zebra: Adding a new dataplane using protobuf

Signed-off-by: Hongyu Li <[email protected]>

Makefile.am

@@ -181,6 +181,7 @@ include zebra/subdir.am
 include watchfrr/subdir.am
 include qpb/subdir.am
 include fpm/subdir.am
+include fpmpbserver/subdir.am
 include grpc/subdir.am
 include tools/subdir.am
 
@@ -272,6 +273,7 @@ EXTRA_DIST += \
 	doc/user/Makefile \
 	eigrpd/Makefile \
 	fpm/Makefile \
+	fpmpbserver/Makefile \
 	grpc/Makefile \
 	isisd/Makefile \
 	ldpd/Makefile \

doc/developer/fpm.rst

@@ -37,6 +37,7 @@ advantages over Netlink:
 
    * ``fpm``
    * ``dplane_fpm_nl``
+   * ``dplane_fpm_pb``
 
 fpm
 ^^^
@@ -55,6 +56,13 @@ netlink functions to translate route event snapshots into formatted binary
 data.
 
 
+dplane_fpm_pb
+^^^^^^^^^^^^^
+
+It has the same implementation as ``dplane_fpm_nl``, using ``zebra``'s data
+plane framework as a plugin. It supports transmitting data in protobuf format.
+
+
 Protocol Specification
 ----------------------
 

doc/user/zebra.rst

@@ -1124,13 +1124,13 @@ as well. We refer to the component that programs the forwarding plane
 
 The relevant zebra code kicks in when zebra is configured with the
 :option:`--enable-fpm` flag and started with the module (``-M fpm``
-or ``-M dplane_fpm_nl``).
+or ``-M dplane_fpm_nl`` or ``-M dplane_fpm_pb``).
 
 .. note::
 
    The ``fpm`` implementation attempts to connect to ``127.0.0.1`` port ``2620``
-   by default without configurations. The ``dplane_fpm_nl`` only attempts to
-   connect to a server if configured.
+   by default without configurations. The ``dplane_fpm_nl`` or ``dplane_fpm_pb`` 
+   only attempts to connect to a server if configured.
 
 Zebra periodically attempts to connect to the well-known FPM port (``2620``).
 Once the connection is up, zebra starts sending messages containing routes
@@ -1144,6 +1144,7 @@ with the module load-time option. The modules accept the following options:
 
 - ``fpm``: ``netlink`` and ``protobuf``.
 - ``dplane_fpm_nl``: none, it only implements netlink.
+- ``dplane_fpm_pb``: none, it only implements protobuf.
 
 The zebra FPM interface uses replace semantics. That is, if a 'route
 add' message for a prefix is followed by another 'route add' message,
@@ -1208,7 +1209,7 @@ FPM Commands
    optional Forwarding Plane Manager (FPM) component.
 
 
-``dplane_fpm_nl`` implementation
+``dplane_fpm_nl`` or ``dplane_fpm_pb`` implementation
 --------------------------------
 
 .. clicmd:: fpm address <A.B.C.D|X:X::X:X> [port (1-65535)]

fpmpbserver/fpm.h

@@ -0,0 +1,278 @@
+/*
+ * Public definitions pertaining to the Forwarding Plane Manager component.
+ *
+ * Permission is granted to use, copy, modify and/or distribute this
+ * software under either one of the licenses below.
+ *
+ * Note that if you use other files from the Quagga tree directly or
+ * indirectly, then the licenses in those files still apply.
+ *
+ * Please retain both licenses below when modifying this code in the
+ * Quagga tree.
+ *
+ * Copyright (C) 2012 by Open Source Routing.
+ * Copyright (C) 2012 by Internet Systems Consortium, Inc. ("ISC")
+ */
+
+/*
+ * License Option 1: GPL
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+/*
+ * License Option 2: ISC License
+ *
+ * Permission to use, copy, modify, and/or distribute this software
+ * for any purpose with or without fee is hereby granted, provided
+ * that the above copyright notice and this permission notice appear
+ * in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
+ * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
+ * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+ * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef _FPM_H
+#define _FPM_H
+
+/*
+ * The Forwarding Plane Manager (FPM) is an optional component that
+ * may be used in scenarios where the router has a forwarding path
+ * that is distinct from the kernel, commonly a hardware-based fast
+ * path. It is responsible for programming forwarding information
+ * (such as routes and nexthops) in the fast path.
+ *
+ * In Quagga, the Routing Information Base is maintained in the
+ * 'zebra' infrastructure daemon. Routing protocols communicate their
+ * best routes to zebra, and zebra computes the best route across
+ * protocols for each prefix. This latter information comprises the
+ * bulk of the Forwarding Information Base.
+ *
+ * This header file defines a point-to-point interface using which
+ * zebra can update the FPM about changes in routes. The communication
+ * takes place over a stream socket. The FPM listens on a well-known
+ * TCP port, and zebra initiates the connection.
+ *
+ * All messages sent over the connection start with a short FPM
+ * header, fpm_msg_hdr_t. In the case of route add/delete messages,
+ * the header is followed by a netlink message. Zebra should send a
+ * complete copy of the forwarding table(s) to the FPM, including
+ * routes that it may have picked up from the kernel.
+ *
+ * The FPM interface uses replace semantics. That is, if a 'route add'
+ * message for a prefix is followed by another 'route add' message, the
+ * information in the second message is complete by itself, and replaces
+ * the information sent in the first message.
+ *
+ * If the connection to the FPM goes down for some reason, the client
+ * (zebra) should send the FPM a complete copy of the forwarding
+ * table(s) when it reconnects.
+ */
+
+#include <stdint.h>
+#include <stddef.h>
+#include <arpa/inet.h>
+#include <assert.h>
+#define FPM_DEFAULT_PORT 2620
+
+/*
+ * Largest message that can be sent to or received from the FPM.
+ */
+#define FPM_MAX_MSG_LEN 4096
+
+/*
+ * Header that precedes each fpm message to/from the FPM.
+ */
+typedef struct fpm_msg_hdr_t_ {
+	/*
+	 * Protocol version.
+	 */
+	uint8_t version;
+
+	/*
+	 * Type of message, see below.
+	 */
+	uint8_t msg_type;
+
+	/*
+	 * Length of entire message, including the header, in network byte
+	 * order.
+	 *
+	 * Note that msg_len is rounded up to make sure that message is at
+	 * the desired alignment. This means that some payloads may need
+	 * padding at the end.
+	 */
+	uint16_t msg_len;
+} fpm_msg_hdr_t;
+
+/*
+ * The current version of the FPM protocol is 1.
+ */
+#define FPM_PROTO_VERSION 1
+
+typedef enum fpm_msg_type_e_ {
+	FPM_MSG_TYPE_NONE = 0,
+
+	/*
+	 * Indicates that the payload is a completely formed netlink
+	 * message.
+	 *
+	 * XXX Netlink cares about the alignment of messages. When any
+	 * FPM_MSG_TYPE_NETLINK messages are sent over a channel, then all
+	 * messages should be sized such that netlink alignment is
+	 * maintained.
+	 */
+	FPM_MSG_TYPE_NETLINK = 1,
+	FPM_MSG_TYPE_PROTOBUF = 2,
+} fpm_msg_type_e;
+
+/*
+ * The FPM message header is aligned to the same boundary as netlink
+ * messages (4). This means that a netlink message does not need
+ * padding when encapsulated in an FPM message.
+ */
+#define FPM_MSG_ALIGNTO 4
+
+/*
+ * fpm_msg_align
+ *
+ * Round up the given length to the desired alignment.
+ */
+static inline size_t fpm_msg_align(size_t len)
+{
+	return (len + FPM_MSG_ALIGNTO - 1) & ~(FPM_MSG_ALIGNTO - 1);
+}
+
+/*
+ * The (rounded up) size of the FPM message header. This ensures that
+ * the message payload always starts at an aligned address.
+ */
+#define FPM_MSG_HDR_LEN (fpm_msg_align(sizeof(fpm_msg_hdr_t)))
+
+/*
+ * fpm_data_len_to_msg_len
+ *
+ * The length value that should be placed in the msg_len field of the
+ * header for a *payload* of size 'data_len'.
+ */
+static inline size_t fpm_data_len_to_msg_len(size_t data_len)
+{
+	return fpm_msg_align(data_len) + FPM_MSG_HDR_LEN;
+}
+
+/*
+ * fpm_msg_data
+ *
+ * Pointer to the payload of the given fpm header.
+ */
+static inline void *fpm_msg_data(fpm_msg_hdr_t *hdr)
+{
+	return ((char *)hdr) + FPM_MSG_HDR_LEN;
+}
+
+/*
+ * fpm_msg_len
+ */
+static inline size_t fpm_msg_len(const fpm_msg_hdr_t *hdr)
+{
+	return ntohs(hdr->msg_len);
+}
+
+/*
+ * fpm_msg_data_len
+ */
+static inline size_t fpm_msg_data_len(const fpm_msg_hdr_t *hdr)
+{
+	return (fpm_msg_len(hdr) - FPM_MSG_HDR_LEN);
+}
+
+/*
+ * fpm_msg_next
+ *
+ * Move to the next message in a buffer.
+ */
+static inline fpm_msg_hdr_t *fpm_msg_next(fpm_msg_hdr_t *hdr, size_t *len)
+{
+	size_t msg_len;
+
+	msg_len = fpm_msg_len(hdr);
+
+	if (len) {
+		if (*len < msg_len) {
+			assert(0);
+			return NULL;
+		}
+		*len -= msg_len;
+	}
+
+	return reinterpret_cast<fpm_msg_hdr_t *>(
+		static_cast<void *>(((char *)hdr) + msg_len));
+}
+
+/*
+ * fpm_msg_hdr_ok
+ *
+ * Returns TRUE if a message header looks well-formed.
+ */
+static inline int fpm_msg_hdr_ok(const fpm_msg_hdr_t *hdr)
+{
+	size_t msg_len;
+
+	if (hdr->msg_type == FPM_MSG_TYPE_NONE)
+		return 0;
+
+	msg_len = fpm_msg_len(hdr);
+
+	if (msg_len < FPM_MSG_HDR_LEN || msg_len > FPM_MAX_MSG_LEN)
+		return 0;
+
+	/*
+	 * Netlink messages must be aligned properly.
+	 */
+	if (hdr->msg_type == FPM_MSG_TYPE_NETLINK &&
+	    fpm_msg_align(msg_len) != msg_len)
+		return 0;
+
+	return 1;
+}
+
+/*
+ * fpm_msg_ok
+ *
+ * Returns true if a message looks well-formed.
+ *
+ * @param len The length in bytes from 'hdr' to the end of the buffer.
+ */
+static inline int fpm_msg_ok(const fpm_msg_hdr_t *hdr, size_t len)
+{
+	if (len < FPM_MSG_HDR_LEN)
+		return 0;
+
+	if (!fpm_msg_hdr_ok(hdr))
+		return 0;
+
+	if (fpm_msg_len(hdr) > len)
+		return 0;
+
+	return 1;
+}
+
+#endif /* _FPM_H */