diff options
Diffstat (limited to '')
| -rw-r--r-- | src/libsystemd/sd-netlink/sd-netlink.c | 909 |
1 files changed, 909 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 0000000..b6730b7 --- /dev/null +++ b/src/libsystemd/sd-netlink/sd-netlink.c @@ -0,0 +1,909 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <poll.h> + +#include "sd-netlink.h" + +#include "alloc-util.h" +#include "fd-util.h" +#include "hashmap.h" +#include "io-util.h" +#include "macro.h" +#include "netlink-genl.h" +#include "netlink-internal.h" +#include "netlink-slot.h" +#include "netlink-util.h" +#include "process-util.h" +#include "socket-util.h" +#include "string-util.h" + +/* Some really high limit, to catch programming errors */ +#define REPLY_CALLBACKS_MAX UINT16_MAX + +static int netlink_new(sd_netlink **ret) { + _cleanup_(sd_netlink_unrefp) sd_netlink *nl = NULL; + + assert_return(ret, -EINVAL); + + nl = new(sd_netlink, 1); + if (!nl) + return -ENOMEM; + + *nl = (sd_netlink) { + .n_ref = 1, + .fd = -EBADF, + .sockaddr.nl.nl_family = AF_NETLINK, + .original_pid = getpid_cached(), + .protocol = -1, + + /* Kernel change notification messages have sequence number 0. We want to avoid that with our + * own serials, in order not to get confused when matching up kernel replies to our earlier + * requests. + * + * Moreover, when using netlink socket activation (i.e. where PID 1 binds an AF_NETLINK + * socket for us and passes it to us across execve()) and we get restarted multiple times + * while the socket sticks around we might get confused by replies from earlier runs coming + * in late — which is pretty likely if we'd start our sequence numbers always from 1. Hence, + * let's start with a value based on the system clock. This should make collisions much less + * likely (though still theoretically possible). We use a 32 bit μs counter starting at boot + * for this (and explicitly exclude the zero, see above). This counter will wrap around after + * a bit more than 1h, but that's hopefully OK as the kernel shouldn't take that long to + * reply to our requests. + * + * We only pick the initial start value this way. For each message we simply increase the + * sequence number by 1. This means we could enqueue 1 netlink message per μs without risking + * collisions, which should be OK. + * + * Note this means the serials will be in the range 1…UINT32_MAX here. + * + * (In an ideal world we'd attach the current serial counter to the netlink socket itself + * somehow, to avoid all this, but I couldn't come up with a nice way to do this) */ + .serial = (uint32_t) (now(CLOCK_MONOTONIC) % UINT32_MAX) + 1, + }; + + *ret = TAKE_PTR(nl); + return 0; +} + +int sd_netlink_open_fd(sd_netlink **ret, int fd) { + _cleanup_(sd_netlink_unrefp) sd_netlink *nl = NULL; + int r, protocol; + + assert_return(ret, -EINVAL); + assert_return(fd >= 0, -EBADF); + + r = netlink_new(&nl); + if (r < 0) + return r; + + r = getsockopt_int(fd, SOL_SOCKET, SO_PROTOCOL, &protocol); + if (r < 0) + return r; + + nl->fd = fd; + nl->protocol = protocol; + + r = setsockopt_int(fd, SOL_NETLINK, NETLINK_EXT_ACK, true); + if (r < 0) + log_debug_errno(r, "sd-netlink: Failed to enable NETLINK_EXT_ACK option, ignoring: %m"); + + r = setsockopt_int(fd, SOL_NETLINK, NETLINK_GET_STRICT_CHK, true); + if (r < 0) + log_debug_errno(r, "sd-netlink: Failed to enable NETLINK_GET_STRICT_CHK option, ignoring: %m"); + + r = socket_bind(nl); + if (r < 0) { + nl->fd = -EBADF; /* on failure, the caller remains owner of the fd, hence don't close it here */ + nl->protocol = -1; + return r; + } + + *ret = TAKE_PTR(nl); + + return 0; +} + +int sd_netlink_open(sd_netlink **ret) { + return netlink_open_family(ret, NETLINK_ROUTE); +} + +int sd_netlink_increase_rxbuf(sd_netlink *nl, size_t size) { + assert_return(nl, -EINVAL); + assert_return(!netlink_pid_changed(nl), -ECHILD); + + return fd_increase_rxbuf(nl->fd, size); +} + +static sd_netlink *netlink_free(sd_netlink *nl) { + sd_netlink_slot *s; + + assert(nl); + + ordered_set_free(nl->rqueue); + hashmap_free(nl->rqueue_by_serial); + hashmap_free(nl->rqueue_partial_by_serial); + free(nl->rbuffer); + + while ((s = nl->slots)) { + assert(s->floating); + netlink_slot_disconnect(s, true); + } + hashmap_free(nl->reply_callbacks); + prioq_free(nl->reply_callbacks_prioq); + + sd_event_source_unref(nl->io_event_source); + sd_event_source_unref(nl->time_event_source); + sd_event_unref(nl->event); + + hashmap_free(nl->broadcast_group_refs); + + genl_clear_family(nl); + + safe_close(nl->fd); + return mfree(nl); +} + +DEFINE_TRIVIAL_REF_UNREF_FUNC(sd_netlink, sd_netlink, netlink_free); + +int sd_netlink_send( + sd_netlink *nl, + sd_netlink_message *message, + uint32_t *serial) { + + int r; + + assert_return(nl, -EINVAL); + assert_return(!netlink_pid_changed(nl), -ECHILD); + assert_return(message, -EINVAL); + assert_return(!message->sealed, -EPERM); + + netlink_seal_message(nl, message); + + r = socket_write_message(nl, message); + if (r < 0) + return r; + + if (serial) + *serial = message_get_serial(message); + + return 1; +} + +static int dispatch_rqueue(sd_netlink *nl, sd_netlink_message **ret) { + sd_netlink_message *m; + int r; + + assert(nl); + assert(ret); + + if (ordered_set_size(nl->rqueue) <= 0) { + /* Try to read a new message */ + r = socket_read_message(nl); + if (r == -ENOBUFS) /* FIXME: ignore buffer overruns for now */ + log_debug_errno(r, "sd-netlink: Got ENOBUFS from netlink socket, ignoring."); + else if (r < 0) + return r; + } + + /* Dispatch a queued message */ + m = ordered_set_steal_first(nl->rqueue); + if (m) + sd_netlink_message_unref(hashmap_remove_value(nl->rqueue_by_serial, UINT32_TO_PTR(message_get_serial(m)), m)); + *ret = m; + return !!m; +} + +static int process_timeout(sd_netlink *nl) { + _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL; + struct reply_callback *c; + sd_netlink_slot *slot; + usec_t n; + int r; + + assert(nl); + + c = prioq_peek(nl->reply_callbacks_prioq); + if (!c) + return 0; + + n = now(CLOCK_MONOTONIC); + if (c->timeout > n) + return 0; + + r = message_new_synthetic_error(nl, -ETIMEDOUT, c->serial, &m); + if (r < 0) + return r; + + assert_se(prioq_pop(nl->reply_callbacks_prioq) == c); + hashmap_remove(nl->reply_callbacks, UINT32_TO_PTR(c->serial)); + + slot = container_of(c, sd_netlink_slot, reply_callback); + + r = c->callback(nl, m, slot->userdata); + if (r < 0) + log_debug_errno(r, "sd-netlink: timedout callback %s%s%sfailed: %m", + slot->description ? "'" : "", + strempty(slot->description), + slot->description ? "' " : ""); + + if (slot->floating) + netlink_slot_disconnect(slot, true); + + return 1; +} + +static int process_reply(sd_netlink *nl, sd_netlink_message *m) { + struct reply_callback *c; + sd_netlink_slot *slot; + uint32_t serial; + uint16_t type; + int r; + + assert(nl); + assert(m); + + serial = message_get_serial(m); + c = hashmap_remove(nl->reply_callbacks, UINT32_TO_PTR(serial)); + if (!c) + return 0; + + if (c->timeout != USEC_INFINITY) + prioq_remove(nl->reply_callbacks_prioq, c, &c->prioq_idx); + + r = sd_netlink_message_get_type(m, &type); + if (r < 0) + return r; + + if (type == NLMSG_DONE) + m = NULL; + + slot = container_of(c, sd_netlink_slot, reply_callback); + + r = c->callback(nl, m, slot->userdata); + if (r < 0) + log_debug_errno(r, "sd-netlink: reply callback %s%s%sfailed: %m", + slot->description ? "'" : "", + strempty(slot->description), + slot->description ? "' " : ""); + + if (slot->floating) + netlink_slot_disconnect(slot, true); + + return 1; +} + +static int process_match(sd_netlink *nl, sd_netlink_message *m) { + uint16_t type; + uint8_t cmd; + int r; + + assert(nl); + assert(m); + + r = sd_netlink_message_get_type(m, &type); + if (r < 0) + return r; + + if (m->protocol == NETLINK_GENERIC) { + r = sd_genl_message_get_command(nl, m, &cmd); + if (r < 0) + return r; + } else + cmd = 0; + + LIST_FOREACH(match_callbacks, c, nl->match_callbacks) { + sd_netlink_slot *slot; + bool found = false; + + if (c->type != type) + continue; + if (c->cmd != 0 && c->cmd != cmd) + continue; + + for (size_t i = 0; i < c->n_groups; i++) + if (c->groups[i] == m->multicast_group) { + found = true; + break; + } + + if (!found) + continue; + + slot = container_of(c, sd_netlink_slot, match_callback); + + r = c->callback(nl, m, slot->userdata); + if (r < 0) + log_debug_errno(r, "sd-netlink: match callback %s%s%sfailed: %m", + slot->description ? "'" : "", + strempty(slot->description), + slot->description ? "' " : ""); + if (r != 0) + break; + } + + return 1; +} + +static int process_running(sd_netlink *nl, sd_netlink_message **ret) { + _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL; + int r; + + assert(nl); + + r = process_timeout(nl); + if (r != 0) + goto null_message; + + r = dispatch_rqueue(nl, &m); + if (r < 0) + return r; + if (!m) + goto null_message; + + if (sd_netlink_message_is_broadcast(m)) + r = process_match(nl, m); + else + r = process_reply(nl, m); + if (r != 0) + goto null_message; + + if (ret) { + *ret = TAKE_PTR(m); + + return 1; + } + + return 1; + +null_message: + if (r >= 0 && ret) + *ret = NULL; + + return r; +} + +int sd_netlink_process(sd_netlink *nl, sd_netlink_message **ret) { + NETLINK_DONT_DESTROY(nl); + int r; + + assert_return(nl, -EINVAL); + assert_return(!netlink_pid_changed(nl), -ECHILD); + assert_return(!nl->processing, -EBUSY); + + nl->processing = true; + r = process_running(nl, ret); + nl->processing = false; + + return r; +} + +static usec_t timespan_to_timestamp(usec_t usec) { + static bool default_timeout_set = false; + static usec_t default_timeout; + int r; + + if (usec == 0) { + if (!default_timeout_set) { + const char *e; + + default_timeout_set = true; + default_timeout = NETLINK_DEFAULT_TIMEOUT_USEC; + + e = secure_getenv("SYSTEMD_NETLINK_DEFAULT_TIMEOUT"); + if (e) { + r = parse_sec(e, &default_timeout); + if (r < 0) + log_debug_errno(r, "sd-netlink: Failed to parse $SYSTEMD_NETLINK_DEFAULT_TIMEOUT environment variable, ignoring: %m"); + } + } + + usec = default_timeout; + } + + return usec_add(now(CLOCK_MONOTONIC), usec); +} + +static int netlink_poll(sd_netlink *nl, bool need_more, usec_t timeout_usec) { + usec_t m = USEC_INFINITY; + int r, e; + + assert(nl); + + e = sd_netlink_get_events(nl); + 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(nl, &until); + if (r < 0) + return r; + + m = usec_sub_unsigned(until, now(CLOCK_MONOTONIC)); + } + + r = fd_wait_for_event(nl->fd, e, MIN(m, timeout_usec)); + if (r <= 0) + return r; + + return 1; +} + +int sd_netlink_wait(sd_netlink *nl, uint64_t timeout_usec) { + int r; + + assert_return(nl, -EINVAL); + assert_return(!netlink_pid_changed(nl), -ECHILD); + + if (ordered_set_size(nl->rqueue) > 0) + return 0; + + r = netlink_poll(nl, false, timeout_usec); + if (ERRNO_IS_NEG_TRANSIENT(r)) /* Convert EINTR to "something happened" and give user a chance to run some code before calling back into us */ + return 1; + return r; +} + +static int timeout_compare(const void *a, const void *b) { + const struct reply_callback *x = a, *y = b; + + return CMP(x->timeout, y->timeout); +} + +size_t netlink_get_reply_callback_count(sd_netlink *nl) { + assert(nl); + + return hashmap_size(nl->reply_callbacks); +} + +int sd_netlink_call_async( + sd_netlink *nl, + sd_netlink_slot **ret_slot, + sd_netlink_message *m, + sd_netlink_message_handler_t callback, + sd_netlink_destroy_t destroy_callback, + void *userdata, + uint64_t usec, + const char *description) { + + _cleanup_free_ sd_netlink_slot *slot = NULL; + int r, k; + + assert_return(nl, -EINVAL); + assert_return(m, -EINVAL); + assert_return(callback, -EINVAL); + assert_return(!netlink_pid_changed(nl), -ECHILD); + + if (hashmap_size(nl->reply_callbacks) >= REPLY_CALLBACKS_MAX) + return -EXFULL; + + r = hashmap_ensure_allocated(&nl->reply_callbacks, &trivial_hash_ops); + if (r < 0) + return r; + + if (usec != UINT64_MAX) { + r = prioq_ensure_allocated(&nl->reply_callbacks_prioq, timeout_compare); + if (r < 0) + return r; + } + + r = netlink_slot_allocate(nl, !ret_slot, NETLINK_REPLY_CALLBACK, sizeof(struct reply_callback), userdata, description, &slot); + if (r < 0) + return r; + + slot->reply_callback.callback = callback; + slot->reply_callback.timeout = timespan_to_timestamp(usec); + + k = sd_netlink_send(nl, m, &slot->reply_callback.serial); + if (k < 0) + return k; + + r = hashmap_put(nl->reply_callbacks, UINT32_TO_PTR(slot->reply_callback.serial), &slot->reply_callback); + if (r < 0) + return r; + + if (slot->reply_callback.timeout != USEC_INFINITY) { + r = prioq_put(nl->reply_callbacks_prioq, &slot->reply_callback, &slot->reply_callback.prioq_idx); + if (r < 0) { + (void) hashmap_remove(nl->reply_callbacks, UINT32_TO_PTR(slot->reply_callback.serial)); + return r; + } + } + + /* Set this at last. Otherwise, some failures in above would call destroy_callback but some would not. */ + slot->destroy_callback = destroy_callback; + + if (ret_slot) + *ret_slot = slot; + + TAKE_PTR(slot); + + return k; +} + +int sd_netlink_read( + sd_netlink *nl, + uint32_t serial, + uint64_t usec, + sd_netlink_message **ret) { + + usec_t timeout; + int r; + + assert_return(nl, -EINVAL); + assert_return(!netlink_pid_changed(nl), -ECHILD); + + timeout = timespan_to_timestamp(usec); + + for (;;) { + _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL; + usec_t left; + + m = hashmap_remove(nl->rqueue_by_serial, UINT32_TO_PTR(serial)); + if (m) { + uint16_t type; + + /* found a match, remove from rqueue and return it */ + sd_netlink_message_unref(ordered_set_remove(nl->rqueue, m)); + + r = sd_netlink_message_get_errno(m); + if (r < 0) + return r; + + r = sd_netlink_message_get_type(m, &type); + if (r < 0) + return r; + + if (type == NLMSG_DONE) { + if (ret) + *ret = NULL; + return 0; + } + + if (ret) + *ret = TAKE_PTR(m); + return 1; + } + + r = socket_read_message(nl); + if (r < 0) + return r; + if (r > 0) + /* received message, so try to process straight away */ + continue; + + if (timeout != USEC_INFINITY) { + usec_t n; + + n = now(CLOCK_MONOTONIC); + if (n >= timeout) + return -ETIMEDOUT; + + left = usec_sub_unsigned(timeout, n); + } else + left = USEC_INFINITY; + + r = netlink_poll(nl, true, left); + if (r < 0) + return r; + if (r == 0) + return -ETIMEDOUT; + } +} + +int sd_netlink_call( + sd_netlink *nl, + sd_netlink_message *message, + uint64_t usec, + sd_netlink_message **ret) { + + uint32_t serial; + int r; + + assert_return(nl, -EINVAL); + assert_return(!netlink_pid_changed(nl), -ECHILD); + assert_return(message, -EINVAL); + + r = sd_netlink_send(nl, message, &serial); + if (r < 0) + return r; + + return sd_netlink_read(nl, serial, usec, ret); +} + +int sd_netlink_get_events(sd_netlink *nl) { + assert_return(nl, -EINVAL); + assert_return(!netlink_pid_changed(nl), -ECHILD); + + return ordered_set_size(nl->rqueue) == 0 ? POLLIN : 0; +} + +int sd_netlink_get_timeout(sd_netlink *nl, uint64_t *timeout_usec) { + struct reply_callback *c; + + assert_return(nl, -EINVAL); + assert_return(timeout_usec, -EINVAL); + assert_return(!netlink_pid_changed(nl), -ECHILD); + + if (ordered_set_size(nl->rqueue) > 0) { + *timeout_usec = 0; + return 1; + } + + c = prioq_peek(nl->reply_callbacks_prioq); + if (!c) { + *timeout_usec = UINT64_MAX; + 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 *nl = ASSERT_PTR(userdata); + int r; + + r = sd_netlink_process(nl, NULL); + if (r < 0) + return r; + + return 1; +} + +static int time_callback(sd_event_source *s, uint64_t usec, void *userdata) { + sd_netlink *nl = ASSERT_PTR(userdata); + int r; + + r = sd_netlink_process(nl, NULL); + if (r < 0) + return r; + + return 1; +} + +static int prepare_callback(sd_event_source *s, void *userdata) { + sd_netlink *nl = ASSERT_PTR(userdata); + int r, enabled; + usec_t until; + + assert(s); + + r = sd_netlink_get_events(nl); + if (r < 0) + return r; + + r = sd_event_source_set_io_events(nl->io_event_source, r); + if (r < 0) + return r; + + enabled = sd_netlink_get_timeout(nl, &until); + if (enabled < 0) + return enabled; + if (enabled > 0) { + r = sd_event_source_set_time(nl->time_event_source, until); + if (r < 0) + return r; + } + + r = sd_event_source_set_enabled(nl->time_event_source, + enabled > 0 ? SD_EVENT_ONESHOT : SD_EVENT_OFF); + if (r < 0) + return r; + + return 1; +} + +int sd_netlink_attach_event(sd_netlink *nl, sd_event *event, int64_t priority) { + int r; + + assert_return(nl, -EINVAL); + assert_return(!nl->event, -EBUSY); + + assert(!nl->io_event_source); + assert(!nl->time_event_source); + + if (event) + nl->event = sd_event_ref(event); + else { + r = sd_event_default(&nl->event); + if (r < 0) + return r; + } + + r = sd_event_add_io(nl->event, &nl->io_event_source, nl->fd, 0, io_callback, nl); + if (r < 0) + goto fail; + + r = sd_event_source_set_priority(nl->io_event_source, priority); + if (r < 0) + goto fail; + + r = sd_event_source_set_description(nl->io_event_source, "netlink-receive-message"); + if (r < 0) + goto fail; + + r = sd_event_source_set_prepare(nl->io_event_source, prepare_callback); + if (r < 0) + goto fail; + + r = sd_event_add_time(nl->event, &nl->time_event_source, CLOCK_MONOTONIC, 0, 0, time_callback, nl); + if (r < 0) + goto fail; + + r = sd_event_source_set_priority(nl->time_event_source, priority); + if (r < 0) + goto fail; + + r = sd_event_source_set_description(nl->time_event_source, "netlink-timer"); + if (r < 0) + goto fail; + + return 0; + +fail: + sd_netlink_detach_event(nl); + return r; +} + +int sd_netlink_detach_event(sd_netlink *nl) { + assert_return(nl, -EINVAL); + assert_return(nl->event, -ENXIO); + + nl->io_event_source = sd_event_source_unref(nl->io_event_source); + + nl->time_event_source = sd_event_source_unref(nl->time_event_source); + + nl->event = sd_event_unref(nl->event); + + return 0; +} + +sd_event* sd_netlink_get_event(sd_netlink *nl) { + assert_return(nl, NULL); + + return nl->event; +} + +int netlink_add_match_internal( + sd_netlink *nl, + sd_netlink_slot **ret_slot, + const uint32_t *groups, + size_t n_groups, + uint16_t type, + uint8_t cmd, + sd_netlink_message_handler_t callback, + sd_netlink_destroy_t destroy_callback, + void *userdata, + const char *description) { + + _cleanup_free_ sd_netlink_slot *slot = NULL; + int r; + + assert(groups); + assert(n_groups > 0); + + for (size_t i = 0; i < n_groups; i++) { + r = socket_broadcast_group_ref(nl, groups[i]); + if (r < 0) + return r; + } + + r = netlink_slot_allocate(nl, !ret_slot, NETLINK_MATCH_CALLBACK, sizeof(struct match_callback), + userdata, description, &slot); + if (r < 0) + return r; + + slot->match_callback.groups = newdup(uint32_t, groups, n_groups); + if (!slot->match_callback.groups) + return -ENOMEM; + + slot->match_callback.n_groups = n_groups; + slot->match_callback.callback = callback; + slot->match_callback.type = type; + slot->match_callback.cmd = cmd; + + LIST_PREPEND(match_callbacks, nl->match_callbacks, &slot->match_callback); + + /* Set this at last. Otherwise, some failures in above call the destroy callback but some do not. */ + slot->destroy_callback = destroy_callback; + + if (ret_slot) + *ret_slot = slot; + + TAKE_PTR(slot); + return 0; +} + +int sd_netlink_add_match( + sd_netlink *rtnl, + sd_netlink_slot **ret_slot, + uint16_t type, + sd_netlink_message_handler_t callback, + sd_netlink_destroy_t destroy_callback, + void *userdata, + const char *description) { + + static const uint32_t + address_groups[] = { RTNLGRP_IPV4_IFADDR, RTNLGRP_IPV6_IFADDR, }, + link_groups[] = { RTNLGRP_LINK, }, + neighbor_groups[] = { RTNLGRP_NEIGH, }, + nexthop_groups[] = { RTNLGRP_NEXTHOP, }, + route_groups[] = { RTNLGRP_IPV4_ROUTE, RTNLGRP_IPV6_ROUTE, }, + rule_groups[] = { RTNLGRP_IPV4_RULE, RTNLGRP_IPV6_RULE, }, + tc_groups[] = { RTNLGRP_TC }; + const uint32_t *groups; + size_t n_groups; + + assert_return(rtnl, -EINVAL); + assert_return(callback, -EINVAL); + assert_return(!netlink_pid_changed(rtnl), -ECHILD); + + switch (type) { + case RTM_NEWLINK: + case RTM_DELLINK: + groups = link_groups; + n_groups = ELEMENTSOF(link_groups); + break; + case RTM_NEWADDR: + case RTM_DELADDR: + groups = address_groups; + n_groups = ELEMENTSOF(address_groups); + break; + case RTM_NEWNEIGH: + case RTM_DELNEIGH: + groups = neighbor_groups; + n_groups = ELEMENTSOF(neighbor_groups); + break; + case RTM_NEWROUTE: + case RTM_DELROUTE: + groups = route_groups; + n_groups = ELEMENTSOF(route_groups); + break; + case RTM_NEWRULE: + case RTM_DELRULE: + groups = rule_groups; + n_groups = ELEMENTSOF(rule_groups); + break; + case RTM_NEWNEXTHOP: + case RTM_DELNEXTHOP: + groups = nexthop_groups; + n_groups = ELEMENTSOF(nexthop_groups); + break; + case RTM_NEWQDISC: + case RTM_DELQDISC: + case RTM_NEWTCLASS: + case RTM_DELTCLASS: + groups = tc_groups; + n_groups = ELEMENTSOF(tc_groups); + break; + default: + return -EOPNOTSUPP; + } + + return netlink_add_match_internal(rtnl, ret_slot, groups, n_groups, type, 0, callback, + destroy_callback, userdata, description); +} + +int sd_netlink_attach_filter(sd_netlink *nl, size_t len, const struct sock_filter *filter) { + assert_return(nl, -EINVAL); + assert_return(len == 0 || filter, -EINVAL); + + if (setsockopt(nl->fd, SOL_SOCKET, + len == 0 ? SO_DETACH_FILTER : SO_ATTACH_FILTER, + &(struct sock_fprog) { + .len = len, + .filter = (struct sock_filter*) filter, + }, sizeof(struct sock_fprog)) < 0) + return -errno; + + return 0; +} |