src/server/handler_door.c

   1 /*
   2  * OpenDispense 2
   3  * UCC (University [of WA] Computer Club) Electronic Accounting System
   4  *
   5  * handler_doror.c - Door Relay code
   6  *
   7  * This file is licenced under the 3-clause BSD Licence. See the file
   8  * COPYING for full details.
   9  */
  10 #define DEBUG   1
  11 #define USE_POPEN       0
  12
  13 #include "common.h"
  14 #include <stdio.h>
  15 #include <string.h>
  16 #include <unistd.h>
  17 #include <sys/stat.h>
  18 #include <fcntl.h>
  19 #include <signal.h>
  20 #if !USE_POPEN
  21 # include <unistd.h>
  22 #endif
  23
  24 #define DOOR_UNLOCKED_DELAY     10      // 10 seconds before it re-locks
  25
  26 // === IMPORTS ===
  27
  28 // === PROTOTYPES ===
  29  int    Door_InitHandler();
  30  int    Door_CanDispense(int User, int Item);
  31  int    Door_DoDispense(int User, int Item);
  32
  33 // === GLOBALS ===
  34 tHandler        gDoor_Handler = {
  35         "door",
  36         Door_InitHandler,
  37         Door_CanDispense,
  38         Door_DoDispense
  39 };
  40 char    *gsDoor_Password = "";
  41 volatile int    giDoor_ChildStatus;
  42
  43 // == CODE ===
  44 void Door_SIGCHLDHandler(int signum)
  45 {
  46         signum = 0;
  47         giDoor_ChildStatus ++;
  48         printf("SIGCHLD: giDoor_ChildStatus = %i \n", giDoor_ChildStatus);
  49 }
  50
  51 int Door_InitHandler(void)
  52 {
  53         signal(SIGCHLD, Door_SIGCHLDHandler);
  54         return 0;
  55 }
  56
  57 /**
  58  */
  59 int Door_CanDispense(int User, int Item)
  60 {
  61         #if DEBUG
  62         printf("Door_CanDispense: (User=%i,Item=%i)\n", User, Item);
  63         #endif
  64         // Sanity please
  65         if( Item != 0 ) return -1;
  66
  67         if( !(Bank_GetFlags(User) & USER_FLAG_DOORGROUP) )
  68         {
  69                 #if DEBUG
  70                 printf("Door_CanDispense: User %i not in door\n", User);
  71                 #endif
  72                 return 1;
  73         }
  74
  75         #if DEBUG
  76         printf("Door_CanDispense: User %i can open the door\n", User);
  77         #endif
  78
  79         return 0;
  80 }
  81
  82 /**
  83  * \brief Actually do a dispense from the coke machine
  84  */
  85 int Door_DoDispense(int User, int Item)
  86 {
  87         FILE    *child_stdin;
  88         char    buf[512];
  89          int    stdin_pair[2];
  90          int    stdout_pair[2];
  91         pid_t   childPid;
  92         pid_t   parentPid;
  93
  94         #if DEBUG
  95         printf("Door_DoDispense: (User=%i,Item=%i)\n", User, Item);
  96         #endif
  97
  98         // Sanity please
  99         if( Item != 0 ) return -1;
 100
 101         // Check if user is in door
 102         if( !(Bank_GetFlags(User) & USER_FLAG_DOORGROUP) )
 103         {
 104                 #if DEBUG
 105                 printf("Door_CanDispense: User %i not in door\n", User);
 106                 #endif
 107                 return 1;
 108         }
 109
 110         // Create stdin/stdout
 111         if( pipe(stdin_pair) || pipe(stdout_pair) )
 112         {
 113                 perror("pipe");
 114                 return -1;
 115         }
 116
 117         giDoor_ChildStatus = 0; // Set child status to zero
 118         parentPid = getpid();
 119         childPid = fork();
 120
 121         if( childPid < 0 )
 122         {
 123                 perror("fork");
 124                 return -1;
 125         }
 126
 127         // Child process
 128         if( childPid == 0 )
 129         {
 130                 // Close write end of stdin, and set it to #0
 131                 close(stdin_pair[1]);   dup2(stdin_pair[0], 0);
 132                 // Close read end of stdout, and set it to #1
 133                 close(stdout_pair[0]);  dup2(stdout_pair[1], 1);
 134
 135                 execl("/bin/sh", "sh", "-c", "llogin door -w-", NULL);
 136                 perror("execl");
 137                 exit(-1);
 138         }
 139
 140         child_stdin = fdopen(stdin_pair[1], "w");
 141         close(stdin_pair[0]);   // child stdin read
 142         close(stdout_pair[1]);  // child stdout write
 143
 144         {
 145                  int    len;
 146                 if( giDoor_ChildStatus || (len = read(stdout_pair[0], buf, 512)) < 0)
 147                 {
 148                         #if DEBUG
 149                         printf("Door_DoDispense: fread fail\n");
 150                         #endif
 151                         return -1;
 152                 }
 153                 buf[len] = '\0';
 154
 155                 #if DEBUG
 156                 printf("Door_DoDispense: buf = %i '%s'\n", len, buf);
 157                 #endif
 158         }
 159
 160         // Send password
 161         if( giDoor_ChildStatus || fputs(gsDoor_Password, child_stdin) <= 0 ) {
 162                 #if DEBUG
 163                 printf("Door_DoDispense: fputs password\n");
 164                 #endif
 165                 return -1;
 166         }
 167         fputs("\n", child_stdin);
 168
 169
 170         #if DEBUG
 171         printf("Door_DoDispense: Door unlock\n");
 172         #endif
 173
 174         // ATH1 - Unlock door
 175         if( giDoor_ChildStatus || fputs("ATH1\n", child_stdin) <= 0) {
 176                 #if DEBUG
 177                 printf("Door_DoDispense: fputs unlock\n");
 178                 #endif
 179                 return -1;
 180         }
 181
 182         // Wait before re-locking
 183         sleep(DOOR_UNLOCKED_DELAY);
 184
 185
 186         #if DEBUG
 187         printf("Door_DoDispense: Door re-lock\n");
 188         #endif
 189
 190         // Re-lock the door
 191         if( giDoor_ChildStatus || fputs("ATH0\n", child_stdin) == 0 ) {
 192                 #if DEBUG
 193                 printf("Door_DoDispense: fputs lock\n");
 194                 #endif
 195                 return -1;
 196         }
 197
 198         fclose(child_stdin);
 199         close(stdin_pair[1]);   // child stdin write
 200         close(stdout_pair[0]);  // child stdout read
 201
 202         #if DEBUG
 203         printf("Door_DoDispense: User %i opened door\n", User);
 204         #endif
 205
 206         kill(childPid, SIGKILL);
 207
 208         return 0;
 209 }
 210