network: add AF_TO_ADDRESS_FAMILY() helper

Make some code a bit shorter.

src/libsystemd/sd-network/network-util.h

@@ -2,6 +2,7 @@
 #pragma once
 
 #include <errno.h>
+#include <netinet/in.h>
 #include <stdbool.h>
 
 #include "constants.h"
@@ -22,6 +23,17 @@ typedef enum AddressFamily {
         _ADDRESS_FAMILY_INVALID = -EINVAL,
 } AddressFamily;
 
+static inline AddressFamily AF_TO_ADDRESS_FAMILY(int af) {
+        switch (af) {
+        case AF_INET:
+                return ADDRESS_FAMILY_IPV4;
+        case AF_INET6:
+                return ADDRESS_FAMILY_IPV6;
+        default:
+                return ADDRESS_FAMILY_NO;
+        }
+}
+
 typedef enum LinkOperationalState {
         LINK_OPERSTATE_MISSING,
         LINK_OPERSTATE_OFF,

src/network/networkd-address.c

@@ -644,12 +644,7 @@ static int address_set_masquerade(Address *address, bool add) {
         if (!address->link->network)
                 return 0;
 
-        if (address->family == AF_INET &&
-            !FLAGS_SET(address->link->network->ip_masquerade, ADDRESS_FAMILY_IPV4))
-                return 0;
-
-        if (address->family == AF_INET6 &&
-            !FLAGS_SET(address->link->network->ip_masquerade, ADDRESS_FAMILY_IPV6))
+        if (!FLAGS_SET(address->link->network->ip_masquerade, AF_TO_ADDRESS_FAMILY(address->family)))
                 return 0;
 
         if (address->scope >= RT_SCOPE_LINK)

src/network/networkd-dhcp-common.c

@@ -71,7 +71,7 @@ bool link_dhcp_enabled(Link *link, int family) {
         if (!link->network)
                 return false;
 
-        return link->network->dhcp & (family == AF_INET ? ADDRESS_FAMILY_IPV4 : ADDRESS_FAMILY_IPV6);
+        return link->network->dhcp & AF_TO_ADDRESS_FAMILY(family);
 }
 
 void network_adjust_dhcp(Network *network) {

src/network/networkd-routing-policy-rule.c

@@ -12,6 +12,7 @@
 #include "hashmap.h"
 #include "ip-protocol-list.h"
 #include "netlink-util.h"
+#include "network-util.h"
 #include "networkd-manager.h"
 #include "networkd-queue.h"
 #include "networkd-route-util.h"

src/network/networkd-sysctl.c

@@ -303,9 +303,7 @@ int link_get_ip_forwarding(Link *link, int family) {
                 return t;
 
         /* If IPMasquerade= is enabled, also enable IP forwarding. */
-        if (family == AF_INET && FLAGS_SET(link->network->ip_masquerade, ADDRESS_FAMILY_IPV4))
-                return true;
-        if (family == AF_INET6 && FLAGS_SET(link->network->ip_masquerade, ADDRESS_FAMILY_IPV6))
+        if (FLAGS_SET(link->network->ip_masquerade, AF_TO_ADDRESS_FAMILY(family)))
                 return true;
 
         /* If IPv6SendRA= is enabled, also enable IPv6 forwarding. */
@@ -377,7 +375,7 @@ static int link_set_ip_forwarding(Link *link, int family) {
 
         /* When IPMasquerade= is enabled and the global setting is unset, enable _global_ IP forwarding, and
          * re-apply per-link setting for all links. */
-        if (FLAGS_SET(link->network->ip_masquerade, family == AF_INET ? ADDRESS_FAMILY_IPV4 : ADDRESS_FAMILY_IPV6) &&
+        if (FLAGS_SET(link->network->ip_masquerade, AF_TO_ADDRESS_FAMILY(family)) &&
             link->manager->ip_forwarding[family == AF_INET6] < 0) {
 
                 link->manager->ip_forwarding[family == AF_INET6] = true;