From f0359dd00d60d72c4b3dec85de8e490692f6015c Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <tridge@samba.org>
Date: Thu, 30 Mar 2000 14:15:00 +0000
Subject: [PATCH] went back to non-blokcing IO

it looks like ssh is willing to accept a non-blocking fd when used as
a transport, this seems to avoid the Solaris socketpair bug
---
 acconfig.h     |  1 +
 clientserver.c |  2 +-
 io.c           | 12 +++++++++++-
 main.c         |  8 ++++++++
 rsync.h        |  9 +++++++++
 util.c         | 40 ++++++++++++++++++++++++++++++++++++----
 6 files changed, 66 insertions(+), 6 deletions(-)

diff --git a/acconfig.h b/acconfig.h
index d35ec3fb..03a77f8c 100644
--- a/acconfig.h
+++ b/acconfig.h
@@ -11,3 +11,4 @@
 #undef HAVE_GETOPT_LONG
 #undef REPLACE_INET_NTOA
 #undef HAVE_GETTIMEOFDAY_TZ
+#undef HAVE_SOCKETPAIR
diff --git a/clientserver.c b/clientserver.c
index df847ffc..7518e3e1 100644
--- a/clientserver.c
+++ b/clientserver.c
@@ -363,7 +363,7 @@ static int start_daemon(int fd)
 
 	set_socket_options(fd,"SO_KEEPALIVE");
 	set_socket_options(fd,lp_socket_options());
-	
+	set_nonblocking(fd);
 
 	io_printf(fd,"@RSYNCD: %d\n", PROTOCOL_VERSION);
 
diff --git a/io.c b/io.c
index 6cdbe6bf..6a55576d 100644
--- a/io.c
+++ b/io.c
@@ -159,6 +159,11 @@ static int read_timeout(int fd, char *buf, int len)
 			continue;
 		}
 
+		if (n == -1 && 
+		    (errno == EWOULDBLOCK || errno == EAGAIN)) {
+			continue;
+		}
+
 
 		if (n == 0) {
 			if (eof_error) {
@@ -364,12 +369,17 @@ static void writefd_unbuffered(int fd,char *buf,int len)
 		if (FD_ISSET(fd, &w_fds)) {
 			int ret, n = len-total;
 			
-			ret = write(fd,buf+total,n?n:1);
+			ret = write(fd,buf+total,n);
 
 			if (ret == -1 && errno == EINTR) {
 				continue;
 			}
 
+			if (ret == -1 && 
+			    (errno == EWOULDBLOCK || errno == EAGAIN)) {
+				continue;
+			}
+
 			if (ret <= 0) {
 				rprintf(FERROR,"erroring writing %d bytes - exiting\n", len);
 				exit_cleanup(RERR_STREAMIO);
diff --git a/main.c b/main.c
index 0c4f2cda..f7e52bed 100644
--- a/main.c
+++ b/main.c
@@ -417,6 +417,9 @@ void start_server(int f_in, int f_out, int argc, char *argv[])
 
 	setup_protocol(f_out, f_in);
 
+	set_nonblocking(f_in);
+	set_nonblocking(f_out);
+
 	if (remote_version >= 23)
 		io_start_multiplex_out(f_out);
 
@@ -440,6 +443,9 @@ int client_run(int f_in, int f_out, int pid, int argc, char *argv[])
 	extern int list_only;
 	extern int remote_version;
 
+	set_nonblocking(f_in);
+	set_nonblocking(f_out);
+
 	setup_protocol(f_out,f_in);
 
 	if (remote_version >= 23)
@@ -695,6 +701,8 @@ int main(int argc,char *argv[])
 #endif
 
 	if (am_server) {
+		set_nonblocking(STDIN_FILENO);
+		set_nonblocking(STDOUT_FILENO);
 		start_server(STDIN_FILENO, STDOUT_FILENO, argc, argv);
 	}
 
diff --git a/rsync.h b/rsync.h
index a4b7e812..f9f0fd4f 100644
--- a/rsync.h
+++ b/rsync.h
@@ -457,6 +457,15 @@ extern int errno;
 #define S_ISREG(mode) (((mode) & (_S_IFMT)) == (_S_IFREG))
 #endif
 
+/* work out what fcntl flag to use for non-blocking */
+#ifdef O_NONBLOCK
+# define NONBLOCK_FLAG O_NONBLOCK
+#elif defined(SYSV)
+# define NONBLOCK_FLAG O_NDELAY
+#else 
+# define NONBLOCK_FLAG FNDELAY
+#endif
+
 
 #define IS_DEVICE(mode) (S_ISCHR(mode) || S_ISBLK(mode) || S_ISSOCK(mode) || S_ISFIFO(mode))
 
diff --git a/util.c b/util.c
index a0e2707e..03a626eb 100644
--- a/util.c
+++ b/util.c
@@ -26,15 +26,47 @@
 
 extern int verbose;
 
-/* create a file descriptor - like pipe() but use socketpair if
-   possible (because of blocking issues on pipes */
+
+/****************************************************************************
+Set a fd into nonblocking mode. Uses POSIX O_NONBLOCK if available,
+else
+if SYSV use O_NDELAY
+if BSD use FNDELAY
+****************************************************************************/
+void set_nonblocking(int fd)
+{
+	int val;
+
+	if((val = fcntl(fd, F_GETFL, 0)) == -1)
+		return;
+	if (!(val & NONBLOCK_FLAG)) {
+		val |= NONBLOCK_FLAG;
+		fcntl(fd, F_SETFL, val);
+	}
+}
+
+
+/* create a file descriptor pair - like pipe() but use socketpair if
+   possible (because of blocking issues on pipes)
+
+   always set non-blocking
+ */
 int fd_pair(int fd[2])
 {
+	int ret;
+
 #if HAVE_SOCKETPAIR
-	return socketpair(AF_UNIX, SOCK_STREAM, 0, fd);
+	ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fd);
 #else
-	return pipe(fd);
+	ret = pipe(fd);
 #endif
+
+	if (ret == 0) {
+		set_nonblocking(fd[0]);
+		set_nonblocking(fd[1]);
+	}
+	
+	return ret;
 }
 
 
-- 
2.34.1