introduce and use xdup2(int, int)

stop checking whether setsockopt_reuseaddr(int fd) was successful (it always is)
remove second parameter (sockllen) from xmalloc_sockaddr2xxxxx functions

sockaddr2str                                         142     156     +14
collect_blk                                          467     474      +7
xdup2                                                 28      33      +5
singlemount                                         4456    4454      -2
print_host                                           214     212      -2
nslookup_main                                        139     137      -2
ftpgetput_main                                       414     412      -2
udhcpd_main                                         1258    1255      -3
udhcpc_main                                         2405    2402      -3
traceroute_main                                     4125    4122      -3
nc_main                                             1072    1069      -3
buffer_fill_and_print                                 76      73      -3
xmalloc_sockaddr2hostonly_noport                      18      14      -4
xmalloc_sockaddr2host_noport                          18      14      -4
xmalloc_sockaddr2host                                 15      11      -4
xmalloc_sockaddr2dotted_noport                        18      14      -4
xmalloc_sockaddr2dotted                               18      14      -4
wget_main                                           2618    2614      -4
ping_main                                            393     389      -4
ip_port_str                                          120     115      -5
dhcprelay_main                                      1146    1141      -5
dnsd_main                                           1531    1525      -6
passwd_main                                         1110    1102      -8
udhcp_kernel_packet                                  206     197      -9
udhcp_listen_socket                                  154     144     -10
getty_main                                          2576    2566     -10
setup                                                655     640     -15
xmove_fd                                              51      34     -17
dolisten                                             759     742     -17
tcpudpsvd_main                                      1866    1836     -30
startservice                                         339     299     -40

6 files changed, 24 insertions, 40 deletions

diff --git a/networking/udhcp/common.h b/networking/udhcp/common.h
index bc21176a5..33417af09 100644
--- a/networking/udhcp/common.h
+++ b/networking/udhcp/common.h
@@ -83,7 +83,7 @@ int udhcp_sp_fd_set(fd_set *rfds, int extra_fd);
 int udhcp_sp_read(fd_set *rfds);
 int raw_socket(int ifindex);
 int read_interface(const char *interface, int *ifindex, uint32_t *addr, uint8_t *arp);
-int listen_socket(uint32_t ip, int port, const char *inf);
+int listen_socket(/*uint32_t ip,*/ int port, const char *inf);
 /* Returns 1 if no reply received */
 int arpping(uint32_t test_ip, uint32_t from_ip, uint8_t *from_mac, const char *interface);
 
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 7d38742b9..f0a3351fd 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -311,7 +311,7 @@ int udhcpc_main(int argc, char **argv)
 
 		if (listen_mode != LISTEN_NONE && sockfd < 0) {
 			if (listen_mode == LISTEN_KERNEL)
-				sockfd = listen_socket(INADDR_ANY, CLIENT_PORT, client_config.interface);
+				sockfd = listen_socket(/*INADDR_ANY,*/ CLIENT_PORT, client_config.interface);
 			else
 				sockfd = raw_socket(client_config.ifindex);
 		}
diff --git a/networking/udhcp/dhcpd.c b/networking/udhcp/dhcpd.c
index fb42e2f73..2fd16ce9b 100644
--- a/networking/udhcp/dhcpd.c
+++ b/networking/udhcp/dhcpd.c
@@ -95,7 +95,7 @@ int udhcpd_main(int argc, char **argv)
 	while (1) { /* loop until universe collapses */
 
 		if (server_socket < 0) {
-			server_socket = listen_socket(INADDR_ANY, SERVER_PORT,
+			server_socket = listen_socket(/*INADDR_ANY,*/ SERVER_PORT,
 					server_config.interface);
 		}
 
diff --git a/networking/udhcp/dhcprelay.c b/networking/udhcp/dhcprelay.c
index 4ed65a2d6..3e1758d5c 100644
--- a/networking/udhcp/dhcprelay.c
+++ b/networking/udhcp/dhcprelay.c
@@ -167,16 +167,17 @@ static int init_sockets(char **client, int num_clients,
 	int i;
 
 	/* talk to real server on bootps */
-	fds[0] = listen_socket(htonl(INADDR_ANY), 67, server);
+	fds[0] = listen_socket(/*INADDR_ANY,*/ 67, server);
 	*max_socket = fds[0];
 
 	/* array starts at 1 since server is 0 */
 	num_clients++;
 
-	for (i=1; i < num_clients; i++) {
+	for (i = 1; i < num_clients; i++) {
 		/* listen for clients on bootps */
-		fds[i] = listen_socket(htonl(INADDR_ANY), 67, client[i-1]);
-		if (fds[i] > *max_socket) *max_socket = fds[i];
+		fds[i] = listen_socket(/*NADDR_ANY,*/ 67, client[i-1]);
+		if (fds[i] > *max_socket)
+			*max_socket = fds[i];
 	}
 
 	return i;
diff --git a/networking/udhcp/packet.c b/networking/udhcp/packet.c
index 272e79df1..41cd32135 100644
--- a/networking/udhcp/packet.c
+++ b/networking/udhcp/packet.c
@@ -194,17 +194,14 @@ int udhcp_kernel_packet(struct dhcpMessage *payload,
 	if (fd < 0)
 		return -1;
 
-	if (setsockopt_reuseaddr(fd) == -1) {
-		close(fd);
-		return -1;
-	}
+	setsockopt_reuseaddr(fd);
 
 	memset(&client, 0, sizeof(client));
 	client.sin_family = AF_INET;
 	client.sin_port = htons(source_port);
 	client.sin_addr.s_addr = source_ip;
 
-	if (bind(fd, (struct sockaddr *)&client, sizeof(struct sockaddr)) == -1) {
+	if (bind(fd, (struct sockaddr *)&client, sizeof(client)) == -1) {
 		close(fd);
 		return -1;
 	}
diff --git a/networking/udhcp/socket.c b/networking/udhcp/socket.c
index 1e62f8e40..79ddfb1e2 100644
--- a/networking/udhcp/socket.c
+++ b/networking/udhcp/socket.c
@@ -45,10 +45,6 @@ int read_interface(const char *interface, int *ifindex, uint32_t *addr, uint8_t
 
 	memset(&ifr, 0, sizeof(ifr));
 	fd = xsocket(AF_INET, SOCK_RAW, IPPROTO_RAW);
-//	if (fd < 0) {
-//		bb_perror_msg("socket failed");
-//		return -1;
-//	}
 
 	ifr.ifr_addr.sa_family = AF_INET;
 	strncpy(ifr.ifr_name, interface, sizeof(ifr.ifr_name));
@@ -87,40 +83,30 @@ int read_interface(const char *interface, int *ifindex, uint32_t *addr, uint8_t
 	return 0;
 }
 
-
-int listen_socket(uint32_t ip, int port, const char *inf)
+/* 1. None of the callers expects it to ever fail */
+/* 2. ip was always INADDR_ANY */
+int listen_socket(/*uint32_t ip,*/ int port, const char *inf)
 {
-	struct ifreq interface;
 	int fd;
+	struct ifreq interface;
 	struct sockaddr_in addr;
 
 	DEBUG("Opening listen socket on 0x%08x:%d %s", ip, port, inf);
 	fd = xsocket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
 
-	memset(&addr, 0, sizeof(addr));
-	addr.sin_family = AF_INET;
-	addr.sin_port = htons(port);
-	addr.sin_addr.s_addr = ip;
-
-	if (setsockopt_reuseaddr(fd) == -1) {
-		close(fd);
-		return -1;
-	}
-	if (setsockopt_broadcast(fd) == -1) {
-		close(fd);
-		return -1;
-	}
+	setsockopt_reuseaddr(fd);
+	if (setsockopt_broadcast(fd) == -1)
+		bb_perror_msg_and_die("SO_BROADCAST");
 
 	strncpy(interface.ifr_name, inf, IFNAMSIZ);
-	if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, &interface, sizeof(interface)) < 0) {
-		close(fd);
-		return -1;
-	}
+	if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, &interface, sizeof(interface)) == -1)
+		bb_perror_msg_and_die("SO_BINDTODEVICE");
 
-	if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
-		close(fd);
-		return -1;
-	}
+	memset(&addr, 0, sizeof(addr));
+	addr.sin_family = AF_INET;
+	addr.sin_port = htons(port);
+	/* addr.sin_addr.s_addr = ip; - all-zeros is INADDR_ANY */
+	xbind(fd, (struct sockaddr *)&addr, sizeof(addr));
 
 	return fd;
 }