net: fill in MODULE_DESCRIPTION()s for ipv4 modules

W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Add descriptions to the IPv4 modules.
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240208164244.3818498-7-leitao@debian.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

net/ipv4/ah4.c

@@ -597,5 +597,6 @@ static void __exit ah4_fini(void)
 
 module_init(ah4_init);
 module_exit(ah4_fini);
+MODULE_DESCRIPTION("IPv4 AH transformation library");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_AH);

net/ipv4/esp4.c

@@ -1247,5 +1247,6 @@ static void __exit esp4_fini(void)
 
 module_init(esp4_init);
 module_exit(esp4_fini);
+MODULE_DESCRIPTION("IPv4 ESP transformation library");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP);

net/ipv4/ip_gre.c

@@ -1793,6 +1793,7 @@ static void __exit ipgre_fini(void)
 
 module_init(ipgre_init);
 module_exit(ipgre_fini);
+MODULE_DESCRIPTION("IPv4 GRE tunnels over IP library");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_RTNL_LINK("gre");
 MODULE_ALIAS_RTNL_LINK("gretap");

net/ipv4/ip_tunnel.c

@@ -1298,4 +1298,5 @@ void ip_tunnel_setup(struct net_device *dev, unsigned int net_id)
 }
 EXPORT_SYMBOL_GPL(ip_tunnel_setup);
 
+MODULE_DESCRIPTION("IPv4 tunnel implementation library");
 MODULE_LICENSE("GPL");

net/ipv4/ip_vti.c

@@ -721,6 +721,7 @@ static void __exit vti_fini(void)
 
 module_init(vti_init);
 module_exit(vti_fini);
+MODULE_DESCRIPTION("Virtual (secure) IP tunneling library");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_RTNL_LINK("vti");
 MODULE_ALIAS_NETDEV("ip_vti0");

net/ipv4/ipip.c

@@ -658,6 +658,7 @@ static void __exit ipip_fini(void)
 
 module_init(ipip_init);
 module_exit(ipip_fini);
+MODULE_DESCRIPTION("IP/IP protocol decoder library");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_RTNL_LINK("ipip");
 MODULE_ALIAS_NETDEV("tunl0");

net/ipv4/tunnel4.c

@@ -294,4 +294,5 @@ static void __exit tunnel4_fini(void)
 
 module_init(tunnel4_init);
 module_exit(tunnel4_fini);
+MODULE_DESCRIPTION("IPv4 XFRM tunnel library");
 MODULE_LICENSE("GPL");

net/ipv4/udp_tunnel_core.c

@@ -253,4 +253,5 @@ struct rtable *udp_tunnel_dst_lookup(struct sk_buff *skb,
 }
 EXPORT_SYMBOL_GPL(udp_tunnel_dst_lookup);
 
+MODULE_DESCRIPTION("IPv4 Foo over UDP tunnel driver");
 MODULE_LICENSE("GPL");

net/ipv4/xfrm4_tunnel.c

@@ -114,5 +114,6 @@ static void __exit ipip_fini(void)
 
 module_init(ipip_init);
 module_exit(ipip_fini);
+MODULE_DESCRIPTION("IPv4 XFRM tunnel driver");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_IPIP);