libcutils/properties.c - platform/system/core - Gitiles

 /*
  * Copyright (C) 2006 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.
  */

 #define LOG_TAG "properties"

 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 #include <cutils/sockets.h>
 #include <errno.h>
 #include <assert.h>

 #include <cutils/properties.h>
 #include "loghack.h"

 #ifdef HAVE_LIBC_SYSTEM_PROPERTIES

 #define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
 #include <sys/_system_properties.h>

 int property_set(const char *key, const char *value)
 {
     return __system_property_set(key, value);
 }

 int property_get(const char *key, char *value, const char *default_value)
 {
     int len;

     len = __system_property_get(key, value);
     if(len > 0) {
         return len;
     }

     if(default_value) {
         len = strlen(default_value);
         memcpy(value, default_value, len + 1);
     }
     return len;
 }

 int property_list(void (*propfn)(const char *key, const char *value, void *cookie),
                   void *cookie)
 {
     char name[PROP_NAME_MAX];
     char value[PROP_VALUE_MAX];
     const prop_info *pi;
     unsigned n;

     for(n = 0; (pi = __system_property_find_nth(n)); n++) {
         __system_property_read(pi, name, value);
         propfn(name, value, cookie);
     }
     return 0;
 }

 #elif defined(HAVE_SYSTEM_PROPERTY_SERVER)

 /*
  * The Linux simulator provides a "system property server" that uses IPC
  * to set/get/list properties.  The file descriptor is shared by all
  * threads in the process, so we use a mutex to ensure that requests
  * from multiple threads don't get interleaved.
  */
 #include <stdio.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <pthread.h>

 static pthread_once_t gInitOnce = PTHREAD_ONCE_INIT;
 static pthread_mutex_t gPropertyFdLock = PTHREAD_MUTEX_INITIALIZER;
 static int gPropFd = -1;

 /*
  * Connect to the properties server.
  *
  * Returns the socket descriptor on success.
  */
 static int connectToServer(const char* fileName)
 {
     int sock = -1;
     int cc;

     struct sockaddr_un addr;

     sock = socket(AF_UNIX, SOCK_STREAM, 0);
     if (sock < 0) {
         LOGW("UNIX domain socket create failed (errno=%d)\n", errno);
         return -1;
     }

     /* connect to socket; fails if file doesn't exist */
     strcpy(addr.sun_path, fileName);    // max 108 bytes
     addr.sun_family = AF_UNIX;
     cc = connect(sock, (struct sockaddr*) &addr, SUN_LEN(&addr));
     if (cc < 0) {
         // ENOENT means socket file doesn't exist
         // ECONNREFUSED means socket exists but nobody is listening
         //LOGW("AF_UNIX connect failed for '%s': %s\n",
         //    fileName, strerror(errno));
         close(sock);
         return -1;
     }

     return sock;
 }

 /*
  * Perform one-time initialization.
  */
 static void init(void)
 {
     assert(gPropFd == -1);

     gPropFd = connectToServer(SYSTEM_PROPERTY_PIPE_NAME);
     if (gPropFd < 0) {
         //LOGW("not connected to system property server\n");
     } else {
         //LOGV("Connected to system property server\n");
     }
 }

 int property_get(const char *key, char *value, const char *default_value)
 {
     char sendBuf[1+PROPERTY_KEY_MAX];
     char recvBuf[1+PROPERTY_VALUE_MAX];
     int len = -1;

     //LOGV("PROPERTY GET [%s]\n", key);

     pthread_once(&gInitOnce, init);
     if (gPropFd < 0) {
         /* this mimics the behavior of the device implementation */
         if (default_value != NULL) {
             strcpy(value, default_value);
             len = strlen(value);
         }
         return len;
     }

     if (strlen(key) >= PROPERTY_KEY_MAX) return -1;

     memset(sendBuf, 0xdd, sizeof(sendBuf));    // placate valgrind

     sendBuf[0] = (char) kSystemPropertyGet;
     strcpy(sendBuf+1, key);

     pthread_mutex_lock(&gPropertyFdLock);
     if (write(gPropFd, sendBuf, sizeof(sendBuf)) != sizeof(sendBuf)) {
         pthread_mutex_unlock(&gPropertyFdLock);
         return -1;
     }
     if (read(gPropFd, recvBuf, sizeof(recvBuf)) != sizeof(recvBuf)) {
         pthread_mutex_unlock(&gPropertyFdLock);
         return -1;
     }
     pthread_mutex_unlock(&gPropertyFdLock);

     /* first byte is 0 if value not defined, 1 if found */
     if (recvBuf[0] == 0) {
         if (default_value != NULL) {
             strcpy(value, default_value);
             len = strlen(value);
         } else {
             /*
              * If the value isn't defined, hand back an empty string and
              * a zero length, rather than a failure.  This seems wrong,
              * since you can't tell the difference between "undefined" and
              * "defined but empty", but it's what the device does.
              */
             value[0] = '\0';
             len = 0;
         }
     } else if (recvBuf[0] == 1) {
         strcpy(value, recvBuf+1);
         len = strlen(value);
     } else {
         LOGE("Got strange response to property_get request (%d)\n",
             recvBuf[0]);
         assert(0);
         return -1;
     }
     //LOGV("PROP [found=%d def='%s'] (%d) [%s]: [%s]\n",
     //    recvBuf[0], default_value, len, key, value);

     return len;
 }


 int property_set(const char *key, const char *value)
 {
     char sendBuf[1+PROPERTY_KEY_MAX+PROPERTY_VALUE_MAX];
     char recvBuf[1];
     int result = -1;

     //LOGV("PROPERTY SET [%s]: [%s]\n", key, value);

     pthread_once(&gInitOnce, init);
     if (gPropFd < 0)
         return -1;

     if (strlen(key) >= PROPERTY_KEY_MAX) return -1;
     if (strlen(value) >= PROPERTY_VALUE_MAX) return -1;

     memset(sendBuf, 0xdd, sizeof(sendBuf));    // placate valgrind

     sendBuf[0] = (char) kSystemPropertySet;
     strcpy(sendBuf+1, key);
     strcpy(sendBuf+1+PROPERTY_KEY_MAX, value);

     pthread_mutex_lock(&gPropertyFdLock);
     if (write(gPropFd, sendBuf, sizeof(sendBuf)) != sizeof(sendBuf)) {
         pthread_mutex_unlock(&gPropertyFdLock);
         return -1;
     }
     if (read(gPropFd, recvBuf, sizeof(recvBuf)) != sizeof(recvBuf)) {
         pthread_mutex_unlock(&gPropertyFdLock);
         return -1;
     }
     pthread_mutex_unlock(&gPropertyFdLock);

     if (recvBuf[0] != 1)
         return -1;
     return 0;
 }

 int property_list(void (*propfn)(const char *key, const char *value, void *cookie),
                   void *cookie)
 {
     //LOGV("PROPERTY LIST\n");
     pthread_once(&gInitOnce, init);
     if (gPropFd < 0)
         return -1;

     return 0;
 }

 #else

 /* SUPER-cheesy place-holder implementation for Win32 */

 #include <cutils/threads.h>

 static mutex_t  env_lock = MUTEX_INITIALIZER;

 int property_get(const char *key, char *value, const char *default_value)
 {
     char ename[PROPERTY_KEY_MAX + 6];
     char *p;
     int len;

     len = strlen(key);
     if(len >= PROPERTY_KEY_MAX) return -1;
     memcpy(ename, "PROP_", 5);
     memcpy(ename + 5, key, len + 1);

     mutex_lock(&env_lock);

     p = getenv(ename);
     if(p == 0) p = "";
     len = strlen(p);
     if(len >= PROPERTY_VALUE_MAX) {
         len = PROPERTY_VALUE_MAX - 1;
     }

     if((len == 0) && default_value) {
         len = strlen(default_value);
         memcpy(value, default_value, len + 1);
     } else {
         memcpy(value, p, len);
         value[len] = 0;
     }

     mutex_unlock(&env_lock);

     return len;
 }


 int property_set(const char *key, const char *value)
 {
     char ename[PROPERTY_KEY_MAX + 6];
     char *p;
     int len;
     int r;

     if(strlen(value) >= PROPERTY_VALUE_MAX) return -1;

     len = strlen(key);
     if(len >= PROPERTY_KEY_MAX) return -1;
     memcpy(ename, "PROP_", 5);
     memcpy(ename + 5, key, len + 1);

     mutex_lock(&env_lock);
 #ifdef HAVE_MS_C_RUNTIME
     {
         char  temp[256];
         snprintf( temp, sizeof(temp), "%s=%s", ename, value);
         putenv(temp);
         r = 0;
     }
 #else
     r = setenv(ename, value, 1);
 #endif
     mutex_unlock(&env_lock);

     return r;
 }

 int property_list(void (*propfn)(const char *key, const char *value, void *cookie),
                   void *cookie)
 {
     return 0;
 }

 #endif
	/*
	* Copyright (C) 2006 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.
	*/

	#define LOG_TAG "properties"

	#include <stdlib.h>
	#include <string.h>
	#include <unistd.h>
	#include <cutils/sockets.h>
	#include <errno.h>
	#include <assert.h>

	#include <cutils/properties.h>
	#include "loghack.h"

	#ifdef HAVE_LIBC_SYSTEM_PROPERTIES

	#define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
	#include <sys/_system_properties.h>

	int property_set(const char key, const char value)
	{
	return __system_property_set(key, value);
	}

	int property_get(const char key, char value, const char *default_value)
	{
	int len;

	len = __system_property_get(key, value);
	if(len > 0) {
	return len;
	}

	if(default_value) {
	len = strlen(default_value);
	memcpy(value, default_value, len + 1);
	}
	return len;
	}

	int property_list(void (propfn)(const char key, const char value, void cookie),
	void *cookie)
	{
	char name[PROP_NAME_MAX];
	char value[PROP_VALUE_MAX];
	const prop_info *pi;
	unsigned n;

	for(n = 0; (pi = __system_property_find_nth(n)); n++) {
	__system_property_read(pi, name, value);
	propfn(name, value, cookie);
	}
	return 0;
	}

	#elif defined(HAVE_SYSTEM_PROPERTY_SERVER)

	/*
	* The Linux simulator provides a "system property server" that uses IPC
	* to set/get/list properties. The file descriptor is shared by all
	* threads in the process, so we use a mutex to ensure that requests
	* from multiple threads don't get interleaved.
	*/
	#include <stdio.h>
	#include <sys/types.h>
	#include <sys/socket.h>
	#include <sys/un.h>
	#include <pthread.h>

	static pthread_once_t gInitOnce = PTHREAD_ONCE_INIT;
	static pthread_mutex_t gPropertyFdLock = PTHREAD_MUTEX_INITIALIZER;
	static int gPropFd = -1;

	/*
	* Connect to the properties server.
	*
	* Returns the socket descriptor on success.
	*/
	static int connectToServer(const char* fileName)
	{
	int sock = -1;
	int cc;

	struct sockaddr_un addr;

	sock = socket(AF_UNIX, SOCK_STREAM, 0);
	if (sock < 0) {
	LOGW("UNIX domain socket create failed (errno=%d)\n", errno);
	return -1;
	}

	/* connect to socket; fails if file doesn't exist */
	strcpy(addr.sun_path, fileName); // max 108 bytes
	addr.sun_family = AF_UNIX;
	cc = connect(sock, (struct sockaddr*) &addr, SUN_LEN(&addr));
	if (cc < 0) {
	// ENOENT means socket file doesn't exist
	// ECONNREFUSED means socket exists but nobody is listening
	//LOGW("AF_UNIX connect failed for '%s': %s\n",
	// fileName, strerror(errno));
	close(sock);
	return -1;
	}

	return sock;
	}

	/*
	* Perform one-time initialization.
	*/
	static void init(void)
	{
	assert(gPropFd == -1);

	gPropFd = connectToServer(SYSTEM_PROPERTY_PIPE_NAME);
	if (gPropFd < 0) {
	//LOGW("not connected to system property server\n");
	} else {
	//LOGV("Connected to system property server\n");
	}
	}

	int property_get(const char key, char value, const char *default_value)
	{
	char sendBuf[1+PROPERTY_KEY_MAX];
	char recvBuf[1+PROPERTY_VALUE_MAX];
	int len = -1;

	//LOGV("PROPERTY GET [%s]\n", key);

	pthread_once(&gInitOnce, init);
	if (gPropFd < 0) {
	/* this mimics the behavior of the device implementation */
	if (default_value != NULL) {
	strcpy(value, default_value);
	len = strlen(value);
	}
	return len;
	}

	if (strlen(key) >= PROPERTY_KEY_MAX) return -1;

	memset(sendBuf, 0xdd, sizeof(sendBuf)); // placate valgrind

	sendBuf[0] = (char) kSystemPropertyGet;
	strcpy(sendBuf+1, key);

	pthread_mutex_lock(&gPropertyFdLock);
	if (write(gPropFd, sendBuf, sizeof(sendBuf)) != sizeof(sendBuf)) {
	pthread_mutex_unlock(&gPropertyFdLock);
	return -1;
	}
	if (read(gPropFd, recvBuf, sizeof(recvBuf)) != sizeof(recvBuf)) {
	pthread_mutex_unlock(&gPropertyFdLock);
	return -1;
	}
	pthread_mutex_unlock(&gPropertyFdLock);

	/* first byte is 0 if value not defined, 1 if found */
	if (recvBuf[0] == 0) {
	if (default_value != NULL) {
	strcpy(value, default_value);
	len = strlen(value);
	} else {
	/*
	* If the value isn't defined, hand back an empty string and
	* a zero length, rather than a failure. This seems wrong,
	* since you can't tell the difference between "undefined" and
	* "defined but empty", but it's what the device does.
	*/
	value[0] = '\0';
	len = 0;
	}
	} else if (recvBuf[0] == 1) {
	strcpy(value, recvBuf+1);
	len = strlen(value);
	} else {
	LOGE("Got strange response to property_get request (%d)\n",
	recvBuf[0]);
	assert(0);
	return -1;
	}
	//LOGV("PROP [found=%d def='%s'] (%d) [%s]: [%s]\n",
	// recvBuf[0], default_value, len, key, value);

	return len;
	}


	int property_set(const char key, const char value)
	{
	char sendBuf[1+PROPERTY_KEY_MAX+PROPERTY_VALUE_MAX];
	char recvBuf[1];
	int result = -1;

	//LOGV("PROPERTY SET [%s]: [%s]\n", key, value);

	pthread_once(&gInitOnce, init);
	if (gPropFd < 0)
	return -1;

	if (strlen(key) >= PROPERTY_KEY_MAX) return -1;
	if (strlen(value) >= PROPERTY_VALUE_MAX) return -1;

	memset(sendBuf, 0xdd, sizeof(sendBuf)); // placate valgrind

	sendBuf[0] = (char) kSystemPropertySet;
	strcpy(sendBuf+1, key);
	strcpy(sendBuf+1+PROPERTY_KEY_MAX, value);

	pthread_mutex_lock(&gPropertyFdLock);
	if (write(gPropFd, sendBuf, sizeof(sendBuf)) != sizeof(sendBuf)) {
	pthread_mutex_unlock(&gPropertyFdLock);
	return -1;
	}
	if (read(gPropFd, recvBuf, sizeof(recvBuf)) != sizeof(recvBuf)) {
	pthread_mutex_unlock(&gPropertyFdLock);
	return -1;
	}
	pthread_mutex_unlock(&gPropertyFdLock);

	if (recvBuf[0] != 1)
	return -1;
	return 0;
	}

	int property_list(void (propfn)(const char key, const char value, void cookie),
	void *cookie)
	{
	//LOGV("PROPERTY LIST\n");
	pthread_once(&gInitOnce, init);
	if (gPropFd < 0)
	return -1;

	return 0;
	}

	#else

	/* SUPER-cheesy place-holder implementation for Win32 */

	#include <cutils/threads.h>

	static mutex_t env_lock = MUTEX_INITIALIZER;

	int property_get(const char key, char value, const char *default_value)
	{
	char ename[PROPERTY_KEY_MAX + 6];
	char *p;
	int len;

	len = strlen(key);
	if(len >= PROPERTY_KEY_MAX) return -1;
	memcpy(ename, "PROP_", 5);
	memcpy(ename + 5, key, len + 1);

	mutex_lock(&env_lock);

	p = getenv(ename);
	if(p == 0) p = "";
	len = strlen(p);
	if(len >= PROPERTY_VALUE_MAX) {
	len = PROPERTY_VALUE_MAX - 1;
	}

	if((len == 0) && default_value) {
	len = strlen(default_value);
	memcpy(value, default_value, len + 1);
	} else {
	memcpy(value, p, len);
	value[len] = 0;
	}

	mutex_unlock(&env_lock);

	return len;
	}


	int property_set(const char key, const char value)
	{
	char ename[PROPERTY_KEY_MAX + 6];
	char *p;
	int len;
	int r;

	if(strlen(value) >= PROPERTY_VALUE_MAX) return -1;

	len = strlen(key);
	if(len >= PROPERTY_KEY_MAX) return -1;
	memcpy(ename, "PROP_", 5);
	memcpy(ename + 5, key, len + 1);

	mutex_lock(&env_lock);
	#ifdef HAVE_MS_C_RUNTIME
	{
	char temp[256];
	snprintf( temp, sizeof(temp), "%s=%s", ename, value);
	putenv(temp);
	r = 0;
	}
	#else
	r = setenv(ename, value, 1);
	#endif
	mutex_unlock(&env_lock);

	return r;
	}

	int property_list(void (propfn)(const char key, const char value, void cookie),
	void *cookie)
	{
	return 0;
	}

	#endif