File: | src/lib/libc/gen/popen.c |
Warning: | line 95, column 13 This assignment is prohibited after a successful vfork |
Press '?' to see keyboard shortcuts
Keyboard shortcuts:
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" ); |