appl/popper/popper.c

   1 /*
   2  * Copyright (c) 1989 Regents of the University of California.
   3  * All rights reserved.  The Berkeley software License Agreement
   4  * specifies the terms and conditions for redistribution.
   5  */
   6
   7 #include <popper.h>
   8 RCSID("$Id$");
   9
  10 int hangup = FALSE ;
  11
  12 static RETSIGTYPE
  13 catchSIGHUP(int sig)
  14 {
  15     hangup = TRUE ;
  16
  17     /* This should not be a problem on BSD systems */
  18     signal(SIGHUP,  catchSIGHUP);
  19     signal(SIGPIPE, catchSIGHUP);
  20     SIGRETURN(0);
  21 }
  22
  23 int     pop_timeout = POP_TIMEOUT;
  24
  25 jmp_buf env;
  26
  27 static RETSIGTYPE
  28 ring(int sig)
  29 {
  30   longjmp(env,1);
  31 }
  32
  33 /*
  34  * fgets, but with a timeout
  35  */
  36 static char *
  37 tgets(char *str, int size, FILE *fp, int timeout)
  38 {
  39     char *ret;
  40
  41     signal(SIGALRM, ring);
  42     alarm(timeout);
  43     if (setjmp(env)) {
  44         alarm(0);
  45         signal(SIGALRM, SIG_DFL);
  46         return NULL;
  47     }
  48     ret = fgets(str, size, fp);
  49     alarm(0);
  50     signal(SIGALRM, SIG_DFL);
  51     return ret;
  52 }
  53
  54 /*
  55  *  popper: Handle a Post Office Protocol version 3 session
  56  */
  57 int
  58 main (int argc, char **argv)
  59 {
  60     POP                 p;
  61     state_table     *   s;
  62     char                message[MAXLINELEN];
  63
  64     signal(SIGHUP,  catchSIGHUP);
  65     signal(SIGPIPE, catchSIGHUP);
  66
  67     /*  Start things rolling */
  68     pop_init(&p,argc,argv);
  69
  70     /*  Tell the user that we are listenting */
  71     pop_msg(&p,POP_SUCCESS, "POP3 server ready");
  72
  73     /*  State loop.  The POP server is always in a particular state in
  74         which a specific suite of commands can be executed.  The following
  75         loop reads a line from the client, gets the command, and processes
  76         it in the current context (if allowed) or rejects it.  This continues
  77         until the client quits or an error occurs. */
  78
  79     for (p.CurrentState=auth1;p.CurrentState!=halt&&p.CurrentState!=error;) {
  80         if (hangup) {
  81             pop_msg(&p, POP_FAILURE, "POP hangup: %s", p.myhost);
  82             if (p.CurrentState > auth2 && !pop_updt(&p))
  83                 pop_msg(&p, POP_FAILURE,
  84                         "POP mailbox update failed: %s", p.myhost);
  85             p.CurrentState = error;
  86         } else if (tgets(message, MAXLINELEN, p.input, pop_timeout) == NULL) {
  87             pop_msg(&p, POP_FAILURE, "POP timeout: %s", p.myhost);
  88             if (p.CurrentState > auth2 && !pop_updt(&p))
  89                 pop_msg(&p,POP_FAILURE,
  90                         "POP mailbox update failed: %s", p.myhost);
  91             p.CurrentState = error;
  92         }
  93         else {
  94             /*  Search for the command in the command/state table */
  95             if ((s = pop_get_command(&p,message)) == NULL) continue;
  96
  97             /*  Call the function associated with this command in
  98                 the current state */
  99             if (s->function) p.CurrentState = s->result[(*s->function)(&p)];
 100
 101             /*  Otherwise assume NOOP and send an OK message to the client */
 102             else {
 103                 p.CurrentState = s->success_state;
 104                 pop_msg(&p,POP_SUCCESS,"time passes");
 105             }
 106         }
 107     }
 108
 109     /*  Say goodbye to the client */
 110     pop_msg(&p,POP_SUCCESS,"Pop server at %s signing off.",p.myhost);
 111
 112     /*  Log the end of activity */
 113     pop_log(&p,POP_PRIORITY,
 114         "(v%s) Ending request from \"%s\" at %s\n",VERSION,p.client,p.ipaddr);
 115
 116     /*  Stop logging */
 117     closelog();
 118
 119     return(0);
 120 }