udp: constify 'struct net' parameter of socket lookups

Following helpers do not touch their 'struct net' argument.

- udp_sk_bound_dev_eq()
- udp4_lib_lookup()
- __udp4_lib_lookup()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20240802134029.3748005-4-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

include/net/udp.h

@@ -79,7 +79,8 @@ struct udp_table {
 extern struct udp_table udp_table;
 void udp_table_init(struct udp_table *, const char *);
 static inline struct udp_hslot *udp_hashslot(struct udp_table *table,
-					     struct net *net, unsigned int num)
+					     const struct net *net,
+					     unsigned int num)
 {
 	return &table->hash[udp_hashfn(net, num, table->mask)];
 }
@@ -245,7 +246,7 @@ static inline int udp_rqueue_get(struct sock *sk)
 	return sk_rmem_alloc_get(sk) - READ_ONCE(udp_sk(sk)->forward_deficit);
 }
 
-static inline bool udp_sk_bound_dev_eq(struct net *net, int bound_dev_if,
+static inline bool udp_sk_bound_dev_eq(const struct net *net, int bound_dev_if,
 				       int dif, int sdif)
 {
 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
@@ -296,9 +297,10 @@ int udp_lib_getsockopt(struct sock *sk, int level, int optname,
 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
 		       sockptr_t optval, unsigned int optlen,
 		       int (*push_pending_frames)(struct sock *));
-struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
+struct sock *udp4_lib_lookup(const struct net *net, __be32 saddr, __be16 sport,
 			     __be32 daddr, __be16 dport, int dif);
-struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
+struct sock *__udp4_lib_lookup(const struct net *net, __be32 saddr,
+			       __be16 sport,
 			       __be32 daddr, __be16 dport, int dif, int sdif,
 			       struct udp_table *tbl, struct sk_buff *skb);
 struct sock *udp4_lib_lookup_skb(const struct sk_buff *skb,

net/ipv4/udp.c

@@ -365,7 +365,7 @@ int udp_v4_get_port(struct sock *sk, unsigned short snum)
 	return udp_lib_get_port(sk, snum, hash2_nulladdr);
 }
 
-static int compute_score(struct sock *sk, struct net *net,
+static int compute_score(struct sock *sk, const struct net *net,
 			 __be32 saddr, __be16 sport,
 			 __be32 daddr, unsigned short hnum,
 			 int dif, int sdif)
@@ -420,7 +420,7 @@ u32 udp_ehashfn(const struct net *net, const __be32 laddr, const __u16 lport,
 }
 
 /* called with rcu_read_lock() */
-static struct sock *udp4_lib_lookup2(struct net *net,
+static struct sock *udp4_lib_lookup2(const struct net *net,
 				     __be32 saddr, __be16 sport,
 				     __be32 daddr, unsigned int hnum,
 				     int dif, int sdif,
@@ -480,7 +480,7 @@ static struct sock *udp4_lib_lookup2(struct net *net,
 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
  * harder than this. -DaveM
  */
-struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
+struct sock *__udp4_lib_lookup(const struct net *net, __be32 saddr,
 		__be16 sport, __be32 daddr, __be16 dport, int dif,
 		int sdif, struct udp_table *udptable, struct sk_buff *skb)
 {
@@ -561,7 +561,7 @@ struct sock *udp4_lib_lookup_skb(const struct sk_buff *skb,
  * Does increment socket refcount.
  */
 #if IS_ENABLED(CONFIG_NF_TPROXY_IPV4) || IS_ENABLED(CONFIG_NF_SOCKET_IPV4)
-struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
+struct sock *udp4_lib_lookup(const struct net *net, __be32 saddr, __be16 sport,
 			     __be32 daddr, __be16 dport, int dif)
 {
 	struct sock *sk;