fou: Support IPv6 in fou

This patch adds receive path support for IPv6 with fou.

- Add address family to fou structure for open sockets. This supports
  AF_INET and AF_INET6. Lookups for fou ports are performed on both the
  port number and family.
- In fou and gue receive adjust tot_len in IPv4 header or payload_len
  based on address family.
- Allow AF_INET6 in FOU_ATTR_AF netlink attribute.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c
index f4f2ddd..5f9207c 100644 (file)
--- a/net/ipv4/fou.c
+++ b/net/ipv4/fou.c
@@ -21,6 +21,7 @@ struct fou {
        u8 protocol;
        u8 flags;
        __be16 port;
+       u8 family;
        u16 type;
        struct list_head list;
        struct rcu_head rcu;
@@ -47,14 +48,17 @@ static inline struct fou *fou_from_sock(struct sock *sk)
        return sk->sk_user_data;
 }
 
-static int fou_recv_pull(struct sk_buff *skb, size_t len)
+static int fou_recv_pull(struct sk_buff *skb, struct fou *fou, size_t len)
 {
-       struct iphdr *iph = ip_hdr(skb);
-
        /* Remove 'len' bytes from the packet (UDP header and
         * FOU header if present).
         */
-       iph->tot_len = htons(ntohs(iph->tot_len) - len);
+       if (fou->family == AF_INET)
+               ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(skb)->tot_len) - len);
+       else
+               ipv6_hdr(skb)->payload_len =
+                   htons(ntohs(ipv6_hdr(skb)->payload_len) - len);
+
        __skb_pull(skb, len);
        skb_postpull_rcsum(skb, udp_hdr(skb), len);
        skb_reset_transport_header(skb);
@@ -68,7 +72,7 @@ static int fou_udp_recv(struct sock *sk, struct sk_buff *skb)
        if (!fou)
                return 1;
 
-       if (fou_recv_pull(skb, sizeof(struct udphdr)))
+       if (fou_recv_pull(skb, fou, sizeof(struct udphdr)))
                goto drop;
 
        return -fou->protocol;
@@ -141,7 +145,11 @@ static int gue_udp_recv(struct sock *sk, struct sk_buff *skb)
 
        hdrlen = sizeof(struct guehdr) + optlen;
 
-       ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(skb)->tot_len) - len);
+       if (fou->family == AF_INET)
+               ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(skb)->tot_len) - len);
+       else
+               ipv6_hdr(skb)->payload_len =
+                   htons(ntohs(ipv6_hdr(skb)->payload_len) - len);
 
        /* Pull csum through the guehdr now . This can be used if
         * there is a remote checksum offload.
@@ -426,7 +434,8 @@ static int fou_add_to_port_list(struct net *net, struct fou *fou)
 
        mutex_lock(&fn->fou_lock);
        list_for_each_entry(fout, &fn->fou_list, list) {
-               if (fou->port == fout->port) {
+               if (fou->port == fout->port &&
+                   fou->family == fout->family) {
                        mutex_unlock(&fn->fou_lock);
                        return -EALREADY;
                }
@@ -471,8 +480,9 @@ static int fou_create(struct net *net, struct fou_cfg *cfg,
 
        sk = sock->sk;
 
-       fou->flags = cfg->flags;
        fou->port = cfg->udp_config.local_udp_port;
+       fou->family = cfg->udp_config.family;
+       fou->flags = cfg->flags;
        fou->type = cfg->type;
        fou->sock = sock;
 
@@ -524,12 +534,13 @@ static int fou_destroy(struct net *net, struct fou_cfg *cfg)
 {
        struct fou_net *fn = net_generic(net, fou_net_id);
        __be16 port = cfg->udp_config.local_udp_port;
+       u8 family = cfg->udp_config.family;
        int err = -EINVAL;
        struct fou *fou;
 
        mutex_lock(&fn->fou_lock);
        list_for_each_entry(fou, &fn->fou_list, list) {
-               if (fou->port == port) {
+               if (fou->port == port && fou->family == family) {
                        fou_release(fou);
                        err = 0;
                        break;
@@ -567,8 +578,15 @@ static int parse_nl_config(struct genl_info *info,
        if (info->attrs[FOU_ATTR_AF]) {
                u8 family = nla_get_u8(info->attrs[FOU_ATTR_AF]);
 
-               if (family != AF_INET)
-                       return -EINVAL;
+               switch (family) {
+               case AF_INET:
+                       break;
+               case AF_INET6:
+                       cfg->udp_config.ipv6_v6only = 1;
+                       break;
+               default:
+                       return -EAFNOSUPPORT;
+               }
 
                cfg->udp_config.family = family;
        }
@@ -659,6 +677,7 @@ static int fou_nl_cmd_get_port(struct sk_buff *skb, struct genl_info *info)
        struct fou_cfg cfg;
        struct fou *fout;
        __be16 port;
+       u8 family;
        int ret;
 
        ret = parse_nl_config(info, &cfg);
@@ -668,6 +687,10 @@ static int fou_nl_cmd_get_port(struct sk_buff *skb, struct genl_info *info)
        if (port == 0)
                return -EINVAL;
 
+       family = cfg.udp_config.family;
+       if (family != AF_INET && family != AF_INET6)
+               return -EINVAL;
+
        msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
        if (!msg)
                return -ENOMEM;
@@ -675,7 +698,7 @@ static int fou_nl_cmd_get_port(struct sk_buff *skb, struct genl_info *info)
        ret = -ESRCH;
        mutex_lock(&fn->fou_lock);
        list_for_each_entry(fout, &fn->fou_list, list) {
-               if (port == fout->port) {
+               if (port == fout->port && family == fout->family) {
                        ret = fou_dump_info(fout, info->snd_portid,
                                            info->snd_seq, 0, msg,
                                            info->genlhdr->cmd);