MobileSubstrate hook c++ function

hookcpp.m

/*
 获取xx助手lua脚本
 By 飘云/P.Y.G
 2015-04-29
  https://www.chinapyg.com
*/

#import <substrate.h>
#import <pthread.h>


// 原始函数
signed int (*orig_XxteaDecrypt)(const char *inBuf, size_t bufLen, const char *key, size_t a4, char *outBuf, int a6);

signed int  myXxteaDecrypt(const char *inBuf, size_t bufLen, const char *key, size_t a4, char *outBuf, int a6)
{
    signed int  ret = orig_XxteaDecrypt(inBuf, bufLen, key, a4, outBuf, a6);
    NSString *str = [NSString stringWithCString:outBuf encoding:NSUTF8StringEncoding];
    
    //NSLog(@"[++++]%s", outBuf);
    NSLog(@"[++++]%@", str);
    return ret;
}

void *threadFun(void*)
{
    while (true)
    {
        void *lpFun = ((void*)MSFindSymbol(NULL, "__Z12XxteaDecryptPKciS0_iPci"));
        if (lpFun)
        {
            NSLog(@"[++++]lpFun = %p", lpFun);
            MSHookFunction(lpFun, (void*)myXxteaDecrypt, (void**)&orig_XxteaDecrypt);
            NSLog(@"[++++]orig_XxteaDecrypt = %p", orig_XxteaDecrypt);
            break;
        }
    }
    return NULL;
}

static __attribute__((constructor)) void piaoyun()
{
    // 用线程来查找，以免xx的dylib后加载而找不到函数
    pthread_t th;
    int err = pthread_create(&th, NULL, threadFun, NULL);
    if (err != 0)
        printf("[++++]pthread_create error: %s\n", strerror(err));
    
    NSLog(@"[++++]inject success!!!!");
}