archival/libarchive/unsafe_prefix.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   4  */
   5
   6 #include "libbb.h"
   7 #include "bb_archive.h"
   8
   9 const char* FAST_FUNC strip_unsafe_prefix(const char *str)
  10 {
  11         const char *cp = str;
  12         while (1) {
  13                 char *cp2;
  14                 if (*cp == '/') {
  15                         cp++;
  16                         continue;
  17                 }
  18                 if (is_prefixed_with(cp, "/../"+1)) {
  19                         cp += 3;
  20                         continue;
  21                 }
  22                 cp2 = strstr(cp, "/../");
  23                 if (!cp2)
  24                         break;
  25                 cp = cp2 + 4;
  26         }
  27         if (cp != str) {
  28                 static smallint warned = 0;
  29                 if (!warned) {
  30                         warned = 1;
  31                         bb_error_msg("removing leading '%.*s' from member names",
  32                                 (int)(cp - str), str);
  33                 }
  34         }
  35         return cp;
  36 }