Add wolfSSH_ChannelIdPeek()

src/ssh.c

@@ -5195,6 +5195,47 @@ static int _ChannelReadExt(WOLFSSH_CHANNEL* channel, byte* buf, word32 bufSz)
 }
 
 
+int wolfSSH_ChannelIdPeek(WOLFSSH* ssh, word32 channelId,
+        byte* buf, word32 bufSz)
+{
+    WOLFSSH_CHANNEL* channel = NULL;
+    WOLFSSH_BUFFER* inputBuffer;
+    word32 avail;
+
+    WLOG(WS_LOG_DEBUG, "Entering wolfSSH_ChannelIdPeek(), ID = %u", channelId);
+
+    if (ssh == NULL)
+        return WS_BAD_ARGUMENT;
+
+    channel = ChannelFind(ssh, channelId, WS_CHANNEL_ID_SELF);
+    if (channel == NULL)
+        return WS_INVALID_CHANID;
+
+    inputBuffer = &channel->inputBuffer;
+    avail = inputBuffer->length - inputBuffer->idx;
+
+    /* Report the EOF only once the buffered data is drained. */
+    if (avail == 0 && channel->eofRxd) {
+        ssh->error = WS_EOF;
+        return WS_ERROR;
+    }
+
+    /* The EOF above outranks this: it names the channel. */
+    if (avail == 0 && ssh->disconnected) {
+        ssh->error = WS_DISCONNECT;
+        return WS_FATAL_ERROR;
+    }
+
+    bufSz = min(bufSz, avail);
+    if (buf != NULL) {
+        WMEMCPY(buf, inputBuffer->buffer + inputBuffer->idx, bufSz);
+    }
+
+    WLOG(WS_LOG_DEBUG, "Leaving wolfSSH_ChannelIdPeek(), rxd = %u", bufSz);
+    return (int)bufSz;
+}
+
+
 int wolfSSH_ChannelIdRead(WOLFSSH* ssh, word32 channelId,
         byte* buf, word32 bufSz)
 {

tests/sftp.c

@@ -469,7 +469,9 @@ int wolfSSH_SftpTest(int flag)
     int ret = 0;
     int argsCount;
 
-    const char* args[10];
+    /* The server thread holds ser.argv, so the client cannot share it. */
+    const char* argsServer[10];
+    const char* argsClient[10];
 #ifndef USE_WINDOWS_API
     char  portNumber[8];
 #endif
@@ -496,40 +498,40 @@ int wolfSSH_SftpTest(int flag)
 #endif
 
     argsCount = 0;
-    args[argsCount++] = ".";
-    args[argsCount++] = "-1";
+    argsServer[argsCount++] = ".";
+    argsServer[argsCount++] = "-1";
 #ifndef USE_WINDOWS_API
-    args[argsCount++] = "-p";
-    args[argsCount++] = "0";
+    argsServer[argsCount++] = "-p";
+    argsServer[argsCount++] = "0";
 #endif
     if (flag)
-        args[argsCount++] = "-N";
+        argsServer[argsCount++] = "-N";
 
-    ser.argv   = (char**)args;
+    ser.argv   = (char**)argsServer;
     ser.argc    = argsCount;
     ser.signal = &ready;
     InitTcpReady(ser.signal);
     ThreadStart(echoserver_test, (void*)&ser, &serThread);
     WaitTcpReady(&ready);
 
     argsCount = 0;
-    args[argsCount++] = ".";
-    args[argsCount++] = "-u";
-    args[argsCount++] = "jill";
-    args[argsCount++] = "-P";
-    args[argsCount++] = "upthehill";
+    argsClient[argsCount++] = ".";
+    argsClient[argsCount++] = "-u";
+    argsClient[argsCount++] = "jill";
+    argsClient[argsCount++] = "-P";
+    argsClient[argsCount++] = "upthehill";
 
 #ifndef USE_WINDOWS_API
     /* use port that server has found */
-    args[argsCount++] = "-p";
+    argsClient[argsCount++] = "-p";
     snprintf(portNumber, sizeof(portNumber), "%d", ready.port);
-    args[argsCount++] = portNumber;
+    argsClient[argsCount++] = portNumber;
 #endif
 
     if (flag)
-        args[argsCount++] = "-N";
+        argsClient[argsCount++] = "-N";
 
-    cli.argv    = (char**)args;
+    cli.argv    = (char**)argsClient;
     cli.argc    = argsCount;
     cli.signal  = &ready;
     cli.sftp_cb = commandCb;

tests/unit.c

@@ -10006,6 +10006,122 @@ static int test_stream_read_deferredWindowAdjust(void)
     return result;
 }
 
+/* wolfSSH_ChannelIdPeek() reports a named channel without consuming it. */
+static int test_ChannelIdPeek(void)
+{
+    WOLFSSH_CTX*     ctx = NULL;
+    WOLFSSH*         ssh = NULL;
+    WOLFSSH_CHANNEL* ch  = NULL;
+    int              result = 0;
+    int              ret;
+    byte             in[32];
+    byte             out[32];
+    word32           i;
+
+    for (i = 0; i < (word32)sizeof(in); i++) {
+        in[i] = (byte)(i + 1);
+    }
+
+    ctx = wolfSSH_CTX_new(WOLFSSH_ENDPOINT_SERVER, NULL);
+    if (ctx == NULL)
+        return -7050;
+
+    ssh = wolfSSH_new(ctx);
+    if (ssh == NULL) { result = -7051; goto done; }
+
+    /* Bad args, before any channel exists. */
+    if (wolfSSH_ChannelIdPeek(NULL, 0, out, (word32)sizeof(out))
+            != WS_BAD_ARGUMENT) {
+        result = -7052; goto done;
+    }
+    if (wolfSSH_ChannelIdPeek(ssh, 99, out, (word32)sizeof(out))
+            != WS_INVALID_CHANID) {
+        result = -7053; goto done;
+    }
+
+    ch = ChannelNew(ssh, ID_CHANTYPE_SESSION,
+                    (word32)sizeof(in), DEFAULT_MAX_PACKET_SZ);
+    if (ch == NULL) { result = -7054; goto done; }
+    if (ChannelAppend(ssh, ch) != WS_SUCCESS) {
+        ChannelDelete(ch, ssh->ctx->heap);
+        result = -7055;
+        goto done;
+    }
+    ch->openConfirmed = 1;
+
+    /* Open and empty: zero, not an error. */
+    ret = wolfSSH_ChannelIdPeek(ssh, ch->channel, out, (word32)sizeof(out));
+    if (ret != 0) { result = -7056; goto done; }
+
+    if (wolfSSH_TestChannelPutData(ch, in, (word32)sizeof(in)) != WS_SUCCESS) {
+        result = -7057; goto done;
+    }
+
+    /* Whole payload reported and copied out. */
+    WMEMSET(out, 0, sizeof(out));
+    ret = wolfSSH_ChannelIdPeek(ssh, ch->channel, out, (word32)sizeof(out));
+    if (ret != (int)sizeof(in)) { result = -7058; goto done; }
+    if (WMEMCMP(out, in, sizeof(in)) != 0) { result = -7059; goto done; }
+
+    /* Consumed nothing, credited nothing. */
+    if (ch->inputBuffer.length - ch->inputBuffer.idx != (word32)sizeof(in)) {
+        result = -7060; goto done;
+    }
+    if (ch->windowSz != 0) { result = -7061; goto done; }
+
+    /* bufSz caps the count and the bytes written. */
+    WMEMSET(out, 0, sizeof(out));
+    ret = wolfSSH_ChannelIdPeek(ssh, ch->channel, out, 8);
+    if (ret != 8) { result = -7062; goto done; }
+    if (WMEMCMP(out, in, 8) != 0) { result = -7063; goto done; }
+    if (out[8] != 0) { result = -7064; goto done; }
+
+    /* A NULL buffer asks only for the count. */
+    ret = wolfSSH_ChannelIdPeek(ssh, ch->channel, NULL, (word32)sizeof(out));
+    if (ret != (int)sizeof(in)) { result = -7065; goto done; }
+
+    /* Still reported mid-rekey, where stream_peek returns WS_REKEYING. */
+    ssh->isKeying = WOLFSSH_SELF_IS_KEYING;
+    if (wolfSSH_stream_peek(ssh, out, (word32)sizeof(out)) != WS_REKEYING) {
+        result = -7066; goto done;
+    }
+    ret = wolfSSH_ChannelIdPeek(ssh, ch->channel, out, (word32)sizeof(out));
+    if (ret != (int)sizeof(in)) { result = -7067; goto done; }
+    ssh->isKeying = 0;
+
+    /* EOF stays hidden until the buffered data is drained. */
+    ch->eofRxd = 1;
+    ret = wolfSSH_ChannelIdPeek(ssh, ch->channel, out, (word32)sizeof(out));
+    if (ret != (int)sizeof(in)) { result = -7068; goto done; }
+
+    ret = wolfSSH_ChannelIdRead(ssh, ch->channel, out, (word32)sizeof(out));
+    if (ret != (int)sizeof(in)) { result = -7069; goto done; }
+
+    ssh->error = WS_SUCCESS;
+    ret = wolfSSH_ChannelIdPeek(ssh, ch->channel, out, (word32)sizeof(out));
+    if (ret != WS_ERROR) { result = -7070; goto done; }
+    if (ssh->error != WS_EOF) { result = -7071; goto done; }
+
+    /* EOF outranks a disconnect. */
+    ssh->disconnected = 1;
+    ssh->error = WS_SUCCESS;
+    ret = wolfSSH_ChannelIdPeek(ssh, ch->channel, out, (word32)sizeof(out));
+    if (ret != WS_ERROR) { result = -7072; goto done; }
+    if (ssh->error != WS_EOF) { result = -7073; goto done; }
+
+    /* Without the EOF, the dead session is reported instead. */
+    ch->eofRxd = 0;
+    ssh->error = WS_SUCCESS;
+    ret = wolfSSH_ChannelIdPeek(ssh, ch->channel, out, (word32)sizeof(out));
+    if (ret != WS_FATAL_ERROR) { result = -7074; goto done; }
+    if (ssh->error != WS_DISCONNECT) { result = -7075; goto done; }
+
+done:
+    wolfSSH_free(ssh);
+    wolfSSH_CTX_free(ctx);
+    return result;
+}
+
 /* wolfSSH_ChannelIdRead() counterpart of
  * test_stream_read_deferredWindowAdjust(): callers break out on a non-positive
  * read, and this entry point has to retire the owed-flush status itself. */
@@ -23094,6 +23210,11 @@ int wolfSSH_UnitTest(int argc, char** argv)
     printf("ChannelIdRead_deferredWindowAdjust: %s\n",
            (unitResult == 0 ? "SUCCESS" : "FAILED"));
     testResult = testResult || unitResult;
+
+    unitResult = test_ChannelIdPeek();
+    printf("ChannelIdPeek: %s\n",
+           (unitResult == 0 ? "SUCCESS" : "FAILED"));
+    testResult = testResult || unitResult;
 #endif /* NO_WOLFSSH_SERVER */
 
     unitResult = test_BuildNameList_emptySrc();

wolfssh/ssh.h

@@ -979,6 +979,12 @@ WOLFSSH_API int wolfSSH_global_request(WOLFSSH* ssh, const unsigned char* data,
  * wolfSSH_ChannelRead() returns WS_REKEYING. */
 WOLFSSH_API int wolfSSH_ChannelIdRead(WOLFSSH* ssh, word32 channelId,
         byte* buf, word32 bufSz);
+/* Peeks the channel named by channelId, with wolfSSH_stream_peek()'s
+ * contract, except that it peeks during a rekey the way
+ * wolfSSH_ChannelIdRead() reads during one. A NULL buf asks only for the
+ * count, still capped at bufSz. */
+WOLFSSH_API int wolfSSH_ChannelIdPeek(WOLFSSH* ssh, word32 channelId,
+        byte* buf, word32 bufSz);
 WOLFSSH_API int wolfSSH_ChannelIdSend(WOLFSSH* ssh, word32 channelId,
         byte* buf, word32 bufSz);
 WOLFSSH_API int wolfSSH_ChannelIdReadExt(WOLFSSH* ssh, word32 channelId,