lib/kafs/afssys.c

   1 /*
   2  * Copyright (c) 1995 - 2000, 2002, 2004 Kungliga Tekniska Högskolan
   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("$Id$");
  37
  38 struct procdata {
  39     unsigned long param4;
  40     unsigned long param3;
  41     unsigned long param2;
  42     unsigned long param1;
  43     unsigned long syscall;
  44 };
  45 #define VIOC_SYSCALL _IOW('C', 1, void *)
  46
  47
  48 int _kafs_debug; /* this should be done in a better way */
  49
  50 #define NO_ENTRY_POINT          0
  51 #define SINGLE_ENTRY_POINT      1
  52 #define MULTIPLE_ENTRY_POINT    2
  53 #define SINGLE_ENTRY_POINT2     3
  54 #define SINGLE_ENTRY_POINT3     4
  55 #define LINUX_PROC_POINT        5
  56 #define AIX_ENTRY_POINTS        6
  57 #define UNKNOWN_ENTRY_POINT     7
  58 static int afs_entry_point = UNKNOWN_ENTRY_POINT;
  59 static int afs_syscalls[2];
  60 static char *afs_procpath;
  61
  62 /* Magic to get AIX syscalls to work */
  63 #ifdef _AIX
  64
  65 static int (*Pioctl)(char*, int, struct ViceIoctl*, int);
  66 static int (*Setpag)(void);
  67
  68 #include "dlfcn.h"
  69
  70 /*
  71  *
  72  */
  73
  74 static int
  75 try_aix(void)
  76 {
  77 #ifdef STATIC_AFS_SYSCALLS
  78     Pioctl = aix_pioctl;
  79     Setpag = aix_setpag;
  80 #else
  81     void *ptr;
  82     char path[MaxPathLen], *p;
  83     /*
  84      * If we are root or running setuid don't trust AFSLIBPATH!
  85      */
  86     if (getuid() != 0 && !issuid() && (p = getenv("AFSLIBPATH")) != NULL)
  87         strlcpy(path, p, sizeof(path));
  88     else
  89         snprintf(path, sizeof(path), "%s/afslib.so", LIBDIR);
  90
  91     ptr = dlopen(path, RTLD_NOW);
  92     if(ptr == NULL) {
  93         if(_kafs_debug) {
  94             if(errno == ENOEXEC && (p = dlerror()) != NULL)
  95                 fprintf(stderr, "dlopen(%s): %s\n", path, p);
  96             else if (errno != ENOENT)
  97                 fprintf(stderr, "dlopen(%s): %s\n", path, strerror(errno));
  98         }
  99         return 1;
 100     }
 101     Setpag = (int (*)(void))dlsym(ptr, "aix_setpag");
 102     Pioctl = (int (*)(char*, int,
 103                       struct ViceIoctl*, int))dlsym(ptr, "aix_pioctl");
 104 #endif
 105     afs_entry_point = AIX_ENTRY_POINTS;
 106     return 0;
 107 }
 108 #endif /* _AIX */
 109
 110 /*
 111  * This probably only works under Solaris and could get confused if
 112  * there's a /etc/name_to_sysnum file.
 113  */
 114
 115 #define _PATH_ETC_NAME_TO_SYSNUM "/etc/name_to_sysnum"
 116
 117 static int
 118 map_syscall_name_to_number (const char *str, int *res)
 119 {
 120     FILE *f;
 121     char buf[256];
 122     size_t str_len = strlen (str);
 123
 124     f = fopen (_PATH_ETC_NAME_TO_SYSNUM, "r");
 125     if (f == NULL)
 126         return -1;
 127     while (fgets (buf, sizeof(buf), f) != NULL) {
 128         if (buf[0] == '#')
 129             continue;
 130
 131         if (strncmp (str, buf, str_len) == 0) {
 132             char *begptr = buf + str_len;
 133             char *endptr;
 134             long val = strtol (begptr, &endptr, 0);
 135
 136             if (val != 0 && endptr != begptr) {
 137                 fclose (f);
 138                 *res = val;
 139                 return 0;
 140             }
 141         }
 142     }
 143     fclose (f);
 144     return -1;
 145 }
 146
 147 static int
 148 try_proc(const char *path)
 149 {
 150     int fd;
 151     fd = open(path, O_RDWR);
 152     if (fd < 0)
 153         return 1;
 154     close(fd);
 155     afs_procpath = strdup(path);
 156     if (afs_procpath == NULL)
 157         return 1;
 158     afs_entry_point = LINUX_PROC_POINT;
 159     return 0;
 160 }
 161
 162 static int
 163 do_proc(struct procdata *data)
 164 {
 165     int fd, ret, saved_errno;
 166     fd = open(afs_procpath, O_RDWR);
 167     if (fd < 0) {
 168         errno = EINVAL;
 169         return -1;
 170     }
 171     ret = ioctl(fd, VIOC_SYSCALL, data);
 172     saved_errno = errno;
 173     close(fd);
 174     errno = saved_errno;
 175     return ret;
 176 }
 177
 178 int
 179 k_pioctl(char *a_path,
 180          int o_opcode,
 181          struct ViceIoctl *a_paramsP,
 182          int a_followSymlinks)
 183 {
 184 #ifndef NO_AFS
 185     switch(afs_entry_point){
 186 #if defined(AFS_SYSCALL) || defined(AFS_SYSCALL2) || defined(AFS_SYSCALL3)
 187     case SINGLE_ENTRY_POINT:
 188     case SINGLE_ENTRY_POINT2:
 189     case SINGLE_ENTRY_POINT3:
 190         return syscall(afs_syscalls[0], AFSCALL_PIOCTL,
 191                        a_path, o_opcode, a_paramsP, a_followSymlinks);
 192 #endif
 193 #if defined(AFS_PIOCTL)
 194     case MULTIPLE_ENTRY_POINT:
 195         return syscall(afs_syscalls[0],
 196                        a_path, o_opcode, a_paramsP, a_followSymlinks);
 197 #endif
 198     case LINUX_PROC_POINT: {
 199         struct procdata data = { 0, 0, 0, 0, AFSCALL_PIOCTL };
 200         data.param1 = (unsigned long)a_path;
 201         data.param2 = (unsigned long)o_opcode;
 202         data.param3 = (unsigned long)a_paramsP;
 203         data.param4 = (unsigned long)a_followSymlinks;
 204         return do_proc(&data);
 205     }
 206 #ifdef _AIX
 207     case AIX_ENTRY_POINTS:
 208         return Pioctl(a_path, o_opcode, a_paramsP, a_followSymlinks);
 209 #endif
 210     }
 211     errno = ENOSYS;
 212 #ifdef SIGSYS
 213     kill(getpid(), SIGSYS);     /* You lose! */
 214 #endif
 215 #endif /* NO_AFS */
 216     return -1;
 217 }
 218
 219 int
 220 k_afs_cell_of_file(const char *path, char *cell, int len)
 221 {
 222     struct ViceIoctl parms;
 223     parms.in = NULL;
 224     parms.in_size = 0;
 225     parms.out = cell;
 226     parms.out_size = len;
 227     return k_pioctl((char*)path, VIOC_FILE_CELL_NAME, &parms, 1);
 228 }
 229
 230 int
 231 k_unlog(void)
 232 {
 233     struct ViceIoctl parms;
 234     memset(&parms, 0, sizeof(parms));
 235     return k_pioctl(0, VIOCUNLOG, &parms, 0);
 236 }
 237
 238 int
 239 k_setpag(void)
 240 {
 241 #ifndef NO_AFS
 242     switch(afs_entry_point){
 243 #if defined(AFS_SYSCALL) || defined(AFS_SYSCALL2) || defined(AFS_SYSCALL3)
 244     case SINGLE_ENTRY_POINT:
 245     case SINGLE_ENTRY_POINT2:
 246     case SINGLE_ENTRY_POINT3:
 247         return syscall(afs_syscalls[0], AFSCALL_SETPAG);
 248 #endif
 249 #if defined(AFS_PIOCTL)
 250     case MULTIPLE_ENTRY_POINT:
 251         return syscall(afs_syscalls[1]);
 252 #endif
 253     case LINUX_PROC_POINT: {
 254         struct procdata data = { 0, 0, 0, 0, AFSCALL_SETPAG };
 255         return do_proc(&data);
 256     }
 257 #ifdef _AIX
 258     case AIX_ENTRY_POINTS:
 259         return Setpag();
 260 #endif
 261     }
 262
 263     errno = ENOSYS;
 264 #ifdef SIGSYS
 265     kill(getpid(), SIGSYS);     /* You lose! */
 266 #endif
 267 #endif /* NO_AFS */
 268     return -1;
 269 }
 270
 271 static jmp_buf catch_SIGSYS;
 272
 273 #ifdef SIGSYS
 274
 275 static RETSIGTYPE
 276 SIGSYS_handler(int sig)
 277 {
 278     errno = 0;
 279     signal(SIGSYS, SIGSYS_handler); /* Need to reinstall handler on SYSV */
 280     longjmp(catch_SIGSYS, 1);
 281 }
 282
 283 #endif
 284
 285 /*
 286  * Try to see if `syscall' is a pioctl.  Return 0 iff succesful.
 287  */
 288
 289 #if defined(AFS_SYSCALL) || defined(AFS_SYSCALL2) || defined(AFS_SYSCALL3)
 290 static int
 291 try_one (int syscall_num)
 292 {
 293     struct ViceIoctl parms;
 294     memset(&parms, 0, sizeof(parms));
 295
 296     if (setjmp(catch_SIGSYS) == 0) {
 297         syscall(syscall_num, AFSCALL_PIOCTL,
 298                 0, VIOCSETTOK, &parms, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
 299         if (errno == EINVAL) {
 300             afs_entry_point = SINGLE_ENTRY_POINT;
 301             afs_syscalls[0] = syscall_num;
 302             return 0;
 303         }
 304     }
 305     return 1;
 306 }
 307 #endif
 308
 309 /*
 310  * Try to see if `syscall_pioctl' is a pioctl syscall.  Return 0 iff
 311  * succesful.
 312  *
 313  */
 314
 315 #ifdef AFS_PIOCTL
 316 static int
 317 try_two (int syscall_pioctl, int syscall_setpag)
 318 {
 319     struct ViceIoctl parms;
 320     memset(&parms, 0, sizeof(parms));
 321
 322     if (setjmp(catch_SIGSYS) == 0) {
 323         syscall(syscall_pioctl,
 324                 0, VIOCSETTOK, &parms, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
 325         if (errno == EINVAL) {
 326             afs_entry_point = MULTIPLE_ENTRY_POINT;
 327             afs_syscalls[0] = syscall_pioctl;
 328             afs_syscalls[1] = syscall_setpag;
 329             return 0;
 330         }
 331     }
 332     return 1;
 333 }
 334 #endif
 335
 336 int
 337 k_hasafs(void)
 338 {
 339 #if !defined(NO_AFS) && defined(SIGSYS)
 340     RETSIGTYPE (*saved_func)(int);
 341 #endif
 342     int saved_errno;
 343     char *env = getenv ("AFS_SYSCALL");
 344
 345     /*
 346      * Already checked presence of AFS syscalls?
 347      */
 348     if (afs_entry_point != UNKNOWN_ENTRY_POINT)
 349         return afs_entry_point != NO_ENTRY_POINT;
 350
 351     /*
 352      * Probe kernel for AFS specific syscalls,
 353      * they (currently) come in two flavors.
 354      * If the syscall is absent we recive a SIGSYS.
 355      */
 356     afs_entry_point = NO_ENTRY_POINT;
 357
 358     saved_errno = errno;
 359 #ifndef NO_AFS
 360 #ifdef SIGSYS
 361     saved_func = signal(SIGSYS, SIGSYS_handler);
 362 #endif
 363
 364 #if defined(AFS_SYSCALL) || defined(AFS_SYSCALL2) || defined(AFS_SYSCALL3)
 365     {
 366         int tmp;
 367
 368         if (env != NULL) {
 369             if (sscanf (env, "%d", &tmp) == 1) {
 370                 if (try_one (tmp) == 0)
 371                     goto done;
 372             } else {
 373                 char *end = NULL;
 374                 char *p;
 375                 char *s = strdup (env);
 376
 377                 if (s != NULL) {
 378                     for (p = strtok_r (s, ",", &end);
 379                          p != NULL;
 380                          p = strtok_r (NULL, ",", &end)) {
 381                         if (map_syscall_name_to_number (p, &tmp) == 0)
 382                             if (try_one (tmp) == 0) {
 383                                 free (s);
 384                                 goto done;
 385                             }
 386                     }
 387                     free (s);
 388                 }
 389             }
 390         }
 391     }
 392 #endif /* AFS_SYSCALL || AFS_SYSCALL2 || AFS_SYSCALL3 */
 393
 394 #ifdef AFS_SYSCALL
 395     if (try_one (AFS_SYSCALL) == 0)
 396         goto done;
 397 #endif /* AFS_SYSCALL */
 398
 399 #ifdef AFS_PIOCTL
 400     {
 401         int tmp[2];
 402
 403         if (env != NULL && sscanf (env, "%d%d", &tmp[0], &tmp[1]) == 2)
 404             if (try_two (tmp[0], tmp[1]) == 2)
 405                 goto done;
 406     }
 407 #endif /* AFS_PIOCTL */
 408
 409 #ifdef AFS_PIOCTL
 410     if (try_two (AFS_PIOCTL, AFS_SETPAG) == 0)
 411         goto done;
 412 #endif /* AFS_PIOCTL */
 413
 414 #ifdef AFS_SYSCALL2
 415     if (try_one (AFS_SYSCALL2) == 0)
 416         goto done;
 417 #endif /* AFS_SYSCALL2 */
 418
 419 #ifdef AFS_SYSCALL3
 420     if (try_one (AFS_SYSCALL3) == 0)
 421         goto done;
 422 #endif /* AFS_SYSCALL3 */
 423
 424 #ifdef _AIX
 425 #if 0
 426     if (env != NULL) {
 427         char *pos = NULL;
 428         char *pioctl_name;
 429         char *setpag_name;
 430
 431         pioctl_name = strtok_r (env, ", \t", &pos);
 432         if (pioctl_name != NULL) {
 433             setpag_name = strtok_r (NULL, ", \t", &pos);
 434             if (setpag_name != NULL)
 435                 if (try_aix (pioctl_name, setpag_name) == 0)
 436                     goto done;
 437         }
 438     }
 439 #endif
 440
 441     if(try_aix() == 0)
 442         goto done;
 443 #endif
 444
 445     if (try_proc("/proc/fs/openafs/afs_ioctl") == 0)
 446         goto done;
 447     if (try_proc("/proc/fs/nnpfs/afs_ioctl") == 0)
 448         goto done;
 449     if (env && try_proc(env) == 0)
 450         goto done;
 451
 452 done:
 453 #ifdef SIGSYS
 454     signal(SIGSYS, saved_func);
 455 #endif
 456 #endif /* NO_AFS */
 457     errno = saved_errno;
 458     return afs_entry_point != NO_ENTRY_POINT;
 459 }