At 16:02 -0800 12/7/00, Jim Browne wrote:
>When TFTP tries to open a file, it is expecting struct open_file 
>member f_devdata to be a pointer to a socket number.  When currdev 
>is "pxe", that assumption is correct.  When currdev is "disk*", that 
>assumption is incorrect.  Specifically, tftp.c does:
>
>tftpfile->iodesc = io = socktodesc(*(int *) (f->f_devdata));
>
>In my case, that often winds up making tftpfile->iodesc = 0.  That 
>parameter is later passed in tftp_makereq to sendrecv as the iodesc, 
>which via sendudp (and possibly the ARP functions) winds up calling 
>netif_put.  netif_put derefs the bogus iodesc to get a function 
>pointer for the put function of the network interface and calls it. 
>WHAM.  QED. :)

How does this look?

*** tftp.c      Thu Dec  7 16:20:02 2000
--- tftp2.c     Thu Dec  7 16:20:55 2000
*************** tftp_open(path, f)
*** 257,260 ****
--- 257,262 ----
 
         tftpfile->iodesc = io = socktodesc(*(int *) (f->f_devdata));
+       if (io == NULL)
+               return (EINVAL);
         io->destip = servip;
         tftpfile->off = 0;

(I suppose I could have included this earlier.  Ugh.)

Jim Browne                                                [EMAIL PROTECTED]
    "We lost our lease.  You lose culture" - sign on SF Arts Comission Bldg


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