[PATCHv3 iproute2-next 3/7] iproute_lwtunnel: add options support for erspan metadata

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

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

Option is expressed as version:index:dir:hwid, dir and hwid will be parsed
when version is 2, while index will be parsed when version is 1. erspan
doesn't support multiple options.

With this patch, users can add and dump erspan 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 erspan1 type erspan key 1 seq erspan 123 \
    local 10.1.0.2 remote 10.1.0.1
  # ip -n b addr add 1.1.1.1/24 dev erspan1
  # ip -n b link set erspan1 up
  # ip -n b route add 2.1.1.0/24 dev erspan1
  # ip -n a link add erspan1 type erspan key 1 seq local 10.1.0.1 external
  # ip -n a addr add 2.1.1.1/24 dev erspan1
  # ip -n a link set erspan1 up
  # ip -n a route add 1.1.1.0/24 encap ip id 1 \
    erspan_opts 2:123:1:2 dst 10.1.0.2 dev erspan1
  # 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
     erspan_opts 02:00000000:01:02 dev erspan1 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=0.124 ms

v1->v2:
  - improve the changelog.
  - use PRINT_ANY to support dumping with json format.
v2->v3:
  - implement proper JSON object for opts instead of just bunch of strings.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 ip/iproute_lwtunnel.c | 145 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 145 insertions(+)

diff --git a/ip/iproute_lwtunnel.c b/ip/iproute_lwtunnel.c
index 7691002..f64ccb1 100644
--- a/ip/iproute_lwtunnel.c
+++ b/ip/iproute_lwtunnel.c
@@ -364,6 +364,43 @@ static void lwtunnel_print_vxlan_opts(struct rtattr *attr)
 	print_uint(PRINT_FP, NULL, "0x%x ", gbp);
 }
 
+static void lwtunnel_print_erspan_opts(struct rtattr *attr)
+{
+	struct rtattr *tb[LWTUNNEL_IP_OPT_ERSPAN_MAX + 1];
+        struct rtattr *i = RTA_DATA(attr);
+        int rem = RTA_PAYLOAD(attr);
+        char *name = "erspan_opts";
+        char strbuf[rem * 2 + 1];
+	__u8 ver, hwid, dir;
+	__u32 idx;
+
+	parse_rtattr(tb, LWTUNNEL_IP_OPT_ERSPAN_MAX, i, RTA_PAYLOAD(attr));
+	ver = rta_getattr_u8(tb[LWTUNNEL_IP_OPT_ERSPAN_VER]);
+	if (ver == 1) {
+		idx = rta_getattr_be32(tb[LWTUNNEL_IP_OPT_ERSPAN_INDEX]);
+		dir = 0;
+		hwid = 0;
+	} else {
+		idx = 0;
+		dir = rta_getattr_u8(tb[LWTUNNEL_IP_OPT_ERSPAN_DIR]);
+		hwid = rta_getattr_u8(tb[LWTUNNEL_IP_OPT_ERSPAN_HWID]);
+	}
+
+	open_json_array(PRINT_JSON, name);
+	open_json_object(NULL);
+	print_uint(PRINT_JSON, "ver", NULL, ver);
+	print_uint(PRINT_JSON, "index", NULL, idx);
+	print_uint(PRINT_JSON, "dir", NULL, dir);
+	print_uint(PRINT_JSON, "hwid", NULL, hwid);
+	close_json_object();
+	close_json_array(PRINT_JSON, name);
+
+	print_nl();
+	print_string(PRINT_FP, name, "\t%s ", name);
+	sprintf(strbuf, "%02x:%08x:%02x:%02x", ver, idx, dir, hwid);
+	print_string(PRINT_FP, NULL, "%s ", strbuf);
+}
+
 static void lwtunnel_print_opts(struct rtattr *attr)
 {
 	struct rtattr *tb_opt[LWTUNNEL_IP_OPTS_MAX + 1];
@@ -373,6 +410,8 @@ static void lwtunnel_print_opts(struct rtattr *attr)
 		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]);
+	else if (tb_opt[LWTUNNEL_IP_OPTS_ERSPAN])
+		lwtunnel_print_erspan_opts(tb_opt[LWTUNNEL_IP_OPTS_ERSPAN]);
 }
 
 static void print_encap_ip(FILE *fp, struct rtattr *encap)
@@ -987,6 +1026,82 @@ static int lwtunnel_parse_vxlan_opts(char *str, size_t len, struct rtattr *rta)
 	return 0;
 }
 
+static int lwtunnel_parse_erspan_opts(char *str, size_t len, struct rtattr *rta)
+{
+	struct rtattr *nest;
+	char *token;
+	int i, err;
+
+	nest = rta_nest(rta, len, LWTUNNEL_IP_OPTS_ERSPAN | NLA_F_NESTED);
+	i = 1;
+	token = strsep(&str, ":");
+	while (token) {
+		switch (i) {
+		case LWTUNNEL_IP_OPT_ERSPAN_VER:
+		{
+			__u8 opt_type;
+
+			if (!strlen(token))
+				break;
+			err = get_u8(&opt_type, token, 16);
+			if (err)
+				return err;
+
+			rta_addattr8(rta, len, i, opt_type);
+			break;
+		}
+		case LWTUNNEL_IP_OPT_ERSPAN_INDEX:
+		{
+			__be32 opt_class;
+
+			if (!strlen(token))
+				break;
+			err = get_be32(&opt_class, token, 16);
+			if (err)
+				return err;
+
+			rta_addattr32(rta, len, i, opt_class);
+			break;
+		}
+		case LWTUNNEL_IP_OPT_ERSPAN_DIR:
+		{
+			__u8 opt_type;
+
+			if (!strlen(token))
+				break;
+			err = get_u8(&opt_type, token, 16);
+			if (err)
+				return err;
+
+			rta_addattr8(rta, len, i, opt_type);
+			break;
+		}
+		case LWTUNNEL_IP_OPT_ERSPAN_HWID:
+		{
+			__u8 opt_type;
+
+			if (!strlen(token))
+				break;
+			err = get_u8(&opt_type, token, 16);
+			if (err)
+				return err;
+
+			rta_addattr8(rta, len, i, opt_type);
+			break;
+		}
+		default:
+			fprintf(stderr, "Unknown \"geneve_opts\" type\n");
+			return -1;
+		}
+
+		token = strsep(&str, ":");
+		i++;
+	}
+
+	rta_nest_end(rta, nest);
+	return 0;
+}
+
 static int parse_encap_ip(struct rtattr *rta, size_t len,
 			  int *argcp, char ***argvp)
 {
@@ -1073,6 +1188,21 @@ static int parse_encap_ip(struct rtattr *rta, size_t len,
 				invarg("\"vxlan_opts\" value is invalid\n",
 				       *argv);
 			rta_nest_end(rta, nest);
+		} else if (strcmp(*argv, "erspan_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_erspan_opts(*argv, len, rta);
+			if (ret)
+				invarg("\"erspan_opts\" value is invalid\n",
+				       *argv);
+			rta_nest_end(rta, nest);
 		} else if (strcmp(*argv, "key") == 0) {
 			if (key_ok++)
 				duparg2("key", *argv);
@@ -1272,6 +1402,21 @@ static int parse_encap_ip6(struct rtattr *rta, size_t len,
 				invarg("\"vxlan_opts\" value is invalid\n",
 				       *argv);
 			rta_nest_end(rta, nest);
+		} else if (strcmp(*argv, "erspan_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_erspan_opts(*argv, len, rta);
+			if (ret)
+				invarg("\"erspan_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