I have a Raspberry Pi that interface a CAN Bus though SPI. I've installed canutils and if I do a cansend the message is received by the controller and applied, but if I do it through code it doesn't. It must be something that I'm doing wrong in building the frame, so if somebody can help me to point out my error I'll appreciate it.
This is the cansend message that I send.
cansend can0 01f801f2#1212121223232323
This is my code to send the same message. The code runs in a pthread.
void *CANUpdate(void *userParam)
{
struct sockaddr_can addr;
struct ifreq ifr;
const char *ifname = "can0";
int can_s;
if ((can_s = socket(PF_CAN, SOCK_RAW, CAN_RAW)) < 0)
{
LogEntry(LOG_ERR, "Error while opening socket\n");
return 0;
}
strcpy(ifr.ifr_name, ifname);
ioctl(can_s, SIOCGIFINDEX, &ifr);
addr.can_family = AF_CAN;
addr.can_ifindex = ifr.ifr_ifindex;
if (bind(can_s, (struct sockaddr *)&addr, sizeof(addr)) < 0)
{
LogEntry(LOG_ERR, "Error in CAN socket bind\n");
return 0;
}
while (!stopServer)
{
if (can_s)
{
struct can_frame frame;
frame.can_id = 0x01f801f2;
frame.can_dlc = 8;
frame.data[0] = 0x12;
frame.data[1] = 0x12;
frame.data[2] = 0x12;
frame.data[3] = 0x12;
frame.data[4] = 0x34;
frame.data[5] = 0x34;
frame.data[6] = 0x34;
frame.data[7] = 0x34;
int res = write(can_s, &frame, sizeof(struct can_frame));
}
msleep(800);
}
}
There was basically 2 problems with the code.
1. I should have used the canfd_frame struct, and I should've 0'ed the values. Here is the code that worked at the end
void *CANUpdate(void *userParam)
{
struct sockaddr_can addr;
struct ifreq ifr;
const char *ifname = "can0";
int can_s;
if ((can_s = socket(PF_CAN, SOCK_RAW, CAN_RAW)) < 0)
{
LogEntry(LOG_ERR, "Error while opening socket\n");
return 0;
}
strcpy(ifr.ifr_name, ifname);
ioctl(can_s, SIOCGIFINDEX, &ifr);
addr.can_family = AF_CAN;
addr.can_ifindex = ifr.ifr_ifindex;
setsockopt(can_s, SOL_CAN_RAW, CAN_RAW_FILTER, NULL, 0);
if (bind(can_s, (struct sockaddr *)&addr, sizeof(addr)) < 0)
{
LogEntry(LOG_ERR, "Error in CAN socket bind\n");
return 0;
}
while (!stopServer)
{
if (can_s)
{
struct canfd_frame frame;
memset(&frame, 0, sizeof(frame)); /* init CAN FD frame, e.g. LEN = 0 */
frame.can_id = 0x01f801f2;
frame.len = 8;
if (!(frame.can_id & CAN_ERR_FLAG)) /* 8 digits but no errorframe? */
frame.can_id |= CAN_EFF_FLAG; /* then it is an extended frame */
frame.data[0] = 0x12;
frame.data[1] = 0x12;
frame.data[2] = 0x12;
frame.data[3] = 0x12;
frame.data[4] = 0x34;
frame.data[5] = 0x34;
frame.data[6] = 0x34;
frame.data[7] = 0x34;
if(write(can_s, &frame, sizeof(struct can_frame)) != sizeof(struct can_frame);
LogEntry(LOG_ERR, "Unable to write CAN message\n");
}
msleep(800);
}
}
Related
I'm trying to make a simple heartbeat check from client to server and vice-versa, if connection on either is broken off unexpectedly it prints a message and calls closesocket.
I spent 8 hours on this and it still isn't acceptable to my mentor. Right now I got something that works, but if breakpoint is placed before while loop and connected client is forcefully closed, trying to go past breakpoint causes crash when it should break the loop and write out error.
Server side code:
int main(int argc, char *argv[])
{
SOCKET s, sa;
WSAData oWSAData;
WORD wVersion = 0x0001;
WSAStartup(wVersion, &oWSAData);
s = socket(AF_INET, SOCK_STREAM, 0);
sockaddr_in srv_address;
memset(&srv_address, 0, sizeof(srv_address));
srv_address.sin_family = AF_INET;
srv_address.sin_addr.S_un.S_addr = htonl(INADDR_ANY);
srv_address.sin_port = htons(1099);
bind(s, (sockaddr*) &srv_address, sizeof(srv_address));
int l = listen(s, 10);
if (l < 0)
printf("Listen error\n");
else
{
printf("Listen OK. Listening on port %u\n",
htons(srv_address.sin_port));
sa = accept(s, NULL, NULL);
while (true)
{
char buffer[1000];
int nRecvLen = recv(sa, buffer, 999, 0);
buffer[nRecvLen] = '\0';
int r = recv(sa, NULL, 0, 0);
if (r == SOCKET_ERROR && WSAGetLastError() == WSAECONNRESET)
{
printf("Konekcija je naglo prekinuta!\n");
break;
}
else
{
if (nRecvLen > 0)
{
for (int i = 0; i < nRecvLen; i++)
{
cout << buffer[i];
}
}
}
}
closesocket(sa);
closesocket(s);
}
WSACleanup();
return 0;
}
and client side:
int main()
{
SOCKET s;
WSAData oWSAData;
WORD wVersion = 0x0001;
WSAStartup(wVersion, &oWSAData);
s = socket(AF_INET, SOCK_STREAM, 0);
sockaddr_in srv_address;
memset(&srv_address, 0, sizeof(srv_address));
srv_address.sin_family = AF_INET;
srv_address.sin_addr.S_un.S_un_b.s_b1 = xxx;
srv_address.sin_addr.S_un.S_un_b.s_b2 = xxx;
srv_address.sin_addr.S_un.S_un_b.s_b3 = x;
srv_address.sin_addr.S_un.S_un_b.s_b4 = xxx;
srv_address.sin_port = htons(1099);
int c = connect(s, (sockaddr*) &srv_address, sizeof(srv_address));
if (c < 0)
{
printf("Connection error\n");
cout << (WSAGetLastError());
}
else
{
string l = "Heartbeat\n";
int p = l.size();
char buff[1000];
strcpy_s(buff, l.c_str());
printf("Connected\n");
while (true)
{
if (send(s, buff, p, 0) > 0)
{
Sleep(1000);
}
else
{
printf("Konekcija je naglo prekinuta\n");
shutdown(s, SD_BOTH);
closesocket(s);
break;
}
}
WSACleanup();
return 0;
}
}
I'm trying to write through a socket using its descriptor. I have used bind() to bind the socket to the address I want. Whenever I'm using sendto() everything is OK. But whenever I'm using write() (or send()) I'll face Destination address required(errno 89).
What I'm trying to do is to write through the socket using iovec. In this case we don't have any alternative for writev() to get destination address. As I don't want to connect every single time, I was wondering whether I can do it without having to use connect() or accept() syscalls.
Here is the code I wrote:
int sock = 0;
struct sockaddr_in serv_addr;
char *hello = "chetori to";
if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
{
printf("\n Socket creation error \n");
return -1;
}
int opt = 1;
if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)))
{
perror("setsockopt");
exit(EXIT_FAILURE);
}
string interface_name = "lo";
ifreq ifr;
memset(&ifr, 0, sizeof(ifr));
snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s", interface_name.c_str());
if (setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, reinterpret_cast<void*>(&ifr), sizeof(ifr)) < 0)
throw exception(); // Imaginary exception
memset(&serv_addr, 0, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
string interface_address = "127.0.0.1";
if (inet_aton(interface_address.c_str(), &serv_addr.sin_addr) == 0)
throw exception(); // Imaginary exception
serv_addr.sin_port = htons(PORT);
if (bind(sock, reinterpret_cast<sockaddr*>(&serv_addr), sizeof(serv_addr)) < 0)
throw exception(); // Imaginary exception
char f[1024] = "Hello there";
char sec[1024] = "How are you";
char th[1024] = "I'm fine";
char fh[1024] = "Bye bye";
struct iovec bufs[] = {
{ .iov_base = f, .iov_len = sizeof(f) },
{ .iov_base = sec, .iov_len = sizeof(sec) },
{ .iov_base = th, .iov_len = sizeof(th) },
{ .iov_base = fh, .iov_len = sizeof(fh) },
};
int iovcnt = sizeof(bufs) / sizeof(struct iovec);
writev(sock, bufs, iovcnt);
Note that Interface name and IP address have no problem and are correct.
I'm attempting to implement a GoBackN protocol and when the server drops a packet, my alarm waits 2 seconds before sending all previously sent packets.
The alarm works and waits 2 seconds, however after the first timeout, the state machine I'm using gets stuck in a loop and continues to timeout. I think it might be because errno is not getting reset, but I'm not sure.
#define TIMEOUT_SECS 2
#define MAXTRIES 10
int base = 0;
int windowSize = 7;
int sendFlag = 1;
int tries = 0;
int numPackets = 0;
packet *packetArray[30];
void addPacket(packet *p)
{
for (int i = 0; i < 30; i++)
{
if (packetArray[i])
{
continue;
}
else
{
packetArray[i] = p;
numPackets++;
break;
}
}
}
void
CatchAlarm(int ignored) /* Handler for SIGALRM */
{
tries += 1;
errno = 0;
}
void
DieWithError()
{
printf("error");
exit (1);
}
int
max(int a, int b)
{
if (b > a)
return b;
return a;
}
int
min(int a, int b)
{
if(b>a)
return a;
return b;
}
typedef enum
{
wait,
sendData,
timeout,
receiveData
} e_state;
int main(int argumentCount, char *argumentVariables[])
{
//Grabbing all input information.
struct hostent *emulatorName;
emulatorName = gethostbyname(argumentVariables[1]);
int receiveFromEmulator = atoi(argumentVariables[3]);
int sendToEmulator = atoi(argumentVariables[2]);
//Setting up UDP socket for receiving from emulator.
int receiveSocket = 0;
receiveSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
//UDP socket configuration.
struct sockaddr_in receiveSocketStruct;
bzero((char *) &receiveSocketStruct, sizeof(receiveSocketStruct));
receiveSocketStruct.sin_family = AF_INET;
receiveSocketStruct.sin_port = htons(receiveFromEmulator);
receiveSocketStruct.sin_addr.s_addr = INADDR_ANY;
socklen_t receiveSocketLen = sizeof(receiveSocketStruct);
//Binding UDP socket so client can locate emulator.
bind(receiveSocket, (struct sockaddr *)&receiveSocketStruct, sizeof(receiveSocketStruct));
//Setting up UDP socket for sending to emulator.
int sendSocket = 0;
sendSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
//UDP socket configuration.
struct sockaddr_in sendSocketStruct;
bzero((char *) &sendSocketStruct, sizeof(sendSocketStruct));
sendSocketStruct.sin_family = AF_INET;
sendSocketStruct.sin_port = htons(sendToEmulator);
sendSocketStruct.sin_addr.s_addr = INADDR_ANY;
socklen_t sendSocketLen = sizeof(sendSocketStruct);
char buffer[1024];
std::ifstream infile (argumentVariables[4], std::ifstream::binary);
infile.seekg (0, infile.end);
int lengthOfFile = infile.tellg();
infile.seekg (0, infile.beg);
int totalPackets = 0;
int nextSeqNum = 0;
while(1)
{
if (lengthOfFile > 30)
{
bzero(buffer, 1024);
char * data = new char[1024];
infile.read(buffer, 30);
strncpy(data, buffer, 1024);
lengthOfFile -= 30;
if (nextSeqNum > 7)
{
nextSeqNum = 0;
}
addPacket(new packet(1, nextSeqNum, strlen(data), data));
totalPackets++;
nextSeqNum++;
}
else
{
bzero(buffer, 1024);
char * data = new char[1024];
infile.read(buffer, 30);
strncpy(data, buffer, 1024);
if (nextSeqNum > 7)
{
nextSeqNum = 0;
}
addPacket(new packet(1, nextSeqNum, strlen(data), data));
totalPackets++;
nextSeqNum++;
addPacket(new packet(3, nextSeqNum, 0, NULL));
totalPackets++;
break;
}
}
infile.close();
nextSeqNum = 0;
int packetsReceived;
int sentPackets;
int receive = 0;
char receivePayload[1024];
char sendPayload[1024];
struct sigaction myAction; /* For setting signal handler */
myAction.sa_handler = CatchAlarm;
if (sigfillset (&myAction.sa_mask) < 0) /* block everything in handler */
DieWithError ();
myAction.sa_flags = 0;
if (sigaction (SIGALRM, &myAction, 0) < 0)
DieWithError ();
e_state currentState = wait;
e_state previousState = wait;
while(1)
{
if (currentState == wait)
{
if (sendFlag == 1)
{
previousState = currentState;
currentState = sendData;
}
else
{
previousState = currentState;
currentState = receiveData;
}
}
else if (currentState == sendData)
{
if ((nextSeqNum < base + windowSize) && (nextSeqNum < totalPackets - 1))
{
//send packet with seqnum.
int sendPacket = 0;
bzero(sendPayload, 1024);
packet * sendpckt = packetArray[nextSeqNum];
sendpckt->serialize(sendPayload);
sendpckt->printContents();
sendPacket = sendto(sendSocket, sendPayload, sizeof(sendPayload), 0, (struct sockaddr *)&sendSocketStruct, sendSocketLen);
if (base == nextSeqNum)
{
alarm(0);
alarm(TIMEOUT_SECS);
}
nextSeqNum++;
}
else
{
sendFlag = 0;
previousState = currentState;
currentState = wait;
}
}
else if (currentState == timeout)
{
alarm(0);
alarm(TIMEOUT_SECS);
for(int counter = base; counter < nextSeqNum; counter++)
{
int sendPacket = 0;
bzero(sendPayload, 1024);
packet * sendpckt = packetArray[counter];
sendpckt->serialize(sendPayload);
sendpckt->printContents();
sendPacket = sendto(sendSocket, sendPayload, sizeof(sendPayload), 0, (struct sockaddr *)&sendSocketStruct, sendSocketLen);
}
sendFlag = 0;
previousState = currentState;
currentState = wait;
}
else if (currentState == receiveData)
{
bzero(receivePayload, 1024);
receive = (recvfrom(receiveSocket, receivePayload, sizeof(receivePayload), 0, (struct sockaddr *)&receiveSocketStruct, &receiveSocketLen));
if (errno == EINTR)
{
printf("timeout");
if (tries > MAXTRIES)
{
alarm(0);
break;
printf("recvfrom() failed.");
}
previousState = currentState;
currentState = timeout;
}
else
{
char buffer[1024];
bzero(buffer, 1024);
int receivePacketType;
int receivePacketSeqNum;
packet recvpckt(0, 0, 0, (char*)buffer);
recvpckt.deserialize((char*)receivePayload);
receivePacketSeqNum = recvpckt.getSeqNum();
receivePacketType = recvpckt.getType();
recvpckt.printContents();
if (receivePacketType == 2)
{
break;
}
base = receivePacketSeqNum + 1;
printf("%d\n", base);
if (base == nextSeqNum)
{
alarm(0);
}
else
{
alarm(0);
alarm(TIMEOUT_SECS);
}
if (nextSeqNum == totalPackets - 1)
{
nextSeqNum++;
int sendPacket = 0;
bzero(sendPayload, 1024);
packet * sendpckt = packetArray[nextSeqNum - 1];
sendpckt->serialize(sendPayload);
sendpckt->printContents();
sendPacket = sendto(sendSocket, sendPayload, sizeof(sendPayload), 0, (struct sockaddr *)&sendSocketStruct, sendSocketLen);
}
if (base <= totalPackets)
{
sendFlag = 1;
previousState = currentState;
currentState = wait;
}
else
{
continue;
}
}
}
else
{
break;
}
}
//Close shop.
close(receiveSocket);
close(sendSocket);
return 0;
}
The location where I suspect the loop to start is in the receiveData state.
Fixed it:
else if (currentState == receiveData)
{
receive = 0;
bzero(receivePayload, 1024);
receive = (recvfrom(receiveSocket, receivePayload, sizeof(receivePayload), 0, (struct sockaddr *)&receiveSocketStruct, &receiveSocketLen));
if (receive < 0)
{
printf("timeout");
if (tries > MAXTRIES)
{
alarm(0);
break;
printf("recvfrom() failed.");
}
previousState = currentState;
currentState = timeout;
}
When I'm connecting with a socket in NDK, as a result of the read call, I always get -1.(Error).
I was looking over the internet several times and I couldn't find a solution. Can you help me?
Here is my code.
void * SocketManager::socketCall(void *ptr) {
int socket_, n;
SocketManager *manager = (SocketManager*) ptr;
while (manager->semaph) ;
manager->semaph = true;
bool didConnect = false;
size_t bufferSize = 32000;
char buffer[bufferSize];
const char* value = manager->host.c_str();
stringstream strValue;
strValue << value;
unsigned int host;
strValue >> host;
struct sockaddr_in server_address;
server_address.sin_family = AF_INET;
server_address.sin_port = htons(10983);
inet_aton(manager->host.c_str(), &server_address.sin_addr);
socket_ = socket(AF_INET, SOCK_STREAM, 0);
if (socket_ < 0)
CCLog("ERROR ABRIENDO EL SOCKET");
n = ::connect(socket_, (struct sockaddr *) &server_address,sizeof(server_address));
if (n < 0)
close(socket_);
manager->onConnect();
didConnect = true;
while (!manager->mustDisconnect) {
n = read(socket_, &buffer, bufferSize);
if(n<=0)
break;
manager->onReadData(buffer, sizeof(buffer));
}
if (socket_) {
close(socket_);
if (didConnect)
manager->onDisconnect();
else
manager->onTimeout();
}
manager->semaph = false;
manager->mustDisconnect = false;
return 0;
}
I followed this nice tutorial to create a simple non-blocking server using select() function. Here's what I have:
void setNonBlocking(int socketFD) {
int x;
x = fcntl(socketFD,F_GETFL,0);
fcntl(socketFD,F_SETFL,x | O_NONBLOCK);
return;
}
int initialize(char * port) {
int yes = 1;
listener = socket(PF_INET,SOCK_STREAM, 0);
if (listener < 0) {
perror("listener");
exit(EXIT_FAILURE);
}
if (setsockopt(listener, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) == -1) {
perror("setsockopt");
exit(EXIT_FAILURE);
}
setNonBlocking(listener);
struct sockaddr_in server_address;
memset((char *) &server_address, 0, sizeof(server_address));
server_address.sin_family = AF_INET;
// server_address.sin_addr.s_addr = htonl(INADDR_ANY);
inet_aton("132.65.151.39",&(server_address.sin_addr));
server_address.sin_port = htons(atoi(port));
if (bind(listener, (struct sockaddr *) &server_address,
sizeof(server_address)) < 0 ) {
perror("bind");
close(listener);
exit(EXIT_FAILURE);
}
listen(listener,BACKLOG);
maxSocket = listener;
memset((char *) &clientQueue, 0, sizeof(clientQueue));
return 0;
}
void readSockets() {
int i;
cout << "in readSockets()" << endl;
if (FD_ISSET(listener,&sockets))
createConnection();
for (i = 0; i < 5; i++) {
if (FD_ISSET(clientQueue[i],&sockets))
readData(i);
} /* for (all entries in queue) */
}
int main(int argc, char* argv[]) {
if (argc != 2) {
fprintf(stderr,"usage: server port\n");
exit(EXIT_FAILURE);
}
if (initialize(argv[1]) != 0) {
exit(EXIT_FAILURE);
}
struct timeval timeout;
int value;
printf("server: waiting for connections...\n");
while(1) { // main accept() loop
build_select_list();
timeout.tv_sec = 1;
timeout.tv_usec = 0;
value = select(maxSocket, &sockets, (fd_set *) 0,(fd_set *) 0, &timeout);
if (value == -1) {
perror("select");
exit(EXIT_FAILURE);
}
if (value == 0) {
printf("%d",value);
fflush(stdout);
} else{
cout << "Value is " << value << endl;
readSockets();
}
}
return EXIT_SUCCESS;
}
My problem is simple - select always returns 0, meaning it does not get or does not respond to a new connection. I checked my client a day ago with a blocking more simple server and it did work, so I don't think its the porblem.
You'll notice that I tried both IP addresses:
server_address.sin_family = AF_INET;
// server_address.sin_addr.s_addr = htonl(INADDR_ANY);
Can anyone please help me? I feel lost :)
Please refer to man select, first parameter should be number of highest descriptor + 1, so in your case:
value = select(maxSocket + 1, &sockets, (fd_set *) 0,(fd_set *) 0, &timeout);