- markus@cvs.openbsd.org 2002/03/25 21:13:51

     [channels.c channels.h compat.c compat.h nchan.c]
     don't send stderr data after EOF, accept this from older known (broken)
     sshd servers only, fixes http://bugzilla.mindrot.org/show_bug.cgi?id=179

diff --git a/ChangeLog b/ChangeLog
index fb8075876715205533ab67117f3cc732538f6bc3..6d6a764c86bee0291e36f709b4d7478f00d35b9c 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -39,6 +39,10 @@
    - markus@cvs.openbsd.org 2002/03/25 21:04:02
      [ssh.c]
      simplify num_identity_files handling
+   - markus@cvs.openbsd.org 2002/03/25 21:13:51
+     [channels.c channels.h compat.c compat.h nchan.c]
+     don't send stderr data after EOF, accept this from older known (broken)
+     sshd servers only, fixes http://bugzilla.mindrot.org/show_bug.cgi?id=179
 
 20020324
  - (stevesk) [session.c] disable LOGIN_NEEDS_TERM until we are sure

diff --git a/channels.c b/channels.c
index 2b1f33f34792d474387854accef728fbe1794d6c..95817624f8c617d9e24d9d62a6d1ab817b0f52cc 100644 (file)
--- a/channels.c
+++ b/channels.c
@@ -39,7 +39,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: channels.c,v 1.171 2002/03/04 19:37:58 markus Exp $");
+RCSID("$OpenBSD: channels.c,v 1.172 2002/03/25 21:13:51 markus Exp $");
 
 #include "ssh.h"
 #include "ssh1.h"
@@ -706,7 +706,11 @@ channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset)
                if (buffer_len(&c->output) > 0) {
                        FD_SET(c->wfd, writeset);
                } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
-                       chan_obuf_empty(c);
+                       if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
+                               debug2("channel %d: obuf_empty delayed efd %d/(%d)",
+                                   c->self, c->efd, buffer_len(&c->extended));
+                       else
+                               chan_obuf_empty(c);
                }
        }
        /** XXX check close conditions, too */
@@ -714,7 +718,8 @@ channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset)
                if (c->extended_usage == CHAN_EXTENDED_WRITE &&
                    buffer_len(&c->extended) > 0)
                        FD_SET(c->efd, writeset);
-               else if (c->extended_usage == CHAN_EXTENDED_READ &&
+               else if (!(c->flags & CHAN_EOF_SENT) &&
+                   c->extended_usage == CHAN_EXTENDED_READ &&
                    buffer_len(&c->extended) < c->remote_window)
                        FD_SET(c->efd, readset);
        }
@@ -1632,12 +1637,18 @@ channel_output_poll(void)
                                fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
                        /*
                         * input-buffer is empty and read-socket shutdown:
-                        * tell peer, that we will not send more data: send IEOF
+                        * tell peer, that we will not send more data: send IEOF.
+                        * hack for extended data: delay EOF if EFD still in use.
                         */
-                       chan_ibuf_empty(c);
+                       if (CHANNEL_EFD_INPUT_ACTIVE(c))
+                               debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
+                                   c->self, c->efd, buffer_len(&c->extended));
+                       else
+                               chan_ibuf_empty(c);
                }
                /* Send extended data, i.e. stderr */
                if (compat20 &&
+                   !(c->flags & CHAN_EOF_SENT) &&
                    c->remote_window > 0 &&
                    (len = buffer_len(&c->extended)) > 0 &&
                    c->extended_usage == CHAN_EXTENDED_READ) {
@@ -1726,6 +1737,13 @@ channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
                log("channel %d: ext data for non open", id);
                return;
        }
+       if (c->flags & CHAN_EOF_RCVD) {
+               if (datafellows & SSH_BUG_EXTEOF)
+                       debug("channel %d: accepting ext data after eof", id);
+               else
+                       packet_disconnect("Received extended_data after EOF "
+                           "on channel %d.", id);
+       }
        tcode = packet_get_int();
        if (c->efd == -1 ||
            c->extended_usage != CHAN_EXTENDED_WRITE ||

diff --git a/channels.h b/channels.h
index 707d9a925820f71f9ef4a99426a936093c3a67c4..0da2d4e5e029c95ad027ce06ee223e865647b1c9 100644 (file)
--- a/channels.h
+++ b/channels.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: channels.h,v 1.65 2002/03/04 17:27:39 stevesk Exp $   */
+/*     $OpenBSD: channels.h,v 1.66 2002/03/25 21:13:51 markus Exp $    */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -135,6 +135,18 @@ struct Channel {
 
 #define CHAN_CLOSE_SENT                        0x01
 #define CHAN_CLOSE_RCVD                        0x02
+#define CHAN_EOF_SENT                  0x04
+#define CHAN_EOF_RCVD                  0x08
+
+/* check whether 'efd' is still in use */
+#define CHANNEL_EFD_INPUT_ACTIVE(c) \
+       (compat20 && c->extended_usage == CHAN_EXTENDED_READ && \
+       (c->efd != -1 || \
+       buffer_len(&c->extended) > 0))
+#define CHANNEL_EFD_OUTPUT_ACTIVE(c) \
+       (compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \
+       ((c->efd != -1 && !(c->flags & CHAN_EOF_RCVD)) || \
+       buffer_len(&c->extended) > 0))
 
 /* channel management */
 

diff --git a/compat.c b/compat.c
index 74d5ed85ed6bd986dc02172c3dbadc194deac6bd..8671e641b43ce95b3c0d3dcde0d8dcea76308026 100644 (file)
--- a/compat.c
+++ b/compat.c
@@ -23,7 +23,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: compat.c,v 1.61 2002/03/06 00:24:39 markus Exp $");
+RCSID("$OpenBSD: compat.c,v 1.62 2002/03/25 21:13:51 markus Exp $");
 
 #include "buffer.h"
 #include "packet.h"
@@ -61,20 +61,26 @@ compat_datafellows(const char *version)
                  "OpenSSH-2.1*,"
                  "OpenSSH_2.1*,"
                  "OpenSSH_2.2*",       SSH_OLD_SESSIONID|SSH_BUG_BANNER|
-                                       SSH_OLD_DHGEX|SSH_BUG_NOREKEY },
+                                       SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
+                                       SSH_BUG_EXTEOF},
                { "OpenSSH_2.3.0*",     SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES|
-                                       SSH_OLD_DHGEX|SSH_BUG_NOREKEY},
+                                       SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
+                                       SSH_BUG_EXTEOF},
                { "OpenSSH_2.3.*",      SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
-                                       SSH_BUG_NOREKEY},
+                                       SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
                { "OpenSSH_2.5.0p1*,"
                  "OpenSSH_2.5.1p1*",
                                        SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
-                                       SSH_BUG_NOREKEY },
+                                       SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
                { "OpenSSH_2.5.0*,"
                  "OpenSSH_2.5.1*,"
-                 "OpenSSH_2.5.2*",     SSH_OLD_DHGEX|SSH_BUG_NOREKEY },
-               { "OpenSSH_2.5.3*",     SSH_BUG_NOREKEY },
-               { "Sun_SSH_1.0*",       SSH_BUG_NOREKEY },
+                 "OpenSSH_2.5.2*",     SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
+                                       SSH_BUG_EXTEOF},
+               { "OpenSSH_2.5.3*",     SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
+               { "OpenSSH_2.*,"
+                 "OpenSSH_3.0*,"
+                 "OpenSSH_3.1*",       SSH_BUG_EXTEOF},
+               { "Sun_SSH_1.0*",       SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
                { "OpenSSH*",           0 },
                { "*MindTerm*",         0 },
                { "2.1.0*",             SSH_BUG_SIGBLOB|SSH_BUG_HMAC|

diff --git a/compat.h b/compat.h
index 0eeb782e861ad770163dccd1bf9f07d606be4c35..3fb0f97999d79a853d69bbd6fb55e2f048e9792a 100644 (file)
--- a/compat.h
+++ b/compat.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: compat.h,v 1.30 2002/03/04 17:27:39 stevesk Exp $     */
+/*     $OpenBSD: compat.h,v 1.31 2002/03/25 21:13:51 markus Exp $      */
 
 /*
  * Copyright (c) 1999, 2000, 2001 Markus Friedl.  All rights reserved.
@@ -52,6 +52,7 @@
 #define SSH_BUG_OPENFAILURE    0x00020000
 #define SSH_BUG_DERIVEKEY      0x00040000
 #define SSH_BUG_DUMMYCHAN      0x00100000
+#define SSH_BUG_EXTEOF         0x00200000
 
 void     enable_compat13(void);
 void     enable_compat20(void);

diff --git a/nchan.c b/nchan.c
index fc8e7f18de6d6ee2bba07c2c3d619795d5cdace3..db38de6acff62fc6c241be307aca78ac752285ef 100644 (file)
--- a/nchan.c
+++ b/nchan.c
@@ -23,7 +23,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: nchan.c,v 1.44 2002/01/21 23:27:10 markus Exp $");
+RCSID("$OpenBSD: nchan.c,v 1.45 2002/03/25 21:13:51 markus Exp $");
 
 #include "ssh1.h"
 #include "ssh2.h"
@@ -302,6 +302,7 @@ static void
 chan_rcvd_eof2(Channel *c)
 {
        debug("channel %d: rcvd eof", c->self);
+       c->flags |= CHAN_EOF_RCVD;
        if (c->ostate == CHAN_OUTPUT_OPEN)
                chan_set_ostate(c, CHAN_OUTPUT_WAIT_DRAIN);
 }
@@ -330,6 +331,7 @@ chan_send_eof2(Channel *c)
                packet_start(SSH2_MSG_CHANNEL_EOF);
                packet_put_int(c->remote_id);
                packet_send();
+               c->flags |= CHAN_EOF_SENT;
                break;
        default:
                error("channel %d: cannot send eof for istate %d",
@@ -365,7 +367,8 @@ chan_rcvd_ieof(Channel *c)
        else
                chan_rcvd_ieof1(c);
        if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN &&
-           buffer_len(&c->output) == 0)
+           buffer_len(&c->output) == 0 && 
+           !CHANNEL_EFD_OUTPUT_ACTIVE(c))
                chan_obuf_empty(c);
 }
 void
@@ -404,39 +407,30 @@ chan_is_dead(Channel *c, int send)
                debug("channel %d: is dead", c->self);
                return 1;
        }
-       /*
-        * we have to delay the close message if the efd (for stderr) is
-        * still active
-        */
-       if (((c->extended_usage != CHAN_EXTENDED_IGNORE) &&
-           buffer_len(&c->extended) > 0)
-#if 0
-           || ((c->extended_usage == CHAN_EXTENDED_READ) &&
-           c->efd != -1)
-#endif
-           ) {
-               debug2("channel %d: active efd: %d len %d type %s",
-                   c->self, c->efd, buffer_len(&c->extended),
-                   c->extended_usage==CHAN_EXTENDED_READ ?
-                   "read": "write");
-       } else {
-               if (!(c->flags & CHAN_CLOSE_SENT)) {
-                       if (send) {
-                               chan_send_close2(c);
-                       } else {
-                               /* channel would be dead if we sent a close */
-                               if (c->flags & CHAN_CLOSE_RCVD) {
-                                       debug("channel %d: almost dead",
-                                           c->self);
-                                       return 1;
-                               }
+       if ((datafellows & SSH_BUG_EXTEOF) &&
+           c->extended_usage == CHAN_EXTENDED_WRITE &&
+           c->efd != -1 &&
+           buffer_len(&c->extended) > 0) {
+                debug2("channel %d: active efd: %d len %d",
+                    c->self, c->efd, buffer_len(&c->extended));
+               return 0;
+       }
+       if (!(c->flags & CHAN_CLOSE_SENT)) {
+               if (send) {
+                       chan_send_close2(c);
+               } else {
+                       /* channel would be dead if we sent a close */
+                       if (c->flags & CHAN_CLOSE_RCVD) {
+                               debug("channel %d: almost dead",
+                                   c->self);
+                               return 1;
                        }
                }
-               if ((c->flags & CHAN_CLOSE_SENT) &&
-                   (c->flags & CHAN_CLOSE_RCVD)) {
-                       debug("channel %d: is dead", c->self);
-                       return 1;
-               }
+       }
+       if ((c->flags & CHAN_CLOSE_SENT) &&
+           (c->flags & CHAN_CLOSE_RCVD)) {
+               debug("channel %d: is dead", c->self);
+               return 1;
        }
        return 0;
 }