1 files changed, 371 insertions, 0 deletions

diff --git a/fuse/cuse_lowlevel.c b/fuse/cuse_lowlevel.c
new file mode 100644
index 000000000..970df7fb7
--- /dev/null
+++ b/fuse/cuse_lowlevel.c
@@ -0,0 +1,371 @@
+/*
+  CUSE: Character device in Userspace
+  Copyright (C) 2008       SUSE Linux Products GmbH
+  Copyright (C) 2008       Tejun Heo <teheo@suse.de>
+
+  This program can be distributed under the terms of the GNU LGPLv2.
+  See the file COPYING.LIB.
+*/
+
+#include "cuse_lowlevel.h"
+#include "fuse_kernel.h"
+#include "fuse_i.h"
+#include "fuse_opt.h"
+#include "fuse_misc.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <errno.h>
+#include <unistd.h>
+
+struct cuse_data {
+	struct cuse_lowlevel_ops	clop;
+	unsigned			max_read;
+	unsigned			dev_major;
+	unsigned			dev_minor;
+	unsigned			flags;
+	unsigned			dev_info_len;
+	char				dev_info[];
+};
+
+static struct cuse_lowlevel_ops *req_clop(fuse_req_t req)
+{
+	return &req->f->cuse_data->clop;
+}
+
+static void cuse_fll_open(fuse_req_t req, fuse_ino_t ino,
+			  struct fuse_file_info *fi)
+{
+	(void)ino;
+	req_clop(req)->open(req, fi);
+}
+
+static void cuse_fll_read(fuse_req_t req, fuse_ino_t ino, size_t size,
+			  off64_t off, struct fuse_file_info *fi)
+{
+	(void)ino;
+	req_clop(req)->read(req, size, off, fi);
+}
+
+static void cuse_fll_write(fuse_req_t req, fuse_ino_t ino, const char *buf,
+			   size_t size, off64_t off, struct fuse_file_info *fi)
+{
+	(void)ino;
+	req_clop(req)->write(req, buf, size, off, fi);
+}
+
+static void cuse_fll_flush(fuse_req_t req, fuse_ino_t ino,
+			   struct fuse_file_info *fi)
+{
+	(void)ino;
+	req_clop(req)->flush(req, fi);
+}
+
+static void cuse_fll_release(fuse_req_t req, fuse_ino_t ino,
+			     struct fuse_file_info *fi)
+{
+	(void)ino;
+	req_clop(req)->release(req, fi);
+}
+
+static void cuse_fll_fsync(fuse_req_t req, fuse_ino_t ino, int datasync,
+			   struct fuse_file_info *fi)
+{
+	(void)ino;
+	req_clop(req)->fsync(req, datasync, fi);
+}
+
+static void cuse_fll_ioctl(fuse_req_t req, fuse_ino_t ino, int cmd, void *arg,
+		       struct fuse_file_info *fi, unsigned int flags,
+		       const void *in_buf, size_t in_bufsz, size_t out_bufsz)
+{
+	(void)ino;
+	req_clop(req)->ioctl(req, cmd, arg, fi, flags, in_buf, in_bufsz,
+			     out_bufsz);
+}
+
+static void cuse_fll_poll(fuse_req_t req, fuse_ino_t ino,
+			  struct fuse_file_info *fi, struct fuse_pollhandle *ph)
+{
+	(void)ino;
+	req_clop(req)->poll(req, fi, ph);
+}
+
+static size_t cuse_pack_info(int argc, const char **argv, char *buf)
+{
+	size_t size = 0;
+	int i;
+
+	for (i = 0; i < argc; i++) {
+		size_t len;
+
+		len = strlen(argv[i]) + 1;
+		size += len;
+		if (buf) {
+			memcpy(buf, argv[i], len);
+			buf += len;
+		}
+	}
+
+	return size;
+}
+
+static struct cuse_data *cuse_prep_data(const struct cuse_info *ci,
+					const struct cuse_lowlevel_ops *clop)
+{
+	struct cuse_data *cd;
+	size_t dev_info_len;
+
+	dev_info_len = cuse_pack_info(ci->dev_info_argc, ci->dev_info_argv,
+				      NULL);
+
+	if (dev_info_len > CUSE_INIT_INFO_MAX) {
+		fprintf(stderr, "cuse: dev_info (%zu) too large, limit=%u\n",
+			dev_info_len, CUSE_INIT_INFO_MAX);
+		return NULL;
+	}
+
+	cd = calloc(1, sizeof(*cd) + dev_info_len);
+	if (!cd) {
+		fprintf(stderr, "cuse: failed to allocate cuse_data\n");
+		return NULL;
+	}
+
+	memcpy(&cd->clop, clop, sizeof(cd->clop));
+	cd->max_read = 131072;
+	cd->dev_major = ci->dev_major;
+	cd->dev_minor = ci->dev_minor;
+	cd->dev_info_len = dev_info_len;
+	cd->flags = ci->flags;
+	cuse_pack_info(ci->dev_info_argc, ci->dev_info_argv, cd->dev_info);
+
+	return cd;
+}
+
+struct fuse_session *cuse_lowlevel_new(struct fuse_args *args,
+				       const struct cuse_info *ci,
+				       const struct cuse_lowlevel_ops *clop,
+				       void *userdata)
+{
+	struct fuse_lowlevel_ops lop;
+	struct cuse_data *cd;
+	struct fuse_session *se;
+	struct fuse_ll *ll;
+
+	cd = cuse_prep_data(ci, clop);
+	if (!cd)
+		return NULL;
+
+	memset(&lop, 0, sizeof(lop));
+	lop.init	= clop->init;
+	lop.destroy	= clop->destroy;
+	lop.open	= clop->open		? cuse_fll_open		: NULL;
+	lop.read	= clop->read		? cuse_fll_read		: NULL;
+	lop.write	= clop->write		? cuse_fll_write	: NULL;
+	lop.flush	= clop->flush		? cuse_fll_flush	: NULL;
+	lop.release	= clop->release		? cuse_fll_release	: NULL;
+	lop.fsync	= clop->fsync		? cuse_fll_fsync	: NULL;
+	lop.ioctl	= clop->ioctl		? cuse_fll_ioctl	: NULL;
+	lop.poll	= clop->poll		? cuse_fll_poll		: NULL;
+
+	se = fuse_lowlevel_new_common(args, &lop, sizeof(lop), userdata);
+	if (!se) {
+		free(cd);
+		return NULL;
+	}
+	ll = se->data;
+	ll->cuse_data = cd;
+
+	return se;
+}
+
+static int cuse_reply_init(fuse_req_t req, struct cuse_init_out *arg,
+			   char *dev_info, unsigned dev_info_len)
+{
+	struct iovec iov[3];
+
+	iov[1].iov_base = arg;
+	iov[1].iov_len = sizeof(struct cuse_init_out);
+	iov[2].iov_base = dev_info;
+	iov[2].iov_len = dev_info_len;
+
+	return fuse_send_reply_iov_nofree(req, 0, iov, 3);
+}
+
+void cuse_lowlevel_init(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
+{
+	struct fuse_init_in *arg = (struct fuse_init_in *) inarg;
+	struct cuse_init_out outarg;
+	struct fuse_ll *f = req->f;
+	struct cuse_data *cd = f->cuse_data;
+	size_t bufsize = fuse_chan_bufsize(req->ch);
+	struct cuse_lowlevel_ops *clop = req_clop(req);
+
+	(void) nodeid;
+	if (f->debug) {
+		fprintf(stderr, "CUSE_INIT: %u.%u\n", arg->major, arg->minor);
+		fprintf(stderr, "flags=0x%08x\n", arg->flags);
+	}
+	f->conn.proto_major = arg->major;
+	f->conn.proto_minor = arg->minor;
+	f->conn.capable = 0;
+	f->conn.want = 0;
+
+	if (arg->major < 7) {
+		fprintf(stderr, "fuse: unsupported protocol version: %u.%u\n",
+			arg->major, arg->minor);
+		fuse_reply_err(req, EPROTO);
+		return;
+	}
+
+	if (bufsize < FUSE_MIN_READ_BUFFER) {
+		fprintf(stderr, "fuse: warning: buffer size too small: %zu\n",
+			bufsize);
+		bufsize = FUSE_MIN_READ_BUFFER;
+	}
+
+	bufsize -= 4096;
+	if (bufsize < f->conn.max_write)
+		f->conn.max_write = bufsize;
+
+	f->got_init = 1;
+	if (f->op.init)
+		f->op.init(f->userdata, &f->conn);
+
+	memset(&outarg, 0, sizeof(outarg));
+	outarg.major = FUSE_KERNEL_VERSION;
+	outarg.minor = FUSE_KERNEL_MINOR_VERSION;
+	outarg.flags = cd->flags;
+	outarg.max_read = cd->max_read;
+	outarg.max_write = f->conn.max_write;
+	outarg.dev_major = cd->dev_major;
+	outarg.dev_minor = cd->dev_minor;
+
+	if (f->debug) {
+		fprintf(stderr, "   CUSE_INIT: %u.%u\n",
+			outarg.major, outarg.minor);
+		fprintf(stderr, "   flags=0x%08x\n", outarg.flags);
+		fprintf(stderr, "   max_read=0x%08x\n", outarg.max_read);
+		fprintf(stderr, "   max_write=0x%08x\n", outarg.max_write);
+		fprintf(stderr, "   dev_major=%u\n", outarg.dev_major);
+		fprintf(stderr, "   dev_minor=%u\n", outarg.dev_minor);
+		fprintf(stderr, "   dev_info: %.*s\n", cd->dev_info_len,
+			cd->dev_info);
+	}
+
+	cuse_reply_init(req, &outarg, cd->dev_info, cd->dev_info_len);
+
+	if (clop->init_done)
+		clop->init_done(f->userdata);
+
+	fuse_free_req(req);
+}
+
+struct fuse_session *cuse_lowlevel_setup(int argc, char *argv[],
+					 const struct cuse_info *ci,
+					 const struct cuse_lowlevel_ops *clop,
+					 int *multithreaded, void *userdata)
+{
+	const char *devname = "/dev/cuse";
+	static const struct fuse_opt kill_subtype_opts[] = {
+		FUSE_OPT_KEY("subtype=",  FUSE_OPT_KEY_DISCARD),
+		FUSE_OPT_END
+	};
+	struct fuse_args args = FUSE_ARGS_INIT(argc, argv);
+	struct fuse_session *se;
+	struct fuse_chan *ch;
+	int fd;
+	int foreground;
+	int res;
+
+	res = fuse_parse_cmdline(&args, NULL, multithreaded, &foreground);
+	if (res == -1)
+		goto err_args;
+
+	res = fuse_opt_parse(&args, NULL, kill_subtype_opts, NULL);
+	if (res == -1)
+		goto err_args;
+
+	/*
+	 * Make sure file descriptors 0, 1 and 2 are open, otherwise chaos
+	 * would ensue.
+	 */
+	do {
+		fd = open("/dev/null", O_RDWR);
+		if (fd > 2)
+			close(fd);
+	} while (fd >= 0 && fd <= 2);
+
+	se = cuse_lowlevel_new(&args, ci, clop, userdata);
+	fuse_opt_free_args(&args);
+	if (se == NULL)
+		goto err_args;
+
+	fd = open(devname, O_RDWR);
+	if (fd == -1) {
+		if (errno == ENODEV || errno == ENOENT)
+			fprintf(stderr, "fuse: device not found, try 'modprobe cuse' first\n");
+		else
+			fprintf(stderr, "fuse: failed to open %s: %s\n",
+				devname, strerror(errno));
+		goto err_se;
+	}
+
+	ch = fuse_kern_chan_new(fd);
+	if (!ch) {
+		close(fd);
+		goto err_se;
+	}
+
+	fuse_session_add_chan(se, ch);
+
+	res = fuse_set_signal_handlers(se);
+	if (res == -1)
+		goto err_se;
+
+	res = fuse_daemonize(foreground);
+	if (res == -1)
+		goto err_sig;
+
+	return se;
+
+err_sig:
+	fuse_remove_signal_handlers(se);
+err_se:
+	fuse_session_destroy(se);
+err_args:
+	fuse_opt_free_args(&args);
+	return NULL;
+}
+
+void cuse_lowlevel_teardown(struct fuse_session *se)
+{
+	fuse_remove_signal_handlers(se);
+	fuse_session_destroy(se);
+}
+
+int cuse_lowlevel_main(int argc, char *argv[], const struct cuse_info *ci,
+		       const struct cuse_lowlevel_ops *clop, void *userdata)
+{
+	struct fuse_session *se;
+	int multithreaded;
+	int res;
+
+	se = cuse_lowlevel_setup(argc, argv, ci, clop, &multithreaded,
+				 userdata);
+	if (se == NULL)
+		return 1;
+
+	if (multithreaded)
+		res = fuse_session_loop_mt(se);
+	else
+		res = fuse_session_loop(se);
+
+	cuse_lowlevel_teardown(se);
+	if (res == -1)
+		return 1;
+
+	return 0;
+}