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from mininet.topo import Topo
class MyTopo( Topo ):
"Simple topology example."
def __init__( self ):
"Create custom topo."
# Initialize topology
Topo.__init__( self )
h1 = self.addHost( 'h1' )
h2 = self.addHost( 'h2' )
h3 = self.addHost( 'h3' )
h4 = self.addHost( 'h4' )
h5 = self.addHost( 'h5' )
h6 = self.addHost( 'h6' )
s1 = self.addSwitch( 's1' )
s2 = self.addSwitch( 's2' )
s3 = self.addSwitch( 's3' )
s4 = self.addSwitch( 's4' )
s5 = self.addSwitch( 's5' )
s6 = self.addSwitch( 's6' )
s7 = self.addSwitch( 's7' )
self.addLink( s1, s2 )
self.addLink( s1, s3 )
self.addLink( s2, s3 )
self.addLink( s2, s4 )
self.addLink( s2, s5 )
self.addLink( s3, s4 )
self.addLink( s3, s5 )
self.addLink( s4, h1 )
self.addLink( s4, h2 )
self.addLink( s5, s3 )
self.addLink( s5, s4 )
self.addLink( s6, h5 )
self.addLink( s7, h6 )
topos = { 'mytopo': ( lambda: MyTopo() ) }
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192.168.12.201 10.3.207.244 192.168.12.202
+------------+ +-----------------+ +------------+
| PC1 | | sFlow Collector | | PC2 |
| | | | | |
| | | | | |
+-----+------+ +---^--------^----+ +-----+------+
| | | |
| | | |
| ^ sFlow ^ |
+---------+ | Data | +----------+
| ^ ^ |
| | | |
| ^ ^ |
| | | |
+--------+---------++ ++-------++---------+
| Switch 1 | | Switch 2 |
| 10.3.207.142 +------+ 10.3.207.143 |
+-------------------+ +-------------------+
/* Example of using alarm() */
#include <unistd.h>
#include <stdio.h>
#include <signal.h>
int main(int argc, char *argv[]) {
sigset_t block;
sigemptyset(&block);
sigaddset(&block, SIGALRM);
sigprocmask(SIG_BLOCK, &block, NULL);
while (1) {
alarm(2);
printf("%d\n", time(NULL));
sigwaitinfo(&block, NULL);
}
return 0;
}
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/* Example of using ualarm() */
#define _XOPEN_SOURCE 500
#include <unistd.h>
#include <stdio.h>
#include <signal.h>
int main(int argc, char *argv[]) {
sigset_t block; sigemptyset(&block);
sigaddset(&block, SIGALRM);
sigprocmask(SIG_BLOCK, &block, NULL);
ualarm(500000, 500000);
while (1) {
printf("%d\n", time(NULL));
sigwaitinfo(&block, NULL);
} return 0;
}
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/* Example of using sigaction() to setup a signal handler with 3 arguments
* including siginfo_t.
*/
#include <stdio.h>
#include <unistd.h>
#include <signal.h>
#include <string.h>
static void hdl (int sig, siginfo_t *siginfo, void *context)
{
printf ("Sending PID: %ld, UID: %ld\n",
(long)siginfo->si_pid, (long)siginfo->si_uid);
}
int main (int argc, char *argv[])
{
struct sigaction act;
memset (&act, '\0', sizeof(act));
/* Use the sa_sigaction field because the handles has two additional parameters */
act.sa_sigaction = &hdl;
/* The SA_SIGINFO flag tells sigaction() to use the sa_sigaction field, not sa_handler. */
act.sa_flags = SA_SIGINFO;
if (sigaction(SIGINT, &act, NULL) < 0) {
perror ("sigaction error");
return 1;
}
while (1)
sleep (10);
return 0;
}
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/* Example of using sigaction() to setup a signal handler
* with setting sa_handler
*/
#include <stdio.h>
#include <unistd.h>
#include <signal.h>
#include <string.h>
#include <errno.h>
#define PROMPT "Do you want to terminate the process?"
char *prompt=PROMPT;
void ctrl_c_oper(int signo)
{
write(STDERR_FILENO,prompt,strlen(prompt));
}
int main()
{
struct sigaction act;
act.sa_handler=ctrl_c_oper;
sigemptyset(&act.sa_mask);
act.sa_flags=0;
if(sigaction(SIGINT,&act,NULL)<0)
{
fprintf(stderr,"Install Signal Action Error:%s\n\a",strerror(errno));
exit(1);
}
while(1);
}
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