/* Starts a Netlink "dump" operation, by sending 'request' to the kernel on a
* Netlink socket created with the given 'protocol', and initializes 'dump' to
* reflect the state of the operation.
*
* nlmsg_len in 'msg' will be finalized to match msg->size, and nlmsg_pid will
* be set to the Netlink socket's pid, before the message is sent. NLM_F_DUMP
* and NLM_F_ACK will be set in nlmsg_flags.
*
* The design of this Netlink socket library ensures that the dump is reliable.
*
* This function provides no status indication. An error status for the entire
* dump operation is provided when it is completed by calling nl_dump_done().
*
* The caller is responsible for destroying 'request'.
*/
void
nl_dump_start(struct nl_dump *dump, int protocol, const struct ofpbuf *request)
{
ofpbuf_init(&dump->buffer, 4096);
dump->status = nl_pool_alloc(protocol, &dump->sock);
if (dump->status) {
return;
}
nl_msg_nlmsghdr(request)->nlmsg_flags |= NLM_F_DUMP | NLM_F_ACK;
dump->status = nl_sock_send__(dump->sock, request,
nl_sock_allocate_seq(dump->sock, 1), true);
dump->seq = nl_msg_nlmsghdr(request)->nlmsg_seq;
}
/* Starts a Netlink "dump" operation, by sending 'request' to the kernel on a
* Netlink socket created with the given 'protocol', and initializes 'dump' to
* reflect the state of the operation.
*
* 'request' must contain a Netlink message. Before sending the message,
* nlmsg_len will be finalized to match request->size, and nlmsg_pid will be
* set to the Netlink socket's pid. NLM_F_DUMP and NLM_F_ACK will be set in
* nlmsg_flags.
*
* The design of this Netlink socket library ensures that the dump is reliable.
*
* This function provides no status indication. nl_dump_done() provides an
* error status for the entire dump operation.
*
* The caller must eventually destroy 'request'.
*/
void
nl_dump_start(struct nl_dump *dump, int protocol, const struct ofpbuf *request)
{
nl_msg_nlmsghdr(request)->nlmsg_flags |= NLM_F_DUMP | NLM_F_ACK;
ovs_mutex_init(&dump->mutex);
ovs_mutex_lock(&dump->mutex);
dump->status = nl_pool_alloc(protocol, &dump->sock);
if (!dump->status) {
dump->status = nl_sock_send__(dump->sock, request,
nl_sock_allocate_seq(dump->sock, 1),
true);
}
dump->nl_seq = nl_msg_nlmsghdr(request)->nlmsg_seq;
ovs_mutex_unlock(&dump->mutex);
}
/* Starts a Netlink "dump" operation, by sending 'request' to the kernel via
* 'sock', and initializes 'dump' to reflect the state of the operation.
*
* 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_DUMP and
* NLM_F_ACK will be set in nlmsg_flags.
*
* This Netlink socket library is designed to ensure that the dump is reliable
* and that it will not interfere with other operations on 'sock', including
* destroying or sending and receiving messages on 'sock'. One corner case is
* not handled:
*
* - If 'sock' has been used to send a request (e.g. with nl_sock_send())
* whose response has not yet been received (e.g. with nl_sock_recv()).
* This is unusual: usually nl_sock_transact() is used to send a message
* and receive its reply all in one go.
*
* This function provides no status indication. An error status for the entire
* dump operation is provided when it is completed by calling nl_dump_done().
*
* The caller is responsible for destroying 'request'.
*
* The new 'dump' is independent of 'sock'. 'sock' and 'dump' may be destroyed
* in either order.
*/
void
nl_dump_start(struct nl_dump *dump,
struct nl_sock *sock, const struct ofpbuf *request)
{
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->status = nl_sock_clone(sock, &dump->sock);
if (dump->status) {
return;
}
} else {
sock->dump = dump;
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, nl_sock_allocate_seq(sock, 1),
true);
dump->seq = nl_msg_nlmsghdr(request)->nlmsg_seq;
}
static int
nl_sock_transact_multiple__(struct nl_sock *sock,
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 nl_transaction *txn = transactions[i];
struct nlmsghdr *nlmsg = nl_msg_nlmsghdr(txn->request);
nlmsg->nlmsg_len = txn->request->size;
nlmsg->nlmsg_seq = base_seq + i;
nlmsg->nlmsg_pid = sock->pid;
iovs[i].iov_base = txn->request->data;
iovs[i].iov_len = txn->request->size;
}
memset(&msg, 0, sizeof msg);
msg.msg_iov = iovs;
msg.msg_iovlen = n;
do {
error = sendmsg(sock->fd, &msg, 0) < 0 ? errno : 0;
} while (error == EINTR);
for (i = 0; i < n; i++) {
struct nl_transaction *txn = transactions[i];
log_nlmsg(__func__, error, txn->request->data, txn->request->size,
sock->protocol);
}
if (!error) {
COVERAGE_ADD(netlink_sent, n);
}
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 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;
}
}
/* Receive a reply. */
error = nl_sock_recv__(sock, buf_txn->reply, false);
if (error) {
if (error == EAGAIN) {
nl_sock_record_errors__(transactions, n, 0);
*done += n;
error = 0;
}
break;
}
/* 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];
/* 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, ovs_strerror(txn->error));
}
} else {
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 error;
}
/* Tries to send 'msg', which must contain a Netlink message, to the kernel on
* 'sock'. nlmsg_len in 'msg' will be finalized to match msg->size, nlmsg_pid
* will be set to 'sock''s pid, and nlmsg_seq will be initialized to a fresh
* sequence number, before the message is sent.
*
* Returns 0 if successful, otherwise a positive errno value. If
* 'wait' is true, then the send will wait until buffer space is ready;
* otherwise, returns EAGAIN if the 'sock' send buffer is full. */
int
nl_sock_send(struct nl_sock *sock, const struct ofpbuf *msg, bool wait)
{
return nl_sock_send_seq(sock, msg, nl_sock_allocate_seq(sock, 1), wait);
}