| /* |
| FUSE: Filesystem in Userspace |
| Copyright (C) 2001-2007 Miklos Szeredi <miklos@szeredi.hu> |
| |
| This program can be distributed under the terms of the GNU GPL. |
| See the file COPYING. |
| |
| gcc -Wall `pkg-config fuse --cflags --libs` hello_ll.c -o hello_ll |
| */ |
| |
| #define FUSE_USE_VERSION 26 |
| |
| #include <fuse_lowlevel.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <unistd.h> |
| #include <assert.h> |
| |
| static const char *hello_str = "Hello World!\n"; |
| static const char *hello_name = "hello"; |
| |
| static int hello_stat(fuse_ino_t ino, struct stat *stbuf) |
| { |
| stbuf->st_ino = ino; |
| switch (ino) { |
| case 1: |
| stbuf->st_mode = S_IFDIR | 0755; |
| stbuf->st_nlink = 2; |
| break; |
| |
| case 2: |
| stbuf->st_mode = S_IFREG | 0444; |
| stbuf->st_nlink = 1; |
| stbuf->st_size = strlen(hello_str); |
| break; |
| |
| default: |
| return -1; |
| } |
| return 0; |
| } |
| |
| static void hello_ll_getattr(fuse_req_t req, fuse_ino_t ino, |
| struct fuse_file_info *fi) |
| { |
| struct stat stbuf; |
| |
| (void) fi; |
| |
| memset(&stbuf, 0, sizeof(stbuf)); |
| if (hello_stat(ino, &stbuf) == -1) |
| fuse_reply_err(req, ENOENT); |
| else |
| fuse_reply_attr(req, &stbuf, 1.0); |
| } |
| |
| static void hello_ll_lookup(fuse_req_t req, fuse_ino_t parent, const char *name) |
| { |
| struct fuse_entry_param e; |
| |
| if (parent != 1 || strcmp(name, hello_name) != 0) |
| fuse_reply_err(req, ENOENT); |
| else { |
| memset(&e, 0, sizeof(e)); |
| e.ino = 2; |
| e.attr_timeout = 1.0; |
| e.entry_timeout = 1.0; |
| hello_stat(e.ino, &e.attr); |
| |
| fuse_reply_entry(req, &e); |
| } |
| } |
| |
| struct dirbuf { |
| char *p; |
| size_t size; |
| }; |
| |
| static void dirbuf_add(fuse_req_t req, struct dirbuf *b, const char *name, |
| fuse_ino_t ino) |
| { |
| struct stat stbuf; |
| size_t oldsize = b->size; |
| b->size += fuse_add_direntry(req, NULL, 0, name, NULL, 0); |
| b->p = (char *) realloc(b->p, b->size); |
| memset(&stbuf, 0, sizeof(stbuf)); |
| stbuf.st_ino = ino; |
| fuse_add_direntry(req, b->p + oldsize, b->size - oldsize, name, &stbuf, |
| b->size); |
| } |
| |
| #define min(x, y) ((x) < (y) ? (x) : (y)) |
| |
| static int reply_buf_limited(fuse_req_t req, const char *buf, size_t bufsize, |
| off_t off, size_t maxsize) |
| { |
| if (off < bufsize) |
| return fuse_reply_buf(req, buf + off, |
| min(bufsize - off, maxsize)); |
| else |
| return fuse_reply_buf(req, NULL, 0); |
| } |
| |
| static void hello_ll_readdir(fuse_req_t req, fuse_ino_t ino, size_t size, |
| off_t off, struct fuse_file_info *fi) |
| { |
| (void) fi; |
| |
| if (ino != 1) |
| fuse_reply_err(req, ENOTDIR); |
| else { |
| struct dirbuf b; |
| |
| memset(&b, 0, sizeof(b)); |
| dirbuf_add(req, &b, ".", 1); |
| dirbuf_add(req, &b, "..", 1); |
| dirbuf_add(req, &b, hello_name, 2); |
| reply_buf_limited(req, b.p, b.size, off, size); |
| free(b.p); |
| } |
| } |
| |
| static void hello_ll_open(fuse_req_t req, fuse_ino_t ino, |
| struct fuse_file_info *fi) |
| { |
| if (ino != 2) |
| fuse_reply_err(req, EISDIR); |
| else if ((fi->flags & 3) != O_RDONLY) |
| fuse_reply_err(req, EACCES); |
| else |
| fuse_reply_open(req, fi); |
| } |
| |
| static void hello_ll_read(fuse_req_t req, fuse_ino_t ino, size_t size, |
| off_t off, struct fuse_file_info *fi) |
| { |
| (void) fi; |
| |
| assert(ino == 2); |
| reply_buf_limited(req, hello_str, strlen(hello_str), off, size); |
| } |
| |
| static struct fuse_lowlevel_ops hello_ll_oper = { |
| .lookup = hello_ll_lookup, |
| .getattr = hello_ll_getattr, |
| .readdir = hello_ll_readdir, |
| .open = hello_ll_open, |
| .read = hello_ll_read, |
| }; |
| |
| int main(int argc, char *argv[]) |
| { |
| struct fuse_args args = FUSE_ARGS_INIT(argc, argv); |
| struct fuse_chan *ch; |
| char *mountpoint; |
| int err = -1; |
| |
| if (fuse_parse_cmdline(&args, &mountpoint, NULL, NULL) != -1 && |
| (ch = fuse_mount(mountpoint, &args)) != NULL) { |
| struct fuse_session *se; |
| |
| se = fuse_lowlevel_new(&args, &hello_ll_oper, |
| sizeof(hello_ll_oper), NULL); |
| if (se != NULL) { |
| if (fuse_set_signal_handlers(se) != -1) { |
| fuse_session_add_chan(se, ch); |
| err = fuse_session_loop(se); |
| fuse_remove_signal_handlers(se); |
| fuse_session_remove_chan(ch); |
| } |
| fuse_session_destroy(se); |
| } |
| fuse_unmount(mountpoint, ch); |
| } |
| fuse_opt_free_args(&args); |
| |
| return err ? 1 : 0; |
| } |