diff options
| -rw-r--r-- | init/README.md | 8 | ||||
| -rw-r--r-- | init/builtins.cpp | 24 | ||||
| -rw-r--r-- | init/init.cpp | 30 | ||||
| -rw-r--r-- | init/init.h | 2 |
4 files changed, 62 insertions, 2 deletions
diff --git a/init/README.md b/init/README.md index cef0dbc43..c76a33bee 100644 --- a/init/README.md +++ b/init/README.md @@ -298,7 +298,8 @@ Commands > Fork and execute command with the given arguments. The command starts after "--" so that an optional security context, user, and supplementary groups can be provided. No other commands will be run until this one - finishes. _seclabel_ can be a - to denote default. + finishes. _seclabel_ can be a - to denote default. Properties are expanded + within _argument_. `export <name> <value>` > Set the environment variable _name_ equal to _value_ in the @@ -412,6 +413,11 @@ Commands or the timeout has been reached. If timeout is not specified it currently defaults to five seconds. +`wait_for_prop <name> <value>` +> Wait for system property _name_ to be _value_. Properties are expanded + within _value_. If property _name_ is already set to _value_, continue + immediately. + `write <path> <content>` > Open the file at _path_ and write a string to it with write(2). If the file does not exist, it will be created. If it does exist, diff --git a/init/builtins.cpp b/init/builtins.cpp index 1186e9db9..965a81fbe 100644 --- a/init/builtins.cpp +++ b/init/builtins.cpp @@ -1003,6 +1003,29 @@ static int do_wait(const std::vector<std::string>& args) { return -1; } +static int do_wait_for_prop(const std::vector<std::string>& args) { + const char* name = args[1].c_str(); + const char* value = args[2].c_str(); + size_t value_len = strlen(value); + + if (!is_legal_property_name(name)) { + LOG(ERROR) << "do_wait_for_prop(\"" << name << "\", \"" << value + << "\") failed: bad name"; + return -1; + } + if (value_len >= PROP_VALUE_MAX) { + LOG(ERROR) << "do_wait_for_prop(\"" << name << "\", \"" << value + << "\") failed: value too long"; + return -1; + } + if (!wait_property(name, value)) { + LOG(ERROR) << "do_wait_for_prop(\"" << name << "\", \"" << value + << "\") failed: init already in waiting"; + return -1; + } + return 0; +} + /* * Callback to make a directory from the ext4 code */ @@ -1074,6 +1097,7 @@ BuiltinFunctionMap::Map& BuiltinFunctionMap::map() const { {"verity_load_state", {0, 0, do_verity_load_state}}, {"verity_update_state", {0, 0, do_verity_update_state}}, {"wait", {1, 2, do_wait}}, + {"wait_for_prop", {2, 2, do_wait_for_prop}}, {"write", {2, 2, do_write}}, }; return builtin_functions; diff --git a/init/init.cpp b/init/init.cpp index 850a9046e..9322eb28e 100644 --- a/init/init.cpp +++ b/init/init.cpp @@ -87,6 +87,10 @@ bool waiting_for_exec = false; static int epoll_fd = -1; +static std::unique_ptr<Timer> waiting_for_prop(nullptr); +static std::string wait_prop_name; +static std::string wait_prop_value; + void register_epoll_handler(int fd, void (*fn)()) { epoll_event ev; ev.events = EPOLLIN; @@ -128,10 +132,34 @@ int add_environment(const char *key, const char *val) return -1; } +bool wait_property(const char *name, const char *value) +{ + if (waiting_for_prop) { + return false; + } + if (property_get(name) != value) { + // Current property value is not equal to expected value + wait_prop_name = name; + wait_prop_value = value; + waiting_for_prop.reset(new Timer()); + } else { + LOG(INFO) << "wait_property(\"" << name << "\", \"" << value << "\"): already set"; + } + return true; +} + void property_changed(const char *name, const char *value) { if (property_triggers_enabled) ActionManager::GetInstance().QueuePropertyTrigger(name, value); + if (waiting_for_prop) { + if (wait_prop_name == name && wait_prop_value == value) { + wait_prop_name.clear(); + wait_prop_value.clear(); + LOG(INFO) << "Wait for property took " << *waiting_for_prop; + waiting_for_prop.reset(); + } + } } static void restart_processes() @@ -876,7 +904,7 @@ int main(int argc, char** argv) { am.QueueBuiltinAction(queue_property_triggers_action, "queue_property_triggers"); while (true) { - if (!waiting_for_exec) { + if (!(waiting_for_exec || waiting_for_prop)) { am.ExecuteOneCommand(); restart_processes(); } diff --git a/init/init.h b/init/init.h index cfb3139a9..4e4da328b 100644 --- a/init/init.h +++ b/init/init.h @@ -36,4 +36,6 @@ void register_epoll_handler(int fd, void (*fn)()); int add_environment(const char* key, const char* val); +bool wait_property(const char *name, const char *value); + #endif /* _INIT_INIT_H */ |