1 /*
2 * Copyright (c) 1997, 2020, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 #include <dlfcn.h>
26 #include <errno.h>
27 #include <net/if.h>
28 #include <netinet/tcp.h> // defines TCP_NODELAY
29 #include <stdlib.h>
30 #include <string.h>
31 #include <sys/ioctl.h>
32 #include <sys/time.h>
33
34 #if defined(__linux__)
35 #include <arpa/inet.h>
36 #include <net/route.h>
37 #include <sys/utsname.h>
38 #endif
39
40 #if defined(MACOSX)
41 #include <sys/sysctl.h>
42 #endif
43
44 #include "jvm.h"
45 #include "net_util.h"
46
47 #include "java_net_SocketOptions.h"
48 #include "java_net_InetAddress.h"
49
50 #if defined(__linux__) && !defined(IPV6_FLOWINFO_SEND)
51 #define IPV6_FLOWINFO_SEND 33
52 #endif
53
54 #define RESTARTABLE(_cmd, _result) do { \
55 do { \
56 _result = _cmd; \
57 } while((_result == -1) && (errno == EINTR)); \
58 } while(0)
59
60 int NET_SocketAvailable(int s, int *pbytes) {
61 int result;
62 RESTARTABLE(ioctl(s, FIONREAD, pbytes), result);
63 return result;
64 }
65
66 void
67 NET_ThrowByNameWithLastError(JNIEnv *env, const char *name,
68 const char *defaultDetail) {
69 JNU_ThrowByNameWithMessageAndLastError(env, name, defaultDetail);
70 }
71
72 void
73 NET_ThrowCurrent(JNIEnv *env, char *msg) {
74 NET_ThrowNew(env, errno, msg);
75 }
76
77 void
78 NET_ThrowNew(JNIEnv *env, int errorNumber, char *msg) {
79 char fullMsg[512];
80 if (!msg) {
81 msg = "no further information";
82 }
83 switch(errorNumber) {
84 case EBADF:
85 jio_snprintf(fullMsg, sizeof(fullMsg), "socket closed: %s", msg);
86 JNU_ThrowByName(env, JNU_JAVANETPKG "SocketException", fullMsg);
87 break;
88 case EINTR:
89 JNU_ThrowByName(env, JNU_JAVAIOPKG "InterruptedIOException", msg);
90 break;
91 default:
92 errno = errorNumber;
93 JNU_ThrowByNameWithLastError(env, JNU_JAVANETPKG "SocketException", msg);
94 break;
95 }
96 }
97
98
99 jfieldID
100 NET_GetFileDescriptorID(JNIEnv *env)
101 {
102 jclass cls = (*env)->FindClass(env, "java/io/FileDescriptor");
103 CHECK_NULL_RETURN(cls, NULL);
104 return (*env)->GetFieldID(env, cls, "fd", "I");
105 }
106
107 jint IPv4_supported()
108 {
109 int fd = socket(AF_INET, SOCK_STREAM, 0) ;
110 if (fd < 0) {
111 return JNI_FALSE;
112 }
113 close(fd);
114 return JNI_TRUE;
115 }
116
117 #if defined(DONT_ENABLE_IPV6)
118 jint IPv6_supported()
119 {
120 return JNI_FALSE;
121 }
122
123 #else /* !DONT_ENABLE_IPV6 */
124
125 jint IPv6_supported()
126 {
127 int fd;
128 void *ipv6_fn;
129 SOCKETADDRESS sa;
130 socklen_t sa_len = sizeof(SOCKETADDRESS);
131
132 fd = socket(AF_INET6, SOCK_STREAM, 0) ;
133 if (fd < 0) {
134 /*
135 * TODO: We really cant tell since it may be an unrelated error
136 * for now we will assume that AF_INET6 is not available
137 */
138 return JNI_FALSE;
139 }
140
141 /*
142 * If fd 0 is a socket it means we may have been launched from inetd or
143 * xinetd. If it's a socket then check the family - if it's an
144 * IPv4 socket then we need to disable IPv6.
145 */
146 if (getsockname(0, &sa.sa, &sa_len) == 0) {
147 if (sa.sa.sa_family == AF_INET) {
148 close(fd);
149 return JNI_FALSE;
150 }
151 }
152
153 /**
154 * Linux - check if any interface has an IPv6 address.
155 * Don't need to parse the line - we just need an indication.
156 */
157 #ifdef __linux__
158 {
159 FILE *fP = fopen("/proc/net/if_inet6", "r");
160 char buf[255];
161 char *bufP;
162
163 if (fP == NULL) {
164 close(fd);
165 return JNI_FALSE;
166 }
167 bufP = fgets(buf, sizeof(buf), fP);
168 fclose(fP);
169 if (bufP == NULL) {
170 close(fd);
171 return JNI_FALSE;
172 }
173 }
174 #endif
175
176 /*
177 * OK we may have the stack available in the kernel,
178 * we should also check if the APIs are available.
179 */
180 ipv6_fn = JVM_FindLibraryEntry(RTLD_DEFAULT, "inet_pton");
181 close(fd);
182 if (ipv6_fn == NULL ) {
183 return JNI_FALSE;
184 } else {
185 return JNI_TRUE;
186 }
187 }
188 #endif /* DONT_ENABLE_IPV6 */
189
190 jint reuseport_supported()
191 {
192 /* Do a simple dummy call, and try to figure out from that */
193 int one = 1;
194 int rv, s;
195 s = socket(PF_INET, SOCK_STREAM, 0);
196 if (s < 0) {
197 return JNI_FALSE;
198 }
199 rv = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, (void *)&one, sizeof(one));
200 if (rv != 0) {
201 rv = JNI_FALSE;
202 } else {
203 rv = JNI_TRUE;
204 }
205 close(s);
206 return rv;
207 }
208
209 void NET_ThrowUnknownHostExceptionWithGaiError(JNIEnv *env,
210 const char* hostname,
211 int gai_error)
212 {
213 int size;
214 char *buf;
215 const char *format = "%s: %s";
216 const char *error_string = gai_strerror(gai_error);
217 if (error_string == NULL)
218 error_string = "unknown error";
219
220 size = strlen(format) + strlen(hostname) + strlen(error_string) + 2;
221 buf = (char *) malloc(size);
222 if (buf) {
223 jstring s;
224 sprintf(buf, format, hostname, error_string);
225 s = JNU_NewStringPlatform(env, buf);
226 if (s != NULL) {
227 jobject x = JNU_NewObjectByName(env,
228 "java/net/UnknownHostException",
229 "(Ljava/lang/String;)V", s);
230 if (x != NULL)
231 (*env)->Throw(env, x);
232 }
233 free(buf);
234 }
235 }
236
237 #if defined(_AIX)
238
239 /* Initialize stubs for blocking I/O workarounds (see src/solaris/native/java/net/linux_close.c) */
240 extern void aix_close_init();
241
242 void platformInit () {
243 aix_close_init();
244 }
245
246 #else
247
248 void platformInit () {}
249
250 #endif
251
252 JNIEXPORT jint JNICALL
253 NET_EnableFastTcpLoopback(int fd) {
254 return 0;
255 }
256
257 /**
258 * See net_util.h for documentation
259 */
260 JNIEXPORT int JNICALL
261 NET_InetAddressToSockaddr(JNIEnv *env, jobject iaObj, int port,
262 SOCKETADDRESS *sa, int *len,
263 jboolean v4MappedAddress)
264 {
265 jint family = getInetAddress_family(env, iaObj);
266 JNU_CHECK_EXCEPTION_RETURN(env, -1);
267 memset((char *)sa, 0, sizeof(SOCKETADDRESS));
268
269 if (ipv6_available() &&
270 !(family == java_net_InetAddress_IPv4 &&
271 v4MappedAddress == JNI_FALSE))
272 {
273 jbyte caddr[16];
274 jint address;
275
276 if (family == java_net_InetAddress_IPv4) {
277 // convert to IPv4-mapped address
278 memset((char *)caddr, 0, 16);
279 address = getInetAddress_addr(env, iaObj);
280 JNU_CHECK_EXCEPTION_RETURN(env, -1);
281 if (address == INADDR_ANY) {
282 /* we would always prefer IPv6 wildcard address
283 * caddr[10] = 0xff;
284 * caddr[11] = 0xff; */
285 } else {
286 caddr[10] = 0xff;
287 caddr[11] = 0xff;
288 caddr[12] = ((address >> 24) & 0xff);
289 caddr[13] = ((address >> 16) & 0xff);
290 caddr[14] = ((address >> 8) & 0xff);
291 caddr[15] = (address & 0xff);
292 }
293 } else {
294 getInet6Address_ipaddress(env, iaObj, (char *)caddr);
295 }
296 sa->sa6.sin6_port = htons(port);
297 memcpy((void *)&sa->sa6.sin6_addr, caddr, sizeof(struct in6_addr));
298 sa->sa6.sin6_family = AF_INET6;
299 if (len != NULL) {
300 *len = sizeof(struct sockaddr_in6);
301 }
302
303 /* handle scope_id */
304 if (family != java_net_InetAddress_IPv4) {
305 if (ia6_scopeidID) {
306 sa->sa6.sin6_scope_id = getInet6Address_scopeid(env, iaObj);
307 }
308 }
309 } else {
310 jint address;
311 if (family != java_net_InetAddress_IPv4) {
312 JNU_ThrowByName(env, JNU_JAVANETPKG "SocketException", "Protocol family unavailable");
313 return -1;
314 }
315 address = getInetAddress_addr(env, iaObj);
316 JNU_CHECK_EXCEPTION_RETURN(env, -1);
317 sa->sa4.sin_port = htons(port);
318 sa->sa4.sin_addr.s_addr = htonl(address);
319 sa->sa4.sin_family = AF_INET;
320 if (len != NULL) {
321 *len = sizeof(struct sockaddr_in);
322 }
323 }
324 return 0;
325 }
326
327 void
328 NET_SetTrafficClass(SOCKETADDRESS *sa, int trafficClass) {
329 if (sa->sa.sa_family == AF_INET6) {
330 sa->sa6.sin6_flowinfo = htonl((trafficClass & 0xff) << 20);
331 }
332 }
333
334 int
335 NET_IsIPv4Mapped(jbyte* caddr) {
336 int i;
337 for (i = 0; i < 10; i++) {
338 if (caddr[i] != 0x00) {
339 return 0; /* false */
340 }
341 }
342
343 if (((caddr[10] & 0xff) == 0xff) && ((caddr[11] & 0xff) == 0xff)) {
344 return 1; /* true */
345 }
346 return 0; /* false */
347 }
348
349 int
350 NET_IPv4MappedToIPv4(jbyte* caddr) {
351 return ((caddr[12] & 0xff) << 24) | ((caddr[13] & 0xff) << 16) | ((caddr[14] & 0xff) << 8)
352 | (caddr[15] & 0xff);
353 }
354
355 int
356 NET_IsEqual(jbyte* caddr1, jbyte* caddr2) {
357 int i;
358 for (i = 0; i < 16; i++) {
359 if (caddr1[i] != caddr2[i]) {
360 return 0; /* false */
361 }
362 }
363 return 1;
364 }
365
366 int NET_IsZeroAddr(jbyte* caddr) {
367 int i;
368 for (i = 0; i < 16; i++) {
369 if (caddr[i] != 0) {
370 return 0;
371 }
372 }
373 return 1;
374 }
375
376 /*
377 * Map the Java level socket option to the platform specific
378 * level and option name.
379 */
380 int
381 NET_MapSocketOption(jint cmd, int *level, int *optname) {
382 static struct {
383 jint cmd;
384 int level;
385 int optname;
386 } const opts[] = {
387 { java_net_SocketOptions_TCP_NODELAY, IPPROTO_TCP, TCP_NODELAY },
388 { java_net_SocketOptions_SO_OOBINLINE, SOL_SOCKET, SO_OOBINLINE },
389 { java_net_SocketOptions_SO_LINGER, SOL_SOCKET, SO_LINGER },
390 { java_net_SocketOptions_SO_SNDBUF, SOL_SOCKET, SO_SNDBUF },
391 { java_net_SocketOptions_SO_RCVBUF, SOL_SOCKET, SO_RCVBUF },
392 { java_net_SocketOptions_SO_KEEPALIVE, SOL_SOCKET, SO_KEEPALIVE },
393 { java_net_SocketOptions_SO_REUSEADDR, SOL_SOCKET, SO_REUSEADDR },
394 { java_net_SocketOptions_SO_REUSEPORT, SOL_SOCKET, SO_REUSEPORT },
395 { java_net_SocketOptions_SO_BROADCAST, SOL_SOCKET, SO_BROADCAST },
396 { java_net_SocketOptions_IP_TOS, IPPROTO_IP, IP_TOS },
397 { java_net_SocketOptions_IP_MULTICAST_IF, IPPROTO_IP, IP_MULTICAST_IF },
398 { java_net_SocketOptions_IP_MULTICAST_IF2, IPPROTO_IP, IP_MULTICAST_IF },
399 { java_net_SocketOptions_IP_MULTICAST_LOOP, IPPROTO_IP, IP_MULTICAST_LOOP },
400 };
401
402 int i;
403
404 if (ipv6_available()) {
405 switch (cmd) {
406 // Different multicast options if IPv6 is enabled
407 case java_net_SocketOptions_IP_MULTICAST_IF:
408 case java_net_SocketOptions_IP_MULTICAST_IF2:
409 *level = IPPROTO_IPV6;
410 *optname = IPV6_MULTICAST_IF;
411 return 0;
412
413 case java_net_SocketOptions_IP_MULTICAST_LOOP:
414 *level = IPPROTO_IPV6;
415 *optname = IPV6_MULTICAST_LOOP;
416 return 0;
417 #if defined(MACOSX)
418 // Map IP_TOS request to IPV6_TCLASS
419 case java_net_SocketOptions_IP_TOS:
420 *level = IPPROTO_IPV6;
421 *optname = IPV6_TCLASS;
422 return 0;
423 #endif
424 }
425 }
426
427 /*
428 * Map the Java level option to the native level
429 */
430 for (i=0; i<(int)(sizeof(opts) / sizeof(opts[0])); i++) {
431 if (cmd == opts[i].cmd) {
432 *level = opts[i].level;
433 *optname = opts[i].optname;
434 return 0;
435 }
436 }
437
438 /* not found */
439 return -1;
440 }
441
442 /*
443 * Wrapper for getsockopt system routine - does any necessary
444 * pre/post processing to deal with OS specific oddities :-
445 *
446 * On Linux the SO_SNDBUF/SO_RCVBUF values must be post-processed
447 * to compensate for an incorrect value returned by the kernel.
448 */
449 int
450 NET_GetSockOpt(int fd, int level, int opt, void *result,
451 int *len)
452 {
453 int rv;
454 socklen_t socklen = *len;
455
456 rv = getsockopt(fd, level, opt, result, &socklen);
457 *len = socklen;
458
459 if (rv < 0) {
460 return rv;
461 }
462
463 #ifdef __linux__
464 /*
465 * On Linux SO_SNDBUF/SO_RCVBUF aren't symmetric. This
466 * stems from additional socket structures in the send
467 * and receive buffers.
468 */
469 if ((level == SOL_SOCKET) && ((opt == SO_SNDBUF)
470 || (opt == SO_RCVBUF))) {
471 int n = *((int *)result);
472 n /= 2;
473 *((int *)result) = n;
474 }
475 #endif
476
477 /* Workaround for Mac OS treating linger value as
478 * signed integer
479 */
480 #ifdef MACOSX
481 if (level == SOL_SOCKET && opt == SO_LINGER) {
482 struct linger* to_cast = (struct linger*)result;
483 to_cast->l_linger = (unsigned short)to_cast->l_linger;
484 }
485 #endif
486 return rv;
487 }
488
489 /*
490 * Wrapper for setsockopt system routine - performs any
491 * necessary pre/post processing to deal with OS specific
492 * issue :-
493 *
494 * On Solaris need to limit the suggested value for SO_SNDBUF
495 * and SO_RCVBUF to the kernel configured limit
496 *
497 * For IP_TOS socket option need to mask off bits as this
498 * aren't automatically masked by the kernel and results in
499 * an error.
500 */
501 int
502 NET_SetSockOpt(int fd, int level, int opt, const void *arg,
503 int len)
504 {
505
506 #ifndef IPTOS_TOS_MASK
507 #define IPTOS_TOS_MASK 0x1e
508 #endif
509 #ifndef IPTOS_PREC_MASK
510 #define IPTOS_PREC_MASK 0xe0
511 #endif
512
513 #if defined(_ALLBSD_SOURCE)
514 #if defined(KIPC_MAXSOCKBUF)
515 int mib[3];
516 size_t rlen;
517 #endif
518
519 int *bufsize;
520
521 #ifdef __APPLE__
522 static int maxsockbuf = -1;
523 #else
524 static long maxsockbuf = -1;
525 #endif
526 #endif
527
528 /*
529 * IPPROTO/IP_TOS :-
530 * 1. IPv6 on Solaris/Mac OS:
531 * Set the TOS OR Traffic Class value to cater for
532 * IPv6 and IPv4 scenarios.
533 * 2. IPv6 on Linux: By default Linux ignores flowinfo
534 * field so enable IPV6_FLOWINFO_SEND so that flowinfo
535 * will be examined. We also set the IPv4 TOS option in this case.
536 * 3. IPv4: set socket option based on ToS and Precedence
537 * fields (otherwise get invalid argument)
538 */
539 if (level == IPPROTO_IP && opt == IP_TOS) {
540 int *iptos;
541
542 #if defined(__linux__)
543 if (ipv6_available()) {
544 int optval = 1;
545 if (setsockopt(fd, IPPROTO_IPV6, IPV6_FLOWINFO_SEND,
546 (void *)&optval, sizeof(optval)) < 0) {
547 return -1;
548 }
549 /*
550 * Let's also set the IPV6_TCLASS flag.
551 * Linux appears to allow both IP_TOS and IPV6_TCLASS to be set
552 * This helps in mixed environments where IPv4 and IPv6 sockets
553 * are connecting.
554 */
555 if (setsockopt(fd, IPPROTO_IPV6, IPV6_TCLASS,
556 arg, len) < 0) {
557 return -1;
558 }
559 }
560 #endif
561
562 iptos = (int *)arg;
563 *iptos &= (IPTOS_TOS_MASK | IPTOS_PREC_MASK);
564 }
565
566 #ifdef _AIX
567 if (level == SOL_SOCKET) {
568 if (opt == SO_SNDBUF || opt == SO_RCVBUF) {
569 /*
570 * Just try to set the requested size. If it fails we will leave the
571 * socket option as is. Setting the buffer size means only a hint in
572 * the jse2/java software layer, see javadoc. In the previous
573 * solution the buffer has always been truncated to a length of
574 * 0x100000 Byte, even if the technical limit has not been reached.
575 * This kind of absolute truncation was unexpected in the jck tests.
576 */
577 int ret = setsockopt(fd, level, opt, arg, len);
578 if ((ret == 0) || (ret == -1 && errno == ENOBUFS)) {
579 // Accept failure because of insufficient buffer memory resources.
580 return 0;
581 } else {
582 // Deliver all other kinds of errors.
583 return ret;
584 }
585 }
586 }
587 #endif
588
589 /*
590 * On Linux the receive buffer is used for both socket
591 * structures and the packet payload. The implication
592 * is that if SO_RCVBUF is too small then small packets
593 * must be discarded.
594 */
595 #ifdef __linux__
596 if (level == SOL_SOCKET && opt == SO_RCVBUF) {
597 int *bufsize = (int *)arg;
598 if (*bufsize < 1024) {
599 *bufsize = 1024;
600 }
601 }
602 #endif
603
604 #if defined(_ALLBSD_SOURCE)
605 /*
606 * SOL_SOCKET/{SO_SNDBUF,SO_RCVBUF} - On FreeBSD need to
607 * ensure that value is <= kern.ipc.maxsockbuf as otherwise we get
608 * an ENOBUFS error.
609 */
610 if (level == SOL_SOCKET) {
611 if (opt == SO_SNDBUF || opt == SO_RCVBUF) {
612 #ifdef KIPC_MAXSOCKBUF
613 if (maxsockbuf == -1) {
614 mib[0] = CTL_KERN;
615 mib[1] = KERN_IPC;
616 mib[2] = KIPC_MAXSOCKBUF;
617 rlen = sizeof(maxsockbuf);
618 if (sysctl(mib, 3, &maxsockbuf, &rlen, NULL, 0) == -1)
619 maxsockbuf = 1024;
620
621 #if 1
622 /* XXXBSD: This is a hack to workaround mb_max/mb_max_adj
623 problem. It should be removed when kern.ipc.maxsockbuf
624 will be real value. */
625 maxsockbuf = (maxsockbuf/5)*4;
626 #endif
627 }
628 #elif defined(__OpenBSD__)
629 maxsockbuf = SB_MAX;
630 #else
631 maxsockbuf = 64 * 1024; /* XXX: NetBSD */
632 #endif
633
634 bufsize = (int *)arg;
635 if (*bufsize > maxsockbuf) {
636 *bufsize = maxsockbuf;
637 }
638
639 if (opt == SO_RCVBUF && *bufsize < 1024) {
640 *bufsize = 1024;
641 }
642
643 }
644 }
645 #endif
646
647 #if defined(_ALLBSD_SOURCE) || defined(_AIX)
648 /*
649 * On Solaris, SO_REUSEADDR will allow multiple datagram
650 * sockets to bind to the same port. The network jck tests check
651 * for this "feature", so we need to emulate it by turning on
652 * SO_REUSEPORT as well for that combination.
653 */
654 if (level == SOL_SOCKET && opt == SO_REUSEADDR) {
655 int sotype;
656 socklen_t arglen;
657
658 arglen = sizeof(sotype);
659 if (getsockopt(fd, SOL_SOCKET, SO_TYPE, (void *)&sotype, &arglen) < 0) {
660 return -1;
661 }
662
663 if (sotype == SOCK_DGRAM) {
664 setsockopt(fd, level, SO_REUSEPORT, arg, len);
665 }
666 }
667 #endif
668
669 return setsockopt(fd, level, opt, arg, len);
670 }
671
672 /*
673 * Wrapper for bind system call - performs any necessary pre/post
674 * processing to deal with OS specific issues :-
675 *
676 * Linux allows a socket to bind to 127.0.0.255 which must be
677 * caught.
678 */
679 int
680 NET_Bind(int fd, SOCKETADDRESS *sa, int len)
681 {
682 int rv;
683 int arg, alen;
684
685 #ifdef __linux__
686 /*
687 * ## get bugId for this issue - goes back to 1.2.2 port ##
688 * ## When IPv6 is enabled this will be an IPv4-mapped
689 * ## with family set to AF_INET6
690 */
691 if (sa->sa.sa_family == AF_INET) {
692 if ((ntohl(sa->sa4.sin_addr.s_addr) & 0x7f0000ff) == 0x7f0000ff) {
693 errno = EADDRNOTAVAIL;
694 return -1;
695 }
696 }
697 #endif
698
699 rv = bind(fd, &sa->sa, len);
700
701 return rv;
702 }
703
704 /**
705 * Wrapper for poll with timeout on a single file descriptor.
706 *
707 * flags (defined in net_util_md.h can be any combination of
708 * NET_WAIT_READ, NET_WAIT_WRITE & NET_WAIT_CONNECT.
709 *
710 * The function will return when either the socket is ready for one
711 * of the specified operations or the timeout expired.
712 *
713 * It returns the time left from the timeout (possibly 0), or -1 if it expired.
714 */
715
716 jint
717 NET_Wait(JNIEnv *env, jint fd, jint flags, jint timeout)
718 {
719 jlong prevNanoTime = JVM_NanoTime(env, 0);
720 jlong nanoTimeout = (jlong) timeout * NET_NSEC_PER_MSEC;
721 jint read_rv;
722
723 while (1) {
724 jlong newNanoTime;
725 struct pollfd pfd;
726 pfd.fd = fd;
727 pfd.events = 0;
728 if (flags & NET_WAIT_READ)
729 pfd.events |= POLLIN;
730 if (flags & NET_WAIT_WRITE)
731 pfd.events |= POLLOUT;
732 if (flags & NET_WAIT_CONNECT)
733 pfd.events |= POLLOUT;
734
735 errno = 0;
736 read_rv = NET_Poll(&pfd, 1, nanoTimeout / NET_NSEC_PER_MSEC);
737
738 newNanoTime = JVM_NanoTime(env, 0);
739 nanoTimeout -= (newNanoTime - prevNanoTime);
740 if (nanoTimeout < NET_NSEC_PER_MSEC) {
741 return read_rv > 0 ? 0 : -1;
742 }
743 prevNanoTime = newNanoTime;
744
745 if (read_rv > 0) {
746 break;
747 }
748 } /* while */
749 return (nanoTimeout / NET_NSEC_PER_MSEC);
750 }