summaryrefslogtreecommitdiffstats
path: root/source/HTTPServer/MultipartParser.cpp
blob: 7df151dc3daa39292eaf57d3fb284999f55befde (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

// MultipartParser.cpp

// Implements the cMultipartParser class that parses messages in "multipart/*" encoding into the separate parts

#include "Globals.h"
#include "MultipartParser.h"
#include "NameValueParser.h"





// Disable MSVC warnings:
#if defined(_MSC_VER)
	#pragma warning(push)
	#pragma warning(disable:4355)  // 'this' : used in base member initializer list
#endif





///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// self-test:

#if 0

class cMultipartParserTest :
	public cMultipartParser::cCallbacks
{
public:
	cMultipartParserTest(void)
	{
		cMultipartParser Parser("multipart/mixed; boundary=\"MyBoundaryString\"; foo=bar", *this);
		const char Data[] =
"ThisIsIgnoredPrologue\r\n\
--MyBoundaryString\r\n\
\r\n\
Body with confusing strings\r\n\
--NotABoundary\r\n\
--MyBoundaryStringWithPostfix\r\n\
--\r\n\
--MyBoundaryString\r\n\
content-disposition: inline\r\n\
\r\n\
This is body\r\n\
--MyBoundaryString\r\n\
\r\n\
Headerless body with trailing CRLF\r\n\
\r\n\
--MyBoundaryString--\r\n\
ThisIsIgnoredEpilogue";
		printf("Multipart parsing test commencing.\n");
		Parser.Parse(Data, sizeof(Data) - 1);
		// DEBUG: Check if the onscreen output corresponds with the data above
		printf("Multipart parsing test finished\n");
	}
	
	virtual void OnPartStart(void) override
	{
		printf("Starting a new part\n");
	}
	
	
	virtual void OnPartHeader(const AString & a_Key, const AString & a_Value) override
	{
		printf("  Hdr: \"%s\"=\"%s\"\n", a_Key.c_str(), a_Value.c_str());
	}
	
	
	virtual void OnPartData(const char * a_Data, int a_Size) override
	{
		printf("  Data: %d bytes, \"%.*s\"\n", a_Size, a_Size, a_Data);
	}
	
	
	virtual void OnPartEnd(void) override
	{
		printf("Part end\n");
	}
} g_Test;

#endif





///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// cMultipartParser:


cMultipartParser::cMultipartParser(const AString & a_ContentType, cCallbacks & a_Callbacks) :
	m_Callbacks(a_Callbacks),
	m_IsValid(true),
	m_EnvelopeParser(*this),
	m_HasHadData(false)
{
	static AString s_Multipart = "multipart/";
	
	// Check that the content type is multipart:
	AString ContentType(a_ContentType);
	if (strncmp(ContentType.c_str(), "multipart/", 10) != 0)
	{
		m_IsValid = false;
		return;
	}
	size_t idxSC = ContentType.find(';', 10);
	if (idxSC == AString::npos)
	{
		m_IsValid = false;
		return;
	}
	
	// Find the multipart boundary:
	ContentType.erase(0, idxSC + 1);
	cNameValueParser CTParser(ContentType.c_str(), ContentType.size());
	if (!CTParser.IsValid())
	{
		m_IsValid = false;
		return;
	}
	m_Boundary = CTParser["boundary"];
	m_IsValid = !m_Boundary.empty();
	if (!m_IsValid)
	{
		return;
	}
	
	// Set the envelope parser for parsing the body, so that our Parse() function parses the ignored prefix data as a body
	m_EnvelopeParser.SetIsInHeaders(false);

	// Append an initial CRLF to the incoming data, so that a body starting with the boundary line will get caught
	m_IncomingData.assign("\r\n");
	
	/*
	m_Boundary = AString("\r\n--") + m_Boundary
	m_BoundaryEnd = m_Boundary + "--\r\n";
	m_Boundary = m_Boundary + "\r\n";
	*/
}





void cMultipartParser::Parse(const char * a_Data, int a_Size)
{
	// Skip parsing if invalid
	if (!m_IsValid)
	{
		return;
	}
	
	// Append to buffer, then parse it:
	m_IncomingData.append(a_Data, a_Size);
	while (true)
	{
		if (m_EnvelopeParser.IsInHeaders())
		{
			int BytesConsumed = m_EnvelopeParser.Parse(m_IncomingData.data(), m_IncomingData.size());
			if (BytesConsumed < 0)
			{
				m_IsValid = false;
				return;
			}
			if ((BytesConsumed == a_Size) && m_EnvelopeParser.IsInHeaders())
			{
				// All the incoming data has been consumed and still waiting for more
				return;
			}
			m_IncomingData.erase(0, BytesConsumed);
		}

		// Search for boundary / boundary end:
		size_t idxBoundary = m_IncomingData.find("\r\n--");
		if (idxBoundary == AString::npos)
		{
			// Boundary string start not present, present as much data to the part callback as possible
			if (m_IncomingData.size() > m_Boundary.size() + 8)
			{
				size_t BytesToReport = m_IncomingData.size() - m_Boundary.size() - 8;
				m_Callbacks.OnPartData(m_IncomingData.data(), BytesToReport);
				m_IncomingData.erase(0, BytesToReport);
			}
			return;
		}
		if (idxBoundary > 0)
		{
			m_Callbacks.OnPartData(m_IncomingData.data(), idxBoundary);
			m_IncomingData.erase(0, idxBoundary);
		}
		idxBoundary = 4;
		size_t LineEnd = m_IncomingData.find("\r\n", idxBoundary);
		if (LineEnd == AString::npos)
		{
			// Not a complete line yet, present as much data to the part callback as possible
			if (m_IncomingData.size() > m_Boundary.size() + 8)
			{
				size_t BytesToReport = m_IncomingData.size() - m_Boundary.size() - 8;
				m_Callbacks.OnPartData(m_IncomingData.data(), BytesToReport);
				m_IncomingData.erase(0, BytesToReport);
			}
			return;
		}
		if (
			(LineEnd - idxBoundary != m_Boundary.size()) &&  // Line length not equal to boundary
			(LineEnd - idxBoundary != m_Boundary.size() + 2)  // Line length not equal to boundary end
		)
		{
			// Got a line, but it's not a boundary, report it as data:
			m_Callbacks.OnPartData(m_IncomingData.data(), LineEnd);
			m_IncomingData.erase(0, LineEnd);
			continue;
		}
		
		if (strncmp(m_IncomingData.c_str() + idxBoundary, m_Boundary.c_str(), m_Boundary.size()) == 0)
		{
			// Boundary or BoundaryEnd found:
			m_Callbacks.OnPartEnd();
			size_t idxSlash = idxBoundary + m_Boundary.size();
			if ((m_IncomingData[idxSlash] == '-') && (m_IncomingData[idxSlash + 1] == '-'))
			{
				// This was the last part
				m_Callbacks.OnPartData(m_IncomingData.data() + idxSlash + 4, m_IncomingData.size() - idxSlash - 4);
				m_IncomingData.clear();
				return;
			}
			m_Callbacks.OnPartStart();
			m_IncomingData.erase(0, LineEnd + 2);
			
			// Keep parsing for the headers that may have come with this data:
			m_EnvelopeParser.Reset();
			continue;
		}
		
		// It's a line, but not a boundary. It can be fully sent to the data receiver, since a boundary cannot cross lines
		m_Callbacks.OnPartData(m_IncomingData.c_str(), LineEnd);
		m_IncomingData.erase(0, LineEnd);
	}  // while (true)
}





void cMultipartParser::OnHeaderLine(const AString & a_Key, const AString & a_Value)
{
	m_Callbacks.OnPartHeader(a_Key, a_Value);
}