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