[multiple] _WIN32 fdevent_pipe_cloexec()

Note: Under _WIN32, serious limitation in Windows APIs:
  select() and WSAPoll() operate only on sockets (not pipes)
  (directly affects mod_cgi; not currently handled)

src/configfile.c

@@ -2240,7 +2240,7 @@ int config_parse_cmd(server *srv, config_t *context, const char *cmd) {
 		}
 	}
 
-	if (pipe(fds)) {
+	if (fdevent_pipe_cloexec(fds, 65536)) {
 		log_perror(srv->errh, __FILE__, __LINE__, "pipe()");
 		ret = -1;
 	}
@@ -2253,7 +2253,6 @@ int config_parse_cmd(server *srv, config_t *context, const char *cmd) {
 		*(const char **)&args[2] = cmd;
 		args[3] = NULL;
 
-		fdevent_setfd_cloexec(fds[0]);
 		pid = fdevent_fork_execve(args[0], args, NULL, -1, fds[1], -1, -1);
 		if (-1 == pid) {
 			log_perror(srv->errh, __FILE__, __LINE__, "fork/exec(%s)", cmd);

src/fdevent.c

@@ -609,6 +609,35 @@ int fdevent_open_dirname(char *path, int symlinks) {
 }
 
 
+#ifdef _WIN32
+#include <stdio.h>
+#endif
+
+int fdevent_pipe_cloexec (int * const fds, const unsigned int bufsz_hint) {
+ #ifdef _WIN32
+    return _pipe(fds, bufsz_hint, _O_BINARY | _O_NOINHERIT);
+ #else
+  #ifdef HAVE_PIPE2
+    if (0 != pipe2(fds, O_CLOEXEC))
+  #endif
+    {
+        if (0 != pipe(fds)
+         #ifdef FD_CLOEXEC
+         || 0 != fcntl(fds[0], F_SETFD, FD_CLOEXEC)
+         || 0 != fcntl(fds[1], F_SETFD, FD_CLOEXEC)
+         #endif
+           )
+        return -1;
+    }
+  #ifdef F_SETPIPE_SZ
+    if (bufsz_hint > 65536)
+        fcntl(fds[1], F_SETPIPE_SZ, bufsz_hint);
+  #endif
+    return 0;
+ #endif
+}
+
+
 int fdevent_mkostemp(char *path, int flags) {
  #if defined(HAVE_MKOSTEMP)
     return mkostemp(path, O_CLOEXEC | flags);

src/fdevent.h

@@ -87,6 +87,7 @@ int fdevent_socket_cloexec(int domain, int type, int protocol);
 int fdevent_socket_nb_cloexec(int domain, int type, int protocol);
 int fdevent_dup_cloexec(int fd);
 int fdevent_open_cloexec(const char *pathname, int symlinks, int flags, mode_t mode);
+int fdevent_pipe_cloexec (int *fds, unsigned int bufsz_hint);
 int fdevent_mkostemp(char *path, int flags);
 int fdevent_rename(const char *oldpath, const char *newpath);
 

src/fdlog_maint.c

@@ -190,10 +190,8 @@ fdlog_pipe_open (const char * const fn)
     }
 
     int fds[2];
-    if (pipe(fds))
+    if (fdevent_pipe_cloexec(fds, 65536))
         return NULL;
-    fdevent_setfd_cloexec(fds[0]);
-    fdevent_setfd_cloexec(fds[1]);
 
     pid_t pid = fdlog_pipe_spawn(fn, fds[0]);
     if (pid > 0) {

src/mod_cgi.c

@@ -27,19 +27,6 @@
 #include <fcntl.h>
 #include <signal.h>
 
-static int pipe_cloexec(int pipefd[2]) {
-  #ifdef HAVE_PIPE2
-    if (0 == pipe2(pipefd, O_CLOEXEC)) return 0;
-  #endif
-    return 0 == pipe(pipefd)
-       #ifdef FD_CLOEXEC
-        && 0 == fcntl(pipefd[0], F_SETFD, FD_CLOEXEC)
-        && 0 == fcntl(pipefd[1], F_SETFD, FD_CLOEXEC)
-       #endif
-      ?  0
-      : -1;
-}
-
 typedef struct {
 	uintptr_t *offsets;
 	size_t osize;
@@ -665,8 +652,6 @@ static int cgi_write_request(handler_ctx *hctx, int fd) {
 	chunkqueue_remove_finished_chunks(cq); /* unnecessary? */
 
 	/* old comment: windows doesn't support select() on pipes - wouldn't be easy to fix for all platforms.
-	 * solution: if this is still a problem on windows, then substitute
-	 * socketpair() for pipe() and closesocket() for close() on windows.
 	 */
 
 	for (c = cq->first; c; c = cq->first) {
@@ -791,11 +776,16 @@ static int cgi_create_env(request_st * const r, plugin_data * const p, handler_c
 	}
   #endif
 
-	if (-1 == to_cgi_fds[0] && pipe_cloexec(to_cgi_fds)) {
+	unsigned int bufsz_hint = 16384;
+  #ifdef _WIN32
+	if (r->reqbody_length <= 1048576)
+		bufsz_hint = (unsigned int)r->reqbody_length;
+  #endif
+	if (-1 == to_cgi_fds[0] && fdevent_pipe_cloexec(to_cgi_fds, bufsz_hint)) {
 		log_perror(r->conf.errh, __FILE__, __LINE__, "pipe failed");
 		return -1;
 	}
-	if (pipe_cloexec(from_cgi_fds)) {
+	if (fdevent_pipe_cloexec(from_cgi_fds, bufsz_hint)) {
 		if (0 == r->reqbody_length) {
 			close(to_cgi_fds[0]);
 		}

src/mod_rrdtool.c

@@ -86,18 +86,16 @@ static int mod_rrd_create_pipe(server *srv, plugin_data *p) {
 	 * If pipes were to be shared, then existing pipes would need to be
 	 * reused here, if they already exist (not -1), and after flushing
 	 * existing contents (read and discard from read-end of pipes). */
-	if (pipe(to_rrdtool_fds)) {
+	if (fdevent_pipe_cloexec(to_rrdtool_fds, 4096)) {
 		log_perror(srv->errh, __FILE__, __LINE__, "pipe()");
 		return 0;
 	}
-	if (pipe(from_rrdtool_fds)) {
+	if (fdevent_pipe_cloexec(from_rrdtool_fds, 4096)) {
 		log_perror(srv->errh, __FILE__, __LINE__, "pipe()");
 		close(to_rrdtool_fds[0]);
 		close(to_rrdtool_fds[1]);
 		return 0;
 	}
-	fdevent_setfd_cloexec(to_rrdtool_fds[1]);
-	fdevent_setfd_cloexec(from_rrdtool_fds[0]);
 	const char * const path_rrdtool_bin = p->path_rrdtool_bin
 	  ? p->path_rrdtool_bin->ptr
 	  : "/usr/bin/rrdtool";

src/server.c

@@ -197,7 +197,7 @@ static int daemonize(void) {
 	signal(SIGTSTP, SIG_IGN);
 #endif
 
-	if (pipe(pipefd) < 0) exit(-1);
+	if (fdevent_pipe_cloexec(pipefd, 64) < 0) exit(-1);
 
 	if (0 > (pid = fork())) exit(-1);
 
@@ -231,7 +231,6 @@ static int daemonize(void) {
 
 	if (0 != chdir("/")) exit(0);
 
-	fdevent_setfd_cloexec(pipefd[1]);
 	return pipefd[1];
 }
 #endif