summaryrefslogtreecommitdiff
path: root/gdhcp/common.c
diff options
context:
space:
mode:
Diffstat (limited to 'gdhcp/common.c')
-rw-r--r--gdhcp/common.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/gdhcp/common.c b/gdhcp/common.c
index 45278a8..ac6b125 100644
--- a/gdhcp/common.c
+++ b/gdhcp/common.c
@@ -144,6 +144,71 @@ int dhcp_end_option(uint8_t *optionptr)
return i;
}
+/* get a rough idea of how long an option will be */
+static const uint8_t len_of_option_as_string[] = {
+ [OPTION_IP] = sizeof("255.255.255.255 "),
+ [OPTION_STRING] = 1,
+ [OPTION_U8] = sizeof("255 "),
+ [OPTION_U16] = sizeof("65535 "),
+ [OPTION_U32] = sizeof("4294967295 "),
+};
+
+static int sprint_nip(char *dest, const char *pre, const uint8_t *ip)
+{
+ return sprintf(dest, "%s%u.%u.%u.%u", pre, ip[0], ip[1], ip[2], ip[3]);
+}
+
+/* Create "opt_value1 option_value2 ..." string */
+char *malloc_option_value_string(uint8_t *option, GDHCPOptionType type)
+{
+ unsigned upper_length;
+ int len, optlen;
+ char *dest, *ret;
+
+ len = option[OPT_LEN - OPT_DATA];
+ type &= OPTION_TYPE_MASK;
+ optlen = dhcp_option_lengths[type];
+ if (optlen == 0)
+ return NULL;
+ upper_length = len_of_option_as_string[type] *
+ ((unsigned)len / (unsigned)optlen);
+ dest = ret = g_malloc(upper_length + 1);
+ if (ret == NULL)
+ return NULL;
+
+ while (len >= optlen) {
+ switch (type) {
+ case OPTION_IP:
+ dest += sprint_nip(dest, "", option);
+ break;
+ case OPTION_U16: {
+ uint16_t val_u16 = get_be16(option);
+ dest += sprintf(dest, "%u", val_u16);
+ break;
+ }
+ case OPTION_U32: {
+ uint32_t val_u32 = get_be32(option);
+ dest += sprintf(dest, "%u", val_u32);
+ break;
+ }
+ case OPTION_STRING:
+ memcpy(dest, option, len);
+ dest[len] = '\0';
+ return ret;
+ default:
+ break;
+ }
+ option += optlen;
+ len -= optlen;
+ if (len <= 0)
+ break;
+ *dest++ = ' ';
+ *dest = '\0';
+ }
+
+ return ret;
+}
+
uint8_t *dhcpv6_get_option(struct dhcpv6_packet *packet, uint16_t pkt_len,
int code, uint16_t *option_len, int *option_count)
{