liblog: introduce ANDROID_LOG_* flags

Move away from using POSIX open(2) flags and introduce ANDROID_LOG_* flags to
replace them. Add security by preventing random mode flags from getting into
underlying POSIX calls. ANDROID_LOG_* flags overlap POSIX O_* flag definitions.

Change-Id: Ib32bb64c287e8bf150be62242e1ba46bb37839fc

6 files changed, 35 insertions, 34 deletions

diff --git a/liblog/README b/liblog/README
index d7472e4..0676aec 100644
--- a/liblog/README
+++ b/liblog/README
@@ -111,20 +111,21 @@ DESCRIPTION
        ger_list_alloc,  calling  in  turn the android_logger_open for each log
        id.  Each entry can be retrieved  with  android_logger_list_read.   The
        log(s) can be closed with android_logger_list_free.  The logs should be
-       opened with an O_RDONLY mode.  O_NDELAY mode will report when  the  log
-       reading  is  done  with  an  EAGAIN  error  return  code, otherwise the
-       android_logger_list_read call will block for new entries.
+       opened  with an  ANDROID_LOG_RDONLY  mode.   ANDROID_LOG_NONBLOCK  mode
+       will report when the  log reading is done with an  EAGAIN  error return
+       code,  otherwise the  android_logger_list_read  call will block for new
+       entries.
 
        The value returned by android_logger_open can be used as a parameter to
        the  android_logger_clear  function to empty the sub-log.  It is recom‐
-       mended to only open log O_WRONLY.
+       mended to only open log ANDROID_LOG_WRONLY in that case.
 
        The value returned by android_logger_open can be used as a parameter to
        the android_logger_get_log_(size|readable_size|version) to retrieve the
        sub-log maximum size, readable size and log buffer format protocol ver‐
        sion  respectively.  android_logger_get_id returns the id that was used
-       when opening the sub-log.  It is recommended to open the  log  O_RDONLY
-       in these cases.
+       when  opening  the  sub-log.    It  is  recommended  to  open  the  log
+       ANDROID_LOG_RDONLY in these cases.
 
 SEE ALSO
        syslogd(8)
diff --git a/liblog/log_read.c b/liblog/log_read.c
index dbed886..0b126cf 100644
--- a/liblog/log_read.c
+++ b/liblog/log_read.c
@@ -582,7 +582,7 @@ int android_logger_list_read(struct logger_list *logger_list,
         return -EINVAL;
     }
 
-    if (logger_list->mode & O_NONBLOCK) {
+    if (logger_list->mode & ANDROID_LOG_NONBLOCK) {
         memset(&ignore, 0, sizeof(ignore));
         ignore.sa_handler = caught_signal;
         sigemptyset(&ignore.sa_mask);
@@ -602,7 +602,7 @@ int android_logger_list_read(struct logger_list *logger_list,
         }
 
         strcpy(buffer,
-               (logger_list->mode & O_NONBLOCK) ? "dumpAndClose" : "stream");
+               (logger_list->mode & ANDROID_LOG_NONBLOCK) ? "dumpAndClose" : "stream");
         cp = buffer + strlen(buffer);
 
         strcpy(cp, " lids");
@@ -640,14 +640,14 @@ int android_logger_list_read(struct logger_list *logger_list,
             cp += ret;
         }
 
-        if (logger_list->mode & O_NONBLOCK) {
+        if (logger_list->mode & ANDROID_LOG_NONBLOCK) {
             /* Deal with an unresponsive logd */
             sigaction(SIGALRM, &ignore, &old_sigaction);
             old_alarm = alarm(30);
         }
         ret = write(sock, buffer, cp - buffer);
         e = errno;
-        if (logger_list->mode & O_NONBLOCK) {
+        if (logger_list->mode & ANDROID_LOG_NONBLOCK) {
             if (e == EINTR) {
                 e = ETIMEDOUT;
             }
@@ -673,7 +673,7 @@ int android_logger_list_read(struct logger_list *logger_list,
     while(1) {
         memset(log_msg, 0, sizeof(*log_msg));
 
-        if (logger_list->mode & O_NONBLOCK) {
+        if (logger_list->mode & ANDROID_LOG_NONBLOCK) {
             /* particularily useful if tombstone is reporting for logd */
             sigaction(SIGALRM, &ignore, &old_sigaction);
             old_alarm = alarm(30);
@@ -681,7 +681,7 @@ int android_logger_list_read(struct logger_list *logger_list,
         /* NOTE: SOCK_SEQPACKET guarantees we read exactly one full entry */
         ret = recv(logger_list->sock, log_msg, LOGGER_ENTRY_MAX_LEN, 0);
         e = errno;
-        if (logger_list->mode & O_NONBLOCK) {
+        if (logger_list->mode & ANDROID_LOG_NONBLOCK) {
             if ((ret == 0) || (e == EINTR)) {
                 e = EAGAIN;
                 ret = -1;
diff --git a/liblog/log_read_kern.c b/liblog/log_read_kern.c
index 41b8a51..bdc7b18 100644
--- a/liblog/log_read_kern.c
+++ b/liblog/log_read_kern.c
@@ -75,10 +75,10 @@ const char *android_log_id_to_name(log_id_t log_id)
 
 static int accessmode(int mode)
 {
-    if ((mode & O_ACCMODE) == O_WRONLY) {
+    if ((mode & ANDROID_LOG_ACCMODE) == ANDROID_LOG_WRONLY) {
         return W_OK;
     }
-    if ((mode & O_ACCMODE) == O_RDWR) {
+    if ((mode & ANDROID_LOG_ACCMODE) == ANDROID_LOG_RDWR) {
         return R_OK | W_OK;
     }
     return R_OK;
@@ -117,7 +117,7 @@ log_id_t android_name_to_log_id(const char *logName)
         ++b;
     }
 
-    ret = check_allocate_accessible(&n, b, O_RDONLY);
+    ret = check_allocate_accessible(&n, b, ANDROID_LOG_RDONLY);
     free(n);
     if (ret) {
         return ret;
@@ -201,8 +201,8 @@ static int logger_ioctl(struct logger *logger, int cmd, int mode)
         return -EFAULT;
     }
 
-    if (((mode & O_ACCMODE) == O_RDWR)
-            || (((mode ^ logger->top->mode) & O_ACCMODE) == 0)) {
+    if (((mode & ANDROID_LOG_ACCMODE) == ANDROID_LOG_RDWR)
+            || (((mode ^ logger->top->mode) & ANDROID_LOG_ACCMODE) == 0)) {
         return ioctl(logger->fd, cmd);
     }
 
@@ -227,13 +227,13 @@ static int logger_ioctl(struct logger *logger, int cmd, int mode)
 
 int android_logger_clear(struct logger *logger)
 {
-    return logger_ioctl(logger, LOGGER_FLUSH_LOG, O_WRONLY);
+    return logger_ioctl(logger, LOGGER_FLUSH_LOG, ANDROID_LOG_WRONLY);
 }
 
 /* returns the total size of the log's ring buffer */
 long android_logger_get_log_size(struct logger *logger)
 {
-    return logger_ioctl(logger, LOGGER_GET_LOG_BUF_SIZE, O_RDWR);
+    return logger_ioctl(logger, LOGGER_GET_LOG_BUF_SIZE, ANDROID_LOG_RDWR);
 }
 
 int android_logger_set_log_size(struct logger *logger __unused,
@@ -248,7 +248,7 @@ int android_logger_set_log_size(struct logger *logger __unused,
  */
 long android_logger_get_log_readable_size(struct logger *logger)
 {
-    return logger_ioctl(logger, LOGGER_GET_LOG_LEN, O_RDONLY);
+    return logger_ioctl(logger, LOGGER_GET_LOG_LEN, ANDROID_LOG_RDONLY);
 }
 
 /*
@@ -256,7 +256,7 @@ long android_logger_get_log_readable_size(struct logger *logger)
  */
 int android_logger_get_log_version(struct logger *logger)
 {
-    int ret = logger_ioctl(logger, LOGGER_GET_VERSION, O_RDWR);
+    int ret = logger_ioctl(logger, LOGGER_GET_VERSION, ANDROID_LOG_RDWR);
     return (ret < 0) ? 1 : ret;
 }
 
@@ -342,7 +342,7 @@ struct logger *android_logger_open(struct logger_list *logger_list,
         goto err_name;
     }
 
-    logger->fd = open(n, logger_list->mode);
+    logger->fd = open(n, logger_list->mode & (ANDROID_LOG_ACCMODE | ANDROID_LOG_NONBLOCK));
     if (logger->fd < 0) {
         goto err_name;
     }
@@ -565,7 +565,7 @@ int android_logger_list_read(struct logger_list *logger_list,
         if (result <= 0) {
             if (result) {
                 error = errno;
-            } else if (logger_list->mode & O_NDELAY) {
+            } else if (logger_list->mode & ANDROID_LOG_NONBLOCK) {
                 error = EAGAIN;
             } else {
                 logger_list->timeout_ms = LOG_TIMEOUT_NEVER;
diff --git a/liblog/tests/libc_test.cpp b/liblog/tests/libc_test.cpp
index 9839729..29501be 100644
--- a/liblog/tests/libc_test.cpp
+++ b/liblog/tests/libc_test.cpp
@@ -39,7 +39,7 @@ TEST(libc, __libc_android_log_event_int) {
     pid_t pid = getpid();
 
     ASSERT_TRUE(NULL != (logger_list = android_logger_list_open(
-        LOG_ID_EVENTS, O_RDONLY | O_NDELAY, 1000, pid)));
+        LOG_ID_EVENTS, ANDROID_LOG_RDONLY | ANDROID_LOG_NONBLOCK, 1000, pid)));
 
     struct timespec ts;
     clock_gettime(CLOCK_MONOTONIC, &ts);
@@ -99,7 +99,7 @@ TEST(libc, __libc_fatal_no_abort) {
     pid_t pid = getpid();
 
     ASSERT_TRUE(NULL != (logger_list = android_logger_list_open(
-        (log_id_t)LOG_ID_CRASH, O_RDONLY | O_NDELAY, 1000, pid)));
+        (log_id_t)LOG_ID_CRASH, ANDROID_LOG_RDONLY | ANDROID_LOG_NONBLOCK, 1000, pid)));
 
     char b[80];
     struct timespec ts;
diff --git a/liblog/tests/liblog_benchmark.cpp b/liblog/tests/liblog_benchmark.cpp
index 549d79e..979aded 100644
--- a/liblog/tests/liblog_benchmark.cpp
+++ b/liblog/tests/liblog_benchmark.cpp
@@ -130,7 +130,7 @@ static void BM_log_latency(int iters) {
     pid_t pid = getpid();
 
     struct logger_list * logger_list = android_logger_list_open(LOG_ID_EVENTS,
-        O_RDONLY, 0, pid);
+        ANDROID_LOG_RDONLY, 0, pid);
 
     if (!logger_list) {
         fprintf(stderr, "Unable to open events log: %s\n", strerror(errno));
@@ -208,7 +208,7 @@ static void BM_log_delay(int iters) {
     pid_t pid = getpid();
 
     struct logger_list * logger_list = android_logger_list_open(LOG_ID_EVENTS,
-        O_RDONLY, 0, pid);
+        ANDROID_LOG_RDONLY, 0, pid);
 
     if (!logger_list) {
         fprintf(stderr, "Unable to open events log: %s\n", strerror(errno));
diff --git a/liblog/tests/liblog_test.cpp b/liblog/tests/liblog_test.cpp
index 393e2cd..33f6481 100644
--- a/liblog/tests/liblog_test.cpp
+++ b/liblog/tests/liblog_test.cpp
@@ -122,7 +122,7 @@ TEST(liblog, __android_log_btwrite__android_logger_list_read) {
     pid_t pid = getpid();
 
     ASSERT_TRUE(NULL != (logger_list = android_logger_list_open(
-        LOG_ID_EVENTS, O_RDONLY | O_NDELAY, 1000, pid)));
+        LOG_ID_EVENTS, ANDROID_LOG_RDONLY | ANDROID_LOG_NONBLOCK, 1000, pid)));
 
     log_time ts(CLOCK_MONOTONIC);
 
@@ -223,7 +223,7 @@ TEST(liblog, android_logger_list_read__cpu) {
     v += pid & 0xFFFF;
 
     ASSERT_TRUE(NULL != (logger_list = android_logger_list_open(
-        LOG_ID_EVENTS, O_RDONLY, 1000, pid)));
+        LOG_ID_EVENTS, ANDROID_LOG_RDONLY, 1000, pid)));
 
     int count = 0;
 
@@ -443,7 +443,7 @@ TEST(liblog, max_payload) {
     struct logger_list *logger_list;
 
     ASSERT_TRUE(NULL != (logger_list = android_logger_list_open(
-        LOG_ID_SYSTEM, O_RDONLY, 100, 0)));
+        LOG_ID_SYSTEM, ANDROID_LOG_RDONLY, 100, 0)));
 
     bool matches = false;
     ssize_t max_len = 0;
@@ -505,7 +505,7 @@ TEST(liblog, too_big_payload) {
     struct logger_list *logger_list;
 
     ASSERT_TRUE(NULL != (logger_list = android_logger_list_open(
-        LOG_ID_SYSTEM, O_RDONLY | O_NDELAY, 100, 0)));
+        LOG_ID_SYSTEM, ANDROID_LOG_RDONLY | ANDROID_LOG_NONBLOCK, 100, 0)));
 
     ssize_t max_len = 0;
 
@@ -552,12 +552,12 @@ TEST(liblog, dual_reader) {
 
     // >25 messages due to liblog.__android_log_buf_print__concurrentXX above.
     ASSERT_TRUE(NULL != (logger_list1 = android_logger_list_open(
-        LOG_ID_MAIN, O_RDONLY | O_NDELAY, 25, 0)));
+        LOG_ID_MAIN, ANDROID_LOG_RDONLY | ANDROID_LOG_NONBLOCK, 25, 0)));
 
     struct logger_list *logger_list2;
 
     if (NULL == (logger_list2 = android_logger_list_open(
-            LOG_ID_MAIN, O_RDONLY | O_NDELAY, 15, 0))) {
+            LOG_ID_MAIN, ANDROID_LOG_RDONLY | ANDROID_LOG_NONBLOCK, 15, 0))) {
         android_logger_list_close(logger_list1);
         ASSERT_TRUE(NULL != logger_list2);
     }
@@ -595,7 +595,7 @@ TEST(liblog, dual_reader) {
 }
 
 TEST(liblog, android_logger_get_) {
-    struct logger_list * logger_list = android_logger_list_alloc(O_WRONLY, 0, 0);
+    struct logger_list * logger_list = android_logger_list_alloc(ANDROID_LOG_WRONLY, 0, 0);
 
     for(int i = LOG_ID_MIN; i < LOG_ID_MAX; ++i) {
         log_id_t id = static_cast<log_id_t>(i);