1.\" 2.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice(s), this list of conditions and the following disclaimer as 9.\" the first lines of this file unmodified other than the possible 10.\" addition of one or more copyright notices. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice(s), this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY 16.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 18.\" DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY 19.\" DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 20.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 22.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 25.\" DAMAGE. 26.\" 27.\" $FreeBSD$ 28.\" 29.Dd November 6, 2014 30.Dt DOMAIN 9 31.Os 32.Sh NAME 33.Nm domain_add , 34.Nm pfctlinput , 35.Nm pfctlinput2 , 36.Nm pffinddomain , 37.Nm pffindproto , 38.Nm pffindtype , 39.Nm DOMAIN_SET 40.Nd "network domain management" 41.Sh SYNOPSIS 42.In sys/param.h 43.In sys/kernel.h 44.In sys/protosw.h 45.In sys/domain.h 46.Ft void 47.Fn domain_add "void *data" 48.Ft void 49.Fn pfctlinput "int cmd" "struct sockaddr *sa" 50.Ft void 51.Fn pfctlinput2 "int cmd" "struct sockaddr *sa" "void *ctlparam" 52.Ft struct domain * 53.Fn pffinddomain "int family" 54.Ft struct protosw * 55.Fn pffindproto "int family" "int protocol" "int type" 56.Ft struct protosw * 57.Fn pffindtype "int family" "int type" 58.Ft void 59.Fn DOMAIN_SET "name" 60.Sh DESCRIPTION 61Network protocols installed in the system are maintained within what 62are called domains 63(for example the 64.Va inetdomain 65and 66.Va localdomain ) . 67.Bd -literal 68struct domain { 69 int dom_family; /* AF_xxx */ 70 char *dom_name; 71 void (*dom_init) /* initialize domain data structures */ 72 (void); 73 void (*dom_destroy) /* cleanup structures / state */ 74 (void); 75 int (*dom_externalize) /* externalize access rights */ 76 (struct mbuf *, struct mbuf **); 77 void (*dom_dispose) /* dispose of internalized rights */ 78 (struct mbuf *); 79 struct protosw *dom_protosw, *dom_protoswNPROTOSW; 80 struct domain *dom_next; 81 int (*dom_rtattach) /* initialize routing table */ 82 (void **, int); 83 int (*dom_rtdetach) /* clean up routing table */ 84 (void **, int); 85 void *(*dom_ifattach)(struct ifnet *); 86 void (*dom_ifdetach)(struct ifnet *, void *); 87 int (*dom_ifmtu)(struct ifnet *); 88 /* af-dependent data on ifnet */ 89}; 90.Ed 91.Pp 92Each domain contains an array of protocol switch structures 93.Pq Vt "struct protosw *" , 94one for each socket type supported. 95.Bd -literal 96struct protosw { 97 short pr_type; /* socket type used for */ 98 struct domain *pr_domain; /* domain protocol a member of */ 99 short pr_protocol; /* protocol number */ 100 short pr_flags; /* see below */ 101/* protocol-protocol hooks */ 102 pr_input_t *pr_input; /* input to protocol (from below) */ 103 pr_output_t *pr_output; /* output to protocol (from above) */ 104 pr_ctlinput_t *pr_ctlinput; /* control input (from below) */ 105 pr_ctloutput_t *pr_ctloutput; /* control output (from above) */ 106/* utility hooks */ 107 pr_init_t *pr_init; 108 pr_destroy_t *pr_destroy; 109 pr_fasttimo_t *pr_fasttimo; /* fast timeout (200ms) */ 110 pr_slowtimo_t *pr_slowtimo; /* slow timeout (500ms) */ 111 pr_drain_t *pr_drain; /* flush any excess space possible */ 112 113 struct pr_usrreqs *pr_usrreqs; /* user-protocol hook */ 114}; 115.Ed 116.Pp 117The following functions handle the registration of a new domain, 118lookups of specific protocols and protocol types within those domains, 119and handle control messages from the system. 120.Pp 121.Fn pfctlinput 122is called by the system whenever an event occurs that could affect every 123domain. 124Examples of those types of events are routing table changes, interface 125shutdowns or certain 126.Tn ICMP 127message types. 128When called, 129.Fn pfctlinput 130calls the protocol specific 131.Fn pr_ctlinput 132function for each protocol in that has defined one, in every domain. 133.Pp 134.Fn pfctlinput2 135provides that same functionality of 136.Fn pfctlinput , 137but with a few additional checks and a new 138.Vt "void *" 139argument that is passed directly to the protocol's 140.Fn pr_ctlinput 141function. 142Unlike 143.Fn pfctlinput , 144.Fn pfctlinput2 145verifies that 146.Fa sa 147is not 148.Dv NULL , 149and that only the protocol families that are the same as 150.Fa sa 151have their 152.Fn pr_ctlinput 153function called. 154.Pp 155.Fn domain_add 156adds a new protocol domain to the system. 157The argument 158.Fa data 159is cast directly to 160.Vt "struct domain *" 161within the function, but is declared 162.Vt "void *" 163in order to prevent compiler warnings when new domains are registered with 164.Fn SYSINIT . 165In most cases 166.Fn domain_add 167is not called directly, instead 168.Fn DOMAIN_SET 169is used. 170.Pp 171If the new domain has defined an initialization routine, it is called by 172.Fn domain_add ; 173as well, each of the protocols within the domain that have defined an 174initialization routine will have theirs called. 175.Pp 176Once a domain is added it cannot be unloaded. 177This is because there is 178no reference counting system in place to determine if there are any 179active references from sockets within that domain. 180.Pp 181.Fn pffinddomain 182finds a domain by family. 183If the domain cannot be found, 184.Dv NULL 185is returned. 186.Pp 187.Fn pffindtype 188and 189.Fn pffindproto 190look up a protocol by its number or by its type. 191In most cases, if the protocol or type cannot be found, 192.Dv NULL 193is returned, but 194.Fn pffindproto 195may return the default if the requested type is 196.Dv SOCK_RAW , 197a protocol switch type of 198.Dv SOCK_RAW 199is found, and the domain has a default raw protocol. 200.Pp 201Both functions are called by 202.Fn socreate 203in order to resolve the protocol for the socket currently being created. 204.Pp 205.Fn DOMAIN_SET 206is a macro that simplifies the registration of a domain via 207.Fn SYSINIT . 208The code resulting from the macro expects there to be a domain structure 209named 210.Dq Fa name Ns Li domain 211where 212.Fa name 213is the argument to 214.Fn DOMAIN_SET : 215.Bd -literal 216struct domain localdomain = 217{ AF_LOCAL, "local", unp_init, unp_externalize, unp_dispose, 218 localsw, &localsw[sizeof(localsw)/sizeof(localsw[0])] }; 219 220DOMAIN_SET(local); 221.Ed 222.Sh RETURN VALUES 223Both 224.Fn pffindtype 225and 226.Fn pffindproto 227return a 228.Vt "struct protosw *" 229for the protocol requested. 230If the protocol or socket type is not found, 231.Dv NULL 232is returned. 233In the case of 234.Fn pffindproto , 235the default protocol may be returned for 236.Dv SOCK_RAW 237types if the domain has a default raw protocol. 238.Sh SEE ALSO 239.Xr socket 2 240.Sh AUTHORS 241This manual page was written by 242.An Chad David Aq Mt davidc@acns.ab.ca . 243