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 7, 2001 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/* user-protocol hook */ 98 pr_usrreq_t *pr_ousrreq; 99/* utility hooks */ 100 pr_init_t *pr_init; 101 pr_fasttimo_t *pr_fasttimo; /* fast timeout (200ms) */ 102 pr_slowtimo_t *pr_slowtimo; /* slow timeout (500ms) */ 103 pr_drain_t *pr_drain; /* flush any excess space possible */ 104 105 struct pr_usrreqs *pr_usrreqs; /* supersedes pr_usrreq() */ 106 struct pfil_head pr_pfh; 107}; 108.Ed 109.Pp 110The following functions handle the registration of a new domain, 111lookups of specific protocols and protocol types within those domains, 112and handle control messages from the system. 113.Pp 114.Fn pfctlinput 115is called by the system whenever an event occurs that could affect every 116domain. 117Examples of those types of events are routing table changes, interface 118shutdowns or certain 119.Tn ICMP 120message types. 121When called, 122.Fn pfctlinput 123calls the protocol specific 124.Fn pr_ctlinput 125function for each protocol in that has defined one, in every domain. 126.Pp 127.Fn pfctlinput2 128provides that same functionality of 129.Fn pfctlinput , 130but with a few additional checks and a new 131.Vt "void *" 132argument that is passed directly to the protocol's 133.Fn pr_ctlinput 134function. 135Unlike 136.Fn pfctlinput , 137.Fn pfctlinput2 138verifies that 139.Fa sa 140is not 141.Dv NULL , 142and that only the protocol families that are the same as 143.Fa sa 144have their 145.Fn pr_ctlinput 146function called. 147.Pp 148.Fn net_add_domain 149adds a new protocol domain to the system. 150The argument 151.Fa data 152is cast directly to 153.Vt "struct domain *" 154within the function, but is declared 155.Vt "void *" 156in order to prevent compiler warnings when new domains are registered with 157.Fn SYSINIT . 158In most cases 159.Fn net_add_domain 160is not called directly, instead 161.Fn DOMAIN_SET 162is used. 163.Pp 164If the new domain has defined an initialization routine, it is called by 165.Fn net_add_domain ; 166as well, each of the protocols within the domain that have defined an 167initialization routine will have theirs called. 168.Pp 169Once a domain is added it cannot be unloaded. 170This is because there is 171no reference counting system in place to determine if there are any 172active references from sockets within that domain. 173.Pp 174.Fn pffindtype 175and 176.Fn pffindproto 177look up a protocol by its number or by its type. 178In most cases, if the protocol or type cannot be found, 179.Dv NULL 180is returned, but 181.Fn pffindproto 182may return the default if the requested type is 183.Dv SOCK_RAW , 184a protocol switch type of 185.Dv SOCK_RAW 186is found, and the domain has a default raw protocol. 187.Pp 188Both functions are called by 189.Fn socreate 190in order to resolve the protocol for the socket currently being created. 191.Pp 192.Fn DOMAIN_SET 193is a macro that simplifies the registration of a domain via 194.Fn SYSINIT . 195The code resulting from the macro expects there to be a domain structure 196named 197.Dq Fa name Ns Li domain 198where 199.Fa name 200is the argument to 201.Fn DOMAIN_SET : 202.Bd -literal 203struct domain localdomain = 204{ AF_LOCAL, "local", unp_init, unp_externalize, unp_dispose, 205 localsw, &localsw[sizeof(localsw)/sizeof(localsw[0])] }; 206 207DOMAIN_SET(local); 208.Ed 209.Sh RETURN VALUES 210Both 211.Fn pffindtype 212and 213.Fn pffindproto 214return a 215.Vt "struct protosw *" 216for the protocol requested. 217If the protocol or socket type is not found, 218.Dv NULL 219is returned. 220In the case of 221.Fn pffindproto , 222the default protocol may be returned for 223.Dv SOCK_RAW 224types if the domain has a default raw protocol. 225.Sh SEE ALSO 226.Xr socket 2 227.Sh AUTHORS 228This manual page was written by 229.An Chad David Aq davidc@acns.ab.ca . 230