/*
 * See the dyninst/COPYRIGHT file for copyright information.
 *
 * We provide the Paradyn Tools (below described as "Paradyn")
 * on an AS IS basis, and do not warrant its validity or performance.
 * We reserve the right to update, modify, or discontinue this
 * software at any time.  We shall have no obligation to supply such
 * updates or modifications or any other form of support to you.
 *
 * By your use of Paradyn, you understand and agree that we (or any
 * other person or entity with proprietary rights in Paradyn) are
 * under no obligation to provide either maintenance services,
 * update services, notices of latent defects, or correction of
 * defects for Paradyn.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "MutateeStart.h"
#include "ParameterDict.h"
#include "test_info_new.h"
#include "test_lib.h"
#include <assert.h>
#include <stdio.h>
#include <set>

using namespace std;

#if !defined(os_windows_test)

#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#if !defined(os_linux_test)
static pid_t fork_mutatee() {
   return fork();
}
#else
static pid_t fork_mutatee() {
   /**
    * Perform a granchild fork.  This code forks off a child, that child
    * then forks off a granchild.  The original child then exits, making
    * the granchild's new parent init.  Both the original process and the
    * granchild then exit from this function.
    *
    * This works around a linux kernel bug in kernel version 2.6.9 to
    * 2.6.11, see https://www.dyninst.org/emails/2006/5678.html for
    * details.
    **/
   int status, result;
   pid_t gchild_pid, child_pid;
   int filedes[2];

   pipe(filedes);

   child_pid = fork();
   if (child_pid < 0) { // This is an error
      close(filedes[0]);
      close(filedes[1]);
      return child_pid;
   }

   if (child_pid) {
      //Read the grandchild pid from the child.
      do {
         result = read(filedes[0], &gchild_pid, sizeof(pid_t));
      } while (result == -1 && errno == EINTR);
      if (result == -1) {
         perror("Couldn't read from pipe");
      }

      int options = 0;
      do {
         result = waitpid(child_pid, &status, options);
         if (result != child_pid) {
            perror("Couldn't join child");
            break;
         }
      } while (!WIFEXITED(status));
      close(filedes[0]);
      close(filedes[1]);
      return gchild_pid;
   }
   //Child

   gchild_pid = fork();
   if (gchild_pid) {
      //Child pid, send grand child pid to parent then terminate
      result = write(filedes[1], &gchild_pid, sizeof(pid_t));
      if (result == -1) {
         perror("Couldn't write to parent");
      }
      close(filedes[0]);
      close(filedes[1]);
      exit(0);
   }

   //Grandchild
   close(filedes[0]);
   close(filedes[1]);
   return 0;
}
#endif
#endif

char **getCParams(const std::string &executable, const std::vector<std::string> &args)
{
   char **argv = (char **) malloc(sizeof(char *) * (args.size()+2));
   assert(argv);

   int offset = 0;
   if (executable != string("")) {
      argv[0] = const_cast<char *>(executable.c_str());
      offset = 1;
   }

   unsigned i;
   for (i=0; i<args.size(); i++) {
      argv[i+offset] = const_cast<char *>(args[i].c_str());
   }
   argv[i+offset] = NULL;
   return argv;
}


#if !defined(os_windows_test)

static bool fds_set = false;
static int fds[2];

static void AddArchAttachArgs(std::vector<std::string> &args, create_mode_t cm, start_state_t gs)
{
   if (cm == USEATTACH && gs != SELFATTACH)
   {
      /* Make a pipe that we will use to signal that the mutatee has started. */
      if (pipe(fds) != 0) {
         fprintf(stderr, "*ERROR*: Unable to create pipe.\n");
         return;
      }

      /* Create the argv string for the child process. */
      char fdstr[32];
      snprintf(fdstr, 32,"%d", fds[1]);

      args.push_back("-attach");
      args.push_back(fdstr);

      fds_set = true;
   }
   else {
      fds_set = false;
   }
}

extern FILE *getOutputLog();
extern FILE *getErrorLog();


static std::string launchMutatee_plat(const std::string &exec_name, const std::vector<std::string> &args, bool needs_grand_fork)
{
   pid_t pid;
   if (needs_grand_fork) {
      pid = fork_mutatee();
   }
   else {
      pid = fork();
   }

   if (pid < 0) {
      return std::string("");
   }
   else if (pid == 0)
   {
      // child
      if (fds_set)
         close(fds[0]);

      if (getOutputLog() != NULL) {
         int outlog_fd = fileno(getOutputLog());
         if (dup2(outlog_fd, 1) == -1) {
            fprintf(stderr, "Error duplicating log fd(1)\n");
         }
      }
      if (getErrorLog() != NULL) {
         int errlog_fd = fileno(getErrorLog());
         if (dup2(errlog_fd, 2) == -1) {
            fprintf(stderr, "Error duplicating log fd(2)\n");
         }
      }
      char *ld_path = getenv("LD_LIBRARY_PATH");
      char *new_ld_path = NULL;
      unsigned liblen = (ld_path ? strlen(ld_path) : 0)
         + strlen("./binaries:")
         + 3;
      new_ld_path = (char *) malloc(liblen);
      strcpy(new_ld_path, "./binaries");
      if (ld_path) {
         strcat(new_ld_path, ":");
         strcat(new_ld_path, ld_path);
      }

      setenv("LD_LIBRARY_PATH", new_ld_path, 1);

      char **argv = getCParams(exec_name, args);
      const char *c_exec_name = exec_name.c_str();

      execvp(exec_name.c_str(), (char * const *) argv);

      string dot_exec_name = std::string("./") + exec_name;
      execvp(dot_exec_name.c_str(), (char * const *) argv);

      fprintf(stderr, "%s[%d]:  Exec failed!\n", __FILE__, __LINE__);
      exit(-1);
   }
   else
   {
      // parent
      if (fds_set)
      {
         close(fds[1]);  // We don't need the write side

         // Wait for the child to write to the pipe
         char ch;
         ssize_t result = read(fds[0], &ch, sizeof(char));
         if (result != sizeof(char)) {
            perror("read");
            fprintf(stderr, "*ERROR*: Error reading from pipe\n");
            return string("");
         }
         if (ch != 'T') {
            fprintf(stderr, "*ERROR*: Child didn't write expected value to pipe.\n");
            return string("");
         }

         /* Random Linux-ism: it's possible to close the pipe before the
            mutatee returns from the write() system call matching the above
            read().  In this case, rather than ignore the close() because the
            write() is on its way out the kernel, Linux sends a SIGPIPE
            to the mutatee, which causes us no end of trouble.  read()ing
            an EOF from the pipe seems to alleviate this problem, and seems
            more reliable than a sleep(1).  The condition test if we somehow
            got any /extra/ bytes on the pipe. */
         if( read( fds[0], & ch, sizeof( char ) ) != 0 ) {
            fprintf(stderr, "*ERROR*: Shouldn't have read anything here.\n");
            return string("");
         }
         close( fds[0] ); // We're done with the pipe
      }
      char ret[32];
      snprintf(ret, 32, "%d", pid);
      return std::string(ret);
   }
}
#else

static bool wait_for_pipe = false;

static void AddArchAttachArgs(std::vector<std::string> &args, create_mode_t cm, start_state_t gs)
{
	if (cm == USEATTACH && gs != SELFATTACH) {
		// Do nothing...
		wait_for_pipe = true;
	}
	else {
		wait_for_pipe = false;
	}

}

static std::string launchMutatee_plat(const std::string &exec_name, const std::vector<std::string> &args, bool needs_grand_fork)
{
	HANDLE mutatee_signal_pipe = (HANDLE) NULL;
	if (wait_for_pipe) {
		LPCTSTR pipeName = "\\\\.\\pipe\\mutatee_signal_pipe";
	   mutatee_signal_pipe = CreateNamedPipe(pipeName,
		  PIPE_ACCESS_INBOUND,
		  PIPE_TYPE_BYTE | PIPE_READMODE_BYTE | PIPE_WAIT,
		  1, // num instances
		  1024, // read buffer
		  1024, // write buffer
		  5000, //timeout
		  NULL); // security descriptor
	   if(mutatee_signal_pipe == INVALID_HANDLE_VALUE) {
		  fprintf(stderr, "*ERROR*: Unable to create pipe.\n");
		  return std::string("");
	   }
	}
   char arg_str[1024];
   strcpy(arg_str, args[0].c_str());
   for (unsigned int i = 1; i < args.size(); i++) {
	   strcat(arg_str, " ");
	   strcat(arg_str, args[i].c_str());
   }
   strcat(arg_str, " -attach");
   STARTUPINFO si;
   memset(&si, 0, sizeof(STARTUPINFO));
   si.cb = sizeof(si);
   PROCESS_INFORMATION pi;
   BOOL result = CreateProcess(exec_name.c_str(), // app name
	   arg_str, // args
	   NULL, // process SD
	   NULL, // thread SD
	   FALSE, // inherit handles?
	   0, // creation flags
	   NULL, // environment
	   NULL, // current directory
	   &si, // startup info
	   &pi); // process info
   if (result == FALSE) {
     DWORD lastError = ::GetLastError();
     TCHAR errBuff[1024];
     ::FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM,
		     NULL,
		     lastError,
		     MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
		     errBuff,
		     sizeof(errBuff)/sizeof(TCHAR) - 1,
		     NULL);
     fprintf(stderr, "Mutatee creation failed: %s\n", errBuff);
      return std::string("");
   }

   if (wait_for_pipe) {
	   // Keep synchronization pattern the same as on Unix...
	   BOOL conn_ok = ConnectNamedPipe(mutatee_signal_pipe, NULL) ?
		  TRUE : (GetLastError() == ERROR_PIPE_CONNECTED);
	   if(!conn_ok) {
		  CloseHandle(mutatee_signal_pipe);
		  return std::string("");
	   }

	   char mutatee_ready = 0x0;
	   DWORD bytes_read;
	   BOOL read_ok = ReadFile(mutatee_signal_pipe,
		  &mutatee_ready, // buffer
		  1, // size
		  &bytes_read,
		  NULL); // not overlapped I/O
	   if (!read_ok || (bytes_read != 1)) {
		  fprintf(stderr, "Couldn't read from mutatee pipe\n");
		  DisconnectNamedPipe(mutatee_signal_pipe);
		  CloseHandle(mutatee_signal_pipe);
		  return std::string("");
	   }
	   if(mutatee_ready != 'T')
	   {
		  fprintf(stderr, "Got unexpected message from mutatee, aborting\n");
		  DisconnectNamedPipe(mutatee_signal_pipe);
		  CloseHandle(mutatee_signal_pipe);
		  return std::string("");
	   }
	   DisconnectNamedPipe(mutatee_signal_pipe);
	   CloseHandle(mutatee_signal_pipe);
   }
   else {
	   // I've seen weird races. CreateProcess should return a fully ready
		// process, but it isn't... so micro-sleep to fix the problem.
	   // FIXME
	   ::Sleep(200);
   }

   char ret[32];
   snprintf(ret, 32, "%d", pi.dwProcessId);
   return std::string(ret);
}
#endif

bool shouldLaunch(RunGroup *group, ParameterDict &params)
{
	return true;
}

std::string launchMutatee(std::string executable, std::vector<std::string> &args, RunGroup *group, ParameterDict &params)
{
   char group_num[32];
   snprintf(group_num, 32, "%d", group->index);

   bool in_runtests = params["in_runtests"]->getInt();
   if (!shouldLaunch(group, params))
      return std::string(group_num) + ":-1";

   string ret = launchMutatee_plat(executable, args, false);
   if (ret == string(""))
      return string("");

   return string(group_num) + ":" + ret;
}

std::string launchMutatee(std::string executable, RunGroup *group, ParameterDict &params)
{
   string exec_name;
   vector<string> args;

   bool result = getMutateeParams(group, params, exec_name, args);
   if (!result)
      return string("");

   if (executable != string(""))
      exec_name = executable;

   return launchMutatee(exec_name, args, group, params);
}

string launchMutatee(RunGroup *group, ParameterDict &params)
{
   return launchMutatee(string(""), group, params);
}

bool getMutateeParams(RunGroup *group, ParameterDict &params, std::string &exec_name,
                      std::vector<std::string> &args)
{
   exec_name = group->mutatee;
   args.push_back(exec_name);
   char *logfilename = params["logfilename"]->getString();
   if (logfilename) {
      args.push_back("-log");
      args.push_back(logfilename);
   }

   char *human_logfilename = params["humanlogname"]->getString();
   if (logfilename) {
      args.push_back("-humanlog");
      args.push_back(human_logfilename);
   }

   if (params["debugPrint"]->getInt()) {
      args.push_back("-verbose");
   }

   if (params["dboutput"]->getString()) {
      args.push_back("-dboutput");
   }

   create_mode_t cm = (create_mode_t) params["createmode"]->getInt();
   start_state_t gs = group->state;
   AddArchAttachArgs(args, cm, gs);

   if (cm == USEATTACH && gs == SELFATTACH) {
      args.push_back("-customattach");
   }

   if (cm == USEATTACH && gs == DELAYEDATTACH) {
	   args.push_back("-delayedattach");
   }

   test_procstate_t ps = (test_procstate_t) params["mp"]->getInt();
   if (ps == SingleProcess)
      args.push_back("-sp");
   else if (ps == MultiProcess)
      args.push_back("-mp");

   test_threadstate_t ts = (test_threadstate_t) params["mt"]->getInt();
   if (ts == SingleThreaded)
      args.push_back("-st");
   else if (ts == MultiThreaded) {
      args.push_back("-mt");
      char s[64];
      snprintf(s, 64, "%d", getNumThreads(params));
      args.push_back(s);
   }

   int signal_fd = params.find("signal_fd_out") != params.end() ? params["signal_fd_out"]->getInt() : -1;
   if (signal_fd != -1) {
      char s[64];
      snprintf(s, 64, "%d", signal_fd);
      args.push_back("-signal_fd");
      args.push_back(std::string(s));
   }

   bool printed_run = false;
   for (unsigned i = 0; i < group->tests.size(); i++) {
      if (!group->tests[i]->disabled && !group->tests[i]->result_reported) {
         if (!printed_run) {
            args.push_back("-run");
            printed_run = true;
         }
         args.push_back(group->tests[i]->name);
      }
   }

   return true;
}

static std::set<int> attach_mutatees;
static std::map<int, std::string> spawned_mutatees;
void registerMutatee(std::string mutatee_string)
{
   int group_id;
   int pid;

   if (strchr(mutatee_string.c_str(), ':')) {
      sscanf(mutatee_string.c_str(), "%d:%d", &group_id, &pid);
      if (pid != -1)
         spawned_mutatees[group_id] = mutatee_string;
   }
   else {
      int pid;
      sscanf(mutatee_string.c_str(), "%d", &pid);
      assert(pid != -1);
      attach_mutatees.insert(pid);
   }
}

Dyninst::PID getMutateePid(RunGroup *group)
{
   if (!attach_mutatees.empty()) {
      std::set<int>::iterator i = attach_mutatees.begin();
      assert(i != attach_mutatees.end());
      int pid = *i;
      attach_mutatees.erase(i);
      return pid;
   }
   std::map<int, std::string>::iterator i = spawned_mutatees.find(group->index);
   if (i == spawned_mutatees.end()) {
      i = spawned_mutatees.find(-1);
   }
   if (i == spawned_mutatees.end())
      return NULL_PID;

   std::string mutatee_string = i->second;
   int group_id;
   int pid;

   sscanf(mutatee_string.c_str(), "%d:%d", &group_id, &pid);
   assert(group->index == group_id || group_id == -1);

   spawned_mutatees.erase(i);

   return pid;
}

