libfuse: fuse-3.9.2/lib/mount_bsd.c Source File

libfuse

mount_bsd.c
1 /*
2 FUSE: Filesystem in Userspace
3 Copyright (C) 2005-2008 Csaba Henk <csaba.henk@creo.hu>
4
5 Architecture specific file system mounting (FreeBSD).
6
7 This program can be distributed under the terms of the GNU LGPLv2.
8 See the file COPYING.LIB.
9 */
10
11 #include "config.h"
12 #include "fuse_i.h"
13 #include "fuse_misc.h"
14 #include "fuse_opt.h"
15
16 #include <sys/param.h>
17 #include <sys/mount.h>
18
19 #include <sys/stat.h>
20 #include <sys/wait.h>
21 #include <sys/sysctl.h>
22 #include <sys/user.h>
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <unistd.h>
26 #include <stddef.h>
27 #include <fcntl.h>
28 #include <errno.h>
29 #include <string.h>
30 #include <paths.h>
31 #include <limits.h>
32
33 #define FUSERMOUNT_PROG "mount_fusefs"
34 #define FUSE_DEV_TRUNK "/dev/fuse"
35
36 enum {
37 KEY_RO,
38 KEY_KERN
39 };
40
41 struct mount_opts {
42 int allow_other;
43 char *kernel_opts;
44 unsigned max_read;
45 };
46
47 #define FUSE_DUAL_OPT_KEY(templ, key) \
48 FUSE_OPT_KEY(templ, key), FUSE_OPT_KEY("no" templ, key)
49
50 static const struct fuse_opt fuse_mount_opts[] = {
51 { "allow_other", offsetof(struct mount_opts, allow_other), 1 },
52 { "max_read=%u", offsetof(struct mount_opts, max_read), 1 },
53 FUSE_OPT_KEY("-r", KEY_RO),
54 /* standard FreeBSD mount options */
55 FUSE_DUAL_OPT_KEY("dev", KEY_KERN),
56 FUSE_DUAL_OPT_KEY("async", KEY_KERN),
57 FUSE_DUAL_OPT_KEY("atime", KEY_KERN),
58 FUSE_DUAL_OPT_KEY("dev", KEY_KERN),
59 FUSE_DUAL_OPT_KEY("exec", KEY_KERN),
60 FUSE_DUAL_OPT_KEY("suid", KEY_KERN),
61 FUSE_DUAL_OPT_KEY("symfollow", KEY_KERN),
62 FUSE_DUAL_OPT_KEY("rdonly", KEY_KERN),
63 FUSE_DUAL_OPT_KEY("sync", KEY_KERN),
64 FUSE_DUAL_OPT_KEY("union", KEY_KERN),
65 FUSE_DUAL_OPT_KEY("userquota", KEY_KERN),
66 FUSE_DUAL_OPT_KEY("groupquota", KEY_KERN),
67 FUSE_DUAL_OPT_KEY("clusterr", KEY_KERN),
68 FUSE_DUAL_OPT_KEY("clusterw", KEY_KERN),
69 FUSE_DUAL_OPT_KEY("suiddir", KEY_KERN),
70 FUSE_DUAL_OPT_KEY("snapshot", KEY_KERN),
71 FUSE_DUAL_OPT_KEY("multilabel", KEY_KERN),
72 FUSE_DUAL_OPT_KEY("acls", KEY_KERN),
73 FUSE_DUAL_OPT_KEY("force", KEY_KERN),
74 FUSE_DUAL_OPT_KEY("update", KEY_KERN),
75 FUSE_DUAL_OPT_KEY("ro", KEY_KERN),
76 FUSE_DUAL_OPT_KEY("rw", KEY_KERN),
77 FUSE_DUAL_OPT_KEY("auto", KEY_KERN),
78 FUSE_DUAL_OPT_KEY("automounted", KEY_KERN),
79 /* options supported under both Linux and FBSD */
80 FUSE_DUAL_OPT_KEY("allow_other", KEY_KERN),
81 FUSE_DUAL_OPT_KEY("default_permissions",KEY_KERN),
82 FUSE_OPT_KEY("max_read=", KEY_KERN),
83 FUSE_OPT_KEY("subtype=", KEY_KERN),
84 /* FBSD FUSE specific mount options */
85 FUSE_DUAL_OPT_KEY("private", KEY_KERN),
86 FUSE_DUAL_OPT_KEY("neglect_shares", KEY_KERN),
87 FUSE_DUAL_OPT_KEY("push_symlinks_in", KEY_KERN),
88 FUSE_OPT_KEY("nosync_unmount", KEY_KERN),
89 #if __FreeBSD_version >= 1200519
90 FUSE_DUAL_OPT_KEY("intr", KEY_KERN),
91 #endif
92 /* stock FBSD mountopt parsing routine lets anything be negated... */
93 /*
94 * Linux specific mount options, but let just the mount util
95 * handle them
96 */
97 FUSE_OPT_KEY("fsname=", KEY_KERN),
98 FUSE_OPT_END
99 };
100
101 void fuse_mount_version(void)
102 {
103 system(FUSERMOUNT_PROG " --version");
104 }
105
106 unsigned get_max_read(struct mount_opts *o)
107 {
108 return o->max_read;
109 }
110
111 static int fuse_mount_opt_proc(void *data, const char *arg, int key,
112 struct fuse_args *outargs)
113 {
114 (void) outargs;
115 struct mount_opts *mo = data;
116
117 switch (key) {
118 case KEY_RO:
119 arg = "ro";
120 /* fall through */
121
122 case KEY_KERN:
123 return fuse_opt_add_opt(&mo->kernel_opts, arg);
124 }
125
126 /* Pass through unknown options */
127 return 1;
128 }
129
130 void fuse_kern_unmount(const char *mountpoint, int fd)
131 {
132 close(fd);
133 unmount(mountpoint, MNT_FORCE);
134 }
135
136 /* Check if kernel is doing init in background */
137 static int init_backgrounded(void)
138 {
139 unsigned ibg;
140 size_t len;
141
142 len = sizeof(ibg);
143
144 if (sysctlbyname("vfs.fuse.init_backgrounded", &ibg, &len, NULL, 0))
145 return 0;
146
147 return ibg;
148 }
149
150
151 static int fuse_mount_core(const char *mountpoint, const char *opts)
152 {
153 const char *mountprog = FUSERMOUNT_PROG;
154 int fd;
155 char *fdnam, *dev;
156 pid_t pid, cpid;
157 int status;
158
159 fdnam = getenv("FUSE_DEV_FD");
160
161 if (fdnam) {
162 char *ep;
163
164 fd = strtol(fdnam, &ep, 10);
165
166 if (*ep != '\0') {
167 fuse_log(FUSE_LOG_ERR, "invalid value given in FUSE_DEV_FD\n");
168 return -1;
169 }
170
171 if (fd < 0)
172 return -1;
173
174 goto mount;
175 }
176
177 dev = getenv("FUSE_DEV_NAME");
178
179 if (! dev)
180 dev = (char *)FUSE_DEV_TRUNK;
181
182 if ((fd = open(dev, O_RDWR)) < 0) {
183 perror("fuse: failed to open fuse device");
184 return -1;
185 }
186
187 mount:
188 if (getenv("FUSE_NO_MOUNT") || ! mountpoint)
189 goto out;
190
191 pid = fork();
192 cpid = pid;
193
194 if (pid == -1) {
195 perror("fuse: fork() failed");
196 close(fd);
197 return -1;
198 }
199
200 if (pid == 0) {
201 if (! init_backgrounded()) {
202 /*
203 * If init is not backgrounded, we have to
204 * call the mount util backgrounded, to avoid
205 * deadlock.
206 */
207
208 pid = fork();
209
210 if (pid == -1) {
211 perror("fuse: fork() failed");
212 close(fd);
213 exit(1);
214 }
215 }
216
217 if (pid == 0) {
218 const char *argv[32];
219 int a = 0;
220 int ret = -1;
221
222 if (! fdnam)
223 {
224 ret = asprintf(&fdnam, "%d", fd);
225 if(ret == -1)
226 {
227 perror("fuse: failed to assemble mount arguments");
228 close(fd);
229 exit(1);
230 }
231 }
232
233 argv[a++] = mountprog;
234 if (opts) {
235 argv[a++] = "-o";
236 argv[a++] = opts;
237 }
238 argv[a++] = fdnam;
239 argv[a++] = mountpoint;
240 argv[a++] = NULL;
241 execvp(mountprog, (char **) argv);
242 perror("fuse: failed to exec mount program");
243 free(fdnam);
244 exit(1);
245 }
246
247 exit(0);
248 }
249
250 if (waitpid(cpid, &status, 0) == -1 || WEXITSTATUS(status) != 0) {
251 perror("fuse: failed to mount file system");
252 close(fd);
253 return -1;
254 }
255
256 out:
257 return fd;
258 }
259
260 struct mount_opts *parse_mount_opts(struct fuse_args *args)
261 {
262 struct mount_opts *mo;
263
264 mo = (struct mount_opts*) malloc(sizeof(struct mount_opts));
265 if (mo == NULL)
266 return NULL;
267
268 memset(mo, 0, sizeof(struct mount_opts));
269
270 if (args &&
271 fuse_opt_parse(args, mo, fuse_mount_opts, fuse_mount_opt_proc) == -1)
272 goto err_out;
273
274 return mo;
275
276 err_out:
277 destroy_mount_opts(mo);
278 return NULL;
279 }
280
281 void destroy_mount_opts(struct mount_opts *mo)
282 {
283 free(mo->kernel_opts);
284 free(mo);
285 }
286
287 int fuse_kern_mount(const char *mountpoint, struct mount_opts *mo)
288 {
289 /* mount util should not try to spawn the daemon */
290 setenv("MOUNT_FUSEFS_SAFE", "1", 1);
291 /* to notify the mount util it's called from lib */
292 setenv("MOUNT_FUSEFS_CALL_BY_LIB", "1", 1);
293
294 return fuse_mount_core(mountpoint, mo->kernel_opts);
295 }
fuse_opt_parse
int fuse_opt_parse(struct fuse_args *args, void *data, const struct fuse_opt opts[], fuse_opt_proc_t proc)
Definition: fuse_opt.c:398
fuse_opt_add_opt
int fuse_opt_add_opt(char **opts, const char *opt)
Definition: fuse_opt.c:139
FUSE_OPT_END
#define FUSE_OPT_END
Definition: fuse_opt.h:104
FUSE_OPT_KEY
#define FUSE_OPT_KEY(templ, key)
Definition: fuse_opt.h:98
fuse_opt
Definition: fuse_opt.h:77
fuse_args
Definition: fuse_opt.h:109
fuse_log
void fuse_log(enum fuse_log_level level, const char *fmt,...)
Definition: fuse_log.c:33