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         printf("\x1B[?25h");    // Re-enable the cursor
  22 //      printf("\x1B[2J");      // Clear Screen
  23
  24         for(;;)
  25         {
  26                 // Validate User
  27                 for(;;)
  28                 {
  29                         sUsername = GetUsername();
  30                         sPassword = GetPassword();
  31                         if( (uid = ValidateUser(sUsername, sPassword)) == -1 )
  32                         {
  33                                 printf("\nInvalid username or password\n");
  34                                 free(sUsername);
  35                                 free(sPassword);
  36                         }
  37                         else
  38                                 break;
  39                 }
  40                 printf("\n");
  41
  42                 // Create child process
  43                 pid = clone(CLONE_VM, 0);
  44                 // Error check
  45                 if(pid == -1) {
  46                         fprintf(stderr, "Unable to fork the login process!\n");
  47                         return -1;
  48                 }
  49
  50                 // Spawn shell in a child process
  51                 if(pid == 0)
  52                 {
  53                         char    *child_argv[2] = {NULL, 0};
  54                         char    **child_envp = NULL;
  55
  56                         // Get user information
  57                         uinfo = GetUserInfo(uid);
  58
  59                         child_argv[0] = uinfo->Shell;
  60                         // Set Environment
  61                         setgid(uinfo->GID);
  62                         //setuid(uid);
  63                         setuid(uinfo->UID);
  64
  65                         execve(uinfo->Shell, child_argv, child_envp);
  66                         exit(-1);
  67                 }
  68
  69                 // Wait for child to terminate
  70                 waittid(pid, &status);
  71         }
  72
  73         return 0;
  74 }
  75
  76 /**
  77  * \fn char *GetUsername()
  78  */
  79 char *GetUsername()
  80 {
  81         char    ret[BUFLEN] = {0};
  82          int    pos = 0;
  83         char    ch;
  84
  85         // Prompt the user
  86         printf("Username: ");
  87
  88         // Read in text
  89         while( (ch = fgetc(stdin)) != -1 && ch != '\n' )
  90         {
  91                 if(ch == '\b') {
  92                         if( pos <= 0 )  continue;
  93                         pos --;
  94                         ret[pos] = '\0';
  95                 }
  96                 else
  97                         ret[pos++] = ch;
  98
  99                 // Echo out to the screen
 100                 fputc(ch, stdout);
 101
 102                 if(pos == BUFLEN-1)     break;
 103         }
 104
 105         // Finish String
 106         ret[pos] = '\0';
 107
 108         printf("\n");
 109         return strdup(ret);
 110 }
 111
 112 /**
 113  * \fn char *GetPassword()
 114  */
 115 char *GetPassword()
 116 {
 117         char    ret[BUFLEN];
 118          int    pos = 0;
 119         char    ch;
 120
 121         // Prompt the user
 122         printf("Password: ");
 123
 124         // Read in text
 125         while( (ch = fgetc(stdin)) != -1 && ch != '\n' )
 126         {
 127                 if(ch == '\b') {
 128                         if( pos <= 0 )  continue;
 129                         pos --;
 130                         ret[pos] = '\0';
 131                 }
 132                 else
 133                         ret[pos++] = ch;
 134
 135                 // Don't echo out to the screen
 136                 //fputc(stdout, ch);
 137
 138                 if(pos == BUFLEN-1)     break;
 139         }
 140
 141         ret[pos] = '\0';
 142
 143         printf("\n");
 144         return strdup(ret);
 145 }