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

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