diff options
Diffstat (limited to 'src/libsystemd/sd-resolve/sd-resolve.c')
| -rw-r--r-- | src/libsystemd/sd-resolve/sd-resolve.c | 1296 |
1 files changed, 1296 insertions, 0 deletions
diff --git a/src/libsystemd/sd-resolve/sd-resolve.c b/src/libsystemd/sd-resolve/sd-resolve.c new file mode 100644 index 0000000..ba88168 --- /dev/null +++ b/src/libsystemd/sd-resolve/sd-resolve.c @@ -0,0 +1,1296 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <errno.h> +#include <poll.h> +#include <pthread.h> +#include <resolv.h> +#include <signal.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/prctl.h> +#include <unistd.h> + +#include "sd-resolve.h" + +#include "alloc-util.h" +#include "dns-def.h" +#include "errno-util.h" +#include "fd-util.h" +#include "io-util.h" +#include "list.h" +#include "memory-util.h" +#include "missing_syscall.h" +#include "missing_threads.h" +#include "process-util.h" +#include "resolve-private.h" +#include "socket-util.h" + +#define WORKERS_MIN 1U +#define WORKERS_MAX 16U +#define QUERIES_MAX 256U +#define BUFSIZE 10240U + +typedef enum { + REQUEST_ADDRINFO, + RESPONSE_ADDRINFO, + REQUEST_NAMEINFO, + RESPONSE_NAMEINFO, + REQUEST_TERMINATE, + RESPONSE_DIED +} QueryType; + +enum { + REQUEST_RECV_FD, + REQUEST_SEND_FD, + RESPONSE_RECV_FD, + RESPONSE_SEND_FD, + _FD_MAX +}; + +struct sd_resolve { + unsigned n_ref; + + bool dead:1; + pid_t original_pid; + + int fds[_FD_MAX]; + + pthread_t workers[WORKERS_MAX]; + unsigned n_valid_workers; + + unsigned current_id; + sd_resolve_query* query_array[QUERIES_MAX]; + unsigned n_queries, n_done, n_outstanding; + + sd_event_source *event_source; + sd_event *event; + + sd_resolve_query *current; + + sd_resolve **default_resolve_ptr; + pid_t tid; + + LIST_HEAD(sd_resolve_query, queries); +}; + +struct sd_resolve_query { + unsigned n_ref; + + sd_resolve *resolve; + + QueryType type:4; + bool done:1; + bool floating:1; + unsigned id; + + int ret; + int _errno; + int _h_errno; + struct addrinfo *addrinfo; + char *serv, *host; + + union { + sd_resolve_getaddrinfo_handler_t getaddrinfo_handler; + sd_resolve_getnameinfo_handler_t getnameinfo_handler; + }; + + void *userdata; + sd_resolve_destroy_t destroy_callback; + + LIST_FIELDS(sd_resolve_query, queries); +}; + +typedef struct RHeader { + QueryType type; + unsigned id; + size_t length; +} RHeader; + +typedef struct AddrInfoRequest { + struct RHeader header; + bool hints_valid; + int ai_flags; + int ai_family; + int ai_socktype; + int ai_protocol; + size_t node_len, service_len; +} AddrInfoRequest; + +typedef struct AddrInfoResponse { + struct RHeader header; + int ret; + int _errno; + int _h_errno; + /* followed by addrinfo_serialization[] */ +} AddrInfoResponse; + +typedef struct AddrInfoSerialization { + 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 */ +} AddrInfoSerialization; + +typedef struct NameInfoRequest { + struct RHeader header; + int flags; + socklen_t sockaddr_len; + bool gethost:1, getserv:1; +} NameInfoRequest; + +typedef struct NameInfoResponse { + struct RHeader header; + size_t hostlen, servlen; + int ret; + int _errno; + int _h_errno; +} NameInfoResponse; + +typedef union Packet { + RHeader rheader; + AddrInfoRequest addrinfo_request; + AddrInfoResponse addrinfo_response; + NameInfoRequest nameinfo_request; + NameInfoResponse nameinfo_response; +} Packet; + +static int getaddrinfo_done(sd_resolve_query* q); +static int getnameinfo_done(sd_resolve_query *q); + +static void resolve_query_disconnect(sd_resolve_query *q); + +#define RESOLVE_DONT_DESTROY(resolve) \ + _cleanup_(sd_resolve_unrefp) _unused_ sd_resolve *_dont_destroy_##resolve = sd_resolve_ref(resolve) + +static void query_assign_errno(sd_resolve_query *q, int ret, int error, int h_error) { + assert(q); + + q->ret = ret; + q->_errno = abs(error); + q->_h_errno = h_error; +} + +static int send_died(int out_fd) { + RHeader rh = { + .type = RESPONSE_DIED, + .length = sizeof(RHeader), + }; + + assert(out_fd >= 0); + + if (send(out_fd, &rh, rh.length, MSG_NOSIGNAL) < 0) + return -errno; + + return 0; +} + +static void *serialize_addrinfo(void *p, const struct addrinfo *ai, size_t *length, size_t maxlength) { + AddrInfoSerialization 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(AddrInfoSerialization) + ai->ai_addrlen + cnl; + + if (*length + l > maxlength) + return NULL; + + s = (AddrInfoSerialization) { + .ai_flags = ai->ai_flags, + .ai_family = ai->ai_family, + .ai_socktype = ai->ai_socktype, + .ai_protocol = ai->ai_protocol, + .ai_addrlen = ai->ai_addrlen, + .canonname_len = cnl, + }; + + memcpy((uint8_t*) p, &s, sizeof(AddrInfoSerialization)); + memcpy((uint8_t*) p + sizeof(AddrInfoSerialization), ai->ai_addr, ai->ai_addrlen); + memcpy_safe((char*) p + sizeof(AddrInfoSerialization) + ai->ai_addrlen, + ai->ai_canonname, cnl); + + *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) { + + AddrInfoResponse resp = {}; + union { + AddrInfoSerialization ais; + uint8_t space[BUFSIZE]; + } buffer; + struct iovec iov[2]; + struct msghdr mh; + + assert(out_fd >= 0); + + resp = (AddrInfoResponse) { + .header.type = RESPONSE_ADDRINFO, + .header.id = id, + .header.length = sizeof(AddrInfoResponse), + .ret = ret, + ._errno = _errno, + ._h_errno = _h_errno, + }; + + msan_unpoison(&resp, sizeof(resp)); + + if (ret == 0 && ai) { + void *p = &buffer; + struct addrinfo *k; + + for (k = ai; k; k = k->ai_next) { + p = serialize_addrinfo(p, k, &resp.header.length, (uint8_t*) &buffer + BUFSIZE - (uint8_t*) p); + if (!p) { + freeaddrinfo(ai); + return -ENOBUFS; + } + } + } + + if (ai) + freeaddrinfo(ai); + + iov[0] = IOVEC_MAKE(&resp, sizeof(AddrInfoResponse)); + iov[1] = IOVEC_MAKE(&buffer, resp.header.length - sizeof(AddrInfoResponse)); + + mh = (struct msghdr) { + .msg_iov = iov, + .msg_iovlen = ELEMENTSOF(iov) + }; + + if (sendmsg(out_fd, &mh, MSG_NOSIGNAL) < 0) + return -errno; + + return 0; +} + +static int send_nameinfo_reply( + int out_fd, + unsigned id, + int ret, + const char *host, + const char *serv, + int _errno, + int _h_errno) { + + NameInfoResponse resp = {}; + struct iovec iov[3]; + struct msghdr mh; + size_t hl, sl; + + assert(out_fd >= 0); + + sl = serv ? strlen(serv)+1 : 0; + hl = host ? strlen(host)+1 : 0; + + resp = (NameInfoResponse) { + .header.type = RESPONSE_NAMEINFO, + .header.id = id, + .header.length = sizeof(NameInfoResponse) + hl + sl, + .hostlen = hl, + .servlen = sl, + .ret = ret, + ._errno = _errno, + ._h_errno = _h_errno, + }; + + msan_unpoison(&resp, sizeof(resp)); + + iov[0] = IOVEC_MAKE(&resp, sizeof(NameInfoResponse)); + iov[1] = IOVEC_MAKE((void*) host, hl); + iov[2] = IOVEC_MAKE((void*) serv, sl); + + mh = (struct msghdr) { + .msg_iov = iov, + .msg_iovlen = ELEMENTSOF(iov) + }; + + if (sendmsg(out_fd, &mh, MSG_NOSIGNAL) < 0) + return -errno; + + return 0; +} + +static int handle_request(int out_fd, const Packet *packet, size_t length) { + const RHeader *req; + + assert(out_fd >= 0); + assert(packet); + + req = &packet->rheader; + + assert_return(length >= sizeof(RHeader), -EIO); + assert_return(length == req->length, -EIO); + + switch (req->type) { + + case REQUEST_ADDRINFO: { + const AddrInfoRequest *ai_req = &packet->addrinfo_request; + struct addrinfo hints, *result = NULL; + const char *node, *service; + int ret; + + assert_return(length >= sizeof(AddrInfoRequest), -EBADMSG); + assert_return(length == sizeof(AddrInfoRequest) + ai_req->node_len + ai_req->service_len, -EBADMSG); + + hints = (struct addrinfo) { + .ai_flags = ai_req->ai_flags, + .ai_family = ai_req->ai_family, + .ai_socktype = ai_req->ai_socktype, + .ai_protocol = ai_req->ai_protocol, + }; + + msan_unpoison(&hints, sizeof(hints)); + + node = ai_req->node_len ? (const char*) ai_req + sizeof(AddrInfoRequest) : NULL; + service = ai_req->service_len ? (const char*) ai_req + sizeof(AddrInfoRequest) + ai_req->node_len : NULL; + + ret = getaddrinfo(node, service, + ai_req->hints_valid ? &hints : NULL, + &result); + + /* send_addrinfo_reply() frees result */ + return send_addrinfo_reply(out_fd, req->id, ret, result, errno, h_errno); + } + + case REQUEST_NAMEINFO: { + const NameInfoRequest *ni_req = &packet->nameinfo_request; + char hostbuf[NI_MAXHOST], servbuf[NI_MAXSERV]; + union sockaddr_union sa; + int ret; + + assert_return(length >= sizeof(NameInfoRequest), -EBADMSG); + assert_return(length == sizeof(NameInfoRequest) + ni_req->sockaddr_len, -EBADMSG); + assert_return(ni_req->sockaddr_len <= sizeof(sa), -EBADMSG); + + memcpy(&sa, (const uint8_t *) ni_req + sizeof(NameInfoRequest), ni_req->sockaddr_len); + + ret = getnameinfo(&sa.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_TERMINATE: + /* Quit */ + return -ECONNRESET; + + default: + assert_not_reached(); + } + + return 0; +} + +static void* thread_worker(void *p) { + sd_resolve *resolve = p; + + /* Assign a pretty name to this thread */ + (void) pthread_setname_np(pthread_self(), "sd-resolve"); + + while (!resolve->dead) { + union { + Packet packet; + uint8_t space[BUFSIZE]; + } buf; + ssize_t length; + + length = recv(resolve->fds[REQUEST_RECV_FD], &buf, sizeof buf, 0); + if (length < 0) { + if (ERRNO_IS_TRANSIENT(errno)) + continue; + + break; + } + if (length == 0) + break; + + if (handle_request(resolve->fds[RESPONSE_SEND_FD], &buf.packet, (size_t) length) < 0) + break; + } + + send_died(resolve->fds[RESPONSE_SEND_FD]); + + return NULL; +} + +static int start_threads(sd_resolve *resolve, unsigned extra) { + sigset_t ss, saved_ss; + unsigned n; + int r, k; + + assert_se(sigfillset(&ss) >= 0); + + /* No signals in forked off threads please. We set the mask before forking, so that the threads never exist + * with a different mask than a fully blocked one */ + r = pthread_sigmask(SIG_BLOCK, &ss, &saved_ss); + if (r > 0) + return -r; + + n = resolve->n_outstanding + extra; + n = CLAMP(n, WORKERS_MIN, WORKERS_MAX); + + while (resolve->n_valid_workers < n) { + r = pthread_create(&resolve->workers[resolve->n_valid_workers], NULL, thread_worker, resolve); + if (r > 0) { + r = -r; + goto finish; + } + + resolve->n_valid_workers++; + } + + r = 0; + +finish: + k = pthread_sigmask(SIG_SETMASK, &saved_ss, NULL); + if (k > 0 && r >= 0) + r = -k; + + return r; +} + +static bool resolve_pid_changed(sd_resolve *r) { + assert(r); + + /* We don't support people creating a resolver and keeping it + * around after fork(). Let's complain. */ + + return r->original_pid != getpid_cached(); +} + +_public_ int sd_resolve_new(sd_resolve **ret) { + _cleanup_(sd_resolve_unrefp) sd_resolve *resolve = NULL; + int i; + + assert_return(ret, -EINVAL); + + resolve = new0(sd_resolve, 1); + if (!resolve) + return -ENOMEM; + + resolve->n_ref = 1; + resolve->original_pid = getpid_cached(); + + for (i = 0; i < _FD_MAX; i++) + resolve->fds[i] = -1; + + if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, resolve->fds + REQUEST_RECV_FD) < 0) + return -errno; + + if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, resolve->fds + RESPONSE_RECV_FD) < 0) + return -errno; + + for (i = 0; i < _FD_MAX; i++) + resolve->fds[i] = fd_move_above_stdio(resolve->fds[i]); + + (void) fd_inc_sndbuf(resolve->fds[REQUEST_SEND_FD], QUERIES_MAX * BUFSIZE); + (void) fd_increase_rxbuf(resolve->fds[REQUEST_RECV_FD], QUERIES_MAX * BUFSIZE); + (void) fd_inc_sndbuf(resolve->fds[RESPONSE_SEND_FD], QUERIES_MAX * BUFSIZE); + (void) fd_increase_rxbuf(resolve->fds[RESPONSE_RECV_FD], QUERIES_MAX * BUFSIZE); + + (void) fd_nonblock(resolve->fds[RESPONSE_RECV_FD], true); + + *ret = TAKE_PTR(resolve); + return 0; +} + +_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 sd_resolve *resolve_free(sd_resolve *resolve) { + PROTECT_ERRNO; + sd_resolve_query *q; + unsigned i; + + assert(resolve); + + while ((q = resolve->queries)) { + assert(q->floating); + resolve_query_disconnect(q); + sd_resolve_query_unref(q); + } + + 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 = { + .type = REQUEST_TERMINATE, + .length = sizeof req, + }; + + /* Send one termination packet for each worker */ + for (i = 0; i < resolve->n_valid_workers; i++) + (void) send(resolve->fds[REQUEST_SEND_FD], &req, req.length, MSG_NOSIGNAL); + } + + /* Now terminate them and wait until they are gone. + If we get an error than most likely the thread already exited. */ + for (i = 0; i < resolve->n_valid_workers; i++) + (void) pthread_join(resolve->workers[i], NULL); + + /* Close all communication channels */ + close_many(resolve->fds, _FD_MAX); + + return mfree(resolve); +} + +DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_resolve, sd_resolve, resolve_free); + +_public_ int sd_resolve_get_fd(sd_resolve *resolve) { + assert_return(resolve, -EINVAL); + assert_return(!resolve_pid_changed(resolve), -ECHILD); + + return resolve->fds[RESPONSE_RECV_FD]; +} + +_public_ int sd_resolve_get_events(sd_resolve *resolve) { + assert_return(resolve, -EINVAL); + assert_return(!resolve_pid_changed(resolve), -ECHILD); + + return resolve->n_queries > resolve->n_done ? POLLIN : 0; +} + +_public_ int sd_resolve_get_timeout(sd_resolve *resolve, uint64_t *usec) { + assert_return(resolve, -EINVAL); + assert_return(usec, -EINVAL); + assert_return(!resolve_pid_changed(resolve), -ECHILD); + + *usec = UINT64_MAX; + return 0; +} + +static sd_resolve_query *lookup_query(sd_resolve *resolve, unsigned id) { + sd_resolve_query *q; + + assert(resolve); + + q = resolve->query_array[id % QUERIES_MAX]; + if (q) + if (q->id == id) + return q; + + return NULL; +} + +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; + resolve->n_done++; + + resolve->current = sd_resolve_query_ref(q); + + switch (q->type) { + + case REQUEST_ADDRINFO: + r = getaddrinfo_done(q); + break; + + case REQUEST_NAMEINFO: + r = getnameinfo_done(q); + break; + + default: + assert_not_reached(); + } + + resolve->current = NULL; + + if (q->floating) { + resolve_query_disconnect(q); + sd_resolve_query_unref(q); + } + + sd_resolve_query_unref(q); + + return r; +} + +static int unserialize_addrinfo(const void **p, size_t *length, struct addrinfo **ret_ai) { + AddrInfoSerialization s; + struct addrinfo *ai; + size_t l; + + assert(p); + assert(*p); + assert(ret_ai); + assert(length); + + if (*length < sizeof(AddrInfoSerialization)) + return -EBADMSG; + + memcpy(&s, *p, sizeof(s)); + + l = sizeof(AddrInfoSerialization) + s.ai_addrlen + s.canonname_len; + if (*length < l) + return -EBADMSG; + + ai = new(struct addrinfo, 1); + if (!ai) + return -ENOMEM; + + *ai = (struct addrinfo) { + .ai_flags = s.ai_flags, + .ai_family = s.ai_family, + .ai_socktype = s.ai_socktype, + .ai_protocol = s.ai_protocol, + .ai_addrlen = s.ai_addrlen, + }; + + if (s.ai_addrlen > 0) { + ai->ai_addr = memdup((const uint8_t*) *p + sizeof(AddrInfoSerialization), s.ai_addrlen); + if (!ai->ai_addr) { + free(ai); + return -ENOMEM; + } + } + + if (s.canonname_len > 0) { + ai->ai_canonname = memdup((const uint8_t*) *p + sizeof(AddrInfoSerialization) + s.ai_addrlen, s.canonname_len); + if (!ai->ai_canonname) { + free(ai->ai_addr); + free(ai); + return -ENOMEM; + } + } + + *length -= l; + *ret_ai = ai; + *p = ((const uint8_t*) *p) + l; + + return 0; +} + +static int handle_response(sd_resolve *resolve, const Packet *packet, size_t length) { + const RHeader *resp; + sd_resolve_query *q; + int r; + + assert(resolve); + assert(packet); + + resp = &packet->rheader; + assert_return(length >= sizeof(RHeader), -EIO); + assert_return(length == resp->length, -EIO); + + if (resp->type == RESPONSE_DIED) { + resolve->dead = true; + return 0; + } + + assert(resolve->n_outstanding > 0); + resolve->n_outstanding--; + + q = lookup_query(resolve, resp->id); + if (!q) + return 0; + + switch (resp->type) { + + case RESPONSE_ADDRINFO: { + const AddrInfoResponse *ai_resp = &packet->addrinfo_response; + const void *p; + size_t l; + struct addrinfo *prev = NULL; + + assert_return(length >= sizeof(AddrInfoResponse), -EBADMSG); + assert_return(q->type == REQUEST_ADDRINFO, -EBADMSG); + + query_assign_errno(q, ai_resp->ret, ai_resp->_errno, ai_resp->_h_errno); + + l = length - sizeof(AddrInfoResponse); + p = (const uint8_t*) resp + sizeof(AddrInfoResponse); + + while (l > 0 && p) { + struct addrinfo *ai = NULL; + + r = unserialize_addrinfo(&p, &l, &ai); + if (r < 0) { + query_assign_errno(q, EAI_SYSTEM, r, 0); + freeaddrinfo(q->addrinfo); + q->addrinfo = NULL; + break; + } + + if (prev) + prev->ai_next = ai; + else + q->addrinfo = ai; + + prev = ai; + } + + return complete_query(resolve, q); + } + + case RESPONSE_NAMEINFO: { + const NameInfoResponse *ni_resp = &packet->nameinfo_response; + + assert_return(length >= sizeof(NameInfoResponse), -EBADMSG); + assert_return(q->type == REQUEST_NAMEINFO, -EBADMSG); + + if (ni_resp->hostlen > DNS_HOSTNAME_MAX || + ni_resp->servlen > DNS_HOSTNAME_MAX || + sizeof(NameInfoResponse) + ni_resp->hostlen + ni_resp->servlen > length) + query_assign_errno(q, EAI_SYSTEM, EIO, 0); + else { + query_assign_errno(q, ni_resp->ret, ni_resp->_errno, ni_resp->_h_errno); + + if (ni_resp->hostlen > 0) { + q->host = strndup((const char*) ni_resp + sizeof(NameInfoResponse), + ni_resp->hostlen-1); + if (!q->host) + query_assign_errno(q, EAI_MEMORY, ENOMEM, 0); + } + + if (ni_resp->servlen > 0) { + q->serv = strndup((const char*) ni_resp + sizeof(NameInfoResponse) + ni_resp->hostlen, + ni_resp->servlen-1); + if (!q->serv) + query_assign_errno(q, EAI_MEMORY, ENOMEM, 0); + } + } + + return complete_query(resolve, q); + } + + default: + return 0; + } +} + +_public_ int sd_resolve_process(sd_resolve *resolve) { + 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); + + /* 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_IS_TRANSIENT(errno)) + return 0; + + return -errno; + } + if (l == 0) + return -ECONNREFUSED; + + r = handle_response(resolve, &buf.packet, (size_t) l); + if (r < 0) + return r; + + return 1; +} + +_public_ int sd_resolve_wait(sd_resolve *resolve, uint64_t timeout_usec) { + int r; + + assert_return(resolve, -EINVAL); + assert_return(!resolve_pid_changed(resolve), -ECHILD); + + if (resolve->n_done >= resolve->n_queries) + return 0; + + do { + r = fd_wait_for_event(resolve->fds[RESPONSE_RECV_FD], POLLIN, timeout_usec); + } while (r == -EINTR); + + if (r < 0) + return r; + if (r == 0) + return -ETIMEDOUT; + + return sd_resolve_process(resolve); +} + +static int alloc_query(sd_resolve *resolve, bool floating, sd_resolve_query **_q) { + sd_resolve_query *q; + int r; + + assert(resolve); + assert(_q); + + if (resolve->n_queries >= QUERIES_MAX) + return -ENOBUFS; + + r = start_threads(resolve, 1); + if (r < 0) + return r; + + while (resolve->query_array[resolve->current_id % QUERIES_MAX]) + resolve->current_id++; + + q = resolve->query_array[resolve->current_id % QUERIES_MAX] = new0(sd_resolve_query, 1); + if (!q) + return -ENOMEM; + + q->n_ref = 1; + q->resolve = resolve; + q->floating = floating; + q->id = resolve->current_id++; + + if (!floating) + sd_resolve_ref(resolve); + + LIST_PREPEND(queries, resolve->queries, q); + resolve->n_queries++; + + *_q = q; + return 0; +} + +int resolve_getaddrinfo_with_destroy_callback( + sd_resolve *resolve, + sd_resolve_query **ret_query, + const char *node, const char *service, + const struct addrinfo *hints, + sd_resolve_getaddrinfo_handler_t callback, + sd_resolve_destroy_t destroy_callback, + void *userdata) { + + _cleanup_(sd_resolve_query_unrefp) sd_resolve_query *q = NULL; + size_t node_len, service_len; + AddrInfoRequest req = {}; + struct iovec iov[3]; + struct msghdr mh = {}; + int r; + + assert_return(resolve, -EINVAL); + assert_return(node || service, -EINVAL); + assert_return(callback, -EINVAL); + assert_return(!resolve_pid_changed(resolve), -ECHILD); + + r = alloc_query(resolve, !ret_query, &q); + if (r < 0) + return r; + + q->type = REQUEST_ADDRINFO; + q->getaddrinfo_handler = callback; + q->userdata = userdata; + + node_len = node ? strlen(node) + 1 : 0; + service_len = service ? strlen(service) + 1 : 0; + + req = (AddrInfoRequest) { + .node_len = node_len, + .service_len = service_len, + + .header.id = q->id, + .header.type = REQUEST_ADDRINFO, + .header.length = sizeof(AddrInfoRequest) + node_len + service_len, + + .hints_valid = hints, + .ai_flags = hints ? hints->ai_flags : 0, + .ai_family = hints ? hints->ai_family : 0, + .ai_socktype = hints ? hints->ai_socktype : 0, + .ai_protocol = hints ? hints->ai_protocol : 0, + }; + + msan_unpoison(&req, sizeof(req)); + + iov[mh.msg_iovlen++] = IOVEC_MAKE(&req, sizeof(AddrInfoRequest)); + if (node) + iov[mh.msg_iovlen++] = IOVEC_MAKE((void*) node, req.node_len); + if (service) + iov[mh.msg_iovlen++] = IOVEC_MAKE((void*) service, req.service_len); + mh.msg_iov = iov; + + if (sendmsg(resolve->fds[REQUEST_SEND_FD], &mh, MSG_NOSIGNAL) < 0) + return -errno; + + resolve->n_outstanding++; + q->destroy_callback = destroy_callback; + + if (ret_query) + *ret_query = q; + + TAKE_PTR(q); + + return 0; +} + +_public_ int sd_resolve_getaddrinfo( + sd_resolve *resolve, + sd_resolve_query **ret_query, + const char *node, const char *service, + const struct addrinfo *hints, + sd_resolve_getaddrinfo_handler_t callback, + void *userdata) { + + return resolve_getaddrinfo_with_destroy_callback(resolve, ret_query, node, service, hints, callback, NULL, userdata); +} + +static int getaddrinfo_done(sd_resolve_query* q) { + assert(q); + assert(q->done); + assert(q->getaddrinfo_handler); + + errno = q->_errno; + h_errno = q->_h_errno; + + return q->getaddrinfo_handler(q, q->ret, q->addrinfo, q->userdata); +} + +int resolve_getnameinfo_with_destroy_callback( + sd_resolve *resolve, + sd_resolve_query **ret_query, + const struct sockaddr *sa, socklen_t salen, + int flags, + uint64_t get, + sd_resolve_getnameinfo_handler_t callback, + sd_resolve_destroy_t destroy_callback, + void *userdata) { + + _cleanup_(sd_resolve_query_unrefp) sd_resolve_query *q = NULL; + NameInfoRequest req = {}; + struct iovec iov[2]; + struct msghdr mh; + int r; + + assert_return(resolve, -EINVAL); + assert_return(sa, -EINVAL); + assert_return(salen >= sizeof(struct sockaddr), -EINVAL); + assert_return(salen <= sizeof(union sockaddr_union), -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, !ret_query, &q); + if (r < 0) + return r; + + q->type = REQUEST_NAMEINFO; + q->getnameinfo_handler = callback; + q->userdata = userdata; + + req = (NameInfoRequest) { + .header.id = q->id, + .header.type = REQUEST_NAMEINFO, + .header.length = sizeof(NameInfoRequest) + salen, + + .flags = flags, + .sockaddr_len = salen, + .gethost = !!(get & SD_RESOLVE_GET_HOST), + .getserv = !!(get & SD_RESOLVE_GET_SERVICE), + }; + + msan_unpoison(&req, sizeof(req)); + + iov[0] = IOVEC_MAKE(&req, sizeof(NameInfoRequest)); + iov[1] = IOVEC_MAKE((void*) sa, salen); + + mh = (struct msghdr) { + .msg_iov = iov, + .msg_iovlen = ELEMENTSOF(iov) + }; + + if (sendmsg(resolve->fds[REQUEST_SEND_FD], &mh, MSG_NOSIGNAL) < 0) + return -errno; + + resolve->n_outstanding++; + q->destroy_callback = destroy_callback; + + if (ret_query) + *ret_query = q; + + TAKE_PTR(q); + + return 0; +} + +_public_ int sd_resolve_getnameinfo( + sd_resolve *resolve, + sd_resolve_query **ret_query, + const struct sockaddr *sa, socklen_t salen, + int flags, + uint64_t get, + sd_resolve_getnameinfo_handler_t callback, + void *userdata) { + + return resolve_getnameinfo_with_destroy_callback(resolve, ret_query, sa, salen, flags, get, callback, NULL, userdata); +} + +static int getnameinfo_done(sd_resolve_query *q) { + + assert(q); + assert(q->done); + assert(q->getnameinfo_handler); + + errno = q->_errno; + h_errno = q->_h_errno; + + return q->getnameinfo_handler(q, q->ret, q->host, q->serv, q->userdata); +} + +static void resolve_freeaddrinfo(struct addrinfo *ai) { + while (ai) { + struct addrinfo *next = ai->ai_next; + + free(ai->ai_addr); + free(ai->ai_canonname); + free(ai); + ai = next; + } +} + +static void resolve_query_disconnect(sd_resolve_query *q) { + sd_resolve *resolve; + unsigned i; + + assert(q); + + if (!q->resolve) + return; + + resolve = q->resolve; + assert(resolve->n_queries > 0); + + if (q->done) { + assert(resolve->n_done > 0); + resolve->n_done--; + } + + i = q->id % QUERIES_MAX; + assert(resolve->query_array[i] == q); + resolve->query_array[i] = NULL; + LIST_REMOVE(queries, resolve->queries, q); + resolve->n_queries--; + + q->resolve = NULL; + if (!q->floating) + sd_resolve_unref(resolve); +} + +static sd_resolve_query *resolve_query_free(sd_resolve_query *q) { + assert(q); + + resolve_query_disconnect(q); + + if (q->destroy_callback) + q->destroy_callback(q->userdata); + + resolve_freeaddrinfo(q->addrinfo); + free(q->host); + free(q->serv); + + return mfree(q); +} + +DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_resolve_query, sd_resolve_query, resolve_query_free); + +_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_query_set_userdata(sd_resolve_query *q, void *userdata) { + void *ret; + + assert_return(q, NULL); + assert_return(!resolve_pid_changed(q->resolve), NULL); + + ret = q->userdata; + q->userdata = userdata; + + return ret; +} + +_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; +} + +_public_ int sd_resolve_query_get_destroy_callback(sd_resolve_query *q, sd_resolve_destroy_t *destroy_callback) { + assert_return(q, -EINVAL); + + if (destroy_callback) + *destroy_callback = q->destroy_callback; + + return !!q->destroy_callback; +} + +_public_ int sd_resolve_query_set_destroy_callback(sd_resolve_query *q, sd_resolve_destroy_t destroy_callback) { + assert_return(q, -EINVAL); + + q->destroy_callback = destroy_callback; + return 0; +} + +_public_ int sd_resolve_query_get_floating(sd_resolve_query *q) { + assert_return(q, -EINVAL); + + return q->floating; +} + +_public_ int sd_resolve_query_set_floating(sd_resolve_query *q, int b) { + assert_return(q, -EINVAL); + + if (q->floating == !!b) + return 0; + + if (!q->resolve) /* Already disconnected */ + return -ESTALE; + + q->floating = b; + + if (b) { + sd_resolve_query_ref(q); + sd_resolve_unref(q->resolve); + } else { + sd_resolve_ref(q->resolve); + sd_resolve_query_unref(q); + } + + return 1; +} + +static int io_callback(sd_event_source *s, int fd, uint32_t revents, void *userdata) { + sd_resolve *resolve = ASSERT_PTR(userdata); + int r; + + r = sd_resolve_process(resolve); + if (r < 0) + return r; + + return 1; +} + +_public_ int sd_resolve_attach_event(sd_resolve *resolve, sd_event *event, int64_t 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; + + resolve->event_source = sd_event_source_disable_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; +} |