[NET]: Introducing socket mark socket option.

A userspace program may wish to set the mark for each packets its send
without using the netfilter MARK target. Changing the mark can be used
for mark based routing without netfilter or for packet filtering.

It requires CAP_NET_ADMIN capability.

Signed-off-by: Laszlo Attila Toth <panther@balabit.hu>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 5 insertions, 0 deletions

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 6e4d5f493bf9..341779e685d9 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -168,6 +168,7 @@ int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
         }
 
         skb->priority = sk->sk_priority;
+        skb->mark = sk->sk_mark;
 
         /* Send it out. */
         return ip_local_out(skb);
@@ -385,6 +386,7 @@ packet_routed:
                              (skb_shinfo(skb)->gso_segs ?: 1) - 1);
 
         skb->priority = sk->sk_priority;
+        skb->mark = sk->sk_mark;
 
         return ip_local_out(skb);
 
@@ -1286,6 +1288,7 @@ int ip_push_pending_frames(struct sock *sk)
         iph->daddr = rt->rt_dst;
 
         skb->priority = sk->sk_priority;
+        skb->mark = sk->sk_mark;
         skb->dst = dst_clone(&rt->u.dst);
 
         if (iph->protocol == IPPROTO_ICMP)
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 85c08696abbe..f863c3dc5421 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -352,6 +352,7 @@ static int raw_send_hdrinc(struct sock *sk, void *from, size_t length,
         skb_reserve(skb, hh_len);
 
         skb->priority = sk->sk_priority;
+        skb->mark = sk->sk_mark;
         skb->dst = dst_clone(&rt->u.dst);
 
         skb_reset_network_header(skb);
@@ -544,6 +545,7 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 
         {
                 struct flowi fl = { .oif = ipc.oif,
+                                    .mark = sk->sk_mark,
                                     .nl_u = { .ip4_u =
                                               { .daddr = daddr,
                                                 .saddr = saddr,