xref: /freebsd/contrib/smbfs/lib/smb/subr.c (revision f56de563)
1 /*
2  * Copyright (c) 2000, Boris Popov
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *    This product includes software developed by Boris Popov.
16  * 4. Neither the name of the author nor the names of any co-contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  * $Id: subr.c,v 1.12 2001/08/22 03:31:37 bp Exp $
33  */
34 
35 #include <sys/param.h>
36 #include <sys/types.h>
37 #include <sys/errno.h>
38 #include <sys/sysctl.h>
39 #include <sys/syscall.h>
40 #include <unistd.h>
41 #include <ctype.h>
42 #include <string.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <stdarg.h>
46 #include <err.h>
47 
48 #include <netsmb/netbios.h>
49 #include <netsmb/smb_lib.h>
50 #include <netsmb/nb_lib.h>
51 #include <cflib.h>
52 
53 #ifdef APPLE
54 #include <sysexits.h>
55 #include <sys/wait.h>
56 #include <mach/mach.h>
57 #include <mach/mach_error.h>
58 
59 uid_t real_uid, eff_uid;
60 #endif
61 
62 extern char *__progname;
63 
64 static int smblib_initialized;
65 
66 struct rcfile *smb_rc;
67 
68 int
smb_lib_init(void)69 smb_lib_init(void)
70 {
71 	int error;
72 	int kv;
73 	size_t kvlen = sizeof(kv);
74 
75 	if (smblib_initialized)
76 		return 0;
77 #if __FreeBSD_version > 400000
78 	error = sysctlbyname("net.smb.version", &kv, &kvlen, NULL, 0);
79 	if (error) {
80 		warnx("%s: can't find kernel module\n", __FUNCTION__);
81 		return error;
82 	}
83 	if (NSMB_VERSION != kv) {
84 		warnx("%s: kernel module version(%d) don't match library(%d).\n", __FUNCTION__, kv, NSMB_VERSION);
85 		return EINVAL;
86 	}
87 #endif
88 	if ((error = nls_setlocale("")) != 0) {
89 		warnx("%s: can't initialise locale\n", __FUNCTION__);
90 		return error;
91 	}
92 	smblib_initialized++;
93 	return 0;
94 }
95 
96 /*
97  * Print a (descriptive) error message
98  * error values:
99  *  	   0 - no specific error code available;
100  *  1..32767 - system error
101  */
102 void
smb_error(const char * fmt,int error,...)103 smb_error(const char *fmt, int error,...) {
104 	va_list ap;
105 	const char *cp;
106 	int errtype = error & SMB_ERRTYPE_MASK;
107 
108 	fprintf(stderr, "%s: ", __progname);
109 	va_start(ap, error);
110 	vfprintf(stderr, fmt, ap);
111 	va_end(ap);
112 	if (error == -1)
113 		error = errno;
114 	else
115 		error &= ~SMB_ERRTYPE_MASK;
116 	switch (errtype) {
117 	    case SMB_SYS_ERROR:
118 		if (error)
119 			fprintf(stderr, ": syserr = %s\n", strerror(error));
120 		else
121 			fprintf(stderr, "\n");
122 		break;
123 	    case SMB_RAP_ERROR:
124 		fprintf(stderr, ": raperr = %d (0x%04x)\n", error, error);
125 		break;
126 	    case SMB_NB_ERROR:
127 		cp = nb_strerror(error);
128 		if (cp == NULL)
129 			fprintf(stderr, ": nberr = unknown (0x%04x)\n", error);
130 		else
131 			fprintf(stderr, ": nberr = %s\n", cp);
132 		break;
133 	    default:
134 		fprintf(stderr, "\n");
135 	}
136 }
137 
138 char *
smb_printb(char * dest,int flags,const struct smb_bitname * bnp)139 smb_printb(char *dest, int flags, const struct smb_bitname *bnp) {
140 	int first = 1;
141 
142 	strcpy(dest, "<");
143 	for(; bnp->bn_bit; bnp++) {
144 		if (flags & bnp->bn_bit) {
145 			strcat(dest, bnp->bn_name);
146 			first = 0;
147 		}
148 		if (!first && (flags & bnp[1].bn_bit))
149 			strcat(dest, "|");
150 	}
151 	strcat(dest, ">");
152 	return dest;
153 }
154 
155 /*
156  * first read ~/.smbrc, next try to merge SMB_CFG_FILE
157  */
158 int
smb_open_rcfile(void)159 smb_open_rcfile(void)
160 {
161 	char *home, *fn;
162 	int error;
163 
164 	home = getenv("HOME");
165 	if (home) {
166 		fn = malloc(strlen(home) + 20);
167 		sprintf(fn, "%s/.nsmbrc", home);
168 		error = rc_open(fn, "r", &smb_rc);
169 		free(fn);
170 	}
171 	error = rc_merge(SMB_CFG_FILE, &smb_rc);
172 	if (smb_rc == NULL) {
173 		printf("Warning: no cfg file(s) found.\n");
174 		return ENOENT;
175 	}
176 	return 0;
177 }
178 
179 void *
smb_dumptree(void)180 smb_dumptree(void)
181 {
182 	size_t len;
183 	void *p;
184 	int error;
185 
186 #ifdef APPLE
187 	seteuid(eff_uid); /* restore setuid root briefly */
188 #endif
189 	error = sysctlbyname("net.smb.treedump", NULL, &len, NULL, 0);
190 #ifdef APPLE
191 	seteuid(real_uid); /* and back to real user */
192 #endif
193 	if (error)
194 		return NULL;
195 	p = malloc(len);
196 	if (p == NULL)
197 		return NULL;
198 #ifdef APPLE
199 	seteuid(eff_uid); /* restore setuid root briefly */
200 #endif
201 	error = sysctlbyname("net.smb.treedump", p, &len, NULL, 0);
202 #ifdef APPLE
203 	seteuid(real_uid); /* and back to real user */
204 #endif
205 	if (error) {
206 		free(p);
207 		return NULL;
208 	}
209 	return p;
210 }
211 
212 char *
smb_simplecrypt(char * dst,const char * src)213 smb_simplecrypt(char *dst, const char *src)
214 {
215 	int ch, pos;
216 	char *dp;
217 
218 	if (dst == NULL) {
219 		dst = malloc(4 + 2 * strlen(src));
220 		if (dst == NULL)
221 			return NULL;
222 	}
223 	dp = dst;
224 	*dst++ = '$';
225 	*dst++ = '$';
226 	*dst++ = '1';
227 	pos = 27;
228 	while (*src) {
229 		ch = *src++;
230 		if (isascii(ch))
231 		    ch = (isupper(ch) ? ('A' + (ch - 'A' + 13) % 26) :
232 			  islower(ch) ? ('a' + (ch - 'a' + 13) % 26) : ch);
233 		ch ^= pos;
234 		pos += 13;
235 		if (pos > 256)
236 			pos -= 256;
237 		sprintf(dst, "%02x", ch);
238 		dst += 2;
239 	}
240 	*dst = 0;
241 	return dp;
242 }
243 
244 int
smb_simpledecrypt(char * dst,const char * src)245 smb_simpledecrypt(char *dst, const char *src)
246 {
247 	char *ep, hexval[3];
248 	int len, ch, pos;
249 
250 	if (strncmp(src, "$$1", 3) != 0)
251 		return EINVAL;
252 	src += 3;
253 	len = strlen(src);
254 	if (len & 1)
255 		return EINVAL;
256 	len /= 2;
257 	hexval[2] = 0;
258 	pos = 27;
259 	while (len--) {
260 		hexval[0] = *src++;
261 		hexval[1] = *src++;
262 		ch = strtoul(hexval, &ep, 16);
263 		if (*ep != 0)
264 			return EINVAL;
265 		ch ^= pos;
266 		pos += 13;
267 		if (pos > 256)
268 			pos -= 256;
269 		if (isascii(ch))
270 		    ch = (isupper(ch) ? ('A' + (ch - 'A' + 13) % 26) :
271 			  islower(ch) ? ('a' + (ch - 'a' + 13) % 26) : ch);
272 		*dst++ = ch;
273 	}
274 	*dst = 0;
275 	return 0;
276 }
277 
278 
279 #ifdef APPLE
280 static int
safe_execv(char * args[])281 safe_execv(char *args[])
282 {
283 	int	     pid;
284 	union wait      status;
285 
286 	pid = fork();
287 	if (pid == 0) {
288 		(void)execv(args[0], args);
289 		errx(EX_OSERR, "%s: execv %s failed, %s\n", __progname,
290 		     args[0], strerror(errno));
291 	}
292 	if (pid == -1) {
293 		fprintf(stderr, "%s: fork failed, %s\n", __progname,
294 			strerror(errno));
295 		return (1);
296 	}
297 	if (wait4(pid, (int *)&status, 0, NULL) != pid) {
298 		fprintf(stderr, "%s: BUG executing %s command\n", __progname,
299 			args[0]);
300 		return (1);
301 	} else if (!WIFEXITED(status)) {
302 		fprintf(stderr, "%s: %s command aborted by signal %d\n",
303 			__progname, args[0], WTERMSIG(status));
304 		return (1);
305 	} else if (WEXITSTATUS(status)) {
306 		fprintf(stderr, "%s: %s command failed, exit status %d: %s\n",
307 			__progname, args[0], WEXITSTATUS(status),
308 			strerror(WEXITSTATUS(status)));
309 		return (1);
310 	}
311 	return (0);
312 }
313 
314 
315 void
dropsuid()316 dropsuid()
317 {
318 	/* drop setuid root privs asap */
319 	eff_uid = geteuid();
320 	real_uid = getuid();
321 	seteuid(real_uid);
322 	return;
323 }
324 
325 
326 static int
kextisloaded(char * kextname)327 kextisloaded(char * kextname)
328 {
329 	mach_port_t kernel_port;
330 	kmod_info_t *k, *loaded_modules = 0;
331 	int err, loaded_count = 0;
332 
333 	/* on error return not loaded - to make loadsmbvfs fail */
334 
335 	err = task_for_pid(mach_task_self(), 0, &kernel_port);
336 	if (err) {
337 		fprintf(stderr, "%s: %s: %s\n", __progname,
338 			"unable to get kernel task port",
339 			mach_error_string(err));
340 		return (0);
341 	}
342 	err = kmod_get_info(kernel_port, (void *)&loaded_modules,
343 			    &loaded_count); /* never freed */
344 	if (err) {
345 		fprintf(stderr, "%s: %s: %s\n", __progname,
346 			"kmod_get_info() failed",
347 			mach_error_string(err));
348 		return (0);
349 	}
350 	for (k = loaded_modules; k; k = k->next ? k+1 : 0)
351 		if (!strcmp(k->name, kextname))
352 			return (1);
353 	return (0);
354 }
355 
356 
357 #define KEXTLOAD_COMMAND	"/sbin/kextload"
358 #define FS_KEXT_DIR		"/System/Library/Extensions/smbfs.kext"
359 #define FULL_KEXTNAME		"com.apple.filesystems.smbfs"
360 
361 
362 int
loadsmbvfs()363 loadsmbvfs()
364 {
365 	const char *kextargs[] = {KEXTLOAD_COMMAND, FS_KEXT_DIR, NULL};
366 	int error = 0;
367 
368 	/*
369 	 * temporarily revert to root (required for kextload)
370 	 */
371 	seteuid(eff_uid);
372 	if (!kextisloaded(FULL_KEXTNAME)) {
373 		error = safe_execv(kextargs);
374 		if (!error)
375 			error = !kextisloaded(FULL_KEXTNAME);
376 	}
377 	seteuid(real_uid); /* and back to real user */
378 	return (error);
379 }
380 #endif /* APPLE */
381