udhcp: dname_dec may return NULL, account for that case
Other random cleanips included...
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/networking/udhcp/script.c b/networking/udhcp/script.c
index 7ebef35..94dabf4 100644
--- a/networking/udhcp/script.c
+++ b/networking/udhcp/script.c
@@ -14,7 +14,7 @@
/* get a rough idea of how long an option will be (rounding up...) */
-static const uint8_t max_option_length[] = {
+static const uint8_t len_of_option_as_string[] = {
[OPTION_IP] = sizeof("255.255.255.255 "),
[OPTION_IP_PAIR] = sizeof("255.255.255.255 ") * 2,
[OPTION_STRING] = 1,
@@ -30,17 +30,10 @@
};
-static inline int upper_length(int length, int opt_index)
-{
- return max_option_length[opt_index] *
- (length / dhcp_option_lengths[opt_index]);
-}
-
-
/* note: ip is a pointer to an IP in network order, possibly misaliged */
static int sprint_nip(char *dest, const char *pre, const uint8_t *ip)
{
- return sprintf(dest, "%s%d.%d.%d.%d", pre, ip[0], ip[1], ip[2], ip[3]);
+ return sprintf(dest, "%s%u.%u.%u.%u", pre, ip[0], ip[1], ip[2], ip[3]);
}
@@ -57,9 +50,10 @@
}
-/* Allocate and fill with the text of option 'option'. */
-static char *alloc_fill_opts(uint8_t *option, const struct dhcp_option *type_p, const char *opt_name)
+/* Create "opt_name=opt_value" string */
+static char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_option *type_p, const char *opt_name)
{
+ unsigned upper_length;
int len, type, optlen;
uint16_t val_u16;
int16_t val_s16;
@@ -67,14 +61,16 @@
int32_t val_s32;
char *dest, *ret;
- len = option[OPT_LEN - 2];
+ /* option points to OPT_DATA, need to go back and get OPT_LEN */
+ len = option[OPT_LEN - OPT_DATA];
type = type_p->flags & TYPE_MASK;
optlen = dhcp_option_lengths[type];
+ upper_length = len_of_option_as_string[type] * (len / optlen);
- dest = ret = xmalloc(upper_length(len, type) + strlen(opt_name) + 2);
+ dest = ret = xmalloc(upper_length + strlen(opt_name) + 2);
dest += sprintf(ret, "%s=", opt_name);
- for (;;) {
+ while (len >= optlen) {
switch (type) {
case OPTION_IP_PAIR:
dest += sprint_nip(dest, "", option);
@@ -114,15 +110,20 @@
case OPTION_STR1035:
/* unpack option into dest; use ret for prefix (i.e., "optname=") */
dest = dname_dec(option, len, ret);
- free(ret);
- return dest;
+ if (dest) {
+ free(ret);
+ return dest;
+ }
+ /* error. return "optname=" string */
+ return ret;
#endif
}
option += optlen;
len -= optlen;
if (len <= 0)
break;
- dest += sprintf(dest, " ");
+ *dest++ = ' ';
+ *dest = '\0';
}
return ret;
}
@@ -174,7 +175,7 @@
temp = get_option(packet, dhcp_options[i].code);
if (!temp)
goto next;
- *curr = alloc_fill_opts(temp, &dhcp_options[i], opt_name);
+ *curr = xmalloc_optname_optval(temp, &dhcp_options[i], opt_name);
putenv(*curr++);
/* Fill in a subnet bits option for things like /24 */