1 /* 2 Copyright (C) 2004 Michael J. Silbersack. All rights reserved. 3 4 Redistribution and use in source and binary forms, with or without 5 modification, are permitted provided that the following conditions 6 are met: 7 1. Redistributions of source code must retain the above copyright 8 notice, this list of conditions and the following disclaimer. 9 2. Redistributions in binary form must reproduce the above copyright 10 notice, this list of conditions and the following disclaimer in the 11 documentation and/or other materials provided with the distribution. 12 13 THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE 17 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 SUCH DAMAGE. 24 */ 25 26 #include <sys/types.h> 27 #include <sys/stat.h> 28 #include <sys/wait.h> 29 #include <assert.h> 30 #include <err.h> 31 #include <errno.h> 32 #include <stdio.h> 33 #include <stdlib.h> 34 #include <string.h> 35 #include <unistd.h> 36 37 /* 38 * This program simply tests writing through the reverse direction of 39 * a pipe. Nothing too fancy, it's only needed because most pipe-using 40 * programs never touch the reverse direction (it doesn't exist on 41 * Linux.) 42 */ 43 44 int 45 main(void) 46 { 47 char buffer[65535], buffer2[65535], go[] = "go", go2[] = "go2"; 48 int desc[2], ipc_coord[2]; 49 size_t i; 50 ssize_t total; 51 int buggy, error; 52 pid_t new_pid; 53 54 buggy = 0; 55 total = 0; 56 57 error = pipe(desc); 58 if (error == -1) 59 err(1, "Couldn't allocate data pipe"); 60 61 error = pipe(ipc_coord); 62 if (error == -1) 63 err(1, "Couldn't allocate IPC coordination pipe"); 64 65 buffer[0] = 'A'; 66 67 for (i = 1; i < (int)sizeof(buffer); i++) { 68 buffer[i] = buffer[i - 1] + 1; 69 if (buffer[i] > 'Z') 70 buffer[i] = 'A'; 71 } 72 73 new_pid = fork(); 74 assert(new_pid != -1); 75 76 #define SYNC_R(i, _buf) do { \ 77 int _error = errno; \ 78 warnx("%d: waiting for synchronization", __LINE__); \ 79 if (read(ipc_coord[i], &_buf, sizeof(_buf)) != sizeof(_buf)) \ 80 err(1, "failed to synchronize (%s)", (i == 0 ? "parent" : "child")); \ 81 errno = _error; \ 82 } while(0) 83 84 #define SYNC_W(i, _buf) do { \ 85 int _error = errno; \ 86 warnx("%d: sending synchronization", __LINE__); \ 87 if (write(ipc_coord[i], &_buf, sizeof(_buf)) != sizeof(_buf)) \ 88 err(1, "failed to synchronize (%s)", (i == 0 ? "child" : "parent")); \ 89 errno = _error; \ 90 } while(0) 91 92 #define WRITE(s) do { \ 93 ssize_t _size; \ 94 if ((_size = write(desc[1], &buffer[total], s)) != s) \ 95 warn("short write; wrote %zd, expected %d", _size, s); \ 96 total += _size; \ 97 } while(0) 98 99 if (new_pid == 0) { 100 SYNC_R(0, go); 101 for (i = 0; i < 8; i++) 102 WRITE(4096); 103 104 SYNC_W(0, go2); 105 SYNC_R(0, go); 106 107 for (i = 0; i < 2; i++) 108 WRITE(4096); 109 110 SYNC_W(0, go2); 111 112 _exit(0); 113 } 114 115 SYNC_W(1, go); 116 SYNC_R(1, go2); 117 118 error = read(desc[0], &buffer2, 8 * 4096); 119 total += error; 120 printf("Read %d bytes\n", error); 121 122 SYNC_W(1, go); 123 SYNC_R(1, go2); 124 125 error = read(desc[0], &buffer2[total], 2 * 4096); 126 total += error; 127 printf("Read %d bytes, done\n", error); 128 129 if (memcmp(buffer, buffer2, total) != 0) { 130 for (i = 0; i < (size_t)total; i++) { 131 if (buffer[i] != buffer2[i]) { 132 buggy = 1; 133 printf("Location %zu input: %hhx " 134 "output: %hhx\n", 135 i, buffer[i], buffer2[i]); 136 } 137 } 138 } 139 140 waitpid(new_pid, NULL, 0); 141 142 if ((buggy == 1) || (total != 10 * 4096)) 143 errx(1, "FAILED"); 144 else 145 printf("SUCCESS\n"); 146 147 exit(0); 148 } 149