On Fri, Nov 16, 2007 at 09:47:08AM +0000, Nj A ([EMAIL PROTECTED]) wrote:
> Hello,
> > Please show at least one bug trace when inet_lookup(&tcp_hashinfo, 0, 0, 0,
> > 0,
> > 0) fails :)
> Trying this the system hangs :-( (setting panic* doesn't change more).
Your code below can not work - you _never_ call inet_lookup().
In your bug inet_lookup() is called, so this wither code is wrong, or
bug is hand written.
And you use inet_iif() which requires dst entry (routing cache), which
you do not setup either.
You can do following to resolve where problem occurs:
$ gdb vmlix
> p inet_lookup
> l *(returned_above_address + 0x300)
it will show you the line where bug occurs.
You have to compile your kernel with debugging symbols.
To prove that inet_lookup() works correctly patch tcv_v4_rcv() to print
lookup result for static source/destination addresses/ports copied from
you message and zero ifindex (the last field).
I'm pretty sure your code, which was not shown yet, has a bug in the
inet_lookup() calling routing.
> However, using (&tcp_hashinfo, ip_src, p_src, ip_dst, p_dst, 0) gives the
> following oops:
Wrong, you do _NOT_ use this in your code.
> BUG: unable to handle kernel NULL pointer dereference at virtual address
> 0000xxxx
> printing eip:
> c02f19e1
> *pde = 00000000
> Oops: 0000 [#1]
> CPU: 0
> EIP: 0060:[<c02f19e1>] Not tainted VLI
> EFLAGS: 00010282 (2.6.18 #1)
> EIP is at inet_lookup+0x300x500
> eax: 9e3779b9 ebx: 00000004 ecx: 9e377a57 edx: f4046f84
> esi: f46a6010 edi: 00000000 ebp: 0000009e esp: f4046f38
> ds: 007b es: 007b ss: 0068
> Process knl-thread (pid: 3068, ti=f4046000 task=f46f0610 task.ti=f4046000)
> Stack: 22921900 f6953840 f46a6010 f46a6000 f4046f84 00000004 f46a6010 f46a6000
> f6953840 f8d3314a 00000004 b7f3a000 00000404 00000005 00000bfe 00000000
> 00000bfe 00000404 00000000 f4046fa8 f6953840 f4aa7880 f4aa7800 f4046fa8
> Code: 00 00 00 8d bc 27 00 00 00 00 55 89 cd 57 0f b7 c9 56 81 e9 47 86 c8 61
> 53 83 ec 14 89 54 24 10 8b b8 54 02 00 00 b8 b9 79 37 9e <8b> 5f 10 29 d8 89
> da 03 44 24 28 c1 ea 0d 29 c8 29 d9 31 d0 89
> EIP: [<c02f19e1>] inet_lookup +0x300x500 SS:ESP 0068:f4046f38
>
> > Yes, to show the code you are using.
> Ok so basically I am receiving via Netlink a state telling me the ip_src,
> psrc, ip_dst, pdst.
> sk =
> inet_lookup (&tcp_hashinfo, payload->src, payload->p_src, payload->dst,
> payload->p_dst, inet_iif (s_skb));
WRONG!
You did not setup s_skb->dst, so inet_iif() will fail.
Use 0 there, as you were told already several times.
This will not catch device binding though.
> if (!sk)
> goto no_tcp_socket;
> if (sk->sk_state == TCP_TIME_WAIT)
> goto time_wait_socket;
> ...
> bh_lock_sock (sk);
> pdev:
> spin_lock (&tmp_lock);
> new_dev = list_entry (&tmp, struct net_device, todo_list);
> spin_unlock (&tmp_lock);
> if (!new_dev)
> goto err;
> s_skb->dev = new_dev;
> ...
> switch (sk->sk_state)
> {
> case TCP_SYN_RECV:
> ..
> case TCP_LISTEN:
> ..
> case TCP_SYN_SENT:
> ..
> }
> bh_unlock_sock (sk);
> ...
> /* send reply via Netlink */
This code _NEVER_ calls inet_lookup(), since the first ckeck for
s_skb->dev will fail and you will select device via your list and then
never return to inet_lookup().
Anyway, until your code is presented fully so that people could show you
exactly wrong line it is pretty impossible to try to convince you that
inet_llokup() does work and you have a bug in setup.
--
Evgeniy Polyakov
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