diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/libsystemd-bus/dns-util.h | 8 | ||||
| -rw-r--r-- | src/libsystemd-bus/sd-dns.c | 1158 | ||||
| -rw-r--r-- | src/libsystemd-bus/test-dns.c | 164 | ||||
| -rw-r--r-- | src/systemd/sd-dns.h | 156 |
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 |