EMS DS tracer

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <dlfcn.h>
#include <execinfo.h>
#include <pthread.h>
#include <list>

const char interp[] __attribute__((section(".interp"))) = "/lib64/ld-linux-x86-64.so.2";

typedef int (*open_fn)(const char *path, int flags, ...);
typedef ssize_t (*write_fn)(int fd, const void *buf, size_t count);
typedef ssize_t (*writev_fn)(int fd, const struct iovec *iov, int count);
typedef ssize_t (*pwritev_fn)(int fd, const struct iovec *iov, int count, off_t offset);
typedef int (*ftruncate_fn)(int fd, off_t length);

static open_fn _open = NULL;
static open_fn _open64 = NULL;
static write_fn _write = NULL;
static writev_fn _writev = NULL;
static pwritev_fn _pwritev = NULL;
static ftruncate_fn _ftruncate = NULL;
static void *handle_libc = NULL;
static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;

#define SYSOUTF(msg, params...) do { char buff[1024]; memset(buff, 0, 1024); snprintf(buff, 1024, msg, params); _write(1,buff,strlen(buff)); } while(0)
#define SYSOUT(msg) _write(1, msg, strlen(msg))

void __attribute__((constructor)) __init(void)
{
    if (handle_libc==NULL)
handle_libc = dlopen ("/lib64/libc.so.6", RTLD_NOW);
    if (handle_libc!=NULL) {
_open = (open_fn) dlsym(handle_libc, "open");
_open64 = (open_fn) dlsym(handle_libc, "open64");
_write = (write_fn) dlsym(handle_libc,"write");
_writev = (writev_fn) dlsym(handle_libc,"writev");
_pwritev = (pwritev_fn) dlsym(handle_libc,"pwritev");
_ftruncate = (ftruncate_fn) dlsym(handle_libc, "ftruncate");
SYSOUT("libemscompanion init completed\r\n");
    }
    else {
exit(-1);
    }
}

void __attribute__((destructor)) __fini(void)
{
    if (handle_libc!=NULL)
dlclose(handle_libc);
}

extern "C" {

    int open(const char *path, int flags, ...) {
va_list vargs;
va_start(vargs, flags);
mode_t mode = va_arg(vargs, mode_t);
va_end(vargs);
int ret = _open(path, flags, mode);
SYSOUTF("Open %s = %d\r\n", path, ret);
return ret;
    }
   
    int open64(const char *path, int flags, ...) {
va_list vargs;
va_start(vargs, flags);
mode_t mode = va_arg(vargs, mode_t);
va_end(vargs);
int ret = _open(path, flags, mode);
SYSOUTF("Open %s = %d\r\n", path, ret);
return ret;
    }
   
    ssize_t write(int fd, const void *buf, size_t count) {
off_t curr = lseek(fd, 0, SEEK_CUR);
SYSOUTF("Writing fd = %d, addr = %d, buff = %x, size = %d\r\n", fd, curr, buff, count);
ssize_t ret = _write(fd, buf, count);
return ret;
    }
}

extern "C" void _main(int argc, char **argv) {
    __init();
    SYSOUT("libEMSCompanion 0.0.1\r\n");
    exit(0);
}