Update ipconfig to enable users to specify multiple devices on the kernel
commandline
ip= option. This allows for up-to 4 devices to be specified, with devices
separated by
a '/' character. For example, to limit autoconfig requests to eth0 and eth2:
ip=:::::eth0/eth2:DHCP
This is required in cases where one might want to allow DHCP requests from
multiple
devices, but not necessarily want to broadcast on all ethernet devices that are
present
in the system.
The implementation manipulates the existing user_dev_name string and replaces
the '/'
characters with NULLs, and then uses a new small array of pointers into the
substrings created by adding the NULLs.
This patch was tested successfully under vmware and qemu. In particular:
verified
via tcpdump that all devices in the list were autoconfiguring. That any other
devices
in the system were not autoconfiguring. Also verified that if an empty string
was
supplied it would behave as it did before (broadcast on all suitable devices).
Verified
that a single device behaved as before, and just used the single device.
Signed-off-by: Sean Kormilo <[EMAIL PROTECTED]>
---
This is my first patch submission request - please be gentle. ;)
I'm not subscribed to the mailing list, so please CC my email address on any
responses.
--- linux-2.6.21.1/Documentation/nfsroot.txt 2007-04-27 17:49:26.000000000
-0400
+++ linux-2.6.21.1-ipconfig/Documentation/nfsroot.txt 2007-05-17
14:35:32.000000000 -0400
@@ -125,13 +125,18 @@ ip=<client-ip>:<server-ip>:<gw-ip>:<netm
Default: Client IP address is used in ASCII notation.
- <device> Name of network device to use.
+ <devices> Name of network device(s) to use.
Default: If the host only has one device, it is used.
Otherwise the device is determined using
autoconfiguration. This is done by sending
autoconfiguration requests out of all devices,
and using the device that received the first reply.
+
+ Up-to 4 devices may be specified. They should be separated by
+ '/' characters. For example, to specify that DHCP requests
+ should only go out eth0 and eth2:
+ ip=:::::eth0/eth2:DHCP
<autoconf> Method to use for autoconfiguration. In the case of options
which specify multiple autoconfiguration protocols,
--- linux-2.6.21.1/net/ipv4/ipconfig.c 2007-05-17 14:35:15.000000000 -0400
+++ linux-2.6.21.1-ipconfig/net/ipv4/ipconfig.c 2007-05-17 14:44:50.000000000
-0400
@@ -101,6 +101,9 @@
#define CONF_NAMESERVERS_MAX 3 /* Maximum number of nameservers
- '3' from resolv.h */
+#define CONF_USER_DEVS_MAX 4 /* Max number of devices passed in with ip=
*/
+#define CONF_USER_DEVS_SEP '/' /* Separator for devices */
+
#define NONE __constant_htonl(INADDR_NONE)
/*
@@ -149,8 +152,11 @@ static u8 ic_domain[64]; /* DNS (not NI
* Private state.
*/
-/* Name of user-selected boot device */
-static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
+/* Name of user-selected boot device(s) */
+static char user_dev_name[IFNAMSIZ * CONF_USER_DEVS_MAX] __initdata = { 0, };
+/* Array of pointers into the user selected boot devices */
+static char *user_dev_ptrs[CONF_USER_DEVS_MAX] __initdata = { 0, };
+
/* Protocols supported by available interfaces */
static int ic_proto_have_if __initdata = 0;
@@ -184,7 +190,10 @@ static int __init ic_open_devs(void)
struct ic_device *d, **last;
struct net_device *dev;
unsigned short oflags;
-
+ int udn_num = 0;
+ int udn_used = (int) user_dev_ptrs[0];
+ int able;
+
last = &ic_first_dev;
rtnl_lock();
@@ -195,43 +204,63 @@ static int __init ic_open_devs(void)
for (dev = dev_base; dev; dev = dev->next) {
if (dev == &loopback_dev)
continue;
- if (user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
- (!(dev->flags & IFF_LOOPBACK) &&
- (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
- strncmp(dev->name, "dummy", 5))) {
- int able = 0;
- if (dev->mtu >= 364)
- able |= IC_BOOTP;
- else
- printk(KERN_WARNING "DHCP/BOOTP: Ignoring
device %s, MTU %d too small", dev->name, dev->mtu);
- if (!(dev->flags & IFF_NOARP))
- able |= IC_RARP;
- able &= ic_proto_enabled;
- if (ic_proto_enabled && !able)
+
+ if (udn_used) {
+ for (udn_num = 0;
+ udn_num < CONF_USER_DEVS_MAX;
+ udn_num++ ) {
+ if (user_dev_ptrs[udn_num] &&
+ !strcmp(dev->name, user_dev_ptrs[udn_num]))
+ /* found a match */
+ break;
+ }
+
+ if (udn_num >= CONF_USER_DEVS_MAX)
+ /* did not find a match for this device */
+ /* skip to the next one */
continue;
- oflags = dev->flags;
- if (dev_change_flags(dev, oflags | IFF_UP) < 0) {
- printk(KERN_ERR "IP-Config: Failed to open
%s\n", dev->name);
+ } else {
+ if (! (!(dev->flags & IFF_LOOPBACK) &&
+ (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
+ strncmp(dev->name, "dummy", 5)))
+ /* not a usable or non-dummy device - skip it */
continue;
- }
- if (!(d = kmalloc(sizeof(struct ic_device),
GFP_KERNEL))) {
- rtnl_unlock();
- return -1;
- }
- d->dev = dev;
- *last = d;
- last = &d->next;
- d->flags = oflags;
- d->able = able;
- if (able & IC_BOOTP)
- get_random_bytes(&d->xid, sizeof(__be32));
- else
- d->xid = 0;
- ic_proto_have_if |= able;
- DBG(("IP-Config: %s UP (able=%d, xid=%08x)\n",
- dev->name, able, d->xid));
}
+
+ able = 0;
+
+ if (dev->mtu >= 364)
+ able |= IC_BOOTP;
+ else
+ printk(KERN_WARNING "DHCP/BOOTP: Ignoring device %s,
MTU %d too small", dev->name, dev->mtu);
+ if (!(dev->flags & IFF_NOARP))
+ able |= IC_RARP;
+ able &= ic_proto_enabled;
+ if (ic_proto_enabled && !able)
+ continue;
+ oflags = dev->flags;
+ if (dev_change_flags(dev, oflags | IFF_UP) < 0) {
+ printk(KERN_ERR "IP-Config: Failed to open %s\n",
dev->name);
+ continue;
+ }
+ if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
+ rtnl_unlock();
+ return -1;
+ }
+ d->dev = dev;
+ *last = d;
+ last = &d->next;
+ d->flags = oflags;
+ d->able = able;
+ if (able & IC_BOOTP)
+ get_random_bytes(&d->xid, sizeof(__be32));
+ else
+ d->xid = 0;
+ ic_proto_have_if |= able;
+ DBG(("IP-Config: %s UP (able=%d, xid=%08x)\n",
+ dev->name, able, d->xid));
}
+
rtnl_unlock();
*last = NULL;
@@ -1438,8 +1467,9 @@ static int __init ic_proto_name(char *na
static int __init ip_auto_config_setup(char *addrs)
{
- char *cp, *ip, *dp;
+ char *cp, *ip, *dp, *udn;
int num = 0;
+ int udn_num;
ic_set_manually = 1;
@@ -1488,6 +1518,32 @@ static int __init ip_auto_config_setup(c
break;
case 5:
strlcpy(user_dev_name, ip,
sizeof(user_dev_name));
+
+ if (!user_dev_name[0])
+ break;
+
+ /* make sure pointers are initialized to 0 */
+ for (udn_num = 0;
+ udn_num < CONF_USER_DEVS_MAX;
+ udn_num++ )
+ user_dev_ptrs[udn_num] = 0;
+
+ udn = user_dev_name;
+ udn_num = 0;
+
+ while (udn && *udn &&
+ (udn_num < CONF_USER_DEVS_MAX)) {
+
+ if ((dp = strchr(udn,
+ CONF_USER_DEVS_SEP)))
+ *dp++ = '\0';
+
+ if (strlen(udn) > 0)
+ user_dev_ptrs[udn_num++] = udn;
+
+ udn = dp;
+ }
+
break;
case 6:
ic_proto_name(ip);
-
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