* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#define FUSE_USE_VERSION 26

#include <sys/resource.h>  
#include <sys/fsuid.h>
#include <sys/types.h>
#include <sys/time.h>
#include <pthread.h>
#include <signal.h>
#include <limits.h>
#include <string.h>
#include <stdarg.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>

 */
#ifndef APPFS_CACHEDIR
#define APPFS_CACHEDIR "/var/cache/appfs"
#endif

/* Debugging macros */
#ifdef DEBUG
int appfs_debug_fd = STDERR_FILENO;
FILE *appfs_debug_fd = NULL;
#define APPFS_DEBUG(x...) { \
	char buf[8192]; \
	int bufoff = 0; \
	if (appfs_debug_fd == -1) { \
		appfs_debug_fd = open("/tmp/appfsd.log", O_WRONLY | O_APPEND | O_CREAT, 0600); \
	if (appfs_debug_fd == NULL) { \
		appfs_debug_fd = fopen("/tmp/appfsd.log", "a"); \
	}; \
	if (appfs_debug_fd == NULL) { appfs_debug_fd = stderr; } \
	bufoff = snprintf(buf, sizeof(buf), "[debug] [t=%llx] %s:%i:%s: ", (unsigned long long) pthread_self(), __FILE__, __LINE__, __func__); \
	if (bufoff < sizeof(buf)) { \
		bufoff += snprintf(buf + bufoff, sizeof(buf) - bufoff, x); \
	}; \
	if (bufoff < sizeof(buf)) { \
		bufoff += snprintf(buf + bufoff, sizeof(buf) - bufoff, "\n");\
	} \
	if (bufoff > sizeof(buf)) { \
		bufoff = sizeof(buf); \
	}; \
	fprintf(appfs_debug_fd, "%.*s", bufoff, buf); \
	write(appfs_debug_fd, buf, bufoff); \
	fflush(appfs_debug_fd); \
}
#define APPFS_ERROR(x...) APPFS_DEBUG(x)
#else
#define APPFS_DEBUG(x...) /**/
#define APPFS_ERROR(x...) fprintf(stderr, x); fprintf(stderr, "\n");
#endif

/*
 * SHA1 Tcl Package initializer, from sha1.o
 */
int Sha1_Init(Tcl_Interp *interp);

/*
 * Global variables for AppFS caching
 */
pthread_mutex_t appfs_path_info_cache_mutex = PTHREAD_MUTEX_INITIALIZER;
int appfs_path_info_cache_size = 8209;
struct appfs_pathinfo *appfs_path_info_cache = NULL;

#ifndef TCL_THREADS
#if !defined(TCL_THREADS) || TCL_THREADS != 1
/*
 * Handle unthreaded Tcl
 */
pthread_mutex_t appfs_tcl_big_global_lock = PTHREAD_MUTEX_INITIALIZER;
#define appfs_call_libtcl_enter pthread_mutex_lock(&appfs_tcl_big_global_lock);
#define appfs_call_libtcl_exit pthread_mutex_unlock(&appfs_tcl_big_global_lock);
#else

	APPFS_DEBUG("Creating new Tcl interpreter for TID = 0x%llx", (unsigned long long) pthread_self());

	appfs_call_libtcl(
		interp = Tcl_CreateInterp();
	)
	if (interp == NULL) {
		fprintf(stderr, "Unable to create Tcl Interpreter.  Aborting.\n");
		APPFS_ERROR("Unable to create Tcl Interpreter.  Aborting.");

		if (error_string) {
			*error_string = strdup("Unable to create Tcl interpreter.");
		}

		return(NULL);
	}

	appfs_call_libtcl(Tcl_Preserve(interp);)

	appfs_call_libtcl(
		tcl_ret = Tcl_Init(interp);
	)
	if (tcl_ret != TCL_OK) {
		fprintf(stderr, "Unable to initialize Tcl.  Aborting.\n");
		APPFS_ERROR("Unable to initialize Tcl.  Aborting.");
		appfs_call_libtcl(
			fprintf(stderr, "Tcl Error is: %s\n", Tcl_GetStringResult(interp));
			APPFS_ERROR("Tcl Error is: %s", Tcl_GetStringResult(interp));
		)

		if (error_string) {
			appfs_call_libtcl(
				*error_string = strdup(Tcl_GetStringResult(interp));
			)
		}

		return(NULL);
	}

	appfs_call_libtcl(
		tcl_ret = Tcl_Eval(interp, "package ifneeded sha1 1.0 [list load {} sha1]");
	)
	if (tcl_ret != TCL_OK) {
		fprintf(stderr, "Unable to initialize Tcl SHA1.  Aborting.\n");
		APPFS_ERROR("Unable to initialize Tcl SHA1.  Aborting.");
		appfs_call_libtcl(
			fprintf(stderr, "Tcl Error is: %s\n", Tcl_GetStringResult(interp));
			APPFS_ERROR("Tcl Error is: %s", Tcl_GetStringResult(interp));
		)

		if (error_string) {
			appfs_call_libtcl(
				*error_string = strdup(Tcl_GetStringResult(interp));
			)
		}

		return(NULL);
	}

	appfs_call_libtcl(
		tcl_ret = Tcl_Eval(interp, "package ifneeded appfsd 1.0 [list load {} appfsd]");
	)
	if (tcl_ret != TCL_OK) {
		fprintf(stderr, "Unable to initialize Tcl AppFS Package.  Aborting.\n");
		APPFS_ERROR("Unable to initialize Tcl AppFS Package.  Aborting.");
		appfs_call_libtcl(
			fprintf(stderr, "Tcl Error is: %s\n", Tcl_GetStringResult(interp));
			APPFS_ERROR("Tcl Error is: %s", Tcl_GetStringResult(interp));
		)

		if (error_string) {
			appfs_call_libtcl(
				*error_string = strdup(Tcl_GetStringResult(interp));
			)
		}

	 */
	appfs_call_libtcl_enter
		tcl_ret = Tcl_Eval(interp, ""
#include "pki.tcl.h"
		"");
	appfs_call_libtcl_exit
	if (tcl_ret != TCL_OK) {
		fprintf(stderr, "Unable to initialize Tcl PKI.  Aborting.\n");
		APPFS_ERROR("Unable to initialize Tcl PKI.  Aborting.");
		appfs_call_libtcl(
			fprintf(stderr, "Tcl Error is: %s\n", Tcl_GetStringResult(interp));
			APPFS_ERROR("Tcl Error is: %s", Tcl_GetStringResult(interp));
		)

		if (error_string) {
			appfs_call_libtcl(
				*error_string = strdup(Tcl_GetStringResult(interp));
			)
		}

	 */
	appfs_call_libtcl_enter
		tcl_ret = Tcl_Eval(interp, ""
#include "appfsd.tcl.h"
		"");
	appfs_call_libtcl_exit
	if (tcl_ret != TCL_OK) {
		fprintf(stderr, "Unable to initialize Tcl AppFS script.  Aborting.\n");
		APPFS_ERROR("Unable to initialize Tcl AppFS script.  Aborting.");
		appfs_call_libtcl(
			fprintf(stderr, "Tcl Error is: %s\n", Tcl_GetStringResult(interp));
			APPFS_ERROR("Tcl Error is: %s", Tcl_GetStringResult(interp));
		)

		if (error_string) {
			appfs_call_libtcl(
				*error_string = strdup(Tcl_GetStringResult(interp));
			)
		}

	/*
	 * Set global variables from C to Tcl
	 */
	appfs_call_libtcl(
		tcl_setvar_ret = Tcl_SetVar(interp, "::appfs::cachedir", appfs_cachedir, TCL_GLOBAL_ONLY);
	)
	if (tcl_setvar_ret == NULL) {
		fprintf(stderr, "Unable to set cache directory.  This should never fail.\n");
		APPFS_ERROR("Unable to set cache directory.  This should never fail.");

		if (error_string) {
			appfs_call_libtcl(
				*error_string = strdup(Tcl_GetStringResult(interp));
			)
		}

	 * Initialize the "appfsd.tcl" environment, which must be done after
	 * global variables are set.
	 */
	appfs_call_libtcl(
		tcl_ret = Tcl_Eval(interp, "::appfs::init");
	)
	if (tcl_ret != TCL_OK) {
		fprintf(stderr, "Unable to initialize Tcl AppFS script (::appfs::init).  Aborting.\n");
		APPFS_ERROR("Unable to initialize Tcl AppFS script (::appfs::init).  Aborting.");
		appfs_call_libtcl(
			fprintf(stderr, "Tcl Error is: %s\n", Tcl_GetStringResult(interp));
			APPFS_ERROR("Tcl Error is: %s", Tcl_GetStringResult(interp));
		)

		if (error_string) {
			appfs_call_libtcl(
				*error_string = strdup(Tcl_GetStringResult(interp));
			)
		}

}

static void appfs_simulate_user_fs_leave(void) {
	setfsuid(0);
	setfsgid(0);
}

#ifdef APPFS_NO_GETPWUID
static char *appfs_get_homedir(uid_t fsuid) {
	return(NULL);
}
#else
/*
 * Look up the home directory for a given UID
 *        Returns a C string containing the user's home directory or NULL if
 *        the user's home directory does not exist or is not correctly
 *        configured
 */
static char *appfs_get_homedir(uid_t fsuid) {

		return(NULL);
	}

	retval = strdup(result->pw_dir);

	return(retval);
}
#endif

/*
 * Generate an inode for a given path.  The inode should be computed in such
 * a way that it is unlikely to be duplicated and remains the same for a given
 * file
 *
 * Current implementation is an FNV-1a 32-bit

	int retval;

	APPFS_DEBUG("Enter (path = %s, buf, size = %lli, offset = %lli, fd = %lli)", path, (long long) size, (long long) offset, (long long) fi->fh);

	retval = 0;

	while (size != 0) {
#ifdef APPFS_NO_PREAD /* XXX:TODO: Write a wrapper function */
		off_t seek_ret;

		seek_ret = lseek(fi->fh, offset, SEEK_SET);
		if (seek_ret == offset) {
			read_ret = read(fi->fh, buf, size);
		} else {
			read_ret = -1;
		}
#else
		read_ret = pread(fi->fh, buf, size, offset);
#endif

		if (read_ret < 0) {
			APPFS_DEBUG("error: read failed");

			return(errno * -1);
		}

#endif

	appfs_get_path_info_cache_rm(path, appfs_get_fsuid());

	retval = 0;

	while (size != 0) {
#ifdef APPFS_NO_PWRITE /* XXX:TODO: Write a wrapper function */
#  if 1
		/* XXX:TODO: Still fails on win32 */
		write_ret = -1;
#else
		off_t seek_ret;

		seek_ret = lseek(fi->fh, offset, SEEK_SET);
		if (seek_ret == offset) {
			write_ret = write(fi->fh, buf, size); 
		} else {
			write_ret = -1;
		}
#  endif
#else
		write_ret = pwrite(fi->fh, buf, size, offset);
#endif

		if (write_ret < 0) {
			APPFS_DEBUG("error: write failed");

			return(errno * -1);
		}

static int appfs_sqlite3(const char *sql) {
	Tcl_Interp *interp;
	const char *sql_ret;
	int tcl_ret;

	interp = appfs_create_TclInterp(NULL);
	if (interp == NULL) {
		fprintf(stderr, "Unable to create a Tcl interpreter.  Aborting.\n");
		APPFS_ERROR("Unable to create a Tcl interpreter.  Aborting.");

		return(1);
	}

	tcl_ret = appfs_Tcl_Eval(interp, 5, "::appfs::db", "eval", sql, "row", "unset -nocomplain row(*); parray row; puts \"----\"");
	sql_ret = Tcl_GetStringResult(interp);

	if (tcl_ret != TCL_OK) {
		fprintf(stderr, "[error] %s\n", sql_ret);
		APPFS_ERROR("[error] %s", sql_ret);

		return(1);
	}

	if (sql_ret && sql_ret[0] != '\0') {
		printf("%s\n", sql_ret);
	}

static int appfs_tcl(const char *tcl) {
	Tcl_Interp *interp;
	const char *tcl_result;
	int tcl_ret;

	interp = appfs_create_TclInterp(NULL);
	if (interp == NULL) {
		fprintf(stderr, "Unable to create a Tcl interpreter.  Aborting.\n");
		APPFS_ERROR("Unable to create a Tcl interpreter.  Aborting.");

		return(1);
	}

	tcl_ret = Tcl_Eval(interp, tcl);
	tcl_result = Tcl_GetStringResult(interp);

	if (tcl_ret != TCL_OK) {
		fprintf(stderr, "[error] %s\n", Tcl_GetVar(interp, "errorInfo", TCL_GLOBAL_ONLY));
		APPFS_ERROR("[error] %s", Tcl_GetVar(interp, "errorInfo", TCL_GLOBAL_ONLY));

		return(1);
	}

	if (tcl_result && tcl_result[0] != '\0') {
		printf("%s\n", tcl_result);
	}

	Tcl_CreateObjCommand(interp, "appfsd::get_path_info_cache_flush", tcl_appfs_get_path_info_cache_flush, NULL, NULL);

	Tcl_PkgProvide(interp, "appfsd", "1.0");

	return(TCL_OK);
}

#ifdef APPFS_NO_SIGNALS
static void appfs_set_sighandler(void) {
	return;
}
#else
#include <signal.h>

/*
 * Hot-restart support
 */
/* Initiate a hot-restart */
static void appfs_hot_restart(void) {
	APPFS_DEBUG("Asked to initiate hot restart");

	if (sig == SIGHUP) {
		appfs_hot_restart();
	}

	return;
}

static void appfs_set_sighandler(void) {
	void *signal_ret;

	/*
	 * Register a signal handler for hot-restart requests
	 */
	signal_ret = signal(SIGHUP, appfs_signal_handler);
	if (signal_ret == SIG_ERR) {
		APPFS_ERROR("Unable to install signal handler for hot-restart");
		APPFS_ERROR("Hot-restart will not be available.");
	}
}
#endif
/*
 * Terminate a thread
 */
static void appfs_terminate_interp_and_thread(void *_interp) {
	Tcl_Interp *interp;

	APPFS_DEBUG("Called: _interp = %p", _interp);

	int ch;
	char *optstr, *optstr_next, *optstr_s;
	char fake_arg[3] = {'-', 0, 0};

	/*
	 * Default values
	 */
#ifdef TCL_THREADS
#if defined(TCL_THREADS) && TCL_THREADS == 1
	appfs_threaded_tcl = 1;
#else
	appfs_threaded_tcl = 0;
#endif

	/**
	 ** Add FUSE arguments which we always supply

						APPFS_DEBUG("Passing option to FUSE: -o allow_other");

						fuse_opt_parse(args, NULL, NULL, NULL);
						fuse_opt_add_arg(args, "-oallow_other");
					} else if (strcmp(optstr, "rw") == 0) {
						/* Ignored */
					} else {
						fprintf(stderr, "appfsd: invalid option: \"-o %s\"\n", optstr);
						APPFS_ERROR("appfsd: invalid option: \"-o %s\"", optstr);

						free(optstr_s);

						return(1);
					}
				}

				return(1);
		}
	}

	if ((optind + 2) != argc) {
		if ((optind + 2) < argc) {
			fprintf(stderr, "Too many arguments\n");
			APPFS_ERROR("Too many arguments");
		} else {
			fprintf(stderr, "Missing cachedir or mountpoint\n");
			APPFS_ERROR("Missing cachedir or mountpoint");
		}

		appfs_print_help(stderr);

		return(1);
	}

	.unlink    = appfs_fuse_unlink_rmdir,
	.rmdir     = appfs_fuse_unlink_rmdir,
	.mkdir     = appfs_fuse_mkdir,
	.chmod     = appfs_fuse_chmod,
	.symlink   = appfs_fuse_symlink,
};


#ifdef APPFS_NO_RLIMIT
static void appfs_set_resource_limits(void) {
	return;
}
#else
#include <sys/resource.h>  

static void appfs_set_resource_limits(void) {
	struct rlimit number_open_files;
	rlim_t number_open_files_max;
	int rlimit_ret;

	/*
	 * Increase resource limits for number of open files
	 * to the maximum values, since we may be asked to
	 * hold open many files on behalf of many other processes
	 */
	number_open_files.rlim_cur = number_open_files.rlim_max = RLIM_INFINITY;

	rlimit_ret = setrlimit(RLIMIT_NOFILE, &number_open_files);

	if (rlimit_ret != 0) {
		rlimit_ret = getrlimit(RLIMIT_NOFILE, &number_open_files);
		if (rlimit_ret == 0) {
			number_open_files_max = number_open_files.rlim_max;

			if (number_open_files_max < (1024 * 1024)) {
				number_open_files.rlim_cur = number_open_files.rlim_max = 1024 * 1024;

				rlimit_ret = setrlimit(RLIMIT_NOFILE, &number_open_files);
			} else {
				number_open_files.rlim_cur = number_open_files.rlim_max;
			}

			rlimit_ret = setrlimit(RLIMIT_NOFILE, &number_open_files);

			if (rlimit_ret != 0 && number_open_files.rlim_cur != number_open_files_max) {
				number_open_files.rlim_cur = number_open_files.rlim_max = number_open_files_max;

				setrlimit(RLIMIT_NOFILE, &number_open_files);
			}
		}
	}

	return;
}
#endif

/*
 * Entry point into this program.
 */
int main(int argc, char **argv) {
	Tcl_Interp *test_interp;
	char *test_interp_error;
	struct fuse_args args = FUSE_ARGS_INIT(0, NULL);
	struct rlimit number_open_files;
	int pthread_ret, aop_ret, rlimit_ret;
	int pthread_ret, aop_ret;
	void *signal_ret;
	char *argv0;
	rlim_t number_open_files_max;
int i;

	/*
	 * Skip passed program name
	 */
	if (argc == 0 || argv == NULL) {
		return(1);
	}

	/*
	 * Create a thread-specific-data (TSD) key for each thread to refer
	 * to its own Tcl interpreter.  Tcl interpreters must be unique per
	 * thread and new threads are dynamically created by FUSE.
	 */
	pthread_ret = pthread_key_create(&interpKey, appfs_terminate_interp_and_thread);
	if (pthread_ret != 0) {
		fprintf(stderr, "Unable to create TSD key for Tcl.  Aborting.\n");
		APPFS_ERROR("Unable to create TSD key for Tcl.  Aborting.");

		return(1);
	}

	/*
	 * Manually specify cache directory, without FUSE callback
	 * This option only works when not using FUSE, since we

	 * Tcl mode, for running raw Tcl in the same environment AppFSd would
	 * run code.
	 */
	if (argc == 2 && strcmp(argv[0], "--tcl") == 0) {
		return(appfs_tcl(argv[1]));
	}

	/*
	 * Register a signal handler for hot-restart requests
	 */
	signal_ret = signal(SIGHUP, appfs_signal_handler);
	if (signal_ret == SIG_ERR) {
		fprintf(stderr, "Unable to install signal handler for hot-restart\n");
		fprintf(stderr, "Hot-restart will not be available.\n");
	}

	/*
	 * Parse command line arguments
	 */
	/**
	 ** Restore argc/argv to original values, replacing argv[0] in case
	 ** it was moified by --cachedir option.
	 **/

	 */
	test_interp = appfs_create_TclInterp(&test_interp_error);
	if (test_interp == NULL) {
		if (test_interp_error == NULL) {
			test_interp_error = "Unknown error";
		}

		fprintf(stderr, "Unable to initialize Tcl interpreter for AppFSd:\n");
		fprintf(stderr, "%s\n", test_interp_error);
		APPFS_ERROR("Unable to initialize Tcl interpreter for AppFSd:");
		APPFS_ERROR("%s", test_interp_error);

		return(1);
	}

	Tcl_DeleteInterp(test_interp);

	if (appfs_threaded_tcl) {
		Tcl_FinalizeNotifier(NULL);
	}

	/*
	 * Increase resource limits for number of open files
	 * to the maximum values, since we may be asked to
	 * hold open many files on behalf of many other processes
	 */
	number_open_files.rlim_cur = number_open_files.rlim_max = RLIM_INFINITY;

	appfs_set_resource_limits();
	rlimit_ret = setrlimit(RLIMIT_NOFILE, &number_open_files);

	appfs_set_sighandler();
	if (rlimit_ret != 0) {
		rlimit_ret = getrlimit(RLIMIT_NOFILE, &number_open_files);
		if (rlimit_ret == 0) {
			number_open_files_max = number_open_files.rlim_max;

			if (number_open_files_max < (1024 * 1024)) {
				number_open_files.rlim_cur = number_open_files.rlim_max = 1024 * 1024;

				rlimit_ret = setrlimit(RLIMIT_NOFILE, &number_open_files);
			} else {
				number_open_files.rlim_cur = number_open_files.rlim_max;
			}

			rlimit_ret = setrlimit(RLIMIT_NOFILE, &number_open_files);

			if (rlimit_ret != 0 && number_open_files.rlim_cur != number_open_files_max) {
				number_open_files.rlim_cur = number_open_files.rlim_max = number_open_files_max;

				setrlimit(RLIMIT_NOFILE, &number_open_files);
			}
		}
	}


	/*
	 * Enter the FUSE main loop -- this will process any arguments
	 * and start servicing requests.
	 */
	appfs_fuse_started = 1;
	return(fuse_main(args.argc, args.argv, &appfs_operations, NULL));
}