udhcp: logging improvements, field and variable renames

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

networking/udhcp/arpping.c

@@ -41,7 +41,7 @@ enum {
 
 /* Returns 1 if no reply received */
 
-int FAST_FUNC arpping(uint32_t test_ip,
+int FAST_FUNC arpping(uint32_t test_nip,
 		const uint8_t *safe_mac,
 		uint32_t from_ip,
 		uint8_t *from_mac,
@@ -78,7 +78,7 @@ int FAST_FUNC arpping(uint32_t test_ip,
 	memcpy(arp.sHaddr, from_mac, 6);                /* source hardware address */
 	memcpy(arp.sInaddr, &from_ip, sizeof(from_ip)); /* source IP address */
 	/* tHaddr is zero-filled */                     /* target hardware address */
-	memcpy(arp.tInaddr, &test_ip, sizeof(test_ip)); /* target IP address */
+	memcpy(arp.tInaddr, &test_nip, sizeof(test_nip));/* target IP address */
 
 	memset(&addr, 0, sizeof(addr));
 	safe_strncpy(addr.sa_data, interface, sizeof(addr.sa_data));
@@ -111,7 +111,7 @@ int FAST_FUNC arpping(uint32_t test_ip,
 			 && arp.operation == htons(ARPOP_REPLY)
 			 /* don't check it: Linux doesn't return proper tHaddr (fixed in 2.6.24?) */
 			 /* && memcmp(arp.tHaddr, from_mac, 6) == 0 */
-			 && *((uint32_t *) arp.sInaddr) == test_ip
+			 && *((uint32_t *) arp.sInaddr) == test_nip
 			) {
 				 /* if ARP source MAC matches safe_mac
 				  * (which is client's MAC), then it's not a conflict

networking/udhcp/common.c

@@ -6,7 +6,7 @@
 #include "common.h"
 
 #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
-int dhcp_verbose;
+unsigned dhcp_verbose;
 #endif
 
 const uint8_t MAC_BCAST_ADDR[6] ALIGN2 = {

networking/udhcp/common.h

@@ -93,14 +93,14 @@ int udhcp_read_interface(const char *interface, int *ifindex, uint32_t *nip, uin
 int udhcp_raw_socket(int ifindex) FAST_FUNC;
 int udhcp_listen_socket(/*uint32_t ip,*/ int port, const char *inf) FAST_FUNC;
 /* Returns 1 if no reply received */
-int arpping(uint32_t test_ip,
+int arpping(uint32_t test_nip,
 		const uint8_t *safe_mac,
 		uint32_t from_ip,
 		uint8_t *from_mac,
 		const char *interface) FAST_FUNC;
 
 #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
-extern int dhcp_verbose;
+extern unsigned dhcp_verbose;
 # define log1(...) do { if (dhcp_verbose >= 1) bb_info_msg(__VA_ARGS__); } while (0)
 # if CONFIG_UDHCP_DEBUG >= 2
 void udhcp_dump_packet(struct dhcp_packet *packet) FAST_FUNC;

networking/udhcp/dhcpd.c

@@ -18,7 +18,7 @@
 
 
 /* globals */
-struct dyn_lease *leases;
+struct dyn_lease *g_leases;
 /* struct server_config_t server_config is in bb_common_bufsiz1 */
 
 
@@ -28,15 +28,13 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
 	fd_set rfds;
 	int server_socket = -1, retval, max_sock;
 	struct dhcp_packet packet;
-	uint8_t *state, *server_id, *requested;
+	uint8_t *state;
-	uint32_t server_id_aligned = server_id_aligned; /* for compiler */
-	uint32_t requested_aligned = requested_aligned;
 	uint32_t static_lease_ip;
 	unsigned timeout_end;
 	unsigned num_ips;
 	unsigned opt;
 	struct option_set *option;
-	struct dyn_lease *lease, static_lease;
+	struct dyn_lease *lease, fake_lease;
 	IF_FEATURE_UDHCP_PORT(char *str_P;)
 
 #if ENABLE_FEATURE_UDHCP_PORT
@@ -84,10 +82,10 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
 	bb_info_msg("%s (v"BB_VER") started", applet_name);
 
 	option = find_option(server_config.options, DHCP_LEASE_TIME);
-	server_config.lease = LEASE_TIME;
+	server_config.max_lease_sec = LEASE_TIME;
 	if (option) {
-		move_from_unaligned32(server_config.lease, option->data + 2);
+		move_from_unaligned32(server_config.max_lease_sec, option->data + OPT_DATA);
-		server_config.lease = ntohl(server_config.lease);
+		server_config.max_lease_sec = ntohl(server_config.max_lease_sec);
 	}
 
 	/* Sanity check */
@@ -98,7 +96,7 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
 		server_config.max_leases = num_ips;
 	}
 
-	leases = xzalloc(server_config.max_leases * sizeof(*leases));
+	g_leases = xzalloc(server_config.max_leases * sizeof(g_leases[0]));
 	read_leases(server_config.lease_file);
 
 	if (udhcp_read_interface(server_config.interface,
@@ -186,13 +184,13 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
 		if (static_lease_ip) {
 			bb_info_msg("Found static lease: %x", static_lease_ip);
 
-			memcpy(&static_lease.lease_mac, &packet.chaddr, 6);
+			memcpy(&fake_lease.lease_mac, &packet.chaddr, 6);
-			static_lease.lease_nip = static_lease_ip;
+			fake_lease.lease_nip = static_lease_ip;
-			static_lease.expires = 0;
+			fake_lease.expires = 0;
 
-			lease = &static_lease;
+			lease = &fake_lease;
 		} else {
-			lease = find_lease_by_chaddr(packet.chaddr);
+			lease = find_lease_by_mac(packet.chaddr);
 		}
 
 		switch (state[0]) {
@@ -203,29 +201,32 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
 				bb_error_msg("send OFFER failed");
 			}
 			break;
-		case DHCPREQUEST:
+		case DHCPREQUEST: {
+			uint8_t *server_id_opt, *requested_opt;
+			uint32_t server_id_net = server_id_net; /* for compiler */
+			uint32_t requested_nip = requested_nip; /* for compiler */
+
 			log1("Received REQUEST");
 
-			requested = get_option(&packet, DHCP_REQUESTED_IP);
+			requested_opt = get_option(&packet, DHCP_REQUESTED_IP);
-			server_id = get_option(&packet, DHCP_SERVER_ID);
+			server_id_opt = get_option(&packet, DHCP_SERVER_ID);
-
+			if (requested_opt)
-			if (requested)
+				move_from_unaligned32(requested_nip, requested_opt);
-				move_from_unaligned32(requested_aligned, requested);
+			if (server_id_opt)
-			if (server_id)
+				move_from_unaligned32(server_id_net, server_id_opt);
-				move_from_unaligned32(server_id_aligned, server_id);
 
 			if (lease) {
-				if (server_id) {
+				if (server_id_opt) {
 					/* SELECTING State */
-					if (server_id_aligned == server_config.server_nip
+					if (server_id_net == server_config.server_nip
-					 && requested
+					 && requested_opt
-					 && requested_aligned == lease->lease_nip
+					 && requested_nip == lease->lease_nip
 					) {
 						send_ACK(&packet, lease->lease_nip);
 					}
-				} else if (requested) {
+				} else if (requested_opt) {
 					/* INIT-REBOOT State */
-					if (lease->lease_nip == requested_aligned)
+					if (lease->lease_nip == requested_nip)
 						send_ACK(&packet, lease->lease_nip);
 					else
 						send_NAK(&packet);
@@ -237,14 +238,14 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
 				}
 
 			/* what to do if we have no record of the client */
-			} else if (server_id) {
+			} else if (server_id_opt) {
 				/* SELECTING State */
 
-			} else if (requested) {
+			} else if (requested_opt) {
 				/* INIT-REBOOT State */
-				lease = find_lease_by_yiaddr(requested_aligned);
+				lease = find_lease_by_nip(requested_nip);
 				if (lease) {
-					if (lease_expired(lease)) {
+					if (is_expired_lease(lease)) {
 						/* probably best if we drop this lease */
 						memset(lease->lease_mac, 0, sizeof(lease->lease_mac));
 					} else {
@@ -252,7 +253,7 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
 						send_NAK(&packet);
 					}
 				} else {
-					uint32_t r = ntohl(requested_aligned);
+					uint32_t r = ntohl(requested_nip);
 					if (r < server_config.start_ip
 				         || r > server_config.end_ip
 					) {
@@ -265,6 +266,7 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
 				/* RENEWING or REBINDING State */
 			}
 			break;
+		}
 		case DHCPDECLINE:
 			log1("Received DECLINE");
 			if (lease) {

networking/udhcp/dhcpd.h

@@ -46,15 +46,15 @@ struct server_config_t {
 	/* 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 */
-	uint32_t lease;	                /* lease time in seconds (host order) */
+	uint32_t max_lease_sec;         /* maximum lease time (host order) */
-	uint32_t max_leases;            /* maximum number of leases (including reserved address) */
+	uint32_t min_lease_sec;         /* minimum lease time a client can request */
+	uint32_t max_leases;            /* maximum number of leases (including reserved addresses) */
 	uint32_t auto_time;             /* how long should udhcpd wait before writing a config file.
 	                                 * if this is zero, it will only write one on SIGUSR1 */
 	uint32_t decline_time;          /* how long an address is reserved if a client returns a
 	                                 * decline message */
 	uint32_t conflict_time;         /* how long an arp conflict offender is leased for */
 	uint32_t offer_time;            /* how long an offered address is reserved */
-	uint32_t min_lease;             /* minimum lease time a client can request */
 	uint32_t siaddr_nip;            /* "next server" bootp option */
 	char *lease_file;
 	char *pidfile;
@@ -89,24 +89,24 @@ struct dyn_lease {
 	/* We use lease_mac[6], since e.g. ARP probing uses
 	 * only 6 first bytes anyway. We check received dhcp packets
 	 * that their hlen == 6 and thus chaddr has only 6 significant bytes
-	 * (dhcp packet has chaddr[16])
+	 * (dhcp packet has chaddr[16], not [6])
 	 */
 	uint8_t lease_mac[6];
 	uint8_t hostname[20];
 	uint8_t pad[2];
 	/* total size is a multiply of 4 */
-};
+} PACKED;
 
-extern struct dyn_lease *leases;
+extern struct dyn_lease *g_leases;
 
 struct dyn_lease *add_lease(
 		const uint8_t *chaddr, uint32_t yiaddr,
 		leasetime_t leasetime, uint8_t *hostname
 		) FAST_FUNC;
-int lease_expired(struct dyn_lease *lease) FAST_FUNC;
+int is_expired_lease(struct dyn_lease *lease) FAST_FUNC;
-struct dyn_lease *find_lease_by_chaddr(const uint8_t *chaddr) FAST_FUNC;
+struct dyn_lease *find_lease_by_mac(const uint8_t *mac) FAST_FUNC;
-struct dyn_lease *find_lease_by_yiaddr(uint32_t yiaddr) FAST_FUNC;
+struct dyn_lease *find_lease_by_nip(uint32_t nip) FAST_FUNC;
-uint32_t find_free_or_expired_address(const uint8_t *chaddr) FAST_FUNC;
+uint32_t find_free_or_expired_nip(const uint8_t *safe_mac) FAST_FUNC;
 
 
 /*** static_leases.h ***/

networking/udhcp/files.c

@@ -295,7 +295,7 @@ static const struct config_keyword keywords[] = {
 	{"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"},
+	{"min_lease",    read_u32, &(server_config.min_lease_sec),"60"},
 	{"lease_file",   read_str, &(server_config.lease_file),   LEASES_FILE},
 	{"pidfile",      read_str, &(server_config.pidfile),      "/var/run/udhcpd.pid"},
 	{"siaddr",       read_nip, &(server_config.siaddr_nip),   "0.0.0.0"},
@@ -359,23 +359,23 @@ void FAST_FUNC write_leases(void)
 	for (i = 0; i < server_config.max_leases; i++) {
 		leasetime_t tmp_time;
 
-		if (leases[i].lease_nip == 0)
+		if (g_leases[i].lease_nip == 0)
 			continue;
 
 		/* Screw with the time in the struct, for easier writing */
-		tmp_time = leases[i].expires;
+		tmp_time = g_leases[i].expires;
 
-		leases[i].expires -= curr;
+		g_leases[i].expires -= curr;
-		if ((signed_leasetime_t) leases[i].expires < 0)
+		if ((signed_leasetime_t) g_leases[i].expires < 0)
-			leases[i].expires = 0;
+			g_leases[i].expires = 0;
-		leases[i].expires = htonl(leases[i].expires);
+		g_leases[i].expires = htonl(g_leases[i].expires);
 
 		/* No error check. If the file gets truncated,
 		 * we lose some leases on restart. Oh well. */
-		full_write(fd, &leases[i], sizeof(leases[i]));
+		full_write(fd, &g_leases[i], sizeof(g_leases[i]));
 
 		/* Then restore it when done */
-		leases[i].expires = tmp_time;
+		g_leases[i].expires = tmp_time;
 	}
 	close(fd);
 

networking/udhcp/leases.c

@@ -17,12 +17,12 @@ static struct dyn_lease *oldest_expired_lease(void)
 	leasetime_t oldest_time = time(NULL);
 	unsigned i;
 
-	/* Unexpired leases have leases[i].expires >= current time
+	/* Unexpired leases have g_leases[i].expires >= current time
 	 * and therefore can't ever match */
 	for (i = 0; i < server_config.max_leases; i++) {
-		if (leases[i].expires < oldest_time) {
+		if (g_leases[i].expires < oldest_time) {
-			oldest_time = leases[i].expires;
+			oldest_time = g_leases[i].expires;
-			oldest_lease = &leases[i];
+			oldest_lease = &g_leases[i];
 		}
 	}
 	return oldest_lease;
@@ -38,10 +38,10 @@ static void clear_lease(const uint8_t *chaddr, uint32_t yiaddr)
 		continue;
 
 	for (i = 0; i < server_config.max_leases; i++) {
-		if ((j != 16 && memcmp(leases[i].lease_mac, chaddr, 6) == 0)
+		if ((j != 16 && memcmp(g_leases[i].lease_mac, chaddr, 6) == 0)
-		 || (yiaddr && leases[i].lease_nip == yiaddr)
+		 || (yiaddr && g_leases[i].lease_nip == yiaddr)
 		) {
-			memset(&leases[i], 0, sizeof(leases[i]));
+			memset(&g_leases[i], 0, sizeof(g_leases[i]));
 		}
 	}
 }
@@ -85,40 +85,40 @@ struct dyn_lease* FAST_FUNC add_lease(
 
 
 /* True if a lease has expired */
-int FAST_FUNC lease_expired(struct dyn_lease *lease)
+int FAST_FUNC is_expired_lease(struct dyn_lease *lease)
 {
 	return (lease->expires < (leasetime_t) time(NULL));
 }
 
 
-/* Find the first lease that matches chaddr, NULL if no match */
+/* Find the first lease that matches MAC, NULL if no match */
-struct dyn_lease* FAST_FUNC find_lease_by_chaddr(const uint8_t *chaddr)
+struct dyn_lease* FAST_FUNC find_lease_by_mac(const uint8_t *mac)
 {
 	unsigned i;
 
 	for (i = 0; i < server_config.max_leases; i++)
-		if (memcmp(leases[i].lease_mac, chaddr, 6) == 0)
+		if (memcmp(g_leases[i].lease_mac, mac, 6) == 0)
-			return &(leases[i]);
+			return &g_leases[i];
 
 	return NULL;
 }
 
 
-/* Find the first lease that matches yiaddr, NULL is no match */
+/* Find the first lease that matches IP, NULL is no match */
-struct dyn_lease* FAST_FUNC find_lease_by_yiaddr(uint32_t yiaddr)
+struct dyn_lease* FAST_FUNC find_lease_by_nip(uint32_t nip)
 {
 	unsigned i;
 
 	for (i = 0; i < server_config.max_leases; i++)
-		if (leases[i].lease_nip == yiaddr)
+		if (g_leases[i].lease_nip == nip)
-			return &leases[i];
+			return &g_leases[i];
 
 	return NULL;
 }
 
 
 /* Check if the IP is taken; if it is, add it to the lease table */
-static int nobody_responds_to_arp(uint32_t addr, const uint8_t *safe_mac)
+static int nobody_responds_to_arp(uint32_t nip, const uint8_t *safe_mac)
 {
 	/* 16 zero bytes */
 	static const uint8_t blank_chaddr[16] = { 0 };
@@ -127,30 +127,30 @@ static int nobody_responds_to_arp(uint32_t addr, const uint8_t *safe_mac)
 	struct in_addr temp;
 	int r;
 
-	r = arpping(addr, safe_mac,
+	r = arpping(nip, safe_mac,
 			server_config.server_nip,
 			server_config.server_mac,
 			server_config.interface);
 	if (r)
 		return r;
 
-	temp.s_addr = addr;
+	temp.s_addr = nip;
 	bb_info_msg("%s belongs to someone, reserving it for %u seconds",
 		inet_ntoa(temp), (unsigned)server_config.conflict_time);
-	add_lease(blank_chaddr, addr, server_config.conflict_time, NULL);
+	add_lease(blank_chaddr, nip, server_config.conflict_time, NULL);
 	return 0;
 }
 
 
 /* Find a new usable (we think) address */
-uint32_t FAST_FUNC find_free_or_expired_address(const uint8_t *chaddr)
+uint32_t FAST_FUNC find_free_or_expired_nip(const uint8_t *safe_mac)
 {
 	uint32_t addr;
 	struct dyn_lease *oldest_lease = NULL;
 
 	addr = server_config.start_ip; /* addr is in host order here */
 	for (; addr <= server_config.end_ip; addr++) {
-		uint32_t net_addr;
+		uint32_t nip;
 		struct dyn_lease *lease;
 
 		/* ie, 192.168.55.0 */
@@ -159,23 +159,23 @@ uint32_t FAST_FUNC find_free_or_expired_address(const uint8_t *chaddr)
 		/* ie, 192.168.55.255 */
 		if ((addr & 0xff) == 0xff)
 			continue;
-		net_addr = htonl(addr);
+		nip = htonl(addr);
 		/* is this a static lease addr? */
-		if (is_nip_reserved(server_config.static_leases, net_addr))
+		if (is_nip_reserved(server_config.static_leases, nip))
 			continue;
 
-		lease = find_lease_by_yiaddr(net_addr);
+		lease = find_lease_by_nip(nip);
 		if (!lease) {
-			if (nobody_responds_to_arp(net_addr, chaddr))
+			if (nobody_responds_to_arp(nip, safe_mac))
-				return net_addr;
+				return nip;
 		} else {
 			if (!oldest_lease || lease->expires < oldest_lease->expires)
 				oldest_lease = lease;
 		}
 	}
 
-	if (oldest_lease && lease_expired(oldest_lease)
+	if (oldest_lease && is_expired_lease(oldest_lease)
-	 && nobody_responds_to_arp(oldest_lease->lease_nip, chaddr)
+	 && nobody_responds_to_arp(oldest_lease->lease_nip, safe_mac)
 	) {
 		return oldest_lease->lease_nip;
 	}

networking/udhcp/options.c

@@ -119,6 +119,20 @@ const uint8_t dhcp_option_lengths[] ALIGN1 = {
 };
 
 
+#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 2
+static void log_option(const char *pfx, const uint8_t *opt)
+{
+	if (dhcp_verbose >= 2) {
+		char buf[256 * 2 + 2];
+		*bin2hex(buf, (void*) (opt + OPT_DATA), opt[OPT_LEN]) = '\0';
+		bb_info_msg("%s: 0x%02x %s", pfx, opt[OPT_CODE], buf);
+	}
+}
+#else
+# define log_option(pfx, opt) ((void)0)
+#endif
+
+
 /* get an option with bounds checking (warning, result is not aligned). */
 uint8_t* FAST_FUNC get_option(struct dhcp_packet *packet, int code)
 {
@@ -167,11 +181,7 @@ uint8_t* FAST_FUNC get_option(struct dhcp_packet *packet, int code)
 			continue; /* complain and return NULL */
 
 		if (optionptr[OPT_CODE] == code) {
-#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 2
+			log_option("Option found", optionptr);
-			char buf[256 * 2 + 2];
-			*bin2hex(buf, (void*) (optionptr + OPT_DATA), optionptr[OPT_LEN]) = '\0';
-			log2("Option 0x%02x found: %s", code, buf);
-#endif
 			return optionptr + OPT_DATA;
 		}
 
@@ -214,7 +224,7 @@ int FAST_FUNC add_option_string(uint8_t *optionptr, uint8_t *string)
 				string[OPT_CODE]);
 		return 0;
 	}
-	log1("Adding option 0x%02x", string[OPT_CODE]);
+	log_option("Adding option", string);
 	memcpy(optionptr + end, string, string[OPT_LEN] + 2);
 	optionptr[end + string[OPT_LEN] + 2] = DHCP_END;
 	return string[OPT_LEN] + 2;

networking/udhcp/packet.c

@@ -78,7 +78,7 @@ void FAST_FUNC udhcp_dump_packet(struct dhcp_packet *packet)
 		//, packet->cookie
 		//, packet->options[]
 	);
-	bin2hex(buf, (void *) packet->chaddr, sizeof(packet->chaddr));
+	*bin2hex(buf, (void *) packet->chaddr, sizeof(packet->chaddr)) = '\0';
 	bb_info_msg(" chaddr %s", buf);
 }
 #endif

networking/udhcp/script.c

@@ -218,17 +218,17 @@ void FAST_FUNC udhcp_run_script(struct dhcp_packet *packet, const char *name)
 	if (client_config.script == NULL)
 		return;
 
-	log1("Executing %s", client_config.script);
-
 	envp = fill_envp(packet);
 
 	/* call script */
+	log1("Executing %s", client_config.script);
 	argv[0] = (char*) client_config.script;
 	argv[1] = (char*) name;
 	argv[2] = NULL;
 	wait4pid(spawn(argv));
 
 	for (curr = envp; *curr; curr++) {
+		log2(" %s", *curr);
 		bb_unsetenv(*curr);
 		free(*curr);
 	}

networking/udhcp/serverpacket.c

@@ -107,14 +107,30 @@ static void add_bootp_options(struct dhcp_packet *packet)
 }
 
 
+static uint32_t select_lease_time(struct dhcp_packet *packet)
+{
+	uint32_t lease_time_sec = server_config.max_lease_sec;
+	uint8_t *lease_time_opt = get_option(packet, DHCP_LEASE_TIME);
+	if (lease_time_opt) {
+		move_from_unaligned32(lease_time_sec, lease_time_opt);
+		lease_time_sec = ntohl(lease_time_sec);
+		if (lease_time_sec > server_config.max_lease_sec)
+			lease_time_sec = server_config.max_lease_sec;
+		if (lease_time_sec < server_config.min_lease_sec)
+			lease_time_sec = server_config.min_lease_sec;
+	}
+	return lease_time_sec;
+}
+
+
 /* send a DHCP OFFER to a DHCP DISCOVER */
 int FAST_FUNC send_offer(struct dhcp_packet *oldpacket)
 {
 	struct dhcp_packet packet;
-	uint32_t req_align;
+	uint32_t req_nip;
-	uint32_t lease_time_aligned = server_config.lease;
+	uint32_t lease_time_sec = server_config.max_lease_sec;
 	uint32_t static_lease_ip;
-	uint8_t *req, *lease_time, *p_host_name;
+	uint8_t *req_ip_opt, *p_host_name;
 	struct option_set *curr;
 	struct in_addr addr;
 
@@ -126,31 +142,31 @@ int FAST_FUNC send_offer(struct dhcp_packet *oldpacket)
 	if (!static_lease_ip) {
 		struct dyn_lease *lease;
 
-		lease = find_lease_by_chaddr(oldpacket->chaddr);
+		lease = find_lease_by_mac(oldpacket->chaddr);
 		/* The client is in our lease/offered table */
 		if (lease) {
 			signed_leasetime_t tmp = lease->expires - time(NULL);
 			if (tmp >= 0)
-				lease_time_aligned = tmp;
+				lease_time_sec = tmp;
 			packet.yiaddr = lease->lease_nip;
 		}
 		/* Or the client has requested an IP */
-		else if ((req = get_option(oldpacket, DHCP_REQUESTED_IP)) != NULL
+		else if ((req_ip_opt = get_option(oldpacket, DHCP_REQUESTED_IP)) != NULL
 		 /* (read IP) */
-		 && (move_from_unaligned32(req_align, req), 1)
+		 && (move_from_unaligned32(req_nip, req_ip_opt), 1)
 		 /* and the IP is in the lease range */
-		 && ntohl(req_align) >= server_config.start_ip
+		 && ntohl(req_nip) >= server_config.start_ip
-		 && ntohl(req_align) <= server_config.end_ip
+		 && ntohl(req_nip) <= server_config.end_ip
 		 /* and is not already taken/offered */
-		 && (!(lease = find_lease_by_yiaddr(req_align))
+		 && (!(lease = find_lease_by_nip(req_nip))
 			/* or its taken, but expired */
-			|| lease_expired(lease))
+			|| is_expired_lease(lease))
 		) {
-			packet.yiaddr = req_align;
+			packet.yiaddr = req_nip;
 		}
 		/* Otherwise, find a free IP */
 		else {
-			packet.yiaddr = find_free_or_expired_address(oldpacket->chaddr);
+			packet.yiaddr = find_free_or_expired_nip(oldpacket->chaddr);
 		}
 
 		if (!packet.yiaddr) {
@@ -162,23 +178,13 @@ int FAST_FUNC send_offer(struct dhcp_packet *oldpacket)
 			bb_error_msg("lease pool is full - OFFER abandoned");
 			return -1;
 		}
-		lease_time = get_option(oldpacket, DHCP_LEASE_TIME);
+		lease_time_sec = select_lease_time(oldpacket);
-		if (lease_time) {
-			move_from_unaligned32(lease_time_aligned, lease_time);
-			lease_time_aligned = ntohl(lease_time_aligned);
-			if (lease_time_aligned > server_config.lease)
-				lease_time_aligned = server_config.lease;
-		}
-
-		/* Make sure we aren't just using the lease time from the previous offer */
-		if (lease_time_aligned < server_config.min_lease)
-			lease_time_aligned = server_config.min_lease;
 	} else {
 		/* It is a static lease... use it */
 		packet.yiaddr = static_lease_ip;
 	}
 
-	add_simple_option(packet.options, DHCP_LEASE_TIME, htonl(lease_time_aligned));
+	add_simple_option(packet.options, DHCP_LEASE_TIME, htonl(lease_time_sec));
 
 	curr = server_config.options;
 	while (curr) {
@@ -210,25 +216,16 @@ int FAST_FUNC send_ACK(struct dhcp_packet *oldpacket, uint32_t yiaddr)
 {
 	struct dhcp_packet packet;
 	struct option_set *curr;
-	uint8_t *lease_time;
+	uint32_t lease_time_sec;
-	uint32_t lease_time_aligned = server_config.lease;
 	struct in_addr addr;
 	uint8_t *p_host_name;
 
 	init_packet(&packet, oldpacket, DHCPACK);
 	packet.yiaddr = yiaddr;
 
-	lease_time = get_option(oldpacket, DHCP_LEASE_TIME);
+	lease_time_sec = select_lease_time(oldpacket);
-	if (lease_time) {
-		move_from_unaligned32(lease_time_aligned, lease_time);
-		lease_time_aligned = ntohl(lease_time_aligned);
-		if (lease_time_aligned > server_config.lease)
-			lease_time_aligned = server_config.lease;
-		else if (lease_time_aligned < server_config.min_lease)
-			lease_time_aligned = server_config.min_lease;
-	}
 
-	add_simple_option(packet.options, DHCP_LEASE_TIME, htonl(lease_time_aligned));
+	add_simple_option(packet.options, DHCP_LEASE_TIME, htonl(lease_time_sec));
 
 	curr = server_config.options;
 	while (curr) {
@@ -246,7 +243,7 @@ int FAST_FUNC send_ACK(struct dhcp_packet *oldpacket, uint32_t yiaddr)
 		return -1;
 
 	p_host_name = get_option(oldpacket, DHCP_HOST_NAME);
-	add_lease(packet.chaddr, packet.yiaddr, lease_time_aligned, p_host_name);
+	add_lease(packet.chaddr, packet.yiaddr, lease_time_sec, p_host_name);
 	if (ENABLE_FEATURE_UDHCPD_WRITE_LEASES_EARLY) {
 		/* rewrite the file with leases at every new acceptance */
 		write_leases();