aboutsummaryrefslogtreecommitdiff
path: root/daemon/FSDriver.cpp
blob: dd8eb804dc99863f67aa42825c0f34b7ff317aca (plain)
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
/**
 * Copyright (C) ARM Limited 2014. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include "FSDriver.h"

#include <fcntl.h>
#include <regex.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

#include "DriverSource.h"
#include "Logging.h"

class FSCounter : public DriverCounter {
public:
	FSCounter(DriverCounter *next, char *name, char *path, const char *regex);
	~FSCounter();

	const char *getPath() const { return mPath; }

	int64_t read();

private:
	char *const mPath;
	regex_t mReg;
	bool mUseRegex;

	// Intentionally unimplemented
	FSCounter(const FSCounter &);
	FSCounter &operator=(const FSCounter &);
};

FSCounter::FSCounter(DriverCounter *next, char *name, char *path, const char *regex) : DriverCounter(next, name), mPath(path), mUseRegex(regex != NULL) {
	if (mUseRegex) {
		int result = regcomp(&mReg, regex, REG_EXTENDED);
		if (result != 0) {
			char buf[128];
			regerror(result, &mReg, buf, sizeof(buf));
			logg->logError(__FILE__, __LINE__, "Invalid regex '%s': %s", regex, buf);
			handleException();
		}
	}
}

FSCounter::~FSCounter() {
	free(mPath);
	if (mUseRegex) {
		regfree(&mReg);
	}
}

int64_t FSCounter::read() {
	int64_t value;
	if (mUseRegex) {
		char buf[4096];
		size_t pos = 0;
		const int fd = open(mPath, O_RDONLY | O_CLOEXEC);
		if (fd < 0) {
			goto fail;
		}
		while (pos < sizeof(buf) - 1) {
			const ssize_t bytes = ::read(fd, buf + pos, sizeof(buf) - pos - 1);
			if (bytes < 0) {
				goto fail;
			} else if (bytes == 0) {
				break;
			}
			pos += bytes;
		}
		close(fd);
		buf[pos] = '\0';

		regmatch_t match[2];
		int result = regexec(&mReg, buf, 2, match, 0);
		if (result != 0) {
			regerror(result, &mReg, buf, sizeof(buf));
			logg->logError(__FILE__, __LINE__, "Parsing %s failed: %s", mPath, buf);
			handleException();
		}

		if (match[1].rm_so < 0) {
			logg->logError(__FILE__, __LINE__, "Parsing %s failed", mPath);
			handleException();
		}

		errno = 0;
		value = strtoll(buf + match[1].rm_so, NULL, 0);
		if (errno != 0) {
			logg->logError(__FILE__, __LINE__, "Parsing %s failed: %s", mPath, strerror(errno));
			handleException();
		}
	} else {
		if (DriverSource::readInt64Driver(mPath, &value) != 0) {
			goto fail;
		}
	}
	return value;

 fail:
	logg->logError(__FILE__, __LINE__, "Unable to read %s", mPath);
	handleException();
}

FSDriver::FSDriver() {
}

FSDriver::~FSDriver() {
}

void FSDriver::readEvents(mxml_node_t *const xml) {
	mxml_node_t *node = xml;
	while (true) {
		node = mxmlFindElement(node, xml, "event", NULL, NULL, MXML_DESCEND);
		if (node == NULL) {
			break;
		}
		const char *counter = mxmlElementGetAttr(node, "counter");
		if (counter == NULL) {
			continue;
		}

		if (counter[0] == '/') {
			logg->logError(__FILE__, __LINE__, "Old style filesystem counter (%s) detected, please create a new unique counter value and move the filename into the path attribute, see events-Filesystem.xml for examples", counter);
			handleException();
		}

		if (strncmp(counter, "filesystem_", 11) != 0) {
			continue;
		}

		const char *path = mxmlElementGetAttr(node, "path");
		if (path == NULL) {
			logg->logError(__FILE__, __LINE__, "The filesystem counter %s is missing the required path attribute", counter);
			handleException();
		}
		const char *regex = mxmlElementGetAttr(node, "regex");
		setCounters(new FSCounter(getCounters(), strdup(counter), strdup(path), regex));
	}
}

int FSDriver::writeCounters(mxml_node_t *root) const {
	int count = 0;
	for (FSCounter *counter = static_cast<FSCounter *>(getCounters()); counter != NULL; counter = static_cast<FSCounter *>(counter->getNext())) {
		if (access(counter->getPath(), R_OK) == 0) {
			mxml_node_t *node = mxmlNewElement(root, "counter");
			mxmlElementSetAttr(node, "name", counter->getName());
			++count;
		}
	}

	return count;
}