exec.mm

   1 #include <Foundation/Foundation.h>
   2 #include <CoreFoundation/CoreFoundation.h>
   3
   4 #include <sys/types.h>
   5 #include <pwd.h>
   6 #include <unistd.h>
   7
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10
  11 const char *Firmware_ = NULL;
  12
  13 unsigned Major_;
  14 unsigned Minor_;
  15 unsigned BugFix_;
  16
  17 #define FW_LEAST(major, minor, bugfix) \
  18     (major < Major_ || major == Major_ && \
  19         (minor < Minor_ || minor == Minor_ && \
  20             bugfix <= BugFix_))
  21
  22 int main(int argc, char *argv[]) {
  23     NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
  24
  25     if (NSDictionary *sysver = [NSDictionary dictionaryWithContentsOfFile:@"/System/Library/CoreServices/SystemVersion.plist"]) {
  26         if (NSString *prover = [sysver valueForKey:@"ProductVersion"]) {
  27             Firmware_ = strdup([prover UTF8String]);
  28             NSArray *versions = [prover componentsSeparatedByString:@"."];
  29             int count = [versions count];
  30             Major_ = count > 0 ? [[versions objectAtIndex:0] intValue] : 0;
  31             Minor_ = count > 1 ? [[versions objectAtIndex:1] intValue] : 0;
  32             BugFix_ = count > 2 ? [[versions objectAtIndex:2] intValue] : 0;
  33         }
  34     }
  35
  36     [pool release];
  37
  38     const char *user;
  39     if (FW_LEAST(1,1,3))
  40         user = "mobile";
  41     else
  42         user = "root";
  43
  44     if (argc == 1)
  45         printf("%s\n", user);
  46     else {
  47         struct passwd *passwd = getpwnam(user);
  48
  49         if (setreuid(passwd->pw_uid, 0) == -1) {
  50             perror("setreuid");
  51             exit(1);
  52         }
  53
  54         if (setregid(passwd->pw_gid, 0) == -1) {
  55             perror("setregid");
  56             exit(1);
  57         }
  58
  59         if (execvp(argv[1], argv + 1) == -1) {
  60             perror("execvp");
  61             exit(1);
  62         }
  63     }
  64
  65     return 0;
  66 }