logd: remove users of __android_logger_property_get_bool()

__android_logger_property_get_bool() has a clunky API and doesn't
belong in liblog, since a vast majority of liblog users will never
query this property.

Specifically
1) Replace with GetBoolProperty() when completely equivalent.
2) Remove checking if property values are 'eng' or 'svelte', since
   there's no evidence that those values were ever used.
3) Remove checking 'persist.logd.statistics' and 'ro.logd.statistics',
   since there's no evidence that those values were ever used.
4) Set ro.logd.kernel explicitly, so other processes don't need to
   replicate the defaults that logd uses.

Test: build
Change-Id: I7c37af64ba7754e839185f46da66bf077f09d9c3
diff --git a/liblog/tests/log_read_test.cpp b/liblog/tests/log_read_test.cpp
index 3e09617..7acd363 100644
--- a/liblog/tests/log_read_test.cpp
+++ b/liblog/tests/log_read_test.cpp
@@ -20,6 +20,7 @@
 
 #include <string>
 
+#include <android-base/properties.h>
 #include <android-base/stringprintf.h>
 #include <android/log.h>  // minimal logging API
 #include <gtest/gtest.h>
@@ -29,6 +30,8 @@
 // Do not use anything in log/log_time.h despite side effects of the above.
 #include <private/android_logger.h>
 
+using android::base::GetBoolProperty;
+
 TEST(liblog, android_logger_get_) {
 #ifdef __ANDROID__
   // This test assumes the log buffers are filled with noise from
@@ -38,31 +41,27 @@
 
   for (int i = LOG_ID_MIN; i < LOG_ID_MAX; ++i) {
     log_id_t id = static_cast<log_id_t>(i);
-    const char* name = android_log_id_to_name(id);
-    if (id != android_name_to_log_id(name)) {
-      continue;
-    }
-    fprintf(stderr, "log buffer %s\r", name);
+    std::string name = android_log_id_to_name(id);
+    fprintf(stderr, "log buffer %s\r", name.c_str());
     struct logger* logger;
     EXPECT_TRUE(NULL != (logger = android_logger_open(logger_list, id)));
     EXPECT_EQ(id, android_logger_get_id(logger));
     ssize_t get_log_size = android_logger_get_log_size(logger);
     /* security buffer is allowed to be denied */
-    if (strcmp("security", name)) {
-      EXPECT_LT(0, get_log_size);
+    if (name != "security") {
+      EXPECT_GT(get_log_size, 0);
       // crash buffer is allowed to be empty, that is actually healthy!
-      // kernel buffer is allowed to be empty on "user" builds
-      // stats buffer is allowed to be empty TEMPORARILY.
-      // TODO: remove stats buffer from here once we start to use it in
-      // framework (b/68266385).
-      EXPECT_LE(  // boolean 1 or 0 depending on expected content or empty
-          !!((strcmp("crash", name) != 0) &&
-             ((strcmp("kernel", name) != 0) ||
-              __android_logger_property_get_bool(
-                  "ro.logd.kernel", BOOL_DEFAULT_TRUE | BOOL_DEFAULT_FLAG_ENG |
-                                        BOOL_DEFAULT_FLAG_SVELTE)) &&
-             (strcmp("stats", name) != 0)),
-          android_logger_get_log_readable_size(logger));
+      // stats buffer is no longer in use.
+      if (name == "crash" || name == "stats") {
+        continue;
+      }
+
+      // kernel buffer is empty if ro.logd.kernel is false
+      if (name == "kernel" && !GetBoolProperty("ro.logd.kernel", false)) {
+        continue;
+      }
+
+      EXPECT_LE(0, android_logger_get_log_readable_size(logger));
     } else {
       EXPECT_NE(0, get_log_size);
       if (get_log_size < 0) {
@@ -71,7 +70,6 @@
         EXPECT_LE(0, android_logger_get_log_readable_size(logger));
       }
     }
-    EXPECT_LT(0, android_logger_get_log_version(logger));
   }
 
   android_logger_list_close(logger_list);
diff --git a/logd/LogAudit.cpp b/logd/LogAudit.cpp
index 0ce9796..0e17476 100644
--- a/logd/LogAudit.cpp
+++ b/logd/LogAudit.cpp
@@ -32,7 +32,7 @@
 #include <sstream>
 
 #include <android-base/macros.h>
-#include <log/log_properties.h>
+#include <android-base/properties.h>
 #include <private/android_filesystem_config.h>
 #include <private/android_logger.h>
 
@@ -40,6 +40,8 @@
 #include "LogUtils.h"
 #include "libaudit.h"
 
+using android::base::GetBoolProperty;
+
 #define KMSG_PRIORITY(PRI)                               \
     '<', '0' + LOG_MAKEPRI(LOG_AUTH, LOG_PRI(PRI)) / 10, \
         '0' + LOG_MAKEPRI(LOG_AUTH, LOG_PRI(PRI)) % 10, '>'
@@ -48,8 +50,8 @@
     : SocketListener(getLogSocket(), false),
       logbuf(buf),
       fdDmesg(fdDmesg),
-      main(__android_logger_property_get_bool("ro.logd.auditd.main", BOOL_DEFAULT_TRUE)),
-      events(__android_logger_property_get_bool("ro.logd.auditd.events", BOOL_DEFAULT_TRUE)),
+      main(GetBoolProperty("ro.logd.auditd.main", true)),
+      events(GetBoolProperty("ro.logd.auditd.events", true)),
       initialized(false),
       stats_(stats) {
     static const char auditd_message[] = { KMSG_PRIORITY(LOG_INFO),
diff --git a/logd/README.property b/logd/README.property
index 1d7d990..8fd7f48 100644
--- a/logd/README.property
+++ b/logd/README.property
@@ -7,8 +7,8 @@
 ro.logd.auditd.events      bool   true   selinux audit messages sent to events.
 persist.logd.security      bool   false  Enable security buffer.
 ro.organization_owned      bool   false  Override persist.logd.security to false
-ro.logd.kernel             bool+ svelte+ Enable klogd daemon
-ro.logd.statistics         bool+ svelte+ Enable logcat -S statistics.
+ro.logd.kernel             bool  svelte+ Enable klogd daemon
+logd.statistics            bool  svelte+ Enable logcat -S statistics.
 ro.debuggable              number        if not "1", logd.statistics &
                                          ro.logd.kernel default false.
 logd.logpersistd.enable    bool   auto   Safe to start logpersist daemon service
@@ -57,11 +57,8 @@
 
 NB:
 - auto - managed by /init
-- bool+ - "true", "false" and comma separated list of "eng" (forced false if
-  ro.debuggable is not "1") or "svelte" (forced false if ro.config.low_ram is
-  true).
 - svelte - see ro.config.low_ram for details.
-- svelte+ - see ro.config.low_ram and ro.debuggable for details.
+- svelte+ - If empty, default to true if `ro.config.low_ram == false && ro.debuggable == true`
 - ro - <base property> temporary override, ro.<base property> platform default.
 - persist - <base property> override, persist.<base property> platform default.
 - build - VERBOSE for native, DEBUG for jvm isLoggable, or developer option.
diff --git a/logd/main.cpp b/logd/main.cpp
index e7a69eb..93dadf5 100644
--- a/logd/main.cpp
+++ b/logd/main.cpp
@@ -62,7 +62,9 @@
 #include "SerializedLogBuffer.h"
 #include "SimpleLogBuffer.h"
 
+using android::base::GetBoolProperty;
 using android::base::GetProperty;
+using android::base::SetProperty;
 
 #define KMSG_PRIORITY(PRI)                                 \
     '<', '0' + LOG_MAKEPRI(LOG_DAEMON, LOG_PRI(PRI)) / 10, \
@@ -82,9 +84,10 @@
         PLOG(FATAL) << "failed to set batch scheduler";
     }
 
-    if (!__android_logger_property_get_bool("ro.debuggable", BOOL_DEFAULT_FALSE) &&
-        prctl(PR_SET_DUMPABLE, 0) == -1) {
-        PLOG(FATAL) << "failed to clear PR_SET_DUMPABLE";
+    if (!GetBoolProperty("ro.debuggable", false)) {
+        if (prctl(PR_SET_DUMPABLE, 0) == -1) {
+            PLOG(FATAL) << "failed to clear PR_SET_DUMPABLE";
+        }
     }
 
     std::unique_ptr<struct _cap_struct, int (*)(void*)> caps(cap_init(), cap_free);
@@ -110,6 +113,14 @@
     }
 }
 
+// GetBoolProperty that defaults to true if `ro.debuggable == true && ro.config.low_rawm == false`.
+static bool GetBoolPropertyEngSvelteDefault(const std::string& name) {
+    bool default_value =
+            GetBoolProperty("ro.debuggable", false) && !GetBoolProperty("ro.config.low_ram", false);
+
+    return GetBoolProperty(name, default_value);
+}
+
 char* android::uidToName(uid_t u) {
     struct Userdata {
         uid_t uid;
@@ -236,10 +247,9 @@
     }
 
     int fdPmesg = -1;
-    bool klogd = __android_logger_property_get_bool(
-        "ro.logd.kernel",
-        BOOL_DEFAULT_TRUE | BOOL_DEFAULT_FLAG_ENG | BOOL_DEFAULT_FLAG_SVELTE);
+    bool klogd = GetBoolPropertyEngSvelteDefault("ro.logd.kernel");
     if (klogd) {
+        SetProperty("ro.logd.kernel", "true");
         static const char proc_kmsg[] = "/proc/kmsg";
         fdPmesg = android_get_control_file(proc_kmsg);
         if (fdPmesg < 0) {
@@ -249,7 +259,7 @@
         if (fdPmesg < 0) PLOG(ERROR) << "Failed to open " << proc_kmsg;
     }
 
-    bool auditd = __android_logger_property_get_bool("ro.logd.auditd", BOOL_DEFAULT_TRUE);
+    bool auditd = GetBoolProperty("ro.logd.auditd", true);
     DropPrivs(klogd, auditd);
 
     // A cache of event log tags
@@ -261,10 +271,8 @@
     std::string buffer_type = GetProperty("logd.buffer_type", "serialized");
 
     // Partial (required for chatty) or full logging statistics.
-    bool enable_full_log_statistics = __android_logger_property_get_bool(
-            "logd.statistics", BOOL_DEFAULT_TRUE | BOOL_DEFAULT_FLAG_PERSIST |
-                                       BOOL_DEFAULT_FLAG_ENG | BOOL_DEFAULT_FLAG_SVELTE);
-    LogStatistics log_statistics(enable_full_log_statistics, buffer_type == "serialized");
+    LogStatistics log_statistics(GetBoolPropertyEngSvelteDefault("logd.statistics"),
+                                 buffer_type == "serialized");
 
     // Serves the purpose of managing the last logs times read on a socket connection, and as a
     // reader lock on a range of log entries.
@@ -309,9 +317,7 @@
     // and LogReader is notified to send updates to connected clients.
     LogAudit* al = nullptr;
     if (auditd) {
-        int dmesg_fd = __android_logger_property_get_bool("ro.logd.auditd.dmesg", BOOL_DEFAULT_TRUE)
-                               ? fdDmesg
-                               : -1;
+        int dmesg_fd = GetBoolProperty("ro.logd.auditd.dmesg", true) ? fdDmesg : -1;
         al = new LogAudit(log_buffer, dmesg_fd, &log_statistics);
     }