436fddaa |
1 | /* -*-c-*- |
2 | * |
436fddaa |
3 | * Packet-buffering select handler |
4 | * |
5 | * (c) 1999 Straylight/Edgeware |
6 | */ |
7 | |
d4efbcd9 |
8 | /*----- Licensing notice --------------------------------------------------* |
436fddaa |
9 | * |
10 | * This file is part of the mLib utilities library. |
11 | * |
12 | * mLib is free software; you can redistribute it and/or modify |
13 | * it under the terms of the GNU Library General Public License as |
14 | * published by the Free Software Foundation; either version 2 of the |
15 | * License, or (at your option) any later version. |
d4efbcd9 |
16 | * |
436fddaa |
17 | * mLib is distributed in the hope that it will be useful, |
18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
20 | * GNU Library General Public License for more details. |
d4efbcd9 |
21 | * |
436fddaa |
22 | * You should have received a copy of the GNU Library General Public |
23 | * License along with mLib; if not, write to the Free |
24 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
25 | * MA 02111-1307, USA. |
26 | */ |
27 | |
436fddaa |
28 | /*----- Header files ------------------------------------------------------*/ |
29 | |
30 | #include <errno.h> |
31 | #include <stdio.h> |
32 | #include <stdlib.h> |
33 | #include <string.h> |
34 | |
35 | #include <sys/types.h> |
36 | #include <sys/time.h> |
37 | #include <unistd.h> |
38 | |
39 | #include "pkbuf.h" |
40 | #include "sel.h" |
41 | #include "selpk.h" |
42 | |
43 | /*----- Main code ---------------------------------------------------------*/ |
44 | |
45 | /* --- @selpk_enable@ --- * |
46 | * |
47 | * Arguments: @selpk *pk@ = pointer to buffer block |
48 | * |
49 | * Returns: --- |
50 | * |
51 | * Use: Enables a buffer for reading, and emits any queued packets |
52 | * to the buffer's owner. |
53 | */ |
54 | |
55 | void selpk_enable(selpk *pk) |
56 | { |
57 | if (!(pk->pk.f & PKBUF_ENABLE)) { |
58 | pk->pk.f |= PKBUF_ENABLE; |
59 | sel_addfile(&pk->reader); |
60 | pkbuf_flush(&pk->pk, 0, 0); |
61 | } |
62 | } |
63 | |
64 | /* --- @selpk_disable@ --- * |
65 | * |
66 | * Arguments: @selpk *pk@ = pointer to a buffer block |
67 | * |
68 | * Returns: --- |
69 | * |
70 | * Use: Disables a buffer. It won't be read from until it's |
71 | * enabled again. |
72 | */ |
73 | |
74 | void selpk_disable(selpk *pk) |
75 | { |
76 | if (pk->pk.f & PKBUF_ENABLE) { |
77 | pk->pk.f &= ~PKBUF_ENABLE; |
78 | sel_rmfile(&pk->reader); |
79 | } |
80 | } |
81 | |
82 | /* --- @selpk_read@ --- * |
83 | * |
84 | * Arguments: @int fd@ = file descriptor to read from |
85 | * @int mode@ = what we can do to the file |
86 | * @void *vp@ = pointer to buffer context |
87 | * |
88 | * Returns: --- |
89 | * |
90 | * Use: Acts on the result of a @select@ call. |
91 | */ |
92 | |
93 | static void selpk_read(int fd, unsigned mode, void *vp) |
94 | { |
95 | selpk *pk = vp; |
96 | octet *p; |
97 | size_t sz; |
98 | int n; |
99 | |
100 | sz = pkbuf_free(&pk->pk, &p); |
101 | n = read(fd, p, sz); |
102 | if (n == 0) |
103 | pkbuf_close(&pk->pk); |
104 | else if (n > 0) |
105 | pkbuf_flush(&pk->pk, p, n); |
106 | else switch (errno) { |
107 | case EINTR: |
108 | case EAGAIN: |
109 | #if EAGAIN != EWOULDBLOCK |
110 | case EWOULDBLOCK: |
111 | #endif |
112 | return; |
113 | default: |
114 | pkbuf_close(&pk->pk); |
115 | } |
116 | } |
117 | |
118 | /* --- @selpk_want@ --- * |
119 | * |
120 | * Arguments: @selpk *pk@ = pointer to buffer block |
121 | * @size_t sz@ = size of buffer |
122 | * |
123 | * Returns: --- |
124 | * |
125 | * Use: Sets the size of the packet to be read next. |
126 | */ |
127 | |
128 | void selpk_want(selpk *pk, size_t sz) |
129 | { |
130 | pkbuf_want(&pk->pk, sz); |
131 | } |
132 | |
133 | /* --- @selpk_init@ --- * |
134 | * |
135 | * Arguments: @selpk *pk@ = pointer to buffer block |
136 | * @sel_state *s@ = pointer to select state to attach to |
137 | * @int fd@ = file descriptor to listen to |
0daaeb18 |
138 | * @pkbuf_func *func@ = function to call |
436fddaa |
139 | * @void *p@ = argument for function |
140 | * |
141 | * Returns: --- |
142 | * |
143 | * Use: Initializes a buffer block. |
144 | */ |
145 | |
0daaeb18 |
146 | void selpk_init(selpk *pk, sel_state *s, int fd, pkbuf_func *func, void *p) |
436fddaa |
147 | { |
148 | pkbuf_init(&pk->pk, func, p); |
149 | pk->pk.f &= ~PKBUF_ENABLE; |
150 | sel_initfile(s, &pk->reader, fd, SEL_READ, selpk_read, pk); |
151 | selpk_enable(pk); |
152 | } |
153 | |
154 | /* --- @selpk_destroy@ --- * |
155 | * |
156 | * Arguments: @selpk *pk@ = pointer to buffer block |
157 | * |
158 | * Returns: --- |
159 | * |
160 | * Use: Deallocates a packet buffer and frees any resources it owned. |
161 | */ |
162 | |
163 | void selpk_destroy(selpk *pk) |
164 | { |
165 | selpk_disable(pk); |
166 | pkbuf_destroy(&pk->pk); |
167 | } |
168 | |
169 | /*----- That's all, folks -------------------------------------------------*/ |