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authorDavid Ahern <dsahern@gmail.com>2019-04-06 02:30:40 +0300
committerDavid S. Miller <davem@davemloft.net>2019-04-09 01:22:41 +0300
commitd15662682db232da77136cd348f4c9df312ca6f9 (patch)
treedfa79b49c8771ca89225749eae14bf422829793a /net/ipv4/fib_frontend.c
parent19a9d136f198cd7c4e26ea6897a0cf067d3f7ecb (diff)
downloadlinux-d15662682db232da77136cd348f4c9df312ca6f9.tar.xz
ipv4: Allow ipv6 gateway with ipv4 routes
Add support for RTA_VIA and allow an IPv6 nexthop for v4 routes: $ ip ro add 172.16.1.0/24 via inet6 2001:db8::1 dev eth0 $ ip ro ls ... 172.16.1.0/24 via inet6 2001:db8::1 dev eth0 For convenience and simplicity, userspace can use RTA_VIA to specify AF_INET or AF_INET6 gateway. The common fib_nexthop_info dump function compares the gateway address family to the nh_common family to know if the gateway should be encoded as RTA_VIA or RTA_GATEWAY. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/fib_frontend.c')
-rw-r--r--net/ipv4/fib_frontend.c60
1 files changed, 57 insertions, 3 deletions
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index f99a2ec32505..310060e67790 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -665,10 +665,55 @@ const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
[RTA_DPORT] = { .type = NLA_U16 },
};
+int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla,
+ struct netlink_ext_ack *extack)
+{
+ struct rtvia *via;
+ int alen;
+
+ if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
+ NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA");
+ return -EINVAL;
+ }
+
+ via = nla_data(nla);
+ alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr);
+
+ switch (via->rtvia_family) {
+ case AF_INET:
+ if (alen != sizeof(__be32)) {
+ NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA");
+ return -EINVAL;
+ }
+ cfg->fc_gw_family = AF_INET;
+ cfg->fc_gw4 = *((__be32 *)via->rtvia_addr);
+ break;
+ case AF_INET6:
+#ifdef CONFIG_IPV6
+ if (alen != sizeof(struct in6_addr)) {
+ NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA");
+ return -EINVAL;
+ }
+ cfg->fc_gw_family = AF_INET6;
+ cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr);
+#else
+ NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel");
+ return -EINVAL;
+#endif
+ break;
+ default:
+ NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
struct nlmsghdr *nlh, struct fib_config *cfg,
struct netlink_ext_ack *extack)
{
+ bool has_gw = false, has_via = false;
struct nlattr *attr;
int err, remaining;
struct rtmsg *rtm;
@@ -709,13 +754,16 @@ static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
cfg->fc_oif = nla_get_u32(attr);
break;
case RTA_GATEWAY:
+ has_gw = true;
cfg->fc_gw_family = AF_INET;
cfg->fc_gw4 = nla_get_be32(attr);
break;
case RTA_VIA:
- NL_SET_ERR_MSG(extack, "IPv4 does not support RTA_VIA attribute");
- err = -EINVAL;
- goto errout;
+ has_via = true;
+ err = fib_gw_from_via(cfg, attr, extack);
+ if (err)
+ goto errout;
+ break;
case RTA_PRIORITY:
cfg->fc_priority = nla_get_u32(attr);
break;
@@ -754,6 +802,12 @@ static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
}
}
+ if (has_gw && has_via) {
+ NL_SET_ERR_MSG(extack,
+ "Nexthop configuration can not contain both GATEWAY and VIA");
+ goto errout;
+ }
+
return 0;
errout:
return err;