1 /* 2 * Copyright (c) 2015 Dmitry V. Levin <ldv (at) altlinux.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include <assert.h> 29 #include <string.h> 30 #include <unistd.h> 31 #include <sys/socket.h> 32 #include <sys/wait.h> 33 34 static void 35 transpose(char *str, int len) 36 { 37 int i; 38 39 for (i = 0; i < len / 2; ++i) { 40 char c = str[i]; 41 str[i] = str[len - 1 - i]; 42 str[len - 1 - i] = c; 43 } 44 } 45 46 int 47 main(int ac, char **av) 48 { 49 assert(ac == 2); 50 const int len = strlen(av[1]); 51 assert(len); 52 53 (void) close(0); 54 (void) close(1); 55 56 int sv[2]; 57 assert(socketpair(AF_UNIX, SOCK_STREAM, 0, sv) == 0); 58 assert(sv[0] == 0); 59 assert(sv[1] == 1); 60 61 pid_t pid = fork(); 62 assert(pid >= 0); 63 64 if (pid) { 65 assert(close(1) == 0); 66 transpose(av[1], len); 67 assert(sendto(0, av[1], len, MSG_DONTROUTE, NULL, 0) == len); 68 assert(recvfrom(0, av[1], len, MSG_WAITALL, NULL, NULL) == len); 69 assert(close(0) == 0); 70 71 int status; 72 assert(waitpid(pid, &status, 0) == pid); 73 assert(status == 0); 74 } else { 75 assert(close(0) == 0); 76 assert(recvfrom(1, av[1], len, MSG_WAITALL, NULL, NULL) == len); 77 transpose(av[1], len); 78 assert(sendto(1, av[1], len, MSG_DONTROUTE, NULL, 0) == len); 79 assert(recvfrom(1, av[1], len, MSG_WAITALL, NULL, NULL) == 0); 80 assert(close(1) == 0); 81 } 82 83 return 0; 84 } 85
