From: Lennart Poettering Date: Tue, 29 Apr 2014 13:44:31 +0000 (+0200) Subject: sd-resolve: rework sd-resolve to be callback based, similar in style to sd-bus and... X-Git-Tag: v213~283 X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=93f1bcf40030a9e98bf2b71c177cbea36c64d5c9 sd-resolve: rework sd-resolve to be callback based, similar in style to sd-bus and sd-event --- diff --git a/Makefile.am b/Makefile.am index 365fa548b..45cf7d930 100644 --- a/Makefile.am +++ b/Makefile.am @@ -2144,6 +2144,9 @@ libsystemd_resolve_la_CFLAGS = \ $(AM_CFLAGS) \ -pthread +libsystemd_resolve_la_LIBADD = \ + -lresolv + noinst_LTLIBRARIES += \ libsystemd-internal.la \ libsystemd-resolve.la @@ -2183,6 +2186,7 @@ nodist_libsystemd_la_SOURCES = \ libsystemd_la_CFLAGS = \ $(libsystemd_internal_la_CFLAGS) \ + $(libsystemd_resolve_la_CFLAGS) \ $(libsystemd_journal_internal_la_CFLAGS) libsystemd_la_LDFLAGS = \ @@ -2192,9 +2196,9 @@ libsystemd_la_LDFLAGS = \ libsystemd_la_LIBADD = \ libsystemd-shared.la \ + $(libsystemd_internal_la_LIBADD) \ $(libsystemd_journal_internal_la_LIBADD) \ - $(RT_LIBS) \ - -lresolv + $(libsystemd_resolve_la_LIBADD) libsystemd-install-hook: libname=libsystemd.so && $(move-to-rootlibdir) @@ -2435,14 +2439,12 @@ test_rtnl_LDADD = \ libsystemd-shared.la test_resolve_SOURCES = \ - src/systemd/sd-resolve.h \ src/libsystemd/sd-resolve/test-resolve.c test_resolve_LDADD = \ - libsystemd-internal.la \ libsystemd-resolve.la \ - libsystemd-shared.la \ - -lresolv + libsystemd-internal.la \ + libsystemd-shared.la test_resolve_CFLAGS = \ $(AM_CFLAGS) \ @@ -5157,7 +5159,8 @@ test-libsystemd-sym.c: \ src/systemd/sd-daemon.h \ src/systemd/sd-login.h \ src/systemd/sd-bus.h \ - src/systemd/sd-utf8.h + src/systemd/sd-utf8.h \ + src/systemd/sd-resolve.h $(generate-sym-test) test-libudev-sym.c: \ diff --git a/src/libsystemd/libsystemd.sym.m4 b/src/libsystemd/libsystemd.sym.m4 index d0ac64386..d18d5767b 100644 --- a/src/libsystemd/libsystemd.sym.m4 +++ b/src/libsystemd/libsystemd.sym.m4 @@ -401,5 +401,30 @@ m4_ifdef(`ENABLE_KDBUS', /* sd-utf8 */ sd_utf8_is_valid; sd_ascii_is_valid; + + /* sd-resolve */ + sd_resolve_default; + sd_resolve_new; + sd_resolve_ref; + sd_resolve_unref; + sd_resolve_get_fd; + sd_resolve_get_events; + sd_resolve_get_timeout; + sd_resolve_process; + sd_resolve_wait; + sd_resolve_get_tid; + sd_resolve_attach_event; + sd_resolve_detach_event; + sd_resolve_get_event; + sd_resolve_getaddrinfo; + sd_resolve_getnameinfo; + sd_resolve_res_query; + sd_resolve_res_search; + sd_resolve_query_ref; + sd_resolve_query_unref; + sd_resolve_query_is_done; + sd_resolve_query_get_userdata; + sd_resolve_query_set_userdata; + sd_resolve_query_get_resolve; ) } LIBSYSTEMD_209; diff --git a/src/libsystemd/sd-bus/sd-bus.c b/src/libsystemd/sd-bus/sd-bus.c index 7074dc724..dc54e211a 100644 --- a/src/libsystemd/sd-bus/sd-bus.c +++ b/src/libsystemd/sd-bus/sd-bus.c @@ -3106,9 +3106,7 @@ _public_ int sd_bus_detach_event(sd_bus *bus) { bus->quit_event_source = sd_event_source_unref(bus->quit_event_source); } - if (bus->event) - bus->event = sd_event_unref(bus->event); - + bus->event = sd_event_unref(bus->event); return 1; } diff --git a/src/libsystemd/sd-resolve/resolve-util.h b/src/libsystemd/sd-resolve/resolve-util.h index 7da1d7b1c..019cdaffe 100644 --- a/src/libsystemd/sd-resolve/resolve-util.h +++ b/src/libsystemd/sd-resolve/resolve-util.h @@ -22,8 +22,10 @@ ***/ #include "util.h" +#include "sd-resolve.h" DEFINE_TRIVIAL_CLEANUP_FUNC(sd_resolve*, sd_resolve_unref); -DEFINE_TRIVIAL_CLEANUP_FUNC(struct addrinfo*, sd_resolve_freeaddrinfo); +DEFINE_TRIVIAL_CLEANUP_FUNC(sd_resolve_query*, sd_resolve_query_unref); + #define _cleanup_resolve_unref_ _cleanup_(sd_resolve_unrefp) -#define _cleanup_resolve_addrinfo_free_ _cleanup_(sd_resolve_freeaddrinfop) +#define _cleanup_resolve_query_unref_ _cleanup_(sd_resolve_query_unrefp) diff --git a/src/libsystemd/sd-resolve/sd-resolve.c b/src/libsystemd/sd-resolve/sd-resolve.c index d81012467..cb8e34e36 100644 --- a/src/libsystemd/sd-resolve/sd-resolve.c +++ b/src/libsystemd/sd-resolve/sd-resolve.c @@ -45,12 +45,14 @@ #include "util.h" #include "list.h" #include "socket-util.h" +#include "missing.h" +#include "resolve-util.h" #include "sd-resolve.h" -#define WORKERS_MIN 1 -#define WORKERS_MAX 16 -#define QUERIES_MAX 256 -#define BUFSIZE 10240 +#define WORKERS_MIN 1U +#define WORKERS_MAX 16U +#define QUERIES_MAX 256U +#define BUFSIZE 10240U typedef enum { REQUEST_ADDRINFO, @@ -73,6 +75,8 @@ enum { }; struct sd_resolve { + unsigned n_ref; + bool dead:1; pid_t original_pid; @@ -83,28 +87,40 @@ struct sd_resolve { unsigned current_id, current_index; sd_resolve_query* queries[QUERIES_MAX]; - unsigned n_queries; + unsigned n_queries, n_done; + + sd_event_source *event_source; + sd_event *event; - LIST_HEAD(sd_resolve_query, done); - sd_resolve_query *done_tail; - unsigned n_done; + sd_resolve_query *current; + + sd_resolve **default_resolve_ptr; + pid_t tid; }; struct sd_resolve_query { + unsigned n_ref; + sd_resolve *resolve; + + QueryType type:4; bool done:1; unsigned id; - QueryType type; int ret; int _errno; int _h_errno; struct addrinfo *addrinfo; char *serv, *host; + unsigned char *answer; - void *userdata; + union { + sd_resolve_getaddrinfo_handler_t getaddrinfo_handler; + sd_resolve_getnameinfo_handler_t getnameinfo_handler; + sd_resolve_res_handler_t res_handler; + }; - LIST_FIELDS(sd_resolve_query, done); + void *userdata; }; typedef struct RHeader { @@ -180,13 +196,21 @@ typedef union Packet { ResResponse res_response; } Packet; +static int getaddrinfo_done(sd_resolve_query* q); +static int getnameinfo_done(sd_resolve_query *q); +static int res_query_done(sd_resolve_query* q); + +#define RESOLVE_DONT_DESTROY(resolve) \ + _cleanup_resolve_unref_ _unused_ sd_resolve *_dont_destroy_##resolve = sd_resolve_ref(resolve) + static int send_died(int out_fd) { - RHeader rh = {}; - assert(out_fd >= 0); + RHeader rh = { + .type = RESPONSE_DIED, + .length = sizeof(RHeader), + }; - rh.type = RESPONSE_DIED; - rh.length = sizeof(rh); + assert(out_fd >= 0); if (send(out_fd, &rh, rh.length, MSG_NOSIGNAL) < 0) return -errno; @@ -234,7 +258,15 @@ static int send_addrinfo_reply( int _errno, int _h_errno) { - AddrInfoResponse resp = {}; + AddrInfoResponse resp = { + .header.type = RESPONSE_ADDRINFO, + .header.id = id, + .header.length = sizeof(AddrInfoResponse), + .ret = ret, + ._errno = _errno, + ._h_errno = _h_errno, + }; + struct msghdr mh = {}; struct iovec iov[2]; union { @@ -244,13 +276,6 @@ static int send_addrinfo_reply( assert(out_fd >= 0); - resp.header.type = RESPONSE_ADDRINFO; - resp.header.id = id; - resp.header.length = sizeof(AddrInfoResponse); - resp.ret = ret; - resp._errno = _errno; - resp._h_errno = _h_errno; - if (ret == 0 && ai) { void *p = &buffer; struct addrinfo *k; @@ -288,7 +313,14 @@ static int send_nameinfo_reply( int _errno, int _h_errno) { - NameInfoResponse resp = {}; + NameInfoResponse resp = { + .header.type = RESPONSE_NAMEINFO, + .header.id = id, + .ret = ret, + ._errno = _errno, + ._h_errno = _h_errno, + }; + struct msghdr mh = {}; struct iovec iov[3]; size_t hl, sl; @@ -298,12 +330,7 @@ static int send_nameinfo_reply( 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(NameInfoResponse) + hl + sl; - resp.ret = ret; - resp._errno = _errno; - resp._h_errno = _h_errno; resp.hostlen = hl; resp.servlen = sl; @@ -321,21 +348,24 @@ static int send_nameinfo_reply( } static int send_res_reply(int out_fd, unsigned id, const unsigned char *answer, int ret, int _errno, int _h_errno) { + + ResResponse resp = { + .header.type = RESPONSE_RES, + .header.id = id, + .ret = ret, + ._errno = _errno, + ._h_errno = _h_errno, + }; + struct msghdr mh = {}; struct iovec iov[2]; - ResResponse resp = {}; size_t l; assert(out_fd >= 0); l = ret > 0 ? (size_t) ret : 0; - resp.header.type = RESPONSE_RES; - resp.header.id = id; resp.header.length = sizeof(ResResponse) + l; - resp.ret = ret; - resp._errno = _errno; - resp._h_errno = _h_errno; iov[0] = (struct iovec) { .iov_base = &resp, .iov_len = sizeof(ResResponse) }; iov[1] = (struct iovec) { .iov_base = (void*) answer, .iov_len = l }; @@ -489,12 +519,8 @@ static int start_threads(sd_resolve *resolve, unsigned extra) { unsigned n; int r; - n = resolve->n_queries - resolve->n_done + extra; - - if (n < WORKERS_MIN) - n = WORKERS_MIN; - if (n > WORKERS_MAX) - n = WORKERS_MAX; + n = resolve->n_queries + extra - resolve->n_done; + n = CLAMP(n, WORKERS_MIN, WORKERS_MAX); while (resolve->n_valid_workers < n) { @@ -527,11 +553,12 @@ _public_ int sd_resolve_new(sd_resolve **ret) { if (!resolve) return -ENOMEM; + resolve->n_ref = 1; + resolve->original_pid = getpid(); + for (i = 0; i < _FD_MAX; i++) resolve->fds[i] = -1; - resolve->original_pid = getpid(); - r = socketpair(PF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, resolve->fds + REQUEST_RECV_FD); if (r < 0) { r = -errno; @@ -555,22 +582,65 @@ _public_ int sd_resolve_new(sd_resolve **ret) { return 0; fail: - if (resolve) - sd_resolve_unref(resolve); - + sd_resolve_unref(resolve); return r; } -_public_ sd_resolve* sd_resolve_unref(sd_resolve *resolve) { - PROTECT_ERRNO; +_public_ int sd_resolve_default(sd_resolve **ret) { + + static thread_local sd_resolve *default_resolve = NULL; + sd_resolve *e = NULL; + int r; + + if (!ret) + return !!default_resolve; + + if (default_resolve) { + *ret = sd_resolve_ref(default_resolve); + return 0; + } + + r = sd_resolve_new(&e); + if (r < 0) + return r; + + e->default_resolve_ptr = &default_resolve; + e->tid = gettid(); + default_resolve = e; + + *ret = e; + return 1; +} + +_public_ int sd_resolve_get_tid(sd_resolve *resolve, pid_t *tid) { + assert_return(resolve, -EINVAL); + assert_return(tid, -EINVAL); + assert_return(!resolve_pid_changed(resolve), -ECHILD); + + if (resolve->tid != 0) { + *tid = resolve->tid; + return 0; + } + + if (resolve->event) + return sd_event_get_tid(resolve->event, tid); + + return -ENXIO; +} +static void resolve_free(sd_resolve *resolve) { + PROTECT_ERRNO; unsigned i; - assert_return(resolve, NULL); - assert_return(!resolve_pid_changed(resolve), NULL); + assert(resolve); + + if (resolve->default_resolve_ptr) + *(resolve->default_resolve_ptr) = NULL; resolve->dead = true; + sd_resolve_detach_event(resolve); + if (resolve->fds[REQUEST_SEND_FD] >= 0) { RHeader req = { @@ -595,11 +665,29 @@ _public_ sd_resolve* sd_resolve_unref(sd_resolve *resolve) { for (i = 0; i < _FD_MAX; i++) safe_close(resolve->fds[i]); - for (i = 0; i < QUERIES_MAX && resolve->n_queries > 0; i++) - if (resolve->queries[i]) - sd_resolve_cancel(resolve->queries[i]); - free(resolve); +} + +_public_ sd_resolve* sd_resolve_ref(sd_resolve *resolve) { + assert_return(resolve, NULL); + + assert(resolve->n_ref >= 1); + resolve->n_ref++; + + return resolve; +} + +_public_ sd_resolve* sd_resolve_unref(sd_resolve *resolve) { + + if (!resolve) + return NULL; + + assert(resolve->n_ref >= 1); + resolve->n_ref--; + + if (resolve->n_ref <= 0) + resolve_free(resolve); + return NULL; } @@ -639,13 +727,40 @@ static sd_resolve_query *lookup_query(sd_resolve *resolve, unsigned id) { return NULL; } -static void complete_query(sd_resolve_query *q) { +static int complete_query(sd_resolve *resolve, sd_resolve_query *q) { + int r; + assert(q); assert(!q->done); + assert(q->resolve == resolve); q->done = true; - LIST_PREPEND(done, q->resolve->done, q); - q->resolve->n_done ++; + resolve->n_done ++; + + resolve->current = q; + + switch (q->type) { + + case REQUEST_ADDRINFO: + r = getaddrinfo_done(q); + break; + + case REQUEST_NAMEINFO: + r = getnameinfo_done(q); + break; + + case REQUEST_RES_QUERY: + case REQUEST_RES_SEARCH: + r = res_query_done(q); + break; + + default: + assert_not_reached("Cannot complete unknown query type"); + } + + resolve->current = NULL; + + return r; } static int unserialize_addrinfo(const void **p, size_t *length, struct addrinfo **ret_ai) { @@ -761,8 +876,7 @@ static int handle_response(sd_resolve *resolve, const Packet *packet, size_t len prev = ai; } - complete_query(q); - break; + return complete_query(resolve, q); } case RESPONSE_NAMEINFO: { @@ -793,8 +907,7 @@ static int handle_response(sd_resolve *resolve, const Packet *packet, size_t len } } - complete_query(q); - break; + return complete_query(resolve, q); } case RESPONSE_RES: { @@ -808,54 +921,53 @@ static int handle_response(sd_resolve *resolve, const Packet *packet, size_t len q->_h_errno = res_resp->_h_errno; if (res_resp->ret >= 0) { - q->serv = memdup((const char *)resp + sizeof(ResResponse), res_resp->ret); - if (!q->serv) { + q->answer = memdup((const char *)resp + sizeof(ResResponse), res_resp->ret); + if (!q->answer) { q->ret = -1; q->_errno = ENOMEM; q->_h_errno = 0; } } - complete_query(q); - break; + return complete_query(resolve, q); } default: - ; + return 0; } - - return 0; } _public_ int sd_resolve_process(sd_resolve *resolve) { - int n_processed = 0, r; + RESOLVE_DONT_DESTROY(resolve); + + union { + Packet packet; + uint8_t space[BUFSIZE]; + } buf; + ssize_t l; + int r; assert_return(resolve, -EINVAL); assert_return(!resolve_pid_changed(resolve), -ECHILD); - for (;;) { - ssize_t l; - union { - Packet packet; - uint8_t space[BUFSIZE]; - } buf; + /* We don't allow recursively invoking sd_resolve_process(). */ + assert_return(!resolve->current, -EBUSY); - l = recv(resolve->fds[RESPONSE_RECV_FD], &buf, sizeof(buf), 0); - if (l < 0) { - if (errno == EAGAIN) - return n_processed; + l = recv(resolve->fds[RESPONSE_RECV_FD], &buf, sizeof(buf), 0); + if (l < 0) { + if (errno == EAGAIN) + return 0; - return -errno; - } - if (l == 0) - return -ECONNREFUSED; + return -errno; + } + if (l == 0) + return -ECONNREFUSED; - r = handle_response(resolve, &buf.packet, (size_t) l); - if (r < 0) - return r; + r = handle_response(resolve, &buf.packet, (size_t) l); + if (r < 0) + return r; - n_processed++; - } + return 1; } _public_ int sd_resolve_wait(sd_resolve *resolve, uint64_t timeout_usec) { @@ -864,7 +976,7 @@ _public_ int sd_resolve_wait(sd_resolve *resolve, uint64_t timeout_usec) { assert_return(resolve, -EINVAL); assert_return(!resolve_pid_changed(resolve), -ECHILD); - if (resolve->n_queries <= 0) + if (resolve->n_done >= resolve->n_queries) return 0; do { @@ -902,11 +1014,12 @@ static int alloc_query(sd_resolve *resolve, sd_resolve_query **_q) { if (!q) return -ENOMEM; - resolve->n_queries++; - - q->resolve = resolve; + q->n_ref = 1; + q->resolve = sd_resolve_ref(resolve); q->id = resolve->current_id; + resolve->n_queries++; + *_q = q; return 0; } @@ -914,9 +1027,9 @@ static int alloc_query(sd_resolve *resolve, sd_resolve_query **_q) { _public_ int sd_resolve_getaddrinfo( sd_resolve *resolve, sd_resolve_query **_q, - const char *node, - const char *service, - const struct addrinfo *hints) { + const char *node, const char *service, + const struct addrinfo *hints, + sd_resolve_getaddrinfo_handler_t callback, void *userdata) { AddrInfoRequest req = {}; struct msghdr mh = {}; @@ -925,19 +1038,24 @@ _public_ int sd_resolve_getaddrinfo( int r; assert_return(resolve, -EINVAL); - assert_return(node || service, -EINVAL); assert_return(_q, -EINVAL); + assert_return(node || service, -EINVAL); + assert_return(callback, -EINVAL); assert_return(!resolve_pid_changed(resolve), -ECHILD); r = alloc_query(resolve, &q); if (r < 0) return r; + q->type = REQUEST_ADDRINFO; + q->getaddrinfo_handler = callback; + q->userdata = userdata; + 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.type = REQUEST_ADDRINFO; req.header.length = sizeof(AddrInfoRequest) + req.node_len + req.service_len; if (hints) { @@ -949,17 +1067,14 @@ _public_ int sd_resolve_getaddrinfo( } iov[mh.msg_iovlen++] = (struct iovec) { .iov_base = &req, .iov_len = sizeof(AddrInfoRequest) }; - if (node) iov[mh.msg_iovlen++] = (struct iovec) { .iov_base = (void*) node, .iov_len = req.node_len }; - if (service) iov[mh.msg_iovlen++] = (struct iovec) { .iov_base = (void*) service, .iov_len = req.service_len }; - mh.msg_iov = iov; if (sendmsg(resolve->fds[REQUEST_SEND_FD], &mh, MSG_NOSIGNAL) < 0) { - sd_resolve_cancel(q); + sd_resolve_query_unref(q); return -errno; } @@ -967,41 +1082,15 @@ _public_ int sd_resolve_getaddrinfo( return 0; } -_public_ int sd_resolve_getaddrinfo_done(sd_resolve_query* q, struct addrinfo **ret_res) { - int ret; - - if (!q) { - errno = EINVAL; - return EAI_SYSTEM; - } - - if (q->type != REQUEST_ADDRINFO) { - errno = ENOTTY; - return EAI_SYSTEM; - } - - if (resolve_pid_changed(q->resolve)) { - errno = ECHILD; - return EAI_SYSTEM; - } - if (!q->done) - return EAI_AGAIN; - - if (ret_res) { - *ret_res = q->addrinfo; - q->addrinfo = NULL; - } - - ret = q->ret; - - if (ret != 0) { - errno = q->_errno; - h_errno = q->_h_errno; - } +static int getaddrinfo_done(sd_resolve_query* q) { + assert(q); + assert(q->done); + assert(q->getaddrinfo_handler); - sd_resolve_cancel(q); + errno = q->_errno; + h_errno = q->_h_errno; - return ret; + return q->getaddrinfo_handler(q, q->ret, q->addrinfo, q->userdata); } _public_ int sd_resolve_getnameinfo( @@ -1009,7 +1098,9 @@ _public_ int sd_resolve_getnameinfo( sd_resolve_query**_q, const struct sockaddr *sa, socklen_t salen, int flags, - int gethost, int getserv) { + uint64_t get, + sd_resolve_getnameinfo_handler_t callback, + void *userdata) { NameInfoRequest req = {}; struct msghdr mh = {}; @@ -1018,24 +1109,30 @@ _public_ int sd_resolve_getnameinfo( int r; assert_return(resolve, -EINVAL); + assert_return(_q, -EINVAL); assert_return(sa, -EINVAL); assert_return(salen >= sizeof(struct sockaddr), -EINVAL); assert_return(salen <= sizeof(union sockaddr_union), -EINVAL); - assert_return(_q, -EINVAL); + assert_return((get & ~SD_RESOLVE_GET_BOTH) == 0, -EINVAL); + assert_return(callback, -EINVAL); assert_return(!resolve_pid_changed(resolve), -ECHILD); r = alloc_query(resolve, &q); if (r < 0) return r; + q->type = REQUEST_NAMEINFO; + q->getnameinfo_handler = callback; + q->userdata = userdata; + req.header.id = q->id; - req.header.type = q->type = REQUEST_NAMEINFO; + req.header.type = REQUEST_NAMEINFO; req.header.length = sizeof(NameInfoRequest) + salen; req.flags = flags; req.sockaddr_len = salen; - req.gethost = !!gethost; - req.getserv = !!getserv; + req.gethost = !!(get & SD_RESOLVE_GET_HOST); + req.getserv = !!(get & SD_RESOLVE_GET_SERVICE); iov[0] = (struct iovec) { .iov_base = &req, .iov_len = sizeof(NameInfoRequest) }; iov[1] = (struct iovec) { .iov_base = (void*) sa, .iov_len = salen }; @@ -1044,7 +1141,7 @@ _public_ int sd_resolve_getnameinfo( mh.msg_iovlen = 2; if (sendmsg(resolve->fds[REQUEST_SEND_FD], &mh, MSG_NOSIGNAL) < 0) { - sd_resolve_cancel(q); + sd_resolve_query_unref(q); return -errno; } @@ -1052,47 +1149,16 @@ _public_ int sd_resolve_getnameinfo( return 0; } -_public_ int sd_resolve_getnameinfo_done(sd_resolve_query* q, char **ret_host, char **ret_serv) { - int ret; - - if (!q) { - errno = EINVAL; - return EAI_SYSTEM; - } +static int getnameinfo_done(sd_resolve_query *q) { - if (q->type != REQUEST_NAMEINFO) { - errno = ENOTTY; - return EAI_SYSTEM; - } - - if (resolve_pid_changed(q->resolve)) { - errno = ECHILD; - return EAI_SYSTEM; - } - - if (!q->done) - return EAI_AGAIN; - - if (ret_host) { - *ret_host = q->host; - q->host = NULL; - } - - if (ret_serv) { - *ret_serv = q->serv; - q->serv = NULL; - } - - ret = q->ret; - - if (ret != 0) { - errno = q->_errno; - h_errno = q->_h_errno; - } + assert(q); + assert(q->done); + assert(q->getnameinfo_handler); - sd_resolve_cancel(q); + errno = q->_errno; + h_errno= q->_h_errno; - return ret; + return q->getnameinfo_handler(q, q->ret, q->host, q->serv, q->userdata); } static int resolve_res( @@ -1100,7 +1166,8 @@ static int resolve_res( sd_resolve_query **_q, QueryType qtype, const char *dname, - int class, int type) { + int class, int type, + sd_resolve_res_handler_t callback, void *userdata) { struct msghdr mh = {}; struct iovec iov[2]; @@ -1109,20 +1176,25 @@ static int resolve_res( int r; assert_return(resolve, -EINVAL); - assert_return(dname, -EINVAL); assert_return(_q, -EINVAL); + assert_return(dname, -EINVAL); + assert_return(callback, -EINVAL); assert_return(!resolve_pid_changed(resolve), -ECHILD); r = alloc_query(resolve, &q); if (r < 0) return r; + q->type = qtype; + q->res_handler = callback; + q->userdata = userdata; + req.dname_len = strlen(dname) + 1; req.class = class; req.type = type; req.header.id = q->id; - req.header.type = q->type = qtype; + req.header.type = qtype; req.header.length = sizeof(ResRequest) + req.dname_len; iov[0] = (struct iovec) { .iov_base = &req, .iov_len = sizeof(ResRequest) }; @@ -1132,7 +1204,7 @@ static int resolve_res( mh.msg_iovlen = 2; if (sendmsg(resolve->fds[REQUEST_SEND_FD], &mh, MSG_NOSIGNAL) < 0) { - sd_resolve_cancel(q); + sd_resolve_query_unref(q); return -errno; } @@ -1140,70 +1212,54 @@ static int resolve_res( return 0; } -_public_ int sd_resolve_res_query(sd_resolve *resolve, sd_resolve_query** q, const char *dname, int class, int type) { - return resolve_res(resolve, q, REQUEST_RES_QUERY, dname, class, type); +_public_ int sd_resolve_res_query(sd_resolve *resolve, sd_resolve_query** q, const char *dname, int class, int type, sd_resolve_res_handler_t callback, void *userdata) { + return resolve_res(resolve, q, REQUEST_RES_QUERY, dname, class, type, callback, userdata); } -_public_ int sd_resolve_res_search(sd_resolve *resolve, sd_resolve_query** q, const char *dname, int class, int type) { - return resolve_res(resolve, q, REQUEST_RES_SEARCH, dname, class, type); +_public_ int sd_resolve_res_search(sd_resolve *resolve, sd_resolve_query** q, const char *dname, int class, int type, sd_resolve_res_handler_t callback, void *userdata) { + return resolve_res(resolve, q, REQUEST_RES_SEARCH, dname, class, type, callback, userdata); } -_public_ int sd_resolve_res_done(sd_resolve_query* q, unsigned char **answer) { - int ret; - - assert_return(q, -EINVAL); - assert_return(answer, -EINVAL); - assert_return(q->type == REQUEST_RES_QUERY || q->type == REQUEST_RES_SEARCH, -ENOTTY); - assert_return(!resolve_pid_changed(q->resolve), -ECHILD); - - if (!q->done) - return -EAGAIN; - - *answer = (unsigned char *) q->serv; - q->serv = NULL; - - ret = q->ret; - - if (ret != 0) { - errno = q->_errno; - h_errno = q->_h_errno; - } +static int res_query_done(sd_resolve_query* q) { + assert(q); + assert(q->done); + assert(q->res_handler); - sd_resolve_cancel(q); + errno = q->_errno; + h_errno = q->_h_errno; - return ret < 0 ? -errno : ret; + return q->res_handler(q, q->ret, q->answer, q->userdata); } -_public_ int sd_resolve_get_next(sd_resolve *resolve, sd_resolve_query **q) { - assert_return(resolve, -EINVAL); - assert_return(q, -EINVAL); - assert_return(!resolve_pid_changed(resolve), -ECHILD); - - *q = resolve->done; - return !!resolve->done; -} +_public_ sd_resolve_query* sd_resolve_query_ref(sd_resolve_query *q) { + assert_return(q, NULL); -_public_ int sd_resolve_get_n_queries(sd_resolve *resolve) { - assert_return(resolve, -EINVAL); - assert_return(!resolve_pid_changed(resolve), -ECHILD); + assert(q->n_ref >= 1); + q->n_ref++; - return resolve->n_queries; + return q; } -_public_ int sd_resolve_cancel(sd_resolve_query* q) { - PROTECT_ERRNO; - int i; +static void resolve_freeaddrinfo(struct addrinfo *ai) { + while (ai) { + struct addrinfo *next = ai->ai_next; - if (!q) - return 0; + free(ai->ai_addr); + free(ai->ai_canonname); + free(ai); + ai = next; + } +} - assert_return(!resolve_pid_changed(q->resolve), -ECHILD); +static void resolve_query_free(sd_resolve_query *q) { + unsigned i; + assert(q); assert(q->resolve); assert(q->resolve->n_queries > 0); if (q->done) { - LIST_REMOVE(done, q->resolve->done, q); + assert(q->resolve->n_done > 0); q->resolve->n_done--; } @@ -1211,36 +1267,36 @@ _public_ int sd_resolve_cancel(sd_resolve_query* q) { assert(q->resolve->queries[i] == q); q->resolve->queries[i] = NULL; q->resolve->n_queries--; + sd_resolve_unref(q->resolve); - sd_resolve_freeaddrinfo(q->addrinfo); + resolve_freeaddrinfo(q->addrinfo); free(q->host); free(q->serv); + free(q->answer); free(q); - - return 0; } -_public_ void sd_resolve_freeaddrinfo(struct addrinfo *ai) { +_public_ sd_resolve_query* sd_resolve_query_unref(sd_resolve_query* q) { + if (!q) + return NULL; - while (ai) { - struct addrinfo *next = ai->ai_next; + assert(q->n_ref >= 1); + q->n_ref--; - free(ai->ai_addr); - free(ai->ai_canonname); - free(ai); + if (q->n_ref <= 0) + resolve_query_free(q); - ai = next; - } + return NULL; } -_public_ int sd_resolve_is_done(sd_resolve_query *q) { +_public_ int sd_resolve_query_is_done(sd_resolve_query *q) { assert_return(q, -EINVAL); assert_return(!resolve_pid_changed(q->resolve), -ECHILD); return q->done; } -_public_ void* sd_resolve_set_userdata(sd_resolve_query *q, void *userdata) { +_public_ void* sd_resolve_query_set_userdata(sd_resolve_query *q, void *userdata) { void *ret; assert_return(q, NULL); @@ -1252,9 +1308,81 @@ _public_ void* sd_resolve_set_userdata(sd_resolve_query *q, void *userdata) { return ret; } -_public_ void* sd_resolve_get_userdata(sd_resolve_query *q) { +_public_ void* sd_resolve_query_get_userdata(sd_resolve_query *q) { assert_return(q, NULL); assert_return(!resolve_pid_changed(q->resolve), NULL); return q->userdata; } + +_public_ sd_resolve *sd_resolve_query_get_resolve(sd_resolve_query *q) { + assert_return(q, NULL); + assert_return(!resolve_pid_changed(q->resolve), NULL); + + return q->resolve; +} + +static int io_callback(sd_event_source *s, int fd, uint32_t revents, void *userdata) { + sd_resolve *resolve = userdata; + int r; + + assert(resolve); + + r = sd_resolve_process(resolve); + if (r < 0) + return r; + + return 1; +} + +_public_ int sd_resolve_attach_event(sd_resolve *resolve, sd_event *event, int priority) { + int r; + + assert_return(resolve, -EINVAL); + assert_return(!resolve->event, -EBUSY); + + assert(!resolve->event_source); + + if (event) + resolve->event = sd_event_ref(event); + else { + r = sd_event_default(&resolve->event); + if (r < 0) + return r; + } + + r = sd_event_add_io(resolve->event, &resolve->event_source, resolve->fds[RESPONSE_RECV_FD], POLLIN, io_callback, resolve); + if (r < 0) + goto fail; + + r = sd_event_source_set_priority(resolve->event_source, priority); + if (r < 0) + goto fail; + + return 0; + +fail: + sd_resolve_detach_event(resolve); + return r; +} + +_public_ int sd_resolve_detach_event(sd_resolve *resolve) { + assert_return(resolve, -EINVAL); + + if (!resolve->event) + return 0; + + if (resolve->event_source) { + sd_event_source_set_enabled(resolve->event_source, SD_EVENT_OFF); + resolve->event_source = sd_event_source_unref(resolve->event_source); + } + + resolve->event = sd_event_unref(resolve->event); + return 1; +} + +_public_ sd_event *sd_resolve_get_event(sd_resolve *resolve) { + assert_return(resolve, NULL); + + return resolve->event; +} diff --git a/src/libsystemd/sd-resolve/test-resolve.c b/src/libsystemd/sd-resolve/test-resolve.c index 6334dad98..3717286c4 100644 --- a/src/libsystemd/sd-resolve/test-resolve.c +++ b/src/libsystemd/sd-resolve/test-resolve.c @@ -37,13 +37,95 @@ #include "resolve-util.h" #include "macro.h" +static int getaddrinfo_handler(sd_resolve_query *q, int ret, const struct addrinfo *ai, void *userdata) { + const struct addrinfo *i; + + assert(q); + + if (ret != 0) { + log_error("getaddrinfo error: %s %i\n", gai_strerror(ret), ret); + return 0; + } + + for (i = ai; i; i = i->ai_next) { + _cleanup_free_ char *addr = NULL; + + assert_se(sockaddr_pretty(i->ai_addr, i->ai_addrlen, false, &addr) == 0); + puts(addr); + } + + printf("canonical name: %s\n", strna(ai->ai_canonname)); + + return 0; +} + +static int getnameinfo_handler(sd_resolve_query *q, int ret, const char *host, const char *serv, void *userdata) { + assert(q); + + if (ret != 0) { + log_error("getnameinfo error: %s %i\n", gai_strerror(ret), ret); + return 0; + } + + printf("Host: %s -- Serv: %s\n", strna(host), strna(serv)); + return 0; +} + +static int res_handler(sd_resolve_query *q, int ret, unsigned char *answer, void *userdata) { + int qdcount, ancount, len; + const unsigned char *pos = answer + sizeof(HEADER); + unsigned char *end = answer + ret; + HEADER *head = (HEADER *) answer; + char name[256]; + assert(q); + + if (ret < 0) { + log_error("res_query() error: %s %i\n", strerror(errno), errno); + return 0; + } + + if (ret == 0) { + log_error("No reply for SRV lookup\n"); + return 0; + } + + 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(answer, end, pos, name, 255)) >= 0) { + assert(len >= 0); + pos += len + QFIXEDSZ; + } + + /* Parse the answers */ + while (ancount-- > 0 && (len = dn_expand(answer, 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(answer, end, pos, name, 255); + printf("\tpreference: %2d weight: %2d port: %d host: %s\n", + pref, weight, port, name); + + pos += len; + } + + return 0; +} + int main(int argc, char *argv[]) { - int r = 0; + _cleanup_resolve_query_unref_ sd_resolve_query *q1 = NULL, *q2 = NULL, *q3 = NULL; _cleanup_resolve_unref_ sd_resolve *resolve = NULL; - _cleanup_resolve_addrinfo_free_ struct addrinfo *ai = NULL; - _cleanup_free_ unsigned char *srv = NULL; - _cleanup_free_ char *host = NULL, *serv = NULL; - sd_resolve_query *q1 = NULL, *q2 = NULL, *q3 = NULL; + int r = 0; struct addrinfo hints = { .ai_family = PF_UNSPEC, @@ -56,28 +138,28 @@ int main(int argc, char *argv[]) { .sin_port = htons(80) }; - assert_se(sd_resolve_new(&resolve) >= 0); + assert_se(sd_resolve_default(&resolve) >= 0); /* Make a name -> address query */ - r = sd_resolve_getaddrinfo(resolve, &q1, argc >= 2 ? argv[1] : "www.heise.de", NULL, &hints); + r = sd_resolve_getaddrinfo(resolve, &q1, argc >= 2 ? argv[1] : "www.heise.de", NULL, &hints, getaddrinfo_handler, NULL); if (r < 0) log_error("sd_resolve_getaddrinfo(): %s\n", strerror(-r)); /* Make an address -> name query */ - sa.sin_addr.s_addr = inet_addr(argc >= 3 ? argv[2] : "193.99.144.71"), - r = sd_resolve_getnameinfo(resolve, &q2, (struct sockaddr*) &sa, sizeof(sa), 0, true, true); + sa.sin_addr.s_addr = inet_addr(argc >= 3 ? argv[2] : "193.99.144.71"); + r = sd_resolve_getnameinfo(resolve, &q2, (struct sockaddr*) &sa, sizeof(sa), 0, SD_RESOLVE_GET_BOTH, getnameinfo_handler, NULL); if (r < 0) log_error("sd_resolve_getnameinfo(): %s\n", strerror(-r)); /* Make a res_query() call */ - r = sd_resolve_res_query(resolve, &q3, "_xmpp-client._tcp.gmail.com", C_IN, T_SRV); + r = sd_resolve_res_query(resolve, &q3, "_xmpp-client._tcp.gmail.com", C_IN, T_SRV, res_handler, NULL); if (r < 0) log_error("sd_resolve_res_query(): %s\n", strerror(-r)); /* Wait until the three queries are completed */ - while (sd_resolve_is_done(q1) == 0 || - sd_resolve_is_done(q2) == 0 || - sd_resolve_is_done(q3) == 0) { + while (sd_resolve_query_is_done(q1) == 0 || + sd_resolve_query_is_done(q2) == 0 || + sd_resolve_query_is_done(q3) == 0) { r = sd_resolve_wait(resolve, (uint64_t) -1); if (r < 0) { @@ -86,74 +168,5 @@ int main(int argc, char *argv[]) { } } - /* Interpret the result of the name -> addr query */ - r = sd_resolve_getaddrinfo_done(q1, &ai); - if (r != 0) - log_error("error: %s %i\n", gai_strerror(r), r); - else { - struct addrinfo *i; - - for (i = ai; i; i = i->ai_next) { - _cleanup_free_ char *addr = NULL; - - assert_se(sockaddr_pretty(i->ai_addr, i->ai_addrlen, false, &addr) == 0); - - puts(addr); - } - - printf("canonical name: %s\n", strna(ai->ai_canonname)); - } - - /* Interpret the result of the addr -> name query */ - r = sd_resolve_getnameinfo_done(q2, &host, &serv); - if (r) - log_error("error: %s %i\n", gai_strerror(r), r); - else - printf("Host: %s -- Serv: %s\n", host, serv); - - /* Interpret the result of the SRV lookup */ - r = sd_resolve_res_done(q3, &srv); - if (r < 0) - log_error("error: %s %i\n", strerror(-r), r); - else if (r == 0) - log_error("No reply for SRV lookup\n"); - else { - int qdcount, ancount, len; - const unsigned char *pos = srv + sizeof(HEADER); - unsigned char *end = srv + r; - 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; - } - } - return 0; } diff --git a/src/systemd/sd-resolve.h b/src/systemd/sd-resolve.h index 132e5d2e0..36cedcd6b 100644 --- a/src/systemd/sd-resolve.h +++ b/src/systemd/sd-resolve.h @@ -27,121 +27,100 @@ #include #include "_sd-common.h" +#include "sd-event.h" _SD_BEGIN_DECLARATIONS; -/** An opaque sd-resolve session structure */ +/* An opaque sd-resolve session structure */ typedef struct sd_resolve sd_resolve; -/** An opaque sd-resolve query structure */ +/* An opaque sd-resolve query structure */ typedef struct sd_resolve_query sd_resolve_query; -/** Allocate a new sd-resolve session. */ +/* A callback on completion */ +typedef int (*sd_resolve_getaddrinfo_handler_t)(sd_resolve_query *q, int ret, const struct addrinfo *ai, void *userdata); +typedef int (*sd_resolve_getnameinfo_handler_t)(sd_resolve_query *q, int ret, const char *host, const char *serv, void *userdata); +typedef int (*sd_resolve_res_handler_t)(sd_resolve_query* q, int ret, unsigned char *answer, void *userdata); + +enum { + SD_RESOLVE_GET_HOST = 1ULL, + SD_RESOLVE_GET_SERVICE = 2ULL, + SD_RESOLVE_GET_BOTH = 3ULL +}; + +int sd_resolve_default(sd_resolve **ret); + +/* Allocate a new sd-resolve session. */ int sd_resolve_new(sd_resolve **ret); -/** Free a sd-resolve session. This destroys all attached +/* Free a sd-resolve session. This destroys all attached * sd_resolve_query objects automatically. */ sd_resolve* sd_resolve_unref(sd_resolve *resolve); +sd_resolve* sd_resolve_ref(sd_resolve *resolve); -/** Return the UNIX file descriptor to poll() for events on. Use this +/* Return the UNIX file descriptor to poll() for events on. Use this * function to integrate sd-resolve with your custom main loop. */ int sd_resolve_get_fd(sd_resolve *resolve); -/** Return the poll() events (a combination of flags like POLLIN, +/* Return the poll() events (a combination of flags like POLLIN, * POLLOUT, ...) to check for. */ int sd_resolve_get_events(sd_resolve *resolve); -/** Return the poll() timeout to pass. Returns (uint64_t) -1 as +/* Return the poll() timeout to pass. Returns (uint64_t) -1 as * timeout if no timeout is needed. */ int sd_resolve_get_timeout(sd_resolve *resolve, uint64_t *timeout_usec); -/** Process pending responses. After this function is called, you can +/* Process pending responses. After this function is called, you can * get the next completed query object(s) using * sd_resolve_get_next(). */ int sd_resolve_process(sd_resolve *resolve); -/** Wait for a resolve event to complete. */ +/* Wait for a resolve event to complete. */ int sd_resolve_wait(sd_resolve *resolve, uint64_t timeout_usec); -/** Issue a name-to-address query on the specified session. The +int sd_resolve_get_tid(sd_resolve *resolve, pid_t *tid); + +int sd_resolve_attach_event(sd_resolve *resolve, sd_event *e, int priority); +int sd_resolve_detach_event(sd_resolve *resolve); +sd_event *sd_resolve_get_event(sd_resolve *resolve); + +/* Issue a name-to-address query on the specified session. The * arguments are compatible with those of libc's * getaddrinfo(3). The function returns a new query object. When the * query is completed, you may retrieve the results using * sd_resolve_getaddrinfo_done(). */ -int sd_resolve_getaddrinfo(sd_resolve *resolve, sd_resolve_query **q, const char *node, const char *service, const struct addrinfo *hints); - -/** Retrieve the results of a preceding sd_resolve_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 sd_resolve_freeaddrinfo() and not - * libc's freeaddrinfo(3)! If the query is not completed yet, EAI_AGAIN - * is returned. */ -int sd_resolve_getaddrinfo_done(sd_resolve_query* q, struct addrinfo **ret_ai); - -/** Free the addrinfo structure as returned by - * sd_resolve_getaddrinfo_done(). Make sure to use this function instead - * of libc's freeaddrinfo()! */ -void sd_resolve_freeaddrinfo(struct addrinfo *ai); - -/** Issue an address-to-name query on the specified session. The +int sd_resolve_getaddrinfo(sd_resolve *resolve, sd_resolve_query **q, const char *node, const char *service, const struct addrinfo *hints, sd_resolve_getaddrinfo_handler_t callback, void *userdata); + +/* Issue an address-to-name query on the specified session. The * arguments are compatible with those of libc's * getnameinfo(3). The function returns a new query object. When the * query is completed, you may retrieve the results using * sd_resolve_getnameinfo_done(). Set gethost (resp. getserv) to non-zero * if you want to query the hostname (resp. the service name). */ -int sd_resolve_getnameinfo(sd_resolve *resolve, sd_resolve_query **q, const struct sockaddr *sa, socklen_t salen, int flags, int gethost, int getserv); +int sd_resolve_getnameinfo(sd_resolve *resolve, sd_resolve_query **q, const struct sockaddr *sa, socklen_t salen, int flags, uint64_t get, sd_resolve_getnameinfo_handler_t callback, void *userdata); -/** Retrieve the results of a preceding sd_resolve_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 sd_resolve_getnameinfo_done(sd_resolve_query* q, char **ret_host, char **ret_serv); - -/** Issue a resolver query on the specified session. The arguments are +/* Issue a resolver query on the specified session. The arguments are * compatible with those of libc's res_query(3). The function returns a new * query object. When the query is completed, you may retrieve the results using * sd_resolve_res_done(). */ -int sd_resolve_res_query(sd_resolve *resolve, sd_resolve_query **q, const char *dname, int clazz, int type); +int sd_resolve_res_query(sd_resolve *resolve, sd_resolve_query **q, const char *dname, int clazz, int type, sd_resolve_res_handler_t callback, void *userdata); -/** Issue a resolver query on the specified session. The arguments are +/* Issue a resolver query on the specified session. The arguments are * compatible with those of libc's res_search(3). The function returns a new * query object. When the query is completed, you may retrieve the results using * sd_resolve_res_done(). */ -int sd_resolve_res_search(sd_resolve *resolve, sd_resolve_query **q, const char *dname, int clazz, int type); - -/** Retrieve the results of a preceding sd_resolve_res_query() or - * resolve_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. */ -int sd_resolve_res_done(sd_resolve_query* 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 - * sd_resolve_wait() before this function will return sensible data. */ -int sd_resolve_get_next(sd_resolve *resolve, sd_resolve_query **q); - -/** Return the number of query objects (completed or not) attached to - * this session. */ -int sd_resolve_get_n_queries(sd_resolve *resolve); - -/** Cancel a currently running query. q is destroyed by this call - * and may not be used any further. */ -int sd_resolve_cancel(sd_resolve_query* q); - -/** Returns non-zero when the query operation specified by q has been completed. */ -int sd_resolve_is_done(sd_resolve_query*q); - -/** Assign some opaque userdata with a query object. */ -void* sd_resolve_set_userdata(sd_resolve_query *q, void *userdata); - -/** Return userdata assigned to a query object. Use - * sd_resolve_setuserdata() to set this data. If no data has been set - * prior to this call, it returns NULL. */ -void* sd_resolve_get_userdata(sd_resolve_query *q); +int sd_resolve_res_search(sd_resolve *resolve, sd_resolve_query **q, const char *dname, int clazz, int type, sd_resolve_res_handler_t callback, void *userdata); + +sd_resolve_query *sd_resolve_query_ref(sd_resolve_query* q); +sd_resolve_query *sd_resolve_query_unref(sd_resolve_query* q); + +/* Returns non-zero when the query operation specified by q has been completed. */ +int sd_resolve_query_is_done(sd_resolve_query*q); + +void *sd_resolve_query_get_userdata(sd_resolve_query *q); +void *sd_resolve_query_set_userdata(sd_resolve_query *q, void *userdata); + +sd_resolve *sd_resolve_query_get_resolve(sd_resolve_query *q); _SD_END_DECLARATIONS;