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 "dynamic-string.h"
30 #include "netlink-protocol.h"
31 #include "odp-netlink.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
53 static struct ovs_mutex portid_mutex
= OVS_MUTEX_INITIALIZER
;
54 static uint32_t g_last_portid
= 0;
56 /* Port IDs must be unique! */
59 OVS_GUARDED_BY(portid_mutex
)
66 /* A single (bad) Netlink message can in theory dump out many, many log
67 * messages, so the burst size is set quite high here to avoid missing useful
68 * information. Also, at high logging levels we log *all* Netlink messages. */
69 static struct vlog_rate_limit rl
= VLOG_RATE_LIMIT_INIT(60, 600);
71 static uint32_t nl_sock_allocate_seq(struct nl_sock
*, unsigned int n
);
72 static void log_nlmsg(const char *function
, int error
,
73 const void *message
, size_t size
, int protocol
);
75 static int get_sock_pid_from_kernel(struct nl_sock
*sock
);
78 /* Netlink sockets. */
83 OVERLAPPED overlapped
;
91 unsigned int rcvbuf
; /* Receive buffer size (SO_RCVBUF). */
94 /* Compile-time limit on iovecs, so that we can allocate a maximum-size array
95 * of iovecs on the stack. */
98 /* Maximum number of iovecs that may be passed to sendmsg, capped at a
99 * minimum of _XOPEN_IOV_MAX (16) and a maximum of MAX_IOVS.
101 * Initialized by nl_sock_create(). */
104 static int nl_pool_alloc(int protocol
, struct nl_sock
**sockp
);
105 static void nl_pool_release(struct nl_sock
*);
107 /* Creates a new netlink socket for the given netlink 'protocol'
108 * (NETLINK_ROUTE, NETLINK_GENERIC, ...). Returns 0 and sets '*sockp' to the
109 * new socket if successful, otherwise returns a positive errno value. */
111 nl_sock_create(int protocol
, struct nl_sock
**sockp
)
113 static struct ovsthread_once once
= OVSTHREAD_ONCE_INITIALIZER
;
114 struct nl_sock
*sock
;
116 struct sockaddr_nl local
, remote
;
118 socklen_t local_size
;
122 if (ovsthread_once_start(&once
)) {
123 int save_errno
= errno
;
126 max_iovs
= sysconf(_SC_UIO_MAXIOV
);
127 if (max_iovs
< _XOPEN_IOV_MAX
) {
128 if (max_iovs
== -1 && errno
) {
129 VLOG_WARN("sysconf(_SC_UIO_MAXIOV): %s", ovs_strerror(errno
));
131 max_iovs
= _XOPEN_IOV_MAX
;
132 } else if (max_iovs
> MAX_IOVS
) {
137 ovsthread_once_done(&once
);
141 sock
= xmalloc(sizeof *sock
);
144 sock
->handle
= CreateFile(OVS_DEVICE_NAME_USER
,
145 GENERIC_READ
| GENERIC_WRITE
,
146 FILE_SHARE_READ
| FILE_SHARE_WRITE
,
148 FILE_FLAG_OVERLAPPED
, NULL
);
150 if (sock
->handle
== INVALID_HANDLE_VALUE
) {
151 VLOG_ERR("fcntl: %s", ovs_lasterror_to_string());
155 memset(&sock
->overlapped
, 0, sizeof sock
->overlapped
);
156 sock
->overlapped
.hEvent
= CreateEvent(NULL
, FALSE
, FALSE
, NULL
);
157 if (sock
->overlapped
.hEvent
== NULL
) {
158 VLOG_ERR("fcntl: %s", ovs_lasterror_to_string());
161 /* Initialize the type/ioctl to Generic */
162 sock
->read_ioctl
= OVS_IOCTL_READ
;
164 sock
->fd
= socket(AF_NETLINK
, SOCK_RAW
, protocol
);
166 VLOG_ERR("fcntl: %s", ovs_strerror(errno
));
171 sock
->protocol
= protocol
;
174 rcvbuf
= 1024 * 1024;
176 sock
->rcvbuf
= rcvbuf
;
177 retval
= get_sock_pid_from_kernel(sock
);
182 if (setsockopt(sock
->fd
, SOL_SOCKET
, SO_RCVBUFFORCE
,
183 &rcvbuf
, sizeof rcvbuf
)) {
184 /* Only root can use SO_RCVBUFFORCE. Everyone else gets EPERM.
185 * Warn only if the failure is therefore unexpected. */
186 if (errno
!= EPERM
) {
187 VLOG_WARN_RL(&rl
, "setting %d-byte socket receive buffer failed "
188 "(%s)", rcvbuf
, ovs_strerror(errno
));
192 retval
= get_socket_rcvbuf(sock
->fd
);
197 sock
->rcvbuf
= retval
;
200 /* Connect to kernel (pid 0) as remote address. */
201 memset(&remote
, 0, sizeof remote
);
202 remote
.nl_family
= AF_NETLINK
;
204 if (connect(sock
->fd
, (struct sockaddr
*) &remote
, sizeof remote
) < 0) {
205 VLOG_ERR("connect(0): %s", ovs_strerror(errno
));
209 /* Obtain pid assigned by kernel. */
210 local_size
= sizeof local
;
211 if (getsockname(sock
->fd
, (struct sockaddr
*) &local
, &local_size
) < 0) {
212 VLOG_ERR("getsockname: %s", ovs_strerror(errno
));
215 if (local_size
< sizeof local
|| local
.nl_family
!= AF_NETLINK
) {
216 VLOG_ERR("getsockname returned bad Netlink name");
220 sock
->pid
= local
.nl_pid
;
234 if (sock
->overlapped
.hEvent
) {
235 CloseHandle(sock
->overlapped
.hEvent
);
237 if (sock
->handle
!= INVALID_HANDLE_VALUE
) {
238 CloseHandle(sock
->handle
);
249 /* Creates a new netlink socket for the same protocol as 'src'. Returns 0 and
250 * sets '*sockp' to the new socket if successful, otherwise returns a positive
253 nl_sock_clone(const struct nl_sock
*src
, struct nl_sock
**sockp
)
255 return nl_sock_create(src
->protocol
, sockp
);
258 /* Destroys netlink socket 'sock'. */
260 nl_sock_destroy(struct nl_sock
*sock
)
264 if (sock
->overlapped
.hEvent
) {
265 CloseHandle(sock
->overlapped
.hEvent
);
267 CloseHandle(sock
->handle
);
276 /* Reads the pid for 'sock' generated in the kernel datapath. The function
277 * uses a separate IOCTL instead of a transaction semantic to avoid unnecessary
278 * message overhead. */
280 get_sock_pid_from_kernel(struct nl_sock
*sock
)
286 if (!DeviceIoControl(sock
->handle
, OVS_IOCTL_GET_PID
,
287 NULL
, 0, &pid
, sizeof(pid
),
291 if (bytes
< sizeof(pid
)) {
304 nl_sock_mcgroup(struct nl_sock
*sock
, unsigned int multicast_group
, bool join
)
306 struct ofpbuf request
;
307 uint64_t request_stub
[128];
308 struct ovs_header
*ovs_header
;
309 struct nlmsghdr
*nlmsg
;
312 ofpbuf_use_stub(&request
, request_stub
, sizeof request_stub
);
314 nl_msg_put_genlmsghdr(&request
, 0, OVS_WIN_NL_CTRL_FAMILY_ID
, 0,
315 OVS_CTRL_CMD_MC_SUBSCRIBE_REQ
,
316 OVS_WIN_CONTROL_VERSION
);
318 ovs_header
= ofpbuf_put_uninit(&request
, sizeof *ovs_header
);
319 ovs_header
->dp_ifindex
= 0;
321 nl_msg_put_u32(&request
, OVS_NL_ATTR_MCAST_GRP
, multicast_group
);
322 nl_msg_put_u8(&request
, OVS_NL_ATTR_MCAST_JOIN
, join
? 1 : 0);
324 error
= nl_sock_send(sock
, &request
, true);
325 ofpbuf_uninit(&request
);
329 /* Tries to add 'sock' as a listener for 'multicast_group'. Returns 0 if
330 * successful, otherwise a positive errno value.
332 * A socket that is subscribed to a multicast group that receives asynchronous
333 * notifications must not be used for Netlink transactions or dumps, because
334 * transactions and dumps can cause notifications to be lost.
336 * Multicast group numbers are always positive.
338 * It is not an error to attempt to join a multicast group to which a socket
339 * already belongs. */
341 nl_sock_join_mcgroup(struct nl_sock
*sock
, unsigned int multicast_group
)
344 /* Set the socket type as a "multicast" socket */
345 sock
->read_ioctl
= OVS_IOCTL_READ_EVENT
;
346 int error
= nl_sock_mcgroup(sock
, multicast_group
, true);
348 sock
->read_ioctl
= OVS_IOCTL_READ
;
349 VLOG_WARN("could not join multicast group %u (%s)",
350 multicast_group
, ovs_strerror(error
));
354 if (setsockopt(sock
->fd
, SOL_NETLINK
, NETLINK_ADD_MEMBERSHIP
,
355 &multicast_group
, sizeof multicast_group
) < 0) {
356 VLOG_WARN("could not join multicast group %u (%s)",
357 multicast_group
, ovs_strerror(errno
));
366 nl_sock_subscribe_packets(struct nl_sock
*sock
)
370 if (sock
->read_ioctl
!= OVS_IOCTL_READ
) {
374 error
= nl_sock_subscribe_packet__(sock
, true);
376 VLOG_WARN("could not subscribe packets (%s)",
377 ovs_strerror(error
));
380 sock
->read_ioctl
= OVS_IOCTL_READ_PACKET
;
386 nl_sock_unsubscribe_packets(struct nl_sock
*sock
)
388 ovs_assert(sock
->read_ioctl
== OVS_IOCTL_READ_PACKET
);
390 int error
= nl_sock_subscribe_packet__(sock
, false);
392 VLOG_WARN("could not unsubscribe to packets (%s)",
393 ovs_strerror(error
));
397 sock
->read_ioctl
= OVS_IOCTL_READ
;
402 nl_sock_subscribe_packet__(struct nl_sock
*sock
, bool subscribe
)
404 struct ofpbuf request
;
405 uint64_t request_stub
[128];
406 struct ovs_header
*ovs_header
;
407 struct nlmsghdr
*nlmsg
;
410 ofpbuf_use_stub(&request
, request_stub
, sizeof request_stub
);
411 nl_msg_put_genlmsghdr(&request
, 0, OVS_WIN_NL_CTRL_FAMILY_ID
, 0,
412 OVS_CTRL_CMD_PACKET_SUBSCRIBE_REQ
,
413 OVS_WIN_CONTROL_VERSION
);
415 ovs_header
= ofpbuf_put_uninit(&request
, sizeof *ovs_header
);
416 ovs_header
->dp_ifindex
= 0;
417 nl_msg_put_u8(&request
, OVS_NL_ATTR_PACKET_SUBSCRIBE
, subscribe
? 1 : 0);
418 nl_msg_put_u32(&request
, OVS_NL_ATTR_PACKET_PID
, sock
->pid
);
420 error
= nl_sock_send(sock
, &request
, true);
421 ofpbuf_uninit(&request
);
426 /* Tries to make 'sock' stop listening to 'multicast_group'. Returns 0 if
427 * successful, otherwise a positive errno value.
429 * Multicast group numbers are always positive.
431 * It is not an error to attempt to leave a multicast group to which a socket
434 * On success, reading from 'sock' will still return any messages that were
435 * received on 'multicast_group' before the group was left. */
437 nl_sock_leave_mcgroup(struct nl_sock
*sock
, unsigned int multicast_group
)
440 int error
= nl_sock_mcgroup(sock
, multicast_group
, false);
442 VLOG_WARN("could not leave multicast group %u (%s)",
443 multicast_group
, ovs_strerror(error
));
446 sock
->read_ioctl
= OVS_IOCTL_READ
;
448 if (setsockopt(sock
->fd
, SOL_NETLINK
, NETLINK_DROP_MEMBERSHIP
,
449 &multicast_group
, sizeof multicast_group
) < 0) {
450 VLOG_WARN("could not leave multicast group %u (%s)",
451 multicast_group
, ovs_strerror(errno
));
459 nl_sock_send__(struct nl_sock
*sock
, const struct ofpbuf
*msg
,
460 uint32_t nlmsg_seq
, bool wait
)
462 struct nlmsghdr
*nlmsg
= nl_msg_nlmsghdr(msg
);
465 nlmsg
->nlmsg_len
= msg
->size
;
466 nlmsg
->nlmsg_seq
= nlmsg_seq
;
467 nlmsg
->nlmsg_pid
= sock
->pid
;
473 if (!DeviceIoControl(sock
->handle
, OVS_IOCTL_WRITE
,
474 msg
->data
, msg
->size
, NULL
, 0,
477 /* XXX: Map to a more appropriate error based on GetLastError(). */
479 VLOG_DBG_RL(&rl
, "fatal driver failure in write: %s",
480 ovs_lasterror_to_string());
485 retval
= send(sock
->fd
, msg
->data
, msg
->size
,
486 wait
? 0 : MSG_DONTWAIT
);
488 error
= retval
< 0 ? errno
: 0;
489 } while (error
== EINTR
);
490 log_nlmsg(__func__
, error
, msg
->data
, msg
->size
, sock
->protocol
);
492 COVERAGE_INC(netlink_sent
);
497 /* Tries to send 'msg', which must contain a Netlink message, to the kernel on
498 * 'sock'. nlmsg_len in 'msg' will be finalized to match msg->size, nlmsg_pid
499 * will be set to 'sock''s pid, and nlmsg_seq will be initialized to a fresh
500 * sequence number, before the message is sent.
502 * Returns 0 if successful, otherwise a positive errno value. If
503 * 'wait' is true, then the send will wait until buffer space is ready;
504 * otherwise, returns EAGAIN if the 'sock' send buffer is full. */
506 nl_sock_send(struct nl_sock
*sock
, const struct ofpbuf
*msg
, bool wait
)
508 return nl_sock_send_seq(sock
, msg
, nl_sock_allocate_seq(sock
, 1), wait
);
511 /* Tries to send 'msg', which must contain a Netlink message, to the kernel on
512 * 'sock'. nlmsg_len in 'msg' will be finalized to match msg->size, nlmsg_pid
513 * will be set to 'sock''s pid, and nlmsg_seq will be initialized to
514 * 'nlmsg_seq', before the message is sent.
516 * Returns 0 if successful, otherwise a positive errno value. If
517 * 'wait' is true, then the send will wait until buffer space is ready;
518 * otherwise, returns EAGAIN if the 'sock' send buffer is full.
520 * This function is suitable for sending a reply to a request that was received
521 * with sequence number 'nlmsg_seq'. Otherwise, use nl_sock_send() instead. */
523 nl_sock_send_seq(struct nl_sock
*sock
, const struct ofpbuf
*msg
,
524 uint32_t nlmsg_seq
, bool wait
)
526 return nl_sock_send__(sock
, msg
, nlmsg_seq
, wait
);
530 nl_sock_recv__(struct nl_sock
*sock
, struct ofpbuf
*buf
, bool wait
)
532 /* We can't accurately predict the size of the data to be received. The
533 * caller is supposed to have allocated enough space in 'buf' to handle the
534 * "typical" case. To handle exceptions, we make available enough space in
535 * 'tail' to allow Netlink messages to be up to 64 kB long (a reasonable
536 * figure since that's the maximum length of a Netlink attribute). */
537 struct nlmsghdr
*nlmsghdr
;
544 ovs_assert(buf
->allocated
>= sizeof *nlmsghdr
);
547 iov
[0].iov_base
= buf
->base
;
548 iov
[0].iov_len
= buf
->allocated
;
549 iov
[1].iov_base
= tail
;
550 iov
[1].iov_len
= sizeof tail
;
552 memset(&msg
, 0, sizeof msg
);
556 /* Receive a Netlink message from the kernel.
558 * This works around a kernel bug in which the kernel returns an error code
559 * as if it were the number of bytes read. It doesn't actually modify
560 * anything in the receive buffer in that case, so we can initialize the
561 * Netlink header with an impossible message length and then, upon success,
562 * check whether it changed. */
563 nlmsghdr
= buf
->base
;
565 nlmsghdr
->nlmsg_len
= UINT32_MAX
;
568 if (!DeviceIoControl(sock
->handle
, sock
->read_ioctl
,
569 NULL
, 0, tail
, sizeof tail
, &bytes
, NULL
)) {
570 VLOG_DBG_RL(&rl
, "fatal driver failure in transact: %s",
571 ovs_lasterror_to_string());
573 /* XXX: Map to a more appropriate error. */
581 if (retval
>= buf
->allocated
) {
582 ofpbuf_reinit(buf
, retval
);
583 nlmsghdr
= buf
->base
;
584 nlmsghdr
->nlmsg_len
= UINT32_MAX
;
586 memcpy(buf
->data
, tail
, retval
);
591 retval
= recvmsg(sock
->fd
, &msg
, wait
? 0 : MSG_DONTWAIT
);
593 error
= (retval
< 0 ? errno
594 : retval
== 0 ? ECONNRESET
/* not possible? */
595 : nlmsghdr
->nlmsg_len
!= UINT32_MAX
? 0
597 } while (error
== EINTR
);
599 if (error
== ENOBUFS
) {
600 /* Socket receive buffer overflow dropped one or more messages that
601 * the kernel tried to send to us. */
602 COVERAGE_INC(netlink_overflow
);
607 if (msg
.msg_flags
& MSG_TRUNC
) {
608 VLOG_ERR_RL(&rl
, "truncated message (longer than %"PRIuSIZE
" bytes)",
613 if (retval
< sizeof *nlmsghdr
614 || nlmsghdr
->nlmsg_len
< sizeof *nlmsghdr
615 || nlmsghdr
->nlmsg_len
> retval
) {
616 VLOG_ERR_RL(&rl
, "received invalid nlmsg (%"PRIuSIZE
" bytes < %"PRIuSIZE
")",
617 retval
, sizeof *nlmsghdr
);
621 buf
->size
= MIN(retval
, buf
->allocated
);
622 if (retval
> buf
->allocated
) {
623 COVERAGE_INC(netlink_recv_jumbo
);
624 ofpbuf_put(buf
, tail
, retval
- buf
->allocated
);
628 log_nlmsg(__func__
, 0, buf
->data
, buf
->size
, sock
->protocol
);
629 COVERAGE_INC(netlink_received
);
634 /* Tries to receive a Netlink message from the kernel on 'sock' into 'buf'. If
635 * 'wait' is true, waits for a message to be ready. Otherwise, fails with
636 * EAGAIN if the 'sock' receive buffer is empty.
638 * The caller must have initialized 'buf' with an allocation of at least
639 * NLMSG_HDRLEN bytes. For best performance, the caller should allocate enough
640 * space for a "typical" message.
642 * On success, returns 0 and replaces 'buf''s previous content by the received
643 * message. This function expands 'buf''s allocated memory, as necessary, to
644 * hold the actual size of the received message.
646 * On failure, returns a positive errno value and clears 'buf' to zero length.
647 * 'buf' retains its previous memory allocation.
649 * Regardless of success or failure, this function resets 'buf''s headroom to
652 nl_sock_recv(struct nl_sock
*sock
, struct ofpbuf
*buf
, bool wait
)
654 return nl_sock_recv__(sock
, buf
, wait
);
658 nl_sock_record_errors__(struct nl_transaction
**transactions
, size_t n
,
663 for (i
= 0; i
< n
; i
++) {
664 struct nl_transaction
*txn
= transactions
[i
];
668 ofpbuf_clear(txn
->reply
);
674 nl_sock_transact_multiple__(struct nl_sock
*sock
,
675 struct nl_transaction
**transactions
, size_t n
,
678 uint64_t tmp_reply_stub
[1024 / 8];
679 struct nl_transaction tmp_txn
;
680 struct ofpbuf tmp_reply
;
683 struct iovec iovs
[MAX_IOVS
];
688 base_seq
= nl_sock_allocate_seq(sock
, n
);
690 for (i
= 0; i
< n
; i
++) {
691 struct nl_transaction
*txn
= transactions
[i
];
692 struct nlmsghdr
*nlmsg
= nl_msg_nlmsghdr(txn
->request
);
694 nlmsg
->nlmsg_len
= txn
->request
->size
;
695 nlmsg
->nlmsg_seq
= base_seq
+ i
;
696 nlmsg
->nlmsg_pid
= sock
->pid
;
698 iovs
[i
].iov_base
= txn
->request
->data
;
699 iovs
[i
].iov_len
= txn
->request
->size
;
703 memset(&msg
, 0, sizeof msg
);
707 error
= sendmsg(sock
->fd
, &msg
, 0) < 0 ? errno
: 0;
708 } while (error
== EINTR
);
710 for (i
= 0; i
< n
; i
++) {
711 struct nl_transaction
*txn
= transactions
[i
];
713 log_nlmsg(__func__
, error
, txn
->request
->data
,
714 txn
->request
->size
, sock
->protocol
);
717 COVERAGE_ADD(netlink_sent
, n
);
724 ofpbuf_use_stub(&tmp_reply
, tmp_reply_stub
, sizeof tmp_reply_stub
);
725 tmp_txn
.request
= NULL
;
726 tmp_txn
.reply
= &tmp_reply
;
729 struct nl_transaction
*buf_txn
, *txn
;
732 /* Find a transaction whose buffer we can use for receiving a reply.
733 * If no such transaction is left, use tmp_txn. */
735 for (i
= 0; i
< n
; i
++) {
736 if (transactions
[i
]->reply
) {
737 buf_txn
= transactions
[i
];
742 /* Receive a reply. */
743 error
= nl_sock_recv__(sock
, buf_txn
->reply
, false);
745 if (error
== EAGAIN
) {
746 nl_sock_record_errors__(transactions
, n
, 0);
753 /* Match the reply up with a transaction. */
754 seq
= nl_msg_nlmsghdr(buf_txn
->reply
)->nlmsg_seq
;
755 if (seq
< base_seq
|| seq
>= base_seq
+ n
) {
756 VLOG_DBG_RL(&rl
, "ignoring unexpected seq %#"PRIx32
, seq
);
760 txn
= transactions
[i
];
762 /* Fill in the results for 'txn'. */
763 if (nl_msg_nlmsgerr(buf_txn
->reply
, &txn
->error
)) {
765 ofpbuf_clear(txn
->reply
);
768 VLOG_DBG_RL(&rl
, "received NAK error=%d (%s)",
769 error
, ovs_strerror(txn
->error
));
773 if (txn
->reply
&& txn
!= buf_txn
) {
775 struct ofpbuf
*reply
= buf_txn
->reply
;
776 buf_txn
->reply
= txn
->reply
;
781 /* Fill in the results for transactions before 'txn'. (We have to do
782 * this after the results for 'txn' itself because of the buffer swap
784 nl_sock_record_errors__(transactions
, i
, 0);
788 transactions
+= i
+ 1;
792 ofpbuf_uninit(&tmp_reply
);
795 uint8_t reply_buf
[65536];
796 for (i
= 0; i
< n
; i
++) {
799 struct nl_transaction
*txn
= transactions
[i
];
800 struct nlmsghdr
*request_nlmsg
, *reply_nlmsg
;
802 ret
= DeviceIoControl(sock
->handle
, OVS_IOCTL_TRANSACT
,
805 reply_buf
, sizeof reply_buf
,
808 if (ret
&& reply_len
== 0) {
810 * The current transaction did not produce any data to read and that
811 * is not an error as such. Continue with the remainder of the
816 ofpbuf_clear(txn
->reply
);
819 /* XXX: Map to a more appropriate error. */
821 VLOG_DBG_RL(&rl
, "fatal driver failure: %s",
822 ovs_lasterror_to_string());
826 if (reply_len
!= 0) {
827 if (reply_len
< sizeof *reply_nlmsg
) {
828 nl_sock_record_errors__(transactions
, n
, 0);
829 VLOG_DBG_RL(&rl
, "insufficient length of reply %#"PRIu32
830 " for seq: %#"PRIx32
, reply_len
, request_nlmsg
->nlmsg_seq
);
834 /* Validate the sequence number in the reply. */
835 request_nlmsg
= nl_msg_nlmsghdr(txn
->request
);
836 reply_nlmsg
= (struct nlmsghdr
*)reply_buf
;
838 if (request_nlmsg
->nlmsg_seq
!= reply_nlmsg
->nlmsg_seq
) {
839 ovs_assert(request_nlmsg
->nlmsg_seq
== reply_nlmsg
->nlmsg_seq
);
840 VLOG_DBG_RL(&rl
, "mismatched seq request %#"PRIx32
841 ", reply %#"PRIx32
, request_nlmsg
->nlmsg_seq
,
842 reply_nlmsg
->nlmsg_seq
);
846 /* Handle errors embedded within the netlink message. */
847 ofpbuf_use_stub(&tmp_reply
, reply_buf
, sizeof reply_buf
);
848 tmp_reply
.size
= sizeof reply_buf
;
849 if (nl_msg_nlmsgerr(&tmp_reply
, &txn
->error
)) {
851 ofpbuf_clear(txn
->reply
);
854 VLOG_DBG_RL(&rl
, "received NAK error=%d (%s)",
855 error
, ovs_strerror(txn
->error
));
860 /* Copy the reply to the buffer specified by the caller. */
861 if (reply_len
> txn
->reply
->allocated
) {
862 ofpbuf_reinit(txn
->reply
, reply_len
);
864 memcpy(txn
->reply
->data
, reply_buf
, reply_len
);
865 txn
->reply
->size
= reply_len
;
868 ofpbuf_uninit(&tmp_reply
);
871 /* Count the number of successful transactions. */
877 COVERAGE_ADD(netlink_sent
, n
);
885 nl_sock_transact_multiple(struct nl_sock
*sock
,
886 struct nl_transaction
**transactions
, size_t n
)
895 /* In theory, every request could have a 64 kB reply. But the default and
896 * maximum socket rcvbuf size with typical Dom0 memory sizes both tend to
897 * be a bit below 128 kB, so that would only allow a single message in a
898 * "batch". So we assume that replies average (at most) 4 kB, which allows
899 * a good deal of batching.
901 * In practice, most of the requests that we batch either have no reply at
902 * all or a brief reply. */
903 max_batch_count
= MAX(sock
->rcvbuf
/ 4096, 1);
904 max_batch_count
= MIN(max_batch_count
, max_iovs
);
910 /* Batch up to 'max_batch_count' transactions. But cap it at about a
911 * page of requests total because big skbuffs are expensive to
912 * allocate in the kernel. */
913 #if defined(PAGESIZE)
914 enum { MAX_BATCH_BYTES
= MAX(1, PAGESIZE
- 512) };
916 enum { MAX_BATCH_BYTES
= 4096 - 512 };
918 bytes
= transactions
[0]->request
->size
;
919 for (count
= 1; count
< n
&& count
< max_batch_count
; count
++) {
920 if (bytes
+ transactions
[count
]->request
->size
> MAX_BATCH_BYTES
) {
923 bytes
+= transactions
[count
]->request
->size
;
926 error
= nl_sock_transact_multiple__(sock
, transactions
, count
, &done
);
927 transactions
+= done
;
930 if (error
== ENOBUFS
) {
931 VLOG_DBG_RL(&rl
, "receive buffer overflow, resending request");
933 VLOG_ERR_RL(&rl
, "transaction error (%s)", ovs_strerror(error
));
934 nl_sock_record_errors__(transactions
, n
, error
);
935 if (error
!= EAGAIN
) {
936 /* A fatal error has occurred. Abort the rest of
945 nl_sock_transact(struct nl_sock
*sock
, const struct ofpbuf
*request
,
946 struct ofpbuf
**replyp
)
948 struct nl_transaction
*transactionp
;
949 struct nl_transaction transaction
;
951 transaction
.request
= CONST_CAST(struct ofpbuf
*, request
);
952 transaction
.reply
= replyp
? ofpbuf_new(1024) : NULL
;
953 transactionp
= &transaction
;
955 nl_sock_transact_multiple(sock
, &transactionp
, 1);
958 if (transaction
.error
) {
959 ofpbuf_delete(transaction
.reply
);
962 *replyp
= transaction
.reply
;
966 return transaction
.error
;
969 /* Drain all the messages currently in 'sock''s receive queue. */
971 nl_sock_drain(struct nl_sock
*sock
)
976 return drain_rcvbuf(sock
->fd
);
980 /* Starts a Netlink "dump" operation, by sending 'request' to the kernel on a
981 * Netlink socket created with the given 'protocol', and initializes 'dump' to
982 * reflect the state of the operation.
984 * 'request' must contain a Netlink message. Before sending the message,
985 * nlmsg_len will be finalized to match request->size, and nlmsg_pid will be
986 * set to the Netlink socket's pid. NLM_F_DUMP and NLM_F_ACK will be set in
989 * The design of this Netlink socket library ensures that the dump is reliable.
991 * This function provides no status indication. nl_dump_done() provides an
992 * error status for the entire dump operation.
994 * The caller must eventually destroy 'request'.
997 nl_dump_start(struct nl_dump
*dump
, int protocol
, const struct ofpbuf
*request
)
999 nl_msg_nlmsghdr(request
)->nlmsg_flags
|= NLM_F_DUMP
| NLM_F_ACK
;
1001 ovs_mutex_init(&dump
->mutex
);
1002 ovs_mutex_lock(&dump
->mutex
);
1003 dump
->status
= nl_pool_alloc(protocol
, &dump
->sock
);
1004 if (!dump
->status
) {
1005 dump
->status
= nl_sock_send__(dump
->sock
, request
,
1006 nl_sock_allocate_seq(dump
->sock
, 1),
1009 dump
->nl_seq
= nl_msg_nlmsghdr(request
)->nlmsg_seq
;
1010 ovs_mutex_unlock(&dump
->mutex
);
1014 nl_dump_refill(struct nl_dump
*dump
, struct ofpbuf
*buffer
)
1015 OVS_REQUIRES(dump
->mutex
)
1017 struct nlmsghdr
*nlmsghdr
;
1020 while (!buffer
->size
) {
1021 error
= nl_sock_recv__(dump
->sock
, buffer
, false);
1023 /* The kernel never blocks providing the results of a dump, so
1024 * error == EAGAIN means that we've read the whole thing, and
1025 * therefore transform it into EOF. (The kernel always provides
1026 * NLMSG_DONE as a sentinel. Some other thread must have received
1027 * that already but not yet signaled it in 'status'.)
1029 * Any other error is just an error. */
1030 return error
== EAGAIN
? EOF
: error
;
1033 nlmsghdr
= nl_msg_nlmsghdr(buffer
);
1034 if (dump
->nl_seq
!= nlmsghdr
->nlmsg_seq
) {
1035 VLOG_DBG_RL(&rl
, "ignoring seq %#"PRIx32
" != expected %#"PRIx32
,
1036 nlmsghdr
->nlmsg_seq
, dump
->nl_seq
);
1037 ofpbuf_clear(buffer
);
1041 if (nl_msg_nlmsgerr(buffer
, &error
) && error
) {
1042 VLOG_INFO_RL(&rl
, "netlink dump request error (%s)",
1043 ovs_strerror(error
));
1044 ofpbuf_clear(buffer
);
1052 nl_dump_next__(struct ofpbuf
*reply
, struct ofpbuf
*buffer
)
1054 struct nlmsghdr
*nlmsghdr
= nl_msg_next(buffer
, reply
);
1056 VLOG_WARN_RL(&rl
, "netlink dump contains message fragment");
1058 } else if (nlmsghdr
->nlmsg_type
== NLMSG_DONE
) {
1065 /* Attempts to retrieve another reply from 'dump' into 'buffer'. 'dump' must
1066 * have been initialized with nl_dump_start(), and 'buffer' must have been
1067 * initialized. 'buffer' should be at least NL_DUMP_BUFSIZE bytes long.
1069 * If successful, returns true and points 'reply->data' and
1070 * 'reply->size' to the message that was retrieved. The caller must not
1071 * modify 'reply' (because it points within 'buffer', which will be used by
1072 * future calls to this function).
1074 * On failure, returns false and sets 'reply->data' to NULL and
1075 * 'reply->size' to 0. Failure might indicate an actual error or merely
1076 * the end of replies. An error status for the entire dump operation is
1077 * provided when it is completed by calling nl_dump_done().
1079 * Multiple threads may call this function, passing the same nl_dump, however
1080 * each must provide independent buffers. This function may cache multiple
1081 * replies in the buffer, and these will be processed before more replies are
1082 * fetched. When this function returns false, other threads may continue to
1083 * process replies in their buffers, but they will not fetch more replies.
1086 nl_dump_next(struct nl_dump
*dump
, struct ofpbuf
*reply
, struct ofpbuf
*buffer
)
1090 /* If the buffer is empty, refill it.
1092 * If the buffer is not empty, we don't check the dump's status.
1093 * Otherwise, we could end up skipping some of the dump results if thread A
1094 * hits EOF while thread B is in the midst of processing a batch. */
1095 if (!buffer
->size
) {
1096 ovs_mutex_lock(&dump
->mutex
);
1097 if (!dump
->status
) {
1098 /* Take the mutex here to avoid an in-kernel race. If two threads
1099 * try to read from a Netlink dump socket at once, then the socket
1100 * error can be set to EINVAL, which will be encountered on the
1101 * next recv on that socket, which could be anywhere due to the way
1102 * that we pool Netlink sockets. Serializing the recv calls avoids
1104 dump
->status
= nl_dump_refill(dump
, buffer
);
1106 retval
= dump
->status
;
1107 ovs_mutex_unlock(&dump
->mutex
);
1110 /* Fetch the next message from the buffer. */
1112 retval
= nl_dump_next__(reply
, buffer
);
1114 /* Record 'retval' as the dump status, but don't overwrite an error
1116 ovs_mutex_lock(&dump
->mutex
);
1117 if (dump
->status
<= 0) {
1118 dump
->status
= retval
;
1120 ovs_mutex_unlock(&dump
->mutex
);
1131 /* Completes Netlink dump operation 'dump', which must have been initialized
1132 * with nl_dump_start(). Returns 0 if the dump operation was error-free,
1133 * otherwise a positive errno value describing the problem. */
1135 nl_dump_done(struct nl_dump
*dump
)
1139 ovs_mutex_lock(&dump
->mutex
);
1140 status
= dump
->status
;
1141 ovs_mutex_unlock(&dump
->mutex
);
1143 /* Drain any remaining messages that the client didn't read. Otherwise the
1144 * kernel will continue to queue them up and waste buffer space.
1146 * XXX We could just destroy and discard the socket in this case. */
1148 uint64_t tmp_reply_stub
[NL_DUMP_BUFSIZE
/ 8];
1149 struct ofpbuf reply
, buf
;
1151 ofpbuf_use_stub(&buf
, tmp_reply_stub
, sizeof tmp_reply_stub
);
1152 while (nl_dump_next(dump
, &reply
, &buf
)) {
1153 /* Nothing to do. */
1155 ofpbuf_uninit(&buf
);
1157 ovs_mutex_lock(&dump
->mutex
);
1158 status
= dump
->status
;
1159 ovs_mutex_unlock(&dump
->mutex
);
1163 nl_pool_release(dump
->sock
);
1164 ovs_mutex_destroy(&dump
->mutex
);
1166 return status
== EOF
? 0 : status
;
1170 /* Pend an I/O request in the driver. The driver completes the I/O whenever
1171 * an event or a packet is ready to be read. Once the I/O is completed
1172 * the overlapped structure event associated with the pending I/O will be set
1175 pend_io_request(struct nl_sock
*sock
)
1177 struct ofpbuf request
;
1178 uint64_t request_stub
[128];
1179 struct ovs_header
*ovs_header
;
1180 struct nlmsghdr
*nlmsg
;
1185 OVERLAPPED
*overlapped
= CONST_CAST(OVERLAPPED
*, &sock
->overlapped
);
1186 uint16_t cmd
= OVS_CTRL_CMD_WIN_PEND_PACKET_REQ
;
1188 ovs_assert(sock
->read_ioctl
== OVS_IOCTL_READ_PACKET
||
1189 sock
->read_ioctl
== OVS_IOCTL_READ_EVENT
);
1190 if (sock
->read_ioctl
== OVS_IOCTL_READ_EVENT
) {
1191 cmd
= OVS_CTRL_CMD_WIN_PEND_REQ
;
1194 int ovs_msg_size
= sizeof (struct nlmsghdr
) + sizeof (struct genlmsghdr
) +
1195 sizeof (struct ovs_header
);
1197 ofpbuf_use_stub(&request
, request_stub
, sizeof request_stub
);
1199 seq
= nl_sock_allocate_seq(sock
, 1);
1200 nl_msg_put_genlmsghdr(&request
, 0, OVS_WIN_NL_CTRL_FAMILY_ID
, 0,
1201 cmd
, OVS_WIN_CONTROL_VERSION
);
1202 nlmsg
= nl_msg_nlmsghdr(&request
);
1203 nlmsg
->nlmsg_seq
= seq
;
1204 nlmsg
->nlmsg_pid
= sock
->pid
;
1206 ovs_header
= ofpbuf_put_uninit(&request
, sizeof *ovs_header
);
1207 ovs_header
->dp_ifindex
= 0;
1209 if (!DeviceIoControl(sock
->handle
, OVS_IOCTL_WRITE
,
1210 request
.data
, request
.size
,
1211 NULL
, 0, &bytes
, overlapped
)) {
1212 error
= GetLastError();
1213 /* Check if the I/O got pended */
1214 if (error
!= ERROR_IO_INCOMPLETE
&& error
!= ERROR_IO_PENDING
) {
1215 VLOG_ERR("nl_sock_wait failed - %s\n", ovs_format_message(error
));
1223 ofpbuf_uninit(&request
);
1228 /* Causes poll_block() to wake up when any of the specified 'events' (which is
1229 * a OR'd combination of POLLIN, POLLOUT, etc.) occur on 'sock'.
1230 * On Windows, 'sock' is not treated as const, and may be modified. */
1232 nl_sock_wait(const struct nl_sock
*sock
, short int events
)
1235 if (sock
->overlapped
.Internal
!= STATUS_PENDING
) {
1236 int ret
= pend_io_request(CONST_CAST(struct nl_sock
*, sock
));
1238 poll_wevent_wait(sock
->overlapped
.hEvent
);
1240 poll_immediate_wake();
1243 poll_wevent_wait(sock
->overlapped
.hEvent
);
1246 poll_fd_wait(sock
->fd
, events
);
1251 /* Returns the underlying fd for 'sock', for use in "poll()"-like operations
1252 * that can't use nl_sock_wait().
1254 * It's a little tricky to use the returned fd correctly, because nl_sock does
1255 * "copy on write" to allow a single nl_sock to be used for notifications,
1256 * transactions, and dumps. If 'sock' is used only for notifications and
1257 * transactions (and never for dump) then the usage is safe. */
1259 nl_sock_fd(const struct nl_sock
*sock
)
1265 /* Returns the PID associated with this socket. */
1267 nl_sock_pid(const struct nl_sock
*sock
)
1272 /* Miscellaneous. */
1274 struct genl_family
{
1275 struct hmap_node hmap_node
;
1280 static struct hmap genl_families
= HMAP_INITIALIZER(&genl_families
);
1282 static const struct nl_policy family_policy
[CTRL_ATTR_MAX
+ 1] = {
1283 [CTRL_ATTR_FAMILY_ID
] = {.type
= NL_A_U16
},
1284 [CTRL_ATTR_MCAST_GROUPS
] = {.type
= NL_A_NESTED
, .optional
= true},
1287 static struct genl_family
*
1288 find_genl_family_by_id(uint16_t id
)
1290 struct genl_family
*family
;
1292 HMAP_FOR_EACH_IN_BUCKET (family
, hmap_node
, hash_int(id
, 0),
1294 if (family
->id
== id
) {
1302 define_genl_family(uint16_t id
, const char *name
)
1304 struct genl_family
*family
= find_genl_family_by_id(id
);
1307 if (!strcmp(family
->name
, name
)) {
1312 family
= xmalloc(sizeof *family
);
1314 hmap_insert(&genl_families
, &family
->hmap_node
, hash_int(id
, 0));
1316 family
->name
= xstrdup(name
);
1320 genl_family_to_name(uint16_t id
)
1322 if (id
== GENL_ID_CTRL
) {
1325 struct genl_family
*family
= find_genl_family_by_id(id
);
1326 return family
? family
->name
: "unknown";
1332 do_lookup_genl_family(const char *name
, struct nlattr
**attrs
,
1333 struct ofpbuf
**replyp
)
1335 struct nl_sock
*sock
;
1336 struct ofpbuf request
, *reply
;
1340 error
= nl_sock_create(NETLINK_GENERIC
, &sock
);
1345 ofpbuf_init(&request
, 0);
1346 nl_msg_put_genlmsghdr(&request
, 0, GENL_ID_CTRL
, NLM_F_REQUEST
,
1347 CTRL_CMD_GETFAMILY
, 1);
1348 nl_msg_put_string(&request
, CTRL_ATTR_FAMILY_NAME
, name
);
1349 error
= nl_sock_transact(sock
, &request
, &reply
);
1350 ofpbuf_uninit(&request
);
1352 nl_sock_destroy(sock
);
1356 if (!nl_policy_parse(reply
, NLMSG_HDRLEN
+ GENL_HDRLEN
,
1357 family_policy
, attrs
, ARRAY_SIZE(family_policy
))
1358 || nl_attr_get_u16(attrs
[CTRL_ATTR_FAMILY_ID
]) == 0) {
1359 nl_sock_destroy(sock
);
1360 ofpbuf_delete(reply
);
1364 nl_sock_destroy(sock
);
1370 do_lookup_genl_family(const char *name
, struct nlattr
**attrs
,
1371 struct ofpbuf
**replyp
)
1373 struct nlmsghdr
*nlmsg
;
1374 struct ofpbuf
*reply
;
1377 const char *family_name
;
1378 uint32_t family_version
;
1379 uint32_t family_attrmax
;
1380 uint32_t mcgrp_id
= OVS_WIN_NL_INVALID_MCGRP_ID
;
1381 const char *mcgrp_name
= NULL
;
1384 reply
= ofpbuf_new(1024);
1386 /* CTRL_ATTR_MCAST_GROUPS is supported only for VPORT family. */
1387 if (!strcmp(name
, OVS_WIN_CONTROL_FAMILY
)) {
1388 family_id
= OVS_WIN_NL_CTRL_FAMILY_ID
;
1389 family_name
= OVS_WIN_CONTROL_FAMILY
;
1390 family_version
= OVS_WIN_CONTROL_VERSION
;
1391 family_attrmax
= OVS_WIN_CONTROL_ATTR_MAX
;
1392 } else if (!strcmp(name
, OVS_DATAPATH_FAMILY
)) {
1393 family_id
= OVS_WIN_NL_DATAPATH_FAMILY_ID
;
1394 family_name
= OVS_DATAPATH_FAMILY
;
1395 family_version
= OVS_DATAPATH_VERSION
;
1396 family_attrmax
= OVS_DP_ATTR_MAX
;
1397 } else if (!strcmp(name
, OVS_PACKET_FAMILY
)) {
1398 family_id
= OVS_WIN_NL_PACKET_FAMILY_ID
;
1399 family_name
= OVS_PACKET_FAMILY
;
1400 family_version
= OVS_PACKET_VERSION
;
1401 family_attrmax
= OVS_PACKET_ATTR_MAX
;
1402 } else if (!strcmp(name
, OVS_VPORT_FAMILY
)) {
1403 family_id
= OVS_WIN_NL_VPORT_FAMILY_ID
;
1404 family_name
= OVS_VPORT_FAMILY
;
1405 family_version
= OVS_VPORT_VERSION
;
1406 family_attrmax
= OVS_VPORT_ATTR_MAX
;
1407 mcgrp_id
= OVS_WIN_NL_VPORT_MCGRP_ID
;
1408 mcgrp_name
= OVS_VPORT_MCGROUP
;
1409 } else if (!strcmp(name
, OVS_FLOW_FAMILY
)) {
1410 family_id
= OVS_WIN_NL_FLOW_FAMILY_ID
;
1411 family_name
= OVS_FLOW_FAMILY
;
1412 family_version
= OVS_FLOW_VERSION
;
1413 family_attrmax
= OVS_FLOW_ATTR_MAX
;
1414 } else if (!strcmp(name
, OVS_WIN_NETDEV_FAMILY
)) {
1415 family_id
= OVS_WIN_NL_NETDEV_FAMILY_ID
;
1416 family_name
= OVS_WIN_NETDEV_FAMILY
;
1417 family_version
= OVS_WIN_NETDEV_VERSION
;
1418 family_attrmax
= OVS_WIN_NETDEV_ATTR_MAX
;
1420 ofpbuf_delete(reply
);
1424 nl_msg_put_genlmsghdr(reply
, 0, GENL_ID_CTRL
, 0,
1425 CTRL_CMD_NEWFAMILY
, family_version
);
1426 /* CTRL_ATTR_HDRSIZE and CTRL_ATTR_OPS are not populated, but the
1427 * callers do not seem to need them. */
1428 nl_msg_put_u16(reply
, CTRL_ATTR_FAMILY_ID
, family_id
);
1429 nl_msg_put_string(reply
, CTRL_ATTR_FAMILY_NAME
, family_name
);
1430 nl_msg_put_u32(reply
, CTRL_ATTR_VERSION
, family_version
);
1431 nl_msg_put_u32(reply
, CTRL_ATTR_MAXATTR
, family_attrmax
);
1433 if (mcgrp_id
!= OVS_WIN_NL_INVALID_MCGRP_ID
) {
1434 size_t mcgrp_ofs1
= nl_msg_start_nested(reply
, CTRL_ATTR_MCAST_GROUPS
);
1435 size_t mcgrp_ofs2
= nl_msg_start_nested(reply
,
1436 OVS_WIN_NL_VPORT_MCGRP_ID
- OVS_WIN_NL_MCGRP_START_ID
);
1437 nl_msg_put_u32(reply
, CTRL_ATTR_MCAST_GRP_ID
, mcgrp_id
);
1438 ovs_assert(mcgrp_name
!= NULL
);
1439 nl_msg_put_string(reply
, CTRL_ATTR_MCAST_GRP_NAME
, mcgrp_name
);
1440 nl_msg_end_nested(reply
, mcgrp_ofs2
);
1441 nl_msg_end_nested(reply
, mcgrp_ofs1
);
1444 /* Set the total length of the netlink message. */
1445 nlmsg
= nl_msg_nlmsghdr(reply
);
1446 nlmsg
->nlmsg_len
= reply
->size
;
1448 if (!nl_policy_parse(reply
, NLMSG_HDRLEN
+ GENL_HDRLEN
,
1449 family_policy
, attrs
, ARRAY_SIZE(family_policy
))
1450 || nl_attr_get_u16(attrs
[CTRL_ATTR_FAMILY_ID
]) == 0) {
1451 ofpbuf_delete(reply
);
1460 /* Finds the multicast group called 'group_name' in genl family 'family_name'.
1461 * When successful, writes its result to 'multicast_group' and returns 0.
1462 * Otherwise, clears 'multicast_group' and returns a positive error code.
1465 nl_lookup_genl_mcgroup(const char *family_name
, const char *group_name
,
1466 unsigned int *multicast_group
)
1468 struct nlattr
*family_attrs
[ARRAY_SIZE(family_policy
)];
1469 const struct nlattr
*mc
;
1470 struct ofpbuf
*reply
;
1474 *multicast_group
= 0;
1475 error
= do_lookup_genl_family(family_name
, family_attrs
, &reply
);
1480 if (!family_attrs
[CTRL_ATTR_MCAST_GROUPS
]) {
1485 NL_NESTED_FOR_EACH (mc
, left
, family_attrs
[CTRL_ATTR_MCAST_GROUPS
]) {
1486 static const struct nl_policy mc_policy
[] = {
1487 [CTRL_ATTR_MCAST_GRP_ID
] = {.type
= NL_A_U32
},
1488 [CTRL_ATTR_MCAST_GRP_NAME
] = {.type
= NL_A_STRING
},
1491 struct nlattr
*mc_attrs
[ARRAY_SIZE(mc_policy
)];
1492 const char *mc_name
;
1494 if (!nl_parse_nested(mc
, mc_policy
, mc_attrs
, ARRAY_SIZE(mc_policy
))) {
1499 mc_name
= nl_attr_get_string(mc_attrs
[CTRL_ATTR_MCAST_GRP_NAME
]);
1500 if (!strcmp(group_name
, mc_name
)) {
1502 nl_attr_get_u32(mc_attrs
[CTRL_ATTR_MCAST_GRP_ID
]);
1510 ofpbuf_delete(reply
);
1514 /* If '*number' is 0, translates the given Generic Netlink family 'name' to a
1515 * number and stores it in '*number'. If successful, returns 0 and the caller
1516 * may use '*number' as the family number. On failure, returns a positive
1517 * errno value and '*number' caches the errno value. */
1519 nl_lookup_genl_family(const char *name
, int *number
)
1522 struct nlattr
*attrs
[ARRAY_SIZE(family_policy
)];
1523 struct ofpbuf
*reply
;
1526 error
= do_lookup_genl_family(name
, attrs
, &reply
);
1528 *number
= nl_attr_get_u16(attrs
[CTRL_ATTR_FAMILY_ID
]);
1529 define_genl_family(*number
, name
);
1533 ofpbuf_delete(reply
);
1535 ovs_assert(*number
!= 0);
1537 return *number
> 0 ? 0 : -*number
;
1541 struct nl_sock
*socks
[16];
1545 static struct ovs_mutex pool_mutex
= OVS_MUTEX_INITIALIZER
;
1546 static struct nl_pool pools
[MAX_LINKS
] OVS_GUARDED_BY(pool_mutex
);
1549 nl_pool_alloc(int protocol
, struct nl_sock
**sockp
)
1551 struct nl_sock
*sock
= NULL
;
1552 struct nl_pool
*pool
;
1554 ovs_assert(protocol
>= 0 && protocol
< ARRAY_SIZE(pools
));
1556 ovs_mutex_lock(&pool_mutex
);
1557 pool
= &pools
[protocol
];
1559 sock
= pool
->socks
[--pool
->n
];
1561 ovs_mutex_unlock(&pool_mutex
);
1567 return nl_sock_create(protocol
, sockp
);
1572 nl_pool_release(struct nl_sock
*sock
)
1575 struct nl_pool
*pool
= &pools
[sock
->protocol
];
1577 ovs_mutex_lock(&pool_mutex
);
1578 if (pool
->n
< ARRAY_SIZE(pool
->socks
)) {
1579 pool
->socks
[pool
->n
++] = sock
;
1582 ovs_mutex_unlock(&pool_mutex
);
1584 nl_sock_destroy(sock
);
1588 /* Sends 'request' to the kernel on a Netlink socket for the given 'protocol'
1589 * (e.g. NETLINK_ROUTE or NETLINK_GENERIC) and waits for a response. If
1590 * successful, returns 0. On failure, returns a positive errno value.
1592 * If 'replyp' is nonnull, then on success '*replyp' is set to the kernel's
1593 * reply, which the caller is responsible for freeing with ofpbuf_delete(), and
1594 * on failure '*replyp' is set to NULL. If 'replyp' is null, then the kernel's
1595 * reply, if any, is discarded.
1597 * Before the message is sent, nlmsg_len in 'request' will be finalized to
1598 * match msg->size, nlmsg_pid will be set to the pid of the socket used
1599 * for sending the request, and nlmsg_seq will be initialized.
1601 * The caller is responsible for destroying 'request'.
1603 * Bare Netlink is an unreliable transport protocol. This function layers
1604 * reliable delivery and reply semantics on top of bare Netlink.
1606 * In Netlink, sending a request to the kernel is reliable enough, because the
1607 * kernel will tell us if the message cannot be queued (and we will in that
1608 * case put it on the transmit queue and wait until it can be delivered).
1610 * Receiving the reply is the real problem: if the socket buffer is full when
1611 * the kernel tries to send the reply, the reply will be dropped. However, the
1612 * kernel sets a flag that a reply has been dropped. The next call to recv
1613 * then returns ENOBUFS. We can then re-send the request.
1617 * 1. Netlink depends on sequence numbers to match up requests and
1618 * replies. The sender of a request supplies a sequence number, and
1619 * the reply echos back that sequence number.
1621 * This is fine, but (1) some kernel netlink implementations are
1622 * broken, in that they fail to echo sequence numbers and (2) this
1623 * function will drop packets with non-matching sequence numbers, so
1624 * that only a single request can be usefully transacted at a time.
1626 * 2. Resending the request causes it to be re-executed, so the request
1627 * needs to be idempotent.
1630 nl_transact(int protocol
, const struct ofpbuf
*request
,
1631 struct ofpbuf
**replyp
)
1633 struct nl_sock
*sock
;
1636 error
= nl_pool_alloc(protocol
, &sock
);
1642 error
= nl_sock_transact(sock
, request
, replyp
);
1644 nl_pool_release(sock
);
1648 /* Sends the 'request' member of the 'n' transactions in 'transactions' on a
1649 * Netlink socket for the given 'protocol' (e.g. NETLINK_ROUTE or
1650 * NETLINK_GENERIC), in order, and receives responses to all of them. Fills in
1651 * the 'error' member of each transaction with 0 if it was successful,
1652 * otherwise with a positive errno value. If 'reply' is nonnull, then it will
1653 * be filled with the reply if the message receives a detailed reply. In other
1654 * cases, i.e. where the request failed or had no reply beyond an indication of
1655 * success, 'reply' will be cleared if it is nonnull.
1657 * The caller is responsible for destroying each request and reply, and the
1658 * transactions array itself.
1660 * Before sending each message, this function will finalize nlmsg_len in each
1661 * 'request' to match the ofpbuf's size, set nlmsg_pid to the pid of the socket
1662 * used for the transaction, and initialize nlmsg_seq.
1664 * Bare Netlink is an unreliable transport protocol. This function layers
1665 * reliable delivery and reply semantics on top of bare Netlink. See
1666 * nl_transact() for some caveats.
1669 nl_transact_multiple(int protocol
,
1670 struct nl_transaction
**transactions
, size_t n
)
1672 struct nl_sock
*sock
;
1675 error
= nl_pool_alloc(protocol
, &sock
);
1677 nl_sock_transact_multiple(sock
, transactions
, n
);
1678 nl_pool_release(sock
);
1680 nl_sock_record_errors__(transactions
, n
, error
);
1686 nl_sock_allocate_seq(struct nl_sock
*sock
, unsigned int n
)
1688 uint32_t seq
= sock
->next_seq
;
1690 sock
->next_seq
+= n
;
1692 /* Make it impossible for the next request for sequence numbers to wrap
1693 * around to 0. Start over with 1 to avoid ever using a sequence number of
1694 * 0, because the kernel uses sequence number 0 for notifications. */
1695 if (sock
->next_seq
>= UINT32_MAX
/ 2) {
1703 nlmsghdr_to_string(const struct nlmsghdr
*h
, int protocol
, struct ds
*ds
)
1709 static const struct nlmsg_flag flags
[] = {
1710 { NLM_F_REQUEST
, "REQUEST" },
1711 { NLM_F_MULTI
, "MULTI" },
1712 { NLM_F_ACK
, "ACK" },
1713 { NLM_F_ECHO
, "ECHO" },
1714 { NLM_F_DUMP
, "DUMP" },
1715 { NLM_F_ROOT
, "ROOT" },
1716 { NLM_F_MATCH
, "MATCH" },
1717 { NLM_F_ATOMIC
, "ATOMIC" },
1719 const struct nlmsg_flag
*flag
;
1720 uint16_t flags_left
;
1722 ds_put_format(ds
, "nl(len:%"PRIu32
", type=%"PRIu16
,
1723 h
->nlmsg_len
, h
->nlmsg_type
);
1724 if (h
->nlmsg_type
== NLMSG_NOOP
) {
1725 ds_put_cstr(ds
, "(no-op)");
1726 } else if (h
->nlmsg_type
== NLMSG_ERROR
) {
1727 ds_put_cstr(ds
, "(error)");
1728 } else if (h
->nlmsg_type
== NLMSG_DONE
) {
1729 ds_put_cstr(ds
, "(done)");
1730 } else if (h
->nlmsg_type
== NLMSG_OVERRUN
) {
1731 ds_put_cstr(ds
, "(overrun)");
1732 } else if (h
->nlmsg_type
< NLMSG_MIN_TYPE
) {
1733 ds_put_cstr(ds
, "(reserved)");
1734 } else if (protocol
== NETLINK_GENERIC
) {
1735 ds_put_format(ds
, "(%s)", genl_family_to_name(h
->nlmsg_type
));
1737 ds_put_cstr(ds
, "(family-defined)");
1739 ds_put_format(ds
, ", flags=%"PRIx16
, h
->nlmsg_flags
);
1740 flags_left
= h
->nlmsg_flags
;
1741 for (flag
= flags
; flag
< &flags
[ARRAY_SIZE(flags
)]; flag
++) {
1742 if ((flags_left
& flag
->bits
) == flag
->bits
) {
1743 ds_put_format(ds
, "[%s]", flag
->name
);
1744 flags_left
&= ~flag
->bits
;
1748 ds_put_format(ds
, "[OTHER:%"PRIx16
"]", flags_left
);
1750 ds_put_format(ds
, ", seq=%"PRIx32
", pid=%"PRIu32
,
1751 h
->nlmsg_seq
, h
->nlmsg_pid
);
1755 nlmsg_to_string(const struct ofpbuf
*buffer
, int protocol
)
1757 struct ds ds
= DS_EMPTY_INITIALIZER
;
1758 const struct nlmsghdr
*h
= ofpbuf_at(buffer
, 0, NLMSG_HDRLEN
);
1760 nlmsghdr_to_string(h
, protocol
, &ds
);
1761 if (h
->nlmsg_type
== NLMSG_ERROR
) {
1762 const struct nlmsgerr
*e
;
1763 e
= ofpbuf_at(buffer
, NLMSG_HDRLEN
,
1764 NLMSG_ALIGN(sizeof(struct nlmsgerr
)));
1766 ds_put_format(&ds
, " error(%d", e
->error
);
1768 ds_put_format(&ds
, "(%s)", ovs_strerror(-e
->error
));
1770 ds_put_cstr(&ds
, ", in-reply-to(");
1771 nlmsghdr_to_string(&e
->msg
, protocol
, &ds
);
1772 ds_put_cstr(&ds
, "))");
1774 ds_put_cstr(&ds
, " error(truncated)");
1776 } else if (h
->nlmsg_type
== NLMSG_DONE
) {
1777 int *error
= ofpbuf_at(buffer
, NLMSG_HDRLEN
, sizeof *error
);
1779 ds_put_format(&ds
, " done(%d", *error
);
1781 ds_put_format(&ds
, "(%s)", ovs_strerror(-*error
));
1783 ds_put_cstr(&ds
, ")");
1785 ds_put_cstr(&ds
, " done(truncated)");
1787 } else if (protocol
== NETLINK_GENERIC
) {
1788 struct genlmsghdr
*genl
= nl_msg_genlmsghdr(buffer
);
1790 ds_put_format(&ds
, ",genl(cmd=%"PRIu8
",version=%"PRIu8
")",
1791 genl
->cmd
, genl
->version
);
1795 ds_put_cstr(&ds
, "nl(truncated)");
1801 log_nlmsg(const char *function
, int error
,
1802 const void *message
, size_t size
, int protocol
)
1804 if (!VLOG_IS_DBG_ENABLED()) {
1808 struct ofpbuf buffer
= ofpbuf_const_initializer(message
, size
);
1809 char *nlmsg
= nlmsg_to_string(&buffer
, protocol
);
1810 VLOG_DBG_RL(&rl
, "%s (%s): %s", function
, ovs_strerror(error
), nlmsg
);