1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
|
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <pthread.h>
#include <utf.h>
#include <fmt.h>
#include "dat.h"
#include "fns.h"
#include "args.h"
enum {
LPORT = 7
};
int lfd, ncpu;
pthread_t *threads;
int debug;
char *argv0;
/*
* (udp)echo service as of rfc862, with echo+ support
*/
void*
udpechosrv(void *a)
{
sockaddr_in csa;
uchar buf[4096];
char caddr[128], *cs;
int n, port;
uint csalen;
UDPEchoPlus ephdr;
struct timespec ts;
uvlong us;
memset(&csa, 0, sizeof(sockaddr_in));
csalen = sizeof(sockaddr_in);
for(;;){
if((n = recvfrom(lfd, buf, sizeof buf, 0, (sockaddr*)&csa, &csalen)) < 0)
continue;
clock_gettime(CLOCK_REALTIME, &ts);
us = ts.tv_sec*1e6;
us += ts.tv_nsec/1e3;
cs = inet_ntoa(csa.sin_addr);
port = ntohs(csa.sin_port);
snprint(caddr, sizeof caddr, "udp!%s!%d", cs, port);
if(debug)
fprint(2, "thr#%lu received %d byte datagram from %s\n", pthread_self(), n, caddr);
/* check for echo+ data */
if(n >= 24){
if(getechoplus(&ephdr, buf) < 0)
goto EchoBack;
ephdr.ressn = ephdr.gensn;
ephdr.rxtime = us;
ephdr.ntxfails = 0; /* being over-optimistic */
clock_gettime(CLOCK_REALTIME, &ts);
us = ts.tv_sec*1e6;
us += ts.tv_nsec/1e3;
ephdr.txtime = us;
putechoplus(&ephdr, buf);
}
EchoBack:
if(sendto(lfd, buf, n, 0, (sockaddr*)&csa, csalen) < 0)
continue;
if(debug)
fprint(2, "thr#%lu sent %d byte datagram to %s\n", pthread_self(), n, caddr);
}
}
static void
usage(void)
{
fprint(2, "usage: %s [-d]\n", argv0);
exit(1);
}
int
main(int argc, char *argv[])
{
int i;
ARGBEGIN{
case 'd': debug++; break;
default: usage();
}ARGEND;
if(argc != 0)
usage();
if((lfd = bindudp(LPORT)) < 0)
sysfatal("bindudp: %r");
ncpu = sysconf(_SC_NPROCESSORS_ONLN);
if(ncpu < 1)
ncpu = 1;
threads = emalloc(sizeof(pthread_t)*ncpu);
for(i = 0; i < ncpu; i++){
pthread_create(threads+i, nil, udpechosrv, nil);
if(debug)
fprint(2, "created thr#%lu\n", *(threads+i));
}
pause();
free(threads);
exit(0);
}
|
