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 December 23, 2008 30.Dt DOMAIN 9 31.Os 32.Sh NAME 33.Nm net_add_domain , 34.Nm pfctlinput , 35.Nm pfctlinput2 , 36.Nm pffindproto , 37.Nm pffindtype , 38.Nm DOMAIN_SET 39.Nd "network domain management" 40.Sh SYNOPSIS 41.In sys/param.h 42.In sys/kernel.h 43.In sys/protosw.h 44.In sys/domain.h 45.Ft void 46.Fn net_add_domain "void *data" 47.Ft void 48.Fn pfctlinput "int cmd" "struct sockaddr *sa" 49.Ft void 50.Fn pfctlinput2 "int cmd" "struct sockaddr *sa" "void *ctlparam" 51.Ft struct protosw * 52.Fn pffindproto "int family" "int protocol" "int type" 53.Ft struct protosw * 54.Fn pffindtype "int family" "int type" 55.Ft void 56.Fn DOMAIN_SET "name" 57.Sh DESCRIPTION 58Network protocols installed in the system are maintained within what 59are called domains 60(for example the 61.Va inetdomain 62and 63.Va localdomain ) . 64.Bd -literal 65struct domain { 66 int dom_family; /* AF_xxx */ 67 char *dom_name; 68 void (*dom_init) /* initialize domain data structures */ 69 (void); 70 int (*dom_externalize) /* externalize access rights */ 71 (struct mbuf *, struct mbuf **); 72 void (*dom_dispose) /* dispose of internalized rights */ 73 (struct mbuf *); 74 struct protosw *dom_protosw, *dom_protoswNPROTOSW; 75 struct domain *dom_next; 76 int (*dom_rtattach) /* initialize routing table */ 77 (void **, int); 78 int dom_rtoffset; /* an arg to rtattach, in bits */ 79 int dom_maxrtkey; /* for routing layer */ 80}; 81.Ed 82.Pp 83Each domain contains an array of protocol switch structures 84.Pq Vt "struct protosw *" , 85one for each socket type supported. 86.Bd -literal 87struct protosw { 88 short pr_type; /* socket type used for */ 89 struct domain *pr_domain; /* domain protocol a member of */ 90 short pr_protocol; /* protocol number */ 91 short pr_flags; /* see below */ 92/* protocol-protocol hooks */ 93 pr_input_t *pr_input; /* input to protocol (from below) */ 94 pr_output_t *pr_output; /* output to protocol (from above) */ 95 pr_ctlinput_t *pr_ctlinput; /* control input (from below) */ 96 pr_ctloutput_t *pr_ctloutput; /* control output (from above) */ 97/* utility hooks */ 98 pr_init_t *pr_init; 99 pr_fasttimo_t *pr_fasttimo; /* fast timeout (200ms) */ 100 pr_slowtimo_t *pr_slowtimo; /* slow timeout (500ms) */ 101 pr_drain_t *pr_drain; /* flush any excess space possible */ 102 103 struct pr_usrreqs *pr_usrreqs; /* supersedes pr_usrreq() */ 104}; 105.Ed 106.Pp 107The following functions handle the registration of a new domain, 108lookups of specific protocols and protocol types within those domains, 109and handle control messages from the system. 110.Pp 111.Fn pfctlinput 112is called by the system whenever an event occurs that could affect every 113domain. 114Examples of those types of events are routing table changes, interface 115shutdowns or certain 116.Tn ICMP 117message types. 118When called, 119.Fn pfctlinput 120calls the protocol specific 121.Fn pr_ctlinput 122function for each protocol in that has defined one, in every domain. 123.Pp 124.Fn pfctlinput2 125provides that same functionality of 126.Fn pfctlinput , 127but with a few additional checks and a new 128.Vt "void *" 129argument that is passed directly to the protocol's 130.Fn pr_ctlinput 131function. 132Unlike 133.Fn pfctlinput , 134.Fn pfctlinput2 135verifies that 136.Fa sa 137is not 138.Dv NULL , 139and that only the protocol families that are the same as 140.Fa sa 141have their 142.Fn pr_ctlinput 143function called. 144.Pp 145.Fn net_add_domain 146adds a new protocol domain to the system. 147The argument 148.Fa data 149is cast directly to 150.Vt "struct domain *" 151within the function, but is declared 152.Vt "void *" 153in order to prevent compiler warnings when new domains are registered with 154.Fn SYSINIT . 155In most cases 156.Fn net_add_domain 157is not called directly, instead 158.Fn DOMAIN_SET 159is used. 160.Pp 161If the new domain has defined an initialization routine, it is called by 162.Fn net_add_domain ; 163as well, each of the protocols within the domain that have defined an 164initialization routine will have theirs called. 165.Pp 166Once a domain is added it cannot be unloaded. 167This is because there is 168no reference counting system in place to determine if there are any 169active references from sockets within that domain. 170.Pp 171.Fn pffindtype 172and 173.Fn pffindproto 174look up a protocol by its number or by its type. 175In most cases, if the protocol or type cannot be found, 176.Dv NULL 177is returned, but 178.Fn pffindproto 179may return the default if the requested type is 180.Dv SOCK_RAW , 181a protocol switch type of 182.Dv SOCK_RAW 183is found, and the domain has a default raw protocol. 184.Pp 185Both functions are called by 186.Fn socreate 187in order to resolve the protocol for the socket currently being created. 188.Pp 189.Fn DOMAIN_SET 190is a macro that simplifies the registration of a domain via 191.Fn SYSINIT . 192The code resulting from the macro expects there to be a domain structure 193named 194.Dq Fa name Ns Li domain 195where 196.Fa name 197is the argument to 198.Fn DOMAIN_SET : 199.Bd -literal 200struct domain localdomain = 201{ AF_LOCAL, "local", unp_init, unp_externalize, unp_dispose, 202 localsw, &localsw[sizeof(localsw)/sizeof(localsw[0])] }; 203 204DOMAIN_SET(local); 205.Ed 206.Sh RETURN VALUES 207Both 208.Fn pffindtype 209and 210.Fn pffindproto 211return a 212.Vt "struct protosw *" 213for the protocol requested. 214If the protocol or socket type is not found, 215.Dv NULL 216is returned. 217In the case of 218.Fn pffindproto , 219the default protocol may be returned for 220.Dv SOCK_RAW 221types if the domain has a default raw protocol. 222.Sh SEE ALSO 223.Xr socket 2 224.Sh AUTHORS 225This manual page was written by 226.An Chad David Aq davidc@acns.ab.ca . 227