[PATCH] libiproute: handle table ids larger than 255

Lukasz Nowak lnowak.tyco at gmail.com
Wed Nov 30 17:35:40 UTC 2016


From: Lukasz Nowak <lnowak at tycoint.com>

Linux kernel, starting from 2.6.19 allows ip table ids to have 32-bit values.
In order to preserve compatibility, the old 8-bit field: rtm_table is still
in use when table id is lower than 256.

Add support for the 32-bit table id (RTA_TABLE attribute) in:
- ip route print
- ip route modify
- ip rule print
- ip rule modify

Add printing of table ids to ip route.

Changes are compatible with the mainline iproute2 utilities.

These changes are required for compatibility with ConnMan, which by default
uses table ids greater than 255.

Signed-off-by: Lukasz Nowak <lnowak at tycoint.com>
---
 networking/libiproute/iproute.c | 22 ++++++++++++++++++----
 networking/libiproute/iprule.c  | 11 +++++++++--
 2 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/networking/libiproute/iproute.c b/networking/libiproute/iproute.c
index 48dc6e3..81af752 100644
--- a/networking/libiproute/iproute.c
+++ b/networking/libiproute/iproute.c
@@ -66,6 +66,7 @@ static int FAST_FUNC print_route(const struct sockaddr_nl *who UNUSED_PARAM,
 	inet_prefix dst;
 	inet_prefix src;
 	int host_len = -1;
+	uint32_t tid;
 
 	if (n->nlmsg_type != RTM_NEWROUTE && n->nlmsg_type != RTM_DELROUTE) {
 		fprintf(stderr, "Not a route: %08x %08x %08x\n",
@@ -78,6 +79,14 @@ static int FAST_FUNC print_route(const struct sockaddr_nl *who UNUSED_PARAM,
 	if (len < 0)
 		bb_error_msg_and_die("wrong nlmsg len %d", len);
 
+	memset(tb, 0, sizeof(tb));
+	parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);
+
+	if (tb[RTA_TABLE])
+		tid = *(uint32_t *)RTA_DATA(tb[RTA_TABLE]);
+	else
+		tid = r->rtm_table;
+
 	if (r->rtm_family == AF_INET6)
 		host_len = 128;
 	else if (r->rtm_family == AF_INET)
@@ -107,7 +116,7 @@ static int FAST_FUNC print_route(const struct sockaddr_nl *who UNUSED_PARAM,
 			}
 		}
 	} else {
-		if (G_filter.tb > 0 && G_filter.tb != r->rtm_table) {
+		if (G_filter.tb > 0 && G_filter.tb != tid) {
 			return 0;
 		}
 	}
@@ -136,10 +145,8 @@ static int FAST_FUNC print_route(const struct sockaddr_nl *who UNUSED_PARAM,
 		return 0;
 	}
 
-	memset(tb, 0, sizeof(tb));
 	memset(&src, 0, sizeof(src));
 	memset(&dst, 0, sizeof(dst));
-	parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);
 
 	if (tb[RTA_SRC]) {
 		src.bitlen = r->rtm_src_len;
@@ -258,6 +265,8 @@ static int FAST_FUNC print_route(const struct sockaddr_nl *who UNUSED_PARAM,
 	if (tb[RTA_OIF]) {
 		printf("dev %s ", ll_index_to_name(*(int*)RTA_DATA(tb[RTA_OIF])));
 	}
+	if (tid && tid != RT_TABLE_MAIN && !G_filter.tb)
+		printf("table %s ", rtnl_rttable_n2a(tid));
 
 	/* Todo: parse & show "proto kernel", "scope link" here */
 
@@ -419,7 +428,12 @@ IF_FEATURE_IP_RULE(ARG_table,)
 			NEXT_ARG();
 			if (rtnl_rttable_a2n(&tid, *argv))
 				invarg_1_to_2(*argv, "table");
-			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);
+			}
 #endif
 		} else if (arg == ARG_dev || arg == ARG_oif) {
 			NEXT_ARG();
diff --git a/networking/libiproute/iprule.c b/networking/libiproute/iprule.c
index c486834..8f3f862 100644
--- a/networking/libiproute/iprule.c
+++ b/networking/libiproute/iprule.c
@@ -114,7 +114,9 @@ static int FAST_FUNC print_rule(const struct sockaddr_nl *who UNUSED_PARAM,
 		printf("iif %s ", (char*)RTA_DATA(tb[RTA_IIF]));
 	}
 
-	if (r->rtm_table)
+	if (tb[RTA_TABLE])
+		printf("lookup %s ", rtnl_rttable_n2a(*(uint32_t*)RTA_DATA(tb[RTA_TABLE])));
+	else if (r->rtm_table)
 		printf("lookup %s ", rtnl_rttable_n2a(r->rtm_table));
 
 	if (tb[RTA_FLOW]) {
@@ -256,7 +258,12 @@ static int iprule_modify(int cmd, char **argv)
 			NEXT_ARG();
 			if (rtnl_rttable_a2n(&tid, *argv))
 				invarg_1_to_2(*argv, "table ID");
-			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 (key == ARG_dev ||
 			   key == ARG_iif
-- 
2.7.4



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