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