I want create socket to connect multi device, and i have a accept call back function
void AcceptCallBack(
CFSocketRef socket,
CFSocketCallBackType type,
CFDataRef address,
const void *data,
void *info)
{
CFReadStreamRef readStream = NULL;
CFWriteStreamRef writeStream = NULL;
CFIndex bytes;
UInt8 buffer[128];
UInt8 recv_len = 0, send_len = 0;
/* The native socket, used for various operations */
CFSocketNativeHandle sock = *(CFSocketNativeHandle *) data;
/* The punch line we stored in the socket context */
char *punchline = info;
/* Create the read and write streams for the socket */
CFStreamCreatePairWithSocket(kCFAllocatorDefault, sock,
&readStream, &writeStream);
if (!readStream || !writeStream) {
close(sock);
fprintf(stderr, "CFStreamCreatePairWithSocket() failed\n");
return;
}
CFReadStreamOpen(readStream);
CFWriteStreamOpen(writeStream);
/* Wait for the client to finish sending the joke; wait for newline */
// How to create a new IOS thread from here to read data from client.
}
I want create NSThread for listening data from Client. Because this is an C++ function i can not access a variable from Object C.
Thanks.
You have a few options here.
You can write an objective C helper function in a new .mm file, and call it from your C++ code
You can change the C++ file to have a .mm extension. That way you can mix Objective C code in with the C++. You will probably need some include magic such as this at the top of the file:-
#ifdef __OBJC__
// prevent C++ compiler errors
#import <Foundation/Foundation.h>
#endif
3.You should also look at using GCD instead. That uses a C interface, and it may be possible to do everything you need using dispatch_async(). Because dispatch_async() uses blocks, you would need to set the -fblocks compiler flag if you were still using a .cpp file extension.
Related
I've looked and followed documentation from LwIP 2.0.2. My project contains the MQTT library supplied in the LwIP 2.0.2. I also found some help at https://dzone.com/articles/mqtt-with-lwip-and-the-nxp-frdm-k64f. I'm unable to get a connection, I've used free public MQTT broker but no hope in connection. I can ping my device. Am I doing something wrong?
static void mqtt_test(mqtt_client_t *mqtt_client)
if (mqtt_client_is_connected(&mqtt_client) == 1)
{
example_subscribe(&mqtt_client, NULL);
} else {
mqtt_do_connect(&mqtt_client);
}
}
when I call this method it always enters mqtt_do_connect() never connecting. Here is mqtt_do_connect
static void mqtt_do_connect(mqtt_client_t *mqtt_client)
{
ip4_addr_t broker_ipaddr;
struct mqtt_connect_client_info_t ci;
err_t err;
if (ipaddr_aton("52.58.177.181", &broker_ipaddr))
{
err = ERR_OK;
}
/* Setup an empty client info structure */
memset( & ci, 0, sizeof(ci));
/* Minimal amount of information required is client identifier, so set it here */
ci.client_id = "test";
/* Initiate client and connect to server, if this fails immediately an error code is returned
otherwise mqtt_connection_cb will be called with connection result after attempting
to establish a connection with the server.
For now MQTT version 3.1.1 is always used */
err = mqtt_client_connect(mqtt_client, & broker_ipaddr, 1883, mqtt_connection_cb, 0, & ci);
/* For now just print the result code if something goes wrong */
if (err != ERR_OK) {
printf("mqtt_connect return %d\n", err);
}
}
I've also noticed in the method mqtt_client_connect in mqtt.c that this exists:
/* Any local address, pick random local port number */
err = tcp_bind(client->conn, IP_ADDR_ANY, 0);
why is this needed? If I replace IP_ADDR_ANY to my local address of the static IP of the device it runs through without throwing a error but no callback mqtt_connection_cb is then called.
I've also initialized the TCP/IP stack as mentioned with static IP. I'm using NO_SYS as 1 but will move it over to FreeRTOS but baby steps first.
I haven't found much support on MQTT in LwIP implementation, am I missing something obvious, any help will be appreciated.
I've used MQTTfx to run a test or two on the broker with good response but nothing from my embedded device (Atmel SAME54).
I've found the solution. I ran my TCP setup in a FreeRTOS thread and opened a socket
static void mqtt_start(void *p)
{
struct sockaddr_in address;
int s_create, new_socket;
int addrlen = sizeof(address);
int opt = 1;
int socket_check;
sys_sem_t sem;
err_t err_sem;
err_sem = sys_sem_new(&sem, 0); /* Create a new semaphore. */
tcpip_init(tcpip_init_done, &sem);
sys_sem_wait(&sem); /* Block until the lwIP stack is initialized. */
sys_sem_free(&sem); /* Free the semaphore. */
/*Create a socket*/
s_create = socket(AF_INET, 1, 0);
setsockopt(s_create, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt));
address.sin_family = AF_INET;
address.sin_addr.s_addr = htonl(IPADDR_ANY);
address.sin_port = htons(HTTP_PORT);
/* bind the connection to port */
socket_check = bind(s_create, (struct sockaddr *)&address, sizeof(address));
if (socket_check < 0) {
LWIP_DEBUGF(LWIP_DBG_ON, ("Bind error=%d\n", socket_check));
goto socket_close;
}
/* tell the connection to listen for incoming connection requests */
listen(s_create, 3);
mqtt_connect(&mqtt_client);
for (;;) {
new_socket = accept(s_create, (struct sockaddr *)&address, (socklen_t *)&addrlen);
socket_close:
close(new_socket);
}
}
I also had a problem with my initialization of my mqtt client, placed a watch on it and saw the struct wasn't initializing. I initialized it globally
mqtt_client_t mqtt_client;
Then use it later in mqtt_start.
In an iPhone app, I create a CFSocket object from an existing native UDP socket and set up a data callback whenever the socket receives some data. I then add that to my main program loop:
//Set socket descriptor field
cbData.s = udpSocket.getSocketDescriptor();
CFSocketContext udpSocketContext;
memset(&udpSocketContext, 0, sizeof(udpSocketContext));
udpSocketContext.info = &cbData;
cbData.socketRef = CFSocketCreateWithNative(NULL, cbData.s, kCFSocketDataCallBack, &getSocketDataCallBack, &udpSocketContext);
cbData.runLoopSourceRef = CFSocketCreateRunLoopSource( NULL, cbData.socketRef, 0);
CFRunLoopAddSource(CFRunLoopGetMain(), cbData.runLoopSourceRef, kCFRunLoopCommonModes);
I send 1024-byte datagrams over WiFi from a separate Mac server app every 5 mS, and receive them on my iPhone in my getSocketDataCallBack routine.
I expect getSocketDataCallBack to be called every 5 mS (to match the period of the datagrams being sent from the Mac), which happens the majority of times. BUT, the calls often get delayed by 10s or 100s of mS. Thereafter, I get a rapid sequence of callbacks (fractions of a mS) to retrieve the multiple datagrams that have piled up over that delay.
As iOS obviously keeps the delayed datagrams around,
is there any way to grab all the delayed datagrams from the system at
once instead of getSocketDataCallBack being called over and over
in quick succession?
[I do query how many bytes are available in the callback ala:
CFDataRef dataRef = (CFDataRef)data;
numBytesReceived = CFDataGetLength(dataRef);
but 'numBytesReceived' is always reported as 1024.]
Alternatively, is there any way to improve/lessen the socket callback
timing variability through other means?
I'm using socket call back for Inter Process Communication (actually, inter thread communication) with UNIX socket. How we use socket is identical to the TCP/UDP.
The code below is written in c/obj-c and using posix thread. To translate it to Swift/NSThread should not be difficult.
Note the program below works as a server side, which means the program creates socket where the clients connect to. Once the client connected to the socket, the system automatically accepts the connection and allocates
another file descriptor to read/write. The socket call back reflects this two stage operation. Initially we create the socket, we then add as run-loop source so the system can call the call back when the client attempted to connect. The system accepts, then allocates and tells the call back
a file descriptor to read/write with the client. We then create another run-loop source from the read/write fd and add to run-loop. This second call back is called when rx/tx data is ready.
MAIN THREAD:
The main thread creates UNIX socket and worker thread. The socket fd is passed as argument of the worker thread.
#import <stdio.h>
#import <string.h>
#import <stdlib.h>
#import <unistd.h>
#import <pthread.h>
#import <sys/socket.h>
#import <sys/un.h>
#import <sys/stat.h>
#import <sys/types.h>
#import <UIKit/UIKit.h>
#import <Foundation/Foundation.h>
int setup(const char *ipcNode) {
int sockfd = socket(AF_UNIX, SOCK_STREAM, 0);
if (sockfd == -1) {
return -1;
}
struct sockaddr_un sa = {0};
sa.sun_len = sizeof(sa);
sa.sun_family = AF_UNIX;
strcpy(sa.sun_path, ipcNode);
remove(sa.sun_path);
if (bind(sockfd, (struct sockaddr*)&sa, sizeof(struct sockaddr_un)) == -1) {
close(sockfd);
return -1;
}
// start up worker thread
pthread_attr_t at;
pthread_attr_init(&at);
pthread_attr_setdetachstate(&at, PTHREAD_CREATE_DETACHED);
pthread_t th;
pthread_create(&th, &at, workerThread, (void *)(long)(sockfd));
return 1;
}
WORKER THREAD:
The program works as a server. So, it waits to get connected by client (via connect()). Once it's connected, the system automatically calls accept() and allocates read/write fd to communicate with the client. This fd is passed to accept-call back routine socketDataCallback(). Then we create another call back clientDataCallback() with the read/write fd.
// worker thread
//
void *workerThread(void *tprm) {
int sockfd = (int)tprm;
int retval = listen(sockfd, 1); // mark as "server" side. here, accept only 1 connection request at a time
if (retval != 0) {
return NULL;
}
// create CFSocket and register it as data source.
CFSocketRef socket = CFSocketCreateWithNative(kCFAllocatorDefault, sockfd, kCFSocketAcceptCallBack, socketDataCallback, nil);
// don't close native fd on CFSocketInvalidate
CFSocketSetSocketFlags(socket, CFSocketGetSocketFlags(socket) & ~kCFSocketCloseOnInvalidate);
// create run loop source
CFRunLoopSourceRef socketRunLoop = CFSocketCreateRunLoopSource(kCFAllocatorDefault, socket, 0);
// add to run loop
CFRunLoopAddSource(CFRunLoopGetCurrent(), socketRunLoop, kCFRunLoopCommonModes);
CFRelease(socketRunLoop);
CFRelease(socket);
CFRunLoopRun();
// not return here untill run loop stops
close(sockfd);
return NULL;
}
// socket connection w/ client side. create another data source and add to run-loop
//
void socketDataCallback(CFSocketRef s, CFSocketCallBackType callbackType, CFDataRef address, const void *data, void *info) {
CFSocketContext socketContext;
memset(&socketContext, 0, sizeof(CFSocketContext));
int clientfd = *((int *)data); // get file descriptor (fd)
socketContext.info = (void *)((long)clientfd); // set fd at info of socketContext
// create CFSocket for tx/rx w/ connected client
CFSocketRef socket = CFSocketCreateWithNative(kCFAllocatorDefault, clientfd, kCFSocketReadCallBack | kCFSocketWriteCallBack, clientDataCallback, &socketContext);
CFSocketDisableCallBacks(socket, kCFSocketWriteCallBack);
CFRunLoopSourceRef socketRunLoop = CFSocketCreateRunLoopSource(kCFAllocatorDefault, socket, 0);
CFRunLoopAddSource(CFRunLoopGetCurrent(), socketRunLoop, kCFRunLoopCommonModes);
CFRelease(socket);
CFRelease(socketRunLoop);
}
// data to/from client
//
void clientDataCallback(CFSocketRef s, CFSocketCallBackType callbackType, CFDataRef address, const void *data, void *info) {
if (callbackType & kCFSocketWriteCallBack) {
// your own tx data prcess here
// txDataCallback(s, callbackType, address, data, info);
}
if (!(callbackType & kCFSocketReadCallBack)) return;
// extract fd
int fd = (int)((long)info);
// read data, and do some work
uint8_t rxdata[1024];
size_t nr = read(fd, rxdata, 1024);
if (!nr) {
// socket closed
handleSocketClosed(s);
return;
}
// your own rx process here
}
// socket closed
//
void handleSocketClosed(CFSocketRef s) {
// any clean up process here, then
CFSocketInvalidate(s);
// stop run loop if necessary
// CFRunLoopStop(CFRunLoopGetCurrent());
}
If you are working at client side, things get a bit easier. You get a read/write fd with connect() call. Then you create CFSockeRef and add to run-loop by using the fd.
Hope this helps.
EDIT: How to wait with POSIX select(). To wait with POSIX select() at worker thread is simpler than socket call back. If you are on client side, then:
int sockfd = socket(...);
bind(sockfd, ...)
connect(sockfd, ...);
while (1) {
int nfds = sockfd+1;
fd_set rfds;
FD_ZERO(&rfds);
FD_SET(sockfd, &rfds);
int retval = select(nfds, &rfds, NULL, NULL, NULL);
if (retval == -1) break;
if (retval > 0) {
uint8_t rxdata[1024];
size_t nr = read(sockfd, rxdata, 1024);
if (!nr) {
// socket closed.
break;
}
// do your rx process here
}
}
Run the code above at your worker thread.
I'm developing an iOS app (using Swift) which uses a TCP connection to a TCP server. Currently, whenever I've sent something, the connection closes automatically. I want to keep the connection open/alive until I manually close it.
From this Objective-C-based question I found that it could be done like this in Objective-C:
#include <sys/socket.h>
...
CFDataRef socketData = CFReadStreamCopyProperty((__bridge CFReadStreamRef)(stream), kCFStreamPropertySocketNativeHandle);
CFSocketNativeHandle socket;
CFDataGetBytes(socketData, CFRangeMake(0, sizeof(CFSocketNativeHandle)), (UInt8 *)&socket);
CFRelease(socketData);
int on = 1;
if (setsockopt(socket, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on)) == -1) {
NSLog(#"setsockopt failed: %s", strerror(errno));
}
My current Swift implementation/translation looks like this:
var socketData = CFReadStreamCopyProperty(inputStream, kCFStreamPropertySocketNativeHandle) as CFDataRef
var socket: CFSocketNativeHandle
CFDataGetBytes(socketData, CFRangeMake(0, sizeof(CFSocketNativeHandle)), (UInt8).self&socket)
var on: UInt8 = 1;
if setsockopt(socket, SOL_SOCKET, SO_KEEPALIVE, &on, 255) == -1 {
}
A few notes:
inputStream is declared as: var inputStream: NSInputStream?
I'm not sure if using 255 as an alternative to sizeof(on) is a good idea.
The code happens in the function func stream(theStream:NSStream, handleEvent streamEvent:NSStreamEvent) which is required by using the NSStreamDelegate protocol.
I'm not sure if using inputStream instead of theStream (function parameter) is a good idea.
I'm getting an Xcode error on the CFDataGetBytes function. It says the following:
'NSData' is not a subtype of of 'CFData'
Any idea how to fix that?
Also, how do I import/include <sys/socket.h> in my Swift file? I've seen something called bridging headers, but isn't that only for Obj-C side-by-side with Swift implementations?
CFDataRef is "toll-free bridged" to NSData, therefore the first part can be
more simply written as
var socketData = CFReadStreamCopyProperty(inputStream, kCFStreamPropertySocketNativeHandle) as NSData
var socket: CFSocketNativeHandle = 0
socketData.getBytes(&socket, length: sizeofValue(socket))
The "option_value" argument of setsockopt() is the address of an int (which is mapped to Swift as UInt32), and the last argument has to be the size of that variable:
var on: UInt32 = 1;
if setsockopt(socket, SOL_SOCKET, SO_KEEPALIVE, &on, socklen_t(sizeofValue(on))) == -1 {
let errmsg = String.fromCString(strerror(errno))
println("setsockopt failed: \(errno) \(errmsg)")
}
<sys/socket.h> is imported by default.
in iOS CFSocket the way handle callback function is as followed
void receiveData(CFSocketRef s,
CFSocketCallBackType type,
CFDataRef address,
const void *data,
void *info)
{
}
int main ()
{
CFSocketRef s = CFSocketCreate(NULL, PF_INET,
SOCK_STREAM, IPPROTO_TCP,
kCFSocketDataCallBack,
receiveData,
NULL);
struct sockaddr_in sin;
struct hostent *host;
host = gethostbyname("localhost");
memset(&sin, 0, sizeof(sin));
memcpy(&(sin.sin_addr), host->h_addr,host->h_length);
sin.sin_family = AF_INET;
sin.sin_port = htons(888);
CFDataRef address, data;
UInt8 message[] = "Hello world";
CFRunLoopSourceRef source;
address = CFDataCreate(NULL, (UInt8 *)&sin, sizeof(sin));
data = CFDataCreate(NULL, message, sizeof(message));
CFSocketConnectToAddress(s, address, 0);
CFSocketSendData(s, NULL, data, 0);
}
in CFSocket when we do a CFSocketCreate we put the callback function in the SocketCreate function.
But for C Code the Socket and read from Socket is as followed.
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (connect(sockfd,(struct sockaddr *) &serv_addr,sizeof(serv_addr)) < 0)
error("ERROR connecting");
printf("Please enter the message: ");
bzero(buffer,256);
fgets(buffer,255,stdin);
n = write(sockfd,buffer,strlen(buffer));
if (n < 0)
error("ERROR writing to socket");
bzero(buffer,256);
n = read(sockfd,buffer,255);
I don't how to implement the callback read function inside the C Code. The callback function would be implemented every time something come into the buffer.
As you noted BSD sockets is not callback based, you need to poll from read to receive new data. You can call this periodically on the main thread or create a custom thread for reading data repeatedly.
CFSocket wraps BSD sockets at a higher level. It has some nice features, I believe that it automatically handles threading, and sleeps the thread until data is received. Reimplemnenting these features would not be a trivial process.
Good resources:
http://beej.us/guide/bgnet/
BSD Sockets - How to use non-blocking sockets?
http://man7.org/linux/man-pages/man2/poll.2.html
Have been doing some google search and some reading on this subject but cannot seem to get it right no matter how much time i spent searching.
What i want to do is to receive broadcast message of devices that are connected on my network by advertising my interest in their services that they supply. Using wireshark i can see the broadcast/notification messages from the network devices that i want to connect to sent over my network but not my broadcast search for interest of their services.
But with network utility i can see that the socket is created but don't know which state it is in, whether listen or connected.
Yes i know that there are libraries that i can use to do this, but i wanted to build something of my own from the ground up and get a better understand of how it works.
MySocket.h
#import <Foundation/Foundation.h>
#import <CoreFoundation/CoreFoundation.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#if TARGET_OS_IPHONE
#import <CFNetwork/CFNetwork.h>
#endif
#interface MySocket : NSObject
{
NSString* _message;
CFSocketRef cfSocket;
CFRunLoopSourceRef cfSource;
}
- (void)listen;
#end
MySocket.m
#import "MySocket.h"
#define MAX_UDP_DATAGRAM_SIZE 65507
#implementation MySocket
static void socketCallback(CFSocketRef cfSocket, CFSocketCallBackType
type, CFDataRef address, const void *data, void *userInfo)
{
NSLog(#"socketCAllBAck was called");
}
- (void)listen
{
//Enable broadcast to network hosts
int yes = 1;
int setSockResult = 0;
_message = [[NSMutableString alloc ] initWithString: #"M-SEARCH *HTTP/1.1\r\nHOST:239.255.255.250:1900\r\nMAN:\"ssdp:discover\"\r\nST:ssdp:all\r\nMX:1\r\n\r\n"];
CFSocketContext socketContext = {0, self, NULL, NULL, NULL};
/* Create the server socket as a UDP IPv4 socket and set a callback */
/* for calls to the socket's lower-level accept() function */
cfSocket = CFSocketCreate(NULL, PF_INET, SOCK_DGRAM, IPPROTO_UDP,
kCFSocketAcceptCallBack | kCFSocketDataCallBack , (CFSocketCallBack)socketCallback, &socketContext);
if (cfSocket == NULL)
NSLog(#"UDP socket could not be created\n");
/* Re-use local addresses, if they're still in TIME_WAIT */
setSockResult = setsockopt(CFSocketGetNative(cfSocket), SOL_SOCKET, SO_BROADCAST, (void *)&yes, sizeof(yes));
if(setSockResult < 0)
NSLog(#"Could not setsockopt for broabcast");
/* Set the port and address we want to listen on */
struct sockaddr_in addr;
memset(&addr, 0, sizeof(addr));
addr.sin_len = sizeof(addr);
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = inet_addr("239.255.255.250");
//inet_pton(AF_INET, "239.255.255.250", &(addr.sin_addr));
addr.sin_port = htons(1900);
//addr.sin_addr.s_addr = htonl(INADDR_ANY);
NSData *address = [ NSData dataWithBytes: &addr length: sizeof(addr) ];
if (address != nil && CFSocketSetAddress(cfSocket, (CFDataRef) address) != kCFSocketSuccess) {
NSLog(#"CFSocketSetAddress() failed\n");
CFRelease(cfSocket);
}
CFDataRef data = CFDataCreate(NULL, (const UInt8*)[_message UTF8String], [_message lengthOfBytesUsingEncoding:NSUTF8StringEncoding]);
setSockResult = CFSocketSendData(cfSocket, (CFDataRef)address, data, 0.0);
if(kCFSocketSuccess != setSockResult) NSLog(#"Unable to send data, %i", setSockResult);
else NSLog(#"Sending data");
cfSource = CFSocketCreateRunLoopSource(kCFAllocatorDefault, cfSocket, 0);
if(cfSource == NULL)
NSLog(#"CFRunLoopSourceRef is null");
CFRunLoopAddSource(CFRunLoopGetCurrent(), cfSource, kCFRunLoopDefaultMode);
NSLog(#"Socket listening on port 1900");
CFRelease(cfSource);
CFRelease(cfSocket);
[address release];
data = nil;
CFRunLoopRun();
}
- (void)dealloc
{
CFRunLoopRemoveSource(CFRunLoopGetCurrent(), cfSource, kCFRunLoopDefaultMode);
CFRelease(cfSource);
CFRelease(cfSocket);
[_message release];
[super dealloc];
}
#end
Edit: Everything runs well until the call to send data.
Is there something small but critical in order for this to work that i'm missing?
Or i'm missing the big picture?
Any help or guide is appreciated.
Thanks in advance and have a nice weekend
remove SetAdress and all will be work fine. i've tested this now;
How about use this initialization with address
CFDataRef address=CFDataCreate(kCFAllocatorDefault,(UInt8 *)&addr,sizeof(addr));