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/*
* Copyright 2010, The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "AsynchronousSocketCloseMonitor.h"
#include "JNIHelp.h"
#include "JniException.h"
#include "JniConstants.h"
#include "NetFd.h"
#include "NetworkUtilities.h"
#include "ScopedUtfChars.h"
#include "ScopedPrimitiveArray.h"
#include "jni.h"
#include <sys/types.h>
#include <sys/socket.h>
#include <linux/rtnetlink.h>
#include <net/if.h>
#include <linux/if_ether.h>
#include <linux/if_packet.h>
#include <arpa/inet.h>
#include <errno.h>
#include <fcntl.h>
#include <poll.h>
#include <netinet/ip.h>
#include <linux/udp.h>
union sockunion {
sockaddr sa;
sockaddr_ll sll;
};
/*
* Creates a socket suitable for raw socket operations. The socket is
* bound to the interface specified by the supplied name. The socket
* value is placed into the supplied FileDescriptor instance.
*
* TODO(chesnutt): consider breaking this into pieces: create a
* variety of constructors for different socket types, then a generic
* setBlocking() method followed by polymorphic bind().
*/
static void RawSocket_create(JNIEnv* env, jclass, jobject fileDescriptor,
jshort protocolType, jstring interfaceName)
{
ScopedUtfChars ifname(env, interfaceName);
if (ifname.c_str() == NULL) {
return;
}
sockunion su;
memset(&su, 0, sizeof(su));
su.sll.sll_family = PF_PACKET;
su.sll.sll_protocol = htons(protocolType);
su.sll.sll_ifindex = if_nametoindex(ifname.c_str());
int sock = socket(PF_PACKET, SOCK_DGRAM, htons(protocolType));
if (sock == -1) {
ALOGE("Can't create socket %s", strerror(errno));
jniThrowSocketException(env, errno);
return;
}
jniSetFileDescriptorOfFD(env, fileDescriptor, sock);
if (!setBlocking(sock, false)) {
ALOGE("Can't set non-blocking mode on socket %s", strerror(errno));
jniThrowSocketException(env, errno);
return;
}
int err = bind(sock, &su.sa, sizeof(su));
if (err != 0) {
ALOGE("Socket bind error %s", strerror(errno));
jniThrowSocketException(env, errno);
return;
}
}
/*
* Writes the L3 (IP) packet to the raw socket supplied in the
* FileDescriptor instance.
*
* Assumes that the caller has validated the offset & byteCount values.
*/
static int RawSocket_sendPacket(JNIEnv* env, jclass, jobject fileDescriptor,
jstring interfaceName, jshort protocolType, jbyteArray destMac,
jbyteArray packet, jint offset, jint byteCount)
{
NetFd fd(env, fileDescriptor);
if (fd.isClosed()) {
return 0;
}
ScopedUtfChars ifname(env, interfaceName);
if (ifname.c_str() == NULL) {
return 0;
}
ScopedByteArrayRO byteArray(env, packet);
if (byteArray.get() == NULL) {
return 0;
}
ScopedByteArrayRO mac(env, destMac);
if (mac.get() == NULL) {
return 0;
}
sockunion su;
memset(&su, 0, sizeof(su));
su.sll.sll_hatype = htons(1); // ARPHRD_ETHER
su.sll.sll_halen = mac.size();
memcpy(&su.sll.sll_addr, mac.get(), mac.size());
su.sll.sll_family = AF_PACKET;
su.sll.sll_protocol = htons(protocolType);
su.sll.sll_ifindex = if_nametoindex(ifname.c_str());
int err;
{
int intFd = fd.get();
AsynchronousSocketCloseMonitor monitor(intFd);
err = NET_FAILURE_RETRY(fd, sendto(intFd, byteArray.get() + offset,
byteCount, 0, &su.sa, sizeof(su)));
}
return err;
}
/*
* Reads a network packet into the user-supplied buffer. Return the
* length of the packet, or a 0 if there was a timeout or an
* unacceptable packet was acquired.
*
* Assumes that the caller has validated the offset & byteCount values.
*/
static jint RawSocket_recvPacket(JNIEnv* env, jclass, jobject fileDescriptor,
jbyteArray packet, jint offset, jint byteCount, jint port,
jint timeout_millis)
{
NetFd fd(env, fileDescriptor);
if (fd.isClosed()) {
return 0;
}
ScopedByteArrayRW body(env, packet);
jbyte* packetData = body.get();
if (packetData == NULL) {
return 0;
}
packetData += offset;
pollfd fds[1];
fds[0].fd = fd.get();
fds[0].events = POLLIN;
int retval = poll(fds, 1, timeout_millis);
if (retval <= 0) {
return 0;
}
unsigned int size = 0;
{
int packetSize = byteCount;
int intFd = fd.get();
AsynchronousSocketCloseMonitor monitor(intFd);
size = NET_FAILURE_RETRY(fd, read(intFd, packetData, packetSize));
}
if (env->ExceptionOccurred()) {
return 0;
}
if (port != -1) {
// quick check for UDP type & UDP port
// the packet is an IP header, UDP header, and UDP payload
if ((size < (sizeof(struct iphdr) + sizeof(struct udphdr)))) {
return 0; // runt packet
}
u_int8_t ip_proto = ((iphdr *) packetData)->protocol;
if (ip_proto != IPPROTO_UDP) {
return 0; // something other than UDP
}
__be16 destPort = htons((reinterpret_cast<udphdr*>(packetData + sizeof(iphdr)))->dest);
if (destPort != port) {
return 0; // something other than requested port
}
}
return size;
}
static JNINativeMethod gRawMethods[] = {
NATIVE_METHOD(RawSocket, create, "(Ljava/io/FileDescriptor;SLjava/lang/String;)V"),
NATIVE_METHOD(RawSocket, sendPacket, "(Ljava/io/FileDescriptor;Ljava/lang/String;S[B[BII)I"),
NATIVE_METHOD(RawSocket, recvPacket, "(Ljava/io/FileDescriptor;[BIIII)I"),
};
void register_libcore_net_RawSocket(JNIEnv* env) {
jniRegisterNativeMethods(env, "libcore/net/RawSocket", gRawMethods, NELEM(gRawMethods));
}
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