From f17400e7389bf1fff7939690e4bfe1caad1e7486 Mon Sep 17 00:00:00 2001
From: Matt Johnston <matt@ucc.asn.au>
Date: Mon, 11 Oct 2021 15:42:14 +0800
Subject: [PATCH] Replace ChanType.sepfds with Channel.bidir_fd
This handles the case where a svrchansess has separate FDs
for nopty, but a single FD for pty mode.
The use of sepfds was also previously incorrect for X11 and
agent forwarding
---
channel.h | 4 +++-
cli-agentfwd.c | 2 +-
cli-chansession.c | 3 +--
cli-tcpfwd.c | 6 ++----
common-channel.c | 6 ++++--
svr-agentfwd.c | 1 -
svr-chansession.c | 3 ++-
svr-tcpfwd.c | 2 --
svr-x11fwd.c | 1 -
9 files changed, 13 insertions(+), 15 deletions(-)
diff --git a/channel.h b/channel.h
index 4c6fe54..6aae9ea 100644
--- a/channel.h
+++ b/channel.h
@@ -60,6 +60,9 @@ struct Channel {
int readfd; /* read from insecure side, written to wire */
int errfd; /* used like writefd or readfd, depending if it's client or server.
Doesn't exactly belong here, but is cleaner here */
+ int bidir_fd; /* a boolean indicating that writefd/readfd are the same
+ file descriptor (bidirectional), such as a network socket or PTY.
+ That is handled differently when closing FDs */
circbuffer *writebuf; /* data from the wire, for local consumption. Can be
initially NULL */
circbuffer *extrabuf; /* extended-data for the program - used like writebuf
@@ -87,7 +90,6 @@ struct Channel {
struct ChanType {
- int sepfds; /* Whether this channel has separate pipes for in/out or not */
const char *name;
/* Sets up the channel */
int (*inithandler)(struct Channel*);
diff --git a/cli-agentfwd.c b/cli-agentfwd.c
index 00454dc..6fb5c4b 100644
--- a/cli-agentfwd.c
+++ b/cli-agentfwd.c
@@ -47,7 +47,6 @@
static int new_agent_chan(struct Channel * channel);
const struct ChanType cli_chan_agent = {
- 0, /* sepfds */
"auth-agent@openssh.com",
new_agent_chan,
NULL,
@@ -94,6 +93,7 @@ static int new_agent_chan(struct Channel * channel) {
channel->readfd = fd;
channel->writefd = fd;
+ channel->bidir_fd = 1;
return 0;
}
diff --git a/cli-chansession.c b/cli-chansession.c
index cfd3401..14a2779 100644
--- a/cli-chansession.c
+++ b/cli-chansession.c
@@ -46,7 +46,6 @@ static int cli_init_netcat(struct Channel *channel);
static void cli_tty_setup(void);
const struct ChanType clichansess = {
- 0, /* sepfds */
"session", /* name */
cli_initchansess, /* inithandler */
NULL, /* checkclosehandler */
@@ -344,6 +343,7 @@ static int cli_init_stdpipe_sess(struct Channel *channel) {
setnonblocking(STDERR_FILENO);
channel->extrabuf = cbuf_new(opts.recv_window);
+ channel->bidir_fd = 0;
return 0;
}
@@ -383,7 +383,6 @@ static int cli_initchansess(struct Channel *channel) {
#if DROPBEAR_CLI_NETCAT
static const struct ChanType cli_chan_netcat = {
- 0, /* sepfds */
"direct-tcpip",
cli_init_netcat, /* inithandler */
NULL,
diff --git a/cli-tcpfwd.c b/cli-tcpfwd.c
index 4ab7748..e61a0c3 100644
--- a/cli-tcpfwd.c
+++ b/cli-tcpfwd.c
@@ -35,7 +35,6 @@
static int newtcpforwarded(struct Channel * channel);
const struct ChanType cli_chan_tcpremote = {
- 1, /* sepfds */
"forwarded-tcpip",
newtcpforwarded,
NULL,
@@ -51,7 +50,6 @@ static int cli_localtcp(const char* listenaddr,
const char* remoteaddr,
unsigned int remoteport);
static const struct ChanType cli_chan_tcplocal = {
- 1, /* sepfds */
"direct-tcpip",
tcp_prio_inithandler,
NULL,
@@ -275,10 +273,10 @@ static int newtcpforwarded(struct Channel * channel) {
}
channel->prio = DROPBEAR_CHANNEL_PRIO_UNKNOWABLE;
-
+
snprintf(portstring, sizeof(portstring), "%u", fwd->connectport);
channel->conn_pending = connect_remote(fwd->connectaddr, portstring, channel_connect_done, channel, NULL, NULL);
-
+
err = SSH_OPEN_IN_PROGRESS;
out:
diff --git a/common-channel.c b/common-channel.c
index 03b3312..5c8d9bc 100644
--- a/common-channel.c
+++ b/common-channel.c
@@ -339,6 +339,7 @@ void channel_connect_done(int result, int sock, void* user_data, const char* err
if (result == DROPBEAR_SUCCESS)
{
channel->readfd = channel->writefd = sock;
+ channel->bidir_fd = 1;
channel->conn_pending = NULL;
send_msg_channel_open_confirmation(channel, channel->recvwindow,
channel->recvmaxpacket);
@@ -1039,7 +1040,7 @@ static void close_chan_fd(struct Channel *channel, int fd, int how) {
int closein = 0, closeout = 0;
- if (channel->type->sepfds) {
+ if (channel->bidir_fd) {
TRACE(("SHUTDOWN(%d, %d)", fd, how))
shutdown(fd, how);
if (how == 0) {
@@ -1069,7 +1070,7 @@ static void close_chan_fd(struct Channel *channel, int fd, int how) {
/* if we called shutdown on it and all references are gone, then we
* need to close() it to stop it lingering */
- if (channel->type->sepfds && channel->readfd == FD_CLOSED
+ if (channel->bidir_fd && channel->readfd == FD_CLOSED
&& channel->writefd == FD_CLOSED && channel->errfd == FD_CLOSED) {
TRACE(("CLOSE (finally) of %d", fd))
m_close(fd);
@@ -1102,6 +1103,7 @@ int send_msg_channel_open_init(int fd, const struct ChanType *type) {
chan->writefd = chan->readfd = fd;
ses.maxfd = MAX(ses.maxfd, fd);
+ chan->bidir_fd = 1;
chan->await_open = 1;
diff --git a/svr-agentfwd.c b/svr-agentfwd.c
index ac9475f..a8941ea 100644
--- a/svr-agentfwd.c
+++ b/svr-agentfwd.c
@@ -186,7 +186,6 @@ void svr_agentcleanup(struct ChanSess * chansess) {
}
static const struct ChanType chan_svr_agent = {
- 0, /* sepfds */
"auth-agent@openssh.com",
NULL,
NULL,
diff --git a/svr-chansession.c b/svr-chansession.c
index 9c26204..e19c8df 100644
--- a/svr-chansession.c
+++ b/svr-chansession.c
@@ -64,7 +64,6 @@ static void send_msg_chansess_exitsignal(const struct Channel * channel,
static void get_termmodes(const struct ChanSess *chansess);
const struct ChanType svrchansess = {
- 0, /* sepfds */
"session", /* name */
newchansess, /* inithandler */
sesscheckclose, /* checkclosehandler */
@@ -769,6 +768,7 @@ static int noptycommand(struct Channel *channel, struct ChanSess *chansess) {
ses.maxfd = MAX(ses.maxfd, channel->writefd);
ses.maxfd = MAX(ses.maxfd, channel->readfd);
ses.maxfd = MAX(ses.maxfd, channel->errfd);
+ channel->bidir_fd = 0;
addchildpid(chansess, chansess->pid);
@@ -895,6 +895,7 @@ static int ptycommand(struct Channel *channel, struct ChanSess *chansess) {
channel->readfd = chansess->master;
/* don't need to set stderr here */
ses.maxfd = MAX(ses.maxfd, chansess->master);
+ channel->bidir_fd = 1;
setnonblocking(chansess->master);
diff --git a/svr-tcpfwd.c b/svr-tcpfwd.c
index f3bab25..9c1edd4 100644
--- a/svr-tcpfwd.c
+++ b/svr-tcpfwd.c
@@ -59,7 +59,6 @@ static int newtcpdirect(struct Channel * channel);
#if DROPBEAR_SVR_REMOTETCPFWD
static const struct ChanType svr_chan_tcpremote = {
- 1, /* sepfds */
"forwarded-tcpip",
tcp_prio_inithandler,
NULL,
@@ -241,7 +240,6 @@ out:
#if DROPBEAR_SVR_LOCALTCPFWD
const struct ChanType svr_chan_tcpdirect = {
- 1, /* sepfds */
"direct-tcpip",
newtcpdirect, /* init */
NULL, /* checkclose */
diff --git a/svr-x11fwd.c b/svr-x11fwd.c
index 460db4c..353cb12 100644
--- a/svr-x11fwd.c
+++ b/svr-x11fwd.c
@@ -211,7 +211,6 @@ static int x11_inithandler(struct Channel *channel) {
}
static const struct ChanType chan_x11 = {
- 0, /* sepfds */
"x11",
x11_inithandler, /* inithandler */
NULL, /* checkclose */