/*
- * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* information. Also, at high logging levels we log *all* Netlink messages. */
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(60, 600);
+static uint32_t nl_sock_allocate_seq(struct nl_sock *, unsigned int n);
static void log_nlmsg(const char *function, int error,
const void *message, size_t size, int protocol);
\f
struct nl_sock
{
int fd;
+ uint32_t next_seq;
uint32_t pid;
int protocol;
struct nl_dump *dump;
* Initialized by nl_sock_create(). */
static int max_iovs;
-static int alloc_pid(uint32_t *);
-static void free_pid(uint32_t);
static int nl_sock_cow__(struct nl_sock *);
/* Creates a new netlink socket for the given netlink 'protocol'
{
struct nl_sock *sock;
struct sockaddr_nl local, remote;
+ socklen_t local_size;
+ int rcvbuf;
int retval = 0;
if (!max_iovs) {
}
sock->protocol = protocol;
sock->dump = NULL;
+ sock->next_seq = 1;
+
+ rcvbuf = 1024 * 1024;
+ if (setsockopt(sock->fd, SOL_SOCKET, SO_RCVBUFFORCE,
+ &rcvbuf, sizeof rcvbuf)) {
+ VLOG_WARN_RL(&rl, "setting %d-byte socket receive buffer failed (%s)",
+ rcvbuf, strerror(errno));
+ }
retval = get_socket_rcvbuf(sock->fd);
if (retval < 0) {
}
sock->rcvbuf = retval;
- retval = alloc_pid(&sock->pid);
- if (retval) {
- goto error;
- }
-
- /* Bind local address as our selected pid. */
- memset(&local, 0, sizeof local);
- local.nl_family = AF_NETLINK;
- local.nl_pid = sock->pid;
- if (bind(sock->fd, (struct sockaddr *) &local, sizeof local) < 0) {
- VLOG_ERR("bind(%"PRIu32"): %s", sock->pid, strerror(errno));
- goto error_free_pid;
- }
-
- /* Bind remote address as the kernel (pid 0). */
+ /* Connect to kernel (pid 0) as remote address. */
memset(&remote, 0, sizeof remote);
remote.nl_family = AF_NETLINK;
remote.nl_pid = 0;
if (connect(sock->fd, (struct sockaddr *) &remote, sizeof remote) < 0) {
VLOG_ERR("connect(0): %s", strerror(errno));
- goto error_free_pid;
+ goto error;
+ }
+
+ /* Obtain pid assigned by kernel. */
+ local_size = sizeof local;
+ if (getsockname(sock->fd, (struct sockaddr *) &local, &local_size) < 0) {
+ VLOG_ERR("getsockname: %s", strerror(errno));
+ goto error;
}
+ if (local_size < sizeof local || local.nl_family != AF_NETLINK) {
+ VLOG_ERR("getsockname returned bad Netlink name");
+ retval = EINVAL;
+ goto error;
+ }
+ sock->pid = local.nl_pid;
*sockp = sock;
return 0;
-error_free_pid:
- free_pid(sock->pid);
error:
if (retval == 0) {
retval = errno;
sock->dump = NULL;
} else {
close(sock->fd);
- free_pid(sock->pid);
free(sock);
}
}
int error;
nlmsg->nlmsg_len = msg->size;
+ nlmsg->nlmsg_seq = nl_sock_allocate_seq(sock, 1);
nlmsg->nlmsg_pid = sock->pid;
do {
int retval;
5, 1, -1, 100);
static int
-nl_sock_recv__(struct nl_sock *sock, struct ofpbuf **bufp, bool wait)
+nl_sock_recv__(struct nl_sock *sock, struct ofpbuf *buf, bool wait)
{
- /* We can't accurately predict the size of the data to be received. Most
- * received data will fit in a 2 kB buffer, so we allocate that much space.
- * In case the data is actually bigger than that, we make available enough
- * additional space to allow Netlink messages to be up to 64 kB long (a
- * reasonable figure since that's the maximum length of a Netlink
- * attribute). */
- enum { MAX_SIZE = 65536 };
- enum { HEAD_SIZE = 2048 };
- enum { TAIL_SIZE = MAX_SIZE - HEAD_SIZE };
-
+ /* We can't accurately predict the size of the data to be received. The
+ * caller is supposed to have allocated enough space in 'buf' to handle the
+ * "typical" case. To handle exceptions, we make available enough space in
+ * 'tail' to allow Netlink messages to be up to 64 kB long (a reasonable
+ * figure since that's the maximum length of a Netlink attribute). */
struct nlmsghdr *nlmsghdr;
- uint8_t tail[TAIL_SIZE];
+ uint8_t tail[65536];
struct iovec iov[2];
- struct ofpbuf *buf;
struct msghdr msg;
ssize_t retval;
- *bufp = NULL;
+ assert(buf->allocated >= sizeof *nlmsghdr);
+ ofpbuf_clear(buf);
- buf = ofpbuf_new(HEAD_SIZE);
- iov[0].iov_base = buf->data;
- iov[0].iov_len = HEAD_SIZE;
+ iov[0].iov_base = buf->base;
+ iov[0].iov_len = buf->allocated;
iov[1].iov_base = tail;
- iov[1].iov_len = TAIL_SIZE;
+ iov[1].iov_len = sizeof tail;
memset(&msg, 0, sizeof msg);
msg.msg_iov = iov;
* the kernel tried to send to us. */
COVERAGE_INC(netlink_overflow);
}
- ofpbuf_delete(buf);
return error;
}
if (msg.msg_flags & MSG_TRUNC) {
- VLOG_ERR_RL(&rl, "truncated message (longer than %d bytes)", MAX_SIZE);
- ofpbuf_delete(buf);
+ VLOG_ERR_RL(&rl, "truncated message (longer than %zu bytes)",
+ sizeof tail);
return E2BIG;
}
- ofpbuf_put_uninit(buf, MIN(retval, HEAD_SIZE));
- if (retval > HEAD_SIZE) {
- COVERAGE_INC(netlink_recv_jumbo);
- ofpbuf_put(buf, tail, retval - HEAD_SIZE);
- }
-
nlmsghdr = buf->data;
if (retval < sizeof *nlmsghdr
|| nlmsghdr->nlmsg_len < sizeof *nlmsghdr
|| nlmsghdr->nlmsg_len > retval) {
- VLOG_ERR_RL(&rl, "received invalid nlmsg (%zd bytes < %d)",
- retval, NLMSG_HDRLEN);
- ofpbuf_delete(buf);
+ VLOG_ERR_RL(&rl, "received invalid nlmsg (%zd bytes < %zu)",
+ retval, sizeof *nlmsghdr);
return EPROTO;
}
if (STRESS(netlink_overflow)) {
- ofpbuf_delete(buf);
return ENOBUFS;
}
- *bufp = buf;
+ buf->size = MIN(retval, buf->allocated);
+ if (retval > buf->allocated) {
+ COVERAGE_INC(netlink_recv_jumbo);
+ ofpbuf_put(buf, tail, retval - buf->allocated);
+ }
+
log_nlmsg(__func__, 0, buf->data, buf->size, sock->protocol);
COVERAGE_INC(netlink_received);
return 0;
}
-/* Tries to receive a netlink message from the kernel on 'sock'. If
- * successful, stores the received message into '*bufp' and returns 0. The
- * caller is responsible for destroying the message with ofpbuf_delete(). On
- * failure, returns a positive errno value and stores a null pointer into
- * '*bufp'.
+/* Tries to receive a Netlink message from the kernel on 'sock' into 'buf'. If
+ * 'wait' is true, waits for a message to be ready. Otherwise, fails with
+ * EAGAIN if the 'sock' receive buffer is empty.
+ *
+ * The caller must have initialized 'buf' with an allocation of at least
+ * NLMSG_HDRLEN bytes. For best performance, the caller should allocate enough
+ * space for a "typical" message.
+ *
+ * On success, returns 0 and replaces 'buf''s previous content by the received
+ * message. This function expands 'buf''s allocated memory, as necessary, to
+ * hold the actual size of the received message.
*
- * If 'wait' is true, nl_sock_recv waits for a message to be ready; otherwise,
- * returns EAGAIN if the 'sock' receive buffer is empty. */
+ * On failure, returns a positive errno value and clears 'buf' to zero length.
+ * 'buf' retains its previous memory allocation.
+ *
+ * Regardless of success or failure, this function resets 'buf''s headroom to
+ * 0. */
int
-nl_sock_recv(struct nl_sock *sock, struct ofpbuf **bufp, bool wait)
+nl_sock_recv(struct nl_sock *sock, struct ofpbuf *buf, bool wait)
{
int error = nl_sock_cow__(sock);
if (error) {
return error;
}
- return nl_sock_recv__(sock, bufp, wait);
-}
-
-static int
-find_nl_transaction_by_seq(struct nl_transaction **transactions, size_t n,
- uint32_t seq)
-{
- int i;
-
- for (i = 0; i < n; i++) {
- struct nl_transaction *t = transactions[i];
-
- if (seq == nl_msg_nlmsghdr(t->request)->nlmsg_seq) {
- return i;
- }
- }
-
- return -1;
+ return nl_sock_recv__(sock, buf, wait);
}
static void
size_t i;
for (i = 0; i < n; i++) {
- transactions[i]->error = error;
- transactions[i]->reply = NULL;
+ struct nl_transaction *txn = transactions[i];
+
+ txn->error = error;
+ if (txn->reply) {
+ ofpbuf_clear(txn->reply);
+ }
}
}
struct nl_transaction **transactions, size_t n,
size_t *done)
{
+ uint64_t tmp_reply_stub[1024 / 8];
+ struct nl_transaction tmp_txn;
+ struct ofpbuf tmp_reply;
+
+ uint32_t base_seq;
struct iovec iovs[MAX_IOVS];
struct msghdr msg;
int error;
int i;
+ base_seq = nl_sock_allocate_seq(sock, n);
*done = 0;
for (i = 0; i < n; i++) {
- struct ofpbuf *request = transactions[i]->request;
- struct nlmsghdr *nlmsg = nl_msg_nlmsghdr(request);
+ struct nl_transaction *txn = transactions[i];
+ struct nlmsghdr *nlmsg = nl_msg_nlmsghdr(txn->request);
- nlmsg->nlmsg_len = request->size;
+ nlmsg->nlmsg_len = txn->request->size;
+ nlmsg->nlmsg_seq = base_seq + i;
nlmsg->nlmsg_pid = sock->pid;
- if (i == n - 1) {
- /* Ensure that we get a reply even if the final request doesn't
- * ordinarily call for one. */
- nlmsg->nlmsg_flags |= NLM_F_ACK;
- }
- iovs[i].iov_base = request->data;
- iovs[i].iov_len = request->size;
+ iovs[i].iov_base = txn->request->data;
+ iovs[i].iov_len = txn->request->size;
}
memset(&msg, 0, sizeof msg);
} while (error == EINTR);
for (i = 0; i < n; i++) {
- struct ofpbuf *request = transactions[i]->request;
+ struct nl_transaction *txn = transactions[i];
- log_nlmsg(__func__, error, request->data, request->size,
+ log_nlmsg(__func__, error, txn->request->data, txn->request->size,
sock->protocol);
}
if (!error) {
return error;
}
+ ofpbuf_use_stub(&tmp_reply, tmp_reply_stub, sizeof tmp_reply_stub);
+ tmp_txn.request = NULL;
+ tmp_txn.reply = &tmp_reply;
+ tmp_txn.error = 0;
while (n > 0) {
- struct ofpbuf *reply;
+ struct nl_transaction *buf_txn, *txn;
+ uint32_t seq;
+
+ /* Find a transaction whose buffer we can use for receiving a reply.
+ * If no such transaction is left, use tmp_txn. */
+ buf_txn = &tmp_txn;
+ for (i = 0; i < n; i++) {
+ if (transactions[i]->reply) {
+ buf_txn = transactions[i];
+ break;
+ }
+ }
- error = nl_sock_recv__(sock, &reply, true);
+ /* Receive a reply. */
+ error = nl_sock_recv__(sock, buf_txn->reply, false);
if (error) {
- return error;
+ if (error == EAGAIN) {
+ nl_sock_record_errors__(transactions, n, 0);
+ *done += n;
+ error = 0;
+ }
+ break;
}
- i = find_nl_transaction_by_seq(transactions, n,
- nl_msg_nlmsghdr(reply)->nlmsg_seq);
- if (i < 0) {
- VLOG_DBG_RL(&rl, "ignoring unexpected seq %#"PRIx32,
- nl_msg_nlmsghdr(reply)->nlmsg_seq);
- ofpbuf_delete(reply);
+ /* Match the reply up with a transaction. */
+ seq = nl_msg_nlmsghdr(buf_txn->reply)->nlmsg_seq;
+ if (seq < base_seq || seq >= base_seq + n) {
+ VLOG_DBG_RL(&rl, "ignoring unexpected seq %#"PRIx32, seq);
continue;
}
+ i = seq - base_seq;
+ txn = transactions[i];
- nl_sock_record_errors__(transactions, i, 0);
- if (nl_msg_nlmsgerr(reply, &error)) {
- transactions[i]->reply = NULL;
- transactions[i]->error = error;
- if (error) {
+ /* Fill in the results for 'txn'. */
+ if (nl_msg_nlmsgerr(buf_txn->reply, &txn->error)) {
+ if (txn->reply) {
+ ofpbuf_clear(txn->reply);
+ }
+ if (txn->error) {
VLOG_DBG_RL(&rl, "received NAK error=%d (%s)",
- error, strerror(error));
+ error, strerror(txn->error));
}
- ofpbuf_delete(reply);
} else {
- transactions[i]->reply = reply;
- transactions[i]->error = 0;
+ txn->error = 0;
+ if (txn->reply && txn != buf_txn) {
+ /* Swap buffers. */
+ struct ofpbuf *reply = buf_txn->reply;
+ buf_txn->reply = txn->reply;
+ txn->reply = reply;
+ }
}
+ /* Fill in the results for transactions before 'txn'. (We have to do
+ * this after the results for 'txn' itself because of the buffer swap
+ * above.) */
+ nl_sock_record_errors__(transactions, i, 0);
+
+ /* Advance. */
*done += i + 1;
transactions += i + 1;
n -= i + 1;
+ base_seq += i + 1;
}
+ ofpbuf_uninit(&tmp_reply);
- return 0;
+ return error;
}
-/* Sends the 'request' member of the 'n' transactions in 'transactions' to the
- * kernel, in order, and waits for responses to all of them. Fills in the
+/* Sends the 'request' member of the 'n' transactions in 'transactions' on
+ * 'sock', in order, and receives responses to all of them. Fills in the
* 'error' member of each transaction with 0 if it was successful, otherwise
- * with a positive errno value. 'reply' will be NULL on error or if the
- * transaction was successful but had no reply beyond an indication of success.
- * For a successful transaction that did have a more detailed reply, 'reply'
- * will be set to the reply message.
+ * with a positive errno value. If 'reply' is nonnull, then it will be filled
+ * with the reply if the message receives a detailed reply. In other cases,
+ * i.e. where the request failed or had no reply beyond an indication of
+ * success, 'reply' will be cleared if it is nonnull.
*
* The caller is responsible for destroying each request and reply, and the
* transactions array itself.
*
* Before sending each message, this function will finalize nlmsg_len in each
- * 'request' to match the ofpbuf's size, and set nlmsg_pid to 'sock''s pid.
- * NLM_F_ACK will be added to some requests' nlmsg_flags.
+ * 'request' to match the ofpbuf's size, set nlmsg_pid to 'sock''s pid, and
+ * initialize nlmsg_seq.
*
* Bare Netlink is an unreliable transport protocol. This function layers
* reliable delivery and reply semantics on top of bare Netlink. See
* on failure '*replyp' is set to NULL. If 'replyp' is null, then the kernel's
* reply, if any, is discarded.
*
- * nlmsg_len in 'msg' will be finalized to match msg->size, and nlmsg_pid will
- * be set to 'sock''s pid, before the message is sent. NLM_F_ACK will be set
- * in nlmsg_flags.
+ * Before the message is sent, nlmsg_len in 'request' will be finalized to
+ * match msg->size, nlmsg_pid will be set to 'sock''s pid, and nlmsg_seq will
+ * be initialized, NLM_F_ACK will be set in nlmsg_flags.
*
* The caller is responsible for destroying 'request'.
*
struct nl_transaction transaction;
transaction.request = (struct ofpbuf *) request;
+ transaction.reply = replyp ? ofpbuf_new(1024) : NULL;
transactionp = &transaction;
+
nl_sock_transact_multiple(sock, &transactionp, 1);
+
if (replyp) {
- *replyp = transaction.reply;
- } else {
- ofpbuf_delete(transaction.reply);
+ if (transaction.error) {
+ ofpbuf_delete(transaction.reply);
+ *replyp = NULL;
+ } else {
+ *replyp = transaction.reply;
+ }
}
+
return transaction.error;
}
nl_dump_start(struct nl_dump *dump,
struct nl_sock *sock, const struct ofpbuf *request)
{
- struct nlmsghdr *nlmsghdr = nl_msg_nlmsghdr(request);
- nlmsghdr->nlmsg_flags |= NLM_F_DUMP | NLM_F_ACK;
- dump->seq = nlmsghdr->nlmsg_seq;
- dump->buffer = NULL;
+ ofpbuf_init(&dump->buffer, 4096);
if (sock->dump) {
/* 'sock' already has an ongoing dump. Clone the socket because
* Netlink only allows one dump at a time. */
dump->sock = sock;
dump->status = 0;
}
+
+ nl_msg_nlmsghdr(request)->nlmsg_flags |= NLM_F_DUMP | NLM_F_ACK;
dump->status = nl_sock_send__(sock, request, true);
+ dump->seq = nl_msg_nlmsghdr(request)->nlmsg_seq;
}
/* Helper function for nl_dump_next(). */
static int
-nl_dump_recv(struct nl_dump *dump, struct ofpbuf **bufferp)
+nl_dump_recv(struct nl_dump *dump)
{
struct nlmsghdr *nlmsghdr;
- struct ofpbuf *buffer;
int retval;
- retval = nl_sock_recv__(dump->sock, bufferp, true);
+ retval = nl_sock_recv__(dump->sock, &dump->buffer, true);
if (retval) {
return retval == EINTR ? EAGAIN : retval;
}
- buffer = *bufferp;
- nlmsghdr = nl_msg_nlmsghdr(buffer);
+ nlmsghdr = nl_msg_nlmsghdr(&dump->buffer);
if (dump->seq != nlmsghdr->nlmsg_seq) {
VLOG_DBG_RL(&rl, "ignoring seq %#"PRIx32" != expected %#"PRIx32,
nlmsghdr->nlmsg_seq, dump->seq);
return EAGAIN;
}
- if (nl_msg_nlmsgerr(buffer, &retval)) {
+ if (nl_msg_nlmsgerr(&dump->buffer, &retval)) {
VLOG_INFO_RL(&rl, "netlink dump request error (%s)",
strerror(retval));
return retval && retval != EAGAIN ? retval : EPROTO;
return false;
}
- if (dump->buffer && !dump->buffer->size) {
- ofpbuf_delete(dump->buffer);
- dump->buffer = NULL;
- }
- while (!dump->buffer) {
- int retval = nl_dump_recv(dump, &dump->buffer);
+ while (!dump->buffer.size) {
+ int retval = nl_dump_recv(dump);
if (retval) {
- ofpbuf_delete(dump->buffer);
- dump->buffer = NULL;
+ ofpbuf_clear(&dump->buffer);
if (retval != EAGAIN) {
dump->status = retval;
return false;
}
}
- nlmsghdr = nl_msg_next(dump->buffer, reply);
+ nlmsghdr = nl_msg_next(&dump->buffer, reply);
if (!nlmsghdr) {
VLOG_WARN_RL(&rl, "netlink dump reply contains message fragment");
dump->status = EPROTO;
nl_sock_destroy(dump->sock);
}
}
- ofpbuf_delete(dump->buffer);
+ ofpbuf_uninit(&dump->buffer);
return dump->status == EOF ? 0 : dump->status;
}
return *number > 0 ? 0 : -*number;
}
\f
-/* Netlink PID.
- *
- * Every Netlink socket must be bound to a unique 32-bit PID. By convention,
- * programs that have a single Netlink socket use their Unix process ID as PID,
- * and programs with multiple Netlink sockets add a unique per-socket
- * identifier in the bits above the Unix process ID.
- *
- * The kernel has Netlink PID 0.
- */
-
-/* Parameters for how many bits in the PID should come from the Unix process ID
- * and how many unique per-socket. */
-#define SOCKET_BITS 10
-#define MAX_SOCKETS (1u << SOCKET_BITS)
-
-#define PROCESS_BITS (32 - SOCKET_BITS)
-#define MAX_PROCESSES (1u << PROCESS_BITS)
-#define PROCESS_MASK ((uint32_t) (MAX_PROCESSES - 1))
-
-/* Bit vector of unused socket identifiers. */
-static uint32_t avail_sockets[ROUND_UP(MAX_SOCKETS, 32)];
-
-/* Allocates and returns a new Netlink PID. */
-static int
-alloc_pid(uint32_t *pid)
+static uint32_t
+nl_sock_allocate_seq(struct nl_sock *sock, unsigned int n)
{
- int i;
+ uint32_t seq = sock->next_seq;
- for (i = 0; i < MAX_SOCKETS; i++) {
- if ((avail_sockets[i / 32] & (1u << (i % 32))) == 0) {
- avail_sockets[i / 32] |= 1u << (i % 32);
- *pid = (getpid() & PROCESS_MASK) | (i << PROCESS_BITS);
- return 0;
- }
+ sock->next_seq += n;
+
+ /* Make it impossible for the next request for sequence numbers to wrap
+ * around to 0. Start over with 1 to avoid ever using a sequence number of
+ * 0, because the kernel uses sequence number 0 for notifications. */
+ if (sock->next_seq >= UINT32_MAX / 2) {
+ sock->next_seq = 1;
}
- VLOG_ERR("netlink pid space exhausted");
- return ENOBUFS;
-}
-/* Makes the specified 'pid' available for reuse. */
-static void
-free_pid(uint32_t pid)
-{
- int sock = pid >> PROCESS_BITS;
- assert(avail_sockets[sock / 32] & (1u << (sock % 32)));
- avail_sockets[sock / 32] &= ~(1u << (sock % 32));
+ return seq;
}
-\f
+
static void
nlmsghdr_to_string(const struct nlmsghdr *h, int protocol, struct ds *ds)
{
if (flags_left) {
ds_put_format(ds, "[OTHER:%"PRIx16"]", flags_left);
}
- ds_put_format(ds, ", seq=%"PRIx32", pid=%"PRIu32"(%d:%d))",
- h->nlmsg_seq, h->nlmsg_pid,
- (int) (h->nlmsg_pid & PROCESS_MASK),
- (int) (h->nlmsg_pid >> PROCESS_BITS));
+ ds_put_format(ds, ", seq=%"PRIx32", pid=%"PRIu32,
+ h->nlmsg_seq, h->nlmsg_pid);
}
static char *
VLOG_DBG_RL(&rl, "%s (%s): %s", function, strerror(error), nlmsg);
free(nlmsg);
}
-
-
git://git.onelab.eu / sliver-openvswitch.git / blobdiff