2 * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014 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"
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
;
199 /* Connect to kernel (pid 0) as remote address. */
200 memset(&remote
, 0, sizeof remote
);
201 remote
.nl_family
= AF_NETLINK
;
203 if (connect(sock
->fd
, (struct sockaddr
*) &remote
, sizeof remote
) < 0) {
204 VLOG_ERR("connect(0): %s", ovs_strerror(errno
));
208 /* Obtain pid assigned by kernel. */
209 local_size
= sizeof local
;
210 if (getsockname(sock
->fd
, (struct sockaddr
*) &local
, &local_size
) < 0) {
211 VLOG_ERR("getsockname: %s", ovs_strerror(errno
));
214 if (local_size
< sizeof local
|| local
.nl_family
!= AF_NETLINK
) {
215 VLOG_ERR("getsockname returned bad Netlink name");
219 sock
->pid
= local
.nl_pid
;
233 if (sock
->overlapped
.hEvent
) {
234 CloseHandle(sock
->overlapped
.hEvent
);
236 if (sock
->handle
!= INVALID_HANDLE_VALUE
) {
237 CloseHandle(sock
->handle
);
248 /* Creates a new netlink socket for the same protocol as 'src'. Returns 0 and
249 * sets '*sockp' to the new socket if successful, otherwise returns a positive
252 nl_sock_clone(const struct nl_sock
*src
, struct nl_sock
**sockp
)
254 return nl_sock_create(src
->protocol
, sockp
);
257 /* Destroys netlink socket 'sock'. */
259 nl_sock_destroy(struct nl_sock
*sock
)
263 if (sock
->overlapped
.hEvent
) {
264 CloseHandle(sock
->overlapped
.hEvent
);
266 CloseHandle(sock
->handle
);
275 /* Reads the pid for 'sock' generated in the kernel datapath. The function
276 * follows a transaction semantic. Eventually this function should call into
279 get_sock_pid_from_kernel(struct nl_sock
*sock
)
281 struct nl_transaction txn
;
282 struct ofpbuf request
;
283 uint64_t request_stub
[128];
285 uint64_t reply_stub
[128];
286 struct ovs_header
*ovs_header
;
287 struct nlmsghdr
*nlmsg
;
291 int ovs_msg_size
= sizeof (struct nlmsghdr
) + sizeof (struct genlmsghdr
) +
292 sizeof (struct ovs_header
);
294 ofpbuf_use_stub(&request
, request_stub
, sizeof request_stub
);
295 txn
.request
= &request
;
296 ofpbuf_use_stub(&reply
, reply_stub
, sizeof reply_stub
);
299 seq
= nl_sock_allocate_seq(sock
, 1);
300 nl_msg_put_genlmsghdr(&request
, 0, OVS_WIN_NL_CTRL_FAMILY_ID
, 0,
301 OVS_CTRL_CMD_WIN_GET_PID
, OVS_WIN_CONTROL_VERSION
);
302 nlmsg
= nl_msg_nlmsghdr(txn
.request
);
303 nlmsg
->nlmsg_seq
= seq
;
305 ovs_header
= ofpbuf_put_uninit(&request
, sizeof *ovs_header
);
306 ovs_header
->dp_ifindex
= 0;
307 ovs_header
= ofpbuf_put_uninit(&reply
, ovs_msg_size
);
309 if (!DeviceIoControl(sock
->handle
, OVS_IOCTL_TRANSACT
,
310 ofpbuf_data(txn
.request
), ofpbuf_size(txn
.request
),
311 ofpbuf_data(txn
.reply
), ofpbuf_size(txn
.reply
),
316 if (bytes
< ovs_msg_size
) {
321 nlmsg
= nl_msg_nlmsghdr(txn
.reply
);
322 if (nlmsg
->nlmsg_seq
!= seq
) {
326 sock
->pid
= nlmsg
->nlmsg_pid
;
331 ofpbuf_uninit(&request
);
332 ofpbuf_uninit(&reply
);
339 nl_sock_mcgroup(struct nl_sock
*sock
, unsigned int multicast_group
, bool join
)
341 struct ofpbuf request
;
342 uint64_t request_stub
[128];
343 struct ovs_header
*ovs_header
;
344 struct nlmsghdr
*nlmsg
;
347 ofpbuf_use_stub(&request
, request_stub
, sizeof request_stub
);
349 nl_msg_put_genlmsghdr(&request
, 0, OVS_WIN_NL_CTRL_FAMILY_ID
, 0,
350 OVS_CTRL_CMD_MC_SUBSCRIBE_REQ
,
351 OVS_WIN_CONTROL_VERSION
);
353 ovs_header
= ofpbuf_put_uninit(&request
, sizeof *ovs_header
);
354 ovs_header
->dp_ifindex
= 0;
356 nl_msg_put_u32(&request
, OVS_NL_ATTR_MCAST_GRP
, multicast_group
);
357 nl_msg_put_u8(&request
, OVS_NL_ATTR_MCAST_JOIN
, join
? 1 : 0);
359 error
= nl_sock_send(sock
, &request
, true);
360 ofpbuf_uninit(&request
);
364 /* Tries to add 'sock' as a listener for 'multicast_group'. Returns 0 if
365 * successful, otherwise a positive errno value.
367 * A socket that is subscribed to a multicast group that receives asynchronous
368 * notifications must not be used for Netlink transactions or dumps, because
369 * transactions and dumps can cause notifications to be lost.
371 * Multicast group numbers are always positive.
373 * It is not an error to attempt to join a multicast group to which a socket
374 * already belongs. */
376 nl_sock_join_mcgroup(struct nl_sock
*sock
, unsigned int multicast_group
)
379 /* Set the socket type as a "multicast" socket */
380 sock
->read_ioctl
= OVS_IOCTL_READ_EVENT
;
381 int error
= nl_sock_mcgroup(sock
, multicast_group
, true);
383 sock
->read_ioctl
= OVS_IOCTL_READ
;
384 VLOG_WARN("could not join multicast group %u (%s)",
385 multicast_group
, ovs_strerror(error
));
389 if (setsockopt(sock
->fd
, SOL_NETLINK
, NETLINK_ADD_MEMBERSHIP
,
390 &multicast_group
, sizeof multicast_group
) < 0) {
391 VLOG_WARN("could not join multicast group %u (%s)",
392 multicast_group
, ovs_strerror(errno
));
401 nl_sock_subscribe_packets(struct nl_sock
*sock
)
405 if (sock
->read_ioctl
!= OVS_IOCTL_READ
) {
409 error
= nl_sock_subscribe_packet__(sock
, true);
411 VLOG_WARN("could not unsubscribe packets (%s)",
412 ovs_strerror(errno
));
415 sock
->read_ioctl
= OVS_IOCTL_READ_PACKET
;
421 nl_sock_unsubscribe_packets(struct nl_sock
*sock
)
423 ovs_assert(sock
->read_ioctl
== OVS_IOCTL_READ_PACKET
);
425 int error
= nl_sock_subscribe_packet__(sock
, false);
427 VLOG_WARN("could not subscribe to packets (%s)",
428 ovs_strerror(errno
));
432 sock
->read_ioctl
= OVS_IOCTL_READ
;
437 nl_sock_subscribe_packet__(struct nl_sock
*sock
, bool subscribe
)
439 struct ofpbuf request
;
440 uint64_t request_stub
[128];
441 struct ovs_header
*ovs_header
;
442 struct nlmsghdr
*nlmsg
;
445 ofpbuf_use_stub(&request
, request_stub
, sizeof request_stub
);
446 nl_msg_put_genlmsghdr(&request
, 0, OVS_WIN_NL_CTRL_FAMILY_ID
, 0,
447 OVS_CTRL_CMD_PACKET_SUBSCRIBE_REQ
,
448 OVS_WIN_CONTROL_VERSION
);
450 ovs_header
= ofpbuf_put_uninit(&request
, sizeof *ovs_header
);
451 ovs_header
->dp_ifindex
= 0;
452 nl_msg_put_u8(&request
, OVS_NL_ATTR_PACKET_SUBSCRIBE
, subscribe
? 1 : 0);
453 nl_msg_put_u32(&request
, OVS_NL_ATTR_PACKET_PID
, sock
->pid
);
455 error
= nl_sock_send(sock
, &request
, true);
456 ofpbuf_uninit(&request
);
461 /* Tries to make 'sock' stop listening to 'multicast_group'. Returns 0 if
462 * successful, otherwise a positive errno value.
464 * Multicast group numbers are always positive.
466 * It is not an error to attempt to leave a multicast group to which a socket
469 * On success, reading from 'sock' will still return any messages that were
470 * received on 'multicast_group' before the group was left. */
472 nl_sock_leave_mcgroup(struct nl_sock
*sock
, unsigned int multicast_group
)
475 int error
= nl_sock_mcgroup(sock
, multicast_group
, false);
477 VLOG_WARN("could not leave multicast group %u (%s)",
478 multicast_group
, ovs_strerror(error
));
481 sock
->read_ioctl
= OVS_IOCTL_READ
;
483 if (setsockopt(sock
->fd
, SOL_NETLINK
, NETLINK_DROP_MEMBERSHIP
,
484 &multicast_group
, sizeof multicast_group
) < 0) {
485 VLOG_WARN("could not leave multicast group %u (%s)",
486 multicast_group
, ovs_strerror(errno
));
494 nl_sock_send__(struct nl_sock
*sock
, const struct ofpbuf
*msg
,
495 uint32_t nlmsg_seq
, bool wait
)
497 struct nlmsghdr
*nlmsg
= nl_msg_nlmsghdr(msg
);
500 nlmsg
->nlmsg_len
= ofpbuf_size(msg
);
501 nlmsg
->nlmsg_seq
= nlmsg_seq
;
502 nlmsg
->nlmsg_pid
= sock
->pid
;
508 if (!DeviceIoControl(sock
->handle
, OVS_IOCTL_WRITE
,
509 ofpbuf_data(msg
), ofpbuf_size(msg
), NULL
, 0,
512 /* XXX: Map to a more appropriate error based on GetLastError(). */
515 retval
= ofpbuf_size(msg
);
518 retval
= send(sock
->fd
, ofpbuf_data(msg
), ofpbuf_size(msg
),
519 wait
? 0 : MSG_DONTWAIT
);
521 error
= retval
< 0 ? errno
: 0;
522 } while (error
== EINTR
);
523 log_nlmsg(__func__
, error
, ofpbuf_data(msg
), ofpbuf_size(msg
), sock
->protocol
);
525 COVERAGE_INC(netlink_sent
);
530 /* Tries to send 'msg', which must contain a Netlink message, to the kernel on
531 * 'sock'. nlmsg_len in 'msg' will be finalized to match ofpbuf_size(msg), nlmsg_pid
532 * will be set to 'sock''s pid, and nlmsg_seq will be initialized to a fresh
533 * sequence number, before the message is sent.
535 * Returns 0 if successful, otherwise a positive errno value. If
536 * 'wait' is true, then the send will wait until buffer space is ready;
537 * otherwise, returns EAGAIN if the 'sock' send buffer is full. */
539 nl_sock_send(struct nl_sock
*sock
, const struct ofpbuf
*msg
, bool wait
)
541 return nl_sock_send_seq(sock
, msg
, nl_sock_allocate_seq(sock
, 1), wait
);
544 /* Tries to send 'msg', which must contain a Netlink message, to the kernel on
545 * 'sock'. nlmsg_len in 'msg' will be finalized to match ofpbuf_size(msg), nlmsg_pid
546 * will be set to 'sock''s pid, and nlmsg_seq will be initialized to
547 * 'nlmsg_seq', before the message is sent.
549 * Returns 0 if successful, otherwise a positive errno value. If
550 * 'wait' is true, then the send will wait until buffer space is ready;
551 * otherwise, returns EAGAIN if the 'sock' send buffer is full.
553 * This function is suitable for sending a reply to a request that was received
554 * with sequence number 'nlmsg_seq'. Otherwise, use nl_sock_send() instead. */
556 nl_sock_send_seq(struct nl_sock
*sock
, const struct ofpbuf
*msg
,
557 uint32_t nlmsg_seq
, bool wait
)
559 return nl_sock_send__(sock
, msg
, nlmsg_seq
, wait
);
563 nl_sock_recv__(struct nl_sock
*sock
, struct ofpbuf
*buf
, bool wait
)
565 /* We can't accurately predict the size of the data to be received. The
566 * caller is supposed to have allocated enough space in 'buf' to handle the
567 * "typical" case. To handle exceptions, we make available enough space in
568 * 'tail' to allow Netlink messages to be up to 64 kB long (a reasonable
569 * figure since that's the maximum length of a Netlink attribute). */
570 struct nlmsghdr
*nlmsghdr
;
577 ovs_assert(buf
->allocated
>= sizeof *nlmsghdr
);
580 iov
[0].iov_base
= ofpbuf_base(buf
);
581 iov
[0].iov_len
= buf
->allocated
;
582 iov
[1].iov_base
= tail
;
583 iov
[1].iov_len
= sizeof tail
;
585 memset(&msg
, 0, sizeof msg
);
589 /* Receive a Netlink message from the kernel.
591 * This works around a kernel bug in which the kernel returns an error code
592 * as if it were the number of bytes read. It doesn't actually modify
593 * anything in the receive buffer in that case, so we can initialize the
594 * Netlink header with an impossible message length and then, upon success,
595 * check whether it changed. */
596 nlmsghdr
= ofpbuf_base(buf
);
598 nlmsghdr
->nlmsg_len
= UINT32_MAX
;
601 if (!DeviceIoControl(sock
->handle
, sock
->read_ioctl
,
602 NULL
, 0, tail
, sizeof tail
, &bytes
, NULL
)) {
611 if (retval
>= buf
->allocated
) {
612 ofpbuf_reinit(buf
, retval
);
613 nlmsghdr
= ofpbuf_base(buf
);
614 nlmsghdr
->nlmsg_len
= UINT32_MAX
;
616 memcpy(ofpbuf_data(buf
), tail
, retval
);
617 ofpbuf_set_size(buf
, retval
);
621 retval
= recvmsg(sock
->fd
, &msg
, wait
? 0 : MSG_DONTWAIT
);
623 error
= (retval
< 0 ? errno
624 : retval
== 0 ? ECONNRESET
/* not possible? */
625 : nlmsghdr
->nlmsg_len
!= UINT32_MAX
? 0
627 } while (error
== EINTR
);
629 if (error
== ENOBUFS
) {
630 /* Socket receive buffer overflow dropped one or more messages that
631 * the kernel tried to send to us. */
632 COVERAGE_INC(netlink_overflow
);
637 if (msg
.msg_flags
& MSG_TRUNC
) {
638 VLOG_ERR_RL(&rl
, "truncated message (longer than %"PRIuSIZE
" bytes)",
643 if (retval
< sizeof *nlmsghdr
644 || nlmsghdr
->nlmsg_len
< sizeof *nlmsghdr
645 || nlmsghdr
->nlmsg_len
> retval
) {
646 VLOG_ERR_RL(&rl
, "received invalid nlmsg (%"PRIuSIZE
" bytes < %"PRIuSIZE
")",
647 retval
, sizeof *nlmsghdr
);
651 ofpbuf_set_size(buf
, MIN(retval
, buf
->allocated
));
652 if (retval
> buf
->allocated
) {
653 COVERAGE_INC(netlink_recv_jumbo
);
654 ofpbuf_put(buf
, tail
, retval
- buf
->allocated
);
658 log_nlmsg(__func__
, 0, ofpbuf_data(buf
), ofpbuf_size(buf
), sock
->protocol
);
659 COVERAGE_INC(netlink_received
);
664 /* Tries to receive a Netlink message from the kernel on 'sock' into 'buf'. If
665 * 'wait' is true, waits for a message to be ready. Otherwise, fails with
666 * EAGAIN if the 'sock' receive buffer is empty.
668 * The caller must have initialized 'buf' with an allocation of at least
669 * NLMSG_HDRLEN bytes. For best performance, the caller should allocate enough
670 * space for a "typical" message.
672 * On success, returns 0 and replaces 'buf''s previous content by the received
673 * message. This function expands 'buf''s allocated memory, as necessary, to
674 * hold the actual size of the received message.
676 * On failure, returns a positive errno value and clears 'buf' to zero length.
677 * 'buf' retains its previous memory allocation.
679 * Regardless of success or failure, this function resets 'buf''s headroom to
682 nl_sock_recv(struct nl_sock
*sock
, struct ofpbuf
*buf
, bool wait
)
684 return nl_sock_recv__(sock
, buf
, wait
);
688 nl_sock_record_errors__(struct nl_transaction
**transactions
, size_t n
,
693 for (i
= 0; i
< n
; i
++) {
694 struct nl_transaction
*txn
= transactions
[i
];
698 ofpbuf_clear(txn
->reply
);
704 nl_sock_transact_multiple__(struct nl_sock
*sock
,
705 struct nl_transaction
**transactions
, size_t n
,
708 uint64_t tmp_reply_stub
[1024 / 8];
709 struct nl_transaction tmp_txn
;
710 struct ofpbuf tmp_reply
;
713 struct iovec iovs
[MAX_IOVS
];
718 base_seq
= nl_sock_allocate_seq(sock
, n
);
720 for (i
= 0; i
< n
; i
++) {
721 struct nl_transaction
*txn
= transactions
[i
];
722 struct nlmsghdr
*nlmsg
= nl_msg_nlmsghdr(txn
->request
);
724 nlmsg
->nlmsg_len
= ofpbuf_size(txn
->request
);
725 nlmsg
->nlmsg_seq
= base_seq
+ i
;
726 nlmsg
->nlmsg_pid
= sock
->pid
;
728 iovs
[i
].iov_base
= ofpbuf_data(txn
->request
);
729 iovs
[i
].iov_len
= ofpbuf_size(txn
->request
);
733 memset(&msg
, 0, sizeof msg
);
737 error
= sendmsg(sock
->fd
, &msg
, 0) < 0 ? errno
: 0;
738 } while (error
== EINTR
);
740 for (i
= 0; i
< n
; i
++) {
741 struct nl_transaction
*txn
= transactions
[i
];
743 log_nlmsg(__func__
, error
, ofpbuf_data(txn
->request
),
744 ofpbuf_size(txn
->request
), sock
->protocol
);
747 COVERAGE_ADD(netlink_sent
, n
);
754 ofpbuf_use_stub(&tmp_reply
, tmp_reply_stub
, sizeof tmp_reply_stub
);
755 tmp_txn
.request
= NULL
;
756 tmp_txn
.reply
= &tmp_reply
;
759 struct nl_transaction
*buf_txn
, *txn
;
762 /* Find a transaction whose buffer we can use for receiving a reply.
763 * If no such transaction is left, use tmp_txn. */
765 for (i
= 0; i
< n
; i
++) {
766 if (transactions
[i
]->reply
) {
767 buf_txn
= transactions
[i
];
772 /* Receive a reply. */
773 error
= nl_sock_recv__(sock
, buf_txn
->reply
, false);
775 if (error
== EAGAIN
) {
776 nl_sock_record_errors__(transactions
, n
, 0);
783 /* Match the reply up with a transaction. */
784 seq
= nl_msg_nlmsghdr(buf_txn
->reply
)->nlmsg_seq
;
785 if (seq
< base_seq
|| seq
>= base_seq
+ n
) {
786 VLOG_DBG_RL(&rl
, "ignoring unexpected seq %#"PRIx32
, seq
);
790 txn
= transactions
[i
];
792 /* Fill in the results for 'txn'. */
793 if (nl_msg_nlmsgerr(buf_txn
->reply
, &txn
->error
)) {
795 ofpbuf_clear(txn
->reply
);
798 VLOG_DBG_RL(&rl
, "received NAK error=%d (%s)",
799 error
, ovs_strerror(txn
->error
));
803 if (txn
->reply
&& txn
!= buf_txn
) {
805 struct ofpbuf
*reply
= buf_txn
->reply
;
806 buf_txn
->reply
= txn
->reply
;
811 /* Fill in the results for transactions before 'txn'. (We have to do
812 * this after the results for 'txn' itself because of the buffer swap
814 nl_sock_record_errors__(transactions
, i
, 0);
818 transactions
+= i
+ 1;
822 ofpbuf_uninit(&tmp_reply
);
825 uint8_t reply_buf
[65536];
826 for (i
= 0; i
< n
; i
++) {
828 struct nl_transaction
*txn
= transactions
[i
];
829 struct nlmsghdr
*request_nlmsg
, *reply_nlmsg
;
831 if (!DeviceIoControl(sock
->handle
, OVS_IOCTL_TRANSACT
,
832 ofpbuf_data(txn
->request
),
833 ofpbuf_size(txn
->request
),
834 reply_buf
, sizeof reply_buf
,
836 /* XXX: Map to a more appropriate error. */
841 if (reply_len
< sizeof *reply_nlmsg
) {
842 nl_sock_record_errors__(transactions
, n
, 0);
843 VLOG_DBG_RL(&rl
, "insufficient length of reply %#"PRIu32
844 " for seq: %#"PRIx32
, reply_len
, request_nlmsg
->nlmsg_seq
);
848 /* Validate the sequence number in the reply. */
849 request_nlmsg
= nl_msg_nlmsghdr(txn
->request
);
850 reply_nlmsg
= (struct nlmsghdr
*)reply_buf
;
852 if (request_nlmsg
->nlmsg_seq
!= reply_nlmsg
->nlmsg_seq
) {
853 ovs_assert(request_nlmsg
->nlmsg_seq
== reply_nlmsg
->nlmsg_seq
);
854 VLOG_DBG_RL(&rl
, "mismatched seq request %#"PRIx32
855 ", reply %#"PRIx32
, request_nlmsg
->nlmsg_seq
,
856 reply_nlmsg
->nlmsg_seq
);
860 /* Handle errors embedded within the netlink message. */
861 ofpbuf_use_stub(&tmp_reply
, reply_buf
, sizeof reply_buf
);
862 ofpbuf_set_size(&tmp_reply
, sizeof reply_buf
);
863 if (nl_msg_nlmsgerr(&tmp_reply
, &txn
->error
)) {
865 ofpbuf_clear(txn
->reply
);
868 VLOG_DBG_RL(&rl
, "received NAK error=%d (%s)",
869 error
, ovs_strerror(txn
->error
));
874 /* Copy the reply to the buffer specified by the caller. */
875 if (reply_len
> txn
->reply
->allocated
) {
876 ofpbuf_reinit(txn
->reply
, reply_len
);
878 memcpy(ofpbuf_data(txn
->reply
), reply_buf
, reply_len
);
879 ofpbuf_set_size(txn
->reply
, reply_len
);
882 ofpbuf_uninit(&tmp_reply
);
884 /* Count the number of successful transactions. */
890 COVERAGE_ADD(netlink_sent
, n
);
898 nl_sock_transact_multiple(struct nl_sock
*sock
,
899 struct nl_transaction
**transactions
, size_t n
)
908 /* In theory, every request could have a 64 kB reply. But the default and
909 * maximum socket rcvbuf size with typical Dom0 memory sizes both tend to
910 * be a bit below 128 kB, so that would only allow a single message in a
911 * "batch". So we assume that replies average (at most) 4 kB, which allows
912 * a good deal of batching.
914 * In practice, most of the requests that we batch either have no reply at
915 * all or a brief reply. */
916 max_batch_count
= MAX(sock
->rcvbuf
/ 4096, 1);
917 max_batch_count
= MIN(max_batch_count
, max_iovs
);
923 /* Batch up to 'max_batch_count' transactions. But cap it at about a
924 * page of requests total because big skbuffs are expensive to
925 * allocate in the kernel. */
926 #if defined(PAGESIZE)
927 enum { MAX_BATCH_BYTES
= MAX(1, PAGESIZE
- 512) };
929 enum { MAX_BATCH_BYTES
= 4096 - 512 };
931 bytes
= ofpbuf_size(transactions
[0]->request
);
932 for (count
= 1; count
< n
&& count
< max_batch_count
; count
++) {
933 if (bytes
+ ofpbuf_size(transactions
[count
]->request
) > MAX_BATCH_BYTES
) {
936 bytes
+= ofpbuf_size(transactions
[count
]->request
);
939 error
= nl_sock_transact_multiple__(sock
, transactions
, count
, &done
);
940 transactions
+= done
;
943 if (error
== ENOBUFS
) {
944 VLOG_DBG_RL(&rl
, "receive buffer overflow, resending request");
946 VLOG_ERR_RL(&rl
, "transaction error (%s)", ovs_strerror(error
));
947 nl_sock_record_errors__(transactions
, n
, error
);
953 nl_sock_transact(struct nl_sock
*sock
, const struct ofpbuf
*request
,
954 struct ofpbuf
**replyp
)
956 struct nl_transaction
*transactionp
;
957 struct nl_transaction transaction
;
959 transaction
.request
= CONST_CAST(struct ofpbuf
*, request
);
960 transaction
.reply
= replyp
? ofpbuf_new(1024) : NULL
;
961 transactionp
= &transaction
;
963 nl_sock_transact_multiple(sock
, &transactionp
, 1);
966 if (transaction
.error
) {
967 ofpbuf_delete(transaction
.reply
);
970 *replyp
= transaction
.reply
;
974 return transaction
.error
;
977 /* Drain all the messages currently in 'sock''s receive queue. */
979 nl_sock_drain(struct nl_sock
*sock
)
984 return drain_rcvbuf(sock
->fd
);
988 /* Starts a Netlink "dump" operation, by sending 'request' to the kernel on a
989 * Netlink socket created with the given 'protocol', and initializes 'dump' to
990 * reflect the state of the operation.
992 * 'request' must contain a Netlink message. Before sending the message,
993 * nlmsg_len will be finalized to match request->size, and nlmsg_pid will be
994 * set to the Netlink socket's pid. NLM_F_DUMP and NLM_F_ACK will be set in
997 * The design of this Netlink socket library ensures that the dump is reliable.
999 * This function provides no status indication. nl_dump_done() provides an
1000 * error status for the entire dump operation.
1002 * The caller must eventually destroy 'request'.
1005 nl_dump_start(struct nl_dump
*dump
, int protocol
, const struct ofpbuf
*request
)
1007 nl_msg_nlmsghdr(request
)->nlmsg_flags
|= NLM_F_DUMP
| NLM_F_ACK
;
1009 ovs_mutex_init(&dump
->mutex
);
1010 ovs_mutex_lock(&dump
->mutex
);
1011 dump
->status
= nl_pool_alloc(protocol
, &dump
->sock
);
1012 if (!dump
->status
) {
1013 dump
->status
= nl_sock_send__(dump
->sock
, request
,
1014 nl_sock_allocate_seq(dump
->sock
, 1),
1017 dump
->nl_seq
= nl_msg_nlmsghdr(request
)->nlmsg_seq
;
1018 ovs_mutex_unlock(&dump
->mutex
);
1022 nl_dump_refill(struct nl_dump
*dump
, struct ofpbuf
*buffer
)
1023 OVS_REQUIRES(dump
->mutex
)
1025 struct nlmsghdr
*nlmsghdr
;
1028 while (!ofpbuf_size(buffer
)) {
1029 error
= nl_sock_recv__(dump
->sock
, buffer
, false);
1031 /* The kernel never blocks providing the results of a dump, so
1032 * error == EAGAIN means that we've read the whole thing, and
1033 * therefore transform it into EOF. (The kernel always provides
1034 * NLMSG_DONE as a sentinel. Some other thread must have received
1035 * that already but not yet signaled it in 'status'.)
1037 * Any other error is just an error. */
1038 return error
== EAGAIN
? EOF
: error
;
1041 nlmsghdr
= nl_msg_nlmsghdr(buffer
);
1042 if (dump
->nl_seq
!= nlmsghdr
->nlmsg_seq
) {
1043 VLOG_DBG_RL(&rl
, "ignoring seq %#"PRIx32
" != expected %#"PRIx32
,
1044 nlmsghdr
->nlmsg_seq
, dump
->nl_seq
);
1045 ofpbuf_clear(buffer
);
1049 if (nl_msg_nlmsgerr(buffer
, &error
) && error
) {
1050 VLOG_INFO_RL(&rl
, "netlink dump request error (%s)",
1051 ovs_strerror(error
));
1052 ofpbuf_clear(buffer
);
1060 nl_dump_next__(struct ofpbuf
*reply
, struct ofpbuf
*buffer
)
1062 struct nlmsghdr
*nlmsghdr
= nl_msg_next(buffer
, reply
);
1064 VLOG_WARN_RL(&rl
, "netlink dump contains message fragment");
1066 } else if (nlmsghdr
->nlmsg_type
== NLMSG_DONE
) {
1073 /* Attempts to retrieve another reply from 'dump' into 'buffer'. 'dump' must
1074 * have been initialized with nl_dump_start(), and 'buffer' must have been
1075 * initialized. 'buffer' should be at least NL_DUMP_BUFSIZE bytes long.
1077 * If successful, returns true and points 'reply->data' and
1078 * 'ofpbuf_size(reply)' to the message that was retrieved. The caller must not
1079 * modify 'reply' (because it points within 'buffer', which will be used by
1080 * future calls to this function).
1082 * On failure, returns false and sets 'reply->data' to NULL and
1083 * 'ofpbuf_size(reply)' to 0. Failure might indicate an actual error or merely
1084 * the end of replies. An error status for the entire dump operation is
1085 * provided when it is completed by calling nl_dump_done().
1087 * Multiple threads may call this function, passing the same nl_dump, however
1088 * each must provide independent buffers. This function may cache multiple
1089 * replies in the buffer, and these will be processed before more replies are
1090 * fetched. When this function returns false, other threads may continue to
1091 * process replies in their buffers, but they will not fetch more replies.
1094 nl_dump_next(struct nl_dump
*dump
, struct ofpbuf
*reply
, struct ofpbuf
*buffer
)
1098 /* If the buffer is empty, refill it.
1100 * If the buffer is not empty, we don't check the dump's status.
1101 * Otherwise, we could end up skipping some of the dump results if thread A
1102 * hits EOF while thread B is in the midst of processing a batch. */
1103 if (!ofpbuf_size(buffer
)) {
1104 ovs_mutex_lock(&dump
->mutex
);
1105 if (!dump
->status
) {
1106 /* Take the mutex here to avoid an in-kernel race. If two threads
1107 * try to read from a Netlink dump socket at once, then the socket
1108 * error can be set to EINVAL, which will be encountered on the
1109 * next recv on that socket, which could be anywhere due to the way
1110 * that we pool Netlink sockets. Serializing the recv calls avoids
1112 dump
->status
= nl_dump_refill(dump
, buffer
);
1114 retval
= dump
->status
;
1115 ovs_mutex_unlock(&dump
->mutex
);
1118 /* Fetch the next message from the buffer. */
1120 retval
= nl_dump_next__(reply
, buffer
);
1122 /* Record 'retval' as the dump status, but don't overwrite an error
1124 ovs_mutex_lock(&dump
->mutex
);
1125 if (dump
->status
<= 0) {
1126 dump
->status
= retval
;
1128 ovs_mutex_unlock(&dump
->mutex
);
1133 ofpbuf_set_data(reply
, NULL
);
1134 ofpbuf_set_size(reply
, 0);
1139 /* Completes Netlink dump operation 'dump', which must have been initialized
1140 * with nl_dump_start(). Returns 0 if the dump operation was error-free,
1141 * otherwise a positive errno value describing the problem. */
1143 nl_dump_done(struct nl_dump
*dump
)
1147 ovs_mutex_lock(&dump
->mutex
);
1148 status
= dump
->status
;
1149 ovs_mutex_unlock(&dump
->mutex
);
1151 /* Drain any remaining messages that the client didn't read. Otherwise the
1152 * kernel will continue to queue them up and waste buffer space.
1154 * XXX We could just destroy and discard the socket in this case. */
1156 uint64_t tmp_reply_stub
[NL_DUMP_BUFSIZE
/ 8];
1157 struct ofpbuf reply
, buf
;
1159 ofpbuf_use_stub(&buf
, tmp_reply_stub
, sizeof tmp_reply_stub
);
1160 while (nl_dump_next(dump
, &reply
, &buf
)) {
1161 /* Nothing to do. */
1163 ofpbuf_uninit(&buf
);
1165 ovs_mutex_lock(&dump
->mutex
);
1166 status
= dump
->status
;
1167 ovs_mutex_unlock(&dump
->mutex
);
1171 nl_pool_release(dump
->sock
);
1172 ovs_mutex_destroy(&dump
->mutex
);
1174 return status
== EOF
? 0 : status
;
1178 /* Pend an I/O request in the driver. The driver completes the I/O whenever
1179 * an event or a packet is ready to be read. Once the I/O is completed
1180 * the overlapped structure event associated with the pending I/O will be set
1183 pend_io_request(struct nl_sock
*sock
)
1185 struct ofpbuf request
;
1186 uint64_t request_stub
[128];
1187 struct ovs_header
*ovs_header
;
1188 struct nlmsghdr
*nlmsg
;
1193 OVERLAPPED
*overlapped
= CONST_CAST(OVERLAPPED
*, &sock
->overlapped
);
1195 int ovs_msg_size
= sizeof (struct nlmsghdr
) + sizeof (struct genlmsghdr
) +
1196 sizeof (struct ovs_header
);
1198 ofpbuf_use_stub(&request
, request_stub
, sizeof request_stub
);
1200 seq
= nl_sock_allocate_seq(sock
, 1);
1201 nl_msg_put_genlmsghdr(&request
, 0, OVS_WIN_NL_CTRL_FAMILY_ID
, 0,
1202 OVS_CTRL_CMD_WIN_PEND_REQ
, OVS_WIN_CONTROL_VERSION
);
1203 nlmsg
= nl_msg_nlmsghdr(&request
);
1204 nlmsg
->nlmsg_seq
= seq
;
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 ofpbuf_data(&request
), ofpbuf_size(&request
),
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
));
1220 /* The I/O was completed synchronously */
1221 poll_immediate_wake();
1226 ofpbuf_uninit(&request
);
1231 /* Causes poll_block() to wake up when any of the specified 'events' (which is
1232 * a OR'd combination of POLLIN, POLLOUT, etc.) occur on 'sock'.
1233 * On Windows, 'sock' is not treated as const, and may be modified. */
1235 nl_sock_wait(const struct nl_sock
*sock
, short int events
)
1238 if (sock
->overlapped
.Internal
!= STATUS_PENDING
) {
1239 pend_io_request(CONST_CAST(struct nl_sock
*, sock
));
1240 /* XXX: poll_wevent_wait(sock->overlapped.hEvent); */
1242 poll_immediate_wake(); /* XXX: temporary. */
1244 poll_fd_wait(sock
->fd
, events
);
1248 /* Returns the underlying fd for 'sock', for use in "poll()"-like operations
1249 * that can't use nl_sock_wait().
1251 * It's a little tricky to use the returned fd correctly, because nl_sock does
1252 * "copy on write" to allow a single nl_sock to be used for notifications,
1253 * transactions, and dumps. If 'sock' is used only for notifications and
1254 * transactions (and never for dump) then the usage is safe. */
1256 nl_sock_fd(const struct nl_sock
*sock
)
1259 BUILD_ASSERT_DECL(sizeof sock
->handle
== sizeof(int));
1260 return (int)sock
->handle
;
1266 /* Returns the PID associated with this socket. */
1268 nl_sock_pid(const struct nl_sock
*sock
)
1273 /* Miscellaneous. */
1275 struct genl_family
{
1276 struct hmap_node hmap_node
;
1281 static struct hmap genl_families
= HMAP_INITIALIZER(&genl_families
);
1283 static const struct nl_policy family_policy
[CTRL_ATTR_MAX
+ 1] = {
1284 [CTRL_ATTR_FAMILY_ID
] = {.type
= NL_A_U16
},
1285 [CTRL_ATTR_MCAST_GROUPS
] = {.type
= NL_A_NESTED
, .optional
= true},
1288 static struct genl_family
*
1289 find_genl_family_by_id(uint16_t id
)
1291 struct genl_family
*family
;
1293 HMAP_FOR_EACH_IN_BUCKET (family
, hmap_node
, hash_int(id
, 0),
1295 if (family
->id
== id
) {
1303 define_genl_family(uint16_t id
, const char *name
)
1305 struct genl_family
*family
= find_genl_family_by_id(id
);
1308 if (!strcmp(family
->name
, name
)) {
1313 family
= xmalloc(sizeof *family
);
1315 hmap_insert(&genl_families
, &family
->hmap_node
, hash_int(id
, 0));
1317 family
->name
= xstrdup(name
);
1321 genl_family_to_name(uint16_t id
)
1323 if (id
== GENL_ID_CTRL
) {
1326 struct genl_family
*family
= find_genl_family_by_id(id
);
1327 return family
? family
->name
: "unknown";
1333 do_lookup_genl_family(const char *name
, struct nlattr
**attrs
,
1334 struct ofpbuf
**replyp
)
1336 struct nl_sock
*sock
;
1337 struct ofpbuf request
, *reply
;
1341 error
= nl_sock_create(NETLINK_GENERIC
, &sock
);
1346 ofpbuf_init(&request
, 0);
1347 nl_msg_put_genlmsghdr(&request
, 0, GENL_ID_CTRL
, NLM_F_REQUEST
,
1348 CTRL_CMD_GETFAMILY
, 1);
1349 nl_msg_put_string(&request
, CTRL_ATTR_FAMILY_NAME
, name
);
1350 error
= nl_sock_transact(sock
, &request
, &reply
);
1351 ofpbuf_uninit(&request
);
1353 nl_sock_destroy(sock
);
1357 if (!nl_policy_parse(reply
, NLMSG_HDRLEN
+ GENL_HDRLEN
,
1358 family_policy
, attrs
, ARRAY_SIZE(family_policy
))
1359 || nl_attr_get_u16(attrs
[CTRL_ATTR_FAMILY_ID
]) == 0) {
1360 nl_sock_destroy(sock
);
1361 ofpbuf_delete(reply
);
1365 nl_sock_destroy(sock
);
1371 do_lookup_genl_family(const char *name
, struct nlattr
**attrs
,
1372 struct ofpbuf
**replyp
)
1374 struct nlmsghdr
*nlmsg
;
1375 struct ofpbuf
*reply
;
1378 const char *family_name
;
1379 uint32_t family_version
;
1380 uint32_t family_attrmax
;
1381 uint32_t mcgrp_id
= OVS_WIN_NL_INVALID_MCGRP_ID
;
1382 const char *mcgrp_name
= NULL
;
1385 reply
= ofpbuf_new(1024);
1387 /* CTRL_ATTR_MCAST_GROUPS is supported only for VPORT family. */
1388 if (!strcmp(name
, OVS_WIN_CONTROL_FAMILY
)) {
1389 family_id
= OVS_WIN_NL_CTRL_FAMILY_ID
;
1390 family_name
= OVS_WIN_CONTROL_FAMILY
;
1391 family_version
= OVS_WIN_CONTROL_VERSION
;
1392 family_attrmax
= OVS_WIN_CONTROL_ATTR_MAX
;
1393 } else if (!strcmp(name
, OVS_DATAPATH_FAMILY
)) {
1394 family_id
= OVS_WIN_NL_DATAPATH_FAMILY_ID
;
1395 family_name
= OVS_DATAPATH_FAMILY
;
1396 family_version
= OVS_DATAPATH_VERSION
;
1397 family_attrmax
= OVS_DP_ATTR_MAX
;
1398 } else if (!strcmp(name
, OVS_PACKET_FAMILY
)) {
1399 family_id
= OVS_WIN_NL_PACKET_FAMILY_ID
;
1400 family_name
= OVS_PACKET_FAMILY
;
1401 family_version
= OVS_PACKET_VERSION
;
1402 family_attrmax
= OVS_PACKET_ATTR_MAX
;
1403 } else if (!strcmp(name
, OVS_VPORT_FAMILY
)) {
1404 family_id
= OVS_WIN_NL_VPORT_FAMILY_ID
;
1405 family_name
= OVS_VPORT_FAMILY
;
1406 family_version
= OVS_VPORT_VERSION
;
1407 family_attrmax
= OVS_VPORT_ATTR_MAX
;
1408 mcgrp_id
= OVS_WIN_NL_VPORT_MCGRP_ID
;
1409 mcgrp_name
= OVS_VPORT_MCGROUP
;
1410 } else if (!strcmp(name
, OVS_FLOW_FAMILY
)) {
1411 family_id
= OVS_WIN_NL_FLOW_FAMILY_ID
;
1412 family_name
= OVS_FLOW_FAMILY
;
1413 family_version
= OVS_FLOW_VERSION
;
1414 family_attrmax
= OVS_FLOW_ATTR_MAX
;
1415 } else if (!strcmp(name
, OVS_WIN_NETDEV_FAMILY
)) {
1416 family_id
= OVS_WIN_NL_NETDEV_FAMILY_ID
;
1417 family_name
= OVS_WIN_NETDEV_FAMILY
;
1418 family_version
= OVS_WIN_NETDEV_VERSION
;
1419 family_attrmax
= OVS_WIN_NETDEV_ATTR_MAX
;
1421 ofpbuf_delete(reply
);
1425 nl_msg_put_genlmsghdr(reply
, 0, GENL_ID_CTRL
, 0,
1426 CTRL_CMD_NEWFAMILY
, family_version
);
1427 /* CTRL_ATTR_HDRSIZE and CTRL_ATTR_OPS are not populated, but the
1428 * callers do not seem to need them. */
1429 nl_msg_put_u16(reply
, CTRL_ATTR_FAMILY_ID
, family_id
);
1430 nl_msg_put_string(reply
, CTRL_ATTR_FAMILY_NAME
, family_name
);
1431 nl_msg_put_u32(reply
, CTRL_ATTR_VERSION
, family_version
);
1432 nl_msg_put_u32(reply
, CTRL_ATTR_MAXATTR
, family_attrmax
);
1434 if (mcgrp_id
!= OVS_WIN_NL_INVALID_MCGRP_ID
) {
1435 size_t mcgrp_ofs1
= nl_msg_start_nested(reply
, CTRL_ATTR_MCAST_GROUPS
);
1436 size_t mcgrp_ofs2
= nl_msg_start_nested(reply
,
1437 OVS_WIN_NL_VPORT_MCGRP_ID
- OVS_WIN_NL_MCGRP_START_ID
);
1438 nl_msg_put_u32(reply
, CTRL_ATTR_MCAST_GRP_ID
, mcgrp_id
);
1439 ovs_assert(mcgrp_name
!= NULL
);
1440 nl_msg_put_string(reply
, CTRL_ATTR_MCAST_GRP_NAME
, mcgrp_name
);
1441 nl_msg_end_nested(reply
, mcgrp_ofs2
);
1442 nl_msg_end_nested(reply
, mcgrp_ofs1
);
1445 /* Set the total length of the netlink message. */
1446 nlmsg
= nl_msg_nlmsghdr(reply
);
1447 nlmsg
->nlmsg_len
= ofpbuf_size(reply
);
1449 if (!nl_policy_parse(reply
, NLMSG_HDRLEN
+ GENL_HDRLEN
,
1450 family_policy
, attrs
, ARRAY_SIZE(family_policy
))
1451 || nl_attr_get_u16(attrs
[CTRL_ATTR_FAMILY_ID
]) == 0) {
1452 ofpbuf_delete(reply
);
1461 /* Finds the multicast group called 'group_name' in genl family 'family_name'.
1462 * When successful, writes its result to 'multicast_group' and returns 0.
1463 * Otherwise, clears 'multicast_group' and returns a positive error code.
1466 nl_lookup_genl_mcgroup(const char *family_name
, const char *group_name
,
1467 unsigned int *multicast_group
)
1469 struct nlattr
*family_attrs
[ARRAY_SIZE(family_policy
)];
1470 const struct nlattr
*mc
;
1471 struct ofpbuf
*reply
;
1475 *multicast_group
= 0;
1476 error
= do_lookup_genl_family(family_name
, family_attrs
, &reply
);
1481 if (!family_attrs
[CTRL_ATTR_MCAST_GROUPS
]) {
1486 NL_NESTED_FOR_EACH (mc
, left
, family_attrs
[CTRL_ATTR_MCAST_GROUPS
]) {
1487 static const struct nl_policy mc_policy
[] = {
1488 [CTRL_ATTR_MCAST_GRP_ID
] = {.type
= NL_A_U32
},
1489 [CTRL_ATTR_MCAST_GRP_NAME
] = {.type
= NL_A_STRING
},
1492 struct nlattr
*mc_attrs
[ARRAY_SIZE(mc_policy
)];
1493 const char *mc_name
;
1495 if (!nl_parse_nested(mc
, mc_policy
, mc_attrs
, ARRAY_SIZE(mc_policy
))) {
1500 mc_name
= nl_attr_get_string(mc_attrs
[CTRL_ATTR_MCAST_GRP_NAME
]);
1501 if (!strcmp(group_name
, mc_name
)) {
1503 nl_attr_get_u32(mc_attrs
[CTRL_ATTR_MCAST_GRP_ID
]);
1511 ofpbuf_delete(reply
);
1515 /* If '*number' is 0, translates the given Generic Netlink family 'name' to a
1516 * number and stores it in '*number'. If successful, returns 0 and the caller
1517 * may use '*number' as the family number. On failure, returns a positive
1518 * errno value and '*number' caches the errno value. */
1520 nl_lookup_genl_family(const char *name
, int *number
)
1523 struct nlattr
*attrs
[ARRAY_SIZE(family_policy
)];
1524 struct ofpbuf
*reply
;
1527 error
= do_lookup_genl_family(name
, attrs
, &reply
);
1529 *number
= nl_attr_get_u16(attrs
[CTRL_ATTR_FAMILY_ID
]);
1530 define_genl_family(*number
, name
);
1534 ofpbuf_delete(reply
);
1536 ovs_assert(*number
!= 0);
1538 return *number
> 0 ? 0 : -*number
;
1542 struct nl_sock
*socks
[16];
1546 static struct ovs_mutex pool_mutex
= OVS_MUTEX_INITIALIZER
;
1547 static struct nl_pool pools
[MAX_LINKS
] OVS_GUARDED_BY(pool_mutex
);
1550 nl_pool_alloc(int protocol
, struct nl_sock
**sockp
)
1552 struct nl_sock
*sock
= NULL
;
1553 struct nl_pool
*pool
;
1555 ovs_assert(protocol
>= 0 && protocol
< ARRAY_SIZE(pools
));
1557 ovs_mutex_lock(&pool_mutex
);
1558 pool
= &pools
[protocol
];
1560 sock
= pool
->socks
[--pool
->n
];
1562 ovs_mutex_unlock(&pool_mutex
);
1568 return nl_sock_create(protocol
, sockp
);
1573 nl_pool_release(struct nl_sock
*sock
)
1576 struct nl_pool
*pool
= &pools
[sock
->protocol
];
1578 ovs_mutex_lock(&pool_mutex
);
1579 if (pool
->n
< ARRAY_SIZE(pool
->socks
)) {
1580 pool
->socks
[pool
->n
++] = sock
;
1583 ovs_mutex_unlock(&pool_mutex
);
1585 nl_sock_destroy(sock
);
1589 /* Sends 'request' to the kernel on a Netlink socket for the given 'protocol'
1590 * (e.g. NETLINK_ROUTE or NETLINK_GENERIC) and waits for a response. If
1591 * successful, returns 0. On failure, returns a positive errno value.
1593 * If 'replyp' is nonnull, then on success '*replyp' is set to the kernel's
1594 * reply, which the caller is responsible for freeing with ofpbuf_delete(), and
1595 * on failure '*replyp' is set to NULL. If 'replyp' is null, then the kernel's
1596 * reply, if any, is discarded.
1598 * Before the message is sent, nlmsg_len in 'request' will be finalized to
1599 * match ofpbuf_size(msg), nlmsg_pid will be set to the pid of the socket used
1600 * for sending the request, and nlmsg_seq will be initialized.
1602 * The caller is responsible for destroying 'request'.
1604 * Bare Netlink is an unreliable transport protocol. This function layers
1605 * reliable delivery and reply semantics on top of bare Netlink.
1607 * In Netlink, sending a request to the kernel is reliable enough, because the
1608 * kernel will tell us if the message cannot be queued (and we will in that
1609 * case put it on the transmit queue and wait until it can be delivered).
1611 * Receiving the reply is the real problem: if the socket buffer is full when
1612 * the kernel tries to send the reply, the reply will be dropped. However, the
1613 * kernel sets a flag that a reply has been dropped. The next call to recv
1614 * then returns ENOBUFS. We can then re-send the request.
1618 * 1. Netlink depends on sequence numbers to match up requests and
1619 * replies. The sender of a request supplies a sequence number, and
1620 * the reply echos back that sequence number.
1622 * This is fine, but (1) some kernel netlink implementations are
1623 * broken, in that they fail to echo sequence numbers and (2) this
1624 * function will drop packets with non-matching sequence numbers, so
1625 * that only a single request can be usefully transacted at a time.
1627 * 2. Resending the request causes it to be re-executed, so the request
1628 * needs to be idempotent.
1631 nl_transact(int protocol
, const struct ofpbuf
*request
,
1632 struct ofpbuf
**replyp
)
1634 struct nl_sock
*sock
;
1637 error
= nl_pool_alloc(protocol
, &sock
);
1643 error
= nl_sock_transact(sock
, request
, replyp
);
1645 nl_pool_release(sock
);
1649 /* Sends the 'request' member of the 'n' transactions in 'transactions' on a
1650 * Netlink socket for the given 'protocol' (e.g. NETLINK_ROUTE or
1651 * NETLINK_GENERIC), in order, and receives responses to all of them. Fills in
1652 * the 'error' member of each transaction with 0 if it was successful,
1653 * otherwise with a positive errno value. If 'reply' is nonnull, then it will
1654 * be filled with the reply if the message receives a detailed reply. In other
1655 * cases, i.e. where the request failed or had no reply beyond an indication of
1656 * success, 'reply' will be cleared if it is nonnull.
1658 * The caller is responsible for destroying each request and reply, and the
1659 * transactions array itself.
1661 * Before sending each message, this function will finalize nlmsg_len in each
1662 * 'request' to match the ofpbuf's size, set nlmsg_pid to the pid of the socket
1663 * used for the transaction, and initialize nlmsg_seq.
1665 * Bare Netlink is an unreliable transport protocol. This function layers
1666 * reliable delivery and reply semantics on top of bare Netlink. See
1667 * nl_transact() for some caveats.
1670 nl_transact_multiple(int protocol
,
1671 struct nl_transaction
**transactions
, size_t n
)
1673 struct nl_sock
*sock
;
1676 error
= nl_pool_alloc(protocol
, &sock
);
1678 nl_sock_transact_multiple(sock
, transactions
, n
);
1679 nl_pool_release(sock
);
1681 nl_sock_record_errors__(transactions
, n
, error
);
1687 nl_sock_allocate_seq(struct nl_sock
*sock
, unsigned int n
)
1689 uint32_t seq
= sock
->next_seq
;
1691 sock
->next_seq
+= n
;
1693 /* Make it impossible for the next request for sequence numbers to wrap
1694 * around to 0. Start over with 1 to avoid ever using a sequence number of
1695 * 0, because the kernel uses sequence number 0 for notifications. */
1696 if (sock
->next_seq
>= UINT32_MAX
/ 2) {
1704 nlmsghdr_to_string(const struct nlmsghdr
*h
, int protocol
, struct ds
*ds
)
1710 static const struct nlmsg_flag flags
[] = {
1711 { NLM_F_REQUEST
, "REQUEST" },
1712 { NLM_F_MULTI
, "MULTI" },
1713 { NLM_F_ACK
, "ACK" },
1714 { NLM_F_ECHO
, "ECHO" },
1715 { NLM_F_DUMP
, "DUMP" },
1716 { NLM_F_ROOT
, "ROOT" },
1717 { NLM_F_MATCH
, "MATCH" },
1718 { NLM_F_ATOMIC
, "ATOMIC" },
1720 const struct nlmsg_flag
*flag
;
1721 uint16_t flags_left
;
1723 ds_put_format(ds
, "nl(len:%"PRIu32
", type=%"PRIu16
,
1724 h
->nlmsg_len
, h
->nlmsg_type
);
1725 if (h
->nlmsg_type
== NLMSG_NOOP
) {
1726 ds_put_cstr(ds
, "(no-op)");
1727 } else if (h
->nlmsg_type
== NLMSG_ERROR
) {
1728 ds_put_cstr(ds
, "(error)");
1729 } else if (h
->nlmsg_type
== NLMSG_DONE
) {
1730 ds_put_cstr(ds
, "(done)");
1731 } else if (h
->nlmsg_type
== NLMSG_OVERRUN
) {
1732 ds_put_cstr(ds
, "(overrun)");
1733 } else if (h
->nlmsg_type
< NLMSG_MIN_TYPE
) {
1734 ds_put_cstr(ds
, "(reserved)");
1735 } else if (protocol
== NETLINK_GENERIC
) {
1736 ds_put_format(ds
, "(%s)", genl_family_to_name(h
->nlmsg_type
));
1738 ds_put_cstr(ds
, "(family-defined)");
1740 ds_put_format(ds
, ", flags=%"PRIx16
, h
->nlmsg_flags
);
1741 flags_left
= h
->nlmsg_flags
;
1742 for (flag
= flags
; flag
< &flags
[ARRAY_SIZE(flags
)]; flag
++) {
1743 if ((flags_left
& flag
->bits
) == flag
->bits
) {
1744 ds_put_format(ds
, "[%s]", flag
->name
);
1745 flags_left
&= ~flag
->bits
;
1749 ds_put_format(ds
, "[OTHER:%"PRIx16
"]", flags_left
);
1751 ds_put_format(ds
, ", seq=%"PRIx32
", pid=%"PRIu32
,
1752 h
->nlmsg_seq
, h
->nlmsg_pid
);
1756 nlmsg_to_string(const struct ofpbuf
*buffer
, int protocol
)
1758 struct ds ds
= DS_EMPTY_INITIALIZER
;
1759 const struct nlmsghdr
*h
= ofpbuf_at(buffer
, 0, NLMSG_HDRLEN
);
1761 nlmsghdr_to_string(h
, protocol
, &ds
);
1762 if (h
->nlmsg_type
== NLMSG_ERROR
) {
1763 const struct nlmsgerr
*e
;
1764 e
= ofpbuf_at(buffer
, NLMSG_HDRLEN
,
1765 NLMSG_ALIGN(sizeof(struct nlmsgerr
)));
1767 ds_put_format(&ds
, " error(%d", e
->error
);
1769 ds_put_format(&ds
, "(%s)", ovs_strerror(-e
->error
));
1771 ds_put_cstr(&ds
, ", in-reply-to(");
1772 nlmsghdr_to_string(&e
->msg
, protocol
, &ds
);
1773 ds_put_cstr(&ds
, "))");
1775 ds_put_cstr(&ds
, " error(truncated)");
1777 } else if (h
->nlmsg_type
== NLMSG_DONE
) {
1778 int *error
= ofpbuf_at(buffer
, NLMSG_HDRLEN
, sizeof *error
);
1780 ds_put_format(&ds
, " done(%d", *error
);
1782 ds_put_format(&ds
, "(%s)", ovs_strerror(-*error
));
1784 ds_put_cstr(&ds
, ")");
1786 ds_put_cstr(&ds
, " done(truncated)");
1788 } else if (protocol
== NETLINK_GENERIC
) {
1789 struct genlmsghdr
*genl
= nl_msg_genlmsghdr(buffer
);
1791 ds_put_format(&ds
, ",genl(cmd=%"PRIu8
",version=%"PRIu8
")",
1792 genl
->cmd
, genl
->version
);
1796 ds_put_cstr(&ds
, "nl(truncated)");
1802 log_nlmsg(const char *function
, int error
,
1803 const void *message
, size_t size
, int protocol
)
1805 struct ofpbuf buffer
;
1808 if (!VLOG_IS_DBG_ENABLED()) {
1812 ofpbuf_use_const(&buffer
, message
, size
);
1813 nlmsg
= nlmsg_to_string(&buffer
, protocol
);
1814 VLOG_DBG_RL(&rl
, "%s (%s): %s", function
, ovs_strerror(error
), nlmsg
);