3 * $Id: bres.h,v 1.4 2003/12/13 20:37:59 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 1.4 2003/12/13 20:37:59 mdw
34 * Add adns support in background resolver.
36 * Revision 1.3 1999/12/10 23:42:04 mdw
37 * Change header file guard names.
39 * Revision 1.2 1999/10/30 11:56:21 mdw
40 * Fix include error, pointed out by Chris Rutter.
42 * Revision 1.1 1999/10/04 21:40:42 mdw
43 * Added background resolver from `fw'.
54 /*----- Header files ------------------------------------------------------*/
56 #include <sys/types.h>
58 #include <sys/socket.h>
59 #include <netinet/in.h>
60 #include <arpa/inet.h>
70 /*----- Data structures ---------------------------------------------------*/
72 /* --- Client allocated request block --- */
74 typedef struct bres_client {
76 adns_query aq; /* ADNS query handle */
77 adns_answer *a; /* Answer for reverse resolution */
78 struct _unused *_pad1; /* And a spare slot */
80 struct bres_client *next, *prev; /* Queue of waiting resolve jobs */
81 struct bres_server *rs; /* Pointer to attached server */
83 int q; /* Query type (name or address) */
85 struct in_addr addr; /* Address to resolve */
86 char *name; /* Name to resolve */
88 void (*func)(struct hostent */*h*/, void */*p*/); /* Handler function */
89 void *p; /* Argument for handler function */
92 /* --- Server maintained resolver blocks --- */
94 typedef struct bres_server {
95 struct bres_server *next, *prev; /* Doubly-linked list of servers */
96 pid_t kid; /* Process id of server process */
97 int fd; /* File descriptors */
98 struct bres_client *rc; /* Pointer to attached client */
99 sel_timer t; /* Timeout for idle servers */
100 sel_file f; /* Read selector for server */
103 /*----- Functions provided ------------------------------------------------*/
105 /* --- @bres_abort@ --- *
107 * Arguments: @bres_client *rc@ = pointer to client block
111 * Use: Removes a queued job.
114 extern void bres_abort(bres_client */*rc*/);
116 /* --- @bres_byaddr@ --- *
118 * Arguments: @bres_client *rc@ = pointer to client block
119 * @struct in_addr addr@ = address to resolve
120 * @void (*func)(struct hostent *h, void *p)@ = handler function
121 * @void *p@ = argument for handler function
125 * Use: Adds an address lookup job to the queue. The job will be
126 * processed when there's a spare resolver process to deal with
130 extern void bres_byaddr(bres_client */*rc*/, struct in_addr /*addr*/,
131 void (*/*func*/)(struct hostent */*h*/, void */*p*/),
134 /* --- @bres_byname@ --- *
136 * Arguments: @bres_client *rc@ = pointer to client block
137 * @const char *name@ = name to resolve
138 * @void (*func)(struct hostent *h, void *p)@ = handler function
139 * @void *p@ = argument for handler function
143 * Use: Adds a name lookup job to the queue. The job will be
144 * processed when there's a spare resolver process to deal with
148 extern void bres_byname(bres_client */*rc*/, const char */*name*/,
149 void (*/*func*/)(struct hostent */*h*/, void */*p*/),
152 /* --- @bres_exec@ --- *
154 * Arguments: @const char *file@ = file containing server code or null
158 * Use: Makes `bres' use a standalone server rather than copies of
159 * the current process. This can reduce memory consumption for
160 * large processes, at the expense of startup time (which
161 * shouldn't be too bad anyway, because of the resolver design).
162 * If the filename is null, a default set up at install time is
163 * used. It's probably a good idea to leave it alone.
166 extern void bres_exec(const char */*file*/);
168 /* --- @bres_init@ --- *
170 * Arguments: @sel_state *s@ = pointer to select multiplexor
174 * Use: Initializes the background resolver for use.
177 extern void bres_init(sel_state */*s*/);
179 /*----- That's all, folks -------------------------------------------------*/