net: port < inet_prot_sock(net) --> inet_port_requires_bind_service(net, port)

Note that the sysctl write accessor functions guarantee that:
  net->ipv4.sysctl_ip_prot_sock <= net->ipv4.ip_local_ports.range[0]
invariant is maintained, and as such the max() in selinux hooks is actually spurious.

ie. even though
  if (snum < max(inet_prot_sock(sock_net(sk)), low) || snum > high) {
per logic is the same as
  if ((snum < inet_prot_sock(sock_net(sk)) && snum < low) || snum > high) {
it is actually functionally equivalent to:
  if (snum < low || snum > high) {
which is equivalent to:
  if (snum < inet_prot_sock(sock_net(sk)) || snum < low || snum > high) {
even though the first clause is spurious.

But we want to hold on to it in case we ever want to change what what
inet_port_requires_bind_service() means (for example by changing
it from a, by default, [0..1024) range to some sort of set).

Test: builds, git 'grep inet_prot_sock' finds no other references
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 4 deletions

diff --git a/include/net/ip.h b/include/net/ip.h
index cebf3e10def1..5a61bd948b18 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -351,9 +351,9 @@ static inline bool sysctl_dev_name_is_allowed(const char *name)
 	return strcmp(name, "default") != 0  && strcmp(name, "all") != 0;
 }
 
-static inline int inet_prot_sock(struct net *net)
+static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port)
 {
-	return net->ipv4.sysctl_ip_prot_sock;
+	return port < net->ipv4.sysctl_ip_prot_sock;
 }
 
 #else
@@ -362,9 +362,9 @@ static inline bool inet_is_local_reserved_port(struct net *net, int port)
 	return false;
 }
 
-static inline int inet_prot_sock(struct net *net)
+static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port)
 {
-	return PROT_SOCK;
+	return port < PROT_SOCK;
 }
 #endif