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[2J");      // Clear Screen
  22
  23         for(;;)
  24         {
  25                 // Validate User
  26                 for(;;)
  27                 {
  28                         sUsername = GetUsername();
  29                         sPassword = GetPassword();
  30                         if( (uid = ValidateUser(sUsername, sPassword)) == -1 )
  31                         {
  32                                 printf("\nInvalid username or password for '%s'\n", sUsername);
  33                                 free(sUsername);
  34                                 free(sPassword);
  35                         }
  36                         else
  37                                 break;
  38                 }
  39                 printf("\n");
  40
  41                 // Create child process
  42                 pid = clone(CLONE_VM, 0);
  43                 // Error check
  44                 if(pid == -1) {
  45                         fprintf(stderr, "Unable to fork the login process!\n");
  46                         return -1;
  47                 }
  48
  49                 printf("pid = %i\n", pid);
  50
  51                 // Spawn shell in a child process
  52                 if(pid == 0)
  53                 {
  54                         char    *child_argv[2] = {NULL, 0};
  55                         char    **child_envp = NULL;
  56
  57                         // Get user information
  58                         uinfo = GetUserInfo(uid);
  59
  60                         child_argv[0] = uinfo->Shell;
  61                         // Set Environment
  62                         setgid(uinfo->GID);
  63                         //setuid(uid);
  64                         setuid(uinfo->UID);
  65
  66                         execve(uinfo->Shell, child_argv, child_envp);
  67                         exit(-1);
  68                 }
  69
  70                 // Wait for child to terminate
  71                 waittid(pid, &status);
  72         }
  73
  74         return 0;
  75 }
  76
  77 /**
  78  * \fn char *GetUsername()
  79  */
  80 char *GetUsername()
  81 {
  82         char    ret[BUFLEN] = {0};
  83          int    pos = 0;
  84         char    ch;
  85
  86         // Prompt the user
  87         printf("Username: ");
  88
  89         // Read in text
  90         while( (ch = fgetc(stdin)) != -1 && ch != '\n' )
  91         {
  92                 if(ch == '\b') {
  93                         if( pos <= 0 )  continue;
  94                         pos --;
  95                         ret[pos] = '\0';
  96                 }
  97                 else
  98                         ret[pos++] = ch;
  99
 100                 // Echo out to the screen
 101                 fputc(ch, stdout);
 102
 103                 if(pos == BUFLEN-1)     break;
 104         }
 105
 106         // Finish String
 107         ret[pos] = '\0';
 108
 109         printf("\n");
 110         return strdup(ret);
 111 }
 112
 113 /**
 114  * \fn char *GetPassword()
 115  */
 116 char *GetPassword()
 117 {
 118         char    ret[BUFLEN];
 119          int    pos = 0;
 120         char    ch;
 121
 122         // Prompt the user
 123         printf("Password: ");
 124
 125         // Read in text
 126         while( (ch = fgetc(stdin)) != -1 && ch != '\n' )
 127         {
 128                 if(ch == '\b') {
 129                         if( pos <= 0 )  continue;
 130                         pos --;
 131                         ret[pos] = '\0';
 132                 }
 133                 else
 134                         ret[pos++] = ch;
 135
 136                 // Don't echo out to the screen
 137                 //fputc(stdout, ch);
 138
 139                 if(pos == BUFLEN-1)     break;
 140         }
 141
 142         ret[pos] = '\0';
 143
 144         printf("\n");
 145         return strdup(ret);
 146 }