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-rw-r--r--lib/fuse.c393
1 files changed, 393 insertions, 0 deletions
diff --git a/lib/fuse.c b/lib/fuse.c
new file mode 100644
index 0000000..f846f74
--- /dev/null
+++ b/lib/fuse.c
@@ -0,0 +1,393 @@
+/*
+ FUSE: Filesystem in Userspace
+ Copyright (C) 2001 Miklos Szeredi (mszeredi@inf.bme.hu)
+
+ This program can be distributed under the terms of the GNU GPL.
+ See the file COPYING.
+*/
+
+#include "fuse_i.h"
+#include <linux/fuse.h>
+
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+
+
+static guint name_hash(const struct node *node)
+{
+ return g_str_hash(node->name) ^ node->parent;
+}
+
+static gint name_compare(const struct node *node1, const struct node *node2)
+{
+ return
+ node1->parent == node2->parent &&
+ strcmp(node1->name, node2->name) == 0;
+}
+
+static struct node *new_node(fino_t parent, const char *name)
+{
+ struct node *node = g_new0(struct node, 1);
+ node->name = strdup(name);
+ node->parent = parent;
+ return node;
+}
+
+static int free_node(struct node *node)
+{
+ g_free(node->name);
+ g_free(node);
+ return 1;
+}
+
+static inline struct node *get_node(fino_t ino)
+{
+ return (struct node *) ino;
+}
+
+static inline fino_t get_ino(struct node *node)
+{
+ return (fino_t) node;
+}
+
+
+static fino_t find_node(struct fuse *f, fino_t parent, char *name, int create)
+{
+ struct node *node;
+ struct node tmp;
+
+ tmp.name = name;
+ tmp.parent = parent;
+
+ node = g_hash_table_lookup(f->nametab, &tmp);
+ if(node != NULL)
+ return get_ino(node);
+
+ if(!create)
+ return (fino_t) -1;
+
+ node = new_node(parent, name);
+ g_hash_table_insert(f->nametab, node, node);
+ return get_ino(node);
+}
+
+static char *get_path(fino_t ino)
+{
+ GString *s;
+ char *ss;
+
+ s = g_string_new("");
+ if(ino == FUSE_ROOT_INO)
+ g_string_prepend_c(s, '/');
+ else {
+ struct node *node;
+ for(; ino != FUSE_ROOT_INO; ino = node->parent) {
+ node = get_node(ino);
+ g_string_prepend(s, node->name);
+ g_string_prepend_c(s, '/');
+ }
+ }
+
+ ss = s->str;
+ g_string_free(s, FALSE);
+
+ return ss;
+}
+
+static void remove_node(struct fuse *f, fino_t ino)
+{
+ struct node *node = get_node(ino);
+ g_hash_table_remove(f->nametab, node);
+ free_node(node);
+}
+
+
+static void convert_stat(struct stat *stbuf, struct fuse_attr *attr)
+{
+ attr->mode = stbuf->st_mode;
+ attr->nlink = stbuf->st_nlink;
+ attr->uid = stbuf->st_uid;
+ attr->gid = stbuf->st_gid;
+ attr->rdev = stbuf->st_rdev;
+ attr->size = stbuf->st_size;
+ attr->blksize = stbuf->st_blksize;
+ attr->blocks = stbuf->st_blocks;
+ attr->atime = stbuf->st_atime;
+ attr->mtime = stbuf->st_mtime;
+ attr->ctime = stbuf->st_ctime;
+}
+
+static int get_attributes(struct fuse *f, fino_t ino, struct fuse_attr *attr)
+{
+ char *path;
+ struct stat buf;
+ int res;
+
+ if(f->op.getattr == NULL)
+ return -ENOSYS;
+
+ path = get_path(ino);
+ res = f->op.getattr(path, &buf);
+ g_free(path);
+ if(res == 0)
+ convert_stat(&buf, attr);
+
+ return res;
+}
+
+static int read_link(struct fuse *f, fino_t ino, char *buf, size_t size)
+{
+ char *path;
+ int res;
+
+ if(f->op.readlink == NULL)
+ return -ENOSYS;
+
+ path = get_path(ino);
+ res = f->op.readlink(path, buf, size);
+ g_free(path);
+
+ return res;
+}
+
+static int fill_dir(struct fuse_dh *dh, char *name, int type)
+{
+ struct fuse_dirent dirent;
+ size_t reclen;
+ size_t res;
+
+ dirent.ino = find_node(dh->fuse, dh->dir, name, 0);
+ dirent.namelen = strlen(name);
+ strncpy(dirent.name, name, sizeof(dirent.name));
+ dirent.type = type;
+ reclen = FUSE_DIRENT_SIZE(&dirent);
+ res = fwrite(&dirent, reclen, 1, dh->fp);
+ if(res == 0) {
+ perror("writing directory file");
+ return -EIO;
+ }
+ return 0;
+}
+
+static int get_dir(struct fuse *f, fino_t ino, FILE *fp)
+{
+ char *path;
+ int res;
+ struct fuse_dh dh;
+
+ if(f->op.getdir == NULL)
+ return -ENOSYS;
+
+ dh.fuse = f;
+ dh.fp = fp;
+ dh.dir = ino;
+
+ path = get_path(ino);
+ res = f->op.getdir(path, &dh, (dirfiller_t) fill_dir);
+ g_free(path);
+
+ return res;
+}
+
+
+static void send_reply(struct fuse *f, struct fuse_in_header *in, int result,
+ void *arg, size_t argsize)
+{
+ int res;
+ char *outbuf;
+ size_t outsize;
+ struct fuse_out_header *out;
+
+ if(result > 0) {
+ fprintf(stderr, "positive result to operation %i : %i\n", in->opcode,
+ result);
+ result = -ERANGE;
+ }
+
+ if(result != 0)
+ argsize = 0;
+
+ outsize = sizeof(struct fuse_out_header) + argsize;
+ outbuf = (char *) g_malloc(outsize);
+ out = (struct fuse_out_header *) outbuf;
+ out->unique = in->unique;
+ out->result = result;
+ if(argsize != 0)
+ memcpy(outbuf + sizeof(struct fuse_out_header), arg, argsize);
+
+ printf(" unique: %i, result: %i (%s), outsize: %i\n", out->unique,
+ out->result, strerror(-out->result), outsize);
+
+ res = write(f->fd, outbuf, outsize);
+ if(res == -1)
+ perror("writing fuse device");
+
+ g_free(outbuf);
+}
+
+static void do_lookup(struct fuse *f, struct fuse_in_header *in, char *name)
+{
+ int res;
+ struct fuse_lookup_out arg;
+
+ arg.ino = find_node(f, in->ino, name, 1);
+ res = get_attributes(f, arg.ino, &arg.attr);
+
+ send_reply(f, in, res, &arg, sizeof(arg));
+}
+
+
+static void do_forget(struct fuse *f, unsigned long *inos, size_t num)
+{
+ size_t i;
+
+ for(i = 0; i < num; i++)
+ remove_node(f, inos[i]);
+}
+
+static void do_getattr(struct fuse *f, struct fuse_in_header *in)
+{
+ int res;
+ struct fuse_getattr_out arg;
+
+ res = get_attributes(f, in->ino, &arg.attr);
+ send_reply(f, in, res, &arg, sizeof(arg));
+}
+
+static void do_readlink(struct fuse *f, struct fuse_in_header *in)
+{
+ int res;
+ char link[PATH_MAX + 1];
+
+ res = read_link(f, in->ino, link, PATH_MAX + 1);
+ send_reply(f, in, res, link, res == 0 ? strlen(link) : 0);
+}
+
+static void do_mknod(struct fuse *f, struct fuse_in_header *in,
+ struct fuse_mknod_in *inarg)
+{
+ int res;
+ struct fuse_mknod_out outarg;
+
+ res = -ENOSYS;
+ if(f->op.mknod != NULL && f->op.getattr != NULL) {
+ char *path;
+ struct stat buf;
+
+ outarg.ino = find_node(f, in->ino, inarg->name, 1);
+ path = get_path(outarg.ino);
+ res = f->op.mknod(path, inarg->mode, inarg->rdev);
+ if(res == 0)
+ res = f->op.getattr(path, &buf);
+ g_free(path);
+
+ if(res == 0)
+ convert_stat(&buf, &outarg.attr);
+ else
+ remove_node(f, outarg.ino);
+ }
+ send_reply(f, in, res, &outarg, sizeof(outarg));
+}
+
+static void do_getdir(struct fuse *f, struct fuse_in_header *in)
+{
+ int res;
+ struct fuse_getdir_out arg;
+ FILE *fp = tmpfile();
+
+ res = get_dir(f, in->ino, fp);
+ fflush(fp);
+ arg.fd = fileno(fp);
+ send_reply(f, in, res, &arg, sizeof(arg));
+ fclose(fp);
+}
+
+void fuse_loop(struct fuse *f)
+{
+ int res;
+ char inbuf[FUSE_MAX_IN];
+ struct fuse_in_header *in = (struct fuse_in_header *) inbuf;
+ void *inarg = inbuf + sizeof(struct fuse_in_header);
+ size_t insize;
+ size_t argsize;
+
+ while(1) {
+ res = read(f->fd, inbuf, sizeof(inbuf));
+ if(res == -1) {
+ perror("reading fuse device");
+ continue;
+ }
+ insize = res;
+
+ if(insize < sizeof(struct fuse_in_header)) {
+ fprintf(stderr, "short read on fuse device\n");
+ continue;
+ }
+ printf("unique: %i, opcode: %i, ino: %li, insize: %i (%i)\n",
+ in->unique, in->opcode, in->ino, insize,
+ g_hash_table_size(f->nametab));
+
+ argsize = insize - sizeof(struct fuse_in_header);
+
+ switch(in->opcode) {
+ case FUSE_LOOKUP:
+ do_lookup(f, in, (char *) inarg);
+ break;
+
+ case FUSE_FORGET:
+ do_forget(f, (unsigned long *) inarg,
+ argsize / sizeof(unsigned long));
+ break;
+
+ case FUSE_GETATTR:
+ do_getattr(f, in);
+ break;
+
+ case FUSE_READLINK:
+ do_readlink(f, in);
+ break;
+
+ case FUSE_GETDIR:
+ do_getdir(f, in);
+ break;
+
+ case FUSE_MKNOD:
+ do_mknod(f, in, (struct fuse_mknod_in *) inarg);
+ break;
+
+ default:
+ fprintf(stderr, "Operation %i not implemented\n", in->opcode);
+ /* No need to send reply to async requests */
+ if(in->unique != 0)
+ send_reply(f, in, -ENOSYS, NULL, 0);
+ }
+ }
+}
+
+struct fuse *fuse_new()
+{
+ struct fuse *f = g_new0(struct fuse, 1);
+
+ f->fd = -1;
+ f->dir = NULL;
+ f->nametab = g_hash_table_new((GHashFunc) name_hash,
+ (GCompareFunc) name_compare);
+
+ return f;
+}
+
+
+void fuse_set_operations(struct fuse *f, const struct fuse_operations *op)
+{
+ f->op = *op;
+}
+
+void fuse_destroy(struct fuse *f)
+{
+ fuse_unmount(f);
+ g_hash_table_foreach_remove(f->nametab, (GHRFunc) free_node, NULL);
+ g_hash_table_destroy(f->nametab);
+ g_free(f);
+}
+
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