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