[ovs-dev] [PATCH 1/8] netlink: provide network namespace id from a msg.
Flavio Leitner
fbl at redhat.com
Thu Nov 2 19:05:02 UTC 2017
The netlink notification's ancillary data contains the network
namespace id (netnsid) needed to identify the device correctly.
(ifindex and netnsid).
Signed-off-by: Flavio Leitner <fbl at redhat.com>
---
configure.ac | 3 +-
lib/automake.mk | 1 +
lib/dpif-netlink.c | 6 +--
lib/netdev-linux.c | 2 +-
lib/netlink-notifier.c | 2 +-
lib/netlink-socket.c | 37 ++++++++++++---
lib/netlink-socket.h | 4 +-
lib/netns.h | 119 +++++++++++++++++++++++++++++++++++++++++++++++++
utilities/nlmon.c | 2 +-
9 files changed, 162 insertions(+), 14 deletions(-)
create mode 100644 lib/netns.h
diff --git a/configure.ac b/configure.ac
index 27425991a..522704f9d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -113,7 +113,8 @@ AC_CHECK_MEMBERS([struct sockaddr_in6.sin6_scope_id], [], [],
[[#include <sys/socket.h>
#include <netinet/in.h>]])
AC_CHECK_FUNCS([mlockall strnlen getloadavg statvfs getmntent_r sendmmsg])
-AC_CHECK_HEADERS([mntent.h sys/statvfs.h linux/types.h linux/if_ether.h stdatomic.h])
+AC_CHECK_HEADERS([mntent.h sys/statvfs.h linux/types.h linux/if_ether.h ])
+AC_CHECK_HEADERS([linux/net_namespace.h stdatomic.h])
AC_CHECK_HEADERS([net/if_mib.h], [], [], [[#include <sys/types.h>
#include <net/if.h>]])
diff --git a/lib/automake.mk b/lib/automake.mk
index ca1cf5dd2..e354cd96f 100644
--- a/lib/automake.mk
+++ b/lib/automake.mk
@@ -140,6 +140,7 @@ lib_libopenvswitch_la_SOURCES = \
lib/netflow.h \
lib/netlink.c \
lib/netlink.h \
+ lib/netns.h \
lib/nx-match.c \
lib/nx-match.h \
lib/object-collection.c \
diff --git a/lib/dpif-netlink.c b/lib/dpif-netlink.c
index 29001fbe4..563eb5638 100644
--- a/lib/dpif-netlink.c
+++ b/lib/dpif-netlink.c
@@ -1287,7 +1287,7 @@ dpif_netlink_port_poll(const struct dpif *dpif_, char **devnamep)
int error;
ofpbuf_use_stub(&buf, buf_stub, sizeof buf_stub);
- error = nl_sock_recv(dpif->port_notifier, &buf, false);
+ error = nl_sock_recv(dpif->port_notifier, &buf, NULL, false);
if (!error) {
struct dpif_netlink_vport vport;
@@ -2621,7 +2621,7 @@ dpif_netlink_recv_windows(struct dpif_netlink *dpif, uint32_t handler_id,
return EAGAIN;
}
- error = nl_sock_recv(sock_pool[i].nl_sock, buf, false);
+ error = nl_sock_recv(sock_pool[i].nl_sock, buf, NULL, false);
if (error == ENOBUFS) {
/* ENOBUFS typically means that we've received so many
* packets that the buffer overflowed. Try again
@@ -2696,7 +2696,7 @@ dpif_netlink_recv__(struct dpif_netlink *dpif, uint32_t handler_id,
return EAGAIN;
}
- error = nl_sock_recv(ch->sock, buf, false);
+ error = nl_sock_recv(ch->sock, buf, NULL, false);
if (error == ENOBUFS) {
/* ENOBUFS typically means that we've received so many
* packets that the buffer overflowed. Try again
diff --git a/lib/netdev-linux.c b/lib/netdev-linux.c
index 2ff3e2bcc..0d03ca876 100644
--- a/lib/netdev-linux.c
+++ b/lib/netdev-linux.c
@@ -638,7 +638,7 @@ netdev_linux_run(const struct netdev_class *netdev_class OVS_UNUSED)
struct ofpbuf buf;
ofpbuf_use_stub(&buf, buf_stub, sizeof buf_stub);
- error = nl_sock_recv(sock, &buf, false);
+ error = nl_sock_recv(sock, &buf, NULL, false);
if (!error) {
struct rtnetlink_change change;
diff --git a/lib/netlink-notifier.c b/lib/netlink-notifier.c
index 3acded418..d33904658 100644
--- a/lib/netlink-notifier.c
+++ b/lib/netlink-notifier.c
@@ -187,7 +187,7 @@ nln_run(struct nln *nln)
int error;
ofpbuf_use_stub(&buf, buf_stub, sizeof buf_stub);
- error = nl_sock_recv(nln->notify_sock, &buf, false);
+ error = nl_sock_recv(nln->notify_sock, &buf, NULL, false);
if (!error) {
int group = nln->parse(&buf, nln->change);
diff --git a/lib/netlink-socket.c b/lib/netlink-socket.c
index ccfd55e92..08eb0c8ee 100644
--- a/lib/netlink-socket.c
+++ b/lib/netlink-socket.c
@@ -19,6 +19,7 @@
#include <errno.h>
#include <inttypes.h>
#include <stdlib.h>
+#include <sys/socket.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <unistd.h>
@@ -607,7 +608,8 @@ nl_sock_send_seq(struct nl_sock *sock, const struct ofpbuf *msg,
}
static int
-nl_sock_recv__(struct nl_sock *sock, struct ofpbuf *buf, bool wait)
+nl_sock_recv__(struct nl_sock *sock, struct ofpbuf *buf, struct netns *ns,
+ bool wait)
{
/* We can't accurately predict the size of the data to be received. The
* caller is supposed to have allocated enough space in 'buf' to handle the
@@ -618,6 +620,8 @@ nl_sock_recv__(struct nl_sock *sock, struct ofpbuf *buf, bool wait)
uint8_t tail[65536];
struct iovec iov[2];
struct msghdr msg;
+ uint8_t msgctrl[64];
+ struct cmsghdr *cmsg;
ssize_t retval;
int error;
@@ -632,6 +636,8 @@ nl_sock_recv__(struct nl_sock *sock, struct ofpbuf *buf, bool wait)
memset(&msg, 0, sizeof msg);
msg.msg_iov = iov;
msg.msg_iovlen = 2;
+ msg.msg_control = msgctrl;
+ msg.msg_controllen = sizeof msgctrl;
/* Receive a Netlink message from the kernel.
*
@@ -706,6 +712,23 @@ nl_sock_recv__(struct nl_sock *sock, struct ofpbuf *buf, bool wait)
}
#endif
+ if (ns) {
+ /* The network namespace id comes as ancillary data. For older
+ * kernels, this data is either not available or it might be -1,
+ * so it falls back to local network namespace (no id). Latest
+ * kernels return a valid ID only if available or nothing. */
+ netns_set_local(ns);
+ cmsg = CMSG_FIRSTHDR(&msg);
+ while (cmsg != NULL) {
+ if (cmsg->cmsg_level == SOL_NETLINK
+ && cmsg->cmsg_type == NETLINK_LISTEN_ALL_NSID) {
+ int *id = ALIGNED_CAST(int *, CMSG_DATA(cmsg));
+ netns_set_id(ns, *id);
+ }
+ cmsg = CMSG_NXTHDR(&msg, cmsg);
+ }
+ }
+
log_nlmsg(__func__, 0, buf->data, buf->size, sock->protocol);
COVERAGE_INC(netlink_received);
@@ -714,7 +737,8 @@ nl_sock_recv__(struct nl_sock *sock, struct ofpbuf *buf, bool wait)
/* Tries to receive a Netlink message from the kernel on 'sock' into 'buf'. If
* 'wait' is true, waits for a message to be ready. Otherwise, fails with
- * EAGAIN if the 'sock' receive buffer is empty.
+ * EAGAIN if the 'sock' receive buffer is empty. If 'ns' is provided, the
+ * network namespace information will be provided.
*
* The caller must have initialized 'buf' with an allocation of at least
* NLMSG_HDRLEN bytes. For best performance, the caller should allocate enough
@@ -730,9 +754,10 @@ nl_sock_recv__(struct nl_sock *sock, struct ofpbuf *buf, bool wait)
* Regardless of success or failure, this function resets 'buf''s headroom to
* 0. */
int
-nl_sock_recv(struct nl_sock *sock, struct ofpbuf *buf, bool wait)
+nl_sock_recv(struct nl_sock *sock, struct ofpbuf *buf, struct netns *ns,
+ bool wait)
{
- return nl_sock_recv__(sock, buf, wait);
+ return nl_sock_recv__(sock, buf, ns, wait);
}
static void
@@ -821,7 +846,7 @@ nl_sock_transact_multiple__(struct nl_sock *sock,
}
/* Receive a reply. */
- error = nl_sock_recv__(sock, buf_txn->reply, false);
+ error = nl_sock_recv__(sock, buf_txn->reply, NULL, false);
if (error) {
if (error == EAGAIN) {
nl_sock_record_errors__(transactions, n, 0);
@@ -1101,7 +1126,7 @@ nl_dump_refill(struct nl_dump *dump, struct ofpbuf *buffer)
int error;
while (!buffer->size) {
- error = nl_sock_recv__(dump->sock, buffer, false);
+ error = nl_sock_recv__(dump->sock, buffer, NULL, false);
if (error) {
/* The kernel never blocks providing the results of a dump, so
* error == EAGAIN means that we've read the whole thing, and
diff --git a/lib/netlink-socket.h b/lib/netlink-socket.h
index d3cc64288..348483fad 100644
--- a/lib/netlink-socket.h
+++ b/lib/netlink-socket.h
@@ -193,6 +193,7 @@
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
+#include "netns.h"
#include "openvswitch/ofpbuf.h"
#include "ovs-atomic.h"
#include "ovs-thread.h"
@@ -221,7 +222,8 @@ int nl_sock_unsubscribe_packets(struct nl_sock *sock);
int nl_sock_send(struct nl_sock *, const struct ofpbuf *, bool wait);
int nl_sock_send_seq(struct nl_sock *, const struct ofpbuf *,
uint32_t nlmsg_seq, bool wait);
-int nl_sock_recv(struct nl_sock *, struct ofpbuf *, bool wait);
+int nl_sock_recv(struct nl_sock *, struct ofpbuf *, struct netns *,
+ bool wait);
int nl_sock_drain(struct nl_sock *);
diff --git a/lib/netns.h b/lib/netns.h
new file mode 100644
index 000000000..2e8bd8b0c
--- /dev/null
+++ b/lib/netns.h
@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2017 Red Hat Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef NETNS_H
+#define NETNS_H 1
+
+#include <stdbool.h>
+
+#ifdef HAVE_LINUX_NET_NAMESPACE_H
+#include <linux/net_namespace.h>
+#define NETNS_NOT_ASSIGNED NETNSA_NSID_NOT_ASSIGNED
+#else
+#define NETNS_NOT_ASSIGNED -1
+#endif
+
+enum netns_state {
+ NETNS_INVALID, /* not initialized yet */
+ NETNS_LOCAL, /* local or not supported on older kernels */
+ NETNS_REMOTE /* on another network namespace with valid ID */
+};
+
+struct netns {
+ enum netns_state state;
+ int id;
+};
+
+/* Prototypes */
+static inline void netns_set_id(struct netns *ns, int id);
+static inline void netns_set_invalid(struct netns *ns);
+static inline bool netns_is_invalid(struct netns *ns);
+static inline void netns_set_local(struct netns *ns);
+static inline bool netns_is_local(struct netns *ns);
+static inline bool netns_is_remote(struct netns *ns);
+static inline bool netns_eq(const struct netns *a, const struct netns *b);
+static inline void netns_copy(struct netns *dst, const struct netns *src);
+
+/* Functions */
+static inline void
+netns_set_id(struct netns *ns, int id)
+{
+ if (!ns) {
+ return;
+ }
+
+ if (id == NETNS_NOT_ASSIGNED) {
+ ns->state = NETNS_LOCAL;
+ } else {
+ ns->state = NETNS_REMOTE;
+ ns->id = id;
+ }
+}
+
+static inline void
+netns_set_invalid(struct netns *ns)
+{
+ ns->state = NETNS_INVALID;
+}
+
+static inline bool
+netns_is_invalid(struct netns *ns)
+{
+ return ns->state == NETNS_INVALID;
+}
+
+static inline void
+netns_set_local(struct netns *ns)
+{
+ ns->state = NETNS_LOCAL;
+}
+
+static inline bool
+netns_is_local(struct netns *ns)
+{
+ return (ns->state == NETNS_LOCAL);
+}
+
+static inline bool
+netns_is_remote(struct netns *ns)
+{
+ return (ns->state == NETNS_REMOTE);
+}
+
+static inline void
+netns_copy(struct netns *dst, const struct netns *src)
+{
+ if (src->state == NETNS_LOCAL || src->state == NETNS_REMOTE) {
+ *dst = *src;
+ }
+}
+
+static inline bool
+netns_eq(const struct netns *a, const struct netns *b)
+{
+ if (a->state == NETNS_LOCAL && b->state == NETNS_LOCAL) {
+ return true;
+ }
+
+ if (a->state == NETNS_REMOTE && b->state == NETNS_REMOTE &&
+ a->id == b->id) {
+ return true;
+ }
+
+ return false;
+}
+
+#endif
diff --git a/utilities/nlmon.c b/utilities/nlmon.c
index 2e16222cb..08a117b58 100644
--- a/utilities/nlmon.c
+++ b/utilities/nlmon.c
@@ -59,7 +59,7 @@ main(int argc OVS_UNUSED, char *argv[])
ofpbuf_use_stub(&buf, buf_stub, sizeof buf_stub);
for (;;) {
- error = nl_sock_recv(sock, &buf, false);
+ error = nl_sock_recv(sock, &buf, NULL, false);
if (error == EAGAIN) {
/* Nothing to do. */
} else if (error == ENOBUFS) {
--
2.13.6
More information about the dev
mailing list