blob: eba305f8ad692580764cefb51b0f8fc7267f6d81 [file] [log] [blame]
/*
* Copyright (C) 2007-2016 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 <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <poll.h>
#include <stdarg.h>
#include <stdatomic.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/un.h>
#include <time.h>
#include <unistd.h>
#include <cutils/sockets.h>
#include <private/android_filesystem_config.h>
#include <private/android_logger.h>
#include "log_portability.h"
#include "logd_reader.h"
#include "logger.h"
/* branchless on many architectures. */
#define min(x, y) ((y) ^ (((x) ^ (y)) & -((x) < (y))))
static int logdAvailable(log_id_t LogId);
static int logdVersion(struct android_log_logger* logger,
struct android_log_transport_context* transp);
static int logdRead(struct android_log_logger_list* logger_list,
struct android_log_transport_context* transp, struct log_msg* log_msg);
static int logdPoll(struct android_log_logger_list* logger_list,
struct android_log_transport_context* transp);
static void logdClose(struct android_log_logger_list* logger_list,
struct android_log_transport_context* transp);
static int logdClear(struct android_log_logger* logger,
struct android_log_transport_context* transp);
static ssize_t logdSetSize(struct android_log_logger* logger,
struct android_log_transport_context* transp, size_t size);
static ssize_t logdGetSize(struct android_log_logger* logger,
struct android_log_transport_context* transp);
static ssize_t logdGetReadableSize(struct android_log_logger* logger,
struct android_log_transport_context* transp);
static ssize_t logdGetPrune(struct android_log_logger_list* logger,
struct android_log_transport_context* transp, char* buf, size_t len);
static ssize_t logdSetPrune(struct android_log_logger_list* logger,
struct android_log_transport_context* transp, char* buf, size_t len);
static ssize_t logdGetStats(struct android_log_logger_list* logger,
struct android_log_transport_context* transp, char* buf, size_t len);
struct android_log_transport_read logdLoggerRead = {
.node = {&logdLoggerRead.node, &logdLoggerRead.node},
.name = "logd",
.available = logdAvailable,
.version = logdVersion,
.read = logdRead,
.poll = logdPoll,
.close = logdClose,
.clear = logdClear,
.getSize = logdGetSize,
.setSize = logdSetSize,
.getReadableSize = logdGetReadableSize,
.getPrune = logdGetPrune,
.setPrune = logdSetPrune,
.getStats = logdGetStats,
};
static int logdAvailable(log_id_t logId) {
if (logId >= LOG_ID_MAX) {
return -EINVAL;
}
if (logId == LOG_ID_SECURITY) {
uid_t uid = __android_log_uid();
if (uid != AID_SYSTEM) {
return -EPERM;
}
}
if (access("/dev/socket/logdw", W_OK) == 0) {
return 0;
}
return -EBADF;
}
// Connects to /dev/socket/<name> and returns the associated fd or returns -1 on error.
// O_CLOEXEC is always set.
static int socket_local_client(const std::string& name, int type) {
sockaddr_un addr = {.sun_family = AF_LOCAL};
std::string path = "/dev/socket/" + name;
if (path.size() + 1 > sizeof(addr.sun_path)) {
return -1;
}
strlcpy(addr.sun_path, path.c_str(), sizeof(addr.sun_path));
int fd = socket(AF_LOCAL, type | SOCK_CLOEXEC, 0);
if (fd == 0) {
return -1;
}
if (connect(fd, reinterpret_cast<sockaddr*>(&addr), sizeof(addr)) == -1) {
close(fd);
return -1;
}
return fd;
}
/* worker for sending the command to the logger */
static ssize_t send_log_msg(struct android_log_logger* logger, const char* msg, char* buf,
size_t buf_size) {
ssize_t ret;
size_t len;
char* cp;
int errno_save = 0;
int sock = socket_local_client("logd", SOCK_STREAM);
if (sock < 0) {
return sock;
}
if (msg) {
snprintf(buf, buf_size, msg, logger ? logger->logId : (unsigned)-1);
}
len = strlen(buf) + 1;
ret = TEMP_FAILURE_RETRY(write(sock, buf, len));
if (ret <= 0) {
goto done;
}
len = buf_size;
cp = buf;
while ((ret = TEMP_FAILURE_RETRY(read(sock, cp, len))) > 0) {
struct pollfd p;
if (((size_t)ret == len) || (buf_size < PAGE_SIZE)) {
break;
}
len -= ret;
cp += ret;
memset(&p, 0, sizeof(p));
p.fd = sock;
p.events = POLLIN;
/* Give other side 20ms to refill pipe */
ret = TEMP_FAILURE_RETRY(poll(&p, 1, 20));
if (ret <= 0) {
break;
}
if (!(p.revents & POLLIN)) {
ret = 0;
break;
}
}
if (ret >= 0) {
ret += buf_size - len;
}
done:
if ((ret == -1) && errno) {
errno_save = errno;
}
close(sock);
if (errno_save) {
errno = errno_save;
}
return ret;
}
ssize_t __send_log_msg(char* buf, size_t buf_size) {
return send_log_msg(NULL, NULL, buf, buf_size);
}
static int check_log_success(char* buf, ssize_t ret) {
if (ret < 0) {
return ret;
}
if (strncmp(buf, "success", 7)) {
errno = EINVAL;
return -1;
}
return 0;
}
static int logdClear(struct android_log_logger* logger,
struct android_log_transport_context* transp __unused) {
char buf[512];
return check_log_success(buf, send_log_msg(logger, "clear %d", buf, sizeof(buf)));
}
/* returns the total size of the log's ring buffer */
static ssize_t logdGetSize(struct android_log_logger* logger,
struct android_log_transport_context* transp __unused) {
char buf[512];
ssize_t ret = send_log_msg(logger, "getLogSize %d", buf, sizeof(buf));
if (ret < 0) {
return ret;
}
if ((buf[0] < '0') || ('9' < buf[0])) {
return -1;
}
return atol(buf);
}
static ssize_t logdSetSize(struct android_log_logger* logger,
struct android_log_transport_context* transp __unused, size_t size) {
char buf[512];
snprintf(buf, sizeof(buf), "setLogSize %d %zu", logger->logId, size);
return check_log_success(buf, send_log_msg(NULL, NULL, buf, sizeof(buf)));
}
/*
* returns the readable size of the log's ring buffer (that is, amount of the
* log consumed)
*/
static ssize_t logdGetReadableSize(struct android_log_logger* logger,
struct android_log_transport_context* transp __unused) {
char buf[512];
ssize_t ret = send_log_msg(logger, "getLogSizeUsed %d", buf, sizeof(buf));
if (ret < 0) {
return ret;
}
if ((buf[0] < '0') || ('9' < buf[0])) {
return -1;
}
return atol(buf);
}
/*
* returns the logger version
*/
static int logdVersion(struct android_log_logger* logger __unused,
struct android_log_transport_context* transp __unused) {
uid_t uid = __android_log_uid();
return ((uid != AID_ROOT) && (uid != AID_LOG) && (uid != AID_SYSTEM)) ? 3 : 4;
}
/*
* returns statistics
*/
static ssize_t logdGetStats(struct android_log_logger_list* logger_list,
struct android_log_transport_context* transp __unused, char* buf,
size_t len) {
struct android_log_logger* logger;
char* cp = buf;
size_t remaining = len;
size_t n;
n = snprintf(cp, remaining, "getStatistics");
n = min(n, remaining);
remaining -= n;
cp += n;
logger_for_each(logger, logger_list) {
n = snprintf(cp, remaining, " %d", logger->logId);
n = min(n, remaining);
remaining -= n;
cp += n;
}
if (logger_list->pid) {
snprintf(cp, remaining, " pid=%u", logger_list->pid);
}
return send_log_msg(NULL, NULL, buf, len);
}
static ssize_t logdGetPrune(struct android_log_logger_list* logger_list __unused,
struct android_log_transport_context* transp __unused, char* buf,
size_t len) {
return send_log_msg(NULL, "getPruneList", buf, len);
}
static ssize_t logdSetPrune(struct android_log_logger_list* logger_list __unused,
struct android_log_transport_context* transp __unused, char* buf,
size_t len) {
const char cmd[] = "setPruneList ";
const size_t cmdlen = sizeof(cmd) - 1;
if (strlen(buf) > (len - cmdlen)) {
return -ENOMEM; /* KISS */
}
memmove(buf + cmdlen, buf, len - cmdlen);
buf[len - 1] = '\0';
memcpy(buf, cmd, cmdlen);
return check_log_success(buf, send_log_msg(NULL, NULL, buf, len));
}
static void caught_signal(int signum __unused) {}
static int logdOpen(struct android_log_logger_list* logger_list,
struct android_log_transport_context* transp) {
struct android_log_logger* logger;
struct sigaction ignore;
struct sigaction old_sigaction;
unsigned int old_alarm = 0;
char buffer[256], *cp, c;
int e, ret, remaining, sock;
if (!logger_list) {
return -EINVAL;
}
sock = atomic_load(&transp->context.sock);
if (sock > 0) {
return sock;
}
sock = socket_local_client("logdr", SOCK_SEQPACKET);
if (sock == 0) {
/* Guarantee not file descriptor zero */
int newsock = socket_local_client("logdr", SOCK_SEQPACKET);
close(sock);
sock = newsock;
}
if (sock <= 0) {
if ((sock == -1) && errno) {
return -errno;
}
return sock;
}
strcpy(buffer, (logger_list->mode & ANDROID_LOG_NONBLOCK) ? "dumpAndClose" : "stream");
cp = buffer + strlen(buffer);
strcpy(cp, " lids");
cp += 5;
c = '=';
remaining = sizeof(buffer) - (cp - buffer);
logger_for_each(logger, logger_list) {
ret = snprintf(cp, remaining, "%c%u", c, logger->logId);
ret = min(ret, remaining);
remaining -= ret;
cp += ret;
c = ',';
}
if (logger_list->tail) {
ret = snprintf(cp, remaining, " tail=%u", logger_list->tail);
ret = min(ret, remaining);
remaining -= ret;
cp += ret;
}
if (logger_list->start.tv_sec || logger_list->start.tv_nsec) {
if (logger_list->mode & ANDROID_LOG_WRAP) {
// ToDo: alternate API to allow timeout to be adjusted.
ret = snprintf(cp, remaining, " timeout=%u", ANDROID_LOG_WRAP_DEFAULT_TIMEOUT);
ret = min(ret, remaining);
remaining -= ret;
cp += ret;
}
ret = snprintf(cp, remaining, " start=%" PRIu32 ".%09" PRIu32, logger_list->start.tv_sec,
logger_list->start.tv_nsec);
ret = min(ret, remaining);
remaining -= ret;
cp += ret;
}
if (logger_list->pid) {
ret = snprintf(cp, remaining, " pid=%u", logger_list->pid);
ret = min(ret, remaining);
cp += ret;
}
if (logger_list->mode & ANDROID_LOG_NONBLOCK) {
/* Deal with an unresponsive logd */
memset(&ignore, 0, sizeof(ignore));
ignore.sa_handler = caught_signal;
sigemptyset(&ignore.sa_mask);
/* particularily useful if tombstone is reporting for logd */
sigaction(SIGALRM, &ignore, &old_sigaction);
old_alarm = alarm(30);
}
ret = write(sock, buffer, cp - buffer);
e = errno;
if (logger_list->mode & ANDROID_LOG_NONBLOCK) {
if (e == EINTR) {
e = ETIMEDOUT;
}
alarm(old_alarm);
sigaction(SIGALRM, &old_sigaction, NULL);
}
if (ret <= 0) {
close(sock);
if ((ret == -1) && e) {
return -e;
}
if (ret == 0) {
return -EIO;
}
return ret;
}
ret = atomic_exchange(&transp->context.sock, sock);
if ((ret > 0) && (ret != sock)) {
close(ret);
}
return sock;
}
/* Read from the selected logs */
static int logdRead(struct android_log_logger_list* logger_list,
struct android_log_transport_context* transp, struct log_msg* log_msg) {
int ret, e;
struct sigaction ignore;
struct sigaction old_sigaction;
unsigned int old_alarm = 0;
ret = logdOpen(logger_list, transp);
if (ret < 0) {
return ret;
}
memset(log_msg, 0, sizeof(*log_msg));
unsigned int new_alarm = 0;
if (logger_list->mode & ANDROID_LOG_NONBLOCK) {
if ((logger_list->mode & ANDROID_LOG_WRAP) &&
(logger_list->start.tv_sec || logger_list->start.tv_nsec)) {
/* b/64143705 */
new_alarm = (ANDROID_LOG_WRAP_DEFAULT_TIMEOUT * 11) / 10 + 10;
logger_list->mode &= ~ANDROID_LOG_WRAP;
} else {
new_alarm = 30;
}
memset(&ignore, 0, sizeof(ignore));
ignore.sa_handler = caught_signal;
sigemptyset(&ignore.sa_mask);
/* particularily useful if tombstone is reporting for logd */
sigaction(SIGALRM, &ignore, &old_sigaction);
old_alarm = alarm(new_alarm);
}
/* NOTE: SOCK_SEQPACKET guarantees we read exactly one full entry */
ret = recv(ret, log_msg, LOGGER_ENTRY_MAX_LEN, 0);
e = errno;
if (new_alarm) {
if ((ret == 0) || (e == EINTR)) {
e = EAGAIN;
ret = -1;
}
alarm(old_alarm);
sigaction(SIGALRM, &old_sigaction, NULL);
}
if ((ret == -1) && e) {
return -e;
}
return ret;
}
static int logdPoll(struct android_log_logger_list* logger_list,
struct android_log_transport_context* transp) {
struct pollfd p;
int ret = logdOpen(logger_list, transp);
if (ret < 0) {
return ret;
}
memset(&p, 0, sizeof(p));
p.fd = ret;
p.events = POLLIN;
ret = poll(&p, 1, 20);
if ((ret > 0) && !(p.revents & POLLIN)) {
ret = 0;
}
if ((ret == -1) && errno) {
return -errno;
}
return ret;
}
/* Close all the logs */
static void logdClose(struct android_log_logger_list* logger_list __unused,
struct android_log_transport_context* transp) {
int sock = atomic_exchange(&transp->context.sock, -1);
if (sock > 0) {
close(sock);
}
}