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Date: Mon, 29 May 2000 22:22:31 -0400
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 $BKY@n$G$9!#(B

 4.0-RELEASE $B$X8~$1$F$N:9J,E,MQ0MMj$G$9!#(B

 grep.1, sed.1, ipfw.8 $B$r(B 4.0-RELEASE $BBP1~$K$7$F$$$?$@$-$?$/!#(B
 o $BC4Ev@k8@$O(B man-jp@jp.FreeBSD.org $B08$K$*4j$$$7$^$9!#(B
 o $B40N;$7$?$i!"(B
   - $B:9J,$r(B man-jp-reviewer@jp.FreeBSD.org $B08$K(B
   - $BA4J8$r(B horikawa@jp.FreeBSD.org $B08$K!"(B
   $B$=$l$>$lAw$C$F$/$@$5$$!#(B

1. $B1QJ8:9J,(B ($BE:IU(B)
2. $BOBJ8(B 4.0-20000127-CURRENT
   (ftp://daemon.jp.FreeBSD.org/pub/FreeBSD-jp/man-jp/work/jpman-4.0-20000127-CURRENT/man
    $B$+$i<h$l$^$9(B)
3. $B1QJ8(B 4.0-RELEASE
   (ftp://daemon.jp.FreeBSD.org/pub/FreeBSD-jp/man-jp/work/fbsd-400r/man 
    $B$+$i$b<h$l$^$9(B)
4. $B1QJ8(B 4.0-20000127-CURRENT
   (ftp://daemon.jp.FreeBSD.org/pub/FreeBSD-jp/man-jp/work/fbsd-4.0-20000127-CURRENT/man
    $B$+$i<h$l$^$9(B)

# ipfw.8 $B$O2~9T0LCV$@$1$NJQ99$b7k9=B?$$$+$b$7$l$^$;$s!#(B
--
$BKY@nOBM:(B
diff -urNP /home/horikawa/man-jp/work/fbsd-4.0-20000127-CURRENT/man/man1/grep.1 man1/grep.1
--- /home/horikawa/man-jp/work/fbsd-4.0-20000127-CURRENT/man/man1/grep.1	Thu Jan 27 23:31:50 2000
+++ man1/grep.1	Tue Mar 21 06:29:05 2000
@@ -1,5 +1,5 @@
 .\" grep man page
-.\" %FreeBSD: src/gnu/usr.bin/grep/grep.1,v 1.15 2000/01/18 09:46:39 ru Exp %
+.\" %FreeBSD: src/gnu/usr.bin/grep/grep.1,v 1.16 2000/01/31 13:28:56 ru Exp %
 .if !\n(.g \{\
 .	if !\w|\*(lq| \{\
 .		ds lq ``
@@ -13,93 +13,39 @@
 .de Id
 .ds Dt \\$4
 ..
-.Id %Id: grep.1,v 1.8 2000/01/17 00:55:06 alainm Exp %
+.Id %Id: grep.1,v 1.9 2000/01/26 03:42:16 alainm Exp %
 .TH GREP 1 \*(Dt "GNU Project"
 .SH NAME
 grep, egrep, fgrep, zgrep \- print lines matching a pattern
 .SH SYNOPSIS
 .B grep
-.RB [ \- [ ABC ]
-.IR NUM ]
-.RB [ \-EFGHLUVZabchilnqrsuvwxyz ]
+.RI [ options ]
+.I PATTERN
+.RI [ FILE .\|.\|.]
+.br
+.B grep
+.RI [ options ]
 .RB [ \-e
 .I PATTERN
 |
 .B \-f
 .IR FILE ]
-.RB [ \-d
-.IR ACTION ]
-.RB [ \-\^\-binary-files=\fITYPE\fP ]
-.RB [ \-\^\-directories=\fIACTION\fP ]
-.RB [ \-\^\-extended-regexp ]
-.RB [ \-\^\-fixed-strings ]
-.RB [ \-\^\-basic-regexp ]
-.RB [ \-\^\-regexp=\fIPATTERN\fP ]
-.RB [ \-\^\-file=\fIFILE\fP ]
-.RB [ \-\^\-ignore-case ]
-.RB [ \-\^\-word-regexp ]
-.RB [ \-\^\-line-regexp ]
-.RB [ \-\^\-line-regexp ]
-.RB [ \-\^\-no-messages ]
-.RB [ \-\^\-invert-match ]
-.RB [ \-\^\-version ]
-.RB [ \-\^\-help ]
-.RB [ \-\^\-byte-offset ]
-.RB [ \-\^\-line-number ]
-.RB [ \-\^\-with-filename ]
-.RB [ \-\^\-no-filename ]
-.RB [ \-\^\-quiet ]
-.RB [ \-\^\-silent ]
-.RB [ \-\^\-text ]
-.RB [ \-\^\-files-without-match ]
-.RB [ \-\^\-files-with-matches ]
-.RB [ \-\^\-count ]
-.RB [ \-\^\-before-context=\fINUM\fP ]
-.RB [ \-\^\-after-context=\fINUM\fP ]
-.RB [ \-\^\-context [ =\fINUM\fP ]]
-.RB [ \-\^\-binary ]
-.RB [ \-\^\-unix-byte-offsets ]
-.RB [ \-\^\-mmap ]
-.RB [ \-\^\-null ]
-.RB [ \-\^\-recursive ]
-.RB [ \-\^\-decompress ]
-.RI [ file .\|.\|.]
+.RI [ FILE .\|.\|.]
 .SH DESCRIPTION
 .PP
 .B grep
 searches the named input
-.I files
+.IR FILE s
 (or standard input if no files are named, or
 the file name
 .B \-
 is given)
 for lines containing a match to the given
-.IR pattern .
+.IR PATTERN .
 By default,
 .B grep
 prints the matching lines.
 .PP
-There are three major variants of
-.BR grep ,
-controlled by the following options.
-.PD 0
-.TP
-.BR \-G ", " \-\^\-basic-regexp
-Interpret
-.I pattern
-as a basic regular expression (see below).  This is the default.
-.TP
-.BR \-E ", " \-\^\-extended-regexp
-Interpret
-.I pattern
-as an extended regular expression (see below).
-.TP
-.BR \-F ", " \-\^\-fixed-strings
-Interpret
-.I pattern
-as a list of fixed strings, separated by newlines,
-any of which is to be matched.
-.PP
 In addition, two variant programs
 .B egrep
 and
@@ -114,40 +60,31 @@
 .B zgrep
 is the same as
 .BR "grep\ \-Z" .
-.PD
-.PP
-All variants of
-.B grep
-understand the following options:
-.PD 0
+.SH OPTIONS
 .TP
 .BI \-A " NUM" "\fR,\fP \-\^\-after-context=" NUM
 Print
 .I NUM
 lines of trailing context after matching lines.
 .TP
+.BR \-a ", " \-\^\-text
+Process a binary file as if it were text; this is equivalent to the
+.B \-\^\-binary-files=text
+option.
+.TP
 .BI \-B " NUM" "\fR,\fP \-\^\-before-context=" NUM
 Print
 .I NUM
 lines of leading context before matching lines.
 .TP
-.BI \-C " \fR[\fPNUM\fR]\fP" "\fR,\fP \-\^\-context\fR[\fP=" NUM\fR]\fP
+\fB\-C\fP [\fINUM\fP], \fB\-\fP\fINUM\fP, \fB\-\^\-context\fP[\fB=\fP\fINUM\fP]
 Print
 .I NUM
 lines (default 2) of output context.
 .TP
-.BI \- NUM
-Same as
-.BI \-\^\-context= NUM
-lines of leading and trailing context.  However,
-.B grep
-will never print any given line more than once.
-.TP
-.BR \-V ", " \-\^\-version
-Print the version number of
-.B grep
-to standard error.  This version number should
-be included in all bug reports (see below).
+.BR \-b ", " \-\^\-byte-offset
+Print the byte offset within the input file before
+each line of output.
 .TP
 .BI \-\^\-binary-files= TYPE
 If the first few bytes of a file indicate that the file contains binary
@@ -167,7 +104,9 @@
 is
 .BR without-match ,
 .B grep
-assumes that a binary file does not match.
+assumes that a binary file does not match; this is equivalent to the 
+.B \-I
+option.
 If
 .I TYPE
 is
@@ -175,8 +114,6 @@
 .B grep
 processes a binary file as if it were text; this is equivalent to the
 .B \-a
-or
-.B \-\^\-text
 option.
 .I Warning:
 .B "grep \-\^\-binary-files=text"
@@ -184,10 +121,6 @@
 which can have nasty side effects if the output is a terminal and if the
 terminal driver interprets some of it as commands.
 .TP
-.BR \-b ", " \-\^\-byte-offset
-Print the byte offset within the input file before
-each line of output.
-.TP
 .BR \-c ", " \-\^\-count
 Suppress normal output; instead print a count of
 matching lines for each input file.
@@ -218,18 +151,34 @@
 .B \-r
 option.
 .TP
+.BR \-E ", " \-\^\-extended-regexp
+Interpret
+.I PATTERN
+as an extended regular expression (see below).
+.TP
 .BI \-e " PATTERN" "\fR,\fP \-\^\-regexp=" PATTERN
 Use
 .I PATTERN
 as the pattern; useful to protect patterns beginning with
 .BR \- .
 .TP
+.BR \-F ", " \-\^\-fixed-strings
+Interpret
+.I PATTERN
+as a list of fixed strings, separated by newlines,
+any of which is to be matched.
+.TP
 .BI \-f " FILE" "\fR,\fP \-\^\-file=" FILE
 Obtain patterns from
 .IR FILE ,
 one per line.
 The empty file contains zero patterns, and therfore matches nothing.
 .TP
+.BR \-G ", " \-\^\-basic-regexp
+Interpret
+.I PATTERN
+as a basic regular expression (see below).  This is the default.
+.TP
 .BR \-H ", " \-\^\-with-filename
 Print the filename for each match.
 .TP
@@ -237,9 +186,18 @@
 Suppress the prefixing of filenames on output
 when multiple files are searched.
 .TP
+.B \-\^\-help
+Output a brief help message.
+.TP
+.BR \-I
+Process a binary file as if it did not contain matching data; this is
+equivalent to the
+.B \-\^\-binary-files=without-match
+option.
+.TP
 .BR \-i ", " \-\^\-ignore-case
 Ignore case distinctions in both the
-.I pattern
+.I PATTERN
 and the input files.
 .TP
 .BR \-L ", " \-\^\-files-without-match
@@ -254,6 +212,21 @@
 would normally have been printed.  The scanning will
 stop on the first match.
 .TP
+.B \-\^\-mmap
+If possible, use the
+.BR mmap (2)
+system call to read input, instead of
+the default
+.BR read (2)
+system call.  In some situations,
+.B \-\^\-mmap
+yields better performance.  However,
+.B \-\^\-mmap
+can cause undefined behavior (including core dumps)
+if an input file shrinks while
+.B grep
+is operating, or if an I/O error occurs.
+.TP
 .BR \-n ", " \-\^\-line-number
 Prefix each line of output with the line number
 within its input file.
@@ -297,29 +270,6 @@
 .B \-s
 and should redirect output to /dev/null instead.
 .TP
-.BR \-a ", " \-\^\-text
-Process a binary file as if it were text; this is equivalent to the
-.B \-\^\-binary-files=text
-option.
-.TP
-.BR \-v ", " \-\^\-invert-match
-Invert the sense of matching, to select non-matching lines.
-.TP
-.BR \-w ", " \-\^\-word-regexp
-Select only those lines containing matches that form whole words.
-The test is that the matching substring must either be at the
-beginning of the line, or preceded by a non-word constituent
-character.  Similarly, it must be either at the end of the line
-or followed by a non-word constituent character.  Word-constituent
-characters are letters, digits, and the underscore.
-.TP
-.BR \-x ", " \-\^\-line-regexp
-Select only those matches that exactly match the whole line.
-.TP
-.B \-y
-Obsolete synonym for
-.BR \-i .
-.TP
 .BR \-U ", " \-\^\-binary
 Treat the file(s) as binary.  By default, under MS-DOS and MS-Windows,
 .BR grep
@@ -351,20 +301,29 @@
 option is also used;
 it has no effect on platforms other than MS-DOS and MS-Windows.
 .TP
-.B \-\^\-mmap
-If possible, use the
-.BR mmap (2)
-system call to read input, instead of
-the default
-.BR read (2)
-system call.  In some situations,
-.B \-\^\-mmap
-yields better performance.  However,
-.B \-\^\-mmap
-can cause undefined behavior (including core dumps)
-if an input file shrinks while
+.BR \-V ", " \-\^\-version
+Print the version number of
 .B grep
-is operating, or if an I/O error occurs.
+to standard error.  This version number should
+be included in all bug reports (see below).
+.TP
+.BR \-v ", " \-\^\-invert-match
+Invert the sense of matching, to select non-matching lines.
+.TP
+.BR \-w ", " \-\^\-word-regexp
+Select only those lines containing matches that form whole words.
+The test is that the matching substring must either be at the
+beginning of the line, or preceded by a non-word constituent
+character.  Similarly, it must be either at the end of the line
+or followed by a non-word constituent character.  Word-constituent
+characters are letters, digits, and the underscore.
+.TP
+.BR \-x ", " \-\^\-line-regexp
+Select only those matches that exactly match the whole line.
+.TP
+.B \-y
+Obsolete synonym for
+.BR \-i .
 .TP
 .BR \-Z ", " \-\^\-null
 Output a zero byte (the \s-1ASCII\s0
@@ -383,14 +342,10 @@
 .B "xargs \-0"
 to process arbitrary file names,
 even those that contain newline characters.
-.PD
-.LP
-Following option is only available if compiled with zlib(3) library:
-.PD 0
 .TP
-.B \-Z, --decompress
+.BR \-Z ", " \-\^\-decompress
 Decompress the input data before searching.
-.PD
+This option is only available if compiled with zlib(3) library.
 .SH "REGULAR EXPRESSIONS"
 .PP
 A regular expression is a pattern that describes a set of strings.
@@ -424,7 +379,7 @@
 in the list.
 For example, the regular expression
 .B [0123456789]
-matches any single digit.  A range of ASCII characters
+matches any single digit.  A range of characters
 may be specified by giving the first and last characters, separated
 by a hyphen.
 Finally, certain named classes of characters are predefined.
@@ -445,8 +400,9 @@
 .B [[:alnum:]]
 means
 .BR [0-9A-Za-z] ,
-except the latter form is dependent upon the ASCII character encoding,
-whereas the former is portable.
+except the latter form depends upon the \s-1POSIX\s0 locale and the
+\s-1ASCII\s0 character encoding, whereas the former is independent
+of locale and character set.
 (Note that the brackets in these class names are part of the symbolic
 names, and must be included in addition to the brackets delimiting
 the bracket list.)  Most metacharacters lose their special meaning
@@ -590,14 +546,84 @@
 instead of reporting a syntax error in the regular expression.
 \s-1POSIX.2\s0 allows this behavior as an extension, but portable scripts
 should avoid it.
-.SH ENVIRONMENT
-The environment variable
+.SH "ENVIRONMENT VARIABLES"
+.TP
 .B GREP_OPTIONS
-can hold a set of default
-options for
-.I grep.
-These options are interpreted first and can be overwritten by explicit command
-line parameters.
+This variable specifies default options to be placed in front of any
+explicit options.  For example, if
+.B GREP_OPTIONS
+is
+.BR "'\-\^\-binary-files=without-match \-\^\-directories=skip'" ,
+.B grep
+behaves as if the two options
+.B \-\^\-binary-files=without-match
+and
+.B \-\^\-directories=skip
+had been specified before any explicit options.
+Option specifications are separated by whitespace.
+A backslash escapes the next character,
+so it can be used to specify an option containing whitespace or a backslash.
+.TP
+\fBLC_ALL\fP, \fBLC_MESSAGES\fP, \fBLANG\fP
+These variables specify the
+.B LC_MESSAGES
+locale, which determines the language that
+.B grep
+uses for messages.
+The locale is determined by the first of these variables that is set.
+American English is used if none of these environment variables are set,
+or if the message catalog is not installed, or if
+.B grep
+was not compiled with national language support (\s-1NLS\s0).
+.TP
+\fBLC_ALL\fP, \fBLC_CTYPE\fP, \fBLANG\fP
+These variables specify the
+.B LC_CTYPE
+locale, which determines the type of characters, e.g., which
+characters are whitespace.
+The locale is determined by the first of these variables that is set.
+The \s-1POSIX\s0 locale is used if none of these environment variables
+are set, or if the locale catalog is not installed, or if
+.B grep
+was not compiled with national language support (\s-1NLS\s0).
+.TP
+.B POSIXLY_CORRECT
+If set,
+.B grep
+behaves as \s-1POSIX.2\s0 requires; otherwise,
+.B grep
+behaves more like other \s-1GNU\s0 programs.
+\s-1POSIX.2\s0 requires that options that follow file names must be
+treated as file names; by default, such options are permuted to the
+front of the operand list and are treated as options.
+Also, \s-1POSIX.2\s0 requires that unrecognized options be diagnosed as
+\*(lqillegal\*(rq, but since they are not really against the law the default
+is to diagnose them as \*(lqinvalid\*(rq.
+.B POSIXLY_CORRECT
+also disables \fB_\fP\fIN\fP\fB_GNU_nonoption_argv_flags_\fP,
+described below.
+.TP
+\fB_\fP\fIN\fP\fB_GNU_nonoption_argv_flags_\fP
+(Here
+.I N
+is
+.BR grep 's
+numeric process ID.)  If the
+.IR i th
+character of this environment variable's value is
+.BR 1 ,
+do not consider the
+.IR i th
+operand of
+.B grep
+to be an option, even if it appears to be one.
+A shell can put this variable in the environment for each command it runs,
+specifying which operands are the results of file name wildcard
+expansion and therefore should not be treated as options.
+This behavior is available only with the \s-1GNU\s0 C library, and only
+when
+.B POSIXLY_CORRECT
+is not set.
 .SH DIAGNOSTICS
 .PP
 Normally, exit status is 0 if matches were found,
diff -urNP /home/horikawa/man-jp/work/fbsd-4.0-20000127-CURRENT/man/man1/sed.1 man1/sed.1
--- /home/horikawa/man-jp/work/fbsd-4.0-20000127-CURRENT/man/man1/sed.1	Thu Jan 27 23:36:31 2000
+++ man1/sed.1	Tue Mar 21 06:31:35 2000
@@ -33,7 +33,7 @@
 .\" SUCH DAMAGE.
 .\"
 .\"	@(#)sed.1	8.2 (Berkeley) 12/30/93
-.\" %FreeBSD: src/usr.bin/sed/sed.1,v 1.8 1999/12/29 22:22:32 steve Exp %
+.\" %FreeBSD: src/usr.bin/sed/sed.1,v 1.9 2000/02/15 03:00:47 unfurl Exp %
 .\"
 .Dd December 30, 1993
 .Dt SED 1
@@ -140,12 +140,16 @@
 A command line with one address selects all of the pattern spaces
 that match the address.
 .Pp
-A command line with two addresses selects the inclusive range from
-the first pattern space that matches the first address through the next
-pattern space that matches the second.
-(If the second address is a number less than or equal to the line number
-first selected, only that line is selected.)
-Starting at the first line following the selected range,
+A command line with two addresses selects an inclusive range.  This
+range starts with the first pattern space that matches the first
+address.  The end of the range is the next following pattern space
+that matches the second address.  If the second address is a number
+less than or equal to the line number first selected, only that
+line is selected.  In the case when the second address is a context
+address, sed does not re-match the second address against the
+pattern space that matched the first address.  Starting at the
+first line following the selected range, sed starts looking again
+for the first address.
 .Nm
 starts looking again for the first address.
 .Pp
diff -urNP /home/horikawa/man-jp/work/fbsd-4.0-20000127-CURRENT/man/man8/ipfw.8 man8/ipfw.8
--- /home/horikawa/man-jp/work/fbsd-4.0-20000127-CURRENT/man/man8/ipfw.8	Thu Jan 27 23:34:07 2000
+++ man8/ipfw.8	Tue Mar 21 06:30:10 2000
@@ -1,7 +1,7 @@
 .\"
-.\" %FreeBSD: src/sbin/ipfw/ipfw.8,v 1.61 2000/01/08 11:19:19 luigi Exp %
+.\" %FreeBSD: src/sbin/ipfw/ipfw.8,v 1.63 2000/02/28 15:21:12 ru Exp %
 .\"
-.Dd July 20, 1996
+.Dd February 16, 2000
 .Dt IPFW 8
 .Os FreeBSD
 .Sh NAME
@@ -12,161 +12,218 @@
 .Op Fl q
 .Oo
 .Fl p Ar preproc
-.Op Fl D Ar macro Ns Op Ns =value
+.Oo Fl D
+.Sm off
+.Ar macro
+.Op = Ar value
+.Sm on
+.Oc
 .Op Fl U Ar macro
 .Oc
 .Ar file
 .Nm ipfw
-.Oo
-.Fl f
-|
-.Fl q
-.Oc
-flush
+.Op Fl f | q
+.Cm flush
 .Nm ipfw
-.Oo
-.Fl q
-.Oc
-{zero|resetlog|delete}
+.Op Fl q
+.Es \&{ \&}
+.En Cm zero | resetlog | delete
 .Op Ar number ...
 .Nm ipfw
+.Op Fl s Op Ar field
 .Op Fl aftN
-{list|show}
+.Es \&{ \&}
+.En Cm list | show
 .Op Ar number ...
 .Nm ipfw
-.Oo
-.Fl q
-.Oc
-add
+.Op Fl q
+.Cm add
 .Op Ar number
-.Ar rule-body 
+.Ar rule-body
 .Nm ipfw
-pipe
+.Cm pipe
 .Ar number
-config
+.Cm config
 .Ar pipe-config-options
 .Nm ipfw
-pipe {delete|list|show}
+.Cm pipe
+.Es \&{ \&}
+.En Cm delete | list | show
 .Op Ar number ...
 .Sh DESCRIPTION
 .Nm
-is the user interface for controlling the IPFW firewall and
-.Nm dummynet
-traffic shaper in FreeBSD.
+is the user interface for controlling the
+.Xr ipfirewall 4
+and the
+.Xr dummynet 4
+traffic shaper in
+.Fx .
 .Pp
 Each incoming or outgoing packet is passed through the
 .Nm
-rules. In case a host is acting as a gateway, packets
-forwarded by the gateway are processed by
+rules.
+If host is acting as a gateway, packets forwarded by
+the gateway are processed by
 .Nm
-twice. In case a host is acting as a bridge, packets
-forwarded by the bridge are processed by
+twice.
+In case a host is acting as a bridge, packets forwarded by
+the bridge are processed by
 .Nm
 once.
 .Pp
-A firewall configuration is made of a list of numbered rules, which are
-scanned for each packet until a match is
-found and the relevant action is performed. Depending on the
-action and certain system settings, packets can be reinjected
-into the firewall at the rule after the matching one for further
-processing. All rules apply to all interfaces, so it is
-responsibility of the sysadmin to write the ruleset in such
-a way to minimize the number of checks.
+A firewall configuration is made of a list of numbered rules,
+which is scanned for each packet until a match is found and
+the relevant action is performed.
+Depending on the action and certain system settings, packets
+can be reinjected into the firewall at the rule after the
+matching one for further processing.
+All rules apply to all interfaces, so it is responsibility
+of the system administrator to write the ruleset in such a
+way as to minimize the number of checks.
 .Pp
 A configuration always includes a
-.Ar DEFAULT
+.Em DEFAULT
 rule (numbered 65535) which cannot be modified by the programmer
-and always matches packets. The action associated with the
-default rule can be either
-.Ar deny
+and always matches packets.
+The action associated with the default rule can be either
+.Cm deny
 or
-.Ar allow
+.Cm allow
 depending on how the kernel is configured.
 .Pp
-All rules have a few associated counters: a packet count and
-a byte count, a log count, and a timestamp indicating the time
-of the last match. Counters can be visualized or reset with
+If the ruleset includes one or more rules with the
+.Cm keep-state
+option, then
+.Nm
+assumes a
+.Em stateful
+behaviour, i.e. upon a match will create dynamic rules matching
+the exact parameters (addresses and ports) of the matching packet.
+.Pp
+These dynamic rules, which have a limited lifetime, are checked
+at the first occurrence of a
+.Cm check-state
+or
+.Cm keep-state
+rule, and are typically used to open the firewall on-demand to
+legitimate traffic only.
+See the
+.Sx RULE FORMAT
+and
+.Sx EXAMPLES
+sections below for more information on the stateful behaviour of
+.Nm ipfw .
+.Pp
+All rules (including dynamic ones) have a few associated counters:
+a packet count, a byte count, a log count and a timestamp
+indicating the time of the last match.
+Counters can be displayed or reset with
 .Nm
 commands.
 .Pp
 Rules can be added with the
-.Ar add
+.Cm add
 command; deleted individually with the
-.Ar delete
+.Cm delete
 command, and globally with the
-.Ar flush
-command; visualized, optionally with the content of
-the counters, using the
-.Ar show
+.Cm flush
+command; displayed, optionally with the content of the
+counters, using the
+.Cm show
 and
-.Ar list
-commands. Finally, counters can be reset with the
-.Ar zero
+.Cm list
+commands.
+Finally, counters can be reset with the
+.Cm zero
 and
-.Ar resetlog
+.Cm resetlog
 commands.
 .Pp
 The following options are available:
 .Bl -tag -width indent
 .It Fl a
-While listing, show counter values.  See also 
-.Dq show
+While listing, show counter values.
+See also the
+.Cm show
 command.
 .It Fl f
-Don't ask for confirmation for commands that can cause problems if misused
-(i.e. flush).
-.Ar Note ,
+Don't ask for confirmation for commands that can cause problems
+if misused,
+.No i.e. Cm flush .
+.Em Note ,
 if there is no tty associated with the process, this is implied.
 .It Fl q
-While adding, zeroing, resetlogging or flushing, be quiet about actions (implies
-.Fl f Ns ).
+While
+.Cm add Ns ing ,
+.Cm zero Ns ing ,
+.Cm resetlog Ns ging
+or
+.Cm flush Ns ing ,
+be quiet about actions
+.Po
+implies
+.Fl f
+.Pc .
 This is useful for adjusting rules by executing multiple
 .Nm
 commands in a script
 .Po
 e.g.,
-.Sq sh /etc/rc.firewall
+.Ql sh\ /etc/rc.firewall
 .Pc ,
 or by processing a file of many
-.Nm 
+.Nm
 rules,
-across a remote login session.  If a flush is performed in normal
-(verbose) mode (with the default kernel configuration), it prints a message.
-Because all rules are flushed, the
-message cannot be delivered to the login session.  This causes the
-remote login session to be closed and the remainder of the ruleset is
-not processed.  Access to the console is required to recover.
+across a remote login session.
+If a
+.Cm flush
+is performed in normal (verbose) mode (with the default kernel
+configuration), it prints a message.
+Because all rules are flushed, the message cannot be delivered
+to the login session.
+This causes the remote login session to be closed and the
+remainder of the ruleset is not processed.
+Access to the console is required to recover.
 .It Fl t
 While listing, show last match timestamp.
 .It Fl N
 Try to resolve addresses and service names in output.
+.It Fl s Op Ar field
+While listing pipes, sort according to one of the four
+counters (total and current packets or bytes).
 .El
 .Pp
-To ease configuration, rules can be put into a file which is processed
-using
+To ease configuration, rules can be put into a file which is
+processed using
 .Nm
-as shown in the first synopsis line. The
+as shown in the first synopsis line.
+The
 .Ar file
-will be read line by line and applied as arguments to the 
+will be read line by line and applied as arguments to the
 .Nm
-command.
+utility.
 .Pp
 Optionally, a preprocessor can be specified using
 .Fl p Ar preproc
 where
 .Ar file
-is to be piped through.  Useful preprocessors include
+is to be piped through.
+Useful preprocessors include
 .Xr cpp 1
 and
 .Xr m4 1 .
 If
 .Ar preproc
-doesn't start with a slash as its first character, the usual
+doesn't start with a slash
+.Pq Ql /
+as its first character, the usual
 .Ev PATH
-name search is performed.  Care should be taken with this in environments
-where not all filesystems are mounted (yet) by the time
+name search is performed.
+Care should be taken with this in environments where not all
+filesystems are mounted (yet) by the time
 .Nm
-is being run (e. g. since they are mounted over NFS).  Once
+is being run (e.g. when they are mounted over NFS).
+Once
 .Fl p
 has been specified, optional
 .Fl D
@@ -179,175 +236,195 @@
 .Pp
 The
 .Nm
-.Ar pipe
-commands are used to configure the traffic shaper, as shown in
-the ``TRAFFIC SHAPER CONFIGURATION'' section below.
-.Pp
+.Cm pipe
+commands are used to configure the traffic shaper, as shown in the
+.Sx TRAFFIC SHAPER CONFIGURATION
+section below.
 .Sh RULE FORMAT
 The
 .Nm
-rule format is the following
-.Pp
-.Op prob Ar match_probability
+rule format is the following:
+.Bd -ragged
+.Op Cm prob Ar match_probability
 .Ar action
-.Op log Op Ar logamount Ar number
+.Op Cm log Op Cm logamount Ar number
 .Ar proto
-from
-.Ar src
-to
-.Ar dst
-.Op interface-spec
+.Cm from Ar src
+.Cm to Ar dst
+.Op Ar interface-spec
 .Op Ar options
+.Ed
 .Pp
 Each packet can be filtered based on the following information that is
 associated with it:
 .Pp
-.Bl -tag -offset indent -compact -width xxxx
-.It Transmit and Receive Interface (by name or address)
-.It Direction (Incoming or Outgoing)
-.It Source and Destination IP Address (possibly masked)
-.It Protocol (TCP, UDP, ICMP, etc.)
-.It Source and Destination Port (lists, ranges or masks)
-.It TCP Flags
-.It IP Fragment Flag
-.It IP Options
-.It ICMP Types
-.It User/Group ID of the socket associated with the packet
+.Bl -tag -width "Source and destination IP address" -offset indent -compact
+.It Transmit and receive interface
+(by name or address)
+.It Direction
+(incoming or outgoing)
+.It Source and destination IP address
+(possibly masked)
+.It Protocol
+(TCP, UDP, ICMP, etc.)
+.It Source and destination port
+(lists, ranges or masks)
+.It TCP flags
+.It IP fragment flag
+.It IP options
+.It ICMP types
+.It User/group ID of the socket associated with the packet
 .El
 .Pp
-Note that may be dangerous to filter on the source IP address or
-source TCP/UDP port because either or both could easily be spoofed.
-.Pp
-.Ar prob match_probability
-.Bd -ragged -offset flag
-A match is only declared with the specified
-probability (floating point number between 0 and 1). This can be useful for a number of applications
-such as random packet drop or (in conjunction with
+Note that it may be dangerous to filter on the source IP
+address or source TCP/UDP port because either or both could
+easily be spoofed.
+.Bl -tag -width indent
+.It Cm prob Ar match_probability
+A match is only declared with the specified probability
+(floating point number between 0 and 1).
+This can be useful for a number of applications such as
+random packet drop or
+.Po
+in conjunction with
 .Xr dummynet 4
-) to simulate the effect of multiple paths leading to out-of-order
+.Pc
+to simulate the effect of multiple paths leading to out-of-order
 packet delivery.
-.Ed
-.Pp
-.Ar action :
-.Bl -hang -offset flag -width 1234567890123456
-.It Ar allow
+.It Ar action :
+.Bl -tag -width indent
+.It Cm allow
 Allow packets that match rule.
-The search terminates. Aliases are
-.Ar pass ,
-.Ar permit ,
+The search terminates.
+Aliases are
+.Cm pass ,
+.Cm permit
 and
-.Ar accept .
-.It Ar deny
+.Cm accept .
+.It Cm deny
 Discard packets that match this rule.
 The search terminates.
-.Ar Drop
+.Cm drop
 is an alias for
-.Ar deny .
-.It Ar reject
-(Deprecated.) Discard packets that match this rule, and try to send an ICMP
+.Cm deny .
+.It Cm reject
+.Pq Deprecated .
+Discard packets that match this rule, and try to send an ICMP
 host unreachable notice.
 The search terminates.
-.It Ar unreach code
+.It Cm unreach Ar code
 Discard packets that match this rule, and try to send an ICMP
 unreachable notice with code
 .Ar code ,
 where
 .Ar code
-is a number from zero to 255, or one of these aliases:
-.Ar net ,
-.Ar host ,
-.Ar protocol ,
-.Ar port ,
-.Ar needfrag ,
-.Ar srcfail ,
-.Ar net-unknown ,
-.Ar host-unknown ,
-.Ar isolated ,
-.Ar net-prohib ,
-.Ar host-prohib ,
-.Ar tosnet ,
-.Ar toshost ,
-.Ar filter-prohib ,
-.Ar host-precedence ,
+is a number from 0 to 255, or one of these aliases:
+.Cm net , host , protocol , port ,
+.Cm needfrag , srcfail , net-unknown , host-unknown ,
+.Cm isolated , net-prohib , host-prohib , tosnet ,
+.Cm toshost , filter-prohib , host-precedence
 or
-.Ar precedence-cutoff .
+.Cm precedence-cutoff .
 The search terminates.
-.It Ar reset
-TCP packets only. Discard packets that match this rule,
-and try to send a TCP reset
-.Pq RST
-notice.
+.It Cm reset
+TCP packets only.
+Discard packets that match this rule, and try to send a TCP
+reset (RST) notice.
 The search terminates.
-.It Ar count
+.It Cm count
 Update counters for all packets that match rule.
 The search continues with the next rule.
-.It Ar divert port
+.It Cm check-state
+Checks the packet against the dynamic ruleset.
+If a match is found then the search terminates, otherwise
+we move to the next rule.
+If no
+.Cm check-state
+rule is found, the dynamic ruleset is checked at the first
+.Cm keep-state
+rule.
+.It Cm divert Ar port
 Divert packets that match this rule to the
 .Xr divert 4
 socket bound to port
 .Ar port .
 The search terminates.
-.It Ar tee port
+.It Cm tee Ar port
 Send a copy of packets matching this rule to the
 .Xr divert 4
 socket bound to port
 .Ar port .
 The search terminates and the original packet is accepted
-(but see BUGS below).
-.It Ar fwd ipaddr Op ,port
+.Po
+but see section
+.Sx BUGS
+below
+.Pc .
+.It Cm fwd Ar ipaddr Ns Xo
+.Op , Ns Ar port
+.Xc
 Change the next-hop on matching packets to
 .Ar ipaddr ,
 which can be an IP address in dotted quad or a host name.
 If
 .Ar ipaddr
-is not a directly-reachable address, the route 
-as found in the local routing table for that IP is used
-instead.
+is not a directly-reachable address, the route as found in
+the local routing table for that IP is used instead.
 If
 .Ar ipaddr
-is a local address, then on a packet entering the system from a remote
-host it will be diverted to
+is a local address, then on a packet entering the system
+from a remote host it will be diverted to
 .Ar port
-on the local machine, keeping the local address of the socket set
-to the original IP address the packet was destined for. This is intended
-for use with transparent proxy servers. If the IP is not
-a local address then the port number (if specified) is ignored and
-the rule only applies to packets leaving the system. This will
-also map addresses to local ports when packets are generated locally.
-The search terminates if this rule matches. If the port number is not 
-given then the port number in the packet is used, so that a packet for
-an external machine port Y would be forwarded to local port Y. The kernel
-must have been compiled with options IPFIREWALL_FORWARD.
-.It Ar pipe pipe_nr
+on the local machine, keeping the local address of the socket
+set to the original IP address the packet was destined for.
+This is intended for use with transparent proxy servers.
+If the IP is not a local address then the port number
+(if specified) is ignored and the rule only applies to packets
+leaving the system.
+This will also map addresses to local ports when packets are
+generated locally.
+The search terminates if this rule matches.
+If the port number is not given then the port number in the
+packet is used, so that a packet for an external machine port
+Y would be forwarded to local port Y.
+The kernel must have been compiled with the
+.Dv IPFIREWALL_FORWARD
+option.
+.It Cm pipe Ar pipe_nr
 Pass packet to a
 .Xr dummynet 4
-``pipe'' (for bandwidth limitation, delay etc.). See the
+.Dq pipe
+(for bandwidth limitation, delay, etc.).
+See the
 .Xr dummynet 4
-manpage for further information. The search terminates; however,
-on exit from the pipe and if the sysctl variable
-net.inet.ip.fw.one_pass is not set, the packet is passed again to
-the firewall code starting from the next rule.
-.It Ar skipto number
+manpage for further information.
+The search terminates; however, on exit from the pipe and if
+the
+.Xr sysctl 8
+variable
+.Em net.inet.ip.fw.one_pass
+is not set, the packet is passed again to the firewall code
+starting from the next rule.
+.It Cm skipto Ar number
 Skip all subsequent rules numbered less than
 .Ar number .
 The search continues with the first rule numbered
 .Ar number
 or higher.
 .El
-.Pp
-.Ar log Op Ar logamount Ar number
-.Bd -ragged -offset flag
+.It Cm log Op Cm logamount Ar number
 If the kernel was compiled with
 .Dv IPFIREWALL_VERBOSE ,
 then when a packet matches a rule with the
-.Ar log
+.Cm log
 keyword a message will be printed on the console.
 If the kernel was compiled with the
 .Dv IPFIREWALL_VERBOSE_LIMIT
 option, then by default logging will cease after the number
 of packets specified by the option are received for that
-particular chain entry. However, if
-.Ar logamount Ar number
+particular chain entry.
+However, if
+.Cm logamount Ar number
 is used, that
 .Ar number
 will be the default logging limit rather than
@@ -359,329 +436,395 @@
 through the
 .Xr sysctl 8
 interface in the MIB base of
-.Dv net.inet.ip.fw .
-.Ed
-.Pp
-.Ar proto :
-.Bd -ragged -offset flag
-An IP protocol specified by number or name (see
-.Pa /etc/protocols
-for a complete list).
+.Em net.inet.ip.fw .
+.It Ar proto
+An IP protocol specified by number or name (for a complete
+list see
+.Pa /etc/protocols ) .
 The
-.Ar ip
+.Cm ip
 or
-.Ar all
+.Cm all
 keywords mean any protocol will match.
-.Ed
-.Pp
-.Ar src 
-and
-.Ar dst :
-.Bd -ragged -offset flag
-.Ar <address/mask> Op Ar ports
+.It Ar src No and Ar dst :
+.Aq Ar address Ns / Ns Ar mask
+.Op Ar ports
 .Pp
 The
-.Em <address/mask>
+.Aq Ar address Ns / Ns Ar mask
 may be specified as:
-.Pp
-.Bl -hang -offset 0n -width 1234567890123456
+.Bl -tag -width indent
 .It Ar ipno
-An ipnumber of the form 1.2.3.4.
-Only this exact ip number match the rule.
-.It Ar ipno/bits
-An ipnumber with a mask width of the form 1.2.3.4/24.
-In this case all ip numbers from 1.2.3.0 to 1.2.3.255 will match.
-.It Ar ipno:mask
-An ipnumber with a mask of the form 1.2.3.4:255.255.240.0.
-In this case all ip numbers from 1.2.0.0 to 1.2.15.255 will match.
+An IP number of the form 1.2.3.4.
+Only this exact IP number will match the rule.
+.It Ar ipno Ns / Ns Ar bits
+An IP number with a mask width of the form 1.2.3.4/24.
+In this case all IP numbers from 1.2.3.0 to 1.2.3.255 will match.
+.It Ar ipno Ns : Ns Ar mask
+An IP number with a mask of the form 1.2.3.4:255.255.240.0.
+In this case all IP numbers from 1.2.0.0 to 1.2.15.255 will match.
 .El
 .Pp
 The sense of the match can be inverted by preceding an address with the
-.Dq not
-modifier, causing all other addresses to be matched instead. This
-does not affect the selection of port numbers.
+.Cm not
+modifier, causing all other addresses to be matched instead.
+This does not affect the selection of port numbers.
 .Pp
 With the TCP and UDP protocols, optional
 .Em ports
 may be specified as:
-.Pp
-.Bl -hang -offset flag
-.It Ns {port|port-port|port:mask} Ns Op ,port Ns Op ,...
-.El
+.Bd -ragged -offset indent
+.Sm off
+.Eo \&{
+.Ar port |
+.Ar port No \&- Ar port |
+.Ar port : mask
+.Ec \&} Op , Ar port Op , Ar ...
+.Sm on
+.Ed
 .Pp
 The
-.Ql -
+.Ql \&-
 notation specifies a range of ports (including boundaries).
 .Pp
 The
-.Ql \:
+.Ql \&:
 notation specifies a port and a mask, a match is declared if
 the port number in the packet matches the one in the rule,
 limited to the bits which are set in the mask.
 .Pp
-Service names (from 
+Service names (from
 .Pa /etc/services )
 may be used instead of numeric port values.
-A range may only be specified as the first value,
-and the length of the port list is limited to
+A range may only be specified as the first value, and the
+length of the port list is limited to
 .Dv IP_FW_MAX_PORTS
-(as defined in 
-.Pa /usr/src/sys/netinet/ip_fw.h )
-ports.
-A
-.Ql \e
-can be used to escape the
-.Ql -
+ports (as defined in
+.Pa /usr/src/sys/netinet/ip_fw.h ) .
+A backslash
+.Pq Ql \e
+can be used to escape the dash
+.Pq Ql -
 character in a service name:
 .Pp
-.Dl ipfw add count tcp from any ftp\e\e-data-ftp to any
+.Dl "ipfw add count tcp from any ftp\e\e-data-ftp to any"
 .Pp
 Fragmented packets which have a non-zero offset (i.e. not the first
 fragment) will never match a rule which has one or more port
-specifications.  See the
-.Ar frag
+specifications.
+See the
+.Cm frag
 option for details on matching fragmented packets.
-.Pp
-.Ed
-.Ar interface-spec :
-.Pp
-.Bd -ragged -offset flag
+.It Ar interface-spec
 Some combinations of the following specifiers are allowed:
-.Bl -hang -offset 0n -width 1234567890123456
-.It Ar in
+.Bl -tag -width "via ipno"
+.It Cm in
 Only match incoming packets.
-.It Ar out
+.It Cm out
 Only match outgoing packets.
-.It Ar via ifX
+.It Cm via Ar ifX
 Packet must be going through interface
-.Ar ifX.
-.It Ar via if*
+.Ar ifX .
+.It Cm via Ar if Ns Cm *
 Packet must be going through interface
 .Ar ifX ,
-where X is any unit number.
-.It Ar via any
+where
+.Ar X
+is any unit number.
+.It Cm via any
 Packet must be going through
 .Em some
 interface.
-.It Ar via ipno
+.It Cm via Ar ipno
 Packet must be going through the interface having IP address
 .Ar ipno .
 .El
 .Pp
 The
-.Ar via
+.Cm via
 keyword causes the interface to always be checked.
 If
-.Ar recv
+.Cm recv
 or
-.Ar xmit
+.Cm xmit
 is used instead of
-.Ar via ,
-then the only receive or transmit interface (respectively) is checked.
-By specifying both, it is possible to match packets based on both receive
-and transmit interface, e.g.:
+.Cm via ,
+then the only receive or transmit interface (respectively)
+is checked.
+By specifying both, it is possible to match packets based on
+both receive and transmit interface, e.g.:
 .Pp
 .Dl "ipfw add 100 deny ip from any to any out recv ed0 xmit ed1"
 .Pp
 The
-.Ar recv
-interface can be tested on either incoming or outgoing packets, while the
-.Ar xmit
-interface can only be tested on outgoing packets. So
-.Ar out
+.Cm recv
+interface can be tested on either incoming or outgoing packets,
+while the
+.Cm xmit
+interface can only be tested on outgoing packets.
+So
+.Cm out
 is required (and
-.Ar in
-invalid) whenever
-.Ar xmit
-is used. Specifying
-.Ar via
+.Cm in
+is invalid) whenever
+.Cm xmit
+is used.
+Specifying
+.Cm via
 together with
-.Ar xmit
+.Cm xmit
 or
-.Ar recv
+.Cm recv
 is invalid.
 .Pp
-A packet may not have a receive or transmit interface: packets originating
-from the local host have no receive interface, while packets destined for
-the local host have no transmit interface.
-.Ed
+A packet may not have a receive or transmit interface: packets
+originating from the local host have no receive interface,
+while packets destined for the local host have no transmit
+interface.
+.It Ar options :
+.Bl -tag -width indent
+.It Cm keep-state Op Ar method
+Upon a match, the firewall will create a dynamic rule, whose
+default behaviour is to matching bidirectional traffic between
+source and destination IP/port using the same protocol.
+The rule has a limited lifetime (controlled by a set of
+.Xr sysctl 8
+variables), and the lifetime is refreshed every time a matching
+packet is found.
 .Pp
-.Ar options :
-.Bl -hang -offset flag -width 1234567890123456
-.It frag
-Match if the packet is a fragment and this is not the first fragment
-of the datagram.
-.Ar frag
+The actual behaviour can be modified by specifying a different
+.Ar method ,
+although at the moment only the default one is specified.
+.It Cm bridged
+Matches only bridged packets.
+This can be useful for multicast or broadcast traffic, which
+would otherwise pass through the firewall twice: once during
+bridging, and a second time when the packet is delivered to
+the local stack.
+.Pp
+Apart from a small performance penalty, this would be a problem
+when using
+.Em pipes
+because the same packet would be accounted for twice in terms
+of bandwidth, queue occupation, and also counters.
+.It Cm frag
+Match if the packet is a fragment and this is not the first
+fragment of the datagram.
+.Cm frag
 may not be used in conjunction with either
-.Ar tcpflags
+.Cm tcpflags
 or TCP/UDP port specifications.
-.It ipoptions Ar spec
-Match if the IP header contains the comma separated list of 
+.It Cm ipoptions Ar spec
+Match if the IP header contains the comma separated list of
 options specified in
 .Ar spec .
 The supported IP options are:
 .Pp
-.Ar ssrr 
+.Cm ssrr
 (strict source route),
-.Ar lsrr 
+.Cm lsrr
 (loose source route),
-.Ar rr 
-(record packet route), and
-.Ar ts 
+.Cm rr
+(record packet route) and
+.Cm ts
 (timestamp).
 The absence of a particular option may be denoted
 with a
-.Dq ! .
-.It established
+.Ql ! .
+.It Cm established
+TCP packets only.
 Match packets that have the RST or ACK bits set.
+.It Cm setup
 TCP packets only.
-.It setup
 Match packets that have the SYN bit set but no ACK bit.
+.It Cm tcpflags Ar spec
 TCP packets only.
-.It tcpflags Ar spec
 Match if the TCP header contains the comma separated list of
 flags specified in
 .Ar spec .
 The supported TCP flags are:
 .Pp
-.Ar fin ,
-.Ar syn ,
-.Ar rst ,
-.Ar psh ,
-.Ar ack ,
+.Cm fin ,
+.Cm syn ,
+.Cm rst ,
+.Cm psh ,
+.Cm ack
 and
-.Ar urg .
+.Cm urg .
 The absence of a particular flag may be denoted
 with a
-.Dq ! .
+.Ql ! .
 A rule which contains a
-.Ar tcpflags
+.Cm tcpflags
 specification can never match a fragmented packet which has
-a non-zero offset.  See the
-.Ar frag
+a non-zero offset.
+See the
+.Cm frag
 option for details on matching fragmented packets.
-.It icmptypes Ar types
+.It Cm icmptypes Ar types
+ICMP packets only.
 Match if the ICMP type is in the list
 .Ar types .
-The list may be specified as any combination of ranges
-or individual types separated by commas.
+The list may be specified as any combination of ranges or
+individual types separated by commas.
 The supported ICMP types are:
 .Pp
 echo reply
-.Pq Ar 0 ,
+.Pq Cm 0 ,
 destination unreachable
-.Pq Ar 3 ,
+.Pq Cm 3 ,
 source quench
-.Pq Ar 4 ,
+.Pq Cm 4 ,
 redirect
-.Pq Ar 5 ,
+.Pq Cm 5 ,
 echo request
-.Pq Ar 8 ,
+.Pq Cm 8 ,
 router advertisement
-.Pq Ar 9 ,
+.Pq Cm 9 ,
 router solicitation
-.Pq Ar 10 ,
+.Pq Cm 10 ,
 time-to-live exceeded
-.Pq Ar 11 ,
+.Pq Cm 11 ,
 IP header bad
-.Pq Ar 12 ,
+.Pq Cm 12 ,
 timestamp request
-.Pq Ar 13 ,timestamp reply
-.Pq Ar 14 ,
+.Pq Cm 13 ,
+timestamp reply
+.Pq Cm 14 ,
 information request
-.Pq Ar 15 ,
+.Pq Cm 15 ,
 information reply
-.Pq Ar 16 ,
+.Pq Cm 16 ,
 address mask request
-.Pq Ar 17 ,
+.Pq Cm 17
 and address mask reply
-.Pq Ar 18
-.It Ar uid user
+.Pq Cm 18 .
+.It Cm uid Ar user
 Match all TCP or UDP packets sent by or received for a
 .Ar user .
 A
 .Ar user
 may be matched by name or identification number.
-.It Ar gid group
+.It Cm gid Ar group
 Match all TCP or UDP packets sent by or received for a
 .Ar group .
 A
 .Ar group
 may be matched by name or identification number.
 .El
+.El
 .Sh TRAFFIC SHAPER CONFIGURATION
-Ipfw is also the user interface for the
+The
+.Nm
+utility is also the user interface for the
 .Xr dummynet 4
 traffic shaper.
 The shaper operates by passing packets to objects called
-.Ar pipes ,
-which emulates a link with given bandwidth, propagation delay,
+.Em pipes ,
+which emulate a link with given bandwidth, propagation delay,
 queue size and packet loss rate.
 The
 .Nm
-pipe configuration format is the following
-.Pp
-.Ar pipe number config
-.Op bw Ar bandwidth
-.Op queue Ar {slots|size}
-.Op delay Ar delay-ms
-.Op plr Ar loss-probability
-.Op mask Ar {all | {dst-ip|src-ip|dst-port|src-port|proto} bitmask}
-.Op buckets Ar hash-table-size
+pipe configuration format is the following:
+.Bd -ragged
+.Cm pipe Ar number Cm config
+.Op Cm bw Ar bandwidth
+.Oo
+.Cm queue
+.Es \&{ \&}
+.En Ar slots | size
+.Oc
+.Op Cm delay Ar ms-delay
+.Op Cm plr Ar loss-probability
+.Op Cm mask Ar mask-specifier
+.Op Cm buckets Ar hash-table-size
+.Ed
 .Pp
 The following parameters can be configured for a pipe:
-.Bl -hang -offset flag -width 1234567890
-.It bw Ar bandwidth
+.Bl -tag -width indent
+.It Cm bw Ar bandwidth
 Bandwidth, measured in
-.Ar [K|M]{bit/s|Byte/s} .
+.Sm off
+.Oo
+.Cm K | M
+.Oc Eo \&{
+.Cm bit/s | Byte/s
+.Ec \&} .
+.Sm on
+.Pp
 A value of 0 (default) means unlimited bandwidth.
 The unit must follow immediately the number, as in
 .Dl "ipfw pipe 1 config bw 300Kbit/s queue 50KBytes"
-.It delay Ar ms-delay
-propagation delay, measured in milliseconds. The value is rounded
-to the next multiple of the clock tick (typically 10ms, but it is
-good practice to run kernels with "options HZ=1000" to reduce
-the granularity to 1ms or less). Default value is 0, meaning
-no delay.
-.It queue Ar {slots|size}
-queue size, in slots or KBytes. Default value is 50 slots, which
-is the typical queue size for Ethernet devices. Note that for
-slow speed links you should keep the queue size short or your
-traffic might be affected by a significant queueing delay. E.g.
-50  max-sized ethernet packets (1500
-bytes) mean 600Kbit or 20s of queue on a 30Kbit/s pipe.
-Even worse effect can result if you get
-packets from an interface with a much larger MTU e.g. the loopback
-interface with its 16KB packets.
-.It plr packet-loss-rate
-packet loss rate. NN is a floating-point number, with 0 meaning
-no loss, 1 means 100% loss. The loss rate is internally represented
-on 31 bits.
-.It mask Ar mask-specifier
-dummynet allows you to generate per-flow queues
-using a single pipe specification. A flow identifier is constructed
-by masking the IP addresses, ports and protocol types as specified
-in the pipe configuration. Packets with the same ID after masking fall
-into the same queue. Available mask specifiers are a combination
-of the following:
-.Ar dst-ip mask , src-ip mask ,
-.Ar dst-port mask , src-port mask ,
-.Ar proto mask
+.It Cm delay Ar ms-delay
+Propagation delay, measured in milliseconds.
+The value is rounded to the next multiple of the clock tick
+(typically 10ms, but it is a good practice to run kernels
+with
+.Dq "options HZ=1000"
+to reduce
+the granularity to 1ms or less).
+Default value is 0, meaning no delay.
+.It Cm queue Xo
+.Es \&{ \&}
+.En Ar slots | size Ns Cm Kbytes
+.Xc
+Queue size, in
+.Ar slots
 or
-.Ar all
+.Cm KBytes .
+Default value is 50 slots, which
+is the typical queue size for Ethernet devices.
+Note that for slow speed links you should keep the queue
+size short or your traffic might be affected by a significant
+queueing delay.
+E.g., 50 max-sized ethernet packets (1500 bytes) mean 600Kbit
+or 20s of queue on a 30Kbit/s pipe.
+Even worse effect can result if you get packets from an
+interface with a much larger MTU, e.g. the loopback interface
+with its 16KB packets.
+.It Cm plr Ar packet-loss-rate
+Packet loss rate.
+Argument
+.Ar packet-loss-rate
+is a floating-point number between 0 and 1, with 0 meaning no
+loss, 1 meaning 100% loss.
+The loss rate is internally represented on 31 bits.
+.It Cm mask Ar mask-specifier
+The
+.Xr dummynet 4
+allows you to generate per-flow queues using a single pipe
+specification.
+A flow identifier is constructed by masking the IP addresses,
+ports and protocol types as specified in the pipe configuration.
+Packets with the same identifier after masking fall into the
+same queue.
+Available mask specifiers are a combination of the following:
+.Cm dst-ip Ar mask ,
+.Cm src-ip Ar mask ,
+.Cm dst-port Ar mask ,
+.Cm src-port Ar mask ,
+.Cm proto Ar mask
+or
+.Cm all ,
 where the latter means all bits in all fields are significant.
-.It buckets Ar NN
-Specifies the size of the hash table used for storing the various queues.
-Default value is 64 controlled by the sysctl variable
-.Ar net.inet.ip.dummynet.hash_size ,
+.It Cm buckets Ar hash-table-size
+Specifies the size of the hash table used for storing the
+various queues.
+Default value is 64 controlled by the
+.Xr sysctl 8
+variable
+.Em net.inet.ip.dummynet.hash_size ,
 allowed range is 16 to 1024.
 .El
 .Sh CHECKLIST
 Here are some important points to consider when designing your
 rules:
-.Bl -bullet -hang -offset flag 
-.It 
-Remember that you filter both packets going in and out.
+.Bl -bullet
+.It
+Remember that you filter both packets going
+.Cm in
+and
+.Cm out .
 Most connections need packets going in both directions.
 .It
 Remember to test very carefully.
@@ -690,28 +833,33 @@
 Don't forget the loopback interface.
 .El
 .Sh FINE POINTS
-There is one kind of packet that the firewall will always discard,
-that is an IP fragment with a fragment offset of one.
-This is a valid packet, but it only has one use, to try to circumvent
-firewalls.
-.Pp
-If you are logged in over a network, loading the KLD version of
+There is one kind of packet that the firewall will always
+discard, that is an IP fragment with a fragment offset of
+one.
+This is a valid packet, but it only has one use, to try
+to circumvent firewalls.
+.Pp
+If you are logged in over a network, loading the
+.Xr kld 4
+version of
 .Nm
 is probably not as straightforward as you would think.
-I recommend this command line:
-.Bd -literal -offset center
+I recommend the following command line:
+.Bd -literal -offset indent
 kldload /modules/ipfw.ko && \e
-ipfw add 32000 allow all from any to any
+ipfw add 32000 allow ip from any to any
 .Ed
 .Pp
 Along the same lines, doing an
-.Bd -literal -offset center
+.Bd -literal -offset indent
 ipfw flush
 .Ed
 .Pp
 in similar surroundings is also a bad idea.
 .Pp
-The IP filter list may not be modified if the system security level
+The
+.Nm
+filter list may not be modified if the system security level
 is set to 3 or higher
 .Po
 see
@@ -719,11 +867,62 @@
 for information on system security levels
 .Pc .
 .Sh PACKET DIVERSION
-A divert socket bound to the specified port will receive all packets diverted
-to that port; see
-.Xr divert 4 .
+A
+.Xr divert 4
+socket bound to the specified port will receive all packets
+diverted to that port.
 If no socket is bound to the destination port, or if the kernel
-wasn't compiled with divert socket support, the packets are dropped.
+wasn't compiled with divert socket support, the packets are
+dropped.
+.Sh SYSCTL VARIABLES
+A set of
+.Xr sysctl 8
+variables controls the behaviour of the firewall.
+These are shown below together with their default value and
+meaning:
+.Bl -tag -width indent
+.It Em net.inet.ip.fw.debug : No 1
+Controls debugging messages produced by
+.Nm ipfw .
+.It Em net.inet.ip.fw.one_pass : No 1
+When set, permits only one pass through the firewall.
+Otherwise, after a pipe or divert action, the packet is
+reinjected in the firewall starting from the next rule.
+.It Em net.inet.ip.fw.verbose : No 1
+Enables verbose messages.
+.It Em net.inet.ip.fw.enable : No 1
+Enables the firewall.
+Setting this variable to 0 lets you run your machine without
+firewall even if compiled in.
+.It Em net.inet.ip.fw.verbose_limit : No 0
+Limits the number of messages produced by a verbose firewall.
+.It Em net.inet.ip.fw.dyn_buckets : No 256
+.It Em net.inet.ip.fw.curr_dyn_buckets : No 256
+The configured and current size of the hash table used to
+hold dynamic rules.
+This must be a power of 2.
+The table can only be resized when empty, so in order to
+resize it on the fly you will probably have to
+.Cm flush
+and reload the ruleset.
+.It Em net.inet.ip.fw.dyn_count : No 3
+Current number of dynamic rules
+.Pq read-only .
+.It Em net.inet.ip.fw.dyn_max : No 1000
+Maximum number of dynamic rules.
+When you hit this limit, no more dynamic rules can be
+installed until old ones expire.
+.It Em net.inet.ip.fw.dyn_ack_lifetime : No 300
+.It Em net.inet.ip.fw.dyn_syn_lifetime : No 20
+.It Em net.inet.ip.fw.dyn_fin_lifetime : No 20
+.It Em net.inet.ip.fw.dyn_rst_lifetime : No 5
+.It Em net.inet.ip.fw.dyn_short_lifetime : No 30
+These variables control the lifetime, in seconds, of dynamic
+rules.
+Upon the initial SYN exchange the lifetime is kept short,
+then increased after both SYN have been seen, then decreased
+again during the final FIN exchange or when a RST
+.El
 .Sh EXAMPLES
 This command adds an entry which denies all tcp packets from
 .Em cracker.evil.org
@@ -731,32 +930,83 @@
 .Em wolf.tambov.su
 from being forwarded by the host:
 .Pp
-.Dl ipfw add deny tcp from cracker.evil.org to wolf.tambov.su 23
-.Pp 
-This one disallows any connection from the entire crackers network to
-my host:
+.Dl "ipfw add deny tcp from cracker.evil.org to wolf.tambov.su telnet"
+.Pp
+This one disallows any connection from the entire crackers
+network to my host:
 .Pp
-.Dl ipfw add deny all from 123.45.67.0/24 to my.host.org
+.Dl "ipfw add deny ip from 123.45.67.0/24 to my.host.org"
+.Pp
+A first and efficient way to limit access (not using dynamic rules)
+is the use of the following rules:
+.Pp
+.Dl "ipfw add allow tcp from any to any established"
+.Dl "ipfw add allow tcp from net1 portlist1 to net2 portlist2 setup"
+.Dl "ipfw add allow tcp from net3 portlist3 to net3 portlist3 setup"
+.Dl "..."
+.Dl "ipfw add deny tcp from any to any"
+.Pp
+The first rule will be a quick match for normal TCP packets,
+but it will not match the initial SYN packet, which will be
+matched by the
+.Cm setup
+rules only for selected source/destination pairs.
+All other SYN packets will be rejected by the final
+.Cm deny
+rule.
+.Pp
+In order to protect a site from flood attacks involving fake
+TCP packets, it is safer to use dynamic rules:
+.Pp
+.Dl "ipfw add check-state"
+.Dl "ipfw add deny tcp from any to any established"
+.Dl "ipfw add allow tcp from my-net to any setup keep-state"
+.Pp
+This will let the firewall install dynamic rules only for
+those connection which start with a regular SYN packet coming
+from the inside of our network.
+Dynamic rules are checked when encountering the first
+.Cm check-state
+or
+.Cm keep-state
+rule.
+A
+.Cm check-state
+rule should be usually placed near the beginning of the
+ruleset to minimize the amount of work scanning the ruleset.
+Your mileage may vary.
+.Pp
+.Em BEWARE :
+stateful rules can be subject to denial-of-service attacks
+by a SYN-flood which opens a huge number of dynamic rules.
+The effects of such attacks can be partially limited by
+acting on a set of
+.Xr sysctl 8
+variables which control the operation of the firewall.
 .Pp
 Here is a good usage of the
-.Ar list
-command to see accounting records
-and timestamp information:
+.Cm list
+command to see accounting records and timestamp information:
 .Pp
-.Dl ipfw -at l
+.Dl ipfw -at list
 .Pp
 or in short form without timestamps:
 .Pp
-.Dl ipfw -a l
+.Dl ipfw -a list
 .Pp
-This rule diverts all incoming packets from 192.168.2.0/24 to divert port 5000:
+Next rule diverts all incoming packets from 192.168.2.0/24
+to divert port 5000:
 .Pp
-.Dl ipfw divert 5000 all from 192.168.2.0/24 to any in
+.Dl ipfw divert 5000 ip from 192.168.2.0/24 to any in
 .Pp
-The following rules show some of the applications of ipfw and
-dummynet for simulations and the like.
+The following rules show some of the applications of
+.Nm
+and
+.Xr dummynet 4
+for simulations and the like.
 .Pp
-This rule drops random packets with a probability of 5%
+This rule drops random incoming packets with a probability
+of 5%:
 .Pp
 .Dl "ipfw add prob 0.05 deny ip from any to any in"
 .Pp
@@ -765,17 +1015,19 @@
 .Dl "ipfw add pipe 10 ip from any to any"
 .Dl "ipfw pipe 10 config plr 0.05"
 .Pp
-We can use pipes to artificially limit bandwidth e.g. on a machine
-acting as a router, if we want to limit traffic from local clients
-on 192.168.2.0/24 we do:
+We can use pipes to artificially limit bandwidth, e.g. on a
+machine acting as a router, if we want to limit traffic from
+local clients on 192.168.2.0/24 we do:
 .Pp
 .Dl "ipfw add pipe 1 ip from 192.168.2.0/24 to any out"
 .Dl "ipfw pipe 1 config bw 300Kbit/s queue 50KBytes"
 .Pp
 note that we use the
-.Ql out
-specifier so that the rule is not used twice. Remember in fact
-that ipfw rules are checked both on incoming and outgoing packets.
+.Cm out
+modifier so that the rule is not used twice.
+Remember in fact that
+.Nm
+rules are checked both on incoming and outgoing packets.
 .Pp
 Should we like to simulate a bidirectional link with bandwidth
 limitations, the correct way is the following:
@@ -785,42 +1037,48 @@
 .Dl "ipfw pipe 1 config bw 64Kbit/s queue 10Kbytes"
 .Dl "ipfw pipe 2 config bw 64Kbit/s queue 10Kbytes"
 .Pp
-The above can be very useful e.g. if you want to see how your fancy
-Web page will look for a residential user which is connected only through
-a slow link.
-You should not use only
-one pipe for both directions, unless you want to simulate a half-duplex
-medium (e.g. appletalk, Ethernet, IRDA).
+The above can be very useful, e.g. if you want to see how
+your fancy Web page will look for a residential user which
+is connected only through a slow link.
+You should not use only one pipe for both directions, unless
+you want to simulate a half-duplex medium (e.g. AppleTalk,
+Ethernet, IRDA).
 It is not necessary that both pipes have the same configuration,
 so we can also simulate asymmetric links.
 .Pp
-Another typical application of the traffic shaper is to introduce some
-delay in the communication. This can affect a lot applications which do
-a lot of Remote Procedure Calls, and where the round-trip-time of the
-connection often becomes a limiting factor much more than bandwidth:
+Another typical application of the traffic shaper is to
+introduce some delay in the communication.
+This can affect a lot applications which do a lot of Remote
+Procedure Calls, and where the round-trip-time of the
+connection often becomes a limiting factor much more than
+bandwidth:
 .Pp
 .Dl "ipfw add pipe 1 ip from any to any out"
 .Dl "ipfw add pipe 2 ip from any to any in"
 .Dl "ipfw pipe 1 config delay 250ms bw 1Mbit/s"
 .Dl "ipfw pipe 2 config delay 250ms bw 1Mbit/s"
 .Pp
-Per-flow queueing can be useful for a variety of purposes. A very
-simple one is counting traffic:
+Per-flow queueing can be useful for a variety of purposes.
+A very simple one is counting traffic:
 .Pp
 .Dl "ipfw add pipe 1 tcp from any to any"
 .Dl "ipfw add pipe 1 udp from any to any"
 .Dl "ipfw add pipe 1 ip from any to any"
 .Dl "ipfw pipe 1 config mask all"
 .Pp
-The above set of rules will create queues (and collect statistics)
-for all traffic. Because the pipes have no limitations, the only
-effect is collecting statistics. Note that we need 3 rules, not just
-the last one, because when ipfw tries to match ip packets it will
-not consider ports, so we would not see connections on separate ports
-as different ones.
+The above set of rules will create queues (and collect
+statistics) for all traffic.
+Because the pipes have no limitations, the only effect is
+collecting statistics.
+Note that we need 3 rules, not just the last one, because
+when
+.Nm
+tries to match IP packets it will not consider ports, so we
+would not see connections on separate ports as different
+ones.
 .Pp
-A more sophisticated example is limiting the outbound traffic on a net
-with per-host limits, rather than per-network limits:
+A more sophisticated example is limiting the outbound traffic
+on a net with per-host limits, rather than per-network limits:
 .Pp
 .Dl "ipfw add pipe 1 ip from 192.168.2.0/24 to any out"
 .Dl "ipfw add pipe 2 ip from any to 192.168.2.0/24 in"
@@ -829,9 +1087,9 @@
 .Sh SEE ALSO
 .Xr cpp 1 ,
 .Xr m4 1 ,
+.Xr bridge 4 ,
 .Xr divert 4 ,
 .Xr dummynet 4 ,
-.Xr bridge 4 ,
 .Xr ip 4 ,
 .Xr ipfirewall 4 ,
 .Xr protocols 5 ,
@@ -847,25 +1105,26 @@
 .Pp
 .Em WARNING!!WARNING!!WARNING!!WARNING!!WARNING!!WARNING!!WARNING!!
 .Pp
-This program can put your computer in rather unusable state. When
-using it for the first time, work on the console of the computer, and
-do
+This program can put your computer in rather unusable state.
+When using it for the first time, work on the console of the
+computer, and do
 .Em NOT
 do anything you don't understand.
 .Pp
-When manipulating/adding chain entries, service and protocol names are
-not accepted.
+When manipulating/adding chain entries, service and protocol names
+are not accepted.
 .Pp
 Incoming packet fragments diverted by
-.Ar divert
+.Cm divert
 or
-.Ar tee
+.Cm tee
 are reassembled before delivery to the socket.
 .Pp
 Packets that match a
-.Ar tee
+.Cm tee
 rule should not be immediately accepted, but should continue
-going through the rule list.  This may be fixed in a later version.
+going through the rule list.
+This may be fixed in a later version.
 .Sh AUTHORS
 .An Ugen J. S. Antsilevich ,
 .An Poul-Henning Kamp ,
@@ -877,11 +1136,16 @@
 Daniel Boulet
 for BSDI.
 .Pp
-Work on dummynet traffic shaper supported by Akamba Corp.
+Work on
+.Xr dummynet 4
+traffic shaper supported by Akamba Corp.
 .Sh HISTORY
-.Nm Ipfw
-first appeared in
+The
+.Nm
+utility first appeared in
 .Fx 2.0 .
-.Nm dummynet
+.Xr dummynet 4
 was introduced in
-.Fx 2.2.8
+.Fx 2.2.8 .
+Stateful extensions were introduced in
+.Fx 4.0 .
