File: json_query.cpp

package info (click to toggle)
falcosecurity-libs 0.1.1dev%2Bgit20220316.e5c53d64-5.1
  • links: PTS, VCS
  • area: main
  • in suites: bookworm
  • size: 4,732 kB
  • sloc: cpp: 55,770; ansic: 37,330; makefile: 74; sh: 13
file content (133 lines) | stat: -rw-r--r-- 2,628 bytes parent folder | download
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
/*
Copyright (C) 2021 The Falco Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

*/
//
// json_parser.h
//
// jq wrapper
//

#ifdef __linux__

#include "json_query.h"
#include "sinsp.h"

json_query::json_query(const std::string& json, const std::string& filter, bool dbg) :
	m_jq(jq_init()), m_input{0}, m_result{0}, m_processed(false)
{
	if(!m_jq) { cleanup(); }
	process(json, filter, dbg);
}

json_query::~json_query()
{
	cleanup();
}

bool json_query::process(const std::string& json, const std::string& filter, bool dbg)
{
	cleanup(m_input);
	cleanup(m_result);
	clear();

	if(!m_jq) { cleanup(); }
	if(!jq_compile(m_jq, filter.c_str()))
	{
		m_error = "Filter parsing failed.";
		return false;
	}

	m_input = jv_parse/*_sized*/(json.c_str()/*, json.length()*/);
	if (!jv_is_valid(m_input))
	{
		cleanup(m_input, "JSON parse error.");
		return false;
	}

	jq_start(m_jq, m_input, dbg ? JQ_DEBUG_TRACE : 0);
	m_input = jv_null(); // jq_start() freed it
	m_result = jq_next(m_jq);
	if (!jv_is_valid(m_result))
	{
		cleanup(m_result, "json_query filtering result invalid.");
		return false;
	}
	m_json = json;
	m_filter = filter;
	return m_processed = true;
}

const std::string& json_query::result(int flags)
{
	if(m_processed)
	{
		static const std::string ret;
		if(!m_error.empty()) { return ret; }
		char* buf;
		size_t len;
		FILE* f = open_memstream(&buf, &len);
		if(f == NULL)
		{
			m_error = "Can't open memory stream for writing.";
			return ret;
		}
		jv_dumpf(m_result, f, flags);
		m_result = jv_null();
		clear();
		fclose (f);
		m_filtered_json.assign(buf, len);
		free (buf);
		m_processed = false;
	}
	return m_filtered_json;
}

void json_query::clear()
{
	m_result = jv_null();
	m_input = jv_null();
	m_filtered_json.clear();
	m_error.clear();
	m_processed = false;
}

void json_query::cleanup()
{
	if(m_jq)
	{
		cleanup(m_input);
		cleanup(m_result);
		clear();
		jq_teardown(&m_jq);
		m_jq = 0;
	}
	else
	{
		throw std::runtime_error("json_query handle is null.");
	}
}

void json_query::cleanup(jv& j, const std::string& msg)
{
	if(j.u.ptr)
	{
		jv_free(j);
		j = jv_null();
	}
	m_error = msg;
}

#endif // __linux__