[PATCH net-next 07/18] ipv4: Add support to fib_config for IPv6 gateway

[David Ahern]

From: David Ahern <dsah...@gmail.com>

Add support for an IPv6 gateway to fib_config. Since a gateway is either
IPv4 or IPv6, make it a union with fc_gw4 where fc_gw_family decides
which address is in use. Update current checks on family and gw4 to
handle ipv6 as well.

Signed-off-by: David Ahern <dsah...@gmail.com>
---
 include/net/ip_fib.h     |  5 ++++-
 net/ipv4/fib_semantics.c | 27 ++++++++++++++++++++++-----
 2 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index 8dee23ae9bde..7cb29140cab3 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -36,7 +36,10 @@ struct fib_config {
        /* 3 bytes unused */
        u32                     fc_table;
        __be32                  fc_dst;
-       __be32                  fc_gw4;
+       union {
+               __be32          fc_gw4;
+               struct in6_addr fc_gw6;
+       };
        int                     fc_oif;
        u32                     fc_flags;
        u32                     fc_priority;
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index d3e26e55f2e1..5e16a0127ddd 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -276,7 +276,7 @@ static inline int nh_comp(const struct fib_info *fi, const 
struct fib_info *ofi)
 
        for_nexthops(fi) {
                if (nh->fib_nh_oif != onh->fib_nh_oif ||
-                   nh->fib_nh_gw4 != onh->fib_nh_gw4 ||
+                   nh->fib_nh_gw_family != onh->fib_nh_gw_family ||
                    nh->fib_nh_scope != onh->fib_nh_scope ||
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
                    nh->fib_nh_weight != onh->fib_nh_weight ||
@@ -287,6 +287,15 @@ static inline int nh_comp(const struct fib_info *fi, const 
struct fib_info *ofi)
                    lwtunnel_cmp_encap(nh->fib_nh_lws, onh->fib_nh_lws) ||
                    ((nh->fib_nh_flags ^ onh->fib_nh_flags) & 
~RTNH_COMPARE_MASK))
                        return -1;
+
+               if (nh->fib_nh_gw_family == AF_INET &&
+                   nh->fib_nh_gw4 != onh->fib_nh_gw4)
+                       return -1;
+
+               if (nh->fib_nh_gw_family == AF_INET6 &&
+                   ipv6_addr_cmp(&nh->fib_nh_gw6, &onh->fib_nh_gw6))
+                       return -1;
+
                onh++;
        } endfor_nexthops(fi);
        return 0;
@@ -511,10 +520,12 @@ int fib_nh_init(struct net *net, struct fib_nh *nh,
                goto init_failure;
 
        nh->fib_nh_oif = cfg->fc_oif;
-       if (cfg->fc_gw_family == AF_INET) {
+       nh->fib_nh_gw_family = cfg->fc_gw_family;
+       if (cfg->fc_gw_family == AF_INET)
                nh->fib_nh_gw4 = cfg->fc_gw4;
-               nh->fib_nh_gw_family = AF_INET;
-       }
+       else if (cfg->fc_gw_family == AF_INET6)
+               nh->fib_nh_gw6 = cfg->fc_gw6;
+
        nh->fib_nh_flags = cfg->fc_flags;
 
 #ifdef CONFIG_IP_ROUTE_CLASSID
@@ -621,7 +632,9 @@ static int fib_get_nhs(struct fib_info *fi, struct 
rtnexthop *rtnh,
        if (cfg->fc_gw_family) {
                if (cfg->fc_gw_family != fi->fib_nh->fib_nh_gw_family ||
                    (cfg->fc_gw_family == AF_INET &&
-                    fi->fib_nh->fib_nh_gw4 != cfg->fc_gw4)) {
+                    fi->fib_nh->fib_nh_gw4 != cfg->fc_gw4) ||
+                   (cfg->fc_gw_family == AF_INET6 &&
+                    ipv6_addr_cmp(&fi->fib_nh->fib_nh_gw6, &cfg->fc_gw6))) {
                        NL_SET_ERR_MSG(extack,
                                       "Nexthop gateway does not match 
RTA_GATEWAY");
                        goto errout;
@@ -745,6 +758,10 @@ int fib_nh_match(struct fib_config *cfg, struct fib_info 
*fi,
                    cfg->fc_gw4 != fi->fib_nh->fib_nh_gw4)
                        return 1;
 
+               if (cfg->fc_gw_family == AF_INET6 &&
+                   ipv6_addr_cmp(&cfg->fc_gw6, &fi->fib_nh->fib_nh_gw6))
+                       return 1;
+
                return 0;
        }
 
-- 
2.11.0