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                 for(;;)
  26                 {
  27                         sUsername = GetUsername();
  28                         sPassword = GetPassword();
  29                         if( (uid = ValidateUser(sUsername, sPassword)) == -1 )
  30                         {
  31                                 printf("\nInvalid username or password for '%s'\n", sUsername);
  32                                 free(sUsername);
  33                                 free(sPassword);
  34                         }
  35                         else
  36                                 break;
  37                 }
  38                 printf("\n");
  39
  40                 // Create child process
  41                 pid = clone(CLONE_VM, 0);
  42                 // Error check
  43                 if(pid == -1) {
  44                         fprintf(stderr, "Unable to fork the login process!\n");
  45                         return -1;
  46                 }
  47
  48                 // Spawn shell in a child process
  49                 if(pid == 0)
  50                 {
  51                         char    *child_argv[2] = {NULL, 0};
  52                         char    **child_envp = NULL;
  53
  54                         // Get user information
  55                         uinfo = GetUserInfo(uid);
  56
  57                         child_argv[0] = uinfo->Shell;
  58                         // Set Environment
  59                         setgid(uinfo->GID);
  60                         setuid(uid);
  61
  62                         execve(uinfo->Shell, child_argv, child_envp);
  63                         exit(-1);
  64                 }
  65
  66                 // Wait for child to terminate
  67                 waittid(pid, &status);
  68         }
  69
  70         return 0;
  71 }
  72
  73 /**
  74  * \fn char *GetUsername()
  75  */
  76 char *GetUsername()
  77 {
  78         char    ret[BUFLEN] = {0};
  79          int    pos = 0;
  80         char    ch;
  81
  82         // Prompt the user
  83         printf("Username: ");
  84
  85         // Read in text
  86         while( (ch = fgetc(stdin)) != -1 && ch != '\n' )
  87         {
  88                 if(ch == '\b') {
  89                         pos --;
  90                         ret[pos] = '\0';
  91                 }
  92                 else
  93                         ret[pos++] = ch;
  94
  95                 // Echo out to the screen
  96                 fputc(ch, stdout);
  97
  98                 if(pos == BUFLEN-1)     break;
  99         }
 100
 101         // Finish String
 102         ret[pos] = '\0';
 103
 104         printf("\n");
 105         return strdup(ret);
 106 }
 107
 108 /**
 109  * \fn char *GetPassword()
 110  */
 111 char *GetPassword()
 112 {
 113         char    ret[BUFLEN];
 114          int    pos = 0;
 115         char    ch;
 116
 117         // Prompt the user
 118         printf("Password: ");
 119
 120         // Read in text
 121         while( (ch = fgetc(stdin)) != -1 && ch != '\n' )
 122         {
 123                 if(ch == '\b') {
 124                         pos --;
 125                         ret[pos] = '\0';
 126                 }
 127                 else
 128                         ret[pos++] = ch;
 129
 130                 // Don't echo out to the screen
 131                 //fputc(stdout, ch);
 132
 133                 if(pos == BUFLEN-1)     break;
 134         }
 135
 136         ret[pos] = '\0';
 137
 138         printf("\n");
 139         return strdup(ret);
 140 }