/*
* Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
#include <ctype.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <netinet/icmp6.h>
#if defined(_ALLBSD_SOURCE)
#include <ifaddrs.h>
#include <net/if.h>
#endif
#include "net_util.h"
#include "java_net_InetAddress.h"
#include "java_net_Inet4AddressImpl.h"
#include "java_net_Inet6AddressImpl.h"
#define SET_NONBLOCKING(fd) { \
int flags = fcntl(fd, F_GETFL); \
flags |= O_NONBLOCK; \
fcntl(fd, F_SETFL, flags); \
}
/*
* Inet6AddressImpl
*/
/*
* Class: java_net_Inet6AddressImpl
* Method: getLocalHostName
* Signature: ()Ljava/lang/String;
*/
JNIEXPORT jstring JNICALL
Java_java_net_Inet6AddressImpl_getLocalHostName(JNIEnv *env, jobject this) {
char hostname[NI_MAXHOST + 1];
hostname[0] = '\0';
if (gethostname(hostname, sizeof(hostname)) != 0) {
strcpy(hostname, "localhost");
} else {
#if defined(__solaris__)
// try to resolve hostname via nameservice
// if it is known but getnameinfo fails, hostname will still be the
// value from gethostname
struct addrinfo hints, *res;
// make sure string is null-terminated
hostname[NI_MAXHOST] = '\0';
memset(&hints, 0, sizeof(hints));
hints.ai_flags = AI_CANONNAME;
hints.ai_family = AF_UNSPEC;
if (getaddrinfo(hostname, NULL, &hints, &res) == 0) {
getnameinfo(res->ai_addr, res->ai_addrlen, hostname, sizeof(hostname),
NULL, 0, NI_NAMEREQD);
freeaddrinfo(res);
}
#else
// make sure string is null-terminated
hostname[NI_MAXHOST] = '\0';
#endif
}
return (*env)->NewStringUTF(env, hostname);
}
#if defined(MACOSX)
/* also called from Inet4AddressImpl.c */
__private_extern__ jobjectArray
lookupIfLocalhost(JNIEnv *env, const char *hostname, jboolean includeV6)
{
jobjectArray result = NULL;
char myhostname[NI_MAXHOST + 1];
struct ifaddrs *ifa = NULL;
int familyOrder = 0;
int count = 0, i, j;
int addrs4 = 0, addrs6 = 0, numV4Loopbacks = 0, numV6Loopbacks = 0;
jboolean includeLoopback = JNI_FALSE;
jobject name;
initInetAddressIDs(env);
JNU_CHECK_EXCEPTION_RETURN(env, NULL);
/* If the requested name matches this host's hostname, return IP addresses
* from all attached interfaces. (#2844683 et al) This prevents undesired
* PPP dialup, but may return addresses that don't actually correspond to
* the name (if the name actually matches something in DNS etc.
*/
myhostname[0] = '\0';
if (gethostname(myhostname, sizeof(myhostname)) == -1) {
/* Something went wrong, maybe networking is not setup? */
return NULL;
}
myhostname[NI_MAXHOST] = '\0';
if (strcmp(myhostname, hostname) != 0) {
// Non-self lookup
return NULL;
}
if (getifaddrs(&ifa) != 0) {
NET_ThrowNew(env, errno, "Can't get local interface addresses");
return NULL;
}
name = (*env)->NewStringUTF(env, hostname);
if (name == NULL) {
freeifaddrs(ifa);
return NULL;
}
/* Iterate over the interfaces, and total up the number of IPv4 and IPv6
* addresses we have. Also keep a count of loopback addresses. We need to
* exclude them in the normal case, but return them if we don't get an IP
* address.
*/
struct ifaddrs *iter = ifa;
while (iter) {
if (iter->ifa_addr != NULL) {
int family = iter->ifa_addr->sa_family;
if (iter->ifa_name[0] != '\0') {
jboolean isLoopback = iter->ifa_flags & IFF_LOOPBACK;
if (family == AF_INET) {
addrs4++;
if (isLoopback) numV4Loopbacks++;
} else if (family == AF_INET6 && includeV6) {
addrs6++;
if (isLoopback) numV6Loopbacks++;
} // else we don't care, e.g. AF_LINK
}
}
iter = iter->ifa_next;
}
if (addrs4 == numV4Loopbacks && addrs6 == numV6Loopbacks) {
// We don't have a real IP address, just loopback. We need to include
// loopback in our results.
includeLoopback = JNI_TRUE;
}
/* Create and fill the Java array. */
int arraySize = addrs4 + addrs6 -
(includeLoopback ? 0 : (numV4Loopbacks + numV6Loopbacks));
result = (*env)->NewObjectArray(env, arraySize, ia_class, NULL);
if (!result) goto done;
if ((*env)->GetStaticBooleanField(env, ia_class, ia_preferIPv6AddressID)) {
i = includeLoopback ? addrs6 : (addrs6 - numV6Loopbacks);
j = 0;
} else {
i = 0;
j = includeLoopback ? addrs4 : (addrs4 - numV4Loopbacks);
}
// Now loop around the ifaddrs
iter = ifa;
while (iter != NULL) {
if (iter->ifa_addr != NULL) {
jboolean isLoopback = iter->ifa_flags & IFF_LOOPBACK;
int family = iter->ifa_addr->sa_family;
if (iter->ifa_name[0] != '\0' &&
(family == AF_INET || (family == AF_INET6 && includeV6)) &&
(!isLoopback || includeLoopback))
{
int port;
int index = (family == AF_INET) ? i++ : j++;
jobject o = NET_SockaddrToInetAddress(env,
(SOCKETADDRESS *)iter->ifa_addr, &port);
if (!o) {
freeifaddrs(ifa);
if (!(*env)->ExceptionCheck(env))
JNU_ThrowOutOfMemoryError(env, "Object allocation failed");
return NULL;
}
setInetAddress_hostName(env, o, name);
if ((*env)->ExceptionCheck(env))
goto done;
(*env)->SetObjectArrayElement(env, result, index, o);
(*env)->DeleteLocalRef(env, o);
}
}
iter = iter->ifa_next;
}
done:
freeifaddrs(ifa);
return result;
}
#endif
/*
* Class: java_net_Inet6AddressImpl
* Method: lookupAllHostAddr
* Signature: (Ljava/lang/String;)[[B
*/
JNIEXPORT jobjectArray JNICALL
Java_java_net_Inet6AddressImpl_lookupAllHostAddr(JNIEnv *env, jobject this,
jstring host) {
jobjectArray ret = NULL;
const char *hostname;
int error = 0;
struct addrinfo hints, *res = NULL, *resNew = NULL, *last = NULL,
*iterator;
initInetAddressIDs(env);
JNU_CHECK_EXCEPTION_RETURN(env, NULL);
if (IS_NULL(host)) {
JNU_ThrowNullPointerException(env, "host argument is null");
return NULL;
}
hostname = JNU_GetStringPlatformChars(env, host, JNI_FALSE);
CHECK_NULL_RETURN(hostname, NULL);
// try once, with our static buffer
memset(&hints, 0, sizeof(hints));
hints.ai_flags = AI_CANONNAME;
hints.ai_family = AF_UNSPEC;
error = getaddrinfo(hostname, NULL, &hints, &res);
if (error) {
#if defined(MACOSX)
// if getaddrinfo fails try getifaddrs
ret = lookupIfLocalhost(env, hostname, JNI_TRUE);
if (ret != NULL || (*env)->ExceptionCheck(env)) {
goto cleanupAndReturn;
}
#endif
// report error
NET_ThrowUnknownHostExceptionWithGaiError(env, hostname, error);
goto cleanupAndReturn;
} else {
int i = 0, inetCount = 0, inet6Count = 0, inetIndex = 0,
inet6Index = 0, originalIndex = 0;
int addressPreference =
(*env)->GetStaticIntField(env, ia_class, ia_preferIPv6AddressID);;
iterator = res;
while (iterator != NULL) {
// skip duplicates
int skip = 0;
struct addrinfo *iteratorNew = resNew;
while (iteratorNew != NULL) {
if (iterator->ai_family == iteratorNew->ai_family &&
iterator->ai_addrlen == iteratorNew->ai_addrlen) {
if (iteratorNew->ai_family == AF_INET) { /* AF_INET */
struct sockaddr_in *addr1, *addr2;
addr1 = (struct sockaddr_in *)iterator->ai_addr;
addr2 = (struct sockaddr_in *)iteratorNew->ai_addr;
if (addr1->sin_addr.s_addr == addr2->sin_addr.s_addr) {
skip = 1;
break;
}
} else {
int t;
struct sockaddr_in6 *addr1, *addr2;
addr1 = (struct sockaddr_in6 *)iterator->ai_addr;
addr2 = (struct sockaddr_in6 *)iteratorNew->ai_addr;
for (t = 0; t < 16; t++) {
if (addr1->sin6_addr.s6_addr[t] !=
addr2->sin6_addr.s6_addr[t]) {
break;
}
}
if (t < 16) {
iteratorNew = iteratorNew->ai_next;
continue;
} else {
skip = 1;
break;
}
}
} else if (iterator->ai_family != AF_INET &&
iterator->ai_family != AF_INET6) {
// we can't handle other family types
skip = 1;
break;
}
iteratorNew = iteratorNew->ai_next;
}
if (!skip) {
struct addrinfo *next
= (struct addrinfo *)malloc(sizeof(struct addrinfo));
if (!next) {
JNU_ThrowOutOfMemoryError(env, "Native heap allocation failed");
ret = NULL;
goto cleanupAndReturn;
}
memcpy(next, iterator, sizeof(struct addrinfo));
next->ai_next = NULL;
if (resNew == NULL) {
resNew = next;
} else {
last->ai_next = next;
}
last = next;
i++;
if (iterator->ai_family == AF_INET) {
inetCount++;
} else if (iterator->ai_family == AF_INET6) {
inet6Count++;
}
}
iterator = iterator->ai_next;
}
// allocate array - at this point i contains the number of addresses
ret = (*env)->NewObjectArray(env, i, ia_class, NULL);
if (IS_NULL(ret)) {
/* we may have memory to free at the end of this */
goto cleanupAndReturn;
}
if (addressPreference == java_net_InetAddress_PREFER_IPV6_VALUE) {
inetIndex = inet6Count;
inet6Index = 0;
} else if (addressPreference == java_net_InetAddress_PREFER_IPV4_VALUE) {
inetIndex = 0;
inet6Index = inetCount;
} else if (addressPreference == java_net_InetAddress_PREFER_SYSTEM_VALUE) {
inetIndex = inet6Index = originalIndex = 0;
}
iterator = resNew;
while (iterator != NULL) {
if (iterator->ai_family == AF_INET) {
jobject iaObj = (*env)->NewObject(env, ia4_class, ia4_ctrID);
if (IS_NULL(iaObj)) {
ret = NULL;
goto cleanupAndReturn;
}
setInetAddress_addr(env, iaObj, ntohl(((struct sockaddr_in*)iterator->ai_addr)->sin_addr.s_addr));
if ((*env)->ExceptionCheck(env))
goto cleanupAndReturn;
setInetAddress_hostName(env, iaObj, host);
if ((*env)->ExceptionCheck(env))
goto cleanupAndReturn;
(*env)->SetObjectArrayElement(env, ret, (inetIndex | originalIndex), iaObj);
inetIndex++;
} else if (iterator->ai_family == AF_INET6) {
jint scope = 0;
jboolean ret1;
jobject iaObj = (*env)->NewObject(env, ia6_class, ia6_ctrID);
if (IS_NULL(iaObj)) {
ret = NULL;
goto cleanupAndReturn;
}
ret1 = setInet6Address_ipaddress(env, iaObj, (char *)&(((struct sockaddr_in6*)iterator->ai_addr)->sin6_addr));
if (ret1 == JNI_FALSE) {
ret = NULL;
goto cleanupAndReturn;
}
scope = ((struct sockaddr_in6 *)iterator->ai_addr)->sin6_scope_id;
if (scope != 0) { // zero is default value, no need to set
setInet6Address_scopeid(env, iaObj, scope);
}
setInetAddress_hostName(env, iaObj, host);
if ((*env)->ExceptionCheck(env))
goto cleanupAndReturn;
(*env)->SetObjectArrayElement(env, ret, (inet6Index | originalIndex), iaObj);
inet6Index++;
}
if (addressPreference == java_net_InetAddress_PREFER_SYSTEM_VALUE) {
originalIndex++;
inetIndex = inet6Index = 0;
}
iterator = iterator->ai_next;
}
}
cleanupAndReturn:
JNU_ReleaseStringPlatformChars(env, host, hostname);
while (resNew != NULL) {
last = resNew;
resNew = resNew->ai_next;
free(last);
}
if (res != NULL) {
freeaddrinfo(res);
}
return ret;
}
/*
* Class: java_net_Inet6AddressImpl
* Method: getHostByAddr
* Signature: (I)Ljava/lang/String;
*
* Theoretically the UnknownHostException could be enriched with gai error
* information. But as it is silently ignored anyway, there's no need for this.
* It's only important that either a valid hostname is returned or an
* UnknownHostException is thrown.
*/
JNIEXPORT jstring JNICALL
Java_java_net_Inet6AddressImpl_getHostByAddr(JNIEnv *env, jobject this,
jbyteArray addrArray) {
jstring ret = NULL;
char host[NI_MAXHOST + 1];
int len = 0;
jbyte caddr[16];
SOCKETADDRESS sa;
memset((void *)&sa, 0, sizeof(SOCKETADDRESS));
// construct a sockaddr_in structure (AF_INET or AF_INET6)
if ((*env)->GetArrayLength(env, addrArray) == 4) {
jint addr;
(*env)->GetByteArrayRegion(env, addrArray, 0, 4, caddr);
addr = ((caddr[0] << 24) & 0xff000000);
addr |= ((caddr[1] << 16) & 0xff0000);
addr |= ((caddr[2] << 8) & 0xff00);
addr |= (caddr[3] & 0xff);
sa.sa4.sin_addr.s_addr = htonl(addr);
sa.sa4.sin_family = AF_INET;
len = sizeof(struct sockaddr_in);
} else {
(*env)->GetByteArrayRegion(env, addrArray, 0, 16, caddr);
memcpy((void *)&sa.sa6.sin6_addr, caddr, sizeof(struct in6_addr));
sa.sa6.sin6_family = AF_INET6;
len = sizeof(struct sockaddr_in6);
}
if (getnameinfo(&sa.sa, len, host, sizeof(host), NULL, 0, NI_NAMEREQD)) {
JNU_ThrowByName(env, "java/net/UnknownHostException", NULL);
} else {
ret = (*env)->NewStringUTF(env, host);
if (ret == NULL) {
JNU_ThrowByName(env, "java/net/UnknownHostException", NULL);
}
}
return ret;
}
/**
* ping implementation using tcp port 7 (echo)
*/
static jboolean
tcp_ping6(JNIEnv *env, SOCKETADDRESS *sa, SOCKETADDRESS *netif, jint timeout,
jint ttl)
{
jint fd;
int connect_rv = -1;
// open a TCP socket
fd = socket(AF_INET6, SOCK_STREAM, 0);
if (fd == -1) {
// note: if you run out of fds, you may not be able to load
// the exception class, and get a NoClassDefFoundError instead.
NET_ThrowNew(env, errno, "Can't create socket");
return JNI_FALSE;
}
// set TTL
if (ttl > 0) {
setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl));
}
// A network interface was specified, so let's bind to it.
if (netif != NULL) {
if (bind(fd, &netif->sa, sizeof(struct sockaddr_in6)) <0) {
NET_ThrowNew(env, errno, "Can't bind socket");
close(fd);
return JNI_FALSE;
}
}
// Make the socket non blocking so we can use select/poll.
SET_NONBLOCKING(fd);
sa->sa6.sin6_port = htons(7); // echo port
connect_rv = NET_Connect(fd, &sa->sa, sizeof(struct sockaddr_in6));
// connection established or refused immediately, either way it means
// we were able to reach the host!
if (connect_rv == 0 || errno == ECONNREFUSED) {
close(fd);
return JNI_TRUE;
}
switch (errno) {
case ENETUNREACH: // Network Unreachable
case EAFNOSUPPORT: // Address Family not supported
case EADDRNOTAVAIL: // address is not available on the remote machine
#if defined(__linux__) || defined(_AIX)
// On some Linux versions, when a socket is bound to the loopback
// interface, connect will fail and errno will be set to EINVAL
// or EHOSTUNREACH. When that happens, don't throw an exception,
// just return false.
case EINVAL:
case EHOSTUNREACH: // No route to host
#endif
close(fd);
return JNI_FALSE;
case EINPROGRESS: // this is expected as we'll probably have to wait
break;
default:
NET_ThrowByNameWithLastError(env, JNU_JAVANETPKG "ConnectException",
"connect failed");
close(fd);
return JNI_FALSE;
}
timeout = NET_Wait(env, fd, NET_WAIT_CONNECT, timeout);
if (timeout >= 0) {
// connection has been established, check for error condition
socklen_t optlen = (socklen_t)sizeof(connect_rv);
if (getsockopt(fd, SOL_SOCKET, SO_ERROR, (void*)&connect_rv,
&optlen) <0)
{
connect_rv = errno;
}
if (connect_rv == 0 || connect_rv == ECONNREFUSED) {
close(fd);
return JNI_TRUE;
}
}
close(fd);
return JNI_FALSE;
}
/**
* ping implementation.
* Send an ICMP_ECHO_REQUEST packet every second until either the timeout
* expires or an answer is received.
* Returns true if an ECHO_REPLY is received, false otherwise.
*/
static jboolean
ping6(JNIEnv *env, jint fd, SOCKETADDRESS *sa, SOCKETADDRESS *netif,
jint timeout, jint ttl)
{
jint n, size = 60 * 1024, tmout2, seq = 1;
socklen_t len;
unsigned char sendbuf[1500], recvbuf[1500];
struct icmp6_hdr *icmp6;
struct sockaddr_in6 sa_recv;
jchar pid;
struct timeval tv;
size_t plen = sizeof(struct icmp6_hdr) + sizeof(tv);
#if defined(__linux__)
/**
* For some strange reason, the linux kernel won't calculate the
* checksum of ICMPv6 packets unless you set this socket option
*/
int csum_offset = 2;
setsockopt(fd, SOL_RAW, IPV6_CHECKSUM, &csum_offset, sizeof(int));
#endif
setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &size, sizeof(size));
// sets the ttl (max number of hops)
if (ttl > 0) {
setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl));
}
// a specific interface was specified, so let's bind the socket
// to that interface to ensure the requests are sent only through it.
if (netif != NULL) {
if (bind(fd, &netif->sa, sizeof(struct sockaddr_in6)) <0) {
NET_ThrowNew(env, errno, "Can't bind socket");
close(fd);
return JNI_FALSE;
}
}
// icmp_id is a 16 bit data type, therefore down cast the pid
pid = (jchar)getpid();
// Make the socket non blocking so we can use select
SET_NONBLOCKING(fd);
do {
// create the ICMP request
icmp6 = (struct icmp6_hdr *)sendbuf;
icmp6->icmp6_type = ICMP6_ECHO_REQUEST;
icmp6->icmp6_code = 0;
// let's tag the ECHO packet with our pid so we can identify it
icmp6->icmp6_id = htons(pid);
icmp6->icmp6_seq = htons(seq);
seq++;
gettimeofday(&tv, NULL);
memcpy(sendbuf + sizeof(struct icmp6_hdr), &tv, sizeof(tv));
icmp6->icmp6_cksum = 0;
// send it
n = sendto(fd, sendbuf, plen, 0, &sa->sa, sizeof(struct sockaddr_in6));
if (n < 0 && errno != EINPROGRESS) {
#if defined(__linux__)
/*
* On some Linux versions, when a socket is bound to the loopback
* interface, sendto will fail and errno will be set to
* EINVAL or EHOSTUNREACH. When that happens, don't throw an
* exception, just return false.
*/
if (errno != EINVAL && errno != EHOSTUNREACH) {
NET_ThrowNew(env, errno, "Can't send ICMP packet");
}
#else
NET_ThrowNew(env, errno, "Can't send ICMP packet");
#endif
close(fd);
return JNI_FALSE;
}
tmout2 = timeout > 1000 ? 1000 : timeout;
do {
tmout2 = NET_Wait(env, fd, NET_WAIT_READ, tmout2);
if (tmout2 >= 0) {
len = sizeof(sa_recv);
n = recvfrom(fd, recvbuf, sizeof(recvbuf), 0,
(struct sockaddr *)&sa_recv, &len);
// check if we received enough data
if (n < (jint)sizeof(struct icmp6_hdr)) {
continue;
}
icmp6 = (struct icmp6_hdr *)recvbuf;
// We did receive something, but is it what we were expecting?
// I.E.: An ICMP6_ECHO_REPLY packet with the proper PID and
// from the host that we are trying to determine is reachable.
if (icmp6->icmp6_type == ICMP6_ECHO_REPLY &&
(ntohs(icmp6->icmp6_id) == pid))
{
if (NET_IsEqual((jbyte *)&sa->sa6.sin6_addr,
(jbyte *)&sa_recv.sin6_addr)) {
close(fd);
return JNI_TRUE;
} else if (NET_IsZeroAddr((jbyte *)&sa->sa6.sin6_addr)) {
close(fd);
return JNI_TRUE;
}
}
}
} while (tmout2 > 0);
timeout -= 1000;
} while (timeout > 0);
close(fd);
return JNI_FALSE;
}
/*
* Class: java_net_Inet6AddressImpl
* Method: isReachable0
* Signature: ([bII[bI)Z
*/
JNIEXPORT jboolean JNICALL
Java_java_net_Inet6AddressImpl_isReachable0(JNIEnv *env, jobject this,
jbyteArray addrArray, jint scope,
jint timeout, jbyteArray ifArray,
jint ttl, jint if_scope)
{
jbyte caddr[16];
jint sz, fd;
SOCKETADDRESS sa, inf, *netif = NULL;
// If IPv6 is not enabled, then we can't reach an IPv6 address, can we?
// Actually, we probably shouldn't even get here.
if (!ipv6_available()) {
return JNI_FALSE;
}
// If it's an IPv4 address, ICMP won't work with IPv4 mapped address,
// therefore, let's delegate to the Inet4Address method.
sz = (*env)->GetArrayLength(env, addrArray);
if (sz == 4) {
return Java_java_net_Inet4AddressImpl_isReachable0(env, this,
addrArray, timeout,
ifArray, ttl);
}
// load address to SOCKETADDRESS
memset((char *)caddr, 0, 16);
(*env)->GetByteArrayRegion(env, addrArray, 0, 16, caddr);
memset((char *)&sa, 0, sizeof(SOCKETADDRESS));
memcpy((void *)&sa.sa6.sin6_addr, caddr, sizeof(struct in6_addr));
sa.sa6.sin6_family = AF_INET6;
if (scope > 0) {
sa.sa6.sin6_scope_id = scope;
}
// load network interface address to SOCKETADDRESS, if specified
if (!(IS_NULL(ifArray))) {
memset((char *)caddr, 0, 16);
(*env)->GetByteArrayRegion(env, ifArray, 0, 16, caddr);
memset((char *)&inf, 0, sizeof(SOCKETADDRESS));
memcpy((void *)&inf.sa6.sin6_addr, caddr, sizeof(struct in6_addr));
inf.sa6.sin6_family = AF_INET6;
inf.sa6.sin6_scope_id = if_scope;
netif = &inf;
}
// Let's try to create a RAW socket to send ICMP packets.
// This usually requires "root" privileges, so it's likely to fail.
fd = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6);
if (fd == -1) {
return tcp_ping6(env, &sa, netif, timeout, ttl);
} else {
// It didn't fail, so we can use ICMP_ECHO requests.
return ping6(env, fd, &sa, netif, timeout, ttl);
}
}