Refactoring Channels

1. Remove the unused channel status callbacks from the echoserver.
2. Add a flag to the threadCtx to be set if the channel is to be SFTP.
3. Modify the subsystem start callback to set the SFTP flag if the
   subsystem is sftp.
4. ssh_worker to return WS_SFTP_COMPLETE if the SFTP flag is set.
5. If worker returns SFTP complete, run the SFTP accept and start
   stfp_worker.

examples/echoserver/echoserver.c

@@ -205,6 +205,9 @@ typedef struct {
 #ifdef WOLFSSH_SHELL
     WS_ShellCtx shellCtx;
     byte shellBuffer[EXAMPLE_BUFFER_SZ];
+#endif
+#ifdef WOLFSSH_SFTP
+    int doSftp;
 #endif
     byte channelBuffer[EXAMPLE_BUFFER_SZ];
     char statsBuffer[EXAMPLE_BUFFER_SZ];
@@ -748,66 +751,16 @@ static int wsSubsysStartCb(WOLFSSH_CHANNEL* channel, void* vCtx)
     cmd = wolfSSH_ChannelGetSessionCommand(channel);
     type = wolfSSH_ChannelGetSessionType(channel);
 
-    WOLFSSH_UNUSED(threadCtx);
-
     if (type == WOLFSSH_SESSION_SUBSYSTEM
             && WSTRCMP(cmd, "sftp") == 0) {
-        /* do nothing */;
+        threadCtx->doSftp = 1;
     }
 
     return 0;
 }
 #endif /* WOLFSSH_SFTP */
 
 
-static int wsChannelOpenCb(WOLFSSH_CHANNEL* channel, void* ctx)
-{
-    word32 id = 0;
-
-    wolfSSH_ChannelGetId(channel, &id, WS_CHANNEL_ID_PEER);
-
-    if (ctx != NULL) {
-        printf("Channel %u open attempt, CTX is %p.\n", id, ctx);
-    }
-    else {
-        printf("Channel %u open attempt, but no CTX.\n", id);
-    }
-    return 0;
-}
-
-
-static int wsChannelEofCb(WOLFSSH_CHANNEL* channel, void* ctx)
-{
-    word32 id = 0;
-
-    wolfSSH_ChannelGetId(channel, &id, WS_CHANNEL_ID_PEER);
-
-    if (ctx != NULL) {
-        printf("Channel %u end of file, CTX is %p.\n", id, ctx);
-    }
-    else {
-        printf("Channel %u end of file, but no CTX.\n", id);
-    }
-    return 0;
-}
-
-
-static int wsChannelCloseCb(WOLFSSH_CHANNEL* channel, void* ctx)
-{
-    word32 id = 0;
-
-    wolfSSH_ChannelGetId(channel, &id, WS_CHANNEL_ID_PEER);
-
-    if (ctx != NULL) {
-        printf("Channel %u closed, CTX is %p.\n", id, ctx);
-    }
-    else {
-        printf("Channel %u closed, but no CTX.\n", id);
-    }
-    return 0;
-}
-
-
 #ifdef SHELL_DEBUG
 
 static void display_ascii(char *p_buf,
@@ -1039,6 +992,11 @@ static int ssh_worker(thread_ctx_t* threadCtx)
                    channel. The additional channel is only used with the
                    agent. */
                 cnt_r = wolfSSH_worker(ssh, &lastChannel);
+                #ifdef WOLFSSH_SFTP
+                if (threadCtx->doSftp) {
+                    return WS_SFTP_COMPLETE;
+                }
+                #endif
                 if (cnt_r < 0) {
                     rc = wolfSSH_get_error(ssh);
                     if (rc == WS_CHAN_RXD) {
@@ -1603,14 +1561,16 @@ static THREAD_RETURN WOLFSSH_THREAD server_worker(void* vArgs)
             ret = 0;
             break;
 
-        #ifdef WOLFSSH_SFTP
-        case WS_SFTP_COMPLETE:
-            ret = sftp_worker(threadCtx);
-            break;
-        #endif
-
         case WS_SUCCESS:
             ret = ssh_worker(threadCtx);
+            #ifdef WOLFSSH_SFTP
+            if (ret == WS_SFTP_COMPLETE) {
+                ret = wolfSSH_SFTP_accept(threadCtx->ssh);
+            }
+            if (ret == WS_SFTP_COMPLETE) {
+                ret = sftp_worker(threadCtx);
+            }
+            #endif
             break;
     }
 
@@ -2655,9 +2615,6 @@ THREAD_RETURN WOLFSSH_THREAD echoserver_test(void* args)
         wolfSSH_SetUserAuth(ctx, ((func_args*)args)->user_auth);
     wolfSSH_SetUserAuthResult(ctx, wsUserAuthResult);
     wolfSSH_CTX_SetBanner(ctx, echoserverBanner);
-    wolfSSH_CTX_SetChannelOpenCb(ctx, wsChannelOpenCb);
-    wolfSSH_CTX_SetChannelEofCb(ctx, wsChannelEofCb);
-    wolfSSH_CTX_SetChannelCloseCb(ctx, wsChannelCloseCb);
 #ifdef WOLFSSH_SHELL
     wolfSSH_CTX_SetChannelReqShellCb(ctx, wsShellStartCb);
 #endif
@@ -2897,8 +2854,6 @@ THREAD_RETURN WOLFSSH_THREAD echoserver_test(void* args)
         wolfSSH_SetKeyingCompletionCbCtx(ssh, (void*)ssh);
         wolfSSH_SetChannelOpenCtx(ssh, (void*)threadCtx);
         wolfSSH_SetChannelReqCtx(ssh, (void*)threadCtx);
-        wolfSSH_SetChannelEofCtx(ssh, (void*)threadCtx);
-        wolfSSH_SetChannelCloseCtx(ssh, (void*)threadCtx);
         /* Use the session object for its own highwater callback ctx */
         if (defaultHighwater > 0) {
             wolfSSH_SetHighwaterCtx(ssh, (void*)ssh);