gre: add support for ERSPAN tunnel

The patch adds ERSPAN type II tunnel support. The implementation is
based on the draft at
 https://tools.ietf.org/html/draft-foschiano-erspan-01.

One of the purposes is for Linux box to be able to receive ERSPAN
monitoring traffic sent from the Cisco switch, by creating a ERSPAN
tunnel device. In addition, the patch also adds ERSPAN TX, so traffic
can also be encapsulated into ERSPAN and sent out.

The implementation reuses the key as ERSPAN session ID, and
field 'erspan' as ERSPAN Index fields:
./ip link add dev ers11 type erspan seq key 100 erspan 123 \
		local 172.16.1.200 remote 172.16.1.100

Signed-off-by: William Tu <u9012063@gmail.com>
Signed-off-by: Meenakshi Vohra <mvohra@vmware.com>

diff --git a/ip/ipaddress.c b/ip/ipaddress.c
index db54b4e3448561030a1fab36b9b8152d94b4ba04..201225f74b1de38cad65dd034b095ffe841f7305 100644 (file)
--- a/ip/ipaddress.c
+++ b/ip/ipaddress.c
@@ -77,7 +77,7 @@ 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 | ip6gre | ip6gretap | vti | nlmon | can |\n");
+       fprintf(stderr, "          gre | gretap | erspan | ip6gre | ip6gretap | vti | nlmon | can |\n");
        fprintf(stderr, "          bond_slave | ipvlan | geneve | bridge_slave | vrf | hsr | macsec }\n");
 
        exit(-1);

diff --git a/ip/iplink.c b/ip/iplink.c
index 19bda1b99f55833c6b5feb17ac27e9a5c50a61fe..a132707fc52e6c31ef06531181d6b9fe95080b65 100644 (file)
--- a/ip/iplink.c
+++ b/ip/iplink.c
@@ -112,8 +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 | ip6gre | ip6gretap | vti | nlmon | team_slave |\n"
-                       "          bond_slave | ipvlan | geneve | bridge_slave | vrf | macsec }\n");
+                       "          gre | gretap | erspan | ip6gre | ip6gretap | vti | nlmon |\n"
+                       "          team_slave | bond_slave | ipvlan | geneve | bridge_slave |\n"
+                       "          vrf | macsec }\n");
        }
        exit(-1);
 }

diff --git a/ip/link_gre.c b/ip/link_gre.c
index 3c9f8194e6c69dfd347bb68a88c99dd949df40ff..9ea2970cadc24ecfbe6aafa0fe9e11f85148e5e8 100644 (file)
--- a/ip/link_gre.c
+++ b/ip/link_gre.c
@@ -26,7 +26,7 @@
 static void print_usage(FILE *f)
 {
        fprintf(f,
-               "Usage: ... { gre | gretap } [ remote ADDR ]\n"
+               "Usage: ... { gre | gretap | erspan } [ remote ADDR ]\n"
                "                            [ local ADDR ]\n"
                "                            [ [i|o]seq ]\n"
                "                            [ [i|o]key KEY ]\n"
@@ -44,6 +44,7 @@ static void print_usage(FILE *f)
                "                            [ [no]encap-csum6 ]\n"
                "                            [ [no]encap-remcsum ]\n"
                "                            [ fwmark MARK ]\n"
+               "                            [ erspan IDX ]\n"
                "\n"
                "Where: ADDR := { IP_ADDRESS | any }\n"
                "       TOS  := { NUMBER | inherit }\n"
@@ -96,6 +97,7 @@ static int gre_parse_opt(struct link_util *lu, int argc, char **argv,
        __u8 metadata = 0;
        __u8 ignore_df = 0;
        __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) {
@@ -172,6 +174,9 @@ 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) {
@@ -328,6 +333,12 @@ get_failed:
                        NEXT_ARG();
                        if (get_u32(&fwmark, *argv, 0))
                                invarg("invalid fwmark\n", *argv);
+               } 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++;
@@ -359,6 +370,8 @@ get_failed:
                addattr_l(n, 1024, IFLA_GRE_TTL, &ttl, 1);
                addattr_l(n, 1024, IFLA_GRE_TOS, &tos, 1);
                addattr32(n, 1024, IFLA_GRE_FWMARK, fwmark);
+               if (erspan_idx != 0)
+                       addattr32(n, 1024, IFLA_GRE_ERSPAN_INDEX, erspan_idx);
        } else {
                addattr_l(n, 1024, IFLA_GRE_COLLECT_METADATA, NULL, 0);
        }
@@ -494,6 +507,12 @@ static void gre_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
        if (tb[IFLA_GRE_IGNORE_DF] && rta_getattr_u8(tb[IFLA_GRE_IGNORE_DF]))
                print_bool(PRINT_ANY, "ignore_df", "ignore-df ", true);
 
+       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]);
@@ -587,3 +606,11 @@ struct link_util gretap_link_util = {
        .print_opt = gre_print_opt,
        .print_help = gre_print_help,
 };
+
+struct link_util erspan_link_util = {
+       .id = "erspan",
+       .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 43385813a1340eacd73bba5e38cdb3db03354078..988a79652f6f2601386bd0fb00063660fba74485 100644 (file)
--- a/man/man8/ip-address.8.in
+++ b/man/man8/ip-address.8.in
@@ -120,6 +120,7 @@ ip-address \- protocol address management
 .BR sit " |"
 .BR gre " |"
 .BR gretap " |"
+.BR erspan " |"
 .BR ip6gre " |"
 .BR ip6gretap " |"
 .BR vti " |"

diff --git a/man/man8/ip-link.8.in b/man/man8/ip-link.8.in
index c0207281905d757a591f6b203e056dd3ca07fa5f..851b308cbe1a268d0a12b8a7ee83509402e023d8 100644 (file)
--- a/man/man8/ip-link.8.in
+++ b/man/man8/ip-link.8.in
@@ -202,6 +202,7 @@ ip-link \- network device configuration
 .BR sit " |"
 .BR gre " |"
 .BR gretap " |"
+.BR erspan " |"
 .BR ip6gre " |"
 .BR ip6gretap " |"
 .BR vti " |"
@@ -297,6 +298,9 @@ Link types:
 .BR gretap
 - Virtual L2 tunnel interface GRE over IPv4
 .sp
+.BR erspan
+- Encapsulated Remote SPAN over GRE and IPv4
+.sp
 .BR ip6gre
 - Virtual tunnel interface GRE over IPv6
 .sp
@@ -643,13 +647,13 @@ keyword.
 .in -8
 
 .TP
-GRE, IPIP, SIT Type Support
+GRE, IPIP, SIT, ERSPAN Type Support
 For a link of types
-.I GRE/IPIP/SIT
+.I GRE/IPIP/SIT/ERSPAN
 the following additional arguments are supported:
 
 .BI "ip link add " DEVICE
-.BR type " { " gre " | " ipip " | " sit " }"
+.BR type " { " gre " | " ipip " | " sit " | " erspan " }"
 .BI " remote " ADDR " local " ADDR
 [
 .BR encap " { " fou " | " gue " | " none " }"
@@ -663,6 +667,8 @@ the following additional arguments are supported:
 .I " [no]encap-remcsum "
 ] [
 .I " mode " { ip6ip | ipip | mplsip | any } "
+] [
+.BR erspan " \fIIDX "
 ]
 
 .in +8
@@ -707,6 +713,13 @@ MPLS-Over-IPv4, "any" indicates IPv6, IPv4 or MPLS Over IPv4. Supported for
 SIT where the default is "ip6ip" and IPIP where the default is "ipip".
 IPv6-Over-IPv4 is not supported for IPIP.
 
+.sp
+.BR erspan " \fIIDX "
+- specifies the ERSPAN index field.
+.IR IDX
+indicates a 20 bit index/port number associated with the ERSPAN
+traffic's source port and direction.
+
 .in -8
 
 .TP