a19e64933

Denis Vlasenko

2009-03-11

FAILED Duration: 32s

Subject

docs/logging_and_backgrounding.txt: new mini-doc dnsd: remove statics, remove nerly-useless SIGINT handler crond: correct more of logfile to 0666 (as usual, umask allows user to remove unwanted bits). nameif: print errors to stderr too, not just to syslog

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Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

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Commit Diff GitHub →

docs/logging_and_backgrounding.txt +89 -0 miscutils/crond.c +1 -1 networking/dnsd.c +46 -50 networking/inetd.c +1 -1 networking/nameif.c +3 -1 networking/udhcp/dhcpc.c +1 -1 networking/udhcp/dhcpd.c +1 -3 networking/udhcp/socket.c +1 -1

docs/logging_and_backgrounding.txt+89 -0

@@ -0,0 +1,89 @@
+	Logging and backgrounding
+
+	By default, bb_[p]error_msg[_and_die] messages go to stderr,
+	and of course, usually applets do not auto-background. :)
+
+	Historically, daemons and inetd services are different.
+
+	Busybox is trying to provide compatible behavior, thus if an applet
+	is emulating an existing utility, it should mimic it. If utility
+	auto-backgrounds itself, busybox applet should do the same.
+	If utility normally logs to syslog, busybox applet should do
+	the same too.
+
+	However, busybox should not needlessly restrict the freedom
+	of the users. And users have different needs and different preferences.
+	Some might like logging everything from daemons to syslog.
+	Others prefer running stuff under runsv/svlogd and thus would like
+	logging to stderr and no daemonization.
+
+	To help with that, busybox applets should have options to override
+	default behavior, whatever that is for a given applet.
+
+
+	Current sutiation is a bit of a mess:
+
+	acpid - auto-backgrounds unless -d
+	crond - auto-backgrounds unless -f, logs to syslog unless -d or -L.
+	option -d logs to stderr, -L FILE logs to FILE
+	devfsd - (obsolete)
+	dnsd - option -d makes it auto-background and log to syslog
+	fakeidentd - inetd service. Auto-backgrounds and logs to syslog
+	if no -f and no -i and no -w (-i is "inetd service" flag,
+	-w is "inetd-wait service" flag)
+	ftpd - inetd service. Logs to syslog always, with -v logs to strerr too
+	httpd - auto-backgrounds unless -f or -i
+	(-i is "inetd service" flag)
+	inetd - auto-backgrounds unless -f, logs to syslog unless -e
+	klogd - auto-backgrounds unless -n
+	syslogd - auto-backgrounds unless -n
+	telnetd - auto-backgrounds unless -f or -i
+	(-i is "inetd service" flag)
+	udhcpc - auto-backgrounds unless -f after lease is obtained,
+	option -b makes it background sooner (when lease attempt
+	fails and retries start),
+	after backgrounding it stops logging to stderr;
+	logs to stderr, but option -S makes it log also to syslog
+	udhcpd - auto-backgrounds and do not log to stderr unless -f,
+	otherwise logs to stderr, but option -S makes it log also to syslog
+	zcip - auto-backgrounds and logs also to syslog unless -f
+
+	miscutils/crond.c: logmode = LOGMODE_SYSLOG;
+	networking/dnsd.c: logmode = LOGMODE_SYSLOG;
+	networking/ftpd.c: logmode = LOGMODE_SYSLOG;
+	networking/ftpd.c: logmode \|= LOGMODE_SYSLOG;
+	networking/inetd.c: logmode = LOGMODE_SYSLOG;
+	networking/isrv_identd.c: logmode = LOGMODE_SYSLOG;
+	networking/telnetd.c: logmode = LOGMODE_SYSLOG;
+	networking/udhcp/dhcpc.c: logmode = LOGMODE_NONE;
+	networking/udhcp/dhcpc.c: logmode \|= LOGMODE_SYSLOG;
+	networking/udhcp/dhcpc.c: logmode &= ~LOGMODE_STDIO;
+	networking/udhcp/dhcpd.c: logmode = LOGMODE_NONE;
+	networking/udhcp/dhcpd.c: logmode \|= LOGMODE_SYSLOG;
+	networking/zcip.c: logmode \|= LOGMODE_SYSLOG;
+
+
+	These daemons seem to never auto-background/log to syslog:
+
+	lpd - inetd service. Has nothing to log so far, though
+	dhcprelay - standard behavior
+	inotifyd - standard behavior
+	runsv - standard behavior
+	runsvdir - standard behavior
+	svlogd - standard behavior
+	tcpsvd, udpsvd - standard behavior
+	tftpd - standard behavior
+
+
+	Non-daemons (seems to be use syslog for a good reason):
+
+	networking/nameif.c: logmode \|= LOGMODE_SYSLOG;
+	loginutils/chpasswd.c: logmode = LOGMODE_BOTH;
+	loginutils/chpasswd.c: logmode = LOGMODE_STDIO;
+	loginutils/getty.c: logmode = LOGMODE_BOTH;
+	loginutils/getty.c: logmode = LOGMODE_NONE;
+	loginutils/passwd.c: logmode = LOGMODE_STDIO;
+	loginutils/passwd.c: logmode = LOGMODE_BOTH;
+	loginutils/sulogin.c: logmode = LOGMODE_SYSLOG; (used if stdio isn't a tty)
+	loginutils/sulogin.c: logmode = LOGMODE_BOTH;
+	util-linux/mount.c: logmode = LOGMODE_SYSLOG; (used in a backgrounded NFS mount helper)

miscutils/crond.c+1 -1

@@ -142,7 +142,7 @@ static void crondlog(const char *ctl, ...)
	/* Syslog mode: all to syslog (logmode = LOGMODE_SYSLOG), */
	if (!DebugOpt && LogFile) {
	/* Otherwise (log to file): we reopen log file at every write: */
-	int logfd = open3_or_warn(LogFile, O_WRONLY \| O_CREAT \| O_APPEND, 0600);
+	int logfd = open3_or_warn(LogFile, O_WRONLY \| O_CREAT \| O_APPEND, 0666);
	if (logfd >= 0)
	xmove_fd(logfd, STDERR_FILENO);
	}

networking/dnsd.c+46 -50

@@ -63,14 +63,7 @@ struct dns_entry { // element of known name, ip address and reversed ip address
	char name[MAX_HOST_LEN];
	};

-	static struct dns_entry *dnsentry;
-	static uint32_t ttl = DEFAULT_TTL;
-
-	static const char *fileconf = "/etc/dnsd.conf";
-
-	// Must match getopt32 call
-	#define OPT_daemon (option_mask32 & 0x10)
-	#define OPT_verbose (option_mask32 & 0x20)
+	#define OPT_verbose (option_mask32)


	/*
@@ -88,7 +81,7 @@ static void convname(char a, uint8_t q)
	/*
	* Insert length of substrings instead of dots
	*/
-	static void undot(uint8_t * rip)
+	static void undot(uint8_t *rip)
	{
	int i = 0, s = 0;
	while (rip[i])
@@ -104,13 +97,13 @@ static void undot(uint8_t * rip)
	/*
	* Read hostname/IP records from file
	*/
-	static void dnsentryinit(void)
+	static struct dns_entry parse_conf_file(const char fileconf)
	{
	char *token[2];
	parser_t *parser;
-	struct dns_entry m, prev;
+	struct dns_entry m, prev, *conf_data;

-	prev = dnsentry = NULL;
+	prev = conf_data = NULL;
	parser = config_open(fileconf);
	while (config_read(parser, token, 2, 2, "# \t", PARSE_NORMAL)) {
	unsigned a, b, c, d;
@@ -132,50 +125,54 @@ static void dnsentryinit(void)
	convname(m->name, (uint8_t*)token[0]);

	if (OPT_verbose)
-	fprintf(stderr, "\tname:%s, ip:%s\n", &(m->name[1]), m->ip);
+	bb_error_msg("name:%s, ip:%s", &(m->name[1]), m->ip);

	if (prev == NULL)
-	dnsentry = m;
+	conf_data = m;
	else
	prev->next = m;
	prev = m;
	}
	config_close(parser);
+	return conf_data;
	}

	/*
	* Look query up in dns records and return answer if found
	* qs is the query string, first byte the string length
	*/
-	static int table_lookup(uint16_t type, uint8_t * as, uint8_t * qs)
+	static int table_lookup(struct dns_entry d, uint16_t type, uint8_t as, uint8_t *qs)
	{
	int i;
-	struct dns_entry *d = dnsentry;

	do {
	#if DEBUG
-	char p,q;
+	char p, q;
	q = (char *)&(qs[1]);
	p = &(d->name[1]);
	fprintf(stderr, "\n%s: %d/%d p:%s q:%s %d",
	__FUNCTION__, (int)strlen(p), (int)(d->name[0]),
	p, q, (int)strlen(q));
	#endif
-	if (type == REQ_A) { /* search by host name */
+	if (type == REQ_A) {
+	/* search by host name */
	for (i = 1; i <= (int)(d->name[0]); i++)
	if (tolower(qs[i]) != d->name[i])
	break;
-	if (i > (int)(d->name[0]) \|\|
-	(d->name[0] == 1 && d->name[1] == '*')) {
+	if (i > (int)(d->name[0])
+	\|\| (d->name[0] == 1 && d->name[1] == '*')
+	) {
	strcpy((char *)as, d->ip);
	#if DEBUG
	fprintf(stderr, " OK as:%s\n", as);
	#endif
	return 0;
	}
-	} else if (type == REQ_PTR) { /* search by IP-address */
-	if ((d->name[0] != 1 \|\| d->name[1] != '*') &&
-	!strncmp((char)&d->rip[1], (char)&qs[1], strlen(d->rip)-1)) {
+	} else if (type == REQ_PTR) {
+	/* search by IP-address */
+	if ((d->name[0] != 1 \|\| d->name[1] != '*')
+	&& !strncmp(d->rip + 1, (char*)qs + 1, strlen(d->rip)-1)
+	) {
	strcpy((char *)as, d->name);
	return 0;
	}
@@ -188,7 +185,7 @@ static int table_lookup(uint16_t type, uint8_t * as, uint8_t * qs)
	/*
	* Decode message and generate answer
	*/
-	static int process_packet(uint8_t *buf)
+	static int process_packet(struct dns_entry conf_data, uint32_t conf_ttl, uint8_t buf)
	{
	uint8_t answstr[MAX_NAME_LEN + 1];
	struct dns_head *head;
@@ -240,7 +237,7 @@ static int process_packet(uint8_t *buf)

	// We have a standard query
	bb_info_msg("%s", (char *)from);
-	lookup_result = table_lookup(type, answstr, from);
+	lookup_result = table_lookup(conf_data, type, answstr, from);
	if (lookup_result != 0) {
	outr_flags = 3 \| 0x0400; // name do not exist and auth
	goto empty_packet;
@@ -267,7 +264,7 @@ static int process_packet(uint8_t *buf)

	// and append answer rr
	// FIXME: unaligned accesses??
-	(uint32_t ) answb = htonl(ttl);
+	(uint32_t ) answb = htonl(conf_ttl);
	answb += 4;
	(uint16_t ) answb = htons(outr_rlen);
	answb += 2;
@@ -290,49 +287,48 @@ static int process_packet(uint8_t *buf)
	/*
	* Exit on signal
	*/
-	static void interrupt(int sig)
-	{
-	/* unlink("/var/run/dnsd.lock"); */
-	bb_error_msg("interrupt, exiting\n");
-	kill_myself_with_sig(sig);
-	}
+	//static void interrupt(int sig)
+	//{
+	// /* unlink("/var/run/dnsd.lock"); */
+	// bb_error_msg("interrupt, exiting\n");
+	// kill_myself_with_sig(sig);
+	//}

	int dnsd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
	int dnsd_main(int argc UNUSED_PARAM, char **argv)
	{
	const char *listen_interface = "0.0.0.0";
+	const char *fileconf = "/etc/dnsd.conf";
+	struct dns_entry *conf_data;
+	uint32_t conf_ttl = DEFAULT_TTL;
	char sttl, sport;
	len_and_sockaddr lsa, from, *to;
	unsigned lsa_size;
-	int udps;
+	int udps, opts;
	uint16_t port = 53;
	/* Paranoid sizing: querystring x2 + ttl + outr_rlen + answstr */
	/* I'd rather see process_packet() fixed instead... */
	uint8_t buf[MAX_PACK_LEN * 2 + 4 + 2 + (MAX_NAME_LEN+1)];

-	getopt32(argv, "i:c:t:p:dv", &listen_interface, &fileconf, &sttl, &sport);
-	//if (option_mask32 & 0x1) // -i
-	//if (option_mask32 & 0x2) // -c
-	if (option_mask32 & 0x4) // -t
-	ttl = xatou_range(sttl, 1, 0xffffffff);
-	if (option_mask32 & 0x8) // -p
+	opts = getopt32(argv, "vi:c:t:p:d", &listen_interface, &fileconf, &sttl, &sport);
+	//if (opts & 0x1) // -v
+	//if (opts & 0x2) // -i
+	//if (opts & 0x4) // -c
+	if (opts & 0x8) // -t
+	conf_ttl = xatou_range(sttl, 1, 0xffffffff);
+	if (opts & 0x10) // -p
	port = xatou_range(sport, 1, 0xffff);
-
-	if (OPT_verbose) {
-	bb_info_msg("listen_interface: %s", listen_interface);
-	bb_info_msg("ttl: %d, port: %d", ttl, port);
-	bb_info_msg("fileconf: %s", fileconf);
-	}
-
-	if (OPT_daemon) {
+	if (opts & 0x20) { // -d
	bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS, argv);
	openlog(applet_name, LOG_PID, LOG_DAEMON);
	logmode = LOGMODE_SYSLOG;
	}
+	/* Clear all except "verbose" bit */
+	option_mask32 &= 1;

-	dnsentryinit();
+	conf_data = parse_conf_file(fileconf);

-	signal(SIGINT, interrupt);
+	// signal(SIGINT, interrupt); - just for one message?
	bb_signals(0
	/* why? + (1 << SIGPIPE) */
	+ (1 << SIGHUP)
@@ -371,7 +367,7 @@ int dnsd_main(int argc UNUSED_PARAM, char **argv)
	if (OPT_verbose)
	bb_info_msg("Got UDP packet");
	buf[r] = '\0'; /* paranoia */
-	r = process_packet(buf);
+	r = process_packet(conf_data, conf_ttl, buf);
	if (r <= 0)
	continue;
	send_to_from(udps, buf, r, 0, &from->u.sa, &to->u.sa, lsa->len);

networking/inetd.c+1 -1

@@ -1299,7 +1299,7 @@ int inetd_main(int argc UNUSED_PARAM, char **argv)
	if (sep->se_builtin) {
	if (pid) { /* "pid" is -1: we did vfork */
	close(sep->se_fd); /* listening socket */
-	logmode = 0; /* make xwrite etc silent */
+	logmode = LOGMODE_NONE; /* make xwrite etc silent */
	}
	restore_sigmask(&omask);
	if (sep->se_socktype == SOCK_STREAM)

networking/nameif.c+3 -1

@@ -144,7 +144,9 @@ int nameif_main(int argc, char **argv)

	if (1 & getopt32(argv, "sc:", &fname)) {
	openlog(applet_name, 0, LOG_LOCAL0);
-	logmode = LOGMODE_SYSLOG;
+	/* Why not just "="? I assume logging to stderr
+	* can't hurt. 2>/dev/null if you don't like it: */
+	logmode \|= LOGMODE_SYSLOG;
	}
	argc -= optind;
	argv += optind;

networking/udhcp/dhcpc.c+1 -1

@@ -280,7 +280,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
	/* on NOMMU reexec (i.e., background) early */
	if (!(opt & OPT_f)) {
	bb_daemonize_or_rexec(0 /* flags */, argv);
-	logmode = 0;
+	logmode = LOGMODE_NONE;
	}
	#endif
	if (opt & OPT_S) {

networking/udhcp/dhcpd.c+1 -3

@@ -46,12 +46,10 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)

	opt = getopt32(argv, "fS" USE_FEATURE_UDHCP_PORT("P:", &str_P));
	argv += optind;
-
	if (!(opt & 1)) { /* no -f */
	bb_daemonize_or_rexec(0, argv);
-	logmode &= ~LOGMODE_STDIO;
+	logmode = LOGMODE_NONE;
	}
-
	if (opt & 2) { /* -S */
	openlog(applet_name, LOG_PID, LOG_DAEMON);
	logmode \|= LOGMODE_SYSLOG;

networking/udhcp/socket.c+1 -1

@@ -57,7 +57,7 @@ int FAST_FUNC udhcp_read_interface(const char interface, int ifindex, uint32_t
	}
	our_ip = (struct sockaddr_in *) &ifr.ifr_addr;
	*addr = our_ip->sin_addr.s_addr;
-	DEBUG("%s (our ip) = %s", ifr.ifr_name, inet_ntoa(our_ip->sin_addr));
+	DEBUG("ip of %s = %s", interface, inet_ntoa(our_ip->sin_addr));
	}

	if (ifindex) {