| File: | src/lib/libc/gen/popen.c |
| Warning: | line 95, column 13 This assignment is prohibited after a successful vfork |
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| 1 | /* $OpenBSD: popen.c,v 1.22 2019/06/28 13:32:41 deraadt Exp $ */ | |||
| 2 | /* | |||
| 3 | * Copyright (c) 1988, 1993 | |||
| 4 | * The Regents of the University of California. All rights reserved. | |||
| 5 | * | |||
| 6 | * This code is derived from software written by Ken Arnold and | |||
| 7 | * published in UNIX Review, Vol. 6, No. 8. | |||
| 8 | * | |||
| 9 | * Redistribution and use in source and binary forms, with or without | |||
| 10 | * modification, are permitted provided that the following conditions | |||
| 11 | * are met: | |||
| 12 | * 1. Redistributions of source code must retain the above copyright | |||
| 13 | * notice, this list of conditions and the following disclaimer. | |||
| 14 | * 2. Redistributions in binary form must reproduce the above copyright | |||
| 15 | * notice, this list of conditions and the following disclaimer in the | |||
| 16 | * documentation and/or other materials provided with the distribution. | |||
| 17 | * 3. Neither the name of the University nor the names of its contributors | |||
| 18 | * may be used to endorse or promote products derived from this software | |||
| 19 | * without specific prior written permission. | |||
| 20 | * | |||
| 21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |||
| 22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |||
| 23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |||
| 24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |||
| 25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |||
| 26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |||
| 27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |||
| 28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |||
| 29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |||
| 30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |||
| 31 | * SUCH DAMAGE. | |||
| 32 | */ | |||
| 33 | ||||
| 34 | #include <sys/wait.h> | |||
| 35 | ||||
| 36 | #include <signal.h> | |||
| 37 | #include <errno(*__errno()).h> | |||
| 38 | #include <fcntl.h> | |||
| 39 | #include <unistd.h> | |||
| 40 | #include <stdio.h> | |||
| 41 | #include <stdlib.h> | |||
| 42 | #include <string.h> | |||
| 43 | #include <paths.h> | |||
| 44 | #include <wchar.h> | |||
| 45 | #include "thread_private.h" | |||
| 46 | ||||
| 47 | static struct pid { | |||
| 48 | struct pid *next; | |||
| 49 | FILE *fp; | |||
| 50 | pid_t pid; | |||
| 51 | } *pidlist; | |||
| 52 | ||||
| 53 | static void *pidlist_lock = NULL((void *)0); | |||
| 54 | ||||
| 55 | FILE * | |||
| 56 | popen(const char *program, const char *type) | |||
| 57 | { | |||
| 58 | struct pid * volatile cur; | |||
| 59 | FILE *iop; | |||
| 60 | int pdes[2]; | |||
| 61 | int target; | |||
| 62 | pid_t pid; | |||
| 63 | ||||
| 64 | if ((*type != 'r' && *type != 'w') || | |||
| ||||
| 65 | (type[1] != '\0' && (type[1] != 'e' || type[2] != '\0'))) { | |||
| 66 | errno(*__errno()) = EINVAL22; | |||
| 67 | return (NULL((void *)0)); | |||
| 68 | } | |||
| 69 | ||||
| 70 | if ((cur = malloc(sizeof(struct pid))) == NULL((void *)0)) | |||
| 71 | return (NULL((void *)0)); | |||
| 72 | ||||
| 73 | if (pipe2(pdes, O_CLOEXEC0x10000) == -1) { | |||
| 74 | free(cur); | |||
| 75 | return (NULL((void *)0)); | |||
| 76 | } | |||
| 77 | ||||
| 78 | _MUTEX_LOCK(&pidlist_lock)do { if (__isthreaded) _thread_cb.tc_mutex_lock(&pidlist_lock ); } while (0); | |||
| 79 | switch (pid = vfork()) { | |||
| 80 | case -1: /* Error. */ | |||
| 81 | _MUTEX_UNLOCK(&pidlist_lock)do { if (__isthreaded) _thread_cb.tc_mutex_unlock(&pidlist_lock ); } while (0); | |||
| 82 | (void)close(pdes[0]); | |||
| 83 | (void)close(pdes[1]); | |||
| 84 | free(cur); | |||
| 85 | return (NULL((void *)0)); | |||
| 86 | /* NOTREACHED */ | |||
| 87 | case 0: /* Child. */ | |||
| 88 | { | |||
| 89 | struct pid *pcur; | |||
| 90 | ||||
| 91 | /* | |||
| 92 | * because vfork() instead of fork(), must leak FILE *, | |||
| 93 | * but luckily we are terminally headed for an execl() | |||
| 94 | */ | |||
| 95 | for (pcur = pidlist; pcur; pcur = pcur->next) | |||
| ||||
| 96 | close(fileno(pcur->fp)(!__isthreaded ? ((pcur->fp)->_file) : (fileno)(pcur-> fp))); | |||
| 97 | ||||
| 98 | target = *type == 'r'; | |||
| 99 | if (pdes[target] != target) { | |||
| 100 | if (dup2(pdes[target], target) == -1) | |||
| 101 | _exit(127); | |||
| 102 | } else { | |||
| 103 | int flags = fcntl(pdes[target], F_GETFD1); | |||
| 104 | if (flags == -1 || ((flags & FD_CLOEXEC1) && | |||
| 105 | fcntl(pdes[target], F_SETFD2, flags & ~FD_CLOEXEC1) | |||
| 106 | == -1)) | |||
| 107 | _exit(127); | |||
| 108 | } | |||
| 109 | ||||
| 110 | execl(_PATH_BSHELL"/bin/sh", "sh", "-c", program, (char *)NULL((void *)0)); | |||
| 111 | _exit(127); | |||
| 112 | /* NOTREACHED */ | |||
| 113 | } | |||
| 114 | } | |||
| 115 | _MUTEX_UNLOCK(&pidlist_lock)do { if (__isthreaded) _thread_cb.tc_mutex_unlock(&pidlist_lock ); } while (0); | |||
| 116 | ||||
| 117 | /* Parent; assume fdopen can't fail. */ | |||
| 118 | target = *type == 'w'; | |||
| 119 | iop = fdopen(pdes[target], type); | |||
| 120 | fwide(iop, -1); | |||
| 121 | (void)close(pdes[!target]); | |||
| 122 | ||||
| 123 | /* Link into list of file descriptors. */ | |||
| 124 | cur->fp = iop; | |||
| 125 | cur->pid = pid; | |||
| 126 | _MUTEX_LOCK(&pidlist_lock)do { if (__isthreaded) _thread_cb.tc_mutex_lock(&pidlist_lock ); } while (0); | |||
| 127 | cur->next = pidlist; | |||
| 128 | pidlist = cur; | |||
| 129 | _MUTEX_UNLOCK(&pidlist_lock)do { if (__isthreaded) _thread_cb.tc_mutex_unlock(&pidlist_lock ); } while (0); | |||
| 130 | ||||
| 131 | /* now that it's in the list, clear FD_CLOEXEC if unwanted */ | |||
| 132 | if (type[1] != 'e') { | |||
| 133 | int flags = fcntl(pdes[target], F_GETFD1); | |||
| 134 | if (flags != -1) | |||
| 135 | fcntl(pdes[target], F_SETFD2, flags & ~FD_CLOEXEC1); | |||
| 136 | } | |||
| 137 | ||||
| 138 | return (iop); | |||
| 139 | } | |||
| 140 | DEF_WEAK(popen)__asm__(".weak " "popen" " ; " "popen" " = " "_libc_popen"); | |||
| 141 | ||||
| 142 | /* | |||
| 143 | * pclose -- | |||
| 144 | * Pclose returns -1 if stream is not associated with a `popened' command, | |||
| 145 | * if already `pclosed', or waitpid returns an error. | |||
| 146 | */ | |||
| 147 | int | |||
| 148 | pclose(FILE *iop) | |||
| 149 | { | |||
| 150 | struct pid *cur, *last; | |||
| 151 | int pstat; | |||
| 152 | pid_t pid; | |||
| 153 | ||||
| 154 | /* Find the appropriate file pointer. */ | |||
| 155 | _MUTEX_LOCK(&pidlist_lock)do { if (__isthreaded) _thread_cb.tc_mutex_lock(&pidlist_lock ); } while (0); | |||
| 156 | for (last = NULL((void *)0), cur = pidlist; cur; last = cur, cur = cur->next) | |||
| 157 | if (cur->fp == iop) | |||
| 158 | break; | |||
| 159 | ||||
| 160 | if (cur == NULL((void *)0)) { | |||
| 161 | _MUTEX_UNLOCK(&pidlist_lock)do { if (__isthreaded) _thread_cb.tc_mutex_unlock(&pidlist_lock ); } while (0); | |||
| 162 | return (-1); | |||
| 163 | } | |||
| 164 | ||||
| 165 | /* Remove the entry from the linked list. */ | |||
| 166 | if (last == NULL((void *)0)) | |||
| 167 | pidlist = cur->next; | |||
| 168 | else | |||
| 169 | last->next = cur->next; | |||
| 170 | _MUTEX_UNLOCK(&pidlist_lock)do { if (__isthreaded) _thread_cb.tc_mutex_unlock(&pidlist_lock ); } while (0); | |||
| 171 | ||||
| 172 | (void)fclose(iop); | |||
| 173 | ||||
| 174 | do { | |||
| 175 | pid = waitpid(cur->pid, &pstat, 0); | |||
| 176 | } while (pid == -1 && errno(*__errno()) == EINTR4); | |||
| 177 | ||||
| 178 | free(cur); | |||
| 179 | ||||
| 180 | return (pid == -1 ? -1 : pstat); | |||
| 181 | } | |||
| 182 | DEF_WEAK(pclose)__asm__(".weak " "pclose" " ; " "pclose" " = " "_libc_pclose" ); |