[lwip-devel] LWIP_HOOK_DHCP6_APPEND_OPTIONS cannot append options

[Craig McQueen]

I am trying to use `LWIP_HOOK_DHCP6_APPEND_OPTIONS()` to append DHCPv6 options. My code is adding options and adjusting `options_out_len` (after I have changed the call to the hook to use `&options_out_len` as I mentioned in my previous message).

However, it looks as though the pbuf can't expand to accommodate the extra options, because it was allocated with a limited size:

      p_out = dhcp6_create_msg(netif, dhcp6, DHCP6_INFOREQUEST, 4 + sizeof(requested_options), &options_out_len);

Namely the parameter `opt_len_alloc` is set to `4 + sizeof(requested_options)`. So the call to `dhcp6_msg_finalize()` is unable to expand the pbuf size.

--
Craig McQueen

		Craig McQueen Embedded Systems Engineer
		t e w	: : :	+61 3 9780 4378 craig.mcqueen@innerrange.com innerrange.com
Inner Range • 1 Millennium Court • Knoxfield • Victoria • 3180 • Australia