| 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 | +} |