blob: c50c7f7bec6afa03cab856b1e1e685f60ebc68c7 [file] [log] [blame]
Mark Salyzyn018a96d2016-03-01 13:45:42 -08001/*
2 * Copyright (C) 2007-2016 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/*
18 * pmsg write handler
19 */
20
21#include <errno.h>
22#include <fcntl.h>
Mark Salyzyndb8a2662016-10-10 07:27:42 -070023#include <stdbool.h>
Mark Salyzyn018a96d2016-03-01 13:45:42 -080024#include <stdlib.h>
25#include <string.h>
26#include <sys/types.h>
27#include <time.h>
28
Steven Moreland1f83aa42017-04-13 23:48:57 -070029#include <log/log_properties.h>
Mark Salyzyn018a96d2016-03-01 13:45:42 -080030#include <private/android_filesystem_config.h>
31#include <private/android_logger.h>
32
33#include "config_write.h"
34#include "log_portability.h"
35#include "logger.h"
36
37static int pmsgOpen();
38static void pmsgClose();
39static int pmsgAvailable(log_id_t logId);
Tom Cherry71ba1642019-01-10 10:37:36 -080040static int pmsgWrite(log_id_t logId, struct timespec* ts, struct iovec* vec, size_t nr);
Mark Salyzyn018a96d2016-03-01 13:45:42 -080041
42LIBLOG_HIDDEN struct android_log_transport_write pmsgLoggerWrite = {
Tom Cherry71ba1642019-01-10 10:37:36 -080043 .node = {&pmsgLoggerWrite.node, &pmsgLoggerWrite.node},
44 .context.fd = -1,
45 .name = "pmsg",
46 .available = pmsgAvailable,
47 .open = pmsgOpen,
48 .close = pmsgClose,
49 .write = pmsgWrite,
Mark Salyzyn018a96d2016-03-01 13:45:42 -080050};
51
Mark Salyzyn2ed51d72017-03-09 08:09:43 -080052static int pmsgOpen() {
53 int fd = atomic_load(&pmsgLoggerWrite.context.fd);
54 if (fd < 0) {
55 int i;
Mark Salyzyndb8a2662016-10-10 07:27:42 -070056
Mark Salyzyn2ed51d72017-03-09 08:09:43 -080057 fd = TEMP_FAILURE_RETRY(open("/dev/pmsg0", O_WRONLY | O_CLOEXEC));
58 i = atomic_exchange(&pmsgLoggerWrite.context.fd, fd);
59 if ((i >= 0) && (i != fd)) {
60 close(i);
Mark Salyzyn018a96d2016-03-01 13:45:42 -080061 }
Mark Salyzyn2ed51d72017-03-09 08:09:43 -080062 }
Mark Salyzyn018a96d2016-03-01 13:45:42 -080063
Mark Salyzyn2ed51d72017-03-09 08:09:43 -080064 return fd;
Mark Salyzyn018a96d2016-03-01 13:45:42 -080065}
66
Mark Salyzyn2ed51d72017-03-09 08:09:43 -080067static void pmsgClose() {
68 int fd = atomic_exchange(&pmsgLoggerWrite.context.fd, -1);
69 if (fd >= 0) {
70 close(fd);
71 }
Mark Salyzyn018a96d2016-03-01 13:45:42 -080072}
73
Mark Salyzyn2ed51d72017-03-09 08:09:43 -080074static int pmsgAvailable(log_id_t logId) {
75 if (logId > LOG_ID_SECURITY) {
76 return -EINVAL;
77 }
Tom Cherry71ba1642019-01-10 10:37:36 -080078 if ((logId != LOG_ID_SECURITY) && (logId != LOG_ID_EVENTS) && !__android_log_is_debuggable()) {
Mark Salyzyn2ed51d72017-03-09 08:09:43 -080079 return -EINVAL;
80 }
81 if (atomic_load(&pmsgLoggerWrite.context.fd) < 0) {
82 if (access("/dev/pmsg0", W_OK) == 0) {
83 return 0;
Mark Salyzyn018a96d2016-03-01 13:45:42 -080084 }
Mark Salyzyn2ed51d72017-03-09 08:09:43 -080085 return -EBADF;
86 }
87 return 1;
Mark Salyzyn018a96d2016-03-01 13:45:42 -080088}
89
Mark Salyzyn7ef52492016-03-25 15:50:46 -070090/*
91 * Extract a 4-byte value from a byte stream.
92 */
Mark Salyzyn2ed51d72017-03-09 08:09:43 -080093static inline uint32_t get4LE(const uint8_t* src) {
94 return src[0] | (src[1] << 8) | (src[2] << 16) | (src[3] << 24);
Mark Salyzyn7ef52492016-03-25 15:50:46 -070095}
96
Tom Cherry71ba1642019-01-10 10:37:36 -080097static int pmsgWrite(log_id_t logId, struct timespec* ts, struct iovec* vec, size_t nr) {
Mark Salyzyn2ed51d72017-03-09 08:09:43 -080098 static const unsigned headerLength = 2;
99 struct iovec newVec[nr + headerLength];
100 android_log_header_t header;
101 android_pmsg_log_header_t pmsgHeader;
102 size_t i, payloadSize;
103 ssize_t ret;
Mark Salyzyn018a96d2016-03-01 13:45:42 -0800104
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800105 if ((logId == LOG_ID_EVENTS) && !__android_log_is_debuggable()) {
106 if (vec[0].iov_len < 4) {
107 return -EINVAL;
Mark Salyzyn7ef52492016-03-25 15:50:46 -0700108 }
109
Tom Cherry71ba1642019-01-10 10:37:36 -0800110 if (SNET_EVENT_LOG_TAG != get4LE(static_cast<uint8_t*>(vec[0].iov_base))) {
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800111 return -EPERM;
Mark Salyzyn018a96d2016-03-01 13:45:42 -0800112 }
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800113 }
Mark Salyzyn018a96d2016-03-01 13:45:42 -0800114
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800115 if (atomic_load(&pmsgLoggerWrite.context.fd) < 0) {
116 return -EBADF;
117 }
Mark Salyzyn018a96d2016-03-01 13:45:42 -0800118
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800119 /*
120 * struct {
121 * // what we provide to pstore
122 * android_pmsg_log_header_t pmsgHeader;
123 * // what we provide to file
124 * android_log_header_t header;
125 * // caller provides
126 * union {
127 * struct {
128 * char prio;
129 * char payload[];
130 * } string;
131 * struct {
132 * uint32_t tag
133 * char payload[];
134 * } binary;
135 * };
136 * };
137 */
Mark Salyzyn018a96d2016-03-01 13:45:42 -0800138
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800139 pmsgHeader.magic = LOGGER_MAGIC;
140 pmsgHeader.len = sizeof(pmsgHeader) + sizeof(header);
141 pmsgHeader.uid = __android_log_uid();
142 pmsgHeader.pid = getpid();
Mark Salyzyn018a96d2016-03-01 13:45:42 -0800143
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800144 header.id = logId;
145 header.tid = gettid();
146 header.realtime.tv_sec = ts->tv_sec;
147 header.realtime.tv_nsec = ts->tv_nsec;
Mark Salyzyn018a96d2016-03-01 13:45:42 -0800148
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800149 newVec[0].iov_base = (unsigned char*)&pmsgHeader;
150 newVec[0].iov_len = sizeof(pmsgHeader);
151 newVec[1].iov_base = (unsigned char*)&header;
152 newVec[1].iov_len = sizeof(header);
Mark Salyzyn018a96d2016-03-01 13:45:42 -0800153
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800154 for (payloadSize = 0, i = headerLength; i < nr + headerLength; i++) {
155 newVec[i].iov_base = vec[i - headerLength].iov_base;
156 payloadSize += newVec[i].iov_len = vec[i - headerLength].iov_len;
157
158 if (payloadSize > LOGGER_ENTRY_MAX_PAYLOAD) {
159 newVec[i].iov_len -= payloadSize - LOGGER_ENTRY_MAX_PAYLOAD;
160 if (newVec[i].iov_len) {
161 ++i;
162 }
163 payloadSize = LOGGER_ENTRY_MAX_PAYLOAD;
164 break;
Mark Salyzyn018a96d2016-03-01 13:45:42 -0800165 }
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800166 }
167 pmsgHeader.len += payloadSize;
Mark Salyzyn018a96d2016-03-01 13:45:42 -0800168
Tom Cherry71ba1642019-01-10 10:37:36 -0800169 ret = TEMP_FAILURE_RETRY(writev(atomic_load(&pmsgLoggerWrite.context.fd), newVec, i));
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800170 if (ret < 0) {
171 ret = errno ? -errno : -ENOTCONN;
172 }
Mark Salyzyn018a96d2016-03-01 13:45:42 -0800173
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800174 if (ret > (ssize_t)(sizeof(header) + sizeof(pmsgHeader))) {
175 ret -= sizeof(header) - sizeof(pmsgHeader);
176 }
Mark Salyzyn018a96d2016-03-01 13:45:42 -0800177
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800178 return ret;
Mark Salyzyn018a96d2016-03-01 13:45:42 -0800179}
Mark Salyzynd4b061b2016-03-10 09:50:08 -0800180
181/*
182 * Virtual pmsg filesystem
183 *
184 * Payload will comprise the string "<basedir>:<basefile>\0<content>" to a
185 * maximum of LOGGER_ENTRY_MAX_PAYLOAD, but scaled to the last newline in the
186 * file.
187 *
188 * Will hijack the header.realtime.tv_nsec field for a sequence number in usec.
189 */
190
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800191static inline const char* strnrchr(const char* buf, size_t len, char c) {
192 const char* cp = buf + len;
193 while ((--cp > buf) && (*cp != c))
194 ;
195 if (cp <= buf) {
196 return buf + len;
197 }
198 return cp;
Mark Salyzynd4b061b2016-03-10 09:50:08 -0800199}
200
201/* Write a buffer as filename references (tag = <basedir>:<basename>) */
Tom Cherry71ba1642019-01-10 10:37:36 -0800202LIBLOG_ABI_PRIVATE ssize_t __android_log_pmsg_file_write(log_id_t logId, char prio,
203 const char* filename, const char* buf,
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800204 size_t len) {
205 bool weOpened;
206 size_t length, packet_len;
207 const char* tag;
208 char *cp, *slash;
209 struct timespec ts;
210 struct iovec vec[3];
Mark Salyzynd4b061b2016-03-10 09:50:08 -0800211
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800212 /* Make sure the logId value is not a bad idea */
213 if ((logId == LOG_ID_KERNEL) || /* Verbotten */
214 (logId == LOG_ID_EVENTS) || /* Do not support binary content */
215 (logId == LOG_ID_SECURITY) || /* Bad idea to allow */
216 ((unsigned)logId >= 32)) { /* fit within logMask on arch32 */
217 return -EINVAL;
218 }
Mark Salyzynd4b061b2016-03-10 09:50:08 -0800219
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800220 clock_gettime(android_log_clockid(), &ts);
Mark Salyzynd4b061b2016-03-10 09:50:08 -0800221
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800222 cp = strdup(filename);
223 if (!cp) {
224 return -ENOMEM;
225 }
Mark Salyzynd4b061b2016-03-10 09:50:08 -0800226
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800227 tag = cp;
228 slash = strrchr(cp, '/');
229 if (slash) {
230 *slash = ':';
Mark Salyzynd4b061b2016-03-10 09:50:08 -0800231 slash = strrchr(cp, '/');
232 if (slash) {
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800233 tag = slash + 1;
234 }
235 }
236
237 length = strlen(tag) + 1;
238 packet_len = LOGGER_ENTRY_MAX_PAYLOAD - sizeof(char) - length;
239
240 vec[0].iov_base = &prio;
241 vec[0].iov_len = sizeof(char);
242 vec[1].iov_base = (unsigned char*)tag;
243 vec[1].iov_len = length;
244
245 weOpened = false;
Tom Cherry71ba1642019-01-10 10:37:36 -0800246 for (ts.tv_nsec = 0, length = len; length; ts.tv_nsec += ANDROID_LOG_PMSG_FILE_SEQUENCE) {
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800247 ssize_t ret;
248 size_t transfer;
249
Tom Cherry71ba1642019-01-10 10:37:36 -0800250 if ((ts.tv_nsec / ANDROID_LOG_PMSG_FILE_SEQUENCE) >= ANDROID_LOG_PMSG_FILE_MAX_SEQUENCE) {
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800251 len -= length;
252 break;
Mark Salyzynd4b061b2016-03-10 09:50:08 -0800253 }
254
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800255 transfer = length;
256 if (transfer > packet_len) {
257 transfer = strnrchr(buf, packet_len - 1, '\n') - buf;
258 if ((transfer < length) && (buf[transfer] == '\n')) {
259 ++transfer;
260 }
Mark Salyzynd4b061b2016-03-10 09:50:08 -0800261 }
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800262
263 vec[2].iov_base = (unsigned char*)buf;
264 vec[2].iov_len = transfer;
265
266 if (atomic_load(&pmsgLoggerWrite.context.fd) < 0) {
267 if (!weOpened) { /* Impossible for weOpened = true here */
268 __android_log_lock();
269 }
270 weOpened = atomic_load(&pmsgLoggerWrite.context.fd) < 0;
271 if (!weOpened) {
272 __android_log_unlock();
273 } else if (pmsgOpen() < 0) {
274 __android_log_unlock();
275 free(cp);
276 return -EBADF;
277 }
278 }
279
280 ret = pmsgWrite(logId, &ts, vec, sizeof(vec) / sizeof(vec[0]));
281
282 if (ret <= 0) {
283 if (weOpened) {
Mark Salyzyndb8a2662016-10-10 07:27:42 -0700284 pmsgClose();
285 __android_log_unlock();
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800286 }
287 free(cp);
288 return ret ? ret : (len - length);
Mark Salyzyndb8a2662016-10-10 07:27:42 -0700289 }
Mark Salyzyn2ed51d72017-03-09 08:09:43 -0800290 length -= transfer;
291 buf += transfer;
292 }
293 if (weOpened) {
294 pmsgClose();
295 __android_log_unlock();
296 }
297 free(cp);
298 return len;
Mark Salyzynd4b061b2016-03-10 09:50:08 -0800299}