summaryrefslogtreecommitdiff
path: root/src/net/messagein.cpp
blob: ce1be48894a8a97c6478d8c16959840dad1e2cc0 (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
/*
 *  The Mana Server
 *  Copyright (C) 2004-2010  The Mana World Development Team
 *  Copyright (C) 2010-2012  The Mana Developers
 *
 *  This file is part of The Mana Server.
 *
 *  The Mana Server 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
 *  any later version.
 *
 *  The Mana Server 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 The Mana Server.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <cstring>
#include <iomanip>
#include <iostream>
#include <string>
#include <enet/enet.h>
#ifndef USE_NATIVE_DOUBLE
#include <sstream>
#endif
#include <stdint.h>

#include "net/messagein.h"
#include "utils/logger.h"

// Not enabled by default since this will cause assertions on message errors,
// which may also originate from the client.
//#define DEBUG_NETWORK

#ifdef DEBUG_NETWORK
#include <cassert>
#define ASSERT_IF(x) assert(x); if (x)
#else
#define ASSERT_IF(x) if (x)
#endif

MessageIn::MessageIn(const char *data, unsigned short length):
    mData(data),
    mLength(length),
    mDebugMode(false),
    mPos(0)
{
    // Read the message ID
    mId = readInt16();

    // Read and clear the debug flag
    mDebugMode = mId & ManaServ::XXMSG_DEBUG_FLAG;
    mId &= ~ManaServ::XXMSG_DEBUG_FLAG;
}

int MessageIn::readInt8()
{
    int value = -1;

    if (!readValueType(ManaServ::Int8))
        return value;

    ASSERT_IF (mPos < mLength)
    {
        value = (unsigned char) mData[mPos];
    }
    else
    {
        LOG_DEBUG("Unable to read 1 byte in " << mId << "!");
    }

    mPos += 1;
    return value;
}

int MessageIn::readInt16()
{
    int value = -1;

    if (!readValueType(ManaServ::Int16))
        return value;

    ASSERT_IF (mPos + 2 <= mLength)
    {
        uint16_t t;
        memcpy(&t, mData + mPos, 2);
        value = (short) ENET_NET_TO_HOST_16(t);
    }
    else
    {
        LOG_DEBUG("Unable to read 2 bytes in " << mId << "!");
    }

    mPos += 2;
    return value;
}

int MessageIn::readInt32()
{
    int value = -1;

    if (!readValueType(ManaServ::Int32))
        return value;

    ASSERT_IF (mPos + 4 <= mLength)
    {
        uint32_t t;
        memcpy(&t, mData + mPos, 4);
        value = ENET_NET_TO_HOST_32(t);
    }
    else
    {
        LOG_DEBUG("Unable to read 4 bytes in " << mId << "!");
    }

    mPos += 4;
    return value;
}

double MessageIn::readDouble()
{
    double value = -1;

    if (!readValueType(ManaServ::Double))
        return value;

#ifdef USE_NATIVE_DOUBLE
    if (mPos + sizeof(double) <= mLength)
        memcpy(&value, mData + mPos, sizeof(double));
    mPos += sizeof(double);
#else
    int length = readInt8();
    std::istringstream i (readString(length));
    i >> value;
#endif
    return value;
}

std::string MessageIn::readString(int length)
{
    if (!readValueType(ManaServ::String))
        return std::string();

    if (mDebugMode)
    {
        int fixedLength = readInt16();
#ifdef DEBUG_NETWORK
        assert(fixedLength == length);
#endif
        if (fixedLength != length)
        {
            LOG_DEBUG("Expected string of length " << length <<
                      " but received length " << fixedLength);
            mPos = mLength + 1;
            return std::string();
        }
    }

    // Get string length
    if (length < 0)
    {
        length = readInt16();
    }

    // Make sure the string isn't erroneous
    if (length < 0 || mPos + length > mLength)
    {
        mPos = mLength + 1;
        return std::string();
    }

    // Read the string
    const char *stringBeg = mData + mPos;
    const char *stringEnd = (const char *)memchr(stringBeg, '\0', length);
    std::string readString(stringBeg,
                           stringEnd ? stringEnd - stringBeg : length);
    mPos += length;

    return readString;
}

bool MessageIn::readValueType(ManaServ::ValueType type)
{
    if (!mDebugMode) // Verification not possible
        return true;

    ASSERT_IF (mPos < mLength)
    {
        int t = (unsigned char) mData[mPos];
        ++mPos;

        ASSERT_IF (t == type)
        {
            return true;
        }
        else
        {
            LOG_DEBUG("Attempt to read " << type << " but got " << t);
        }
    }
    else
    {
        LOG_DEBUG("Attempt to read " << type << " but no more data available");
    }

    return false;
}

std::ostream&
operator <<(std::ostream &os, const MessageIn &msg)
{
    os << std::setw(6) << std::hex << std::showbase << std::internal
       << std::setfill('0') << msg.getId() << std::dec;

    if (!msg.mDebugMode)
    {
        os << " (" << msg.getLength() << " B)";
    }
    else
    {
        os << " { ";

        MessageIn m(msg.mData, msg.mLength);

        while (m.getUnreadLength() > 0)
        {
            if (m.mPos > 3)
                os << ", ";

            unsigned char valueType = m.mData[m.mPos];
            switch (valueType)
            {
            case ManaServ::Int8:
                os << "B " << m.readInt8();
                break;
            case ManaServ::Int16:
                os << "W " << m.readInt16();
                break;
            case ManaServ::Int32:
                os << "D " << m.readInt32();
                break;
            case ManaServ::String: {
                // Peak ahead at a possible fixed length
                unsigned short pos = m.mPos;
                m.mPos++;
                int length = m.readInt16();
                m.mPos = pos;

                if (length < 0)
                    os << "S " << m.readString();
                else
                    os << "S[" << length << "] " << m.readString(length);
                break;
            }
            case ManaServ::Double:
                os << "d " << m.readDouble();
                break;
            default:
                os << "??? }";
                return os; // Stop after error
            }
        }

        os << " }";
    }

    return os;
}