aboutsummaryrefslogtreecommitdiffstats
path: root/src/neighbor/plugins/SmbclientNeighborPlugin.cxx
blob: ea3a6c2fde9e4b5f2d2db2e2bea34c39528f531e (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
/*
 * 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 "SmbclientNeighborPlugin.hxx"
#include "lib/smbclient/Init.hxx"
#include "neighbor/NeighborPlugin.hxx"
#include "neighbor/Explorer.hxx"
#include "neighbor/Listener.hxx"
#include "neighbor/Info.hxx"
#include "thread/Mutex.hxx"
#include "thread/Cond.hxx"
#include "thread/Thread.hxx"
#include "thread/Name.hxx"
#include "util/Macros.hxx"
#include "util/Domain.hxx"
#include "util/Error.hxx"
#include "Log.hxx"

#include <libsmbclient.h>

#include <list>
#include <algorithm>

static constexpr Domain smbclient_domain("smbclient");

class SmbclientNeighborExplorer final : public NeighborExplorer {
	struct Server {
		std::string name, comment;

		bool alive;

		Server(std::string &&_name, std::string &&_comment)
			:name(std::move(_name)), comment(std::move(_comment)),
			 alive(true) {}
		Server(const Server &) = delete;

		gcc_pure
		bool operator==(const Server &other) const {
			return name == other.name;
		}

		gcc_pure
		NeighborInfo Export() const {
			return { "smb://" + name + "/", comment };
		}
	};

	Thread thread;

	mutable Mutex mutex;
	Cond cond;

	List list;

	bool quit;

public:
	SmbclientNeighborExplorer(NeighborListener &_listener)
		:NeighborExplorer(_listener) {}

	/* virtual methods from class NeighborExplorer */
	virtual bool Open(Error &error) override;
	virtual void Close() override;
	virtual List GetList() const override;

private:
	void Run();
	void ThreadFunc();
	static void ThreadFunc(void *ctx);
};

bool
SmbclientNeighborExplorer::Open(Error &error)
{
	quit = false;
	return thread.Start(ThreadFunc, this, error);
}

void
SmbclientNeighborExplorer::Close()
{
	mutex.lock();
	quit = true;
	cond.signal();
	mutex.unlock();

	thread.Join();
}

NeighborExplorer::List
SmbclientNeighborExplorer::GetList() const
{
	const ScopeLock protect(mutex);
	/*
	List list;
	for (const auto &i : servers)
		list.emplace_front(i.Export());
	*/
	return list;
}

static void
ReadServer(NeighborExplorer::List &list, const smbc_dirent &e)
{
	const std::string name(e.name, e.namelen);
	const std::string comment(e.comment, e.commentlen);

	list.emplace_front("smb://" + name, name + " (" + comment + ")");
}

static void
ReadServers(NeighborExplorer::List &list, const char *uri);

static void
ReadWorkgroup(NeighborExplorer::List &list, const std::string &name)
{
	std::string uri = "smb://" + name;
	ReadServers(list, uri.c_str());
}

static void
ReadEntry(NeighborExplorer::List &list, const smbc_dirent &e)
{
	switch (e.smbc_type) {
	case SMBC_WORKGROUP:
		ReadWorkgroup(list, std::string(e.name, e.namelen));
		break;

	case SMBC_SERVER:
		ReadServer(list, e);
		break;
	}
}

static void
ReadServers(NeighborExplorer::List &list, int fd)
{
	smbc_dirent *e;
	while ((e = smbc_readdir(fd)) != nullptr)
		ReadEntry(list, *e);

	smbc_closedir(fd);
}

static void
ReadServers(NeighborExplorer::List &list, const char *uri)
{
	int fd = smbc_opendir(uri);
	if (fd >= 0) {
		ReadServers(list, fd);
		smbc_closedir(fd);
	} else
		FormatErrno(smbclient_domain, "smbc_opendir('%s') failed",
			    uri);
}

gcc_pure
static NeighborExplorer::List
DetectServers()
{
	NeighborExplorer::List list;
	ReadServers(list, "smb://");
	return list;
}

gcc_pure
static NeighborExplorer::List::const_iterator
FindBeforeServerByURI(NeighborExplorer::List::const_iterator prev,
		      NeighborExplorer::List::const_iterator end,
		      const std::string &uri)
{
	for (auto i = std::next(prev); i != end; prev = i, i = std::next(prev))
		if (i->uri == uri)
			return prev;

	return end;
}

inline void
SmbclientNeighborExplorer::Run()
{
	List found = DetectServers(), lost;

	mutex.lock();

	const auto found_before_begin = found.before_begin();
	const auto found_end = found.end();

	for (auto prev = list.before_begin(), i = std::next(prev), end = list.end();
	     i != end; i = std::next(prev)) {
		auto f = FindBeforeServerByURI(found_before_begin, found_end,
					       i->uri);
		if (f != found_end) {
			/* still visible: remove from "found" so we
			   don't believe it's a new one */
			*i = std::move(*std::next(f));
			found.erase_after(f);
			prev = i;
		} else {
			/* can't see it anymore: move to "lost" */
#if defined(__clang__) || GCC_CHECK_VERSION(4,7)
			lost.splice_after(lost.before_begin(), list, prev);
#else
			/* the forward_list::splice_after() lvalue
			   reference overload is missing in gcc 4.6 */
			lost.emplace_front(std::move(*i));
			list.erase_after(prev);
#endif
		}
	}

	for (auto prev = found_before_begin, i = std::next(prev);
	     i != found_end; prev = i, i = std::next(prev))
		list.push_front(*i);

	mutex.unlock();

	for (auto &i : lost)
		listener.LostNeighbor(i);

	for (auto &i : found)
		listener.FoundNeighbor(i);
}

inline void
SmbclientNeighborExplorer::ThreadFunc()
{
	mutex.lock();

	while (!quit) {
		mutex.unlock();

		Run();

		mutex.lock();
		if (quit)
			break;

		// TODO: sleep for how long?
		cond.timed_wait(mutex, 10000);
	}

	mutex.unlock();
}

void
SmbclientNeighborExplorer::ThreadFunc(void *ctx)
{
	SetThreadName("smbclient");

	SmbclientNeighborExplorer &e = *(SmbclientNeighborExplorer *)ctx;
	e.ThreadFunc();
}

static NeighborExplorer *
smbclient_neighbor_create(gcc_unused EventLoop &loop,
			  NeighborListener &listener,
			  gcc_unused const config_param &param,
			  gcc_unused Error &error)
{
	if (!SmbclientInit(error))
		return nullptr;

	return new SmbclientNeighborExplorer(listener);
}

const NeighborPlugin smbclient_neighbor_plugin = {
	"smbclient",
	smbclient_neighbor_create,
};