#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; /* * Data for a given thread (most likely these will become just globable variables soon.) */ struct appfs_thread_data { const char *cachedir; time_t boottime; struct { int writable; } options; }; /* The global thread data (likely to go away) */ struct appfs_thread_data globalThread; /* * 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; const char *cachedir = globalThread.cachedir; 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", 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); } /* * AppFS: Request that a host's package index be updated locally */ static void appfs_update_index(const char *hostname) { Tcl_Interp *interp; int tcl_ret; APPFS_DEBUG("Enter: hostname = %s", hostname); interp = appfs_TclInterp(); if (interp == NULL) { return; } tcl_ret = appfs_Tcl_Eval(interp, 2, "::appfs::getindex", hostname); if (tcl_ret != TCL_OK) { APPFS_DEBUG("Call to ::appfs::getindex failed: %s", Tcl_GetStringResult(interp)); return; } return; } /* * AppFS: Get a SHA1 from a host * Returns a local file name, or NULL if it cannot be fetched */ static const char *appfs_getfile(const char *hostname, const char *sha1) { Tcl_Interp *interp; char *retval; int tcl_ret; interp = appfs_TclInterp(); if (interp == NULL) { return(NULL); } tcl_ret = appfs_Tcl_Eval(interp, 3, "::appfs::download", hostname, sha1); if (tcl_ret != TCL_OK) { APPFS_DEBUG("Call to ::appfs::download failed: %s", Tcl_GetStringResult(interp)); return(NULL); } retval = strdup(Tcl_GetStringResult(interp)); return(retval); } /* * AppFS: Update the manifest for a specific package (by the package SHA1) on * a given host */ static void appfs_update_manifest(const char *hostname, const char *sha1) { Tcl_Interp *interp; int tcl_ret; interp = appfs_TclInterp(); if (interp == NULL) { return; } tcl_ret = appfs_Tcl_Eval(interp, 3, "::appfs::getpkgmanifest", hostname, sha1); if (tcl_ret != TCL_OK) { APPFS_DEBUG("Call to ::appfs::getpkgmanifest failed: %s", Tcl_GetStringResult(interp)); return; } return; } /* * 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_INVALID; res = appfs_get_path_info(path, &pathinfo, NULL); if (res != 0) { return(res); } 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 (globalThread.options.writable) { 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) { struct appfs_pathinfo pathinfo; struct appfs_children *children, *child; int retval; APPFS_DEBUG("Enter (path = %s, ...)", path); retval = appfs_get_path_info(path, &pathinfo, &children); if (retval != 0) { return(retval); } filler(buf, ".", NULL, 0); filler(buf, "..", NULL, 0); for (child = children; child; child = child->_next) { filler(buf, child->name, NULL, 0); } // appfs_free_list_children(children); 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; globalThread.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. */ globalThread.cachedir = APPFS_CACHEDIR; globalThread.options.writable = 1; /* * Set global variable for "boot time" to set a time on directories * that we fake. */ globalThread.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 */ if (argc >= 2) { if (strcmp(argv[0], "--cachedir") == 0) { globalThread.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)); }