/*
 * Copyright 2002-2019 Intel Corporation.
 * 
 * This software is provided to you as Sample Source Code as defined in the accompanying
 * End User License Agreement for the Intel(R) Software Development Products ("Agreement")
 * section 1.L.
 * 
 * This software and the related documents are provided as is, with no express or implied
 * warranties, other than those that are expressly stated in the License.
 */

#include <stdlib.h>
#include <dlfcn.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/syscall.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>

#define MAX_COMMAND_LINE_SIZE 15    // the size for the array of arguments to execv (this value is arbitrary)
#define EXPORT_SYM extern "C"

EXPORT_SYM bool AfterAttach1();

EXPORT_SYM bool AfterAttach2();

static int MAX_SIZE = 128; /*maximum line size*/

enum ExitType {
    RES_SUCCESS = 0,      // 0
    RES_FORK_FAILED,      // 1
    RES_EXEC_FAILED,      // 2
    RES_LOAD_FAILED,      // 3
    RES_RES_INVALID_ARGS  // 4
};


bool AfterAttach1()
{
    // Pin sets an anslysis function here to notify the application when Pin attaches to it.
    return false;
}

bool AfterAttach2()
{
    // Pin sets an anslysis function here to notify the application when Pin attaches to it.
    return false;
}

/*
 * block only the signals in the list: "signalsListToBlock"
 */
void BlockSignals(int signalsListToBlock[] , int len, sigset_t * sigmask)
{
    sigemptyset(sigmask);
    int i;
    for(i=0; i< len; ++i) 
        sigaddset(sigmask, signalsListToBlock[i]);
    pthread_sigmask(SIG_SETMASK, sigmask, NULL);
}


/*
    Expected argv arguments:
    [1] first image to load
    [2] second image to load
    [3] pin executable
    [4] Pin flags (e.g. -slow_asserts)
        >> zero or more flags possible
    [5] "-probe"
    [6] "-t"
    [7] tool
    [8] output file
    [9] represent if SIGTRAP should be blocked by the application
    argv[9]=0 - SIGTRAP shouldn't be blocked
    argv[9]=1 - SIGTRAP should be blocked
*/

int main(int argc, char** argv)
{
    if(argc < 9)
    {
        fprintf(stderr, "No enough arguments\n" );
        fflush(stderr);
        exit(RES_RES_INVALID_ARGS);
    }
    if (argc > MAX_COMMAND_LINE_SIZE){      // added: -pid attachPid -o NULL, omitted: argv[0..2], argv[9]
        fprintf(stderr, "Too many arguments\n" );
        fflush(stderr);
        exit(RES_RES_INVALID_ARGS);
    }
    if (strcmp(argv[argc-1], "1") == 0) // Need to block the SIGTRAP signal
    {
        int sigList[1] = {SIGTRAP};
        sigset_t sigmask;
        BlockSignals(sigList, 1, &sigmask);
    }
   
    pid_t parentPid = getpid();
    pid_t child = fork();
    if (child < 0)
    {
        perror("fork failed while creating application process");
        exit(RES_FORK_FAILED);
    }

    if (child)
    {
        // inside parent
        while(!AfterAttach1())
        {
            sleep(1);
        }

        void *handle = dlopen(argv[1], RTLD_LAZY);
        if (!handle)
        {
            fprintf(stderr, " Failed to load: %s because: %s\n", argv[1], dlerror());
            fflush(stderr);
            exit(RES_LOAD_FAILED);
        }

        while(!AfterAttach2())
        {
            sleep(1);
        }

        handle = dlopen(argv[2], RTLD_LAZY);
        if (!handle)
        {
            fprintf(stderr, " Failed to load: %s because: %s\n", argv[2], dlerror());
            fflush(stderr);
            exit(RES_LOAD_FAILED);
        }

        while(1)
        {
            // expected to be stopped by tool.
            sleep(1);
        }
    }

    if ( child == 0 )
    {
        // inside child
        char attachPid[MAX_SIZE];
        snprintf(attachPid ,MAX_SIZE , "%d", parentPid);
        char* args[MAX_COMMAND_LINE_SIZE] = {NULL};    // arguments for execv command
        int args_count = 0;
        int argv_count = 3;                            // to start from argv[3]...
        args[args_count++] = argv[argv_count++];       // by convention, first arg is the filename of the executed file (pin)
        args[args_count++] = (char*)"-pid";
        args[args_count++] = attachPid;
        while (strcmp(argv[argv_count], "-t") != 0){   // additional Pin flags (optional)
            args[args_count++] = argv[argv_count++];   // including "-probe" (mandatory for test)
        }
        args[args_count++] = argv[argv_count++];       // "-t"
        args[args_count++] = argv[argv_count++];       // tool
        args[args_count++] = (char*)"-o";
        args[args_count++] = argv[argv_count++];       // output file
        args[args_count++] = NULL;                     // end
        execv(argv[3], (char * const *)args);          // never returns
        perror("execv failed while trying to attach Pin to the application\n");
        exit(RES_EXEC_FAILED);
    }
    return RES_SUCCESS;
}