Merge branch 'ipv4-convert-__fib_validate_source-and-its-callers-to-dscp_t'

Guillaume Nault says:

====================
ipv4: Convert __fib_validate_source() and its callers to dscp_t.

This patch series continues to prepare users of ->flowi4_tos to a
future conversion of this field (__u8 to dscp_t). This time, we convert
__fib_validate_source() and its call chain.

The objective is to eventually make all users of ->flowi4_tos use a
dscp_t value. Making ->flowi4_tos a dscp_t field will help avoiding
regressions where ECN bits are erroneously interpreted as DSCP bits.
====================

Link: https://patch.msgid.link/cover.1728302212.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

6 files changed, 38 insertions, 41 deletions

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index 967e4dc555fa..06130933542d 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -449,8 +449,9 @@ int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla,
 __be32 fib_compute_spec_dst(struct sk_buff *skb);
 bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev);
 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
-			u8 tos, int oif, struct net_device *dev,
+			dscp_t dscp, int oif, struct net_device *dev,
 			struct in_device *idev, u32 *itag);
+
 #ifdef CONFIG_IP_ROUTE_CLASSID
 static inline int fib_num_tclassid_users(struct net *net)
 {
diff --git a/include/net/route.h b/include/net/route.h
index 5e4374d66927..586e59f7ed8a 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -198,13 +198,14 @@ static inline struct rtable *ip_route_output_gre(struct net *net, struct flowi4
 	fl4->fl4_gre_key = gre_key;
 	return ip_route_output_key(net, fl4);
 }
+
 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
-			  u8 tos, struct net_device *dev,
+			  dscp_t dscp, struct net_device *dev,
 			  struct in_device *in_dev, u32 *itag);
 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 			 dscp_t dscp, struct net_device *dev);
-int ip_route_use_hint(struct sk_buff *skb, __be32 dst, __be32 src,
-		      u8 tos, struct net_device *devin,
+int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr,
+		      dscp_t dscp, struct net_device *dev,
 		      const struct sk_buff *hint);
 
 static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src,
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 793e6781399a..8353518b110a 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -342,7 +342,7 @@ EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev);
  * called with rcu_read_lock()
  */
 static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
-				 u8 tos, int oif, struct net_device *dev,
+				 dscp_t dscp, int oif, struct net_device *dev,
 				 int rpf, struct in_device *idev, u32 *itag)
 {
 	struct net *net = dev_net(dev);
@@ -357,7 +357,7 @@ static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 	fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
 	fl4.daddr = src;
 	fl4.saddr = dst;
-	fl4.flowi4_tos = tos;
+	fl4.flowi4_tos = inet_dscp_to_dsfield(dscp);
 	fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
 	fl4.flowi4_tun_key.tun_id = 0;
 	fl4.flowi4_flags = 0;
@@ -419,7 +419,7 @@ e_rpf:
 
 /* Ignore rp_filter for packets protected by IPsec. */
 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
-			u8 tos, int oif, struct net_device *dev,
+			dscp_t dscp, int oif, struct net_device *dev,
 			struct in_device *idev, u32 *itag)
 {
 	int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
@@ -448,7 +448,8 @@ ok:
 	}
 
 full_check:
-	return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
+	return __fib_validate_source(skb, src, dst, dscp, oif, dev, r, idev,
+				     itag);
 }
 
 static inline __be32 sk_extract_addr(struct sockaddr *addr)
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index c0a2490eb7c1..89bb63da6852 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -325,8 +325,8 @@ static int ip_rcv_finish_core(struct net *net, struct sock *sk,
 	drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
 
 	if (ip_can_use_hint(skb, iph, hint)) {
-		err = ip_route_use_hint(skb, iph->daddr, iph->saddr, iph->tos,
-					dev, hint);
+		err = ip_route_use_hint(skb, iph->daddr, iph->saddr,
+					ip4h_dscp(iph), dev, hint);
 		if (unlikely(err))
 			goto drop_error;
 	}
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 6e1cd0065b87..a0b091a7df87 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1666,7 +1666,7 @@ EXPORT_SYMBOL(rt_dst_clone);
 
 /* called in rcu_read_lock() section */
 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
-			  u8 tos, struct net_device *dev,
+			  dscp_t dscp, struct net_device *dev,
 			  struct in_device *in_dev, u32 *itag)
 {
 	int err;
@@ -1687,8 +1687,8 @@ int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 		    ip_hdr(skb)->protocol != IPPROTO_IGMP)
 			return -EINVAL;
 	} else {
-		err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
-					  in_dev, itag);
+		err = fib_validate_source(skb, saddr, 0, dscp, 0, dev, in_dev,
+					  itag);
 		if (err < 0)
 			return err;
 	}
@@ -1697,7 +1697,7 @@ int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 
 /* called in rcu_read_lock() section */
 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
-			     u8 tos, struct net_device *dev, int our)
+			     dscp_t dscp, struct net_device *dev, int our)
 {
 	struct in_device *in_dev = __in_dev_get_rcu(dev);
 	unsigned int flags = RTCF_MULTICAST;
@@ -1705,7 +1705,8 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 	u32 itag = 0;
 	int err;
 
-	err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag);
+	err = ip_mc_validate_source(skb, daddr, saddr, dscp, dev, in_dev,
+				    &itag);
 	if (err)
 		return err;
 
@@ -1764,10 +1765,9 @@ static void ip_handle_martian_source(struct net_device *dev,
 }
 
 /* called in rcu_read_lock() section */
-static int __mkroute_input(struct sk_buff *skb,
-			   const struct fib_result *res,
-			   struct in_device *in_dev,
-			   __be32 daddr, __be32 saddr, u32 tos)
+static int __mkroute_input(struct sk_buff *skb, const struct fib_result *res,
+			   struct in_device *in_dev, __be32 daddr,
+			   __be32 saddr, dscp_t dscp)
 {
 	struct fib_nh_common *nhc = FIB_RES_NHC(*res);
 	struct net_device *dev = nhc->nhc_dev;
@@ -1785,7 +1785,7 @@ static int __mkroute_input(struct sk_buff *skb,
 		return -EINVAL;
 	}
 
-	err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
+	err = fib_validate_source(skb, saddr, daddr, dscp, FIB_RES_OIF(*res),
 				  in_dev->dev, in_dev, &itag);
 	if (err < 0) {
 		ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
@@ -2112,11 +2112,9 @@ int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
 }
 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
 
-static int ip_mkroute_input(struct sk_buff *skb,
-			    struct fib_result *res,
-			    struct in_device *in_dev,
-			    __be32 daddr, __be32 saddr, u32 tos,
-			    struct flow_keys *hkeys)
+static int ip_mkroute_input(struct sk_buff *skb, struct fib_result *res,
+			    struct in_device *in_dev, __be32 daddr,
+			    __be32 saddr, dscp_t dscp, struct flow_keys *hkeys)
 {
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 	if (res->fi && fib_info_num_path(res->fi) > 1) {
@@ -2128,7 +2126,7 @@ static int ip_mkroute_input(struct sk_buff *skb,
 #endif
 
 	/* create a routing cache entry */
-	return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
+	return __mkroute_input(skb, res, in_dev, daddr, saddr, dscp);
 }
 
 /* Implements all the saddr-related checks as ip_route_input_slow(),
@@ -2136,7 +2134,7 @@ static int ip_mkroute_input(struct sk_buff *skb,
  * Uses the provided hint instead of performing a route lookup.
  */
 int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr,
-		      u8 tos, struct net_device *dev,
+		      dscp_t dscp, struct net_device *dev,
 		      const struct sk_buff *hint)
 {
 	struct in_device *in_dev = __in_dev_get_rcu(dev);
@@ -2160,8 +2158,8 @@ int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 	if (rt->rt_type != RTN_LOCAL)
 		goto skip_validate_source;
 
-	tos &= INET_DSCP_MASK;
-	err = fib_validate_source(skb, saddr, daddr, tos, 0, dev, in_dev, &tag);
+	err = fib_validate_source(skb, saddr, daddr, dscp, 0, dev, in_dev,
+				  &tag);
 	if (err < 0)
 		goto martian_source;
 
@@ -2299,8 +2297,7 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 	}
 
 	if (res->type == RTN_LOCAL) {
-		err = fib_validate_source(skb, saddr, daddr,
-					  inet_dscp_to_dsfield(dscp), 0, dev,
+		err = fib_validate_source(skb, saddr, daddr, dscp, 0, dev,
 					  in_dev, &itag);
 		if (err < 0)
 			goto martian_source;
@@ -2315,8 +2312,7 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 		goto martian_destination;
 
 make_route:
-	err = ip_mkroute_input(skb, res, in_dev, daddr, saddr,
-			       inet_dscp_to_dsfield(dscp), flkeys);
+	err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, dscp, flkeys);
 out:	return err;
 
 brd_input:
@@ -2324,9 +2320,8 @@ brd_input:
 		goto e_inval;
 
 	if (!ipv4_is_zeronet(saddr)) {
-		err = fib_validate_source(skb, saddr, 0,
-					  inet_dscp_to_dsfield(dscp), 0, dev,
-					  in_dev, &itag);
+		err = fib_validate_source(skb, saddr, 0, dscp, 0, dev, in_dev,
+					  &itag);
 		if (err < 0)
 			goto martian_source;
 	}
@@ -2459,9 +2454,8 @@ static int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 		     IN_DEV_MFORWARD(in_dev))
 #endif
 		   ) {
-			err = ip_route_input_mc(skb, daddr, saddr,
-						inet_dscp_to_dsfield(dscp),
-						dev, our);
+			err = ip_route_input_mc(skb, daddr, saddr, dscp, dev,
+						our);
 		}
 		return err;
 	}
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 8accbf4cb295..4b74a25d0b6e 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -100,6 +100,7 @@
 #include <net/net_namespace.h>
 #include <net/icmp.h>
 #include <net/inet_hashtables.h>
+#include <net/ip.h>
 #include <net/ip_tunnels.h>
 #include <net/route.h>
 #include <net/checksum.h>
@@ -115,7 +116,6 @@
 #include <net/addrconf.h>
 #include <net/udp_tunnel.h>
 #include <net/gro.h>
-#include <net/inet_dscp.h>
 #if IS_ENABLED(CONFIG_IPV6)
 #include <net/ipv6_stubs.h>
 #endif
@@ -2619,7 +2619,7 @@ int udp_v4_early_demux(struct sk_buff *skb)
 		if (!inet_sk(sk)->inet_daddr && in_dev)
 			return ip_mc_validate_source(skb, iph->daddr,
 						     iph->saddr,
-						     iph->tos & INET_DSCP_MASK,
+						     ip4h_dscp(iph),
 						     skb->dev, in_dev, &itag);
 	}
 	return 0;