From 19e1afbd1ca6d306166ce74bcd6c6889f8d196f3 Mon Sep 17 00:00:00 2001
From: Matt Johnston <matt@ucc.asn.au>
Date: Sat, 2 May 2015 22:47:25 +0800
Subject: [PATCH] Fix no-writev fallback
---
LICENSE | 2 +-
circbuffer.c | 31 ----------------------
circbuffer.h | 3 +--
common-channel.c | 68 +++++++++++++++++++++++++++++++-----------------
common-session.c | 6 ++---
packet.c | 6 +++++
6 files changed, 55 insertions(+), 61 deletions(-)
diff --git a/LICENSE b/LICENSE
index 828b9af3..c400d946 100644
--- a/LICENSE
+++ b/LICENSE
@@ -8,7 +8,7 @@ The majority of code is written by Matt Johnston, under the license below.
Portions of the client-mode work are (c) 2004 Mihnea Stoenescu, under the
same license:
-Copyright (c) 2002-2014 Matt Johnston
+Copyright (c) 2002-2015 Matt Johnston
Portions copyright (c) 2004 Mihnea Stoenescu
All rights reserved.
diff --git a/circbuffer.c b/circbuffer.c
index 949fa848..c0c8641d 100644
--- a/circbuffer.c
+++ b/circbuffer.c
@@ -67,23 +67,6 @@ unsigned int cbuf_getavail(circbuffer * cbuf) {
}
-unsigned int cbuf_readlen(circbuffer *cbuf) {
-
- dropbear_assert(((2*cbuf->size)+cbuf->writepos-cbuf->readpos)%cbuf->size == cbuf->used%cbuf->size);
- dropbear_assert(((2*cbuf->size)+cbuf->readpos-cbuf->writepos)%cbuf->size == (cbuf->size-cbuf->used)%cbuf->size);
-
- if (cbuf->used == 0) {
- TRACE(("cbuf_readlen: unused buffer"))
- return 0;
- }
-
- if (cbuf->readpos < cbuf->writepos) {
- return cbuf->writepos - cbuf->readpos;
- }
-
- return cbuf->size - cbuf->readpos;
-}
-
unsigned int cbuf_writelen(circbuffer *cbuf) {
dropbear_assert(cbuf->used <= cbuf->size);
@@ -102,14 +85,6 @@ unsigned int cbuf_writelen(circbuffer *cbuf) {
return cbuf->size - cbuf->writepos;
}
-unsigned char* cbuf_readptr(circbuffer *cbuf, unsigned int len) {
- if (len > cbuf_readlen(cbuf)) {
- dropbear_exit("Bad cbuf read");
- }
-
- return &cbuf->data[cbuf->readpos];
-}
-
void cbuf_readptrs(circbuffer *cbuf,
unsigned char **p1, unsigned int *len1,
unsigned char **p2, unsigned int *len2) {
@@ -146,12 +121,6 @@ void cbuf_incrwrite(circbuffer *cbuf, unsigned int len) {
void cbuf_incrread(circbuffer *cbuf, unsigned int len) {
-#if 0
- if (len > cbuf_readlen(cbuf)) {
- dropbear_exit("Bad cbuf read");
- }
-#endif
-
dropbear_assert(cbuf->used >= len);
cbuf->used -= len;
cbuf->readpos = (cbuf->readpos + len) % cbuf->size;
diff --git a/circbuffer.h b/circbuffer.h
index 81bb91db..744a2c10 100644
--- a/circbuffer.h
+++ b/circbuffer.h
@@ -40,10 +40,9 @@ void cbuf_free(circbuffer * cbuf);
unsigned int cbuf_getused(circbuffer * cbuf); /* how much data stored */
unsigned int cbuf_getavail(circbuffer * cbuf); /* how much we can write */
-unsigned int cbuf_readlen(circbuffer *cbuf); /* max linear read len */
unsigned int cbuf_writelen(circbuffer *cbuf); /* max linear write len */
-unsigned char* cbuf_readptr(circbuffer *cbuf, unsigned int len);
+/* returns pointers to the two portions of the circular buffer that can be read */
void cbuf_readptrs(circbuffer *cbuf,
unsigned char **p1, unsigned int *len1,
unsigned char **p2, unsigned int *len2);
diff --git a/common-channel.c b/common-channel.c
index 6dce4977..5f4051e5 100644
--- a/common-channel.c
+++ b/common-channel.c
@@ -434,10 +434,36 @@ static void send_msg_channel_eof(struct Channel *channel) {
TRACE(("leave send_msg_channel_eof"))
}
-/* Called to write data out to the local side of the channel.
- Writes the circular buffer contents and also the "moredata" buffer
- if not null. Will ignore EAGAIN */
-static void writechannel(struct Channel* channel, int fd, circbuffer *cbuf,
+#ifndef HAVE_WRITEV
+static void writechannel_fallback(struct Channel* channel, int fd, circbuffer *cbuf,
+ const unsigned char *UNUSED(moredata), unsigned int *morelen) {
+
+ unsigned char *circ_p1, *circ_p2;
+ unsigned int circ_len1, circ_len2;
+ ssize_t written;
+
+ if (morelen) {
+ /* fallback doesn't consume moredata */
+ *morelen = 0;
+ }
+
+ /* Write the first portion of the circular buffer */
+ cbuf_readptrs(cbuf, &circ_p1, &circ_len1, &circ_p2, &circ_len2);
+ written = write(fd, circ_p1, circ_len1);
+ if (written < 0) {
+ if (errno != EINTR && errno != EAGAIN) {
+ TRACE(("channel IO write error fd %d %s", fd, strerror(errno)))
+ close_chan_fd(channel, fd, SHUT_WR);
+ }
+ } else {
+ cbuf_incrread(cbuf, written);
+ channel->recvdonelen += written;
+ }
+}
+#endif /* !HAVE_WRITEV */
+
+#ifdef HAVE_WRITEV
+static void writechannel_writev(struct Channel* channel, int fd, circbuffer *cbuf,
const unsigned char *moredata, unsigned int *morelen) {
struct iovec iov[3];
@@ -445,9 +471,7 @@ static void writechannel(struct Channel* channel, int fd, circbuffer *cbuf,
unsigned int circ_len1, circ_len2;
int io_count = 0;
- int written;
-
- TRACE(("enter writechannel fd %d", fd))
+ ssize_t written;
cbuf_readptrs(cbuf, &circ_p1, &circ_len1, &circ_p2, &circ_len2);
@@ -502,24 +526,19 @@ static void writechannel(struct Channel* channel, int fd, circbuffer *cbuf,
channel->recvdonelen += written;
}
-#if 0
-
- maxlen = cbuf_readlen(cbuf);
-
- /* Write the data out */
- len = write(fd, cbuf_readptr(cbuf, maxlen), maxlen);
- if (len <= 0) {
- TRACE(("errno %d len %d", errno, len))
- if (len < 0 && errno != EINTR) {
- close_chan_fd(channel, fd, SHUT_WR);
- }
- TRACE(("leave writechannel: len <= 0"))
- return;
- }
- TRACE(("writechannel wrote %d", len))
+}
+#endif /* HAVE_WRITEV */
- cbuf_incrread(cbuf, len);
- channel->recvdonelen += len;
+/* Called to write data out to the local side of the channel.
+ Writes the circular buffer contents and also the "moredata" buffer
+ if not null. Will ignore EAGAIN */
+static void writechannel(struct Channel* channel, int fd, circbuffer *cbuf,
+ const unsigned char *moredata, unsigned int *morelen) {
+ TRACE(("enter writechannel fd %d", fd))
+#ifdef HAVE_WRITEV
+ writechannel_writev(channel, fd, cbuf, moredata, morelen);
+#else
+ writechannel_fallback(channel, fd, cbuf, moredata, morelen);
#endif
/* Window adjust handling */
@@ -537,6 +556,7 @@ static void writechannel(struct Channel* channel, int fd, circbuffer *cbuf,
TRACE(("leave writechannel"))
}
+
/* Set the file descriptors for the main select in session.c
* This avoid channels which don't have any window available, are closed, etc*/
void setchannelfds(fd_set *readfds, fd_set *writefds, int allow_reads) {
diff --git a/common-session.c b/common-session.c
index 44e70308..083b5c52 100644
--- a/common-session.c
+++ b/common-session.c
@@ -1,7 +1,7 @@
/*
* Dropbear - a SSH2 server
*
- * Copyright (c) 2002,2003 Matt Johnston
+ * Copyright (c) Matt Johnston
* All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -280,7 +280,7 @@ void session_cleanup() {
return;
}
- /* Beware of changing order of functions here. */
+ /* BEWARE of changing order of functions here. */
/* Must be before extra_session_cleanup() */
chancleanup();
@@ -289,7 +289,7 @@ void session_cleanup() {
ses.extra_session_cleanup();
}
- /* After these are freed most functions will exit */
+ /* After these are freed most functions will fail */
#ifdef DROPBEAR_CLEANUP
/* listeners call cleanup functions, this should occur before
other session state is freed. */
diff --git a/packet.c b/packet.c
index 1d1be843..19b57592 100644
--- a/packet.c
+++ b/packet.c
@@ -61,6 +61,10 @@ void write_packet() {
/* 50 is somewhat arbitrary */
unsigned int iov_count = 50;
struct iovec iov[50];
+#else
+ int len;
+ buffer* writebuf;
+ int packet_type;
#endif
TRACE2(("enter write_packet"))
@@ -97,6 +101,8 @@ void write_packet() {
* a cleartext packet_type indicator */
packet_type = writebuf->data[writebuf->len-1];
len = writebuf->len - 1 - writebuf->pos;
+ TRACE2(("write_packet type %d len %d/%d", packet_type,
+ len, writebuf->len-1))
dropbear_assert(len > 0);
/* Try to write as much as possible */
written = write(ses.sock_out, buf_getptr(writebuf, len), len);
--
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