SFTP Large File Fix

1. There were a couple spots during a large file transfer where the
   client rekeying the session would interrupt the transfer and/or
   reset the amount of file data transfered. Fixed that with a check
   for WS_CHAN_RXD.
2. Added a build option to interrupt a file transfer after 2 minutes.
   Large files will take longer.

ChangeLog.md

@@ -19,6 +19,7 @@
 - Fixes for compiler complaints using GCC 4.0.2
 - Fixes for the directory path cleanup function for SFTP
 - Fixes for SFTP directory listing when on Windows
+- Fixes for large file transfers with SFTP
 - Fixes for port forwarding
 - Fix for building with QNX
 - Fix for the wolfSSHd grace time alarm

examples/sftpclient/sftpclient.c

@@ -123,12 +123,14 @@ static void myStatusCb(WOLFSSH* sshIn, word32* bytes, char* name)
     currentTime = current_time(0) - startTime;
     WSNPRINTF(buf, sizeof(buf), "Processed %8llu\t bytes in %d seconds\r",
             (unsigned long long)longBytes, currentTime);
+#ifndef WOLFSSH_NO_SFTP_TIMEOUT
     if (currentTime > TIMEOUT_VALUE) {
         WSNPRINTF(buf, sizeof(buf), "\nProcess timed out at %d seconds, "
                 "stopping\r", currentTime);
         WMEMSET(currentFile, 0, WOLFSSH_MAX_FILENAME);
         wolfSSH_SFTP_Interrupt(ssh);
     }
+#endif
 #else
     WSNPRINTF(buf, sizeof(buf), "Processed %8llu\t bytes \r",
             (unsigned long long)longBytes);
@@ -1016,7 +1018,8 @@ static int doCmds(func_args* args)
                 if (ret != WS_SUCCESS) {
                     ret = wolfSSH_get_error(ssh);
                 }
-            } while (ret == WS_WANT_READ || ret == WS_WANT_WRITE);
+            } while (ret == WS_WANT_READ || ret == WS_WANT_WRITE ||
+                    ret == WS_CHAN_RXD);
 
 #ifndef WOLFSSH_NO_TIMESTAMP
             WMEMSET(currentFile, 0, WOLFSSH_MAX_FILENAME);
@@ -1111,8 +1114,8 @@ static int doCmds(func_args* args)
             do {
                 ret = wolfSSH_SFTP_Put(ssh, pt, to, resume, &myStatusCb);
                 err = wolfSSH_get_error(ssh);
-            } while ((err == WS_WANT_READ || err == WS_WANT_WRITE)
-                        && ret != WS_SUCCESS);
+            } while ((err == WS_WANT_READ || err == WS_WANT_WRITE ||
+                        err == WS_CHAN_RXD) && ret != WS_SUCCESS);
 
 #ifndef WOLFSSH_NO_TIMESTAMP
             WMEMSET(currentFile, 0, WOLFSSH_MAX_FILENAME);
@@ -1521,8 +1524,8 @@ static int doAutopilot(int cmd, char* local, char* remote)
             ret = wolfSSH_SFTP_Get(ssh, fullpath, local, 0, NULL);
         }
         err = wolfSSH_get_error(ssh);
-    } while ((err == WS_WANT_READ || err == WS_WANT_WRITE) &&
-            ret != WS_SUCCESS);
+    } while ((err == WS_WANT_READ || err == WS_WANT_WRITE ||
+                err == WS_CHAN_RXD) && ret != WS_SUCCESS);
 
     if (ret != WS_SUCCESS) {
         if (cmd == AUTOPILOT_PUT) {

src/wolfsftp.c

@@ -398,6 +398,16 @@ static WS_SFTPNAME* wolfSSH_SFTPNAME_new(void* heap);
 static int SFTP_CreateLongName(WS_SFTPNAME* name);
 
 
+/* A few errors are OK to get. They are a notice rather that a fault.
+ * return TRUE if ssh->error is one of the following: */
+INLINE int NoticeError(WOLFSSH* ssh)
+{
+    return (ssh->error == WS_WANT_READ ||
+            ssh->error == WS_WANT_WRITE ||
+            ssh->error == WS_CHAN_RXD);
+}
+
+
 static byte* wolfSSH_SFTP_buffer_data(WS_SFTP_BUFFER* buffer)
 {
     byte* ret = NULL;
@@ -8117,8 +8127,7 @@ int wolfSSH_SFTP_Get(WOLFSSH* ssh, char* from,
                             state->gOfst, state->r,
                             WOLFSSH_MAX_SFTP_RW);
                     if (sz < 0) {
-                        if (ssh->error == WS_WANT_READ ||
-                                ssh->error == WS_WANT_WRITE) {
+                        if (NoticeError(ssh)) {
                             return WS_FATAL_ERROR;
                         }
                         WLOG(WS_LOG_SFTP, "Error reading packet");