| /* |
| 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 "config.h" |
| #include "cuse_lowlevel.h" |
| #include "fuse_kernel.h" |
| #include "fuse_i.h" |
| #include "fuse_opt.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->se->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, |
| off_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, off_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; |
| |
| 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_session_new(args, &lop, sizeof(lop), userdata); |
| if (!se) { |
| free(cd); |
| return NULL; |
| } |
| se->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_session *se = req->se; |
| struct cuse_data *cd = se->cuse_data; |
| size_t bufsize = se->bufsize; |
| struct cuse_lowlevel_ops *clop = req_clop(req); |
| |
| (void) nodeid; |
| if (se->debug) { |
| fprintf(stderr, "CUSE_INIT: %u.%u\n", arg->major, arg->minor); |
| fprintf(stderr, "flags=0x%08x\n", arg->flags); |
| } |
| se->conn.proto_major = arg->major; |
| se->conn.proto_minor = arg->minor; |
| se->conn.capable = 0; |
| se->conn.want = 0; |
| |
| if (arg->major < 7) { |
| fprintf(stderr, "cuse: unsupported protocol version: %u.%u\n", |
| arg->major, arg->minor); |
| fuse_reply_err(req, EPROTO); |
| return; |
| } |
| |
| if (bufsize < FUSE_MIN_READ_BUFFER) { |
| fprintf(stderr, "cuse: warning: buffer size too small: %zu\n", |
| bufsize); |
| bufsize = FUSE_MIN_READ_BUFFER; |
| } |
| |
| bufsize -= 4096; |
| if (bufsize < se->conn.max_write) |
| se->conn.max_write = bufsize; |
| |
| se->got_init = 1; |
| if (se->op.init) |
| se->op.init(se->userdata, &se->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 = se->conn.max_write; |
| outarg.dev_major = cd->dev_major; |
| outarg.dev_minor = cd->dev_minor; |
| |
| if (se->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(se->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_cmdline_opts opts; |
| int fd; |
| int res; |
| |
| if (fuse_parse_cmdline(&args, &opts) == -1) |
| return NULL; |
| *multithreaded = !opts.singlethread; |
| |
| /* Remove subtype= option */ |
| res = fuse_opt_parse(&args, NULL, kill_subtype_opts, NULL); |
| if (res == -1) |
| goto out1; |
| |
| /* |
| * 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); |
| if (se == NULL) |
| goto out1; |
| |
| fd = open(devname, O_RDWR); |
| if (fd == -1) { |
| if (errno == ENODEV || errno == ENOENT) |
| fprintf(stderr, "cuse: device not found, try 'modprobe cuse' first\n"); |
| else |
| fprintf(stderr, "cuse: failed to open %s: %s\n", |
| devname, strerror(errno)); |
| goto err_se; |
| } |
| se->fd = fd; |
| |
| res = fuse_set_signal_handlers(se); |
| if (res == -1) |
| goto err_se; |
| |
| res = fuse_daemonize(opts.foreground); |
| if (res == -1) |
| goto err_sig; |
| |
| return se; |
| |
| err_sig: |
| fuse_remove_signal_handlers(se); |
| err_se: |
| fuse_session_destroy(se); |
| out1: |
| free(opts.mountpoint); |
| 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, 0); |
| else |
| res = fuse_session_loop(se); |
| |
| cuse_lowlevel_teardown(se); |
| if (res == -1) |
| return 1; |
| |
| return 0; |
| } |