Nasty.

--HG--
extra : convert_revision : e1229cd01c3007206d2937ea390ad4966c289a5a

Makefile.in

@@ -28,12 +28,12 @@ SVROBJS=svr-kex.o svr-algo.o svr-auth.o sshpty.o \
 
 CLIOBJS=cli-algo.o cli-main.o cli-auth.o cli-authpasswd.o cli-kex.o \
 		cli-session.o cli-service.o cli-runopts.o cli-chansession.o \
-		cli-authpubkey.o cli-tcpfwd.o
+		cli-authpubkey.o cli-tcpfwd.o cli-channel.o
 
 CLISVROBJS=common-session.o packet.o common-algo.o common-kex.o \
 			common-channel.o common-chansession.o termcodes.o loginrec.o \
 			tcp-accept.o listener.o process-packet.o \
-			common-runopts.o 
+			common-runopts.o circbuffer.o
 
 KEYOBJS=dropbearkey.o gendss.o genrsa.o
 

TODO

@@ -2,6 +2,8 @@ Current:
 
 Things which might need doing:
 
+- errfd needs fixing
+
 - Make options.h generated from configure perhaps?
 
 - Improved queueing of unauthed connections

channel.h

@@ -27,6 +27,7 @@
 
 #include "includes.h"
 #include "buffer.h"
+#include "circbuffer.h"
 
 /* channel->type values */
 #define CHANNEL_ID_NONE 0
@@ -50,6 +51,8 @@
 #define CHAN_EXTEND_SIZE 3 /* how many extra slots to add when we need more */
 
 #define RECV_MAXWINDOW 6000 /* tweak */
+#define RECV_WINDOWEXTEND (RECV_MAXWINDOW/2) /* We send a "window extend" every
+												RECV_WINDOWEXTEND bytes */
 #define RECV_MAXPACKET 1400 /* tweak */
 #define RECV_MINWINDOW 19000 /* when we get below this, we send a windowadjust */
 
@@ -62,13 +65,13 @@ struct Channel {
 	unsigned int recvwindow, transwindow;
 	unsigned int recvmaxpacket, transmaxpacket;
 	void* typedata; /* a pointer to type specific data */
-	int infd; /* stdin for the program, we write to this */
-	int outfd; /* stdout for the program, we read from this */
-	int errfd; /* stdout for a program. This doesn't really fit here,
-				  but makes the code a lot tidyer without being too bad. This
-				  is -1 for channels which don't requre it. Currently only
-				  a 'session' without a pty will use it */
-	buffer *writebuf; /* data for the program */
+	int infd; /* data to send over the wire */
+	int outfd; /* data for consumption, what was in writebuf */
+	int errfd; /* used like infd or errfd, depending if it's client or server.
+				  Doesn't exactly belong here, but is cleaner here */
+	circbuffer *writebuf; /* data from the wire, for local consumption */
+	circbuffer *extrabuf; /* extended-data for the program - used like writebuf
+					     but for stderr */
 
 	int sentclosed, recvclosed;
 
@@ -97,6 +100,7 @@ void chaninitialise();
 void chancleanup();
 void setchannelfds(fd_set *readfd, fd_set *writefd);
 void channelio(fd_set *readfd, fd_set *writefd);
+struct Channel* getchannel(unsigned int chan);
 struct Channel* newchannel(unsigned int remotechan, 
 		const struct ChanType *type, 
 		unsigned int transwindow, unsigned int transmaxpacket);
@@ -106,10 +110,16 @@ void recv_msg_channel_request();
 void send_msg_channel_failure(struct Channel *channel);
 void send_msg_channel_success(struct Channel *channel);
 void recv_msg_channel_data();
+void recv_msg_channel_extended_data();
 void recv_msg_channel_window_adjust();
 void recv_msg_channel_close();
 void recv_msg_channel_eof();
 
+void common_recv_msg_channel_data(struct Channel *channel, int fd, 
+		circbuffer * buf);
+
+const struct ChanType clichansess;
+
 #ifdef USING_LISTENERS
 int send_msg_channel_open_init(int fd, const struct ChanType *type);
 void recv_msg_channel_open_confirmation();

cli-channel.c

@@ -0,0 +1,65 @@
+/*
+ * Dropbear SSH
+ * 
+ * Copyright (c) 2002-2004 Matt Johnston
+ * All rights reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE. */
+
+#include "includes.h"
+#include "channel.h"
+#include "buffer.h"
+#include "circbuffer.h"
+#include "dbutil.h"
+#include "session.h"
+#include "ssh.h"
+
+/* We receive channel data - only used by the client chansession code*/
+void recv_msg_channel_extended_data() {
+
+	unsigned int chan;
+	struct Channel *channel;
+	unsigned int datatype;
+
+	TRACE(("enter recv_msg_channel_extended_data"));
+
+	chan = buf_getint(ses.payload);
+	channel = getchannel(chan);
+
+	if (channel == NULL) {
+		dropbear_exit("Unknown channel");
+	}
+
+	if (channel->type != &clichansess) {
+		TRACE(("leave recv_msg_channel_extended_data: chantype is wrong"));
+		return; /* we just ignore it */
+	}
+
+	datatype = buf_getint(ses.payload);
+	
+	if (datatype != SSH_EXTENDED_DATA_STDERR) {
+		TRACE(("leave recv_msg_channel_extended_data: wrong datatype: %d",
+					datatype));
+		return;	
+	}
+
+	common_recv_msg_channel_data(channel, channel->errfd, channel->extrabuf);
+
+	TRACE(("leave recv_msg_channel_extended_data"));
+}

cli-chansession.c

@@ -44,7 +44,7 @@ static void send_chansess_shell_req(struct Channel *channel);
 static void cli_tty_setup();
 void cli_tty_cleanup();
 
-static const struct ChanType clichansess = {
+const struct ChanType clichansess = {
 	0, /* sepfds */
 	"session", /* name */
 	cli_initchansess, /* inithandler */
@@ -316,7 +316,8 @@ static int cli_initchansess(struct Channel *channel) {
 
 	channel->infd = STDOUT_FILENO;
 	channel->outfd = STDIN_FILENO;
-	//channel->errfd = STDERR_FILENO;
+	channel->errfd = STDERR_FILENO;
+	channel->extrabuf = buf_new(RECV_MAXWINDOW);
 
 	if (cli_opts.wantpty) {
 		send_chansess_pty_req(channel);

cli-session.c

@@ -48,6 +48,7 @@ struct clientsession cli_ses; /* GLOBAL */
 static const packettype cli_packettypes[] = {
 	/* TYPE, FUNCTION */
 	{SSH_MSG_CHANNEL_DATA, recv_msg_channel_data},
+	{SSH_MSG_CHANNEL_EXTENDED_DATA, recv_msg_channel_extended_data},
 	{SSH_MSG_CHANNEL_WINDOW_ADJUST, recv_msg_channel_window_adjust},
 	{SSH_MSG_USERAUTH_FAILURE, recv_msg_userauth_failure}, /* client */
 	{SSH_MSG_USERAUTH_SUCCESS, recv_msg_userauth_success}, /* client */

common-channel.c

@@ -1,7 +1,7 @@
 /*
- * Dropbear - a SSH2 server
+ * Dropbear SSH
  * 
- * Copyright (c) 2002,2003 Matt Johnston
+ * Copyright (c) 2002-2004 Matt Johnston
  * All rights reserved.
  * 
  * Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -29,6 +29,7 @@
 #include "packet.h"
 #include "ssh.h"
 #include "buffer.h"
+#include "circbuffer.h"
 #include "dbutil.h"
 #include "channel.h"
 #include "ssh.h"
@@ -147,7 +148,8 @@ struct Channel* newchannel(unsigned int remotechan,
 	newchan->errfd = FD_CLOSED; /* this isn't always set to start with */
 	newchan->initconn = 0;
 
-	newchan->writebuf = buf_new(RECV_MAXWINDOW);
+	newchan->writebuf = cbuf_new(RECV_MAXWINDOW);
+	newchan->extrabuf = NULL; /* The user code can set it up */
 	newchan->recvwindow = RECV_MAXWINDOW;
 	newchan->recvmaxpacket = RECV_MAXPACKET;
 
@@ -160,7 +162,7 @@ struct Channel* newchannel(unsigned int remotechan,
 }
 
 /* Get the channel structure corresponding to a channel number */
-static struct Channel* getchannel(unsigned int chan) {
+struct Channel* getchannel(unsigned int chan) {
 	if (chan >= ses.chansize || ses.channels[chan] == NULL) {
 		return NULL;
 	}
@@ -345,21 +347,23 @@ static void send_msg_channel_eof(struct Channel *channel) {
 	TRACE(("leave send_msg_channel_eof"));
 }
 
-/* Called to write data out to the server side of a channel (eg a shell or a
- * program.
+/* Called to write data out to the local side of the channel. 
  * Only called when we know we can write to a channel, writes as much as
  * possible */
 static void writechannel(struct Channel* channel) {
 
 	int len, maxlen;
-	buffer *buf;
+	circbuffer *cbuf;
 
 	TRACE(("enter writechannel"));
 
-	buf = channel->writebuf;
-	maxlen = buf->len - buf->pos;
+	cbuf = channel->writebuf;
+	maxlen = cbuf_readlen(cbuf);
 
-	len = write(channel->infd, buf_getptr(buf, maxlen), maxlen);
+	TRACE(("maxlen = %d", maxlen));
+
+	/* Write the data out */
+	len = write(channel->infd, cbuf_readptr(cbuf, maxlen), maxlen);
 	if (len <= 0) {
 		if (len < 0 && errno != EINTR) {
 			/* no more to write */
@@ -369,25 +373,26 @@ static void writechannel(struct Channel* channel) {
 		return;
 	}
 
-	if (len == maxlen) {
-		buf_setpos(buf, 0);
-		buf_setlen(buf, 0);
+	TRACE(("len = %d", len));
+	cbuf_incrread(cbuf, len);
 
-		if (channel->recveof) {
-			/* we're closing up */
+	if (len == maxlen && channel->recveof) { 
+		/* Check if we're closing up */
 		closeinfd(channel);
 		return;
 		TRACE(("leave writechannel: recveof set"));
+
 	}
 
-		/* extend the window if we're at the end*/
-		/* TODO - this is inefficient */
-		send_msg_channel_window_adjust(channel, buf->size
-				- channel->recvwindow);
-		channel->recvwindow = buf->size;
-	} else {
-		buf_incrpos(buf, len);
+	/* Window adjust handling */
+	if (channel->recvwindow < (RECV_MAXWINDOW - RECV_WINDOWEXTEND)) {
+		/* Set it back to max window */
+		send_msg_channel_window_adjust(channel, RECV_MAXWINDOW -
+				channel->recvwindow);
+		channel->recvwindow = RECV_MAXWINDOW;
 	}
+	
+	
 	TRACE(("leave writechannel"));
 }
 
@@ -405,32 +410,38 @@ void setchannelfds(fd_set *readfd, fd_set *writefd) {
 			continue;
 		}
 
-		/* stdout and stderr */
+		/* Stuff to put over the wire */
 		if (channel->transwindow > 0) {
 
-			/* stdout */
 			if (channel->outfd >= 0) {
-				/* there's space to read more from the program */
 				FD_SET(channel->outfd, readfd);
 			}
-			/* stderr */
-			if (channel->errfd >= 0) {
+			
+			if (channel->extrabuf == NULL && channel->errfd >= 0) {
 					FD_SET(channel->errfd, readfd);
 			}
 		}
 
+		/* For checking FD status (ie closure etc) - we don't actually
+		 * read data from infd */
 		if (channel->infd >= 0 && channel->infd != channel->outfd) {
 			FD_SET(channel->infd, readfd);
 		}
 
-		/* stdin */
-		if (channel->infd >= 0 &&
-				(channel->writebuf->pos < channel->writebuf->len ||
-				 channel->initconn)) {
-			/* there's space to write more to the program */
+		/* Stuff from the wire, to local program/shell/user etc */
+		if ((channel->infd >= 0 && cbuf_getused(channel->writebuf) > 0 )
+				|| channel->initconn) {
+
 				FD_SET(channel->infd, writefd);
 		}
 
+		/*
+		if (channel->extrabuf != NULL && channel->errfd >= 0 
+				&& cbuf_getavail(channel->extrabuf) > 0 ) {
+				FD_SET(channel->errfd, writefd);
+		}
+		*/
+
 	} /* foreach channel */
 
 #ifdef USING_LISTENERS
@@ -457,7 +468,7 @@ void recv_msg_channel_eof() {
 	}
 
 	channel->recveof = 1;
-	if (channel->writebuf->len == 0) {
+	if (cbuf_getused(channel->writebuf) == 0) {
 		closeinfd(channel);
 	}
 
@@ -499,9 +510,15 @@ static void removechannel(struct Channel * channel) {
 	TRACE(("enter removechannel"));
 	TRACE(("channel index is %d", channel->index));
 
-	buf_free(channel->writebuf);
+	cbuf_free(channel->writebuf);
 	channel->writebuf = NULL;
 
+	if (channel->extrabuf) {
+		cbuf_free(channel->extrabuf);
+		channel->extrabuf = NULL;
+	}
+
+
 	/* close the FDs in case they haven't been done
 	 * yet (ie they were shutdown etc */
 	close(channel->infd);
@@ -623,60 +640,75 @@ static void send_msg_channel_data(struct Channel *channel, int isextended,
 	TRACE(("leave send_msg_channel_data"));
 }
 
-
-/* when we receive channel data, put it in a buffer for writing to the program/
- * shell etc */
+/* We receive channel data */
 void recv_msg_channel_data() {
 
 	unsigned int chan;
 	struct Channel *channel;
-	unsigned int datalen;
-	unsigned int pos;
-	unsigned int maxdata;
-
-	TRACE(("enter recv_msg_channel_data"));
 
 	chan = buf_getint(ses.payload);
 	channel = getchannel(chan);
+
 	if (channel == NULL) {
 		dropbear_exit("Unknown channel");
 	}
 
+	common_recv_msg_channel_data(channel, channel->infd, channel->writebuf);
+}
+
+/* Shared for data and stderr data - when we receive data, put it in a buffer
+ * for writing to the local file descriptor */
+void common_recv_msg_channel_data(struct Channel *channel, int fd, 
+		circbuffer * cbuf) {
+
+	unsigned int datalen;
+	unsigned int maxdata;
+	unsigned int buflen;
+	unsigned int len;
+
+	TRACE(("enter recv_msg_channel_data"));
+
 	if (channel->recveof) {
 		dropbear_exit("received data after eof");
 	}
 
- 	if (channel->infd < 0) {
+ 	if (fd < 0) {
 		dropbear_exit("received data with bad infd");
 	}
 
 	datalen = buf_getint(ses.payload);
 
+	TRACE(("datalen = %d", datalen));
+
 	/* if the client is going to send us more data than we've allocated, then 
 	 * it has ignored the windowsize, so we "MAY ignore all extra data" */
-	maxdata = channel->writebuf->size - channel->writebuf->pos;
+	maxdata = cbuf_getavail(cbuf);
+	TRACE(("maxdata = %d", maxdata));
 	if (datalen > maxdata) {
 		TRACE(("Warning: recv_msg_channel_data: extra data past window"));
 		datalen = maxdata;
 	}
 
-	/* write to the buffer - we always append to the end of the buffer */
-	pos = channel->writebuf->pos;
-	buf_setpos(channel->writebuf, channel->writebuf->len);
-	memcpy(buf_getwriteptr(channel->writebuf, datalen), 
-			buf_getptr(ses.payload, datalen), datalen);
-	buf_incrwritepos(channel->writebuf, datalen);
-	buf_setpos(channel->writebuf, pos); /* revert pos */
+
+	/* We may have to run throught twice, if the buffer wraps around. Can't
+	 * just "leave it for next time" like with writechannel, since this
+	 * is payload data */
+	len = datalen;
+	while (len > 0) {
+		buflen = cbuf_writelen(cbuf);
+		TRACE(("buflen = %d", buflen));
+		buflen = MIN(buflen, len);
+		TRACE(("buflenmin = %d", buflen));
+
+		memcpy(cbuf_writeptr(cbuf, buflen), 
+				buf_getptr(ses.payload, buflen), buflen);
+		cbuf_incrwrite(cbuf, buflen);
+		len -= buflen;
+		TRACE(("len = %d", buflen));
+	}
 
 	channel->recvwindow -= datalen;
 
-	/* matt - this might be for later */
-/*	if (channel->recvwindow < RECV_MINWINDOW) {
-		send_msg_channel_window_adjust(channel, 
-				RECV_MAXWINDOW - channel->recvwindow);
-		channel->recvwindow = RECV_MAXWINDOW;
-	}*/
-
 	TRACE(("leave recv_msg_channel_data"));
 }
 

common-session.c

@@ -235,7 +235,7 @@ void session_identification() {
 	 * account for wrappers/cruft etc. According to the spec only the client
 	 * needs to handle this, but no harm in letting the server handle it too */
 	for (i = 0; i < 10; i++) {
-		len = ident_readln(ses.sock, linebuf, sizzeof(linebuf));
+		len = ident_readln(ses.sock, linebuf, sizeof(linebuf));
 
 		if (len < 0 && errno != EINTR) {
 			/* It failed */

dbutil.c

@@ -146,6 +146,7 @@ void dropbear_trace(const char* format, ...) {
 	fprintf(stderr, "TRACE: ");
 	vfprintf(stderr, format, param);
 	fprintf(stderr, "\n");
+	fflush(stderr);
 	va_end(param);
 }
 #endif /* DEBUG_TRACE */

debug.h

@@ -38,7 +38,7 @@
  * Caution: Don't use this in an unfriendly environment (ie unfirewalled),
  * since the printing may not sanitise strings etc. This will add a reasonable
  * amount to your executable size. */
-/* #define DEBUG_TRACE */
+ #define DEBUG_TRACE 
 
 /* All functions writing to the cleartext payload buffer call
  * CHECKCLEARTOWRITE() before writing. This is only really useful if you're

signkey.c

@@ -153,6 +153,7 @@ int buf_get_priv_key(buffer *buf, sign_key *key, int *type) {
 	m_free(ident);
 
 	if (*type != DROPBEAR_SIGNKEY_ANY && *type != keytype) {
+		TRACE(("wrong key type: %d %d", *type, keytype));
 		return DROPBEAR_FAILURE;
 	}