X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fnetlink-socket.c;h=e4cc4ad62810cd5520ea1d3518c295b2ecd9f118;hb=HEAD;hp=dfe39ac9feada082a09c5c037fd84c99a795a5f1;hpb=10a89ef04df5669c5cdd02f786150a7ab8454e01;p=sliver-openvswitch.git diff --git a/lib/netlink-socket.c b/lib/netlink-socket.c index dfe39ac9f..e4cc4ad62 100644 --- a/lib/netlink-socket.c +++ b/lib/netlink-socket.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc. + * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014 Nicira, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -29,9 +29,10 @@ #include "netlink.h" #include "netlink-protocol.h" #include "ofpbuf.h" +#include "ovs-thread.h" #include "poll-loop.h" +#include "seq.h" #include "socket-util.h" -#include "stress.h" #include "util.h" #include "vlog.h" @@ -40,7 +41,6 @@ VLOG_DEFINE_THIS_MODULE(netlink_socket); COVERAGE_DEFINE(netlink_overflow); COVERAGE_DEFINE(netlink_received); COVERAGE_DEFINE(netlink_recv_jumbo); -COVERAGE_DEFINE(netlink_send); COVERAGE_DEFINE(netlink_sent); /* Linux header file confusion causes this to be undefined. */ @@ -64,7 +64,6 @@ struct nl_sock { uint32_t next_seq; uint32_t pid; int protocol; - struct nl_dump *dump; unsigned int rcvbuf; /* Receive buffer size (SO_RCVBUF). */ }; @@ -78,21 +77,23 @@ struct nl_sock { * Initialized by nl_sock_create(). */ static int max_iovs; -static int nl_sock_cow__(struct nl_sock *); +static int nl_pool_alloc(int protocol, struct nl_sock **sockp); +static void nl_pool_release(struct nl_sock *); /* Creates a new netlink socket for the given netlink 'protocol' * (NETLINK_ROUTE, NETLINK_GENERIC, ...). Returns 0 and sets '*sockp' to the - * new socket if successful, otherwise returns a positive errno value. */ + * new socket if successful, otherwise returns a positive errno value. */ int nl_sock_create(int protocol, struct nl_sock **sockp) { + static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER; struct nl_sock *sock; struct sockaddr_nl local, remote; socklen_t local_size; int rcvbuf; int retval = 0; - if (!max_iovs) { + if (ovsthread_once_start(&once)) { int save_errno = errno; errno = 0; @@ -107,6 +108,7 @@ nl_sock_create(int protocol, struct nl_sock **sockp) } errno = save_errno; + ovsthread_once_done(&once); } *sockp = NULL; @@ -118,7 +120,6 @@ nl_sock_create(int protocol, struct nl_sock **sockp) goto error; } sock->protocol = protocol; - sock->dump = NULL; sock->next_seq = 1; rcvbuf = 1024 * 1024; @@ -192,12 +193,8 @@ void nl_sock_destroy(struct nl_sock *sock) { if (sock) { - if (sock->dump) { - sock->dump = NULL; - } else { - close(sock->fd); - free(sock); - } + close(sock->fd); + free(sock); } } @@ -215,10 +212,6 @@ nl_sock_destroy(struct nl_sock *sock) int nl_sock_join_mcgroup(struct nl_sock *sock, unsigned int multicast_group) { - int error = nl_sock_cow__(sock); - if (error) { - return error; - } if (setsockopt(sock->fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &multicast_group, sizeof multicast_group) < 0) { VLOG_WARN("could not join multicast group %u (%s)", @@ -241,7 +234,6 @@ nl_sock_join_mcgroup(struct nl_sock *sock, unsigned int multicast_group) int nl_sock_leave_mcgroup(struct nl_sock *sock, unsigned int multicast_group) { - ovs_assert(!sock->dump); if (setsockopt(sock->fd, SOL_NETLINK, NETLINK_DROP_MEMBERSHIP, &multicast_group, sizeof multicast_group) < 0) { VLOG_WARN("could not leave multicast group %u (%s)", @@ -258,15 +250,15 @@ nl_sock_send__(struct nl_sock *sock, const struct ofpbuf *msg, struct nlmsghdr *nlmsg = nl_msg_nlmsghdr(msg); int error; - nlmsg->nlmsg_len = msg->size; + nlmsg->nlmsg_len = ofpbuf_size(msg); nlmsg->nlmsg_seq = nlmsg_seq; nlmsg->nlmsg_pid = sock->pid; do { int retval; - retval = send(sock->fd, msg->data, msg->size, wait ? 0 : MSG_DONTWAIT); + retval = send(sock->fd, ofpbuf_data(msg), ofpbuf_size(msg), wait ? 0 : MSG_DONTWAIT); error = retval < 0 ? errno : 0; } while (error == EINTR); - log_nlmsg(__func__, error, msg->data, msg->size, sock->protocol); + log_nlmsg(__func__, error, ofpbuf_data(msg), ofpbuf_size(msg), sock->protocol); if (!error) { COVERAGE_INC(netlink_sent); } @@ -274,7 +266,7 @@ nl_sock_send__(struct nl_sock *sock, const struct ofpbuf *msg, } /* 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 + * 'sock'. nlmsg_len in 'msg' will be finalized to match ofpbuf_size(msg), 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. * @@ -288,7 +280,7 @@ nl_sock_send(struct nl_sock *sock, const struct ofpbuf *msg, bool wait) } /* 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 + * 'sock'. nlmsg_len in 'msg' will be finalized to match ofpbuf_size(msg), nlmsg_pid * will be set to 'sock''s pid, and nlmsg_seq will be initialized to * 'nlmsg_seq', before the message is sent. * @@ -302,22 +294,9 @@ int nl_sock_send_seq(struct nl_sock *sock, const struct ofpbuf *msg, uint32_t nlmsg_seq, bool wait) { - int error = nl_sock_cow__(sock); - if (error) { - return error; - } return nl_sock_send__(sock, msg, nlmsg_seq, wait); } -/* This stress option is useful for testing that OVS properly tolerates - * -ENOBUFS on NetLink sockets. Such errors are unavoidable because they can - * occur if the kernel cannot temporarily allocate enough GFP_ATOMIC memory to - * reply to a request. They can also occur if messages arrive on a multicast - * channel faster than OVS can process them. */ -STRESS_OPTION( - netlink_overflow, "simulate netlink socket receive buffer overflow", - 5, 1, -1, 100); - static int nl_sock_recv__(struct nl_sock *sock, struct ofpbuf *buf, bool wait) { @@ -335,7 +314,7 @@ nl_sock_recv__(struct nl_sock *sock, struct ofpbuf *buf, bool wait) ovs_assert(buf->allocated >= sizeof *nlmsghdr); ofpbuf_clear(buf); - iov[0].iov_base = buf->base; + iov[0].iov_base = ofpbuf_base(buf); iov[0].iov_len = buf->allocated; iov[1].iov_base = tail; iov[1].iov_len = sizeof tail; @@ -359,31 +338,27 @@ nl_sock_recv__(struct nl_sock *sock, struct ofpbuf *buf, bool wait) } if (msg.msg_flags & MSG_TRUNC) { - VLOG_ERR_RL(&rl, "truncated message (longer than %zu bytes)", + VLOG_ERR_RL(&rl, "truncated message (longer than %"PRIuSIZE" bytes)", sizeof tail); return E2BIG; } - nlmsghdr = buf->data; + nlmsghdr = ofpbuf_data(buf); if (retval < sizeof *nlmsghdr || nlmsghdr->nlmsg_len < sizeof *nlmsghdr || nlmsghdr->nlmsg_len > retval) { - VLOG_ERR_RL(&rl, "received invalid nlmsg (%zd bytes < %zu)", + VLOG_ERR_RL(&rl, "received invalid nlmsg (%"PRIuSIZE"d bytes < %"PRIuSIZE")", retval, sizeof *nlmsghdr); return EPROTO; } - if (STRESS(netlink_overflow)) { - return ENOBUFS; - } - - buf->size = MIN(retval, buf->allocated); + ofpbuf_set_size(buf, 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); + log_nlmsg(__func__, 0, ofpbuf_data(buf), ofpbuf_size(buf), sock->protocol); COVERAGE_INC(netlink_received); return 0; @@ -409,10 +384,6 @@ nl_sock_recv__(struct nl_sock *sock, struct ofpbuf *buf, bool wait) int 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, buf, wait); } @@ -453,12 +424,12 @@ nl_sock_transact_multiple__(struct nl_sock *sock, struct nl_transaction *txn = transactions[i]; struct nlmsghdr *nlmsg = nl_msg_nlmsghdr(txn->request); - nlmsg->nlmsg_len = txn->request->size; + nlmsg->nlmsg_len = ofpbuf_size(txn->request); 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; + iovs[i].iov_base = ofpbuf_data(txn->request); + iovs[i].iov_len = ofpbuf_size(txn->request); } memset(&msg, 0, sizeof msg); @@ -471,7 +442,7 @@ nl_sock_transact_multiple__(struct nl_sock *sock, for (i = 0; i < n; i++) { struct nl_transaction *txn = transactions[i]; - log_nlmsg(__func__, error, txn->request->data, txn->request->size, + log_nlmsg(__func__, error, ofpbuf_data(txn->request), ofpbuf_size(txn->request), sock->protocol); } if (!error) { @@ -585,12 +556,6 @@ nl_sock_transact_multiple(struct nl_sock *sock, return; } - error = nl_sock_cow__(sock); - if (error) { - nl_sock_record_errors__(transactions, n, error); - return; - } - /* In theory, every request could have a 64 kB reply. But the default and * maximum socket rcvbuf size with typical Dom0 memory sizes both tend to * be a bit below 128 kB, so that would only allow a single message in a @@ -614,12 +579,12 @@ nl_sock_transact_multiple(struct nl_sock *sock, #else enum { MAX_BATCH_BYTES = 4096 - 512 }; #endif - bytes = transactions[0]->request->size; + bytes = ofpbuf_size(transactions[0]->request); for (count = 1; count < n && count < max_batch_count; count++) { - if (bytes + transactions[count]->request->size > MAX_BATCH_BYTES) { + if (bytes + ofpbuf_size(transactions[count]->request) > MAX_BATCH_BYTES) { break; } - bytes += transactions[count]->request->size; + bytes += ofpbuf_size(transactions[count]->request); } error = nl_sock_transact_multiple__(sock, transactions, count, &done); @@ -644,7 +609,7 @@ nl_sock_transact_multiple(struct nl_sock *sock, * reply, if any, is discarded. * * 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 + * match ofpbuf_size(msg), 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'. @@ -704,169 +669,132 @@ nl_sock_transact(struct nl_sock *sock, const struct ofpbuf *request, int nl_sock_drain(struct nl_sock *sock) { - int error = nl_sock_cow__(sock); - if (error) { - return error; - } return drain_rcvbuf(sock->fd); } -/* The client is attempting some operation on 'sock'. If 'sock' has an ongoing - * dump operation, then replace 'sock''s fd with a new socket and hand 'sock''s - * old fd over to the dump. */ -static int -nl_sock_cow__(struct nl_sock *sock) -{ - struct nl_sock *copy; - uint32_t tmp_pid; - int tmp_fd; - int error; - - if (!sock->dump) { - return 0; - } - - error = nl_sock_clone(sock, ©); - if (error) { - return error; - } - - tmp_fd = sock->fd; - sock->fd = copy->fd; - copy->fd = tmp_fd; - - tmp_pid = sock->pid; - sock->pid = copy->pid; - copy->pid = tmp_pid; - - sock->dump->sock = copy; - sock->dump = NULL; - - return 0; -} - -/* 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. +/* 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. * - * 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: + * '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. * - * - 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. + * 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'. + * This function provides no status indication. nl_dump_done() provides an + * error status for the entire dump operation. * - * The new 'dump' is independent of 'sock'. 'sock' and 'dump' may be destroyed - * in either order. + * The caller must eventually destroy 'request'. */ void -nl_dump_start(struct nl_dump *dump, - struct nl_sock *sock, const struct ofpbuf *request) +nl_dump_start(struct nl_dump *dump, int protocol, 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; - } + int status = nl_pool_alloc(protocol, &dump->sock); - 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; -} - -/* Helper function for nl_dump_next(). */ -static int -nl_dump_recv(struct nl_dump *dump) -{ - struct nlmsghdr *nlmsghdr; - int retval; - - retval = nl_sock_recv__(dump->sock, &dump->buffer, true); - if (retval) { - return retval == EINTR ? EAGAIN : retval; - } - - 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(&dump->buffer, &retval)) { - VLOG_INFO_RL(&rl, "netlink dump request error (%s)", - ovs_strerror(retval)); - return retval && retval != EAGAIN ? retval : EPROTO; + if (status) { + return; } - return 0; + nl_msg_nlmsghdr(request)->nlmsg_flags |= NLM_F_DUMP | NLM_F_ACK; + status = nl_sock_send__(dump->sock, request, + nl_sock_allocate_seq(dump->sock, 1), true); + atomic_init(&dump->status, status << 1); + dump->nl_seq = nl_msg_nlmsghdr(request)->nlmsg_seq; + dump->status_seq = seq_create(); } -/* Attempts to retrieve another reply from 'dump', which must have been - * initialized with nl_dump_start(). +/* Attempts to retrieve another reply from 'dump' into 'buffer'. 'dump' must + * have been initialized with nl_dump_start(), and 'buffer' must have been + * initialized. 'buffer' should be at least NL_DUMP_BUFSIZE bytes long. * - * If successful, returns true and points 'reply->data' and 'reply->size' to - * the message that was retrieved. The caller must not modify 'reply' (because - * it points into the middle of a larger buffer). + * If successful, returns true and points 'reply->data' and 'ofpbuf_size(reply)' to + * the message that was retrieved. The caller must not modify 'reply' (because + * it points within 'buffer', which will be used by future calls to this + * function). * - * On failure, returns false and sets 'reply->data' to NULL and 'reply->size' + * On failure, returns false and sets 'reply->data' to NULL and 'ofpbuf_size(reply)' * to 0. Failure might indicate an actual error or merely the end of replies. * An error status for the entire dump operation is provided when it is * completed by calling nl_dump_done(). + * + * Multiple threads may call this function, passing the same nl_dump, however + * each must provide independent buffers. This function may cache multiple + * replies in the buffer, and these will be processed before more replies are + * fetched. When this function returns false, other threads may continue to + * process replies in their buffers, but they will not fetch more replies. */ bool -nl_dump_next(struct nl_dump *dump, struct ofpbuf *reply) +nl_dump_next(struct nl_dump *dump, struct ofpbuf *reply, struct ofpbuf *buffer) { struct nlmsghdr *nlmsghdr; + int error = 0; - reply->data = NULL; - reply->size = 0; - if (dump->status) { - return false; - } + ofpbuf_set_data(reply, NULL); + ofpbuf_set_size(reply, 0); - while (!dump->buffer.size) { - int retval = nl_dump_recv(dump); + /* If 'buffer' is empty, fetch another batch of nlmsgs. */ + while (!ofpbuf_size(buffer)) { + unsigned int status; + int retval, seq; + + seq = seq_read(dump->status_seq); + atomic_read(&dump->status, &status); + if (status) { + return false; + } + + retval = nl_sock_recv__(dump->sock, buffer, false); if (retval) { - ofpbuf_clear(&dump->buffer); - if (retval != EAGAIN) { - dump->status = retval; - return false; + ofpbuf_clear(buffer); + if (retval == EAGAIN) { + nl_sock_wait(dump->sock, POLLIN); + seq_wait(dump->status_seq, seq); + poll_block(); + continue; + } else { + error = retval; + goto exit; } } + + nlmsghdr = nl_msg_nlmsghdr(buffer); + if (dump->nl_seq != nlmsghdr->nlmsg_seq) { + VLOG_DBG_RL(&rl, "ignoring seq %#"PRIx32" != expected %#"PRIx32, + nlmsghdr->nlmsg_seq, dump->nl_seq); + ofpbuf_clear(buffer); + continue; + } + + if (nl_msg_nlmsgerr(buffer, &retval) && retval) { + VLOG_INFO_RL(&rl, "netlink dump request error (%s)", + ovs_strerror(retval)); + error = retval == EAGAIN ? EPROTO : retval; + ofpbuf_clear(buffer); + goto exit; + } } - nlmsghdr = nl_msg_next(&dump->buffer, reply); + /* Fetch the next nlmsg in the current batch. */ + nlmsghdr = nl_msg_next(buffer, reply); if (!nlmsghdr) { VLOG_WARN_RL(&rl, "netlink dump reply contains message fragment"); - dump->status = EPROTO; - return false; + error = EPROTO; } else if (nlmsghdr->nlmsg_type == NLMSG_DONE) { - dump->status = EOF; - return false; + error = EOF; } - return true; +exit: + if (error == EOF) { + unsigned int old; + atomic_or(&dump->status, 1, &old); + seq_change(dump->status_seq); + } else if (error) { + atomic_store(&dump->status, error << 1); + seq_change(dump->status_seq); + } + return !error; } /* Completes Netlink dump operation 'dump', which must have been initialized @@ -875,24 +803,28 @@ nl_dump_next(struct nl_dump *dump, struct ofpbuf *reply) int nl_dump_done(struct nl_dump *dump) { - /* Drain any remaining messages that the client didn't read. Otherwise the - * kernel will continue to queue them up and waste buffer space. */ - while (!dump->status) { - struct ofpbuf reply; - if (!nl_dump_next(dump, &reply)) { - ovs_assert(dump->status); - } - } + int status; - if (dump->sock) { - if (dump->sock->dump) { - dump->sock->dump = NULL; - } else { - nl_sock_destroy(dump->sock); + /* Drain any remaining messages that the client didn't read. Otherwise the + * kernel will continue to queue them up and waste buffer space. + * + * XXX We could just destroy and discard the socket in this case. */ + atomic_read(&dump->status, &status); + if (!status) { + uint64_t tmp_reply_stub[NL_DUMP_BUFSIZE / 8]; + struct ofpbuf reply, buf; + + ofpbuf_use_stub(&buf, tmp_reply_stub, sizeof tmp_reply_stub); + while (nl_dump_next(dump, &reply, &buf)) { + /* Nothing to do. */ } + atomic_read(&dump->status, &status); + ovs_assert(status); + ofpbuf_uninit(&buf); } - ofpbuf_uninit(&dump->buffer); - return dump->status == EOF ? 0 : dump->status; + nl_pool_release(dump->sock); + seq_destroy(dump->status_seq); + return status >> 1; } /* Causes poll_block() to wake up when any of the specified 'events' (which is @@ -1022,12 +954,10 @@ do_lookup_genl_family(const char *name, struct nlattr **attrs, /* Finds the multicast group called 'group_name' in genl family 'family_name'. * When successful, writes its result to 'multicast_group' and returns 0. * Otherwise, clears 'multicast_group' and returns a positive error code. - * - * Some kernels do not support looking up a multicast group with this function. - * In this case, 'multicast_group' will be populated with 'fallback'. */ + */ int nl_lookup_genl_mcgroup(const char *family_name, const char *group_name, - unsigned int *multicast_group, unsigned int fallback) + unsigned int *multicast_group) { struct nlattr *family_attrs[ARRAY_SIZE(family_policy)]; const struct nlattr *mc; @@ -1042,10 +972,7 @@ nl_lookup_genl_mcgroup(const char *family_name, const char *group_name, } if (!family_attrs[CTRL_ATTR_MCAST_GROUPS]) { - *multicast_group = fallback; - VLOG_WARN("%s-%s: has no multicast group, using fallback %d", - family_name, group_name, *multicast_group); - error = 0; + error = EPROTO; goto exit; } @@ -1103,6 +1030,90 @@ nl_lookup_genl_family(const char *name, int *number) } return *number > 0 ? 0 : -*number; } + +struct nl_pool { + struct nl_sock *socks[16]; + int n; +}; + +static struct ovs_mutex pool_mutex = OVS_MUTEX_INITIALIZER; +static struct nl_pool pools[MAX_LINKS] OVS_GUARDED_BY(pool_mutex); + +static int +nl_pool_alloc(int protocol, struct nl_sock **sockp) +{ + struct nl_sock *sock = NULL; + struct nl_pool *pool; + + ovs_assert(protocol >= 0 && protocol < ARRAY_SIZE(pools)); + + ovs_mutex_lock(&pool_mutex); + pool = &pools[protocol]; + if (pool->n > 0) { + sock = pool->socks[--pool->n]; + } + ovs_mutex_unlock(&pool_mutex); + + if (sock) { + *sockp = sock; + return 0; + } else { + return nl_sock_create(protocol, sockp); + } +} + +static void +nl_pool_release(struct nl_sock *sock) +{ + if (sock) { + struct nl_pool *pool = &pools[sock->protocol]; + + ovs_mutex_lock(&pool_mutex); + if (pool->n < ARRAY_SIZE(pool->socks)) { + pool->socks[pool->n++] = sock; + sock = NULL; + } + ovs_mutex_unlock(&pool_mutex); + + nl_sock_destroy(sock); + } +} + +int +nl_transact(int protocol, const struct ofpbuf *request, + struct ofpbuf **replyp) +{ + struct nl_sock *sock; + int error; + + error = nl_pool_alloc(protocol, &sock); + if (error) { + *replyp = NULL; + return error; + } + + error = nl_sock_transact(sock, request, replyp); + + nl_pool_release(sock); + return error; +} + +void +nl_transact_multiple(int protocol, + struct nl_transaction **transactions, size_t n) +{ + struct nl_sock *sock; + int error; + + error = nl_pool_alloc(protocol, &sock); + if (!error) { + nl_sock_transact_multiple(sock, transactions, n); + nl_pool_release(sock); + } else { + nl_sock_record_errors__(transactions, n, error); + } +} + static uint32_t nl_sock_allocate_seq(struct nl_sock *sock, unsigned int n)