| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * Packet-buffering select handler |
| 4 | * |
| 5 | * (c) 1999 Straylight/Edgeware |
| 6 | */ |
| 7 | |
| 8 | /*----- Licensing notice --------------------------------------------------* |
| 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. |
| 16 | * |
| 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. |
| 21 | * |
| 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 | |
| 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 |
| 138 | * @pkbuf_func *func@ = function to call |
| 139 | * @void *p@ = argument for function |
| 140 | * |
| 141 | * Returns: --- |
| 142 | * |
| 143 | * Use: Initializes a buffer block. |
| 144 | */ |
| 145 | |
| 146 | void selpk_init(selpk *pk, sel_state *s, int fd, pkbuf_func *func, void *p) |
| 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 -------------------------------------------------*/ |