X-Git-Url: https://git.distorted.org.uk/~mdw/fwd/blobdiff_plain/d857515ea12cdb08062bd60a2eca04908622f55c..372a98e2893234a482e59ca32313db1bb86146d7:/fw.1

diff --git a/fw.1 b/fw.1
index 6125c4f..878ad3a 100644
--- a/fw.1
+++ b/fw.1
@@ -1,6 +1,6 @@
 .\" -*-nroff-*-
 .\"
-.\" $Id: fw.1,v 1.7 1999/10/22 22:45:15 mdw Exp $
+.\" $Id: fw.1,v 1.10 2001/02/03 20:30:03 mdw Exp $
 .\"
 .\" Manual page for fw
 .\"
@@ -28,6 +28,16 @@
 .\" ---- Revision history ---------------------------------------------------
 .\" 
 .\" $Log: fw.1,v $
+.\" Revision 1.10  2001/02/03 20:30:03  mdw
+.\" Support re-reading config files on SIGHUP.
+.\"
+.\" Revision 1.9  2000/03/23 00:37:33  mdw
+.\" Add option to change user and group after initialization.  Naughtily
+.\" reassign short equivalents of --grammar and --options.
+.\"
+.\" Revision 1.8  1999/12/22 15:44:43  mdw
+.\" Fix some errors, and document new option.
+.\"
 .\" Revision 1.7  1999/10/22 22:45:15  mdw
 .\" Describe new socket connection options.
 .\"
@@ -123,9 +133,13 @@ fw \- port forwarder
 .SH SYNOPSIS
 .
 .B fw
-.RB [ \-dq ]
+.RB [ \-dlq ]
 .RB [ \-f
 .IR file ]
+.RB [ \-s
+.IR user ]
+.RB [ \-g
+.IR group ]
 .IR config-stmt ...
 .
 .\"--------------------------------------------------------------------------
@@ -172,6 +186,14 @@ Writes the version number to standard output and exits successfully.
 .B "\-u, \-\-usage"
 Writes a terse usage summary to standard output and exits successfully.
 .TP
+.B "\-G, \-\-grammar"
+Writes a summary of the configuration file grammar to standard output
+and exits successfully.
+.TP
+.B "\-O, \-\-options"
+Writes a summary of the source and target options to standard output and
+exits successfully.
+.TP
 .BI "\-f, \-\-file=" file
 Read configuration information from
 .IR file .
@@ -184,10 +206,27 @@ configuration file statement.
 Forks into the background after reading the configuration and
 initializing properly.
 .TP
-.B "-q, \-\-quiet"
+.B "\-l, \-\-syslog, \-\-log"
+Emit logging information to the system log, rather than standard error.
+.TP
+.B "\-q, \-\-quiet"
 Don't output any logging information.  This option is not recommended
 for normal use, although it can make system call traces clearer so I use
 it when debugging.
+.TP
+.BI "\-s, \-\-setuid=" user
+Change uid to that of
+.IR user ,
+which may be either a user name or uid number, after initializing all
+the sources.  This will usually require elevated privileges.
+.TP
+.BI "\-g, \-\-setgid=" group
+Change gid to that of
+.IR group ,
+which may be either a group name or gid number, after initializing all
+the sources.  If the operating system understands supplementary groups
+then the supplementary groups list is altered to include only
+.IR group .
 .PP
 Any further command line arguments are interpreted as configuration
 lines to be read.  Configuration supplied in command line arguments has
@@ -234,8 +273,8 @@ are self-delimiting.  Note that while some characters, e.g.,
 .RB ` [ '
 and
 .RB ` ; ',
-require escaping by the shell, they are strictly optional in the grammar
-and can be omitted in quick hacks at the shell prompt.
+require escaping by the shell, they are mostly optional in the grammar
+and can tend to be omitted in quick hacks at the shell prompt.
 .TP
 .I "whitespace characters"
 Whitespace characters separate words but are otherwise ignored.  All
@@ -782,13 +821,10 @@ are accepted in place of
 Sets the root directory for the program, using the
 .BR chroot (2)
 system call.  You must be the superuser for this option to work.  The
-default is not to set a root directory.  The synonyms
-.BR cd ,
-.B chdir
-and
-.B cwd
-are accepted in place of
-.B dir .
+default is not to set a root directory.  The synonym
+.B chroot
+is accepted in place of
+.BR root .
 .OE
 .OS "Exec options"
 .B exec.user
@@ -1064,7 +1100,9 @@ options to control the attributes of the socket file created.
 Sockets are removed if
 .B fw
 exits normally (which it will do if it runs out of sources or
-connections, or if killed by SIGINT or SIGTERM).
+connections, or if
+.B fw
+shuts down in a clean way).
 .SH "EXAMPLES"
 To forward the local port 25 to a main mail server:
 .VS
@@ -1086,6 +1124,49 @@ from stdin, null to null, stdout
 .VE
 .
 .\"--------------------------------------------------------------------------
+.SH "SIGNAL HANDLING"
+.
+The
+.B fw
+program responds to various signals when it's running.  If it receives
+.B SIGTERM
+or
+.BR SIGINT ,
+.B fw
+performs a
+.I graceful
+shutdown: it removes all of its sources, and will exit when no more
+connections are running.  (Note that if the disposition
+.B SIGINT
+was to ignore it,
+.B fw
+does not re-enable the signal.  You'll have to send
+.B SIGTERM
+in that case.)  If
+.B fw
+receives
+.BR SIGQUIT ,
+it performs an
+.I abrupt
+shutdown: it removes all sources and extant connections and closes down
+more-or-less immediately.
+.PP
+Finally, if any configuration files (other than standard input) were
+provided to
+.B fw
+on its command line using the
+.B \-f
+option, a
+.B SIGHUP
+signal may be sent to instruct
+.B fw
+to reload its configuration.  Any existing connections are allowed to
+run their course.  If no such configuration files are available,
+.B fw
+just logs a message about the signal and continues.
+.PP
+.
+.\"--------------------------------------------------------------------------
 .SH "GRAMMAR SUMMARY"
 .
 .SS "Basic syntax"