--- /dev/null
+ 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)
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)
/*
/*
* 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])
/*
* 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;
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;
}
/*
* 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;
// 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;
// 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;
/*
* 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)
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);
projects / platform / upstream / busybox.git / commitdiff