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authorTom Gundersen <teg@jklm.no>2015-06-12 16:31:33 +0200
committerTom Gundersen <teg@jklm.no>2015-06-13 19:52:54 +0200
commit1c4baffc1895809bae9ac36b670af90a4cb9cd7d (patch)
treea0ad5af06e5aa9cf8998cc20e97780cfe375bcb9 /src/libsystemd/sd-netlink/sd-netlink.c
parenteb59b6094197a7dcef89639ec3e91eef61b639bb (diff)
sd-netlink: rename from sd-rtnl
Diffstat (limited to 'src/libsystemd/sd-netlink/sd-netlink.c')
-rw-r--r--src/libsystemd/sd-netlink/sd-netlink.c1056
1 files changed, 1056 insertions, 0 deletions
diff --git a/src/libsystemd/sd-netlink/sd-netlink.c b/src/libsystemd/sd-netlink/sd-netlink.c
new file mode 100644
index 0000000000..14cc75915d
--- /dev/null
+++ b/src/libsystemd/sd-netlink/sd-netlink.c
@@ -0,0 +1,1056 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2013 Tom Gundersen <teg@jklm.no>
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <sys/socket.h>
+#include <poll.h>
+
+#include "missing.h"
+#include "macro.h"
+#include "util.h"
+#include "hashmap.h"
+
+#include "sd-netlink.h"
+#include "netlink-internal.h"
+#include "netlink-util.h"
+
+static int sd_netlink_new(sd_netlink **ret) {
+ _cleanup_netlink_unref_ sd_netlink *rtnl = NULL;
+
+ assert_return(ret, -EINVAL);
+
+ rtnl = new0(sd_netlink, 1);
+ if (!rtnl)
+ return -ENOMEM;
+
+ rtnl->n_ref = REFCNT_INIT;
+
+ rtnl->fd = -1;
+
+ rtnl->sockaddr.nl.nl_family = AF_NETLINK;
+
+ rtnl->original_pid = getpid();
+
+ LIST_HEAD_INIT(rtnl->match_callbacks);
+
+ /* We guarantee that wqueue always has space for at least
+ * one entry */
+ if (!GREEDY_REALLOC(rtnl->wqueue, rtnl->wqueue_allocated, 1))
+ return -ENOMEM;
+
+ /* We guarantee that the read buffer has at least space for
+ * a message header */
+ if (!greedy_realloc((void**)&rtnl->rbuffer, &rtnl->rbuffer_allocated,
+ sizeof(struct nlmsghdr), sizeof(uint8_t)))
+ return -ENOMEM;
+
+ /* Change notification responses have sequence 0, so we must
+ * start our request sequence numbers at 1, or we may confuse our
+ * responses with notifications from the kernel */
+ rtnl->serial = 1;
+
+ *ret = rtnl;
+ rtnl = NULL;
+
+ return 0;
+}
+
+int sd_netlink_new_from_netlink(sd_netlink **ret, int fd) {
+ _cleanup_netlink_unref_ sd_netlink *rtnl = NULL;
+ socklen_t addrlen;
+ int r;
+
+ assert_return(ret, -EINVAL);
+
+ r = sd_netlink_new(&rtnl);
+ if (r < 0)
+ return r;
+
+ addrlen = sizeof(rtnl->sockaddr);
+
+ r = getsockname(fd, &rtnl->sockaddr.sa, &addrlen);
+ if (r < 0)
+ return -errno;
+
+ rtnl->fd = fd;
+
+ *ret = rtnl;
+ rtnl = NULL;
+
+ return 0;
+}
+
+static bool rtnl_pid_changed(sd_netlink *rtnl) {
+ assert(rtnl);
+
+ /* We don't support people creating an rtnl connection and
+ * keeping it around over a fork(). Let's complain. */
+
+ return rtnl->original_pid != getpid();
+}
+
+int sd_netlink_open_fd(sd_netlink **ret, int fd) {
+ _cleanup_netlink_unref_ sd_netlink *rtnl = NULL;
+ socklen_t addrlen;
+ int r, one = 1;
+
+ assert_return(ret, -EINVAL);
+ assert_return(fd >= 0, -EINVAL);
+
+ r = sd_netlink_new(&rtnl);
+ if (r < 0)
+ return r;
+
+ r = setsockopt(fd, SOL_NETLINK, NETLINK_PKTINFO, &one, sizeof(one));
+ if (r < 0)
+ return -errno;
+
+ addrlen = sizeof(rtnl->sockaddr);
+
+ r = bind(fd, &rtnl->sockaddr.sa, addrlen);
+ /* ignore EINVAL to allow opening an already bound socket */
+ if (r < 0 && errno != EINVAL)
+ return -errno;
+
+ r = getsockname(fd, &rtnl->sockaddr.sa, &addrlen);
+ if (r < 0)
+ return -errno;
+
+ rtnl->fd = fd;
+
+ *ret = rtnl;
+ rtnl = NULL;
+
+ return 0;
+}
+
+int sd_netlink_open(sd_netlink **ret) {
+ _cleanup_close_ int fd = -1;
+ int r;
+
+ fd = socket(PF_NETLINK, SOCK_RAW|SOCK_CLOEXEC|SOCK_NONBLOCK, NETLINK_ROUTE);
+ if (fd < 0)
+ return -errno;
+
+ r = sd_netlink_open_fd(ret, fd);
+ if (r < 0)
+ return r;
+
+ fd = -1;
+
+ return 0;
+}
+
+static int rtnl_join_broadcast_group(sd_netlink *rtnl, unsigned group) {
+ int r;
+
+ assert(rtnl);
+ assert(rtnl->fd >= 0);
+ assert(group > 0);
+
+ r = setsockopt(rtnl->fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &group, sizeof(group));
+ if (r < 0)
+ return -errno;
+
+ return 0;
+}
+
+int sd_netlink_inc_rcvbuf(const sd_netlink *const rtnl, const int size) {
+ return fd_inc_rcvbuf(rtnl->fd, size);
+}
+
+sd_netlink *sd_netlink_ref(sd_netlink *rtnl) {
+ assert_return(rtnl, NULL);
+ assert_return(!rtnl_pid_changed(rtnl), NULL);
+
+ if (rtnl)
+ assert_se(REFCNT_INC(rtnl->n_ref) >= 2);
+
+ return rtnl;
+}
+
+sd_netlink *sd_netlink_unref(sd_netlink *rtnl) {
+ if (!rtnl)
+ return NULL;
+
+ assert_return(!rtnl_pid_changed(rtnl), NULL);
+
+ if (REFCNT_DEC(rtnl->n_ref) == 0) {
+ struct match_callback *f;
+ unsigned i;
+
+ for (i = 0; i < rtnl->rqueue_size; i++)
+ sd_netlink_message_unref(rtnl->rqueue[i]);
+ free(rtnl->rqueue);
+
+ for (i = 0; i < rtnl->rqueue_partial_size; i++)
+ sd_netlink_message_unref(rtnl->rqueue_partial[i]);
+ free(rtnl->rqueue_partial);
+
+ for (i = 0; i < rtnl->wqueue_size; i++)
+ sd_netlink_message_unref(rtnl->wqueue[i]);
+ free(rtnl->wqueue);
+
+ free(rtnl->rbuffer);
+
+ hashmap_free_free(rtnl->reply_callbacks);
+ prioq_free(rtnl->reply_callbacks_prioq);
+
+ sd_event_source_unref(rtnl->io_event_source);
+ sd_event_source_unref(rtnl->time_event_source);
+ sd_event_source_unref(rtnl->exit_event_source);
+ sd_event_unref(rtnl->event);
+
+ while ((f = rtnl->match_callbacks)) {
+ LIST_REMOVE(match_callbacks, rtnl->match_callbacks, f);
+ free(f);
+ }
+
+ safe_close(rtnl->fd);
+ free(rtnl);
+ }
+
+ return NULL;
+}
+
+static void rtnl_seal_message(sd_netlink *rtnl, sd_netlink_message *m) {
+ assert(rtnl);
+ assert(!rtnl_pid_changed(rtnl));
+ assert(m);
+ assert(m->hdr);
+
+ /* don't use seq == 0, as that is used for broadcasts, so we
+ would get confused by replies to such messages */
+ m->hdr->nlmsg_seq = rtnl->serial++ ? : rtnl->serial++;
+
+ rtnl_message_seal(m);
+
+ return;
+}
+
+int sd_netlink_send(sd_netlink *nl,
+ sd_netlink_message *message,
+ uint32_t *serial) {
+ int r;
+
+ assert_return(nl, -EINVAL);
+ assert_return(!rtnl_pid_changed(nl), -ECHILD);
+ assert_return(message, -EINVAL);
+ assert_return(!message->sealed, -EPERM);
+
+ rtnl_seal_message(nl, message);
+
+ if (nl->wqueue_size <= 0) {
+ /* send directly */
+ r = socket_write_message(nl, message);
+ if (r < 0)
+ return r;
+ else if (r == 0) {
+ /* nothing was sent, so let's put it on
+ * the queue */
+ nl->wqueue[0] = sd_netlink_message_ref(message);
+ nl->wqueue_size = 1;
+ }
+ } else {
+ /* append to queue */
+ if (nl->wqueue_size >= RTNL_WQUEUE_MAX) {
+ log_debug("rtnl: exhausted the write queue size (%d)", RTNL_WQUEUE_MAX);
+ return -ENOBUFS;
+ }
+
+ if (!GREEDY_REALLOC(nl->wqueue, nl->wqueue_allocated, nl->wqueue_size + 1))
+ return -ENOMEM;
+
+ nl->wqueue[nl->wqueue_size ++] = sd_netlink_message_ref(message);
+ }
+
+ if (serial)
+ *serial = rtnl_message_get_serial(message);
+
+ return 1;
+}
+
+int rtnl_rqueue_make_room(sd_netlink *rtnl) {
+ assert(rtnl);
+
+ if (rtnl->rqueue_size >= RTNL_RQUEUE_MAX) {
+ log_debug("rtnl: exhausted the read queue size (%d)", RTNL_RQUEUE_MAX);
+ return -ENOBUFS;
+ }
+
+ if (!GREEDY_REALLOC(rtnl->rqueue, rtnl->rqueue_allocated, rtnl->rqueue_size + 1))
+ return -ENOMEM;
+
+ return 0;
+}
+
+int rtnl_rqueue_partial_make_room(sd_netlink *rtnl) {
+ assert(rtnl);
+
+ if (rtnl->rqueue_partial_size >= RTNL_RQUEUE_MAX) {
+ log_debug("rtnl: exhausted the partial read queue size (%d)", RTNL_RQUEUE_MAX);
+ return -ENOBUFS;
+ }
+
+ if (!GREEDY_REALLOC(rtnl->rqueue_partial, rtnl->rqueue_partial_allocated,
+ rtnl->rqueue_partial_size + 1))
+ return -ENOMEM;
+
+ return 0;
+}
+
+static int dispatch_rqueue(sd_netlink *rtnl, sd_netlink_message **message) {
+ int r;
+
+ assert(rtnl);
+ assert(message);
+
+ if (rtnl->rqueue_size <= 0) {
+ /* Try to read a new message */
+ r = socket_read_message(rtnl);
+ if (r <= 0)
+ return r;
+ }
+
+ /* Dispatch a queued message */
+ *message = rtnl->rqueue[0];
+ rtnl->rqueue_size --;
+ memmove(rtnl->rqueue, rtnl->rqueue + 1, sizeof(sd_netlink_message*) * rtnl->rqueue_size);
+
+ return 1;
+}
+
+static int dispatch_wqueue(sd_netlink *rtnl) {
+ int r, ret = 0;
+
+ assert(rtnl);
+
+ while (rtnl->wqueue_size > 0) {
+ r = socket_write_message(rtnl, rtnl->wqueue[0]);
+ if (r < 0)
+ return r;
+ else if (r == 0)
+ /* Didn't do anything this time */
+ return ret;
+ else {
+ /* see equivalent in sd-bus.c */
+ sd_netlink_message_unref(rtnl->wqueue[0]);
+ rtnl->wqueue_size --;
+ memmove(rtnl->wqueue, rtnl->wqueue + 1, sizeof(sd_netlink_message*) * rtnl->wqueue_size);
+
+ ret = 1;
+ }
+ }
+
+ return ret;
+}
+
+static int process_timeout(sd_netlink *rtnl) {
+ _cleanup_netlink_message_unref_ sd_netlink_message *m = NULL;
+ struct reply_callback *c;
+ usec_t n;
+ int r;
+
+ assert(rtnl);
+
+ c = prioq_peek(rtnl->reply_callbacks_prioq);
+ if (!c)
+ return 0;
+
+ n = now(CLOCK_MONOTONIC);
+ if (c->timeout > n)
+ return 0;
+
+ r = rtnl_message_new_synthetic_error(-ETIMEDOUT, c->serial, &m);
+ if (r < 0)
+ return r;
+
+ assert_se(prioq_pop(rtnl->reply_callbacks_prioq) == c);
+ hashmap_remove(rtnl->reply_callbacks, &c->serial);
+
+ r = c->callback(rtnl, m, c->userdata);
+ if (r < 0)
+ log_debug_errno(r, "sd-netlink: timedout callback failed: %m");
+
+ free(c);
+
+ return 1;
+}
+
+static int process_reply(sd_netlink *rtnl, sd_netlink_message *m) {
+ _cleanup_free_ struct reply_callback *c = NULL;
+ uint64_t serial;
+ uint16_t type;
+ int r;
+
+ assert(rtnl);
+ assert(m);
+
+ serial = rtnl_message_get_serial(m);
+ c = hashmap_remove(rtnl->reply_callbacks, &serial);
+ if (!c)
+ return 0;
+
+ if (c->timeout != 0)
+ prioq_remove(rtnl->reply_callbacks_prioq, c, &c->prioq_idx);
+
+ r = sd_netlink_message_get_type(m, &type);
+ if (r < 0)
+ return 0;
+
+ if (type == NLMSG_DONE)
+ m = NULL;
+
+ r = c->callback(rtnl, m, c->userdata);
+ if (r < 0)
+ log_debug_errno(r, "sd-netlink: callback failed: %m");
+
+ return 1;
+}
+
+static int process_match(sd_netlink *rtnl, sd_netlink_message *m) {
+ struct match_callback *c;
+ uint16_t type;
+ int r;
+
+ assert(rtnl);
+ assert(m);
+
+ r = sd_netlink_message_get_type(m, &type);
+ if (r < 0)
+ return r;
+
+ LIST_FOREACH(match_callbacks, c, rtnl->match_callbacks) {
+ if (type == c->type) {
+ r = c->callback(rtnl, m, c->userdata);
+ if (r != 0) {
+ if (r < 0)
+ log_debug_errno(r, "sd-netlink: match callback failed: %m");
+
+ break;
+ }
+ }
+ }
+
+ return 1;
+}
+
+static int process_running(sd_netlink *rtnl, sd_netlink_message **ret) {
+ _cleanup_netlink_message_unref_ sd_netlink_message *m = NULL;
+ int r;
+
+ assert(rtnl);
+
+ r = process_timeout(rtnl);
+ if (r != 0)
+ goto null_message;
+
+ r = dispatch_wqueue(rtnl);
+ if (r != 0)
+ goto null_message;
+
+ r = dispatch_rqueue(rtnl, &m);
+ if (r < 0)
+ return r;
+ if (!m)
+ goto null_message;
+
+ if (sd_netlink_message_is_broadcast(m)) {
+ r = process_match(rtnl, m);
+ if (r != 0)
+ goto null_message;
+ } else {
+ r = process_reply(rtnl, m);
+ if (r != 0)
+ goto null_message;
+ }
+
+ if (ret) {
+ *ret = m;
+ m = NULL;
+
+ return 1;
+ }
+
+ return 1;
+
+null_message:
+ if (r >= 0 && ret)
+ *ret = NULL;
+
+ return r;
+}
+
+int sd_netlink_process(sd_netlink *rtnl, sd_netlink_message **ret) {
+ RTNL_DONT_DESTROY(rtnl);
+ int r;
+
+ assert_return(rtnl, -EINVAL);
+ assert_return(!rtnl_pid_changed(rtnl), -ECHILD);
+ assert_return(!rtnl->processing, -EBUSY);
+
+ rtnl->processing = true;
+ r = process_running(rtnl, ret);
+ rtnl->processing = false;
+
+ return r;
+}
+
+static usec_t calc_elapse(uint64_t usec) {
+ if (usec == (uint64_t) -1)
+ return 0;
+
+ if (usec == 0)
+ usec = RTNL_DEFAULT_TIMEOUT;
+
+ return now(CLOCK_MONOTONIC) + usec;
+}
+
+static int rtnl_poll(sd_netlink *rtnl, bool need_more, uint64_t timeout_usec) {
+ struct pollfd p[1] = {};
+ struct timespec ts;
+ usec_t m = USEC_INFINITY;
+ int r, e;
+
+ assert(rtnl);
+
+ e = sd_netlink_get_events(rtnl);
+ if (e < 0)
+ return e;
+
+ if (need_more)
+ /* Caller wants more data, and doesn't care about
+ * what's been read or any other timeouts. */
+ e |= POLLIN;
+ else {
+ usec_t until;
+ /* Caller wants to process if there is something to
+ * process, but doesn't care otherwise */
+
+ r = sd_netlink_get_timeout(rtnl, &until);
+ if (r < 0)
+ return r;
+ if (r > 0) {
+ usec_t nw;
+ nw = now(CLOCK_MONOTONIC);
+ m = until > nw ? until - nw : 0;
+ }
+ }
+
+ if (timeout_usec != (uint64_t) -1 && (m == (uint64_t) -1 || timeout_usec < m))
+ m = timeout_usec;
+
+ p[0].fd = rtnl->fd;
+ p[0].events = e;
+
+ r = ppoll(p, 1, m == (uint64_t) -1 ? NULL : timespec_store(&ts, m), NULL);
+ if (r < 0)
+ return -errno;
+
+ return r > 0 ? 1 : 0;
+}
+
+int sd_netlink_wait(sd_netlink *nl, uint64_t timeout_usec) {
+ assert_return(nl, -EINVAL);
+ assert_return(!rtnl_pid_changed(nl), -ECHILD);
+
+ if (nl->rqueue_size > 0)
+ return 0;
+
+ return rtnl_poll(nl, false, timeout_usec);
+}
+
+static int timeout_compare(const void *a, const void *b) {
+ const struct reply_callback *x = a, *y = b;
+
+ if (x->timeout != 0 && y->timeout == 0)
+ return -1;
+
+ if (x->timeout == 0 && y->timeout != 0)
+ return 1;
+
+ if (x->timeout < y->timeout)
+ return -1;
+
+ if (x->timeout > y->timeout)
+ return 1;
+
+ return 0;
+}
+
+int sd_netlink_call_async(sd_netlink *nl,
+ sd_netlink_message *m,
+ sd_netlink_message_handler_t callback,
+ void *userdata,
+ uint64_t usec,
+ uint32_t *serial) {
+ struct reply_callback *c;
+ uint32_t s;
+ int r, k;
+
+ assert_return(nl, -EINVAL);
+ assert_return(m, -EINVAL);
+ assert_return(callback, -EINVAL);
+ assert_return(!rtnl_pid_changed(nl), -ECHILD);
+
+ r = hashmap_ensure_allocated(&nl->reply_callbacks, &uint64_hash_ops);
+ if (r < 0)
+ return r;
+
+ if (usec != (uint64_t) -1) {
+ r = prioq_ensure_allocated(&nl->reply_callbacks_prioq, timeout_compare);
+ if (r < 0)
+ return r;
+ }
+
+ c = new0(struct reply_callback, 1);
+ if (!c)
+ return -ENOMEM;
+
+ c->callback = callback;
+ c->userdata = userdata;
+ c->timeout = calc_elapse(usec);
+
+ k = sd_netlink_send(nl, m, &s);
+ if (k < 0) {
+ free(c);
+ return k;
+ }
+
+ c->serial = s;
+
+ r = hashmap_put(nl->reply_callbacks, &c->serial, c);
+ if (r < 0) {
+ free(c);
+ return r;
+ }
+
+ if (c->timeout != 0) {
+ r = prioq_put(nl->reply_callbacks_prioq, c, &c->prioq_idx);
+ if (r > 0) {
+ c->timeout = 0;
+ sd_netlink_call_async_cancel(nl, c->serial);
+ return r;
+ }
+ }
+
+ if (serial)
+ *serial = s;
+
+ return k;
+}
+
+int sd_netlink_call_async_cancel(sd_netlink *nl, uint32_t serial) {
+ struct reply_callback *c;
+ uint64_t s = serial;
+
+ assert_return(nl, -EINVAL);
+ assert_return(serial != 0, -EINVAL);
+ assert_return(!rtnl_pid_changed(nl), -ECHILD);
+
+ c = hashmap_remove(nl->reply_callbacks, &s);
+ if (!c)
+ return 0;
+
+ if (c->timeout != 0)
+ prioq_remove(nl->reply_callbacks_prioq, c, &c->prioq_idx);
+
+ free(c);
+ return 1;
+}
+
+int sd_netlink_call(sd_netlink *rtnl,
+ sd_netlink_message *message,
+ uint64_t usec,
+ sd_netlink_message **ret) {
+ usec_t timeout;
+ uint32_t serial;
+ int r;
+
+ assert_return(rtnl, -EINVAL);
+ assert_return(!rtnl_pid_changed(rtnl), -ECHILD);
+ assert_return(message, -EINVAL);
+
+ r = sd_netlink_send(rtnl, message, &serial);
+ if (r < 0)
+ return r;
+
+ timeout = calc_elapse(usec);
+
+ for (;;) {
+ usec_t left;
+ unsigned i;
+
+ for (i = 0; i < rtnl->rqueue_size; i++) {
+ uint32_t received_serial;
+
+ received_serial = rtnl_message_get_serial(rtnl->rqueue[i]);
+
+ if (received_serial == serial) {
+ _cleanup_netlink_message_unref_ sd_netlink_message *incoming = NULL;
+ uint16_t type;
+
+ incoming = rtnl->rqueue[i];
+
+ /* found a match, remove from rqueue and return it */
+ memmove(rtnl->rqueue + i,rtnl->rqueue + i + 1,
+ sizeof(sd_netlink_message*) * (rtnl->rqueue_size - i - 1));
+ rtnl->rqueue_size--;
+
+ r = sd_netlink_message_get_errno(incoming);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_get_type(incoming, &type);
+ if (r < 0)
+ return r;
+
+ if (type == NLMSG_DONE) {
+ *ret = NULL;
+ return 0;
+ }
+
+ if (ret) {
+ *ret = incoming;
+ incoming = NULL;
+ }
+
+ return 1;
+ }
+ }
+
+ r = socket_read_message(rtnl);
+ if (r < 0)
+ return r;
+ if (r > 0)
+ /* received message, so try to process straight away */
+ continue;
+
+ if (timeout > 0) {
+ usec_t n;
+
+ n = now(CLOCK_MONOTONIC);
+ if (n >= timeout)
+ return -ETIMEDOUT;
+
+ left = timeout - n;
+ } else
+ left = (uint64_t) -1;
+
+ r = rtnl_poll(rtnl, true, left);
+ if (r < 0)
+ return r;
+ else if (r == 0)
+ return -ETIMEDOUT;
+
+ r = dispatch_wqueue(rtnl);
+ if (r < 0)
+ return r;
+ }
+}
+
+int sd_netlink_flush(sd_netlink *rtnl) {
+ int r;
+
+ assert_return(rtnl, -EINVAL);
+ assert_return(!rtnl_pid_changed(rtnl), -ECHILD);
+
+ if (rtnl->wqueue_size <= 0)
+ return 0;
+
+ for (;;) {
+ r = dispatch_wqueue(rtnl);
+ if (r < 0)
+ return r;
+
+ if (rtnl->wqueue_size <= 0)
+ return 0;
+
+ r = rtnl_poll(rtnl, false, (uint64_t) -1);
+ if (r < 0)
+ return r;
+ }
+}
+
+int sd_netlink_get_events(sd_netlink *rtnl) {
+ int flags = 0;
+
+ assert_return(rtnl, -EINVAL);
+ assert_return(!rtnl_pid_changed(rtnl), -ECHILD);
+
+ if (rtnl->rqueue_size <= 0)
+ flags |= POLLIN;
+ if (rtnl->wqueue_size > 0)
+ flags |= POLLOUT;
+
+ return flags;
+}
+
+int sd_netlink_get_timeout(sd_netlink *rtnl, uint64_t *timeout_usec) {
+ struct reply_callback *c;
+
+ assert_return(rtnl, -EINVAL);
+ assert_return(timeout_usec, -EINVAL);
+ assert_return(!rtnl_pid_changed(rtnl), -ECHILD);
+
+ if (rtnl->rqueue_size > 0) {
+ *timeout_usec = 0;
+ return 1;
+ }
+
+ c = prioq_peek(rtnl->reply_callbacks_prioq);
+ if (!c) {
+ *timeout_usec = (uint64_t) -1;
+ return 0;
+ }
+
+ *timeout_usec = c->timeout;
+
+ return 1;
+}
+
+static int io_callback(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+ sd_netlink *rtnl = userdata;
+ int r;
+
+ assert(rtnl);
+
+ r = sd_netlink_process(rtnl, NULL);
+ if (r < 0)
+ return r;
+
+ return 1;
+}
+
+static int time_callback(sd_event_source *s, uint64_t usec, void *userdata) {
+ sd_netlink *rtnl = userdata;
+ int r;
+
+ assert(rtnl);
+
+ r = sd_netlink_process(rtnl, NULL);
+ if (r < 0)
+ return r;
+
+ return 1;
+}
+
+static int prepare_callback(sd_event_source *s, void *userdata) {
+ sd_netlink *rtnl = userdata;
+ int r, e;
+ usec_t until;
+
+ assert(s);
+ assert(rtnl);
+
+ e = sd_netlink_get_events(rtnl);
+ if (e < 0)
+ return e;
+
+ r = sd_event_source_set_io_events(rtnl->io_event_source, e);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_get_timeout(rtnl, &until);
+ if (r < 0)
+ return r;
+ if (r > 0) {
+ int j;
+
+ j = sd_event_source_set_time(rtnl->time_event_source, until);
+ if (j < 0)
+ return j;
+ }
+
+ r = sd_event_source_set_enabled(rtnl->time_event_source, r > 0);
+ if (r < 0)
+ return r;
+
+ return 1;
+}
+
+static int exit_callback(sd_event_source *event, void *userdata) {
+ sd_netlink *rtnl = userdata;
+
+ assert(event);
+
+ sd_netlink_flush(rtnl);
+
+ return 1;
+}
+
+int sd_netlink_attach_event(sd_netlink *rtnl, sd_event *event, int priority) {
+ int r;
+
+ assert_return(rtnl, -EINVAL);
+ assert_return(!rtnl->event, -EBUSY);
+
+ assert(!rtnl->io_event_source);
+ assert(!rtnl->time_event_source);
+
+ if (event)
+ rtnl->event = sd_event_ref(event);
+ else {
+ r = sd_event_default(&rtnl->event);
+ if (r < 0)
+ return r;
+ }
+
+ r = sd_event_add_io(rtnl->event, &rtnl->io_event_source, rtnl->fd, 0, io_callback, rtnl);
+ if (r < 0)
+ goto fail;
+
+ r = sd_event_source_set_priority(rtnl->io_event_source, priority);
+ if (r < 0)
+ goto fail;
+
+ r = sd_event_source_set_description(rtnl->io_event_source, "rtnl-receive-message");
+ if (r < 0)
+ goto fail;
+
+ r = sd_event_source_set_prepare(rtnl->io_event_source, prepare_callback);
+ if (r < 0)
+ goto fail;
+
+ r = sd_event_add_time(rtnl->event, &rtnl->time_event_source, CLOCK_MONOTONIC, 0, 0, time_callback, rtnl);
+ if (r < 0)
+ goto fail;
+
+ r = sd_event_source_set_priority(rtnl->time_event_source, priority);
+ if (r < 0)
+ goto fail;
+
+ r = sd_event_source_set_description(rtnl->time_event_source, "rtnl-timer");
+ if (r < 0)
+ goto fail;
+
+ r = sd_event_add_exit(rtnl->event, &rtnl->exit_event_source, exit_callback, rtnl);
+ if (r < 0)
+ goto fail;
+
+ r = sd_event_source_set_description(rtnl->exit_event_source, "rtnl-exit");
+ if (r < 0)
+ goto fail;
+
+ return 0;
+
+fail:
+ sd_netlink_detach_event(rtnl);
+ return r;
+}
+
+int sd_netlink_detach_event(sd_netlink *rtnl) {
+ assert_return(rtnl, -EINVAL);
+ assert_return(rtnl->event, -ENXIO);
+
+ if (rtnl->io_event_source)
+ rtnl->io_event_source = sd_event_source_unref(rtnl->io_event_source);
+
+ if (rtnl->time_event_source)
+ rtnl->time_event_source = sd_event_source_unref(rtnl->time_event_source);
+
+ if (rtnl->exit_event_source)
+ rtnl->exit_event_source = sd_event_source_unref(rtnl->exit_event_source);
+
+ if (rtnl->event)
+ rtnl->event = sd_event_unref(rtnl->event);
+
+ return 0;
+}
+
+int sd_netlink_add_match(sd_netlink *rtnl,
+ uint16_t type,
+ sd_netlink_message_handler_t callback,
+ void *userdata) {
+ _cleanup_free_ struct match_callback *c = NULL;
+ int r;
+
+ assert_return(rtnl, -EINVAL);
+ assert_return(callback, -EINVAL);
+ assert_return(!rtnl_pid_changed(rtnl), -ECHILD);
+
+ c = new0(struct match_callback, 1);
+ if (!c)
+ return -ENOMEM;
+
+ c->callback = callback;
+ c->type = type;
+ c->userdata = userdata;
+
+ switch (type) {
+ case RTM_NEWLINK:
+ case RTM_SETLINK:
+ case RTM_GETLINK:
+ case RTM_DELLINK:
+ r = rtnl_join_broadcast_group(rtnl, RTNLGRP_LINK);
+ if (r < 0)
+ return r;
+
+ break;
+ case RTM_NEWADDR:
+ case RTM_GETADDR:
+ case RTM_DELADDR:
+ r = rtnl_join_broadcast_group(rtnl, RTNLGRP_IPV4_IFADDR);
+ if (r < 0)
+ return r;
+
+ r = rtnl_join_broadcast_group(rtnl, RTNLGRP_IPV6_IFADDR);
+ if (r < 0)
+ return r;
+
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ LIST_PREPEND(match_callbacks, rtnl->match_callbacks, c);
+
+ c = NULL;
+
+ return 0;
+}
+
+int sd_netlink_remove_match(sd_netlink *rtnl,
+ uint16_t type,
+ sd_netlink_message_handler_t callback,
+ void *userdata) {
+ struct match_callback *c;
+
+ assert_return(rtnl, -EINVAL);
+ assert_return(callback, -EINVAL);
+ assert_return(!rtnl_pid_changed(rtnl), -ECHILD);
+
+ /* we should unsubscribe from the broadcast groups at this point, but it is not so
+ trivial for a few reasons: the refcounting is a bit of a mess and not obvious
+ how it will look like after we add genetlink support, and it is also not possible
+ to query what broadcast groups were subscribed to when we inherit the socket to get
+ the initial refcount. The latter could indeed be done for the first 32 broadcast
+ groups (which incidentally is all we currently support in .socket units anyway),
+ but we better not rely on only ever using 32 groups. */
+ LIST_FOREACH(match_callbacks, c, rtnl->match_callbacks)
+ if (c->callback == callback && c->type == type && c->userdata == userdata) {
+ LIST_REMOVE(match_callbacks, rtnl->match_callbacks, c);
+ free(c);
+
+ return 1;
+ }
+
+ return 0;
+}