1 files changed, 19 insertions, 8 deletions

diff --git a/networking/udhcp/common.c b/networking/udhcp/common.c
index bc41c8d4d..0cf4dab63 100644
--- a/networking/udhcp/common.c
+++ b/networking/udhcp/common.c
@@ -142,7 +142,7 @@ const char dhcp_option_strings[] ALIGN1 =
  * udhcp_str2optset: to determine how many bytes to allocate.
  * xmalloc_optname_optval: to estimate string length
  * from binary option length: (option[LEN] / dhcp_option_lengths[opt_type])
- * is the number of elements, multiply in by one element's string width
+ * is the number of elements, multiply it by one element's string width
  * (len_of_option_as_string[opt_type]) and you know how wide string you need.
  */
 const uint8_t dhcp_option_lengths[] ALIGN1 = {
@@ -162,7 +162,18 @@ const uint8_t dhcp_option_lengths[] ALIGN1 = {
         [OPTION_S32] =     4,
         /* Just like OPTION_STRING, we use minimum length here */
         [OPTION_STATIC_ROUTES] = 5,
-        [OPTION_6RD] =    22,  /* ignored by udhcp_str2optset */
+        [OPTION_6RD] =    12,  /* ignored by udhcp_str2optset */
+        /* The above value was chosen as follows:
+         * len_of_option_as_string[] for this option is >60: it's a string of the form
+         * "32 128 ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff 255.255.255.255 ".
+         * Each additional ipv4 address takes 4 bytes in binary option and appends
+         * another "255.255.255.255 " 16-byte string. We can set [OPTION_6RD] = 4
+         * but this severely overestimates string length: instead of 16 bytes,
+         * it adds >60 for every 4 bytes in binary option.
+         * We cheat and declare here that option is in units of 12 bytes.
+         * This adds more than 60 bytes for every three ipv4 addresses - more than enough.
+         * (Even 16 instead of 12 should work, but let's be paranoid).
+         */
 };
 
 
@@ -172,7 +183,7 @@ 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);
+                bb_error_msg("%s: 0x%02x %s", pfx, opt[OPT_CODE], buf);
         }
 }
 #else
@@ -246,7 +257,7 @@ uint8_t* FAST_FUNC udhcp_get_option(struct dhcp_packet *packet, int code)
                         continue; /* complain and return NULL */
 
                 if (optionptr[OPT_CODE] == code) {
-                        log_option("Option found", optionptr);
+                        log_option("option found", optionptr);
                         return optionptr + OPT_DATA;
                 }
 
@@ -258,7 +269,7 @@ uint8_t* FAST_FUNC udhcp_get_option(struct dhcp_packet *packet, int code)
         }
 
         /* log3 because udhcpc uses it a lot - very noisy */
-        log3("Option 0x%02x not found", code);
+        log3("option 0x%02x not found", code);
         return NULL;
 }
 
@@ -292,7 +303,7 @@ void FAST_FUNC udhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addo
                                 addopt[OPT_CODE]);
                 return;
         }
-        log_option("Adding option", addopt);
+        log_option("adding option", addopt);
         memcpy(optionptr + end, addopt, len);
         optionptr[end + len] = DHCP_END;
 }
@@ -391,7 +402,7 @@ static NOINLINE void attach_option(
                 struct option_set *new, **curr;
 
                 /* make a new option */
-                log2("Attaching option %02x to list", optflag->code);
+                log2("attaching option %02x to list", optflag->code);
                 new = xmalloc(sizeof(*new));
                 new->data = xmalloc(length + OPT_DATA);
                 new->data[OPT_CODE] = optflag->code;
@@ -411,7 +422,7 @@ static NOINLINE void attach_option(
                 unsigned old_len;
 
                 /* add it to an existing option */
-                log2("Attaching option %02x to existing member of list", optflag->code);
+                log2("attaching option %02x to existing member of list", optflag->code);
                 old_len = existing->data[OPT_LEN];
                 if (old_len + length < 255) {
                         /* actually 255 is ok too, but adding a space can overlow it */