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DEFINITIONS
This source file includes following definitions.
- help
- parse_args
- fullpath
- mount_ok
- do_mount
- main
1 /*
2 * smbmnt.c
3 *
4 * Copyright (C) 1995-1998 by Paal-Kr. Engstad and Volker Lendecke
5 * extensively modified by Tridge
6 *
7 */
8
9 #include "includes.h"
10
11 #include <mntent.h>
12 #include <sys/utsname.h>
13
14 #include <asm/types.h>
15 #include <asm/posix_types.h>
16 #include <linux/smb.h>
17 #include <linux/smb_mount.h>
18 #include <asm/unistd.h>
19
20 #ifndef MS_MGC_VAL
21 /* This may look strange but MS_MGC_VAL is what we are looking for and
22 is what we need from <linux/fs.h> under libc systems and is
23 provided in standard includes on glibc systems. So... We
24 switch on what we need... */
25 #include <linux/fs.h>
26 #endif
27
28 static uid_t mount_uid;
29 static gid_t mount_gid;
30 static int mount_ro;
31 static uint_t mount_fmask;
32 static uint_t mount_dmask;
33 static int user_mount;
34 static char *options;
35
36 static void
37 help(void)
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38 {
39 printf("\n");
40 printf("Usage: smbmnt mount-point [options]\n");
41 printf("Version %s\n\n",VERSION);
42 printf("-s share share name on server\n"
43 "-r mount read-only\n"
44 "-u uid mount as uid\n"
45 "-g gid mount as gid\n"
46 "-f mask permission mask for files\n"
47 "-d mask permission mask for directories\n"
48 "-o options name=value, list of options\n"
49 "-h print this help text\n");
50 }
51
52 static int
53 parse_args(int argc, char *argv[], struct smb_mount_data *data, char **share)
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54 {
55 int opt;
56
57 while ((opt = getopt (argc, argv, "s:u:g:rf:d:o:")) != EOF)
58 {
59 switch (opt)
60 {
61 case 's':
62 *share = optarg;
63 break;
64 case 'u':
65 if (!user_mount) {
66 mount_uid = strtol(optarg, NULL, 0);
67 }
68 break;
69 case 'g':
70 if (!user_mount) {
71 mount_gid = strtol(optarg, NULL, 0);
72 }
73 break;
74 case 'r':
75 mount_ro = 1;
76 break;
77 case 'f':
78 mount_fmask = strtol(optarg, NULL, 8);
79 break;
80 case 'd':
81 mount_dmask = strtol(optarg, NULL, 8);
82 break;
83 case 'o':
84 options = optarg;
85 break;
86 default:
87 return -1;
88 }
89 }
90 return 0;
91
92 }
93
94 static char *
95 fullpath(const char *p)
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96 {
97 char path[MAXPATHLEN];
98
99 if (strlen(p) > MAXPATHLEN-1) {
100 return NULL;
101 }
102
103 if (realpath(p, path) == NULL) {
104 fprintf(stderr,"Failed to find real path for mount point\n");
105 exit(1);
106 }
107 return strdup(path);
108 }
109
110 /* Check whether user is allowed to mount on the specified mount point. If it's
111 OK then we change into that directory - this prevents race conditions */
112 static int mount_ok(char *mount_point)
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113 {
114 struct stat st;
115
116 if (chdir(mount_point) != 0) {
117 return -1;
118 }
119
120 if (stat(".", &st) != 0) {
121 return -1;
122 }
123
124 if (!S_ISDIR(st.st_mode)) {
125 errno = ENOTDIR;
126 return -1;
127 }
128
129 if ((getuid() != 0) &&
130 ((getuid() != st.st_uid) ||
131 ((st.st_mode & S_IRWXU) != S_IRWXU))) {
132 errno = EPERM;
133 return -1;
134 }
135
136 return 0;
137 }
138
139 /* Tries to mount using the appropriate format. For 2.2 the struct,
140 for 2.4 the ascii version. */
141 static int
142 do_mount(char *share_name, uint_t flags, struct smb_mount_data *data)
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143 {
144 pstring opts;
145 struct utsname uts;
146 char *release, *major, *minor;
147 char *data1, *data2;
148
149 uname(&uts);
150 release = uts.release;
151 major = strtok(release, ".");
152 minor = strtok(NULL, ".");
153 if (major && minor && atoi(major) == 2 && atoi(minor) < 4) {
154 /* < 2.4, assume struct */
155 data1 = (char *) data;
156 data2 = opts;
157 } else {
158 /* >= 2.4, assume ascii but fall back on struct */
159 data1 = opts;
160 data2 = (char *) data;
161 }
162
163 slprintf(opts, sizeof(opts)-1,
164 "version=7,uid=%d,gid=%d,file_mode=0%o,dir_mode=0%o,%s",
165 data->uid, data->gid, data->file_mode, data->dir_mode,options);
166 if (mount(share_name, ".", "smbfs", flags, data1) == 0)
167 return 0;
168 return mount(share_name, ".", "smbfs", flags, data2);
169 }
170
171 int main(int argc, char *argv[])
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172 {
173 char *mount_point, *share_name = NULL;
174 FILE *mtab;
175 int fd;
176 uint_t flags;
177 struct smb_mount_data data;
178 struct mntent ment;
179
180 memset(&data, 0, sizeof(struct smb_mount_data));
181
182 if (argc < 2) {
183 help();
184 exit(1);
185 }
186
187 if (argv[1][0] == '-') {
188 help();
189 exit(1);
190 }
191
192 if (getuid() != 0) {
193 user_mount = 1;
194 }
195
196 if (geteuid() != 0) {
197 fprintf(stderr, "smbmnt must be installed suid root for direct user mounts (%d,%d)\n", getuid(), geteuid());
198 exit(1);
199 }
200
201 mount_uid = getuid();
202 mount_gid = getgid();
203 mount_fmask = umask(0);
204 umask(mount_fmask);
205 mount_fmask = ~mount_fmask;
206
207 mount_point = fullpath(argv[1]);
208
209 argv += 1;
210 argc -= 1;
211
212 if (mount_ok(mount_point) != 0) {
213 fprintf(stderr, "cannot mount on %s: %s\n",
214 mount_point, strerror(errno));
215 exit(1);
216 }
217
218 data.version = SMB_MOUNT_VERSION;
219
220 /* getuid() gives us the real uid, who may umount the fs */
221 data.mounted_uid = getuid();
222
223 if (parse_args(argc, argv, &data, &share_name) != 0) {
224 help();
225 return -1;
226 }
227
228 data.uid = mount_uid;
229 data.gid = mount_gid;
230 data.file_mode = (S_IRWXU|S_IRWXG|S_IRWXO) & mount_fmask;
231 data.dir_mode = (S_IRWXU|S_IRWXG|S_IRWXO) & mount_dmask;
232
233 if (mount_dmask == 0) {
234 data.dir_mode = data.file_mode;
235 if ((data.dir_mode & S_IRUSR) != 0)
236 data.dir_mode |= S_IXUSR;
237 if ((data.dir_mode & S_IRGRP) != 0)
238 data.dir_mode |= S_IXGRP;
239 if ((data.dir_mode & S_IROTH) != 0)
240 data.dir_mode |= S_IXOTH;
241 }
242
243 flags = MS_MGC_VAL;
244
245 if (mount_ro) flags |= MS_RDONLY;
246
247 if (do_mount(share_name, flags, &data) < 0) {
248 switch (errno) {
249 case ENODEV:
250 fprintf(stderr, "ERROR: smbfs filesystem not supported by the kernel\n");
251 break;
252 default:
253 perror("mount error");
254 }
255 fprintf(stderr, "Please refer to the smbmnt(8) manual page\n");
256 return -1;
257 }
258
259 ment.mnt_fsname = share_name ? share_name : "none";
260 ment.mnt_dir = mount_point;
261 ment.mnt_type = "smbfs";
262 ment.mnt_opts = "";
263 ment.mnt_freq = 0;
264 ment.mnt_passno= 0;
265
266 mount_point = ment.mnt_dir;
267
268 if (mount_point == NULL)
269 {
270 fprintf(stderr, "Mount point too long\n");
271 return -1;
272 }
273
274 if ((fd = open(MOUNTED"~", O_RDWR|O_CREAT|O_EXCL, 0600)) == -1)
275 {
276 fprintf(stderr, "Can't get "MOUNTED"~ lock file");
277 return 1;
278 }
279 close(fd);
280
281 if ((mtab = setmntent(MOUNTED, "a+")) == NULL)
282 {
283 fprintf(stderr, "Can't open " MOUNTED);
284 return 1;
285 }
286
287 if (addmntent(mtab, &ment) == 1)
288 {
289 fprintf(stderr, "Can't write mount entry");
290 return 1;
291 }
292 if (fchmod(fileno(mtab), 0644) == -1)
293 {
294 fprintf(stderr, "Can't set perms on "MOUNTED);
295 return 1;
296 }
297 endmntent(mtab);
298
299 if (unlink(MOUNTED"~") == -1)
300 {
301 fprintf(stderr, "Can't remove "MOUNTED"~");
302 return 1;
303 }
304
305 return 0;
306 }