是否可以在Apple iOS设备上激活TCP keepalive
Apple设备===路由器=== WiFi模块是否可以在Apple iOS设备上激活TCP keepalive
Apple设备(iPhone)通过TCP连接连接到WiFi模块端口2000。我想在Apple设备上激活TCP keepalive数据包发送,以了解何时TCP模块的TCP连接丢失(模块关闭)。
我流设置
CFReadStreamRef readStream;
CFWriteStreamRef writeStream;
CFStreamCreatePairWithSocketToHost(NULL, (CFStringRef)CFBridgingRetain(moduleIPaddress), port2000, &readStream, &writeStream);
outputStream = (NSOutputStream *)CFBridgingRelease(writeStream);
inputStream = (NSInputStream *)CFBridgingRelease(readStream);
[outputStream setDelegate:(id)self];
[inputStream setDelegate:(id)self];
[outputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[outputStream open];
[inputStream open];
我试图根据大卫小时后Keeping socket connection alive in iOS
- (void) stream:(NSStream *)theStream handleEvent:(NSStreamEvent)streamEvent {
switch (streamEvent) {
case NSStreamEventOpenCompleted:
if (theStream == outputStream) {
/*
CFDataRef data = (CFDataRef)CFWriteStreamCopyProperty((__bridge CFWriteStreamRef)theStream, kCFStreamPropertySocketNativeHandle);
if(data) {
CFSocketNativeHandle socket_handle = *(CFSocketNativeHandle *)CFDataGetBytePtr(data);
CFRelease(data);
NSLog(@"SOCK HANDLE: %x", socket_handle);
//Enabling keep alive
int opt = 1;
if(setsockopt(socket_handle, SOL_SOCKET, SO_KEEPALIVE, &opt, sizeof(opt)) < 0)
{
NSLog(@"Yikes 2: failed to set keepalive! ERRNO: %s", strerror(errno));
}
}
*/
NSData *data = (NSData *)[theStream propertyForKey:(__bridge NSString *)kCFStreamPropertySocketNativeHandle];
if(data) {
CFSocketNativeHandle socket_handle = *(CFSocketNativeHandle *)[data bytes];
NSLog(@"SOCK HANDLE: %x", socket_handle);
//Enabling keep alive
int opt = 1;
if(setsockopt(socket_handle, SOL_SOCKET, SO_KEEPALIVE, &opt, sizeof(opt)) < 0)
{
NSLog(@"Yikes 2: failed to set keepalive! ERRNO: %s", strerror(errno));
}
}
}
两个选项都打印出来SOCK句柄激活存活:9,没有错误消息。当WiFi模块关闭时,当我不向输出流发送数据时,连接仍然保持打开30分钟或更长时间。如果我将数据发送到outputstream,则会在60秒后收到NSStreamEventErrorOccurred - 错误域= NSPOSIXErrorDomain代码= 60“操作无法完成,操作超时”。我尝试过使用Apple设备。当我尝试iOS模拟器时,我没有看到Wireshark的Keepalive数据包。
NSStream tcp keepalive in iOS也描述了keepalive设置。 Martin R示例代码激活了输入流的keepalive,这似乎是错误的。
是否可以在Apple iOS设备上激活TCP keepalive,如iPhone(应该按照David H的说法)?如果有可能应该怎么做(我的代码中缺少什么)?
看到:http://en.wikipedia.org/wiki/Keepalive#TCP_keepalive
通常情况下,存活时间(net.inet.tcp.keepidle
)默认7200sec。 我不知道在iOS中是否属实,但“不少于2小时”显然是RFC 1122所要求的。
此间隔必须是 可配置,并务必默认不少于两个小时。
那么,你怎么配置它在你的应用程序?请尝试:
#import <sys/types.h>
#import <sys/socket.h>
#import <netinet/in.h>
#import <netinet/tcp.h>
int on = 1;
int delay = 120;
setsockopt(socket_handle, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on));
setsockopt(socket_handle, IPPROTO_TCP, TCP_KEEPALIVE, &delay, sizeof(delay));
请参阅man tcp
。
我确认这适用于iOS模拟器(iPhone 5s/iOS 8.0)。
谢谢rintaro指导我走向正确的方向。
流设置保持不变,在我的问题。 我测试了不同的设置,并没有发现我的问题中描述的套接字句柄检测示例之间的差异。该激活与iPod设备存活和iOS 7.1
case NSStreamEventOpenCompleted:
@try {
if (theStream == outputStream)
{
NSData *data = (NSData *)[theStream propertyForKey:(__bridge NSString *)kCFStreamPropertySocketNativeHandle];
if(data)
{
CFSocketNativeHandle socket_handle = *(CFSocketNativeHandle *)[data bytes];
//NSLog(@"SOCK HANDLE: %x", socket_handle);
//SO_KEEPALIVE option to activate
int option = 1;
//TCP_NODELAY option to activate
int option2 = 1;
//Idle time used when SO_KEEPALIVE is enabled. Sets how long connection must be idle before keepalive is sent
int keepaliveIdle = 10;
//Interval between keepalives when there is no reply. Not same as idle time
int keepaliveIntvl = 2;
//Number of keepalives before close (including first keepalive packet)
int keepaliveCount = 4;
//Time after which tcp packet retransmissions will be stopped and the connection will be dropped.Stream is closed
int retransmissionTimeout = 5;
if (setsockopt(socket_handle, SOL_SOCKET, SO_KEEPALIVE, &option, sizeof (int)) == -1)
{
NSLog(@"setsockopt SO_KEEPALIVE failed: %s", strerror(errno));
}else
{
NSLog(@"setsockopt SO_KEEPALIVE ok");
}
if (setsockopt(socket_handle, IPPROTO_TCP, TCP_KEEPCNT, &keepaliveCount, sizeof(int)) == -1)
{
NSLog(@"setsockopt TCP_KEEPCNT failed: %s", strerror(errno));
}else
{
NSLog(@"setsockopt TCP_KEEPCNT ok");
}
if (setsockopt(socket_handle, IPPROTO_TCP, TCP_KEEPALIVE, &keepaliveIdle, sizeof(int)) == -1)
{
NSLog(@"setsockopt TCP_KEEPALIVE failed: %s", strerror(errno));
}else
{
NSLog(@"setsockopt TCP_KEEPALIVE ok");
}
if (setsockopt(socket_handle, IPPROTO_TCP, TCP_KEEPINTVL, &keepaliveIntvl, sizeof(int)) == -1)
{
NSLog(@"setsockopt TCP_KEEPINTVL failed: %s", strerror(errno));
}else
{
NSLog(@"setsockopt TCP_KEEPINTVL ok");
}
if (setsockopt(socket_handle, IPPROTO_TCP, TCP_RXT_CONNDROPTIME, &retransmissionTimeout, sizeof(int)) == -1)
{
NSLog(@"setsockopt TCP_RXT_CONNDROPTIME failed: %s", strerror(errno));
}else
{
NSLog(@"setsockopt TCP_RXT_CONNDROPTIME ok");
}
if (setsockopt(socket_handle, IPPROTO_TCP, TCP_NODELAY, &option2, sizeof(int)) == -1)
{
NSLog(@"setsockopt TCP_NODELAY failed: %s", strerror(errno));
}else
{
NSLog(@"setsockopt TCP_NODELAY ok");
}
}
}
当TCP连接处于空闲
代码,应用程序启动后的10秒的时间间隔来发送保活。当没有应答时,app开始以2秒的时间间隔发送keepalive数据包,并在有4个keepalive数据包没有应答时关闭数据流。这意味着,当成功进行Keepalive交换后关闭WiFi模块时,闲置时最多需要18秒,以便在连接丢失时关闭流。
另一个参数是重发超时值。默认似乎是6秒左右。该定时器在有第一个数据包重传时启动。 App尝试重新传输数据包,但如果数据包重新传输在5秒内失败,则会关闭数据流。
注意!设备和模拟器的不同结果。
iPod设置激活日志
- setsockopt的SO_KEEPALIVE确定
- setsockopt的TCP_KEEPCNT确定
- setsockopt的TCP_KEEPALIVE确定
- setsockopt的TCP_KEEPINTVL确定
- setsockopt的TCP_RXT_CONNDROPTIME确定
- setsockopt的TCP_NODELAY确定
仿真器设置激活日志
- setsockopt的SO_KEEPALIVE确定
- setsockopt的TCP_KEEPCNT失败:协议不可
- setsockopt的TCP_KEEPALIVE确定
- setsockopt的TCP_KEEPINTVL失败:协议不可
- setsockopt的TCP_RXT_CONNDROPTIME确定
- setsockopt TCP_NODELAY ok
这意味着无法使用iOS模拟器激活和跟踪。 我没有找到为什么错误消息“协议不可用”显示在模拟器中。
感谢您的详细调查! – rintaro 2014-09-08 14:06:38
如果上述代码中的某些定义未在您的项目中声明,则必须包含以下内容:#include #include # #include –
Despotovic
2015-12-15 11:35:13
本示例中所选值如何映射到推荐值?我已经尝试过这些设置,但网络在少数设备(约5台)上有些不稳定。我们怀疑这主要是由于'retransmissionTimeout',你会同意吗? – 2015-12-15 18:23:05