1 /*
2 * Copyright (C) 2012-2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <ctype.h>
18 #include <endian.h>
19 #include <fcntl.h>
20 #include <stdio.h>
21 #include <string.h>
22 #include <time.h>
23 #include <unistd.h>
24
25 #include <private/android_logger.h>
26
27 #include "LogBuffer.h"
28 #include "LogBufferElement.h"
29 #include "LogCommand.h"
30 #include "LogReader.h"
31 #include "LogUtils.h"
32
33 const log_time LogBufferElement::FLUSH_ERROR((uint32_t)-1, (uint32_t)-1);
34 atomic_int_fast64_t LogBufferElement::sequence(1);
35
LogBufferElement(log_id_t log_id,log_time realtime,uid_t uid,pid_t pid,pid_t tid,const char * msg,unsigned short len)36 LogBufferElement::LogBufferElement(log_id_t log_id, log_time realtime,
37 uid_t uid, pid_t pid, pid_t tid,
38 const char* msg, unsigned short len)
39 : mUid(uid),
40 mPid(pid),
41 mTid(tid),
42 mRealTime(realtime),
43 mMsgLen(len),
44 mLogId(log_id) {
45 mMsg = new char[len];
46 memcpy(mMsg, msg, len);
47 mTag = (isBinary() && (mMsgLen >= sizeof(uint32_t)))
48 ? le32toh(reinterpret_cast<android_event_header_t*>(mMsg)->tag)
49 : 0;
50 }
51
LogBufferElement(const LogBufferElement & elem)52 LogBufferElement::LogBufferElement(const LogBufferElement& elem)
53 : mTag(elem.mTag),
54 mUid(elem.mUid),
55 mPid(elem.mPid),
56 mTid(elem.mTid),
57 mRealTime(elem.mRealTime),
58 mMsgLen(elem.mMsgLen),
59 mLogId(elem.mLogId) {
60 mMsg = new char[mMsgLen];
61 memcpy(mMsg, elem.mMsg, mMsgLen);
62 }
63
~LogBufferElement()64 LogBufferElement::~LogBufferElement() {
65 delete[] mMsg;
66 }
67
68 // caller must own and free character string
tidToName(pid_t tid)69 char* android::tidToName(pid_t tid) {
70 char* retval = NULL;
71 char buffer[256];
72 snprintf(buffer, sizeof(buffer), "/proc/%u/comm", tid);
73 int fd = open(buffer, O_RDONLY);
74 if (fd >= 0) {
75 ssize_t ret = read(fd, buffer, sizeof(buffer));
76 if (ret >= (ssize_t)sizeof(buffer)) {
77 ret = sizeof(buffer) - 1;
78 }
79 while ((ret > 0) && isspace(buffer[ret - 1])) {
80 --ret;
81 }
82 if (ret > 0) {
83 buffer[ret] = '\0';
84 retval = strdup(buffer);
85 }
86 close(fd);
87 }
88
89 // if nothing for comm, check out cmdline
90 char* name = android::pidToName(tid);
91 if (!retval) {
92 retval = name;
93 name = NULL;
94 }
95
96 // check if comm is truncated, see if cmdline has full representation
97 if (name) {
98 // impossible for retval to be NULL if name not NULL
99 size_t retval_len = strlen(retval);
100 size_t name_len = strlen(name);
101 // KISS: ToDo: Only checks prefix truncated, not suffix, or both
102 if ((retval_len < name_len) &&
103 !fastcmp<strcmp>(retval, name + name_len - retval_len)) {
104 free(retval);
105 retval = name;
106 } else {
107 free(name);
108 }
109 }
110 return retval;
111 }
112
113 // assumption: mMsg == NULL
populateDroppedMessage(char * & buffer,LogBuffer * parent,bool lastSame)114 size_t LogBufferElement::populateDroppedMessage(char*& buffer, LogBuffer* parent,
115 bool lastSame) {
116 static const char tag[] = "chatty";
117
118 if (!__android_log_is_loggable_len(ANDROID_LOG_INFO, tag, strlen(tag),
119 ANDROID_LOG_VERBOSE)) {
120 return 0;
121 }
122
123 static const char format_uid[] = "uid=%u%s%s %s %u line%s";
124 parent->lock();
125 const char* name = parent->uidToName(mUid);
126 parent->unlock();
127 const char* commName = android::tidToName(mTid);
128 if (!commName && (mTid != mPid)) {
129 commName = android::tidToName(mPid);
130 }
131 if (!commName) {
132 parent->lock();
133 commName = parent->pidToName(mPid);
134 parent->unlock();
135 }
136 if (name && name[0] && commName && (name[0] == commName[0])) {
137 size_t len = strlen(name + 1);
138 if (!strncmp(name + 1, commName + 1, len)) {
139 if (commName[len + 1] == '\0') {
140 free(const_cast<char*>(commName));
141 commName = NULL;
142 } else {
143 free(const_cast<char*>(name));
144 name = NULL;
145 }
146 }
147 }
148 if (name) {
149 char* buf = NULL;
150 asprintf(&buf, "(%s)", name);
151 if (buf) {
152 free(const_cast<char*>(name));
153 name = buf;
154 }
155 }
156 if (commName) {
157 char* buf = NULL;
158 asprintf(&buf, " %s", commName);
159 if (buf) {
160 free(const_cast<char*>(commName));
161 commName = buf;
162 }
163 }
164 // identical to below to calculate the buffer size required
165 const char* type = lastSame ? "identical" : "expire";
166 size_t len = snprintf(NULL, 0, format_uid, mUid, name ? name : "",
167 commName ? commName : "", type, mDropped,
168 (mDropped > 1) ? "s" : "");
169
170 size_t hdrLen;
171 if (isBinary()) {
172 hdrLen = sizeof(android_log_event_string_t);
173 } else {
174 hdrLen = 1 + sizeof(tag);
175 }
176
177 buffer = static_cast<char*>(calloc(1, hdrLen + len + 1));
178 if (!buffer) {
179 free(const_cast<char*>(name));
180 free(const_cast<char*>(commName));
181 return 0;
182 }
183
184 size_t retval = hdrLen + len;
185 if (isBinary()) {
186 android_log_event_string_t* event =
187 reinterpret_cast<android_log_event_string_t*>(buffer);
188
189 event->header.tag = htole32(CHATTY_LOG_TAG);
190 event->type = EVENT_TYPE_STRING;
191 event->length = htole32(len);
192 } else {
193 ++retval;
194 buffer[0] = ANDROID_LOG_INFO;
195 strcpy(buffer + 1, tag);
196 }
197
198 snprintf(buffer + hdrLen, len + 1, format_uid, mUid, name ? name : "",
199 commName ? commName : "", type, mDropped,
200 (mDropped > 1) ? "s" : "");
201 free(const_cast<char*>(name));
202 free(const_cast<char*>(commName));
203
204 return retval;
205 }
206
flushTo(SocketClient * reader,LogBuffer * parent,bool privileged,bool lastSame)207 log_time LogBufferElement::flushTo(SocketClient* reader, LogBuffer* parent,
208 bool privileged, bool lastSame) {
209 struct logger_entry_v4 entry;
210
211 memset(&entry, 0, sizeof(struct logger_entry_v4));
212
213 entry.hdr_size = privileged ? sizeof(struct logger_entry_v4)
214 : sizeof(struct logger_entry_v3);
215 entry.lid = mLogId;
216 entry.pid = mPid;
217 entry.tid = mTid;
218 entry.uid = mUid;
219 entry.sec = mRealTime.tv_sec;
220 entry.nsec = mRealTime.tv_nsec;
221
222 struct iovec iovec[2];
223 iovec[0].iov_base = &entry;
224 iovec[0].iov_len = entry.hdr_size;
225
226 char* buffer = NULL;
227
228 if (!mMsg) {
229 entry.len = populateDroppedMessage(buffer, parent, lastSame);
230 if (!entry.len) return mRealTime;
231 iovec[1].iov_base = buffer;
232 } else {
233 entry.len = mMsgLen;
234 iovec[1].iov_base = mMsg;
235 }
236 iovec[1].iov_len = entry.len;
237
238 log_time retval = reader->sendDatav(iovec, 1 + (entry.len != 0))
239 ? FLUSH_ERROR
240 : mRealTime;
241
242 if (buffer) free(buffer);
243
244 return retval;
245 }
246