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                 printf("pid = %i\n", pid);
  51
  52                 // Spawn shell in a child process
  53                 if(pid == 0)
  54                 {
  55                         char    *child_argv[2] = {NULL, 0};
  56                         char    **child_envp = NULL;
  57
  58                         // Get user information
  59                         uinfo = GetUserInfo(uid);
  60
  61                         child_argv[0] = uinfo->Shell;
  62                         // Set Environment
  63                         setgid(uinfo->GID);
  64                         //setuid(uid);
  65                         setuid(uinfo->UID);
  66
  67                         execve(uinfo->Shell, child_argv, child_envp);
  68                         exit(-1);
  69                 }
  70
  71                 // Wait for child to terminate
  72                 waittid(pid, &status);
  73         }
  74
  75         return 0;
  76 }
  77
  78 /**
  79  * \fn char *GetUsername()
  80  */
  81 char *GetUsername()
  82 {
  83         char    ret[BUFLEN] = {0};
  84          int    pos = 0;
  85         char    ch;
  86
  87         // Prompt the user
  88         printf("Username: ");
  89
  90         // Read in text
  91         while( (ch = fgetc(stdin)) != -1 && ch != '\n' )
  92         {
  93                 if(ch == '\b') {
  94                         if( pos <= 0 )  continue;
  95                         pos --;
  96                         ret[pos] = '\0';
  97                 }
  98                 else
  99                         ret[pos++] = ch;
 100
 101                 // Echo out to the screen
 102                 fputc(ch, stdout);
 103
 104                 if(pos == BUFLEN-1)     break;
 105         }
 106
 107         // Finish String
 108         ret[pos] = '\0';
 109
 110         printf("\n");
 111         return strdup(ret);
 112 }
 113
 114 /**
 115  * \fn char *GetPassword()
 116  */
 117 char *GetPassword()
 118 {
 119         char    ret[BUFLEN];
 120          int    pos = 0;
 121         char    ch;
 122
 123         // Prompt the user
 124         printf("Password: ");
 125
 126         // Read in text
 127         while( (ch = fgetc(stdin)) != -1 && ch != '\n' )
 128         {
 129                 if(ch == '\b') {
 130                         if( pos <= 0 )  continue;
 131                         pos --;
 132                         ret[pos] = '\0';
 133                 }
 134                 else
 135                         ret[pos++] = ch;
 136
 137                 // Don't echo out to the screen
 138                 //fputc(stdout, ch);
 139
 140                 if(pos == BUFLEN-1)     break;
 141         }
 142
 143         ret[pos] = '\0';
 144
 145         printf("\n");
 146         return strdup(ret);
 147 }