#define FUSE_USE_VERSION 26
#include <sys/types.h>
#include <pthread.h>
#include <string.h>
#include <stdarg.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <fuse.h>
#include <pwd.h>
#include <tcl.h>
/*
* Default cache directory
*/
#ifndef APPFS_CACHEDIR
#define APPFS_CACHEDIR "/var/cache/appfs"
#endif
/* Debugging macros */
#ifdef DEBUG
#define APPFS_DEBUG(x...) { fprintf(stderr, "[debug] %s:%i:%s: ", __FILE__, __LINE__, __func__); fprintf(stderr, x); fprintf(stderr, "\n"); }
#else
#define APPFS_DEBUG(x...) /**/
#endif
/*
* SHA1 Tcl Package initializer, from sha1.o
*/
int Sha1_Init(Tcl_Interp *interp);
/*
* Thread Specific Data (TSD) for Tcl Interpreter for the current thread
*/
static pthread_key_t interpKey;
/*
* Global variables, needed for all threads but only initialized before any
* FUSE threads are created
*/
const char *appfs_cachedir;
time_t appfs_boottime;
/*
* AppFS Path Type: Describes the type of path a given file is
*/
typedef enum {
APPFS_PATHTYPE_INVALID,
APPFS_PATHTYPE_FILE,
APPFS_PATHTYPE_DIRECTORY,
APPFS_PATHTYPE_SYMLINK
} appfs_pathtype_t;
/*
* AppFS Children Files linked-list
*/
struct appfs_children {
struct appfs_children *_next;
char name[256];
};
/*
* AppFS Path Information:
* Completely describes a specific path, how it should be returned to
* to the kernel
*/
struct appfs_pathinfo {
appfs_pathtype_t type;
time_t time;
char hostname[256];
int packaged;
unsigned long long inode;
union {
struct {
int childcount;
} dir;
struct {
int executable;
off_t size;
} file;
struct {
off_t size;
char source[256];
} symlink;
} typeinfo;
};
/*
* Create a new Tcl interpreter and completely initialize it
*/
static Tcl_Interp *appfs_create_TclInterp(void) {
Tcl_Interp *interp;
int tcl_ret;
APPFS_DEBUG("Creating new Tcl interpreter for TID = 0x%llx", (unsigned long long) pthread_self());
interp = Tcl_CreateInterp();
if (interp == NULL) {
fprintf(stderr, "Unable to create Tcl Interpreter. Aborting.\n");
return(NULL);
}
tcl_ret = Tcl_Init(interp);
if (tcl_ret != TCL_OK) {
fprintf(stderr, "Unable to initialize Tcl. Aborting.\n");
fprintf(stderr, "Tcl Error is: %s\n", Tcl_GetStringResult(interp));
Tcl_DeleteInterp(interp);
return(NULL);
}
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");
fprintf(stderr, "Tcl Error is: %s\n", Tcl_GetStringResult(interp));
Tcl_DeleteInterp(interp);
return(NULL);
}
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");
fprintf(stderr, "Tcl Error is: %s\n", Tcl_GetStringResult(interp));
Tcl_DeleteInterp(interp);
return(NULL);
}
/*
* Load the "appfsd.tcl" script, which is "compiled" into a C header
* so that it does not need to exist on the filesystem and can be
* directly evaluated.
*/
tcl_ret = Tcl_Eval(interp, ""
#include "appfsd.tcl.h"
"");
if (tcl_ret != TCL_OK) {
fprintf(stderr, "Unable to initialize Tcl AppFS script. Aborting.\n");
fprintf(stderr, "Tcl Error is: %s\n", Tcl_GetStringResult(interp));
Tcl_DeleteInterp(interp);
return(NULL);
}
/*
* Set global variables from C to Tcl
*/
if (Tcl_SetVar(interp, "::appfs::cachedir", appfs_cachedir, TCL_GLOBAL_ONLY) == NULL) {
fprintf(stderr, "Unable to set cache directory. This should never fail.\n");
Tcl_DeleteInterp(interp);
return(NULL);
}
/*
* Initialize the "appfsd.tcl" environment, which must be done after
* global variables are set.
*/
tcl_ret = Tcl_Eval(interp, "::appfs::init");
if (tcl_ret != TCL_OK) {
fprintf(stderr, "Unable to initialize Tcl AppFS script (::appfs::init). Aborting.\n");
fprintf(stderr, "Tcl Error is: %s\n", Tcl_GetStringResult(interp));
Tcl_DeleteInterp(interp);
return(NULL);
}
/*
* Hide some Tcl commands that we do not care to use and which may
* slow down run-time operations.
*/
Tcl_HideCommand(interp, "auto_load_index", "auto_load_index");
Tcl_HideCommand(interp, "unknown", "unknown");
/*
* Return the completely initialized interpreter
*/
return(interp);
}
/*
* Return the thread-specific Tcl interpreter, creating it if needed
*/
static Tcl_Interp *appfs_TclInterp(void) {
Tcl_Interp *interp;
int pthread_ret;
interp = pthread_getspecific(interpKey);
if (interp == NULL) {
interp = appfs_create_TclInterp();
if (interp == NULL) {
return(NULL);
}
pthread_ret = pthread_setspecific(interpKey, interp);
if (pthread_ret != 0) {
Tcl_DeleteInterp(interp);
return(NULL);
}
}
return(interp);
}
/*
* Evaluate a Tcl script constructed by concatenating a bunch of C strings
* together.
*/
static int appfs_Tcl_Eval(Tcl_Interp *interp, int objc, const char *cmd, ...) {
Tcl_Obj **objv;
const char *arg;
va_list argp;
int retval;
int i;
if (interp == NULL) {
return(TCL_ERROR);
}
objv = (void *) ckalloc(sizeof(*objv) * objc);
objv[0] = Tcl_NewStringObj(cmd, -1);
Tcl_IncrRefCount(objv[0]);
va_start(argp, cmd);
for (i = 1; i < objc; i++) {
arg = va_arg(argp, const char *);
objv[i] = Tcl_NewStringObj(arg, -1);
Tcl_IncrRefCount(objv[i]);
}
va_end(argp);
retval = Tcl_EvalObjv(interp, objc, objv, 0);
for (i = 0; i < objc; i++) {
Tcl_DecrRefCount(objv[i]);
}
ckfree((void *) objv);
if (retval != TCL_OK) {
APPFS_DEBUG("Tcl command failed, ::errorInfo contains: %s\n", Tcl_GetVar(interp, "::errorInfo", 0));
}
return(retval);
}
/*
* Determine the UID for the user making the current FUSE filesystem request.
* This will be used to lookup the user's home directory so we can search for
* locally modified files.
*/
static uid_t appfs_get_fsuid(void) {
struct fuse_context *ctx;
ctx = fuse_get_context();
if (ctx == NULL) {
/* Unable to lookup user for some reason */
/* Return an unprivileged user ID */
return(1);
}
return(ctx->uid);
}
/*
* 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) {
struct passwd entry, *result;
struct stat stbuf;
char buf[1024], *retval;
int gpu_ret, stat_ret;
gpu_ret = getpwuid_r(fsuid, &entry, buf, sizeof(buf), &result);
if (gpu_ret != 0) {
APPFS_DEBUG("getpwuid_r(%llu, ...) returned in failure", (unsigned long long) fsuid);
return(NULL);
}
if (result == NULL) {
APPFS_DEBUG("getpwuid_r(%llu, ...) returned NULL result", (unsigned long long) fsuid);
return(NULL);
}
if (result->pw_dir == NULL) {
APPFS_DEBUG("getpwuid_r(%llu, ...) returned NULL home directory", (unsigned long long) fsuid);
return(NULL);
}
stat_ret = stat(result->pw_dir, &stbuf);
if (stat_ret != 0) {
APPFS_DEBUG("stat(%s) returned in failure", result->pw_dir);
return(NULL);
}
if (stbuf.st_uid != fsuid) {
APPFS_DEBUG("UID mis-match on user %llu's home directory (%s). It's owned by %llu.",
(unsigned long long) fsuid,
result->pw_dir,
(unsigned long long) stbuf.st_uid
);
return(NULL);
}
retval = strdup(result->pw_dir);
return(retval);
}
/*
* Tcl interface to get the home directory for the user making the "current"
* FUSE I/O request
*/
static int tcl_appfs_get_homedir(ClientData cd, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[]) {
char *homedir;
if (objc != 1) {
Tcl_WrongNumArgs(interp, 1, objv, NULL);
return(TCL_ERROR);
}
homedir = appfs_get_homedir(appfs_get_fsuid());
if (homedir == NULL) {
return(TCL_ERROR);
}
Tcl_SetObjResult(interp, Tcl_NewStringObj(homedir, -1));
free(homedir);
return(TCL_OK);
}
/*
* 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
*/
static long long appfs_get_path_inode(const char *path) {
long long retval;
const char *p;
retval = 10;
for (p = path; *p; p++) {
retval %= 4290960290ULL;
retval += *p;
retval <<= 7;
}
retval += 10;
retval %= 4294967296ULL;
return(retval);
}
/* Get information about a path, and optionally list children */
static int appfs_get_path_info(const char *_path, struct appfs_pathinfo *pathinfo, struct appfs_children **children) {
}
static int appfs_fuse_readlink(const char *path, char *buf, size_t size) {
struct appfs_pathinfo pathinfo;
int res = 0;
APPFS_DEBUG("Enter (path = %s, ...)", path);
pathinfo.type = APPFS_PATHTYPE_INVALID;
res = appfs_get_path_info(path, &pathinfo, NULL);
if (res != 0) {
return(res);
}
if (pathinfo.type != APPFS_PATHTYPE_SYMLINK) {
return(-EINVAL);
}
if ((strlen(pathinfo.typeinfo.symlink.source) + 1) > size) {
return(-ENAMETOOLONG);
}
memcpy(buf, pathinfo.typeinfo.symlink.source, strlen(pathinfo.typeinfo.symlink.source) + 1);
return(0);
}
static int appfs_fuse_getattr(const char *path, struct stat *stbuf) {
struct appfs_pathinfo pathinfo;
int res = 0;
APPFS_DEBUG("Enter (path = %s, ...)", path);
pathinfo.type = APPFS_PATHTYPE_DIRECTORY;
pathinfo.typeinfo.dir.childcount = 0;
memset(stbuf, 0, sizeof(struct stat));
stbuf->st_mtime = pathinfo.time;
stbuf->st_ctime = pathinfo.time;
stbuf->st_atime = pathinfo.time;
stbuf->st_ino = pathinfo.inode;
stbuf->st_mode = 0;
switch (pathinfo.type) {
case APPFS_PATHTYPE_DIRECTORY:
stbuf->st_mode = S_IFDIR | 0555;
stbuf->st_nlink = 2 + pathinfo.typeinfo.dir.childcount;
break;
case APPFS_PATHTYPE_FILE:
if (pathinfo.typeinfo.file.executable) {
stbuf->st_mode = S_IFREG | 0555;
} else {
stbuf->st_mode = S_IFREG | 0444;
}
stbuf->st_nlink = 1;
stbuf->st_size = pathinfo.typeinfo.file.size;
break;
case APPFS_PATHTYPE_SYMLINK:
stbuf->st_mode = S_IFLNK | 0555;
stbuf->st_nlink = 1;
stbuf->st_size = pathinfo.typeinfo.symlink.size;
break;
case APPFS_PATHTYPE_INVALID:
res = -EIO;
break;
}
if (pathinfo.packaged) {
if (0) {
stbuf->st_mode |= 0222;
}
}
return res;
}
static int appfs_fuse_readdir(const char *path, void *buf, fuse_fill_dir_t filler, off_t offset, struct fuse_file_info *fi) {
Tcl_Interp *interp;
Tcl_Obj **children;
int children_count, idx;
int tcl_ret;
int retval;
APPFS_DEBUG("Enter (path = %s, ...)", path);
interp = appfs_TclInterp();
if (interp == NULL) {
return(0);
}
filler(buf, ".", NULL, 0);
filler(buf, "..", NULL, 0);
tcl_ret = appfs_Tcl_Eval(interp, 2, "::appfs::getchildren", path);
if (tcl_ret != TCL_OK) {
APPFS_DEBUG("::appfs::getchildren(%s) failed.", path);
APPFS_DEBUG("Tcl Error is: %s", Tcl_GetStringResult(interp));
return(0);
}
tcl_ret = Tcl_ListObjGetElements(interp, Tcl_GetObjResult(interp), &children_count, &children);
if (tcl_ret != TCL_OK) {
APPFS_DEBUG("Parsing list of children on path %s failed.", path);
APPFS_DEBUG("Tcl Error is: %s", Tcl_GetStringResult(interp));
return(0);
}
for (idx = 0; idx < children_count; idx++) {
filler(buf, Tcl_GetString(children[idx]), NULL, 0);
}
return(0);
}
static int appfs_fuse_open(const char *path, struct fuse_file_info *fi) {
struct appfs_pathinfo pathinfo;
const char *real_path;
int fh;
int gpi_ret;
APPFS_DEBUG("Enter (path = %s, ...)", path);
#if 0
if ((fi->flags & 3) != O_RDONLY) {
return(-EACCES);
}
gpi_ret = appfs_get_path_info(path, &pathinfo, NULL);
if (gpi_ret != 0) {
return(gpi_ret);
}
if (pathinfo.type == APPFS_PATHTYPE_DIRECTORY) {
return(-EISDIR);
}
real_path = appfs_getfile(pathinfo.hostname, pathinfo.typeinfo.file.sha1);
if (real_path == NULL) {
return(-EIO);
}
fh = open(real_path, O_RDONLY);
free((void *) real_path);
if (fh < 0) {
return(-EIO);
}
fi->fh = fh;
#endif
return(0);
}
static int appfs_fuse_close(const char *path, struct fuse_file_info *fi) {
int close_ret;
close_ret = close(fi->fh);
if (close_ret != 0) {
return(-EIO);
}
return(0);
}
static int appfs_fuse_read(const char *path, char *buf, size_t size, off_t offset, struct fuse_file_info *fi) {
off_t lseek_ret;
ssize_t read_ret;
APPFS_DEBUG("Enter (path = %s, ...)", path);
lseek_ret = lseek(fi->fh, offset, SEEK_SET);
if (lseek_ret != offset) {
return(-EIO);
}
read_ret = read(fi->fh, buf, size);
return(read_ret);
}
/*
* SQLite3 mode: Execute raw SQL and return success or failure
*/
static int appfs_sqlite3(const char *sql) {
Tcl_Interp *interp;
const char *sql_ret;
int tcl_ret;
interp = appfs_create_TclInterp();
if (interp == NULL) {
fprintf(stderr, "Unable to create a Tcl interpreter. Aborting.\n");
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);
return(1);
}
if (sql_ret && sql_ret[0] != '\0') {
printf("%s\n", sql_ret);
}
return(0);
}
/*
* Tcl mode: Execute raw Tcl and return success or failure
*/
static int appfs_tcl(const char *tcl) {
Tcl_Interp *interp;
const char *tcl_result;
int tcl_ret;
interp = appfs_create_TclInterp();
if (interp == NULL) {
fprintf(stderr, "Unable to create a Tcl interpreter. Aborting.\n");
return(1);
}
tcl_ret = Tcl_Eval(interp, tcl);
tcl_result = Tcl_GetStringResult(interp);
if (tcl_ret != TCL_OK) {
fprintf(stderr, "[error] %s\n", tcl_result);
return(1);
}
if (tcl_result && tcl_result[0] != '\0') {
printf("%s\n", tcl_result);
}
return(0);
}
/*
* AppFSd Package for Tcl:
* Bridge for I/O operations to request information about the current
* transaction
*/
static int Appfsd_Init(Tcl_Interp *interp) {
#ifdef USE_TCL_STUBS
if (Tcl_InitStubs(interp, TCL_VERSION, 0) == 0L) {
return(TCL_ERROR);
}
#endif
Tcl_CreateObjCommand(interp, "appfsd::get_homedir", tcl_appfs_get_homedir, NULL, NULL);
Tcl_PkgProvide(interp, "appfsd", "1.0");
return(TCL_OK);
}
/*
* FUSE operations structure
*/
static struct fuse_operations appfs_operations = {
.getattr = appfs_fuse_getattr,
.readdir = appfs_fuse_readdir,
.readlink = appfs_fuse_readlink,
.open = appfs_fuse_open,
.release = appfs_fuse_close,
.read = appfs_fuse_read
};
/*
* FUSE option parsing callback
*/
static int appfs_fuse_opt_cb(void *data, const char *arg, int key, struct fuse_args *outargs) {
static seen_cachedir = 0;
if (key == FUSE_OPT_KEY_NONOPT && seen_cachedir == 0) {
seen_cachedir = 1;
appfs_cachedir = strdup(arg);
return(0);
}
return(1);
}
/*
* Entry point into this program.
*/
int main(int argc, char **argv) {
struct fuse_args args = FUSE_ARGS_INIT(argc, argv);
int pthread_ret;
/*
* Skip passed program name
*/
if (argc == 0 || argv == NULL) {
return(1);
}
argc--;
argv++;
/*
* Set global variables, these should be configuration options.
*/
appfs_cachedir = APPFS_CACHEDIR;
/*
* Set global variable for "boot time" to set a time on directories
* that we fake.
*/
appfs_boottime = time(NULL);
/*
* Register "sha1" and "appfsd" package with libtcl so that any new
* interpreters created (which are done dynamically by FUSE) can have
* the appropriate configuration done automatically.
*/
Tcl_StaticPackage(NULL, "sha1", Sha1_Init, NULL);
Tcl_StaticPackage(NULL, "appfsd", Appfsd_Init, NULL);
/*
* 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, NULL);
if (pthread_ret != 0) {
fprintf(stderr, "Unable to create TSD key for Tcl. Aborting.\n");
return(1);
}
/*
* Manually specify cache directory, without FUSE callback
* This option only works when not using FUSE, since we
* do not process it with FUSEs option processing.
*/
if (argc >= 2) {
if (strcmp(argv[0], "--cachedir") == 0) {
appfs_cachedir = strdup(argv[1]);
argc -= 2;
argv += 2;
}
}
/*
* SQLite3 mode, for running raw SQL against the cache database
*/
if (argc == 2 && strcmp(argv[0], "--sqlite3") == 0) {
return(appfs_sqlite3(argv[1]));
}
/*
* 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]));
}
/*
* Add FUSE arguments which we always supply
*/
fuse_opt_parse(&args, NULL, NULL, appfs_fuse_opt_cb);
fuse_opt_add_arg(&args, "-odefault_permissions,fsname=appfs,subtype=appfsd,use_ino,kernel_cache,entry_timeout=60,attr_timeout=3600,intr,big_writes");
if (getuid() == 0) {
fuse_opt_parse(&args, NULL, NULL, NULL);
fuse_opt_add_arg(&args, "-oallow_other");
}
/*
* Enter the FUSE main loop -- this will process any arguments
* and start servicing requests.
*/
return(fuse_main(args.argc, args.argv, &appfs_operations, NULL));
}