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>

diff --git a/include/linux/sctp.h b/include/linux/sctp.h
index b36c76635f182007584076ff5fb4d644cb134a0f..83d94341e0032795035b9545483f3cc32a6d9500 100644 (file)
--- a/include/linux/sctp.h
+++ b/include/linux/sctp.h
@@ -801,4 +801,11 @@ struct sctp_strreset_resptsn {
        __be32 receivers_next_tsn;
 };
 
+enum {
+       SCTP_DSCP_SET_MASK = 0x1,
+       SCTP_DSCP_VAL_MASK = 0xfc,
+       SCTP_FLOWLABEL_SET_MASK = 0x100000,
+       SCTP_FLOWLABEL_VAL_MASK = 0xfffff
+};
+
 #endif /* __LINUX_SCTP_H__ */

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 701a51736fa53477a2f9b62afeea7319b7d80623..ab869e0d83267b730d7b0758dbf90f233962c714 100644 (file)
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -193,6 +193,9 @@ struct sctp_sock {
        /* This is the max_retrans value for new associations. */
        __u16 pathmaxrxt;
 
+       __u32 flowlabel;
+       __u8  dscp;
+
        /* The initial Path MTU to use for new associations. */
        __u32 pathmtu;
 
@@ -895,6 +898,9 @@ struct sctp_transport {
         */
        __u16 pathmaxrxt;
 
+       __u32 flowlabel;
+       __u8  dscp;
+
        /* This is the partially failed retrans value for the transport
         * and will be initialized from the assocs value.  This can be changed
         * using the SCTP_PEER_ADDR_THLDS socket option
@@ -1772,6 +1778,9 @@ struct sctp_association {
         */
        __u16 pathmaxrxt;
 
+       __u32 flowlabel;
+       __u8  dscp;
+
        /* Flag that path mtu update is pending */
        __u8   pmtu_pending;
 

diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index 5d5a16204d50516eca7d5322a60aac6511178c38..16ecfbc956149a6066fd961f1d5cda15852a1bdb 100644 (file)
--- a/net/sctp/associola.c
+++ b/net/sctp/associola.c
@@ -115,6 +115,9 @@ static struct sctp_association *sctp_association_init(
        /* Initialize path max retrans value. */
        asoc->pathmaxrxt = sp->pathmaxrxt;
 
+       asoc->flowlabel = sp->flowlabel;
+       asoc->dscp = sp->dscp;
+
        /* Initialize default path MTU. */
        asoc->pathmtu = sp->pathmtu;
 
@@ -647,6 +650,10 @@ struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
        peer->sackdelay = asoc->sackdelay;
        peer->sackfreq = asoc->sackfreq;
 
+       if (addr->sa.sa_family == AF_INET6)
+               peer->flowlabel = asoc->flowlabel;
+       peer->dscp = asoc->dscp;
+
        /* Enable/disable heartbeat, SACK delay, and path MTU discovery
         * based on association setting.
         */

diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index 0cd2e764f47ff0874438301324de25e4bf33dd95..38102bf7f13e850bb24dac869021641cd1e910cf 100644 (file)
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c
@@ -209,12 +209,17 @@ static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
        struct sock *sk = skb->sk;
        struct ipv6_pinfo *np = inet6_sk(sk);
        struct flowi6 *fl6 = &transport->fl.u.ip6;
+       __u8 tclass = np->tclass;
        int res;
 
        pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
                 skb->len, &fl6->saddr, &fl6->daddr);
 
-       IP6_ECN_flow_xmit(sk, fl6->flowlabel);
+       if (transport->dscp & SCTP_DSCP_SET_MASK)
+               tclass = transport->dscp & SCTP_DSCP_VAL_MASK;
+
+       if (INET_ECN_is_capable(tclass))
+               IP6_ECN_flow_xmit(sk, fl6->flowlabel);
 
        if (!(transport->param_flags & SPP_PMTUD_ENABLE))
                skb->ignore_df = 1;
@@ -223,7 +228,7 @@ static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
 
        rcu_read_lock();
        res = ip6_xmit(sk, skb, fl6, sk->sk_mark, rcu_dereference(np->opt),
-                      np->tclass);
+                      tclass);
        rcu_read_unlock();
        return res;
 }
@@ -254,6 +259,8 @@ static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
                fl6->flowi6_oif = daddr->v6.sin6_scope_id;
        else if (asoc)
                fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
+       if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK)
+               fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK);
 
        pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
 

diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 67f73d3a1356b93d3896b6985a65e70615902b18..e948db29ab539a588e8526d2f4fc22428a9f4685 100644 (file)
--- 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;