1 /* 2 * Copyright (c) 2016 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 "tests.h" 29 #include <limits.h> 30 #include <unistd.h> 31 #include <sys/resource.h> 32 33 static void 34 move_fd(int *from, int *to) 35 { 36 for (; *to > *from; --*to) { 37 if (dup2(*from, *to) != *to) 38 continue; 39 close(*from); 40 *from = *to; 41 break; 42 } 43 } 44 45 void 46 pipe_maxfd(int pipefd[2]) 47 { 48 struct rlimit rlim; 49 if (getrlimit(RLIMIT_NOFILE, &rlim)) 50 perror_msg_and_fail("getrlimit"); 51 if (rlim.rlim_cur < rlim.rlim_max) { 52 struct rlimit rlim_new; 53 rlim_new.rlim_cur = rlim_new.rlim_max = rlim.rlim_max; 54 if (!setrlimit(RLIMIT_NOFILE, &rlim_new)) 55 rlim.rlim_cur = rlim.rlim_max; 56 } 57 58 if (pipe(pipefd)) 59 perror_msg_and_fail("pipe"); 60 61 int max_fd = (rlim.rlim_cur > 0 && rlim.rlim_cur < INT_MAX) 62 ? rlim.rlim_cur - 1 : INT_MAX; 63 64 move_fd(&pipefd[1], &max_fd); 65 --max_fd; 66 move_fd(&pipefd[0], &max_fd); 67 } 68
