root-context/dcookie.c

   1 /* dcookie retrieval vsys entry, required by Chopstix.
   2  * The lookup_dcookie system call retrieves a pathname */
   3
   4 #define __NR_LOOKUP_DCOOKIE 253
   5
   6 #include <sys/syscall.h>
   7 /*#include <asm/page.h>*/
   8 #include <stdint.h>
   9 #include <stdlib.h>
  10 #include <stdio.h>
  11 #include <errno.h>
  12 #include <string.h>
  13
  14 #define INT64_MAXSZ     "18446744073709551615Z"
  15
  16 int lookup_dcookie(uint64_t cookie, char * buf, size_t size)
  17 {
  18                 return syscall(__NR_LOOKUP_DCOOKIE, cookie, buf, size);
  19 }
  20
  21 int main(int argc,char *argv[]) {
  22                 /* fs/dcookie.c uses PAGE_SIZE */
  23                 char path_buf[16384],dcookie_buf[sizeof(INT64_MAXSZ)];
  24
  25                 /* In case nothing happens */
  26                 path_buf[0]='\0';
  27
  28                 while (fgets(dcookie_buf, sizeof(dcookie_buf),stdin)) {
  29                         if (lookup_dcookie(atoll(dcookie_buf), path_buf, sizeof(path_buf))>0) {
  30                                         printf("%s\n",path_buf);
  31                         }
  32                         else {
  33                                         printf("%% Not found\n");
  34                         }
  35                 }
  36 }