sctp: add support for dscp and flowlabel per transport

Like some other per transport params, flowlabel and dscp are added
in transport, asoc and sctp_sock. By default, transport sets its
value from asoc's, and asoc does it from sctp_sock. flowlabel
only works for ipv6 transport.

Other than that they need to be passed down in sctp_xmit, flow4/6
also needs to set them before looking up route in get_dst.

Note that it uses '& 0x100000' to check if flowlabel is set and
'& 0x1' (tos 1st bit is unused) to check if dscp is set by users,
so that they could be set to 0 by sockopt in next patch.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 12 insertions, 4 deletions

diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 67f73d3a1356..e948db29ab53 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -426,13 +426,16 @@ static void sctp_v4_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
         struct dst_entry *dst = NULL;
         union sctp_addr *daddr = &t->ipaddr;
         union sctp_addr dst_saddr;
+        __u8 tos = inet_sk(sk)->tos;
 
+        if (t->dscp & SCTP_DSCP_SET_MASK)
+                tos = t->dscp & SCTP_DSCP_VAL_MASK;
         memset(fl4, 0x0, sizeof(struct flowi4));
         fl4->daddr  = daddr->v4.sin_addr.s_addr;
         fl4->fl4_dport = daddr->v4.sin_port;
         fl4->flowi4_proto = IPPROTO_SCTP;
         if (asoc) {
-                fl4->flowi4_tos = RT_CONN_FLAGS(asoc->base.sk);
+                fl4->flowi4_tos = RT_CONN_FLAGS_TOS(asoc->base.sk, tos);
                 fl4->flowi4_oif = asoc->base.sk->sk_bound_dev_if;
                 fl4->fl4_sport = htons(asoc->base.bind_addr.port);
         }
@@ -495,7 +498,7 @@ static void sctp_v4_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
                 fl4->fl4_sport = laddr->a.v4.sin_port;
                 flowi4_update_output(fl4,
                                      asoc->base.sk->sk_bound_dev_if,
-                                     RT_CONN_FLAGS(asoc->base.sk),
+                                     RT_CONN_FLAGS_TOS(asoc->base.sk, tos),
                                      daddr->v4.sin_addr.s_addr,
                                      laddr->a.v4.sin_addr.s_addr);
 
@@ -971,16 +974,21 @@ static inline int sctp_v4_xmit(struct sk_buff *skb,
                                struct sctp_transport *transport)
 {
         struct inet_sock *inet = inet_sk(skb->sk);
+        __u8 dscp = inet->tos;
 
         pr_debug("%s: skb:%p, len:%d, src:%pI4, dst:%pI4\n", __func__, skb,
-                 skb->len, &transport->fl.u.ip4.saddr, &transport->fl.u.ip4.daddr);
+                 skb->len, &transport->fl.u.ip4.saddr,
+                 &transport->fl.u.ip4.daddr);
+
+        if (transport->dscp & SCTP_DSCP_SET_MASK)
+                dscp = transport->dscp & SCTP_DSCP_VAL_MASK;
 
         inet->pmtudisc = transport->param_flags & SPP_PMTUD_ENABLE ?
                          IP_PMTUDISC_DO : IP_PMTUDISC_DONT;
 
         SCTP_INC_STATS(sock_net(&inet->sk), SCTP_MIB_OUTSCTPPACKS);
 
-        return ip_queue_xmit(&inet->sk, skb, &transport->fl);
+        return __ip_queue_xmit(&inet->sk, skb, &transport->fl, dscp);
 }
 
 static struct sctp_af sctp_af_inet;