summaryrefslogtreecommitdiffstats
path: root/src/master/dgram_server.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/master/dgram_server.c')
-rw-r--r--src/master/dgram_server.c665
1 files changed, 665 insertions, 0 deletions
diff --git a/src/master/dgram_server.c b/src/master/dgram_server.c
new file mode 100644
index 0000000..2ef3a5a
--- /dev/null
+++ b/src/master/dgram_server.c
@@ -0,0 +1,665 @@
+/*++
+/* NAME
+/* dgram_server 3
+/* SUMMARY
+/* skeleton datagram server subsystem
+/* SYNOPSIS
+/* #include <mail_server.h>
+/*
+/* NORETURN dgram_server_main(argc, argv, service, key, value, ...)
+/* int argc;
+/* char **argv;
+/* void (*service)(char *buf, int len, char *service_name, char **argv);
+/* int key;
+/* DESCRIPTION
+/* This module implements a skeleton for mail subsystem programs
+/* that wake up on client request and perform some activity
+/* without further client interaction. This module supports
+/* local IPC via a UNIX-domain datagram socket. The resulting
+/* program expects to be run from the \fBmaster\fR process.
+/*
+/* dgram_server_main() is the skeleton entry point. It should
+/* be called from the application main program. The skeleton
+/* does the generic command-line options processing, initialization
+/* of configurable parameters, and receiving datagrams. The
+/* skeleton never returns.
+/*
+/* Arguments:
+/* .IP "void (*service)(char *buf, int len, char *service_name, char **argv)"
+/* A pointer to a function that is called by the skeleton each
+/* time a client sends a datagram to the program's service
+/* port. The function is run after the program has irrevocably
+/* dropped its privileges. The buffer argument specifies the
+/* data read from the datagram port; this data corresponds to
+/* request. The len argument specifies how much client data
+/* is available. The maximal size of the buffer is specified
+/* via the DGRAM_BUF_SIZE manifest constant. 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.
+/* .sp
+/* Only the last instance of this parameter type is remembered.
+/* .IP "CA_MAIL_SERVER_PRE_ACCEPT(void *(char *service_name, char **argv))"
+/* Function to be executed prior to accepting a new request.
+/* .sp
+/* Only the last instance of this parameter type is remembered.
+/* .IP "CA_MAIL_SERVER_IN_FLOW_DELAY(none)"
+/* 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_WATCHDOG(int *)"
+/* Override the default 1000s watchdog timeout. The value is
+/* used after command-line and main.cf file processing.
+/* .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
+/* 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_use_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
+/* Google, Inc.
+/* 111 8th Avenue
+/* New York, NY 10011, USA
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+#include <sys/socket.h>
+#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>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <msg_vstream.h>
+#include <chroot_uid.h>
+#include <vstring.h>
+#include <vstream.h>
+#include <msg_vstream.h>
+#include <mymalloc.h>
+#include <events.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_params.h>
+#include <mail_task.h>
+#include <debug_process.h>
+#include <mail_conf.h>
+#include <mail_dict.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 use_count;
+
+static DGRAM_SERVER_FN dgram_server_service;
+static char *dgram_server_name;
+static char **dgram_server_argv;
+static void (*dgram_server_accept) (int, void *);
+static void (*dgram_server_onexit) (char *, char **);
+static void (*dgram_server_pre_accept) (char *, char **);
+static VSTREAM *dgram_server_lock;
+static int dgram_server_in_flow_delay;
+static unsigned dgram_server_generation;
+static int dgram_server_watchdog = 1000;
+
+/* dgram_server_exit - normal termination */
+
+static NORETURN dgram_server_exit(void)
+{
+ if (dgram_server_onexit)
+ dgram_server_onexit(dgram_server_name, dgram_server_argv);
+ exit(0);
+}
+
+/* dgram_server_abort - terminate after abnormal master exit */
+
+static void dgram_server_abort(int unused_event, void *unused_context)
+{
+ if (msg_verbose)
+ msg_info("master disconnect -- exiting");
+ dgram_server_exit();
+}
+
+/* dgram_server_timeout - idle time exceeded */
+
+static void dgram_server_timeout(int unused_event, void *unused_context)
+{
+ if (msg_verbose)
+ msg_info("idle timeout -- exiting");
+ dgram_server_exit();
+}
+
+/* dgram_server_wakeup - wake up application */
+
+static void dgram_server_wakeup(int fd)
+{
+ char buf[DGRAM_BUF_SIZE];
+ ssize_t len;
+
+ /*
+ * Commit suicide when the master process disconnected from us, after
+ * handling the client request.
+ */
+ if (master_notify(var_pid, dgram_server_generation, MASTER_STAT_TAKEN) < 0)
+ /* void */ ;
+ if (dgram_server_in_flow_delay && mail_flow_get(1) < 0)
+ doze(var_in_flow_delay * 1000000);
+ if ((len = recv(fd, buf, sizeof(buf), 0)) >= 0)
+ dgram_server_service(buf, len, dgram_server_name, dgram_server_argv);
+ if (master_notify(var_pid, dgram_server_generation, MASTER_STAT_AVAIL) < 0)
+ dgram_server_abort(EVENT_NULL_TYPE, EVENT_NULL_CONTEXT);
+ if (var_idle_limit > 0)
+ event_request_timer(dgram_server_timeout, (void *) 0, var_idle_limit);
+ /* Avoid integer wrap-around in a persistent process. */
+ if (use_count < INT_MAX)
+ use_count++;
+}
+
+/* dgram_server_accept_unix - handle UNIX-domain socket event */
+
+static void dgram_server_accept_unix(int unused_event, void *context)
+{
+ const char *myname = "dgram_server_accept";
+ int listen_fd = CAST_ANY_PTR_TO_INT(context);
+
+ if (dgram_server_lock != 0
+ && myflock(vstream_fileno(dgram_server_lock), INTERNAL_LOCK,
+ MYFLOCK_OP_NONE) < 0)
+ msg_fatal("select unlock: %m");
+
+ if (msg_verbose)
+ msg_info("%s: request arrived", myname);
+
+ /*
+ * Read whatever the other side wrote. The socket is non-blocking so we
+ * won't get stuck when multiple processes wake up.
+ */
+ if (dgram_server_pre_accept)
+ dgram_server_pre_accept(dgram_server_name, dgram_server_argv);
+ dgram_server_wakeup(listen_fd);
+}
+
+/* dgram_server_main - the real main program */
+
+NORETURN dgram_server_main(int argc, char **argv, DGRAM_SERVER_FN service,...)
+{
+ const char *myname = "dgram_server_main";
+ 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 socket_count = 1;
+ 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;
+ char *lock_path;
+ VSTRING *why;
+ 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:t: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 't':
+ transport = optarg;
+ break;
+ case 'u':
+ user_name = "setme";
+ 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 dictionarles.
+ */
+ mail_dict_init();
+
+ /*
+ * If not connected to stdin, stdin must not be a terminal.
+ */
+ if (daemon_mode && 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:
+ dgram_server_onexit = va_arg(ap, MAIL_SERVER_EXIT_FN);
+ break;
+ case MAIL_SERVER_PRE_ACCEPT:
+ dgram_server_pre_accept = va_arg(ap, MAIL_SERVER_ACCEPT_FN);
+ break;
+ case MAIL_SERVER_IN_FLOW_DELAY:
+ dgram_server_in_flow_delay = 1;
+ break;
+ case MAIL_SERVER_SOLITARY:
+ if (!alone)
+ msg_fatal("service %s requires a process limit of 1",
+ service_name);
+ break;
+ case MAIL_SERVER_UNLIMITED:
+ if (!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_WATCHDOG:
+ dgram_server_watchdog = *va_arg(ap, int *);
+ 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 (transport == 0)
+ msg_fatal("no transport type specified");
+ else if (strcasecmp(transport, MASTER_XPORT_NAME_UXDG) == 0)
+ dgram_server_accept = dgram_server_accept_unix;
+ 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(dgram_server_generation, generation);
+ if (msg_verbose)
+ msg_info("process generation: %s (%o)",
+ generation, dgram_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.
+ */
+ if (!alone) {
+ lock_path = concatenate(DEF_PID_DIR, "/", transport,
+ ".", service_name, (char *) 0);
+ why = vstring_alloc(1);
+ if ((dgram_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(dgram_server_lock), CLOSE_ON_EXEC);
+ myfree(lock_path);
+ vstring_free(why);
+ }
+
+ /*
+ * Set up call-back info.
+ */
+ dgram_server_service = service;
+ dgram_server_name = service_name;
+ dgram_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(dgram_server_name, dgram_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(dgram_server_name, dgram_server_argv);
+
+ /*
+ * Running as a semi-resident server. Service requests. Terminate when we
+ * have serviced a sufficient number of requests, 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(dgram_server_timeout, (void *) 0, var_idle_limit);
+ for (fd = MASTER_LISTEN_FD; fd < MASTER_LISTEN_FD + socket_count; fd++) {
+ event_enable_read(fd, dgram_server_accept, CAST_INT_TO_VOID_PTR(fd));
+ close_on_exec(fd, CLOSE_ON_EXEC);
+ }
+ event_enable_read(MASTER_STATUS_FD, dgram_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(dgram_server_watchdog,
+ (WATCHDOG_FN) 0, (void *) 0);
+
+ /*
+ * The event loop, at last.
+ */
+ while (var_use_limit == 0 || use_count < var_use_limit) {
+ if (dgram_server_lock != 0) {
+ watchdog_stop(watchdog);
+ if (myflock(vstream_fileno(dgram_server_lock), INTERNAL_LOCK,
+ MYFLOCK_OP_EXCLUSIVE) < 0)
+ msg_fatal("select lock: %m");
+ }
+ watchdog_start(watchdog);
+ delay = loop ? loop(dgram_server_name, dgram_server_argv) : -1;
+ event_loop(delay);
+ }
+ dgram_server_exit();
+}