ip: Display ip rule protocol used

Modify 'ip rule' command to notice when the kernel passes
to us the originating protocol.

Add code to allow the `ip rule flush protocol XXX`
command to be accepted and properly handled.

Modify the documentation to reflect these code changes.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Signed-off-by: David Ahern <dsahern@gmail.com>

ip/iprule.c

@@ -47,6 +47,7 @@ static void usage(void)
 		"            [ iif STRING ] [ oif STRING ] [ pref NUMBER ] [ l3mdev ]\n"
 		"            [ uidrange NUMBER-NUMBER ]\n"
 		"ACTION := [ table TABLE_ID ]\n"
+		"          [ protocol PROTO ]\n"
 		"          [ nat ADDRESS ]\n"
 		"          [ realms [SRCREALM/]DSTREALM ]\n"
 		"          [ goto NUMBER ]\n"
@@ -71,6 +72,8 @@ static struct
 	struct fib_rule_uid_range range;
 	inet_prefix src;
 	inet_prefix dst;
+	int protocol;
+	int protocolmask;
 } filter;
 
 static inline int frh_get_table(struct fib_rule_hdr *frh, struct rtattr **tb)
@@ -338,6 +341,16 @@ int print_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
 			rtnl_rtntype_n2a(frh->action,
 					 b1, sizeof(b1)));
 
+	if (tb[FRA_PROTOCOL]) {
+		__u8 protocol = rta_getattr_u8(tb[FRA_PROTOCOL]);
+
+		if ((protocol && protocol != RTPROT_KERNEL) ||
+		    show_details > 0) {
+			fprintf(fp, " proto %s ",
+				rtnl_rtprot_n2a(protocol, b1, sizeof(b1)));
+		}
+	}
+
 	fprintf(fp, "\n");
 	fflush(fp);
 	return 0;
@@ -391,6 +404,13 @@ static int flush_rule(const struct sockaddr_nl *who, struct nlmsghdr *n,
 
 	parse_rtattr(tb, FRA_MAX, RTM_RTA(frh), len);
 
+	if (tb[FRA_PROTOCOL]) {
+		__u8 protocol = rta_getattr_u8(tb[FRA_PROTOCOL]);
+
+		if ((filter.protocol ^ protocol) & filter.protocolmask)
+			return 0;
+	}
+
 	if (tb[FRA_PRIORITY]) {
 		n->nlmsg_type = RTM_DELRULE;
 		n->nlmsg_flags = NLM_F_REQUEST;
@@ -415,9 +435,8 @@ static int iprule_list_flush_or_save(int argc, char **argv, int action)
 	if (af == AF_UNSPEC)
 		af = AF_INET;
 
-	if (action != IPRULE_LIST && argc > 0) {
+	if (action == IPRULE_SAVE && argc > 0) {
-		fprintf(stderr, "\"ip rule %s\" does not take any arguments.\n",
+		fprintf(stderr, "\"ip rule save\" does not take any arguments.\n");
-				action == IPRULE_SAVE ? "save" : "flush");
 		return -1;
 	}
 
@@ -508,7 +527,18 @@ static int iprule_list_flush_or_save(int argc, char **argv, int action)
 			NEXT_ARG();
 			if (get_prefix(&filter.src, *argv, af))
 				invarg("from value is invalid\n", *argv);
-		} else {
+		} else if (matches(*argv, "protocol") == 0) {
+			__u32 prot;
+			NEXT_ARG();
+			filter.protocolmask = -1;
+			if (rtnl_rtprot_a2n(&prot, *argv)) {
+				if (strcmp(*argv, "all") != 0)
+					invarg("invalid \"protocol\"\n", *argv);
+				prot = 0;
+				filter.protocolmask = 0;
+			}
+			filter.protocol = prot;
+		} else{
 			if (matches(*argv, "dst") == 0 ||
 			    matches(*argv, "to") == 0) {
 				NEXT_ARG();

man/man8/ip-rule.8

@@ -50,6 +50,8 @@ ip-rule \- routing policy database management
 .IR ACTION " := [ "
 .B  table
 .IR TABLE_ID " ] [ "
+.B  protocol
+.IR PROTO " ] [ "
 .B  nat
 .IR ADDRESS " ] [ "
 .B realms
@@ -240,6 +242,10 @@ The options preference and order are synonyms with priority.
 the routing table identifier to lookup if the rule selector matches.
 It is also possible to use lookup instead of table.
 
+.TP
+.BI protocol " PROTO"
+the routing protocol who installed the rule in question.  As an example when zebra installs a rule it would get RTPROT_ZEBRA as the installing protocol.
+
 .TP
 .BI suppress_prefixlength " NUMBER"
 reject routing decisions that have a prefix length of NUMBER or less.
@@ -275,7 +281,11 @@ updates, it flushes the routing cache with
 .RE
 .TP
 .B ip rule flush - also dumps all the deleted rules.
-This command has no arguments.
+.RS
+.TP
+.BI protocol " PROTO"
+Select the originating protocol.
+.RE
 .TP
 .B ip rule show - list rules
 This command has no arguments.
@@ -283,6 +293,12 @@ The options list or lst are synonyms with show.
 
 .TP
 .B ip rule save
+.RS
+.TP
+.BI protocol " PROTO"
+Select the originating protocol.
+.RE
+.TP
 save rules table information to stdout
 .RS
 This command behaves like