[PATCHv2 net-next 0/5] sctp: fully support for dscp and flowlabel per transport

[PATCHv2 net-next 0/5] sctp: fully support for dscp and flowlabel per transport

[Xin Long]

Now dscp and flowlabel are set from sock when sending the packets,
but being multi-homing, sctp also supports for dscp and flowlabel
per transport, which is described in section 8.1.12 in RFC6458.

v1->v2:
  - define ip_queue_xmit as inline in net/ip.h, instead of exporting
    it in Patch 1/5 according to David's suggestion.
  - fix the param len check in sctp_s/getsockopt_peer_addr_params()
    in Patch 3/5 to guarantee that an old app built with old kernel
    headers could work on the newer kernel per Marcelo's point.

Xin Long (5):
  ipv4: add __ip_queue_xmit() that supports tos param
  sctp: add support for dscp and flowlabel per transport
  sctp: add spp_ipv6_flowlabel and spp_dscp for sctp_paddrparams
  sctp: add support for setting flowlabel when adding a transport
  sctp: check for ipv6_pinfo legal sndflow with flowlabel in
    sctp_v6_get_dst

 include/linux/sctp.h       |   7 ++
 include/net/ip.h           |   9 ++-
 include/net/sctp/structs.h |   9 +++
 include/uapi/linux/sctp.h  |   4 +
 net/ipv4/ip_output.c       |   9 ++-
 net/sctp/associola.c       |  15 ++++
 net/sctp/ipv6.c            |  20 ++++-
 net/sctp/protocol.c        |  16 +++-
 net/sctp/socket.c          | 182 +++++++++++++++++++++++++++++++++++++++++++--
 9 files changed, 254 insertions(+), 17 deletions(-)

-- 
2.1.0

[PATCHv2 net-next 1/5] ipv4: add __ip_queue_xmit() that supports tos param

[Xin Long]

This patch introduces __ip_queue_xmit(), through which the callers
can pass tos param into it without having to set inet->tos. For
ipv6, ip6_xmit() already allows passing tclass parameter.

It's needed when some transport protocol doesn't use inet->tos,
like sctp's per transport dscp, which will be added in next patch.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 include/net/ip.h     | 9 ++++++++-
 net/ipv4/ip_output.c | 9 +++++----
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/include/net/ip.h b/include/net/ip.h
index 0d2281b..09da79d 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -148,7 +148,8 @@ void ip_send_check(struct iphdr *ip);
 int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 
-int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
+int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
+		    __u8 tos);
 void ip_init(void);
 int ip_append_data(struct sock *sk, struct flowi4 *fl4,
 		   int getfrag(void *from, char *to, int offset, int len,
@@ -174,6 +175,12 @@ struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
 			    struct ipcm_cookie *ipc, struct rtable **rtp,
 			    struct inet_cork *cork, unsigned int flags);
 
+static inline int ip_queue_xmit(struct sock *sk, struct sk_buff *skb,
+				struct flowi *fl)
+{
+	return __ip_queue_xmit(sk, skb, fl, inet_sk(sk)->tos);
+}
+
 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
 {
 	return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index b3308e9..188cc58 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -423,7 +423,8 @@ static void ip_copy_addrs(struct iphdr *iph, const struct flowi4 *fl4)
 }
 
 /* Note: skb->sk can be different from sk, in case of tunnels */
-int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl)
+int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
+		    __u8 tos)
 {
 	struct inet_sock *inet = inet_sk(sk);
 	struct net *net = sock_net(sk);
@@ -462,7 +463,7 @@ int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl)
 					   inet->inet_dport,
 					   inet->inet_sport,
 					   sk->sk_protocol,
-					   RT_CONN_FLAGS(sk),
+					   RT_CONN_FLAGS_TOS(sk, tos),
 					   sk->sk_bound_dev_if);
 		if (IS_ERR(rt))
 			goto no_route;
@@ -478,7 +479,7 @@ int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl)
 	skb_push(skb, sizeof(struct iphdr) + (inet_opt ? inet_opt->opt.optlen : 0));
 	skb_reset_network_header(skb);
 	iph = ip_hdr(skb);
-	*((__be16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff));
+	*((__be16 *)iph) = htons((4 << 12) | (5 << 8) | (tos & 0xff));
 	if (ip_dont_fragment(sk, &rt->dst) && !skb->ignore_df)
 		iph->frag_off = htons(IP_DF);
 	else
@@ -511,7 +512,7 @@ int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl)
 	kfree_skb(skb);
 	return -EHOSTUNREACH;
 }
-EXPORT_SYMBOL(ip_queue_xmit);
+EXPORT_SYMBOL(__ip_queue_xmit);
 
 static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from)
 {
-- 
2.1.0

[PATCHv2 net-next 2/5] sctp: add support for dscp and flowlabel per transport

[Xin Long]

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>
---
 include/linux/sctp.h       |  7 +++++++
 include/net/sctp/structs.h |  9 +++++++++
 net/sctp/associola.c       |  7 +++++++
 net/sctp/ipv6.c            | 11 +++++++++--
 net/sctp/protocol.c        | 16 ++++++++++++----
 5 files changed, 44 insertions(+), 6 deletions(-)

diff --git a/include/linux/sctp.h b/include/linux/sctp.h
index b36c766..83d9434 100644
--- 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 701a517..ab869e0 100644
--- 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 5d5a162..16ecfbc 100644
--- 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 7339918..772513d 100644
--- 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 5dffbc4..d57fd30 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;
-- 
2.1.0

[PATCHv2 net-next 3/5] sctp: add spp_ipv6_flowlabel and spp_dscp for sctp_paddrparams

[Xin Long]

spp_ipv6_flowlabel and spp_dscp are added in sctp_paddrparams in
this patch so that users could set sctp_sock/asoc/transport dscp
and flowlabel with spp_flags SPP_IPV6_FLOWLABEL or SPP_DSCP by
SCTP_PEER_ADDR_PARAMS , as described section 8.1.12 in RFC6458.

As said in last patch, it uses '| 0x100000' or '|0x1' to mark
flowlabel or dscp is set,  so that their values could be set
to 0.

Note that to guarantee that an old app built with old kernel
headers could work on the newer kernel, the param's check in
sctp_g/setsockopt_peer_addr_params() is also improved, which
follows the way that sctp_g/setsockopt_delayed_ack() or some
other sockopts' process that accept two types of params does.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 include/uapi/linux/sctp.h |   4 ++
 net/sctp/socket.c         | 177 ++++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 175 insertions(+), 6 deletions(-)

diff --git a/include/uapi/linux/sctp.h b/include/uapi/linux/sctp.h
index c02986a..b479db5 100644
--- a/include/uapi/linux/sctp.h
+++ b/include/uapi/linux/sctp.h
@@ -763,6 +763,8 @@ enum  sctp_spp_flags {
 	SPP_SACKDELAY_DISABLE = 1<<6,	/*Disable SACK*/
 	SPP_SACKDELAY = SPP_SACKDELAY_ENABLE | SPP_SACKDELAY_DISABLE,
 	SPP_HB_TIME_IS_ZERO = 1<<7,	/* Set HB delay to 0 */
+	SPP_IPV6_FLOWLABEL = 1<<8,
+	SPP_DSCP = 1<<9,
 };
 
 struct sctp_paddrparams {
@@ -773,6 +775,8 @@ struct sctp_paddrparams {
 	__u32			spp_pathmtu;
 	__u32			spp_sackdelay;
 	__u32			spp_flags;
+	__u32			spp_ipv6_flowlabel;
+	__u8			spp_dscp;
 } __attribute__((packed, aligned(4)));
 
 /*
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index bf11f9c..452029f 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -2393,6 +2393,8 @@ static int sctp_setsockopt_autoclose(struct sock *sk, char __user *optval,
  *     uint32_t                spp_pathmtu;
  *     uint32_t                spp_sackdelay;
  *     uint32_t                spp_flags;
+ *     uint32_t                spp_ipv6_flowlabel;
+ *     uint8_t                 spp_dscp;
  * };
  *
  *   spp_assoc_id    - (one-to-many style socket) This is filled in the
@@ -2472,6 +2474,45 @@ static int sctp_setsockopt_autoclose(struct sock *sk, char __user *optval,
  *                     also that this field is mutually exclusive to
  *                     SPP_SACKDELAY_ENABLE, setting both will have undefined
  *                     results.
+ *
+ *                     SPP_IPV6_FLOWLABEL:  Setting this flag enables the
+ *                     setting of the IPV6 flow label value.  The value is
+ *                     contained in the spp_ipv6_flowlabel field.
+ *                     Upon retrieval, this flag will be set to indicate that
+ *                     the spp_ipv6_flowlabel field has a valid value returned.
+ *                     If a specific destination address is set (in the
+ *                     spp_address field), then the value returned is that of
+ *                     the address.  If just an association is specified (and
+ *                     no address), then the association's default flow label
+ *                     is returned.  If neither an association nor a destination
+ *                     is specified, then the socket's default flow label is
+ *                     returned.  For non-IPv6 sockets, this flag will be left
+ *                     cleared.
+ *
+ *                     SPP_DSCP:  Setting this flag enables the setting of the
+ *                     Differentiated Services Code Point (DSCP) value
+ *                     associated with either the association or a specific
+ *                     address.  The value is obtained in the spp_dscp field.
+ *                     Upon retrieval, this flag will be set to indicate that
+ *                     the spp_dscp field has a valid value returned.  If a
+ *                     specific destination address is set when called (in the
+ *                     spp_address field), then that specific destination
+ *                     address's DSCP value is returned.  If just an association
+ *                     is specified, then the association's default DSCP is
+ *                     returned.  If neither an association nor a destination is
+ *                     specified, then the socket's default DSCP is returned.
+ *
+ *   spp_ipv6_flowlabel
+ *                   - This field is used in conjunction with the
+ *                     SPP_IPV6_FLOWLABEL flag and contains the IPv6 flow label.
+ *                     The 20 least significant bits are used for the flow
+ *                     label.  This setting has precedence over any IPv6-layer
+ *                     setting.
+ *
+ *   spp_dscp        - This field is used in conjunction with the SPP_DSCP flag
+ *                     and contains the DSCP.  The 6 most significant bits are
+ *                     used for the DSCP.  This setting has precedence over any
+ *                     IPv4- or IPv6- layer setting.
  */
 static int sctp_apply_peer_addr_params(struct sctp_paddrparams *params,
 				       struct sctp_transport   *trans,
@@ -2611,6 +2652,51 @@ static int sctp_apply_peer_addr_params(struct sctp_paddrparams *params,
 		}
 	}
 
+	if (params->spp_flags & SPP_IPV6_FLOWLABEL) {
+		if (trans && trans->ipaddr.sa.sa_family = AF_INET6) {
+			trans->flowlabel = params->spp_ipv6_flowlabel &
+					   SCTP_FLOWLABEL_VAL_MASK;
+			trans->flowlabel |= SCTP_FLOWLABEL_SET_MASK;
+		} else if (asoc) {
+			list_for_each_entry(trans,
+					    &asoc->peer.transport_addr_list,
+					    transports) {
+				if (trans->ipaddr.sa.sa_family != AF_INET6)
+					continue;
+				trans->flowlabel = params->spp_ipv6_flowlabel &
+						   SCTP_FLOWLABEL_VAL_MASK;
+				trans->flowlabel |= SCTP_FLOWLABEL_SET_MASK;
+			}
+			asoc->flowlabel = params->spp_ipv6_flowlabel &
+					  SCTP_FLOWLABEL_VAL_MASK;
+			asoc->flowlabel |= SCTP_FLOWLABEL_SET_MASK;
+		} else if (sctp_opt2sk(sp)->sk_family = AF_INET6) {
+			sp->flowlabel = params->spp_ipv6_flowlabel &
+					SCTP_FLOWLABEL_VAL_MASK;
+			sp->flowlabel |= SCTP_FLOWLABEL_SET_MASK;
+		}
+	}
+
+	if (params->spp_flags & SPP_DSCP) {
+		if (trans) {
+			trans->dscp = params->spp_dscp & SCTP_DSCP_VAL_MASK;
+			trans->dscp |= SCTP_DSCP_SET_MASK;
+		} else if (asoc) {
+			list_for_each_entry(trans,
+					    &asoc->peer.transport_addr_list,
+					    transports) {
+				trans->dscp = params->spp_dscp &
+					      SCTP_DSCP_VAL_MASK;
+				trans->dscp |= SCTP_DSCP_SET_MASK;
+			}
+			asoc->dscp = params->spp_dscp & SCTP_DSCP_VAL_MASK;
+			asoc->dscp |= SCTP_DSCP_SET_MASK;
+		} else {
+			sp->dscp = params->spp_dscp & SCTP_DSCP_VAL_MASK;
+			sp->dscp |= SCTP_DSCP_SET_MASK;
+		}
+	}
+
 	return 0;
 }
 
@@ -2625,11 +2711,18 @@ static int sctp_setsockopt_peer_addr_params(struct sock *sk,
 	int error;
 	int hb_change, pmtud_change, sackdelay_change;
 
-	if (optlen != sizeof(struct sctp_paddrparams))
+	if (optlen = sizeof(params)) {
+		if (copy_from_user(&params, optval, optlen))
+			return -EFAULT;
+	} else if (optlen = ALIGN(offsetof(struct sctp_paddrparams,
+					    spp_ipv6_flowlabel), 4)) {
+		if (copy_from_user(&params, optval, optlen))
+			return -EFAULT;
+		if (params.spp_flags & (SPP_DSCP | SPP_IPV6_FLOWLABEL))
+			return -EINVAL;
+	} else {
 		return -EINVAL;
-
-	if (copy_from_user(&params, optval, optlen))
-		return -EFAULT;
+	}
 
 	/* Validate flags and value parameters. */
 	hb_change        = params.spp_flags & SPP_HB;
@@ -5453,6 +5546,45 @@ static int sctp_getsockopt_peeloff_flags(struct sock *sk, int len,
  *                     also that this field is mutually exclusive to
  *                     SPP_SACKDELAY_ENABLE, setting both will have undefined
  *                     results.
+ *
+ *                     SPP_IPV6_FLOWLABEL:  Setting this flag enables the
+ *                     setting of the IPV6 flow label value.  The value is
+ *                     contained in the spp_ipv6_flowlabel field.
+ *                     Upon retrieval, this flag will be set to indicate that
+ *                     the spp_ipv6_flowlabel field has a valid value returned.
+ *                     If a specific destination address is set (in the
+ *                     spp_address field), then the value returned is that of
+ *                     the address.  If just an association is specified (and
+ *                     no address), then the association's default flow label
+ *                     is returned.  If neither an association nor a destination
+ *                     is specified, then the socket's default flow label is
+ *                     returned.  For non-IPv6 sockets, this flag will be left
+ *                     cleared.
+ *
+ *                     SPP_DSCP:  Setting this flag enables the setting of the
+ *                     Differentiated Services Code Point (DSCP) value
+ *                     associated with either the association or a specific
+ *                     address.  The value is obtained in the spp_dscp field.
+ *                     Upon retrieval, this flag will be set to indicate that
+ *                     the spp_dscp field has a valid value returned.  If a
+ *                     specific destination address is set when called (in the
+ *                     spp_address field), then that specific destination
+ *                     address's DSCP value is returned.  If just an association
+ *                     is specified, then the association's default DSCP is
+ *                     returned.  If neither an association nor a destination is
+ *                     specified, then the socket's default DSCP is returned.
+ *
+ *   spp_ipv6_flowlabel
+ *                   - This field is used in conjunction with the
+ *                     SPP_IPV6_FLOWLABEL flag and contains the IPv6 flow label.
+ *                     The 20 least significant bits are used for the flow
+ *                     label.  This setting has precedence over any IPv6-layer
+ *                     setting.
+ *
+ *   spp_dscp        - This field is used in conjunction with the SPP_DSCP flag
+ *                     and contains the DSCP.  The 6 most significant bits are
+ *                     used for the DSCP.  This setting has precedence over any
+ *                     IPv4- or IPv6- layer setting.
  */
 static int sctp_getsockopt_peer_addr_params(struct sock *sk, int len,
 					    char __user *optval, int __user *optlen)
@@ -5462,9 +5594,15 @@ static int sctp_getsockopt_peer_addr_params(struct sock *sk, int len,
 	struct sctp_association *asoc = NULL;
 	struct sctp_sock        *sp = sctp_sk(sk);
 
-	if (len < sizeof(struct sctp_paddrparams))
+	if (len >= sizeof(params))
+		len = sizeof(params);
+	else if (len >= ALIGN(offsetof(struct sctp_paddrparams,
+				       spp_ipv6_flowlabel), 4))
+		len = ALIGN(offsetof(struct sctp_paddrparams,
+				     spp_ipv6_flowlabel), 4);
+	else
 		return -EINVAL;
-	len = sizeof(struct sctp_paddrparams);
+
 	if (copy_from_user(&params, optval, len))
 		return -EFAULT;
 
@@ -5499,6 +5637,15 @@ static int sctp_getsockopt_peer_addr_params(struct sock *sk, int len,
 
 		/*draft-11 doesn't say what to return in spp_flags*/
 		params.spp_flags      = trans->param_flags;
+		if (trans->flowlabel & SCTP_FLOWLABEL_SET_MASK) {
+			params.spp_ipv6_flowlabel = trans->flowlabel &
+						    SCTP_FLOWLABEL_VAL_MASK;
+			params.spp_flags |= SPP_IPV6_FLOWLABEL;
+		}
+		if (trans->dscp & SCTP_DSCP_SET_MASK) {
+			params.spp_dscp	= trans->dscp & SCTP_DSCP_VAL_MASK;
+			params.spp_flags |= SPP_DSCP;
+		}
 	} else if (asoc) {
 		/* Fetch association values. */
 		params.spp_hbinterval = jiffies_to_msecs(asoc->hbinterval);
@@ -5508,6 +5655,15 @@ static int sctp_getsockopt_peer_addr_params(struct sock *sk, int len,
 
 		/*draft-11 doesn't say what to return in spp_flags*/
 		params.spp_flags      = asoc->param_flags;
+		if (asoc->flowlabel & SCTP_FLOWLABEL_SET_MASK) {
+			params.spp_ipv6_flowlabel = asoc->flowlabel &
+						    SCTP_FLOWLABEL_VAL_MASK;
+			params.spp_flags |= SPP_IPV6_FLOWLABEL;
+		}
+		if (asoc->dscp & SCTP_DSCP_SET_MASK) {
+			params.spp_dscp	= asoc->dscp & SCTP_DSCP_VAL_MASK;
+			params.spp_flags |= SPP_DSCP;
+		}
 	} else {
 		/* Fetch socket values. */
 		params.spp_hbinterval = sp->hbinterval;
@@ -5517,6 +5673,15 @@ static int sctp_getsockopt_peer_addr_params(struct sock *sk, int len,
 
 		/*draft-11 doesn't say what to return in spp_flags*/
 		params.spp_flags      = sp->param_flags;
+		if (sp->flowlabel & SCTP_FLOWLABEL_SET_MASK) {
+			params.spp_ipv6_flowlabel = sp->flowlabel &
+						    SCTP_FLOWLABEL_VAL_MASK;
+			params.spp_flags |= SPP_IPV6_FLOWLABEL;
+		}
+		if (sp->dscp & SCTP_DSCP_SET_MASK) {
+			params.spp_dscp	= sp->dscp & SCTP_DSCP_VAL_MASK;
+			params.spp_flags |= SPP_DSCP;
+		}
 	}
 
 	if (copy_to_user(optval, &params, len))
-- 
2.1.0

[PATCHv2 net-next 4/5] sctp: add support for setting flowlabel when adding a transport

[Xin Long]

Struct sockaddr_in6 has the member sin6_flowinfo that includes the
ipv6 flowlabel, it should also support for setting flowlabel when
adding a transport whose ipaddr is from userspace.

Note that addrinfo in sctp_sendmsg is using struct in6_addr for
the secondary addrs, which doesn't contain sin6_flowinfo, and
it needs to copy sin6_flowinfo from the primary addr.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 net/sctp/associola.c | 12 ++++++++++--
 net/sctp/socket.c    |  5 +++++
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index 16ecfbc..297d9cf 100644
--- a/net/sctp/associola.c
+++ b/net/sctp/associola.c
@@ -650,8 +650,16 @@ 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;
+	if (addr->sa.sa_family = AF_INET6) {
+		__be32 info = addr->v6.sin6_flowinfo;
+
+		if (info) {
+			peer->flowlabel = ntohl(info & IPV6_FLOWLABEL_MASK);
+			peer->flowlabel |= SCTP_FLOWLABEL_SET_MASK;
+		} else {
+			peer->flowlabel = asoc->flowlabel;
+		}
+	}
 	peer->dscp = asoc->dscp;
 
 	/* Enable/disable heartbeat, SACK delay, and path MTU discovery
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 452029f..2607b50 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -1697,6 +1697,7 @@ static int sctp_sendmsg_new_asoc(struct sock *sk, __u16 sflags,
 	struct sctp_association *asoc;
 	enum sctp_scope scope;
 	struct cmsghdr *cmsg;
+	__be32 flowinfo = 0;
 	struct sctp_af *af;
 	int err;
 
@@ -1781,6 +1782,9 @@ static int sctp_sendmsg_new_asoc(struct sock *sk, __u16 sflags,
 	if (!cmsgs->addrs_msg)
 		return 0;
 
+	if (daddr->sa.sa_family = AF_INET6)
+		flowinfo = daddr->v6.sin6_flowinfo;
+
 	/* sendv addr list parse */
 	for_each_cmsghdr(cmsg, cmsgs->addrs_msg) {
 		struct sctp_transport *transport;
@@ -1813,6 +1817,7 @@ static int sctp_sendmsg_new_asoc(struct sock *sk, __u16 sflags,
 			}
 
 			dlen = sizeof(struct in6_addr);
+			daddr->v6.sin6_flowinfo = flowinfo;
 			daddr->v6.sin6_family = AF_INET6;
 			daddr->v6.sin6_port = htons(asoc->peer.port);
 			memcpy(&daddr->v6.sin6_addr, CMSG_DATA(cmsg), dlen);
-- 
2.1.0

[PATCHv2 net-next 5/5] sctp: check for ipv6_pinfo legal sndflow with flowlabel in sctp_v6_get_dst

[Xin Long]

The transport with illegal flowlabel should not be allowed to send
packets. Other transport protocols already denies this.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 net/sctp/ipv6.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index 772513d..d83ddc4 100644
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c
@@ -262,6 +262,15 @@ static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 	if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK)
 		fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK);
 
+	if (np->sndflow && (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) {
+		struct ip6_flowlabel *flowlabel;
+
+		flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
+		if (!flowlabel)
+			goto out;
+		fl6_sock_release(flowlabel);
+	}
+
 	pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
 
 	if (asoc)
-- 
2.1.0

Re: [PATCHv2 net-next 0/5] sctp: fully support for dscp and flowlabel per transport

[Marcelo Ricardo Leitner]

On Mon, Jul 02, 2018 at 06:21:10PM +0800, Xin Long wrote:
> Now dscp and flowlabel are set from sock when sending the packets,
> but being multi-homing, sctp also supports for dscp and flowlabel
> per transport, which is described in section 8.1.12 in RFC6458.
> 
> v1->v2:
>   - define ip_queue_xmit as inline in net/ip.h, instead of exporting
>     it in Patch 1/5 according to David's suggestion.
>   - fix the param len check in sctp_s/getsockopt_peer_addr_params()
>     in Patch 3/5 to guarantee that an old app built with old kernel
>     headers could work on the newer kernel per Marcelo's point.
> 
> Xin Long (5):
>   ipv4: add __ip_queue_xmit() that supports tos param
>   sctp: add support for dscp and flowlabel per transport
>   sctp: add spp_ipv6_flowlabel and spp_dscp for sctp_paddrparams
>   sctp: add support for setting flowlabel when adding a transport
>   sctp: check for ipv6_pinfo legal sndflow with flowlabel in
>     sctp_v6_get_dst

Series
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>

Re: [PATCHv2 net-next 0/5] sctp: fully support for dscp and flowlabel per transport

[Neil Horman]

On Mon, Jul 02, 2018 at 06:21:10PM +0800, Xin Long wrote:
> Now dscp and flowlabel are set from sock when sending the packets,
> but being multi-homing, sctp also supports for dscp and flowlabel
> per transport, which is described in section 8.1.12 in RFC6458.
> 
> v1->v2:
>   - define ip_queue_xmit as inline in net/ip.h, instead of exporting
>     it in Patch 1/5 according to David's suggestion.
>   - fix the param len check in sctp_s/getsockopt_peer_addr_params()
>     in Patch 3/5 to guarantee that an old app built with old kernel
>     headers could work on the newer kernel per Marcelo's point.
> 
> Xin Long (5):
>   ipv4: add __ip_queue_xmit() that supports tos param
>   sctp: add support for dscp and flowlabel per transport
>   sctp: add spp_ipv6_flowlabel and spp_dscp for sctp_paddrparams
>   sctp: add support for setting flowlabel when adding a transport
>   sctp: check for ipv6_pinfo legal sndflow with flowlabel in
>     sctp_v6_get_dst
> 
>  include/linux/sctp.h       |   7 ++
>  include/net/ip.h           |   9 ++-
>  include/net/sctp/structs.h |   9 +++
>  include/uapi/linux/sctp.h  |   4 +
>  net/ipv4/ip_output.c       |   9 ++-
>  net/sctp/associola.c       |  15 ++++
>  net/sctp/ipv6.c            |  20 ++++-
>  net/sctp/protocol.c        |  16 +++-
>  net/sctp/socket.c          | 182 +++++++++++++++++++++++++++++++++++++++++++--
>  9 files changed, 254 insertions(+), 17 deletions(-)
> 
> -- 
> 2.1.0
> 
> 
For the Series
Acked-by: Neil Horman <nhorman@tuxdriver.com>