From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Tue, 11 Jul 2023 01:53:27 +0000 (+0900)
Subject: network/address: merge address_needs_to_set_broadcast() with address_get_broadcast()
X-Git-Tag: v255-rc1~888
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=1a1f4a809214bb8f408296bf853451693748472c;p=thirdparty%2Fsystemd.git

network/address: merge address_needs_to_set_broadcast() with address_get_broadcast()

No functional change, preparation for later commits.
---

diff --git a/src/network/networkd-address.c b/src/network/networkd-address.c
index 3345f83506b..a96ed8feb8a 100644
--- a/src/network/networkd-address.c
+++ b/src/network/networkd-address.c
@@ -205,41 +205,55 @@ void link_mark_addresses(Link *link, NetworkConfigSource source) {
         }
 }
 
-static bool address_needs_to_set_broadcast(const Address *a, Link *link) {
+int address_get_broadcast(const Address *a, Link *link, struct in_addr *ret) {
+        struct in_addr b_addr = {};
+
         assert(a);
         assert(link);
 
+        /* Returns 0 when broadcast address is null, 1 when non-null broadcast address, -EAGAIN when the main
+         * address is null. */
+
+        /* broadcast is only for IPv4. */
         if (a->family != AF_INET)
-                return false;
+                goto finalize;
 
+        /* broadcast address cannot be used when peer address is specified. */
         if (in4_addr_is_set(&a->in_addr_peer.in))
-                return false;
+                goto finalize;
 
         /* A /31 or /32 IPv4 address does not have a broadcast address.
          * See https://tools.ietf.org/html/rfc3021 */
         if (a->prefixlen > 30)
-                return false;
+                goto finalize;
 
-        /* If explicitly configured, do not update the address. */
-        if (in4_addr_is_set(&a->broadcast))
-                return false;
+        /* If explicitly configured, use the address as is. */
+        if (in4_addr_is_set(&a->broadcast)) {
+                b_addr = a->broadcast;
+                goto finalize;
+        }
 
-        if (a->set_broadcast >= 0)
-                return a->set_broadcast;
+        /* If explicitly disabled, then return null address. */
+        if (a->set_broadcast == 0)
+                goto finalize;
 
-        /* Defaults to true, except for wireguard, as typical configuration for wireguard does not set
-         * broadcast. */
-        return !streq_ptr(link->kind, "wireguard");
-}
+        /* For wireguard interfaces, broadcast is disabled by default. */
+        if (a->set_broadcast < 0 && streq_ptr(link->kind, "wireguard"))
+                goto finalize;
 
-void address_set_broadcast(Address *a, Link *link) {
-        assert(a);
-        assert(link);
+        /* If the main address is null, e.g. Address=0.0.0.0/24, the broadcast address will be automatically
+         * determined after an address is acquired. */
+        if (!in4_addr_is_set(&a->in_addr.in))
+                return -EAGAIN;
 
-        if (!address_needs_to_set_broadcast(a, link))
-                return;
+        /* Otherwise, generate a broadcast address from the main address and prefix length. */
+        b_addr.s_addr = a->in_addr.in.s_addr | htobe32(UINT32_C(0xffffffff) >> a->prefixlen);
+
+finalize:
+        if (ret)
+                *ret = b_addr;
 
-        a->broadcast.s_addr = a->in_addr.in.s_addr | htobe32(UINT32_C(0xffffffff) >> a->prefixlen);
+        return in4_addr_is_set(&b_addr);
 }
 
 static void address_set_cinfo(Manager *m, const Address *a, struct ifa_cacheinfo *cinfo) {
diff --git a/src/network/networkd-address.h b/src/network/networkd-address.h
index 5cb1cc388e7..9c926dc5878 100644
--- a/src/network/networkd-address.h
+++ b/src/network/networkd-address.h
@@ -83,7 +83,11 @@ int address_remove_and_drop(Address *address);
 int address_dup(const Address *src, Address **ret);
 bool address_is_ready(const Address *a);
 bool link_check_addresses_ready(Link *link, NetworkConfigSource source);
-void address_set_broadcast(Address *a, Link *link);
+int address_get_broadcast(const Address *a, Link *link, struct in_addr *ret);
+static inline void address_set_broadcast(Address *a, Link *link) {
+        assert(a);
+        assert_se(address_get_broadcast(a, link, &a->broadcast) >= 0);
+}
 
 DEFINE_SECTION_CLEANUP_FUNCTIONS(Address, address_free);