/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2013 Tom Gundersen 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 . ***/ #include #include #include "sd-netlink.h" #include "fd-util.h" #include "hashmap.h" #include "macro.h" #include "missing.h" #include "netlink-internal.h" #include "netlink-util.h" #include "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 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; int r; assert_return(ret, -EINVAL); assert_return(fd >= 0, -EBADF); r = sd_netlink_new(&rtnl); if (r < 0) return r; rtnl->fd = fd; r = socket_bind(rtnl); if (r < 0) return r; *ret = rtnl; rtnl = NULL; return 0; } int sd_netlink_open(sd_netlink **ret) { _cleanup_close_ int fd = -1; int r; fd = socket_open(NETLINK_ROUTE); if (fd < 0) return fd; r = sd_netlink_open_fd(ret, fd); if (r < 0) return r; fd = -1; 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); 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_unref(rtnl->event); while ((f = rtnl->match_callbacks)) { sd_netlink_remove_match(rtnl, f->type, f->callback, f->userdata); } hashmap_free(rtnl->broadcast_group_refs); 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); r = socket_write_message(nl, message); if (r < 0) return r; 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 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_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; } } int sd_netlink_get_events(sd_netlink *rtnl) { assert_return(rtnl, -EINVAL); assert_return(!rtnl_pid_changed(rtnl), -ECHILD); if (rtnl->rqueue_size == 0) return POLLIN; else return 0; } 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; } 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; 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); rtnl->io_event_source = sd_event_source_unref(rtnl->io_event_source); rtnl->time_event_source = sd_event_source_unref(rtnl->time_event_source); 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_DELLINK: r = socket_broadcast_group_ref(rtnl, RTNLGRP_LINK); if (r < 0) return r; break; case RTM_NEWADDR: case RTM_DELADDR: r = socket_broadcast_group_ref(rtnl, RTNLGRP_IPV4_IFADDR); if (r < 0) return r; r = socket_broadcast_group_ref(rtnl, RTNLGRP_IPV6_IFADDR); if (r < 0) return r; break; case RTM_NEWROUTE: case RTM_DELROUTE: r = socket_broadcast_group_ref(rtnl, RTNLGRP_IPV4_ROUTE); if (r < 0) return r; r = socket_broadcast_group_ref(rtnl, RTNLGRP_IPV6_ROUTE); 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; int r; assert_return(rtnl, -EINVAL); assert_return(callback, -EINVAL); assert_return(!rtnl_pid_changed(rtnl), -ECHILD); 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); switch (type) { case RTM_NEWLINK: case RTM_DELLINK: r = socket_broadcast_group_unref(rtnl, RTNLGRP_LINK); if (r < 0) return r; break; case RTM_NEWADDR: case RTM_DELADDR: r = socket_broadcast_group_unref(rtnl, RTNLGRP_IPV4_IFADDR); if (r < 0) return r; r = socket_broadcast_group_unref(rtnl, RTNLGRP_IPV6_IFADDR); if (r < 0) return r; break; case RTM_NEWROUTE: case RTM_DELROUTE: r = socket_broadcast_group_unref(rtnl, RTNLGRP_IPV4_ROUTE); if (r < 0) return r; r = socket_broadcast_group_unref(rtnl, RTNLGRP_IPV6_ROUTE); if (r < 0) return r; break; default: return -EOPNOTSUPP; } return 1; } return 0; }