Add support for larger number of routing tables

[IPROUTE]: Add support for larger number of routing tables

Support support for 2^32 routing tables by using the new RTA_TABLE
attribute for specifying tables > 255 and intepreting it if it is
sent by the kernel.

When tables > 255 are used on a kernel not supporting it an error will
occur because of the unknown netlink attribute.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>

include/linux/rtnetlink.h

@@ -238,9 +238,8 @@ enum rt_class_t
 	RT_TABLE_DEFAULT=253,
 	RT_TABLE_MAIN=254,
 	RT_TABLE_LOCAL=255,
-	__RT_TABLE_MAX
+	RT_TABLE_MAX=0xFFFFFFFF,
 };
-#define RT_TABLE_MAX (__RT_TABLE_MAX - 1)
 
 
 
@@ -263,6 +262,7 @@ enum rtattr_type_t
 	RTA_CACHEINFO,
 	RTA_SESSION,
 	RTA_MP_ALGO,
+	RTA_TABLE,
 	__RTA_MAX
 };
 

include/rt_names.h

@@ -5,7 +5,7 @@
 
 char* rtnl_rtprot_n2a(int id, char *buf, int len);
 char* rtnl_rtscope_n2a(int id, char *buf, int len);
-char* rtnl_rttable_n2a(int id, char *buf, int len);
+char* rtnl_rttable_n2a(__u32 id, char *buf, int len);
 char* rtnl_rtrealm_n2a(int id, char *buf, int len);
 char* rtnl_dsfield_n2a(int id, char *buf, int len);
 int rtnl_rtprot_a2n(__u32 *id, char *arg);

ip/ip_common.h

@@ -32,4 +32,12 @@ extern int do_multiaddr(int argc, char **argv);
 extern int do_multiroute(int argc, char **argv);
 extern int do_xfrm(int argc, char **argv);
 
+static inline int rtm_get_table(struct rtmsg *r, struct rtattr **tb)
+{
+	__u32 table = r->rtm_table;
+	if (tb[RTA_TABLE])
+		table = *(__u32*) RTA_DATA(tb[RTA_TABLE]);
+	return table;
+}
+
 extern struct rtnl_handle rth;

ip/iproute.c

@@ -140,6 +140,7 @@ int print_route(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
 	inet_prefix via;
 	int host_len = -1;
 	static int ip6_multiple_tables;
+	__u32 table;
 	SPRINT_BUF(b1);
 	
 
@@ -165,7 +166,10 @@ int print_route(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
 	else if (r->rtm_family == AF_IPX)
 		host_len = 80;
 
-	if (r->rtm_family == AF_INET6 && r->rtm_table != RT_TABLE_MAIN)
+	parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);
+	table = rtm_get_table(r, tb);
+
+	if (r->rtm_family == AF_INET6 && table != RT_TABLE_MAIN)
 		ip6_multiple_tables = 1;
 
 	if (r->rtm_family == AF_INET6 && !ip6_multiple_tables) {
@@ -187,7 +191,7 @@ int print_route(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
 			}
 		}
 	} else {
-		if (filter.tb > 0 && filter.tb != r->rtm_table)
+		if (filter.tb > 0 && filter.tb != table)
 			return 0;
 	}
 	if ((filter.protocol^r->rtm_protocol)&filter.protocolmask)
@@ -217,8 +221,6 @@ int print_route(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
 	if (filter.rprefsrc.family && r->rtm_family != filter.rprefsrc.family)
 		return 0;
 
-	parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);
-
 	memset(&dst, 0, sizeof(dst));
 	dst.family = r->rtm_family;
 	if (tb[RTA_DST])
@@ -371,8 +373,8 @@ int print_route(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
 		fprintf(fp, "dev %s ", ll_index_to_name(*(int*)RTA_DATA(tb[RTA_OIF])));
 
 	if (!(r->rtm_flags&RTM_F_CLONED)) {
-		if (r->rtm_table != RT_TABLE_MAIN && !filter.tb)
+		if (table != RT_TABLE_MAIN && !filter.tb)
-			fprintf(fp, " table %s ", rtnl_rttable_n2a(r->rtm_table, b1, sizeof(b1)));
+			fprintf(fp, " table %s ", rtnl_rttable_n2a(table, b1, sizeof(b1)));
 		if (r->rtm_protocol != RTPROT_BOOT && filter.protocolmask != -1)
 			fprintf(fp, " proto %s ", rtnl_rtprot_n2a(r->rtm_protocol, b1, sizeof(b1)));
 		if (r->rtm_scope != RT_SCOPE_UNIVERSE && filter.scopemask != -1)
@@ -875,7 +877,12 @@ int iproute_modify(int cmd, unsigned flags, int argc, char **argv)
 			NEXT_ARG();
 			if (rtnl_rttable_a2n(&tid, *argv))
 				invarg("\"table\" value is invalid\n", *argv);
-			req.r.rtm_table = tid;
+			if (tid < 256)
+				req.r.rtm_table = tid;
+			else {
+				req.r.rtm_table = RT_TABLE_UNSPEC;
+				addattr32(&req.n, sizeof(req), RTA_TABLE, tid);
+			}
 			table_ok = 1;
 		} else if (strcmp(*argv, "dev") == 0 ||
 			   strcmp(*argv, "oif") == 0) {

ip/iprule.c

@@ -27,6 +27,7 @@
 
 #include "rt_names.h"
 #include "utils.h"
+#include "ip_common.h"
 
 extern struct rtnl_handle rth;
 
@@ -51,6 +52,7 @@ static int print_rule(const struct sockaddr_nl *who, struct nlmsghdr *n,
 	struct rtmsg *r = NLMSG_DATA(n);
 	int len = n->nlmsg_len;
 	int host_len = -1;
+	__u32 table;
 	struct rtattr * tb[RTA_MAX+1];
 	char abuf[256];
 	SPRINT_BUF(b1);
@@ -129,8 +131,9 @@ static int print_rule(const struct sockaddr_nl *who, struct nlmsghdr *n,
 		fprintf(fp, "iif %s ", (char*)RTA_DATA(tb[RTA_IIF]));
 	}
 
-	if (r->rtm_table)
+	table = rtm_get_table(r, tb);
-		fprintf(fp, "lookup %s ", rtnl_rttable_n2a(r->rtm_table, b1, sizeof(b1)));
+	if (table)
+		fprintf(fp, "lookup %s ", rtnl_rttable_n2a(table, b1, sizeof(b1)));
 
 	if (tb[RTA_FLOW]) {
 		__u32 to = *(__u32*)RTA_DATA(tb[RTA_FLOW]);
@@ -257,7 +260,12 @@ static int iprule_modify(int cmd, int argc, char **argv)
 			NEXT_ARG();
 			if (rtnl_rttable_a2n(&tid, *argv))
 				invarg("invalid table ID\n", *argv);
-			req.r.rtm_table = tid;
+			if (tid < 256)
+				req.r.rtm_table = tid;
+			else {
+				req.r.rtm_table = RT_TABLE_UNSPEC;
+				addattr32(&req.n, sizeof(req), RTA_TABLE, tid);
+			}
 			table_ok = 1;
 		} else if (strcmp(*argv, "dev") == 0 ||
 			   strcmp(*argv, "iif") == 0) {

lib/rt_names.c

@@ -329,7 +329,7 @@ static void rtnl_rttable_initialize(void)
 			     rtnl_rttable_hash, 256);
 }
 
-char * rtnl_rttable_n2a(int id, char *buf, int len)
+char * rtnl_rttable_n2a(__u32 id, char *buf, int len)
 {
 	struct rtnl_hash_entry *entry;
 
@@ -354,7 +354,7 @@ int rtnl_rttable_a2n(__u32 *id, char *arg)
 	static unsigned long res;
 	struct rtnl_hash_entry *entry;
 	char *end;
-	int i;
+	__u32 i;
 
 	if (cache && strcmp(cache, arg) == 0) {
 		*id = res;