chiark / gitweb /
Added background resolver from `fw'.
[mLib] / bres.h
CommitLineData
a759efa6 1/* -*-c-*-
2 *
3 * $Id: bres.h,v 1.1 1999/10/04 21:40:42 mdw Exp $
4 *
5 * Background reverse name resolution
6 *
7 * (c) 1999 Straylight/Edgeware
8 */
9
10/*----- Licensing notice --------------------------------------------------*
11 *
12 * This file is part of the mLib utilities library.
13 *
14 * mLib is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU Library General Public License as
16 * published by the Free Software Foundation; either version 2 of the
17 * License, or (at your option) any later version.
18 *
19 * mLib is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU Library General Public License for more details.
23 *
24 * You should have received a copy of the GNU Library General Public
25 * License along with mLib; if not, write to the Free
26 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
27 * MA 02111-1307, USA.
28 */
29
30/*----- Revision history --------------------------------------------------*
31 *
32 * $Log: bres.h,v $
33 * Revision 1.1 1999/10/04 21:40:42 mdw
34 * Added background resolver from `fw'.
35 *
36 */
37
38#ifndef RES_H
39#define RES_H
40
41#ifdef __cplusplus
42 extern "C" {
43#endif
44
45/*----- Header files ------------------------------------------------------*/
46
47#include <sys/types.h>
48
49#include <sys/socket.h>
50#include <netinet/in.h>
51#include <arpa/inet.h>
52#include <netdb.h>
53
54#include <mLib/sel.h>
55#include <mLib/selbuf.h>
56
57/*----- Data structures ---------------------------------------------------*/
58
59/* --- Client allocated request block --- */
60
61typedef struct bres_client {
62 struct bres_client *next, *prev; /* Queue of waiting resolve jobs */
63 struct bres_server *rs; /* Pointer to attached server */
64 int q; /* Query type (name or address) */
65 union {
66 struct in_addr addr; /* Address to resolve */
67 char *name; /* Name to resolve */
68 } u;
69 void (*func)(struct hostent */*h*/, void */*p*/); /* Handler function */
70 void *p; /* Argument for handler function */
71} bres_client;
72
73/* --- Server maintained resolver blocks --- */
74
75typedef struct bres_server {
76 struct bres_server *next, *prev; /* Doubly-linked list of servers */
77 pid_t kid; /* Process id of server process */
78 int fd; /* File descriptors */
79 struct bres_client *rc; /* Pointer to attached client */
80 sel_timer t; /* Timeout for idle servers */
81 sel_file f; /* Read selector for server */
82} bres_server;
83
84/*----- Functions provided ------------------------------------------------*/
85
86/* --- @bres_abort@ --- *
87 *
88 * Arguments: @bres_client *rc@ = pointer to client block
89 *
90 * Returns: ---
91 *
92 * Use: Removes a queued job.
93 */
94
95extern void bres_abort(bres_client */*rc*/);
96
97/* --- @bres_byaddr@ --- *
98 *
99 * Arguments: @bres_client *rc@ = pointer to client block
100 * @struct in_addr addr@ = address to resolve
101 * @void (*func)(struct hostent *h, void *p)@ = handler function
102 * @void *p@ = argument for handler function
103 *
104 * Returns: ---
105 *
106 * Use: Adds an address lookup job to the queue. The job will be
107 * processed when there's a spare resolver process to deal with
108 * it.
109 */
110
111extern void bres_byaddr(bres_client */*rc*/, struct in_addr /*addr*/,
112 void (*/*func*/)(struct hostent */*h*/, void */*p*/),
113 void */*p*/);
114
115/* --- @bres_byname@ --- *
116 *
117 * Arguments: @bres_client *rc@ = pointer to client block
118 * @const char *name@ = name to resolve
119 * @void (*func)(struct hostent *h, void *p)@ = handler function
120 * @void *p@ = argument for handler function
121 *
122 * Returns: ---
123 *
124 * Use: Adds a name lookup job to the queue. The job will be
125 * processed when there's a spare resolver process to deal with
126 * it.
127 */
128
129extern void bres_byname(bres_client */*rc*/, const char */*name*/,
130 void (*/*func*/)(struct hostent */*h*/, void */*p*/),
131 void */*p*/);
132
133/* --- @bres_exec@ --- *
134 *
135 * Arguments: @const char *file@ = file containing server code or null
136 *
137 * Returns: ---
138 *
139 * Use: Makes `bres' use a standalone server rather than copies of
140 * the current process. This can reduce memory consumption for
141 * large processes, at the expense of startup time (which
142 * shouldn't be too bad anyway, because of the resolver design).
143 * If the filename is null, a default set up at install time is
144 * used. It's probably a good idea to leave it alone.
145 */
146
147extern void bres_exec(const char */*file*/);
148
149/* --- @bres_init@ --- *
150 *
151 * Arguments: @sel_state *s@ = pointer to select multiplexor
152 *
153 * Returns: ---
154 *
155 * Use: Initializes the background resolver for use.
156 */
157
158extern void bres_init(sel_state */*s*/);
159
160/*----- That's all, folks -------------------------------------------------*/
161
162#ifdef __cplusplus
163 }
164#endif
165
166#endif