summaryrefslogtreecommitdiffstats
blob: 2d627b957ad3496329bcd2218b6ba03a3e6d92d1 (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
/*
 * Copyright (C) 2012-2014 The Android Open Source Project
 *
 * 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.
 */

#include <ctype.h>
#include <endian.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include <private/android_logger.h>

#include "LogBuffer.h"
#include "LogBufferElement.h"
#include "LogCommand.h"
#include "LogReader.h"
#include "LogUtils.h"

const log_time LogBufferElement::FLUSH_ERROR((uint32_t)-1, (uint32_t)-1);
atomic_int_fast64_t LogBufferElement::sequence(1);

LogBufferElement::LogBufferElement(log_id_t log_id, log_time realtime,
                                   uid_t uid, pid_t pid, pid_t tid,
                                   const char* msg, unsigned short len)
    : mUid(uid),
      mPid(pid),
      mTid(tid),
      mRealTime(realtime),
      mMsgLen(len),
      mLogId(log_id),
      mDropped(false) {
    mMsg = new char[len];
    memcpy(mMsg, msg, len);
}

LogBufferElement::LogBufferElement(const LogBufferElement& elem)
    : mUid(elem.mUid),
      mPid(elem.mPid),
      mTid(elem.mTid),
      mRealTime(elem.mRealTime),
      mMsgLen(elem.mMsgLen),
      mLogId(elem.mLogId),
      mDropped(elem.mDropped) {
    mMsg = new char[mMsgLen];
    memcpy(mMsg, elem.mMsg, mMsgLen);
}

LogBufferElement::~LogBufferElement() {
    delete[] mMsg;
}

uint32_t LogBufferElement::getTag() const {
    return (isBinary() &&
            ((mDropped && mMsg != nullptr) ||
             (!mDropped && mMsgLen >= sizeof(android_event_header_t))))
               ? reinterpret_cast<const android_event_header_t*>(mMsg)->tag
               : 0;
}

unsigned short LogBufferElement::setDropped(unsigned short value) {
    // The tag information is saved in mMsg data, if the tag is non-zero
    // save only the information needed to get the tag.
    if (getTag() != 0) {
        if (mMsgLen > sizeof(android_event_header_t)) {
            char* truncated_msg = new char[sizeof(android_event_header_t)];
            memcpy(truncated_msg, mMsg, sizeof(android_event_header_t));
            delete[] mMsg;
            mMsg = truncated_msg;
        }  // mMsgLen == sizeof(android_event_header_t), already at minimum.
    } else {
        delete[] mMsg;
        mMsg = nullptr;
    }
    mDropped = true;
    return mDroppedCount = value;
}

// caller must own and free character string
char* android::tidToName(pid_t tid) {
    char* retval = nullptr;
    char buffer[256];
    snprintf(buffer, sizeof(buffer), "/proc/%u/comm", tid);
    int fd = open(buffer, O_RDONLY);
    if (fd >= 0) {
        ssize_t ret = read(fd, buffer, sizeof(buffer));
        if (ret >= (ssize_t)sizeof(buffer)) {
            ret = sizeof(buffer) - 1;
        }
        while ((ret > 0) && isspace(buffer[ret - 1])) {
            --ret;
        }
        if (ret > 0) {
            buffer[ret] = '\0';
            retval = strdup(buffer);
        }
        close(fd);
    }

    // if nothing for comm, check out cmdline
    char* name = android::pidToName(tid);
    if (!retval) {
        retval = name;
        name = nullptr;
    }

    // check if comm is truncated, see if cmdline has full representation
    if (name) {
        // impossible for retval to be NULL if name not NULL
        size_t retval_len = strlen(retval);
        size_t name_len = strlen(name);
        // KISS: ToDo: Only checks prefix truncated, not suffix, or both
        if ((retval_len < name_len) &&
            !fastcmp<strcmp>(retval, name + name_len - retval_len)) {
            free(retval);
            retval = name;
        } else {
            free(name);
        }
    }
    return retval;
}

// assumption: mMsg == NULL
size_t LogBufferElement::populateDroppedMessage(char*& buffer, LogBuffer* parent,
                                                bool lastSame) {
    static const char tag[] = "chatty";

    if (!__android_log_is_loggable_len(ANDROID_LOG_INFO, tag, strlen(tag),
                                       ANDROID_LOG_VERBOSE)) {
        return 0;
    }

    static const char format_uid[] = "uid=%u%s%s %s %u line%s";
    parent->wrlock();
    const char* name = parent->uidToName(mUid);
    parent->unlock();
    const char* commName = android::tidToName(mTid);
    if (!commName && (mTid != mPid)) {
        commName = android::tidToName(mPid);
    }
    if (!commName) {
        parent->wrlock();
        commName = parent->pidToName(mPid);
        parent->unlock();
    }
    if (name && name[0] && commName && (name[0] == commName[0])) {
        size_t len = strlen(name + 1);
        if (!strncmp(name + 1, commName + 1, len)) {
            if (commName[len + 1] == '\0') {
                free(const_cast<char*>(commName));
                commName = nullptr;
            } else {
                free(const_cast<char*>(name));
                name = nullptr;
            }
        }
    }
    if (name) {
        char* buf = nullptr;
        asprintf(&buf, "(%s)", name);
        if (buf) {
            free(const_cast<char*>(name));
            name = buf;
        }
    }
    if (commName) {
        char* buf = nullptr;
        asprintf(&buf, " %s", commName);
        if (buf) {
            free(const_cast<char*>(commName));
            commName = buf;
        }
    }
    // identical to below to calculate the buffer size required
    const char* type = lastSame ? "identical" : "expire";
    size_t len = snprintf(nullptr, 0, format_uid, mUid, name ? name : "",
                          commName ? commName : "", type, getDropped(),
                          (getDropped() > 1) ? "s" : "");

    size_t hdrLen;
    if (isBinary()) {
        hdrLen = sizeof(android_log_event_string_t);
    } else {
        hdrLen = 1 + sizeof(tag);
    }

    buffer = static_cast<char*>(calloc(1, hdrLen + len + 1));
    if (!buffer) {
        free(const_cast<char*>(name));
        free(const_cast<char*>(commName));
        return 0;
    }

    size_t retval = hdrLen + len;
    if (isBinary()) {
        android_log_event_string_t* event =
            reinterpret_cast<android_log_event_string_t*>(buffer);

        event->header.tag = htole32(CHATTY_LOG_TAG);
        event->type = EVENT_TYPE_STRING;
        event->length = htole32(len);
    } else {
        ++retval;
        buffer[0] = ANDROID_LOG_INFO;
        strcpy(buffer + 1, tag);
    }

    snprintf(buffer + hdrLen, len + 1, format_uid, mUid, name ? name : "",
             commName ? commName : "", type, getDropped(),
             (getDropped() > 1) ? "s" : "");
    free(const_cast<char*>(name));
    free(const_cast<char*>(commName));

    return retval;
}

log_time LogBufferElement::flushTo(SocketClient* reader, LogBuffer* parent,
                                   bool privileged, bool lastSame) {
    struct logger_entry_v4 entry;

    memset(&entry, 0, sizeof(struct logger_entry_v4));

    entry.hdr_size = privileged ? sizeof(struct logger_entry_v4)
                                : sizeof(struct logger_entry_v3);
    entry.lid = mLogId;
    entry.pid = mPid;
    entry.tid = mTid;
    entry.uid = mUid;
    entry.sec = mRealTime.tv_sec;
    entry.nsec = mRealTime.tv_nsec;

    struct iovec iovec[2];
    iovec[0].iov_base = &entry;
    iovec[0].iov_len = entry.hdr_size;

    char* buffer = nullptr;

    if (mDropped) {
        entry.len = populateDroppedMessage(buffer, parent, lastSame);
        if (!entry.len) return mRealTime;
        iovec[1].iov_base = buffer;
    } else {
        entry.len = mMsgLen;
        iovec[1].iov_base = mMsg;
    }
    iovec[1].iov_len = entry.len;

    log_time retval = reader->sendDatav(iovec, 1 + (entry.len != 0))
                          ? FLUSH_ERROR
                          : mRealTime;

    if (buffer) free(buffer);

    return retval;
}