[PATCHv3 iproute2-next 2/7] iproute_lwtunnel: add options support for vxlan metadata

[Xin Long <lucien.xin@gmail.com>]

This patch is to add LWTUNNEL_IP_OPTS_VXLAN's parse and print to implement
vxlan options support in iproute_lwtunnel.

Option is expressed one hex value for gbp only, and vxlan doesn't support
multiple options.

With this patch, users can add and dump vxlan options like:

  # ip netns add a
  # ip netns add b
  # ip -n a link add eth0 type veth peer name eth0 netns b
  # ip -n a link set eth0 up
  # ip -n b link set eth0 up
  # ip -n a addr add 10.1.0.1/24 dev eth0
  # ip -n b addr add 10.1.0.2/24 dev eth0
  # ip -n b link add vxlan1 type vxlan id 1 local 10.1.0.2 remote 10.1.0.1 \
    dev eth0 ttl 64 gbp
  # ip -n b addr add 1.1.1.1/24 dev vxlan1
  # ip -n b link set vxlan1 up
  # ip -n b route add 2.1.1.0/24 dev vxlan1
  # ip -n a link add vxlan1 type vxlan local 10.1.0.1 dev eth0 ttl 64 \
    gbp external
  # ip -n a addr add 2.1.1.1/24 dev vxlan1
  # ip -n a link set vxlan1 up
  # ip -n a route add 1.1.1.0/24 encap ip id 1 \
    vxlan_opts 0x456 dst 10.1.0.2 dev vxlan1
  # ip -n a route show
  # ip netns exec a ping 1.1.1.1 -c 1

   1.1.1.0/24  encap ip id 1 src 0.0.0.0 dst 10.1.0.2 ttl 0 tos 0
     vxlan_opts 0x456 dev vxlan1 scope link

   PING 1.1.1.1 (1.1.1.1) 56(84) bytes of data.
   64 bytes from 1.1.1.1: icmp_seq=1 ttl=64 time=0.111 ms

v1->v2:
  - improve the changelog.
  - get_u32 with base = 0 for gbp.
  - use PRINT_ANY to support dumping with json format.
v2->v3:
  - implement proper JSON array for opts.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 ip/iproute_lwtunnel.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)

diff --git a/ip/iproute_lwtunnel.c b/ip/iproute_lwtunnel.c
index 737d7da..7691002 100644
--- a/ip/iproute_lwtunnel.c
+++ b/ip/iproute_lwtunnel.c
@@ -342,6 +342,28 @@ static void lwtunnel_print_geneve_opts(struct rtattr *attr)
 	close_json_array(PRINT_JSON, name);
 }
 
+static void lwtunnel_print_vxlan_opts(struct rtattr *attr)
+{
+        struct rtattr *tb[LWTUNNEL_IP_OPT_VXLAN_MAX + 1];
+        struct rtattr *i = RTA_DATA(attr);
+        int rem = RTA_PAYLOAD(attr);
+        char *name = "vxlan_opts";
+        __u32 gbp;
+
+	parse_rtattr(tb, LWTUNNEL_IP_OPT_VXLAN_MAX, i, rem);
+	gbp = rta_getattr_u32(tb[LWTUNNEL_IP_OPT_VXLAN_GBP]);
+
+	open_json_array(PRINT_JSON, name);
+	open_json_object(NULL);
+	print_uint(PRINT_JSON, "gbp", NULL, gbp);
+	close_json_object();
+	close_json_array(PRINT_JSON, name);
+
+	print_nl();
+	print_string(PRINT_FP, name, "\t%s ", name);
+	print_uint(PRINT_FP, NULL, "0x%x ", gbp);
+}
+
 static void lwtunnel_print_opts(struct rtattr *attr)
 {
 	struct rtattr *tb_opt[LWTUNNEL_IP_OPTS_MAX + 1];
@@ -349,6 +371,8 @@ static void lwtunnel_print_opts(struct rtattr *attr)
 	parse_rtattr_nested(tb_opt, LWTUNNEL_IP_OPTS_MAX, attr);
 	if (tb_opt[LWTUNNEL_IP_OPTS_GENEVE])
 		lwtunnel_print_geneve_opts(tb_opt[LWTUNNEL_IP_OPTS_GENEVE]);
+	else if (tb_opt[LWTUNNEL_IP_OPTS_VXLAN])
+		lwtunnel_print_vxlan_opts(tb_opt[LWTUNNEL_IP_OPTS_VXLAN]);
 }
 
 static void print_encap_ip(FILE *fp, struct rtattr *encap)
@@ -947,6 +971,22 @@ static int lwtunnel_parse_geneve_opts(char *str, size_t len, struct rtattr *rta)
 	return 0;
 }
 
+static int lwtunnel_parse_vxlan_opts(char *str, size_t len, struct rtattr *rta)
+{
+	struct rtattr *nest;
+	__u32 gbp;
+	int err;
+
+	nest = rta_nest(rta, len, LWTUNNEL_IP_OPTS_VXLAN | NLA_F_NESTED);
+	err = get_u32(&gbp, str, 0);
+	if (err)
+		return err;
+	rta_addattr32(rta, len, LWTUNNEL_IP_OPT_VXLAN_GBP, gbp);
+
+	rta_nest_end(rta, nest);
+	return 0;
+}
+
 static int parse_encap_ip(struct rtattr *rta, size_t len,
 			  int *argcp, char ***argvp)
 {
@@ -1018,6 +1058,21 @@ static int parse_encap_ip(struct rtattr *rta, size_t len,
 				invarg("\"geneve_opts\" value is invalid\n",
 				       *argv);
 			rta_nest_end(rta, nest);
+		} else if (strcmp(*argv, "vxlan_opts") == 0) {
+			struct rtattr *nest;
+
+			if (opts_ok++)
+				duparg2("opts", *argv);
+
+			NEXT_ARG();
+
+			nest = rta_nest(rta, len,
+					LWTUNNEL_IP_OPTS | NLA_F_NESTED);
+			ret = lwtunnel_parse_vxlan_opts(*argv, len, rta);
+			if (ret)
+				invarg("\"vxlan_opts\" value is invalid\n",
+				       *argv);
+			rta_nest_end(rta, nest);
 		} else if (strcmp(*argv, "key") == 0) {
 			if (key_ok++)
 				duparg2("key", *argv);
@@ -1202,6 +1257,21 @@ static int parse_encap_ip6(struct rtattr *rta, size_t len,
 				invarg("\"geneve_opts\" value is invalid\n",
 				       *argv);
 			rta_nest_end(rta, nest);
+		} else if (strcmp(*argv, "vxlan_opts") == 0) {
+			struct rtattr *nest;
+
+			if (opts_ok++)
+				duparg2("opts", *argv);
+
+			NEXT_ARG();
+
+			nest = rta_nest(rta, len,
+					LWTUNNEL_IP_OPTS | NLA_F_NESTED);
+			ret = lwtunnel_parse_vxlan_opts(*argv, len, rta);
+			if (ret)
+				invarg("\"vxlan_opts\" value is invalid\n",
+				       *argv);
+			rta_nest_end(rta, nest);
 		} else if (strcmp(*argv, "key") == 0) {
 			if (key_ok++)
 				duparg2("key", *argv);
-- 
2.1.0