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Native incoming data

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This commit is contained in:
M66B 2016-01-14 15:02:32 +01:00
parent 175a6aed9b
commit 2636a4dddb
4 changed files with 158 additions and 56 deletions
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1
.gitignore vendored
View file

@ -6,3 +6,4 @@
.DS_Store
/build
/captures
/*.sh

10
app/build.gradle
View file

@ -34,6 +34,16 @@ model {
release {
minifyEnabled = true
proguardFiles.add(file('proguard-rules.pro'))
ndk.with {
debuggable = true
}
}
}
android.buildTypes {
debug {
ndk.with {
debuggable = true
}
}
}
android.productFlavors {

4
app/src/main/java/eu/faircode/netguard/SinkholeService.java
View file

@ -113,6 +113,8 @@ public class SinkholeService extends VpnService implements SharedPreferences.OnS
private static final String ACTION_SCREEN_OFF_DELAYED = "eu.faircode.netguard.SCREEN_OFF_DELAYED";
private native void jni_init();
private native void jni_start(int tun);
private native void jni_stop(int tun);
@ -849,6 +851,8 @@ public class SinkholeService extends VpnService implements SharedPreferences.OnS
public void onCreate() {
Log.i(TAG, "Create");
jni_init();
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
prefs.registerOnSharedPreferenceChangeListener(this);

199
app/src/main/jni/netguard/netguard.c
View file

@ -35,9 +35,8 @@ struct arguments {
};
struct data {
uint32_t seq; // host notation
jbyte *data;
uint32_t len;
uint8_t *data;
struct data *next;
};
@ -52,14 +51,13 @@ struct connection {
uint8_t state;
jint socket;
uint32_t lport; // host notation
struct data *received;
struct data *sent;
struct connection *next;
};
void *handle_events(void *);
void handle_tcp(JNIEnv *, jobject, const uint8_t *, const uint16_t);
void handle_tcp(JNIEnv *, jobject, const struct arguments *args, const uint8_t *, const uint16_t);
int openSocket(JNIEnv *, jobject, const struct sockaddr_in *);
@ -69,7 +67,7 @@ int canWrite(const int);
int writeSYN(const struct connection *, const int);
void decode(JNIEnv *, jobject, const uint8_t *, const uint16_t);
void decode(JNIEnv *, jobject, const struct arguments *args, const uint8_t *, const uint16_t);
jint getUid(const int, const int, const void *, const uint16_t);
@ -88,6 +86,12 @@ struct connection *connection = NULL;
// JNI
JNIEXPORT void JNICALL
Java_eu_faircode_netguard_SinkholeService_jni_1init(JNIEnv *env, jobject instance) {
__android_log_print(ANDROID_LOG_DEBUG, TAG, "Init");
connection = NULL;
}
JNIEXPORT void JNICALL
Java_eu_faircode_netguard_SinkholeService_jni_1start(JNIEnv *env, jobject instance, jint tun) {
__android_log_print(ANDROID_LOG_DEBUG, TAG, "Starting tun=%d", tun);
@ -202,26 +206,12 @@ void *handle_events(void *a) {
__android_log_print(ANDROID_LOG_DEBUG, TAG, "Idle %s/%u lport %u",
dest, ntohs(cur->dest), cur->lport);
// TODO check if open
shutdown(cur->socket, SHUT_RDWR);
// TODO check for errors
if (last == NULL)
connection = cur->next;
else
last->next = cur->next;
struct data *prev;
struct data *received = cur->received;
while (received != NULL) {
prev = received;
received = received->next;
if (prev->data != NULL)
free(prev->data);
free(prev);
}
struct data *sent = cur->sent;
while (sent != NULL) {
prev = sent;
@ -231,11 +221,18 @@ void *handle_events(void *a) {
free(prev);
}
free(cur);
if (last == NULL)
connection = cur->next;
else
last->next = cur->next;
struct connection *c = cur;
cur = cur->next;
free(c);
continue;
} else {
if (cur->state == TCP_SYN_RECV) {
// TODO check if tun writable?
FD_SET(cur->socket, &wfds);
if (cur->socket > max)
max = cur->socket;
@ -274,12 +271,13 @@ void *handle_events(void *a) {
if (ready == 0)
__android_log_print(ANDROID_LOG_DEBUG, TAG, "Yield");
else {
// Check tun
// Check tun exception
if (FD_ISSET(args->tun, &efds)) {
__android_log_print(ANDROID_LOG_ERROR, TAG, "tun exception");
break;
}
// Check tun read
if (FD_ISSET(args->tun, &rfds)) {
uint8_t buffer[MAXPKT];
ssize_t length = read(args->tun, buffer, MAXPKT);
@ -289,7 +287,7 @@ void *handle_events(void *a) {
break;
}
if (length > 0)
decode(env, args->instance, buffer, length);
decode(env, args->instance, args, buffer, length);
else {
__android_log_print(ANDROID_LOG_ERROR, TAG, "tun empty read");
break;
@ -299,7 +297,7 @@ void *handle_events(void *a) {
// Check sockets
struct connection *cur = connection;
while (cur != NULL) {
// Check exceptions
// Check socket exception
if (FD_ISSET(cur->socket, &efds)) {
int serr;
socklen_t optlen = sizeof(serr);
@ -317,8 +315,8 @@ void *handle_events(void *a) {
}
}
// Check connects
if (cur->state == TCP_SYN_RECV) {
// Check socket connect
if (FD_ISSET(cur->socket, &wfds) && canWrite(args->tun)) {
// Log
char dest[20];
@ -333,22 +331,23 @@ void *handle_events(void *a) {
}
}
// Check incoming data
if (cur->state == TCP_ESTABLISHED) {
else if (cur->state == TCP_ESTABLISHED) {
// Check socket read
if (FD_ISSET(cur->socket, &rfds)) {
uint8_t buffer[MAXPKT];
ssize_t bytes = recv(cur->socket, buffer, MAXPKT, MSG_DONTWAIT);
ssize_t bytes = recv(cur->socket, buffer, MAXPKT, 0);
if (bytes < 0) {
// TODO handle EINTR
__android_log_print(ANDROID_LOG_ERROR, TAG, "recv error %d: %s",
__android_log_print(ANDROID_LOG_ERROR, TAG, "recv socket error %d: %s",
errno, strerror(errno));
cur->state = TCP_CLOSE;
if (errno != EINTR)
cur->state = TCP_CLOSE;
}
else if (bytes == 0) {
__android_log_print(ANDROID_LOG_ERROR, TAG, "recv empty");
__android_log_print(ANDROID_LOG_ERROR, TAG, "recv socket empty");
cur->state = TCP_CLOSE;
} else {
__android_log_print(ANDROID_LOG_DEBUG, TAG, "recv lport %u bytes %d",
__android_log_print(ANDROID_LOG_DEBUG, TAG,
"recv socket lport %u bytes %d",
cur->lport, bytes);
}
}
@ -369,9 +368,10 @@ void *handle_events(void *a) {
args->tun, thread_id);
}
void handle_tcp(JNIEnv *env, jobject instance, const uint8_t *buffer, uint16_t length) {
void handle_tcp(JNIEnv *env, jobject instance, const struct arguments *args,
const uint8_t *buffer, uint16_t length) {
// Check version
jbyte version = (*buffer) >> 4;
uint8_t version = (*buffer) >> 4;
if (version != 4)
return;
@ -379,6 +379,7 @@ void handle_tcp(JNIEnv *env, jobject instance, const uint8_t *buffer, uint16_t l
struct iphdr *iphdr = buffer;
uint8_t optlen = (iphdr->ihl - 5) * 4;
struct tcphdr *tcphdr = buffer + sizeof(struct iphdr) + optlen;
__android_log_print(ANDROID_LOG_DEBUG, TAG, "optlen %d", optlen);
if (ntohs(iphdr->tot_len) != length)
__android_log_print(ANDROID_LOG_WARN, TAG, "Invalid length %u/%d", iphdr->tot_len, length);
@ -386,13 +387,14 @@ void handle_tcp(JNIEnv *env, jobject instance, const uint8_t *buffer, uint16_t l
// Get data
uint16_t dataoff = sizeof(struct iphdr) + optlen + sizeof(struct tcphdr);
uint16_t datalen = length - dataoff;
struct data *data = malloc(sizeof(struct data));
data->seq = ntohl(tcphdr->seq);
data->data = malloc(datalen); // TODO free
data->next = NULL;
if (datalen)
struct data *data = NULL;
if (datalen > 0) {
data = malloc(sizeof(struct data));
data->len = datalen;
data->data = malloc(datalen); // TODO free
memcpy(data->data, buffer + dataoff, datalen);
data->len = datalen;
data->next = NULL;
}
// Search connection
struct connection *last = NULL;
@ -416,21 +418,21 @@ void handle_tcp(JNIEnv *env, jobject instance, const uint8_t *buffer, uint16_t l
// Register connection
struct connection *syn = malloc(sizeof(struct connection)); // TODO check/free
syn->time = time(NULL);
syn->remote_seq = ntohl(tcphdr->seq);
syn->local_seq = 123; // TODO randomize
syn->remote_seq = ntohl(tcphdr->seq); // ISN remote
syn->local_seq = 123; // ISN local TODO randomize
syn->saddr = iphdr->saddr;
syn->source = tcphdr->source;
syn->daddr = iphdr->daddr;
syn->dest = tcphdr->dest;
syn->state = TCP_SYN_RECV;
syn->received = NULL;
syn->sent = NULL;
syn->next = NULL;
// Ignore data
if (data->data != NULL)
if (data != NULL) {
free(data->data);
free(data);
free(data);
}
// Build target address
struct sockaddr_in daddr;
@ -470,9 +472,10 @@ void handle_tcp(JNIEnv *env, jobject instance, const uint8_t *buffer, uint16_t l
if (cur->state == TCP_SYN_SENT) {
// TODO proper warp around
if (ntohl(tcphdr->ack_seq) == cur->local_seq + 1 &&
ntohl(tcphdr->seq) == cur->remote_seq + 1) {
ntohl(tcphdr->seq) >= cur->remote_seq + 1) {
cur->local_seq += 1;
cur->remote_seq += 1;
// TODO process data
__android_log_print(ANDROID_LOG_DEBUG, TAG, "Established");
cur->state = TCP_ESTABLISHED;
@ -482,14 +485,31 @@ void handle_tcp(JNIEnv *env, jobject instance, const uint8_t *buffer, uint16_t l
}
else if (cur->state == TCP_ESTABLISHED) {
// TODO proper wrap around
if (ntohl(tcphdr->seq) + 1 == cur->remote_seq)
// TODO respond to keepalive?
__android_log_print(ANDROID_LOG_DEBUG, TAG, "Keep alive");
else
__android_log_print(ANDROID_LOG_DEBUG, TAG, "Data");
else if (ntohl(tcphdr->seq) < cur->remote_seq)
__android_log_print(ANDROID_LOG_WARN, TAG, "Processed ack");
else {
__android_log_print(ANDROID_LOG_DEBUG, TAG, "New ack");
if (data != NULL && data->len) {
// TODO non blocking
__android_log_print(ANDROID_LOG_DEBUG, TAG, "send socket data %u",
data->len);
if (send(cur->socket, data->data, data->len, 0) < 0)
__android_log_print(ANDROID_LOG_ERROR, TAG, "send error %d: %s",
errno, strerror(errno));
else {
if (writeACK(cur, data->len, args->tun))
cur->remote_seq += data->len;
}
}
}
}
else {
__android_log_print(ANDROID_LOG_WARN, TAG, "Ignored");
__android_log_print(ANDROID_LOG_WARN, TAG, "Ignored state %d", cur->state);
}
}
}
@ -543,7 +563,7 @@ int openSocket(JNIEnv *env, jobject instance, const struct sockaddr_in *daddr) {
}
// Set blocking
if (fcntl(sock, F_SETFL, flags) < 0) {
if (fcntl(sock, F_SETFL, flags & ~O_NONBLOCK) < 0) {
__android_log_print(ANDROID_LOG_ERROR, TAG, "fcntl error %d: %s",
errno, strerror(errno));
return -1;
@ -600,10 +620,11 @@ int writeSYN(const struct connection *cur, int tun) {
tcp->doff = sizeof(struct tcphdr) >> 2;
tcp->syn = 1;
tcp->ack = 1;
tcp->window = htons(2048);
// Calculate TCP checksum
uint16_t clen = sizeof(struct ippseudo) + sizeof(struct tcphdr);
jbyte csum[clen];
uint8_t csum[clen];
// Build pseudo header
struct ippseudo *pseudo = csum;
@ -638,7 +659,73 @@ int writeSYN(const struct connection *cur, int tun) {
return res;
}
void decode(JNIEnv *env, jobject instance, const uint8_t *buffer, const uint16_t length) {
int writeACK(const struct connection *cur, uint32_t datalen, int tun) {
// Build packet
uint16_t len = sizeof(struct iphdr) + sizeof(struct tcphdr); // no data
u_int8_t *buffer = calloc(len, 1);
struct iphdr *ip = buffer;
struct tcphdr *tcp = buffer + sizeof(struct iphdr);
// Build IP header
ip->version = 4;
ip->ihl = sizeof(struct iphdr) >> 2;
ip->tot_len = htons(len);
ip->ttl = TTL;
ip->protocol = IPPROTO_TCP;
ip->saddr = cur->daddr;
ip->daddr = cur->saddr;
// Calculate IP checksum
ip->check = checksum(ip, sizeof(struct iphdr));
// Build TCP header
tcp->source = cur->dest;
tcp->dest = cur->source;
tcp->seq = htonl(cur->local_seq);
tcp->ack_seq = htonl(cur->remote_seq + datalen); // TODO proper wrap around
tcp->doff = sizeof(struct tcphdr) >> 2;
tcp->ack = 1;
tcp->window = htons(2048);
// Calculate TCP checksum
uint16_t clen = sizeof(struct ippseudo) + sizeof(struct tcphdr);
uint8_t csum[clen];
// Build pseudo header
struct ippseudo *pseudo = csum;
pseudo->ippseudo_src.s_addr = ip->saddr;
pseudo->ippseudo_dst.s_addr = ip->daddr;
pseudo->ippseudo_pad = 0;
pseudo->ippseudo_p = ip->protocol;
pseudo->ippseudo_len = htons(sizeof(struct tcphdr)); // no data
// Copy TCP header
memcpy(csum + sizeof(struct ippseudo), tcp, sizeof(struct tcphdr));
tcp->check = checksum(csum, clen);
char to[20];
inet_ntop(AF_INET, &(ip->daddr), to, sizeof(to));
// Send packet
__android_log_print(ANDROID_LOG_DEBUG, TAG,
"Sending ACK to tun %s/%u seq %u ack %u",
to, ntohs(tcp->dest),
ntohl(tcp->seq), ntohl(tcp->ack_seq));
int res = write(tun, buffer, len);
if (res < 0) {
// TODO handle EINTR
__android_log_print(ANDROID_LOG_ERROR, TAG, "write error %d: %s",
errno, strerror(errno));
}
free(buffer);
return res;
}
void decode(JNIEnv *env, jobject instance, const struct arguments *args,
const uint8_t *buffer, const uint16_t length) {
uint8_t protocol;
void *saddr;
void *daddr;
@ -649,7 +736,7 @@ void decode(JNIEnv *env, jobject instance, const uint8_t *buffer, const uint16_t
uint8_t *payload;
// Get protocol, addresses & payload
jbyte version = (*buffer) >> 4;
uint8_t version = (*buffer) >> 4;
if (version == 4) {
struct iphdr *ip4hdr = buffer;
@ -752,7 +839,7 @@ void decode(JNIEnv *env, jobject instance, const uint8_t *buffer, const uint16_t
version, source, sport, dest, dport, protocol, flags, uid);
if (protocol == IPPROTO_TCP)
handle_tcp(env, instance, buffer, length);
handle_tcp(env, instance, args, buffer, length);
// Call back
jclass cls = (*env)->GetObjectClass(env, instance);