Re: IPCONFIG fails for BOOTP

Re: IPCONFIG fails for BOOTP

[H . J . Lu]

This is the patch I have been using since May.


H.J.
----
--- linux-2.4.5-ac3-ext3/net/ipv4/ipconfig.c.dhcp	Tue May  1 20:59:24 2001
+++ linux-2.4.5-ac3-ext3/net/ipv4/ipconfig.c	Tue May 29 09:30:16 2001
@@ -816,61 +816,63 @@ static int __init ic_bootp_recv(struct s
 		u8 *ext;
 
 #ifdef IPCONFIG_DHCP
+		if (ic_proto_enabled & IC_USE_DHCP) {
 
-		u32 server_id = INADDR_NONE;
-		int mt = 0;
+			u32 server_id = INADDR_NONE;
+			int mt = 0;
 
-		ext = &b->exten[4];
-		while (ext < end && *ext != 0xff) {
-			u8 *opt = ext++;
-			if (*opt == 0)	/* Padding */
-				continue;
-			ext += *ext + 1;
-			if (ext >= end)
-				break;
-			switch (*opt) {
-			case 53:	/* Message type */
-				if (opt[1])
-					mt = opt[2];
-				break;
-			case 54:	/* Server ID (IP address) */
-				if (opt[1] >= 4)
-					memcpy(&server_id, opt + 2, 4);
-				break;
+			ext = &b->exten[4];
+			while (ext < end && *ext != 0xff) {
+				u8 *opt = ext++;
+				if (*opt == 0)	/* Padding */
+					continue;
+				ext += *ext + 1;
+				if (ext >= end)
+					break;
+				switch (*opt) {
+				case 53:	/* Message type */
+					if (opt[1])
+						mt = opt[2];
+					break;
+				case 54:	/* Server ID (IP address) */
+					if (opt[1] >= 4)
+						memcpy(&server_id, opt + 2, 4);
+					break;
+				}
 			}
-		}
 
 #ifdef IPCONFIG_DEBUG
-		printk("DHCP: Got message type %d\n", mt);
+			printk("DHCP: Got message type %d\n", mt);
 #endif
 
-		switch (mt) {
-		    case DHCPOFFER:
-			/* While in the process of accepting one offer,
-			   ignore all others. */
-			if (ic_myaddr != INADDR_NONE)
-				goto drop;
-			/* Let's accept that offer. */
-			ic_myaddr = b->your_ip;
-			ic_servaddr = server_id;
+			switch (mt) {
+			case DHCPOFFER:
+				/* While in the process of accepting one offer,
+				   ignore all others. */
+				if (ic_myaddr != INADDR_NONE)
+					goto drop;
+				/* Let's accept that offer. */
+				ic_myaddr = b->your_ip;
+				ic_servaddr = server_id;
 #ifdef IPCONFIG_DEBUG
-			printk("DHCP: Offered address %u.%u.%u.%u", NIPQUAD(ic_myaddr));
-			printk(" by server %u.%u.%u.%u\n", NIPQUAD(ic_servaddr));
+				printk("DHCP: Offered address %u.%u.%u.%u", NIPQUAD(ic_myaddr));
+				printk(" by server %u.%u.%u.%u\n", NIPQUAD(ic_servaddr));
 #endif
-			break;
+				break;
 
-		    case DHCPACK:
-			/* Yeah! */
-			break;
-
-		    default:
-			/* Urque.  Forget it*/
-			ic_myaddr = INADDR_NONE;
-			ic_servaddr = INADDR_NONE;
-			goto drop;
-		}
+			case DHCPACK:
+				/* Yeah! */
+				break;
+
+			default:
+				/* Urque.  Forget it*/
+				ic_myaddr = INADDR_NONE;
+				ic_servaddr = INADDR_NONE;
+				goto drop;
+			}
 
-		ic_dhcp_msgtype = mt;
+			ic_dhcp_msgtype = mt;
+		}
 
 #endif /* IPCONFIG_DHCP */
 

Re: IPCONFIG fails for BOOTP

[David S. Miller]

   From: "H . J . Lu" <hjl@lucon.org>
   Date: Thu, 30 Aug 2001 08:32:17 -0700

   This is the patch I have been using since May.
   
Thanks HJ, I've applied your patch.  Sorry for taking so long.

Franks a lot,
David S. Miller
davem@redhat.com

IPCONFIG fails for BOOTP

[Ian Dall]

Kernel version 2.4.8-ac9

I am attempting to set up a linux based xterm. The kernel loads
but times out attempting to get ipaddresses etc in ipconfig.
The following are defined in "include/linux/autoconf.h":

#define CONFIG_IP_PNP 1
#define CONFIG_IP_PNP_DHCP 1
#define CONFIG_IP_PNP_BOOTP 1
#undef  CONFIG_IP_PNP_RARP


A few printk's latter and it seems that the problem is in ic_bootp_recv()
around line 843:

#ifdef IPCONFIG_DEBUG
		printk("DHCP: Got message type %d\n", mt);
#endif

		switch (mt) {
		    case DHCPOFFER:

			 [.....]

		    default:
			/* Urque.  Forget it*/
			ic_myaddr = INADDR_NONE;
			ic_servaddr = INADDR_NONE;
			goto drop;
		}

At this point we could be receiving either DHCP *or* BOOTP extensions.
The code to handle the BOOTP extension follows, but is never executed
because of the "goto drop" in the default case for handling dhcp packets.
If the kernel were compiled without DHCP this problem would go away.

There are two possibilities to fix this. One is to fall through to the
bootp case instead of going to drop, or maybe fold the bootp code into
the default case of the switch statement. The only problem then seems to
be how to conditionalize the DHCP support.

Ian