| /* |
| * 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 <errno.h> |
| #include <stdatomic.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/time.h> |
| |
| #ifdef __BIONIC__ |
| #include <android/set_abort_message.h> |
| #endif |
| |
| #include <log/event_tag_map.h> |
| #include <private/android_filesystem_config.h> |
| #include <private/android_logger.h> |
| |
| #include "config_write.h" |
| #include "log_portability.h" |
| #include "logger.h" |
| |
| #define LOG_BUF_SIZE 1024 |
| |
| static int __write_to_log_init(log_id_t, struct iovec *vec, size_t nr); |
| static int (*write_to_log)(log_id_t, struct iovec *vec, size_t nr) = __write_to_log_init; |
| |
| /* |
| * This is used by the C++ code to decide if it should write logs through |
| * the C code. Basically, if /dev/socket/logd is available, we're running in |
| * the simulator rather than a desktop tool and want to use the device. |
| */ |
| static enum { |
| kLogUninitialized, kLogNotAvailable, kLogAvailable |
| } g_log_status = kLogUninitialized; |
| |
| static int check_log_uid_permissions() |
| { |
| #if defined(__BIONIC__) |
| uid_t uid = __android_log_uid(); |
| |
| /* Matches clientHasLogCredentials() in logd */ |
| if ((uid != AID_SYSTEM) && (uid != AID_ROOT) && (uid != AID_LOG)) { |
| uid = geteuid(); |
| if ((uid != AID_SYSTEM) && (uid != AID_ROOT) && (uid != AID_LOG)) { |
| gid_t gid = getgid(); |
| if ((gid != AID_SYSTEM) && |
| (gid != AID_ROOT) && |
| (gid != AID_LOG)) { |
| gid = getegid(); |
| if ((gid != AID_SYSTEM) && |
| (gid != AID_ROOT) && |
| (gid != AID_LOG)) { |
| int num_groups; |
| gid_t *groups; |
| |
| num_groups = getgroups(0, NULL); |
| if (num_groups <= 0) { |
| return -EPERM; |
| } |
| groups = calloc(num_groups, sizeof(gid_t)); |
| if (!groups) { |
| return -ENOMEM; |
| } |
| num_groups = getgroups(num_groups, groups); |
| while (num_groups > 0) { |
| if (groups[num_groups - 1] == AID_LOG) { |
| break; |
| } |
| --num_groups; |
| } |
| free(groups); |
| if (num_groups <= 0) { |
| return -EPERM; |
| } |
| } |
| } |
| } |
| } |
| #endif |
| return 0; |
| } |
| |
| static void __android_log_cache_available( |
| struct android_log_transport_write *node) |
| { |
| size_t i; |
| |
| if (node->logMask) { |
| return; |
| } |
| |
| for (i = LOG_ID_MIN; i < LOG_ID_MAX; ++i) { |
| if (node->write && |
| (i != LOG_ID_KERNEL) && |
| ((i != LOG_ID_SECURITY) || |
| (check_log_uid_permissions() == 0)) && |
| (!node->available || ((*node->available)(i) >= 0))) { |
| node->logMask |= 1 << i; |
| } |
| } |
| } |
| |
| LIBLOG_ABI_PUBLIC int __android_log_dev_available() |
| { |
| struct android_log_transport_write *node; |
| |
| if (list_empty(&__android_log_transport_write)) { |
| return kLogUninitialized; |
| } |
| |
| write_transport_for_each(node, &__android_log_transport_write) { |
| __android_log_cache_available(node); |
| if (node->logMask) { |
| return kLogAvailable; |
| } |
| } |
| return kLogNotAvailable; |
| } |
| |
| #if defined(__BIONIC__) |
| static atomic_uintptr_t tagMap; |
| #endif |
| |
| /* |
| * Release any logger resources. A new log write will immediately re-acquire. |
| */ |
| LIBLOG_ABI_PUBLIC void __android_log_close() |
| { |
| struct android_log_transport_write *transport; |
| #if defined(__BIONIC__) |
| EventTagMap *m; |
| #endif |
| |
| __android_log_lock(); |
| |
| write_to_log = __write_to_log_init; |
| |
| /* |
| * Threads that are actively writing at this point are not held back |
| * by a lock and are at risk of dropping the messages with a return code |
| * -EBADF. Prefer to return error code than add the overhead of a lock to |
| * each log writing call to guarantee delivery. In addition, anyone |
| * calling this is doing so to release the logging resources and shut down, |
| * for them to do so with outstanding log requests in other threads is a |
| * disengenuous use of this function. |
| */ |
| |
| write_transport_for_each(transport, &__android_log_persist_write) { |
| if (transport->close) { |
| (*transport->close)(); |
| } |
| } |
| |
| write_transport_for_each(transport, &__android_log_transport_write) { |
| if (transport->close) { |
| (*transport->close)(); |
| } |
| } |
| |
| #if defined(__BIONIC__) |
| /* |
| * Additional risk here somewhat mitigated by immediately unlock flushing |
| * the processor cache. The multi-threaded race that we choose to accept, |
| * to minimize locking, is an atomic_load in a writer picking up a value |
| * just prior to entering this routine. There will be an use after free. |
| * |
| * Again, anyone calling this is doing so to release the logging resources |
| * is most probably going to quiesce then shut down; or to restart after |
| * a fork so the risk should be non-existent. For this reason we |
| * choose a mitigation stance for efficiency instead of incuring the cost |
| * of a lock for every log write. |
| */ |
| m = (EventTagMap *)atomic_exchange(&tagMap, (uintptr_t)0); |
| #endif |
| |
| __android_log_unlock(); |
| |
| #if defined(__BIONIC__) |
| if (m != (EventTagMap *)(uintptr_t)-1LL) android_closeEventTagMap(m); |
| #endif |
| |
| } |
| |
| /* log_init_lock assumed */ |
| static int __write_to_log_initialize() |
| { |
| struct android_log_transport_write *transport; |
| struct listnode *n; |
| int i = 0, ret = 0; |
| |
| __android_log_config_write(); |
| write_transport_for_each_safe(transport, n, &__android_log_transport_write) { |
| __android_log_cache_available(transport); |
| if (!transport->logMask) { |
| list_remove(&transport->node); |
| continue; |
| } |
| if (!transport->open || ((*transport->open)() < 0)) { |
| if (transport->close) { |
| (*transport->close)(); |
| } |
| list_remove(&transport->node); |
| continue; |
| } |
| ++ret; |
| } |
| write_transport_for_each_safe(transport, n, &__android_log_persist_write) { |
| __android_log_cache_available(transport); |
| if (!transport->logMask) { |
| list_remove(&transport->node); |
| continue; |
| } |
| if (!transport->open || ((*transport->open)() < 0)) { |
| if (transport->close) { |
| (*transport->close)(); |
| } |
| list_remove(&transport->node); |
| continue; |
| } |
| ++i; |
| } |
| if (!ret && !i) { |
| return -ENODEV; |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * Extract a 4-byte value from a byte stream. le32toh open coded |
| */ |
| static inline uint32_t get4LE(const uint8_t* src) |
| { |
| return src[0] | (src[1] << 8) | (src[2] << 16) | (src[3] << 24); |
| } |
| |
| static int __write_to_log_daemon(log_id_t log_id, struct iovec *vec, size_t nr) |
| { |
| struct android_log_transport_write *node; |
| int ret; |
| struct timespec ts; |
| size_t len, i; |
| |
| for (len = i = 0; i < nr; ++i) { |
| len += vec[i].iov_len; |
| } |
| if (!len) { |
| return -EINVAL; |
| } |
| |
| #if defined(__BIONIC__) |
| if (log_id == LOG_ID_SECURITY) { |
| if (vec[0].iov_len < 4) { |
| return -EINVAL; |
| } |
| |
| ret = check_log_uid_permissions(); |
| if (ret < 0) { |
| return ret; |
| } |
| if (!__android_log_security()) { |
| /* If only we could reset downstream logd counter */ |
| return -EPERM; |
| } |
| } else if (log_id == LOG_ID_EVENTS) { |
| const char *tag; |
| size_t len; |
| EventTagMap *m, *f; |
| |
| if (vec[0].iov_len < 4) { |
| return -EINVAL; |
| } |
| |
| tag = NULL; |
| len = 0; |
| f = NULL; |
| m = (EventTagMap *)atomic_load(&tagMap); |
| |
| if (!m) { |
| ret = __android_log_trylock(); |
| m = (EventTagMap *)atomic_load(&tagMap); /* trylock flush cache */ |
| if (!m) { |
| m = android_openEventTagMap(EVENT_TAG_MAP_FILE); |
| if (ret) { /* trylock failed, use local copy, mark for close */ |
| f = m; |
| } else { |
| if (!m) { /* One chance to open map file */ |
| m = (EventTagMap *)(uintptr_t)-1LL; |
| } |
| atomic_store(&tagMap, (uintptr_t)m); |
| } |
| } |
| if (!ret) { /* trylock succeeded, unlock */ |
| __android_log_unlock(); |
| } |
| } |
| if (m && (m != (EventTagMap *)(uintptr_t)-1LL)) { |
| tag = android_lookupEventTag_len(m, &len, get4LE(vec[0].iov_base)); |
| } |
| ret = __android_log_is_loggable_len(ANDROID_LOG_INFO, |
| tag, len, |
| ANDROID_LOG_VERBOSE); |
| if (f) { /* local copy marked for close */ |
| android_closeEventTagMap(f); |
| } |
| if (!ret) { |
| return -EPERM; |
| } |
| } else { |
| /* Validate the incoming tag, tag content can not split across iovec */ |
| char prio = ANDROID_LOG_VERBOSE; |
| const char *tag = vec[0].iov_base; |
| size_t len = vec[0].iov_len; |
| if (!tag) { |
| len = 0; |
| } |
| if (len > 0) { |
| prio = *tag; |
| if (len > 1) { |
| --len; |
| ++tag; |
| } else { |
| len = vec[1].iov_len; |
| tag = ((const char *)vec[1].iov_base); |
| if (!tag) { |
| len = 0; |
| } |
| } |
| } |
| /* tag must be nul terminated */ |
| if (strnlen(tag, len) >= len) { |
| tag = NULL; |
| } |
| |
| if (!__android_log_is_loggable_len(prio, |
| tag, len - 1, |
| ANDROID_LOG_VERBOSE)) { |
| return -EPERM; |
| } |
| } |
| |
| clock_gettime(android_log_clockid(), &ts); |
| #else |
| /* simulate clock_gettime(CLOCK_REALTIME, &ts); */ |
| { |
| struct timeval tv; |
| gettimeofday(&tv, NULL); |
| ts.tv_sec = tv.tv_sec; |
| ts.tv_nsec = tv.tv_usec * 1000; |
| } |
| #endif |
| |
| ret = 0; |
| i = 1 << log_id; |
| write_transport_for_each(node, &__android_log_transport_write) { |
| if (node->logMask & i) { |
| ssize_t retval; |
| retval = (*node->write)(log_id, &ts, vec, nr); |
| if (ret >= 0) { |
| ret = retval; |
| } |
| } |
| } |
| |
| write_transport_for_each(node, &__android_log_persist_write) { |
| if (node->logMask & i) { |
| (void)(*node->write)(log_id, &ts, vec, nr); |
| } |
| } |
| |
| return ret; |
| } |
| |
| static int __write_to_log_init(log_id_t log_id, struct iovec *vec, size_t nr) |
| { |
| __android_log_lock(); |
| |
| if (write_to_log == __write_to_log_init) { |
| int ret; |
| |
| ret = __write_to_log_initialize(); |
| if (ret < 0) { |
| __android_log_unlock(); |
| if (!list_empty(&__android_log_persist_write)) { |
| __write_to_log_daemon(log_id, vec, nr); |
| } |
| return ret; |
| } |
| |
| write_to_log = __write_to_log_daemon; |
| } |
| |
| __android_log_unlock(); |
| |
| return write_to_log(log_id, vec, nr); |
| } |
| |
| LIBLOG_ABI_PUBLIC int __android_log_write(int prio, const char *tag, |
| const char *msg) |
| { |
| return __android_log_buf_write(LOG_ID_MAIN, prio, tag, msg); |
| } |
| |
| LIBLOG_ABI_PUBLIC int __android_log_buf_write(int bufID, int prio, |
| const char *tag, const char *msg) |
| { |
| struct iovec vec[3]; |
| char tmp_tag[32]; |
| |
| if (!tag) |
| tag = ""; |
| |
| /* XXX: This needs to go! */ |
| if ((bufID != LOG_ID_RADIO) && |
| (!strcmp(tag, "HTC_RIL") || |
| !strncmp(tag, "RIL", 3) || /* Any log tag with "RIL" as the prefix */ |
| !strncmp(tag, "IMS", 3) || /* Any log tag with "IMS" as the prefix */ |
| !strcmp(tag, "AT") || |
| !strcmp(tag, "GSM") || |
| !strcmp(tag, "STK") || |
| !strcmp(tag, "CDMA") || |
| !strcmp(tag, "PHONE") || |
| !strcmp(tag, "SMS"))) { |
| bufID = LOG_ID_RADIO; |
| /* Inform third party apps/ril/radio.. to use Rlog or RLOG */ |
| snprintf(tmp_tag, sizeof(tmp_tag), "use-Rlog/RLOG-%s", tag); |
| tag = tmp_tag; |
| } |
| |
| #if __BIONIC__ |
| if (prio == ANDROID_LOG_FATAL) { |
| android_set_abort_message(msg); |
| } |
| #endif |
| |
| vec[0].iov_base = (unsigned char *)&prio; |
| vec[0].iov_len = 1; |
| vec[1].iov_base = (void *)tag; |
| vec[1].iov_len = strlen(tag) + 1; |
| vec[2].iov_base = (void *)msg; |
| vec[2].iov_len = strlen(msg) + 1; |
| |
| return write_to_log(bufID, vec, 3); |
| } |
| |
| LIBLOG_ABI_PUBLIC int __android_log_vprint(int prio, const char *tag, |
| const char *fmt, va_list ap) |
| { |
| char buf[LOG_BUF_SIZE]; |
| |
| vsnprintf(buf, LOG_BUF_SIZE, fmt, ap); |
| |
| return __android_log_write(prio, tag, buf); |
| } |
| |
| LIBLOG_ABI_PUBLIC int __android_log_print(int prio, const char *tag, |
| const char *fmt, ...) |
| { |
| va_list ap; |
| char buf[LOG_BUF_SIZE]; |
| |
| va_start(ap, fmt); |
| vsnprintf(buf, LOG_BUF_SIZE, fmt, ap); |
| va_end(ap); |
| |
| return __android_log_write(prio, tag, buf); |
| } |
| |
| LIBLOG_ABI_PUBLIC int __android_log_buf_print(int bufID, int prio, |
| const char *tag, |
| const char *fmt, ...) |
| { |
| va_list ap; |
| char buf[LOG_BUF_SIZE]; |
| |
| va_start(ap, fmt); |
| vsnprintf(buf, LOG_BUF_SIZE, fmt, ap); |
| va_end(ap); |
| |
| return __android_log_buf_write(bufID, prio, tag, buf); |
| } |
| |
| LIBLOG_ABI_PUBLIC void __android_log_assert(const char *cond, const char *tag, |
| const char *fmt, ...) |
| { |
| char buf[LOG_BUF_SIZE]; |
| |
| if (fmt) { |
| va_list ap; |
| va_start(ap, fmt); |
| vsnprintf(buf, LOG_BUF_SIZE, fmt, ap); |
| va_end(ap); |
| } else { |
| /* Msg not provided, log condition. N.B. Do not use cond directly as |
| * format string as it could contain spurious '%' syntax (e.g. |
| * "%d" in "blocks%devs == 0"). |
| */ |
| if (cond) |
| snprintf(buf, LOG_BUF_SIZE, "Assertion failed: %s", cond); |
| else |
| strcpy(buf, "Unspecified assertion failed"); |
| } |
| |
| __android_log_write(ANDROID_LOG_FATAL, tag, buf); |
| abort(); /* abort so we have a chance to debug the situation */ |
| /* NOTREACHED */ |
| } |
| |
| LIBLOG_ABI_PUBLIC int __android_log_bwrite(int32_t tag, |
| const void *payload, size_t len) |
| { |
| struct iovec vec[2]; |
| |
| vec[0].iov_base = &tag; |
| vec[0].iov_len = sizeof(tag); |
| vec[1].iov_base = (void*)payload; |
| vec[1].iov_len = len; |
| |
| return write_to_log(LOG_ID_EVENTS, vec, 2); |
| } |
| |
| LIBLOG_ABI_PUBLIC int __android_log_security_bwrite(int32_t tag, |
| const void *payload, |
| size_t len) |
| { |
| struct iovec vec[2]; |
| |
| vec[0].iov_base = &tag; |
| vec[0].iov_len = sizeof(tag); |
| vec[1].iov_base = (void*)payload; |
| vec[1].iov_len = len; |
| |
| return write_to_log(LOG_ID_SECURITY, vec, 2); |
| } |
| |
| /* |
| * Like __android_log_bwrite, but takes the type as well. Doesn't work |
| * for the general case where we're generating lists of stuff, but very |
| * handy if we just want to dump an integer into the log. |
| */ |
| LIBLOG_ABI_PUBLIC int __android_log_btwrite(int32_t tag, char type, |
| const void *payload, size_t len) |
| { |
| struct iovec vec[3]; |
| |
| vec[0].iov_base = &tag; |
| vec[0].iov_len = sizeof(tag); |
| vec[1].iov_base = &type; |
| vec[1].iov_len = sizeof(type); |
| vec[2].iov_base = (void*)payload; |
| vec[2].iov_len = len; |
| |
| return write_to_log(LOG_ID_EVENTS, vec, 3); |
| } |
| |
| /* |
| * Like __android_log_bwrite, but used for writing strings to the |
| * event log. |
| */ |
| LIBLOG_ABI_PUBLIC int __android_log_bswrite(int32_t tag, const char *payload) |
| { |
| struct iovec vec[4]; |
| char type = EVENT_TYPE_STRING; |
| uint32_t len = strlen(payload); |
| |
| vec[0].iov_base = &tag; |
| vec[0].iov_len = sizeof(tag); |
| vec[1].iov_base = &type; |
| vec[1].iov_len = sizeof(type); |
| vec[2].iov_base = &len; |
| vec[2].iov_len = sizeof(len); |
| vec[3].iov_base = (void*)payload; |
| vec[3].iov_len = len; |
| |
| return write_to_log(LOG_ID_EVENTS, vec, 4); |
| } |
| |
| /* |
| * Like __android_log_security_bwrite, but used for writing strings to the |
| * security log. |
| */ |
| LIBLOG_ABI_PUBLIC int __android_log_security_bswrite(int32_t tag, |
| const char *payload) |
| { |
| struct iovec vec[4]; |
| char type = EVENT_TYPE_STRING; |
| uint32_t len = strlen(payload); |
| |
| vec[0].iov_base = &tag; |
| vec[0].iov_len = sizeof(tag); |
| vec[1].iov_base = &type; |
| vec[1].iov_len = sizeof(type); |
| vec[2].iov_base = &len; |
| vec[2].iov_len = sizeof(len); |
| vec[3].iov_base = (void*)payload; |
| vec[3].iov_len = len; |
| |
| return write_to_log(LOG_ID_SECURITY, vec, 4); |
| } |