/*
- * Copyright (c) 2008, 2009, 2010 Nicira Networks.
+ * 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.
#include <config.h>
#include "netlink.h"
-#include <assert.h>
#include <errno.h>
#include <inttypes.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <time.h>
+#include <sys/types.h>
#include <unistd.h>
#include "coverage.h"
-#include "dynamic-string.h"
+#include "flow.h"
#include "netlink-protocol.h"
#include "ofpbuf.h"
-#include "poll-loop.h"
#include "timeval.h"
-#include "util.h"
+#include "unaligned.h"
#include "vlog.h"
VLOG_DEFINE_THIS_MODULE(netlink);
-COVERAGE_DEFINE(netlink_overflow);
-COVERAGE_DEFINE(netlink_received);
-COVERAGE_DEFINE(netlink_recv_retry);
-COVERAGE_DEFINE(netlink_send);
-COVERAGE_DEFINE(netlink_sent);
-
-/* Linux header file confusion causes this to be undefined. */
-#ifndef SOL_NETLINK
-#define SOL_NETLINK 270
-#endif
-
/* A single (bad) Netlink message can in theory dump out many, many log
* messages, so the burst size is set quite high here to avoid missing useful
* information. Also, at high logging levels we log *all* Netlink messages. */
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);
-\f
-/* Netlink sockets. */
-
-struct nl_sock
-{
- int fd;
- uint32_t pid;
-};
-
-/* Next nlmsghdr sequence number.
- *
- * This implementation uses sequence numbers that are unique process-wide, to
- * avoid a hypothetical race: send request, close socket, open new socket that
- * reuses the old socket's PID value, send request on new socket, receive reply
- * from kernel to old socket but with same PID and sequence number. (This race
- * could be avoided other ways, e.g. by preventing PIDs from being quickly
- * reused). */
-static uint32_t next_seq;
-
-static int alloc_pid(uint32_t *);
-static void free_pid(uint32_t);
-
-/* 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.
- */
-int
-nl_sock_create(int protocol, int multicast_group,
- size_t so_sndbuf, size_t so_rcvbuf, struct nl_sock **sockp)
-{
- struct nl_sock *sock;
- struct sockaddr_nl local, remote;
- int retval = 0;
-
- if (next_seq == 0) {
- /* Pick initial sequence number. */
- next_seq = getpid() ^ time_wall();
- }
-
- *sockp = NULL;
- sock = malloc(sizeof *sock);
- if (sock == NULL) {
- return ENOMEM;
- }
-
- sock->fd = socket(AF_NETLINK, SOCK_RAW, protocol);
- if (sock->fd < 0) {
- VLOG_ERR("fcntl: %s", strerror(errno));
- goto error;
- }
-
- 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;
- }
-
- /* Bind remote address as the kernel (pid 0). */
- 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;
- }
-
- /* 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;
-
-error_free_pid:
- free_pid(sock->pid);
-error:
- if (retval == 0) {
- retval = errno;
- if (retval == 0) {
- retval = EINVAL;
- }
- }
- if (sock->fd >= 0) {
- close(sock->fd);
- }
- free(sock);
- return retval;
-}
-
-/* Destroys netlink socket 'sock'. */
-void
-nl_sock_destroy(struct nl_sock *sock)
-{
- if (sock) {
- 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.
- *
- * 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)
-{
- struct nlmsghdr *nlmsg = nl_msg_nlmsghdr(msg);
- int error;
-
- nlmsg->nlmsg_len = msg->size;
- nlmsg->nlmsg_pid = sock->pid;
- do {
- int retval;
- 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);
- if (!error) {
- COVERAGE_INC(netlink_sent);
- }
- return error;
-}
-
-/* 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.)
- *
- * 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_sendv(struct nl_sock *sock, const struct iovec iov[], size_t n_iov,
- bool wait)
-{
- struct msghdr msg;
- int error;
-
- COVERAGE_INC(netlink_send);
- memset(&msg, 0, sizeof msg);
- msg.msg_iov = (struct iovec *) iov;
- msg.msg_iovlen = n_iov;
- do {
- int retval;
- retval = sendmsg(sock->fd, &msg, wait ? 0 : MSG_DONTWAIT);
- error = retval < 0 ? errno : 0;
- } while (error == EINTR);
- if (error != EAGAIN) {
- log_nlmsg(__func__, error, iov[0].iov_base, iov[0].iov_len);
- if (!error) {
- COVERAGE_INC(netlink_sent);
- }
- }
- return error;
-}
-
-/* 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)
-{
- uint8_t tmp;
- ssize_t bufsize = 2048;
- ssize_t nbytes, nbytes2;
- struct ofpbuf *buf;
- struct nlmsghdr *nlmsghdr;
- struct iovec iov;
- struct msghdr msg = {
- .msg_name = NULL,
- .msg_namelen = 0,
- .msg_iov = &iov,
- .msg_iovlen = 1,
- .msg_control = NULL,
- .msg_controllen = 0,
- .msg_flags = 0
- };
-
- buf = ofpbuf_new(bufsize);
- *bufp = NULL;
-
-try_again:
- /* Attempt to read the message. We don't know the size of the data
- * yet, so we take a guess at 2048. If we're wrong, we keep trying
- * and doubling the buffer size each time.
- */
- nlmsghdr = ofpbuf_put_uninit(buf, bufsize);
- iov.iov_base = nlmsghdr;
- iov.iov_len = bufsize;
- do {
- nbytes = recvmsg(sock->fd, &msg, (wait ? 0 : MSG_DONTWAIT) | MSG_PEEK);
- } while (nbytes < 0 && errno == EINTR);
- if (nbytes < 0) {
- ofpbuf_delete(buf);
- return errno;
- }
- if (msg.msg_flags & MSG_TRUNC) {
- COVERAGE_INC(netlink_recv_retry);
- bufsize *= 2;
- ofpbuf_reinit(buf, bufsize);
- goto try_again;
- }
- buf->size = nbytes;
-
- /* We successfully read the message, so recv again to clear the queue */
- iov.iov_base = &tmp;
- iov.iov_len = 1;
- do {
- nbytes2 = recvmsg(sock->fd, &msg, MSG_DONTWAIT);
- } while (nbytes2 < 0 && errno == EINTR);
- if (nbytes2 < 0) {
- if (errno == ENOBUFS) {
- /* The kernel is notifying us that a message it tried to send to us
- * was dropped. We have to pass this along to the caller in case
- * it wants to retry a request. So kill the buffer, which we can
- * re-read next time. */
- COVERAGE_INC(netlink_overflow);
- ofpbuf_delete(buf);
- return ENOBUFS;
- } else {
- VLOG_ERR_RL(&rl, "failed to remove nlmsg from socket: %s\n",
- strerror(errno));
- }
- }
- if (nbytes < sizeof *nlmsghdr
- || nlmsghdr->nlmsg_len < sizeof *nlmsghdr
- || nlmsghdr->nlmsg_len > nbytes) {
- VLOG_ERR_RL(&rl, "received invalid nlmsg (%zd bytes < %d)",
- bufsize, NLMSG_HDRLEN);
- ofpbuf_delete(buf);
- return EPROTO;
- }
- *bufp = buf;
- log_nlmsg(__func__, 0, buf->data, buf->size);
- COVERAGE_INC(netlink_received);
- return 0;
-}
-
-/* Sends 'request' to the kernel via 'sock' and waits for a response. If
- * successful, returns 0. On failure, returns a positive errno value.
- *
- * If 'replyp' is nonnull, then on success '*replyp' is set to the kernel's
- * reply, which the caller is responsible for freeing with ofpbuf_delete(), and
- * 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.
- *
- * The caller is responsible for destroying 'request'.
- *
- * Bare Netlink is an unreliable transport protocol. This function layers
- * reliable delivery and reply semantics on top of bare Netlink.
- *
- * In Netlink, sending a request to the kernel is reliable enough, because the
- * kernel will tell us if the message cannot be queued (and we will in that
- * case put it on the transmit queue and wait until it can be delivered).
- *
- * Receiving the reply is the real problem: if the socket buffer is full when
- * the kernel tries to send the reply, the reply will be dropped. However, the
- * kernel sets a flag that a reply has been dropped. The next call to recv
- * then returns ENOBUFS. We can then re-send the request.
- *
- * Caveats:
- *
- * 1. Netlink depends on sequence numbers to match up requests and
- * replies. The sender of a request supplies a sequence number, and
- * the reply echos back that sequence number.
- *
- * This is fine, but (1) some kernel netlink implementations are
- * broken, in that they fail to echo sequence numbers and (2) this
- * function will drop packets with non-matching sequence numbers, so
- * that only a single request can be usefully transacted at a time.
- *
- * 2. Resending the request causes it to be re-executed, so the request
- * needs to be idempotent.
- */
-int
-nl_sock_transact(struct nl_sock *sock,
- const struct ofpbuf *request, struct ofpbuf **replyp)
-{
- uint32_t seq = nl_msg_nlmsghdr(request)->nlmsg_seq;
- struct nlmsghdr *nlmsghdr;
- struct ofpbuf *reply;
- int retval;
-
- if (replyp) {
- *replyp = NULL;
- }
-
- /* Ensure that we get a reply even if this message doesn't ordinarily call
- * for one. */
- nl_msg_nlmsghdr(request)->nlmsg_flags |= NLM_F_ACK;
-
-send:
- retval = nl_sock_send(sock, request, true);
- if (retval) {
- return retval;
- }
-
-recv:
- retval = nl_sock_recv(sock, &reply, true);
- if (retval) {
- if (retval == ENOBUFS) {
- COVERAGE_INC(netlink_overflow);
- VLOG_DBG_RL(&rl, "receive buffer overflow, resending request");
- goto send;
- } else {
- return retval;
- }
- }
- nlmsghdr = nl_msg_nlmsghdr(reply);
- if (seq != nlmsghdr->nlmsg_seq) {
- VLOG_DBG_RL(&rl, "ignoring seq %"PRIu32" != expected %"PRIu32,
- nl_msg_nlmsghdr(reply)->nlmsg_seq, seq);
- ofpbuf_delete(reply);
- goto recv;
- }
-
- /* If the reply is an error, discard the reply and return the error code.
- *
- * Except: if the reply is just an acknowledgement (error code of 0), and
- * the caller is interested in the reply (replyp != NULL), pass the reply
- * up to the caller. Otherwise the caller will get a return value of 0
- * and null '*replyp', which makes unwary callers likely to segfault. */
- if (nl_msg_nlmsgerr(reply, &retval) && (retval || !replyp)) {
- ofpbuf_delete(reply);
- if (retval) {
- VLOG_DBG_RL(&rl, "received NAK error=%d (%s)",
- retval, strerror(retval));
- }
- return retval != EAGAIN ? retval : EPROTO;
- }
-
- if (replyp) {
- *replyp = reply;
- } else {
- ofpbuf_delete(reply);
- }
- 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.
- *
- * 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.
- *
- * - 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.
- *
- * 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()).
- */
-void
-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->sock = sock;
- dump->status = nl_sock_send(sock, request, true);
- dump->buffer = NULL;
-}
-
-/* Helper function for nl_dump_next(). */
-static int
-nl_dump_recv(struct nl_dump *dump, struct ofpbuf **bufferp)
-{
- struct nlmsghdr *nlmsghdr;
- struct ofpbuf *buffer;
- int retval;
-
- retval = nl_sock_recv(dump->sock, bufferp, true);
- if (retval) {
- return retval == EINTR ? EAGAIN : retval;
- }
- buffer = *bufferp;
-
- nlmsghdr = nl_msg_nlmsghdr(buffer);
- if (dump->seq != nlmsghdr->nlmsg_seq) {
- VLOG_DBG_RL(&rl, "ignoring seq %"PRIu32" != expected %"PRIu32,
- nlmsghdr->nlmsg_seq, dump->seq);
- return EAGAIN;
- }
-
- if (nl_msg_nlmsgerr(buffer, &retval)) {
- VLOG_INFO_RL(&rl, "netlink dump request error (%s)",
- strerror(retval));
- return retval && retval != EAGAIN ? retval : EPROTO;
- }
-
- return 0;
-}
-
-/* Attempts to retrieve another reply from 'dump', which must have been
- * initialized with nl_dump_start().
- *
- * 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).
- *
- * On failure, returns false and sets 'reply->data' to NULL and 'reply->size'
- * 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().
- */
-bool
-nl_dump_next(struct nl_dump *dump, struct ofpbuf *reply)
-{
- struct nlmsghdr *nlmsghdr;
-
- reply->data = NULL;
- reply->size = 0;
- if (dump->status) {
- 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);
- if (retval) {
- ofpbuf_delete(dump->buffer);
- dump->buffer = NULL;
- if (retval != EAGAIN) {
- dump->status = retval;
- return false;
- }
- }
- }
-
- nlmsghdr = nl_msg_next(dump->buffer, reply);
- if (!nlmsghdr) {
- VLOG_WARN_RL(&rl, "netlink dump reply contains message fragment");
- dump->status = EPROTO;
- return false;
- } else if (nlmsghdr->nlmsg_type == NLMSG_DONE) {
- dump->status = EOF;
- return false;
- }
-
- return true;
-}
-
-/* Completes Netlink dump operation 'dump', which must have been initialized
- * with nl_dump_start(). Returns 0 if the dump operation was error-free,
- * otherwise a positive errno value describing the problem. */
-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)) {
- assert(dump->status);
- }
- }
-
- ofpbuf_delete(dump->buffer);
- return dump->status == EOF ? 0 : dump->status;
-}
-
-/* Causes poll_block() to wake up when any of the specified 'events' (which is
- * a OR'd combination of POLLIN, POLLOUT, etc.) occur on 'sock'. */
-void
-nl_sock_wait(const struct nl_sock *sock, short int events)
-{
- poll_fd_wait(sock->fd, events);
-}
-\f
-/* Netlink messages. */
-
/* Returns the nlmsghdr at the head of 'msg'.
*
* 'msg' must be at least as large as a nlmsghdr. */
struct nlmsgerr *err = ofpbuf_at(msg, NLMSG_HDRLEN, sizeof *err);
int code = EPROTO;
if (!err) {
- VLOG_ERR_RL(&rl, "received invalid nlmsgerr (%zd bytes < %zd)",
- msg->size, NLMSG_HDRLEN + sizeof *err);
+ VLOG_ERR_RL(&rl, "received invalid nlmsgerr (%"PRIu32"d bytes < %"PRIuSIZE"d)",
+ ofpbuf_size(msg), NLMSG_HDRLEN + sizeof *err);
} else if (err->error <= 0 && err->error > INT_MIN) {
code = -err->error;
}
* is often NLM_F_REQUEST indicating that a request is being made, commonly
* or'd with NLM_F_ACK to request an acknowledgement.
*
- * Sets the new nlmsghdr's nlmsg_pid field to 0 for now. nl_sock_send() will
- * fill it in just before sending the message.
+ * Sets the new nlmsghdr's nlmsg_len, nlmsg_seq, and nlmsg_pid fields to 0 for
+ * now. Functions that send Netlink messages will fill these in just before
+ * sending the message.
*
* nl_msg_put_genlmsghdr() is more convenient for composing a Generic Netlink
* message. */
{
struct nlmsghdr *nlmsghdr;
- assert(msg->size == 0);
+ ovs_assert(ofpbuf_size(msg) == 0);
nl_msg_reserve(msg, NLMSG_HDRLEN + expected_payload);
nlmsghdr = nl_msg_put_uninit(msg, NLMSG_HDRLEN);
nlmsghdr->nlmsg_len = 0;
nlmsghdr->nlmsg_type = type;
nlmsghdr->nlmsg_flags = flags;
- nlmsghdr->nlmsg_seq = ++next_seq;
+ nlmsghdr->nlmsg_seq = 0;
nlmsghdr->nlmsg_pid = 0;
}
struct genlmsghdr *genlmsghdr;
nl_msg_put_nlmsghdr(msg, GENL_HDRLEN + expected_payload, family, flags);
- assert(msg->size == NLMSG_HDRLEN);
+ ovs_assert(ofpbuf_size(msg) == NLMSG_HDRLEN);
genlmsghdr = nl_msg_put_uninit(msg, GENL_HDRLEN);
genlmsghdr->cmd = cmd;
genlmsghdr->version = version;
void *
nl_msg_put_uninit(struct ofpbuf *msg, size_t size)
{
- size_t pad = NLMSG_ALIGN(size) - size;
+ size_t pad = PAD_SIZE(size, NLMSG_ALIGNTO);
char *p = ofpbuf_put_uninit(msg, size + pad);
if (pad) {
memset(p + size, 0, pad);
return p;
}
+/* Prepends the 'size' bytes of data in 'p', plus Netlink padding if needed, to
+ * the head end of 'msg'. Data in 'msg' is reallocated and copied if
+ * necessary. */
+void
+nl_msg_push(struct ofpbuf *msg, const void *data, size_t size)
+{
+ memcpy(nl_msg_push_uninit(msg, size), data, size);
+}
+
+/* Prepends 'size' bytes of data, plus Netlink padding if needed, to the head
+ * end of 'msg', reallocating and copying its data if necessary. Returns a
+ * pointer to the first byte of the new data, which is left uninitialized. */
+void *
+nl_msg_push_uninit(struct ofpbuf *msg, size_t size)
+{
+ size_t pad = PAD_SIZE(size, NLMSG_ALIGNTO);
+ char *p = ofpbuf_push_uninit(msg, size + pad);
+ if (pad) {
+ memset(p + size, 0, pad);
+ }
+ return p;
+}
+
/* Appends a Netlink attribute of the given 'type' and room for 'size' bytes of
* data as its payload, plus Netlink padding if needed, to the tail end of
* 'msg', reallocating and copying its data if necessary. Returns a pointer to
{
size_t total_size = NLA_HDRLEN + size;
struct nlattr* nla = nl_msg_put_uninit(msg, total_size);
- assert(NLA_ALIGN(total_size) <= UINT16_MAX);
+ ovs_assert(NLA_ALIGN(total_size) <= UINT16_MAX);
nla->nla_len = total_size;
nla->nla_type = type;
return nla + 1;
}
+/* Appends a Netlink attribute of the given 'type' and room for 'size' bytes of
+ * data as its payload, plus Netlink padding if needed, to the tail end of
+ * 'msg', reallocating and copying its data if necessary. Returns a pointer to
+ * the first byte of data in the attribute, which is zeroed. */
+void *
+nl_msg_put_unspec_zero(struct ofpbuf *msg, uint16_t type, size_t size)
+{
+ void *data = nl_msg_put_unspec_uninit(msg, type, size);
+ memset(data, 0, size);
+ return data;
+}
+
/* Appends a Netlink attribute of the given 'type' and the 'size' bytes of
* 'data' as its payload, to the tail end of 'msg', reallocating and copying
* its data if necessary. Returns a pointer to the first byte of data in the
nl_msg_put_unspec(msg, type, &value, sizeof value);
}
-/* Appends a Netlink attribute of the given 'type' and the given 16-bit 'value'
- * to 'msg'. */
+/* Appends a Netlink attribute of the given 'type' and the given 16-bit host
+ * byte order 'value' to 'msg'. */
void
nl_msg_put_u16(struct ofpbuf *msg, uint16_t type, uint16_t value)
{
nl_msg_put_unspec(msg, type, &value, sizeof value);
}
-/* Appends a Netlink attribute of the given 'type' and the given 32-bit 'value'
- * to 'msg'. */
+/* Appends a Netlink attribute of the given 'type' and the given 32-bit host
+ * byte order 'value' to 'msg'. */
void
nl_msg_put_u32(struct ofpbuf *msg, uint16_t type, uint32_t value)
{
nl_msg_put_unspec(msg, type, &value, sizeof value);
}
-/* Appends a Netlink attribute of the given 'type' and the given 64-bit 'value'
- * to 'msg'. */
+/* Appends a Netlink attribute of the given 'type' and the given 64-bit host
+ * byte order 'value' to 'msg'. */
void
nl_msg_put_u64(struct ofpbuf *msg, uint16_t type, uint64_t value)
{
nl_msg_put_unspec(msg, type, &value, sizeof value);
}
+/* Appends a Netlink attribute of the given 'type' and the given 16-bit network
+ * byte order 'value' to 'msg'. */
+void
+nl_msg_put_be16(struct ofpbuf *msg, uint16_t type, ovs_be16 value)
+{
+ nl_msg_put_unspec(msg, type, &value, sizeof value);
+}
+
+/* Appends a Netlink attribute of the given 'type' and the given 32-bit network
+ * byte order 'value' to 'msg'. */
+void
+nl_msg_put_be32(struct ofpbuf *msg, uint16_t type, ovs_be32 value)
+{
+ nl_msg_put_unspec(msg, type, &value, sizeof value);
+}
+
+/* Appends a Netlink attribute of the given 'type' and the given 64-bit network
+ * byte order 'value' to 'msg'. */
+void
+nl_msg_put_be64(struct ofpbuf *msg, uint16_t type, ovs_be64 value)
+{
+ nl_msg_put_unspec(msg, type, &value, sizeof value);
+}
+
+/* Appends a Netlink attribute of the given 'type' and the given odp_port_t
+ * 'value' to 'msg'. */
+void
+nl_msg_put_odp_port(struct ofpbuf *msg, uint16_t type, odp_port_t value)
+{
+ nl_msg_put_u32(msg, type, odp_to_u32(value));
+}
+
+
/* Appends a Netlink attribute of the given 'type' and the given
* null-terminated string 'value' to 'msg'. */
void
nl_msg_put_unspec(msg, type, value, strlen(value) + 1);
}
+/* Prepends a Netlink attribute of the given 'type' and room for 'size' bytes
+ * of data as its payload, plus Netlink padding if needed, to the head end of
+ * 'msg', reallocating and copying its data if necessary. Returns a pointer to
+ * the first byte of data in the attribute, which is left uninitialized. */
+void *
+nl_msg_push_unspec_uninit(struct ofpbuf *msg, uint16_t type, size_t size)
+{
+ size_t total_size = NLA_HDRLEN + size;
+ struct nlattr* nla = nl_msg_push_uninit(msg, total_size);
+ ovs_assert(!nl_attr_oversized(size));
+ nla->nla_len = total_size;
+ nla->nla_type = type;
+ return nla + 1;
+}
+
+/* Prepends a Netlink attribute of the given 'type' and the 'size' bytes of
+ * 'data' as its payload, to the head end of 'msg', reallocating and copying
+ * its data if necessary. Returns a pointer to the first byte of data in the
+ * attribute, which is left uninitialized. */
+void
+nl_msg_push_unspec(struct ofpbuf *msg, uint16_t type,
+ const void *data, size_t size)
+{
+ memcpy(nl_msg_push_unspec_uninit(msg, type, size), data, size);
+}
+
+/* Prepends a Netlink attribute of the given 'type' and no payload to 'msg'.
+ * (Some Netlink protocols use the presence or absence of an attribute as a
+ * Boolean flag.) */
+void
+nl_msg_push_flag(struct ofpbuf *msg, uint16_t type)
+{
+ nl_msg_push_unspec(msg, type, NULL, 0);
+}
+
+/* Prepends a Netlink attribute of the given 'type' and the given 8-bit 'value'
+ * to 'msg'. */
+void
+nl_msg_push_u8(struct ofpbuf *msg, uint16_t type, uint8_t value)
+{
+ nl_msg_push_unspec(msg, type, &value, sizeof value);
+}
+
+/* Prepends a Netlink attribute of the given 'type' and the given 16-bit host
+ * byte order 'value' to 'msg'. */
+void
+nl_msg_push_u16(struct ofpbuf *msg, uint16_t type, uint16_t value)
+{
+ nl_msg_push_unspec(msg, type, &value, sizeof value);
+}
+
+/* Prepends a Netlink attribute of the given 'type' and the given 32-bit host
+ * byte order 'value' to 'msg'. */
+void
+nl_msg_push_u32(struct ofpbuf *msg, uint16_t type, uint32_t value)
+{
+ nl_msg_push_unspec(msg, type, &value, sizeof value);
+}
+
+/* Prepends a Netlink attribute of the given 'type' and the given 64-bit host
+ * byte order 'value' to 'msg'. */
+void
+nl_msg_push_u64(struct ofpbuf *msg, uint16_t type, uint64_t value)
+{
+ nl_msg_push_unspec(msg, type, &value, sizeof value);
+}
+
+/* Prepends a Netlink attribute of the given 'type' and the given 16-bit
+ * network byte order 'value' to 'msg'. */
+void
+nl_msg_push_be16(struct ofpbuf *msg, uint16_t type, ovs_be16 value)
+{
+ nl_msg_push_unspec(msg, type, &value, sizeof value);
+}
+
+/* Prepends a Netlink attribute of the given 'type' and the given 32-bit
+ * network byte order 'value' to 'msg'. */
+void
+nl_msg_push_be32(struct ofpbuf *msg, uint16_t type, ovs_be32 value)
+{
+ nl_msg_push_unspec(msg, type, &value, sizeof value);
+}
+
+/* Prepends a Netlink attribute of the given 'type' and the given 64-bit
+ * network byte order 'value' to 'msg'. */
+void
+nl_msg_push_be64(struct ofpbuf *msg, uint16_t type, ovs_be64 value)
+{
+ nl_msg_push_unspec(msg, type, &value, sizeof value);
+}
+
+/* Prepends a Netlink attribute of the given 'type' and the given
+ * null-terminated string 'value' to 'msg'. */
+void
+nl_msg_push_string(struct ofpbuf *msg, uint16_t type, const char *value)
+{
+ nl_msg_push_unspec(msg, type, value, strlen(value) + 1);
+}
+
/* Adds the header for nested Netlink attributes to 'msg', with the specified
* 'type', and returns the header's offset within 'msg'. The caller should add
* the content for the nested Netlink attribute to 'msg' (e.g. using the other
size_t
nl_msg_start_nested(struct ofpbuf *msg, uint16_t type)
{
- size_t offset = msg->size;
+ size_t offset = ofpbuf_size(msg);
nl_msg_put_unspec(msg, type, NULL, 0);
return offset;
}
nl_msg_end_nested(struct ofpbuf *msg, size_t offset)
{
struct nlattr *attr = ofpbuf_at_assert(msg, offset, sizeof *attr);
- attr->nla_len = msg->size - offset;
+ attr->nla_len = ofpbuf_size(msg) - offset;
}
/* Appends a nested Netlink attribute of the given 'type', with the 'size'
/* If 'buffer' begins with a valid "struct nlmsghdr", pulls the header and its
* payload off 'buffer', stores header and payload in 'msg->data' and
- * 'msg->size', and returns a pointer to the header.
+ * 'ofpbuf_size(msg)', and returns a pointer to the header.
*
* If 'buffer' does not begin with a "struct nlmsghdr" or begins with one that
* is invalid, returns NULL without modifying 'buffer'. */
struct nlmsghdr *
nl_msg_next(struct ofpbuf *buffer, struct ofpbuf *msg)
{
- if (buffer->size >= sizeof(struct nlmsghdr)) {
+ if (ofpbuf_size(buffer) >= sizeof(struct nlmsghdr)) {
struct nlmsghdr *nlmsghdr = nl_msg_nlmsghdr(buffer);
size_t len = nlmsghdr->nlmsg_len;
- if (len >= sizeof *nlmsghdr && len <= buffer->size) {
- msg->data = nlmsghdr;
- msg->size = len;
+ if (len >= sizeof *nlmsghdr && len <= ofpbuf_size(buffer)) {
+ ofpbuf_use_const(msg, nlmsghdr, len);
ofpbuf_pull(buffer, len);
return nlmsghdr;
}
}
- msg->data = NULL;
- msg->size = 0;
+ ofpbuf_set_data(msg, NULL);
+ ofpbuf_set_size(msg, 0);
return NULL;
}
+
+/* Returns true if a Netlink attribute with a payload that is 'payload_size'
+ * bytes long would be oversized, that is, if it's not possible to create an
+ * nlattr of that size because its size wouldn't fit in the 16-bit nla_len
+ * field. */
+bool
+nl_attr_oversized(size_t payload_size)
+{
+ return NL_ATTR_SIZE(payload_size) > UINT16_MAX;
+}
\f
/* Attributes. */
+/* Returns the bits of 'nla->nla_type' that are significant for determining its
+ * type. */
+int
+nl_attr_type(const struct nlattr *nla)
+{
+ return nla->nla_type & NLA_TYPE_MASK;
+}
+
/* Returns the first byte in the payload of attribute 'nla'. */
const void *
nl_attr_get(const struct nlattr *nla)
{
- assert(nla->nla_len >= NLA_HDRLEN);
+ ovs_assert(nla->nla_len >= NLA_HDRLEN);
return nla + 1;
}
size_t
nl_attr_get_size(const struct nlattr *nla)
{
- assert(nla->nla_len >= NLA_HDRLEN);
+ ovs_assert(nla->nla_len >= NLA_HDRLEN);
return nla->nla_len - NLA_HDRLEN;
}
const void *
nl_attr_get_unspec(const struct nlattr *nla, size_t size)
{
- assert(nla->nla_len >= NLA_HDRLEN + size);
+ ovs_assert(nla->nla_len >= NLA_HDRLEN + size);
return nla + 1;
}
return NL_ATTR_GET_AS(nla, uint8_t);
}
-/* Returns the 16-bit value in 'nla''s payload.
+/* Returns the 16-bit host byte order value in 'nla''s payload.
*
* Asserts that 'nla''s payload is at least 2 bytes long. */
uint16_t
return NL_ATTR_GET_AS(nla, uint16_t);
}
-/* Returns the 32-bit value in 'nla''s payload.
+/* Returns the 32-bit host byte order value in 'nla''s payload.
*
* Asserts that 'nla''s payload is at least 4 bytes long. */
uint32_t
return NL_ATTR_GET_AS(nla, uint32_t);
}
-/* Returns the 64-bit value in 'nla''s payload.
+/* Returns the 64-bit host byte order value in 'nla''s payload.
*
* Asserts that 'nla''s payload is at least 8 bytes long. */
uint64_t
nl_attr_get_u64(const struct nlattr *nla)
{
- return NL_ATTR_GET_AS(nla, uint64_t);
+ const ovs_32aligned_u64 *x = nl_attr_get_unspec(nla, sizeof *x);
+ return get_32aligned_u64(x);
+}
+
+/* Returns the 16-bit network byte order value in 'nla''s payload.
+ *
+ * Asserts that 'nla''s payload is at least 2 bytes long. */
+ovs_be16
+nl_attr_get_be16(const struct nlattr *nla)
+{
+ return NL_ATTR_GET_AS(nla, ovs_be16);
+}
+
+/* Returns the 32-bit network byte order value in 'nla''s payload.
+ *
+ * Asserts that 'nla''s payload is at least 4 bytes long. */
+ovs_be32
+nl_attr_get_be32(const struct nlattr *nla)
+{
+ return NL_ATTR_GET_AS(nla, ovs_be32);
+}
+
+/* Returns the 64-bit network byte order value in 'nla''s payload.
+ *
+ * Asserts that 'nla''s payload is at least 8 bytes long. */
+ovs_be64
+nl_attr_get_be64(const struct nlattr *nla)
+{
+ const ovs_32aligned_be64 *x = nl_attr_get_unspec(nla, sizeof *x);
+ return get_32aligned_be64(x);
+}
+
+/* Returns the 32-bit odp_port_t value in 'nla''s payload.
+ *
+ * Asserts that 'nla''s payload is at least 4 bytes long. */
+odp_port_t
+nl_attr_get_odp_port(const struct nlattr *nla)
+{
+ return u32_to_odp(nl_attr_get_u32(nla));
}
/* Returns the null-terminated string value in 'nla''s payload.
const char *
nl_attr_get_string(const struct nlattr *nla)
{
- assert(nla->nla_len > NLA_HDRLEN);
- assert(memchr(nl_attr_get(nla), '\0', nla->nla_len - NLA_HDRLEN) != NULL);
+ ovs_assert(nla->nla_len > NLA_HDRLEN);
+ ovs_assert(memchr(nl_attr_get(nla), '\0', nla->nla_len - NLA_HDRLEN));
return nl_attr_get(nla);
}
-/* Initializes 'nested' to the payload of 'nla'. Doesn't initialize every
- * field in 'nested', but enough to poke around with it in a read-only way. */
+/* Initializes 'nested' to the payload of 'nla'. */
void
nl_attr_get_nested(const struct nlattr *nla, struct ofpbuf *nested)
{
- nested->data = (void *) nl_attr_get(nla);
- nested->size = nl_attr_get_size(nla);
+ ofpbuf_use_const(nested, nl_attr_get(nla), nl_attr_get_size(nla));
+}
+
+/* Default minimum payload size for each type of attribute. */
+static size_t
+min_attr_len(enum nl_attr_type type)
+{
+ switch (type) {
+ case NL_A_NO_ATTR: return 0;
+ case NL_A_UNSPEC: return 0;
+ case NL_A_U8: return 1;
+ case NL_A_U16: return 2;
+ case NL_A_U32: return 4;
+ case NL_A_U64: return 8;
+ case NL_A_STRING: return 1;
+ case NL_A_FLAG: return 0;
+ case NL_A_NESTED: return 0;
+ case N_NL_ATTR_TYPES: default: OVS_NOT_REACHED();
+ }
+}
+
+/* Default maximum payload size for each type of attribute. */
+static size_t
+max_attr_len(enum nl_attr_type type)
+{
+ switch (type) {
+ case NL_A_NO_ATTR: return SIZE_MAX;
+ case NL_A_UNSPEC: return SIZE_MAX;
+ case NL_A_U8: return 1;
+ case NL_A_U16: return 2;
+ case NL_A_U32: return 4;
+ case NL_A_U64: return 8;
+ case NL_A_STRING: return SIZE_MAX;
+ case NL_A_FLAG: return SIZE_MAX;
+ case NL_A_NESTED: return SIZE_MAX;
+ case N_NL_ATTR_TYPES: default: OVS_NOT_REACHED();
+ }
}
-/* Default minimum and maximum payload sizes for each type of attribute. */
-static const size_t attr_len_range[][2] = {
- [0 ... N_NL_ATTR_TYPES - 1] = { 0, SIZE_MAX },
- [NL_A_U8] = { 1, 1 },
- [NL_A_U16] = { 2, 2 },
- [NL_A_U32] = { 4, 4 },
- [NL_A_U64] = { 8, 8 },
- [NL_A_STRING] = { 1, SIZE_MAX },
- [NL_A_FLAG] = { 0, SIZE_MAX },
- [NL_A_NESTED] = { 0, SIZE_MAX },
-};
+bool
+nl_attr_validate(const struct nlattr *nla, const struct nl_policy *policy)
+{
+ uint16_t type = nl_attr_type(nla);
+ size_t min_len;
+ size_t max_len;
+ size_t len;
+
+ if (policy->type == NL_A_NO_ATTR) {
+ return true;
+ }
+
+ /* Figure out min and max length. */
+ min_len = policy->min_len;
+ if (!min_len) {
+ min_len = min_attr_len(policy->type);
+ }
+ max_len = policy->max_len;
+ if (!max_len) {
+ max_len = max_attr_len(policy->type);
+ }
+
+ /* Verify length. */
+ len = nl_attr_get_size(nla);
+ if (len < min_len || len > max_len) {
+ VLOG_DBG_RL(&rl, "attr %"PRIu16" length %"PRIuSIZE" not in "
+ "allowed range %"PRIuSIZE"...%"PRIuSIZE, type, len, min_len, max_len);
+ return false;
+ }
+
+ /* Strings must be null terminated and must not have embedded nulls. */
+ if (policy->type == NL_A_STRING) {
+ if (((char *) nla)[nla->nla_len - 1]) {
+ VLOG_DBG_RL(&rl, "attr %"PRIu16" lacks null at end", type);
+ return false;
+ }
+ if (memchr(nla + 1, '\0', len - 1) != NULL) {
+ VLOG_DBG_RL(&rl, "attr %"PRIu16" has bad length", type);
+ return false;
+ }
+ }
+
+ return true;
+}
/* Parses the 'msg' starting at the given 'nla_offset' as a sequence of Netlink
* attributes. 'policy[i]', for 0 <= i < n_attrs, specifies how the attribute
const struct nl_policy policy[],
struct nlattr *attrs[], size_t n_attrs)
{
- void *p, *tail;
- size_t n_required;
+ struct nlattr *nla;
+ size_t left;
size_t i;
- n_required = 0;
- for (i = 0; i < n_attrs; i++) {
- attrs[i] = NULL;
+ memset(attrs, 0, n_attrs * sizeof *attrs);
- assert(policy[i].type < N_NL_ATTR_TYPES);
- if (policy[i].type != NL_A_NO_ATTR
- && policy[i].type != NL_A_FLAG
- && !policy[i].optional) {
- n_required++;
- }
- }
-
- p = ofpbuf_at(msg, nla_offset, 0);
- if (p == NULL) {
+ if (ofpbuf_size(msg) < nla_offset) {
VLOG_DBG_RL(&rl, "missing headers in nl_policy_parse");
return false;
}
- tail = ofpbuf_tail(msg);
-
- while (p < tail) {
- size_t offset = (char*)p - (char*)msg->data;
- struct nlattr *nla = p;
- size_t len, aligned_len;
- uint16_t type;
-
- /* Make sure its claimed length is plausible. */
- if (nla->nla_len < NLA_HDRLEN) {
- VLOG_DBG_RL(&rl, "%zu: attr shorter than NLA_HDRLEN (%"PRIu16")",
- offset, nla->nla_len);
- return false;
- }
- len = nla->nla_len - NLA_HDRLEN;
- aligned_len = NLA_ALIGN(len);
- if (aligned_len > (char*)tail - (char*)p) {
- VLOG_DBG_RL(&rl, "%zu: attr %"PRIu16" aligned data len (%zu) "
- "> bytes left (%tu)",
- offset, nla->nla_type, aligned_len,
- (char*)tail - (char*)p);
- return false;
- }
- type = nla->nla_type;
+ NL_ATTR_FOR_EACH (nla, left, ofpbuf_at(msg, nla_offset, 0),
+ ofpbuf_size(msg) - nla_offset)
+ {
+ uint16_t type = nl_attr_type(nla);
if (type < n_attrs && policy[type].type != NL_A_NO_ATTR) {
const struct nl_policy *e = &policy[type];
- size_t min_len, max_len;
-
- /* Validate length and content. */
- min_len = e->min_len ? e->min_len : attr_len_range[e->type][0];
- max_len = e->max_len ? e->max_len : attr_len_range[e->type][1];
- if (len < min_len || len > max_len) {
- VLOG_DBG_RL(&rl, "%zu: attr %"PRIu16" length %zu not in "
- "allowed range %zu...%zu",
- offset, type, len, min_len, max_len);
+ if (!nl_attr_validate(nla, e)) {
return false;
}
- if (e->type == NL_A_STRING) {
- if (((char *) nla)[nla->nla_len - 1]) {
- VLOG_DBG_RL(&rl, "%zu: attr %"PRIu16" lacks null at end",
- offset, type);
- return false;
- }
- if (memchr(nla + 1, '\0', len - 1) != NULL) {
- VLOG_DBG_RL(&rl, "%zu: attr %"PRIu16" has bad length",
- offset, type);
- return false;
- }
- }
- if (!e->optional && attrs[type] == NULL) {
- assert(n_required > 0);
- --n_required;
+ if (attrs[type]) {
+ VLOG_DBG_RL(&rl, "duplicate attr %"PRIu16, type);
}
attrs[type] = nla;
- } else {
- /* Skip attribute type that we don't care about. */
}
- p = (char*)p + NLA_ALIGN(nla->nla_len);
}
- if (n_required) {
- VLOG_DBG_RL(&rl, "%zu required attrs missing", n_required);
+ if (left) {
+ VLOG_DBG_RL(&rl, "attributes followed by garbage");
return false;
}
+
+ for (i = 0; i < n_attrs; i++) {
+ const struct nl_policy *e = &policy[i];
+ if (!e->optional && e->type != NL_A_NO_ATTR && !attrs[i]) {
+ VLOG_DBG_RL(&rl, "required attr %"PRIuSIZE" missing", i);
+ return false;
+ }
+ }
return true;
}
nl_attr_get_nested(nla, &buf);
return nl_policy_parse(&buf, 0, policy, attrs, n_attrs);
}
-\f
-/* Miscellaneous. */
-
-static const struct nl_policy family_policy[CTRL_ATTR_MAX + 1] = {
- [CTRL_ATTR_FAMILY_ID] = {.type = NL_A_U16},
-};
-
-static int do_lookup_genl_family(const char *name)
-{
- struct nl_sock *sock;
- struct ofpbuf request, *reply;
- struct nlattr *attrs[ARRAY_SIZE(family_policy)];
- int retval;
-
- retval = nl_sock_create(NETLINK_GENERIC, 0, 0, 0, &sock);
- if (retval) {
- return -retval;
- }
-
- ofpbuf_init(&request, 0);
- nl_msg_put_genlmsghdr(&request, 0, GENL_ID_CTRL, NLM_F_REQUEST,
- CTRL_CMD_GETFAMILY, 1);
- nl_msg_put_string(&request, CTRL_ATTR_FAMILY_NAME, name);
- retval = nl_sock_transact(sock, &request, &reply);
- ofpbuf_uninit(&request);
- if (retval) {
- nl_sock_destroy(sock);
- return -retval;
- }
-
- if (!nl_policy_parse(reply, NLMSG_HDRLEN + GENL_HDRLEN,
- family_policy, attrs, ARRAY_SIZE(family_policy))) {
- nl_sock_destroy(sock);
- ofpbuf_delete(reply);
- return -EPROTO;
- }
-
- retval = nl_attr_get_u16(attrs[CTRL_ATTR_FAMILY_ID]);
- if (retval == 0) {
- retval = -EPROTO;
- }
- nl_sock_destroy(sock);
- ofpbuf_delete(reply);
- return retval;
-}
-
-/* If '*number' is 0, translates the given Generic Netlink family 'name' to a
- * number and stores it in '*number'. If successful, returns 0 and the caller
- * may use '*number' as the family number. On failure, returns a positive
- * errno value and '*number' caches the errno value. */
-int
-nl_lookup_genl_family(const char *name, int *number)
-{
- if (*number == 0) {
- *number = do_lookup_genl_family(name);
- assert(*number != 0);
- }
- 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)
+const struct nlattr *
+nl_attr_find__(const struct nlattr *attrs, size_t size, uint16_t type)
{
- int i;
+ const struct nlattr *nla;
+ size_t left;
- 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;
+ NL_ATTR_FOR_EACH (nla, left, attrs, size) {
+ if (nl_attr_type(nla) == type) {
+ return nla;
}
}
- 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));
-}
-\f
-static void
-nlmsghdr_to_string(const struct nlmsghdr *h, struct ds *ds)
-{
- struct nlmsg_flag {
- unsigned int bits;
- const char *name;
- };
- static const struct nlmsg_flag flags[] = {
- { NLM_F_REQUEST, "REQUEST" },
- { NLM_F_MULTI, "MULTI" },
- { NLM_F_ACK, "ACK" },
- { NLM_F_ECHO, "ECHO" },
- { NLM_F_DUMP, "DUMP" },
- { NLM_F_ROOT, "ROOT" },
- { NLM_F_MATCH, "MATCH" },
- { NLM_F_ATOMIC, "ATOMIC" },
- };
- const struct nlmsg_flag *flag;
- uint16_t flags_left;
-
- ds_put_format(ds, "nl(len:%"PRIu32", type=%"PRIu16,
- h->nlmsg_len, h->nlmsg_type);
- if (h->nlmsg_type == NLMSG_NOOP) {
- ds_put_cstr(ds, "(no-op)");
- } else if (h->nlmsg_type == NLMSG_ERROR) {
- ds_put_cstr(ds, "(error)");
- } else if (h->nlmsg_type == NLMSG_DONE) {
- ds_put_cstr(ds, "(done)");
- } else if (h->nlmsg_type == NLMSG_OVERRUN) {
- ds_put_cstr(ds, "(overrun)");
- } else if (h->nlmsg_type < NLMSG_MIN_TYPE) {
- ds_put_cstr(ds, "(reserved)");
- } else {
- ds_put_cstr(ds, "(family-defined)");
- }
- ds_put_format(ds, ", flags=%"PRIx16, h->nlmsg_flags);
- flags_left = h->nlmsg_flags;
- for (flag = flags; flag < &flags[ARRAY_SIZE(flags)]; flag++) {
- if ((flags_left & flag->bits) == flag->bits) {
- ds_put_format(ds, "[%s]", flag->name);
- flags_left &= ~flag->bits;
- }
- }
- 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));
+ return NULL;
}
-static char *
-nlmsg_to_string(const struct ofpbuf *buffer)
+/* Returns the first Netlink attribute within 'buf' with the specified 'type',
+ * skipping a header of 'hdr_len' bytes at the beginning of 'buf'.
+ *
+ * This function does not validate the attribute's length. */
+const struct nlattr *
+nl_attr_find(const struct ofpbuf *buf, size_t hdr_len, uint16_t type)
{
- struct ds ds = DS_EMPTY_INITIALIZER;
- const struct nlmsghdr *h = ofpbuf_at(buffer, 0, NLMSG_HDRLEN);
- if (h) {
- nlmsghdr_to_string(h, &ds);
- if (h->nlmsg_type == NLMSG_ERROR) {
- const struct nlmsgerr *e;
- e = ofpbuf_at(buffer, NLMSG_HDRLEN,
- NLMSG_ALIGN(sizeof(struct nlmsgerr)));
- if (e) {
- ds_put_format(&ds, " error(%d", e->error);
- if (e->error < 0) {
- ds_put_format(&ds, "(%s)", strerror(-e->error));
- }
- ds_put_cstr(&ds, ", in-reply-to(");
- nlmsghdr_to_string(&e->msg, &ds);
- ds_put_cstr(&ds, "))");
- } else {
- ds_put_cstr(&ds, " error(truncated)");
- }
- } else if (h->nlmsg_type == NLMSG_DONE) {
- int *error = ofpbuf_at(buffer, NLMSG_HDRLEN, sizeof *error);
- if (error) {
- ds_put_format(&ds, " done(%d", *error);
- if (*error < 0) {
- ds_put_format(&ds, "(%s)", strerror(-*error));
- }
- ds_put_cstr(&ds, ")");
- } else {
- ds_put_cstr(&ds, " done(truncated)");
- }
- }
- } else {
- ds_put_cstr(&ds, "nl(truncated)");
- }
- return ds.string;
+ return nl_attr_find__(ofpbuf_at(buf, hdr_len, 0), ofpbuf_size(buf) - hdr_len,
+ type);
}
-static void
-log_nlmsg(const char *function, int error,
- const void *message, size_t size)
+/* Returns the first Netlink attribute within 'nla' with the specified
+ * 'type'.
+ *
+ * This function does not validate the attribute's length. */
+const struct nlattr *
+nl_attr_find_nested(const struct nlattr *nla, uint16_t type)
{
- struct ofpbuf buffer;
- char *nlmsg;
-
- if (!VLOG_IS_DBG_ENABLED()) {
- return;
- }
-
- buffer.data = (void *) message;
- buffer.size = size;
- nlmsg = nlmsg_to_string(&buffer);
- VLOG_DBG_RL(&rl, "%s (%s): %s", function, strerror(error), nlmsg);
- free(nlmsg);
+ return nl_attr_find__(nl_attr_get(nla), nl_attr_get_size(nla), type);
}
-
git://git.onelab.eu / sliver-openvswitch.git / blobdiff