--- a/packet.c	Sun Apr 14 22:49:10 2013 +0800
+++ b/packet.c	Sun Apr 14 22:49:19 2013 +0800
@@ -55,10 +55,62 @@
 	buffer * writebuf = NULL;
 	time_t now;
 	unsigned packet_type;
+	int all_ignore = 1;
+#ifdef HAVE_WRITEV
+	struct iovec *iov = NULL;
+	int i;
+	struct Link *l;
+#endif
 	
-	TRACE(("enter write_packet"))
+	TRACE2(("enter write_packet"))
 	dropbear_assert(!isempty(&ses.writequeue));
 
+#ifdef HAVE_WRITEV
+	iov = m_malloc(sizeof(*iov) * ses.writequeue.count);
+	for (l = ses.writequeue.head, i = 0; l; l = l->link, i++)
+	{
+		writebuf = (buffer*)l->item;
+		packet_type = writebuf->data[writebuf->len-1];
+		len = writebuf->len - 1 - writebuf->pos;
+		dropbear_assert(len > 0);
+		all_ignore &= (packet_type == SSH_MSG_IGNORE);
+		TRACE2(("write_packet writev #%d  type %d len %d/%d", i, packet_type,
+				len, writebuf->len-1))
+		iov[i].iov_base = buf_getptr(writebuf, len);
+		iov[i].iov_len = len;
+	}
+	written = writev(ses.sock_out, iov, ses.writequeue.count);
+	if (written < 0) {
+		if (errno == EINTR) {
+			m_free(iov);
+			TRACE2(("leave writepacket: EINTR"))
+			return;
+		} else {
+			dropbear_exit("Error writing");
+		}
+	} 
+
+	if (written == 0) {
+		ses.remoteclosed();
+	}
+
+	while (written > 0) {
+		writebuf = (buffer*)examine(&ses.writequeue);
+		len = writebuf->len - 1 - writebuf->pos;
+		if (len > written) {
+			// partial buffer write
+			buf_incrpos(writebuf, written);
+			written = 0;
+		} else {
+			written -= len;
+			dequeue(&ses.writequeue);
+			buf_free(writebuf);
+		}
+	}
+
+	m_free(iov);
+
+#else
 	/* Get the next buffer in the queue of encrypted packets to write*/
 	writebuf = (buffer*)examine(&ses.writequeue);
 
@@ -72,19 +124,13 @@
 
 	if (written < 0) {
 		if (errno == EINTR) {
-			TRACE(("leave writepacket: EINTR"))
+			TRACE2(("leave writepacket: EINTR"))
 			return;
 		} else {
 			dropbear_exit("Error writing");
 		}
 	} 
-	
-	now = time(NULL);
-	ses.last_trx_packet_time = now;
-
-	if (packet_type != SSH_MSG_IGNORE) {
-		ses.last_packet_time = now;
-	}
+	all_ignore = (packet_type == SSH_MSG_IGNORE);
 
 	if (written == 0) {
 		ses.remoteclosed();
@@ -100,7 +146,15 @@
 		buf_incrpos(writebuf, written);
 	}
 
-	TRACE(("leave write_packet"))
+#endif
+	now = time(NULL);
+	ses.last_trx_packet_time = now;
+
+	if (!all_ignore) {
+		ses.last_packet_time = now;
+	}
+
+	TRACE2(("leave write_packet"))
 }
 
 /* Non-blocking function reading available portion of a packet into the
@@ -112,7 +166,7 @@
 	unsigned int maxlen;
 	unsigned char blocksize;
 
-	TRACE(("enter read_packet"))
+	TRACE2(("enter read_packet"))
 	blocksize = ses.keys->recv.algo_crypt->blocksize;
 	
 	if (ses.readbuf == NULL || ses.readbuf->len < blocksize) {
@@ -125,7 +179,7 @@
 
 		if (ret == DROPBEAR_FAILURE) {
 			/* didn't read enough to determine the length */
-			TRACE(("leave read_packet: packetinit done"))
+			TRACE2(("leave read_packet: packetinit done"))
 			return;
 		}
 	}
@@ -147,7 +201,7 @@
 
 		if (len < 0) {
 			if (errno == EINTR || errno == EAGAIN) {
-				TRACE(("leave read_packet: EINTR or EAGAIN"))
+				TRACE2(("leave read_packet: EINTR or EAGAIN"))
 				return;
 			} else {
 				dropbear_exit("Error reading: %s", strerror(errno));
@@ -163,7 +217,7 @@
 		/* The main select() loop process_packet() to
 		 * handle the packet contents... */
 	}
-	TRACE(("leave read_packet"))
+	TRACE2(("leave read_packet"))
 }
 
 /* Function used to read the initial portion of a packet, and determine the
@@ -197,7 +251,7 @@
 	}
 	if (slen < 0) {
 		if (errno == EINTR) {
-			TRACE(("leave read_packet_init: EINTR"))
+			TRACE2(("leave read_packet_init: EINTR"))
 			return DROPBEAR_FAILURE;
 		}
 		dropbear_exit("Error reading: %s", strerror(errno));
@@ -221,7 +275,7 @@
 	}
 	len = buf_getint(ses.readbuf) + 4 + macsize;
 
-	TRACE(("packet size is %d, block %d mac %d", len, blocksize, macsize))
+	TRACE2(("packet size is %d, block %d mac %d", len, blocksize, macsize))
 
 
 	/* check packet length */
@@ -247,7 +301,7 @@
 	unsigned int padlen;
 	unsigned int len;
 
-	TRACE(("enter decrypt_packet"))
+	TRACE2(("enter decrypt_packet"))
 	blocksize = ses.keys->recv.algo_crypt->blocksize;
 	macsize = ses.keys->recv.algo_mac->hashsize;
 
@@ -304,7 +358,7 @@
 
 	ses.recvseq++;
 
-	TRACE(("leave decrypt_packet"))
+	TRACE2(("leave decrypt_packet"))
 }
 
 /* Checks the mac at the end of a decrypted readbuf.
@@ -314,7 +368,7 @@
 	unsigned char mac_bytes[MAX_MAC_LEN];
 	unsigned int mac_size, contents_len;
 	
-	mac_size = ses.keys->trans.algo_mac->hashsize;
+	mac_size = ses.keys->recv.algo_mac->hashsize;
 	contents_len = ses.readbuf->len - mac_size;
 
 	buf_setpos(ses.readbuf, 0);
@@ -403,7 +457,6 @@
 		ses.reply_queue_head = new_item;
 	}
 	ses.reply_queue_tail = new_item;
-	TRACE(("leave enqueue_reply_packet"))
 }
 
 void maybe_flush_reply_queue() {
@@ -440,24 +493,18 @@
 	unsigned int len, encrypt_buf_size;
 	unsigned char mac_bytes[MAX_MAC_LEN];
 	
-	TRACE(("enter encrypt_packet()"))
+	TRACE2(("enter encrypt_packet()"))
 
 	buf_setpos(ses.writepayload, 0);
 	packet_type = buf_getbyte(ses.writepayload);
 	buf_setpos(ses.writepayload, 0);
 
-	TRACE(("encrypt_packet type is %d", packet_type))
+	TRACE2(("encrypt_packet type is %d", packet_type))
 	
-	if ((!ses.dataallowed && !packet_is_okay_kex(packet_type))
-			|| ses.kexstate.sentnewkeys) {
+	if ((!ses.dataallowed && !packet_is_okay_kex(packet_type))) {
 		/* During key exchange only particular packets are allowed.
 			Since this packet_type isn't OK we just enqueue it to send 
 			after the KEX, see maybe_flush_reply_queue */
-
-		/* We also enqueue packets here when we have sent a MSG_NEWKEYS
-		 * packet but are yet to received one. For simplicity we just switch
-		 * over all the keys at once. This is the 'ses.kexstate.sentnewkeys'
-		 * case. */
 		enqueue_reply_packet();
 		return;
 	}
@@ -559,7 +606,7 @@
 	ses.kexstate.datatrans += writebuf->len;
 	ses.transseq++;
 
-	TRACE(("leave encrypt_packet()"))
+	TRACE2(("leave encrypt_packet()"))
 }
 
 
@@ -572,8 +619,6 @@
 	unsigned long bufsize;
 	hmac_state hmac;
 
-	TRACE(("enter writemac"))
-
 	if (key_state->algo_mac->hashsize > 0) {
 		/* calculate the mac */
 		if (hmac_init(&hmac, 
@@ -602,7 +647,7 @@
 			dropbear_exit("HMAC error");
 		}
 	}
-	TRACE(("leave writemac"))
+	TRACE2(("leave writemac"))
 }
 
 #ifndef DISABLE_ZLIB
@@ -613,7 +658,7 @@
 	unsigned int endpos = src->pos + len;
 	int result;
 
-	TRACE(("enter buf_compress"))
+	TRACE2(("enter buf_compress"))
 
 	while (1) {
 
@@ -647,6 +692,6 @@
 		buf_resize(dest, dest->size + ZLIB_COMPRESS_INCR);
 
 	}
-	TRACE(("leave buf_compress"))
+	TRACE2(("leave buf_compress"))
 }
 #endif