external/ibm-public/postfix/dist/src/util/upass_trigger.c

   1 /*      $NetBSD$        */
   2
   3 /*++
   4 /* NAME
   5 /*      upass_trigger 3
   6 /* SUMMARY
   7 /*      wakeup UNIX-domain file descriptor listener
   8 /* SYNOPSIS
   9 /*      #include <trigger.h>
  10 /*
  11 /*      int     upass_trigger(service, buf, len, timeout)
  12 /*      const char *service;
  13 /*      const char *buf;
  14 /*      ssize_t len;
  15 /*      int     timeout;
  16 /* DESCRIPTION
  17 /*      upass_trigger() wakes up the named UNIX-domain server by sending
  18 /*      a brief connection to it and writing the named buffer.
  19 /*
  20 /*      The connection is closed by a background thread. Some kernels
  21 /*      cannot handle client-side disconnect before the server has
  22 /*      received the message.
  23 /*
  24 /*      Arguments:
  25 /* .IP service
  26 /*      Name of the communication endpoint.
  27 /* .IP buf
  28 /*      Address of data to be written.
  29 /* .IP len
  30 /*      Amount of data to be written.
  31 /* .IP timeout
  32 /*      Deadline in seconds. Specify a value <= 0 to disable
  33 /*      the time limit.
  34 /* DIAGNOSTICS
  35 /*      The result is zero in case of success, -1 in case of problems.
  36 /* SEE ALSO
  37 /*      upass_connect(3), UNIX-domain client
  38 /* LICENSE
  39 /* .ad
  40 /* .fi
  41 /*      The Secure Mailer license must be distributed with this software.
  42 /* AUTHOR(S)
  43 /*      Wietse Venema
  44 /*      IBM T.J. Watson Research
  45 /*      P.O. Box 704
  46 /*      Yorktown Heights, NY 10598, USA
  47 /*--*/
  48
  49 /* System library. */
  50
  51 #include <sys_defs.h>
  52 #include <sys/socket.h>
  53 #include <unistd.h>
  54 #include <string.h>
  55
  56 /* Utility library. */
  57
  58 #include <msg.h>
  59 #include <connect.h>
  60 #include <iostuff.h>
  61 #include <mymalloc.h>
  62 #include <events.h>
  63 #include <trigger.h>
  64
  65 struct upass_trigger {
  66     int     fd;
  67     char   *service;
  68 };
  69
  70 /* upass_trigger_event - disconnect from peer */
  71
  72 static void upass_trigger_event(int event, char *context)
  73 {
  74     struct upass_trigger *up = (struct upass_trigger *) context;
  75     static const char *myname = "upass_trigger_event";
  76
  77     /*
  78      * Disconnect.
  79      */
  80     if (event == EVENT_TIME)
  81         msg_warn("%s: read timeout for service %s", myname, up->service);
  82     event_disable_readwrite(up->fd);
  83     event_cancel_timer(upass_trigger_event, context);
  84     if (close(up->fd) < 0)
  85         msg_warn("%s: close %s: %m", myname, up->service);
  86     myfree(up->service);
  87     myfree((char *) up);
  88 }
  89
  90 /* upass_trigger - wakeup UNIX-domain server */
  91
  92 int     upass_trigger(const char *service, const char *buf, ssize_t len, int timeout)
  93 {
  94     const char *myname = "upass_trigger";
  95     struct upass_trigger *up;
  96     int     fd;
  97
  98     if (msg_verbose > 1)
  99         msg_info("%s: service %s", myname, service);
 100
 101     /*
 102      * Connect...
 103      */
 104     if ((fd = upass_connect(service, BLOCKING, timeout)) < 0) {
 105         if (msg_verbose)
 106             msg_warn("%s: connect to %s: %m", myname, service);
 107         return (-1);
 108     }
 109     close_on_exec(fd, CLOSE_ON_EXEC);
 110
 111     /*
 112      * Stash away context.
 113      */
 114     up = (struct upass_trigger *) mymalloc(sizeof(*up));
 115     up->fd = fd;
 116     up->service = mystrdup(service);
 117
 118     /*
 119      * Write the request...
 120      */
 121     if (write_buf(fd, buf, len, timeout) < 0
 122         || write_buf(fd, "", 1, timeout) < 0)
 123         if (msg_verbose)
 124             msg_warn("%s: write to %s: %m", myname, service);
 125
 126     /*
 127      * Wakeup when the peer disconnects, or when we lose patience.
 128      */
 129     if (timeout > 0)
 130         event_request_timer(upass_trigger_event, (char *) up, timeout + 100);
 131     event_enable_read(fd, upass_trigger_event, (char *) up);
 132     return (0);
 133 }