/*
- * Copyright (c) 2008, 2009, 2010 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include <unistd.h>
#include "coverage.h"
#include "dynamic-string.h"
+#include "hash.h"
+#include "hmap.h"
#include "netlink.h"
#include "netlink-protocol.h"
#include "ofpbuf.h"
#include "poll-loop.h"
+#include "socket-util.h"
#include "stress.h"
#include "vlog.h"
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(60, 600);
static void log_nlmsg(const char *function, int error,
- const void *message, size_t size);
+ const void *message, size_t size, int protocol);
\f
/* Netlink sockets. */
{
int fd;
uint32_t pid;
+ int protocol;
+ bool any_groups;
+ struct nl_dump *dump;
};
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'
* (NETLINK_ROUTE, NETLINK_GENERIC, ...). Returns 0 and sets '*sockp' to the
- * new socket if successful, otherwise returns a positive errno value.
- *
- * If 'multicast_group' is nonzero, the new socket subscribes to the specified
- * netlink multicast group. (A netlink socket may listen to an arbitrary
- * number of multicast groups, but so far we only need one at a time.)
- *
- * Nonzero 'so_sndbuf' or 'so_rcvbuf' override the kernel default send or
- * receive buffer size, respectively.
- */
+ * new socket if successful, otherwise returns a positive errno value. */
int
-nl_sock_create(int protocol, int multicast_group,
- size_t so_sndbuf, size_t so_rcvbuf, struct nl_sock **sockp)
+nl_sock_create(int protocol, struct nl_sock **sockp)
{
struct nl_sock *sock;
struct sockaddr_nl local, remote;
VLOG_ERR("fcntl: %s", strerror(errno));
goto error;
}
+ sock->protocol = protocol;
+ sock->any_groups = false;
+ sock->dump = NULL;
retval = alloc_pid(&sock->pid);
if (retval) {
goto error;
}
- if (so_sndbuf != 0
- && setsockopt(sock->fd, SOL_SOCKET, SO_SNDBUF,
- &so_sndbuf, sizeof so_sndbuf) < 0) {
- VLOG_ERR("setsockopt(SO_SNDBUF,%zu): %s", so_sndbuf, strerror(errno));
- goto error_free_pid;
- }
-
- if (so_rcvbuf != 0
- && setsockopt(sock->fd, SOL_SOCKET, SO_RCVBUF,
- &so_rcvbuf, sizeof so_rcvbuf) < 0) {
- VLOG_ERR("setsockopt(SO_RCVBUF,%zu): %s", so_rcvbuf, strerror(errno));
- goto error_free_pid;
- }
-
/* Bind local address as our selected pid. */
memset(&local, 0, sizeof local);
local.nl_family = AF_NETLINK;
local.nl_pid = sock->pid;
- if (multicast_group > 0 && multicast_group <= 32) {
- /* This method of joining multicast groups is supported by old kernels,
- * but it only allows 32 multicast groups per protocol. */
- local.nl_groups |= 1ul << (multicast_group - 1);
- }
if (bind(sock->fd, (struct sockaddr *) &local, sizeof local) < 0) {
VLOG_ERR("bind(%"PRIu32"): %s", sock->pid, strerror(errno));
goto error_free_pid;
goto error_free_pid;
}
- /* Older kernel headers failed to define this macro. We want our programs
- * to support the newer kernel features even if compiled with older
- * headers, so define it ourselves in such a case. */
-#ifndef NETLINK_ADD_MEMBERSHIP
-#define NETLINK_ADD_MEMBERSHIP 1
-#endif
-
- /* This method of joining multicast groups is only supported by newish
- * kernels, but it allows for an arbitrary number of multicast groups. */
- if (multicast_group > 32
- && setsockopt(sock->fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP,
- &multicast_group, sizeof multicast_group) < 0) {
- VLOG_ERR("setsockopt(NETLINK_ADD_MEMBERSHIP,%d): %s",
- multicast_group, strerror(errno));
- goto error_free_pid;
- }
-
*sockp = sock;
return 0;
return retval;
}
+/* Creates a new netlink socket for the same protocol as 'src'. Returns 0 and
+ * sets '*sockp' to the new socket if successful, otherwise returns a positive
+ * errno value. */
+int
+nl_sock_clone(const struct nl_sock *src, struct nl_sock **sockp)
+{
+ return nl_sock_create(src->protocol, sockp);
+}
+
/* Destroys netlink socket 'sock'. */
void
nl_sock_destroy(struct nl_sock *sock)
{
if (sock) {
- close(sock->fd);
- free_pid(sock->pid);
- free(sock);
+ if (sock->dump) {
+ sock->dump = NULL;
+ } else {
+ close(sock->fd);
+ free_pid(sock->pid);
+ free(sock);
+ }
}
}
-/* 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, and
- * nlmsg_pid will be set to 'sock''s pid, before the message is sent.
+/* Tries to add 'sock' as a listener for 'multicast_group'. Returns 0 if
+ * successful, otherwise a positive errno value.
*
- * 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. */
+ * Multicast group numbers are always positive.
+ *
+ * It is not an error to attempt to join a multicast group to which a socket
+ * already belongs. */
int
-nl_sock_send(struct nl_sock *sock, const struct ofpbuf *msg, bool wait)
+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)",
+ multicast_group, strerror(errno));
+ return errno;
+ }
+ sock->any_groups = true;
+ return 0;
+}
+
+/* Tries to make 'sock' stop listening to 'multicast_group'. Returns 0 if
+ * successful, otherwise a positive errno value.
+ *
+ * Multicast group numbers are always positive.
+ *
+ * It is not an error to attempt to leave a multicast group to which a socket
+ * does not belong.
+ *
+ * On success, reading from 'sock' will still return any messages that were
+ * received on 'multicast_group' before the group was left. */
+int
+nl_sock_leave_mcgroup(struct nl_sock *sock, unsigned int multicast_group)
+{
+ 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)",
+ multicast_group, strerror(errno));
+ return errno;
+ }
+ return 0;
+}
+
+static int
+nl_sock_send__(struct nl_sock *sock, const struct ofpbuf *msg, bool wait)
{
struct nlmsghdr *nlmsg = nl_msg_nlmsghdr(msg);
int error;
retval = send(sock->fd, msg->data, msg->size, wait ? 0 : MSG_DONTWAIT);
error = retval < 0 ? errno : 0;
} while (error == EINTR);
- log_nlmsg(__func__, error, msg->data, msg->size);
+ log_nlmsg(__func__, error, msg->data, msg->size, sock->protocol);
if (!error) {
COVERAGE_INC(netlink_sent);
}
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, and
+ * nlmsg_pid will be set to 'sock''s pid, 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)
+{
+ int error = nl_sock_cow__(sock);
+ if (error) {
+ return error;
+ }
+ return nl_sock_send__(sock, msg, wait);
+}
+
/* Tries to send the 'n_iov' chunks of data in 'iov' to the kernel on 'sock' as
* a single Netlink message. (The message must be fully formed and not require
* finalization of its nlmsg_len or nlmsg_pid fields.)
error = retval < 0 ? errno : 0;
} while (error == EINTR);
if (error != EAGAIN) {
- log_nlmsg(__func__, error, iov[0].iov_base, iov[0].iov_len);
+ log_nlmsg(__func__, error, iov[0].iov_base, iov[0].iov_len,
+ sock->protocol);
if (!error) {
COVERAGE_INC(netlink_sent);
}
netlink_overflow, "simulate netlink socket receive buffer overflow",
5, 1, -1, 100);
-/* 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'.
- *
- * If 'wait' is true, nl_sock_recv waits for a message to be ready; otherwise,
- * returns EAGAIN if the 'sock' receive buffer is empty. */
-int
-nl_sock_recv(struct nl_sock *sock, struct ofpbuf **bufp, bool wait)
+static int
+nl_sock_recv__(struct nl_sock *sock, struct ofpbuf **bufp, bool wait)
{
uint8_t tmp;
ssize_t bufsize = 2048;
}
*bufp = buf;
- log_nlmsg(__func__, 0, buf->data, buf->size);
+ 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'.
+ *
+ * If 'wait' is true, nl_sock_recv waits for a message to be ready; otherwise,
+ * returns EAGAIN if the 'sock' receive buffer is empty. */
+int
+nl_sock_recv(struct nl_sock *sock, struct ofpbuf **bufp, bool wait)
+{
+ int error = nl_sock_cow__(sock);
+ if (error) {
+ return error;
+ }
+ return nl_sock_recv__(sock, bufp, wait);
+}
+
/* Sends 'request' to the kernel via 'sock' and waits for a response. If
* successful, returns 0. On failure, returns a positive errno value.
*
}
nlmsghdr = nl_msg_nlmsghdr(reply);
if (seq != nlmsghdr->nlmsg_seq) {
- VLOG_DBG_RL(&rl, "ignoring seq %"PRIu32" != expected %"PRIu32,
+ VLOG_DBG_RL(&rl, "ignoring seq %#"PRIx32" != expected %#"PRIx32,
nl_msg_nlmsghdr(reply)->nlmsg_seq, seq);
ofpbuf_delete(reply);
goto recv;
return 0;
}
+/* Drain all the messages currently in 'sock''s receive queue. */
+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.
*
* be set to 'sock''s pid, before the message is sent. NLM_F_DUMP and
* NLM_F_ACK will be set in nlmsg_flags.
*
- * The properties of Netlink make dump operations reliable as long as all of
- * the following are true:
- *
- * - At most a single dump is in progress at a time on a given nl_sock.
+ * 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:
*
- * - The nl_sock is not subscribed to any multicast groups.
- *
- * - The nl_sock is not used to send any other messages before the dump
- * operation is complete.
+ * - 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 caller must not
- * close 'sock' before it completes the dump operation (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 nlmsghdr *nlmsghdr = nl_msg_nlmsghdr(request);
nlmsghdr->nlmsg_flags |= NLM_F_DUMP | NLM_F_ACK;
dump->seq = nlmsghdr->nlmsg_seq;
- dump->sock = sock;
- dump->status = nl_sock_send(sock, request, true);
dump->buffer = NULL;
+ if (sock->any_groups || sock->dump) {
+ /* 'sock' might belong to some multicast group, or it already has an
+ * onoging dump. Clone the socket to avoid possibly intermixing
+ * multicast messages or previous dump results with our results. */
+ dump->status = nl_sock_clone(sock, &dump->sock);
+ if (dump->status) {
+ return;
+ }
+ } else {
+ sock->dump = dump;
+ dump->sock = sock;
+ dump->status = 0;
+ }
+ dump->status = nl_sock_send__(sock, request, true);
}
/* Helper function for nl_dump_next(). */
struct ofpbuf *buffer;
int retval;
- retval = nl_sock_recv(dump->sock, bufferp, true);
+ retval = nl_sock_recv__(dump->sock, bufferp, true);
if (retval) {
return retval == EINTR ? EAGAIN : retval;
}
nlmsghdr = nl_msg_nlmsghdr(buffer);
if (dump->seq != nlmsghdr->nlmsg_seq) {
- VLOG_DBG_RL(&rl, "ignoring seq %"PRIu32" != expected %"PRIu32,
+ VLOG_DBG_RL(&rl, "ignoring seq %#"PRIx32" != expected %#"PRIx32,
nlmsghdr->nlmsg_seq, dump->seq);
return EAGAIN;
}
}
}
+ if (dump->sock) {
+ if (dump->sock->dump) {
+ dump->sock->dump = NULL;
+ } else {
+ nl_sock_destroy(dump->sock);
+ }
+ }
ofpbuf_delete(dump->buffer);
return dump->status == EOF ? 0 : dump->status;
}
\f
/* Miscellaneous. */
+struct genl_family {
+ struct hmap_node hmap_node;
+ uint16_t id;
+ char *name;
+};
+
+static struct hmap genl_families = HMAP_INITIALIZER(&genl_families);
+
static const struct nl_policy family_policy[CTRL_ATTR_MAX + 1] = {
[CTRL_ATTR_FAMILY_ID] = {.type = NL_A_U16},
};
+static struct genl_family *
+find_genl_family_by_id(uint16_t id)
+{
+ struct genl_family *family;
+
+ HMAP_FOR_EACH_IN_BUCKET (family, hmap_node, hash_int(id, 0),
+ &genl_families) {
+ if (family->id == id) {
+ return family;
+ }
+ }
+ return NULL;
+}
+
+static void
+define_genl_family(uint16_t id, const char *name)
+{
+ struct genl_family *family = find_genl_family_by_id(id);
+
+ if (family) {
+ if (!strcmp(family->name, name)) {
+ return;
+ }
+ free(family->name);
+ } else {
+ family = xmalloc(sizeof *family);
+ family->id = id;
+ hmap_insert(&genl_families, &family->hmap_node, hash_int(id, 0));
+ }
+ family->name = xstrdup(name);
+}
+
+static const char *
+genl_family_to_name(uint16_t id)
+{
+ if (id == GENL_ID_CTRL) {
+ return "control";
+ } else {
+ struct genl_family *family = find_genl_family_by_id(id);
+ return family ? family->name : "unknown";
+ }
+}
+
static int do_lookup_genl_family(const char *name)
{
struct nl_sock *sock;
struct nlattr *attrs[ARRAY_SIZE(family_policy)];
int retval;
- retval = nl_sock_create(NETLINK_GENERIC, 0, 0, 0, &sock);
+ retval = nl_sock_create(NETLINK_GENERIC, &sock);
if (retval) {
return -retval;
}
retval = nl_attr_get_u16(attrs[CTRL_ATTR_FAMILY_ID]);
if (retval == 0) {
retval = -EPROTO;
+ } else {
+ define_genl_family(retval, name);
}
nl_sock_destroy(sock);
ofpbuf_delete(reply);
+
return retval;
}
}
\f
static void
-nlmsghdr_to_string(const struct nlmsghdr *h, struct ds *ds)
+nlmsghdr_to_string(const struct nlmsghdr *h, int protocol, struct ds *ds)
{
struct nlmsg_flag {
unsigned int bits;
ds_put_cstr(ds, "(overrun)");
} else if (h->nlmsg_type < NLMSG_MIN_TYPE) {
ds_put_cstr(ds, "(reserved)");
+ } else if (protocol == NETLINK_GENERIC) {
+ ds_put_format(ds, "(%s)", genl_family_to_name(h->nlmsg_type));
} else {
ds_put_cstr(ds, "(family-defined)");
}
}
static char *
-nlmsg_to_string(const struct ofpbuf *buffer)
+nlmsg_to_string(const struct ofpbuf *buffer, int protocol)
{
struct ds ds = DS_EMPTY_INITIALIZER;
const struct nlmsghdr *h = ofpbuf_at(buffer, 0, NLMSG_HDRLEN);
if (h) {
- nlmsghdr_to_string(h, &ds);
+ nlmsghdr_to_string(h, protocol, &ds);
if (h->nlmsg_type == NLMSG_ERROR) {
const struct nlmsgerr *e;
e = ofpbuf_at(buffer, NLMSG_HDRLEN,
ds_put_format(&ds, "(%s)", strerror(-e->error));
}
ds_put_cstr(&ds, ", in-reply-to(");
- nlmsghdr_to_string(&e->msg, &ds);
+ nlmsghdr_to_string(&e->msg, protocol, &ds);
ds_put_cstr(&ds, "))");
} else {
ds_put_cstr(&ds, " error(truncated)");
} else {
ds_put_cstr(&ds, " done(truncated)");
}
+ } else if (protocol == NETLINK_GENERIC) {
+ struct genlmsghdr *genl = nl_msg_genlmsghdr(buffer);
+ if (genl) {
+ ds_put_format(&ds, ",genl(cmd=%"PRIu8",version=%"PRIu8")",
+ genl->cmd, genl->version);
+ }
}
} else {
ds_put_cstr(&ds, "nl(truncated)");
static void
log_nlmsg(const char *function, int error,
- const void *message, size_t size)
+ const void *message, size_t size, int protocol)
{
struct ofpbuf buffer;
char *nlmsg;
}
ofpbuf_use_const(&buffer, message, size);
- nlmsg = nlmsg_to_string(&buffer);
+ nlmsg = nlmsg_to_string(&buffer, protocol);
VLOG_DBG_RL(&rl, "%s (%s): %s", function, strerror(error), nlmsg);
free(nlmsg);
}
git://git.onelab.eu / sliver-openvswitch.git / blobdiff