ipv4: support for fib route lwtunnel encap attributes

This patch adds support in ipv4 fib functions to parse user
provided encap attributes and attach encap state data to fib_nh
and rtable.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 95 insertions, 1 deletions

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index c7358ea4ae93..6754c64b2fe0 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -42,6 +42,7 @@
 #include <net/ip_fib.h>
 #include <net/netlink.h>
 #include <net/nexthop.h>
+#include <net/lwtunnel.h>
 
 #include "fib_lookup.h"
 
@@ -208,6 +209,7 @@ static void free_fib_info_rcu(struct rcu_head *head)
         change_nexthops(fi) {
                 if (nexthop_nh->nh_dev)
                         dev_put(nexthop_nh->nh_dev);
+                lwtunnel_state_put(nexthop_nh->nh_lwtstate);
                 free_nh_exceptions(nexthop_nh);
                 rt_fibinfo_free_cpus(nexthop_nh->nh_pcpu_rth_output);
                 rt_fibinfo_free(&nexthop_nh->nh_rth_input);
@@ -266,6 +268,7 @@ static inline int nh_comp(const struct fib_info *fi, const struct fib_info *ofi)
 #ifdef CONFIG_IP_ROUTE_CLASSID
                     nh->nh_tclassid != onh->nh_tclassid ||
 #endif
+                    lwtunnel_cmp_encap(nh->nh_lwtstate, onh->nh_lwtstate) ||
                     ((nh->nh_flags ^ onh->nh_flags) & ~RTNH_COMPARE_MASK))
                         return -1;
                 onh++;
@@ -366,6 +369,7 @@ static inline size_t fib_nlmsg_size(struct fib_info *fi)
         payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
 
         if (fi->fib_nhs) {
+                size_t nh_encapsize = 0;
                 /* Also handles the special case fib_nhs == 1 */
 
                 /* each nexthop is packed in an attribute */
@@ -374,8 +378,21 @@ static inline size_t fib_nlmsg_size(struct fib_info *fi)
                 /* may contain flow and gateway attribute */
                 nhsize += 2 * nla_total_size(4);
 
+                /* grab encap info */
+                for_nexthops(fi) {
+                        if (nh->nh_lwtstate) {
+                                /* RTA_ENCAP_TYPE */
+                                nh_encapsize += lwtunnel_get_encap_size(
+                                                nh->nh_lwtstate);
+                                /* RTA_ENCAP */
+                                nh_encapsize +=  nla_total_size(2);
+                        }
+                } endfor_nexthops(fi);
+
                 /* all nexthops are packed in a nested attribute */
-                payload += nla_total_size(fi->fib_nhs * nhsize);
+                payload += nla_total_size((fi->fib_nhs * nhsize) +
+                                          nh_encapsize);
+
         }
 
         return payload;
@@ -452,6 +469,9 @@ static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining)
 static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
                        int remaining, struct fib_config *cfg)
 {
+        struct net *net = cfg->fc_nlinfo.nl_net;
+        int ret;
+
         change_nexthops(fi) {
                 int attrlen;
 
@@ -475,18 +495,66 @@ static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
                         if (nexthop_nh->nh_tclassid)
                                 fi->fib_net->ipv4.fib_num_tclassid_users++;
 #endif
+                        nla = nla_find(attrs, attrlen, RTA_ENCAP);
+                        if (nla) {
+                                struct lwtunnel_state *lwtstate;
+                                struct net_device *dev = NULL;
+                                struct nlattr *nla_entype;
+
+                                nla_entype = nla_find(attrs, attrlen,
+                                                      RTA_ENCAP_TYPE);
+                                if (!nla_entype)
+                                        goto err_inval;
+                                if (cfg->fc_oif)
+                                        dev = __dev_get_by_index(net, cfg->fc_oif);
+                                ret = lwtunnel_build_state(dev, nla_get_u16(
+                                                           nla_entype),
+                                                           nla, &lwtstate);
+                                if (ret)
+                                        goto errout;
+                                lwtunnel_state_get(lwtstate);
+                                nexthop_nh->nh_lwtstate = lwtstate;
+                        }
                 }
 
                 rtnh = rtnh_next(rtnh, &remaining);
         } endfor_nexthops(fi);
 
         return 0;
+
+err_inval:
+        ret = -EINVAL;
+
+errout:
+        return ret;
 }
 
 #endif
 
+int fib_encap_match(struct net *net, u16 encap_type,
+                    struct nlattr *encap,
+                    int oif, const struct fib_nh *nh)
+{
+        struct lwtunnel_state *lwtstate;
+        struct net_device *dev = NULL;
+        int ret;
+
+        if (encap_type == LWTUNNEL_ENCAP_NONE)
+                return 0;
+
+        if (oif)
+                dev = __dev_get_by_index(net, oif);
+        ret = lwtunnel_build_state(dev, encap_type,
+                                   encap, &lwtstate);
+        if (!ret)
+                return lwtunnel_cmp_encap(lwtstate, nh->nh_lwtstate);
+
+        return 0;
+}
+
 int fib_nh_match(struct fib_config *cfg, struct fib_info *fi)
 {
+        struct net *net = cfg->fc_nlinfo.nl_net;
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
         struct rtnexthop *rtnh;
         int remaining;
@@ -496,6 +564,12 @@ int fib_nh_match(struct fib_config *cfg, struct fib_info *fi)
                 return 1;
 
         if (cfg->fc_oif || cfg->fc_gw) {
+                if (cfg->fc_encap) {
+                        if (fib_encap_match(net, cfg->fc_encap_type,
+                                            cfg->fc_encap, cfg->fc_oif,
+                                            fi->fib_nh))
+                            return 1;
+                }
                 if ((!cfg->fc_oif || cfg->fc_oif == fi->fib_nh->nh_oif) &&
                     (!cfg->fc_gw  || cfg->fc_gw == fi->fib_nh->nh_gw))
                         return 0;
@@ -882,6 +956,22 @@ struct fib_info *fib_create_info(struct fib_config *cfg)
         } else {
                 struct fib_nh *nh = fi->fib_nh;
 
+                if (cfg->fc_encap) {
+                        struct lwtunnel_state *lwtstate;
+                        struct net_device *dev = NULL;
+
+                        if (cfg->fc_encap_type == LWTUNNEL_ENCAP_NONE)
+                                goto err_inval;
+                        if (cfg->fc_oif)
+                                dev = __dev_get_by_index(net, cfg->fc_oif);
+                        err = lwtunnel_build_state(dev, cfg->fc_encap_type,
+                                                   cfg->fc_encap, &lwtstate);
+                        if (err)
+                                goto failure;
+
+                        lwtunnel_state_get(lwtstate);
+                        nh->nh_lwtstate = lwtstate;
+                }
                 nh->nh_oif = cfg->fc_oif;
                 nh->nh_gw = cfg->fc_gw;
                 nh->nh_flags = cfg->fc_flags;
@@ -1055,6 +1145,8 @@ int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
                     nla_put_u32(skb, RTA_FLOW, fi->fib_nh[0].nh_tclassid))
                         goto nla_put_failure;
 #endif
+                if (fi->fib_nh->nh_lwtstate)
+                        lwtunnel_fill_encap(skb, fi->fib_nh->nh_lwtstate);
         }
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
         if (fi->fib_nhs > 1) {
@@ -1090,6 +1182,8 @@ int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
                             nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid))
                                 goto nla_put_failure;
 #endif
+                        if (nh->nh_lwtstate)
+                                lwtunnel_fill_encap(skb, nh->nh_lwtstate);
                         /* length of rtnetlink header + attributes */
                         rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *) rtnh;
                 } endfor_nexthops(fi);