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I have some modbus ethernet tcp communications that I'm attempting to do in a DLL. I get numerous TCP Retransmissions from the target device, as seen in WireShark.
(In this image, 192.168.1.5 is the Modbus device. 192.168.1.72 is the computer)
However, when the same code is inserted directly into an application, there are no communication errors.
I'm wondering if DLLs have some sort of lower priority that can cause slower communications, or if anyone may have any insight as to why this code would run without TCP issue in an application, but not in a DLL.
Here is the dll header:
#ifndef __MAIN_H__
#define __MAIN_H__
#include <windows.h>
typedef void *eioTHandle;
#ifdef __cplusplus
extern "C"
{
#endif
__declspec(dllexport) int __stdcall eioConnect( unsigned short ModelId, char *Ip, eioTHandle *Handle );
#ifdef __cplusplus
}
#endif
#endif
And here is the source file:
#include "main.h"
#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdint.h>
#define EIO500_S 0
#define EIO500_MS 1000
#define eioERROR -1
#define eioSUCCESS 0
static uint8_t m_UnitId = 0xff;
static SOCKET m_Sock;
BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpReserved )
{
// Perform actions based on the reason for calling.
switch( fdwReason )
{
case DLL_PROCESS_ATTACH:
// Initialize once for each new process.
// Return FALSE to fail DLL load.
break;
case DLL_THREAD_ATTACH:
// Do thread-specific initialization.
break;
case DLL_THREAD_DETACH:
// Do thread-specific cleanup.
break;
case DLL_PROCESS_DETACH:
// Perform any necessary cleanup.
break;
}
return TRUE; // Successful DLL_PROCESS_ATTACH.
}
int __stdcall eioConnect( unsigned short ModelId, char *Ip, eioTHandle *Handle )
{
WSADATA Wsa;
struct sockaddr_in Server;
int Result;
char Buffer[256];
char InBuffer[256];
// CONNECTION --------------------------------------------------------------
if (WSAStartup(MAKEWORD(2,2), &Wsa) != 0)
{
return eioERROR;
}
m_Sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (m_Sock == INVALID_SOCKET)
{
WSACleanup();
return eioERROR;
}
Server.sin_addr.s_addr = inet_addr(Ip);
Server.sin_family = AF_INET;
Server.sin_port = htons(502);
if (connect(m_Sock, (struct sockaddr *)&Server, sizeof(Server))
== SOCKET_ERROR)
{
closesocket(m_Sock);
m_Sock = INVALID_SOCKET;
WSACleanup();
return eioERROR;
}
// -------------------------------------------------------------------------
for (int Ctr = 0; Ctr < 50000; Ctr++)
{
// SEND COMMAND --------------------------------------------------------
// 5 bytes in a Send Read Multiple Coils command.
int NumBytes = 5;
Buffer[0] = 0;
Buffer[1] = 0;
Buffer[2] = 0;
Buffer[3] = 0;
Buffer[4] = 0;
Buffer[5] = NumBytes + 1; // 1 for unit id.
Buffer[6] = m_UnitId;
// 0 = Function code.
Buffer[7] = 0x01;
// 1+2 = Address.
Buffer[8] = 0;
Buffer[9] = 8;
// 3+4 = Number of bits to read.
Buffer[10] = 0;
Buffer[11] = 8;
if (send(m_Sock, Buffer, NumBytes + 7, 0) == SOCKET_ERROR)
{
continue;
}
// ---------------------------------------------------------------------
// WAIT FOR RECEIVE ----------------------------------------------------
WSAEVENT RecvEvent;
int Ret;
RecvEvent = WSACreateEvent();
WSAEventSelect( m_Sock, RecvEvent, FD_READ );
Ret = WSAWaitForMultipleEvents(1, &RecvEvent, TRUE, 1000, FALSE);
WSAResetEvent(RecvEvent);
if (Ret == WSA_WAIT_TIMEOUT)
continue;
// -------------------------------------------------------------------------
// Check for any reply.
recv(m_Sock, InBuffer, 256, 0);
}
// DISCONNECT --------------------------------------------------------------
Result = shutdown(m_Sock, SD_SEND);
if (Result == SOCKET_ERROR)
{
closesocket(m_Sock);
WSACleanup();
m_Sock = INVALID_SOCKET;
return eioERROR;
}
// Receive until the peer closes the connection.
while (recv(m_Sock, Buffer, 256, 0) > 0);
closesocket(m_Sock);
WSACleanup();
m_Sock = INVALID_SOCKET;
// ------------------------------------------------------------------------
return eioSUCCESS;
}
I've simplified the code as much as possible. The communication is in a loop for testing. The original application would poll this data from the device.
No. From the network's perspective there's no difference in TCP segments sent some way or other. There may be a protocol prioritation though (QoS) that may cause packet drops when links are saturated.
A more likely cause could be a problem with the checksums: invalid checksums cause packet drops which in turn cause retransmissions. Possibly the API works slightly different when called from a DLL, so the checksums are calculated (correctly).
I am trying to call the HappyTime onvif library from Swift.
I have the library linked in to my project and I am able to call some simple functions, but I am having trouble getting the syntax right in my call which passes my callback function.
Here is the Swift code:
func discoverCameras()
{
HappyInterface.sharedInstance().startProb()
//this line gives syntax error
HappyInterface.sharedInstance().setProbeCB(cameraDiscovered)
}
func cameraDiscovered(cameraFound:UnsafeMutablePointer<DEVICE_BINFO>)
{
table.reloadData()
}
my setProbeCB call gives this error:
Cannot convert value of type '(UnsafeMutablePointer) -> ()' to expected argument type 'UnsafeMutablePointer' (aka 'UnsafeMutablePointer, UnsafeMutablePointer<()>) -> ()>>')
Here is the Obj C implementation:
- (void) setProbeCB:(onvif_probe_cb *)cb {
set_probe_cb(*cb, 0);
}
This is the Obj C header:
- (void) setProbeCB:(onvif_probe_cb *)cb;
This is the C header:
#ifndef __H_ONVIF_PROBE_H__
#define __H_ONVIF_PROBE_H__
#include "onvif.h"
typedef void (* onvif_probe_cb)(DEVICE_BINFO * p_res, void * pdata);
#ifdef __cplusplus
extern "C" {
#endif
ONVIF_API void set_probe_cb(onvif_probe_cb cb, void * pdata);
ONVIF_API void set_probe_interval(int interval);
ONVIF_API int start_probe(int interval);
ONVIF_API void stop_probe();
ONVIF_API void send_probe_req();
#ifdef __cplusplus
}
#endif
#endif // __H_ONVIF_PROBE_H__
This is the C code:
/***************************************************************************************/
#define MAX_PROBE_FD 8
/***************************************************************************************/
onvif_probe_cb g_probe_cb = 0;
void * g_probe_cb_data = 0;
pthread_t g_probe_thread = 0;
int g_probe_fd[MAX_PROBE_FD];
int g_probe_interval = 30;
BOOL g_probe_running = FALSE;
/***************************************************************************************/
int onvif_probe_init(unsigned int ip)
{
int opt = 1;
SOCKET fd;
struct sockaddr_in addr;
struct ip_mreq mcast;
fd = socket(AF_INET, SOCK_DGRAM, 0);
if(fd < 0)
{
log_print(LOG_ERR, "socket SOCK_DGRAM error!\n");
return -1;
}
addr.sin_family = AF_INET;
addr.sin_port = htons(3702);
addr.sin_addr.s_addr = ip;
if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) == -1)
{
// if port 3702 already occupied, only receive unicast message
addr.sin_port = 0;
if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) == -1)
{
closesocket(fd);
log_print(LOG_ERR, "bind error! %s\n", sys_os_get_socket_error());
return -1;
}
}
/* reuse socket addr */
if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char*)&opt, sizeof(opt)))
{
log_print(LOG_WARN, "setsockopt SO_REUSEADDR error!\n");
}
memset(&mcast, 0, sizeof(mcast));
mcast.imr_multiaddr.s_addr = inet_addr("239.255.255.250");
mcast.imr_interface.s_addr = ip;
if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char*)&mcast, sizeof(mcast)) < 0)
{
#if __WIN32_OS__
if(setsockopt(fd, IPPROTO_IP, 5, (char*)&mcast, sizeof(mcast)) < 0)
#endif
{
closesocket(fd);
log_print(LOG_ERR, "setsockopt IP_ADD_MEMBERSHIP error! %s\n", sys_os_get_socket_error());
return -1;
}
}
return fd;
}
char probe_req1[] =
"<?xml version=\"1.0\" encoding=\"utf-8\"?>"
"<Envelope xmlns:tds=\"http://www.onvif.org/ver10/device/wsdl\" xmlns=\"http://www.w3.org/2003/05/soap-envelope\">"
"<Header>"
"<wsa:MessageID xmlns:wsa=\"http://schemas.xmlsoap.org/ws/2004/08/addressing\">uuid:%s</wsa:MessageID>"
"<wsa:To xmlns:wsa=\"http://schemas.xmlsoap.org/ws/2004/08/addressing\">urn:schemas-xmlsoap-org:ws:2005:04:discovery</wsa:To>"
"<wsa:Action xmlns:wsa=\"http://schemas.xmlsoap.org/ws/2004/08/addressing\">http://schemas.xmlsoap.org/ws/2005/04/discovery/Probe</wsa:Action>"
"</Header>"
"<Body>"
"<Probe xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns=\"http://schemas.xmlsoap.org/ws/2005/04/discovery\">"
"<Types>tds:Device</Types>"
"<Scopes />"
"</Probe>"
"</Body>"
"</Envelope>";
char probe_req2[] =
"<?xml version=\"1.0\" encoding=\"utf-8\"?>"
"<Envelope xmlns:dn=\"http://www.onvif.org/ver10/network/wsdl\" xmlns=\"http://www.w3.org/2003/05/soap-envelope\">"
"<Header>"
"<wsa:MessageID xmlns:wsa=\"http://schemas.xmlsoap.org/ws/2004/08/addressing\">uuid:%s</wsa:MessageID>"
"<wsa:To xmlns:wsa=\"http://schemas.xmlsoap.org/ws/2004/08/addressing\">urn:schemas-xmlsoap-org:ws:2005:04:discovery</wsa:To>"
"<wsa:Action xmlns:wsa=\"http://schemas.xmlsoap.org/ws/2004/08/addressing\">http://schemas.xmlsoap.org/ws/2005/04/discovery/Probe</wsa:Action>"
"</Header>"
"<Body>"
"<Probe xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns=\"http://schemas.xmlsoap.org/ws/2005/04/discovery\">"
"<Types>dn:NetworkVideoTransmitter</Types>"
"<Scopes />"
"</Probe>"
"</Body>"
"</Envelope>";
int onvif_probe_req_tx(int fd)
{
int len;
int rlen;
char * p_bufs = NULL;
struct sockaddr_in addr;
int buflen = 10*1024;
p_bufs = (char *)malloc(buflen);
if (NULL == p_bufs)
{
return -1;
}
memset(p_bufs, 0, buflen);
sprintf(p_bufs, probe_req1, onvif_uuid_create());
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = inet_addr("239.255.255.250");
addr.sin_port = htons(3702);
len = strlen(p_bufs);
rlen = sendto(fd, p_bufs, len, 0, (struct sockaddr *)&addr, sizeof(struct sockaddr_in));
if (rlen != len)
{
log_print(LOG_ERR, "onvif_probe_req_tx::rlen = %d,slen = %d\r\n", rlen, len);
}
usleep(1000);
memset(p_bufs, 0, buflen);
sprintf(p_bufs, probe_req2, onvif_uuid_create());
len = strlen(p_bufs);
rlen = sendto(fd, p_bufs, len, 0, (struct sockaddr *)&addr, sizeof(struct sockaddr_in));
if (rlen != len)
{
log_print(LOG_ERR, "onvif_probe_req_tx::rlen = %d,slen = %d\r\n", rlen, len);
}
free(p_bufs);
return rlen;
}
BOOL onvif_parse_device_binfo(XMLN * p_node, DEVICE_BINFO * p_res)
{
XMLN * p_EndpointReference;
XMLN * p_Types;
XMLN * p_XAddrs;
p_EndpointReference = xml_node_soap_get(p_node, "EndpointReference");
if (p_EndpointReference)
{
XMLN * p_Address = xml_node_soap_get(p_EndpointReference, "Address");
if (p_Address && p_Address->data)
{
strncpy(p_res->EndpointReference, p_Address->data, sizeof(p_res->EndpointReference)-1);
}
}
p_Types = xml_node_soap_get(p_node, "Types");
if (p_Types && p_Types->data)
{
p_res->type = parse_DeviceType(p_Types->data);
}
p_XAddrs = xml_node_soap_get(p_node, "XAddrs");
if (p_XAddrs && p_XAddrs->data)
{
parse_XAddr(p_XAddrs->data, &p_res->XAddr);
if (p_res->XAddr.host[0] == '\0' || p_res->XAddr.port == 0)
{
return FALSE;
}
}
else
{
return FALSE;
}
return TRUE;
}
BOOL onvif_probe_res(XMLN * p_node, DEVICE_BINFO * p_res)
{
XMLN * p_body = xml_node_soap_get(p_node, "Body");
if (p_body)
{
XMLN * p_ProbeMatches = xml_node_soap_get(p_body, "ProbeMatches");
if (p_ProbeMatches)
{
XMLN * p_ProbeMatch = xml_node_soap_get(p_ProbeMatches, "ProbeMatch");
while (p_ProbeMatch && soap_strcmp(p_ProbeMatch->name, "ProbeMatch") == 0)
{
if (onvif_parse_device_binfo(p_ProbeMatch, p_res))
{
if (g_probe_cb)
{
g_probe_cb(p_res, g_probe_cb_data);
}
}
p_ProbeMatch = p_ProbeMatch->next;
}
}
else
{
XMLN * p_Hello = xml_node_soap_get(p_body, "Hello");
if (p_Hello)
{
if (onvif_parse_device_binfo(p_Hello, p_res))
{
if (g_probe_cb)
{
g_probe_cb(p_res, g_probe_cb_data);
}
}
}
}
}
return TRUE;
}
int onvif_probe_net_rx()
{
int i;
int ret;
int maxfd = 0;
int fd = 0;
char rbuf[10*1024];
fd_set fdread;
struct timeval tv = {1, 0};
FD_ZERO(&fdread);
for (i = 0; i < MAX_PROBE_FD; i++)
{
if (g_probe_fd[i] > 0)
{
FD_SET(g_probe_fd[i], &fdread);
if (g_probe_fd[i] > maxfd)
{
maxfd = g_probe_fd[i];
}
}
}
ret = select(maxfd+1, &fdread, NULL, NULL, &tv);
if (ret == 0) // Time expired
{
return 0;
}
for (i = 0; i < MAX_PROBE_FD; i++)
{
if (g_probe_fd[i] > 0 && FD_ISSET(g_probe_fd[i], &fdread))
{
int rlen;
int addr_len;
struct sockaddr_in addr;
unsigned int src_ip;
unsigned int src_port;
XMLN * p_node;
fd = g_probe_fd[i];
addr_len = sizeof(struct sockaddr_in);
rlen = recvfrom(fd, rbuf, sizeof(rbuf), 0, (struct sockaddr *)&addr, (socklen_t*)&addr_len);
if (rlen <= 0)
{
log_print(LOG_ERR, "onvif_probe_net_rx::rlen = %d, fd = %d\r\n", rlen, fd);
continue;
}
src_ip = addr.sin_addr.s_addr;
src_port = addr.sin_port;
p_node = xxx_hxml_parse(rbuf, rlen);
if (p_node == NULL)
{
log_print(LOG_ERR, "onvif_probe_net_rx::hxml parse err!!!\r\n");
}
else
{
DEVICE_BINFO res;
memset(&res, 0, sizeof(DEVICE_BINFO));
onvif_probe_res(p_node, &res);
}
xml_node_del(p_node);
}
}
return 1;
}
void * onvif_probe_thread(void * argv)
{
int count = 0;
int i = 0;
int j = 0;
for (; i < get_if_nums() && j < MAX_PROBE_FD; i++, j++)
{
unsigned int ip = get_if_ip(i);
if (ip != 0 && ip != inet_addr("127.0.0.1"))
{
g_probe_fd[j] = onvif_probe_init(ip);
}
}
for (i = 0; i < MAX_PROBE_FD; i++)
{
if (g_probe_fd[i] > 0)
{
onvif_probe_req_tx(g_probe_fd[i]);
}
}
while (g_probe_running)
{
if (onvif_probe_net_rx() == 0)
{
count++;
}
if (count >= g_probe_interval)
{
count = 0;
for (i = 0; i < MAX_PROBE_FD; i++)
{
if (g_probe_fd[i] > 0)
{
onvif_probe_req_tx(g_probe_fd[i]);
}
}
}
usleep(1000);
}
g_probe_thread = 0;
return NULL;
}
ONVIF_API void set_probe_cb(onvif_probe_cb cb, void * pdata)
{
g_probe_cb = cb;
g_probe_cb_data = pdata;
}
ONVIF_API void send_probe_req()
{
int i;
for (i = 0; i < MAX_PROBE_FD; i++)
{
if (g_probe_fd[i] > 0)
{
onvif_probe_req_tx(g_probe_fd[i]);
}
}
}
ONVIF_API void set_probe_interval(int interval)
{
g_probe_interval = interval;
if (g_probe_interval < 10)
{
g_probe_interval = 30;
}
}
ONVIF_API int start_probe(int interval)
{
g_probe_running = TRUE;
set_probe_interval(interval);
g_probe_thread = sys_os_create_thread((void *)onvif_probe_thread, NULL);
if (g_probe_thread)
{
return 0;
}
return -1;
}
ONVIF_API void stop_probe()
{
int i;
g_probe_running = FALSE;
while (g_probe_thread)
{
usleep(1000);
}
for (i = 0; i < MAX_PROBE_FD; i++)
{
if (g_probe_fd[i] > 0)
{
closesocket(g_probe_fd[i]);
g_probe_fd[i] = 0;
}
}
}
Here is what the DEVICE_BINFO struct looks like:
typedef struct
{
int type; // device type
char EndpointReference[100];
onvif_XAddr XAddr; // xaddr, include port host, url
} DEVICE_BINFO;
One thing that should be fixed is a mismatch in the number of arguments to the callback. Swift calls the Objective-C setProbeCB() method, giving it a pointer to the cameraDiscovered() function, which takes a single argument. Then setProbeCB() gives the function pointer to the C set_probe_cb() function, which expects a pointer to a function that takes two arguments.
Another observation is that setProbeCB() could just take onvif_probe_cb instead of onvif_probe_cb* and then call C code simply as set_probe_cb(cb, 0). However, I don't think it makes much difference.
Also, I think the question could have been distilled to a smaller size.
The following is a simplified example based on your original code. It shows how to implement a callback in Swift and have C code call it, but the real fun starts when passing data via callback parameters and return values. It gets very tricky very fast, and that's why the example doesn't show how to deal with DEVICE_BINFO in Swift code. It's a topic in its own right.
The clue to using (Objective-)C functions and types in Swift is figuring out how they are imported into Swift. For example, to find out how onvif_probe_cb is imported, type it on a line in the Swift code, place the cursor in it, and Quick Help will show you this:
Declaration: typealias onvif_probe_cb = (UnsafeMutablePointer<DEVICE_BINFO>, UnsafeMutablePointer<Void>) -> Void
Declared in: clib.h
That tells us the parameter and return types to use in our Swift implementation of the callback.
The example is by no means production quality: there are all kinds of things that can go haywire in terms of memory management etc. Please see the code comments for additional info.
First, here is the C code header (clib.h):
#ifndef clib_h
#define clib_h
#include <stdio.h>
typedef struct {
char hostname[50];
int32_t port;
char url[200];
} onvif_XAddr;
typedef struct
{
int type; // device type
char EndpointReference[100];
onvif_XAddr XAddr; // xaddr, include port host, url
} DEVICE_BINFO;
/**
* This is the typedef of the function pointer to be used for our callback.
* The function takes a pointer to DEVICE_BINFO and a pointer to some arbitrary
* data meaningful to the code that provides the callback implementation. It will
* be NULL in this example.
*/
typedef void (* onvif_probe_cb)(DEVICE_BINFO * p_res, void * pdata);
/**
* A function to set the callback.
*/
void set_probe_cb(onvif_probe_cb cb, void * pdata);
/**
* This is a function that calls the callback.
*/
void find_device();
#endif /* clib_h */
Here is the rest of our C source (clib.c):
#include "clib.h"
#include <string.h>
onvif_probe_cb gCB = 0; // global variable to store the callback pointer
void * gUserData = 0; // global variable to store pointer to user data
DEVICE_BINFO gDeviceInfo; // global variable to store device info struct
void find_device() {
// Set up gDeviceInfo
gDeviceInfo.XAddr.port = 1234;
strcpy( gDeviceInfo.XAddr.hostname, "myhost");
strcpy( gDeviceInfo.XAddr.url, "http://junk.com");
gDeviceInfo.type = 777;
// ... and, if a callback is available, call it with the device info
if (gCB) gCB(&gDeviceInfo, gUserData);
else puts("No callback available");
}
void set_probe_cb(onvif_probe_cb cb, void * pdata) {
gCB = cb;
gUserData = pdata;
}
Here is the Objective-C wrapper header (oclib.h):
#ifndef oclib_h
#define oclib_h
#import "clib.h"
#import <Foundation/Foundation.h>
/**
* Interface of an Objective-C wrapper around C code in clib.*. We could have
* gone straight to C from Swift, but I'm trying to keep the example close to the
* code in the question. Also, this extra Objective C layer could be helpful in
* translating data structures, such as DEVICE_BINFO, between C and Swift, since
* Objective-C plays much nicer with C data types. This is no surprise: any C code
* is valid Objective-C (Objective-C is a strict superset of C).
*/
#interface MyWrapper : NSObject
-(id)init;
// Please note: this one takes a single argument, while the C function it wraps
// takes 2; see the implementation.
-(void) setProbeCB:(onvif_probe_cb) cb;
-(void) findDevice;
#end
#endif /* oclib_h */
And the wrapper implementation (oclib.m):
#import "oclib.h"
/**
* Implementation of our Objective-C wrapper.
*/
#implementation MyWrapper
-(id)init { return self; }
-(void) setProbeCB:(onvif_probe_cb) cb {
// We don't want anything other than device info to be passed back and
// forth via the callback, so this wrapper function takes a single argument
// and passes 0 as the 2nd argument to the wrapped C function.
set_probe_cb(cb, 0);
}
-(void) findDevice {
find_device();
}
#end
Finally, here is the Swift code that implements the callback (main.swift):
var w : MyWrapper = MyWrapper()
/**
* This is the callback implementation in Swift. We don't use the 2nd argument, userData, but it still
* has to be present to satisfy the way the callback function pointer is specified in C code.
*/
func cameraDiscovered( info : UnsafeMutablePointer<DEVICE_BINFO>, userData : UnsafeMutablePointer<Void>) {
print("Called the Swift callback!")
let devInfo : DEVICE_BINFO = info.memory;
print( "The device type is \(devInfo.type)")
print( "The device port is \(devInfo.XAddr.port)")
}
// Provide the callback to C code via Objective-C
w.setProbeCB(cameraDiscovered)
// ... and call a function that will cause the C code to invoke the callback.
w.findDevice()
The bridging header just has #import oclib.h, thus exposing the contents of both C and Objective-C headers to Swift.
The expected output:
Called the Swift callback!
The device type is 777
The device port is 1234
I would like to search Sat>IP servers on the network. Sat>IP servers advertise their presence to other Sat>IP servers and clients.
I must not continuosly send M-SEARCH messages but that instead it listens to server NOTIFY messages.
After initalizing network settings of my device, I'm sending M-SEARCH message and getting response if there is already any active Sat>IP server.
However, I couldn't get any response, If I opens Sat>IP server after sending M-SEARCH message.
Here's my code.
void SatIP::InitDiscoverThread()
{
if(INVALID_THREAD_CHK == DiscoverThreadChk)
{
pthread_attr_t attr;
pthread_attr_init(&attr);
pthread_attr_setstacksize(&attr, PTHREAD_STACK_SIZE);
printf("InitDiscoverThread pthread_create\n");
DiscoverThreadChk = PTH_RET_CHK(pthread_create(&DiscoverThreadID, &attr, DiscoverThreadFunc, this));
if(DiscoverThreadChk != 0)
{
ASSERT(0);
}
}
}
void SatIP::FinalizeDiscoverThread()
{
if(INVALID_THREAD_CHK != DiscoverThreadChk)
{
printf("FinalizeDiscoverThread pthread_cancel\n");
pthread_cancel(DiscoverThreadID);
DiscoverThreadChk = INVALID_THREAD_CHK;
close(discoverSocket);
}
}
void *SatIP::DiscoverThreadFunc(void* arg)
{
SatIP* satip = (SatIP *)arg;
satip->ListenSSDPResponse();
pthread_exit(NULL);
}
bool SatIP::SendMSearchMessage()
{
vSatIPServers.clear();
FinalizeDiscoverThread();
const char *searchSatIPDevice = "M-SEARCH * HTTP/1.1\r\n" \
"HOST: 239.255.255.250:1900\r\n" \
"MAN: \"ssdp:discover\"\r\n" \
"MX: 2\r\n" \
"ST: urn:ses-com:device:SatIPServer:1\r\n\r\n";
struct sockaddr_in upnpControl, broadcast_addr;
discoverSocket = socket(AF_INET, SOCK_DGRAM, 0);
if (discoverSocket == INVALID_SOCKET)
{
printf("socked failed INVALID_SOCKET\n");
return false;
}
struct timeval tv;
tv.tv_sec = 1;
tv.tv_usec = 0;
if(setsockopt(discoverSocket, SOL_SOCKET, SO_RCVTIMEO, (char*)&tv, sizeof(tv)) == SOCKET_ERROR)
{
printf("setsockopt timeout failed\n");
close(discoverSocket);
return false;
}
socklen_t ttl = 2;
if(setsockopt(discoverSocket, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) == SOCKET_ERROR)
{
printf("setsockopt TTL failed\n");
close(discoverSocket);
return false;
}
if(setsockopt(discoverSocket, SOL_SOCKET, SO_BROADCAST, searchSatIPDevice, sizeof(searchSatIPDevice)) == SOCKET_ERROR)
{
printf("setsockopt broadcast failed\n");
close(discoverSocket);
return false;
}
upnpControl.sin_family = AF_INET;
upnpControl.sin_port = htons(0);
upnpControl.sin_addr.s_addr = INADDR_ANY;
if (bind(discoverSocket, (sockaddr*)&upnpControl, sizeof(upnpControl)) == SOCKET_ERROR)
{
printf("bind failed\n");
close(discoverSocket);
return false;
}
broadcast_addr.sin_family = AF_INET;
broadcast_addr.sin_port = htons(1900);
broadcast_addr.sin_addr.s_addr = inet_addr("239.255.255.250");
for(int i = 0; i < 3; i++)
{
if(sendto(discoverSocket, searchSatIPDevice, strlen(searchSatIPDevice), 0, (sockaddr *)&broadcast_addr, sizeof(broadcast_addr)) == SOCKET_ERROR)
{
//printf("sendto failed\n");
close(discoverSocket);
return false;
}
else
{
usleep(10*100);
}
}
InitDiscoverThread();
return true;
}
void SatIP::ListenSSDPResponse()
{
while(1)
{
char buf[512];
memset(buf, 0, 512);
struct sockaddr_in broadcast_addr;
broadcast_addr.sin_family = AF_INET;
broadcast_addr.sin_port = htons(1900);
broadcast_addr.sin_addr.s_addr = inet_addr("239.255.255.250");
int bcLen = sizeof(broadcast_addr);
//bool bRet = false;
while (recvfrom(discoverSocket, buf, 512, 0, (struct sockaddr*)&broadcast_addr, (socklen_t*)&bcLen) > 0)
{
printf("buf:%s\n",buf);
SATIP_SERVER_DESCRIPTION stServerDesc;
ostringstream ss;
if(strstr(buf, "device:SatIPServer"))
{
int i = 0;
char *deviceIp = strstr(buf, "LOCATION:") + 9; // get xml location including server description
while(deviceIp[i] == ' ') i++; // remove spaces from string
while(!isspace(deviceIp[i]))
{
ss << deviceIp[i];
++i;
}
stServerDesc.location = ss.str().c_str();
printf("location:%s\n",stServerDesc.location.c_str());
ss.str(""); // clear ss
i=0; // clear counter
deviceIp = strstr(buf, "http://") + 7; // get ip address
while(deviceIp[i] != ':')
{
ss << deviceIp[i];
++i;
}
stServerDesc.ipAddr = ss.str().c_str();
printf("ipAddr:%s\n", stServerDesc.ipAddr.c_str());
DownloadDeviceDescription(&stServerDesc);
stServerDesc.macAddr = GetMACAddressviaIP(stServerDesc.ipAddr);
printf("macAddr:%s\n", stServerDesc.macAddr.c_str());
if(IsServerProperToAdd(&stServerDesc))
vSatIPServers.push_back(stServerDesc);
printf("\n");
//bRet = true;
}
memset(buf, 0, 512);
}
}
}
How can I fix this issue? Any help would be appreciated.
Listening SSDP notify message is not related to sending M-SEARCH message. Devices like Sat>IP send NOTIFY message to 239.255.255.250 periodically even if you don't send M-SEARCH message. So, you should join a multicast group and receives from the group.
You can use the listener program in the following link by changing HELLO_PORT as 1900 and HELLO_GROUP as "239.255.255.250".
http://ntrg.cs.tcd.ie/undergrad/4ba2/multicast/antony/example.html
/*
* listener.c -- joins a multicast group and echoes all data it receives from
* the group to its stdout...
*
* Antony Courtney, 25/11/94
* Modified by: Frédéric Bastien (25/03/04)
* to compile without warning and work correctly
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <time.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#define HELLO_PORT 1900
#define HELLO_GROUP "239.255.255.250"
#define MSGBUFSIZE 256
main(int argc, char *argv[])
{
struct sockaddr_in addr;
int fd, nbytes,addrlen;
struct ip_mreq mreq;
char msgbuf[MSGBUFSIZE];
u_int yes=1; /*** MODIFICATION TO ORIGINAL */
/* create what looks like an ordinary UDP socket */
if ((fd=socket(AF_INET,SOCK_DGRAM,0)) < 0) {
perror("socket");
exit(1);
}
/**** MODIFICATION TO ORIGINAL */
/* allow multiple sockets to use the same PORT number */
if (setsockopt(fd,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(yes)) < 0) {
perror("Reusing ADDR failed");
exit(1);
}
/*** END OF MODIFICATION TO ORIGINAL */
/* set up destination address */
memset(&addr,0,sizeof(addr));
addr.sin_family=AF_INET;
addr.sin_addr.s_addr=htonl(INADDR_ANY); /* N.B.: differs from sender */
addr.sin_port=htons(HELLO_PORT);
/* bind to receive address */
if (bind(fd,(struct sockaddr *) &addr,sizeof(addr)) < 0) {
perror("bind");
exit(1);
}
/* use setsockopt() to request that the kernel join a multicast group */
mreq.imr_multiaddr.s_addr=inet_addr(HELLO_GROUP);
mreq.imr_interface.s_addr=htonl(INADDR_ANY);
if (setsockopt(fd,IPPROTO_IP,IP_ADD_MEMBERSHIP,&mreq,sizeof(mreq)) < 0) {
perror("setsockopt");
exit(1);
}
/* now just enter a read-print loop */
while (1) {
addrlen=sizeof(addr);
if ((nbytes=recvfrom(fd,msgbuf,MSGBUFSIZE,0,
(struct sockaddr *) &addr,&addrlen)) < 0) {
perror("recvfrom");
exit(1);
}
puts(msgbuf);
}
}
i'm a beginner in network programming and i have a project in which i have to create a system explorer. That means that i will have the ability to write a http request with a directory in a browser and if the connection with the server is succesfull, the files from the above directory will open.
int main(int argc, char** argv)
{
typedef struct tcpip_connection
{
int connfd;
struct sockaddr_in peer_addr;
} tcpip_connection;
int s_socket, *fd, port;
char buffer[256];
struct sockaddr_in lis_addr;
struct sockaddr_in peer_addr;
int sopt = 1, n;
s_socket=socket(AF_INET, SOCK_STREAM, 0);
if(s_socket<0){
printf("error: the socket was not created!");
}
if(setsockopt(s_socket , SOL_SOCKET, SO_REUSEADDR, &sopt, sizeof(sopt))){
printf("Setsokopt error!");
}
memset(&lis_addr, 0, sizeof(lis_addr));
lis_addr.sin_family = AF_INET;
lis_addr.sin_addr.s_addr = htonl(INADDR_ANY);
lis_addr.sin_port = htons(port);
if ( bind( s_socket, (struct sockaddr*) &lis_addr, sizeof(lis_addr) ) < 0 ){
perror(NULL);
exit(-1);
}
if(listen(s_socket,15)<0){
perror("server.listen");
}
socklen_t peer_addrlen;
while(1){
if((fd = malloc(sizeof(int))) == NULL){
fprintf(stderr, "Out of memory\n");
abort();
}
*fd=accept(s_socket, (struct sockaddr*)&peer_addr,&peer_addrlen);
if(fd<0){
if( errno==EINTR /* Call interrupted by signal */
|| errno==ECONNABORTED /* connection was aborted */
|| errno==EMFILE /* per-process limit of open fds */
|| errno==ENFILE /* system-wide limit of open fds */
|| errno==ENOBUFS /* no space for socket buffers */
|| errno==ENOMEM /* no space for socket buffers */
|| errno==EPERM /* Firewall blocked the connection */
)
continue;
}
}
if(errno == EBADF)
break; /* return, the server_socket is closed */
}
bzero(buffer,1024);
n = read(*fd,buffer,1023);
if (n < 0)
{
perror("ERROR reading from socket");
exit(1);
}
printf("Here is the message: %s\n",buffer);
/* Write a response to the client
n = write(*fd,"I got your message",18);
if (n < 0)
{
perror("ERROR writing to socket");
exit(1);
}
return 0;*/
}
I don't know if there is anything wrong with my code, but the main problem is that i don't know how to make the browser connect with the server. Is there anything i have to write in the browser or do i have to add some extra code?
You forgot to initialize the port variable. Try setting port = 8080 before you call bind and listen.
Then, in your browser, go to http://localhost:8080/ and it should connect.
I want to use libusb library for writing some test applications for USB.
Can any one please suggest how to set control transfers using usb_control_msg call?
I am getting bad descriptor error while running the following code.
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include "usb.h"
static int vendor_id;
static int product_id;
typedef struct{
int requesttype;
int request;
int value;
int index;
char *bytes;
int size;
int timeout;
}ctrlmsg_param;
void print_endpoint(struct usb_endpoint_descriptor *endpoint)
{
printf("=====End point Information====\n");
printf("bEndpointAddress: %x\n", endpoint->bEndpointAddress);
printf("bmAttributes: %x\n", endpoint->bmAttributes);
printf("wMaxPacketSize: %d\n", endpoint->wMaxPacketSize);
printf("bInterval: %d\n", endpoint->bInterval);
printf("bRefresh: %d\n", endpoint->bRefresh);
printf("bSynchAddress: %d\n", endpoint->bSynchAddress);
}
void print_altsetting(struct usb_interface_descriptor *interface)
{
int i;
printf("\n=====Alternate Setting Information====\n");
printf("bInterfaceNumber: %d\n", interface->bInterfaceNumber);
printf("bAlternateSetting: %d\n", interface->bAlternateSetting);
printf("bNumEndpoints: %d\n", interface->bNumEndpoints);
printf("bInterfaceClass: %d\n", interface->bInterfaceClass);
printf("bInterfaceSubClass: %d\n", interface->bInterfaceSubClass);
printf("bInterfaceProtocol: %d\n", interface->bInterfaceProtocol);
printf("iInterface: %d\n", interface->iInterface);
for (i = 0; i < interface->bNumEndpoints; i++)
print_endpoint(&interface->endpoint[i]);
}
void print_interface(struct usb_interface *interface)
{
int i;
for (i = 0; i < interface->num_altsetting; i++)
print_altsetting(&interface->altsetting[i]);
}
void print_configuration(struct usb_config_descriptor *config)
{
int i;
printf("=====Configuration Information====\n");
printf("wTotalLength: %d\n", config->wTotalLength);
printf("bNumInterfaces: %d\n", config->bNumInterfaces);
printf("bConfigurationValue: %d\n", config->bConfigurationValue);
printf("iConfiguration: %d\n", config->iConfiguration);
printf("bmAttributes: %x\n", config->bmAttributes);
printf("MaxPower: %d\n", config->MaxPower);
for (i = 0; i < config->bNumInterfaces; i++)
print_interface(&config->interface[i]);
}
int print_device(struct usb_device *dev)
{
usb_dev_handle *udev;
char str[100];
int ret, i;
udev = usb_open(dev);
if (udev) {
if (dev->descriptor.iManufacturer) {
ret = usb_get_string_simple(udev, dev->descriptor.iManufacturer, str, sizeof(str));
if (ret > 0)
{
printf("Manufacturer is %s\n",str);
}
}
if (dev->descriptor.iProduct) {
ret = usb_get_string_simple(udev, dev->descriptor.iProduct, str, sizeof(str));
if (ret > 0)
{
printf("Product is %s\n",str);
}
}
}
if (udev)
usb_close(udev);
printf("Possible configurations are %x\n",dev->descriptor.bNumConfigurations);
sleep(2);
for (i = 0; i < dev->descriptor.bNumConfigurations; i++)
print_configuration(&dev->config[i]);
return 0;
}
int htod( const char* str )
{
int decimal;
sscanf( str, "%x", &decimal);
return decimal;
}
void set_data(struct usb_device *dev)
{
ctrlmsg_param param;
param.requesttype= 0;
param.request=0;
param.value=0;
param.index=0;
param.bytes=10;
param.size=0;
param.timeout=5000;
usb_control_msg(dev, param.requesttype, param.request, param.value, param.index, param.bytes, param.size, param.timeout);
printf("error is %s\n",strerror(errno));
return;
}
int main(int argc, char *argv[])
{
struct usb_bus *bus;
struct usb_device *dev;
if(argc != 3)
{
printf("Error in number of arguments\n");
printf("Usage:./usb_info <vendor id> <product id>\n");
exit(0);
}
vendor_id=htod(argv[1]);
product_id=htod(argv[2]);
printf("initializing USB library\n");
usb_init();
printf("Finding Buses and Devices\n");
usb_find_busses();
usb_find_devices();
for (bus = usb_get_busses(); bus; bus = bus->next) {
for (dev = bus->devices; dev; dev = dev->next) {
if ((dev->descriptor.idProduct == product_id) && (dev->descriptor.idVendor == vendor_id)){
printf("Found device with produxt id %x and vendor id %x\n",product_id,vendor_id);
print_device(dev);
set_data(dev);
print_device(dev);
}
}
}
return 0;
}
Regards,
Sandeep
I think that you mean usb_control_msg() is returns an error code for "bad descriptor". Please clarify if this is incorrect.
USB control transfers have some very specific formatting rules, and if the packet you are forming is sent to any compliant device, it will return a request error / stall on the bus.
You are sending the control transfer:
bmRequestType = 0x00
bRequest = 0x00
wValue = 0x0000
wIndex = 0x0000
wSize = 0x0000
this should be interpreted by the USB device as a GET_STATUS request, so wLength is required to be 2, and bmRequestType needs to have the top bit set, indicating this is an IN direction request (from the host's point of view). This is all from Chapter 9 of the USB specification 1.1/2.0/3.1 available at www.usb.org.
The parameter char *bytes (your param.bytes) also needs to be an address/pointer in the call you are making.
A good standard control transfer to test with would be:
bmRequestType = 0x80
bRequest = 0x06
wValue = 0x0001
wIndex = 0x0000
wSize = 0x0008
This request will return the first 8 bytes of the Device Descriptor, it is valid for every USB device, in all states.
The other transfer types (bulk, interrupt) don't have these strict formatting rules, and can be an easier place to start. I'd imagine you have already moved past this issue, since the question has been posted for quite a while, but maybe this response will still help someone else.