udhcpc: add -x OPT:VAL option

function                                             old     new   delta
udhcp_str2optset                                       -     443    +443
add_client_options                                     -     160    +160
udhcpc_main                                         2753    2857    +104
packed_usage                                       26670   26689     +19
attach_option                                        380     385      +5
udhcpd_main                                         1964    1965      +1
udhcp_add_option_string                               94      86      -8
add_param_req_option                                 128       -    -128
read_opt                                             443       -    -443
------------------------------------------------------------------------------
(add/remove: 2/2 grow/shrink: 4/1 up/down: 732/-579)          Total: 153 bytes

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

1 files changed, 6 insertions, 4 deletions

diff --git a/networking/udhcp/options.c b/networking/udhcp/options.c
index b4d2d2de3..af3c217e8 100644
--- a/networking/udhcp/options.c
+++ b/networking/udhcp/options.c
@@ -212,7 +212,7 @@ int FAST_FUNC udhcp_end_option(uint8_t *optionptr)
 
         while (optionptr[i] != DHCP_END) {
                 if (optionptr[i] != DHCP_PADDING)
-                        i += optionptr[i + OPT_LEN] + 1;
+                        i += optionptr[i + OPT_LEN] + OPT_DATA-1;
                 i++;
         }
         return i;
@@ -222,7 +222,8 @@ int FAST_FUNC udhcp_end_option(uint8_t *optionptr)
 /* option bytes: [code][len][data1][data2]..[dataLEN] */
 void FAST_FUNC udhcp_add_option_string(uint8_t *optionptr, uint8_t *string)
 {
-        int end = udhcp_end_option(optionptr);
+        unsigned len;
+        unsigned end = udhcp_end_option(optionptr);
 
         /* end position + string length + option code/length + end option */
         if (end + string[OPT_LEN] + 2 + 1 >= DHCP_OPTIONS_BUFSIZE) {
@@ -231,8 +232,9 @@ void FAST_FUNC udhcp_add_option_string(uint8_t *optionptr, uint8_t *string)
                 return;
         }
         log_option("Adding option", string);
-        memcpy(optionptr + end, string, string[OPT_LEN] + 2);
-        optionptr[end + string[OPT_LEN] + 2] = DHCP_END;
+        len = OPT_DATA + string[OPT_LEN];
+        memcpy(optionptr + end, string, len);
+        optionptr[end + len] = DHCP_END;
 }
 
 /* add a one to four byte option to a packet */