logd: Allow flags "eng" and "svelte" in boolean

- enhance property_get_bool, drop property_get_bool_svelte
- enhance base properties with ro and persist variants
- update and fortify README.property
- primarily move auditd and kernel logger into a realm where
  they can be controlled by build properties.
- Move logd.klogd to logd.kernel, and add ro.logd.kernel
  and persist.logd.kernel.
- Add ro.logd.auditd and persist.logd.auditd.
- Document persist.logd.security
- Document log.tag and persist.logd.tag properties.
- Document ro.logd.size, persist.logd.size and logd.size
  properties.

Bug: 26178938
Bug: 26029733
Bug: 17760225
Change-Id: Ibc1a497e45d69db5cf52133937f7ba6fb1d6cd21

4 files changed, 132 insertions, 52 deletions

diff --git a/logd/LogBuffer.cpp b/logd/LogBuffer.cpp
index 12aa84e27..110395c9b 100644
--- a/logd/LogBuffer.cpp
+++ b/logd/LogBuffer.cpp
@@ -101,9 +101,10 @@ void LogBuffer::init() {
     if (!default_size) {
         default_size = property_get_size(global_default);
         if (!default_size) {
-            default_size = property_get_bool("ro.config.low_ram", false) ?
-                LOG_BUFFER_MIN_SIZE : // 64K
-                LOG_BUFFER_SIZE;      // 256K
+            default_size = property_get_bool("ro.config.low_ram",
+                                             BOOL_DEFAULT_FALSE)
+                ? LOG_BUFFER_MIN_SIZE // 64K
+                : LOG_BUFFER_SIZE;    // 256K
         }
     }
 
diff --git a/logd/LogUtils.h b/logd/LogUtils.h
index fccba6152..fd4800efa 100644
--- a/logd/LogUtils.h
+++ b/logd/LogUtils.h
@@ -44,7 +44,14 @@ bool clientHasLogCredentials(uid_t uid, gid_t gid, pid_t pid);
 bool clientHasLogCredentials(SocketClient *cli);
 
 // Furnished in main.cpp
-bool property_get_bool(const char *key, bool def);
+#define BOOL_DEFAULT_FLAG_TRUE_FALSE 0x1
+#define BOOL_DEFAULT_FALSE       0x0     // false if property not present
+#define BOOL_DEFAULT_TRUE        0x1     // true if property not present
+#define BOOL_DEFAULT_FLAG_PERSIST    0x2 // <key>, persist.<key>, ro.<key>
+#define BOOL_DEFAULT_FLAG_ENG        0x4 // off for user
+#define BOOL_DEFAULT_FLAG_SVELTE     0x8 // off for low_ram
+
+bool property_get_bool(const char *key, int def);
 
 static inline bool worstUidEnabledForLogid(log_id_t id) {
     return (id == LOG_ID_MAIN) || (id == LOG_ID_SYSTEM) || (id == LOG_ID_RADIO);
diff --git a/logd/README.property b/logd/README.property
index e4b23a9b9..019bd4006 100644
--- a/logd/README.property
+++ b/logd/README.property
@@ -1,37 +1,53 @@
 The properties that logd responds to are:
 
 name                       type default  description
-logd.auditd                 bool  true   Enable selinux audit daemon
-logd.auditd.dmesg           bool  true   selinux audit messages duplicated and
+ro.logd.auditd             bool   true   Enable selinux audit daemon
+ro.logd.auditd.dmesg       bool   true   selinux audit messages duplicated and
                                          sent on to dmesg log
-logd.klogd                  bool depends Enable klogd daemon
-logd.statistics             bool depends Enable logcat -S statistics.
-ro.config.low_ram           bool  false  if true, logd.statistics & logd.klogd
-                                         default false
-ro.build.type               string       if user, logd.statistics & logd.klogd
-                                         default false
-persist.logd.logpersistd    string       Enable logpersist daemon, "logcatd"
+persist.logd.security      bool   false  Enable security buffer.
+ro.device_owner            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.build.type              string        if user, logd.statistics &
+                                         ro.logd.kernel default false.
+persist.logd.logpersistd   string        Enable logpersist daemon, "logcatd"
                                          turns on logcat -f in logd context
-persist.logd.size          number 256K   Global default size of the buffer for
+persist.logd.size          number  ro    Global default size of the buffer for
                                          all log ids at initial startup, at
                                          runtime use: logcat -b all -G <value>
-persist.logd.size.main     number 256K   Size of the buffer for the main log
-persist.logd.size.system   number 256K   Size of the buffer for the system log
-persist.logd.size.radio    number 256K   Size of the buffer for the radio log
-persist.logd.size.event    number 256K   Size of the buffer for the event log
-persist.logd.size.crash    number 256K   Size of the buffer for the crash log
-persist.logd.filter         string       Pruning filter to optimize content,
-                                         default is ro.logd.filter or
-                                         "~!" which means to prune the oldest
-                                         entries of chattiest UID. At runtime
-                                         use: logcat -P "<string>"
-persist.logd.timestamp      string       The recording timestamp source. Default
-                                         is ro.logd.timestamp. "m[onotonic]" is
-                                         the only supported key character,
-                                         otherwise assumes realtime.
+ro.logd.size               number svelte default for persist.logd.size
+persist.logd.size.<buffer> number  ro    Size of the buffer for <buffer> log
+ro.logd.size.<buffer>      number svelte default for persist.logd.size.<buffer>
+ro.config.low_ram          bool   false  if true, logd.statistics, logd.kernel
+                                         default false, logd.size 64K instead
+                                         of 256K.
+persist.logd.filter        string        Pruning filter to optimize content.
+                                         At runtime use: logcat -P "<string>"
+ro.logd.filter             string "~!"   default for persist.logd.filter.
+                                         This default means to prune the
+                                         oldest entries of chattiest UID.
+persist.logd.timestamp     string  ro    The recording timestamp source.
+                                         "m[onotonic]" is the only supported
+                                         key character, otherwise realtime.
+ro.logd.timestamp        string realtime default for persist.logd.timestamp
+log.tag                   string persist The global logging level, VERBOSE,
+                                         DEBUG, INFO, WARN, ERROR, ASSERT or
+                                         SILENT. Only the first character is
+                                         the key character.
+persist.log.tag            string build  default for log.tag
+log.tag.<tag>             string persist The <tag> specific logging level.
+persist.log.tag.<tag>      string build  default for log.tag.<tag>
 
 NB:
-- Number support multipliers (K or M) for convenience. Range is limited
+- bool+ - "true", "false" and comma separated list of "eng" (forced false if
+  ro.build.type is "user") 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.build.type for details.
+- 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.
+- number - support multipliers (K or M) for convenience. Range is limited
   to between 64K and 256M for log buffer sizes. Individual log buffer ids
   such as main, system, ... override global default.
 - Pruning filter is of form of a space-separated list of [~][UID][/PID]
diff --git a/logd/main.cpp b/logd/main.cpp
index 2fcabdc9d..ba56e576b 100644
--- a/logd/main.cpp
+++ b/logd/main.cpp
@@ -143,18 +143,72 @@ static int drop_privs() {
 }
 
 // Property helper
-bool property_get_bool(const char *key, bool def) {
-    char property[PROPERTY_VALUE_MAX];
-    property_get(key, property, "");
+static bool check_flag(const char *prop, const char *flag) {
+    const char *cp = strcasestr(prop, flag);
+    if (!cp) {
+        return false;
+    }
+    // We only will document comma (,)
+    static const char sep[] = ",:;|+ \t\f";
+    if ((cp != prop) && !strchr(sep, cp[-1])) {
+        return false;
+    }
+    cp += strlen(flag);
+    return !*cp || !!strchr(sep, *cp);
+}
 
-    if (!strcasecmp(property, "true")) {
+bool property_get_bool(const char *key, int flag) {
+    char def[PROPERTY_VALUE_MAX];
+    char property[PROPERTY_VALUE_MAX];
+    def[0] = '\0';
+    if (flag & BOOL_DEFAULT_FLAG_PERSIST) {
+        char newkey[PROPERTY_KEY_MAX];
+        snprintf(newkey, sizeof(newkey), "ro.%s", key);
+        property_get(newkey, property, "");
+        // persist properties set by /data require innoculation with
+        // logd-reinit. They may be set in init.rc early and function, but
+        // otherwise are defunct unless reset. Do not rely on persist
+        // properties for startup-only keys unless you are willing to restart
+        // logd daemon (not advised).
+        snprintf(newkey, sizeof(newkey), "persist.%s", key);
+        property_get(newkey, def, property);
+    }
+
+    property_get(key, property, def);
+
+    if (check_flag(property, "true")) {
         return true;
     }
-    if (!strcasecmp(property, "false")) {
+    if (check_flag(property, "false")) {
+        return false;
+    }
+    if (check_flag(property, "eng")) {
+       flag |= BOOL_DEFAULT_FLAG_ENG;
+    }
+    // this is really a "not" flag
+    if (check_flag(property, "svelte")) {
+       flag |= BOOL_DEFAULT_FLAG_SVELTE;
+    }
+
+    // Sanity Check
+    if (flag & (BOOL_DEFAULT_FLAG_SVELTE | BOOL_DEFAULT_FLAG_ENG)) {
+        flag &= ~BOOL_DEFAULT_FLAG_TRUE_FALSE;
+        flag |= BOOL_DEFAULT_TRUE;
+    }
+
+    if ((flag & BOOL_DEFAULT_FLAG_SVELTE)
+            && property_get_bool("ro.config.low_ram",
+                                 BOOL_DEFAULT_FALSE)) {
         return false;
     }
+    if (flag & BOOL_DEFAULT_FLAG_ENG) {
+        property_get("ro.build.type", property, "");
+        if (!strcmp(property, "user")) {
+            return false;
+        }
+    }
 
-    return def;
+    return (flag & BOOL_DEFAULT_FLAG_TRUE_FALSE) != BOOL_DEFAULT_FALSE;
 }
 
 // Remove the static, and use this variable
@@ -266,17 +320,6 @@ const char *android::tagToName(uint32_t tag) {
     return android_lookupEventTag(map, tag);
 }
 
-static bool property_get_bool_svelte(const char *key) {
-    bool not_user;
-    {
-        char property[PROPERTY_VALUE_MAX];
-        property_get("ro.build.type", property, "");
-        not_user = !!strcmp(property, "user");
-    }
-    return property_get_bool(key, not_user
-            && !property_get_bool("ro.config.low_ram", false));
-}
-
 static void readDmesg(LogAudit *al, LogKlog *kl) {
     if (!al && !kl) {
         return;
@@ -325,7 +368,11 @@ static void readDmesg(LogAudit *al, LogKlog *kl) {
 // transitory per-client threads are created for each reader.
 int main(int argc, char *argv[]) {
     int fdPmesg = -1;
-    bool klogd = property_get_bool_svelte("logd.klogd");
+    bool klogd = property_get_bool("logd.kernel",
+                                   BOOL_DEFAULT_TRUE |
+                                   BOOL_DEFAULT_FLAG_PERSIST |
+                                   BOOL_DEFAULT_FLAG_ENG |
+                                   BOOL_DEFAULT_FLAG_SVELTE);
     if (klogd) {
         fdPmesg = open("/proc/kmsg", O_RDONLY | O_NDELAY);
     }
@@ -405,7 +452,11 @@ int main(int argc, char *argv[]) {
 
     signal(SIGHUP, reinit_signal_handler);
 
-    if (property_get_bool_svelte("logd.statistics")) {
+    if (property_get_bool("logd.statistics",
+                          BOOL_DEFAULT_TRUE |
+                          BOOL_DEFAULT_FLAG_PERSIST |
+                          BOOL_DEFAULT_FLAG_ENG |
+                          BOOL_DEFAULT_FLAG_SVELTE)) {
         logBuf->enableStatistics();
     }
 
@@ -439,12 +490,17 @@ int main(int argc, char *argv[]) {
     // initiated log messages. New log entries are added to LogBuffer
     // and LogReader is notified to send updates to connected clients.
 
-    bool auditd = property_get_bool("logd.auditd", true);
-
+    bool auditd = property_get_bool("logd.auditd",
+                                    BOOL_DEFAULT_TRUE |
+                                    BOOL_DEFAULT_FLAG_PERSIST);
     LogAudit *al = NULL;
     if (auditd) {
-        bool dmesg = property_get_bool("logd.auditd.dmesg", true);
-        al = new LogAudit(logBuf, reader, dmesg ? fdDmesg : -1);
+        al = new LogAudit(logBuf, reader,
+                          property_get_bool("logd.auditd.dmesg",
+                                            BOOL_DEFAULT_TRUE |
+                                            BOOL_DEFAULT_FLAG_PERSIST)
+                              ? fdDmesg
+                              : -1);
     }
 
     LogKlog *kl = NULL;