netifd/system-linux: add VTI tunnel support

This patch adds support for VTI interfaces. VTI interfaces can be used to
tunnel IPsec ESP traffic to a device so common firewall zones may be used.
This also enables routing protocols to work over IPsec tunnels.

Signed-off-by: André Valentin <avalentin@marcant.net>

diff --git a/system-linux.c b/system-linux.c
index 2b17764..909ba0f 100644 (file)
--- a/system-linux.c
+++ b/system-linux.c
@@ -2133,6 +2133,103 @@ failure:
 }
 #endif
 
+#ifdef IFLA_VTI_MAX
+static int system_add_vti_tunnel(const char *name, const char *kind,
+                                const unsigned int link, struct blob_attr **tb, bool v6)
+{
+       struct nl_msg *nlm;
+       struct ifinfomsg ifi = { .ifi_family = AF_UNSPEC, };
+       struct blob_attr *cur;
+       uint32_t ikey = 0, okey = 0;
+       int ret = 0;
+
+       nlm = nlmsg_alloc_simple(RTM_NEWLINK, NLM_F_REQUEST | NLM_F_REPLACE | NLM_F_CREATE);
+       if (!nlm)
+               return -1;
+
+       nlmsg_append(nlm, &ifi, sizeof(ifi), 0);
+       nla_put_string(nlm, IFLA_IFNAME, name);
+
+       struct nlattr *linkinfo = nla_nest_start(nlm, IFLA_LINKINFO);
+       if (!linkinfo) {
+               ret = -ENOMEM;
+               goto failure;
+       }
+
+       nla_put_string(nlm, IFLA_INFO_KIND, kind);
+       struct nlattr *infodata = nla_nest_start(nlm, IFLA_INFO_DATA);
+       if (!infodata) {
+               ret = -ENOMEM;
+               goto failure;
+       }
+
+       if (link)
+               nla_put_u32(nlm, IFLA_VTI_LINK, link);
+
+       if ((cur = tb[TUNNEL_ATTR_INFO]) && (blobmsg_type(cur) == BLOBMSG_TYPE_STRING)) {
+               if (sscanf(blobmsg_get_string(cur), "%u,%u",
+                       &ikey, &okey) < 2) {
+                       ret = -EINVAL;
+                       goto failure;
+               }
+       }
+
+       if (v6) {
+               struct in6_addr in6buf;
+               if ((cur = tb[TUNNEL_ATTR_LOCAL])) {
+                       if (inet_pton(AF_INET6, blobmsg_data(cur), &in6buf) < 1) {
+                               ret = -EINVAL;
+                               goto failure;
+                       }
+                       nla_put(nlm, IFLA_VTI_LOCAL, sizeof(in6buf), &in6buf);
+               }
+
+               if ((cur = tb[TUNNEL_ATTR_REMOTE])) {
+                       if (inet_pton(AF_INET6, blobmsg_data(cur), &in6buf) < 1) {
+                               ret = -EINVAL;
+                               goto failure;
+                       }
+                       nla_put(nlm, IFLA_VTI_REMOTE, sizeof(in6buf), &in6buf);
+               }
+
+       } else {
+               struct in_addr inbuf;
+
+               if ((cur = tb[TUNNEL_ATTR_LOCAL])) {
+                       if (inet_pton(AF_INET, blobmsg_data(cur), &inbuf) < 1) {
+                               ret = -EINVAL;
+                               goto failure;
+                       }
+                       nla_put(nlm, IFLA_VTI_LOCAL, sizeof(inbuf), &inbuf);
+               }
+
+               if ((cur = tb[TUNNEL_ATTR_REMOTE])) {
+                       if (inet_pton(AF_INET, blobmsg_data(cur), &inbuf) < 1) {
+                               ret = -EINVAL;
+                               goto failure;
+                       }
+                       nla_put(nlm, IFLA_VTI_REMOTE, sizeof(inbuf), &inbuf);
+               }
+
+       }
+
+       if (okey)
+               nla_put_u32(nlm, IFLA_VTI_OKEY, okey);
+
+       if (ikey)
+               nla_put_u32(nlm, IFLA_VTI_IKEY, ikey);
+
+       nla_nest_end(nlm, infodata);
+       nla_nest_end(nlm, linkinfo);
+
+       return system_rtnl_call(nlm);
+
+failure:
+       nlmsg_free(nlm);
+       return ret;
+}
+#endif
+
 static int system_add_proto_tunnel(const char *name, const uint8_t proto, const unsigned int link, struct blob_attr **tb)
 {
        struct blob_attr *cur;
@@ -2201,7 +2298,8 @@ static int __system_del_ip_tunnel(const char *name, struct blob_attr **tb)
        str = blobmsg_data(cur);
 
        if (!strcmp(str, "greip") || !strcmp(str, "gretapip") ||
-           !strcmp(str, "greip6") || !strcmp(str, "gretapip6"))
+           !strcmp(str, "greip6") || !strcmp(str, "gretapip6") ||
+           !strcmp(str, "vtiip") || !strcmp(str, "vtiip6"))
                return system_link_del(name);
        else
                return tunnel_ioctl(name, SIOCDELTUNNEL, NULL);
@@ -2415,6 +2513,12 @@ failure:
                return system_add_gre_tunnel(name, "ip6gre", link, tb, true);
        } else if (!strcmp(str, "gretapip6")) {
                return system_add_gre_tunnel(name, "ip6gretap", link, tb, true);
+#ifdef IFLA_VTI_MAX
+       } else if (!strcmp(str, "vtiip")) {
+               return system_add_vti_tunnel(name, "vti", link, tb, false);
+       } else if (!strcmp(str, "vtiip6")) {
+               return system_add_vti_tunnel(name, "vti6", link, tb, true);
+#endif
 #endif
        } else if (!strcmp(str, "ipip")) {
                return system_add_proto_tunnel(name, IPPROTO_IPIP, link, tb);