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                         printf("\n");
  30                 } while( (uid = ValidateUser(sUsername, sPassword)) == -1 );
  31                 printf("\n");
  32
  33                 // Create child process
  34                 pid = clone(CLONE_VM, 0);
  35                 // Error check
  36                 if(pid == -1) {
  37                         fprintf(stderr, "Unable to fork the login process!\n");
  38                         return -1;
  39                 }
  40
  41                 // Spawn shell in a child process
  42                 if(pid == 0)
  43                 {
  44                         char    *child_argv[2] = {NULL, 0};
  45                         char    **child_envp = NULL;
  46
  47                         // Get user information
  48                         uinfo = GetUserInfo(uid);
  49
  50                         child_argv[0] = uinfo->Shell;
  51                         // Set Environment
  52                         setgid(uinfo->GID);
  53                         setuid(uid);
  54
  55                         execve(uinfo->Shell, child_argv, child_envp);
  56                         exit(-1);
  57                 }
  58
  59                 // Wait for child to terminate
  60                 waittid(pid, &status);
  61         }
  62
  63         return 0;
  64 }
  65
  66 /**
  67  * \fn char *GetUsername()
  68  */
  69 char *GetUsername()
  70 {
  71         char    ret[BUFLEN];
  72          int    pos = 0;
  73         char    ch;
  74
  75         // Prompt the user
  76         printf("Username: ");
  77
  78         // Read in text
  79         while( (ch = fgetc(stdin)) != -1 && ch != '\n' )
  80         {
  81                 if(ch == '\b') {
  82                         pos --;
  83                         ret[pos] = '\0';
  84                 }
  85                 else
  86                         ret[pos++] = ch;
  87
  88                 // Echo out to the screen
  89                 fputc(ch, stdout);
  90
  91                 if(pos == BUFLEN-1)     break;
  92         }
  93
  94         // Finish String
  95         ret[pos] = '\0';
  96
  97         printf("\n");
  98         return strdup(ret);
  99 }
 100
 101 /**
 102  * \fn char *GetPassword()
 103  */
 104 char *GetPassword()
 105 {
 106         char    ret[BUFLEN];
 107          int    pos = 0;
 108         char    ch;
 109
 110         // Prompt the user
 111         printf("Password: ");
 112
 113         // Read in text
 114         while( (ch = fgetc(stdin)) != -1 && ch != '\n' )
 115         {
 116                 if(ch == '\b') {
 117                         pos --;
 118                         ret[pos] = '\0';
 119                 }
 120                 else
 121                         ret[pos++] = ch;
 122
 123                 // Don't echo out to the screen
 124                 //fputc(stdout, ch);
 125
 126                 if(pos == BUFLEN-1)     break;
 127         }
 128
 129         ret[pos] = '\0';
 130
 131         printf("\n");
 132         return strdup(ret);
 133 }