On Friday, October 22, 2010 04:36:25 Jason Liu wrote:
From: Gray Remlin g_remlin@rocketmail.com
Can't get IP address with dhcp due to the dhcp server not allow the empty param list request under some network env
--- a/net/bootp.c +++ b/net/bootp.c @@ -417,9 +417,19 @@ static int DhcpExtended (u8 * e, int message_type, IPaddr_t ServerID, IPaddr_t R return x - start; #endif
+#if defined(CONFIG_BOOTP_SUBNETMASK) || \
- defined(CONFIG_BOOTP_TIMEOFFSET) || \
- defined(CONFIG_BOOTP_GATEWAY) || \
- defined(CONFIG_BOOTP_DNS) || \
- defined(CONFIG_BOOTP_HOSTNAME) || \
- defined(CONFIG_BOOTP_BOOTFILESIZE) || \
- defined(CONFIG_BOOTP_BOOTPATH) || \
- defined(CONFIG_BOOTP_NISDOMAIN) || \
- defined(CONFIG_BOOTP_NTPSERVER) *e++ = 55; /* Parameter Request List */ cnt = e++; /* Pointer to count of requested items */ *cnt = 0;
+#endif
this list is pretty ugly and prone to breakage. how about having the code back itself up and let gcc optimize things away ? two ways of doing this ...
(1) after the current ifdef list and before the "*e++ = 255;", add like: /* no options, so back up to avoid sending an empty request list */ if (*cnt == 0) e -= 2;
(2) add a "bool empty_list" to this func. where we set "*cnt = 0", do: empty_list = true; then in every ifdef currently, add: empty_list = false; and at the end, do: /* no options, so back up to avoid sending an empty request list */ if (empty_list) e -= 2; -mike