lib: enhance pbr_rule structure for zapi encode and for common usage

The pbr_rule structure is derived from zebra_pbr_rule, and is
defined, so that a zclient will be able to encode the zebra_pbr_rule to
send ADD_RULE or DEL_RULE command. Also, the same structure can be used
by other daemons to derive a structure ( this will be the case for
zebra_pbr_rule).
Adding to this, an encoding function is defined, and will be used by
remote daemon to encode that message.
Those definitions are moved in new file pbr.h file.

Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>

4 files changed, 143 insertions, 6 deletions

diff --git a/lib/pbr.h b/lib/pbr.h
new file mode 100644
index 000000000..b49cb562a
--- /dev/null
+++ b/lib/pbr.h
@@ -0,0 +1,86 @@
+/* Policy Based Routing (PBR) main header
+ * Copyright (C) 2018 6WIND
+ *
+ * FRR 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, or (at your option) any
+ * later version.
+ *
+ * FRR 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 FRR; see the file COPYING.  If not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+
+#ifndef _PBR_H
+#define _PBR_H
+
+/*
+ * A PBR filter
+ *
+ * The filter or match criteria in a PBR rule.
+ * For simplicity, all supported filters are grouped into a structure rather
+ * than delineating further. A bitmask denotes which filters are actually
+ * specified.
+ */
+struct pbr_filter {
+	uint32_t filter_bm; /* not encoded by zapi
+			     */
+#define PBR_FILTER_SRC_IP     (1 << 0)
+#define PBR_FILTER_DST_IP     (1 << 1)
+#define PBR_FILTER_SRC_PORT   (1 << 2)
+#define PBR_FILTER_DST_PORT   (1 << 3)
+#define PBR_FILTER_FWMARK     (1 << 4)
+
+	/* Source and Destination IP address with masks. */
+	struct prefix src_ip;
+	struct prefix dst_ip;
+
+	/* Source and Destination higher-layer (TCP/UDP) port numbers. */
+	uint16_t src_port;
+	uint16_t dst_port;
+
+	/* Filter with fwmark */
+	uint32_t fwmark;
+};
+
+/*
+ * A PBR action
+ *
+ * The action corresponding to a PBR rule.
+ * While the user specifies the action in a particular way, the forwarding
+ * plane implementation (Linux only) requires that to be encoded into a
+ * route table and the rule then point to that route table; in some cases,
+ * the user criteria may directly point to a table too.
+ */
+struct pbr_action {
+	uint32_t table;
+};
+
+/*
+ * A PBR rule
+ *
+ * This is a combination of the filter criteria and corresponding action.
+ * Rules also have a user-defined sequence number which defines the relative
+ * order amongst rules.
+ */
+struct pbr_rule {
+	vrf_id_t vrf_id;
+
+	uint32_t seq;
+	uint32_t priority;
+	uint32_t unique;
+	struct pbr_filter filter;
+	struct pbr_action action;
+	uint32_t ifindex;
+};
+
+extern int zapi_pbr_rule_encode(uint8_t cmd, struct stream *s,
+				struct pbr_rule *zrule);
+
+#endif /* _PBR_H */
diff --git a/lib/subdir.am b/lib/subdir.am
index 7d85b7a24..0319f7764 100644
--- a/lib/subdir.am
+++ b/lib/subdir.am
@@ -167,6 +167,7 @@ pkginclude_HEADERS += \
 	lib/zclient.h \
 	lib/zebra.h \
 	lib/logicalrouter.h \
+	lib/pbr.h \
 	# end
 
 nodist_pkginclude_HEADERS += \
diff --git a/lib/zclient.c b/lib/zclient.c
index 34f49c0b4..e1ce40ce7 100644
--- a/lib/zclient.c
+++ b/lib/zclient.c
@@ -36,6 +36,7 @@
 #include "nexthop.h"
 #include "mpls.h"
 #include "sockopt.h"
+#include "pbr.h"
 
 DEFINE_MTYPE_STATIC(LIB, ZCLIENT, "Zclient")
 DEFINE_MTYPE_STATIC(LIB, REDIST_INST, "Redistribution instance IDs")
@@ -1229,6 +1230,55 @@ stream_failure:
 	return 0;
 }
 
+static void zapi_encode_prefix(struct stream *s,
+			      struct prefix *p,
+			      uint8_t family)
+{
+	struct prefix any;
+
+	if (!p) {
+		memset(&any, 0, sizeof(any));
+		any.family = family;
+		p = &any;
+	}
+
+	stream_putc(s, p->family);
+	stream_putc(s, p->prefixlen);
+	stream_put(s, &p->u.prefix, prefix_blen(p));
+}
+
+int zapi_pbr_rule_encode(uint8_t cmd, struct stream *s,
+			 struct pbr_rule *zrule)
+{
+	stream_reset(s);
+	zclient_create_header(s, cmd, zrule->vrf_id);
+
+	/*
+	 * We are sending one item at a time at the moment
+	 */
+	stream_putl(s, 1);
+
+	stream_putl(s, zrule->seq);
+	stream_putl(s, zrule->priority);
+	stream_putl(s, zrule->unique);
+
+	zapi_encode_prefix(s, &(zrule->filter.src_ip),
+			   zrule->filter.src_ip.family);
+	stream_putw(s, zrule->filter.src_port);  /* src port */
+	zapi_encode_prefix(s, &(zrule->filter.dst_ip),
+			   zrule->filter.src_ip.family);
+	stream_putw(s, zrule->filter.dst_port);  /* dst port */
+	stream_putw(s, zrule->filter.fwmark);    /* fwmark */
+
+	stream_putl(s, zrule->action.table);
+	stream_putl(s, zrule->ifindex);
+
+	/* Put length at the first point of the stream. */
+	stream_putw_at(s, 0, stream_get_endp(s));
+
+	return 0;
+}
+
 bool zapi_route_notify_decode(struct stream *s, struct prefix *p,
 			      uint32_t *tableid,
 			      enum zapi_route_notify_owner *note)
diff --git a/lib/zclient.h b/lib/zclient.h
index 2cdcefd5e..985239b32 100644
--- a/lib/zclient.h
+++ b/lib/zclient.h
@@ -393,6 +393,12 @@ enum zapi_route_notify_owner {
 	ZAPI_ROUTE_REMOVE_FAIL,
 };
 
+enum zapi_rule_notify_owner {
+	ZAPI_RULE_FAIL_INSTALL,
+	ZAPI_RULE_INSTALLED,
+	ZAPI_RULE_REMOVED,
+};
+
 enum ipset_type {
 	IPSET_NET_NET = 1,
 	IPSET_NET_PORT_NET,
@@ -400,12 +406,6 @@ enum ipset_type {
 	IPSET_NET
 };
 
-enum zapi_rule_notify_owner {
-	ZAPI_RULE_FAIL_INSTALL,
-	ZAPI_RULE_INSTALLED,
-	ZAPI_RULE_REMOVED,
-};
-
 enum zapi_ipset_notify_owner {
 	ZAPI_IPSET_FAIL_INSTALL,
 	ZAPI_IPSET_INSTALLED,