udhcp: new config option "Rewrite the lease file at every new acknowledge"

       (Mats Erik Andersson <mats@blue2net.com> (Blue2Net AB))
udhcp: consistently treat server_config.start/end IPs as host-order
       fix IP parsing for 64bit machines
       fix unsafe hton macro usage in read_opt()
       do not chdir("/") when daemonizing
       fix help text

10 files changed, 151 insertions, 115 deletions

diff --git a/include/usage.h b/include/usage.h
index 6d02c8bbf..68325046f 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -3575,7 +3575,8 @@ USE_FEATURE_RUN_PARTS_FANCY("\n	-l	Prints names of all matching files even when
        "Adjust filesystem options on ext[23] filesystems"
 
 #define udhcpc_trivial_usage \
-       "[-Cfbnqtv] [-c CID] [-V VCLS] [-H HOSTNAME] [-i INTERFACE]\n[-p pidfile] [-r IP] [-s script]"
+       "[-Cfbnqtv] [-c CID] [-V VCLS] [-H HOSTNAME] [-i INTERFACE]\n" \
+       "	[-p pidfile] [-r IP] [-s script]"
 #define udhcpc_full_usage \
        "	-V,--vendorclass=CLASSID	Set vendor class identifier\n" \
        "	-i,--interface=INTERFACE	Interface to use (default: eth0)\n" \
@@ -3594,7 +3595,7 @@ USE_FEATURE_RUN_PARTS_FANCY("\n	-l	Prints names of all matching files even when
        "	-v,--version	Display version" \
 
 #define udhcpd_trivial_usage \
-       "[configfile]\n" \
+       "[configfile]" \
 
 #define udhcpd_full_usage \
        ""
diff --git a/networking/udhcp/Config.in b/networking/udhcp/Config.in
index 9dd02c497..7a3eda9cc 100644
--- a/networking/udhcp/Config.in
+++ b/networking/udhcp/Config.in
@@ -32,6 +32,16 @@ config APP_DUMPLEASES
 
 	  See http://udhcp.busybox.net for further details.
 
+config FEATURE_UDHCPD_WRITE_LEASES_EARLY
+	bool "Rewrite the lease file at every new acknowledge"
+	default n
+	depends on APP_UDHCPD
+	help
+	  If selected, udhcpd will write a new file with leases every
+	  time a new lease has been accepted, thus eleminating the need
+	  to send SIGUSR1 for the initial writing, or updating. Any timed
+	  rewriting remains undisturbed
+
 config APP_UDHCPC
 	bool "udhcp Client (udhcpc)"
 	default n
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 06806ec66..50ac31e61 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -114,8 +114,7 @@ static void client_background(void)
  * If that will be properly disabled for NOMMU, client_background()
  * will work on NOMMU too */
 #else
-// chdir(/) is problematic. Imagine that e.g. pidfile name is RELATIVE! what will unlink do then, eh?
-	bb_daemonize(DAEMON_CHDIR_ROOT);
+	bb_daemonize(0);
 	/* rewrite pidfile, as our pid is different now */
 	if (client_config.pidfile)
 		write_pidfile(client_config.pidfile);
diff --git a/networking/udhcp/dhcpc.h b/networking/udhcp/dhcpc.h
index fa091bf72..09b014239 100644
--- a/networking/udhcp/dhcpc.h
+++ b/networking/udhcp/dhcpc.h
@@ -17,12 +17,12 @@ struct client_config_t {
 	/* (can be set directly to the result of getopt32) */
 	char foreground;                /* Do not fork */
 	char quit_after_lease;          /* Quit after obtaining lease */
-	char release_on_quit;           /* perform release on quit */
+	char release_on_quit;           /* Perform release on quit */
 	char abort_if_no_lease;         /* Abort if no lease */
 	char background_if_no_lease;    /* Fork to background if no lease */
-	const char *interface;                /* The name of the interface to use */
+	const char *interface;          /* The name of the interface to use */
 	char *pidfile;                  /* Optionally store the process ID */
-	const char *script;                   /* User script to run at dhcp events */
+	const char *script;             /* User script to run at dhcp events */
 	uint8_t *clientid;              /* Optional client id to use */
 	uint8_t *vendorclass;           /* Optional vendor class-id to use */
 	uint8_t *hostname;              /* Optional hostname to use */
diff --git a/networking/udhcp/dhcpd.c b/networking/udhcp/dhcpd.c
index 778121b61..6be3c0e2e 100644
--- a/networking/udhcp/dhcpd.c
+++ b/networking/udhcp/dhcpd.c
@@ -37,7 +37,7 @@ int udhcpd_main(int argc, char **argv)
 //Huh, dhcpd don't have --foreground, --syslog options?? TODO
 
 	if (!ENABLE_FEATURE_UDHCP_DEBUG) {
-		bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
+		bb_daemonize_or_rexec(0, argv);
 		logmode &= ~LOGMODE_STDIO;
 	}
 
@@ -60,15 +60,15 @@ int udhcpd_main(int argc, char **argv)
 	}
 
 	/* Sanity check */
-	num_ips = ntohl(server_config.end) - ntohl(server_config.start) + 1;
+	num_ips = server_config.end_ip - server_config.start_ip + 1;
 	if (server_config.max_leases > num_ips) {
-		bb_error_msg("max_leases value (%lu) not sane, "
-			"setting to %lu instead",
+		bb_error_msg("max_leases=%lu is too big, "
+			"setting to %lu",
 			server_config.max_leases, num_ips);
 		server_config.max_leases = num_ips;
 	}
 
-	leases = xzalloc(server_config.max_leases * sizeof(struct dhcpOfferedAddr));
+	leases = xzalloc(server_config.max_leases * sizeof(*leases));
 	read_leases(server_config.lease_file);
 
 	if (read_interface(server_config.interface, &server_config.ifindex,
@@ -207,10 +207,13 @@ int udhcpd_main(int argc, char **argv)
 					/* make some contention for this address */
 					} else
 						sendNAK(&packet);
-				} else if (requested_align < server_config.start
-				        || requested_align > server_config.end
-				) {
-					sendNAK(&packet);
+				} else {
+					uint32_t r = ntohl(requested_align);
+					if (r < server_config.start_ip
+				         || r > server_config.end_ip
+					) {
+						sendNAK(&packet);
+					}
 				} /* else remain silent */
 
 			} else {
diff --git a/networking/udhcp/dhcpd.h b/networking/udhcp/dhcpd.h
index 7c4fe695a..05e3cf004 100644
--- a/networking/udhcp/dhcpd.h
+++ b/networking/udhcp/dhcpd.h
@@ -27,23 +27,24 @@ struct static_lease {
 
 struct server_config_t {
 	uint32_t server;		/* Our IP, in network order */
-	uint32_t start;			/* Start address of leases, network order */
-	uint32_t end;			/* End of leases, network order */
+	/* start,end are in host order: we need to compare start <= ip <= end */
+	uint32_t start_ip;		/* Start address of leases, in host order */
+	uint32_t end_ip;		/* End of leases, in host order */
 	struct option_set *options;	/* List of DHCP options loaded from the config file */
 	char *interface;		/* The name of the interface to use */
 	int ifindex;			/* Index number of the interface to use */
 	uint8_t arp[6];			/* Our arp address */
-	unsigned long lease;		/* lease time in seconds (host order) */
-	unsigned long max_leases;	/* maximum number of leases (including reserved address) */
 	char remaining;			/* should the lease file be interpreted as lease time remaining, or
 					 * as the time the lease expires */
+	unsigned long lease;		/* lease time in seconds (host order) */
+	unsigned long max_leases;	/* maximum number of leases (including reserved address) */
 	unsigned long auto_time;	/* how long should udhcpd wait before writing a config file.
 					 * if this is zero, it will only write one on SIGUSR1 */
 	unsigned long decline_time;	/* how long an address is reserved if a client returns a
 					 * decline message */
 	unsigned long conflict_time;	/* how long an arp conflict offender is leased for */
 	unsigned long offer_time;	/* how long an offered address is reserved */
-	unsigned long min_lease;	/* minimum lease a client can request*/
+	unsigned long min_lease;	/* minimum lease a client can request */
 	char *lease_file;
 	char *pidfile;
 	char *notify_file;		/* What to run whenever leases are written */
@@ -95,13 +96,6 @@ int send_inform(struct dhcpMessage *oldpacket);
 
 /*** files.h ***/
 
-struct config_keyword {
-	const char *keyword;
-	int (* const handler)(const char *line, void *var);
-	void *var;
-	const char *def;
-};
-
 int read_config(const char *file);
 void write_leases(void);
 void read_leases(const char *file);
diff --git a/networking/udhcp/files.c b/networking/udhcp/files.c
index 41c8717cd..7fc734889 100644
--- a/networking/udhcp/files.c
+++ b/networking/udhcp/files.c
@@ -11,42 +11,30 @@
 #include "options.h"
 
 
-/*
- * Domain names may have 254 chars, and string options can be 254
- * chars long. However, 80 bytes will be enough for most, and won't
- * hog up memory. If you have a special application, change it
- */
-#define READ_CONFIG_BUF_SIZE 80
-
-/* on these functions, make sure you datatype matches */
+/* on these functions, make sure your datatype matches */
 static int read_ip(const char *line, void *arg)
 {
 	len_and_sockaddr *lsa;
-	int retval = 0;
 
 	lsa = host_and_af2sockaddr(line, 0, AF_INET);
 	if (lsa) {
-		*(struct in_addr*)arg = lsa->sin.sin_addr;
+		*(uint32_t*)arg = lsa->sin.sin_addr.s_addr;
 		free(lsa);
-		retval = 1;
+		return 1;
 	}
-	return retval;
+	return 0;
 }
 
 static int read_mac(const char *line, void *arg)
 {
 	uint8_t *mac_bytes = arg;
 	struct ether_addr *temp_ether_addr;
-	int retval = 1;
 
 	temp_ether_addr = ether_aton(line);
-
 	if (temp_ether_addr == NULL)
-		retval = 0;
-	else
-		memcpy(mac_bytes, temp_ether_addr, 6);
-
-	return retval;
+		return 0;
+	memcpy(mac_bytes, temp_ether_addr, 6);
+	return 1;
 }
 
 
@@ -56,14 +44,13 @@ static int read_str(const char *line, void *arg)
 
 	free(*dest);
 	*dest = xstrdup(line);
-
 	return 1;
 }
 
 
 static int read_u32(const char *line, void *arg)
 {
-	*((uint32_t*)arg) = bb_strtou32(line, NULL, 10);
+	*(uint32_t*)arg = bb_strtou32(line, NULL, 10);
 	return errno == 0;
 }
 
@@ -71,15 +58,16 @@ static int read_u32(const char *line, void *arg)
 static int read_yn(const char *line, void *arg)
 {
 	char *dest = arg;
-	int retval = 1;
 
-	if (!strcasecmp("yes", line))
+	if (!strcasecmp("yes", line)) {
 		*dest = 1;
-	else if (!strcasecmp("no", line))
+		return 1;
+	}
+	if (!strcasecmp("no", line)) {
 		*dest = 0;
-	else retval = 0;
-
-	return retval;
+		return 1;
+	}
+	return 0;
 }
 
 
@@ -89,8 +77,9 @@ struct option_set *find_option(struct option_set *opt_list, char code)
 	while (opt_list && opt_list->data[OPT_CODE] < code)
 		opt_list = opt_list->next;
 
-	if (opt_list && opt_list->data[OPT_CODE] == code) return opt_list;
-	else return NULL;
+	if (opt_list && opt_list->data[OPT_CODE] == code)
+		return opt_list;
+	return NULL;
 }
 
 
@@ -111,7 +100,7 @@ static void attach_option(struct option_set **opt_list,
 #endif
 
 		/* make a new option */
-		new = xmalloc(sizeof(struct option_set));
+		new = xmalloc(sizeof(*new));
 		new->data = xmalloc(length + 2);
 		new->data[OPT_CODE] = option->code;
 		new->data[OPT_LEN] = length;
@@ -184,7 +173,7 @@ static int read_opt(const char *const_line, void *arg)
 			return 0;
 		if (!strcasecmp(option->name, opt))
 			break;
-		 option++;
+		option++;
 	}
 
 	do {
@@ -199,8 +188,11 @@ static int read_opt(const char *const_line, void *arg)
 			break;
 		case OPTION_IP_PAIR:
 			retval = read_ip(val, buffer);
-			if (!(val = strtok(NULL, ", \t/-"))) retval = 0;
-			if (retval) retval = read_ip(val, buffer + 4);
+			val = strtok(NULL, ", \t/-");
+			if (!val)
+				retval = 0;
+			if (retval)
+				retval = read_ip(val, buffer + 4);
 			break;
 		case OPTION_STRING:
 #if ENABLE_FEATURE_RFC3397
@@ -220,22 +212,33 @@ static int read_opt(const char *const_line, void *arg)
 			buffer[0] = strtoul(val, &endptr, 0);
 			retval = (endptr[0] == '\0');
 			break;
-		case OPTION_U16:
-			*result_u16 = htons(strtoul(val, &endptr, 0));
-			retval = (endptr[0] == '\0');
+		/* htonX are macros in older libc's, using temp var
+		 * in code below for safety */
+		/* TODO: use bb_strtoX? */
+		case OPTION_U16: {
+			unsigned long tmp = strtoul(val, &endptr, 0);
+			*result_u16 = htons(tmp);
+			retval = (endptr[0] == '\0' /*&& tmp < 0x10000*/);
 			break;
-		case OPTION_S16:
-			*result_u16 = htons(strtol(val, &endptr, 0));
+		}
+		case OPTION_S16: {
+			long tmp = strtol(val, &endptr, 0);
+			*result_u16 = htons(tmp);
 			retval = (endptr[0] == '\0');
 			break;
-		case OPTION_U32:
-			*result_u32 = htonl(strtoul(val, &endptr, 0));
+		}
+		case OPTION_U32: {
+			unsigned long tmp = strtoul(val, &endptr, 0);
+			*result_u32 = htonl(tmp);
 			retval = (endptr[0] == '\0');
 			break;
-		case OPTION_S32:
-			*result_u32 = htonl(strtol(val, &endptr, 0));
+		}
+		case OPTION_S32: {
+			long tmp = strtol(val, &endptr, 0);
+			*result_u32 = htonl(tmp);
 			retval = (endptr[0] == '\0');
 			break;
+		}
 		default:
 			break;
 		}
@@ -253,7 +256,6 @@ static int read_staticlease(const char *const_line, void *arg)
 	uint8_t *mac_bytes;
 	uint32_t *ip;
 
-
 	/* Allocate memory for addresses */
 	mac_bytes = xmalloc(sizeof(unsigned char) * 8);
 	ip = xmalloc(sizeof(uint32_t));
@@ -275,39 +277,54 @@ static int read_staticlease(const char *const_line, void *arg)
 }
 
 
+struct config_keyword {
+	const char *keyword;
+	int (*handler)(const char *line, void *var);
+	void *var;
+	const char *def;
+};
+
 static const struct config_keyword keywords[] = {
-	/* keyword	handler   variable address		default */
-	{"start",	read_ip,  &(server_config.start),	"192.168.0.20"},
-	{"end",		read_ip,  &(server_config.end),		"192.168.0.254"},
-	{"interface",	read_str, &(server_config.interface),	"eth0"},
-	{"option",	read_opt, &(server_config.options),	""},
-	{"opt",		read_opt, &(server_config.options),	""},
-	{"max_leases",	read_u32, &(server_config.max_leases),	"254"},
-	{"remaining",	read_yn,  &(server_config.remaining),	"yes"},
-	{"auto_time",	read_u32, &(server_config.auto_time),	"7200"},
-	{"decline_time",read_u32, &(server_config.decline_time),"3600"},
-	{"conflict_time",read_u32,&(server_config.conflict_time),"3600"},
-	{"offer_time",	read_u32, &(server_config.offer_time),	"60"},
-	{"min_lease",	read_u32, &(server_config.min_lease),	"60"},
-	{"lease_file",	read_str, &(server_config.lease_file),	LEASES_FILE},
-	{"pidfile",	read_str, &(server_config.pidfile),	"/var/run/udhcpd.pid"},
-	{"notify_file", read_str, &(server_config.notify_file),	""},
-	{"siaddr",	read_ip,  &(server_config.siaddr),	"0.0.0.0"},
-	{"sname",	read_str, &(server_config.sname),	""},
-	{"boot_file",	read_str, &(server_config.boot_file),	""},
-	{"static_lease",read_staticlease, &(server_config.static_leases),	""},
-	/*ADDME: static lease */
-	{"",		NULL,	  NULL,				""}
+	/* keyword       handler   variable address               default */
+	{"start",        read_ip,  &(server_config.start_ip),     "192.168.0.20"},
+	{"end",          read_ip,  &(server_config.end_ip),       "192.168.0.254"},
+	{"interface",    read_str, &(server_config.interface),    "eth0"},
+	{"option",       read_opt, &(server_config.options),      ""},
+	{"opt",          read_opt, &(server_config.options),      ""},
+	/* Avoid "max_leases value not sane" warning by setting default
+	 * to default_end_ip - default_start_ip + 1: */
+	{"max_leases",   read_u32, &(server_config.max_leases),   "235"},
+	{"remaining",    read_yn,  &(server_config.remaining),    "yes"},
+	{"auto_time",    read_u32, &(server_config.auto_time),    "7200"},
+	{"decline_time", read_u32, &(server_config.decline_time), "3600"},
+	{"conflict_time",read_u32, &(server_config.conflict_time),"3600"},
+	{"offer_time",   read_u32, &(server_config.offer_time),   "60"},
+	{"min_lease",    read_u32, &(server_config.min_lease),    "60"},
+	{"lease_file",   read_str, &(server_config.lease_file),   LEASES_FILE},
+	{"pidfile",      read_str, &(server_config.pidfile),      "/var/run/udhcpd.pid"},
+	{"notify_file",  read_str, &(server_config.notify_file),  ""},
+	{"siaddr",       read_ip,  &(server_config.siaddr),       "0.0.0.0"},
+	{"sname",        read_str, &(server_config.sname),        ""},
+	{"boot_file",    read_str, &(server_config.boot_file),    ""},
+	{"static_lease", read_staticlease, &(server_config.static_leases), ""},
+	/* ADDME: static lease */
 };
 
 
+/*
+ * Domain names may have 254 chars, and string options can be 254
+ * chars long. However, 80 bytes will be enough for most, and won't
+ * hog up memory. If you have a special application, change it
+ */
+#define READ_CONFIG_BUF_SIZE 80
+
 int read_config(const char *file)
 {
 	FILE *in;
 	char buffer[READ_CONFIG_BUF_SIZE], *token, *line;
 	int i, lm = 0;
 
-	for (i = 0; keywords[i].keyword[0]; i++)
+	for (i = 0; i < ARRAY_SIZE(keywords); i++)
 		if (keywords[i].def[0])
 			keywords[i].handler(keywords[i].def, keywords[i].var);
 
@@ -337,7 +354,7 @@ int read_config(const char *file)
 		while (i >= 0 && isspace(line[i]))
 			line[i--] = '\0';
 
-		for (i = 0; keywords[i].keyword[0]; i++)
+		for (i = 0; i < ARRAY_SIZE(keywords); i++)
 			if (!strcasecmp(token, keywords[i].keyword))
 				if (!keywords[i].handler(line, keywords[i].var)) {
 					bb_error_msg("cannot parse line %d of %s", lm, file);
@@ -348,6 +365,10 @@ int read_config(const char *file)
 				}
 	}
 	fclose(in);
+
+	server_config.start_ip = ntohl(server_config.start_ip);
+	server_config.end_ip = ntohl(server_config.end_ip);
+
 	return 1;
 }
 
@@ -408,9 +429,11 @@ void read_leases(const char *file)
 	 && full_read(fp, &lease, sizeof(lease)) == sizeof(lease)
 	) {
 		/* ADDME: is it a static lease */
-		if (lease.yiaddr >= server_config.start && lease.yiaddr <= server_config.end) {
+		uint32_t y = ntohl(lease.yiaddr);
+		if (y >= server_config.start_ip && y <= server_config.end_ip) {
 			lease.expires = ntohl(lease.expires);
-			if (!server_config.remaining) lease.expires -= time(0);
+			if (!server_config.remaining)
+				lease.expires -= time(0);
 			if (!(add_lease(lease.chaddr, lease.yiaddr, lease.expires))) {
 				bb_error_msg("too many leases while loading %s", file);
 				break;
diff --git a/networking/udhcp/leases.c b/networking/udhcp/leases.c
index 5d8775f63..ceec07345 100644
--- a/networking/udhcp/leases.c
+++ b/networking/udhcp/leases.c
@@ -119,8 +119,8 @@ uint32_t find_address(int check_expired)
 	uint32_t addr, ret;
 	struct dhcpOfferedAddr *lease = NULL;
 
-	addr = ntohl(server_config.start); /* addr is in host order here */
-	for (;addr <= ntohl(server_config.end); addr++) {
+	addr = server_config.start_ip; /* addr is in host order here */
+	for (;addr <= server_config.end_ip; addr++) {
 
 		/* ie, 192.168.55.0 */
 		if (!(addr & 0xFF)) continue;
diff --git a/networking/udhcp/serverpacket.c b/networking/udhcp/serverpacket.c
index e1a88addd..ecbf50a14 100644
--- a/networking/udhcp/serverpacket.c
+++ b/networking/udhcp/serverpacket.c
@@ -122,19 +122,18 @@ int sendOffer(struct dhcpMessage *oldpacket)
 			if (!lease_expired(lease))
 				lease_time_align = lease->expires - time(0);
 			packet.yiaddr = lease->yiaddr;
-
 		/* Or the client has a requested ip */
 		} else if ((req = get_option(oldpacket, DHCP_REQUESTED_IP))
-			/* Don't look here (ugly hackish thing to do) */
-			&& memcpy(&req_align, req, 4)
-			/* and the ip is in the lease range */
-			&& ntohl(req_align) >= ntohl(server_config.start)
-			&& ntohl(req_align) <= ntohl(server_config.end)
-			&& !static_lease_ip /* Check that its not a static lease */
-			/* and is not already taken/offered */
-			&& (!(lease = find_lease_by_yiaddr(req_align))
-				/* or its taken, but expired */ /* ADDME: or maybe in here */
-				|| lease_expired(lease))
+		 /* Don't look here (ugly hackish thing to do) */
+		 && memcpy(&req_align, req, 4)
+		 /* and the ip is in the lease range */
+		 && ntohl(req_align) >= server_config.start_ip
+		 && ntohl(req_align) <= server_config.end_ip
+		 && !static_lease_ip /* Check that its not a static lease */
+		 /* and is not already taken/offered */
+		 && (!(lease = find_lease_by_yiaddr(req_align))
+			/* or its taken, but expired */ /* ADDME: or maybe in here */
+			|| lease_expired(lease))
 		) {
 			packet.yiaddr = req_align; /* FIXME: oh my, is there a host using this IP? */
 			/* otherwise, find a free IP */
@@ -142,7 +141,8 @@ int sendOffer(struct dhcpMessage *oldpacket)
 			/* Is it a static lease? (No, because find_address skips static lease) */
 			packet.yiaddr = find_address(0);
 			/* try for an expired lease */
-			if (!packet.yiaddr) packet.yiaddr = find_address(1);
+			if (!packet.yiaddr)
+				packet.yiaddr = find_address(1);
 		}
 
 		if (!packet.yiaddr) {
@@ -209,7 +209,8 @@ int sendACK(struct dhcpMessage *oldpacket, uint32_t yiaddr)
 	init_packet(&packet, oldpacket, DHCPACK);
 	packet.yiaddr = yiaddr;
 
-	if ((lease_time = get_option(oldpacket, DHCP_LEASE_TIME))) {
+	lease_time = get_option(oldpacket, DHCP_LEASE_TIME);
+	if (lease_time) {
 		memcpy(&lease_time_align, lease_time, 4);
 		lease_time_align = ntohl(lease_time_align);
 		if (lease_time_align > server_config.lease)
@@ -236,6 +237,10 @@ int sendACK(struct dhcpMessage *oldpacket, uint32_t yiaddr)
 		return -1;
 
 	add_lease(packet.chaddr, packet.yiaddr, lease_time_align);
+	if (ENABLE_FEATURE_UDHCPD_WRITE_LEASES_EARLY) {
+		/* rewrite the file with leases at every new acceptance */
+		write_leases();
+	}
 
 	return 0;
 }
diff --git a/networking/udhcp/socket.c b/networking/udhcp/socket.c
index d294fb259..be5985f88 100644
--- a/networking/udhcp/socket.c
+++ b/networking/udhcp/socket.c
@@ -43,7 +43,7 @@ int read_interface(const char *interface, int *ifindex, uint32_t *addr, uint8_t
 	struct ifreq ifr;
 	struct sockaddr_in *our_ip;
 
-	memset(&ifr, 0, sizeof(struct ifreq));
+	memset(&ifr, 0, sizeof(ifr));
 	fd = socket(AF_INET, SOCK_RAW, IPPROTO_RAW);
 	if (fd < 0) {
 		bb_perror_msg("socket failed");
@@ -54,7 +54,8 @@ int read_interface(const char *interface, int *ifindex, uint32_t *addr, uint8_t
 	strncpy(ifr.ifr_name, interface, sizeof(ifr.ifr_name));
 	if (addr) {
 		if (ioctl(fd, SIOCGIFADDR, &ifr) != 0) {
-			bb_perror_msg("SIOCGIFADDR failed, is the interface up and configured?");
+			bb_perror_msg("SIOCGIFADDR failed (is interface %s "
+					"up and configured?)", interface);
 			close(fd);
 			return -1;
 		}
@@ -117,7 +118,7 @@ int listen_socket(uint32_t ip, int port, const char *inf)
 		return -1;
 	}
 
-	if (bind(fd, (struct sockaddr *)&addr, sizeof(struct sockaddr)) == -1) {
+	if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
 		close(fd);
 		return -1;
 	}