[src/trunk]: src/usr.sbin/syslogd syslogd: make -d accept an optional argument

[uwe <uwe%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/e4ee79a5536b
branches:  trunk
changeset: 372281:e4ee79a5536b
user:      uwe <uwe%NetBSD.org@localhost>
date:      Tue Nov 08 01:43:09 2022 +0000

description:
syslogd: make -d accept an optional argument

Make it possible to specify the debug message categories with an
optional numeric argument.  You'll have to read the fine source to
find out what they are.  The number can be specified as the usual
decimal, hex (0x), or octal (0) literal with an optional ~negation.

Since syslogd uses getopt(3), not getopt_long(3), do a bit of
gymnastics so that both -d42 and -d 42 are accepted (I'm not inventing
long names for all the existing options just to support an optional
argument to -d).

-d without an argument still uses the old D_DEFAULT selection just in
case someone really relies on that.  You can disable all debug
messages with -d0 but still get syslogd not daemonized.

diffstat:

 usr.sbin/syslogd/syslogd.8 |  24 +++++++++---
 usr.sbin/syslogd/syslogd.c |  92 +++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 104 insertions(+), 12 deletions(-)

diffs (188 lines):

diff -r ad3e1a8ea846 -r e4ee79a5536b usr.sbin/syslogd/syslogd.8
--- a/usr.sbin/syslogd/syslogd.8        Tue Nov 08 01:05:10 2022 +0000
+++ b/usr.sbin/syslogd/syslogd.8        Tue Nov 08 01:43:09 2022 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: syslogd.8,v 1.58 2018/11/05 09:22:30 wiz Exp $
+.\"    $NetBSD: syslogd.8,v 1.59 2022/11/08 01:43:09 uwe Exp $
 .\"
 .\" Copyright (c) 1983, 1986, 1991, 1993
 .\"    The Regents of the University of California.  All rights reserved.
@@ -29,7 +29,7 @@
 .\"
 .\"     from: @(#)syslogd.8    8.1 (Berkeley) 6/6/93
 .\"
-.Dd November 4, 2018
+.Dd November 8, 2022
 .Dt SYSLOGD 8
 .Os
 .Sh NAME
@@ -37,9 +37,10 @@
 .Nd log systems messages
 .Sh SYNOPSIS
 .Nm
-.Op Fl dnrSsTUvX
+.Op Fl nrSsTUvX
 .Op Fl B Ar buffer_length
 .Op Fl b Ar bind_address
+.Op Fl d Op Oo Cm \&~ Oc Ns Ar what
 .Op Fl f Ar config_file
 .Op Fl g Ar group
 .Op Fl m Ar mark_interval
@@ -68,9 +69,20 @@
 Specify one specific IP address or hostname to bind to.
 If a hostname is specified, the IPv4 or IPv6 address
 which corresponds to it is used.
-.It Fl d
-Enable debugging to the standard output,
-and do not disassociate from the controlling terminal.
+.It Fl d Op Oo Cm \&~ Oc Ns Ar what
+Do not disassociate from the controlling terminal and
+enable debugging to the standard output.
+The optional
+.Ar what
+argument is a number that selects which categories of the debug
+messages are to be enabled.
+A tilde
+.Pq Sq Cm \&~
+before
+.Ar what
+inverts its meaning so that all messages except those selected by
+.Ar what
+are enabled.
 .It Fl f Ar config_file
 Specify the pathname of an alternative configuration file;
 the default is
diff -r ad3e1a8ea846 -r e4ee79a5536b usr.sbin/syslogd/syslogd.c
--- a/usr.sbin/syslogd/syslogd.c        Tue Nov 08 01:05:10 2022 +0000
+++ b/usr.sbin/syslogd/syslogd.c        Tue Nov 08 01:43:09 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: syslogd.c,v 1.139 2022/05/20 19:34:23 andvar Exp $     */
+/*     $NetBSD: syslogd.c,v 1.140 2022/11/08 01:43:09 uwe Exp $        */
 
 /*
  * Copyright (c) 1983, 1988, 1993, 1994
@@ -39,7 +39,7 @@
 #if 0
 static char sccsid[] = "@(#)syslogd.c  8.3 (Berkeley) 4/4/94";
 #else
-__RCSID("$NetBSD: syslogd.c,v 1.139 2022/05/20 19:34:23 andvar Exp $");
+__RCSID("$NetBSD: syslogd.c,v 1.140 2022/11/08 01:43:09 uwe Exp $");
 #endif
 #endif /* not lint */
 
@@ -212,6 +212,7 @@
 
 /* init and setup */
 void           usage(void) __attribute__((__noreturn__));
+void           set_debug(const char *);
 void           logpath_add(char ***, int *, int *, const char *);
 void           logpath_fileadd(char ***, int *, int *, const char *);
 void           init(int fd, short event, void *ev);  /* SIGHUP kevent dispatch routine */
@@ -318,7 +319,7 @@
        /* should we set LC_TIME="C" to ensure correct timestamps&parsing? */
        (void)setlocale(LC_ALL, "");
 
-       while ((ch = getopt(argc, argv, "b:B:dnsSf:m:o:p:P:ru:g:t:TUvX")) != -1)
+       while ((ch = getopt(argc, argv, "b:B:d::nsSf:m:o:p:P:ru:g:t:TUvX")) != -1)
                switch(ch) {
                case 'b':
                        bindhostname = optarg;
@@ -329,9 +330,27 @@
                                buflen = RCVBUFLEN;
                        break;
                case 'd':               /* debug */
-                       Debug = D_DEFAULT;
-                       /* is there a way to read the integer value
-                        * for Debug as an optional argument? */
+                       if (optarg != NULL) {
+                               /*
+                                * getopt passes as optarg everything
+                                * after 'd' in -darg, manually accept
+                                * -d=arg too.
+                                */
+                               if (optarg[0] == '=')
+                                       ++optarg;
+                       } else if (optind < argc) {
+                               /*
+                                * :: treats "-d ..." as missing
+                                * optarg, so look ahead manually and
+                                * pick up the next arg if it looks
+                                * like one.
+                                */
+                               if (argv[optind][0] != '-') {
+                                       optarg = argv[optind];
+                                       ++optind;
+                               }
+                       }
+                       set_debug(optarg);
                        break;
                case 'f':               /* configuration file */
                        ConfFile = optarg;
@@ -4875,6 +4894,67 @@
        return tot == 0 ? nw : tot;
 }
 
+
+#ifdef NDEBUG
+/*
+ * -d also controls daemoniziation, so it makes sense even with
+ * NDEBUG, but if the user also tries to specify the logging details
+ * with an argument, warn them it's not compiled into this binary.
+ */
+void
+set_debug(const char *level)
+{
+       Debug = D_DEFAULT;
+       if (level == NULL)
+               return;
+
+       /* don't bother parsing the argument */
+       fprintf(stderr,
+               "%s: debug logging is not compiled\n",
+               getprogname());
+}
+
+#else  /* !NDEBUG */
+void
+set_debug(const char *level)
+{
+       if (level == NULL) {
+               Debug = D_DEFAULT; /* compat */
+               return;
+       }
+
+       /* skip initial whitespace for consistency with strto*l */
+       while (isspace((unsigned char)*level))
+               ++level;
+
+       /* accept ~num to mean "all except num" */
+       bool invert = level[0] == '~';
+       if (invert)
+               ++level;
+
+       errno = 0;
+       char *endp = NULL;
+       unsigned long bits = strtoul(level, &endp, 0);
+       if (errno || endp == level || *endp != '\0') {
+               fprintf(stderr, "%s: bad argument to -d\n", getprogname());
+               usage();
+       }
+       if (invert)
+               bits = ~bits;
+
+       Debug = bits & D_ALL;
+
+       /*
+        * make it possible to use -d to stay in the foreground but
+        * suppress all dbprintf output (there better be free bits in
+        * typeof(Debug) that are not in D_ALL).
+        */
+       if (Debug == 0)
+               Debug = ~D_ALL;
+}
+#endif /* !NDEBUG */
+
+
 #ifndef NDEBUG
 void
 dbprintf(const char *fname, const char *funname,