X-Git-Url: https://git.distorted.org.uk/~mdw/fwd/blobdiff_plain/046a152e4526d789407a3d020a2c38cdd956f4f3..858a73afbf5018d74920761f7015ac2e7d3987b6:/chan.c

diff --git a/chan.c b/chan.c
index ffec633..5fbecb1 100644
--- a/chan.c
+++ b/chan.c
@@ -1,73 +1,36 @@
 /* -*-c-*-
  *
- * $Id: chan.c,v 1.5 2000/07/19 17:55:43 mdw Exp $
- *
  * Channel management
  *
  * (c) 1999 Straylight/Edgeware
  */
 
-/*----- Licensing notice --------------------------------------------------* 
+/*----- Licensing notice --------------------------------------------------*
  *
- * This file is part of the `fw' port forwarder.
+ * This file is part of the `fwd' port forwarder.
  *
- * `fw' is free software; you can redistribute it and/or modify
+ * `fwd' is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
- * 
- * `fw' is distributed in the hope that it will be useful,
+ *
+ * `fwd' is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU General Public License
- * along with `fw'; if not, write to the Free Software Foundation,
+ * along with `fwd'; if not, write to the Free Software Foundation,
  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
-/*----- Revision history --------------------------------------------------* 
- *
- * $Log: chan.c,v $
- * Revision 1.5  2000/07/19 17:55:43  mdw
- * (writechan): Pointless tweak: when the buffer is empty, reset the start
- * pointer to the beginning.  This saves doing slightly trickier
- * @writev(2)@ calls when loading is light.
- *
- * Revision 1.4  1999/08/31 17:42:49  mdw
- * Use `sel_force' to avoid a `select' call between reads and writes.
- *
- * Revision 1.3  1999/07/27 18:30:53  mdw
- * Various minor portability fixes.
- *
- * Revision 1.2  1999/07/26 23:27:52  mdw
- * Minor modifications for new design.
- *
- * Revision 1.1.1.1  1999/07/01 08:56:23  mdw
- * Initial revision.
- *
- */
+#include "fwd.h"
 
-/*----- Header files ------------------------------------------------------*/
-
-#include "config.h"
-
-#include <errno.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include <sys/types.h>
-#include <sys/time.h>
-#include <unistd.h>
-#include <sys/uio.h>
-
-#include <mLib/alloc.h>
-#include <mLib/conn.h>
-#include <mLib/sel.h>
-
-#include "chan.h"
-#include "fw.h"
+#ifdef CHAN_DEBUG
+#  define D(x) x
+#else
+#  define D(x)
+#endif
 
 /*----- Main code ---------------------------------------------------------*/
 
@@ -95,29 +58,36 @@ static void writechan(int fd, unsigned mode, void *vp)
 
     /* --- Do the write --- */
 
-    if (base + len <= CHAN_BUFSZ)
+    D( printf("writechan %d: base = %u, len = %u; ", fd, base, len); )
+    if (base + len <= CHAN_BUFSZ) {
+      D( printf("%u:%u", base, len); )
       w = write(fd, c->buf + base, len);
-    else {
+    } else {
       struct iovec iov[2];
       iov[0].iov_base = c->buf + base;
       iov[0].iov_len = CHAN_BUFSZ - base;
       iov[1].iov_base = c->buf;
       iov[1].iov_len = len - iov[0].iov_len;
+      D( printf("%u:%u, %u:%u",
+		base, CHAN_BUFSZ - base,
+		0, len + base - CHAN_BUFSZ); )
       w = writev(fd, iov, 2);
     }
+    D( printf("; returned %d\n", w); )
 
     /* --- Sift through the results --- */
 
     if (w < 0) {
       if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)
 	return;
+      c->err = errno;
       goto close;
-    }
-    else if (w == 0)
+    } else if (w == 0)
       goto close;
     else if (c->len == CHAN_BUFSZ && !(c->f & CHANF_CLOSE))
       sel_addfile(&c->r);
     c->len -= w;
+    c->base += w;
   }
   if (c->len == 0)
     sel_rmfile(&c->w);
@@ -153,30 +123,39 @@ static void readchan(int fd, unsigned mode, void *vp)
 {
   chan *c = vp;
   int r;
-  unsigned base = (c->base + c->len) & (CHAN_BUFSZ - 1);
-  unsigned len = CHAN_BUFSZ - c->len;
+  unsigned base = c->base;
+  unsigned len = c->len;
 
   /* --- Do the read --- */
 
-  if (base + len <= CHAN_BUFSZ)
-    r = read(fd, c->buf + base, len);
-  else {
+  D( printf("readchan %d: base = %u, len = %u; ", fd, base, len); )
+  if (base == 0) {
+    D( printf("%u:%u", len, CHAN_BUFSZ - len); )
+    r = read(fd, c->buf + len, CHAN_BUFSZ - len);
+  } else if (base + len >= CHAN_BUFSZ) {
+    D( printf("%u:%u", base + len - CHAN_BUFSZ, CHAN_BUFSZ - len); )
+    r = read(fd, c->buf + base + len - CHAN_BUFSZ, CHAN_BUFSZ - len);
+  } else {
     struct iovec iov[2];
-    iov[0].iov_base = c->buf + base;
-    iov[0].iov_len = CHAN_BUFSZ - base;
+    iov[0].iov_base = c->buf + base + len;
+    iov[0].iov_len = CHAN_BUFSZ - base - len;
     iov[1].iov_base = c->buf;
-    iov[1].iov_len = len - iov[0].iov_len;
+    iov[1].iov_len = base;
+    D( printf("%u:%u, %u:%u",
+	      base + len, CHAN_BUFSZ - base - len,
+	      0, base); )
     r = readv(fd, iov, 2);
   }
+  D( printf("; returned %d\n", r); )
 
   /* --- Sift through the results --- */
 
   if (r < 0) {
     if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)
       return;
+    c->err = errno;
     goto close;
-  }
-  else if (r == 0)
+  } else if (r == 0)
     goto close;
   else if (c->len == 0 && (c->f & CHANF_READY)) {
     sel_addfile(&c->w);