- andreas@cvs.openbsd.org 2009/06/27 09:32:43

[roaming_common.c roaming.h]
     It may be necessary to retransmit some data when resuming, so add it
     to a buffer when roaming is enabled.
     Most of this code was written by Martin Forssen, maf at appgate dot com.
     ok markus@

ChangeLog

@@ -4,6 +4,12 @@
      packet_bacup_state() and packet_restore_state() will be used to
      temporarily save the current state ren resuming a suspended connection.
      ok markus@
+   - andreas@cvs.openbsd.org 2009/06/27 09:32:43
+     [roaming_common.c roaming.h]
+     It may be necessary to retransmit some data when resuming, so add it
+     to a buffer when roaming is enabled.
+     Most of this code was written by Martin Forssen, maf at appgate dot com.
+     ok markus@
 
 20090622
  - (dtucker) OpenBSD CVS Sync

roaming.h

@@ -1,4 +1,4 @@
-/* $OpenBSD: roaming.h,v 1.3 2009/06/21 09:04:03 dtucker Exp $ */
+/* $OpenBSD: roaming.h,v 1.4 2009/06/27 09:32:43 andreas Exp $ */
 /*
  * Copyright (c) 2004-2009 AppGate Network Security AB
  *
@@ -18,15 +18,21 @@
 #ifndef ROAMING_H
 #define ROAMING_H
 
+#define DEFAULT_ROAMBUF 65536
+
 extern int resume_in_progress;
 
+int	get_snd_buf_size(void);
+int	get_recv_buf_size(void);
 void	add_recv_bytes(u_int64_t);
+void	set_out_buffer_size(size_t);
 ssize_t	roaming_write(int, const void *, size_t, int *);
 ssize_t	roaming_read(int, void *, size_t, int *);
 size_t	roaming_atomicio(ssize_t (*)(int, void *, size_t), int, void *, size_t);
 u_int64_t	get_recv_bytes(void);
 u_int64_t	get_sent_bytes(void);
 void	roam_set_bytes(u_int64_t, u_int64_t);
+void	resend_bytes(int, u_int64_t *);
 int	resume_kex(void);
 
 #endif /* ROAMING */

roaming_common.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: roaming_common.c,v 1.4 2009/06/21 09:04:03 dtucker Exp $ */
+/* $OpenBSD: roaming_common.c,v 1.5 2009/06/27 09:32:43 andreas Exp $ */
 /*
  * Copyright (c) 2004-2009 AppGate Network Security AB
  *
@@ -26,6 +26,7 @@
 #include <inttypes.h>
 #endif
 #include <stdarg.h>
+#include <string.h>
 #include <unistd.h>
 
 #include "atomicio.h"
@@ -36,11 +37,56 @@
 #include "buffer.h"
 #include "roaming.h"
 
+static size_t out_buf_size = 0;
+static char *out_buf = NULL;
+static size_t out_start;
+static size_t out_last;
+
 static u_int64_t write_bytes = 0;
 static u_int64_t read_bytes = 0;
 
+int roaming_enabled = 0;
 int resume_in_progress = 0;
 
+int
+get_snd_buf_size()
+{
+	int fd = packet_get_connection_out();
+	int optval, optvallen;
+
+	optvallen = sizeof(optval);
+	if (getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &optval, &optvallen) != 0)
+		optval = DEFAULT_ROAMBUF;
+	return optval;
+}
+
+int
+get_recv_buf_size()
+{
+	int fd = packet_get_connection_in();
+	int optval, optvallen;
+
+	optvallen = sizeof(optval);
+	if (getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &optval, &optvallen) != 0)
+		optval = DEFAULT_ROAMBUF;
+	return optval;
+}
+
+void
+set_out_buffer_size(size_t size)
+{
+	/*
+	 * The buffer size can only be set once and the buffer will live
+	 * as long as the session lives.
+	 */
+	if (out_buf == NULL) {
+		out_buf_size = size;
+		out_buf = xmalloc(size);
+		out_start = 0;
+		out_last = 0;
+	}
+}
+
 u_int64_t
 get_recv_bytes(void)
 {
@@ -66,6 +112,28 @@ roam_set_bytes(u_int64_t sent, u_int64_t recvd)
 	write_bytes = sent;
 }
 
+static void
+buf_append(const char *buf, size_t count)
+{
+	if (count > out_buf_size) {
+		buf += count - out_buf_size;
+		count = out_buf_size;
+	}
+	if (count < out_buf_size - out_last) {
+		memcpy(out_buf + out_last, buf, count);
+		if (out_start > out_last)
+			out_start += count;
+		out_last += count;
+	} else {
+		/* data will wrap */
+		size_t chunk = out_buf_size - out_last;
+		memcpy(out_buf + out_last, buf, chunk);
+		memcpy(out_buf, buf + chunk, count - chunk);
+		out_last = count - chunk;
+		out_start = out_last + 1;
+	}
+}
+
 ssize_t
 roaming_write(int fd, const void *buf, size_t count, int *cont)
 {
@@ -74,6 +142,8 @@ roaming_write(int fd, const void *buf, size_t count, int *cont)
 	ret = write(fd, buf, count);
 	if (ret > 0 && !resume_in_progress) {
 		write_bytes += ret;
+		if (out_buf_size > 0)
+			buf_append(buf, ret);
 	}
 	debug3("Wrote %ld bytes for a total of %llu", (long)ret,
 	    (unsigned long long)write_bytes);
@@ -105,3 +175,27 @@ roaming_atomicio(ssize_t(*f)(int, void*, size_t), int fd, void *buf,
 	}
 	return ret;
 }
+
+void
+resend_bytes(int fd, u_int64_t *offset)
+{
+	size_t available, needed;
+
+	if (out_start < out_last)
+		available = out_last - out_start;
+	else
+		available = out_buf_size;
+	needed = write_bytes - *offset;
+	debug3("resend_bytes: resend %lu bytes from %llu",
+	    (unsigned long)needed, (unsigned long long)*offset);
+	if (needed > available)
+		fatal("Needed to resend more data than in the cache");
+	if (out_last < needed) {
+		int chunkend = needed - out_last;
+		atomicio(vwrite, fd, out_buf + out_buf_size - chunkend,
+		    chunkend);
+		atomicio(vwrite, fd, out_buf, out_last);
+	} else {
+		atomicio(vwrite, fd, out_buf + (out_last - needed), needed);
+	}
+}