udhcpd: untangle incredibly messy handling of DHCPREQUEST

Also fixes attacks possible via DHCPDECLINE / DHCPRELEASE

function                                             old     new   delta
udhcpd_main                                         1846    1949    +103
send_renew                                           105     142     +37
send_NAK                                              61       -     -61
send_ACK                                             180       -    -180
------------------------------------------------------------------------------
(add/remove: 0/2 grow/shrink: 2/0 up/down: 140/-241)         Total: -101 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/networking/udhcp/options.c b/networking/udhcp/options.c
index 5bef985bc..29a264047 100644
--- a/networking/udhcp/options.c
+++ b/networking/udhcp/options.c
@@ -252,7 +252,7 @@ void FAST_FUNC add_simple_option(uint8_t *optionptr, uint8_t code, uint32_t data
                         uint8_t option[6], len;
 
                         option[OPT_CODE] = code;
-                        len = dhcp_option_lengths[dh->flags & TYPE_MASK];
+                        len = dhcp_option_lengths[dh->flags & OPTION_TYPE_MASK];
                         option[OPT_LEN] = len;
                         if (BB_BIG_ENDIAN)
                                 data <<= 8 * (4 - len);