2 * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2016 Nicira, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
18 #include "netlink-socket.h"
22 #include <sys/types.h>
26 #include "openvswitch/dynamic-string.h"
30 #include "netlink-protocol.h"
31 #include "odp-netlink.h"
32 #include "openvswitch/ofpbuf.h"
33 #include "ovs-thread.h"
34 #include "poll-loop.h"
36 #include "socket-util.h"
38 #include "openvswitch/vlog.h"
40 VLOG_DEFINE_THIS_MODULE(netlink_socket);
42 COVERAGE_DEFINE(netlink_overflow);
43 COVERAGE_DEFINE(netlink_received);
44 COVERAGE_DEFINE(netlink_recv_jumbo);
45 COVERAGE_DEFINE(netlink_sent);
47 /* Linux header file confusion causes this to be undefined. */
49 #define SOL_NETLINK 270
52 /* A single (bad) Netlink message can in theory dump out many, many log
53 * messages, so the burst size is set quite high here to avoid missing useful
54 * information. Also, at high logging levels we log *all* Netlink messages. */
55 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(60, 600);
57 static uint32_t nl_sock_allocate_seq(struct nl_sock *, unsigned int n);
58 static void log_nlmsg(const char *function, int error,
59 const void *message, size_t size, int protocol);
61 static int get_sock_pid_from_kernel(struct nl_sock *sock);
62 static int set_sock_property(struct nl_sock *sock);
65 /* Netlink sockets. */
70 OVERLAPPED overlapped;
78 unsigned int rcvbuf; /* Receive buffer size (SO_RCVBUF). */
81 /* Compile-time limit on iovecs, so that we can allocate a maximum-size array
82 * of iovecs on the stack. */
85 /* Maximum number of iovecs that may be passed to sendmsg, capped at a
86 * minimum of _XOPEN_IOV_MAX (16) and a maximum of MAX_IOVS.
88 * Initialized by nl_sock_create(). */
91 static int nl_pool_alloc(int protocol, struct nl_sock **sockp);
92 static void nl_pool_release(struct nl_sock *);
94 /* Creates a new netlink socket for the given netlink 'protocol'
95 * (NETLINK_ROUTE, NETLINK_GENERIC, ...). Returns 0 and sets '*sockp' to the
96 * new socket if successful, otherwise returns a positive errno value. */
98 nl_sock_create(int protocol, struct nl_sock **sockp)
100 static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER;
101 struct nl_sock *sock;
103 struct sockaddr_nl local, remote;
105 socklen_t local_size;
109 if (ovsthread_once_start(&once)) {
110 int save_errno = errno;
113 max_iovs = sysconf(_SC_UIO_MAXIOV);
114 if (max_iovs < _XOPEN_IOV_MAX) {
115 if (max_iovs == -1 && errno) {
116 VLOG_WARN("sysconf(_SC_UIO_MAXIOV): %s", ovs_strerror(errno));
118 max_iovs = _XOPEN_IOV_MAX;
119 } else if (max_iovs > MAX_IOVS) {
124 ovsthread_once_done(&once);
128 sock = xmalloc(sizeof *sock);
131 sock->overlapped.hEvent = NULL;
132 sock->handle = CreateFile(OVS_DEVICE_NAME_USER,
133 GENERIC_READ | GENERIC_WRITE,
134 FILE_SHARE_READ | FILE_SHARE_WRITE,
136 FILE_FLAG_OVERLAPPED, NULL);
138 if (sock->handle == INVALID_HANDLE_VALUE) {
139 VLOG_ERR("fcntl: %s", ovs_lasterror_to_string());
143 memset(&sock->overlapped, 0, sizeof sock->overlapped);
144 sock->overlapped.hEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
145 if (sock->overlapped.hEvent == NULL) {
146 VLOG_ERR("fcntl: %s", ovs_lasterror_to_string());
149 /* Initialize the type/ioctl to Generic */
150 sock->read_ioctl = OVS_IOCTL_READ;
152 sock->fd = socket(AF_NETLINK, SOCK_RAW, protocol);
154 VLOG_ERR("fcntl: %s", ovs_strerror(errno));
159 sock->protocol = protocol;
162 rcvbuf = 1024 * 1024;
164 sock->rcvbuf = rcvbuf;
165 retval = get_sock_pid_from_kernel(sock);
169 retval = set_sock_property(sock);
174 if (setsockopt(sock->fd, SOL_SOCKET, SO_RCVBUFFORCE,
175 &rcvbuf, sizeof rcvbuf)) {
176 /* Only root can use SO_RCVBUFFORCE. Everyone else gets EPERM.
177 * Warn only if the failure is therefore unexpected. */
178 if (errno != EPERM) {
179 VLOG_WARN_RL(&rl, "setting %d-byte socket receive buffer failed "
180 "(%s)", rcvbuf, ovs_strerror(errno));
184 retval = get_socket_rcvbuf(sock->fd);
189 sock->rcvbuf = retval;
192 /* Connect to kernel (pid 0) as remote address. */
193 memset(&remote, 0, sizeof remote);
194 remote.nl_family = AF_NETLINK;
196 if (connect(sock->fd, (struct sockaddr *) &remote, sizeof remote) < 0) {
197 VLOG_ERR("connect(0): %s", ovs_strerror(errno));
201 /* Obtain pid assigned by kernel. */
202 local_size = sizeof local;
203 if (getsockname(sock->fd, (struct sockaddr *) &local, &local_size) < 0) {
204 VLOG_ERR("getsockname: %s", ovs_strerror(errno));
207 if (local_size < sizeof local || local.nl_family != AF_NETLINK) {
208 VLOG_ERR("getsockname returned bad Netlink name");
212 sock->pid = local.nl_pid;
226 if (sock->overlapped.hEvent) {
227 CloseHandle(sock->overlapped.hEvent);
229 if (sock->handle != INVALID_HANDLE_VALUE) {
230 CloseHandle(sock->handle);
241 /* Creates a new netlink socket for the same protocol as 'src'. Returns 0 and
242 * sets '*sockp' to the new socket if successful, otherwise returns a positive
245 nl_sock_clone(const struct nl_sock *src, struct nl_sock **sockp)
247 return nl_sock_create(src->protocol, sockp);
250 /* Destroys netlink socket 'sock'. */
252 nl_sock_destroy(struct nl_sock *sock)
256 if (sock->overlapped.hEvent) {
257 CloseHandle(sock->overlapped.hEvent);
259 CloseHandle(sock->handle);
268 /* Reads the pid for 'sock' generated in the kernel datapath. The function
269 * uses a separate IOCTL instead of a transaction semantic to avoid unnecessary
270 * message overhead. */
272 get_sock_pid_from_kernel(struct nl_sock *sock)
278 if (!DeviceIoControl(sock->handle, OVS_IOCTL_GET_PID,
279 NULL, 0, &pid, sizeof(pid),
283 if (bytes < sizeof(pid)) {
293 /* Used for setting and managing socket properties in userspace and kernel.
294 * Currently two attributes are tracked - pid and protocol
295 * protocol - supplied by userspace based on the netlink family. Windows uses
296 * this property to set the value in kernel datapath.
297 * eg: (NETLINK_GENERIC/ NETLINK_NETFILTER)
298 * pid - generated by windows kernel and set in userspace. The property
300 * Also verify if Protocol and PID in Kernel reflects the values in userspace
303 set_sock_property(struct nl_sock *sock)
305 static const struct nl_policy ovs_socket_policy[] = {
306 [OVS_NL_ATTR_SOCK_PROTO] = { .type = NL_A_BE32, .optional = true },
307 [OVS_NL_ATTR_SOCK_PID] = { .type = NL_A_BE32, .optional = true }
310 struct ofpbuf request, *reply;
311 struct ovs_header *ovs_header;
312 struct nlattr *attrs[ARRAY_SIZE(ovs_socket_policy)];
316 ofpbuf_init(&request, 0);
317 nl_msg_put_genlmsghdr(&request, 0, OVS_WIN_NL_CTRL_FAMILY_ID, 0,
318 OVS_CTRL_CMD_SOCK_PROP, OVS_WIN_CONTROL_VERSION);
319 ovs_header = ofpbuf_put_uninit(&request, sizeof *ovs_header);
320 ovs_header->dp_ifindex = 0;
322 nl_msg_put_be32(&request, OVS_NL_ATTR_SOCK_PROTO, sock->protocol);
323 /* pid is already set as part of get_sock_pid_from_kernel()
324 * This is added to maintain consistency
326 nl_msg_put_be32(&request, OVS_NL_ATTR_SOCK_PID, sock->pid);
328 error = nl_sock_transact(sock, &request, &reply);
329 ofpbuf_uninit(&request);
334 if (!nl_policy_parse(reply,
335 NLMSG_HDRLEN + GENL_HDRLEN + sizeof *ovs_header,
336 ovs_socket_policy, attrs,
337 ARRAY_SIZE(ovs_socket_policy))) {
338 ofpbuf_delete(reply);
341 /* Verify if the properties are setup properly */
342 if (attrs[OVS_NL_ATTR_SOCK_PROTO]) {
343 int protocol = nl_attr_get_be32(attrs[OVS_NL_ATTR_SOCK_PROTO]);
344 if (protocol != sock->protocol) {
345 VLOG_ERR("Invalid protocol returned:%d expected:%d",
346 protocol, sock->protocol);
351 if (attrs[OVS_NL_ATTR_SOCK_PID]) {
352 int pid = nl_attr_get_be32(attrs[OVS_NL_ATTR_SOCK_PID]);
353 if (pid != sock->pid) {
354 VLOG_ERR("Invalid pid returned:%d expected:%d",
366 nl_sock_mcgroup(struct nl_sock *sock, unsigned int multicast_group, bool join)
368 struct ofpbuf request;
369 uint64_t request_stub[128];
370 struct ovs_header *ovs_header;
371 struct nlmsghdr *nlmsg;
374 ofpbuf_use_stub(&request, request_stub, sizeof request_stub);
376 nl_msg_put_genlmsghdr(&request, 0, OVS_WIN_NL_CTRL_FAMILY_ID, 0,
377 OVS_CTRL_CMD_MC_SUBSCRIBE_REQ,
378 OVS_WIN_CONTROL_VERSION);
380 ovs_header = ofpbuf_put_uninit(&request, sizeof *ovs_header);
381 ovs_header->dp_ifindex = 0;
383 nl_msg_put_u32(&request, OVS_NL_ATTR_MCAST_GRP, multicast_group);
384 nl_msg_put_u8(&request, OVS_NL_ATTR_MCAST_JOIN, join ? 1 : 0);
386 error = nl_sock_send(sock, &request, true);
387 ofpbuf_uninit(&request);
391 /* Tries to add 'sock' as a listener for 'multicast_group'. Returns 0 if
392 * successful, otherwise a positive errno value.
394 * A socket that is subscribed to a multicast group that receives asynchronous
395 * notifications must not be used for Netlink transactions or dumps, because
396 * transactions and dumps can cause notifications to be lost.
398 * Multicast group numbers are always positive.
400 * It is not an error to attempt to join a multicast group to which a socket
401 * already belongs. */
403 nl_sock_join_mcgroup(struct nl_sock *sock, unsigned int multicast_group)
406 /* Set the socket type as a "multicast" socket */
407 sock->read_ioctl = OVS_IOCTL_READ_EVENT;
408 int error = nl_sock_mcgroup(sock, multicast_group, true);
410 sock->read_ioctl = OVS_IOCTL_READ;
411 VLOG_WARN("could not join multicast group %u (%s)",
412 multicast_group, ovs_strerror(error));
416 if (setsockopt(sock->fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP,
417 &multicast_group, sizeof multicast_group) < 0) {
418 VLOG_WARN("could not join multicast group %u (%s)",
419 multicast_group, ovs_strerror(errno));
428 nl_sock_subscribe_packets(struct nl_sock *sock)
432 if (sock->read_ioctl != OVS_IOCTL_READ) {
436 error = nl_sock_subscribe_packet__(sock, true);
438 VLOG_WARN("could not subscribe packets (%s)",
439 ovs_strerror(error));
442 sock->read_ioctl = OVS_IOCTL_READ_PACKET;
448 nl_sock_unsubscribe_packets(struct nl_sock *sock)
450 ovs_assert(sock->read_ioctl == OVS_IOCTL_READ_PACKET);
452 int error = nl_sock_subscribe_packet__(sock, false);
454 VLOG_WARN("could not unsubscribe to packets (%s)",
455 ovs_strerror(error));
459 sock->read_ioctl = OVS_IOCTL_READ;
464 nl_sock_subscribe_packet__(struct nl_sock *sock, bool subscribe)
466 struct ofpbuf request;
467 uint64_t request_stub[128];
468 struct ovs_header *ovs_header;
469 struct nlmsghdr *nlmsg;
472 ofpbuf_use_stub(&request, request_stub, sizeof request_stub);
473 nl_msg_put_genlmsghdr(&request, 0, OVS_WIN_NL_CTRL_FAMILY_ID, 0,
474 OVS_CTRL_CMD_PACKET_SUBSCRIBE_REQ,
475 OVS_WIN_CONTROL_VERSION);
477 ovs_header = ofpbuf_put_uninit(&request, sizeof *ovs_header);
478 ovs_header->dp_ifindex = 0;
479 nl_msg_put_u8(&request, OVS_NL_ATTR_PACKET_SUBSCRIBE, subscribe ? 1 : 0);
480 nl_msg_put_u32(&request, OVS_NL_ATTR_PACKET_PID, sock->pid);
482 error = nl_sock_send(sock, &request, true);
483 ofpbuf_uninit(&request);
488 /* Tries to make 'sock' stop listening to 'multicast_group'. Returns 0 if
489 * successful, otherwise a positive errno value.
491 * Multicast group numbers are always positive.
493 * It is not an error to attempt to leave a multicast group to which a socket
496 * On success, reading from 'sock' will still return any messages that were
497 * received on 'multicast_group' before the group was left. */
499 nl_sock_leave_mcgroup(struct nl_sock *sock, unsigned int multicast_group)
502 int error = nl_sock_mcgroup(sock, multicast_group, false);
504 VLOG_WARN("could not leave multicast group %u (%s)",
505 multicast_group, ovs_strerror(error));
508 sock->read_ioctl = OVS_IOCTL_READ;
510 if (setsockopt(sock->fd, SOL_NETLINK, NETLINK_DROP_MEMBERSHIP,
511 &multicast_group, sizeof multicast_group) < 0) {
512 VLOG_WARN("could not leave multicast group %u (%s)",
513 multicast_group, ovs_strerror(errno));
521 nl_sock_send__(struct nl_sock *sock, const struct ofpbuf *msg,
522 uint32_t nlmsg_seq, bool wait)
524 struct nlmsghdr *nlmsg = nl_msg_nlmsghdr(msg);
527 nlmsg->nlmsg_len = msg->size;
528 nlmsg->nlmsg_seq = nlmsg_seq;
529 nlmsg->nlmsg_pid = sock->pid;
535 if (!DeviceIoControl(sock->handle, OVS_IOCTL_WRITE,
536 msg->data, msg->size, NULL, 0,
539 /* XXX: Map to a more appropriate error based on GetLastError(). */
541 VLOG_DBG_RL(&rl, "fatal driver failure in write: %s",
542 ovs_lasterror_to_string());
547 retval = send(sock->fd, msg->data, msg->size,
548 wait ? 0 : MSG_DONTWAIT);
550 error = retval < 0 ? errno : 0;
551 } while (error == EINTR);
552 log_nlmsg(__func__, error, msg->data, msg->size, sock->protocol);
554 COVERAGE_INC(netlink_sent);
559 /* Tries to send 'msg', which must contain a Netlink message, to the kernel on
560 * 'sock'. nlmsg_len in 'msg' will be finalized to match msg->size, nlmsg_pid
561 * will be set to 'sock''s pid, and nlmsg_seq will be initialized to a fresh
562 * sequence number, before the message is sent.
564 * Returns 0 if successful, otherwise a positive errno value. If
565 * 'wait' is true, then the send will wait until buffer space is ready;
566 * otherwise, returns EAGAIN if the 'sock' send buffer is full. */
568 nl_sock_send(struct nl_sock *sock, const struct ofpbuf *msg, bool wait)
570 return nl_sock_send_seq(sock, msg, nl_sock_allocate_seq(sock, 1), wait);
573 /* Tries to send 'msg', which must contain a Netlink message, to the kernel on
574 * 'sock'. nlmsg_len in 'msg' will be finalized to match msg->size, nlmsg_pid
575 * will be set to 'sock''s pid, and nlmsg_seq will be initialized to
576 * 'nlmsg_seq', before the message is sent.
578 * Returns 0 if successful, otherwise a positive errno value. If
579 * 'wait' is true, then the send will wait until buffer space is ready;
580 * otherwise, returns EAGAIN if the 'sock' send buffer is full.
582 * This function is suitable for sending a reply to a request that was received
583 * with sequence number 'nlmsg_seq'. Otherwise, use nl_sock_send() instead. */
585 nl_sock_send_seq(struct nl_sock *sock, const struct ofpbuf *msg,
586 uint32_t nlmsg_seq, bool wait)
588 return nl_sock_send__(sock, msg, nlmsg_seq, wait);
592 nl_sock_recv__(struct nl_sock *sock, struct ofpbuf *buf, bool wait)
594 /* We can't accurately predict the size of the data to be received. The
595 * caller is supposed to have allocated enough space in 'buf' to handle the
596 * "typical" case. To handle exceptions, we make available enough space in
597 * 'tail' to allow Netlink messages to be up to 64 kB long (a reasonable
598 * figure since that's the maximum length of a Netlink attribute). */
599 struct nlmsghdr *nlmsghdr;
606 ovs_assert(buf->allocated >= sizeof *nlmsghdr);
609 iov[0].iov_base = buf->base;
610 iov[0].iov_len = buf->allocated;
611 iov[1].iov_base = tail;
612 iov[1].iov_len = sizeof tail;
614 memset(&msg, 0, sizeof msg);
618 /* Receive a Netlink message from the kernel.
620 * This works around a kernel bug in which the kernel returns an error code
621 * as if it were the number of bytes read. It doesn't actually modify
622 * anything in the receive buffer in that case, so we can initialize the
623 * Netlink header with an impossible message length and then, upon success,
624 * check whether it changed. */
625 nlmsghdr = buf->base;
627 nlmsghdr->nlmsg_len = UINT32_MAX;
630 if (!DeviceIoControl(sock->handle, sock->read_ioctl,
631 NULL, 0, tail, sizeof tail, &bytes, NULL)) {
632 VLOG_DBG_RL(&rl, "fatal driver failure in transact: %s",
633 ovs_lasterror_to_string());
635 /* XXX: Map to a more appropriate error. */
643 if (retval >= buf->allocated) {
644 ofpbuf_reinit(buf, retval);
645 nlmsghdr = buf->base;
646 nlmsghdr->nlmsg_len = UINT32_MAX;
648 memcpy(buf->data, tail, retval);
653 retval = recvmsg(sock->fd, &msg, wait ? 0 : MSG_DONTWAIT);
655 error = (retval < 0 ? errno
656 : retval == 0 ? ECONNRESET /* not possible? */
657 : nlmsghdr->nlmsg_len != UINT32_MAX ? 0
659 } while (error == EINTR);
661 if (error == ENOBUFS) {
662 /* Socket receive buffer overflow dropped one or more messages that
663 * the kernel tried to send to us. */
664 COVERAGE_INC(netlink_overflow);
669 if (msg.msg_flags & MSG_TRUNC) {
670 VLOG_ERR_RL(&rl, "truncated message (longer than %"PRIuSIZE" bytes)",
675 if (retval < sizeof *nlmsghdr
676 || nlmsghdr->nlmsg_len < sizeof *nlmsghdr
677 || nlmsghdr->nlmsg_len > retval) {
678 VLOG_ERR_RL(&rl, "received invalid nlmsg (%"PRIuSIZE" bytes < %"PRIuSIZE")",
679 retval, sizeof *nlmsghdr);
683 buf->size = MIN(retval, buf->allocated);
684 if (retval > buf->allocated) {
685 COVERAGE_INC(netlink_recv_jumbo);
686 ofpbuf_put(buf, tail, retval - buf->allocated);
690 log_nlmsg(__func__, 0, buf->data, buf->size, sock->protocol);
691 COVERAGE_INC(netlink_received);
696 /* Tries to receive a Netlink message from the kernel on 'sock' into 'buf'. If
697 * 'wait' is true, waits for a message to be ready. Otherwise, fails with
698 * EAGAIN if the 'sock' receive buffer is empty.
700 * The caller must have initialized 'buf' with an allocation of at least
701 * NLMSG_HDRLEN bytes. For best performance, the caller should allocate enough
702 * space for a "typical" message.
704 * On success, returns 0 and replaces 'buf''s previous content by the received
705 * message. This function expands 'buf''s allocated memory, as necessary, to
706 * hold the actual size of the received message.
708 * On failure, returns a positive errno value and clears 'buf' to zero length.
709 * 'buf' retains its previous memory allocation.
711 * Regardless of success or failure, this function resets 'buf''s headroom to
714 nl_sock_recv(struct nl_sock *sock, struct ofpbuf *buf, bool wait)
716 return nl_sock_recv__(sock, buf, wait);
720 nl_sock_record_errors__(struct nl_transaction **transactions, size_t n,
725 for (i = 0; i < n; i++) {
726 struct nl_transaction *txn = transactions[i];
730 ofpbuf_clear(txn->reply);
736 nl_sock_transact_multiple__(struct nl_sock *sock,
737 struct nl_transaction **transactions, size_t n,
740 uint64_t tmp_reply_stub[1024 / 8];
741 struct nl_transaction tmp_txn;
742 struct ofpbuf tmp_reply;
745 struct iovec iovs[MAX_IOVS];
750 base_seq = nl_sock_allocate_seq(sock, n);
752 for (i = 0; i < n; i++) {
753 struct nl_transaction *txn = transactions[i];
754 struct nlmsghdr *nlmsg = nl_msg_nlmsghdr(txn->request);
756 nlmsg->nlmsg_len = txn->request->size;
757 nlmsg->nlmsg_seq = base_seq + i;
758 nlmsg->nlmsg_pid = sock->pid;
760 iovs[i].iov_base = txn->request->data;
761 iovs[i].iov_len = txn->request->size;
765 memset(&msg, 0, sizeof msg);
769 error = sendmsg(sock->fd, &msg, 0) < 0 ? errno : 0;
770 } while (error == EINTR);
772 for (i = 0; i < n; i++) {
773 struct nl_transaction *txn = transactions[i];
775 log_nlmsg(__func__, error, txn->request->data,
776 txn->request->size, sock->protocol);
779 COVERAGE_ADD(netlink_sent, n);
786 ofpbuf_use_stub(&tmp_reply, tmp_reply_stub, sizeof tmp_reply_stub);
787 tmp_txn.request = NULL;
788 tmp_txn.reply = &tmp_reply;
791 struct nl_transaction *buf_txn, *txn;
794 /* Find a transaction whose buffer we can use for receiving a reply.
795 * If no such transaction is left, use tmp_txn. */
797 for (i = 0; i < n; i++) {
798 if (transactions[i]->reply) {
799 buf_txn = transactions[i];
804 /* Receive a reply. */
805 error = nl_sock_recv__(sock, buf_txn->reply, false);
807 if (error == EAGAIN) {
808 nl_sock_record_errors__(transactions, n, 0);
815 /* Match the reply up with a transaction. */
816 seq = nl_msg_nlmsghdr(buf_txn->reply)->nlmsg_seq;
817 if (seq < base_seq || seq >= base_seq + n) {
818 VLOG_DBG_RL(&rl, "ignoring unexpected seq %#"PRIx32, seq);
822 txn = transactions[i];
824 /* Fill in the results for 'txn'. */
825 if (nl_msg_nlmsgerr(buf_txn->reply, &txn->error)) {
827 ofpbuf_clear(txn->reply);
830 VLOG_DBG_RL(&rl, "received NAK error=%d (%s)",
831 error, ovs_strerror(txn->error));
835 if (txn->reply && txn != buf_txn) {
837 struct ofpbuf *reply = buf_txn->reply;
838 buf_txn->reply = txn->reply;
843 /* Fill in the results for transactions before 'txn'. (We have to do
844 * this after the results for 'txn' itself because of the buffer swap
846 nl_sock_record_errors__(transactions, i, 0);
850 transactions += i + 1;
854 ofpbuf_uninit(&tmp_reply);
857 uint8_t reply_buf[65536];
858 for (i = 0; i < n; i++) {
861 struct nl_transaction *txn = transactions[i];
862 struct nlmsghdr *request_nlmsg, *reply_nlmsg;
864 ret = DeviceIoControl(sock->handle, OVS_IOCTL_TRANSACT,
867 reply_buf, sizeof reply_buf,
870 if (ret && reply_len == 0) {
872 * The current transaction did not produce any data to read and that
873 * is not an error as such. Continue with the remainder of the
878 ofpbuf_clear(txn->reply);
881 /* XXX: Map to a more appropriate error. */
883 VLOG_DBG_RL(&rl, "fatal driver failure: %s",
884 ovs_lasterror_to_string());
888 if (reply_len != 0) {
889 if (reply_len < sizeof *reply_nlmsg) {
890 nl_sock_record_errors__(transactions, n, 0);
891 VLOG_DBG_RL(&rl, "insufficient length of reply %#"PRIu32
892 " for seq: %#"PRIx32, reply_len, request_nlmsg->nlmsg_seq);
896 /* Validate the sequence number in the reply. */
897 request_nlmsg = nl_msg_nlmsghdr(txn->request);
898 reply_nlmsg = (struct nlmsghdr *)reply_buf;
900 if (request_nlmsg->nlmsg_seq != reply_nlmsg->nlmsg_seq) {
901 ovs_assert(request_nlmsg->nlmsg_seq == reply_nlmsg->nlmsg_seq);
902 VLOG_DBG_RL(&rl, "mismatched seq request %#"PRIx32
903 ", reply %#"PRIx32, request_nlmsg->nlmsg_seq,
904 reply_nlmsg->nlmsg_seq);
908 /* Handle errors embedded within the netlink message. */
909 ofpbuf_use_stub(&tmp_reply, reply_buf, sizeof reply_buf);
910 tmp_reply.size = sizeof reply_buf;
911 if (nl_msg_nlmsgerr(&tmp_reply, &txn->error)) {
913 ofpbuf_clear(txn->reply);
916 VLOG_DBG_RL(&rl, "received NAK error=%d (%s)",
917 error, ovs_strerror(txn->error));
922 /* Copy the reply to the buffer specified by the caller. */
923 if (reply_len > txn->reply->allocated) {
924 ofpbuf_reinit(txn->reply, reply_len);
926 memcpy(txn->reply->data, reply_buf, reply_len);
927 txn->reply->size = reply_len;
930 ofpbuf_uninit(&tmp_reply);
933 /* Count the number of successful transactions. */
939 COVERAGE_ADD(netlink_sent, n);
947 nl_sock_transact_multiple(struct nl_sock *sock,
948 struct nl_transaction **transactions, size_t n)
957 /* In theory, every request could have a 64 kB reply. But the default and
958 * maximum socket rcvbuf size with typical Dom0 memory sizes both tend to
959 * be a bit below 128 kB, so that would only allow a single message in a
960 * "batch". So we assume that replies average (at most) 4 kB, which allows
961 * a good deal of batching.
963 * In practice, most of the requests that we batch either have no reply at
964 * all or a brief reply. */
965 max_batch_count = MAX(sock->rcvbuf / 4096, 1);
966 max_batch_count = MIN(max_batch_count, max_iovs);
972 /* Batch up to 'max_batch_count' transactions. But cap it at about a
973 * page of requests total because big skbuffs are expensive to
974 * allocate in the kernel. */
975 #if defined(PAGESIZE)
976 enum { MAX_BATCH_BYTES = MAX(1, PAGESIZE - 512) };
978 enum { MAX_BATCH_BYTES = 4096 - 512 };
980 bytes = transactions[0]->request->size;
981 for (count = 1; count < n && count < max_batch_count; count++) {
982 if (bytes + transactions[count]->request->size > MAX_BATCH_BYTES) {
985 bytes += transactions[count]->request->size;
988 error = nl_sock_transact_multiple__(sock, transactions, count, &done);
989 transactions += done;
992 if (error == ENOBUFS) {
993 VLOG_DBG_RL(&rl, "receive buffer overflow, resending request");
995 VLOG_ERR_RL(&rl, "transaction error (%s)", ovs_strerror(error));
996 nl_sock_record_errors__(transactions, n, error);
997 if (error != EAGAIN) {
998 /* A fatal error has occurred. Abort the rest of
1007 nl_sock_transact(struct nl_sock *sock, const struct ofpbuf *request,
1008 struct ofpbuf **replyp)
1010 struct nl_transaction *transactionp;
1011 struct nl_transaction transaction;
1013 transaction.request = CONST_CAST(struct ofpbuf *, request);
1014 transaction.reply = replyp ? ofpbuf_new(1024) : NULL;
1015 transactionp = &transaction;
1017 nl_sock_transact_multiple(sock, &transactionp, 1);
1020 if (transaction.error) {
1021 ofpbuf_delete(transaction.reply);
1024 *replyp = transaction.reply;
1028 return transaction.error;
1031 /* Drain all the messages currently in 'sock''s receive queue. */
1033 nl_sock_drain(struct nl_sock *sock)
1038 return drain_rcvbuf(sock->fd);
1042 /* Starts a Netlink "dump" operation, by sending 'request' to the kernel on a
1043 * Netlink socket created with the given 'protocol', and initializes 'dump' to
1044 * reflect the state of the operation.
1046 * 'request' must contain a Netlink message. Before sending the message,
1047 * nlmsg_len will be finalized to match request->size, and nlmsg_pid will be
1048 * set to the Netlink socket's pid. NLM_F_DUMP and NLM_F_ACK will be set in
1051 * The design of this Netlink socket library ensures that the dump is reliable.
1053 * This function provides no status indication. nl_dump_done() provides an
1054 * error status for the entire dump operation.
1056 * The caller must eventually destroy 'request'.
1059 nl_dump_start(struct nl_dump *dump, int protocol, const struct ofpbuf *request)
1061 nl_msg_nlmsghdr(request)->nlmsg_flags |= NLM_F_DUMP | NLM_F_ACK;
1063 ovs_mutex_init(&dump->mutex);
1064 ovs_mutex_lock(&dump->mutex);
1065 dump->status = nl_pool_alloc(protocol, &dump->sock);
1066 if (!dump->status) {
1067 dump->status = nl_sock_send__(dump->sock, request,
1068 nl_sock_allocate_seq(dump->sock, 1),
1071 dump->nl_seq = nl_msg_nlmsghdr(request)->nlmsg_seq;
1072 ovs_mutex_unlock(&dump->mutex);
1076 nl_dump_refill(struct nl_dump *dump, struct ofpbuf *buffer)
1077 OVS_REQUIRES(dump->mutex)
1079 struct nlmsghdr *nlmsghdr;
1082 while (!buffer->size) {
1083 error = nl_sock_recv__(dump->sock, buffer, false);
1085 /* The kernel never blocks providing the results of a dump, so
1086 * error == EAGAIN means that we've read the whole thing, and
1087 * therefore transform it into EOF. (The kernel always provides
1088 * NLMSG_DONE as a sentinel. Some other thread must have received
1089 * that already but not yet signaled it in 'status'.)
1091 * Any other error is just an error. */
1092 return error == EAGAIN ? EOF : error;
1095 nlmsghdr = nl_msg_nlmsghdr(buffer);
1096 if (dump->nl_seq != nlmsghdr->nlmsg_seq) {
1097 VLOG_DBG_RL(&rl, "ignoring seq %#"PRIx32" != expected %#"PRIx32,
1098 nlmsghdr->nlmsg_seq, dump->nl_seq);
1099 ofpbuf_clear(buffer);
1103 if (nl_msg_nlmsgerr(buffer, &error) && error) {
1104 VLOG_INFO_RL(&rl, "netlink dump request error (%s)",
1105 ovs_strerror(error));
1106 ofpbuf_clear(buffer);
1114 nl_dump_next__(struct ofpbuf *reply, struct ofpbuf *buffer)
1116 struct nlmsghdr *nlmsghdr = nl_msg_next(buffer, reply);
1118 VLOG_WARN_RL(&rl, "netlink dump contains message fragment");
1120 } else if (nlmsghdr->nlmsg_type == NLMSG_DONE) {
1127 /* Attempts to retrieve another reply from 'dump' into 'buffer'. 'dump' must
1128 * have been initialized with nl_dump_start(), and 'buffer' must have been
1129 * initialized. 'buffer' should be at least NL_DUMP_BUFSIZE bytes long.
1131 * If successful, returns true and points 'reply->data' and
1132 * 'reply->size' to the message that was retrieved. The caller must not
1133 * modify 'reply' (because it points within 'buffer', which will be used by
1134 * future calls to this function).
1136 * On failure, returns false and sets 'reply->data' to NULL and
1137 * 'reply->size' to 0. Failure might indicate an actual error or merely
1138 * the end of replies. An error status for the entire dump operation is
1139 * provided when it is completed by calling nl_dump_done().
1141 * Multiple threads may call this function, passing the same nl_dump, however
1142 * each must provide independent buffers. This function may cache multiple
1143 * replies in the buffer, and these will be processed before more replies are
1144 * fetched. When this function returns false, other threads may continue to
1145 * process replies in their buffers, but they will not fetch more replies.
1148 nl_dump_next(struct nl_dump *dump, struct ofpbuf *reply, struct ofpbuf *buffer)
1152 /* If the buffer is empty, refill it.
1154 * If the buffer is not empty, we don't check the dump's status.
1155 * Otherwise, we could end up skipping some of the dump results if thread A
1156 * hits EOF while thread B is in the midst of processing a batch. */
1157 if (!buffer->size) {
1158 ovs_mutex_lock(&dump->mutex);
1159 if (!dump->status) {
1160 /* Take the mutex here to avoid an in-kernel race. If two threads
1161 * try to read from a Netlink dump socket at once, then the socket
1162 * error can be set to EINVAL, which will be encountered on the
1163 * next recv on that socket, which could be anywhere due to the way
1164 * that we pool Netlink sockets. Serializing the recv calls avoids
1166 dump->status = nl_dump_refill(dump, buffer);
1168 retval = dump->status;
1169 ovs_mutex_unlock(&dump->mutex);
1172 /* Fetch the next message from the buffer. */
1174 retval = nl_dump_next__(reply, buffer);
1176 /* Record 'retval' as the dump status, but don't overwrite an error
1178 ovs_mutex_lock(&dump->mutex);
1179 if (dump->status <= 0) {
1180 dump->status = retval;
1182 ovs_mutex_unlock(&dump->mutex);
1193 /* Completes Netlink dump operation 'dump', which must have been initialized
1194 * with nl_dump_start(). Returns 0 if the dump operation was error-free,
1195 * otherwise a positive errno value describing the problem. */
1197 nl_dump_done(struct nl_dump *dump)
1201 ovs_mutex_lock(&dump->mutex);
1202 status = dump->status;
1203 ovs_mutex_unlock(&dump->mutex);
1205 /* Drain any remaining messages that the client didn't read. Otherwise the
1206 * kernel will continue to queue them up and waste buffer space.
1208 * XXX We could just destroy and discard the socket in this case. */
1210 uint64_t tmp_reply_stub[NL_DUMP_BUFSIZE / 8];
1211 struct ofpbuf reply, buf;
1213 ofpbuf_use_stub(&buf, tmp_reply_stub, sizeof tmp_reply_stub);
1214 while (nl_dump_next(dump, &reply, &buf)) {
1215 /* Nothing to do. */
1217 ofpbuf_uninit(&buf);
1219 ovs_mutex_lock(&dump->mutex);
1220 status = dump->status;
1221 ovs_mutex_unlock(&dump->mutex);
1225 nl_pool_release(dump->sock);
1226 ovs_mutex_destroy(&dump->mutex);
1228 return status == EOF ? 0 : status;
1232 /* Pend an I/O request in the driver. The driver completes the I/O whenever
1233 * an event or a packet is ready to be read. Once the I/O is completed
1234 * the overlapped structure event associated with the pending I/O will be set
1237 pend_io_request(struct nl_sock *sock)
1239 struct ofpbuf request;
1240 uint64_t request_stub[128];
1241 struct ovs_header *ovs_header;
1242 struct nlmsghdr *nlmsg;
1247 OVERLAPPED *overlapped = CONST_CAST(OVERLAPPED *, &sock->overlapped);
1248 uint16_t cmd = OVS_CTRL_CMD_WIN_PEND_PACKET_REQ;
1250 ovs_assert(sock->read_ioctl == OVS_IOCTL_READ_PACKET ||
1251 sock->read_ioctl == OVS_IOCTL_READ_EVENT);
1252 if (sock->read_ioctl == OVS_IOCTL_READ_EVENT) {
1253 cmd = OVS_CTRL_CMD_WIN_PEND_REQ;
1256 int ovs_msg_size = sizeof (struct nlmsghdr) + sizeof (struct genlmsghdr) +
1257 sizeof (struct ovs_header);
1259 ofpbuf_use_stub(&request, request_stub, sizeof request_stub);
1261 seq = nl_sock_allocate_seq(sock, 1);
1262 nl_msg_put_genlmsghdr(&request, 0, OVS_WIN_NL_CTRL_FAMILY_ID, 0,
1263 cmd, OVS_WIN_CONTROL_VERSION);
1264 nlmsg = nl_msg_nlmsghdr(&request);
1265 nlmsg->nlmsg_seq = seq;
1266 nlmsg->nlmsg_pid = sock->pid;
1268 ovs_header = ofpbuf_put_uninit(&request, sizeof *ovs_header);
1269 ovs_header->dp_ifindex = 0;
1270 nlmsg->nlmsg_len = request.size;
1272 if (!DeviceIoControl(sock->handle, OVS_IOCTL_WRITE,
1273 request.data, request.size,
1274 NULL, 0, &bytes, overlapped)) {
1275 error = GetLastError();
1276 /* Check if the I/O got pended */
1277 if (error != ERROR_IO_INCOMPLETE && error != ERROR_IO_PENDING) {
1278 VLOG_ERR("nl_sock_wait failed - %s\n", ovs_format_message(error));
1286 ofpbuf_uninit(&request);
1291 /* Causes poll_block() to wake up when any of the specified 'events' (which is
1292 * a OR'd combination of POLLIN, POLLOUT, etc.) occur on 'sock'.
1293 * On Windows, 'sock' is not treated as const, and may be modified. */
1295 nl_sock_wait(const struct nl_sock *sock, short int events)
1298 if (sock->overlapped.Internal != STATUS_PENDING) {
1299 int ret = pend_io_request(CONST_CAST(struct nl_sock *, sock));
1301 poll_wevent_wait(sock->overlapped.hEvent);
1303 poll_immediate_wake();
1306 poll_wevent_wait(sock->overlapped.hEvent);
1309 poll_fd_wait(sock->fd, events);
1314 /* Returns the underlying fd for 'sock', for use in "poll()"-like operations
1315 * that can't use nl_sock_wait().
1317 * It's a little tricky to use the returned fd correctly, because nl_sock does
1318 * "copy on write" to allow a single nl_sock to be used for notifications,
1319 * transactions, and dumps. If 'sock' is used only for notifications and
1320 * transactions (and never for dump) then the usage is safe. */
1322 nl_sock_fd(const struct nl_sock *sock)
1328 /* Returns the PID associated with this socket. */
1330 nl_sock_pid(const struct nl_sock *sock)
1335 /* Miscellaneous. */
1337 struct genl_family {
1338 struct hmap_node hmap_node;
1343 static struct hmap genl_families = HMAP_INITIALIZER(&genl_families);
1345 static const struct nl_policy family_policy[CTRL_ATTR_MAX + 1] = {
1346 [CTRL_ATTR_FAMILY_ID] = {.type = NL_A_U16},
1347 [CTRL_ATTR_MCAST_GROUPS] = {.type = NL_A_NESTED, .optional = true},
1350 static struct genl_family *
1351 find_genl_family_by_id(uint16_t id)
1353 struct genl_family *family;
1355 HMAP_FOR_EACH_IN_BUCKET (family, hmap_node, hash_int(id, 0),
1357 if (family->id == id) {
1365 define_genl_family(uint16_t id, const char *name)
1367 struct genl_family *family = find_genl_family_by_id(id);
1370 if (!strcmp(family->name, name)) {
1375 family = xmalloc(sizeof *family);
1377 hmap_insert(&genl_families, &family->hmap_node, hash_int(id, 0));
1379 family->name = xstrdup(name);
1383 genl_family_to_name(uint16_t id)
1385 if (id == GENL_ID_CTRL) {
1388 struct genl_family *family = find_genl_family_by_id(id);
1389 return family ? family->name : "unknown";
1395 do_lookup_genl_family(const char *name, struct nlattr **attrs,
1396 struct ofpbuf **replyp)
1398 struct nl_sock *sock;
1399 struct ofpbuf request, *reply;
1403 error = nl_sock_create(NETLINK_GENERIC, &sock);
1408 ofpbuf_init(&request, 0);
1409 nl_msg_put_genlmsghdr(&request, 0, GENL_ID_CTRL, NLM_F_REQUEST,
1410 CTRL_CMD_GETFAMILY, 1);
1411 nl_msg_put_string(&request, CTRL_ATTR_FAMILY_NAME, name);
1412 error = nl_sock_transact(sock, &request, &reply);
1413 ofpbuf_uninit(&request);
1415 nl_sock_destroy(sock);
1419 if (!nl_policy_parse(reply, NLMSG_HDRLEN + GENL_HDRLEN,
1420 family_policy, attrs, ARRAY_SIZE(family_policy))
1421 || nl_attr_get_u16(attrs[CTRL_ATTR_FAMILY_ID]) == 0) {
1422 nl_sock_destroy(sock);
1423 ofpbuf_delete(reply);
1427 nl_sock_destroy(sock);
1433 do_lookup_genl_family(const char *name, struct nlattr **attrs,
1434 struct ofpbuf **replyp)
1436 struct nlmsghdr *nlmsg;
1437 struct ofpbuf *reply;
1440 const char *family_name;
1441 uint32_t family_version;
1442 uint32_t family_attrmax;
1443 uint32_t mcgrp_id = OVS_WIN_NL_INVALID_MCGRP_ID;
1444 const char *mcgrp_name = NULL;
1447 reply = ofpbuf_new(1024);
1449 /* CTRL_ATTR_MCAST_GROUPS is supported only for VPORT family. */
1450 if (!strcmp(name, OVS_WIN_CONTROL_FAMILY)) {
1451 family_id = OVS_WIN_NL_CTRL_FAMILY_ID;
1452 family_name = OVS_WIN_CONTROL_FAMILY;
1453 family_version = OVS_WIN_CONTROL_VERSION;
1454 family_attrmax = OVS_WIN_CONTROL_ATTR_MAX;
1455 } else if (!strcmp(name, OVS_DATAPATH_FAMILY)) {
1456 family_id = OVS_WIN_NL_DATAPATH_FAMILY_ID;
1457 family_name = OVS_DATAPATH_FAMILY;
1458 family_version = OVS_DATAPATH_VERSION;
1459 family_attrmax = OVS_DP_ATTR_MAX;
1460 } else if (!strcmp(name, OVS_PACKET_FAMILY)) {
1461 family_id = OVS_WIN_NL_PACKET_FAMILY_ID;
1462 family_name = OVS_PACKET_FAMILY;
1463 family_version = OVS_PACKET_VERSION;
1464 family_attrmax = OVS_PACKET_ATTR_MAX;
1465 } else if (!strcmp(name, OVS_VPORT_FAMILY)) {
1466 family_id = OVS_WIN_NL_VPORT_FAMILY_ID;
1467 family_name = OVS_VPORT_FAMILY;
1468 family_version = OVS_VPORT_VERSION;
1469 family_attrmax = OVS_VPORT_ATTR_MAX;
1470 mcgrp_id = OVS_WIN_NL_VPORT_MCGRP_ID;
1471 mcgrp_name = OVS_VPORT_MCGROUP;
1472 } else if (!strcmp(name, OVS_FLOW_FAMILY)) {
1473 family_id = OVS_WIN_NL_FLOW_FAMILY_ID;
1474 family_name = OVS_FLOW_FAMILY;
1475 family_version = OVS_FLOW_VERSION;
1476 family_attrmax = OVS_FLOW_ATTR_MAX;
1477 } else if (!strcmp(name, OVS_WIN_NETDEV_FAMILY)) {
1478 family_id = OVS_WIN_NL_NETDEV_FAMILY_ID;
1479 family_name = OVS_WIN_NETDEV_FAMILY;
1480 family_version = OVS_WIN_NETDEV_VERSION;
1481 family_attrmax = OVS_WIN_NETDEV_ATTR_MAX;
1483 ofpbuf_delete(reply);
1487 nl_msg_put_genlmsghdr(reply, 0, GENL_ID_CTRL, 0,
1488 CTRL_CMD_NEWFAMILY, family_version);
1489 /* CTRL_ATTR_HDRSIZE and CTRL_ATTR_OPS are not populated, but the
1490 * callers do not seem to need them. */
1491 nl_msg_put_u16(reply, CTRL_ATTR_FAMILY_ID, family_id);
1492 nl_msg_put_string(reply, CTRL_ATTR_FAMILY_NAME, family_name);
1493 nl_msg_put_u32(reply, CTRL_ATTR_VERSION, family_version);
1494 nl_msg_put_u32(reply, CTRL_ATTR_MAXATTR, family_attrmax);
1496 if (mcgrp_id != OVS_WIN_NL_INVALID_MCGRP_ID) {
1497 size_t mcgrp_ofs1 = nl_msg_start_nested(reply, CTRL_ATTR_MCAST_GROUPS);
1498 size_t mcgrp_ofs2= nl_msg_start_nested(reply,
1499 OVS_WIN_NL_VPORT_MCGRP_ID - OVS_WIN_NL_MCGRP_START_ID);
1500 nl_msg_put_u32(reply, CTRL_ATTR_MCAST_GRP_ID, mcgrp_id);
1501 ovs_assert(mcgrp_name != NULL);
1502 nl_msg_put_string(reply, CTRL_ATTR_MCAST_GRP_NAME, mcgrp_name);
1503 nl_msg_end_nested(reply, mcgrp_ofs2);
1504 nl_msg_end_nested(reply, mcgrp_ofs1);
1507 /* Set the total length of the netlink message. */
1508 nlmsg = nl_msg_nlmsghdr(reply);
1509 nlmsg->nlmsg_len = reply->size;
1511 if (!nl_policy_parse(reply, NLMSG_HDRLEN + GENL_HDRLEN,
1512 family_policy, attrs, ARRAY_SIZE(family_policy))
1513 || nl_attr_get_u16(attrs[CTRL_ATTR_FAMILY_ID]) == 0) {
1514 ofpbuf_delete(reply);
1523 /* Finds the multicast group called 'group_name' in genl family 'family_name'.
1524 * When successful, writes its result to 'multicast_group' and returns 0.
1525 * Otherwise, clears 'multicast_group' and returns a positive error code.
1528 nl_lookup_genl_mcgroup(const char *family_name, const char *group_name,
1529 unsigned int *multicast_group)
1531 struct nlattr *family_attrs[ARRAY_SIZE(family_policy)];
1532 const struct nlattr *mc;
1533 struct ofpbuf *reply;
1537 *multicast_group = 0;
1538 error = do_lookup_genl_family(family_name, family_attrs, &reply);
1543 if (!family_attrs[CTRL_ATTR_MCAST_GROUPS]) {
1548 NL_NESTED_FOR_EACH (mc, left, family_attrs[CTRL_ATTR_MCAST_GROUPS]) {
1549 static const struct nl_policy mc_policy[] = {
1550 [CTRL_ATTR_MCAST_GRP_ID] = {.type = NL_A_U32},
1551 [CTRL_ATTR_MCAST_GRP_NAME] = {.type = NL_A_STRING},
1554 struct nlattr *mc_attrs[ARRAY_SIZE(mc_policy)];
1555 const char *mc_name;
1557 if (!nl_parse_nested(mc, mc_policy, mc_attrs, ARRAY_SIZE(mc_policy))) {
1562 mc_name = nl_attr_get_string(mc_attrs[CTRL_ATTR_MCAST_GRP_NAME]);
1563 if (!strcmp(group_name, mc_name)) {
1565 nl_attr_get_u32(mc_attrs[CTRL_ATTR_MCAST_GRP_ID]);
1573 ofpbuf_delete(reply);
1577 /* If '*number' is 0, translates the given Generic Netlink family 'name' to a
1578 * number and stores it in '*number'. If successful, returns 0 and the caller
1579 * may use '*number' as the family number. On failure, returns a positive
1580 * errno value and '*number' caches the errno value. */
1582 nl_lookup_genl_family(const char *name, int *number)
1585 struct nlattr *attrs[ARRAY_SIZE(family_policy)];
1586 struct ofpbuf *reply;
1589 error = do_lookup_genl_family(name, attrs, &reply);
1591 *number = nl_attr_get_u16(attrs[CTRL_ATTR_FAMILY_ID]);
1592 define_genl_family(*number, name);
1596 ofpbuf_delete(reply);
1598 ovs_assert(*number != 0);
1600 return *number > 0 ? 0 : -*number;
1604 struct nl_sock *socks[16];
1608 static struct ovs_mutex pool_mutex = OVS_MUTEX_INITIALIZER;
1609 static struct nl_pool pools[MAX_LINKS] OVS_GUARDED_BY(pool_mutex);
1612 nl_pool_alloc(int protocol, struct nl_sock **sockp)
1614 struct nl_sock *sock = NULL;
1615 struct nl_pool *pool;
1617 ovs_assert(protocol >= 0 && protocol < ARRAY_SIZE(pools));
1619 ovs_mutex_lock(&pool_mutex);
1620 pool = &pools[protocol];
1622 sock = pool->socks[--pool->n];
1624 ovs_mutex_unlock(&pool_mutex);
1630 return nl_sock_create(protocol, sockp);
1635 nl_pool_release(struct nl_sock *sock)
1638 struct nl_pool *pool = &pools[sock->protocol];
1640 ovs_mutex_lock(&pool_mutex);
1641 if (pool->n < ARRAY_SIZE(pool->socks)) {
1642 pool->socks[pool->n++] = sock;
1645 ovs_mutex_unlock(&pool_mutex);
1647 nl_sock_destroy(sock);
1651 /* Sends 'request' to the kernel on a Netlink socket for the given 'protocol'
1652 * (e.g. NETLINK_ROUTE or NETLINK_GENERIC) and waits for a response. If
1653 * successful, returns 0. On failure, returns a positive errno value.
1655 * If 'replyp' is nonnull, then on success '*replyp' is set to the kernel's
1656 * reply, which the caller is responsible for freeing with ofpbuf_delete(), and
1657 * on failure '*replyp' is set to NULL. If 'replyp' is null, then the kernel's
1658 * reply, if any, is discarded.
1660 * Before the message is sent, nlmsg_len in 'request' will be finalized to
1661 * match msg->size, nlmsg_pid will be set to the pid of the socket used
1662 * for sending the request, and nlmsg_seq will be initialized.
1664 * The caller is responsible for destroying 'request'.
1666 * Bare Netlink is an unreliable transport protocol. This function layers
1667 * reliable delivery and reply semantics on top of bare Netlink.
1669 * In Netlink, sending a request to the kernel is reliable enough, because the
1670 * kernel will tell us if the message cannot be queued (and we will in that
1671 * case put it on the transmit queue and wait until it can be delivered).
1673 * Receiving the reply is the real problem: if the socket buffer is full when
1674 * the kernel tries to send the reply, the reply will be dropped. However, the
1675 * kernel sets a flag that a reply has been dropped. The next call to recv
1676 * then returns ENOBUFS. We can then re-send the request.
1680 * 1. Netlink depends on sequence numbers to match up requests and
1681 * replies. The sender of a request supplies a sequence number, and
1682 * the reply echos back that sequence number.
1684 * This is fine, but (1) some kernel netlink implementations are
1685 * broken, in that they fail to echo sequence numbers and (2) this
1686 * function will drop packets with non-matching sequence numbers, so
1687 * that only a single request can be usefully transacted at a time.
1689 * 2. Resending the request causes it to be re-executed, so the request
1690 * needs to be idempotent.
1693 nl_transact(int protocol, const struct ofpbuf *request,
1694 struct ofpbuf **replyp)
1696 struct nl_sock *sock;
1699 error = nl_pool_alloc(protocol, &sock);
1705 error = nl_sock_transact(sock, request, replyp);
1707 nl_pool_release(sock);
1711 /* Sends the 'request' member of the 'n' transactions in 'transactions' on a
1712 * Netlink socket for the given 'protocol' (e.g. NETLINK_ROUTE or
1713 * NETLINK_GENERIC), in order, and receives responses to all of them. Fills in
1714 * the 'error' member of each transaction with 0 if it was successful,
1715 * otherwise with a positive errno value. If 'reply' is nonnull, then it will
1716 * be filled with the reply if the message receives a detailed reply. In other
1717 * cases, i.e. where the request failed or had no reply beyond an indication of
1718 * success, 'reply' will be cleared if it is nonnull.
1720 * The caller is responsible for destroying each request and reply, and the
1721 * transactions array itself.
1723 * Before sending each message, this function will finalize nlmsg_len in each
1724 * 'request' to match the ofpbuf's size, set nlmsg_pid to the pid of the socket
1725 * used for the transaction, and initialize nlmsg_seq.
1727 * Bare Netlink is an unreliable transport protocol. This function layers
1728 * reliable delivery and reply semantics on top of bare Netlink. See
1729 * nl_transact() for some caveats.
1732 nl_transact_multiple(int protocol,
1733 struct nl_transaction **transactions, size_t n)
1735 struct nl_sock *sock;
1738 error = nl_pool_alloc(protocol, &sock);
1740 nl_sock_transact_multiple(sock, transactions, n);
1741 nl_pool_release(sock);
1743 nl_sock_record_errors__(transactions, n, error);
1749 nl_sock_allocate_seq(struct nl_sock *sock, unsigned int n)
1751 uint32_t seq = sock->next_seq;
1753 sock->next_seq += n;
1755 /* Make it impossible for the next request for sequence numbers to wrap
1756 * around to 0. Start over with 1 to avoid ever using a sequence number of
1757 * 0, because the kernel uses sequence number 0 for notifications. */
1758 if (sock->next_seq >= UINT32_MAX / 2) {
1766 nlmsghdr_to_string(const struct nlmsghdr *h, int protocol, struct ds *ds)
1772 static const struct nlmsg_flag flags[] = {
1773 { NLM_F_REQUEST, "REQUEST" },
1774 { NLM_F_MULTI, "MULTI" },
1775 { NLM_F_ACK, "ACK" },
1776 { NLM_F_ECHO, "ECHO" },
1777 { NLM_F_DUMP, "DUMP" },
1778 { NLM_F_ROOT, "ROOT" },
1779 { NLM_F_MATCH, "MATCH" },
1780 { NLM_F_ATOMIC, "ATOMIC" },
1782 const struct nlmsg_flag *flag;
1783 uint16_t flags_left;
1785 ds_put_format(ds, "nl(len:%"PRIu32", type=%"PRIu16,
1786 h->nlmsg_len, h->nlmsg_type);
1787 if (h->nlmsg_type == NLMSG_NOOP) {
1788 ds_put_cstr(ds, "(no-op)");
1789 } else if (h->nlmsg_type == NLMSG_ERROR) {
1790 ds_put_cstr(ds, "(error)");
1791 } else if (h->nlmsg_type == NLMSG_DONE) {
1792 ds_put_cstr(ds, "(done)");
1793 } else if (h->nlmsg_type == NLMSG_OVERRUN) {
1794 ds_put_cstr(ds, "(overrun)");
1795 } else if (h->nlmsg_type < NLMSG_MIN_TYPE) {
1796 ds_put_cstr(ds, "(reserved)");
1797 } else if (protocol == NETLINK_GENERIC) {
1798 ds_put_format(ds, "(%s)", genl_family_to_name(h->nlmsg_type));
1800 ds_put_cstr(ds, "(family-defined)");
1802 ds_put_format(ds, ", flags=%"PRIx16, h->nlmsg_flags);
1803 flags_left = h->nlmsg_flags;
1804 for (flag = flags; flag < &flags[ARRAY_SIZE(flags)]; flag++) {
1805 if ((flags_left & flag->bits) == flag->bits) {
1806 ds_put_format(ds, "[%s]", flag->name);
1807 flags_left &= ~flag->bits;
1811 ds_put_format(ds, "[OTHER:%"PRIx16"]", flags_left);
1813 ds_put_format(ds, ", seq=%"PRIx32", pid=%"PRIu32,
1814 h->nlmsg_seq, h->nlmsg_pid);
1818 nlmsg_to_string(const struct ofpbuf *buffer, int protocol)
1820 struct ds ds = DS_EMPTY_INITIALIZER;
1821 const struct nlmsghdr *h = ofpbuf_at(buffer, 0, NLMSG_HDRLEN);
1823 nlmsghdr_to_string(h, protocol, &ds);
1824 if (h->nlmsg_type == NLMSG_ERROR) {
1825 const struct nlmsgerr *e;
1826 e = ofpbuf_at(buffer, NLMSG_HDRLEN,
1827 NLMSG_ALIGN(sizeof(struct nlmsgerr)));
1829 ds_put_format(&ds, " error(%d", e->error);
1831 ds_put_format(&ds, "(%s)", ovs_strerror(-e->error));
1833 ds_put_cstr(&ds, ", in-reply-to(");
1834 nlmsghdr_to_string(&e->msg, protocol, &ds);
1835 ds_put_cstr(&ds, "))");
1837 ds_put_cstr(&ds, " error(truncated)");
1839 } else if (h->nlmsg_type == NLMSG_DONE) {
1840 int *error = ofpbuf_at(buffer, NLMSG_HDRLEN, sizeof *error);
1842 ds_put_format(&ds, " done(%d", *error);
1844 ds_put_format(&ds, "(%s)", ovs_strerror(-*error));
1846 ds_put_cstr(&ds, ")");
1848 ds_put_cstr(&ds, " done(truncated)");
1850 } else if (protocol == NETLINK_GENERIC) {
1851 struct genlmsghdr *genl = nl_msg_genlmsghdr(buffer);
1853 ds_put_format(&ds, ",genl(cmd=%"PRIu8",version=%"PRIu8")",
1854 genl->cmd, genl->version);
1858 ds_put_cstr(&ds, "nl(truncated)");
1864 log_nlmsg(const char *function, int error,
1865 const void *message, size_t size, int protocol)
1867 if (!VLOG_IS_DBG_ENABLED()) {
1871 struct ofpbuf buffer = ofpbuf_const_initializer(message, size);
1872 char *nlmsg = nlmsg_to_string(&buffer, protocol);
1873 VLOG_DBG_RL(&rl, "%s (%s): %s", function, ovs_strerror(error), nlmsg);