input/nfs: new plugin using libnfs

Makefile.am

@@ -914,6 +914,7 @@ libinput_a_SOURCES = \
 libinput_a_CPPFLAGS = $(AM_CPPFLAGS) \
 	$(CURL_CFLAGS) \
 	$(SMBCLIENT_CFLAGS) \
+	$(NFS_CFLAGS) \
 	$(CDIO_PARANOIA_CFLAGS) \
 	$(FFMPEG_CFLAGS) \
 	$(DESPOTIFY_CFLAGS) \
@@ -923,6 +924,7 @@ INPUT_LIBS = \
 	libinput.a \
 	$(CURL_LIBS) \
 	$(SMBCLIENT_LIBS) \
+	$(NFS_LIBS) \
 	$(CDIO_PARANOIA_LIBS) \
 	$(FFMPEG_LIBS) \
 	$(DESPOTIFY_LIBS) \
@@ -948,6 +950,11 @@ libinput_a_SOURCES += \
 	src/input/plugins/SmbclientInputPlugin.cxx src/input/plugins/SmbclientInputPlugin.hxx
 endif
 
+if ENABLE_NFS
+libinput_a_SOURCES += \
+	src/input/plugins/NfsInputPlugin.cxx src/input/plugins/NfsInputPlugin.hxx
+endif
+
 if ENABLE_CDIO_PARANOIA
 libinput_a_SOURCES += \
 	src/input/plugins/CdioParanoiaInputPlugin.cxx \

NEWS

@@ -14,6 +14,7 @@ ver 0.19 (not yet released)
   - read tags from songs in an archive
 * input
   - alsa: new input plugin
+  - nfs: new input plugin
   - smbclient: new input plugin
 * filter
   - volume: improved software volume dithering

configure.ac

@@ -310,6 +310,11 @@ AC_ARG_ENABLE(smbclient,
 		[enable support for libsmbclient (default: auto)]),,
 	[enable_smbclient=auto])
 
+AC_ARG_ENABLE(nfs,
+	AS_HELP_STRING([--enable-nfs],
+		[enable support for libnfs (default: auto)]),,
+	[enable_nfs=auto])
+
 AC_ARG_ENABLE(debug,
 	AS_HELP_STRING([--enable-debug],
 		[enable debugging (default: disabled)]),,
@@ -859,6 +864,14 @@ if test x$enable_smbclient = xyes; then
 fi
 AM_CONDITIONAL(ENABLE_SMBCLIENT, test x$enable_smbclient = xyes)
 
+dnl ----------------------------------- NFS -----------------------------
+MPD_AUTO_PKG(nfs, NFS, [libnfs],
+	[NFS input plugin], [libnfs not found])
+if test x$enable_nfs = xyes; then
+	AC_DEFINE(ENABLE_NFS, 1, [Define when libnfs is used])
+fi
+AM_CONDITIONAL(ENABLE_NFS, test x$enable_nfs = xyes)
+
 dnl --------------------------------- Despotify ---------------------------------
 MPD_AUTO_PKG(despotify, DESPOTIFY, [despotify],
 	[Despotify support], [despotify not found])

doc/user.xml

@@ -1152,6 +1152,35 @@ systemctl start mpd.socket</programlisting>
         </para>
       </section>
 
+      <section>
+        <title><varname>nfs</varname></title>
+
+        <para>
+          Allows MPD to access files on NFSv3 servers without actually
+          mounting them (i.e. in userspace, without help from the
+          kernel's VFS layer).  All URIs with the
+          <filename>nfs://</filename> scheme are used according to
+          <ulink
+          url="http://tools.ietf.org/html/rfc2224">RFC2224</ulink>.
+          Example:
+        </para>
+
+        <para>
+          <filename>mpc add nfs://servername/path/filename.ogg</filename>
+        </para>
+
+        <para>
+          Note that this usually requires enabling the "insecure" flag
+          in the server's <filename>/etc/exports</filename> file,
+          because MPD cannot bind to so-called "privileged" ports.
+          Don't fear: this will not make your file server insecure;
+          the flag was named in a time long ago when privileged ports
+          were thought to be meaningful for security.  By today's
+          standards, NFSv3 is not secure at all, and if you believe it
+          is, you're already doomed.
+        </para>
+      </section>
+
       <section>
         <title><varname>smbclient</varname></title>
 

src/input/Registry.cxx

@@ -42,6 +42,10 @@
 #include "plugins/SmbclientInputPlugin.hxx"
 #endif
 
+#ifdef ENABLE_NFS
+#include "plugins/NfsInputPlugin.hxx"
+#endif
+
 #ifdef ENABLE_MMS
 #include "plugins/MmsInputPlugin.hxx"
 #endif
@@ -71,6 +75,9 @@ const InputPlugin *const input_plugins[] = {
 #ifdef ENABLE_SMBCLIENT
 	&input_plugin_smbclient,
 #endif
+#ifdef ENABLE_NFS
+	&input_plugin_nfs,
+#endif
 #ifdef ENABLE_MMS
 	&input_plugin_mms,
 #endif

src/input/plugins/NfsInputPlugin.cxx

@@ -0,0 +1,202 @@
+/*
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program 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.
+ *
+ * This program 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 this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "NfsInputPlugin.hxx"
+#include "../InputStream.hxx"
+#include "../InputPlugin.hxx"
+#include "util/StringUtil.hxx"
+#include "util/Error.hxx"
+#include "util/Domain.hxx"
+
+extern "C" {
+#include <nfsc/libnfs.h>
+}
+
+#include <sys/stat.h>
+#include <fcntl.h>
+
+static constexpr Domain nfs_domain("nfs");
+
+class NfsInputStream {
+	InputStream base;
+
+	nfs_context *ctx;
+	nfsfh *fh;
+
+public:
+	NfsInputStream(const char *uri,
+		       Mutex &mutex, Cond &cond,
+		       nfs_context *_ctx, nfsfh *_fh,
+		       InputStream::offset_type size)
+		:base(input_plugin_nfs, uri, mutex, cond),
+		 ctx(_ctx), fh(_fh) {
+		base.ready = true;
+		base.seekable = true;
+		base.size = size;
+	}
+
+	~NfsInputStream() {
+		nfs_close(ctx, fh);
+		nfs_destroy_context(ctx);
+	}
+
+	InputStream *GetBase() {
+		return &base;
+	}
+
+	bool IsEOF() const {
+		return base.offset >= base.size;
+	}
+
+	size_t Read(void *ptr, size_t size, Error &error) {
+		int nbytes = nfs_read(ctx, fh, size, (char *)ptr);
+		if (nbytes < 0) {
+			error.SetErrno(-nbytes, "nfs_read() failed");
+			nbytes = 0;
+		}
+
+		return nbytes;
+	}
+
+	bool Seek(InputStream::offset_type offset, int whence, Error &error) {
+		uint64_t current_offset;
+		int result = nfs_lseek(ctx, fh, offset, whence, &current_offset);
+		if (result < 0) {
+			error.SetErrno(-result, "smbc_lseek() failed");
+			return false;
+		}
+
+		base.offset = current_offset;
+		return true;
+	}
+};
+
+/*
+ * InputPlugin methods
+ *
+ */
+
+static InputStream *
+input_nfs_open(const char *uri,
+	       Mutex &mutex, Cond &cond,
+	       Error &error)
+{
+	if (!StringStartsWith(uri, "nfs://"))
+		return nullptr;
+
+	uri += 6;
+
+	const char *slash = strchr(uri, '/');
+	if (slash == nullptr) {
+		error.Set(nfs_domain, "Malformed nfs:// URI");
+		return nullptr;
+	}
+
+	const std::string server(uri, slash);
+
+	uri = slash;
+	slash = strrchr(uri + 1, '/');
+	if (slash == nullptr || slash[1] == 0) {
+		error.Set(nfs_domain, "Malformed nfs:// URI");
+		return nullptr;
+	}
+
+	const std::string mount(uri, slash);
+	uri = slash;
+
+	nfs_context *ctx = nfs_init_context();
+	if (ctx == nullptr) {
+		error.Set(nfs_domain, "nfs_init_context() failed");
+		return nullptr;
+	}
+
+	int result = nfs_mount(ctx, server.c_str(), mount.c_str());
+	if (result < 0) {
+		nfs_destroy_context(ctx);
+		error.SetErrno(-result, "nfs_mount() failed");
+		return nullptr;
+	}
+
+	nfsfh *fh;
+	result = nfs_open(ctx, uri, O_RDONLY, &fh);
+	if (result < 0) {
+		nfs_destroy_context(ctx);
+		error.SetErrno(-result, "nfs_open() failed");
+		return nullptr;
+	}
+
+	struct stat st;
+	result = nfs_fstat(ctx, fh, &st);
+	if (result < 0) {
+		nfs_close(ctx, fh);
+		nfs_destroy_context(ctx);
+		error.SetErrno(-result, "nfs_fstat() failed");
+		return nullptr;
+	}
+
+	auto is = new NfsInputStream(uri, mutex, cond, ctx, fh, st.st_size);
+	return is->GetBase();
+}
+
+static size_t
+input_nfs_read(InputStream *is, void *ptr, size_t size,
+		     Error &error)
+{
+	NfsInputStream &s = *(NfsInputStream *)is;
+	return s.Read(ptr, size, error);
+}
+
+static void
+input_nfs_close(InputStream *is)
+{
+	NfsInputStream *s = (NfsInputStream *)is;
+	delete s;
+}
+
+static bool
+input_nfs_eof(InputStream *is)
+{
+	NfsInputStream &s = *(NfsInputStream *)is;
+	return s.IsEOF();
+}
+
+static bool
+input_nfs_seek(InputStream *is,
+		     InputPlugin::offset_type offset, int whence,
+		     Error &error)
+{
+	NfsInputStream &s = *(NfsInputStream *)is;
+	return s.Seek(offset, whence, error);
+}
+
+const InputPlugin input_plugin_nfs = {
+	"nfs",
+	nullptr,
+	nullptr,
+	input_nfs_open,
+	input_nfs_close,
+	nullptr,
+	nullptr,
+	nullptr,
+	nullptr,
+	input_nfs_read,
+	input_nfs_eof,
+	input_nfs_seek,
+};

src/input/plugins/NfsInputPlugin.hxx

@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program 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.
+ *
+ * This program 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 this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_INPUT_NFS_H
+#define MPD_INPUT_NFS_H
+
+extern const struct InputPlugin input_plugin_nfs;
+
+#endif

src/ls.cxx

@@ -52,6 +52,9 @@ static const char *remoteUrlPrefixes[] = {
 #ifdef ENABLE_SMBCLIENT
 	"smb://",
 #endif
+#ifdef ENABLE_NFS
+	"nfs://",
+#endif
 #ifdef ENABLE_CDIO_PARANOIA
 	"cdda://",
 #endif