1 /*
2 FUSE: Filesystem in Userspace
3 Copyright (C) 2017 Nikolaus Rath <Nikolaus@rath.org>
4
5 This program can be distributed under the terms of the GNU GPLv2.
6 See the file COPYING.
7 */
8
9 /** @file
10 *
11 * minimal example filesystem that prints out all capabilities
12 * supported by the kernel and then exits.
13 *
14 * Compile with:
15 *
16 * gcc -Wall printcap.c `pkg-config fuse3 --cflags --libs` -o printcap
17 *
18 * ## Source code ##
19 * \include printcap.c
20 */
21
22 #define FUSE_USE_VERSION 31
23
24 #include <fuse_lowlevel.h>
25 #include <stdio.h>
26 #include <unistd.h>
27 #include <string.h>
28 #include <stdlib.h>
29
30 struct fuse_session *se;
31
pc_init(void * userdata,struct fuse_conn_info * conn)32 static void pc_init(void *userdata,
33 struct fuse_conn_info *conn)
34 {
35 (void) userdata;
36
37 printf("Protocol version: %d.%d\n", conn->proto_major,
38 conn->proto_minor);
39 printf("Capabilities:\n");
40 if(conn->capable & FUSE_CAP_ASYNC_READ)
41 printf("\tFUSE_CAP_ASYNC_READ\n");
42 if(conn->capable & FUSE_CAP_POSIX_LOCKS)
43 printf("\tFUSE_CAP_POSIX_LOCKS\n");
44 if(conn->capable & FUSE_CAP_ATOMIC_O_TRUNC)
45 printf("\tFUSE_CAP_ATOMIC_O_TRUNC\n");
46 if(conn->capable & FUSE_CAP_EXPORT_SUPPORT)
47 printf("\tFUSE_CAP_EXPORT_SUPPORT\n");
48 if(conn->capable & FUSE_CAP_DONT_MASK)
49 printf("\tFUSE_CAP_DONT_MASK\n");
50 if(conn->capable & FUSE_CAP_SPLICE_MOVE)
51 printf("\tFUSE_CAP_SPLICE_MOVE\n");
52 if(conn->capable & FUSE_CAP_SPLICE_READ)
53 printf("\tFUSE_CAP_SPLICE_READ\n");
54 if(conn->capable & FUSE_CAP_SPLICE_WRITE)
55 printf("\tFUSE_CAP_SPLICE_WRITE\n");
56 if(conn->capable & FUSE_CAP_FLOCK_LOCKS)
57 printf("\tFUSE_CAP_FLOCK_LOCKS\n");
58 if(conn->capable & FUSE_CAP_IOCTL_DIR)
59 printf("\tFUSE_CAP_IOCTL_DIR\n");
60 if(conn->capable & FUSE_CAP_AUTO_INVAL_DATA)
61 printf("\tFUSE_CAP_AUTO_INVAL_DATA\n");
62 if(conn->capable & FUSE_CAP_READDIRPLUS)
63 printf("\tFUSE_CAP_READDIRPLUS\n");
64 if(conn->capable & FUSE_CAP_READDIRPLUS_AUTO)
65 printf("\tFUSE_CAP_READDIRPLUS_AUTO\n");
66 if(conn->capable & FUSE_CAP_ASYNC_DIO)
67 printf("\tFUSE_CAP_ASYNC_DIO\n");
68 if(conn->capable & FUSE_CAP_WRITEBACK_CACHE)
69 printf("\tFUSE_CAP_WRITEBACK_CACHE\n");
70 if(conn->capable & FUSE_CAP_NO_OPEN_SUPPORT)
71 printf("\tFUSE_CAP_NO_OPEN_SUPPORT\n");
72 if(conn->capable & FUSE_CAP_PARALLEL_DIROPS)
73 printf("\tFUSE_CAP_PARALLEL_DIROPS\n");
74 if(conn->capable & FUSE_CAP_POSIX_ACL)
75 printf("\tFUSE_CAP_POSIX_ACL\n");
76 if(conn->capable & FUSE_CAP_CACHE_SYMLINKS)
77 printf("\tFUSE_CAP_CACHE_SYMLINKS\n");
78 if(conn->capable & FUSE_CAP_NO_OPENDIR_SUPPORT)
79 printf("\tFUSE_CAP_NO_OPENDIR_SUPPORT\n");
80 if(conn->capable & FUSE_CAP_EXPLICIT_INVAL_DATA)
81 printf("\tFUSE_CAP_EXPLICIT_INVAL_DATA\n");
82 if(conn->capable & FUSE_CAP_EXPIRE_ONLY)
83 printf("\tFUSE_CAP_EXPIRE_ONLY\n");
84 fuse_session_exit(se);
85 }
86
87
88 static const struct fuse_lowlevel_ops pc_oper = {
89 .init = pc_init,
90 };
91
main(int argc,char ** argv)92 int main(int argc, char **argv)
93 {
94 struct fuse_args args = FUSE_ARGS_INIT(argc, argv);
95 char *mountpoint;
96 int ret = -1;
97
98 mountpoint = strdup("/tmp/fuse_printcap_XXXXXX");
99 if(mkdtemp(mountpoint) == NULL) {
100 perror("mkdtemp");
101 return 1;
102 }
103
104 printf("FUSE library version %s\n", fuse_pkgversion());
105 fuse_lowlevel_version();
106
107 se = fuse_session_new(&args, &pc_oper,
108 sizeof(pc_oper), NULL);
109 if (se == NULL)
110 goto err_out1;
111
112 if (fuse_set_signal_handlers(se) != 0)
113 goto err_out2;
114
115 if (fuse_session_mount(se, mountpoint) != 0)
116 goto err_out3;
117
118 ret = fuse_session_loop(se);
119
120 fuse_session_unmount(se);
121 err_out3:
122 fuse_remove_signal_handlers(se);
123 err_out2:
124 fuse_session_destroy(se);
125 err_out1:
126 rmdir(mountpoint);
127 free(mountpoint);
128 fuse_opt_free_args(&args);
129
130 return ret ? 1 : 0;
131 }
132