src/main.c

   1 /*   (C) 2011, 2012 rofl0r
   2  *                                                                         *
   3  *   This program is free software; you can redistribute it and/or modify  *
   4  *   it under the terms of the GNU General Public License as published by  *
   5  *   the Free Software Foundation; either version 2 of the License, or     *
   6  *   (at your option) any later version.                                   *
   7  *                                                                         *
   8  ***************************************************************************/
   9
  10 #define _DEFAULT_SOURCE
  11 #include <stdio.h>
  12 #include <unistd.h>
  13 #include <stdlib.h>
  14 #include <string.h>
  15 #include <errno.h>
  16 #include <sys/types.h>
  17 #include <sys/wait.h>
  18
  19 #ifdef IS_MAC
  20 #define _DARWIN_C_SOURCE
  21 #endif
  22 #include <dlfcn.h>
  23
  24 #include "common.h"
  25
  26 static int usage(char **argv) {
  27         printf("\nUsage:\t%s -q -f config_file program_name [arguments]\n"
  28                "\t-q makes proxychains quiet - this overrides the config setting\n"
  29                "\t-f allows one to manually specify a configfile to use\n"
  30                "\tfor example : proxychains telnet somehost.com\n" "More help in README file\n\n", argv[0]);
  31         return EXIT_FAILURE;
  32 }
  33
  34 static const char *dll_name = DLL_NAME;
  35
  36 static char own_dir[256];
  37 static const char *dll_dirs[] = {
  38 #ifndef SUPER_SECURE /* CVE-2015-3887 */
  39         ".",
  40 #endif
  41         own_dir,
  42         LIB_DIR,
  43         "/lib",
  44         "/usr/lib",
  45         "/usr/local/lib",
  46         "/lib64",
  47         NULL
  48 };
  49
  50 static void set_own_dir(const char *argv0) {
  51         size_t l = strlen(argv0);
  52         while(l && argv0[l - 1] != '/')
  53                 l--;
  54         if(l == 0 || l >= sizeof(own_dir))
  55 #ifdef SUPER_SECURE
  56                 memcpy(own_dir, "/dev/null/", 11);
  57 #else
  58                 memcpy(own_dir, ".", 2);
  59 #endif
  60         else {
  61                 memcpy(own_dir, argv0, l - 1);
  62                 own_dir[l] = 0;
  63         }
  64 }
  65
  66 #define MAX_COMMANDLINE_FLAGS 2
  67
  68 int main(int argc, char *argv[]) {
  69         char *path = NULL;
  70         char buf[256];
  71         char pbuf[256];
  72         int start_argv = 1;
  73         int quiet = 0;
  74         size_t i;
  75         const char *prefix = NULL;
  76
  77         if(argc == 2 && !strcmp(argv[1], "--help"))
  78                 return usage(argv);
  79
  80         for(i = 0; i < MAX_COMMANDLINE_FLAGS; i++) {
  81                 if(start_argv < argc && argv[start_argv][0] == '-') {
  82                         if(argv[start_argv][1] == 'q') {
  83                                 quiet = 1;
  84                                 start_argv++;
  85                         } else if(argv[start_argv][1] == 'f') {
  86
  87                                 if(start_argv + 1 < argc)
  88                                         path = argv[start_argv + 1];
  89                                 else
  90                                         return usage(argv);
  91
  92                                 start_argv += 2;
  93                         }
  94                 } else
  95                         break;
  96         }
  97
  98         if(start_argv >= argc)
  99                 return usage(argv);
 100
 101         /* check if path of config file has not been passed via command line */
 102         path = get_config_path(path, pbuf, sizeof(pbuf));
 103
 104         if(!quiet)
 105                 fprintf(stderr, LOG_PREFIX "config file found: %s\n", path);
 106
 107         /* Set PROXYCHAINS_CONF_FILE to get proxychains lib to use new config file. */
 108         setenv(PROXYCHAINS_CONF_FILE_ENV_VAR, path, 1);
 109
 110         if(quiet)
 111                 setenv(PROXYCHAINS_QUIET_MODE_ENV_VAR, "1", 1);
 112
 113
 114         // search DLL
 115
 116         Dl_info dli;
 117         dladdr(own_dir, &dli);
 118         set_own_dir(dli.dli_fname);
 119
 120         i = 0;
 121
 122         while(dll_dirs[i]) {
 123                 snprintf(buf, sizeof(buf), "%s/%s", dll_dirs[i], dll_name);
 124                 if(access(buf, R_OK) != -1) {
 125                         prefix = dll_dirs[i];
 126                         break;
 127                 }
 128                 i++;
 129         }
 130
 131         if(!prefix) {
 132                 fprintf(stderr, "couldnt locate %s\n", dll_name);
 133                 return EXIT_FAILURE;
 134         }
 135         if(!quiet)
 136                 fprintf(stderr, LOG_PREFIX "preloading %s/%s\n", prefix, dll_name);
 137
 138 #if defined(IS_MAC) || defined(IS_OPENBSD)
 139 #define LD_PRELOAD_SEP ":"
 140 #else
 141 /* Dynlinkers for Linux and most BSDs seem to support space
 142    as LD_PRELOAD separator, with colon added only recently.
 143    We use the old syntax for maximum compat */
 144 #define LD_PRELOAD_SEP " "
 145 #endif
 146
 147 #ifdef IS_MAC
 148         putenv("DYLD_FORCE_FLAT_NAMESPACE=1");
 149 #define LD_PRELOAD_ENV "DYLD_INSERT_LIBRARIES"
 150 #else
 151 #define LD_PRELOAD_ENV "LD_PRELOAD"
 152 #endif
 153         char *old_val = getenv(LD_PRELOAD_ENV);
 154         snprintf(buf, sizeof(buf), LD_PRELOAD_ENV "=%s/%s%s%s",
 155                  prefix, dll_name,
 156                  /* append previous LD_PRELOAD content, if existent */
 157                  old_val ? LD_PRELOAD_SEP : "",
 158                  old_val ? old_val : "");
 159         putenv(buf);
 160         execvp(argv[start_argv], &argv[start_argv]);
 161         fprintf(stderr, "proxychains: can't load process '%s'.", argv[start_argv]);
 162         perror(" (hint: it's probably a typo)");
 163
 164         return EXIT_FAILURE;
 165 }