- reyk@cvs.openbsd.org 2005/12/30 15:56:37

     [channels.c channels.h clientloop.c]
     add channel output filter interface.
     ok djm@, suggested by markus@

1 files changed, 24 insertions, 11 deletions

diff --git a/channels.c b/channels.c
index b431532a3..ed5903f6f 100644
--- a/channels.c
+++ b/channels.c
@@ -39,7 +39,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: channels.c,v 1.230 2005/12/28 22:46:06 stevesk Exp $");
+RCSID("$OpenBSD: channels.c,v 1.231 2005/12/30 15:56:36 reyk Exp $");
 
 #include "ssh.h"
 #include "ssh1.h"
@@ -58,8 +58,6 @@ RCSID("$OpenBSD: channels.c,v 1.230 2005/12/28 22:46:06 stevesk Exp $");
 
 /* -- channel core */
 
-#define CHAN_RBUF       16*1024
-
 /*
  * Pointer to an array containing all allocated channels.  The array is
  * dynamically extended as needed.
@@ -301,6 +299,7 @@ channel_new(char *ctype, int type, int rfd, int wfd, int efd,
         c->confirm = NULL;
         c->confirm_ctx = NULL;
         c->input_filter = NULL;
+        c->output_filter = NULL;
         debug("channel %d: new [%s]", found, remote_name);
         return c;
 }
@@ -681,7 +680,8 @@ channel_cancel_cleanup(int id)
         c->detach_close = 0;
 }
 void
-channel_register_filter(int id, channel_filter_fn *fn)
+channel_register_filter(int id, channel_infilter_fn *ifn,
+    channel_outfilter_fn *ofn)
 {
         Channel *c = channel_lookup(id);
 
@@ -689,7 +689,8 @@ channel_register_filter(int id, channel_filter_fn *fn)
                 logit("channel_register_filter: %d: bad id", id);
                 return;
         }
-        c->input_filter = fn;
+        c->input_filter = ifn;
+        c->output_filter = ofn;
 }
 
 void
@@ -1454,7 +1455,7 @@ static int
 channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
 {
         struct termios tio;
-        u_char *data;
+        u_char *data = NULL, *buf;
         u_int dlen;
         int len;
 
@@ -1462,11 +1463,22 @@ channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
         if (c->wfd != -1 &&
             FD_ISSET(c->wfd, writeset) &&
             buffer_len(&c->output) > 0) {
+                if (c->output_filter != NULL) {
+                        if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
+                                debug2("channel %d: filter stops", c->self);
+                                chan_read_failed(c);
+                        }
+                } else if (c->datagram) {
+                        buf = data = buffer_get_string(&c->output, &dlen);
+                } else {
+                        buf = data = buffer_ptr(&c->output);
+                        dlen = buffer_len(&c->output);
+                }
+
                 if (c->datagram) {
-                        data = buffer_get_string(&c->output, &dlen);
                         /* ignore truncated writes, datagrams might get lost */
                         c->local_consumed += dlen + 4;
-                        len = write(c->wfd, data, dlen);
+                        len = write(c->wfd, buf, dlen);
                         xfree(data);
                         if (len < 0 && (errno == EINTR || errno == EAGAIN))
                                 return 1;
@@ -1486,7 +1498,8 @@ channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
                 if (compat20 && c->wfd_isatty)
                         dlen = MIN(dlen, 8*1024);
 #endif
-                len = write(c->wfd, data, dlen);
+
+                len = write(c->wfd, buf, dlen);
                 if (len < 0 && (errno == EINTR || errno == EAGAIN))
                         return 1;
                 if (len <= 0) {
@@ -1503,14 +1516,14 @@ channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
                         }
                         return -1;
                 }
-                if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') {
+                if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
                         if (tcgetattr(c->wfd, &tio) == 0 &&
                             !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
                                 /*
                                  * Simulate echo to reduce the impact of
                                  * traffic analysis. We need to match the
                                  * size of a SSH2_MSG_CHANNEL_DATA message
-                                 * (4 byte channel id + data)
+                                 * (4 byte channel id + buf)
                                  */
                                 packet_send_ignore(4 + len);
                                 packet_send();