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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: bres.h,v 1.5 2004/04/08 01:36:11 mdw Exp $ |
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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 | |
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30 | #ifndef MLIB_RES_H |
31 | #define MLIB_RES_H |
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32 | |
33 | #ifdef __cplusplus |
34 | extern "C" { |
35 | #endif |
36 | |
37 | /*----- Header files ------------------------------------------------------*/ |
38 | |
39 | #include <sys/types.h> |
40 | |
41 | #include <sys/socket.h> |
42 | #include <netinet/in.h> |
43 | #include <arpa/inet.h> |
44 | #include <netdb.h> |
45 | |
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46 | #ifdef HAVE_ADNS |
47 | # include <adns.h> |
48 | #endif |
49 | |
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50 | #include "sel.h" |
51 | #include "selbuf.h" |
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52 | |
53 | /*----- Data structures ---------------------------------------------------*/ |
54 | |
55 | /* --- Client allocated request block --- */ |
56 | |
57 | typedef struct bres_client { |
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58 | #ifdef HAVE_ADNS |
59 | adns_query aq; /* ADNS query handle */ |
60 | adns_answer *a; /* Answer for reverse resolution */ |
61 | struct _unused *_pad1; /* And a spare slot */ |
62 | #else |
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63 | struct bres_client *next, *prev; /* Queue of waiting resolve jobs */ |
64 | struct bres_server *rs; /* Pointer to attached server */ |
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65 | #endif |
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66 | int q; /* Query type (name or address) */ |
67 | union { |
68 | struct in_addr addr; /* Address to resolve */ |
69 | char *name; /* Name to resolve */ |
70 | } u; |
71 | void (*func)(struct hostent */*h*/, void */*p*/); /* Handler function */ |
72 | void *p; /* Argument for handler function */ |
73 | } bres_client; |
74 | |
75 | /* --- Server maintained resolver blocks --- */ |
76 | |
77 | typedef struct bres_server { |
78 | struct bres_server *next, *prev; /* Doubly-linked list of servers */ |
79 | pid_t kid; /* Process id of server process */ |
80 | int fd; /* File descriptors */ |
81 | struct bres_client *rc; /* Pointer to attached client */ |
82 | sel_timer t; /* Timeout for idle servers */ |
83 | sel_file f; /* Read selector for server */ |
84 | } bres_server; |
85 | |
86 | /*----- Functions provided ------------------------------------------------*/ |
87 | |
88 | /* --- @bres_abort@ --- * |
89 | * |
90 | * Arguments: @bres_client *rc@ = pointer to client block |
91 | * |
92 | * Returns: --- |
93 | * |
94 | * Use: Removes a queued job. |
95 | */ |
96 | |
97 | extern void bres_abort(bres_client */*rc*/); |
98 | |
99 | /* --- @bres_byaddr@ --- * |
100 | * |
101 | * Arguments: @bres_client *rc@ = pointer to client block |
102 | * @struct in_addr addr@ = address to resolve |
103 | * @void (*func)(struct hostent *h, void *p)@ = handler function |
104 | * @void *p@ = argument for handler function |
105 | * |
106 | * Returns: --- |
107 | * |
108 | * Use: Adds an address lookup job to the queue. The job will be |
109 | * processed when there's a spare resolver process to deal with |
110 | * it. |
111 | */ |
112 | |
113 | extern void bres_byaddr(bres_client */*rc*/, struct in_addr /*addr*/, |
114 | void (*/*func*/)(struct hostent */*h*/, void */*p*/), |
115 | void */*p*/); |
116 | |
117 | /* --- @bres_byname@ --- * |
118 | * |
119 | * Arguments: @bres_client *rc@ = pointer to client block |
120 | * @const char *name@ = name to resolve |
121 | * @void (*func)(struct hostent *h, void *p)@ = handler function |
122 | * @void *p@ = argument for handler function |
123 | * |
124 | * Returns: --- |
125 | * |
126 | * Use: Adds a name lookup job to the queue. The job will be |
127 | * processed when there's a spare resolver process to deal with |
128 | * it. |
129 | */ |
130 | |
131 | extern void bres_byname(bres_client */*rc*/, const char */*name*/, |
132 | void (*/*func*/)(struct hostent */*h*/, void */*p*/), |
133 | void */*p*/); |
134 | |
135 | /* --- @bres_exec@ --- * |
136 | * |
137 | * Arguments: @const char *file@ = file containing server code or null |
138 | * |
139 | * Returns: --- |
140 | * |
141 | * Use: Makes `bres' use a standalone server rather than copies of |
142 | * the current process. This can reduce memory consumption for |
143 | * large processes, at the expense of startup time (which |
144 | * shouldn't be too bad anyway, because of the resolver design). |
145 | * If the filename is null, a default set up at install time is |
146 | * used. It's probably a good idea to leave it alone. |
147 | */ |
148 | |
149 | extern void bres_exec(const char */*file*/); |
150 | |
151 | /* --- @bres_init@ --- * |
152 | * |
153 | * Arguments: @sel_state *s@ = pointer to select multiplexor |
154 | * |
155 | * Returns: --- |
156 | * |
157 | * Use: Initializes the background resolver for use. |
158 | */ |
159 | |
160 | extern void bres_init(sel_state */*s*/); |
161 | |
162 | /*----- That's all, folks -------------------------------------------------*/ |
163 | |
164 | #ifdef __cplusplus |
165 | } |
166 | #endif |
167 | |
168 | #endif |