maybHi,
I've been using BusyBox 1.34.1 for IPv6 stuff. I noticed that the
DHCPv6 RELEASE does not include the client ID option (required by
RFC8415, sec. 18.2.7), even though there is code to do it in
send_d6_release:
/* Client-id */
ci = udhcp_find_option(client_data.options, D6_OPT_CLIENTID);
if (ci)
opt_ptr = mempcpy(opt_ptr, ci->data, D6_OPT_DATA + 2+2 + 6);
When udhcpc6 first starts, it creates its own client ID option if none
is provided, so it *should* be there:
clientid_mac_ptr = NULL;
if (!udhcp_find_option(client_data.options, D6_OPT_CLIENTID)) {
/* not set, set the default client ID */
clientid_mac_ptr = udhcp_insert_new_option(
&client_data.options, D6_OPT_CLIENTID,
2+2 + 6, /*dhcp6:*/ 1);
clientid_mac_ptr += 2+2; /* skip option code, len */
clientid_mac_ptr[1] = 3; /* DUID-LL */
clientid_mac_ptr[3] = 1; /* type: ethernet */
clientid_mac_ptr += 2+2; /* skip DUID-LL, ethernet */
}
I found that even if I insert another udhcp_find_option after the
udhcp_insert_new_option call, the just-now-added option is *still* not
found. I think it is due to an issue with the OPT_CODE handling.
D6_OPT_CLIENTID is 1, so it fits within a single byte but nonetheless,
the following occurs:
* udhcp_insert_new_option treats code for IPv6 as follows:
new->data[D6_OPT_CODE] = code >> 8;
new->data[D6_OPT_CODE + 1] = code & 0xff;
* udhcp_find_option tests the code as follows:
while (opt_list && opt_list->data[OPT_CODE] < code)
...
if (opt_list && opt_list->data[OPT_CODE] == code)
So yes, OPT_CODE and D6_OPT_CODE are both 0, but the D6_OPT_CLIENTID =
1 value means that the 1 is in the seconds byte, and udhcp_find_option
is only looking at the first byte, So the send_d6_release can never
find it the created option.
Maybe udhcp_find_option needs a "bool dhcpv6" arg just like
udhcp_insert_new_option, or else maybe there needs to be a
udhcp_find_option6 option?
Danomi -
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