Develop Reference

android ndk - execute .so binary file

Problem:
Want to run my build .so file with android runtime.exec or processbuilder
C side code: example.cpp
#include
using namespace std;
int main( int argc, char* argv[])
{
cout << "Count: " << argc << endl;
for (int i = 0; i < argc; i++) {
cout << "Command: " << argv[i] << endl;
}
}
Android side code(kotlin):
try{
val rt = Runtime.getRuntime()
val command = arrayOf(applicationContext.applicationInfo.nativeLibraryDir+"/libexample.so","-c","Hello world")
val proc = rt.exec(command)
val br = BufferedReader(InputStreamReader(proc.errorStream))
var line = ""
while(br.readLine().also { line = it } != null){
Log.e("TEST",line)
}
proc.waitFor()
val exitvalue = proc.exitValue()
Log.e("TEST","Exitvalue: ${exitvalue}")
}catch (ex:Exception){
Log.e("TEST",ex.toString())
}
Errors: Exit value = 139
Note: CPP code is working on console and there are no errors in cpp code. and i am using NDK.)
Question: May I execute .so file like this without using JNI?

Write Lock Block command for NfcV

I am trying to lock data to a NXP ICODE SLIX SL2S2002 tag type 5 (ISO 15693) to make it readonly by using the WRITE SINGLE BLOCKS command through the NfcV object in an ionic based app:
private readonly cmdISO15693 = {
READ_SINGLE_BLOCK: 0x20,
WRITE_SINGLE_BLOCK: 0x21,
LOCK_BLOCK: 0x22
};
this.nfc.connect('android.nfc.tech.NfcV', 500)
.then(
(data) => {
console.log('connected to', this.nfc.bytesToHexString(tag.id.reverse()).toUpperCase());
console.log('maxTransceiveLength: ', data);
const offset = 0; // offset of first block to read
const blocks = 8; // number of blocks to read
const bytesOfText: number[] = this.nfc.stringToBytes(text);
console.log('bytesOfText: ', bytesOfText);
console.log('hex string: ', this.nfc.bytesToHexString(bytesOfText));
let cmd = new Int8Array([
0x60, // 0: flags: addressed (= UID field present) or 0x90 0x60 0x40 0x20??
this.cmdISO15693.READ_SINGLE_BLOCK, // 1: command
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 2-9 placeholder for tag UID
0x00 // 10: block number
// 0x00, 0x00, 0x00, 0x00 // 11- DATA
// ((blocks - 1) & 0x0ff) // number of blocks (-1 as 0x00 means one block)
]);
console.log('cmd: ', [...cmd]);
// tag uid in which direction
cmd = arrayCopy(tag.id.reverse(), 0, cmd, 2, 8);
console.log('cmd new: ', [...cmd]);
console.log('cmd buffer: ', cmd.buffer);
// arrayCopy(bytesOfText, 0, cmd, 11, 4);
this.nfc.transceive(cmd.buffer)
.then((res: ArrayBuffer) => {
console.log('transceive result:', res);
try {
console.log(Utf8ArrayToStr(res));
} catch (e) {
console.log('Utf8ArrayToStr not possible', e);
}
this.nfc.close().then(() => console.log('closed connection'))
.catch((err) => console.log('error closing', err));
})
.catch((err) => {
console.log('error while transceive', err);
this.displayToast('Error to write the RFID-Chips.', 'warning');
});
I don't know which bytes I have to pass for each block. I use the phoneGap-NFC plugin for ionic. Every time I try to set it readonly I get the answer 'Tag was lost' and by the READ_SINGLE_BLOCK command, too.
The Ionic method makeReadOnly() does not work because this is blocked by the tag. I have to set it by means of the bytes.
I dont know do I have to use Int8Array or Unit8Array, do I have to use reverse() on the tagId because the hex is mirrored or do I just pass the UID bytestring instead of the hexstring?

this.nfc.connect('android.nfc.tech.NfcV', 500)
.then(
async () => {
const blocks = 28; // 28 read by app TagInfo memory size: 28 blocks with 4 bytes per block
const cmdLock = this.cmdISO15693.OPTION_FLAG // 0 flag addressed
+ ' ' + this.cmdISO15693.LOCK_BLOCK // 1 command
+ ' ' + this.tagIdHexArr.join(' '); // 2-9 tag uid
let blockError = false;
let resTransceive: ArrayBuffer;
for (let i = 0; i < blocks; i++) {
const block = this.nfc.bytesToHexString([i]).toUpperCase();
const cmd = cmdLock + ' ' + block;
try {
resTransceive = await this.nfc.transceive(cmd);
try {
const view = new Uint8Array(resTransceive);
const resHex = this.nfc.bytesToHexString([...view]);
console.log(resHex);
} catch (e) {
console.log(e);
}
} catch (e) {
blockError = true;
return;
}
if (blockError) {
return;
}
}
if (blockError) {
this.notification.push(new Notification(NotificationType.ERROR, 'Fehler beim Setzen des Schreibschutzes.'));
}
this.nfc.close().then(() => console.log('Closed connection'))
.catch((err) => console.log('Error closing: ', err));
});
Fixed the problem!

Rust JNI async callback with Tokio and Reqwest for Android

I'm testing Rust with JNI async execution. I want to do execute requests in Rust and return the result to Android asynchronously with callback. I'm testing code to execute the request in the command line and it works fine.
That is how it works on command line:
Callback struck:
struct Processor {
pub(crate) callback: Box<dyn FnMut(String)>,
}
impl Processor {
fn set_callback(&mut self, c: impl FnMut(String) + 'static) {
self.callback = Box::new(c);
}
fn process_events(&mut self, result: String) {
(self.callback)(result);
}
}
Tokio/reqwest:
const DATA_URL: &str = "https://pokeapi.co/api/v2/pokemon/1/";
#[tokio::main]
pub async fn load_swapi_async_with_cb(callback: Box<dyn FnMut(String)>) -> Result<(), Box<dyn std::error::Error>> {
println!("load_swload_swapi_async_with_cbapi_async started");
let mut cb = Processor {
callback: Box::new(callback),
};
let body = reqwest::get(DATA_URL)
.await?
.json::<HashMap<String, String>>()
.await?;
//println!("{:#?}", body);
let name = match body.get("name") {
Some(name) => name,
None => "Failed to parse"
}.to_string();
println!("Name is: {} ", name);
cb.process_events(name);
Ok(())
}
And JNI part:
#[no_mangle]
#[allow(non_snake_case)]
pub extern "C" fn Java_com_omg_app_greetings_MainActivity_callback(env: JNIEnv,
_class: JClass,
callback: JObject) {
static callback: dyn FnMut(String) + 'static = |name| {
let response = env.new_string(&name).expect("Couldn't create java string!");
env.call_method(callback, "rustCallbackResult", "(Ljava/lang/String;)V",
&[JValue::from(JObject::from(response))]).unwrap();
};
pokemon_api(callback);
}
And pokemon API method:
#[no_mangle]
pub extern fn pokemon_api(callback: impl FnMut(String) + 'static) {
let cb_box = Box::new(callback);
swapi::load_swapi_async_with_cb(cb_box);
}
The error I'm facing:
JNI ENV env non-constant value:
let response = env.new_string(&name).expect("Couldn't create java string!");
| ^^^ non-constant value
callback - doesn't have a size known at compile-time:
static callback: dyn FnMut(String) + 'static = |name| {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
I was checking how this working, but example seems to be out of date:
* https://github.com/mozilla/rust-android-gradle/blob/master/samples/rust/src/lib.rs

I fixed with my problem with the usage of the https://github.com/Dushistov/rust_swig
After you integrate it, it will autogenerate code and you can check how it does it.

Data transfer over wifi

I have create a hotspot/wifi-direct on an android device.And connect this wifi with iOS devices.
Now i want to create a iOS App which will be able to send and receive the data over wifi.
Is it possible if yes then how I can do this ?

yes it is possible, you can run local server on android, I recommend https://github.com/NanoHttpd/nanohttpd
then you must get ip address on iOS device to do http requests, there is c method to get route ip address
#include "IpHelper.h" // my header file
#include <stdio.h>
#include <netinet/in.h>
#include <stdlib.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <string.h>
#include <arpa/inet.h>
#if TARGET_IPHONE_SIMULATOR
#include <net/route.h>
#else
#include "route.h"
#endif
#define CTL_NET 4 /* network, see socket.h */
#if defined(BSD) || defined(__APPLE__)
#define ROUNDUP(a) \
((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
int getdefaultgateway(in_addr_t * addr)
{
int mib[] = {CTL_NET, PF_ROUTE, 0, AF_INET,
NET_RT_FLAGS, RTF_GATEWAY};
size_t l;
char * buf, * p;
struct rt_msghdr * rt;
struct sockaddr * sa;
struct sockaddr * sa_tab[RTAX_MAX];
int i;
int r = -1;
if(sysctl(mib, sizeof(mib)/sizeof(int), 0, &l, 0, 0) < 0) {
return -1;
}
if(l>0) {
buf = malloc(l);
if(sysctl(mib, sizeof(mib)/sizeof(int), buf, &l, 0, 0) < 0) {
return -1;
}
for(p=buf; p<buf+l; p+=rt->rtm_msglen) {
rt = (struct rt_msghdr *)p;
sa = (struct sockaddr *)(rt + 1);
for(i=0; i<RTAX_MAX; i++) {
if(rt->rtm_addrs & (1 << i)) {
sa_tab[i] = sa;
sa = (struct sockaddr *)((char *)sa + ROUNDUP(sa->sa_len));
} else {
sa_tab[i] = NULL;
}
}
if( ((rt->rtm_addrs & (RTA_DST|RTA_GATEWAY)) == (RTA_DST|RTA_GATEWAY))
&& sa_tab[RTAX_DST]->sa_family == AF_INET
&& sa_tab[RTAX_GATEWAY]->sa_family == AF_INET) {
if(((struct sockaddr_in *)sa_tab[RTAX_DST])->sin_addr.s_addr == 0) {
char ifName[128];
if_indextoname(rt->rtm_index,ifName);
if(strcmp("en0",ifName)==0){
*addr = ((struct sockaddr_in *)(sa_tab[RTAX_GATEWAY]))->sin_addr.s_addr;
r = 0;
}
}
}
}
free(buf);
}
return r;
}
#endif
also you need to download and import route.h from apple open-sources from here https://opensource.apple.com/source/xnu/xnu-1456.1.26/bsd/net/route.h
And at the end you are able to get local http url http://+'ip you get before'+ :'port of server you lunched on android'
so, now you are ready to do http request via ALamofire(or other) to local server.
EDIT 1:
I found this code in my old projects you can do data transfer with CocoaAsyncSocket, it is written in swift 3, I know that you want some code written on objC, but can not find such , sorry if i can't fully answer your question.
import CocoaAsyncSocket
import UIKit
enum TAG: Int {
case header = 1
case body = 2
}
class ViewController: UIViewController, NetServiceDelegate, NetServiceBrowserDelegate, GCDAsyncSocketDelegate {
var service : NetService!
var socket : GCDAsyncSocket!
var newSocket: GCDAsyncSocket!
var serviceBrowser = NetServiceBrowser()
var adresses: [Data]?
override func viewDidLoad() {
super.viewDidLoad()
startTalking()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
func parseHeader(data: NSData) -> UInt {
var out: UInt = 0
data.getBytes(&out, length: MemoryLayout<UInt>.size)
return out
}
func handleResponseBody(data: NSData) {
if let message = NSString(data: data as Data, encoding: String.Encoding.utf8.rawValue) {
print(message)
}
}
func sendText() {
if let data = "aaaaa".data(using: String.Encoding.utf8) {
var header = data.count
let headerData = NSData(bytes: &header, length: MemoryLayout<UInt>.size)
self.socket.write(headerData as Data, withTimeout: -1.0, tag: TAG.header.rawValue)
self.socket.write(data, withTimeout: -1.0, tag: TAG.body.rawValue)
}
}
func startTalking () {
self.socket = GCDAsyncSocket(delegate: self, delegateQueue: DispatchQueue.main)
self.socket.isIPv4PreferredOverIPv6 = false
do {
try self.socket.connect(toHost: "localhost", onPort: UInt16(8080), withTimeout: -1)
} catch let err {
print(err)
}
}
/*
* Delegates of NSNetService
**/
func netServiceBrowser(_ browser: NetServiceBrowser, didFindDomain domainString: String, moreComing: Bool) {
print(111)
}
func netService(_ sender: NetService, didNotResolve errorDict: [String : NSNumber]) {
print("aaaaaaa")
}
func netServiceDidPublish(_ sender: NetService) {
print("Bonjour service published. domain: \(sender.domain), type: \(sender.type), name: \(sender.name), port: \(sender.port)")
}
func netService(_ sender: NetService, didNotPublish errorDict: [String : NSNumber]) {
print("Unable to create socket. domain: \(sender.domain), type: \(sender.type), name: \(sender.name), port: \(sender.port), Error \(errorDict)")
}
func netService(_ sender: NetService, didAcceptConnectionWith inputStream: InputStream, outputStream: OutputStream) {
print("4")
}
/*
* END OF Delegates
**/
/*
* Delegates of GCDAsyncSokcket
**/
func socketDidSecure(_ sock: GCDAsyncSocket) {
print("3")
}
func socket(_ sock: GCDAsyncSocket, didConnectToHost host: String, port: UInt16) {
print("connected")
self.socket.readData(toLength: UInt(MemoryLayout<UInt64>.size), withTimeout: -1, tag: 0)
}
func socket(_ sock: GCDAsyncSocket, didAcceptNewSocket newSocket: GCDAsyncSocket) {
print("Did accept new socket")
self.newSocket = newSocket
self.newSocket.readData(toLength: UInt(MemoryLayout<UInt64>.size), withTimeout: -1.0, tag: 0)
print("Connected to " + self.service.name)
}
func socketDidDisconnect(_ sock: GCDAsyncSocket, withError err: Error?) {
print("Socket disconnected: error \(err)")
if self.socket == socket {
// print("Disconnected from " + self.service.name)
}
}
func socket(_ sock: GCDAsyncSocket, didRead data: Data, withTag tag: Int) {
if data.count == MemoryLayout<UInt>.size {
let bodyLength: UInt = self.parseHeader(data: data as NSData)
sock.readData(toLength: bodyLength, withTimeout: -1, tag: TAG.body.rawValue)
} else {
self.handleResponseBody(data: data as NSData)
sock.readData(toLength: UInt(MemoryLayout<UInt>.size), withTimeout: -1, tag: TAG.header.rawValue)
}
}
func socket(_ sock: GCDAsyncSocket, didWriteDataWithTag tag: Int) {
print("Write data with tag of \(tag)")
}
func socket(_ sock: GCDAsyncSocket, didReceive trust: SecTrust, completionHandler: #escaping (Bool) -> Void) {
completionHandler(true)
}
/*
* END OF Delegates
**/
}
EDIT 2:
To parse ip to human readable string here is Objc method for it
+ (NSString *)getGatewayIP {
NSString *ipString = nil;
struct in_addr gatewayaddr;
int r = getdefaultgateway(&(gatewayaddr.s_addr));
if(r >= 0) {
ipString = [NSString stringWithFormat: #"%s",inet_ntoa(gatewayaddr)];
NSLog(#"default gateway : %#", ipString );
} else {
NSLog(#"getdefaultgateway() failed");
}
return ipString;
}

ffmpeg error on decode

I'm developing an android app with the libav and I'm trying decode a 3gp with code below:
#define simbiLog(...) __android_log_print(ANDROID_LOG_DEBUG, "simbiose", __VA_ARGS__)
...
AVCodec *codec;
AVCodecContext *c = NULL;
int len;
FILE *infile, *outfile;
uint8_t inbuf[AUDIO_INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE];
AVPacket avpkt;
AVFrame *decoded_frame = NULL;
simbiLog("inbuf size: %d", sizeof(inbuf) / sizeof(inbuf[0]));
av_register_all();
av_init_packet(&avpkt);
codec = avcodec_find_decoder(AV_CODEC_ID_AMR_NB);
if (!codec) {
simbiLog("codec not found");
return ERROR;
}
c = avcodec_alloc_context3(codec);
if (!c) {
simbiLog("Could not allocate audio codec context");
return ERROR;
}
int open = avcodec_open2(c, codec, NULL);
if (open < 0) {
simbiLog("could not open codec %d", open);
return ERROR;
}
infile = fopen(inputPath, "rb");
if (!infile) {
simbiLog("could not open %s", inputPath);
return ERROR;
}
outfile = fopen(outputPath, "wb");
if (!outfile) {
simbiLog("could not open %s", outputPath);
return ERROR;
}
avpkt.data = inbuf;
avpkt.size = fread(inbuf, 1, AUDIO_INBUF_SIZE, infile);
int iterations = 0;
while (avpkt.size > 0) {
simbiLog("iteration %d", (++iterations));
simbiLog("avpkt.size %d avpkt.data %X", avpkt.size, avpkt.data);
int got_frame = 0;
if (!decoded_frame) {
if (!(decoded_frame = avcodec_alloc_frame())) {
simbiLog("out of memory");
return ERROR;
}
} else {
avcodec_get_frame_defaults(decoded_frame);
}
//below the error, but it isn't occur on first time, only in 4th loop interation
len = avcodec_decode_audio4(c, decoded_frame, &got_frame, &avpkt);
if (len < 0) {
simbiLog("Error while decoding error %d frame %d duration %d", len, got_frame, avpkt.duration);
return ERROR;
} else {
simbiLog("Decoding length %d frame %d duration %d", len, got_frame, avpkt.duration);
}
if (got_frame) {
int data_size = av_samples_get_buffer_size(NULL, c->channels, decoded_frame->nb_samples, c->sample_fmt, 1);
size_t* fwrite_size = fwrite(decoded_frame->data[0], 1, data_size, outfile);
simbiLog("fwrite returned %d", fwrite_size);
}
avpkt.size -= len;
avpkt.data += len;
if (avpkt.size < AUDIO_REFILL_THRESH) {
memmove(inbuf, avpkt.data, avpkt.size);
avpkt.data = inbuf;
len = fread(avpkt.data + avpkt.size, 1, AUDIO_INBUF_SIZE - avpkt.size, infile);
if (len > 0)
avpkt.size += len;
simbiLog("fread returned %d", len);
}
}
fclose(outfile);
fclose(infile);
avcodec_close(c);
av_free(c);
av_free(decoded_frame);
but I'm getting the follow log and error:
inbuf size: 20488
iteration 1
avpkt.size 3305 avpkt.data BEEED40C
Decoding length 13 frame 1 duration 0
fwrite returned 640
fread returned 0
iteration 2
avpkt.size 3292 avpkt.data BEEED40C
Decoding length 13 frame 1 duration 0
fwrite returned 640
fread returned 0
iteration 3
avpkt.size 3279 avpkt.data BEEED40C
Decoding length 14 frame 1 duration 0
fwrite returned 640
fread returned 0
iteration 4
avpkt.size 3265 avpkt.data BEEED40C
Error while decoding error -1052488119 frame 0 duration 0
the audio file I'm trying decode:
$ avprobe blue.3gp
avprobe version 0.8.6-6:0.8.6-1ubuntu2, Copyright (c) 2007-2013 the Libav developers
built on Mar 30 2013 22:23:21 with gcc 4.7.2
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'blue.3gp':
Metadata:
major_brand : 3gp4
minor_version : 0
compatible_brands: isom3gp4
creation_time : 2013-09-19 18:53:38
Duration: 00:00:01.52, start: 0.000000, bitrate: 17 kb/s
Stream #0.0(eng): Audio: amrnb, 8000 Hz, 1 channels, flt, 12 kb/s
Metadata:
creation_time : 2013-09-19 18:53:38
thanks a lot!
EDITED
I read on ffmper documentation about the method avcodec_decode_audio4 the follow:
#warning The input buffer, avpkt->data must be FF_INPUT_BUFFER_PADDING_SIZE larger than the actual read bytes because some optimized bitstream readers read 32 or 64 bits at once and could read over the end.
#note You might have to align the input buffer. The alignment requirements depend on the CPU and the decoder.
and I see here a solution using posix_memalign, to android i founded a similar method called memalign, so i did the change:
removed:
uint8_t inbuf[AUDIO_INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE];
inserted:
int inbufSize = sizeof(uint8_t) * (AUDIO_INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
uint8_t *inbuf = memalign(FF_INPUT_BUFFER_PADDING_SIZE, inbufSize);
simbiLog("inbuf size: %d", inbufSize);
for (; inbufSize >= 0; inbufSize--)
simbiLog("inbuf position: %d index: %p", inbufSize, &inbuf[inbufSize]);
I'm getting the correct memory sequence position, but the error not changed.
A piece of outpout:
inbuf position: 37 index: 0x4e43d745
inbuf position: 36 index: 0x4e43d744
inbuf position: 35 index: 0x4e43d743
inbuf position: 34 index: 0x4e43d742
inbuf position: 33 index: 0x4e43d741
inbuf position: 32 index: 0x4e43d740
inbuf position: 31 index: 0x4e43d73f
inbuf position: 30 index: 0x4e43d73e
inbuf position: 29 index: 0x4e43d73d
inbuf position: 28 index: 0x4e43d73c
inbuf position: 27 index: 0x4e43d73b
inbuf position: 26 index: 0x4e43d73a
inbuf position: 25 index: 0x4e43d739
inbuf position: 24 index: 0x4e43d738
inbuf position: 23 index: 0x4e43d737
inbuf position: 22 index: 0x4e43d736
inbuf position: 21 index: 0x4e43d735
inbuf position: 20 index: 0x4e43d734
inbuf position: 19 index: 0x4e43d733

You are trying to decode without demuxing.