new "mountpoint" export option.
[nfs-utils.git] / support / nfs / exports.c
1 /*
2  * support/nfs/export.c
3  *
4  * Parse the exports file. Derived from the unfsd implementation.
5  *
6  * Authors:     Donald J. Becker, <becker@super.org>
7  *              Rick Sladkey, <jrs@world.std.com>
8  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
9  *              Olaf Kirch, <okir@monad.swb.de>
10  *              Alexander O. Yuriev, <alex@bach.cis.temple.edu>
11  *
12  *              This software maybe be used for any purpose provided
13  *              the above copyright notice is retained.  It is supplied
14  *              as is, with no warranty expressed or implied.
15  */
16
17 #include "config.h"
18
19 #include <sys/param.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <stdio.h>
23 #include <ctype.h>
24 #include <unistd.h>
25 #include <errno.h>
26 #include "nfslib.h"
27 #include "exportfs.h"
28 #include "xmalloc.h"
29 #include "xlog.h"
30 #include "xio.h"
31
32 #define EXPORT_DEFAULT_FLAGS    \
33   (NFSEXP_READONLY|NFSEXP_ROOTSQUASH|NFSEXP_GATHERED_WRITES)
34
35 int export_errno;
36
37 static char     *efname = NULL;
38 static XFILE    *efp = NULL;
39 static int      first;
40 static int      *squids = NULL, nsquids = 0,
41                 *sqgids = NULL, nsqgids = 0;
42
43 static int      getexport(char *exp, int len);
44 static int      getpath(char *path, int len);
45 static int      parseopts(char *cp, struct exportent *ep, int warn);
46 static int      parsesquash(char *list, int **idp, int *lenp, char **ep);
47 static int      parsenum(char **cpp);
48 static int      parsemaptype(char *type);
49 static void     freesquash(void);
50 static void     syntaxerr(char *msg);
51
52 void
53 setexportent(char *fname, char *type)
54 {
55         if (efp)
56                 endexportent();
57         if (!fname)
58                 fname = _PATH_EXPORTS;
59         if (!(efp = xfopen(fname, type)))
60                 xlog(L_ERROR, "can't open %s for %sing",
61                                 fname, strcmp(type, "r")? "writ" : "read");
62         efname = strdup(fname);
63         first = 1;
64 }
65
66 struct exportent *
67 getexportent(int fromkernel, int fromexports)
68 {
69         static struct exportent ee;
70         char            exp[512];
71         char            rpath[MAXPATHLEN+1];
72         char            *opt, *sp;
73         int             ok;
74
75         if (!efp)
76                 return NULL;
77
78         freesquash();
79         ee.e_flags = EXPORT_DEFAULT_FLAGS;
80         /* some kernels assume the default is sync rather than
81          * async.  More recent kernels always report one or other,
82          * but this test makes sure we assume same as kernel
83          * Ditto for wgather
84          */
85         if (fromkernel) {
86                 ee.e_flags &= ~NFSEXP_ASYNC;
87                 ee.e_flags &= ~NFSEXP_GATHERED_WRITES;
88         }
89         ee.e_maptype = CLE_MAP_IDENT;
90         ee.e_anonuid = -2;
91         ee.e_anongid = -2;
92         ee.e_squids = NULL;
93         ee.e_sqgids = NULL;
94         ee.e_mountpoint = NULL;
95         ee.e_nsquids = 0;
96         ee.e_nsqgids = 0;
97
98         if (first || (ok = getexport(exp, sizeof(exp))) == 0) {
99                 ok = getpath(ee.e_path, sizeof(ee.e_path));
100                 if (ok <= 0)
101                         return NULL;
102                 strncpy (ee.m_path, ee.e_path, sizeof (ee.m_path) - 1);
103                 ee.m_path [sizeof (ee.m_path) - 1] = '\0';
104                 ok = getexport(exp, sizeof(exp));
105         }
106         if (ok < 0) {
107                 xlog(L_ERROR, "expected client(options...)");
108                 export_errno = EINVAL;
109                 return NULL;
110         }
111         first = 0;
112
113         /* Check for default client */
114         if (ok == 0)
115                 exp[0] = '\0';
116         if ((opt = strchr(exp, '(')) != NULL) {
117                 if (opt == exp) 
118                         xlog(L_WARNING, "No host name given with %s %s, suggest *%s to avoid warning", ee.e_path, exp, exp);
119                 *opt++ = '\0';
120                 if (!(sp = strchr(opt, ')')) || sp[1] != '\0') {
121                         syntaxerr("bad option list");
122                         export_errno = EINVAL;
123                         return NULL;
124                 }
125                 *sp = '\0';
126         } else {
127             xlog(L_WARNING, "No options for %s %s: suggest %s(sync) to avoid warning", ee.e_path, exp, exp);
128         }
129         if (strlen(exp) >= sizeof(ee.e_hostname)) {
130                 syntaxerr("client name too long");
131                 export_errno = EINVAL;
132                 return NULL;
133         }
134         strncpy(ee.e_hostname, exp, sizeof (ee.e_hostname) - 1);
135         ee.e_hostname[sizeof (ee.e_hostname) - 1] = '\0';
136
137         if (parseopts(opt, &ee, fromexports) < 0)
138                 return NULL;
139
140         /* resolve symlinks */
141         if (realpath(ee.e_path, rpath) != NULL) {
142                 rpath[sizeof (rpath) - 1] = '\0';
143                 strncpy(ee.e_path, rpath, sizeof (ee.e_path) - 1);
144                 ee.e_path[sizeof (ee.e_path) - 1] = '\0';
145                 strncpy (ee.m_path, ee.e_path, sizeof (ee.m_path) - 1);
146                 ee.m_path [sizeof (ee.m_path) - 1] = '\0';
147         }
148
149         return &ee;
150 }
151
152 void
153 putexportent(struct exportent *ep)
154 {
155         FILE    *fp;
156         int     *id, i;
157         char    *esc=ep->e_path;
158
159         if (!efp)
160                 return;
161
162         fp = efp->x_fp;
163         for (i=0; esc[i]; i++)
164                 if (iscntrl(esc[i]) || esc[i] == '"' || esc[i] == '\\'|| isspace(esc[i]))
165                         fprintf(fp, "\\%03o", esc[i]);
166                 else
167                         fprintf(fp, "%c", esc[i]);
168
169         fprintf(fp, "\t%s(", ep->e_hostname);
170         fprintf(fp, "%s,", (ep->e_flags & NFSEXP_READONLY)? "ro" : "rw");
171         fprintf(fp, "%ssync,", (ep->e_flags & NFSEXP_ASYNC)? "a" : "");
172         fprintf(fp, "%swdelay,", (ep->e_flags & NFSEXP_GATHERED_WRITES)?
173                                 "" : "no_");
174         fprintf(fp, "%shide,", (ep->e_flags & NFSEXP_NOHIDE)?
175                                 "no" : "");
176         fprintf(fp, "%scrossmnt,", (ep->e_flags & NFSEXP_CROSSMNT)?
177                                 "" : "no");
178         fprintf(fp, "%ssecure,", (ep->e_flags & NFSEXP_INSECURE_PORT)?
179                                 "in" : "");
180         fprintf(fp, "%sroot_squash,", (ep->e_flags & NFSEXP_ROOTSQUASH)?
181                                 "" : "no_");
182         fprintf(fp, "%sall_squash,", (ep->e_flags & NFSEXP_ALLSQUASH)?
183                                 "" : "no_");
184         fprintf(fp, "%ssubtree_check,", (ep->e_flags & NFSEXP_NOSUBTREECHECK)?
185                 "no_" : "");
186         fprintf(fp, "%ssecure_locks,", (ep->e_flags & NFSEXP_NOAUTHNLM)?
187                 "in" : "");
188         if (ep->e_flags & NFSEXP_FSID) {
189                 fprintf(fp, "fsid=%d,", ep->e_fsid);
190         }
191         if (ep->e_mountpoint)
192                 fprintf(fp, "mountpoint%s%s,",
193                         ep->e_mountpoint[0]?"=":"", ep->e_mountpoint);
194
195         fprintf(fp, "mapping=");
196         switch (ep->e_maptype) {
197         case CLE_MAP_IDENT:
198                 fprintf(fp, "identity,");
199                 break;
200         case CLE_MAP_UGIDD:
201                 fprintf(fp, "ugidd,");
202                 break;
203         case CLE_MAP_FILE:
204                 fprintf(fp, "file,");
205                 break;
206         default:
207                 xlog(L_ERROR, "unknown mapping type for %s:%s",
208                                         ep->e_hostname, ep->e_path);
209         }
210         if ((id = ep->e_squids) != NULL) {
211                 fprintf(fp, "squash_uids=");
212                 for (i = 0; i < ep->e_nsquids; i += 2)
213                         if (id[i] != id[i+1])
214                                 fprintf(fp, "%d-%d,", id[i], id[i+1]);
215                         else
216                                 fprintf(fp, "%d,", id[i]);
217         }
218         if ((id = ep->e_sqgids) != NULL) {
219                 fprintf(fp, "squash_gids=");
220                 for (i = 0; i < ep->e_nsquids; i += 2)
221                         if (id[i] != id[i+1])
222                                 fprintf(fp, "%d-%d,", id[i], id[i+1]);
223                         else
224                                 fprintf(fp, "%d,", id[i]);
225         }
226         fprintf(fp, "anonuid=%d,anongid=%d)\n", ep->e_anonuid, ep->e_anongid);
227 }
228
229 void
230 endexportent(void)
231 {
232         if (efp)
233                 xfclose(efp);
234         efp = NULL;
235         if (efname)
236                 free(efname);
237         efname = NULL;
238         freesquash();
239 }
240
241 void
242 dupexportent(struct exportent *dst, struct exportent *src)
243 {
244         int     n;
245
246         *dst = *src;
247         if ((n = src->e_nsquids) != 0) {
248                 dst->e_squids = (int *) xmalloc(n * sizeof(int));
249                 memcpy(dst->e_squids, src->e_squids, n * sizeof(int));
250         }
251         if ((n = src->e_nsqgids) != 0) {
252                 dst->e_sqgids = (int *) xmalloc(n * sizeof(int));
253                 memcpy(dst->e_sqgids, src->e_sqgids, n * sizeof(int));
254         }
255         if (src->e_mountpoint)
256                 dst->e_mountpoint = strdup(src->e_mountpoint);
257 }
258
259 struct exportent *
260 mkexportent(char *hname, char *path, char *options)
261 {
262         static struct exportent ee;
263
264         ee.e_flags = EXPORT_DEFAULT_FLAGS;
265         ee.e_maptype = CLE_MAP_IDENT;
266         ee.e_anonuid = -2;
267         ee.e_anongid = -2;
268         ee.e_squids = NULL;
269         ee.e_sqgids = NULL;
270         ee.e_mountpoint = NULL;
271         ee.e_nsquids = 0;
272         ee.e_nsqgids = 0;
273
274         if (strlen(hname) >= sizeof(ee.e_hostname)) {
275                 xlog(L_WARNING, "client name %s too long", hname);
276                 return NULL;
277         }
278         strncpy(ee.e_hostname, hname, sizeof (ee.e_hostname) - 1);
279         ee.e_hostname[sizeof (ee.e_hostname) - 1] = '\0';
280         if (strlen(path) >= sizeof(ee.e_path)) {
281                 xlog(L_WARNING, "path name %s too long", path);
282                 return NULL;
283         }
284         strncpy(ee.e_path, path, sizeof (ee.e_path));
285         ee.e_path[sizeof (ee.e_path) - 1] = '\0';
286         strncpy (ee.m_path, ee.e_path, sizeof (ee.m_path) - 1);
287         ee.m_path [sizeof (ee.m_path) - 1] = '\0';
288         if (parseopts(options, &ee, 0) < 0)
289                 return NULL;
290         return &ee;
291 }
292
293 int
294 updateexportent(struct exportent *eep, char *options)
295 {
296         if (parseopts(options, eep, 0) < 0)
297                 return 0;
298         return 1;
299 }
300
301 /*
302  * Parse option string pointed to by cp and set mount options accordingly.
303  */
304 static int
305 parseopts(char *cp, struct exportent *ep, int warn)
306 {
307         int     had_sync_opt = 0;
308         char    *flname = efname?efname:"command line";
309         int     flline = efp?efp->x_line:0;
310
311         squids = ep->e_squids; nsquids = ep->e_nsquids;
312         sqgids = ep->e_sqgids; nsqgids = ep->e_nsqgids;
313
314         if (!cp)
315                 goto out;
316
317         while (isblank(*cp))
318                 cp++;
319
320         while (*cp) {
321                 char *opt = strdup(cp);
322                 char *optstart = cp;
323                 while (*cp && *cp != ',')
324                         cp++;
325                 if (*cp) {
326                         opt[cp-optstart] = '\0';
327                         cp++;
328                 }
329
330                 /* process keyword */
331                 if (strcmp(opt, "ro") == 0)
332                         ep->e_flags |= NFSEXP_READONLY;
333                 else if (strcmp(opt, "rw") == 0)
334                         ep->e_flags &= ~NFSEXP_READONLY;
335                 else if (!strcmp(opt, "secure"))
336                         ep->e_flags &= ~NFSEXP_INSECURE_PORT;
337                 else if (!strcmp(opt, "insecure"))
338                         ep->e_flags |= NFSEXP_INSECURE_PORT;
339                 else if (!strcmp(opt, "sync")) {
340                         had_sync_opt = 1;
341                         ep->e_flags &= ~NFSEXP_ASYNC;
342                 } else if (!strcmp(opt, "async")) {
343                         had_sync_opt = 1;
344                         ep->e_flags |= NFSEXP_ASYNC;
345                 } else if (!strcmp(opt, "nohide"))
346                         ep->e_flags |= NFSEXP_NOHIDE;
347                 else if (!strcmp(opt, "hide"))
348                         ep->e_flags &= ~NFSEXP_NOHIDE;
349                 else if (!strcmp(opt, "crossmnt"))
350                         ep->e_flags |= NFSEXP_CROSSMNT;
351                 else if (!strcmp(opt, "nocrossmnt"))
352                         ep->e_flags &= ~NFSEXP_CROSSMNT;
353                 else if (!strcmp(opt, "wdelay"))
354                         ep->e_flags |= NFSEXP_GATHERED_WRITES;
355                 else if (!strcmp(opt, "no_wdelay"))
356                         ep->e_flags &= ~NFSEXP_GATHERED_WRITES;
357                 else if (strcmp(opt, "root_squash") == 0)
358                         ep->e_flags |= NFSEXP_ROOTSQUASH;
359                 else if (!strcmp(opt, "no_root_squash"))
360                         ep->e_flags &= ~NFSEXP_ROOTSQUASH;
361                 else if (strcmp(opt, "all_squash") == 0)
362                         ep->e_flags |= NFSEXP_ALLSQUASH;
363                 else if (strcmp(opt, "no_all_squash") == 0)
364                         ep->e_flags &= ~NFSEXP_ALLSQUASH;
365                 else if (strcmp(opt, "subtree_check") == 0)
366                         ep->e_flags &= ~NFSEXP_NOSUBTREECHECK;
367                 else if (strcmp(opt, "no_subtree_check") == 0)
368                         ep->e_flags |= NFSEXP_NOSUBTREECHECK;
369                 else if (strcmp(opt, "auth_nlm") == 0)
370                         ep->e_flags &= ~NFSEXP_NOAUTHNLM;
371                 else if (strcmp(opt, "no_auth_nlm") == 0)
372                         ep->e_flags |= NFSEXP_NOAUTHNLM;
373                 else if (strcmp(opt, "secure_locks") == 0)
374                         ep->e_flags &= ~NFSEXP_NOAUTHNLM;
375                 else if (strcmp(opt, "insecure_locks") == 0)
376                         ep->e_flags |= NFSEXP_NOAUTHNLM;
377                 else if (strncmp(opt, "mapping=", 8) == 0)
378                         ep->e_maptype = parsemaptype(opt+8);
379                 else if (strcmp(opt, "map_identity") == 0)      /* old style */
380                         ep->e_maptype = CLE_MAP_IDENT;
381                 else if (strcmp(opt, "map_daemon") == 0)        /* old style */
382                         ep->e_maptype = CLE_MAP_UGIDD;
383                 else if (strncmp(opt, "anonuid=", 8) == 0) {
384                         char *oe;
385                         ep->e_anonuid = strtol(opt+8, &oe, 10);
386                         if (opt[8]=='\0' || *oe != '\0') {
387                                 xlog(L_ERROR, "%s: %d: bad anonuid \"%s\"\n",
388                                      flname, flline, opt);      
389 bad_option:
390                                 free(opt);
391                                 export_errno = EINVAL;
392                                 return -1;
393                         }
394                 } else if (strncmp(opt, "anongid=", 8) == 0) {
395                         char *oe;
396                         ep->e_anongid = strtol(opt+8, &oe, 10);
397                         if (opt[8]=='\0' || *oe != '\0') {
398                                 xlog(L_ERROR, "%s: %d: bad anongid \"%s\"\n",
399                                      flname, flline, opt);      
400                                 goto bad_option;
401                         }
402                 } else if (strncmp(opt, "squash_uids=", 12) == 0) {
403                         if (parsesquash(opt+12, &squids, &nsquids, &cp) < 0) {
404                                 goto bad_option;
405                         }
406                 } else if (strncmp(opt, "squash_gids=", 12) == 0) {
407                         if (parsesquash(opt+12, &sqgids, &nsqgids, &cp) < 0) {
408                                 goto bad_option;
409                         }
410                 } else if (strncmp(opt, "fsid=", 5) == 0) {
411                         char *oe;
412                         ep->e_fsid = strtoul(opt+5, &oe, 0);
413                         if (opt[5]=='\0' || *oe != '\0') {
414                                 xlog(L_ERROR, "%s: %d: bad fsid \"%s\"\n",
415                                      flname, flline, opt);      
416                                 goto bad_option;
417                         }
418                         ep->e_flags |= NFSEXP_FSID;
419                 } else if (strcmp(opt, "mountpoint")==0 ||
420                            strcmp(opt, "mp") == 0 ||
421                            strncmp(opt, "mountpoint=", 11)==0 ||
422                            strncmp(opt, "mp=", 3) == 0) {
423                         char * mp = strchr(opt, '=');
424                         if (mp)
425                                 ep->e_mountpoint = strdup(mp+1);
426                         else
427                                 ep->e_mountpoint = strdup("");
428                 } else {
429                         xlog(L_ERROR, "%s:%d: unknown keyword \"%s\"\n",
430                                         flname, flline, opt);
431                         ep->e_flags |= NFSEXP_ALLSQUASH | NFSEXP_READONLY;
432                         goto bad_option;
433                 }
434                 free(opt);
435                 while (isblank(*cp))
436                         cp++;
437         }
438
439         ep->e_squids = squids;
440         ep->e_sqgids = sqgids;
441         ep->e_nsquids = nsquids;
442         ep->e_nsqgids = nsqgids;
443
444 out:
445         if (warn && !had_sync_opt)
446                 xlog(L_WARNING, "%s [%d]: No 'sync' or 'async' option specified for export \"%s:%s\".\n"
447                                 "  Assuming default behaviour ('sync').\n"
448                                 "  NOTE: this default has changed from previous versions\n",
449
450                                 flname, flline,
451                                 ep->e_hostname, ep->e_path);
452
453         return 1;
454 }
455
456 static int
457 parsesquash(char *list, int **idp, int *lenp, char **ep)
458 {
459         char    *cp = list;
460         int     id0, id1;
461         int     len = *lenp;
462         int     *id = *idp;
463
464         if (**ep)
465             *--(*ep) = ',';
466
467         do {
468                 id0 = parsenum(&cp);
469                 if (*cp == '-') {
470                         cp++;
471                         id1 = parsenum(&cp);
472                 } else {
473                         id1 = id0;
474                 }
475                 if (id0 == -1 || id1 == -1) {
476                         syntaxerr("uid/gid -1 not permitted");
477                         return -1;
478                 }
479                 if ((len % 8) == 0)
480                         id = (int *) xrealloc(id, (len + 8) * sizeof(*id));
481                 id[len++] = id0;
482                 id[len++] = id1;
483                 if (!*cp || *cp == ')' || (*cp == ',' && !isdigit(cp[1])))
484                         break;
485                 if (*cp != ',') {
486                         syntaxerr("bad uid/gid list");
487                         return -1;
488                 }
489                 cp++;
490         } while(1);
491
492         if (**ep == ',') (*ep)++;
493
494         *lenp = len;
495         *idp = id;
496         return 1;
497 }
498
499 static void
500 freesquash(void)
501 {
502         if (squids) {
503                 xfree (squids);
504                 squids = NULL;
505                 nsquids = 0;
506         }
507         if (sqgids) {
508                 xfree (sqgids);
509                 sqgids = NULL;
510                 nsqgids = 0;
511         }
512 }
513
514 static int
515 parsenum(char **cpp)
516 {
517         char    *cp = *cpp, c;
518         int     num = 0;
519
520         if (**cpp == '-')
521                 (*cpp)++;
522         while (isdigit(**cpp))
523                 (*cpp)++;
524         c = **cpp; **cpp = '\0'; num = atoi(cp); **cpp = c;
525         return num;
526 }
527
528 static int
529 parsemaptype(char *type)
530 {
531         if (!strcmp(type, "identity"))
532                 return CLE_MAP_IDENT;
533         if (!strcmp(type, "ugidd"))
534                 return CLE_MAP_UGIDD;
535         if (!strcmp(type, "file"))
536                 return CLE_MAP_FILE;
537         syntaxerr("invalid map type");
538         return CLE_MAP_IDENT;   /* default */
539 }
540
541 static int
542 getpath(char *path, int len)
543 {
544         xskip(efp, " \t\n");
545         return xgettok(efp, 0, path, len);
546 }
547
548 static int
549 getexport(char *exp, int len)
550 {
551         int     ok;
552
553         xskip(efp, " \t");
554         if ((ok = xgettok(efp, 0, exp, len)) < 0)
555                 xlog(L_ERROR, "%s:%d: syntax error",
556                         efname?"command line":efname, efp->x_line);
557         return ok;
558 }
559
560 static void
561 syntaxerr(char *msg)
562 {
563         xlog(L_ERROR, "%s:%d: syntax error: %s",
564                         efname, efp?efp->x_line:0, msg);
565 }
566