inet_trigger.c revision 1.2
1/* $NetBSD: inet_trigger.c,v 1.2 2017/02/14 01:16:49 christos Exp $ */ 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 67struct inet_trigger { 68 int fd; 69 char *service; 70}; 71 72/* inet_trigger_event - disconnect from peer */ 73 74static void inet_trigger_event(int event, void *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((void *) ip); 90} 91 92 93/* inet_trigger - wakeup INET-domain server */ 94 95int 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, (void *) ip, timeout + 100); 130 event_enable_read(fd, inet_trigger_event, (void *) ip); 131 return (0); 132} 133