backout, this will go in in little pieces

as advised by theo and henning

1 files changed, 465 insertions, 457 deletions

diff --git a/share/man/man5/pf.conf.5 b/share/man/man5/pf.conf.5
index 8a65c30c1cc..44cd4105678 100644
--- a/share/man/man5/pf.conf.5
+++ b/share/man/man5/pf.conf.5
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: pf.conf.5,v 1.67 2002/07/29 22:40:45 pb Exp $
+.\"	$OpenBSD: pf.conf.5,v 1.68 2002/07/30 08:55:12 pb Exp $
 .\"
 .\" Copyright (c) 2002, Daniel Hartmeier
 .\" All rights reserved.
@@ -27,70 +27,365 @@
 .\" ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 .\" POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd July 29, 2002
+.Dd July 2, 2002
 .Dt PF.CONF 5
 .Os
 .Sh NAME
 .Nm pf.conf
-.Nd packet filter configuration file
+.Nd filtering and translation (NAT) rules file for the
+packet filter
 .Sh DESCRIPTION
 The
 .Xr pf 4
-packet filter handles packets according to the
+packet filter drops, passes and modifies packets according to the
 rules defined in this file.
-This file is evaluated and loaded by
-.Xr pfctl 8 .
-.Sh RULESET EVALUATION
-Rules are grouped into sections which must appear in this order:
-.Pp
-.Bl -tag -item -width "O normalization " -compact
-.It Em options
-parameters to the packet filter
-.It Em normalization
-packet sanitizing (scrub)
-.It Em translation
-Network Address Translation
-.It Em filter
-block or pass the packet
-.El
+Filter rules are used to selectively pass traffic while translation
+rules specify which addresses are to be mapped and which are to be
+redirected.
+For each packet inspected by the filter, the set of rules is evaluated
+from top to bottom, and the last matching rule decides what action is
+performed.
+For each packet inspected by the translator, the set of rules is evaluated
+from top to bottom, and the first matching rule decides what action is
+performed.
+In short: filters are last match, nat is first match.
+Rules must be in order: scrub, nat, filter.
+
+.Sh GRAMMAR
+Syntax for filter rules in BNF:
+.Bd -literal
+option         = set ( [ "timeout" ( timeout | "{" timeout-list "}" ) ] |
+                       [ "optimization" [ "default" | "normal" | 
+				"high-latency" | "satellite" | 
+				"aggressive" | "conservative" ] ]
+                       [ "limit" ( limit | "{" limit-list "}" ) ] |
+		       [ "loginterface" interface-name ] ) .
+rule           = action ( "in" | "out" )
+                 [ "log" | "log-all" ] [ "quick" ]
+                 [ "on" ( interface-name | "{" interface-list "}" ) ]
+                 [ route ] [ af ]
+                 [ "proto" ( proto-name | proto-number |
+                             "{" proto-list "}" ) ]
+                 hosts
+                 [ user ] [ group ] [ flags ]
+                 [ icmp-type | ipv6-icmp-type ]
+                 [ ( "keep" | "modulate" ) "state" [ "(" state-opts ")" ] ]
+                 [ "fragment" ] [ "no-df" ] [ "min-ttl" number ]
+                 [ "max-mss" number ] [ "allow-opts" ]
+                 [ "label" string ] .
+
+action         = "pass" | "block" [ return ] | "scrub" .
+return         = "return-rst" [ "(" "ttl" number ")" ] |
+                 "return-icmp"
+                     [ "(" ( icmp-code-name | icmp-code-number ) ")" ] |
+                 "return-icmp6"
+                     [ "(" ( icmp-code-name | icmp-code-number ) ")" ] .
+
+interface-list = interface-name [ "," interface-list ] .
+route          = "fastroute" |
+                 "route-to" "(" interface-name address ")" |
+                 "dup-to" interface-name
+                 "route-to" "(" interface-name address ")" |
+                 "dup-to" interface-name
+af	       = "inet" | "inet6" .
+proto-list     = ( proto-name | proto-number ) [ "," proto-list ] .
+
+hosts          = "all" |
+                 "from" ( "any" | "no-route" | host | "{" host-list "}" )
+                     [ port ]
+                 "to"   ( "any" | "no-route" | host | "{" host-list "}" )
+                     [ port ] .
+
+host           = [ "!" ] address [ "/" mask-bits ] .
+address        = ( interface-name | "(" interface-name ")" | host-name |
+                   ipv4-dotted-quad | ipv6-coloned-hex ) .
+host-list      = host [ "," host-list ] .
+
+port           = "port" ( unary-op | binary-op | "{" op-list "}" ) .
+user           = "user" ( unary-op | binary-op | "{" op-list "}" ) .
+group          = "group" ( unary-op | binary-op | "{" op-list "}" ) .
+
+unary-op       = [ "=" | "!=" | "<" | "<=" | ">" | ">=" ]
+                 ( name | number ) .
+binary-op      = number ( "<>" | "><" ) number .
+op-list        = ( unary-op | binary-op ) [ "," op-list ] .
+
+flags          = "flags" ( flag-set | flag-set "/" flag-set |
+                           "/" flag-set ) .
+flag-set       = [ "F" ] [ "S" ] [ "R" ] [ "P" ] [ "A" ] [ "U" ] [ "E" ]
+                 [ "W" ] .
+
+icmp-type      = "icmp-type" ( icmp-type-code | "{" icmp-list "}" ) . 
+ipv6-icmp-type = "ipv6-icmp-type" ( icmp-type-code | "{" icmp-list "}" ) . 
+icmp-type-code = ( icmp-type-name | icmp-type-number )
+                 [ "code" ( icmp-code-name | icmp-code-number ) ] .
+icmp-list      = icmp-type-code [ "," icmp-list ] . 
+
+state-opts     = state-opt [ "," state-opts ] .
+state-opt      = ( "max" seconds ) | ( timeout seconds ) .
+
+timeout-list   = timeout [ "," timeout-list ] .
+timeout        = ( "tcp.first" | "tcp.opening" | "tcp.established" |
+                 "tcp.closing" | "tcp.finwait" | "tcp.closed" |
+                 "udp.first" | "udp.single" | "udp.multiple" |
+                 "icmp.first" | "icmp.error" |
+                 "other.first" | "other.multiple" ) seconds .
+seconds        = number .
+
+limit-list     = limit [ "," limit-list ] . 
+limit          = ( "states" | "frags" ) number .
+.Ed
 .Pp
-Every section is optional.
-If the sections are not in order,
+Syntax for translation rules in BNF:
+.Bd -literal
+rule      = [ "no" ] ( nat_rule | binat_rule | rdr_rule ) .
+
+nat_rule  = "nat" "on" [ "!" ] ifname [ protospec ] hosts
+            [ "->" address [ portspec ] ] .
+
+binat_rule = "binat" "on" ifname [ protospec ] "from" address
+             "to" ipspec [ "->" address ] .
+
+rdr_rule  = "rdr" "on" [ "!" ] ifname [ protospec ] "from" ipspec
+            "to" ipspec [ portspec ] [ "->" address [ portspec ] ] .
+
+protospec = "proto" ( number | "tcp" | "udp" | "icmp" ) .
+
+ipspec    = "any" | host | "{" host-list "}" .
+
+portspec  = "port" ( number | name ) [ ":" ( "*" | number | name ) ] .
+
+hosts     = "all" |
+            "from" ( "any" | host | "{" host-list "}" ) [ port ]
+            "to"   ( "any" | host | "{" host-list "}" ) [ port ] .
+
+host      = [ "!" ] address [ "/" mask-bits ] .
+address   = ( interface-name | "(" interface-name ")" | host-name |
+              ipv4-dotted-quad | ipv6-coloned-hex ) .
+host-list = host [ "," host-list ] .
+
+port      = "port" ( unary-op | binary-op | "{" op-list "}" ) .
+unary-op  = [ "=" | "!=" | "<" | "<=" | ">" | ">=" ]
+            ( name | number ) .
+binary-op = number ( "<>" | "><" ) number .
+op-list   = ( unary-op | binary-op ) [ "," op-list ] .
+.Ed
+.Sh FILTER RULES
+While filter rules are typically manipulated using
 .Xr pfctl 8
-will fail to load them.
-The order of the rules in this file is the order in which a packet will
-traverse them.
-.Sh PACKET TRANSLATION
-.Bl -tag -width Fl
-.It Em nat
-A
-.Em nat
-rule specifies that IP addresses are to be changed as the packet
-traverses the given interface.
-.It Em binat
-A
-.Em binat
-rule specifies a bidirectional mapping between an external IP address
-and an internal IP address.
-.It Em rdr
-The packet is redirected to another destination and possibly a
-different port.
-.Em rdr
-rules can optionally specify port ranges instead of single ports.
+other utilities may be written using the
+.Xr ioctl 2
+interface described in
+.Xr pf 4 .
+Filter and NAT rules are loaded from a text file into the kernel using
+.Pp
+.Cm # pfctl -f file
+.Pp
+which replaces the active rule set with the new one.
+To load only the filter rules from a file, one would use the command
 .Pp
-The first rule below redirects port 2003 on the local machine to port
-22 on 10.10.2.3; and the second rule controls NAT for that subnet:
+.Cm # pfctl -R -f file
+.Pp
+To load only the NAT rules from a file, one would use the command
+.Pp
+.Cm # pfctl -N -f file
+.Pp
+To load only the options from a file, one would use the command
+.Pp
+.Cm # pfctl -O -f file
+.Pp
+The active filter rule set can be displayed using
+.Pp
+.Cm # pfctl -s r
+.Pp
+The active translation rule set can be displayed using
+.Pp
+.Cm # pfctl -s n
+.Pp
+The active options can be displayed using pfctl as well:
+.Pp
+.Cm # pfctl -s t
+.Pp
+shows the current timeouts.
+.Pp
+.Cm # pfctl -s m
+.Pp
+shows the current limits.
+.Pp
+For each packet processed by the packet filter, the filter rules are
+evaluated in sequential order, from first to last.
+Each rule either matches the packet or doesn't.
+The last matching rule decides what action is taken.
+.Pp
+If no rule matches the packet, the default action is
+.Em pass .
+.Pp
+To block everything by default and only pass packets
+that match explicit rules, one uses
 .Bd -literal
-    rdr on $ext_if proto tcp from any to $ext_if port 2004 -> 10.10.2.3 port 22
-    nat on $ext_if from 10.10.0.0/16 to any -> $ext_if
+.Cm block in all
+.Cm block out all
 .Ed
-.It Em no
-The
-.Em no
-action applies to nat, rdr and binat rules. If a packet matches this rule,
-the evaluation of translation rules stop and the packet is translated.
+.Pp
+as the first two rules.
+.Pp
+For each packet processed by the translator, the translation rules are
+evaluated in sequential order, from first to last.
+Each rule either matches the packet or doesn't.
+The first matching rule decides what action is taken.
+.Pp
+If no rule matches the packet, the default action is to pass the packet
+up to the filter unmodified.
+It should be noted that all translations of packets occur before
+the filters are applied.
+Hence, rules for redirected packets should specify the address and port
+after translation.
+Note that all translation rules apply only to packets that pass through
+the specified interface.
+For instance, redirecting port 80 on an external interface to an internal
+web server will only work for connections originating from the outside.
+Connections to the address of the external interface from local hosts will
+not be redirected, since such packets do not actually pass through the
+external interface.
+Redirections can't reflect packets back through the interface they arrive
+on, they can only be redirected to hosts connected to different interfaces
+or to the firewall itself.
+.Sh OPTIONS
+.Ss timeout
+.Bl -tag -width interval -compact
+.It Em interval
+Interval between purging expired states and fragments.
+.It Em frag
+Seconds before an unassembled fragment is expired.
 .El
-.Sh FILTER
+.Pp
+When a packet matches a stateful connection, the seconds to live of the
+connection will be updated to that of the proto.modifier which corresponds
+to the connection state.
+Each packet which matches this state will reset the TTL.
+Tuning these values may improve the performance of the
+firewall at the risk of dropping valid idled connections.
+.Pp
+.Bl -tag -width "tcp.established " -compact
+.It Em tcp.first
+The state after the first packet.
+.It Em tcp.opening
+The state before the destination host ever sends a packet.
+.It Em tcp.established
+The fully established state.
+.It Em tcp.closing
+The state after the first FIN has been sent.
+.It Em tcp.finwait
+The state after both FINs have been exchanged and the connection is closed.
+Some hosts (notably web servers on Solaris) send TCP packets even after closing
+the connection.
+Increasing tcp.finwait (and possibly tcp.closing) can prevent blocking of
+such packets.
+.It Em tcp.closed
+The state after one endpoint sends a RST.
+.El
+.Pp
+ICMP and UDP are handled in a similar fashion to TCP but with a much more
+limited set of states:
+.Pp
+.Bl -tag -width "udp.multiple " -compact
+.It Em udp.first
+The state after the first packet.
+.It Em udp.single
+The state if the source host sends more than one packet but the destination
+host has never sent one back.
+.It Em udp.multiple
+The state if both hosts have sent packets.
+.It Em icmp.first
+The state after the first packet.
+.It Em icmp.error
+The state after an icmp error came back in response to an icmp packet.
+.El
+.Pp
+Other protocols are handled similarly to UDP:
+.Pp
+.Bl -tag -width "other.multiple " -compact
+.It Em other.first
+.It Em other.single
+.It Em other.multiple
+.El
+.Pp
+Example:
+.Bd -literal
+    set timeout tcp.established 3600
+    set timeout { tcp.opening 30, tcp.closing 900 }
+.Ed
+.Ss loginterface
+Enable collection of packet and byte count statistics for the given interface.
+These statistics can be viewed using
+.Bd -literal
+    # pfctl -s info
+.Ed
+.Pp
+In this example pf is told to collect statistics on the interface named dc0:
+.Bd -literal
+    set loginterface dc0
+.Ed
+.Pp
+One can unset the loginterface using
+.Bd -literal
+    set loginterface none
+.Ed
+.Pp
+.Ss limit
+Sets hard limits on the memory pools used by the packet filter.
+See
+.Xr pool 9
+for an explanation of memory pools.
+.Pp
+For example,
+.Bd -literal
+    set limit states 20000
+.Ed
+.Pp
+sets the maximum number of entries in the memory pool used by state table
+entries (generated by 'keep state' rules) to 20000.
+.Bd -literal
+    set limit frags 20000
+.Ed
+.Pp
+set the maximum number of entries in the memory pool used for fragment
+reassemble (generated by 'scrub' rules) to 20000.
+.Pp
+These can be combined:
+.Bd -literal
+    set limit { states 20000, frags 20000 }
+.Ed
+.Ss optimization
+Optimize the engine to one of the following network topographies or
+environments:
+.Bl -tag -width "O high-latency " -compact
+.It Em default
+A normal network environment.
+Suitable for almost all networks.
+.It Em normal
+Alias for
+.Em default
+.It Em high-latency
+A high-latency environment (such as a satellite connection)
+.It Em satellite
+Alias for
+.Em high-latency
+.It Em aggressive
+Aggressively expire connections when they are likely no longer valid.
+This can greatly reduce the memory usage of the firewall at the cost of
+dropping idle connections early.
+.It Em conservative
+Extremely conservative settings.
+Pains will be taken to avoid dropping legitimate connections at the
+expense of greater memory utilization (possibly much greater on a busy
+network) and slightly increased processor utilization.
+.El
+Example:
+.Bd -literal
+    set optimization aggressive
+.Ed
+.Sh ACTIONS
 .Bl -tag -width Fl
 .It Em block
 The packet is blocked.
@@ -100,30 +395,53 @@ Returning ICMP packets can have
 an ICMP code set by number or name, TCP RST can have a TTL set.
 .It Em pass
 The packet is passed.
-.Sh QUICK
-If a packet matches a filter rule which has the
-.Sq quick
-option set, this rule
-is considered the last matching rule, and evaluation of subsequent rules
-is skipped.
+.It Em scrub
+The packet is run through normalization/defragmentation.
+Scrub rules are not considered last matching rules.
+IPv6 packets are not defragmented.
+.It Em binat
+A
+.Em binat
+rule specifies a bidirectional mapping between an external IP address
+and an internal IP address.
+.It Em nat
+A
+.Em nat
+rule specifies that IP addresses are to be changed as the packet
+traverses the given interface.
+This technique allows a single IP address
+on the translating host to support network traffic for a larger range of
+machines on an "inside" network.
+Although in theory any IP address can be used on the inside, it is strongly
+recommended that one of the address ranges defined by RFC 1918 be used.
+These netblocks are:
+.Bd -literal
+10.0.0.0    - 10.255.255.255 (all of net 10, i.e., 10/8)
+172.16.0.0  - 172.31.255.255 (i.e., 172.16/12)
+192.168.0.0 - 192.168.255.255 (i.e., 192.168/16)
+.Ed
+.It Em rdr
+The packet is redirected to another destination and possibly a
+different port.
+.Em rdr
+rules can optionally specify port ranges instead of single ports.
+\'rdr ... port 2000:2999 -> ... port 4000\' redirects ports 2000 to 2999
+(including port 2000 and 2999) to the same port 4000.
+\'rdr ... port 2000:2999 -> ... port 4000:*\' redirects port 2000 to 4000,
+2001 to 4001, ..., 2999 to 4999.
+.El
 .Sh LOGGING
 .Bl -tag -width Fl
 .It Em log
 In addition to the action specified, a log message is generated.
 .It Em log-all
-Used with
+Used with 
 .Sq keep state
 or
 .Sq modulate state
 rules.
 Not only the packet that creates state is logged, but all packets of
 the connection.
-.Pp
-One can only log
-.Em pass
-or
-.Em block
-rules.
 .El
 .Pp
 The logged packets are sent to the
@@ -140,37 +458,46 @@ The log files can be read using tcpdump:
 .Bd -literal
 .Cm # tcpdump -n -e -ttt -r /var/log/pflog
 .Ed
-.Sh MACROS
-.Em pfctl
-supports macro definition and expansion like:
-.Bd -literal
-    ext_if = "kue0"
-    pass out on $ext_if           from any to any         keep state
-    pass in  on $ext_if proto tcp from any to any port 25 keep state
-.Ed
-Additionally you can concatenate strings:
-.Bd -literal
-    hostone = "10.1.1.1"
-    hosttwo = "10.2.1.1"
-    hosts = "$hostone $hosttwo 10.3.1.1"
-.Pp
-Macro names must start with a letter and may contain letters, digits
-and underscores.
-Macros are not expanded recursively.
+.Sh QUICK
+If a packet matches a rule which has the 
+.Sq quick
+option set, this rule
+is considered the last matching rule, and evaluation of subsequent rules
+is skipped.
+.Sh NO
+The
+.Sq no
+option is to a NAT rule what the
+.Sq quick
+option is to a filter rule.
+This option causes matching packets to remain untranslated.
+.Sh ROUTING
+If a packet matches a rule with a route option set, the packet filter will
+route the packet according to the type of route option.
+.Ss fastroute
+The
+.Em fastroute
+option does a normal route lookup to find the next hop for the packet.
+.Ss route-to
+The
+.Em route-to
+option routes the packet to the specified interface with an optional address
+for the next hop.
+.Ss dup-to
+The
+.Em dup-to
+option creates a duplicate of the packet and routes it like
+.Em route-to.
+The original packet gets routed as it normally would.
 .Sh PARAMETERS
 The rule parameters specify for what packets a rule applies.
 A packet always comes in on or goes out through one interface.
 Most parameters are optional.
-Not all parameters are applicable to all rule-types and they
-have to be in a certain order. See the
-.Em GRAMMAR
-section below for exact details.
 If a parameter is specified, the rule only applies to packets with
 matching attributes.
 Certain parameters can be expressed as lists, in which case
-.Xr pfctl 8
+.Em pfctl
 generates all needed rule combinations.
-Lists are comprised by enclosing braces.
 .Ss in or out
 The rule applies to incoming or outgoing packets.
 Either
@@ -197,27 +524,18 @@ symbolic host names or interface names, or as any of the following keywords:
 .Bl -tag -width no-route -compact
 .It Em any
 means any address;
-.It Em all
-means
-.Sq from any to any
-;
 .It Em no-route
 means any address which is not currently routable.
 .El
 .Pp
 Host name resolution and interface to address translation are done at
-rule set load-time.
+rule set load-time. 
 When the address of an interface (or host name) changes (by DHCP or PPP,
 for instance), the rule set must be reloaded for the change to be reflected
 in the kernel.
-Multiple IP addresses on one interface are expanded at rule evalutation
-time. If one has IPv4 and IPv6 addresses, the protocol family has
-to be defined.
 Interface names surrounded by parentheses cause an automatic update of
 the rule whenever the referenced interface changes its address.
 Reloading the rule set is not required in this case.
-(XXX. expanding in () does work?)
-
 .Pp
 Ports can be specified using these operators
 .Bd -literal
@@ -229,16 +547,17 @@ Ports can be specified using these operators
 doesn't include the limits, for instance:
 .Bl -tag -width Fl
 .It Em port 2000 >< 2004
-means
+means 
 .Sq all ports > 2000 and < 2004 ,
 hence ports 2001, 2002 and 2003.
 .It Em port 2000 <> 2004
-means
+means 
 .Sq all ports < 2000 or > 2004 ,
 hence ports 1-1999 and 2005-65535.
 .El
 .Pp
-The host and port specifications are optional:
+The host and port specifications are optional, as the following examples
+show:
 .Bd -literal
     pass in all
     pass in from any to any
@@ -246,10 +565,9 @@ The host and port specifications are optional:
     pass in proto tcp from any to any port 25
     pass in proto tcp from 10.0.0.0/8 port > 1024 to ! 10.1.2.3 port != 22
 .Ed
-.Ss user <user>
-.Ss group <group>
+.Ss user <user> group <group>
 The rule only applies to packets of sockets owned by the specified user
-or group.
+and group.
 For outgoing connections initiated from the firewall, this is the user
 that opened the connection.
 For incoming connections to the firewall itself, this is the user that
@@ -283,7 +601,8 @@ that explicitely compare against
 .Em unknown
 with operator = or !=, for instance 'user >= 0' does not match
 forwarded packets.
-This example allows only selected users to open outgoing connections:
+The following example allows only selected users to open outgoing
+connections:
 .Bd -literal
     block out proto { tcp, udp } all
     pass  out proto { tcp, udp } all user { < 1000, dhartmei } keep state
@@ -304,13 +623,12 @@ SYN, SYN+PSH, SYN+RST match, but SYN+ACK, ACK and ACK+RST don't.
 This is more restrictive than the previous example.
 .It Em flags S
 If the second set is not specified, it defaults to FSRPAUEW.
-Hence, only packets with SYN set and all other flags unset match this
+Hence, only packets with SYN set and all other flags unset match this 
 rule.
 This is more restrictive than the previous example.
 .It Em flags /SFRA
 If the first set is not specified, it defaults to none.
 All of SYN, FIN, RST and ACK must be unset.
-.\" XXX -- this needs an example
 .El
 .Ss icmp-type <type> code <code> and ipv6-icmp-type <type> code <code>
 The rule only applies to ICMP or ICMPv6 packets with the specified type
@@ -338,7 +656,6 @@ Adds a label (name) to the rule, which can be used to identify the rule.
 For instance,
 .Em pfctl -s labels
 shows per-rule statistics for rules that have labels.
-The maximum size of an expanded label is 64 characters.
 .Pp
 The following macros can be used in labels:
 .Pp
@@ -370,6 +687,18 @@ expands to
 .Ed
 .Pp
 Note that evaluation takes place at parse time.
+.Sh MACROS
+.Em pfctl
+supports macro definition and expansion like:
+.Bd -literal
+    ext_if = "kue0"
+    pass out on $ext_if           from any to any         keep state
+    pass in  on $ext_if proto tcp from any to any port 25 keep state
+.Ed
+.Pp
+Macro names must start with a letter and may contain letters, digits
+and underscores.
+Macros are not expanded recursively.
 .Sh STATEFUL INSPECTION
 .Em pf
 is a stateful packet filter, which means it can track the state of
@@ -378,8 +707,8 @@ Instead of passing all traffic to port 25, for instance, one can pass
 only the initial packet and keep state.
 .Pp
 If a packet matches a pass ... keep state rule, the filter creates
-a state for this connection and automatically passes all subsequent
-packets for that connection.
+a state for this connection and automatically lets pass all following
+packets of that connection.
 .Pp
 Before any rules are evaluated, the filter checks whether the packet
 matches any state.
@@ -398,8 +727,8 @@ numbers.
 Also, looking up states is usually faster than evaluating rules.
 If one has 50 rules, all of them are evaluated sequentially in O(n).
 Even with 50000 states, only 16 comparisons are needed to match a
-state, since states are stored in a binary tree that allows searches
-in O(log2 n).
+state, since states are stored in a binary search tree that allows
+searches in O(log2 n).
 .Pp
 For instance:
 .Bd -literal
@@ -411,15 +740,14 @@ For instance:
 .Pp
 This rule set blocks everything by default.
 Only outgoing connections and incoming connection to port 25 are allowed.
-The initial packet of each connection (has the SYN flag set), creates a
-state as it is passed.
-If a packet is not the initial packet of a connection, it is passed only
-if it matches a state.
+The inital packet of each connection has the SYN flag set, will be passed
+and creates state.
+All further packets of these connections are passed if they match a state.
 .Pp
 Specifying flags S/SA restricts state creation to the initial SYN
 packet of the TCP handshake.
 One can also be less restrictive, and allow state creation from
-intermediate
+intermediate 
 .Pq non-SYN
 packets.
 This will cause
@@ -428,10 +756,11 @@ to synchronize to existing connections, for instance
 if one flushes the state table.
 .Pp
 For UDP, which is stateless by nature, keep state will create state
-using only host addresses and ports.
+as well.
+UDP packets are matched to states using only host addresses and ports.
 .Pp
 ICMP messages fall in two categories: ICMP error messages, which always
-refer to a TCP or UDP packet, are matched against the relevant connection.
+refer to a TCP or UDP packet, are matched against the refered to connection.
 If one keeps state on a TCP connection, and an ICMP source quench message
 referring to this TCP connection arrives, it will be matched to the right
 state and get passed.
@@ -444,9 +773,9 @@ For example
     pass out inet proto icmp all icmp-type echoreq keep state
 .Ed
 .Pp
-lets echo requests
+lets echo requests 
 .Pq pings
-out, creates a state and matches incoming echo replies correctly.
+out, creates state, and matches incoming echo replies correctly to states.
 .Pp
 Note: nat/rdr rules implicitly create state for connections.
 .Sh STATE MODULATION
@@ -455,7 +784,7 @@ initial sequence numbers (ISNs) are chosen.
 Some popular stack implementations choose
 .Cm very
 poor ISNs and thus are normally susceptible to ISN prediction exploits.
-By applying a "modulate state" rule to a TCP connection,
+By applying a "modulate state" rule to a TCP connection, 
 .Em pf
 will create a high quality random sequence number for each connection
 endpoint.
@@ -482,7 +811,6 @@ it will not be able to safely modulate the state of that connection.
 will fall back and operate as if "keep state" was specified instead.
 Without this fallback, modulation would cause each host to
 think that the other end had somehow lost sync.
-.\" XXX -- are the above and below caveats contradictory?
 .Pp
 Caveat:  If the state table is flushed or the firewall is rebooted,
 currently modulated connections can not be continued or picked
@@ -493,7 +821,7 @@ shift the sequencing of each side of a connection
 add a random number to each side.
 .Pc
 Both sides of the connection will notice, that its peer has suddenly
-shifted its sequence by a random amount.
+shifted its sequence by a random amount. 
 Neither side
 will be able to recover and the connection will stall and eventually close.
 .Sh STATE OPTIONS
@@ -506,160 +834,14 @@ create state are dropped, until existing states time out.
 .It Em timeout seconds
 Changes the timeout values used for states created by this rule.
 For a list of all valid timeout names, see
-.Em OPTIONS .
+.Xr pfctl 8 .
 .El
 .Pp
-Multiple options can be specified enclosed by parenthesis:
+Multiple options can be specified, separated by commas:
 .Bd -literal
     pass in proto tcp from any to any port www flags S/SA \\
       keep state (max 100, tcp.established 60, tcp.closing 5)
 .Ed
-.Sh OPTIONS
-The syntax for global options is
-.Bd -literal
-.Cm set option parameters
-.Ed
-.Pp
-Per-rule options are described at the appropriate places.
-.Ss optimization
-The
-.Em optimization
-options are just bundles of
-.Em timeout
-options.
-Optimize the engine to one of the following network topographies or
-environments:
-.Bl -tag -width "O high-latency " -compact
-.It Em default
-A normal network environment.
-Suitable for almost all networks.
-.It Em normal
-Alias for
-.Em default
-.It Em high-latency
-A high-latency environment (such as a satellite connection)
-.It Em satellite
-Alias for
-.Em high-latency
-.It Em aggressive
-Aggressively expire connections when they are likely no longer valid.
-This can greatly reduce the memory usage of the firewall at the cost of
-dropping idle connections early.
-.It Em conservative
-Extremely conservative settings.
-Pains will be taken to avoid dropping legitimate connections at the
-expense of greater memory utilization (possibly much greater on a busy
-network) and slightly increased processor utilization.
-.El
-Example:
-.Bd -literal
-    set optimization aggressive
-.Ed
-.Ss timeout
-.Bl -tag -width interval -compact
-.It Em interval
-Interval between purging expired states and fragments.
-.It Em frag
-Seconds before an unassembled fragment is expired.
-.El
-.Pp
-When a packet matches a stateful connection, the seconds to live of the
-connection will be updated to that of the proto.modifier which corresponds
-to the connection state.
-Each packet which matches this state will reset the TTL.
-Tuning these values may improve the performance of the
-firewall at the risk of dropping valid idled connections.
-.Pp
-.Bl -tag -width "tcp.established " -compact
-.It Em tcp.first
-The state after the first packet.
-.It Em tcp.opening
-The state before the destination host ever sends a packet.
-.It Em tcp.established
-The fully established state.
-.It Em tcp.closing
-The state after the first FIN has been sent.
-.It Em tcp.finwait
-The state after both FINs have been exchanged and the connection is closed.
-Some hosts (notably web servers on Solaris) send TCP packets even after closing
-the connection.
-Increasing tcp.finwait (and possibly tcp.closing) can prevent blocking of
-such packets.
-.It Em tcp.closed
-The state after one endpoint sends a RST.
-.El
-.Pp
-ICMP and UDP are handled in a similar fashion to TCP but with a much more
-limited set of states:
-.Pp
-.Bl -tag -width "udp.multiple " -compact
-.It Em udp.first
-The state after the first packet.
-.It Em udp.single
-The state if the source host sends more than one packet but the destination
-host has never sent one back.
-.It Em udp.multiple
-The state if both hosts have sent packets.
-.It Em icmp.first
-The state after the first packet.
-.It Em icmp.error
-The state after an icmp error came back in response to an icmp packet.
-.El
-.Pp
-Other protocols are handled similarly to UDP:
-.Pp
-.Bl -tag -width "other.multiple " -compact
-.It Em other.first
-.It Em other.single
-.It Em other.multiple
-.El
-.Pp
-Example:
-.Bd -literal
-    set timeout tcp.established 3600
-    set timeout { tcp.opening 30, tcp.closing 900 }
-.Ed
-.Ss loginterface
-Enable collection of packet and byte count statistics for the given interface.
-These statistics can be viewed using
-.Bd -literal
-    # pfctl -s info
-.Ed
-.Pp
-In this example pf is told to collect statistics on the interface named dc0:
-.Bd -literal
-    set loginterface dc0
-.Ed
-.Pp
-One can unset the loginterface using
-.Bd -literal
-    set loginterface none
-.Ed
-.Pp
-.Ss limit
-Sets hard limits on the memory pools used by the packet filter.
-See
-.Xr pool 9
-for an explanation of memory pools.
-.Pp
-For example,
-.Bd -literal
-    set limit states 20000
-.Ed
-.Pp
-sets the maximum number of entries in the memory pool used by state table
-entries (generated by 'keep state' rules) to 20000.
-.Bd -literal
-    set limit frags 20000
-.Ed
-.Pp
-set the maximum number of entries in the memory pool used for fragment
-reassemble (generated by 'scrub' rules) to 20000.
-.Pp
-These can be combined:
-.Bd -literal
-    set limit { states 20000, frags 20000 }
-.Ed
 .Sh NORMALIZATION
 Packet normalization is invoked via the
 .Pa scrub
@@ -682,10 +864,10 @@ Enforces a maximum mss for matching tcp packets.
 .Pp
 Normalization occurs before filtering, scrub rules and pass/block
 rules are evaluated independently.
-XXX Hence, their relative position in the rule set is not relevant,
-XXX and packets can't be blocked before normalization.
+Hence, their relative position in the rule set is not relevant,
+and packets can't be blocked before normalization.
 .Sh FRAGMENT HANDLING
-IP datagrams (packets) can have a size of up to 65535 bytes.
+IP datagrams (packets) can have a size of up to 65335 bytes.
 Most network links, however, have a maximum transmission unit (MTU)
 that is significantly lower (1500 bytes is common).
 When an IP packet's size exceeds the MTU of the interface it has to
@@ -737,33 +919,14 @@ In most cases, the benefits of reassembly outweigh the additional
 memory cost, and it's recommended to use scrub rules to reassemble
 all fragments.
 .Pp
-The memory allocated for fragment caching can be limited. See
-.Em OPTIONS
-for parameters.
+The memory allocated for fragment caching can be limited using
+.Xr pfctl 8 .
 Once this limit is reached, fragments that would have to be cached
 are dropped until other entries time out. The timeout value can
 also be adjusted.
 .Pp
 Currently, only IPv4 fragments are supported and IPv6 fragments
 are blocked unconditionally.
-.Sh ROUTING
-If a packet matches a rule with a route option set, the packet filter will
-route the packet according to the type of route option.
-.Ss fastroute
-The
-.Em fastroute
-option does a normal route lookup to find the next hop for the packet.
-.Ss route-to
-The
-.Em route-to
-option routes the packet to the specified interface with an optional address
-for the next hop.
-.Ss dup-to
-The
-.Em dup-to
-option creates a duplicate of the packet and routes it like
-.Em route-to.
-The original packet gets routed as it normally would.
 .Sh FILTER EXAMPLES
 .Bd -literal
 # The external interface is kue0
@@ -834,18 +997,18 @@ pass in on $ext_if proto tcp from any to 157.161.48.183 port >= 49152 \\
 	flags S/SA keep state
 
 .Ed
-.Sh NAT EXAMPLES
+.SH NAT EXAMPLES
 This example maps incoming requests on port 80 to port 8080, on
 which Apache Tomcat is running (say Tomcat is not run as root,
 therefore lacks permission to bind to port 80).
 .Bd -literal
 # map tomcat on 8080 to appear to be on 80
-rdr on $ext_if proto tcp from any to any port 80 -> 127.0.0.1 port 8080
+rdr on ne3 proto tcp from any to any port 80 -> 127.0.0.1 port 8080
 .Ed
 .Pp
-In the example below, vlan12 is configured for 192.168.168.1;
-the machine translates all packets coming from 192.168.168.0/24 to 
-204.92.77.111 when they are going out any interface except vlan12.
+In the example below, vlan12 is configured for the 192.168.168.1;
+the machine translates all packets coming from 192.168.168.0/24 to 204.92.77.111
+when they are going out any interface except vlan12.
 This has the net effect of making traffic from the 192.168.168.0/24
 network appear as though it is the Internet routeable address
 204.92.77.111 to nodes behind any interface on the router except
@@ -872,7 +1035,7 @@ are not proxied, all other connections are.
 # NO RDR
 no rdr on fxp0 from any        to $server port 80
 no rdr on fxp0 from $sysadmins to any     port 80
-   rdr on fxp0 from any        to any     port 80 -> 127.0.0.1 port 3128
+   rdr on fxp0 from any        to any     port 80 -> 127.0.0.1 port 80
 .Ed
 .Pp
 This longer example uses both a NAT and a redirection.
@@ -908,163 +1071,10 @@ rdr on kue0 inet proto tcp from any to (kue0) port 8080 -> 10.1.2.151 \\
 rdr on kue0 inet proto udp from any to (kue0) port 8080 -> 10.1.2.151 \\
 	port 53
 
+# RDR
 # translate outgoing ftp control connections to send them to localhost
 # for proxying with ftp-proxy(8) running on port 8081
 rdr on fxp0 proto tcp from any to any port 21 -> 127.0.0.1 port 8081
-
-# redirect a range of ports
-# will redirect anything from port 2000 to 2999 to port 4000
-rdr on kue0 inet proto tcp from any to (kue0) port 2000:2999 -> 10.1.2.151 \\
-	 port 4000
-# will redirect anything from port 2000 to 2999 to port 4000 to 4999 (1:1)
-rdr on kue0 inet proto tcp from any to (kue0) port 2000:2999 -> 10.1.2.151 \\
-	 port 4000:*
-.Ed
-.Sh CAVEATS
-.Ss normalization
-IPv6 packets are not sanitized and are inspected by the filter as usual.
-.Ss translation
-If no rule matches the packet, the default action is to pass the packet
-up to the filter unmodified.
-It should be noted that all translations of packets occur before
-the filters are applied.
-Hence, rules for translated packets should specify the address and port
-after translation.
-Note that all translation rules apply only to packets that pass through
-the specified interface.
-For instance, redirecting port 80 on an external interface to an internal
-web server will only work for connections originating from the outside.
-Connections to the address of the external interface from local hosts will
-not be redirected, since such packets do not actually pass through the
-external interface.
-Redirections can't reflect packets back through the interface they arrive
-on, they can only be redirected to hosts connected to different interfaces
-or to the firewall itself. This applies also to connections originating
-from the firewall itself, like if one tries to use the
-.Xr ftp-proxy 8
-and uses:
-.Bd -literal
-rdr on $ext_if from $fw_ip to any port 21 -> 127.0.0.1 port 8081
-.Ed
-this wont work.
-.Ss filter
-Filtering on a
-.Xr bridge 4
-can have unwanted blocking of packets, if more then one interface is
-configured. See the
-.Em NOTES
-section there.
-.Sh GRAMMAR
-Syntax for
-.Em pf.conf
-in BNF:
-.Bd -literal
-line           = ( option | pf_rule | macro | [ "no" ] ( nat_rule | 
-                 binat_rule | rdr_rule ) )
-
-option         = set ( [ "timeout" ( timeout | "{" timeout-list "}" ) ] |
-                       [ "optimization" [ "default" | "normal" |
-				"high-latency" | "satellite" |
-				"aggressive" | "conservative" ] ]
-                       [ "limit" ( limit | "{" limit-list "}" ) ] |
-		       [ "loginterface" ( interface-name | "none" ) ] ) .
-
-pf_rule        = action ( "in" | "out" )
-                 [ "log" | "log-all" ] [ "quick" ]
-                 [ "on" ( [ "!" ] interface-name | "{" interface-list "}" ) ]
-                 [ route ] [ af ]
-                 [ protospec ] 
-                 hosts
-                 [ user ] [ group ] [ flags ]
-                 [ icmp-type | ipv6-icmp-type ]
-                 [ ( "keep" | "modulate" ) "state" [ "(" state-opts ")" ] ]
-                 [ "fragment" ] [ "no-df" ] [ "min-ttl" number ]
-                 [ "max-mss" number ] [ "allow-opts" ]
-                 [ "label" string ] .
-
-action         = "pass" | "block" [ return ] | "scrub" .
-
-return         = "return-rst" [ "(" "ttl" number ")" ] |
-                 "return-icmp"
-                     [ "(" ( icmp-code-name | icmp-code-number ) ")" ] |
-                 "return-icmp6"
-                     [ "(" ( icmp-code-name | icmp-code-number ) ")" ] .
-
-interface-list = [ "!" ] interface-name [ [ "," ] interface-list ] .
-
-route          = "fastroute" |
-                 "route-to" "(" interface-name address ")" |
-                 "route-to" interface-name |
-                 "dup-to" "(" interface-name address ")" |
-                 "dup-to" interface-name
-
-af	       = "inet" | "inet6" .
-
-protospec      = "proto" ( proto-name | proto-number | "{" proto-list "}" ) .
-
-proto-list     = ( proto-name | proto-number ) [ [ "," ] proto-list ] .
-
-hosts          = "all" |
-                 "from" ( "any" | "no-route" | "self" | host | 
-                 "{" host-list "}" ) [ port ]
-                 "to"   ( "any" | "no-route" | "self" | host | 
-                 "{" host-list "}" ) [ port ] .
-
-host           = [ "!" ] address [ "/" mask-bits ] .
-address        = ( interface-name | "(" interface-name ")" | host-name |
-                   ipv4-dotted-quad | ipv6-coloned-hex ) .
-host-list      = host [ [ "," ] host-list ] .
-
-port           = "port" ( unary-op | binary-op | "{" op-list "}" ) .
-user           = "user" ( unary-op | binary-op | "{" op-list "}" ) .
-group          = "group" ( unary-op | binary-op | "{" op-list "}" ) .
-
-binary-op      = number ( "<>" | "><" ) number .
-op-list        = ( unary-op | binary-op ) [ [ "," ] op-list ] .
-
-flags          = "flags" ( flag-set | flag-set "/" flag-set |
-                           "/" flag-set ) .
-flag-set       = [ "F" ] [ "S" ] [ "R" ] [ "P" ] [ "A" ] [ "U" ] [ "E" ]
-                 [ "W" ] .
-
-icmp-type      = "icmp-type" ( icmp-type-code | "{" icmp-list "}" ) .
-ipv6-icmp-type = "ipv6-icmp-type" ( icmp-type-code | "{" icmp-list "}" ) .
-icmp-type-code = ( icmp-type-name | icmp-type-number )
-                 [ "code" ( icmp-code-name | icmp-code-number ) ] .
-icmp-list      = icmp-type-code [ [ "," ] icmp-list ] .
-
-state-opts     = state-opt [ [ "," ] state-opts ] .
-state-opt      = ( "max" seconds ) | ( timeout seconds ) .
-
-timeout-list   = timeout [ [ "," ] timeout-list ] .
-timeout        = ( "tcp.first" | "tcp.opening" | "tcp.established" |
-                 "tcp.closing" | "tcp.finwait" | "tcp.closed" |
-                 "udp.first" | "udp.single" | "udp.multiple" |
-                 "icmp.first" | "icmp.error" |
-                 "other.first" | "other.multiple" ) seconds .
-seconds        = number .
-
-limit-list     = limit [ [ "," ] limit-list ] .
-limit          = ( "states" | "frags" ) number .
-
-macro          = string "=" string
-
-nat_rule       = "nat" "on" [ "!" ] interface-list [ protospec ] hosts
-                 [ "->" address [ portspec ] ] .
-
-binat_rule     = "binat" "on" ifname [ protospec ] "from" address
-                 "to" ipspec [ "->" address ] .
-
-rdr_rule       = "rdr" "on" [ "!" ] interface-list [ ( proto-name | 
-                 proto-number ) ] "from" ipspec "to" ipspec [ portspec ]
-                 [ "->" address [ portspec ] ] .
-
-ipspec         = "any" | host | "{" host-list "}" .
-
-portspec       = "port" ( number | name ) [ ":" ( "*" | number | name ) ] .
-
-unary-op       = [ "=" | "!=" | "<" | "<=" | ">" | ">=" ]
-                 ( name | number ) .
 .Ed
 .Sh FILES
 .Bl -tag -width "/etc/pf.conf" -compact
@@ -1072,10 +1082,8 @@ unary-op       = [ "=" | "!=" | "<" | "<=" | ">" | ">=" ]
 .It Pa /etc/pf.conf
 .It Pa /etc/protocols
 .It Pa /etc/services
-.It Pa /usr/share/pf/README
 .El
 .Sh SEE ALSO
-.Xr bridge 4 ,
 .Xr pf 4 ,
 .Xr hosts 5 ,
 .Xr protocols 5 ,