xref: /freebsd/crypto/heimdal/lib/kafs/afssys.c (revision 17d6c636720d00f77e5d098daf4c278f89d84f7b)
1 /*
2  * Copyright (c) 1995 - 200 Kungliga Tekniska H�gskolan
3  * (Royal Institute of Technology, Stockholm, Sweden).
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  *
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * 3. Neither the name of the Institute nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include "kafs_locl.h"
35 
36 RCSID("$Id: afssys.c,v 1.67 2000/07/08 12:06:03 assar Exp $");
37 
38 int _kafs_debug; /* this should be done in a better way */
39 
40 #define NO_ENTRY_POINT		0
41 #define SINGLE_ENTRY_POINT	1
42 #define MULTIPLE_ENTRY_POINT	2
43 #define SINGLE_ENTRY_POINT2	3
44 #define SINGLE_ENTRY_POINT3	4
45 #define AIX_ENTRY_POINTS	5
46 #define UNKNOWN_ENTRY_POINT	6
47 static int afs_entry_point = UNKNOWN_ENTRY_POINT;
48 static int afs_syscalls[2];
49 
50 /* Magic to get AIX syscalls to work */
51 #ifdef _AIX
52 
53 static int (*Pioctl)(char*, int, struct ViceIoctl*, int);
54 static int (*Setpag)(void);
55 
56 #include "dlfcn.h"
57 
58 /*
59  *
60  */
61 
62 static int
63 try_aix(void)
64 {
65 #ifdef STATIC_AFS_SYSCALLS
66     Pioctl = aix_pioctl;
67     Setpag = aix_setpag;
68 #else
69     void *ptr;
70     char path[MaxPathLen], *p;
71     /*
72      * If we are root or running setuid don't trust AFSLIBPATH!
73      */
74     if (getuid() != 0 && !issuid() && (p = getenv("AFSLIBPATH")) != NULL)
75 	strlcpy(path, p, sizeof(path));
76     else
77 	snprintf(path, sizeof(path), "%s/afslib.so", LIBDIR);
78 
79     ptr = dlopen(path, RTLD_NOW);
80     if(ptr == NULL) {
81 	if(_kafs_debug) {
82 	    if(errno == ENOEXEC && (p = dlerror()) != NULL)
83 		fprintf(stderr, "dlopen(%s): %s\n", path, p);
84 	    else if (errno != ENOENT)
85 		fprintf(stderr, "dlopen(%s): %s\n", path, strerror(errno));
86 	}
87 	return 1;
88     }
89     Setpag = (int (*)(void))dlsym(ptr, "aix_setpag");
90     Pioctl = (int (*)(char*, int,
91 		      struct ViceIoctl*, int))dlsym(ptr, "aix_pioctl");
92 #endif
93     afs_entry_point = AIX_ENTRY_POINTS;
94     return 0;
95 }
96 #endif /* _AIX */
97 
98 /*
99  * This probably only works under Solaris and could get confused if
100  * there's a /etc/name_to_sysnum file.
101  */
102 
103 #define _PATH_ETC_NAME_TO_SYSNUM "/etc/name_to_sysnum"
104 
105 static int
106 map_syscall_name_to_number (const char *str, int *res)
107 {
108     FILE *f;
109     char buf[256];
110     size_t str_len = strlen (str);
111 
112     f = fopen (_PATH_ETC_NAME_TO_SYSNUM, "r");
113     if (f == NULL)
114 	return -1;
115     while (fgets (buf, sizeof(buf), f) != NULL) {
116 	if (buf[0] == '#')
117 	    continue;
118 
119 	if (strncmp (str, buf, str_len) == 0) {
120 	    char *begptr = buf + str_len;
121 	    char *endptr;
122 	    long val = strtol (begptr, &endptr, 0);
123 
124 	    if (val != 0 && endptr != begptr) {
125 		fclose (f);
126 		*res = val;
127 		return 0;
128 	    }
129 	}
130     }
131     fclose (f);
132     return -1;
133 }
134 
135 int
136 k_pioctl(char *a_path,
137 	 int o_opcode,
138 	 struct ViceIoctl *a_paramsP,
139 	 int a_followSymlinks)
140 {
141 #ifndef NO_AFS
142     switch(afs_entry_point){
143 #if defined(AFS_SYSCALL) || defined(AFS_SYSCALL2) || defined(AFS_SYSCALL3)
144     case SINGLE_ENTRY_POINT:
145     case SINGLE_ENTRY_POINT2:
146     case SINGLE_ENTRY_POINT3:
147 	return syscall(afs_syscalls[0], AFSCALL_PIOCTL,
148 		       a_path, o_opcode, a_paramsP, a_followSymlinks);
149 #endif
150 #if defined(AFS_PIOCTL)
151     case MULTIPLE_ENTRY_POINT:
152 	return syscall(afs_syscalls[0],
153 		       a_path, o_opcode, a_paramsP, a_followSymlinks);
154 #endif
155 #ifdef _AIX
156     case AIX_ENTRY_POINTS:
157 	return Pioctl(a_path, o_opcode, a_paramsP, a_followSymlinks);
158 #endif
159     }
160 
161     errno = ENOSYS;
162 #ifdef SIGSYS
163     kill(getpid(), SIGSYS);	/* You loose! */
164 #endif
165 #endif /* NO_AFS */
166     return -1;
167 }
168 
169 int
170 k_afs_cell_of_file(const char *path, char *cell, int len)
171 {
172     struct ViceIoctl parms;
173     parms.in = NULL;
174     parms.in_size = 0;
175     parms.out = cell;
176     parms.out_size = len;
177     return k_pioctl((char*)path, VIOC_FILE_CELL_NAME, &parms, 1);
178 }
179 
180 int
181 k_unlog(void)
182 {
183     struct ViceIoctl parms;
184     memset(&parms, 0, sizeof(parms));
185     return k_pioctl(0, VIOCUNLOG, &parms, 0);
186 }
187 
188 int
189 k_setpag(void)
190 {
191 #ifndef NO_AFS
192     switch(afs_entry_point){
193 #if defined(AFS_SYSCALL) || defined(AFS_SYSCALL2) || defined(AFS_SYSCALL3)
194     case SINGLE_ENTRY_POINT:
195     case SINGLE_ENTRY_POINT2:
196     case SINGLE_ENTRY_POINT3:
197 	return syscall(afs_syscalls[0], AFSCALL_SETPAG);
198 #endif
199 #if defined(AFS_PIOCTL)
200     case MULTIPLE_ENTRY_POINT:
201 	return syscall(afs_syscalls[1]);
202 #endif
203 #ifdef _AIX
204     case AIX_ENTRY_POINTS:
205 	return Setpag();
206 #endif
207     }
208 
209     errno = ENOSYS;
210 #ifdef SIGSYS
211     kill(getpid(), SIGSYS);	/* You loose! */
212 #endif
213 #endif /* NO_AFS */
214     return -1;
215 }
216 
217 static jmp_buf catch_SIGSYS;
218 
219 #ifdef SIGSYS
220 
221 static RETSIGTYPE
222 SIGSYS_handler(int sig)
223 {
224     errno = 0;
225     signal(SIGSYS, SIGSYS_handler); /* Need to reinstall handler on SYSV */
226     longjmp(catch_SIGSYS, 1);
227 }
228 
229 #endif
230 
231 /*
232  * Try to see if `syscall' is a pioctl.  Return 0 iff succesful.
233  */
234 
235 #if defined(AFS_SYSCALL) || defined(AFS_SYSCALL2) || defined(AFS_SYSCALL3)
236 static int
237 try_one (int syscall_num)
238 {
239     struct ViceIoctl parms;
240     memset(&parms, 0, sizeof(parms));
241 
242     if (setjmp(catch_SIGSYS) == 0) {
243 	syscall(syscall_num, AFSCALL_PIOCTL,
244 		0, VIOCSETTOK, &parms, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
245 	if (errno == EINVAL) {
246 	    afs_entry_point = SINGLE_ENTRY_POINT;
247 	    afs_syscalls[0] = syscall_num;
248 	    return 0;
249 	}
250     }
251     return 1;
252 }
253 #endif
254 
255 /*
256  * Try to see if `syscall_pioctl' is a pioctl syscall.  Return 0 iff
257  * succesful.
258  *
259  */
260 
261 #ifdef AFS_PIOCTL
262 static int
263 try_two (int syscall_pioctl, int syscall_setpag)
264 {
265     struct ViceIoctl parms;
266     memset(&parms, 0, sizeof(parms));
267 
268     if (setjmp(catch_SIGSYS) == 0) {
269 	syscall(syscall_pioctl,
270 		0, VIOCSETTOK, &parms, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
271 	if (errno == EINVAL) {
272 	    afs_entry_point = MULTIPLE_ENTRY_POINT;
273 	    afs_syscalls[0] = syscall_pioctl;
274 	    afs_syscalls[1] = syscall_setpag;
275 	    return 0;
276 	}
277     }
278     return 1;
279 }
280 #endif
281 
282 int
283 k_hasafs(void)
284 {
285 #if !defined(NO_AFS) && defined(SIGSYS)
286     RETSIGTYPE (*saved_func)(int);
287 #endif
288     int saved_errno;
289     char *env = getenv ("AFS_SYSCALL");
290 
291     /*
292      * Already checked presence of AFS syscalls?
293      */
294     if (afs_entry_point != UNKNOWN_ENTRY_POINT)
295 	return afs_entry_point != NO_ENTRY_POINT;
296 
297     /*
298      * Probe kernel for AFS specific syscalls,
299      * they (currently) come in two flavors.
300      * If the syscall is absent we recive a SIGSYS.
301      */
302     afs_entry_point = NO_ENTRY_POINT;
303 
304     saved_errno = errno;
305 #ifndef NO_AFS
306 #ifdef SIGSYS
307     saved_func = signal(SIGSYS, SIGSYS_handler);
308 #endif
309 
310 #if defined(AFS_SYSCALL) || defined(AFS_SYSCALL2) || defined(AFS_SYSCALL3)
311     {
312 	int tmp;
313 
314 	if (env != NULL) {
315 	    if (sscanf (env, "%d", &tmp) == 1) {
316 		if (try_one (tmp) == 0)
317 		    goto done;
318 	    } else {
319 		char *end = NULL;
320 		char *p;
321 		char *s = strdup (env);
322 
323 		if (s != NULL) {
324 		    for (p = strtok_r (s, ",", &end);
325 			 p != NULL;
326 			 p = strtok_r (NULL, ",", &end)) {
327 			if (map_syscall_name_to_number (p, &tmp) == 0)
328 			    if (try_one (tmp) == 0) {
329 				free (s);
330 				goto done;
331 			    }
332 		    }
333 		    free (s);
334 		}
335 	    }
336 	}
337     }
338 #endif /* AFS_SYSCALL || AFS_SYSCALL2 || AFS_SYSCALL3 */
339 
340 #ifdef AFS_SYSCALL
341     if (try_one (AFS_SYSCALL) == 0)
342 	goto done;
343 #endif /* AFS_SYSCALL */
344 
345 #ifdef AFS_PIOCTL
346     {
347 	int tmp[2];
348 
349 	if (env != NULL && sscanf (env, "%d%d", &tmp[0], &tmp[1]) == 2)
350 	    if (try_two (tmp[0], tmp[1]) == 2)
351 		goto done;
352     }
353 #endif /* AFS_PIOCTL */
354 
355 #ifdef AFS_PIOCTL
356     if (try_two (AFS_PIOCTL, AFS_SETPAG) == 0)
357 	goto done;
358 #endif /* AFS_PIOCTL */
359 
360 #ifdef AFS_SYSCALL2
361     if (try_one (AFS_SYSCALL2) == 0)
362 	goto done;
363 #endif /* AFS_SYSCALL2 */
364 
365 #ifdef AFS_SYSCALL3
366     if (try_one (AFS_SYSCALL3) == 0)
367 	goto done;
368 #endif /* AFS_SYSCALL3 */
369 
370 #ifdef _AIX
371 #if 0
372     if (env != NULL) {
373 	char *pos = NULL;
374 	char *pioctl_name;
375 	char *setpag_name;
376 
377 	pioctl_name = strtok_r (env, ", \t", &pos);
378 	if (pioctl_name != NULL) {
379 	    setpag_name = strtok_r (NULL, ", \t", &pos);
380 	    if (setpag_name != NULL)
381 		if (try_aix (pioctl_name, setpag_name) == 0)
382 		    goto done;
383 	}
384     }
385 #endif
386 
387     if(try_aix() == 0)
388 	goto done;
389 #endif
390 
391 done:
392 #ifdef SIGSYS
393     signal(SIGSYS, saved_func);
394 #endif
395 #endif /* NO_AFS */
396     errno = saved_errno;
397     return afs_entry_point != NO_ENTRY_POINT;
398 }
399