netlink: Split into generic and Linux-specific parts.

The parts of the netlink module that are related to sockets are
Linux-specific, since only Linux has AF_NETLINK sockets.  The rest can be
built anywhere.  This commit breaks them into two modules, and builds the
generic one on all platforms.

Acked-by: Jesse Gross <jesse@nicira.com>

1 files changed, 78 insertions, 0 deletions

diff --git a/lib/netlink-socket.h b/lib/netlink-socket.h
new file mode 100644
index 00000000..dc21ce83
--- /dev/null
+++ b/lib/netlink-socket.h
@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2008, 2009, 2010 Nicira Networks.
+ *
+ * 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 NETLINK_SOCKET_H
+#define NETLINK_SOCKET_H 1
+
+/* Netlink socket definitions.
+ *
+ * Netlink is a datagram-based network protocol primarily for communication
+ * between user processes and the kernel, and mainly on Linux.  Netlink is
+ * specified in RFC 3549, "Linux Netlink as an IP Services Protocol".
+ *
+ * Netlink is not suitable for use in physical networks of heterogeneous
+ * machines because host byte order is used throughout.
+ *
+ * This header file defines functions for working with Netlink sockets, which
+ * are Linux-specific.  For Netlink protocol definitions, see
+ * netlink-protocol.h.  For helper functions for working with Netlink messages,
+ * see netlink.h.
+ */
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <sys/uio.h>
+
+struct ofpbuf;
+struct nl_sock;
+
+#ifndef HAVE_NETLINK
+#error "netlink-socket.h is only for hosts that support Netlink sockets"
+#endif
+
+/* Netlink sockets. */
+int nl_sock_create(int protocol, int multicast_group,
+                   size_t so_sndbuf, size_t so_rcvbuf,
+                   struct nl_sock **);
+void nl_sock_destroy(struct nl_sock *);
+
+int nl_sock_send(struct nl_sock *, const struct ofpbuf *, bool wait);
+int nl_sock_sendv(struct nl_sock *sock, const struct iovec iov[], size_t n_iov,
+                  bool wait);
+int nl_sock_recv(struct nl_sock *, struct ofpbuf **, bool wait);
+int nl_sock_transact(struct nl_sock *, const struct ofpbuf *request,
+                     struct ofpbuf **reply);
+
+void nl_sock_wait(const struct nl_sock *, short int events);
+
+/* Table dumping. */
+struct nl_dump {
+    struct nl_sock *sock;       /* Socket being dumped. */
+    uint32_t seq;               /* Expected nlmsg_seq for replies. */
+    struct ofpbuf *buffer;      /* Receive buffer currently being iterated. */
+    int status;                 /* 0=OK, EOF=done, or positive errno value. */
+};
+
+void nl_dump_start(struct nl_dump *, struct nl_sock *,
+                   const struct ofpbuf *request);
+bool nl_dump_next(struct nl_dump *, struct ofpbuf *reply);
+int nl_dump_done(struct nl_dump *);
+
+/* Miscellaneous */
+int nl_lookup_genl_family(const char *name, int *number);
+
+#endif /* netlink-socket.h */