Introduce to the !program specification a capability similar to the one

that already exists for hosts: being able to specify a section that applies
to every program *except* the one in question.

The normal syntax for program specification is still valid. For the new
capability, one uses:

!-program

Since there is no way to specify a program beginning with a dash in the old
syntax, as it would be interpreted as the case above, the following
alternative syntax to the original capability is provided:

!+program

This shouldn't introduce incompatibilities with any syslogd configuration
in production because -stable's syslogd does not support a dash anywhere in
the program specification.

MFC after:	2 weeks

2 files changed, 25 insertions, 2 deletions

diff --git a/usr.sbin/syslogd/syslog.conf.5 b/usr.sbin/syslogd/syslog.conf.5
index 18579a3..099b9cb 100644
--- a/usr.sbin/syslogd/syslog.conf.5
+++ b/usr.sbin/syslogd/syslog.conf.5
@@ -185,6 +185,17 @@ specification for
 .Ql foo
 will also match any message logged by the kernel with the prefix
 .Ql "foo: " .
+The
+.Ql #!+prog
+or
+.Ql !+prog
+specification works just like the previous one,
+and the
+.Ql #!-prog
+or
+.Ql !-prog
+specification will match any message but the ones from that
+program.
 A
 .Em hostname
 specification of the form
diff --git a/usr.sbin/syslogd/syslogd.c b/usr.sbin/syslogd/syslogd.c
index 999254a..c3887ac 100644
--- a/usr.sbin/syslogd/syslogd.c
+++ b/usr.sbin/syslogd/syslogd.c
@@ -853,8 +853,20 @@ logmsg(int pri, const char *msg, const char *from, int flags)
 
 		/* skip messages with the incorrect program name */
 		if (f->f_program)
-			if (strcmp(prog, f->f_program) != 0)
-				continue;
+			switch (f->f_program[0]) {
+			case '+':
+				if (strcmp(prog, f->f_program + 1) != 0)
+					continue;
+				break;
+			case '-':
+				if (strcmp(prog, f->f_program + 1) == 0)
+					continue;
+				break;
+			default:
+				if (strcmp(prog, f->f_program) != 0)
+					continue;
+				break;
+			}
 
 		if (f->f_type == F_CONSOLE && (flags & IGN_CONS))
 			continue;