ip link gre: Add support to configure FOU and GUE

This patch adds support to configure foo-over-udp (FOU) and Generic
UDP Encapsulation for GRE tunnels. This configuration allows selection
of FOU or GUE for the tunnel, specification of the source and
destination ports for UDP tunnel, and enabling TX checksum. This
configuration only affects the transmit side of a tunnel.

Example:

ip link add name tun1 type gre remote 192.168.1.1 local 192.168.1.2 \
   ttl 225 encap fou encap-sport auto encap-dport 7777 encap-csum

This would create an GRE tunnel in GUE encapsulation where the source
port is automatically selected (based on hash of inner packet) and
checksums in the encapsulating UDP header are enabled.

Signed-off-by: Tom Herbert <therbert@google.com>

diff --git a/ip/link_gre.c b/ip/link_gre.c
index 83653d006cedfb20d849c920448d8842716f3d5c..47b64cb806e4b777e75bd8eb61a16e999dbfea4d 100644 (file)
--- a/ip/link_gre.c
+++ b/ip/link_gre.c
@@ -29,6 +29,9 @@ static void print_usage(FILE *f)
        fprintf(f, "          type { gre | gretap } [ remote ADDR ] [ local ADDR ]\n");
        fprintf(f, "          [ [i|o]seq ] [ [i|o]key KEY ] [ [i|o]csum ]\n");
        fprintf(f, "          [ ttl TTL ] [ tos TOS ] [ [no]pmtudisc ] [ dev PHYS_DEV ]\n");
+       fprintf(f, "          [ noencap ] [ encap { fou | gue | none } ]\n");
+       fprintf(f, "          [ encap-sport PORT ] [ encap-dport PORT ]\n");
+       fprintf(f, "          [ [no]encap-csum ] [ [no]encap-csum6 ]\n");
        fprintf(f, "\n");
        fprintf(f, "Where: NAME := STRING\n");
        fprintf(f, "       ADDR := { IP_ADDRESS | any }\n");
@@ -67,6 +70,10 @@ static int gre_parse_opt(struct link_util *lu, int argc, char **argv,
        __u8 ttl = 0;
        __u8 tos = 0;
        int len;
+       __u16 encaptype = 0;
+       __u16 encapflags = 0;
+       __u16 encapsport = 0;
+       __u16 encapdport = 0;
 
        if (!(n->nlmsg_flags & NLM_F_CREATE)) {
                memset(&req, 0, sizeof(req));
@@ -132,6 +139,15 @@ get_failed:
 
                if (greinfo[IFLA_GRE_LINK])
                        link = rta_getattr_u8(greinfo[IFLA_GRE_LINK]);
+
+               if (greinfo[IFLA_GRE_ENCAP_TYPE])
+                       encaptype = rta_getattr_u16(greinfo[IFLA_GRE_ENCAP_TYPE]);
+               if (greinfo[IFLA_GRE_ENCAP_FLAGS])
+                       encapflags = rta_getattr_u16(greinfo[IFLA_GRE_ENCAP_FLAGS]);
+               if (greinfo[IFLA_GRE_ENCAP_SPORT])
+                       encapsport = rta_getattr_u16(greinfo[IFLA_GRE_ENCAP_SPORT]);
+               if (greinfo[IFLA_GRE_ENCAP_DPORT])
+                       encapdport = rta_getattr_u16(greinfo[IFLA_GRE_ENCAP_DPORT]);
        }
 
        while (argc > 0) {
@@ -241,6 +257,36 @@ get_failed:
                                tos = uval;
                        } else
                                tos = 1;
+               } else if (strcmp(*argv, "noencap") == 0) {
+                       encaptype = TUNNEL_ENCAP_NONE;
+               } else if (strcmp(*argv, "encap") == 0) {
+                       NEXT_ARG();
+                       if (strcmp(*argv, "fou") == 0)
+                               encaptype = TUNNEL_ENCAP_FOU;
+                       else if (strcmp(*argv, "gue") == 0)
+                               encaptype = TUNNEL_ENCAP_GUE;
+                       else if (strcmp(*argv, "none") == 0)
+                               encaptype = TUNNEL_ENCAP_NONE;
+                       else
+                               invarg("Invalid encap type.", *argv);
+               } else if (strcmp(*argv, "encap-sport") == 0) {
+                       NEXT_ARG();
+                       if (strcmp(*argv, "auto") == 0)
+                               encapsport = 0;
+                       else if (get_u16(&encapsport, *argv, 0))
+                               invarg("Invalid source port.", *argv);
+               } else if (strcmp(*argv, "encap-dport") == 0) {
+                       NEXT_ARG();
+                       if (get_u16(&encapdport, *argv, 0))
+                               invarg("Invalid destination port.", *argv);
+               } else if (strcmp(*argv, "encap-csum") == 0) {
+                       encapflags |= TUNNEL_ENCAP_FLAG_CSUM;
+               } else if (strcmp(*argv, "noencap-csum") == 0) {
+                       encapflags &= ~TUNNEL_ENCAP_FLAG_CSUM;
+               } else if (strcmp(*argv, "encap-udp6-csum") == 0) {
+                       encapflags |= TUNNEL_ENCAP_FLAG_CSUM6;
+               } else if (strcmp(*argv, "noencap-udp6-csum") == 0) {
+                       encapflags |= ~TUNNEL_ENCAP_FLAG_CSUM6;
                } else
                        usage();
                argc--; argv++;
@@ -271,6 +317,11 @@ get_failed:
        addattr_l(n, 1024, IFLA_GRE_TTL, &ttl, 1);
        addattr_l(n, 1024, IFLA_GRE_TOS, &tos, 1);
 
+       addattr16(n, 1024, IFLA_GRE_ENCAP_TYPE, encaptype);
+       addattr16(n, 1024, IFLA_GRE_ENCAP_FLAGS, encapflags);
+       addattr16(n, 1024, IFLA_GRE_ENCAP_SPORT, htons(encapsport));
+       addattr16(n, 1024, IFLA_GRE_ENCAP_DPORT, htons(encapdport));
+
        return 0;
 }
 
@@ -357,6 +408,44 @@ static void gre_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
                fputs("icsum ", f);
        if (oflags & GRE_CSUM)
                fputs("ocsum ", f);
+
+       if (tb[IFLA_GRE_ENCAP_TYPE] &&
+           *(__u16 *)RTA_DATA(tb[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE) {
+               __u16 type = rta_getattr_u16(tb[IFLA_GRE_ENCAP_TYPE]);
+               __u16 flags = rta_getattr_u16(tb[IFLA_GRE_ENCAP_FLAGS]);
+               __u16 sport = rta_getattr_u16(tb[IFLA_GRE_ENCAP_SPORT]);
+               __u16 dport = rta_getattr_u16(tb[IFLA_GRE_ENCAP_DPORT]);
+
+               fputs("encap ", f);
+               switch (type) {
+               case TUNNEL_ENCAP_FOU:
+                       fputs("fou ", f);
+                       break;
+               case TUNNEL_ENCAP_GUE:
+                       fputs("gue ", f);
+                       break;
+               default:
+                       fputs("unknown ", f);
+                       break;
+               }
+
+               if (sport == 0)
+                       fputs("encap-sport auto ", f);
+               else
+                       fprintf(f, "encap-sport %u", ntohs(sport));
+
+               fprintf(f, "encap-dport %u ", ntohs(dport));
+
+               if (flags & TUNNEL_ENCAP_FLAG_CSUM)
+                       fputs("encap-csum ", f);
+               else
+                       fputs("noencap-csum ", f);
+
+               if (flags & TUNNEL_ENCAP_FLAG_CSUM6)
+                       fputs("encap-csum6 ", f);
+               else
+                       fputs("noencap-csum6 ", f);
+       }
 }
 
 static void gre_print_help(struct link_util *lu, int argc, char **argv,