udhcp: pass pointer to whole packet to "add option" functions

This is needed for "overflow option" support

function                                             old     new   delta
udhcp_find_option                                      -      34     +34
udhcp_add_binary_option                               94     106     +12
write_leases                                         227     223      -4
udhcp_init_header                                     86      82      -4
send_release                                         104      99      -5
init_packet                                           87      81      -6
add_client_options                                   160     154      -6
add_server_options                                   100      92      -8
udhcpd_main                                         1964    1954     -10
udhcpc_main                                         2859    2837     -22
find_option                                           34       -     -34
------------------------------------------------------------------------------
(add/remove: 1/1 grow/shrink: 1/8 up/down: 46/-99)            Total: -53 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 2c76080..717c92c 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -319,22 +319,22 @@
 	udhcp_init_header(packet, type);
 	memcpy(packet->chaddr, client_config.client_mac, 6);
 	if (client_config.clientid)
-		udhcp_add_binary_option(packet->options, client_config.clientid);
+		udhcp_add_binary_option(packet, client_config.clientid);
 	if (client_config.hostname)
-		udhcp_add_binary_option(packet->options, client_config.hostname);
+		udhcp_add_binary_option(packet, client_config.hostname);
 	if (client_config.fqdn)
-		udhcp_add_binary_option(packet->options, client_config.fqdn);
+		udhcp_add_binary_option(packet, client_config.fqdn);
 	if (type != DHCPDECLINE
 	 && type != DHCPRELEASE
 	 && client_config.vendorclass
 	) {
-		udhcp_add_binary_option(packet->options, client_config.vendorclass);
+		udhcp_add_binary_option(packet, client_config.vendorclass);
 	}
 }
 
 static void add_client_options(struct dhcp_packet *packet)
 {
-	/* Add am "param req" option with the list of options we'd like to have
+	/* Add a "param req" option with the list of options we'd like to have
 	 * from stubborn DHCP servers. Pull the data from the struct in common.c.
 	 * No bounds checking because it goes towards the head of the packet. */
 	uint8_t c;
@@ -361,7 +361,7 @@
 	{
 		struct option_set *curr = client_config.options;
 		while (curr) {
-			udhcp_add_binary_option(packet->options, curr->data);
+			udhcp_add_binary_option(packet, curr->data);
 			curr = curr->next;
 		}
 //		if (client_config.sname)
@@ -405,10 +405,10 @@
 	init_packet(&packet, DHCPDISCOVER);
 	packet.xid = xid;
 	if (requested)
-		udhcp_add_simple_option(packet.options, DHCP_REQUESTED_IP, requested);
+		udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
 	/* Explicitly saying that we want RFC-compliant packets helps
 	 * some buggy DHCP servers to NOT send bigger packets */
-	udhcp_add_simple_option(packet.options, DHCP_MAX_SIZE, htons(576));
+	udhcp_add_simple_option(&packet, DHCP_MAX_SIZE, htons(576));
 	add_client_options(&packet);
 
 	bb_info_msg("Sending discover...");
@@ -426,8 +426,8 @@
 
 	init_packet(&packet, DHCPREQUEST);
 	packet.xid = xid;
-	udhcp_add_simple_option(packet.options, DHCP_REQUESTED_IP, requested);
-	udhcp_add_simple_option(packet.options, DHCP_SERVER_ID, server);
+	udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
+	udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
 	add_client_options(&packet);
 
 	addr.s_addr = requested;
@@ -461,8 +461,8 @@
 
 	init_packet(&packet, DHCPDECLINE);
 	packet.xid = xid;
-	udhcp_add_simple_option(packet.options, DHCP_REQUESTED_IP, requested);
-	udhcp_add_simple_option(packet.options, DHCP_SERVER_ID, server);
+	udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
+	udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
 
 	bb_info_msg("Sending decline...");
 	return raw_bcast_from_client_config_ifindex(&packet);
@@ -478,7 +478,7 @@
 	packet.xid = random_xid();
 	packet.ciaddr = ciaddr;
 
-	udhcp_add_simple_option(packet.options, DHCP_SERVER_ID, server);
+	udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
 
 	bb_info_msg("Sending release...");
 	return udhcp_send_kernel_packet(&packet, ciaddr, CLIENT_PORT, server, SERVER_PORT);