This patch extends the current keep-alive code (which currently only
handles silences in the generator's output) to deal with potential
silences in the sender's output when it is reading a lot of checksum
data from the generator (caused by the transfer of a large file).

After applying this patch, run "make proto".

--- orig/clientserver.c	2005-04-09 17:38:31
+++ clientserver.c	2005-05-16 01:02:41
@@ -40,8 +40,6 @@ extern int sanitize_paths;
 extern int filesfrom_fd;
 extern int remote_protocol;
 extern int protocol_version;
-extern int io_timeout;
-extern int select_timeout;
 extern int orig_umask;
 extern int no_detach;
 extern int default_af_hint;
@@ -518,11 +516,8 @@ static int rsync_module(int f_in, int f_
 		exit_cleanup(RERR_UNSUPPORTED);
 	}
 
-	if (lp_timeout(i)) {
-		io_timeout = lp_timeout(i);
-		if (io_timeout < select_timeout)
-			select_timeout = io_timeout;
-	}
+	if (lp_timeout(i))
+		set_io_timeout(lp_timeout(i));
 
 	start_server(f_in, f_out, argc, argp);
 
--- orig/generator.c	2005-05-14 19:51:15
+++ generator.c	2005-05-16 01:02:43
@@ -59,8 +59,8 @@ extern int csum_length;
 extern int ignore_times;
 extern int size_only;
 extern OFF_T max_size;
-extern int io_timeout;
 extern int io_error;
+extern int allowed_lull;
 extern int sock_f_out;
 extern int ignore_timeout;
 extern int protocol_version;
@@ -89,8 +89,6 @@ extern int backup_suffix_len;
 extern struct file_list *the_file_list;
 extern struct filter_list_struct server_filter_list;
 
-int allowed_lull = 0;
-
 static int deletion_count = 0; /* used to implement --max-delete */
 
 
@@ -1145,10 +1143,11 @@ notify_others:
 
 void generate_files(int f_out, struct file_list *flist, char *local_name)
 {
-	int i, lull_mod;
+	int i;
 	char fbuf[MAXPATHLEN];
 	int itemizing, maybe_PERMS_REPORT;
 	enum logcode code;
+	int lull_mod = allowed_lull * 5;
 	int need_retouch_dir_times = preserve_times && !omit_dir_times;
 	int need_retouch_dir_perms = 0;
 	int save_only_existing = only_existing;
@@ -1156,9 +1155,6 @@ void generate_files(int f_out, struct fi
 	int save_do_progress = do_progress;
 	int save_make_backups = make_backups;
 
-	allowed_lull = read_batch ? 0 : (io_timeout + 1) / 2;
-	lull_mod = allowed_lull * 5;
-
 	if (protocol_version >= 29) {
 		itemizing = 1;
 		maybe_PERMS_REPORT = log_format_has_i ? 0 : PERMS_REPORT;
--- orig/io.c	2005-05-12 17:42:08
+++ io.c	2005-05-18 23:19:18
@@ -42,13 +42,13 @@
 extern int bwlimit;
 extern size_t bwlimit_writemax;
 extern int verbose;
-extern int io_timeout;
 extern int allowed_lull;
 extern int am_server;
 extern int am_daemon;
 extern int am_sender;
 extern int am_generator;
 extern int eol_nulls;
+extern int read_batch;
 extern int csum_length;
 extern int checksum_seed;
 extern int protocol_version;
@@ -59,7 +59,6 @@ extern struct stats stats;
 extern struct file_list *the_file_list;
 
 const char phase_unknown[] = "unknown";
-int select_timeout = SELECT_TIMEOUT;
 int ignore_timeout = 0;
 int batch_fd = -1;
 int batch_gen_fd = -1;
@@ -90,7 +89,8 @@ int sock_f_out = -1;
 
 static int io_multiplexing_out;
 static int io_multiplexing_in;
-static time_t last_io;
+static time_t last_in_io;
+static time_t last_out_io;
 static int no_flush;
 
 static int write_batch_monitor_in = -1;
@@ -103,6 +103,8 @@ static char *io_filesfrom_bp;
 static char io_filesfrom_lastchar;
 static int io_filesfrom_buflen;
 static size_t contiguous_write_len = 0;
+static int io_timeout;
+static int select_timeout = SELECT_TIMEOUT;
 
 static void read_loop(int fd, char *buf, size_t len);
 
@@ -166,17 +168,17 @@ static void check_timeout(void)
 	if (!io_timeout || ignore_timeout)
 		return;
 
-	if (!last_io) {
-		last_io = time(NULL);
+	if (!last_in_io) {
+		last_in_io = time(NULL);
 		return;
 	}
 
 	t = time(NULL);
 
-	if (t - last_io >= io_timeout) {
+	if (t - last_in_io >= io_timeout) {
 		if (!am_server && !am_daemon) {
 			rprintf(FERROR, "io timeout after %d seconds -- exiting\n",
-				(int)(t-last_io));
+				(int)(t-last_in_io));
 		}
 		exit_cleanup(RERR_TIMEOUT);
 	}
@@ -190,6 +192,18 @@ void io_set_sock_fds(int f_in, int f_out
 	sock_f_out = f_out;
 }
 
+void set_io_timeout(int secs)
+{
+	io_timeout = secs;
+
+	if (!io_timeout || io_timeout > SELECT_TIMEOUT)
+		select_timeout = SELECT_TIMEOUT;
+	else
+		select_timeout = io_timeout;
+
+	allowed_lull = read_batch ? 0 : (io_timeout + 1) / 2;
+}
+
 /* Setup the fd used to receive MSG_* messages.  Only needed during the
  * early stages of being a local sender (up through the sending of the
  * file list) or when we're the generator (to fetch the messages from
@@ -574,8 +588,8 @@ static int read_timeout(int fd, char *bu
 		len -= n;
 		ret += n;
 
-		if (fd == sock_f_in && (io_timeout || am_generator))
-			last_io = time(NULL);
+		if (fd == sock_f_in && io_timeout)
+			last_in_io = time(NULL);
 	}
 
 	return ret;
@@ -667,14 +681,14 @@ void io_end_buffering(void)
 
 void maybe_flush_socket(void)
 {
-	if (iobuf_out && iobuf_out_cnt && time(NULL) - last_io >= 5)
+	if (iobuf_out && iobuf_out_cnt && time(NULL) - last_out_io >= 5)
 		io_flush(NORMAL_FLUSH);
 }
 
 
 void maybe_send_keepalive(void)
 {
-	if (time(NULL) - last_io >= allowed_lull) {
+	if (time(NULL) - last_out_io >= allowed_lull) {
 		if (!iobuf_out || !iobuf_out_cnt) {
 			if (protocol_version < 29)
 				return; /* there's nothing we can do */
@@ -1077,7 +1091,7 @@ static void writefd_unbuffered(int fd,ch
 			/* If the other side is sending us error messages, try
 			 * to grab any messages they sent before they died. */
 			while (fd == sock_f_out && io_multiplexing_in) {
-				io_timeout = select_timeout = 30;
+				set_io_timeout(30);
 				ignore_timeout = 0;
 				readfd_unbuffered(sock_f_in, io_filesfrom_buf,
 						  sizeof io_filesfrom_buf);
@@ -1089,7 +1103,7 @@ static void writefd_unbuffered(int fd,ch
 
 		if (fd == sock_f_out) {
 			if (io_timeout || am_generator)
-				last_io = time(NULL);
+				last_out_io = time(NULL);
 			sleep_for_bwlimit(ret);
 		}
 	}
--- orig/options.c	2005-05-10 15:32:58
+++ options.c	2005-05-16 01:02:43
@@ -23,7 +23,6 @@
 
 extern int module_id;
 extern int sanitize_paths;
-extern int select_timeout;
 extern struct filter_list_struct filter_list;
 extern struct filter_list_struct server_filter_list;
 
@@ -75,7 +74,7 @@ int relative_paths = -1;
 int implied_dirs = 1;
 int numeric_ids = 0;
 int force_delete = 0;
-int io_timeout = 0;
+int allowed_lull = 0;
 char *files_from = NULL;
 int filesfrom_fd = -1;
 char *filesfrom_host = NULL;
@@ -161,6 +160,7 @@ int list_only = 0;
 char *batch_name = NULL;
 
 static int daemon_opt;   /* sets am_daemon after option error-reporting */
+static int timeout_val;
 static int F_option_cnt = 0;
 static int modify_window_set;
 static int itemize_changes = 0;
@@ -363,8 +363,7 @@ void usage(enum logcode F)
 enum {OPT_VERSION = 1000, OPT_DAEMON, OPT_SENDER, OPT_EXCLUDE, OPT_EXCLUDE_FROM,
       OPT_FILTER, OPT_COMPARE_DEST, OPT_COPY_DEST, OPT_LINK_DEST,
       OPT_INCLUDE, OPT_INCLUDE_FROM, OPT_MODIFY_WINDOW,
-      OPT_READ_BATCH, OPT_WRITE_BATCH, OPT_ONLY_WRITE_BATCH,
-      OPT_TIMEOUT, OPT_MAX_SIZE,
+      OPT_READ_BATCH, OPT_WRITE_BATCH, OPT_ONLY_WRITE_BATCH, OPT_MAX_SIZE,
       OPT_REFUSED_BASE = 9000};
 
 static struct poptOption long_options[] = {
@@ -428,7 +427,7 @@ static struct poptOption long_options[] 
   {"block-size",      'B', POPT_ARG_LONG,   &block_size, 0, 0, 0 },
   {"max-delete",       0,  POPT_ARG_INT,    &max_delete, 0, 0, 0 },
   {"max-size",         0,  POPT_ARG_STRING, &max_size_arg,  OPT_MAX_SIZE, 0, 0 },
-  {"timeout",          0,  POPT_ARG_INT,    &io_timeout, OPT_TIMEOUT, 0, 0 },
+  {"timeout",          0,  POPT_ARG_INT,    &timeout_val, 0, 0, 0 },
   {"temp-dir",        'T', POPT_ARG_STRING, &tmpdir, 0, 0, 0 },
   {"compare-dest",     0,  POPT_ARG_STRING, 0, OPT_COMPARE_DEST, 0, 0 },
   {"copy-dest",        0,  POPT_ARG_STRING, 0, OPT_COPY_DEST, 0, 0 },
@@ -844,11 +843,6 @@ int parse_arguments(int *argc, const cha
 			}
 			break;
 
-		case OPT_TIMEOUT:
-			if (io_timeout && io_timeout < select_timeout)
-				select_timeout = io_timeout;
-			break;
-
 		case OPT_LINK_DEST:
 #ifdef HAVE_LINK
 			link_dest = 1;
@@ -1115,6 +1109,8 @@ int parse_arguments(int *argc, const cha
 	if (dry_run)
 		do_xfers = 0;
 
+	set_io_timeout(timeout_val);
+
 	if (verbose && !log_format) {
 		log_format = "%n%L";
 		log_before_transfer = !am_server;
@@ -1357,8 +1353,8 @@ void server_options(char **args,int *arg
 		args[ac++] = max_size_arg;
 	}
 
-	if (io_timeout) {
-		if (asprintf(&arg, "--timeout=%d", io_timeout) < 0)
+	if (timeout_val) {
+		if (asprintf(&arg, "--timeout=%d", timeout_val) < 0)
 			goto oom;
 		args[ac++] = arg;
 	}
--- orig/sender.c	2005-04-14 01:53:12
+++ sender.c	2005-05-16 01:02:44
@@ -28,6 +28,7 @@ extern int log_format_has_i;
 extern int daemon_log_format_has_i;
 extern int csum_length;
 extern int io_error;
+extern int allowed_lull;
 extern int protocol_version;
 extern int remove_sent_files;
 extern int updating_basis_file;
@@ -56,6 +57,7 @@ static struct sum_struct *receive_sums(i
 {
 	struct sum_struct *s;
 	int32 i;
+	int lull_mod = allowed_lull * 5;
 	OFF_T offset = 0;
 
 	if (!(s = new(struct sum_struct)))
@@ -89,6 +91,9 @@ static struct sum_struct *receive_sums(i
 			s->sums[i].len = s->blength;
 		offset += s->sums[i].len;
 
+		if (allowed_lull && !(i % lull_mod))
+			maybe_send_keepalive();
+
 		if (verbose > 3) {
 			rprintf(FINFO,
 				"chunk[%d] len=%d offset=%.0f sum1=%08x\n",