From 3c32b27d8bab7547f48f6bfbfcc3847ccca24894 Mon Sep 17 00:00:00 2001
From: =?utf8?q?David=20H=C3=A4rdeman?= <david@hardeman.nu>
Date: Fri, 17 Oct 2025 13:57:14 +0200
Subject: [PATCH] dhcpv4: simplify error handling in dhcpv4_setup_interface()
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Remove the "ret" variable which can anyway always just be -1 on error,
and rename the "out" label to "error" to clarify that it's only used on
error.

Signed-off-by: David Härdeman <david@hardeman.nu>
Link: https://github.com/openwrt/odhcpd/pull/318
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
---
 src/config.c |  6 ------
 src/dhcpv4.c | 41 +++++++++++++++--------------------------
 src/odhcpd.h |  6 +++++-
 3 files changed, 20 insertions(+), 33 deletions(-)

diff --git a/src/config.c b/src/config.c
index 865dadf..01bd375 100644
--- a/src/config.c
+++ b/src/config.c
@@ -372,9 +372,7 @@ static void close_interface(struct interface *iface)
 	router_setup_interface(iface, false);
 	dhcpv6_setup_interface(iface, false);
 	ndp_setup_interface(iface, false);
-#ifdef DHCPV4_SUPPORT
 	dhcpv4_setup_interface(iface, false);
-#endif
 
 	/* make sure timer is not on the timeouts list before freeing */
 	uloop_timeout_cancel(&iface->timer_rs);
@@ -1918,17 +1916,13 @@ void reload_services(struct interface *iface)
 		router_setup_interface(iface, iface->ra != MODE_DISABLED);
 		dhcpv6_setup_interface(iface, iface->dhcpv6 != MODE_DISABLED);
 		ndp_setup_interface(iface, iface->ndp != MODE_DISABLED);
-#ifdef DHCPV4_SUPPORT
 		dhcpv4_setup_interface(iface, iface->dhcpv4 != MODE_DISABLED);
-#endif
 	} else {
 		debug("Disabling services with %s not running", iface->ifname);
 		router_setup_interface(iface, false);
 		dhcpv6_setup_interface(iface, false);
 		ndp_setup_interface(iface, false);
-#ifdef DHCPV4_SUPPORT
 		dhcpv4_setup_interface(iface, false);
-#endif
 	}
 }
 
diff --git a/src/dhcpv4.c b/src/dhcpv4.c
index c31d521..5d49b76 100644
--- a/src/dhcpv4.c
+++ b/src/dhcpv4.c
@@ -1435,9 +1435,8 @@ static int dhcpv4_setup_addresses(struct interface *iface)
 	return 0;
 }
 
-int dhcpv4_setup_interface(struct interface *iface, bool enable)
+bool dhcpv4_setup_interface(struct interface *iface, bool enable)
 {
-	int ret = 0;
 	struct sockaddr_in bind_addr = {
 		.sin_family = AF_INET,
 		.sin_port = htons(DHCPV4_SERVER_PORT),
@@ -1457,75 +1456,65 @@ int dhcpv4_setup_interface(struct interface *iface, bool enable)
 
 		avl_remove_all_elements(&iface->dhcpv4_leases, lease, iface_avl, tmp)
 			dhcpv4_free_lease(lease);
-		return 0;
+		return true;
 	}
 
 	fd = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
 	if (fd < 0) {
 		error("socket(AF_INET): %m");
-		ret = -1;
-		goto out;
+		goto error;
 	}
 
 	/* Basic IPv4 configuration */
 	if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val)) < 0) {
 		error("setsockopt(SO_REUSEADDR): %m");
-		ret = -1;
-		goto out;
+		goto error;
 	}
 
 	if (setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &val, sizeof(val)) < 0) {
 		error("setsockopt(SO_BROADCAST): %m");
-		ret = -1;
-		goto out;
+		goto error;
 	}
 
 	if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &val, sizeof(val)) < 0) {
 		error("setsockopt(IP_PKTINFO): %m");
-		ret = -1;
-		goto out;
+		goto error;
 	}
 
 	val = IPTOS_CLASS_CS6;
 	if (setsockopt(fd, IPPROTO_IP, IP_TOS, &val, sizeof(val)) < 0) {
 		error("setsockopt(IP_TOS): %m");
-		ret = -1;
-		goto out;
+		goto error;
 	}
 
 	val = IP_PMTUDISC_DONT;
 	if (setsockopt(fd, IPPROTO_IP, IP_MTU_DISCOVER, &val, sizeof(val)) < 0) {
 		error("setsockopt(IP_MTU_DISCOVER): %m");
-		ret = -1;
-		goto out;
+		goto error;
 	}
 
 	if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, iface->ifname,
 		       strlen(iface->ifname)) < 0) {
 		error("setsockopt(SO_BINDTODEVICE): %m");
-		ret = -1;
-		goto out;
+		goto error;
 	}
 
 	if (bind(fd, (struct sockaddr *)&bind_addr, sizeof(bind_addr)) < 0) {
 		error("bind(): %m");
-		ret = -1;
-		goto out;
+		goto error;
 	}
 
-	if (dhcpv4_setup_addresses(iface) < 0) {
-		ret = -1;
-		goto out;
-	}
+	if (dhcpv4_setup_addresses(iface) < 0)
+		goto error;
 
 	iface->dhcpv4_event.uloop.fd = fd;
 	iface->dhcpv4_event.handle_dgram = dhcpv4_handle_dgram;
 	odhcpd_register(&iface->dhcpv4_event);
-	return 0;
+	return true;
 
-out:
+error:
 	close(fd);
-	return ret;
+	return false;
 }
 
 static void dhcpv4_addrlist_change(struct interface *iface)
diff --git a/src/odhcpd.h b/src/odhcpd.h
index 018426f..28478ab 100644
--- a/src/odhcpd.h
+++ b/src/odhcpd.h
@@ -644,11 +644,15 @@ int ndp_init(void);
 #ifdef DHCPV4_SUPPORT
 int dhcpv4_init(void);
 void dhcpv4_free_lease(struct dhcpv4_lease *a);
-int dhcpv4_setup_interface(struct interface *iface, bool enable);
+bool dhcpv4_setup_interface(struct interface *iface, bool enable);
 void dhcpv4_handle_msg(void *addr, void *data, size_t len,
 		       struct interface *iface, _o_unused void *dest_addr,
 		       send_reply_cb_t send_reply, void *opaque);
 #else
+static inline bool dhcpv4_setup_interface(struct interface *iface, bool enable) {
+	return true;
+}
+
 static inline void dhcpv4_free_lease(struct dhcpv4_lease *lease) {
 	error("Trying to free IPv4 assignment 0x%p", lease);
 }
-- 
2.30.2