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 function old new delta udhcp_read_interface 308 306 -2 ttl 4 - -4 fileconf 4 - -4 dnsentry 4 - -4 interrupt 19 - -19 dnsd_main 1463 1394 -69 ------------------------------------------------------------------------------ (add/remove: 0/4 grow/shrink: 0/2 up/down: 0/-102) Total: -102 bytes text data bss dec hex filename 808161 476 7864 816501 c7575 busybox_old 807994 468 7856 816318 c74be busybox_unstripped
This commit is contained in:
Denis Vlasenko
parent
4774179cb9
commit
a19e64933c
89
docs/logging_and_backgrounding.txt
Normal file
89
docs/logging_and_backgrounding.txt
Normal file
@ -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)
|
||||
@ -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);
|
||||
}
|
||||
|
||||
@ -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);
|
||||
|
||||
@ -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)
|
||||
|
||||
@ -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;
|
||||
|
||||
@ -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) {
|
||||
|
||||
@ -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;
|
||||
|
||||
@ -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) {
|
||||
|
||||
Loading…
Reference in New Issue
Block a user