So I am getting started with SCTP and have written the basics of the SCTP server application(which I intend to modify to make it a peer-to-peer app). The code is incomplete but I compiled and ran it to test the socket options and the first setsockopt returns error 10042(protocol not supported). I have determined that it's the first call of setsockopt() that returns an error. So here is the incomplete code:
#include "stdafx.h"
#include <iostream>
#include <iostream>
#include <string.h>
#include <stdlib.h>
#ifndef UNICODE
#define UNICODE
#endif
#define WIN32_LEAN_AND_MEAN
#include <WinSock2.h>
#include <WS2tcpip.h>
#include <WS2spi.h>
#include <ws2sctp.h>
#include <wsipv6ok.h>
#include <if.h>
#include "ws2isatap.h"
#include "if_tunnel.h"
#pragma comment(lib, "ws2_32.lib")
#pragma comment(lib, "sctpsp.lib")
using namespace std;
using namespace System;
static int LISTENQ = 5;
void isatap_enable(void);
int main(int argc, char* argv[]){
WSADATA wsaData;
int iResult;
int optv = 10;
u_long imode = 1;
bool connected = false;
char *optval = (char*)&optv;
int optlen = sizeof(optval);
sockaddr_in6 servAddr;
sctp_sndrcvinfo sr;
sctp_event_subscribe evnts;
sctp_initmsg init;
memset(&sr,0,sizeof(sr));
memset(&evnts,0,sizeof(evnts));
memset(&init,0,sizeof(init));
memset(&servAddr,0,sizeof(servAddr));
iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
if (iResult != NO_ERROR) {
wprintf(L"WSAStartup function failed with error: %d\n", iResult);
return 1;
}
SOCKET servSock = socket(AF_INET6,SOCK_STREAM,IPPROTO_SCTP);
if(servSock==INVALID_SOCKET){
printf("Socket function failed with error: %d\n",GetLastError());
return 1;
}
if(setsockopt(servSock,IPPROTO_IPV6,IPV6_PROTECTION_LEVEL,optval,sizeof(optval))<0){
printf("setsockopt function failed with error: %d\n", GetLastError());
return 1;
}
u_int servPort = 5000;
servAddr.sin6_family = AF_INET6;
servAddr.sin6_addr = in6addr_any;
servAddr.sin6_port = htons(servPort);
if(setsockopt(servSock,IPPROTO_SCTP,SCTP_EVENTS,(const char*)&evnts,sizeof(evnts)) < 0){
printf("setsockopt function failed with error: %d\n", GetLastError());
return 1;
}
ioctlsocket(servSock,FIONBIO, &imode);
if(bind(servSock,(struct sockaddr*)&servAddr,sizeof(servAddr))<0){
printf("Bind function failed with error: %d\n", GetLastError());
return 1;
}
evnts.sctp_data_io_event = 1;
evnts.sctp_association_event = *(u_char*)optval;
for(;;){
if(listen(servSock,LISTENQ) < 0){
printf("Listen function failed with error: %d/n",GetLastError());
return 1;
}else{
printf("Listening on port %d\n",servPort);
}
}
}
If it's related to python packages nameko/kombu/amqp, then it's reported here Issue with 2.1.4 version.
Temporary soln: Roll-back the version to 2.1.3 till it's fixed.
OK guys, I fixed it(for now lol). What I did is substitute the IPPROTO_IPV6 with IPPROTO_SCTP and it seems to work.
Related
When I have the following C source code, which is running on an IBM i Midrange, then I get a non-zero result from pthread_create, specifically 3025, which is ENOENT (No such path or directory), which doesn't make any sense to me. Anyone have any thoughts on what the error actually means in this context.
#define _MULTI_THREADED
#define _XOPEN_SOURCE 520
#include <pthread.h>
#include <stdio.h>
#include <errno.h>
void* workerThread(void* parm) {
// Do some work here
pthread_exit(NULL);
}
int main(int argc, char* argv[]) {
pthread_t t;
int rc;
rc = pthread_create(&t, NULL, workerThread, NULL);
if (rc != 0) {
char *msg = strerror(errno);
perror("pthread_create failed");
}
// Other code here
return 0;
}
pthread_create doesn't set errno. You should be checking strerror of rc.
http://pubs.opengroup.org/onlinepubs/7908799/xsh/pthread_create.html
char *msg = strerror(rc);
When i set the position and velocities of the joints in the trajectory msgs i got an error: \
[state_publisher-2] process has died [pid 13362, exit code -11, cmd /home/rob/catkin_ws/devel/lib/r2d2/state_publisher __name:=state_publisher __log:=/home/rob/.ros/log/9980f352-cf74-11e6-8644-d4c9efe8bd37/state_publisher-2.log].
log file: /home/rob/.ros/log/9980f352-cf74-11e6-8644-d4c9efe8bd37/state_publisher-2*.log
My ros node to send geometry_msgs is:
#include <string>
#include <ros/ros.h>
#include <sensor_msgs/JointState.h>
#include <tf/transform_broadcaster.h>
#include <trajectory_msgs/JointTrajectory.h>
#include <vector>
int main(int argc, char** argv) {
ros::init(argc, argv, "state_publisher");
ros::NodeHandle n;
ros::Publisher joint_pub = n.advertise<trajectory_ms
gs::JointTrajectory>("set_joint_trajectory", 1);
ros::Rate loop_rate(30);
const double degree = M_PI/180;
// robot state
double tilt = 0, tinc = degree, swivel=0, angle=0, height=0, hinc=0.005;
// message declarations
trajectory_msgs::JointTrajectory joint_state;
std::vector<trajectory_msgs::JointTrajectoryPoint> points_n(3);
points_n[0].positions[0] = 1; points_n[0].velocities[0]=10;
while (ros::ok()) {
//update joint_state
joint_state.header.stamp = ros::Time::now();
joint_state.joint_names.resize(3);
joint_state.points.resize(3);
joint_state.joint_names[0] ="swivel";
joint_state.points[0] = points_n[0];
joint_state.joint_names[1] ="tilt";
joint_state.points[1] = points_n[1];
joint_state.joint_names[2] ="periscope";
joint_state.points[2] = points_n[2];
joint_pub.publish(joint_state);
// This will adjust as needed per iteration
loop_rate.sleep();
}
return 0;
}
Here when i donot set the position and velocity value it runs without error and when i run rostopic echo /set_joint_trajectory i can clearly see the outputs as all the parameters of points is 0. I also tried below program but it published nothing:
#include <string>
#include <ros/ros.h>
#include <sensor_msgs/JointState.h>
#include <tf/transform_broadcaster.h>
#include <trajectory_msgs/JointTrajectory.h>
#include <vector>
int main(int argc, char** argv) {
ros::init(argc, argv, "state_publisher");
ros::NodeHandle n;
ros::Publisher joint_pub = n.advertise<trajectory_msgs::JointTrajectory>("set_joint_trajectory", 1);
trajectory_msgs::JointTrajectory joint_state;
joint_state.header.stamp = ros::Time::now();
joint_state.header.frame_id = "camera_link";
joint_state.joint_names.resize(3);
joint_state.points.resize(3);
joint_state.joint_names[0] ="swivel";
joint_state.joint_names[1] ="tilt";
joint_state.joint_names[2] ="periscope";
size_t size = 2;
for(size_t i=0;i<=size;i++) {
trajectory_msgs::JointTrajectoryPoint points_n;
int j = i%3;
points_n.positions.push_back(j);
points_n.positions.push_back(j+1);
points_n.positions.push_back(j*2);
joint_state.points.push_back(points_n);
joint_state.points[i].time_from_start = ros::Duration(0.01);
}
joint_pub.publish(joint_state);
ros::spinOnce();
return 0;
}
You are accessing points_n[0].positions[0] and points_n[0].velocities[0] without allocating the memory for positions and velocities. Use
...
// message declarations
trajectory_msgs::JointTrajectory joint_state;
std::vector<trajectory_msgs::JointTrajectoryPoint> points_n(3);
points_n[0].positions.resize(1);
points_n[0].velocities.resize(1);
...
then set the values or use points_n[0].positions.push_back(...) instead. The same applies to points_n[1] and points_n[2].
In your second example it looks like your program terminates before anything is sent. Try to publish repeatedly in a while-loop with
while(ros::ok()){
...
ros::spinOnce();
}
I am trying to build a network scanner.
I know the procedure so I want to ping all available hosts in the network and then get the ARP table so I can map the MAC address for each IP.
I Googled for ARP table but I didn't find any guide how to implement this feature.
I also found these similar questions on Stack overflow:
Link1
Link2
The answer are unclear on how to implement the ARP feature.
Is there any official guide for this one? Is Apple approving the ARP table feature?
UPDATE AFTER 10.2
Check the library here
I finally got it working so I will post the procedure in detail to save some time for other guys:
Go to Applications and right click on Xcode -> Show package contents and browse to: Developer ▸ Platforms ▸ MacOSX.platform ▸ Developer ▸ SDKs ▸ MacOSX10.10.sdk ▸ usr ▸ include. From "net" folder copy the route.h and if_types.h and from the "netinet" folder copy the if_ether.h into your Xcode project.
Then import the following .m and .h files:
MacFinder.h
#import <Foundation/Foundation.h>
#include <sys/param.h>
#include <sys/file.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_dl.h>
#include "if_types.h"
#if TARGET_IPHONE_SIMULATOR
#include <net/route.h>
#else
#include "route.h"
#endif
#include "if_ether.h"
#include <netinet/in.h>
#include <arpa/inet.h>
#include <err.h>
#include <errno.h>
#include <netdb.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#interface MacFinder : NSObject{
int nflag;
}
-(NSString*) ip2mac: (char*)ip;
#end
MacFinder.m
#import "MacFinder.h"
#implementation MacFinder
-(NSString*) ip2mac: (char*)ip
{
int found_entry = 0;
NSString *mAddr = nil;
u_long addr = inet_addr(ip);
int mib[6];
size_t needed;
char *host, *lim, *buf, *next;
struct rt_msghdr *rtm;
struct sockaddr_inarp *sin;
struct sockaddr_dl *sdl;
extern int h_errno;
struct hostent *hp;
mib[0] = CTL_NET;
mib[1] = PF_ROUTE;
mib[2] = 0;
mib[3] = AF_INET;
mib[4] = NET_RT_FLAGS;
mib[5] = RTF_LLINFO;
if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
err(1, "route-sysctl-estimate");
if ((buf = malloc(needed)) == NULL)
err(1, "malloc");
if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
err(1, "actual retrieval of routing table");
lim = buf + needed;
for (next = buf; next < lim; next += rtm->rtm_msglen) {
rtm = (struct rt_msghdr *)next;
sin = (struct sockaddr_inarp *)(rtm + 1);
sdl = (struct sockaddr_dl *)(sin + 1);
if (addr) {
if (addr != sin->sin_addr.s_addr)
continue;
found_entry = 1;
}
if (nflag == 0)
hp = gethostbyaddr((caddr_t)&(sin->sin_addr),
sizeof sin->sin_addr, AF_INET);
else
hp = 0;
if (hp)
host = hp->h_name;
else {
host = "?";
if (h_errno == TRY_AGAIN)
nflag = 1;
}
if (sdl->sdl_alen) {
u_char *cp = LLADDR(sdl);
mAddr = [NSString stringWithFormat:#"%x:%x:%x:%x:%x:%x", cp[0], cp[1], cp[2], cp[3], cp[4], cp[5]];
// ether_print((u_char *)LLADDR(sdl));
}
else
mAddr = nil;
}
if (found_entry == 0) {
return nil;
} else {
return mAddr;
}
}
#end
Then import the MacFinder.h file in your ViewController
Example how to use it for each host you want to find the MAC Address:
MacFinder *mc = [[MacFinder alloc]init];
NSString *mac = [mc ip2mac:"192.168.10.24"];
NSLog(#"Mac:%#",mac);
If you still having trouble here is tutorial and here the full working project (Including the necessary files)
I got the D-Bus server.c and client.c code, and made some modification.
I want the result that when type for example "hi" from client.c
server will print "receive message hi", and reply "reply_content!!!!!!" to client.c
But it seems that now client.c cannot get the reply message.
Anyone have the idea?
Thanks in advance.
"server.c"
/* server.c */
#include <dbus/dbus.h>
#include <stdbool.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
static DBusHandlerResult
filter_func(DBusConnection *connection, DBusMessage *message, void *usr_data)
{
DBusMessage *reply;
dbus_bool_t handled = false;
char *word = NULL;
DBusError dberr;
dbus_error_init(&dberr);
dbus_message_get_args(message, &dberr, DBUS_TYPE_STRING, &word, DBUS_TYPE_INVALID);
printf("receive message: %s\n", word);
handled = true;
reply = dbus_message_new_method_return(message);
char * reply_content = "reply_content!!!!!!";
dbus_message_append_args(reply, DBUS_TYPE_STRING, &reply_content, DBUS_TYPE_INVALID);
dbus_connection_send(connection, reply, NULL);
dbus_connection_flush(connection);
dbus_message_unref(reply);
return (handled ? DBUS_HANDLER_RESULT_HANDLED : DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
}
int main(int argc, char *argv[])
{
DBusError dberr;
DBusConnection *dbconn;
dbus_error_init(&dberr);
dbconn = dbus_bus_get(DBUS_BUS_SESSION, &dberr);
if (!dbus_connection_add_filter(dbconn, filter_func, NULL, NULL)) {
return -1;
}
dbus_bus_add_match(dbconn, "type='signal',interface='client.signal.Type'", &dberr);
while(dbus_connection_read_write_dispatch(dbconn, -1)) {
/* loop */
}
return 0;
}
Here is client.c
#include <dbus/dbus.h>
#include <stdbool.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
static DBusHandlerResult
filter_func(DBusConnection *connection, DBusMessage *message, void *usr_data)
{
dbus_bool_t handled = false;
char *word = NULL;
DBusError dberr;
dbus_error_init(&dberr);
dbus_message_get_args(message, &dberr, DBUS_TYPE_STRING, &word, DBUS_TYPE_INVALID);
printf("receive message %s\n", word);
handled = true;
return (handled ? DBUS_HANDLER_RESULT_HANDLED : DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
}
int db_send(DBusConnection *dbconn)
{
DBusMessage *dbmsg;
char *word = (char *)malloc(sizeof(char));
int i;
dbmsg = dbus_message_new_signal("/client/signal/Object", "client.signal.Type", "Test");
scanf("%s", word);
if (!dbus_message_append_args(dbmsg, DBUS_TYPE_STRING, &word, DBUS_TYPE_INVALID)) {
return -1;
}
if (!dbus_connection_send(dbconn, dbmsg, NULL)) {
return -1;
}
dbus_connection_flush(dbconn);
printf("send message %s\n", word);
dbus_message_unref(dbmsg);
return 0;
}
int main(int argc, char *argv[])
{
DBusError dberr;
DBusConnection *dbconn;
dbus_error_init(&dberr);
dbconn = dbus_bus_get(DBUS_BUS_SESSION, &dberr);
if (!dbus_connection_add_filter(dbconn, filter_func, NULL, NULL)) {
return -1;
}
db_send(dbconn);
while(dbus_connection_read_write_dispatch(dbconn, -1)) {
db_send(dbconn);
}
dbus_connection_unref(dbconn);
return 0;
}
You're communicating only with signals at the moment, which don't have a return value.
In client.c, use dbus_message_new_method_call instead of dbus_message_new_signal, and in server.c you probably have to change type='signal' to type='method_call'.
I am learning socket programming in c, I wrote this simple program to accept connections on port 5072. i connect to it using telnet. This works fine the first time but when i try to run it again immediately it fails showing BIND : Address already in use, but then again starts to work after a minute or so. What am i doing wromg?
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <stdlib.h>
int main(){
//variables
int listenfd, clientfd;
socklen_t clilen;
struct sockaddr_in cliaddr,servaddr;
//getsocket
if((listenfd = socket(AF_INET,SOCK_STREAM,0)) == -1){
perror("SOCKET");
exit(0);
}
//prep the servaddr
bzero(&servaddr,sizeof servaddr);
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr = inet_addr ("127.0.0.1");
servaddr.sin_port = htons(5072);
//bind
if(bind(listenfd, (struct sockaddr *) &servaddr,sizeof servaddr)<0){
perror("BIND");
exit(0);
}
//listen
if(listen(listenfd,20)<0){
perror("LISTEN");
exit(0);
}
//accept
int counter = 1;
clilen = sizeof cliaddr;
while(counter<3){
clientfd = accept(listenfd,(struct sockaddr *) &cliaddr,&clilen);
if(clientfd == -1){
perror("ACCEPT");
exit(0);
}
if(fork()==0){
close(listenfd);
printf("CONNECTION NO. %d\n",counter);
close(clientfd);
exit(0);
}
counter++;
close(clientfd);
}
close(listenfd);
}
Thanks
You must setsockopt(SO_REUSEADDR)
See this faq for explanation why.
Or simply wait a couple minutes. The TCP/IP stack holds onto the socket for twice the maximum segment lifetime after close,to prevent any stray packets from the first connection from showing up after a second one's established, which will make it all confused.