udhcpc6: improvements

Several small improvements to udhcpc6.

- Remove usage text for the nonexistent -B option.
- Fix a segfault when renewing an IA_PD lease without IA_NA (which means
the client hasn't been assigned an ip, so we cannot locally bind to it).
- Fix NAK management: check the option length, and print the status code
and status message
- Add a -m option to always send renew requests as multicast.

 These last two changes are useful to deal with hopelessly broken DHCPv6
servers such as the one from the Orange Livebox (one of the main French
ISPs) which I'm currently having the displeasure to have to talk to,
hence the patch.

function                                             old     new   delta
static.send_d6_renew                                   -     126    +126
.rodata                                           105598  105649     +51
udhcpc6_main                                        2607    2650     +43
packed_usage                                       34933   34953     +20
d6_send_kernel_packet_from_client_data_ifindex       266     282     +16
send_d6_renew                                        174       -    -174
------------------------------------------------------------------------------
(add/remove: 1/1 grow/shrink: 4/0 up/down: 256/-174)           Total: 82 bytes

Signed-off-by: Laurent Bercot <ska-dietlibc@skarnet.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

0 files changed, 0 insertions, 0 deletions