NFS and Network Driver Question

Hello,

I'm trying to build a kernel that mounts a NFS root file system. This is an embedded system; it uses an SMSC LAN91C111 network chip that is hardwired to I/O addres 0x300 and IRQ 5. I've been using the driver (as supplied by SMSC) as a module, and it works fine. Now I'm trying to incorporate it into the kernel build so that I can mount an NFS file system when the system boots.

I've added the source code to the kernel tree, and modified the Makefile(s) and Config.in files so that the driver <<appears>> to be compiled into the kernel. The kernel will load, but the chip is not initialized and the NFS fails.

Since I don't know how to pass the io address and irq number to the kernel, I've hard-coded them into the driver's init function (which I don't see being called).

If someone could point me in the right direction, I'd appreciate it.

Thank you,

Bob Wirka
Realtime Control Works

Hello,

I'm trying to build a kernel that mounts a NFS root file system. This is an embedded system; it uses an SMSC LAN91C111 network chip that is hardwired to I/O addres 0x300 and IRQ 5. I've been using the driver (as supplied by SMSC) as a module, and it works fine. Now I'm trying to incorporate it into the kernel build so that I can mount an NFS file system when the system boots.

I've added the source code to the kernel tree, and modified the Makefile(s) and Config.in files so that the driver <<appears>> to be compiled into the kernel. The kernel will load, but the chip is not initialized and the NFS fails.

Since I don't know how to pass the io address and irq number to the kernel, I've hard-coded them into the driver's init function (which I don't see being called).

If someone could point me in the right direction, I'd appreciate it.

Thank you,

Bob Wirka
Realtime Control Works

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"Bob" == Bob Wirka <[email protected]> writes:

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"Bob" == Bob Wirka <[email protected]> writes:

Bob> Ok, now I feel like I'm taking crazy pills...

Bob> The embedded system boots up and mounts the root file system on Bob> my host laptop. The 'rc.sysinit' startup script executes the Bob> command 'mount -a' which should mount /proc, /dev/pts, and Bob> /dev/shm, as listed in /etc/fstab. When executed, that command Bob> returns "mount: only root can do that".

Bob> When I get to the bash prompt, 'whoami' reports that I am, Bob> indeed, root. A 'mount -a' from the command prompt gives the Bob> same result; it doesn't think I'm root for the mount command.

The mount command is perhaps setuid root, but you aren't mounting the
root file system in a way that permits it to be identified as such.
Or, the file is in fact not owned by root, and is in fact setuid not-root.

- --

]     "Elmo went to the wrong fundraiser" - The Simpson         |  firewalls  [
]   Michael Richardson,    Xelerance Corporation, Ottawa, ON    |net architect[
] [email protected]      http://www.sandelman.ottawa.on.ca/mcr/ |device driver[

] panic("Just another Debian GNU/Linux using, kernel hacking, security guy"); [ -----BEGIN PGP SIGNATURE-----
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Ok, now I feel like I'm taking crazy pills...

The embedded system boots up and mounts the root file system on my host laptop. The 'rc.sysinit' startup script executes the command 'mount -a' which should mount /proc, /dev/pts, and /dev/shm, as listed in /etc/fstab. When executed, that command returns "mount: only root can do that".

When I get to the bash prompt, 'whoami' reports that I am, indeed, root. A 'mount -a' from the command prompt gives the same result; it doesn't think I'm root for the mount command.

I can chown a file owned by root to some other user, and I can create a file or directory in a directory owned by root; so it doesn't always think I'm not root.

Quoted 8 lines · Bob Wirka

Ok, now I feel like I'm taking crazy pills...

The embedded system boots up and mounts the root file system on my host laptop. The 'rc.sysinit' startup script executes the command 'mount -a' which should mount /proc, /dev/pts, and /dev/shm, as listed in /etc/fstab. When executed, that command returns "mount: only root can do that".

When I get to the bash prompt, 'whoami' reports that I am, indeed, root. A 'mount -a' from the command prompt gives the same result; it doesn't think I'm root for the mount command.

I can chown a file owned by root to some other user, and I can create a file or directory in a directory owned by root; so it doesn't always think I'm not root.

Are you getting bit by the nfs uid mapping on the server. Is it mapping your local "root" to "nobody" on the server?

Quoted 8 lines · Bob Wirka

Ok, now I feel like I'm taking crazy pills...

The embedded system boots up and mounts the root file system on my host laptop. The 'rc.sysinit' startup script executes the command 'mount -a' which should mount /proc, /dev/pts, and /dev/shm, as listed in /etc/fstab. When executed, that command returns "mount: only root can do that".

When I get to the bash prompt, 'whoami' reports that I am, indeed, root. A 'mount -a' from the command prompt gives the same result; it doesn't think I'm root for the mount command.

I can chown a file owned by root to some other user, and I can create a file or directory in a directory owned by root; so it doesn't always think I'm not root.

Are you getting bit by the nfs uid mapping on the server. Is it mapping your local "root" to "nobody" on the server?

Here is another wrinkle: The program on my embedded system cannot send UDP broadcast messages when NFS mounted. When the system is booted without NFS (using the DiskOnChip for root file system) I can send UDP broadcasts. When the system is booted with NFS (using my laptop for root file system) UDP broadcasts result in "Network unreachable" errors, though it CAN send directed UDP messages and TCP messages.

The kernel configuration is identical, except for kernel IP autoconfiguration, root over nfs, and compiled-in network driver. The NFS configuration on the host has 'no_root_squash', and <<now>> all the files on the host root file system are owned by root.

Any ideas?

Thanks,

Bob Wirka
Realtime Control Works

Quoted 13 lines · Stephen Hemminger

Quoted 8 lines · Bob Wirka

Ok, now I feel like I'm taking crazy pills...

The embedded system boots up and mounts the root file system on my host laptop. The 'rc.sysinit' startup script executes the command 'mount -a' which should mount /proc, /dev/pts, and /dev/shm, as listed in /etc/fstab. When executed, that command returns "mount: only root can do that".

When I get to the bash prompt, 'whoami' reports that I am, indeed, root. A 'mount -a' from the command prompt gives the same result; it doesn't think I'm root for the mount command.

I can chown a file owned by root to some other user, and I can create a file or directory in a directory owned by root; so it doesn't always think I'm not root.

Are you getting bit by the nfs uid mapping on the server. Is it mapping your local "root" to "nobody" on the server?

The kernel configuration is identical, except for kernel IP autoconfiguration, root over nfs, and compiled-in network driver. The NFS configuration on the host has 'no_root_squash', and <<now>> all the files on the host root file system are owned by root.