grabpkg

[bcc]

So I made a grabpkg that runs on the native 2.4.20 tivo kernel (it dynamically finds the sys_call_table). Is everyone else running custom kernels to capture slices? I could post the changes if there's interest.

[cheer]

Please do. Not running a custom kernel, just a kernel module from AO.

[bcc]

Please do. Not running a custom kernel, just a kernel module from AO.Oh, so it's been done already? Ie if the AO kernel module works on stock tivo kernels then a new grabpkg is unnecessary.

[cheer]

From AO, courtesy of embeem:#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <syscall.h>
#include <linux/fs.h>
#include <strings.h>
#include <asm/uaccess.h>
#include <sys/mman.h>

extern void *sys_call_table[];
extern struct task_struct *current_set[NR_CPUS];

static asmlinkage int (*orig_open)(const char * filename,int flags,int mode);
static asmlinkage int (*link)(const char * oldname, const char * newname);
static asmlinkage int (*symlink)(const char * oldname, const char * newname);

extern unsigned long do_mmap(struct file * file, unsigned long addr, unsigned long len,
unsigned long prot, unsigned long flags, unsigned long off);
extern int do_munmap(unsigned long, size_t);

static char *from = "/var/packages/";
static int from_len = 14;
MODULE_PARM(from,"s");

static char *to = "/tmp/";
static int to_len = 5;
MODULE_PARM(to,"s");


static int new_open(const char * filename,int flags,int mode)
{
int ret;
if (filename && !strncmp(filename,from,from_len) && flags&O_WRONLY)
{
int len = strlen(filename) + 1 - from_len + to_len;
char *new_file = (char *)do_mmap(0,0,len,PROT_READ | PROT_WRITE | PROT_EXEC,MAP_PRIVATE,0);

__copy_tofrom_user((void *)(new_file+0),(const void *)to,to_len);
__copy_tofrom_user((void *)(new_file+to_len),(const void *)(filename+from_len),len-to_len);

ret = (*orig_open)(new_file,flags,mode);
if ((*link)((const char *)new_file,(const char *)filename)<0) {
(*symlink)((const char *)new_file,(const char *)filename);
}
do_munmap((unsigned long)new_file,(size_t)len);
} else {
ret = (*orig_open)(filename,flags,mode);
}

return ret;
}

int init_module( void )
{
to_len = strlen(to);
from_len = strlen(from);

symlink = sys_call_table[__NR_symlink];
link = sys_call_table[__NR_link];

orig_open = sys_call_table[__NR_open];
sys_call_table[__NR_open] = new_open;
return 0;
}
void cleanup_module( void ) {
sys_call_table[__NR_open] = orig_open;
}

[bcc]

... which requires sys_call_table to be exported, which implies you're using a custom kernel.

Why do you say you're not using a custom kernel then? By custom I mean a kernel other than the stock (or killhdinitd patched) one.

[cheer]

Ah, fair enough. I had not even noticed that. I am running a custom kernel, but only for increased extraction speed. My bad.

[bcc]

Ah, fair enough. I had not even noticed that. I am running a custom kernel, but only for increased extraction speed. My bad.Ok, then you don't need a tweaked grabpkg, as the original will work fine in your case.