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