dropbear: fix keepalive more

Add a further upstream commit to more closely match the keepalive
to OpenSSH.

Should now really fix #17523.

Signed-off-by: Jonas Gorski <jogo@openwrt.org>

SVN-Revision: 42249
This commit is contained in:
Jonas Gorski 2014-08-21 11:29:02 +00:00
parent 51e1f1476f
commit 932305f854

View file

@ -0,0 +1,333 @@
# HG changeset patch
# User Matt Johnston <matt@ucc.asn.au>
# Date 1408460936 -28800
# Node ID 0bb16232e7c4162daa43e8618521cf453847ac16
# Parent 939944f0fca9b2dcdf8470bb24efcc37a3843e8b
Make keepalive handling more robust, this should now match what OpenSSH does
diff -r 939944f0fca9 -r 0bb16232e7c4 LICENSE
--- a/LICENSE Wed Aug 13 22:07:43 2014 +0800
+++ b/LICENSE Tue Aug 19 23:08:56 2014 +0800
@@ -8,7 +8,7 @@
Portions of the client-mode work are (c) 2004 Mihnea Stoenescu, under the
same license:
-Copyright (c) 2002-2013 Matt Johnston
+Copyright (c) 2002-2014 Matt Johnston
Portions copyright (c) 2004 Mihnea Stoenescu
All rights reserved.
diff -r 939944f0fca9 -r 0bb16232e7c4 auth.h
--- a/auth.h Wed Aug 13 22:07:43 2014 +0800
+++ b/auth.h Tue Aug 19 23:08:56 2014 +0800
@@ -106,7 +106,7 @@
valid */
unsigned int failcount; /* Number of (failed) authentication attempts.*/
unsigned authdone : 1; /* 0 if we haven't authed, 1 if we have. Applies for
- client and server (though has differing [obvious]
+ client and server (though has differing
meanings). */
unsigned perm_warn : 1; /* Server only, set if bad permissions on
~/.ssh/authorized_keys have already been
diff -r 939944f0fca9 -r 0bb16232e7c4 channel.h
--- a/channel.h Wed Aug 13 22:07:43 2014 +0800
+++ b/channel.h Tue Aug 19 23:08:56 2014 +0800
@@ -105,6 +105,9 @@
void setchannelfds(fd_set *readfd, fd_set *writefd);
void channelio(fd_set *readfd, fd_set *writefd);
struct Channel* getchannel();
+/* Returns an arbitrary channel that is in a ready state - not
+being initialised and no EOF in either direction. NULL if none. */
+struct Channel* get_any_ready_channel();
void recv_msg_channel_open();
void recv_msg_channel_request();
@@ -128,8 +131,10 @@
void recv_msg_channel_open_confirmation();
void recv_msg_channel_open_failure();
#endif
+void start_send_channel_request(struct Channel *channel, unsigned char *type);
void send_msg_request_success();
void send_msg_request_failure();
+
#endif /* _CHANNEL_H_ */
diff -r 939944f0fca9 -r 0bb16232e7c4 chansession.h
--- a/chansession.h Wed Aug 13 22:07:43 2014 +0800
+++ b/chansession.h Tue Aug 19 23:08:56 2014 +0800
@@ -89,7 +89,6 @@
#ifdef ENABLE_CLI_NETCAT
void cli_send_netcat_request();
#endif
-void cli_start_send_channel_request(struct Channel *channel, unsigned char *type);
void svr_chansessinitialise();
extern const struct ChanType svrchansess;
diff -r 939944f0fca9 -r 0bb16232e7c4 cli-agentfwd.c
--- a/cli-agentfwd.c Wed Aug 13 22:07:43 2014 +0800
+++ b/cli-agentfwd.c Tue Aug 19 23:08:56 2014 +0800
@@ -234,7 +234,7 @@
return;
}
- cli_start_send_channel_request(channel, "auth-agent-req@openssh.com");
+ start_send_channel_request(channel, "auth-agent-req@openssh.com");
/* Don't want replies */
buf_putbyte(ses.writepayload, 0);
encrypt_packet();
diff -r 939944f0fca9 -r 0bb16232e7c4 cli-chansession.c
--- a/cli-chansession.c Wed Aug 13 22:07:43 2014 +0800
+++ b/cli-chansession.c Tue Aug 19 23:08:56 2014 +0800
@@ -92,17 +92,6 @@
}
}
-void cli_start_send_channel_request(struct Channel *channel,
- unsigned char *type) {
-
- CHECKCLEARTOWRITE();
- buf_putbyte(ses.writepayload, SSH_MSG_CHANNEL_REQUEST);
- buf_putint(ses.writepayload, channel->remotechan);
-
- buf_putstring(ses.writepayload, type, strlen(type));
-
-}
-
/* Taken from OpenSSH's sshtty.c:
* RCSID("OpenBSD: sshtty.c,v 1.5 2003/09/19 17:43:35 markus Exp "); */
static void cli_tty_setup() {
@@ -287,7 +276,7 @@
TRACE(("enter send_chansess_pty_req"))
- cli_start_send_channel_request(channel, "pty-req");
+ start_send_channel_request(channel, "pty-req");
/* Don't want replies */
buf_putbyte(ses.writepayload, 0);
@@ -330,7 +319,7 @@
reqtype = "shell";
}
- cli_start_send_channel_request(channel, reqtype);
+ start_send_channel_request(channel, reqtype);
/* XXX TODO */
buf_putbyte(ses.writepayload, 0); /* Don't want replies */
diff -r 939944f0fca9 -r 0bb16232e7c4 cli-session.c
--- a/cli-session.c Wed Aug 13 22:07:43 2014 +0800
+++ b/cli-session.c Tue Aug 19 23:08:56 2014 +0800
@@ -70,11 +70,15 @@
{SSH_MSG_USERAUTH_BANNER, recv_msg_userauth_banner}, /* client */
{SSH_MSG_USERAUTH_SPECIFIC_60, recv_msg_userauth_specific_60}, /* client */
{SSH_MSG_GLOBAL_REQUEST, recv_msg_global_request_cli},
+ {SSH_MSG_CHANNEL_SUCCESS, ignore_recv_response},
+ {SSH_MSG_CHANNEL_FAILURE, ignore_recv_response},
#ifdef ENABLE_CLI_REMOTETCPFWD
{SSH_MSG_REQUEST_SUCCESS, cli_recv_msg_request_success}, /* client */
{SSH_MSG_REQUEST_FAILURE, cli_recv_msg_request_failure}, /* client */
#else
- {SSH_MSG_REQUEST_FAILURE, ignore_recv_msg_request_failure}, /* for keepalive */
+ /* For keepalive */
+ {SSH_MSG_REQUEST_SUCCESS, ignore_recv_response},
+ {SSH_MSG_REQUEST_FAILURE, ignore_recv_response},
#endif
{0, 0} /* End */
};
diff -r 939944f0fca9 -r 0bb16232e7c4 common-channel.c
--- a/common-channel.c Wed Aug 13 22:07:43 2014 +0800
+++ b/common-channel.c Tue Aug 19 23:08:56 2014 +0800
@@ -627,7 +627,12 @@
&& !channel->close_handler_done) {
channel->type->reqhandler(channel);
} else {
- send_msg_channel_failure(channel);
+ int wantreply;
+ buf_eatstring(ses.payload);
+ wantreply = buf_getbool(ses.payload);
+ if (wantreply) {
+ send_msg_channel_failure(channel);
+ }
}
TRACE(("leave recv_msg_channel_request"))
@@ -1134,3 +1139,30 @@
buf_putbyte(ses.writepayload, SSH_MSG_REQUEST_FAILURE);
encrypt_packet();
}
+
+struct Channel* get_any_ready_channel() {
+ if (ses.chancount == 0) {
+ return NULL;
+ }
+ size_t i;
+ for (i = 0; i < ses.chansize; i++) {
+ struct Channel *chan = ses.channels[i];
+ if (chan
+ && !(chan->sent_eof || chan->recv_eof)
+ && !(chan->await_open || chan->initconn)) {
+ return chan;
+ }
+ }
+ return NULL;
+}
+
+void start_send_channel_request(struct Channel *channel,
+ unsigned char *type) {
+
+ CHECKCLEARTOWRITE();
+ buf_putbyte(ses.writepayload, SSH_MSG_CHANNEL_REQUEST);
+ buf_putint(ses.writepayload, channel->remotechan);
+
+ buf_putstring(ses.writepayload, type, strlen(type));
+
+}
diff -r 939944f0fca9 -r 0bb16232e7c4 common-session.c
--- a/common-session.c Wed Aug 13 22:07:43 2014 +0800
+++ b/common-session.c Tue Aug 19 23:08:56 2014 +0800
@@ -394,19 +394,30 @@
return pos+1;
}
-void ignore_recv_msg_request_failure() {
+void ignore_recv_response() {
// Do nothing
- TRACE(("Ignored msg_request_failure"))
+ TRACE(("Ignored msg_request_response"))
}
static void send_msg_keepalive() {
CHECKCLEARTOWRITE();
time_t old_time_idle = ses.last_packet_time_idle;
- /* Try to force a response from the other end. Some peers will
- reply with SSH_MSG_REQUEST_FAILURE, some will reply with SSH_MSG_UNIMPLEMENTED */
- buf_putbyte(ses.writepayload, SSH_MSG_GLOBAL_REQUEST);
- /* A short string */
- buf_putstring(ses.writepayload, "k@dropbear.nl", 0);
+
+ struct Channel *chan = get_any_ready_channel();
+
+ if (chan) {
+ /* Channel requests are preferable, more implementations
+ handle them than SSH_MSG_GLOBAL_REQUEST */
+ TRACE(("keepalive channel request %d", chan->index))
+ start_send_channel_request(chan, DROPBEAR_KEEPALIVE_STRING);
+ } else {
+ TRACE(("keepalive global request"))
+ /* Some peers will reply with SSH_MSG_REQUEST_FAILURE,
+ some will reply with SSH_MSG_UNIMPLEMENTED, some will exit. */
+ buf_putbyte(ses.writepayload, SSH_MSG_GLOBAL_REQUEST);
+ buf_putstring(ses.writepayload, DROPBEAR_KEEPALIVE_STRING,
+ strlen(DROPBEAR_KEEPALIVE_STRING));
+ }
buf_putbyte(ses.writepayload, 1); /* want_reply */
encrypt_packet();
@@ -435,7 +446,10 @@
send_msg_kexinit();
}
- if (opts.keepalive_secs > 0) {
+ if (opts.keepalive_secs > 0 && ses.authstate.authdone) {
+ /* Avoid sending keepalives prior to auth - those are
+ not valid pre-auth packet types */
+
/* Send keepalives if we've been idle */
if (now - ses.last_packet_time_any_sent >= opts.keepalive_secs) {
send_msg_keepalive();
diff -r 939944f0fca9 -r 0bb16232e7c4 session.h
--- a/session.h Wed Aug 13 22:07:43 2014 +0800
+++ b/session.h Tue Aug 19 23:08:56 2014 +0800
@@ -47,7 +47,7 @@
void session_cleanup();
void send_session_identification();
void send_msg_ignore();
-void ignore_recv_msg_request_failure();
+void ignore_recv_response();
void update_channel_prio();
diff -r 939944f0fca9 -r 0bb16232e7c4 svr-chansession.c
--- a/svr-chansession.c Wed Aug 13 22:07:43 2014 +0800
+++ b/svr-chansession.c Tue Aug 19 23:08:56 2014 +0800
@@ -53,6 +53,7 @@
static void closechansess(struct Channel *channel);
static int newchansess(struct Channel *channel);
static void chansessionrequest(struct Channel *channel);
+static int sesscheckclose(struct Channel *channel);
static void send_exitsignalstatus(struct Channel *channel);
static void send_msg_chansess_exitstatus(struct Channel * channel,
@@ -61,6 +62,14 @@
struct ChanSess * chansess);
static void get_termmodes(struct ChanSess *chansess);
+const struct ChanType svrchansess = {
+ 0, /* sepfds */
+ "session", /* name */
+ newchansess, /* inithandler */
+ sesscheckclose, /* checkclosehandler */
+ chansessionrequest, /* reqhandler */
+ closechansess, /* closehandler */
+};
/* required to clear environment */
extern char** environ;
@@ -968,16 +977,6 @@
dropbear_exit("Child failed");
}
-const struct ChanType svrchansess = {
- 0, /* sepfds */
- "session", /* name */
- newchansess, /* inithandler */
- sesscheckclose, /* checkclosehandler */
- chansessionrequest, /* reqhandler */
- closechansess, /* closehandler */
-};
-
-
/* Set up the general chansession environment, in particular child-exit
* handling */
void svr_chansessinitialise() {
diff -r 939944f0fca9 -r 0bb16232e7c4 svr-main.c
--- a/svr-main.c Wed Aug 13 22:07:43 2014 +0800
+++ b/svr-main.c Tue Aug 19 23:08:56 2014 +0800
@@ -409,7 +409,7 @@
size_t sockpos = 0;
int nsock;
- TRACE(("listensockets: %d to try\n", svr_opts.portcount))
+ TRACE(("listensockets: %d to try", svr_opts.portcount))
for (i = 0; i < svr_opts.portcount; i++) {
diff -r 939944f0fca9 -r 0bb16232e7c4 svr-session.c
--- a/svr-session.c Wed Aug 13 22:07:43 2014 +0800
+++ b/svr-session.c Tue Aug 19 23:08:56 2014 +0800
@@ -58,7 +58,10 @@
{SSH_MSG_CHANNEL_OPEN, recv_msg_channel_open},
{SSH_MSG_CHANNEL_EOF, recv_msg_channel_eof},
{SSH_MSG_CHANNEL_CLOSE, recv_msg_channel_close},
- {SSH_MSG_REQUEST_FAILURE, ignore_recv_msg_request_failure}, /* for keepalive */
+ {SSH_MSG_CHANNEL_SUCCESS, ignore_recv_response},
+ {SSH_MSG_CHANNEL_FAILURE, ignore_recv_response},
+ {SSH_MSG_REQUEST_FAILURE, ignore_recv_response}, /* for keepalive */
+ {SSH_MSG_REQUEST_SUCCESS, ignore_recv_response}, /* client */
#ifdef USING_LISTENERS
{SSH_MSG_CHANNEL_OPEN_CONFIRMATION, recv_msg_channel_open_confirmation},
{SSH_MSG_CHANNEL_OPEN_FAILURE, recv_msg_channel_open_failure},
diff -r 939944f0fca9 -r 0bb16232e7c4 sysoptions.h
--- a/sysoptions.h Wed Aug 13 22:07:43 2014 +0800
+++ b/sysoptions.h Tue Aug 19 23:08:56 2014 +0800
@@ -257,4 +257,7 @@
#define DROPBEAR_LISTEN_BACKLOG MAX_CHANNELS
#endif
+/* Use this string since some implementations might special-case it */
+#define DROPBEAR_KEEPALIVE_STRING "keepalive@openssh.com"
+
/* no include guard for this file */