3 * $Id: bres.h,v 1.3 1999/12/10 23:42:04 mdw Exp $
5 * Background reverse name resolution
7 * (c) 1999 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of the mLib utilities library.
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.
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.
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,
30 /*----- Revision history --------------------------------------------------*
33 * Revision 1.3 1999/12/10 23:42:04 mdw
34 * Change header file guard names.
36 * Revision 1.2 1999/10/30 11:56:21 mdw
37 * Fix include error, pointed out by Chris Rutter.
39 * Revision 1.1 1999/10/04 21:40:42 mdw
40 * Added background resolver from `fw'.
51 /*----- Header files ------------------------------------------------------*/
53 #include <sys/types.h>
55 #include <sys/socket.h>
56 #include <netinet/in.h>
57 #include <arpa/inet.h>
63 /*----- Data structures ---------------------------------------------------*/
65 /* --- Client allocated request block --- */
67 typedef struct bres_client
{
68 struct bres_client
*next
, *prev
; /* Queue of waiting resolve jobs */
69 struct bres_server
*rs
; /* Pointer to attached server */
70 int q
; /* Query type (name or address) */
72 struct in_addr addr
; /* Address to resolve */
73 char *name
; /* Name to resolve */
75 void (*func
)(struct hostent */
*h*/
, void */
*p*/
); /* Handler function */
76 void *p
; /* Argument for handler function */
79 /* --- Server maintained resolver blocks --- */
81 typedef struct bres_server
{
82 struct bres_server
*next
, *prev
; /* Doubly-linked list of servers */
83 pid_t kid
; /* Process id of server process */
84 int fd
; /* File descriptors */
85 struct bres_client
*rc
; /* Pointer to attached client */
86 sel_timer t
; /* Timeout for idle servers */
87 sel_file f
; /* Read selector for server */
90 /*----- Functions provided ------------------------------------------------*/
92 /* --- @bres_abort@ --- *
94 * Arguments: @bres_client *rc@ = pointer to client block
98 * Use: Removes a queued job.
101 extern void bres_abort(bres_client */
*rc*/
);
103 /* --- @bres_byaddr@ --- *
105 * Arguments: @bres_client *rc@ = pointer to client block
106 * @struct in_addr addr@ = address to resolve
107 * @void (*func)(struct hostent *h, void *p)@ = handler function
108 * @void *p@ = argument for handler function
112 * Use: Adds an address lookup job to the queue. The job will be
113 * processed when there's a spare resolver process to deal with
117 extern void bres_byaddr(bres_client */
*rc*/
, struct in_addr
/*addr*/,
118 void (*/
*func*/
)(struct hostent */
*h*/
, void */
*p*/
),
121 /* --- @bres_byname@ --- *
123 * Arguments: @bres_client *rc@ = pointer to client block
124 * @const char *name@ = name to resolve
125 * @void (*func)(struct hostent *h, void *p)@ = handler function
126 * @void *p@ = argument for handler function
130 * Use: Adds a name lookup job to the queue. The job will be
131 * processed when there's a spare resolver process to deal with
135 extern void bres_byname(bres_client */
*rc*/
, const char */
*name*/
,
136 void (*/
*func*/
)(struct hostent */
*h*/
, void */
*p*/
),
139 /* --- @bres_exec@ --- *
141 * Arguments: @const char *file@ = file containing server code or null
145 * Use: Makes `bres' use a standalone server rather than copies of
146 * the current process. This can reduce memory consumption for
147 * large processes, at the expense of startup time (which
148 * shouldn't be too bad anyway, because of the resolver design).
149 * If the filename is null, a default set up at install time is
150 * used. It's probably a good idea to leave it alone.
153 extern void bres_exec(const char */
*file*/
);
155 /* --- @bres_init@ --- *
157 * Arguments: @sel_state *s@ = pointer to select multiplexor
161 * Use: Initializes the background resolver for use.
164 extern void bres_init(sel_state */
*s*/
);
166 /*----- That's all, folks -------------------------------------------------*/