summaryrefslogtreecommitdiffstats
path: root/src/libsystemd/sd-resolve
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--src/libsystemd/sd-resolve/resolve-private.h39
-rw-r--r--src/libsystemd/sd-resolve/sd-resolve.c1290
-rw-r--r--src/libsystemd/sd-resolve/test-resolve.c109
3 files changed, 1438 insertions, 0 deletions
diff --git a/src/libsystemd/sd-resolve/resolve-private.h b/src/libsystemd/sd-resolve/resolve-private.h
new file mode 100644
index 0000000..a0feb36
--- /dev/null
+++ b/src/libsystemd/sd-resolve/resolve-private.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include "sd-resolve.h"
+
+int resolve_getaddrinfo_with_destroy_callback(
+ sd_resolve *resolve, sd_resolve_query **q,
+ const char *node, const char *service, const struct addrinfo *hints,
+ sd_resolve_getaddrinfo_handler_t callback,
+ sd_resolve_destroy_t destroy_callback, void *userdata);
+int resolve_getnameinfo_with_destroy_callback(
+ 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,
+ sd_resolve_destroy_t destroy_callback, void *userdata);
+
+#define resolve_getaddrinfo(resolve, ret_query, node, service, hints, callback, destroy_callback, userdata) \
+ ({ \
+ int (*_callback_)(sd_resolve_query*, int, const struct addrinfo*, typeof(userdata)) = callback; \
+ void (*_destroy_)(typeof(userdata)) = destroy_callback; \
+ resolve_getaddrinfo_with_destroy_callback( \
+ resolve, ret_query, \
+ node, service, hints, \
+ (sd_resolve_getaddrinfo_handler_t) _callback_, \
+ (sd_resolve_destroy_t) _destroy_, \
+ userdata); \
+ })
+
+#define resolve_getnameinfo(resolve, ret_query, sa, salen, flags, get, callback, destroy_callback, userdata) \
+ ({ \
+ int (*_callback_)(sd_resolve_query*, int, const char*, const char*, typeof(userdata)) = callback; \
+ void (*_destroy_)(typeof(userdata)) = destroy_callback; \
+ resolve_getaddrinfo_with_destroy_callback( \
+ resolve, ret_query, \
+ sa, salen, flags, get, \
+ (sd_resolve_getnameinfo_handler_t) _callback_, \
+ (sd_resolve_destroy_t) _destroy_, \
+ userdata); \
+ })
diff --git a/src/libsystemd/sd-resolve/sd-resolve.c b/src/libsystemd/sd-resolve/sd-resolve.c
new file mode 100644
index 0000000..36b9c8d
--- /dev/null
+++ b/src/libsystemd/sd-resolve/sd-resolve.c
@@ -0,0 +1,1290 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#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-domain.h"
+#include "fd-util.h"
+#include "io-util.h"
+#include "list.h"
+#include "missing.h"
+#include "resolve-private.h"
+#include "socket-util.h"
+#include "util.h"
+#include "process-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,
+ };
+
+ 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,
+ };
+
+ 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,
+ };
+
+ 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("Unknown request");
+ }
+
+ 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 == EINTR)
+ 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(PF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, resolve->fds + REQUEST_RECV_FD) < 0)
+ return -errno;
+
+ if (socketpair(PF_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_inc_rcvbuf(resolve->fds[REQUEST_RECV_FD], QUERIES_MAX * BUFSIZE);
+ (void) fd_inc_sndbuf(resolve->fds[RESPONSE_SEND_FD], QUERIES_MAX * BUFSIZE);
+ (void) fd_inc_rcvbuf(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_t) -1;
+ 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("Cannot complete unknown query type");
+ }
+
+ 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 == EAGAIN)
+ 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,
+ };
+
+ 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),
+ };
+
+ 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 = 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, 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;
+
+ 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
new file mode 100644
index 0000000..8de7adc
--- /dev/null
+++ b/src/libsystemd/sd-resolve/test-resolve.c
@@ -0,0 +1,109 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <arpa/inet.h>
+#include <errno.h>
+#include <netinet/in.h>
+#include <resolv.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/socket.h>
+
+#include "sd-resolve.h"
+
+#include "alloc-util.h"
+#include "macro.h"
+#include "socket-util.h"
+#include "string-util.h"
+#include "time-util.h"
+
+#define TEST_TIMEOUT_USEC (20*USEC_PER_SEC)
+
+static int getaddrinfo_handler(sd_resolve_query *q, int ret, const struct addrinfo *ai, void *userdata) {
+ const struct addrinfo *i;
+
+ assert_se(q);
+
+ if (ret != 0) {
+ log_error("getaddrinfo error: %s %i", 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, true, &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_se(q);
+
+ if (ret != 0) {
+ log_error("getnameinfo error: %s %i", gai_strerror(ret), ret);
+ return 0;
+ }
+
+ printf("Host: %s — Serv: %s\n", strna(host), strna(serv));
+ return 0;
+}
+
+int main(int argc, char *argv[]) {
+ _cleanup_(sd_resolve_query_unrefp) sd_resolve_query *q1 = NULL, *q2 = NULL;
+ _cleanup_(sd_resolve_unrefp) sd_resolve *resolve = NULL;
+ int r = 0;
+
+ struct addrinfo hints = {
+ .ai_family = PF_UNSPEC,
+ .ai_socktype = SOCK_STREAM,
+ .ai_flags = AI_CANONNAME
+ };
+
+ struct sockaddr_in sa = {
+ .sin_family = AF_INET,
+ .sin_port = htons(80)
+ };
+
+ assert_se(sd_resolve_default(&resolve) >= 0);
+
+ /* Test a floating resolver query */
+ r = sd_resolve_getaddrinfo(resolve, NULL, "redhat.com", "http", NULL, getaddrinfo_handler, NULL);
+ if (r < 0)
+ log_error_errno(r, "sd_resolve_getaddrinfo(): %m");
+
+ /* Make a name -> address query */
+ r = sd_resolve_getaddrinfo(resolve, &q1, argc >= 2 ? argv[1] : "www.heise.de", NULL, &hints, getaddrinfo_handler, NULL);
+ if (r < 0)
+ log_error_errno(r, "sd_resolve_getaddrinfo(): %m");
+
+ /* 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, SD_RESOLVE_GET_BOTH, getnameinfo_handler, NULL);
+ if (r < 0)
+ log_error_errno(r, "sd_resolve_getnameinfo(): %m");
+
+ /* Wait until all queries are completed */
+ for (;;) {
+ r = sd_resolve_wait(resolve, TEST_TIMEOUT_USEC);
+ if (r == 0)
+ break;
+ if (r == -ETIMEDOUT) {
+ /* Let's catch timeouts here, so that we can run safely in a CI that has no reliable DNS. Note
+ * that we invoke exit() directly here, as the stuck NSS call will not allow us to exit
+ * cleanly. */
+
+ log_notice_errno(r, "sd_resolve_wait() timed out, but that's OK");
+ exit(EXIT_SUCCESS);
+ }
+ if (r < 0) {
+ log_error_errno(r, "sd_resolve_wait(): %m");
+ assert_not_reached("sd_resolve_wait() failed");
+ }
+ }
+
+ return 0;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-04 07:29:57 +0000