From 604f3d64764270c052cfb43081ec522237bbdb75 Mon Sep 17 00:00:00 2001 From: Ludovic Pouzenc Date: Fri, 5 May 2017 11:28:51 +0200 Subject: Massive add for all draft stuff to keep it in sync --- draft/fuse-examples/cusexmp.c | 294 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 294 insertions(+) create mode 100644 draft/fuse-examples/cusexmp.c (limited to 'draft/fuse-examples/cusexmp.c') diff --git a/draft/fuse-examples/cusexmp.c b/draft/fuse-examples/cusexmp.c new file mode 100644 index 0000000..01fcdf7 --- /dev/null +++ b/draft/fuse-examples/cusexmp.c @@ -0,0 +1,294 @@ +/* + CUSE example: Character device in Userspace + Copyright (C) 2008-2009 SUSE Linux Products GmbH + Copyright (C) 2008-2009 Tejun Heo + + This program can be distributed under the terms of the GNU GPL. + See the file COPYING. + + gcc -Wall cusexmp.c `pkg-config fuse --cflags --libs` -o cusexmp +*/ + +#define FUSE_USE_VERSION 29 + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "fioc.h" + +static void *cusexmp_buf; +static size_t cusexmp_size; + +static const char *usage = +"usage: cusexmp [options]\n" +"\n" +"options:\n" +" --help|-h print this help message\n" +" --maj=MAJ|-M MAJ device major number\n" +" --min=MIN|-m MIN device minor number\n" +" --name=NAME|-n NAME device name (mandatory)\n" +"\n"; + +static int cusexmp_resize(size_t new_size) +{ + void *new_buf; + + if (new_size == cusexmp_size) + return 0; + + new_buf = realloc(cusexmp_buf, new_size); + if (!new_buf && new_size) + return -ENOMEM; + + if (new_size > cusexmp_size) + memset(new_buf + cusexmp_size, 0, new_size - cusexmp_size); + + cusexmp_buf = new_buf; + cusexmp_size = new_size; + + return 0; +} + +static int cusexmp_expand(size_t new_size) +{ + if (new_size > cusexmp_size) + return cusexmp_resize(new_size); + return 0; +} + +static void cusexmp_open(fuse_req_t req, struct fuse_file_info *fi) +{ + fuse_reply_open(req, fi); +} + +static void cusexmp_read(fuse_req_t req, size_t size, off_t off, + struct fuse_file_info *fi) +{ + (void)fi; + + if (off >= cusexmp_size) + off = cusexmp_size; + if (size > cusexmp_size - off) + size = cusexmp_size - off; + + fuse_reply_buf(req, cusexmp_buf + off, size); +} + +static void cusexmp_write(fuse_req_t req, const char *buf, size_t size, + off_t off, struct fuse_file_info *fi) +{ + (void)fi; + + if (cusexmp_expand(off + size)) { + fuse_reply_err(req, ENOMEM); + return; + } + + memcpy(cusexmp_buf + off, buf, size); + fuse_reply_write(req, size); +} + +static void fioc_do_rw(fuse_req_t req, void *addr, const void *in_buf, + size_t in_bufsz, size_t out_bufsz, int is_read) +{ + const struct fioc_rw_arg *arg; + struct iovec in_iov[2], out_iov[3], iov[3]; + size_t cur_size; + + /* read in arg */ + in_iov[0].iov_base = addr; + in_iov[0].iov_len = sizeof(*arg); + if (!in_bufsz) { + fuse_reply_ioctl_retry(req, in_iov, 1, NULL, 0); + return; + } + arg = in_buf; + in_buf += sizeof(*arg); + in_bufsz -= sizeof(*arg); + + /* prepare size outputs */ + out_iov[0].iov_base = + addr + (unsigned long)&(((struct fioc_rw_arg *)0)->prev_size); + out_iov[0].iov_len = sizeof(arg->prev_size); + + out_iov[1].iov_base = + addr + (unsigned long)&(((struct fioc_rw_arg *)0)->new_size); + out_iov[1].iov_len = sizeof(arg->new_size); + + /* prepare client buf */ + if (is_read) { + out_iov[2].iov_base = arg->buf; + out_iov[2].iov_len = arg->size; + if (!out_bufsz) { + fuse_reply_ioctl_retry(req, in_iov, 1, out_iov, 3); + return; + } + } else { + in_iov[1].iov_base = arg->buf; + in_iov[1].iov_len = arg->size; + if (arg->size && !in_bufsz) { + fuse_reply_ioctl_retry(req, in_iov, 2, out_iov, 2); + return; + } + } + + /* we're all set */ + cur_size = cusexmp_size; + iov[0].iov_base = &cur_size; + iov[0].iov_len = sizeof(cur_size); + + iov[1].iov_base = &cusexmp_size; + iov[1].iov_len = sizeof(cusexmp_size); + + if (is_read) { + size_t off = arg->offset; + size_t size = arg->size; + + if (off >= cusexmp_size) + off = cusexmp_size; + if (size > cusexmp_size - off) + size = cusexmp_size - off; + + iov[2].iov_base = cusexmp_buf + off; + iov[2].iov_len = size; + fuse_reply_ioctl_iov(req, size, iov, 3); + } else { + if (cusexmp_expand(arg->offset + in_bufsz)) { + fuse_reply_err(req, ENOMEM); + return; + } + + memcpy(cusexmp_buf + arg->offset, in_buf, in_bufsz); + fuse_reply_ioctl_iov(req, in_bufsz, iov, 2); + } +} + +static void cusexmp_ioctl(fuse_req_t req, int cmd, void *arg, + struct fuse_file_info *fi, unsigned flags, + const void *in_buf, size_t in_bufsz, size_t out_bufsz) +{ + int is_read = 0; + + (void)fi; + + if (flags & FUSE_IOCTL_COMPAT) { + fuse_reply_err(req, ENOSYS); + return; + } + + switch (cmd) { + case FIOC_GET_SIZE: + if (!out_bufsz) { + struct iovec iov = { arg, sizeof(size_t) }; + + fuse_reply_ioctl_retry(req, NULL, 0, &iov, 1); + } else + fuse_reply_ioctl(req, 0, &cusexmp_size, + sizeof(cusexmp_size)); + break; + + case FIOC_SET_SIZE: + if (!in_bufsz) { + struct iovec iov = { arg, sizeof(size_t) }; + + fuse_reply_ioctl_retry(req, &iov, 1, NULL, 0); + } else { + cusexmp_resize(*(size_t *)in_buf); + fuse_reply_ioctl(req, 0, NULL, 0); + } + break; + + case FIOC_READ: + is_read = 1; + case FIOC_WRITE: + fioc_do_rw(req, arg, in_buf, in_bufsz, out_bufsz, is_read); + break; + + default: + fuse_reply_err(req, EINVAL); + } +} + +struct cusexmp_param { + unsigned major; + unsigned minor; + char *dev_name; + int is_help; +}; + +#define CUSEXMP_OPT(t, p) { t, offsetof(struct cusexmp_param, p), 1 } + +static const struct fuse_opt cusexmp_opts[] = { + CUSEXMP_OPT("-M %u", major), + CUSEXMP_OPT("--maj=%u", major), + CUSEXMP_OPT("-m %u", minor), + CUSEXMP_OPT("--min=%u", minor), + CUSEXMP_OPT("-n %s", dev_name), + CUSEXMP_OPT("--name=%s", dev_name), + FUSE_OPT_KEY("-h", 0), + FUSE_OPT_KEY("--help", 0), + FUSE_OPT_END +}; + +static int cusexmp_process_arg(void *data, const char *arg, int key, + struct fuse_args *outargs) +{ + struct cusexmp_param *param = data; + + (void)outargs; + (void)arg; + + switch (key) { + case 0: + param->is_help = 1; + fprintf(stderr, "%s", usage); + return fuse_opt_add_arg(outargs, "-ho"); + default: + return 1; + } +} + +static const struct cuse_lowlevel_ops cusexmp_clop = { + .open = cusexmp_open, + .read = cusexmp_read, + .write = cusexmp_write, + .ioctl = cusexmp_ioctl, +}; + +int main(int argc, char **argv) +{ + struct fuse_args args = FUSE_ARGS_INIT(argc, argv); + struct cusexmp_param param = { 0, 0, NULL, 0 }; + char dev_name[128] = "DEVNAME="; + const char *dev_info_argv[] = { dev_name }; + struct cuse_info ci; + + if (fuse_opt_parse(&args, ¶m, cusexmp_opts, cusexmp_process_arg)) { + printf("failed to parse option\n"); + return 1; + } + + if (!param.is_help) { + if (!param.dev_name) { + fprintf(stderr, "Error: device name missing\n"); + return 1; + } + strncat(dev_name, param.dev_name, sizeof(dev_name) - 9); + } + + memset(&ci, 0, sizeof(ci)); + ci.dev_major = param.major; + ci.dev_minor = param.minor; + ci.dev_info_argc = 1; + ci.dev_info_argv = dev_info_argv; + ci.flags = CUSE_UNRESTRICTED_IOCTL; + + return cuse_lowlevel_main(args.argc, args.argv, &ci, &cusexmp_clop, + NULL); +} -- cgit v1.2.3