asyncns, q);
+
+ return NULL;
+}
+
+int asyncns_getnameinfo_done(asyncns_t *asyncns, asyncns_query_t* q, char *ret_host, size_t hostlen, char *ret_serv, size_t servlen) {
+ int ret;
+ assert(asyncns);
+ assert(q);
+ assert(q->asyncns == asyncns);
+ assert(q->type == REQUEST_NAMEINFO);
+ assert(!ret_host || hostlen);
+ assert(!ret_serv || servlen);
+
+ if (asyncns->dead) {
+ errno = ECHILD;
+ return EAI_SYSTEM;
+ }
+
+ if (!q->done)
+ return EAI_AGAIN;
+
+ if (ret_host && q->host) {
+ strncpy(ret_host, q->host, hostlen);
+ ret_host[hostlen-1] = 0;
+ }
+
+ if (ret_serv && q->serv) {
+ strncpy(ret_serv, q->serv, servlen);
+ ret_serv[servlen-1] = 0;
+ }
+
+ ret = q->ret;
+
+ if (ret == EAI_SYSTEM)
+ errno = q->_errno;
+
+ if (ret != 0)
+ h_errno = q->_h_errno;
+
+ asyncns_cancel(asyncns, q);
+
+ return ret;
+}
+
+static asyncns_query_t * asyncns_res(asyncns_t *asyncns, query_type_t qtype, const char *dname, int class, int type) {
+ res_request_t data[BUFSIZE/sizeof(res_request_t) + 1];
+ res_request_t *req = data;
+ asyncns_query_t *q;
+
+ assert(asyncns);
+ assert(dname);
+
+ if (asyncns->dead) {
+ errno = ECHILD;
+ return NULL;
+ }
+
+ if (!(q = alloc_query(asyncns)))
+ return NULL;
+
+ req->dname_len = strlen(dname) + 1;
+
+ req->header.id = q->id;
+ req->header.type = q->type = qtype;
+ req->header.length = sizeof(res_request_t) + req->dname_len;
+
+ if (req->header.length > BUFSIZE) {
+ errno = ENOMEM;
+ goto fail;
+ }
+
+ req->class = class;
+ req->type = type;
+
+ strcpy((char*) req + sizeof(res_request_t), dname);
+
+ if (send(asyncns->fds[REQUEST_SEND_FD], req, req->header.length, MSG_NOSIGNAL) < 0)
+ goto fail;
+
+ return q;
+
+fail:
+ if (q)
+ asyncns_cancel(asyncns, q);
+
+ return NULL;
+}
+
+asyncns_query_t* asyncns_res_query(asyncns_t *asyncns, const char *dname, int class, int type) {
+ return asyncns_res(asyncns, REQUEST_RES_QUERY, dname, class, type);
+}
+
+asyncns_query_t* asyncns_res_search(asyncns_t *asyncns, const char *dname, int class, int type) {
+ return asyncns_res(asyncns, REQUEST_RES_SEARCH, dname, class, type);
+}
+
+int asyncns_res_done(asyncns_t *asyncns, asyncns_query_t* q, unsigned char **answer) {
+ int ret;
+ assert(asyncns);
+ assert(q);
+ assert(q->asyncns == asyncns);
+ assert(q->type == REQUEST_RES_QUERY || q->type == REQUEST_RES_SEARCH);
+ assert(answer);
+
+ if (asyncns->dead) {
+ errno = ECHILD;
+ return -ECHILD;
+ }
+
+ if (!q->done) {
+ errno = EAGAIN;
+ return -EAGAIN;
+ }
+
+ *answer = (unsigned char *)q->serv;
+ q->serv = NULL;
+
+ ret = q->ret;
+
+ if (ret < 0) {
+ errno = q->_errno;
+ h_errno = q->_h_errno;
+ }
+
+ asyncns_cancel(asyncns, q);
+
+ return ret < 0 ? -errno : ret;
+}
+
+asyncns_query_t* asyncns_getnext(asyncns_t *asyncns) {
+ assert(asyncns);
+ return asyncns->done_head;
+}
+
+int asyncns_getnqueries(asyncns_t *asyncns) {
+ assert(asyncns);
+ return asyncns->n_queries;
+}
+
+void asyncns_cancel(asyncns_t *asyncns, asyncns_query_t* q) {
+ int i;
+ int saved_errno = errno;
+
+ assert(asyncns);
+ assert(q);
+ assert(q->asyncns == asyncns);
+ assert(asyncns->n_queries > 0);
+
+ if (q->done) {
+
+ if (q->done_prev)
+ q->done_prev->done_next = q->done_next;
+ else
+ asyncns->done_head = q->done_next;
+
+ if (q->done_next)
+ q->done_next->done_prev = q->done_prev;
+ else
+ asyncns->done_tail = q->done_prev;
+ }
+
+ i = q->id % MAX_QUERIES;
+ assert(asyncns->queries[i] == q);
+ asyncns->queries[i] = NULL;
+
+ asyncns_freeaddrinfo(q->addrinfo);
+ free(q->host);
+ free(q->serv);
+
+ asyncns->n_queries--;
+ free(q);
+
+ errno = saved_errno;
+}
+
+void asyncns_freeaddrinfo(struct addrinfo *ai) {
+ int saved_errno = errno;
+
+ while (ai) {
+ struct addrinfo *next = ai->ai_next;
+
+ free(ai->ai_addr);
+ free(ai->ai_canonname);
+ free(ai);
+
+ ai = next;
+ }
+
+ errno = saved_errno;
+}
+
+void asyncns_freeanswer(unsigned char *answer) {
+ int saved_errno = errno;
+
+ if (!answer)
+ return;
+
+ /* Please note that this function is new in libasyncns 0.4. In
+ * older versions you were supposed to free the answer directly
+ * with free(). Hence, if this function is changed to do more than
+ * just a simple free() this must be considered ABI/API breakage! */
+
+ free(answer);
+
+ errno = saved_errno;
+}
+
+int asyncns_isdone(asyncns_t *asyncns, asyncns_query_t*q) {
+ assert(asyncns);
+ assert(q);
+ assert(q->asyncns == asyncns);
+
+ return q->done;
+}
+
+void asyncns_setuserdata(asyncns_t *asyncns, asyncns_query_t *q, void *userdata) {
+ assert(q);
+ assert(asyncns);
+ assert(q->asyncns = asyncns);
+
+ q->userdata = userdata;
+}
+
+void* asyncns_getuserdata(asyncns_t *asyncns, asyncns_query_t *q) {
+ assert(q);
+ assert(asyncns);
+ assert(q->asyncns = asyncns);
+
+ return q->userdata;
+}
diff --git a/src/libsystemd-bus/test-dns.c b/src/libsystemd-bus/test-dns.c
new file mode 100644
index 0000000000..56654ec047
--- /dev/null
+++ b/src/libsystemd-bus/test-dns.c
@@ -0,0 +1,164 @@
+/***
+ This file is part of libasyncns.
+
+ Copyright 2005-2008 Lennart Poettering
+
+ libasyncns 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.
+
+ libasyncns 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 libasyncns. If not, see
+ <http://www.gnu.org/licenses/>.
+ ***/
+
+#if HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <stdio.h>
+#include <netinet/in.h>
+#include <arpa/nameser.h>
+#include <resolv.h>
+#include <assert.h>
+#include <signal.h>
+#include <errno.h>
+
+#include "sd-dns.h"
+#include "dns-util.h"
+#include "macro.h"
+
+int main(int argc, char *argv[]) {
+ int r = 1, ret;
+ _cleanup_asyncns_free_ asyncns_t *asyncns = NULL;
+ _cleanup_asyncns_addrinfo_free_ struct addrinfo *ai = NULL;
+ _cleanup_asyncns_answer_free_ unsigned char *srv = NULL;
+ asyncns_query_t *q1, *q2, *q3;
+ struct addrinfo hints = {};
+ struct sockaddr_in sa = {};
+ char host[NI_MAXHOST] = "", serv[NI_MAXSERV] = "";
+
+ signal(SIGCHLD, SIG_IGN);
+
+ asyncns = asyncns_new(2);
+ if (!asyncns)
+ log_oom();
+
+ /* Make a name -> address query */
+ hints.ai_family = PF_UNSPEC;
+ hints.ai_socktype = SOCK_STREAM;
+
+ q1 = asyncns_getaddrinfo(asyncns, argc >= 2 ? argv[1] : "www.heise.de", NULL, &hints);
+
+ if (!q1)
+ fprintf(stderr, "asyncns_getaddrinfo(): %s\n", strerror(errno));
+
+ /* Make an address -> name query */
+ sa.sin_family = AF_INET;
+ sa.sin_addr.s_addr = inet_addr(argc >= 3 ? argv[2] : "193.99.144.71");
+ sa.sin_port = htons(80);
+
+ q2 = asyncns_getnameinfo(asyncns, (struct sockaddr*) &sa, sizeof(sa), 0, 1, 1);
+
+ if (!q2)
+ fprintf(stderr, "asyncns_getnameinfo(): %s\n", strerror(errno));
+
+ /* Make a res_query() call */
+ q3 = asyncns_res_query(asyncns, "_xmpp-client._tcp.gmail.com", C_IN, T_SRV);
+
+ if (!q3)
+ fprintf(stderr, "asyncns_res_query(): %s\n", strerror(errno));
+
+ /* Wait until the three queries are completed */
+ while (!asyncns_isdone(asyncns, q1)
+ || !asyncns_isdone(asyncns, q2)
+ || !asyncns_isdone(asyncns, q3)) {
+ if (asyncns_wait(asyncns, 1) < 0) {
+ fprintf(stderr, "asyncns_wait(): %s\n", strerror(errno));
+ }
+ }
+
+ /* Interpret the result of the name -> addr query */
+ if ((ret = asyncns_getaddrinfo_done(asyncns, q1, &ai)))
+ fprintf(stderr, "error: %s %i\n", gai_strerror(ret), ret);
+ else {
+ struct addrinfo *i;
+
+ for (i = ai; i; i = i->ai_next) {
+ char t[256];
+ const char *p = NULL;
+
+ if (i->ai_family == PF_INET)
+ p = inet_ntop(AF_INET, &((struct sockaddr_in*) i->ai_addr)->sin_addr, t, sizeof(t));
+ else if (i->ai_family == PF_INET6)
+ p = inet_ntop(AF_INET6, &((struct sockaddr_in6*) i->ai_addr)->sin6_addr, t, sizeof(t));
+
+ printf("%s\n", p);
+ }
+ }
+
+ /* Interpret the result of the addr -> name query */
+ if ((ret = asyncns_getnameinfo_done(asyncns, q2, host, sizeof(host), serv, sizeof(serv))))
+ fprintf(stderr, "error: %s %i\n", gai_strerror(ret), ret);
+ else
+ printf("%s -- %s\n", host, serv);
+
+ /* Interpret the result of the SRV lookup */
+ if ((ret = asyncns_res_done(asyncns, q3, &srv)) < 0) {
+ fprintf(stderr, "error: %s %i\n", strerror(errno), ret);
+ } else if (ret == 0) {
+ fprintf(stderr, "No reply for SRV lookup\n");
+ } else {
+ int qdcount;
+ int ancount;
+ int len;
+ const unsigned char *pos = srv + sizeof(HEADER);
+ unsigned char *end = srv + ret;
+ HEADER *head = (HEADER *)srv;
+ char name[256];
+
+ qdcount = ntohs(head->qdcount);
+ ancount = ntohs(head->ancount);
+
+ printf("%d answers for srv lookup:\n", ancount);
+
+ /* Ignore the questions */
+ while (qdcount-- > 0 && (len = dn_expand(srv, end, pos, name, 255)) >= 0) {
+ assert(len >= 0);
+ pos += len + QFIXEDSZ;
+ }
+
+ /* Parse the answers */
+ while (ancount-- > 0 && (len = dn_expand(srv, end, pos, name, 255)) >= 0) {
+ /* Ignore the initial string */
+ uint16_t pref, weight, port;
+ assert(len >= 0);
+ pos += len;
+ /* Ignore type, ttl, class and dlen */
+ pos += 10;
+
+ GETSHORT(pref, pos);
+ GETSHORT(weight, pos);
+ GETSHORT(port, pos);
+ len = dn_expand(srv, end, pos, name, 255);
+ printf("\tpreference: %2d weight: %2d port: %d host: %s\n",
+ pref, weight, port, name);
+
+ pos += len;
+ }
+ }
+
+ r = 0;
+
+ return r;
+}
diff --git a/src/systemd/sd-dns.h b/src/systemd/sd-dns.h
new file mode 100644
index 0000000000..72bc1213ed
--- /dev/null
+++ b/src/systemd/sd-dns.h
@@ -0,0 +1,156 @@
+#ifndef fooasyncnshfoo
+#define fooasyncnshfoo
+
+/***
+ This file is part of libasyncns.
+
+ Copyright 2005-2008 Lennart Poettering
+
+ libasyncns 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.
+
+ libasyncns 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 libasyncns. If not, see
+ <http://www.gnu.org/licenses/>.
+***/
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+#include "macro.h"
+#include "util.h"
+/** \mainpage
+ *
+ * \section moo Method of operation
+ *
+ * To use libasyncns allocate an asyncns_t object with
+ * asyncns_new(). This will spawn a number of worker threads (or processes, depending on what is available) which
+ * are subsequently used to process the queries the controlling
+ * program issues via asyncns_getaddrinfo() and
+ * asyncns_getnameinfo(). Use asyncns_free() to shut down the worker
+ * threads/processes.
+ *
+ * Since libasyncns may fork off new processes you have to make sure that
+ * your program is not irritated by spurious SIGCHLD signals.
+ */
+
+/** \example asyncns-test.c
+ * An example program */
+
+/** An opaque libasyncns session structure */
+typedef struct asyncns asyncns_t;
+
+/** An opaque libasyncns query structure */
+typedef struct asyncns_query asyncns_query_t;
+
+/** Allocate a new libasyncns session with n_proc worker processes/threads */
+asyncns_t* asyncns_new(unsigned n_proc);
+
+/** Free a libasyncns session. This destroys all attached
+ * asyncns_query_t objects automatically */
+void asyncns_free(asyncns_t *asyncns);
+
+/** Return the UNIX file descriptor to select() for readability
+ * on. Use this function to integrate libasyncns with your custom main
+ * loop. */
+int asyncns_fd(asyncns_t *asyncns);
+
+/** Process pending responses. After this function is called you can
+ * get the next completed query object(s) using asyncns_getnext(). If
+ * block is non-zero wait until at least one response has been
+ * processed. If block is zero, process all pending responses and
+ * return. */
+int asyncns_wait(asyncns_t *asyncns, int block);
+
+/** Issue a name to address query on the specified session. The
+ * arguments are compatible with the ones of libc's
+ * getaddrinfo(3). The function returns a new query object. When the
+ * query is completed you may retrieve the results using
+ * asyncns_getaddrinfo_done().*/
+asyncns_query_t* asyncns_getaddrinfo(asyncns_t *asyncns, const char *node, const char *service, const struct addrinfo *hints);
+
+/** Retrieve the results of a preceding asyncns_getaddrinfo()
+ * call. Returns a addrinfo structure and a return value compatible
+ * with libc's getaddrinfo(3). The query object q is destroyed by this
+ * call and may not be used any further. Make sure to free the
+ * returned addrinfo structure with asyncns_freeaddrinfo() and not
+ * libc's freeaddrinfo(3)! If the query is not completed yet EAI_AGAIN
+ * is returned.*/
+int asyncns_getaddrinfo_done(asyncns_t *asyncns, asyncns_query_t* q, struct addrinfo **ret_res);
+
+/** Issue an address to name query on the specified session. The
+ * arguments are compatible with the ones of libc's
+ * getnameinfo(3). The function returns a new query object. When the
+ * query is completed you may retrieve the results using
+ * asyncns_getnameinfo_done(). Set gethost (resp. getserv) to non-zero
+ * if you want to query the hostname (resp. the service name). */
+asyncns_query_t* asyncns_getnameinfo(asyncns_t *asyncns, const struct sockaddr *sa, socklen_t salen, int flags, int gethost, int getserv);
+
+/** Retrieve the results of a preceding asyncns_getnameinfo()
+ * call. Returns the hostname and the service name in ret_host and
+ * ret_serv. The query object q is destroyed by this call and may not
+ * be used any further. If the query is not completed yet EAI_AGAIN is
+ * returned. */
+int asyncns_getnameinfo_done(asyncns_t *asyncns, asyncns_query_t* q, char *ret_host, size_t hostlen, char *ret_serv, size_t servlen);
+
+/** Issue a resolver query on the specified session. The arguments are
+ * compatible with the ones of libc's res_query(3). The function returns a new
+ * query object. When the query is completed you may retrieve the results using
+ * asyncns_res_done(). */
+asyncns_query_t* asyncns_res_query(asyncns_t *asyncns, const char *dname, int class, int type);
+
+/** Issue an resolver query on the specified session. The arguments are
+ * compatible with the ones of libc's res_search(3). The function returns a new
+ * query object. When the query is completed you may retrieve the results using
+ * asyncns_res_done(). */
+asyncns_query_t* asyncns_res_search(asyncns_t *asyncns, const char *dname, int class, int type);
+
+/** Retrieve the results of a preceding asyncns_res_query() or
+ * asyncns_res_search call. The query object q is destroyed by this
+ * call and may not be used any further. Returns a pointer to the
+ * answer of the res_query call. If the query is not completed yet
+ * -EAGAIN is returned, on failure -errno is returned, otherwise the
+ * length of answer is returned. Make sure to free the answer is a
+ * call to asyncns_freeanswer(). */
+int asyncns_res_done(asyncns_t *asyncns, asyncns_query_t* q, unsigned char **answer);
+
+/** Return the next completed query object. If no query has been
+ * completed yet, return NULL. Please note that you need to run
+ * asyncns_wait() before this function will return sensible data. */
+asyncns_query_t* asyncns_getnext(asyncns_t *asyncns);
+
+/** Return the number of query objects (completed or not) attached to
+ * this session */
+int asyncns_getnqueries(asyncns_t *asyncns);
+
+/** Cancel a currently running query. q is is destroyed by this call
+ * and may not be used any futher. */
+void asyncns_cancel(asyncns_t *asyncns, asyncns_query_t* q);
+
+/** Free the addrinfo structure as returned by
+ * asyncns_getaddrinfo_done(). Make sure to use this functions instead
+ * of the libc's freeaddrinfo()! */
+void asyncns_freeaddrinfo(struct addrinfo *ai);
+
+/** Free the answer data as returned by asyncns_res_done().*/
+void asyncns_freeanswer(unsigned char *answer);
+
+/** Returns non-zero when the query operation specified by q has been completed */
+int asyncns_isdone(asyncns_t *asyncns, asyncns_query_t*q);
+
+/** Assign some opaque userdata with a query object */
+void asyncns_setuserdata(asyncns_t *asyncns, asyncns_query_t *q, void *userdata);
+
+/** Return userdata assigned to a query object. Use
+ * asyncns_setuserdata() to set this data. If no data has been set
+ * prior to this call it returns NULL. */
+void* asyncns_getuserdata(asyncns_t *asyncns, asyncns_query_t *q);
+
+#endif