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>

1 files changed, 9 insertions, 7 deletions

diff --git a/networking/udhcp/common.c b/networking/udhcp/common.c
index bc458ac7a..9316774ff 100644
--- a/networking/udhcp/common.c
+++ b/networking/udhcp/common.c
@@ -226,14 +226,16 @@ int FAST_FUNC udhcp_end_option(uint8_t *optionptr)
 /* Add an option (supplied in binary form) to the options.
  * Option format: [code][len][data1][data2]..[dataLEN]
  */
-void FAST_FUNC udhcp_add_binary_option(uint8_t *optionptr, uint8_t *addopt)
+void FAST_FUNC udhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt)
 {
         unsigned len;
+        uint8_t *optionptr = packet->options;
         unsigned end = udhcp_end_option(optionptr);
 
-        /* end position + option code/length + addopt length + end option */
         len = OPT_DATA + addopt[OPT_LEN];
+        /* end position + (option code/length + addopt length) + end option */
         if (end + len + 1 >= DHCP_OPTIONS_BUFSIZE) {
+//TODO: learn how to use overflow option if we exhaust packet->options[]
                 bb_error_msg("option 0x%02x did not fit into the packet",
                                 addopt[OPT_CODE]);
                 return;
@@ -243,8 +245,8 @@ void FAST_FUNC udhcp_add_binary_option(uint8_t *optionptr, uint8_t *addopt)
         optionptr[end + len] = DHCP_END;
 }
 
-/* Add a one to four byte option to a packet */
-void FAST_FUNC udhcp_add_simple_option(uint8_t *optionptr, uint8_t code, uint32_t data)
+/* Add an one to four byte option to a packet */
+void FAST_FUNC udhcp_add_simple_option(struct dhcp_packet *packet, uint8_t code, uint32_t data)
 {
         const struct dhcp_option *dh;
 
@@ -259,7 +261,7 @@ void FAST_FUNC udhcp_add_simple_option(uint8_t *optionptr, uint8_t code, uint32_
                                 data <<= 8 * (4 - len);
                         /* Assignment is unaligned! */
                         move_to_unaligned32(&option[OPT_DATA], data);
-                        udhcp_add_binary_option(optionptr, option);
+                        udhcp_add_binary_option(packet, option);
                         return;
                 }
         }
@@ -268,7 +270,7 @@ void FAST_FUNC udhcp_add_simple_option(uint8_t *optionptr, uint8_t code, uint32_
 }
 
 /* Find option 'code' in opt_list */
-struct option_set* FAST_FUNC find_option(struct option_set *opt_list, uint8_t code)
+struct option_set* FAST_FUNC udhcp_find_option(struct option_set *opt_list, uint8_t code)
 {
         while (opt_list && opt_list->data[OPT_CODE] < code)
                 opt_list = opt_list->next;
@@ -307,7 +309,7 @@ static NOINLINE void attach_option(
         char *allocated = NULL;
 #endif
 
-        existing = find_option(*opt_list, option->code);
+        existing = udhcp_find_option(*opt_list, option->code);
         if (!existing) {
                 log2("Attaching option %02x to list", option->code);
 #if ENABLE_FEATURE_UDHCP_RFC3397