/* $NetBSD: multi_server.c,v 1.4 2022/10/08 16:12:46 christos Exp $ */
/*++
/* NAME
/* multi_server 3
/* SUMMARY
/* skeleton multi-threaded mail subsystem
/* SYNOPSIS
/* #include <mail_server.h>
/*
/* NORETURN multi_server_main(argc, argv, service, key, value, ...)
/* int argc;
/* char **argv;
/* void (*service)(VSTREAM *stream, char *service_name, char **argv);
/* int key;
/*
/* void multi_server_disconnect(stream)
/* VSTREAM *stream;
/*
/* void multi_server_drain()
/* DESCRIPTION
/* This module implements a skeleton for multi-threaded
/* mail subsystems: mail subsystem programs that service multiple
/* clients at the same time. The resulting program expects to be run
/* from the \fBmaster\fR process.
/*
/* multi_server_main() is the skeleton entry point. It should be
/* called from the application main program. The skeleton does all
/* the generic command-line processing, initialization of
/* configurable parameters, and connection management.
/* The skeleton never returns.
/*
/* Arguments:
/* .IP "void (*service)(VSTREAM *stream, char *service_name, char **argv)"
/* A pointer to a function that is called by the skeleton each
/* time a client sends data to the program's service port. The
/* function is run after the program has optionally dropped its
/* privileges. This function should not attempt to preserve state
/* across calls. The stream initial state is non-blocking mode.
/* The service name argument corresponds to the service name in the
/* master.cf file.
/* The argv argument specifies command-line arguments left over
/* after options processing.
/* .PP
/* Optional arguments are specified as a null-terminated list
/* with macros that have zero or more arguments:
/* .IP "CA_MAIL_SERVER_INT_TABLE(CONFIG_INT_TABLE *)"
/* A table with configurable parameters, to be loaded from the
/* global Postfix configuration file. Tables are loaded in the
/* order as specified, and multiple instances of the same type
/* are allowed.
/* .IP "CA_MAIL_SERVER_LONG_TABLE(CONFIG_LONG_TABLE *)"
/* A table with configurable parameters, to be loaded from the
/* global Postfix configuration file. Tables are loaded in the
/* order as specified, and multiple instances of the same type
/* are allowed.
/* .IP "CA_MAIL_SERVER_STR_TABLE(CONFIG_STR_TABLE *)"
/* A table with configurable parameters, to be loaded from the
/* global Postfix configuration file. Tables are loaded in the
/* order as specified, and multiple instances of the same type
/* are allowed.
/* .IP "CA_MAIL_SERVER_BOOL_TABLE(CONFIG_BOOL_TABLE *)"
/* A table with configurable parameters, to be loaded from the
/* global Postfix configuration file. Tables are loaded in the
/* order as specified, and multiple instances of the same type
/* are allowed.
/* .IP "CA_MAIL_SERVER_TIME_TABLE(CONFIG_TIME_TABLE *)"
/* A table with configurable parameters, to be loaded from the
/* global Postfix configuration file. Tables are loaded in the
/* order as specified, and multiple instances of the same type
/* are allowed.
/* .IP "CA_MAIL_SERVER_RAW_TABLE(CONFIG_RAW_TABLE *)"
/* A table with configurable parameters, to be loaded from the
/* global Postfix configuration file. Tables are loaded in the
/* order as specified, and multiple instances of the same type
/* are allowed. Raw parameters are not subjected to $name
/* evaluation.
/* .IP "CA_MAIL_SERVER_NINT_TABLE(CONFIG_NINT_TABLE *)"
/* A table with configurable parameters, to be loaded from the
/* global Postfix configuration file. Tables are loaded in the
/* order as specified, and multiple instances of the same type
/* are allowed.
/* .IP "CA_MAIL_SERVER_NBOOL_TABLE(CONFIG_NBOOL_TABLE *)"
/* A table with configurable parameters, to be loaded from the
/* global Postfix configuration file. Tables are loaded in the
/* order as specified, and multiple instances of the same type
/* are allowed.
/* .IP "CA_MAIL_SERVER_PRE_INIT(void *(char *service_name, char **argv))"
/* A pointer to a function that is called once
/* by the skeleton after it has read the global configuration file
/* and after it has processed command-line arguments, but before
/* the skeleton has optionally relinquished the process privileges.
/* .sp
/* Only the last instance of this parameter type is remembered.
/* .IP "CA_MAIL_SERVER_POST_INIT(void *(char *service_name, char **argv))"
/* A pointer to a function that is called once
/* by the skeleton after it has optionally relinquished the process
/* privileges, but before servicing client connection requests.
/* .sp
/* Only the last instance of this parameter type is remembered.
/* .IP "CA_MAIL_SERVER_LOOP(int *(char *service_name, char **argv))"
/* A pointer to function that is executed from
/* within the event loop, whenever an I/O or timer event has happened,
/* or whenever nothing has happened for a specified amount of time.
/* The result value of the function specifies how long to wait until
/* the next event. Specify -1 to wait for "as long as it takes".
/* .sp
/* Only the last instance of this parameter type is remembered.
/* .IP "CA_MAIL_SERVER_EXIT(void *(char *service_name, char **argv))"
/* A pointer to function that is executed immediately before normal
/* process termination.
/* .IP "CA_MAIL_SERVER_PRE_ACCEPT(void *(char *service_name, char **argv))"
/* Function to be executed prior to accepting a new connection.
/* .sp
/* Only the last instance of this parameter type is remembered.
/* .IP "CA_MAIL_SERVER_POST_ACCEPT(void *(VSTREAM *stream, char *service_name, char **argv, HTABLE *attr))"
/* Function to be executed after accepting a new connection.
/* The stream, service_name and argv arguments are the same
/* as with the "service" argument. The attr argument is null
/* or a pointer to a table with 'pass' connection attributes.
/* The table is destroyed after the function returns.
/* .sp
/* Only the last instance of this parameter type is remembered.
/* .IP "CA_MAIL_SERVER_PRE_DISCONN(VSTREAM *, char *service_name, char **argv)"
/* A pointer to a function that is called
/* by the multi_server_disconnect() function (see below).
/* .sp
/* Only the last instance of this parameter type is remembered.
/* .IP CA_MAIL_SERVER_IN_FLOW_DELAY
/* Pause $in_flow_delay seconds when no "mail flow control token"
/* is available. A token is consumed for each connection request.
/* .IP CA_MAIL_SERVER_SOLITARY
/* This service must be configured with process limit of 1.
/* .IP CA_MAIL_SERVER_UNLIMITED
/* This service must be configured with process limit of 0.
/* .IP CA_MAIL_SERVER_PRIVILEGED
/* This service must be configured as privileged.
/* .IP "CA_MAIL_SERVER_BOUNCE_INIT(const char *, const char **)"
/* Initialize the DSN filter for the bounce/defer service
/* clients with the specified map source and map names.
/* .PP
/* multi_server_disconnect() should be called by the application
/* to close a client connection.
/*
/* multi_server_drain() should be called when the application
/* no longer wishes to accept new client connections. Existing
/* clients are handled in a background process, and the process
/* terminates when the last client is disconnected. A non-zero
/* result means this call should be tried again later.
/*
/* The var_use_limit variable limits the number of clients that
/* a server can service before it commits suicide.
/* This value is taken from the global \fBmain.cf\fR configuration
/* file. Setting \fBvar_use_limit\fR to zero disables the client limit.
/*
/* The var_idle_limit variable limits the time that a service
/* receives no client connection requests before it commits suicide.
/* This value is taken from the global \fBmain.cf\fR configuration
/* file. Setting \fBvar_idle_limit\fR to zero disables the idle limit.
/* DIAGNOSTICS
/* Problems and transactions are logged to \fBsyslogd\fR(8)
/* or \fBpostlogd\fR(8).
/* SEE ALSO
/* master(8), master process
/* postlogd(8), Postfix logging
/* syslogd(8), system logging
/* 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 <sys/time.h> /* select() */
#include <unistd.h>
#include <signal.h>
#include <stdlib.h>
#include <limits.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#ifdef STRCASECMP_IN_STRINGS_H
#include <strings.h>
#endif
#include <time.h>
#ifdef USE_SYS_SELECT_H
#include <sys/select.h> /* select() */
#endif
/* Utility library. */
#include <msg.h>
#include <msg_vstream.h>
#include <chroot_uid.h>
#include <listen.h>
#include <events.h>
#include <vstring.h>
#include <vstream.h>
#include <msg_vstream.h>
#include <mymalloc.h>
#include <iostuff.h>
#include <stringops.h>
#include <sane_accept.h>
#include <myflock.h>
#include <safe_open.h>
#include <listen.h>
#include <watchdog.h>
#include <split_at.h>
/* Global library. */
#include <mail_task.h>
#include <debug_process.h>
#include <mail_params.h>
#include <mail_conf.h>
#include <mail_dict.h>
#include <timed_ipc.h>
#include <resolve_local.h>
#include <mail_flow.h>
#include <mail_version.h>
#include <bounce.h>
#include <maillog_client.h>
/* Process manager. */
#include "master_proto.h"
/* Application-specific */
#include "mail_server.h"
/*
* Global state.
*/
static int client_count;
static int use_count;
static int socket_count = 1;
static void (*multi_server_service) (VSTREAM *, char *, char **);
static char *multi_server_name;
static char **multi_server_argv;
static void (*multi_server_accept) (int, void *);
static void (*multi_server_onexit) (char *, char **);
static void (*multi_server_pre_accept) (char *, char **);
static void (*multi_server_post_accept) (VSTREAM *, char *, char **, HTABLE *);
static VSTREAM *multi_server_lock;
static int multi_server_in_flow_delay;
static unsigned multi_server_generation;
static void (*multi_server_pre_disconn) (VSTREAM *, char *, char **);
/* multi_server_exit - normal termination */
static NORETURN multi_server_exit(void)
{
if (multi_server_onexit)
multi_server_onexit(multi_server_name, multi_server_argv);
exit(0);
}
/* multi_server_abort - terminate after abnormal master exit */
static void multi_server_abort(int unused_event, void *unused_context)
{
if (msg_verbose)
msg_info("master disconnect -- exiting");
multi_server_exit();
}
/* multi_server_timeout - idle time exceeded */
static void multi_server_timeout(int unused_event, void *unused_context)
{
if (msg_verbose)
msg_info("idle timeout -- exiting");
multi_server_exit();
}
/* multi_server_drain - stop accepting new clients */
int multi_server_drain(void)
{
const char *myname = "multi_server_drain";
int fd;
switch (fork()) {
/* Try again later. */
case -1:
return (-1);
/* Finish existing clients in the background, then terminate. */
case 0:
(void) msg_cleanup((MSG_CLEANUP_FN) 0);
event_fork();
for (fd = MASTER_LISTEN_FD; fd < MASTER_LISTEN_FD + socket_count; fd++) {
event_disable_readwrite(fd);
(void) close(fd);
/* Play safe - don't reuse this file number. */
if (DUP2(STDIN_FILENO, fd) < 0)
msg_warn("%s: dup2(%d, %d): %m", myname, STDIN_FILENO, fd);
}
var_use_limit = 1;
return (0);
/* Let the master start a new process. */
default:
exit(0);
}
}
/* multi_server_disconnect - terminate client session */
void multi_server_disconnect(VSTREAM *stream)
{
if (msg_verbose)
msg_info("connection closed fd %d", vstream_fileno(stream));
if (multi_server_pre_disconn)
multi_server_pre_disconn(stream, multi_server_name, multi_server_argv);
event_disable_readwrite(vstream_fileno(stream));
(void) vstream_fclose(stream);
client_count--;
/* Avoid integer wrap-around in a persistent process. */
if (use_count < INT_MAX)
use_count++;
if (client_count == 0 && var_idle_limit > 0)
event_request_timer(multi_server_timeout, (void *) 0, var_idle_limit);
}
/* multi_server_execute - in case (char *) != (struct *) */
static void multi_server_execute(int unused_event, void *context)
{
VSTREAM *stream = (VSTREAM *) context;
if (multi_server_lock != 0
&& myflock(vstream_fileno(multi_server_lock), INTERNAL_LOCK,
MYFLOCK_OP_NONE) < 0)
msg_fatal("select unlock: %m");
/*
* Do not bother the application when the client disconnected. Don't drop
* the already accepted client request after "postfix reload"; that would
* be rude.
*/
if (peekfd(vstream_fileno(stream)) > 0) {
if (master_notify(var_pid, multi_server_generation, MASTER_STAT_TAKEN) < 0)
/* void */ ;
multi_server_service(stream, multi_server_name, multi_server_argv);
if (master_notify(var_pid, multi_server_generation, MASTER_STAT_AVAIL) < 0)
multi_server_abort(EVENT_NULL_TYPE, EVENT_NULL_CONTEXT);
} else {
multi_server_disconnect(stream);
}
}
/* multi_server_enable_read - enable read events */
static void multi_server_enable_read(int unused_event, void *context)
{
VSTREAM *stream = (VSTREAM *) context;
event_enable_read(vstream_fileno(stream), multi_server_execute, (void *) stream);
}
/* multi_server_wakeup - wake up application */
static void multi_server_wakeup(int fd, HTABLE *attr)
{
VSTREAM *stream;
char *tmp;
#if defined(F_DUPFD) && (EVENTS_STYLE != EVENTS_STYLE_SELECT)
#ifndef THRESHOLD_FD_WORKAROUND
#define THRESHOLD_FD_WORKAROUND 128
#endif
int new_fd;
/*
* Leave some handles < FD_SETSIZE for DBMS libraries, in the unlikely
* case of a multi-server with a thousand clients.
*/
if (fd < THRESHOLD_FD_WORKAROUND) {
if ((new_fd = fcntl(fd, F_DUPFD, THRESHOLD_FD_WORKAROUND)) < 0)
msg_fatal("fcntl F_DUPFD: %m");
(void) close(fd);
fd = new_fd;
}
#endif
if (msg_verbose)
msg_info("connection established fd %d", fd);
non_blocking(fd, BLOCKING);
close_on_exec(fd, CLOSE_ON_EXEC);
client_count++;
stream = vstream_fdopen(fd, O_RDWR);
tmp = concatenate(multi_server_name, " socket", (char *) 0);
vstream_control(stream,
CA_VSTREAM_CTL_PATH(tmp),
CA_VSTREAM_CTL_END);
myfree(tmp);
timed_ipc_setup(stream);
if (multi_server_in_flow_delay && mail_flow_get(1) < 0)
event_request_timer(multi_server_enable_read, (void *) stream,
var_in_flow_delay);
else
multi_server_enable_read(0, (void *) stream);
if (multi_server_post_accept)
multi_server_post_accept(stream, multi_server_name, multi_server_argv, attr);
else if (attr)
msg_warn("service ignores 'pass' connection attributes");
if (attr)
htable_free(attr, myfree);
}
/* multi_server_accept_local - accept client connection request */
static void multi_server_accept_local(int unused_event, void *context)
{
int listen_fd = CAST_ANY_PTR_TO_INT(context);
int time_left = -1;
int fd;
/*
* Be prepared for accept() to fail because some other process already
* got the connection (the number of processes competing for clients is
* kept small, so this is not a "thundering herd" problem). If the
* accept() succeeds, be sure to disable non-blocking I/O, in order to
* minimize confusion.
*/
if (client_count == 0 && var_idle_limit > 0)
time_left = event_cancel_timer(multi_server_timeout, (void *) 0);
if (multi_server_pre_accept)
multi_server_pre_accept(multi_server_name, multi_server_argv);
fd = LOCAL_ACCEPT(listen_fd);
if (multi_server_lock != 0
&& myflock(vstream_fileno(multi_server_lock), INTERNAL_LOCK,
MYFLOCK_OP_NONE) < 0)
msg_fatal("select unlock: %m");
if (fd < 0) {
if (errno != EAGAIN)
msg_error("accept connection: %m");
if (time_left >= 0)
event_request_timer(multi_server_timeout, (void *) 0, time_left);
return;
}
multi_server_wakeup(fd, (HTABLE *) 0);
}
#ifdef MASTER_XPORT_NAME_PASS
/* multi_server_accept_pass - accept descriptor */
static void multi_server_accept_pass(int unused_event, void *context)
{
int listen_fd = CAST_ANY_PTR_TO_INT(context);
int time_left = -1;
int fd;
HTABLE *attr = 0;
/*
* Be prepared for accept() to fail because some other process already
* got the connection (the number of processes competing for clients is
* kept small, so this is not a "thundering herd" problem). If the
* accept() succeeds, be sure to disable non-blocking I/O, in order to
* minimize confusion.
*/
if (client_count == 0 && var_idle_limit > 0)
time_left = event_cancel_timer(multi_server_timeout, (void *) 0);
if (multi_server_pre_accept)
multi_server_pre_accept(multi_server_name, multi_server_argv);
fd = pass_accept_attr(listen_fd, &attr);
if (multi_server_lock != 0
&& myflock(vstream_fileno(multi_server_lock), INTERNAL_LOCK,
MYFLOCK_OP_NONE) < 0)
msg_fatal("select unlock: %m");
if (fd < 0) {
if (errno != EAGAIN)
msg_error("accept connection: %m");
if (time_left >= 0)
event_request_timer(multi_server_timeout, (void *) 0, time_left);
return;
}
multi_server_wakeup(fd, attr);
}
#endif
/* multi_server_accept_inet - accept client connection request */
static void multi_server_accept_inet(int unused_event, void *context)
{
int listen_fd = CAST_ANY_PTR_TO_INT(context);
int time_left = -1;
int fd;
/*
* Be prepared for accept() to fail because some other process already
* got the connection (the number of processes competing for clients is
* kept small, so this is not a "thundering herd" problem). If the
* accept() succeeds, be sure to disable non-blocking I/O, in order to
* minimize confusion.
*/
if (client_count == 0 && var_idle_limit > 0)
time_left = event_cancel_timer(multi_server_timeout, (void *) 0);
if (multi_server_pre_accept)
multi_server_pre_accept(multi_server_name, multi_server_argv);
fd = inet_accept(listen_fd);
if (multi_server_lock != 0
&& myflock(vstream_fileno(multi_server_lock), INTERNAL_LOCK,
MYFLOCK_OP_NONE) < 0)
msg_fatal("select unlock: %m");
if (fd < 0) {
if (errno != EAGAIN)
msg_error("accept connection: %m");
if (time_left >= 0)
event_request_timer(multi_server_timeout, (void *) 0, time_left);
return;
}
multi_server_wakeup(fd, (HTABLE *) 0);
}
/* multi_server_main - the real main program */
NORETURN multi_server_main(int argc, char **argv, MULTI_SERVER_FN service,...)
{
const char *myname = "multi_server_main";
VSTREAM *stream = 0;
char *root_dir = 0;
char *user_name = 0;
int debug_me = 0;
int daemon_mode = 1;
char *service_name = basename(argv[0]);
int delay;
int c;
int fd;
va_list ap;
MAIL_SERVER_INIT_FN pre_init = 0;
MAIL_SERVER_INIT_FN post_init = 0;
MAIL_SERVER_LOOP_FN loop = 0;
int key;
char *transport = 0;
#if 0
char *lock_path;
VSTRING *why;
#endif
int alone = 0;
int zerolimit = 0;
WATCHDOG *watchdog;
char *oname_val;
char *oname;
char *oval;
const char *err;
char *generation;
int msg_vstream_needed = 0;
const char *dsn_filter_title;
const char **dsn_filter_maps;
/*
* Process environment options as early as we can.
*/
if (getenv(CONF_ENV_VERB))
msg_verbose = 1;
if (getenv(CONF_ENV_DEBUG))
debug_me = 1;
/*
* Don't die when a process goes away unexpectedly.
*/
signal(SIGPIPE, SIG_IGN);
/*
* Don't die for frivolous reasons.
*/
#ifdef SIGXFSZ
signal(SIGXFSZ, SIG_IGN);
#endif
/*
* May need this every now and then.
*/
var_procname = mystrdup(basename(argv[0]));
set_mail_conf_str(VAR_PROCNAME, var_procname);
/*
* Initialize logging and exit handler. Do the syslog first, so that its
* initialization completes before we enter the optional chroot jail.
*/
maillog_client_init(mail_task(var_procname), MAILLOG_CLIENT_FLAG_NONE);
if (msg_verbose)
msg_info("daemon started");
/*
* Check the Postfix library version as soon as we enable logging.
*/
MAIL_VERSION_CHECK;
/*
* Initialize from the configuration file. Allow command-line options to
* override compiled-in defaults or configured parameter values.
*/
mail_conf_suck();
/*
* After database open error, continue execution with reduced
* functionality.
*/
dict_allow_surrogate = 1;
/*
* Pick up policy settings from master process. Shut up error messages to
* stderr, because no-one is going to see them.
*/
opterr = 0;
while ((c = GETOPT(argc, argv, "cdDi:lm:n:o:s:St:uvVz")) > 0) {
switch (c) {
case 'c':
root_dir = "setme";
break;
case 'd':
daemon_mode = 0;
break;
case 'D':
debug_me = 1;
break;
case 'i':
mail_conf_update(VAR_MAX_IDLE, optarg);
break;
case 'l':
alone = 1;
break;
case 'm':
mail_conf_update(VAR_MAX_USE, optarg);
break;
case 'n':
service_name = optarg;
break;
case 'o':
oname_val = mystrdup(optarg);
if ((err = split_nameval(oname_val, &oname, &oval)) != 0)
msg_fatal("invalid \"-o %s\" option value: %s", optarg, err);
mail_conf_update(oname, oval);
myfree(oname_val);
break;
case 's':
if ((socket_count = atoi(optarg)) <= 0)
msg_fatal("invalid socket_count: %s", optarg);
break;
case 'S':
stream = VSTREAM_IN;
break;
case 'u':
user_name = "setme";
break;
case 't':
transport = optarg;
break;
case 'v':
msg_verbose++;
break;
case 'V':
if (++msg_vstream_needed == 1)
msg_vstream_init(mail_task(var_procname), VSTREAM_ERR);
break;
case 'z':
zerolimit = 1;
break;
default:
msg_fatal("invalid option: %c", optopt);
break;
}
}
set_mail_conf_str(VAR_SERVNAME, service_name);
/*
* Initialize generic parameters and re-initialize logging in case of a
* non-default program name or logging destination.
*/
mail_params_init();
maillog_client_init(mail_task(var_procname), MAILLOG_CLIENT_FLAG_NONE);
/*
* Register higher-level dictionaries and initialize the support for
* dynamically-loaded dictionaries.
*/
mail_dict_init();
/*
* If not connected to stdin, stdin must not be a terminal.
*/
if (daemon_mode && stream == 0 && isatty(STDIN_FILENO)) {
msg_vstream_init(var_procname, VSTREAM_ERR);
msg_fatal("do not run this command by hand");
}
/*
* Application-specific initialization.
*/
va_start(ap, service);
while ((key = va_arg(ap, int)) != 0) {
switch (key) {
case MAIL_SERVER_INT_TABLE:
get_mail_conf_int_table(va_arg(ap, CONFIG_INT_TABLE *));
break;
case MAIL_SERVER_LONG_TABLE:
get_mail_conf_long_table(va_arg(ap, CONFIG_LONG_TABLE *));
break;
case MAIL_SERVER_STR_TABLE:
get_mail_conf_str_table(va_arg(ap, CONFIG_STR_TABLE *));
break;
case MAIL_SERVER_BOOL_TABLE:
get_mail_conf_bool_table(va_arg(ap, CONFIG_BOOL_TABLE *));
break;
case MAIL_SERVER_TIME_TABLE:
get_mail_conf_time_table(va_arg(ap, CONFIG_TIME_TABLE *));
break;
case MAIL_SERVER_RAW_TABLE:
get_mail_conf_raw_table(va_arg(ap, CONFIG_RAW_TABLE *));
break;
case MAIL_SERVER_NINT_TABLE:
get_mail_conf_nint_table(va_arg(ap, CONFIG_NINT_TABLE *));
break;
case MAIL_SERVER_NBOOL_TABLE:
get_mail_conf_nbool_table(va_arg(ap, CONFIG_NBOOL_TABLE *));
break;
case MAIL_SERVER_PRE_INIT:
pre_init = va_arg(ap, MAIL_SERVER_INIT_FN);
break;
case MAIL_SERVER_POST_INIT:
post_init = va_arg(ap, MAIL_SERVER_INIT_FN);
break;
case MAIL_SERVER_LOOP:
loop = va_arg(ap, MAIL_SERVER_LOOP_FN);
break;
case MAIL_SERVER_EXIT:
multi_server_onexit = va_arg(ap, MAIL_SERVER_EXIT_FN);
break;
case MAIL_SERVER_PRE_ACCEPT:
multi_server_pre_accept = va_arg(ap, MAIL_SERVER_ACCEPT_FN);
break;
case MAIL_SERVER_POST_ACCEPT:
multi_server_post_accept = va_arg(ap, MAIL_SERVER_POST_ACCEPT_FN);
break;
case MAIL_SERVER_PRE_DISCONN:
multi_server_pre_disconn = va_arg(ap, MAIL_SERVER_DISCONN_FN);
break;
case MAIL_SERVER_IN_FLOW_DELAY:
multi_server_in_flow_delay = 1;
break;
case MAIL_SERVER_SOLITARY:
if (stream == 0 && !alone)
msg_fatal("service %s requires a process limit of 1",
service_name);
break;
case MAIL_SERVER_UNLIMITED:
if (stream == 0 && !zerolimit)
msg_fatal("service %s requires a process limit of 0",
service_name);
break;
case MAIL_SERVER_PRIVILEGED:
if (user_name)
msg_fatal("service %s requires privileged operation",
service_name);
break;
case MAIL_SERVER_BOUNCE_INIT:
dsn_filter_title = va_arg(ap, const char *);
dsn_filter_maps = va_arg(ap, const char **);
bounce_client_init(dsn_filter_title, *dsn_filter_maps);
break;
default:
msg_panic("%s: unknown argument type: %d", myname, key);
}
}
va_end(ap);
if (root_dir)
root_dir = var_queue_dir;
if (user_name)
user_name = var_mail_owner;
/*
* Can options be required?
*/
if (stream == 0) {
if (transport == 0)
msg_fatal("no transport type specified");
if (strcasecmp(transport, MASTER_XPORT_NAME_INET) == 0)
multi_server_accept = multi_server_accept_inet;
else if (strcasecmp(transport, MASTER_XPORT_NAME_UNIX) == 0)
multi_server_accept = multi_server_accept_local;
#ifdef MASTER_XPORT_NAME_PASS
else if (strcasecmp(transport, MASTER_XPORT_NAME_PASS) == 0)
multi_server_accept = multi_server_accept_pass;
#endif
else
msg_fatal("unsupported transport type: %s", transport);
}
/*
* Retrieve process generation from environment.
*/
if ((generation = getenv(MASTER_GEN_NAME)) != 0) {
if (!alldig(generation))
msg_fatal("bad generation: %s", generation);
OCTAL_TO_UNSIGNED(multi_server_generation, generation);
if (msg_verbose)
msg_info("process generation: %s (%o)",
generation, multi_server_generation);
}
/*
* Optionally start the debugger on ourself.
*/
if (debug_me)
debug_process();
/*
* Traditionally, BSD select() can't handle multiple processes selecting
* on the same socket, and wakes up every process in select(). See TCP/IP
* Illustrated volume 2 page 532. We avoid select() collisions with an
* external lock file.
*/
/*
* XXX Can't compete for exclusive access to the listen socket because we
* also have to monitor existing client connections for service requests.
*/
#if 0
if (stream == 0 && !alone) {
lock_path = concatenate(DEF_PID_DIR, "/", transport,
".", service_name, (char *) 0);
why = vstring_alloc(1);
if ((multi_server_lock = safe_open(lock_path, O_CREAT | O_RDWR, 0600,
(struct stat *) 0, -1, -1, why)) == 0)
msg_fatal("open lock file %s: %s", lock_path, vstring_str(why));
close_on_exec(vstream_fileno(multi_server_lock), CLOSE_ON_EXEC);
myfree(lock_path);
vstring_free(why);
}
#endif
/*
* Set up call-back info.
*/
multi_server_service = service;
multi_server_name = service_name;
multi_server_argv = argv + optind;
/*
* Run pre-jail initialization.
*/
if (chdir(var_queue_dir) < 0)
msg_fatal("chdir(\"%s\"): %m", var_queue_dir);
if (pre_init)
pre_init(multi_server_name, multi_server_argv);
/*
* Optionally, restrict the damage that this process can do.
*/
resolve_local_init();
tzset();
chroot_uid(root_dir, user_name);
/*
* Run post-jail initialization.
*/
if (post_init)
post_init(multi_server_name, multi_server_argv);
/*
* Are we running as a one-shot server with the client connection on
* standard input? If so, make sure the output is written to stdout so as
* to satisfy common expectation.
*/
if (stream != 0) {
vstream_control(stream,
CA_VSTREAM_CTL_DOUBLE,
CA_VSTREAM_CTL_WRITE_FD(STDOUT_FILENO),
CA_VSTREAM_CTL_END);
service(stream, multi_server_name, multi_server_argv);
vstream_fflush(stream);
multi_server_exit();
}
/*
* Running as a semi-resident server. Service connection requests.
* Terminate when we have serviced a sufficient number of clients, when
* no-one has been talking to us for a configurable amount of time, or
* when the master process terminated abnormally.
*/
if (var_idle_limit > 0)
event_request_timer(multi_server_timeout, (void *) 0, var_idle_limit);
for (fd = MASTER_LISTEN_FD; fd < MASTER_LISTEN_FD + socket_count; fd++) {
event_enable_read(fd, multi_server_accept, CAST_INT_TO_VOID_PTR(fd));
close_on_exec(fd, CLOSE_ON_EXEC);
}
event_enable_read(MASTER_STATUS_FD, multi_server_abort, (void *) 0);
close_on_exec(MASTER_STATUS_FD, CLOSE_ON_EXEC);
close_on_exec(MASTER_FLOW_READ, CLOSE_ON_EXEC);
close_on_exec(MASTER_FLOW_WRITE, CLOSE_ON_EXEC);
watchdog = watchdog_create(var_daemon_timeout, (WATCHDOG_FN) 0, (void *) 0);
/*
* The event loop, at last.
*/
while (var_use_limit == 0 || use_count < var_use_limit || client_count > 0) {
if (multi_server_lock != 0) {
watchdog_stop(watchdog);
if (myflock(vstream_fileno(multi_server_lock), INTERNAL_LOCK,
MYFLOCK_OP_EXCLUSIVE) < 0)
msg_fatal("select lock: %m");
}
watchdog_start(watchdog);
delay = loop ? loop(multi_server_name, multi_server_argv) : -1;
event_loop(delay);
}
multi_server_exit();
}