added a wrapper for fork()

in a fork we have to close all server connections otherwise we can end
up with two processes writing to the same socket.
(This used to be commit b7ecbca3aff34ff06a445e5ee39efba48261b7e8)

7 files changed, 91 insertions, 2 deletions

diff --git a/source3/configure b/source3/configure
index a807413bb63..938d6c55c7d 100755
--- a/source3/configure
+++ b/source3/configure
@@ -4401,7 +4401,7 @@ else
 fi
 done
 
-for ac_func in _write __write
+for ac_func in _write __write _fork __fork
 do
 echo $ac_n "checking for $ac_func""... $ac_c" 1>&6
 echo "configure:4408: checking for $ac_func" >&5
diff --git a/source3/configure.in b/source3/configure.in
index c9f3ff6150e..0815343ecde 100644
--- a/source3/configure.in
+++ b/source3/configure.in
@@ -189,7 +189,7 @@ AC_CHECK_FUNCS(_stat _lstat _fstat __stat __lstat __fstat)
 AC_CHECK_FUNCS(_acl __acl _facl __facl _open __open _chdir __chdir)
 AC_CHECK_FUNCS(_close __close _fchdir __fchdir _fcntl __fcntl)
 AC_CHECK_FUNCS(_getdents __getdents _lseek __lseek _read __read)
-AC_CHECK_FUNCS(_write __write)
+AC_CHECK_FUNCS(_write __write _fork __fork)
 AC_CHECK_FUNCS(_stat64 __stat64 _fstat64 __fstat64 _lstat64 __lstat64)
 AC_CHECK_FUNCS(llseek _llseek __llseek readdir64 _readdir64 __readdir64)
 AC_CHECK_FUNCS(pread _pread __pread pread64 _pread64 __pread64)
diff --git a/source3/include/config.h.in b/source3/include/config.h.in
index 930832a8bd5..92056f075af 100644
--- a/source3/include/config.h.in
+++ b/source3/include/config.h.in
@@ -165,6 +165,9 @@
 /* Define if you have the __fcntl function.  */
 #undef HAVE___FCNTL
 
+/* Define if you have the __fork function.  */
+#undef HAVE___FORK
+
 /* Define if you have the __fstat function.  */
 #undef HAVE___FSTAT
 
@@ -270,6 +273,9 @@
 /* Define if you have the _fcntl function.  */
 #undef HAVE__FCNTL
 
+/* Define if you have the _fork function.  */
+#undef HAVE__FORK
+
 /* Define if you have the _fstat function.  */
 #undef HAVE__FSTAT
 
diff --git a/source3/smbwrapper/realcalls.h b/source3/smbwrapper/realcalls.h
index 338e1950874..65431bf53f7 100644
--- a/source3/smbwrapper/realcalls.h
+++ b/source3/smbwrapper/realcalls.h
@@ -51,6 +51,14 @@
 #define NO_OPEN64_ALIAS
 #endif
 
+#ifdef HAVE__FORK
+#define real_fork()            	(_fork())
+#elif HAVE___FORK
+#define real_fork()            	(__fork())
+#elif SYS_fork
+#define real_fork()		(syscall(SYS_fork,()))
+#endif
+
 #ifdef HAVE__OPENDIR
 #define real_opendir(fn)            	((DIR *)_opendir(fn))
 #elif SYS_opendir
diff --git a/source3/smbwrapper/smbw.c b/source3/smbwrapper/smbw.c
index e5359360c3d..6096f096a30 100644
--- a/source3/smbwrapper/smbw.c
+++ b/source3/smbwrapper/smbw.c
@@ -1229,3 +1229,72 @@ int smbw_dup2(int fd, int fd2)
 	return -1;
 }
 
+
+/***************************************************** 
+close a connection to a server
+*******************************************************/
+static void smbw_srv_close(struct smbw_server *srv)
+{
+	smbw_busy++;
+
+	cli_shutdown(&srv->cli);
+
+	free(srv->server_name);
+	free(srv->share_name);
+
+	DLIST_REMOVE(smbw_srvs, srv);
+
+	ZERO_STRUCTP(srv);
+
+	free(srv);
+	
+	smbw_busy--;
+}
+
+/***************************************************** 
+when we fork we have to close all connections and files
+in the child
+*******************************************************/
+int smbw_fork(void)
+{
+	pid_t child;
+	int p[2];
+	char c=0;
+
+	struct smbw_file *file, *next_file;
+	struct smbw_server *srv, *next_srv;
+
+	if (pipe(p)) return real_fork();
+
+	child = real_fork();
+
+	if (child) {
+		/* block the parent for a moment until the sockets are
+                   closed */
+		close(p[1]);
+		read(p[0], &c, 1);
+		close(p[0]);
+		return child;
+	}
+
+	close(p[0]);
+
+	/* close all files */
+	for (file=smbw_files;file;file=next_file) {
+		next_file = file->next;
+		close(file->fd);
+	}
+
+	/* close all server connections */
+	for (srv=smbw_srvs;srv;srv=next_srv) {
+		next_srv = srv->next;
+		smbw_srv_close(srv);
+	}
+
+	/* unblock the parent */
+	write(p[1], &c, 1);
+	close(p[1]);
+
+	/* and continue in the child */
+	return 0;
+}
diff --git a/source3/smbwrapper/smbw_dir.c b/source3/smbwrapper/smbw_dir.c
index a932c102dc3..2c1b7ef9ecb 100644
--- a/source3/smbwrapper/smbw_dir.c
+++ b/source3/smbwrapper/smbw_dir.c
@@ -664,3 +664,4 @@ off_t smbw_telldir(DIR *dirp)
 	struct smbw_dir *d = (struct smbw_dir *)dirp;
 	return smbw_dir_lseek(d->fd,0,SEEK_CUR);
 }
+
diff --git a/source3/smbwrapper/wrapped.c b/source3/smbwrapper/wrapped.c
index bda0ed1abe1..10b22b35dd4 100644
--- a/source3/smbwrapper/wrapped.c
+++ b/source3/smbwrapper/wrapped.c
@@ -908,3 +908,8 @@ static void dirent64_convert(struct dirent *d, struct dirent64 *d64)
 	return real_readdir64(dir);
 }
 #endif
+
+ int fork(void)
+{
+	return smbw_fork();
+}