Usermode/Applications/login_src/main.c

   1 /*
   2  * Acess 2 Login
   3  */
   4 #include "header.h"
   5
   6 // === CONSTANTS ===
   7 #define BUFLEN  1024
   8
   9 // === PROTOTYPES ===
  10 char    *GetUsername();
  11 char    *GetPassword();
  12
  13 // === CODE ===
  14 int main(int argc, char *argv[])
  15 {
  16         char    *sUsername, *sPassword;
  17          int    pid, uid = 0;
  18          int    status = 0;
  19         tUserInfo       *uinfo;
  20
  21         for(;;)
  22         {
  23                 printf("\x1B[2J");      // Clear Screen
  24                 // Validate User
  25                 do {
  26                         if(uid == -1)   printf("\n");
  27                         sUsername = GetUsername();
  28                         sPassword = GetPassword();
  29                 } while( (uid = ValidateUser(sUsername, sPassword)) == -1 );
  30                 printf("\n");
  31
  32                 // Create child process
  33                 pid = clone(CLONE_VM, 0);
  34                 // Error check
  35                 if(pid == -1) {
  36                         fprintf(stderr, "Unable to fork the login process!\n");
  37                         return -1;
  38                 }
  39
  40                 // Spawn shell in a child process
  41                 if(pid == 0)
  42                 {
  43                         char    *child_argv[2] = {NULL, 0};
  44                         char    **child_envp = NULL;
  45
  46                         // Get user information
  47                         uinfo = GetUserInfo(uid);
  48
  49                         child_argv[0] = uinfo->Shell;
  50                         // Set Environment
  51                         setgid(uinfo->GID);
  52                         setuid(uid);
  53
  54                         execve(uinfo->Shell, child_argv, child_envp);
  55                         exit(-1);
  56                 }
  57
  58                 // Wait for child to terminate
  59                 waittid(pid, &status);
  60         }
  61
  62         return 0;
  63 }
  64
  65 /**
  66  * \fn char *GetUsername()
  67  */
  68 char *GetUsername()
  69 {
  70         char    ret[BUFLEN];
  71          int    pos = 0;
  72         char    ch;
  73
  74         // Prompt the user
  75         printf("Username: ");
  76
  77         // Read in text
  78         while( (ch = fgetc(stdin)) != -1 && ch != '\n' )
  79         {
  80                 if(ch == '\b') {
  81                         pos --;
  82                         ret[pos] = '\0';
  83                 }
  84                 else
  85                         ret[pos++] = ch;
  86
  87                 // Echo out to the screen
  88                 fputc(ch, stdout);
  89
  90                 if(pos == BUFLEN-1)     break;
  91         }
  92
  93         // Finish String
  94         ret[pos] = '\0';
  95
  96         printf("\n");
  97         return strdup(ret);
  98 }
  99
 100 /**
 101  * \fn char *GetPassword()
 102  */
 103 char *GetPassword()
 104 {
 105         char    ret[BUFLEN];
 106          int    pos = 0;
 107         char    ch;
 108
 109         // Prompt the user
 110         printf("Password: ");
 111
 112         // Read in text
 113         while( (ch = fgetc(stdin)) != -1 && ch != '\n' )
 114         {
 115                 if(ch == '\b') {
 116                         pos --;
 117                         ret[pos] = '\0';
 118                 }
 119                 else
 120                         ret[pos++] = ch;
 121
 122                 // Don't echo out to the screen
 123                 //fputc(stdout, ch);
 124
 125                 if(pos == BUFLEN-1)     break;
 126         }
 127
 128         ret[pos] = '\0';
 129
 130         printf("\n");
 131         return strdup(ret);
 132 }