diff options
Diffstat (limited to 'usr/src/lib/libast/common/comp/spawnveg.c')
| -rw-r--r-- | usr/src/lib/libast/common/comp/spawnveg.c | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/usr/src/lib/libast/common/comp/spawnveg.c b/usr/src/lib/libast/common/comp/spawnveg.c new file mode 100644 index 0000000000..fd6768c6b9 --- /dev/null +++ b/usr/src/lib/libast/common/comp/spawnveg.c @@ -0,0 +1,270 @@ +/*********************************************************************** +* * +* This software is part of the ast package * +* Copyright (c) 1985-2007 AT&T Knowledge Ventures * +* and is licensed under the * +* Common Public License, Version 1.0 * +* by AT&T Knowledge Ventures * +* * +* A copy of the License is available at * +* http://www.opensource.org/licenses/cpl1.0.txt * +* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) * +* * +* Information and Software Systems Research * +* AT&T Research * +* Florham Park NJ * +* * +* Glenn Fowler <gsf@research.att.com> * +* David Korn <dgk@research.att.com> * +* Phong Vo <kpv@research.att.com> * +* * +***********************************************************************/ +#pragma prototyped + +/* + * spawnveg -- spawnve with process group or session control + * + * pgid <0 setsid() [session group leader] + * 0 nothing [retain session and process group] + * 1 setpgid(0,0) [process group leader] + * >1 setpgid(0,pgid) [join process group] + */ + +#include <ast.h> + +#if _lib_spawnveg + +NoN(spawnveg) + +#else + +#if _lib_posix_spawn > 1 /* reports underlying exec() errors */ + +#include <spawn.h> +#include <error.h> +#include <wait.h> + +pid_t +spawnveg(const char* path, char* const argv[], char* const envv[], pid_t pgid) +{ + int err; + pid_t pid; + posix_spawnattr_t attr; + + if (err = posix_spawnattr_init(&attr)) + goto bad; + if (pgid) + { + if (pgid <= 1) + pgid = 0; + if (err = posix_spawnattr_setpgroup(&attr, pgid)) + goto bad; + if (err = posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETPGROUP)) + goto bad; + } + if (err = posix_spawn(&pid, path, NiL, &attr, argv, envv ? envv : environ)) + goto bad; + posix_spawnattr_destroy(&attr); +#if _lib_posix_spawn < 2 + if (waitpid(pid, &err, WNOHANG|WNOWAIT) == pid && EXIT_STATUS(err) == 127) + { + while (waitpid(pid, NiL, 0) == -1 && errno == EINTR); + if (!access(path, X_OK)) + errno = ENOEXEC; + pid = -1; + } +#endif + return pid; + bad: + errno = err; + return -1; +} + +#else + +#if _lib_spawn_mode + +#include <process.h> + +#ifndef P_NOWAIT +#define P_NOWAIT _P_NOWAIT +#endif +#ifndef P_DETACH +#define P_DETACH _P_DETACH +#endif + +pid_t +spawnveg(const char* path, char* const argv[], char* const envv[], pid_t pgid) +{ + return spawnve(pgid ? P_DETACH : P_NOWAIT, path, argv, envv ? envv : environ); +} + +#else + +#if _lib_spawn && _hdr_spawn && _mem_pgroup_inheritance + +#include <spawn.h> + +/* + * open-edition/mvs/zos fork+exec+(setpgid) + */ + +pid_t +spawnveg(const char* path, char* const argv[], char* const envv[], pid_t pgid) +{ + struct inheritance inherit; + + inherit.flags = 0; + if (pgid) + { + inherit.flags |= SPAWN_SETGROUP; + inherit.pgroup = (pgid > 1) ? pgid : SPAWN_NEWPGROUP; + } + return spawn(path, 0, (int*)0, &inherit, (const char**)argv, (const char**)envv); +} + +#else + +#include <error.h> +#include <wait.h> +#include <sig.h> +#include <ast_vfork.h> + +#ifndef ENOSYS +#define ENOSYS EINVAL +#endif + +#if _lib_spawnve && _hdr_process +#include <process.h> +#if defined(P_NOWAIT) || defined(_P_NOWAIT) +#undef _lib_spawnve +#endif +#endif + +#if !_lib_vfork +#undef _real_vfork +#endif + +/* + * fork+exec+(setsid|setpgid) + */ + +pid_t +spawnveg(const char* path, char* const argv[], char* const envv[], pid_t pgid) +{ +#if _lib_fork || _lib_vfork + int n; + int m; + pid_t pid; + pid_t rid; +#if _real_vfork + volatile int exec_errno; + volatile int* volatile exec_errno_ptr; +#else + int err[2]; +#endif +#endif + +#if 0 + if (access(path, X_OK)) + return -1; +#endif + if (!envv) + envv = environ; +#if _lib_spawnve +#if _lib_fork || _lib_vfork + if (!pgid) +#endif + return spawnve(path, argv, envv); +#endif +#if _lib_fork || _lib_vfork + n = errno; +#if _real_vfork + exec_errno = 0; + exec_errno_ptr = &exec_errno; +#else + if (pipe(err) < 0) + err[0] = -1; + else + { + fcntl(err[0], F_SETFD, FD_CLOEXEC); + fcntl(err[1], F_SETFD, FD_CLOEXEC); + } +#endif + sigcritical(1); +#if _lib_vfork + pid = vfork(); +#else + pid = fork(); +#endif + sigcritical(0); + if (!pid) + { + if (pgid < 0) + setsid(); + else if (pgid > 0) + { + if (pgid == 1) + pgid = 0; + if (setpgid(0, pgid) < 0 && pgid && errno == EPERM) + setpgid(0, 0); + } + execve(path, argv, envv); +#if _real_vfork + *exec_errno_ptr = errno; +#else + if (err[0] != -1) + { + n = errno; + write(err[1], &n, sizeof(n)); + } +#endif + _exit(errno == ENOENT ? EXIT_NOTFOUND : EXIT_NOEXEC); + } + rid = pid; +#if _real_vfork + if (pid != -1 && (m = *exec_errno_ptr)) + { + while (waitpid(pid, NiL, 0) == -1 && errno == EINTR); + rid = pid = -1; + n = m; + } +#else + if (pid != -1 && err[0] != -1) + { + close(err[1]); + if (read(err[0], &m, sizeof(m)) == sizeof(m) && m) + { + while (waitpid(pid, NiL, 0) == -1 && errno == EINTR); + rid = pid = -1; + n = m; + } + close(err[0]); + } +#endif + if (pid != -1 && pgid > 0) + { + /* + * parent and child are in a race here + */ + + if (pgid == 1) + pgid = pid; + if (setpgid(pid, pgid) < 0 && pid != pgid && errno == EPERM) + setpgid(pid, pid); + } + errno = n; + return rid; +#else + errno = ENOSYS; + return -1; +#endif +} + +#endif + +#endif + +#endif + +#endif |