diff options
Diffstat (limited to 'stdio/spawn.c')
| -rw-r--r-- | stdio/spawn.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/stdio/spawn.c b/stdio/spawn.c new file mode 100644 index 0000000..5dc3980 --- /dev/null +++ b/stdio/spawn.c @@ -0,0 +1,115 @@ +/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│ +│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│ +╞══════════════════════════════════════════════════════════════════════════════╡ +│ Copyright 2021 Justine Alexandra Roberts Tunney │ +│ │ +│ Permission to use, copy, modify, and/or distribute this software for │ +│ any purpose with or without fee is hereby granted, provided that the │ +│ above copyright notice and this permission notice appear in all copies. │ +│ │ +│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │ +│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │ +│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │ +│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │ +│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │ +│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │ +│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │ +│ PERFORMANCE OF THIS SOFTWARE. │ +╚─────────────────────────────────────────────────────────────────────────────*/ +#include "libc/calls/calls.h" +#include "libc/calls/scheduler.h" +#include "libc/calls/sigbits.h" +#include "libc/calls/struct/sigaction.h" +#include "libc/errno.h" +#include "libc/fmt/fmt.h" +#include "libc/stdio/spawn.h" +#include "libc/stdio/spawna.internal.h" +#include "libc/str/str.h" + +/** + * Spawns process the POSIX way. + * + * @param pid is non-NULL and will be set to child pid in parent + * @param path of executable that is not PATH searched + * @return 0 on success or error number on failure + */ +int posix_spawn(int *pid, const char *path, + const posix_spawn_file_actions_t *file_actions, + const posix_spawnattr_t *attrp, char *const argv[], + char *const envp[]) { + unsigned mode; + sigset_t allsigs; + struct sigaction dfl; + char *p, *q, opath[PATH_MAX]; + int s, fd, newfd, oflag, tempfd; + if (!(*pid = vfork())) { + if (attrp) { + if (attrp->posix_attr_flags & POSIX_SPAWN_SETPGROUP) { + if (setpgid(0, attrp->posix_attr_pgroup)) _exit(127); + } + if (attrp->posix_attr_flags & POSIX_SPAWN_SETSIGMASK) { + sigprocmask(SIG_SETMASK, &attrp->posix_attr_sigmask, NULL); + } + if (attrp->posix_attr_flags & POSIX_SPAWN_RESETIDS) { + setuid(getuid()); + setgid(getgid()); + } + if (attrp->posix_attr_flags & POSIX_SPAWN_SETSIGDEF) { + dfl.sa_handler = SIG_DFL; + dfl.sa_flags = 0; + sigfillset(&allsigs); + for (s = 0; sigismember(&allsigs, s); s++) { + if (sigismember(&attrp->posix_attr_sigdefault, s)) { + if (sigaction(s, &dfl, NULL) == -1) _exit(127); + } + } + } + } + if (file_actions) { + for (p = *file_actions; *p; p = strchr(p, ')') + 1) { + if (!strncmp(p, "close(", 6)) { + if (sscanf(p + 6, "%d)", &fd) != 1) _exit(127); + if (close(fd) == -1) _exit(127); + } else if (!strncmp(p, "dup2(", 5)) { + if (sscanf(p + 5, "%d,%d)", &fd, &newfd) != 2) _exit(127); + if (dup2(fd, newfd) == -1) _exit(127); + } else if (!strncmp(p, "open(", 5)) { + if (sscanf(p + 5, "%d,", &fd) != 1) _exit(127); + p = strchr(p, ',') + 1; + q = strchr(p, '*'); + if (!q || q - p + 1 > PATH_MAX) _exit(127); + strncpy(opath, p, q - p); + opath[q - p] = '\0'; + if (sscanf(q + 1, "%o,%o)", &oflag, &mode) != 2) _exit(127); + if (close(fd) == -1 && errno != EBADF) _exit(127); + tempfd = open(opath, oflag, mode); + if (tempfd == -1) _exit(127); + if (tempfd != fd) { + if (dup2(tempfd, fd) == -1) _exit(127); + if (close(tempfd) == -1) _exit(127); + } + } else { + _exit(127); + } + } + } + if (attrp) { + if (attrp->posix_attr_flags & POSIX_SPAWN_SETSCHEDULER) { + if (sched_setscheduler(0, attrp->posix_attr_schedpolicy, + &attrp->posix_attr_schedparam) == -1) { + _exit(127); + } + } + if (attrp->posix_attr_flags & POSIX_SPAWN_SETSCHEDPARAM) { + if (sched_setparam(0, &attrp->posix_attr_schedparam) == -1) { + _exit(127); + } + } + } + execve(path, argv, envp); + _exit(127); + } else { + if (*pid == -1) return errno; + return 0; + } +} |