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/* ISC license. */
/* MT-unsafe */
#include <skalibs/sysdeps.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/wait.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
#ifdef SKALIBS_HASPOSIXSPAWN
#include <stdlib.h>
#include <spawn.h>
#include <skalibs/config.h>
#else
#include <string.h>
#include <skalibs/sig.h>
#include <skalibs/strerr2.h>
#endif
#include <skalibs/types.h>
#include <skalibs/allreadwrite.h>
#include <skalibs/env.h>
#include <skalibs/djbunix.h>
pid_t child_spawn3 (char const *prog, char const *const *argv, char const *const *envp, int *fds)
{
#ifdef SKALIBS_HASPOSIXSPAWN
posix_spawn_file_actions_t actions ;
posix_spawnattr_t attr ;
#else
int syncpipe[2] ;
#endif
int p[3][2] ;
pid_t pid ;
int e ;
size_t m = sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR) ;
char modifs[sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR) + UINT_FMT] = SKALIBS_CHILD_SPAWN_FDS_ENVVAR "=" ;
if (pipe(p[0]) < 0 || ndelay_on(p[0][0]) < 0 || coe(p[0][0]) < 0) return 0 ;
if (pipe(p[1]) < 0 || ndelay_on(p[1][1]) < 0 || coe(p[1][1]) < 0) goto errp0 ;
if (pipe(p[2]) < 0 || ndelay_on(p[2][0]) < 0 || coe(p[2][0]) < 0) goto errp1 ;
m += uint_fmt(modifs + sizeof(SKALIBS_CHILD_SPAWN_FDS_ENVVAR), p[2][1]) ;
modifs[m++] = 0 ;
#ifdef SKALIBS_HASPOSIXSPAWN
e = posix_spawnattr_init(&attr) ;
if (e) goto errp2 ;
{
sigset_t set ;
sigemptyset(&set) ;
e = posix_spawnattr_setsigmask(&attr, &set) ;
if (e) goto errattr ;
e = posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETSIGMASK) ;
if (e) goto errattr ;
}
e = posix_spawn_file_actions_init(&actions) ;
if (e) goto errattr ;
if (p[1][0] != fds[0])
{
e = posix_spawn_file_actions_adddup2(&actions, p[1][0], fds[0]) ;
if (e) goto erractions ;
e = posix_spawn_file_actions_addclose(&actions, p[1][0]) ;
if (e) goto erractions ;
}
if (p[0][1] != fds[1])
{
e = posix_spawn_file_actions_adddup2(&actions, p[0][1], fds[1]) ;
if (e) goto erractions ;
e = posix_spawn_file_actions_addclose(&actions, p[0][1]) ;
if (e) goto erractions ;
}
{
int haspath = !!getenv("PATH") ;
size_t envlen = env_len(envp) ;
char const *newenv[envlen + 2] ;
if (!env_merge(newenv, envlen+2, envp, envlen, modifs, m)) goto erractions ;
if (!haspath && (setenv("PATH", SKALIBS_DEFAULTPATH, 0) < 0))
{
e = errno ; goto erractions ;
}
e = posix_spawnp(&pid, prog, &actions, &attr, (char *const *)argv, (char *const *)newenv) ;
if (!haspath) unsetenv("PATH") ;
if (e) goto erractions ;
}
posix_spawn_file_actions_destroy(&actions) ;
posix_spawnattr_destroy(&attr) ;
#else
if (pipe(syncpipe) < 0) { e = errno ; goto errp2 ; }
if (coe(syncpipe[1]) < 0) { e = errno ; goto errsp ; }
pid = fork() ;
if (pid < 0) { e = errno ; goto errsp ; }
else if (!pid)
{
size_t len = strlen(PROG) ;
char name[len + 9] ;
memcpy(name, PROG, len) ;
memcpy(name + len, " (child)", 9) ;
PROG = name ;
fd_close(syncpipe[0]) ;
if (fd_move2(fds[0], p[1][0], fds[1], p[0][1]) < 0) goto syncdie ;
sig_blocknone() ;
pathexec_r_name(prog, argv, envp, env_len(envp), modifs, m) ;
syncdie:
{
char c = errno ;
fd_write(syncpipe[1], &c, 1) ;
}
_exit(127) ;
}
fd_close(syncpipe[1]) ;
{
char c ;
syncpipe[1] = fd_read(syncpipe[0], &c, 1) ;
if (syncpipe[1])
{
if (syncpipe[1] < 0) e = errno ;
else
{
kill(pid, SIGKILL) ;
e = c ;
}
wait_pid(pid, &syncpipe[1]) ;
goto errsp0 ;
}
}
fd_close(syncpipe[0]) ;
#endif
fd_close(p[2][1]) ;
fd_close(p[1][0]) ;
fd_close(p[0][1]) ;
fds[0] = p[0][0] ;
fds[1] = p[1][1] ;
fds[2] = p[2][0] ;
return pid ;
#ifdef SKALIBS_HASPOSIXSPAWN
erractions:
posix_spawn_file_actions_destroy(&actions) ;
errattr:
posix_spawnattr_destroy(&attr) ;
#endif
#ifndef SKALIBS_HASPOSIXSPAWN
errsp:
fd_close(syncpipe[1]) ;
errsp0:
fd_close(syncpipe[0]) ;
#endif
errp2:
fd_close(p[2][1]) ;
fd_close(p[2][0]) ;
errp1:
fd_close(p[1][1]) ;
fd_close(p[1][0]) ;
errp0:
fd_close(p[0][1]) ;
fd_close(p[0][0]) ;
return 0 ;
}
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