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5f03e364 J |
1 | diff --git a/src/posix_spawn.c b/src/posix_spawn.c |
2 | new file mode 100644 | |
3 | index 0000000..18ceb06 | |
4 | --- /dev/null | |
5 | +++ b/src/posix_spawn.c | |
6 | @@ -0,0 +1,156 @@ | |
7 | +/* | |
8 | + * dhcpcd - DHCP client daemon | |
9 | + * Copyright (c) 2006-2012 Roy Marples <roy@marples.name> | |
10 | + * All rights reserved | |
11 | + | |
12 | + * Redistribution and use in source and binary forms, with or without | |
13 | + * modification, are permitted provided that the following conditions | |
14 | + * are met: | |
15 | + * 1. Redistributions of source code must retain the above copyright | |
16 | + * notice, this list of conditions and the following disclaimer. | |
17 | + * 2. Redistributions in binary form must reproduce the above copyright | |
18 | + * notice, this list of conditions and the following disclaimer in the | |
19 | + * documentation and/or other materials provided with the distribution. | |
20 | + * | |
21 | + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 | +/* This implementation of posix_spawn is only suitable for the needs of dhcpcd | |
35 | + * but it could easily be extended to other applications. */ | |
36 | + | |
37 | +#include <sys/types.h> | |
38 | +#include <sys/wait.h> | |
39 | + | |
40 | +#include <errno.h> | |
41 | +#include <signal.h> | |
42 | +#include <stdlib.h> | |
43 | +#include <string.h> | |
44 | +#include <unistd.h> | |
45 | + | |
46 | +#include "posix_spawn.h" | |
47 | + | |
48 | +#ifndef _NSIG | |
49 | +#ifdef _SIG_MAXSIG | |
50 | +#define _NSIG _SIG_MAXSIG + 1 | |
51 | +#else | |
52 | +/* Guess */ | |
53 | +#define _NSIG SIGPWR + 1 | |
54 | +#endif | |
55 | +#endif | |
56 | + | |
57 | +extern char **environ; | |
58 | + | |
59 | +static int | |
60 | +posix_spawnattr_handle(const posix_spawnattr_t *attrp) | |
61 | +{ | |
62 | + struct sigaction sa; | |
63 | + int i; | |
64 | + | |
65 | + if (attrp->posix_attr_flags & POSIX_SPAWN_SETSIGMASK) | |
66 | + sigprocmask(SIG_SETMASK, &attrp->posix_attr_sigmask, NULL); | |
67 | + | |
68 | + if (attrp->posix_attr_flags & POSIX_SPAWN_SETSIGDEF) { | |
69 | + memset(&sa, 0, sizeof(sa)); | |
70 | + sa.sa_handler = SIG_DFL; | |
71 | + for (i = 1; i < _NSIG; i++) { | |
72 | + if (sigismember(&attrp->posix_attr_sigdefault, i)) { | |
73 | + if (sigaction(i, &sa, NULL) == -1) | |
74 | + return -1; | |
75 | + } | |
76 | + } | |
77 | + } | |
78 | + | |
79 | + return 0; | |
80 | +} | |
81 | + | |
82 | +inline static int | |
83 | +is_vfork_safe(short int flags) | |
84 | +{ | |
85 | + return !(flags & (POSIX_SPAWN_SETSIGDEF | POSIX_SPAWN_SETSIGMASK)); | |
86 | +} | |
87 | + | |
88 | +int | |
89 | +posix_spawn(pid_t *pid, const char *path, | |
90 | + const posix_spawn_file_actions_t *file_actions, | |
91 | + const posix_spawnattr_t *attrp, | |
92 | + char *const argv[], char *const envp[]) | |
93 | +{ | |
94 | + short int flags; | |
95 | + pid_t p; | |
96 | + volatile int error; | |
97 | + | |
98 | + error = 0; | |
99 | + flags = attrp ? attrp->posix_attr_flags : 0; | |
100 | + if (file_actions == NULL && is_vfork_safe(flags)) | |
101 | + p = vfork(); | |
102 | + else | |
103 | +#ifdef THERE_IS_NO_FORK | |
104 | + return ENOSYS; | |
105 | +#else | |
106 | + p = fork(); | |
107 | +#endif | |
108 | + switch (p) { | |
109 | + case -1: | |
110 | + return errno; | |
111 | + case 0: | |
112 | + if (attrp) { | |
113 | + error = posix_spawnattr_handle(attrp); | |
114 | + if (error) | |
115 | + _exit(127); | |
116 | + } | |
117 | + execve(path, argv, envp); | |
118 | + error = errno; | |
119 | + _exit(127); | |
120 | + default: | |
121 | + if (error != 0) | |
122 | + waitpid(p, NULL, WNOHANG); | |
123 | + else if (pid != NULL) | |
124 | + *pid = p; | |
125 | + return error; | |
126 | + } | |
127 | +} | |
128 | + | |
129 | +int | |
130 | +posix_spawnattr_init(posix_spawnattr_t *attr) | |
131 | +{ | |
132 | + | |
133 | + memset(attr, 0, sizeof(*attr)); | |
134 | + attr->posix_attr_flags = 0; | |
135 | + sigprocmask(0, NULL, &attr->posix_attr_sigmask); | |
136 | + sigemptyset(&attr->posix_attr_sigdefault); | |
137 | + return 0; | |
138 | +} | |
139 | + | |
140 | +int | |
141 | +posix_spawnattr_setflags(posix_spawnattr_t *attr, short flags) | |
142 | +{ | |
143 | + | |
144 | + attr->posix_attr_flags = flags; | |
145 | + return 0; | |
146 | +} | |
147 | + | |
148 | +int | |
149 | +posix_spawnattr_setsigmask(posix_spawnattr_t *attr, const sigset_t *sigmask) | |
150 | +{ | |
151 | + | |
152 | + attr->posix_attr_sigmask = *sigmask; | |
153 | + return 0; | |
154 | +} | |
155 | + | |
156 | +int | |
157 | +posix_spawnattr_setsigdefault(posix_spawnattr_t *attr, const sigset_t *sigmask) | |
158 | +{ | |
159 | + | |
160 | + attr->posix_attr_sigdefault = *sigmask; | |
161 | + return 0; | |
162 | +} |