1 |
#if defined(__linux) |
2 |
# define ENABLE_IPV6 1 // if you get compilation problems try to disable IPv6 |
3 |
#else |
4 |
# define ENABLE_IPV6 0 |
5 |
#endif |
6 |
|
7 |
#include "EXTERN.h" |
8 |
#include "perl.h" |
9 |
#include "XSUB.h" |
10 |
|
11 |
#include <pthread.h> |
12 |
|
13 |
#include <math.h> |
14 |
#include <stdio.h> |
15 |
#include <stdlib.h> |
16 |
#include <string.h> |
17 |
|
18 |
#include <time.h> |
19 |
#include <poll.h> |
20 |
#include <unistd.h> |
21 |
#include <inttypes.h> |
22 |
#include <fcntl.h> |
23 |
#include <errno.h> |
24 |
|
25 |
#include <sys/types.h> |
26 |
#include <sys/time.h> |
27 |
#include <sys/socket.h> |
28 |
|
29 |
#include <netinet/in.h> |
30 |
#include <arpa/inet.h> |
31 |
|
32 |
#ifdef __linux |
33 |
# include <linux/icmp.h> |
34 |
#endif |
35 |
#if ENABLE_IPV6 |
36 |
# include <netinet/icmp6.h> |
37 |
#endif |
38 |
|
39 |
#define ICMP4_ECHO 8 |
40 |
#define ICMP4_ECHO_REPLY 0 |
41 |
#define ICMP6_ECHO 128 |
42 |
#define ICMP6_ECHO_REPLY 129 |
43 |
|
44 |
#define DRAIN_INTERVAL .000001 // how long to wait when sendto returns ENOBUFS, in seconds |
45 |
#define MIN_INTERVAL .000001 // minimum packet send interval, in seconds |
46 |
|
47 |
#define HDR_SIZE_IP4 20 |
48 |
#define HDR_SIZE_IP6 48 |
49 |
|
50 |
//TODO: xread/xwrite for atomicity? we currently rely on the fact that the pip buffersize divides exactly by pointer sizes |
51 |
|
52 |
typedef uint8_t addr_t[16]; |
53 |
|
54 |
typedef double tstamp; |
55 |
|
56 |
static tstamp |
57 |
NOW (void) |
58 |
{ |
59 |
struct timeval tv; |
60 |
gettimeofday (&tv, 0); |
61 |
return tv.tv_sec + tv.tv_usec * 0.000001; |
62 |
} |
63 |
|
64 |
typedef struct { |
65 |
int family; |
66 |
addr_t lo, hi; |
67 |
double interval; |
68 |
tstamp next; |
69 |
} RANGE; |
70 |
|
71 |
typedef struct { |
72 |
SV *id; |
73 |
double interval; |
74 |
int nranges; |
75 |
RANGE *ranges; |
76 |
uint32_t payload; |
77 |
} REQ; |
78 |
|
79 |
typedef struct { |
80 |
uint8_t version_ihl; |
81 |
uint8_t tos; |
82 |
uint16_t tot_len; |
83 |
|
84 |
uint16_t id; |
85 |
uint16_t flags; |
86 |
|
87 |
uint8_t ttl; |
88 |
uint8_t protocol; |
89 |
uint16_t cksum; |
90 |
|
91 |
uint32_t src; |
92 |
uint32_t dst; |
93 |
} IP4HDR; |
94 |
|
95 |
typedef struct { |
96 |
uint8_t version; |
97 |
uint8_t x1, x2, x3; |
98 |
|
99 |
uint16_t payload_len; |
100 |
uint8_t nxt_hdr; |
101 |
uint8_t hop_limit; |
102 |
|
103 |
uint8_t src[16]; |
104 |
uint8_t dst[16]; |
105 |
} IP6HDR; |
106 |
|
107 |
#define MAGIC 0xca4c |
108 |
|
109 |
static uint16_t magic; |
110 |
|
111 |
typedef struct { |
112 |
uint8_t type, code; |
113 |
uint16_t cksum; |
114 |
uint16_t id, seq; |
115 |
uint32_t payload; |
116 |
tstamp stamp; // be careful when accessing this |
117 |
} PKT; |
118 |
|
119 |
static pthread_t pthrid; |
120 |
static int thr_send[2]; // send to worker |
121 |
static int thr_recv[2]; // receive from worker |
122 |
|
123 |
static int icmp4_fd, icmp6_fd; |
124 |
|
125 |
static AV *cbs; |
126 |
|
127 |
static uint16_t |
128 |
icmp_cksum (void *data, unsigned int len) |
129 |
{ |
130 |
register int sum = 0; |
131 |
uint16_t *wp; |
132 |
|
133 |
assert (~len & 1); |
134 |
|
135 |
for (wp = (uint16_t *)data; len; wp++, len -= 2) |
136 |
sum += *wp; |
137 |
|
138 |
sum = (sum >> 16) + (sum & 0xffff); /* add high 16 to low 16 */ |
139 |
sum += sum >> 16; /* add carry */ |
140 |
|
141 |
return ~sum; |
142 |
} |
143 |
|
144 |
static void |
145 |
inc_addr (addr_t *addr) |
146 |
{ |
147 |
int len = sizeof (addr_t) - 1; |
148 |
|
149 |
do |
150 |
{ |
151 |
if ((*addr)[len] != 0xff) |
152 |
{ |
153 |
++(*addr)[len]; |
154 |
break; |
155 |
} |
156 |
|
157 |
(*addr)[len] = 0; |
158 |
} |
159 |
while (len--); |
160 |
} |
161 |
|
162 |
static void * |
163 |
ping_proc (void *unused) |
164 |
{ |
165 |
PKT pkt; |
166 |
struct sockaddr_in sa4; |
167 |
#if ENABLE_IPV6 |
168 |
struct sockaddr_in6 sa6; |
169 |
#endif |
170 |
|
171 |
memset (&pkt, 0, sizeof (pkt)); |
172 |
|
173 |
memset (&sa4, 0, sizeof (sa4)); |
174 |
sa4.sin_family = AF_INET; |
175 |
sa4.sin_port = 0; |
176 |
#if ENABLE_IPV6 |
177 |
memset (&sa6, 0, sizeof (sa6)); |
178 |
sa6.sin6_family = AF_INET6; |
179 |
sa6.sin6_port = 0; |
180 |
#endif |
181 |
|
182 |
for (;;) |
183 |
{ |
184 |
REQ *req; |
185 |
int len = read (thr_send [0], &req, sizeof (req)); |
186 |
|
187 |
if (!len) |
188 |
pthread_exit (0); |
189 |
else if (len != sizeof (req)) |
190 |
{ |
191 |
perror ("AnyEvent::FastPing: short reead or read error"); |
192 |
pthread_exit ((void *)-1); |
193 |
} |
194 |
|
195 |
//TODO: bind to source address |
196 |
|
197 |
pkt.code = 0; |
198 |
pkt.id = (uint16_t)magic; |
199 |
pkt.seq = (uint16_t)~magic; |
200 |
pkt.payload = req->payload; |
201 |
|
202 |
tstamp now = NOW (); |
203 |
tstamp next = now; |
204 |
|
205 |
{ |
206 |
int r; |
207 |
for (r = req->nranges; r--; ) |
208 |
inc_addr (&req->ranges [r].hi); |
209 |
} |
210 |
|
211 |
while (req->nranges) |
212 |
{ |
213 |
RANGE *range = req->ranges; |
214 |
|
215 |
if (!memcmp (&range->lo, &range->hi, sizeof (addr_t))) |
216 |
req->ranges [0] = req->ranges [--req->nranges]; |
217 |
else |
218 |
{ |
219 |
// ranges [0] is always the next range to ping |
220 |
tstamp wait = range->next - now; |
221 |
|
222 |
// compare with the global frequency limit |
223 |
{ |
224 |
tstamp diff = next - now; |
225 |
|
226 |
if (wait < diff) |
227 |
wait = diff; |
228 |
else if (range) |
229 |
next = range->next; |
230 |
} |
231 |
|
232 |
if (wait > 0.) |
233 |
{ |
234 |
struct timespec ts; |
235 |
|
236 |
ts.tv_sec = wait; |
237 |
ts.tv_nsec = (wait - ts.tv_sec) * 1000000000.; |
238 |
|
239 |
nanosleep (&ts, 0); |
240 |
} |
241 |
|
242 |
now = NOW (); |
243 |
|
244 |
pkt.stamp = now; |
245 |
pkt.cksum = 0; |
246 |
|
247 |
if (range->family == AF_INET) |
248 |
{ |
249 |
pkt.type = ICMP4_ECHO; |
250 |
pkt.cksum = icmp_cksum (&pkt, sizeof (pkt)); |
251 |
|
252 |
memcpy (&sa4.sin_addr, |
253 |
sizeof (addr_t) - sizeof (sa4.sin_addr) + (char *)&range->lo, |
254 |
sizeof (sa4.sin_addr)); |
255 |
|
256 |
if (sendto (icmp4_fd, &pkt, sizeof (pkt), 0, (struct sockaddr *)&sa4, sizeof (sa4)) > 0) |
257 |
errno = 0; |
258 |
} |
259 |
else |
260 |
{ |
261 |
#if ENABLE_IPV6 |
262 |
pkt.type = ICMP6_ECHO; |
263 |
|
264 |
memcpy (&sa6.sin6_addr, |
265 |
sizeof (addr_t) - sizeof (sa6.sin6_addr) + (char *)&range->lo, |
266 |
sizeof (sa6.sin6_addr)); |
267 |
|
268 |
if (sendto (icmp6_fd, &pkt, sizeof (pkt), 0, (struct sockaddr *)&sa6, sizeof (sa6)) > 0) |
269 |
errno = 0; |
270 |
#endif |
271 |
} |
272 |
|
273 |
if (errno == ENOBUFS) |
274 |
{ |
275 |
struct timespec ts; |
276 |
|
277 |
ts.tv_sec = 0; |
278 |
ts.tv_nsec = DRAIN_INTERVAL * 1000000000; |
279 |
|
280 |
nanosleep (&ts, 0); |
281 |
} |
282 |
else |
283 |
{ |
284 |
inc_addr (&range->lo); |
285 |
|
286 |
range->next = next; |
287 |
range->next += range->interval; |
288 |
} |
289 |
|
290 |
next += req->interval; |
291 |
} |
292 |
|
293 |
// make a downheap operation |
294 |
int k = 0; |
295 |
int n = 0; |
296 |
for (;;) |
297 |
{ |
298 |
++n; |
299 |
int j = k * 2 + 1; |
300 |
|
301 |
if (j >= req->nranges) |
302 |
break; |
303 |
else if (j < req->nranges - 1) |
304 |
if (req->ranges [j].next > req->ranges [j + 1].next) |
305 |
++j; |
306 |
|
307 |
if (req->ranges [j].next >= req->ranges [k].next) |
308 |
break; |
309 |
|
310 |
RANGE temp = req->ranges [k]; |
311 |
req->ranges [k] = req->ranges [j]; |
312 |
req->ranges [j] = temp; |
313 |
|
314 |
k = j; |
315 |
} |
316 |
} |
317 |
|
318 |
write (thr_recv [1], &req, sizeof (req)); |
319 |
} |
320 |
|
321 |
return 0; |
322 |
} |
323 |
|
324 |
static void |
325 |
feed_reply (AV *res_av) |
326 |
{ |
327 |
if (av_len (res_av) < 0) |
328 |
return; |
329 |
|
330 |
dSP; |
331 |
SV *res = sv_2mortal (newRV_inc ((SV *)res_av)); |
332 |
int i; |
333 |
|
334 |
ENTER; |
335 |
SAVETMPS; |
336 |
|
337 |
for (i = av_len (cbs) + 1; i--; ) |
338 |
{ |
339 |
SV *cb = *av_fetch (cbs, i, 1); |
340 |
|
341 |
PUSHMARK (SP); |
342 |
XPUSHs (res); |
343 |
PUTBACK; |
344 |
call_sv (cb, G_DISCARD | G_VOID); |
345 |
} |
346 |
|
347 |
FREETMPS; |
348 |
LEAVE; |
349 |
} |
350 |
|
351 |
static void |
352 |
boot () |
353 |
{ |
354 |
sigset_t fullsigset, oldsigset; |
355 |
pthread_attr_t attr; |
356 |
|
357 |
if (pipe (thr_send) < 0) |
358 |
croak ("AnyEvent::FastPing: unable to create send pipe"); |
359 |
|
360 |
if (pipe (thr_recv) < 0) |
361 |
croak ("AnyEvent::FastPing: unable to create receive pipe"); |
362 |
|
363 |
icmp4_fd = socket (AF_INET, SOCK_RAW, IPPROTO_ICMP); |
364 |
fcntl (icmp4_fd, F_SETFL, O_NONBLOCK); |
365 |
#ifdef ICMP_FILTER |
366 |
{ |
367 |
struct icmp_filter oval; |
368 |
oval.data = 0xffffffff & ~(1 << ICMP4_ECHO_REPLY); |
369 |
setsockopt (icmp4_fd, SOL_RAW, ICMP_FILTER, &oval, sizeof oval); |
370 |
} |
371 |
#endif |
372 |
|
373 |
#if ENABLE_IPV6 |
374 |
icmp6_fd = socket (AF_INET6, SOCK_RAW, IPPROTO_ICMPV6); |
375 |
fcntl (icmp6_fd, F_SETFL, O_NONBLOCK); |
376 |
# ifdef ICMP6_FILTER |
377 |
{ |
378 |
struct icmp6_filter oval; |
379 |
ICMP6_FILTER_SETBLOCKALL (&oval); |
380 |
ICMP6_FILTER_SETPASS (ICMP6_ECHO_REPLY, &oval); |
381 |
setsockopt (icmp6_fd, IPPROTO_ICMPV6, ICMP6_FILTER, &oval, sizeof oval); |
382 |
} |
383 |
# endif |
384 |
#endif |
385 |
|
386 |
pthread_attr_init (&attr); |
387 |
pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED); |
388 |
#ifdef PTHREAD_SCOPE_PROCESS |
389 |
pthread_attr_setscope (&attr, PTHREAD_SCOPE_PROCESS); |
390 |
#endif |
391 |
|
392 |
sigfillset (&fullsigset); |
393 |
|
394 |
pthread_sigmask (SIG_SETMASK, &fullsigset, &oldsigset); |
395 |
|
396 |
if (pthread_create (&pthrid, &attr, ping_proc, 0)) |
397 |
croak ("AnyEvent::FastPing: unable to create pinger thread"); |
398 |
|
399 |
pthread_sigmask (SIG_SETMASK, &oldsigset, 0); |
400 |
|
401 |
sv_setiv (get_sv ("AnyEvent::FastPing::THR_REQ_FD", 1), thr_send [1]); |
402 |
sv_setiv (get_sv ("AnyEvent::FastPing::THR_RES_FD", 1), thr_recv [0]); |
403 |
|
404 |
sv_setiv (get_sv ("AnyEvent::FastPing::ICMP4_FD", 1), icmp4_fd); |
405 |
sv_setiv (get_sv ("AnyEvent::FastPing::ICMP6_FD", 1), icmp6_fd); |
406 |
} |
407 |
|
408 |
MODULE = AnyEvent::FastPing PACKAGE = AnyEvent::FastPing |
409 |
|
410 |
BOOT: |
411 |
{ |
412 |
HV *stash = gv_stashpv ("AnyEvent::FastPing", 1); |
413 |
|
414 |
cbs = get_av ("AnyEvent::FastPing::CB", 1); |
415 |
magic = getpid () ^ MAGIC; |
416 |
|
417 |
boot (); |
418 |
|
419 |
newCONSTSUB (stash, "ipv4_supported", newSViv (icmp4_fd >= 0)); |
420 |
newCONSTSUB (stash, "ipv6_supported", newSViv (icmp6_fd >= 0)); |
421 |
|
422 |
newCONSTSUB (stash, "icmp4_pktsize", newSViv (HDR_SIZE_IP4 + sizeof (PKT))); |
423 |
newCONSTSUB (stash, "icmp6_pktsize", newSViv (HDR_SIZE_IP6 + sizeof (PKT))); |
424 |
} |
425 |
|
426 |
PROTOTYPES: DISABLE |
427 |
|
428 |
SV * |
429 |
_req_icmp_ping (SV *ranges, NV interval, U32 payload, SV *id) |
430 |
CODE: |
431 |
{ |
432 |
if (!SvROK (ranges) || SvTYPE (SvRV (ranges)) != SVt_PVAV) |
433 |
croak ("address ranges must be given as arrayref with lo, hi pairs"); |
434 |
|
435 |
AV *rav = (AV *)SvRV (ranges); |
436 |
int nranges = av_len (rav) + 1; |
437 |
|
438 |
REQ *req = malloc (sizeof (REQ)); |
439 |
int i; |
440 |
|
441 |
if (interval < MIN_INTERVAL) |
442 |
interval = MIN_INTERVAL; |
443 |
|
444 |
req->id = newSVsv (id); |
445 |
req->interval = interval; |
446 |
req->payload = payload; |
447 |
req->nranges = nranges; |
448 |
req->ranges = (RANGE *)malloc (nranges * sizeof (RANGE)); |
449 |
|
450 |
while (nranges--) |
451 |
{ |
452 |
SV *sv = *av_fetch (rav, nranges, 1); |
453 |
|
454 |
if (!SvROK (sv) || SvTYPE (SvRV (sv)) != SVt_PVAV) |
455 |
croak ("address range must be given as arrayref with lo, hi, interval arrayrefs"); |
456 |
|
457 |
AV *av = (AV *)SvRV (sv); |
458 |
RANGE *r = req->ranges + nranges; |
459 |
|
460 |
SV *lo = *av_fetch (av, 0, 1); |
461 |
SV *hi = *av_fetch (av, 1, 1); |
462 |
|
463 |
sv_utf8_downgrade (lo, 0); |
464 |
sv_utf8_downgrade (hi, 0); |
465 |
|
466 |
memset (&r->lo, 0, sizeof (addr_t)); |
467 |
memset (&r->hi, 0, sizeof (addr_t)); |
468 |
|
469 |
if (SvPOKp (lo) && SvPOKp (hi)) |
470 |
{ |
471 |
if (SvCUR (lo) != SvCUR (hi)) |
472 |
croak ("all addresses in range must be of the same size (either 4 or 16 bytes)"); |
473 |
|
474 |
if (SvCUR (lo) == 4) |
475 |
{ |
476 |
r->family = AF_INET; |
477 |
memcpy (sizeof (addr_t) - 4 + (char *)&r->lo, SvPVX (lo), 4); |
478 |
memcpy (sizeof (addr_t) - 4 + (char *)&r->hi, SvPVX (hi), 4); |
479 |
} |
480 |
else if (SvCUR (lo) == 16) |
481 |
{ |
482 |
#if ENABLE_IPV6 |
483 |
r->family = AF_INET6; |
484 |
memcpy (&r->lo, SvPVX (lo), sizeof (addr_t)); |
485 |
memcpy (&r->hi, SvPVX (hi), sizeof (addr_t)); |
486 |
#else |
487 |
croak ("IPv6 not supported in this configuration"); |
488 |
#endif |
489 |
} |
490 |
else |
491 |
croak ("addresses in range must be either 4 (IPv4) or 16 (IPv6) bytes in length"); |
492 |
} |
493 |
else if (SvIOK (lo) && SvIOK (hi)) |
494 |
{ |
495 |
r->family = AF_INET; |
496 |
|
497 |
uint32_t addr; |
498 |
addr = htonl (SvUV (lo)); memcpy (sizeof (addr_t) - 4 + (char *)&r->lo, &addr, 4); |
499 |
addr = htonl (SvUV (hi)); memcpy (sizeof (addr_t) - 4 + (char *)&r->hi, &addr, 4); |
500 |
} |
501 |
else |
502 |
croak ("addresses in range must be strings with either 4 (IPv4) or 16 (IPv6) octets"); |
503 |
|
504 |
if (r->family == AF_INET) |
505 |
{ |
506 |
if (icmp4_fd < 0) |
507 |
croak ("AnyEvent::FastPing: IPv4 ping support not available on this system"); |
508 |
} |
509 |
else |
510 |
{ |
511 |
if (icmp6_fd < 0) |
512 |
croak ("AnyEvent::FastPing: IPv6 ping support not available on this system"); |
513 |
} |
514 |
|
515 |
r->interval = SvNV (*av_fetch (av, 2, 1)); |
516 |
|
517 |
if (r->interval < req->interval) |
518 |
r->interval = req->interval; |
519 |
|
520 |
r->next = 0.; |
521 |
} |
522 |
|
523 |
RETVAL = newSVpvn ((char *)&req, sizeof (req)); |
524 |
} |
525 |
OUTPUT: |
526 |
RETVAL |
527 |
|
528 |
SV * |
529 |
_read_res () |
530 |
CODE: |
531 |
{ |
532 |
REQ *req; |
533 |
|
534 |
if (read (thr_recv [0], &req, sizeof (req)) != sizeof (req)) |
535 |
RETVAL = &PL_sv_undef; |
536 |
|
537 |
RETVAL = req->id; |
538 |
free (req->ranges); |
539 |
free (req); |
540 |
} |
541 |
OUTPUT: |
542 |
RETVAL |
543 |
|
544 |
void |
545 |
_recv_icmp4 (...) |
546 |
CODE: |
547 |
{ |
548 |
char buf [512]; |
549 |
struct sockaddr_in sa; |
550 |
socklen_t sl = sizeof (sa); |
551 |
AV *res_av = av_len (cbs) < 0 ? 0 : (AV *)sv_2mortal ((SV *)newAV ()); |
552 |
tstamp now = NOW (); |
553 |
|
554 |
for (;;) |
555 |
{ |
556 |
int len = recvfrom (icmp4_fd, buf, sizeof (buf), MSG_TRUNC, (struct sockaddr *)&sa, &sl); |
557 |
|
558 |
if (len <= HDR_SIZE_IP4) |
559 |
break; |
560 |
|
561 |
IP4HDR *iphdr = (IP4HDR *)buf; |
562 |
|
563 |
int hdrlen = (iphdr->version_ihl & 15) * 4; |
564 |
int totlen = ntohs (iphdr->tot_len); |
565 |
|
566 |
// packet corrupt? |
567 |
if (!res_av |
568 |
|| totlen > len |
569 |
|| iphdr->protocol != IPPROTO_ICMP |
570 |
|| hdrlen < HDR_SIZE_IP4 || hdrlen + sizeof (PKT) != totlen) |
571 |
continue; |
572 |
|
573 |
PKT *pkt = (PKT *)(buf + hdrlen); |
574 |
|
575 |
if (pkt->type != ICMP4_ECHO_REPLY |
576 |
|| pkt->id != (uint16_t) magic |
577 |
|| pkt->seq != (uint16_t)~magic |
578 |
|| !isnormal (pkt->stamp)) |
579 |
continue; |
580 |
|
581 |
AV *av = newAV (); |
582 |
av_push (av, newSVpvn ((char *)&sa.sin_addr, 4)); |
583 |
av_push (av, newSVnv (now - pkt->stamp)); |
584 |
av_push (av, newSVuv (pkt->payload)); |
585 |
|
586 |
av_push (res_av, newRV_noinc ((SV *)av)); |
587 |
} |
588 |
|
589 |
if (res_av) |
590 |
feed_reply (res_av); |
591 |
} |
592 |
|
593 |
void |
594 |
_recv_icmp6 (...) |
595 |
CODE: |
596 |
{ |
597 |
struct sockaddr_in6 sa; |
598 |
socklen_t sl = sizeof (sa); |
599 |
AV *res_av = av_len (cbs) < 0 ? 0 : (AV *)sv_2mortal ((SV *)newAV ()); |
600 |
PKT pkt; |
601 |
tstamp now = NOW (); |
602 |
|
603 |
for (;;) |
604 |
{ |
605 |
int len = recvfrom (icmp6_fd, &pkt, sizeof (pkt), MSG_TRUNC, (struct sockaddr *)&sa, &sl); |
606 |
|
607 |
if (len != sizeof (PKT)) |
608 |
break; |
609 |
|
610 |
if (!res_av |
611 |
|| pkt.type != ICMP6_ECHO_REPLY |
612 |
|| pkt.id != (uint16_t) magic |
613 |
|| pkt.seq != (uint16_t)~magic |
614 |
|| !isnormal (pkt.stamp)) |
615 |
continue; |
616 |
|
617 |
AV *av = newAV (); |
618 |
av_push (av, newSVpvn ((char *)&sa.sin6_addr, 16)); |
619 |
av_push (av, newSVnv (now - pkt.stamp)); |
620 |
av_push (av, newSVuv (pkt.payload)); |
621 |
|
622 |
av_push (res_av, newRV_noinc ((SV *)av)); |
623 |
} |
624 |
|
625 |
if (res_av) |
626 |
feed_reply (res_av); |
627 |
} |
628 |
|