lib/nfs/Connection: use new class NfsClientError

Allows callers to extract the NFS error code.

Makefile.am

@@ -713,6 +713,7 @@ NFS_SOURCES = \
 	src/lib/nfs/Cancellable.hxx \
 	src/lib/nfs/Lease.hxx \
 	src/lib/nfs/Connection.cxx src/lib/nfs/Connection.hxx \
+	src/lib/nfs/Error.cxx src/lib/nfs/Error.hxx \
 	src/lib/nfs/Manager.cxx src/lib/nfs/Manager.hxx \
 	src/lib/nfs/Glue.cxx src/lib/nfs/Glue.hxx \
 	src/lib/nfs/Base.cxx src/lib/nfs/Base.hxx \

src/input/Error.cxx

@@ -21,6 +21,11 @@
 #include "Error.hxx"
 #include "system/Error.hxx"
 
+#ifdef ENABLE_NFS
+#include "lib/nfs/Error.hxx"
+#include <nfsc/libnfs-raw-nfs.h>
+#endif
+
 bool
 IsFileNotFound(std::exception_ptr ep)
 {
@@ -28,6 +33,10 @@ IsFileNotFound(std::exception_ptr ep)
 		std::rethrow_exception(ep);
 	} catch (const std::system_error &e) {
 		return IsFileNotFound(e);
+#ifdef ENABLE_NFS
+	} catch (const NfsClientError &e) {
+		return e.GetCode() == NFS3ERR_NOENT;
+#endif
 	} catch (...) {
 	}
 

src/lib/nfs/Connection.cxx

@@ -19,6 +19,7 @@
 
 #include "config.h"
 #include "Connection.hxx"
+#include "Error.hxx"
 #include "Lease.hxx"
 #include "Callback.hxx"
 #include "event/Loop.hxx"
@@ -139,7 +140,7 @@ NfsConnection::CancellableCallback::Callback(int err, void *data)
 		if (err >= 0)
 			cb.OnNfsCallback((unsigned)err, data);
 		else
-			cb.OnNfsError(std::make_exception_ptr(std::runtime_error((const char *)data)));
+			cb.OnNfsError(std::make_exception_ptr(NfsClientError(-err, (const char *)data)));
 	} else {
 		if (open) {
 			/* a nfs_open_async() call was cancelled - to

src/lib/nfs/Error.cxx

@@ -0,0 +1,76 @@
+/*
+ * Copyright 2007-2017 Content Management AG
+ * All rights reserved.
+ *
+ * author: Max Kellermann <mk@cm4all.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "Error.hxx"
+#include "util/StringFormat.hxx"
+
+extern "C" {
+#include <nfsc/libnfs.h>
+}
+
+#include <assert.h>
+#include <string.h>
+
+static StringBuffer<256>
+FormatNfsClientError(struct nfs_context *nfs, const char *msg) noexcept
+{
+	assert(msg != nullptr);
+
+	const char *msg2 = nfs_get_error(nfs);
+	return StringFormat<256>("%s: %s", msg, msg2);
+}
+
+NfsClientError::NfsClientError(struct nfs_context *nfs, const char *msg) noexcept
+	:std::runtime_error(FormatNfsClientError(nfs, msg).c_str()),
+	 code(0) {}
+
+static StringBuffer<256>
+FormatNfsClientError(int err, struct nfs_context *nfs, void *data,
+		     const char *msg) noexcept
+{
+	assert(msg != nullptr);
+	assert(err < 0);
+
+	const char *msg2 = (const char *)data;
+	if (data == nullptr || *(const char *)data == 0) {
+		msg2 = nfs_get_error(nfs);
+		if (msg2 == nullptr)
+			msg2 = strerror(-err);
+	}
+
+	return StringFormat<256>("%s: %s", msg, msg2);
+}
+
+NfsClientError::NfsClientError(int err, struct nfs_context *nfs, void *data,
+			       const char *msg) noexcept
+	:std::runtime_error(FormatNfsClientError(err, nfs, data, msg).c_str()),
+	 code(-err) {}

src/lib/nfs/Error.hxx

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2007-2017 Content Management AG
+ * All rights reserved.
+ *
+ * author: Max Kellermann <mk@cm4all.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef NFS_ERROR_HXX
+#define NFS_ERROR_HXX
+
+#include <stdexcept>
+
+class NfsClientError : public std::runtime_error {
+	int code;
+
+public:
+	explicit NfsClientError(const char *_msg) noexcept
+		:std::runtime_error(_msg), code(0) {}
+
+	NfsClientError(int _code, const char *_msg) noexcept
+		:std::runtime_error(_msg), code(_code) {}
+
+	NfsClientError(struct nfs_context *nfs, const char *msg) noexcept;
+
+	NfsClientError(int err, struct nfs_context *nfs, void *data,
+		       const char *msg) noexcept;
+
+	int GetCode() const noexcept {
+		return code;
+	}
+};
+
+#endif