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

8 files changed, 143 insertions, 58 deletions

diff --git a/docs/logging_and_backgrounding.txt b/docs/logging_and_backgrounding.txt
new file mode 100644
index 000000000..39f015883
--- /dev/null
+++ b/docs/logging_and_backgrounding.txt
@@ -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)
diff --git a/miscutils/crond.c b/miscutils/crond.c
index 767aa120a..2e158bcf0 100644
--- a/miscutils/crond.c
+++ b/miscutils/crond.c
@@ -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);
                 }
diff --git a/networking/dnsd.c b/networking/dnsd.c
index 434903fe1..f95ba6b40 100644
--- a/networking/dnsd.c
+++ b/networking/dnsd.c
@@ -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);
diff --git a/networking/inetd.c b/networking/inetd.c
index bf018d774..72d51010e 100644
--- a/networking/inetd.c
+++ b/networking/inetd.c
@@ -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)
diff --git a/networking/nameif.c b/networking/nameif.c
index 4d68c8d63..fb31fbfff 100644
--- a/networking/nameif.c
+++ b/networking/nameif.c
@@ -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;
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 903f3d326..e9f99e39c 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -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) {
diff --git a/networking/udhcp/dhcpd.c b/networking/udhcp/dhcpd.c
index 15b31eb3d..a82fd8c47 100644
--- a/networking/udhcp/dhcpd.c
+++ b/networking/udhcp/dhcpd.c
@@ -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;
diff --git a/networking/udhcp/socket.c b/networking/udhcp/socket.c
index fdb558db4..edf4355b5 100644
--- a/networking/udhcp/socket.c
+++ b/networking/udhcp/socket.c
@@ -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) {