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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: selpk.c,v 1.3 2004/04/08 01:36:13 mdw Exp $ |
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4 | * |
5 | * Packet-buffering select handler |
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 | /*----- Header files ------------------------------------------------------*/ |
31 | |
32 | #include <errno.h> |
33 | #include <stdio.h> |
34 | #include <stdlib.h> |
35 | #include <string.h> |
36 | |
37 | #include <sys/types.h> |
38 | #include <sys/time.h> |
39 | #include <unistd.h> |
40 | |
41 | #include "pkbuf.h" |
42 | #include "sel.h" |
43 | #include "selpk.h" |
44 | |
45 | /*----- Main code ---------------------------------------------------------*/ |
46 | |
47 | /* --- @selpk_enable@ --- * |
48 | * |
49 | * Arguments: @selpk *pk@ = pointer to buffer block |
50 | * |
51 | * Returns: --- |
52 | * |
53 | * Use: Enables a buffer for reading, and emits any queued packets |
54 | * to the buffer's owner. |
55 | */ |
56 | |
57 | void selpk_enable(selpk *pk) |
58 | { |
59 | if (!(pk->pk.f & PKBUF_ENABLE)) { |
60 | pk->pk.f |= PKBUF_ENABLE; |
61 | sel_addfile(&pk->reader); |
62 | pkbuf_flush(&pk->pk, 0, 0); |
63 | } |
64 | } |
65 | |
66 | /* --- @selpk_disable@ --- * |
67 | * |
68 | * Arguments: @selpk *pk@ = pointer to a buffer block |
69 | * |
70 | * Returns: --- |
71 | * |
72 | * Use: Disables a buffer. It won't be read from until it's |
73 | * enabled again. |
74 | */ |
75 | |
76 | void selpk_disable(selpk *pk) |
77 | { |
78 | if (pk->pk.f & PKBUF_ENABLE) { |
79 | pk->pk.f &= ~PKBUF_ENABLE; |
80 | sel_rmfile(&pk->reader); |
81 | } |
82 | } |
83 | |
84 | /* --- @selpk_read@ --- * |
85 | * |
86 | * Arguments: @int fd@ = file descriptor to read from |
87 | * @int mode@ = what we can do to the file |
88 | * @void *vp@ = pointer to buffer context |
89 | * |
90 | * Returns: --- |
91 | * |
92 | * Use: Acts on the result of a @select@ call. |
93 | */ |
94 | |
95 | static void selpk_read(int fd, unsigned mode, void *vp) |
96 | { |
97 | selpk *pk = vp; |
98 | octet *p; |
99 | size_t sz; |
100 | int n; |
101 | |
102 | sz = pkbuf_free(&pk->pk, &p); |
103 | n = read(fd, p, sz); |
104 | if (n == 0) |
105 | pkbuf_close(&pk->pk); |
106 | else if (n > 0) |
107 | pkbuf_flush(&pk->pk, p, n); |
108 | else switch (errno) { |
109 | case EINTR: |
110 | case EAGAIN: |
111 | #if EAGAIN != EWOULDBLOCK |
112 | case EWOULDBLOCK: |
113 | #endif |
114 | return; |
115 | default: |
116 | pkbuf_close(&pk->pk); |
117 | } |
118 | } |
119 | |
120 | /* --- @selpk_want@ --- * |
121 | * |
122 | * Arguments: @selpk *pk@ = pointer to buffer block |
123 | * @size_t sz@ = size of buffer |
124 | * |
125 | * Returns: --- |
126 | * |
127 | * Use: Sets the size of the packet to be read next. |
128 | */ |
129 | |
130 | void selpk_want(selpk *pk, size_t sz) |
131 | { |
132 | pkbuf_want(&pk->pk, sz); |
133 | } |
134 | |
135 | /* --- @selpk_init@ --- * |
136 | * |
137 | * Arguments: @selpk *pk@ = pointer to buffer block |
138 | * @sel_state *s@ = pointer to select state to attach to |
139 | * @int fd@ = file descriptor to listen to |
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140 | * @pkbuf_func *func@ = function to call |
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141 | * @void *p@ = argument for function |
142 | * |
143 | * Returns: --- |
144 | * |
145 | * Use: Initializes a buffer block. |
146 | */ |
147 | |
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148 | void selpk_init(selpk *pk, sel_state *s, int fd, pkbuf_func *func, void *p) |
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149 | { |
150 | pkbuf_init(&pk->pk, func, p); |
151 | pk->pk.f &= ~PKBUF_ENABLE; |
152 | sel_initfile(s, &pk->reader, fd, SEL_READ, selpk_read, pk); |
153 | selpk_enable(pk); |
154 | } |
155 | |
156 | /* --- @selpk_destroy@ --- * |
157 | * |
158 | * Arguments: @selpk *pk@ = pointer to buffer block |
159 | * |
160 | * Returns: --- |
161 | * |
162 | * Use: Deallocates a packet buffer and frees any resources it owned. |
163 | */ |
164 | |
165 | void selpk_destroy(selpk *pk) |
166 | { |
167 | selpk_disable(pk); |
168 | pkbuf_destroy(&pk->pk); |
169 | } |
170 | |
171 | /*----- That's all, folks -------------------------------------------------*/ |