xref: /freebsd/crypto/heimdal/lib/kafs/afssys.c (revision daf1cffce2e07931f27c6c6998652e90df6ba87e)
1 /*
2  * Copyright (c) 1995, 1996, 1997, 1998, 1999 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 1.65 1999/12/02 16:58:40 joda 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 (strncmp (str, buf, str_len) == 0) {
117 	    char *begptr = buf + str_len;
118 	    char *endptr;
119 	    long val = strtol (begptr, &endptr, 0);
120 
121 	    if (val != 0 && endptr != begptr) {
122 		fclose (f);
123 		*res = val;
124 		return 0;
125 	    }
126 	}
127     }
128     fclose (f);
129     return -1;
130 }
131 
132 int
133 k_pioctl(char *a_path,
134 	 int o_opcode,
135 	 struct ViceIoctl *a_paramsP,
136 	 int a_followSymlinks)
137 {
138 #ifndef NO_AFS
139     switch(afs_entry_point){
140 #if defined(AFS_SYSCALL) || defined(AFS_SYSCALL2) || defined(AFS_SYSCALL3)
141     case SINGLE_ENTRY_POINT:
142     case SINGLE_ENTRY_POINT2:
143     case SINGLE_ENTRY_POINT3:
144 	return syscall(afs_syscalls[0], AFSCALL_PIOCTL,
145 		       a_path, o_opcode, a_paramsP, a_followSymlinks);
146 #endif
147 #if defined(AFS_PIOCTL)
148     case MULTIPLE_ENTRY_POINT:
149 	return syscall(afs_syscalls[0],
150 		       a_path, o_opcode, a_paramsP, a_followSymlinks);
151 #endif
152 #ifdef _AIX
153     case AIX_ENTRY_POINTS:
154 	return Pioctl(a_path, o_opcode, a_paramsP, a_followSymlinks);
155 #endif
156     }
157 
158     errno = ENOSYS;
159 #ifdef SIGSYS
160     kill(getpid(), SIGSYS);	/* You loose! */
161 #endif
162 #endif /* NO_AFS */
163     return -1;
164 }
165 
166 int
167 k_afs_cell_of_file(const char *path, char *cell, int len)
168 {
169     struct ViceIoctl parms;
170     parms.in = NULL;
171     parms.in_size = 0;
172     parms.out = cell;
173     parms.out_size = len;
174     return k_pioctl((char*)path, VIOC_FILE_CELL_NAME, &parms, 1);
175 }
176 
177 int
178 k_unlog(void)
179 {
180     struct ViceIoctl parms;
181     memset(&parms, 0, sizeof(parms));
182     return k_pioctl(0, VIOCUNLOG, &parms, 0);
183 }
184 
185 int
186 k_setpag(void)
187 {
188 #ifndef NO_AFS
189     switch(afs_entry_point){
190 #if defined(AFS_SYSCALL) || defined(AFS_SYSCALL2) || defined(AFS_SYSCALL3)
191     case SINGLE_ENTRY_POINT:
192     case SINGLE_ENTRY_POINT2:
193     case SINGLE_ENTRY_POINT3:
194 	return syscall(afs_syscalls[0], AFSCALL_SETPAG);
195 #endif
196 #if defined(AFS_PIOCTL)
197     case MULTIPLE_ENTRY_POINT:
198 	return syscall(afs_syscalls[1]);
199 #endif
200 #ifdef _AIX
201     case AIX_ENTRY_POINTS:
202 	return Setpag();
203 #endif
204     }
205 
206     errno = ENOSYS;
207 #ifdef SIGSYS
208     kill(getpid(), SIGSYS);	/* You loose! */
209 #endif
210 #endif /* NO_AFS */
211     return -1;
212 }
213 
214 static jmp_buf catch_SIGSYS;
215 
216 #ifdef SIGSYS
217 
218 static RETSIGTYPE
219 SIGSYS_handler(int sig)
220 {
221     errno = 0;
222     signal(SIGSYS, SIGSYS_handler); /* Need to reinstall handler on SYSV */
223     longjmp(catch_SIGSYS, 1);
224 }
225 
226 #endif
227 
228 /*
229  * Try to see if `syscall' is a pioctl.  Return 0 iff succesful.
230  */
231 
232 #if defined(AFS_SYSCALL) || defined(AFS_SYSCALL2) || defined(AFS_SYSCALL3)
233 static int
234 try_one (int syscall_num)
235 {
236     struct ViceIoctl parms;
237     memset(&parms, 0, sizeof(parms));
238 
239     if (setjmp(catch_SIGSYS) == 0) {
240 	syscall(syscall_num, AFSCALL_PIOCTL,
241 		0, VIOCSETTOK, &parms, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
242 	if (errno == EINVAL) {
243 	    afs_entry_point = SINGLE_ENTRY_POINT;
244 	    afs_syscalls[0] = syscall_num;
245 	    return 0;
246 	}
247     }
248     return 1;
249 }
250 #endif
251 
252 /*
253  * Try to see if `syscall_pioctl' is a pioctl syscall.  Return 0 iff
254  * succesful.
255  *
256  */
257 
258 #ifdef AFS_PIOCTL
259 static int
260 try_two (int syscall_pioctl, int syscall_setpag)
261 {
262     struct ViceIoctl parms;
263     memset(&parms, 0, sizeof(parms));
264 
265     if (setjmp(catch_SIGSYS) == 0) {
266 	syscall(syscall_pioctl,
267 		0, VIOCSETTOK, &parms, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
268 	if (errno == EINVAL) {
269 	    afs_entry_point = MULTIPLE_ENTRY_POINT;
270 	    afs_syscalls[0] = syscall_pioctl;
271 	    afs_syscalls[1] = syscall_setpag;
272 	    return 0;
273 	}
274     }
275     return 1;
276 }
277 #endif
278 
279 int
280 k_hasafs(void)
281 {
282 #if !defined(NO_AFS) && defined(SIGSYS)
283     RETSIGTYPE (*saved_func)();
284 #endif
285     int saved_errno;
286     char *env = getenv ("AFS_SYSCALL");
287 
288     /*
289      * Already checked presence of AFS syscalls?
290      */
291     if (afs_entry_point != UNKNOWN_ENTRY_POINT)
292 	return afs_entry_point != NO_ENTRY_POINT;
293 
294     /*
295      * Probe kernel for AFS specific syscalls,
296      * they (currently) come in two flavors.
297      * If the syscall is absent we recive a SIGSYS.
298      */
299     afs_entry_point = NO_ENTRY_POINT;
300 
301     saved_errno = errno;
302 #ifndef NO_AFS
303 #ifdef SIGSYS
304     saved_func = signal(SIGSYS, SIGSYS_handler);
305 #endif
306 
307 #if defined(AFS_SYSCALL) || defined(AFS_SYSCALL2) || defined(AFS_SYSCALL3)
308     {
309 	int tmp;
310 
311 	if (env != NULL) {
312 	    if (sscanf (env, "%d", &tmp) == 1) {
313 		if (try_one (tmp) == 0)
314 		    goto done;
315 	    } else {
316 		char *end = NULL;
317 		char *p;
318 		char *s = strdup (env);
319 
320 		if (s != NULL) {
321 		    for (p = strtok_r (s, ",", &end);
322 			 p != NULL;
323 			 p = strtok_r (NULL, ",", &end)) {
324 			if (map_syscall_name_to_number (p, &tmp) == 0)
325 			    if (try_one (tmp) == 0) {
326 				free (s);
327 				goto done;
328 			    }
329 		    }
330 		    free (s);
331 		}
332 	    }
333 	}
334     }
335 #endif /* AFS_SYSCALL || AFS_SYSCALL2 || AFS_SYSCALL3 */
336 
337 #ifdef AFS_SYSCALL
338     if (try_one (AFS_SYSCALL) == 0)
339 	goto done;
340 #endif /* AFS_SYSCALL */
341 
342 #ifdef AFS_PIOCTL
343     {
344 	int tmp[2];
345 
346 	if (env != NULL && sscanf (env, "%d%d", &tmp[0], &tmp[1]) == 2)
347 	    if (try_two (tmp[0], tmp[1]) == 2)
348 		goto done;
349     }
350 #endif /* AFS_PIOCTL */
351 
352 #ifdef AFS_PIOCTL
353     if (try_two (AFS_PIOCTL, AFS_SETPAG) == 0)
354 	goto done;
355 #endif /* AFS_PIOCTL */
356 
357 #ifdef AFS_SYSCALL2
358     if (try_one (AFS_SYSCALL2) == 0)
359 	goto done;
360 #endif /* AFS_SYSCALL2 */
361 
362 #ifdef AFS_SYSCALL3
363     if (try_one (AFS_SYSCALL3) == 0)
364 	goto done;
365 #endif /* AFS_SYSCALL3 */
366 
367 #ifdef _AIX
368 #if 0
369     if (env != NULL) {
370 	char *pos = NULL;
371 	char *pioctl_name;
372 	char *setpag_name;
373 
374 	pioctl_name = strtok_r (env, ", \t", &pos);
375 	if (pioctl_name != NULL) {
376 	    setpag_name = strtok_r (NULL, ", \t", &pos);
377 	    if (setpag_name != NULL)
378 		if (try_aix (pioctl_name, setpag_name) == 0)
379 		    goto done;
380 	}
381     }
382 #endif
383 
384     if(try_aix() == 0)
385 	goto done;
386 #endif
387 
388 done:
389 #ifdef SIGSYS
390     signal(SIGSYS, saved_func);
391 #endif
392 #endif /* NO_AFS */
393     errno = saved_errno;
394     return afs_entry_point != NO_ENTRY_POINT;
395 }
396