optimize 16- and 32-bit moves

function                                             old     new   delta
udhcpd_main                                         1239    1257     +18
udhcp_add_simple_option                               93      92      -1
buffer_read_le_u32                                    19      18      -1
unpack_gz_stream_with_info                           526     520      -6
dnsd_main                                           1470    1463      -7
udhcp_run_script                                    1208    1186     -22
send_ACK                                             255     229     -26
arping_main                                         1661    1623     -38
send_offer                                           470     428     -42
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/8 up/down: 18/-143)          Total: -125 bytes

networking/udhcp/dhcpc.c

@@ -503,7 +503,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
 						/* still selecting - this server looks bad */
 					}
 					/* it IS unaligned sometimes, don't "optimize" */
-					server_addr = get_unaligned_u32p((uint32_t*)temp);
+					move_from_unaligned32(server_addr, temp);
 					xid = packet.xid;
 					requested_ip = packet.yiaddr;
 
@@ -525,7 +525,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
 						lease_seconds = 60 * 60;
 					} else {
 						/* it IS unaligned sometimes, don't "optimize" */
-						lease_seconds = get_unaligned_u32p((uint32_t*)temp);
+						move_from_unaligned32(lease_seconds, temp);
 						lease_seconds = ntohl(lease_seconds);
 						lease_seconds &= 0x0fffffff; /* paranoia: must not be prone to overflows */
 						if (lease_seconds < 10) /* and not too small */

networking/udhcp/dhcpd.c

@@ -30,7 +30,9 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
 	int server_socket = -1, bytes, retval, max_sock;
 	struct dhcpMessage packet;
 	uint8_t *state, *server_id, *requested;
-	uint32_t server_id_align, requested_align, static_lease_ip;
+	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;
@@ -79,7 +81,7 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
 	option = find_option(server_config.options, DHCP_LEASE_TIME);
 	server_config.lease = LEASE_TIME;
 	if (option) {
-		memcpy(&server_config.lease, option->data + 2, 4);
+		move_from_unaligned32(server_config.lease, option->data + 2);
 		server_config.lease = ntohl(server_config.lease);
 	}
 
@@ -190,21 +192,24 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
 			requested = get_option(&packet, DHCP_REQUESTED_IP);
 			server_id = get_option(&packet, DHCP_SERVER_ID);
 
-			if (requested) memcpy(&requested_align, requested, 4);
-			if (server_id) memcpy(&server_id_align, server_id, 4);
+			if (requested)
+				move_from_unaligned32(requested_aligned, requested);
+			if (server_id)
+				move_from_unaligned32(server_id_aligned, server_id);
 
 			if (lease) {
 				if (server_id) {
 					/* SELECTING State */
-					DEBUG("server_id = %08x", ntohl(server_id_align));
-					if (server_id_align == server_config.server && requested
-					 && requested_align == lease->yiaddr
+					DEBUG("server_id = %08x", ntohl(server_id_aligned));
+					if (server_id_aligned == server_config.server
+					 && requested
+					 && requested_aligned == lease->yiaddr
 					) {
 						send_ACK(&packet, lease->yiaddr);
 					}
 				} else if (requested) {
 					/* INIT-REBOOT State */
-					if (lease->yiaddr == requested_align)
+					if (lease->yiaddr == requested_aligned)
 						send_ACK(&packet, lease->yiaddr);
 					else
 						send_NAK(&packet);
@@ -221,7 +226,7 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
 
 			} else if (requested) {
 				/* INIT-REBOOT State */
-				lease = find_lease_by_yiaddr(requested_align);
+				lease = find_lease_by_yiaddr(requested_aligned);
 				if (lease) {
 					if (lease_expired(lease)) {
 						/* probably best if we drop this lease */
@@ -230,7 +235,7 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
 					} else
 						send_NAK(&packet);
 				} else {
-					uint32_t r = ntohl(requested_align);
+					uint32_t r = ntohl(requested_aligned);
 					if (r < server_config.start_ip
 				         || r > server_config.end_ip
 					) {

networking/udhcp/options.c

@@ -224,9 +224,8 @@ int FAST_FUNC add_simple_option(uint8_t *optionptr, uint8_t code, uint32_t data)
 			option[OPT_LEN] = len;
 			if (BB_BIG_ENDIAN)
 				data <<= 8 * (4 - len);
-			/* This memcpy is for processors which can't
-			 * handle a simple unaligned 32-bit assignment */
-			memcpy(&option[OPT_DATA], &data, 4);
+			/* Assignment is unaligned! */
+			move_to_unaligned32(&option[OPT_DATA], data);
 			return add_option_string(optionptr, option);
 		}
 	}

networking/udhcp/script.c

@@ -90,19 +90,19 @@ static char *alloc_fill_opts(uint8_t *option, const struct dhcp_option *type_p,
 			dest += sprintf(dest, "%u", *option);
 			break;
 		case OPTION_U16:
-			memcpy(&val_u16, option, 2);
+			move_from_unaligned16(val_u16, option);
 			dest += sprintf(dest, "%u", ntohs(val_u16));
 			break;
 		case OPTION_S16:
-			memcpy(&val_s16, option, 2);
+			move_from_unaligned16(val_s16, option);
 			dest += sprintf(dest, "%d", ntohs(val_s16));
 			break;
 		case OPTION_U32:
-			memcpy(&val_u32, option, 4);
+			move_from_unaligned32(val_u32, option);
 			dest += sprintf(dest, "%lu", (unsigned long) ntohl(val_u32));
 			break;
 		case OPTION_S32:
-			memcpy(&val_s32, option, 4);
+			move_from_unaligned32(val_s32, option);
 			dest += sprintf(dest, "%ld", (long) ntohl(val_s32));
 			break;
 		case OPTION_STRING:
@@ -183,7 +183,7 @@ static char **fill_envp(struct dhcpMessage *packet)
 		/* Fill in a subnet bits option for things like /24 */
 		if (dhcp_options[i].code == DHCP_SUBNET) {
 			uint32_t subnet;
-			memcpy(&subnet, temp, 4);
+			move_from_unaligned32(subnet, temp);
 			envp[j++] = xasprintf("mask=%d", mton(subnet));
 		}
  next:

networking/udhcp/serverpacket.c

@@ -103,7 +103,8 @@ int FAST_FUNC send_offer(struct dhcpMessage *oldpacket)
 {
 	struct dhcpMessage packet;
 	struct dhcpOfferedAddr *lease = NULL;
-	uint32_t req_align, lease_time_align = server_config.lease;
+	uint32_t req_align;
+	uint32_t lease_time_aligned = server_config.lease;
 	uint8_t *req, *lease_time;
 	struct option_set *curr;
 	struct in_addr addr;
@@ -120,7 +121,7 @@ int FAST_FUNC send_offer(struct dhcpMessage *oldpacket)
 		lease = find_lease_by_chaddr(oldpacket->chaddr);
 		if (lease) {
 			if (!lease_expired(lease))
-				lease_time_align = lease->expires - time(0);
+				lease_time_aligned = lease->expires - time(0);
 			packet.yiaddr = lease->yiaddr;
 		/* Or the client has a requested ip */
 		} else if ((req = get_option(oldpacket, DHCP_REQUESTED_IP))
@@ -155,22 +156,22 @@ int FAST_FUNC send_offer(struct dhcpMessage *oldpacket)
 		}
 		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)
-				lease_time_align = server_config.lease;
+			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_align < server_config.min_lease)
-			lease_time_align = server_config.lease;
+		if (lease_time_aligned < server_config.min_lease)
+			lease_time_aligned = server_config.lease;
 		/* ADDME: end of short circuit */
 	} else {
 		/* It is a static lease... use it */
 		packet.yiaddr = static_lease_ip;
 	}
 
-	add_simple_option(packet.options, DHCP_LEASE_TIME, htonl(lease_time_align));
+	add_simple_option(packet.options, DHCP_LEASE_TIME, htonl(lease_time_aligned));
 
 	curr = server_config.options;
 	while (curr) {
@@ -203,7 +204,7 @@ int FAST_FUNC send_ACK(struct dhcpMessage *oldpacket, uint32_t yiaddr)
 	struct dhcpMessage packet;
 	struct option_set *curr;
 	uint8_t *lease_time;
-	uint32_t lease_time_align = server_config.lease;
+	uint32_t lease_time_aligned = server_config.lease;
 	struct in_addr addr;
 
 	init_packet(&packet, oldpacket, DHCPACK);
@@ -211,15 +212,15 @@ int FAST_FUNC send_ACK(struct dhcpMessage *oldpacket, uint32_t yiaddr)
 
 	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)
-			lease_time_align = server_config.lease;
-		else if (lease_time_align < server_config.min_lease)
-			lease_time_align = server_config.lease;
+		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.lease;
 	}
 
-	add_simple_option(packet.options, DHCP_LEASE_TIME, htonl(lease_time_align));
+	add_simple_option(packet.options, DHCP_LEASE_TIME, htonl(lease_time_aligned));
 
 	curr = server_config.options;
 	while (curr) {
@@ -236,7 +237,7 @@ int FAST_FUNC send_ACK(struct dhcpMessage *oldpacket, uint32_t yiaddr)
 	if (send_packet(&packet, 0) < 0)
 		return -1;
 
-	add_lease(packet.chaddr, packet.yiaddr, lease_time_align);
+	add_lease(packet.chaddr, packet.yiaddr, lease_time_aligned);
 	if (ENABLE_FEATURE_UDHCPD_WRITE_LEASES_EARLY) {
 		/* rewrite the file with leases at every new acceptance */
 		write_leases();