[net-next,iproute2] ip6_gre: add support for ERSPAN tunnel

diff --git a/ip/ipaddress.c b/ip/ipaddress.c
index 9e9a7e0a6477..c0cd66538ea2 100644
--- a/ip/ipaddress.c
+++ b/ip/ipaddress.c
@@ -77,8 +77,9 @@  static void usage(void)
 	fprintf(stderr, "LFT := forever | SECONDS\n");
 	fprintf(stderr, "TYPE := { vlan | veth | vcan | dummy | ifb | macvlan | macvtap |\n");
 	fprintf(stderr, "          bridge | bond | ipoib | ip6tnl | ipip | sit | vxlan | lowpan |\n");
-	fprintf(stderr, "          gre | gretap | erspan | ip6gre | ip6gretap | vti | nlmon | can |\n");
-	fprintf(stderr, "          bond_slave | ipvlan | geneve | bridge_slave | vrf | hsr | macsec }\n");
+	fprintf(stderr, "          gre | gretap | erspan | ip6gre | ip6gretap | ip6erspan | vti |\n");
+	fprintf(stderr, "          nlmon | can | bond_slave | ipvlan | geneve | bridge_slave |\n");
+	fprintf(stderr, "          hsr | macsec\n");
 
 	exit(-1);
 }
diff --git a/ip/iplink.c b/ip/iplink.c
index 6a96ea9ff56a..be41749af036 100644
--- a/ip/iplink.c
+++ b/ip/iplink.c
@@ -112,9 +112,9 @@  void iplink_usage(void)
 			"\n"
 			"TYPE := { vlan | veth | vcan | dummy | ifb | macvlan | macvtap |\n"
 			"          bridge | bond | team | ipoib | ip6tnl | ipip | sit | vxlan |\n"
-			"          gre | gretap | erspan | ip6gre | ip6gretap | vti | nlmon |\n"
-			"          team_slave | bond_slave | ipvlan | geneve | bridge_slave |\n"
-			"          vrf | macsec }\n");
+			"          gre | gretap | erspan | ip6gre | ip6gretap | ip6erspan |\n"
+			"          vti | nlmon | team_slave | bond_slave | ipvlan | geneve |\n"
+			"          bridge_slave | vrf | macsec }\n");
 	}
 	exit(-1);
 }
diff --git a/ip/link_gre6.c b/ip/link_gre6.c
index 7d07932a60f0..a738739ff1e8 100644
--- a/ip/link_gre6.c
+++ b/ip/link_gre6.c
@@ -33,7 +33,7 @@ 
 static void print_usage(FILE *f)
 {
 	fprintf(f,
-		"Usage: ... { ip6gre | ip6gretap } [ remote ADDR ]\n"
+		"Usage: ... { ip6gre | ip6gretap | ip6erspan} [ remote ADDR ]\n"
 		"                                  [ local ADDR ]\n"
 		"                                  [ [i|o]seq ]\n"
 		"                                  [ [i|o]key KEY ]\n"
@@ -52,6 +52,7 @@  static void print_usage(FILE *f)
 		"                                  [ [no]encap-csum ]\n"
 		"                                  [ [no]encap-csum6 ]\n"
 		"                                  [ [no]encap-remcsum ]\n"
+		"                                  [ erspan IDX ]\n"
 		"\n"
 		"Where: ADDR      := IPV6_ADDRESS\n"
 		"       TTL       := { 0..255 } (default=%d)\n"
@@ -106,6 +107,7 @@  static int gre_parse_opt(struct link_util *lu, int argc, char **argv,
 	__u16 encapdport = 0;
 	int len;
 	__u32 fwmark = 0;
+	__u32 erspan_idx = 0;
 
 	if (!(n->nlmsg_flags & NLM_F_CREATE)) {
 		if (rtnl_talk(&rth, &req.n, &req.n, sizeof(req)) < 0) {
@@ -180,6 +182,9 @@  get_failed:
 
 		if (greinfo[IFLA_GRE_FWMARK])
 			fwmark = rta_getattr_u32(greinfo[IFLA_GRE_FWMARK]);
+
+		if (greinfo[IFLA_GRE_ERSPAN_INDEX])
+			erspan_idx = rta_getattr_u32(greinfo[IFLA_GRE_ERSPAN_INDEX]);
 	}
 
 	while (argc > 0) {
@@ -369,6 +374,12 @@  get_failed:
 				encap_limit = uval;
 				flags &= ~IP6_TNL_F_IGN_ENCAP_LIMIT;
 			}
+		} else if (strcmp(*argv, "erspan") == 0) {
+			NEXT_ARG();
+			if (get_u32(&erspan_idx, *argv, 0))
+				invarg("invalid erspan index\n", *argv);
+			if (erspan_idx & ~((1<<20) - 1) || erspan_idx == 0)
+				invarg("erspan index must be > 0 and <= 20-bit\n", *argv);
 		} else
 			usage();
 		argc--; argv++;
@@ -387,6 +398,8 @@  get_failed:
 	addattr_l(n, 1024, IFLA_GRE_FLOWINFO, &flowinfo, 4);
 	addattr32(n, 1024, IFLA_GRE_FLAGS, flags);
 	addattr32(n, 1024, IFLA_GRE_FWMARK, fwmark);
+	if (erspan_idx != 0)
+		addattr32(n, 1024, IFLA_GRE_ERSPAN_INDEX, erspan_idx);
 
 	addattr16(n, 1024, IFLA_GRE_ENCAP_TYPE, encaptype);
 	addattr16(n, 1024, IFLA_GRE_ENCAP_FLAGS, encapflags);
@@ -554,6 +567,11 @@  static void gre_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 		}
 	}
 
+	if (tb[IFLA_GRE_ERSPAN_INDEX]) {
+		__u32 erspan_idx = rta_getattr_u32(tb[IFLA_GRE_ERSPAN_INDEX]);
+		fprintf(f, "erspan_index %u ", erspan_idx);
+	}
+
 	if (tb[IFLA_GRE_ENCAP_TYPE] &&
 	    rta_getattr_u16(tb[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE) {
 		__u16 type = rta_getattr_u16(tb[IFLA_GRE_ENCAP_TYPE]);
@@ -636,3 +654,11 @@  struct link_util ip6gretap_link_util = {
 	.print_opt = gre_print_opt,
 	.print_help = gre_print_help,
 };
+
+struct link_util ip6erspan_link_util = {
+	.id = "ip6erspan",
+	.maxattr = IFLA_GRE_MAX,
+	.parse_opt = gre_parse_opt,
+	.print_opt = gre_print_opt,
+	.print_help = gre_print_help,
+};
diff --git a/man/man8/ip-address.8.in b/man/man8/ip-address.8.in
index 988a79652f6f..eaa179c6de91 100644
--- a/man/man8/ip-address.8.in
+++ b/man/man8/ip-address.8.in
@@ -123,6 +123,7 @@  ip-address \- protocol address management
 .BR erspan " |"
 .BR ip6gre " |"
 .BR ip6gretap " |"
+.BR ip6erspan " |"
 .BR vti " |"
 .BR vrf " |"
 .BR nlmon " |"
diff --git a/man/man8/ip-link.8.in b/man/man8/ip-link.8.in
index d96ee28815a7..e4c5346104aa 100644
--- a/man/man8/ip-link.8.in
+++ b/man/man8/ip-link.8.in
@@ -205,6 +205,7 @@  ip-link \- network device configuration
 .BR erspan " |"
 .BR ip6gre " |"
 .BR ip6gretap " |"
+.BR ip6erspan " |"
 .BR vti " |"
 .BR nlmon " |"
 .BR ipvlan " |"
@@ -308,6 +309,9 @@  Link types:
 .BR ip6gretap
 - Virtual L2 tunnel interface GRE over IPv6
 .sp
+.BR ip6erspan
+- Encapsulated Remote SPAN over GRE and IPv6
+.sp
 .BR vti
 - Virtual tunnel interface
 .sp