commit 6b69c1f8921d0f692e9aaa65d21349e01ecc670b
parent ed40369c8610914085d568ec57701a035bf8dd29
Author: Laurent Bercot <ska-skaware@skarnet.org>
Date: Wed, 3 Jan 2018 12:09:01 +0000
Add child_spawn3, make textclient_startf use it
Diffstat:
6 files changed, 183 insertions(+), 7 deletions(-)
diff --git a/COPYING b/COPYING
@@ -1,4 +1,4 @@
-Copyright (c) 2011-2017 Laurent Bercot <ska-skaware@skarnet.org>
+Copyright (c) 2011-2018 Laurent Bercot <ska-skaware@skarnet.org>
Permission to use, copy, modify, and distribute this software for any
purpose with or without fee is hereby granted, provided that the above
diff --git a/package/deps.mak b/package/deps.mak
@@ -276,6 +276,7 @@ src/libstddjb/child_spawn1_internal.o src/libstddjb/child_spawn1_internal.lo: sr
src/libstddjb/child_spawn1_pipe.o src/libstddjb/child_spawn1_pipe.lo: src/libstddjb/child_spawn1_pipe.c src/libstddjb/djbunix-internal.h src/include/skalibs/djbunix.h
src/libstddjb/child_spawn1_socket.o src/libstddjb/child_spawn1_socket.lo: src/libstddjb/child_spawn1_socket.c src/libstddjb/djbunix-internal.h src/include/skalibs/djbunix.h src/include/skalibs/webipc.h
src/libstddjb/child_spawn2.o src/libstddjb/child_spawn2.lo: src/libstddjb/child_spawn2.c src/include/skalibs/allreadwrite.h src/include/skalibs/config.h src/include/skalibs/djbunix.h src/include/skalibs/sig.h src/include/skalibs/strerr2.h src/include/skalibs/sysdeps.h
+src/libstddjb/child_spawn3.o src/libstddjb/child_spawn3.lo: src/libstddjb/child_spawn3.c src/include/skalibs/allreadwrite.h src/include/skalibs/config.h src/include/skalibs/djbunix.h src/include/skalibs/env.h src/include/skalibs/sig.h src/include/skalibs/strerr2.h src/include/skalibs/sysdeps.h src/include/skalibs/types.h
src/libstddjb/coe.o src/libstddjb/coe.lo: src/libstddjb/coe.c src/include/skalibs/djbunix.h
src/libstddjb/deepsleepuntil.o src/libstddjb/deepsleepuntil.lo: src/libstddjb/deepsleepuntil.c src/include/skalibs/iopause.h src/include/skalibs/tai.h
src/libstddjb/dir_close.o src/libstddjb/dir_close.lo: src/libstddjb/dir_close.c src/include/skalibs/direntry.h
diff --git a/src/include/skalibs/djbunix.h b/src/include/skalibs/djbunix.h
@@ -183,14 +183,24 @@ extern pid_t child_spawn2 (char const *, char const *const *, char const *const
/*
- Unified function to fork a child with communication channels (pipes).
+ Same, with an additional pipe from the child to the parent.
+ The int * points to 3 fds.
+ The additional fd# is available to the child in the defined env variable.
+ */
+
+#define SKALIBS_CHILD_SPAWN_FDS_ENVVAR "SKALIBS_CHILD_SPAWN_FDS"
+
+extern pid_t child_spawn3 (char const *, char const *const *, char const *const *, int *) ;
+
+
+ /*
+ Generalization of the previous functions.
* uses posix_spawn() if available, else uses fork+exec
- * requests n (the last arg) communication fds between parent and child
+ * requests n (the last arg) communication fds between parent and child. Uses pipes.
* if n=1, equivalent to child_spawn1_pipe; child writes, parent reads.
* if n>=2, parent reads on even and writes on odd.
*/
-#define SKALIBS_CHILD_SPAWN_FDS_ENVVAR "SKALIBS_CHILD_SPAWN_FDS"
extern pid_t child_spawn (char const *, char const *const *, char const *const *, int *, unsigned int) ;
diff --git a/src/libstddjb/child_spawn.c b/src/libstddjb/child_spawn.c
@@ -95,7 +95,7 @@ pid_t child_spawn (char const *prog, char const *const *argv, char const *const
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 errsp ;
+ if (!env_merge(newenv, envlen+2, envp, envlen, modifs, m)) goto erractions ;
if (!haspath && (setenv("PATH", SKALIBS_DEFAULTPATH, 0) < 0))
{
e = errno ; goto erractions ;
diff --git a/src/libstddjb/child_spawn3.c b/src/libstddjb/child_spawn3.c
@@ -0,0 +1,165 @@
+/* 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 ;
+ 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 ;
+ 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 ;
+}
diff --git a/src/libunixonacid/textclient_startf.c b/src/libunixonacid/textclient_startf.c
@@ -12,8 +12,8 @@
int textclient_startf (textclient_t *a, char const *const *argv, char const *const *envp, uint32_t options, char const *before, size_t beforelen, char const *after, size_t afterlen, tain_t const *deadline, tain_t *stamp)
{
struct iovec v ;
- int fd[3] ;
- pid_t pid = child_spawn(argv[0], argv, envp, fd, 3) ;
+ int fd[3] = { 0, 1 } ;
+ pid_t pid = child_spawn3(argv[0], argv, envp, fd) ;
if (!pid) return 0 ;
textmessage_receiver_init(&a->syncin, fd[0], a->syncbuf, TEXTCLIENT_BUFSIZE, TEXTMESSAGE_MAXLEN) ;
textmessage_receiver_init(&a->asyncin, fd[2], a->asyncbuf, TEXTCLIENT_BUFSIZE, TEXTMESSAGE_MAXLEN) ;
