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/*++
/* NAME
/* master_listen 3
/* SUMMARY
/* Postfix master - start/stop listeners
/* SYNOPSIS
/* #include "master.h"
/*
/* void master_listen_init(serv)
/* MASTER_SERV *serv;
/*
/* void master_listen_cleanup(serv)
/* MASTER_SERV *serv;
/* DESCRIPTION
/* master_listen_init() turns on the listener implemented by the
/* named process. FIFOs and UNIX-domain sockets are created with
/* mode 0622 and with ownership mail_owner.
/*
/* master_listen_cleanup() turns off the listener implemented by the
/* named process.
/* DIAGNOSTICS
/* BUGS
/* SEE ALSO
/* inet_listen(3), internet-domain listener
/* unix_listen(3), unix-domain listener
/* fifo_listen(3), named-pipe listener
/* upass_listen(3), file descriptor passing listener
/* set_eugid(3), set effective user/group attributes
/* LICENSE
/* .ad
/* .fi
/* The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/* Wietse Venema
/* IBM T.J. Watson Research
/* P.O. Box 704
/* Yorktown Heights, NY 10598, USA
/*
/* Wietse Venema
/* Google, Inc.
/* 111 8th Avenue
/* New York, NY 10011, USA
/*--*/
/* System library. */
#include <sys_defs.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <string.h>
/* Utility library. */
#include <msg.h>
#include <listen.h>
#include <mymalloc.h>
#include <stringops.h>
#include <inet_addr_list.h>
#include <set_eugid.h>
#include <set_ugid.h>
#include <iostuff.h>
#include <myaddrinfo.h>
#include <sock_addr.h>
/* Global library. */
#include <mail_params.h>
/* Application-specific. */
#include "master.h"
/* master_listen_init - enable connection requests */
void master_listen_init(MASTER_SERV *serv)
{
const char *myname = "master_listen_init";
char *end_point;
int n;
MAI_HOSTADDR_STR hostaddr;
struct sockaddr *sa;
/*
* Find out what transport we should use, then create one or more
* listener sockets. Make the listener sockets non-blocking, so that
* child processes don't block in accept() when multiple processes are
* selecting on the same socket and only one of them gets the connection.
*/
switch (serv->type) {
/*
* UNIX-domain or stream listener endpoints always come as singlets.
*/
case MASTER_SERV_TYPE_UNIX:
set_eugid(var_owner_uid, var_owner_gid);
serv->listen_fd[0] =
LOCAL_LISTEN(serv->name, serv->max_proc > var_proc_limit ?
serv->max_proc : var_proc_limit, NON_BLOCKING);
close_on_exec(serv->listen_fd[0], CLOSE_ON_EXEC);
set_ugid(getuid(), getgid());
break;
/*
* UNIX-domain datagram listener endpoints always come as singlets.
*/
case MASTER_SERV_TYPE_UXDG:
set_eugid(var_owner_uid, var_owner_gid);
serv->listen_fd[0] =
unix_dgram_listen(serv->name, NON_BLOCKING);
close_on_exec(serv->listen_fd[0], CLOSE_ON_EXEC);
set_ugid(getuid(), getgid());
break;
/*
* FIFO listener endpoints always come as singlets.
*/
case MASTER_SERV_TYPE_FIFO:
set_eugid(var_owner_uid, var_owner_gid);
serv->listen_fd[0] = fifo_listen(serv->name, 0622, NON_BLOCKING);
close_on_exec(serv->listen_fd[0], CLOSE_ON_EXEC);
set_ugid(getuid(), getgid());
break;
/*
* INET-domain listener endpoints can be wildcarded (the default) or
* bound to specific interface addresses.
*
* With dual-stack IPv4/6 systems it does not matter, we have to specify
* the addresses anyway, either explicit or wild-card.
*/
case MASTER_SERV_TYPE_INET:
for (n = 0; n < serv->listen_fd_count; n++) {
sa = SOCK_ADDR_PTR(MASTER_INET_ADDRLIST(serv)->addrs + n);
SOCKADDR_TO_HOSTADDR(sa, SOCK_ADDR_LEN(sa), &hostaddr,
(MAI_SERVPORT_STR *) 0, 0);
end_point = concatenate(hostaddr.buf,
":", MASTER_INET_PORT(serv), (char *) 0);
serv->listen_fd[n]
= inet_listen(end_point, serv->max_proc > var_proc_limit ?
serv->max_proc : var_proc_limit, NON_BLOCKING);
close_on_exec(serv->listen_fd[n], CLOSE_ON_EXEC);
myfree(end_point);
}
break;
/*
* Descriptor passing endpoints always come as singlets.
*/
#ifdef MASTER_SERV_TYPE_PASS
case MASTER_SERV_TYPE_PASS:
set_eugid(var_owner_uid, var_owner_gid);
serv->listen_fd[0] =
LOCAL_LISTEN(serv->name, serv->max_proc > var_proc_limit ?
serv->max_proc : var_proc_limit, NON_BLOCKING);
close_on_exec(serv->listen_fd[0], CLOSE_ON_EXEC);
set_ugid(getuid(), getgid());
break;
#endif
default:
msg_panic("%s: unknown service type: %d", myname, serv->type);
}
}
/* master_listen_cleanup - disable connection requests */
void master_listen_cleanup(MASTER_SERV *serv)
{
const char *myname = "master_listen_cleanup";
int n;
/*
* XXX The listen socket is shared with child processes. Closing the
* socket in the master process does not really disable listeners in
* child processes. There seems to be no documented way to turn off a
* listener. The 4.4BSD shutdown(2) man page promises an ENOTCONN error
* when shutdown(2) is applied to a socket that is not connected.
*/
for (n = 0; n < serv->listen_fd_count; n++) {
if (close(serv->listen_fd[n]) < 0)
msg_warn("%s: close listener socket %d: %m",
myname, serv->listen_fd[n]);
serv->listen_fd[n] = -1;
}
}
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