~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/sunrpc/auth_gss/svcauth_gss.c

Version: ~ [ linux-5.11-rc3 ] ~ [ linux-5.10.7 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.89 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.167 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.215 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.251 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.251 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * Neil Brown <neilb@cse.unsw.edu.au>
  3  * J. Bruce Fields <bfields@umich.edu>
  4  * Andy Adamson <andros@umich.edu>
  5  * Dug Song <dugsong@monkey.org>
  6  *
  7  * RPCSEC_GSS server authentication.
  8  * This implements RPCSEC_GSS as defined in rfc2203 (rpcsec_gss) and rfc2078
  9  * (gssapi)
 10  *
 11  * The RPCSEC_GSS involves three stages:
 12  *  1/ context creation
 13  *  2/ data exchange
 14  *  3/ context destruction
 15  *
 16  * Context creation is handled largely by upcalls to user-space.
 17  *  In particular, GSS_Accept_sec_context is handled by an upcall
 18  * Data exchange is handled entirely within the kernel
 19  *  In particular, GSS_GetMIC, GSS_VerifyMIC, GSS_Seal, GSS_Unseal are in-kernel.
 20  * Context destruction is handled in-kernel
 21  *  GSS_Delete_sec_context is in-kernel
 22  *
 23  * Context creation is initiated by a RPCSEC_GSS_INIT request arriving.
 24  * The context handle and gss_token are used as a key into the rpcsec_init cache.
 25  * The content of this cache includes some of the outputs of GSS_Accept_sec_context,
 26  * being major_status, minor_status, context_handle, reply_token.
 27  * These are sent back to the client.
 28  * Sequence window management is handled by the kernel.  The window size if currently
 29  * a compile time constant.
 30  *
 31  * When user-space is happy that a context is established, it places an entry
 32  * in the rpcsec_context cache. The key for this cache is the context_handle.
 33  * The content includes:
 34  *   uid/gidlist - for determining access rights
 35  *   mechanism type
 36  *   mechanism specific information, such as a key
 37  *
 38  */
 39 
 40 #include <linux/slab.h>
 41 #include <linux/types.h>
 42 #include <linux/module.h>
 43 #include <linux/pagemap.h>
 44 #include <linux/user_namespace.h>
 45 
 46 #include <linux/sunrpc/auth_gss.h>
 47 #include <linux/sunrpc/gss_err.h>
 48 #include <linux/sunrpc/svcauth.h>
 49 #include <linux/sunrpc/svcauth_gss.h>
 50 #include <linux/sunrpc/cache.h>
 51 #include "gss_rpc_upcall.h"
 52 
 53 
 54 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 55 # define RPCDBG_FACILITY        RPCDBG_AUTH
 56 #endif
 57 
 58 /* The rpcsec_init cache is used for mapping RPCSEC_GSS_{,CONT_}INIT requests
 59  * into replies.
 60  *
 61  * Key is context handle (\x if empty) and gss_token.
 62  * Content is major_status minor_status (integers) context_handle, reply_token.
 63  *
 64  */
 65 
 66 static int netobj_equal(struct xdr_netobj *a, struct xdr_netobj *b)
 67 {
 68         return a->len == b->len && 0 == memcmp(a->data, b->data, a->len);
 69 }
 70 
 71 #define RSI_HASHBITS    6
 72 #define RSI_HASHMAX     (1<<RSI_HASHBITS)
 73 
 74 struct rsi {
 75         struct cache_head       h;
 76         struct xdr_netobj       in_handle, in_token;
 77         struct xdr_netobj       out_handle, out_token;
 78         int                     major_status, minor_status;
 79 };
 80 
 81 static struct rsi *rsi_update(struct cache_detail *cd, struct rsi *new, struct rsi *old);
 82 static struct rsi *rsi_lookup(struct cache_detail *cd, struct rsi *item);
 83 
 84 static void rsi_free(struct rsi *rsii)
 85 {
 86         kfree(rsii->in_handle.data);
 87         kfree(rsii->in_token.data);
 88         kfree(rsii->out_handle.data);
 89         kfree(rsii->out_token.data);
 90 }
 91 
 92 static void rsi_put(struct kref *ref)
 93 {
 94         struct rsi *rsii = container_of(ref, struct rsi, h.ref);
 95         rsi_free(rsii);
 96         kfree(rsii);
 97 }
 98 
 99 static inline int rsi_hash(struct rsi *item)
100 {
101         return hash_mem(item->in_handle.data, item->in_handle.len, RSI_HASHBITS)
102              ^ hash_mem(item->in_token.data, item->in_token.len, RSI_HASHBITS);
103 }
104 
105 static int rsi_match(struct cache_head *a, struct cache_head *b)
106 {
107         struct rsi *item = container_of(a, struct rsi, h);
108         struct rsi *tmp = container_of(b, struct rsi, h);
109         return netobj_equal(&item->in_handle, &tmp->in_handle) &&
110                netobj_equal(&item->in_token, &tmp->in_token);
111 }
112 
113 static int dup_to_netobj(struct xdr_netobj *dst, char *src, int len)
114 {
115         dst->len = len;
116         dst->data = (len ? kmemdup(src, len, GFP_KERNEL) : NULL);
117         if (len && !dst->data)
118                 return -ENOMEM;
119         return 0;
120 }
121 
122 static inline int dup_netobj(struct xdr_netobj *dst, struct xdr_netobj *src)
123 {
124         return dup_to_netobj(dst, src->data, src->len);
125 }
126 
127 static void rsi_init(struct cache_head *cnew, struct cache_head *citem)
128 {
129         struct rsi *new = container_of(cnew, struct rsi, h);
130         struct rsi *item = container_of(citem, struct rsi, h);
131 
132         new->out_handle.data = NULL;
133         new->out_handle.len = 0;
134         new->out_token.data = NULL;
135         new->out_token.len = 0;
136         new->in_handle.len = item->in_handle.len;
137         item->in_handle.len = 0;
138         new->in_token.len = item->in_token.len;
139         item->in_token.len = 0;
140         new->in_handle.data = item->in_handle.data;
141         item->in_handle.data = NULL;
142         new->in_token.data = item->in_token.data;
143         item->in_token.data = NULL;
144 }
145 
146 static void update_rsi(struct cache_head *cnew, struct cache_head *citem)
147 {
148         struct rsi *new = container_of(cnew, struct rsi, h);
149         struct rsi *item = container_of(citem, struct rsi, h);
150 
151         BUG_ON(new->out_handle.data || new->out_token.data);
152         new->out_handle.len = item->out_handle.len;
153         item->out_handle.len = 0;
154         new->out_token.len = item->out_token.len;
155         item->out_token.len = 0;
156         new->out_handle.data = item->out_handle.data;
157         item->out_handle.data = NULL;
158         new->out_token.data = item->out_token.data;
159         item->out_token.data = NULL;
160 
161         new->major_status = item->major_status;
162         new->minor_status = item->minor_status;
163 }
164 
165 static struct cache_head *rsi_alloc(void)
166 {
167         struct rsi *rsii = kmalloc(sizeof(*rsii), GFP_KERNEL);
168         if (rsii)
169                 return &rsii->h;
170         else
171                 return NULL;
172 }
173 
174 static void rsi_request(struct cache_detail *cd,
175                        struct cache_head *h,
176                        char **bpp, int *blen)
177 {
178         struct rsi *rsii = container_of(h, struct rsi, h);
179 
180         qword_addhex(bpp, blen, rsii->in_handle.data, rsii->in_handle.len);
181         qword_addhex(bpp, blen, rsii->in_token.data, rsii->in_token.len);
182         (*bpp)[-1] = '\n';
183 }
184 
185 static int rsi_parse(struct cache_detail *cd,
186                     char *mesg, int mlen)
187 {
188         /* context token expiry major minor context token */
189         char *buf = mesg;
190         char *ep;
191         int len;
192         struct rsi rsii, *rsip = NULL;
193         time_t expiry;
194         int status = -EINVAL;
195 
196         memset(&rsii, 0, sizeof(rsii));
197         /* handle */
198         len = qword_get(&mesg, buf, mlen);
199         if (len < 0)
200                 goto out;
201         status = -ENOMEM;
202         if (dup_to_netobj(&rsii.in_handle, buf, len))
203                 goto out;
204 
205         /* token */
206         len = qword_get(&mesg, buf, mlen);
207         status = -EINVAL;
208         if (len < 0)
209                 goto out;
210         status = -ENOMEM;
211         if (dup_to_netobj(&rsii.in_token, buf, len))
212                 goto out;
213 
214         rsip = rsi_lookup(cd, &rsii);
215         if (!rsip)
216                 goto out;
217 
218         rsii.h.flags = 0;
219         /* expiry */
220         expiry = get_expiry(&mesg);
221         status = -EINVAL;
222         if (expiry == 0)
223                 goto out;
224 
225         /* major/minor */
226         len = qword_get(&mesg, buf, mlen);
227         if (len <= 0)
228                 goto out;
229         rsii.major_status = simple_strtoul(buf, &ep, 10);
230         if (*ep)
231                 goto out;
232         len = qword_get(&mesg, buf, mlen);
233         if (len <= 0)
234                 goto out;
235         rsii.minor_status = simple_strtoul(buf, &ep, 10);
236         if (*ep)
237                 goto out;
238 
239         /* out_handle */
240         len = qword_get(&mesg, buf, mlen);
241         if (len < 0)
242                 goto out;
243         status = -ENOMEM;
244         if (dup_to_netobj(&rsii.out_handle, buf, len))
245                 goto out;
246 
247         /* out_token */
248         len = qword_get(&mesg, buf, mlen);
249         status = -EINVAL;
250         if (len < 0)
251                 goto out;
252         status = -ENOMEM;
253         if (dup_to_netobj(&rsii.out_token, buf, len))
254                 goto out;
255         rsii.h.expiry_time = expiry;
256         rsip = rsi_update(cd, &rsii, rsip);
257         status = 0;
258 out:
259         rsi_free(&rsii);
260         if (rsip)
261                 cache_put(&rsip->h, cd);
262         else
263                 status = -ENOMEM;
264         return status;
265 }
266 
267 static const struct cache_detail rsi_cache_template = {
268         .owner          = THIS_MODULE,
269         .hash_size      = RSI_HASHMAX,
270         .name           = "auth.rpcsec.init",
271         .cache_put      = rsi_put,
272         .cache_request  = rsi_request,
273         .cache_parse    = rsi_parse,
274         .match          = rsi_match,
275         .init           = rsi_init,
276         .update         = update_rsi,
277         .alloc          = rsi_alloc,
278 };
279 
280 static struct rsi *rsi_lookup(struct cache_detail *cd, struct rsi *item)
281 {
282         struct cache_head *ch;
283         int hash = rsi_hash(item);
284 
285         ch = sunrpc_cache_lookup(cd, &item->h, hash);
286         if (ch)
287                 return container_of(ch, struct rsi, h);
288         else
289                 return NULL;
290 }
291 
292 static struct rsi *rsi_update(struct cache_detail *cd, struct rsi *new, struct rsi *old)
293 {
294         struct cache_head *ch;
295         int hash = rsi_hash(new);
296 
297         ch = sunrpc_cache_update(cd, &new->h,
298                                  &old->h, hash);
299         if (ch)
300                 return container_of(ch, struct rsi, h);
301         else
302                 return NULL;
303 }
304 
305 
306 /*
307  * The rpcsec_context cache is used to store a context that is
308  * used in data exchange.
309  * The key is a context handle. The content is:
310  *  uid, gidlist, mechanism, service-set, mech-specific-data
311  */
312 
313 #define RSC_HASHBITS    10
314 #define RSC_HASHMAX     (1<<RSC_HASHBITS)
315 
316 #define GSS_SEQ_WIN     128
317 
318 struct gss_svc_seq_data {
319         /* highest seq number seen so far: */
320         int                     sd_max;
321         /* for i such that sd_max-GSS_SEQ_WIN < i <= sd_max, the i-th bit of
322          * sd_win is nonzero iff sequence number i has been seen already: */
323         unsigned long           sd_win[GSS_SEQ_WIN/BITS_PER_LONG];
324         spinlock_t              sd_lock;
325 };
326 
327 struct rsc {
328         struct cache_head       h;
329         struct xdr_netobj       handle;
330         struct svc_cred         cred;
331         struct gss_svc_seq_data seqdata;
332         struct gss_ctx          *mechctx;
333 };
334 
335 static struct rsc *rsc_update(struct cache_detail *cd, struct rsc *new, struct rsc *old);
336 static struct rsc *rsc_lookup(struct cache_detail *cd, struct rsc *item);
337 
338 static void rsc_free(struct rsc *rsci)
339 {
340         kfree(rsci->handle.data);
341         if (rsci->mechctx)
342                 gss_delete_sec_context(&rsci->mechctx);
343         free_svc_cred(&rsci->cred);
344 }
345 
346 static void rsc_put(struct kref *ref)
347 {
348         struct rsc *rsci = container_of(ref, struct rsc, h.ref);
349 
350         rsc_free(rsci);
351         kfree(rsci);
352 }
353 
354 static inline int
355 rsc_hash(struct rsc *rsci)
356 {
357         return hash_mem(rsci->handle.data, rsci->handle.len, RSC_HASHBITS);
358 }
359 
360 static int
361 rsc_match(struct cache_head *a, struct cache_head *b)
362 {
363         struct rsc *new = container_of(a, struct rsc, h);
364         struct rsc *tmp = container_of(b, struct rsc, h);
365 
366         return netobj_equal(&new->handle, &tmp->handle);
367 }
368 
369 static void
370 rsc_init(struct cache_head *cnew, struct cache_head *ctmp)
371 {
372         struct rsc *new = container_of(cnew, struct rsc, h);
373         struct rsc *tmp = container_of(ctmp, struct rsc, h);
374 
375         new->handle.len = tmp->handle.len;
376         tmp->handle.len = 0;
377         new->handle.data = tmp->handle.data;
378         tmp->handle.data = NULL;
379         new->mechctx = NULL;
380         init_svc_cred(&new->cred);
381 }
382 
383 static void
384 update_rsc(struct cache_head *cnew, struct cache_head *ctmp)
385 {
386         struct rsc *new = container_of(cnew, struct rsc, h);
387         struct rsc *tmp = container_of(ctmp, struct rsc, h);
388 
389         new->mechctx = tmp->mechctx;
390         tmp->mechctx = NULL;
391         memset(&new->seqdata, 0, sizeof(new->seqdata));
392         spin_lock_init(&new->seqdata.sd_lock);
393         new->cred = tmp->cred;
394         init_svc_cred(&tmp->cred);
395 }
396 
397 static struct cache_head *
398 rsc_alloc(void)
399 {
400         struct rsc *rsci = kmalloc(sizeof(*rsci), GFP_KERNEL);
401         if (rsci)
402                 return &rsci->h;
403         else
404                 return NULL;
405 }
406 
407 static int rsc_parse(struct cache_detail *cd,
408                      char *mesg, int mlen)
409 {
410         /* contexthandle expiry [ uid gid N <n gids> mechname ...mechdata... ] */
411         char *buf = mesg;
412         int id;
413         int len, rv;
414         struct rsc rsci, *rscp = NULL;
415         time_t expiry;
416         int status = -EINVAL;
417         struct gss_api_mech *gm = NULL;
418 
419         memset(&rsci, 0, sizeof(rsci));
420         /* context handle */
421         len = qword_get(&mesg, buf, mlen);
422         if (len < 0) goto out;
423         status = -ENOMEM;
424         if (dup_to_netobj(&rsci.handle, buf, len))
425                 goto out;
426 
427         rsci.h.flags = 0;
428         /* expiry */
429         expiry = get_expiry(&mesg);
430         status = -EINVAL;
431         if (expiry == 0)
432                 goto out;
433 
434         rscp = rsc_lookup(cd, &rsci);
435         if (!rscp)
436                 goto out;
437 
438         /* uid, or NEGATIVE */
439         rv = get_int(&mesg, &id);
440         if (rv == -EINVAL)
441                 goto out;
442         if (rv == -ENOENT)
443                 set_bit(CACHE_NEGATIVE, &rsci.h.flags);
444         else {
445                 int N, i;
446 
447                 /*
448                  * NOTE: we skip uid_valid()/gid_valid() checks here:
449                  * instead, * -1 id's are later mapped to the
450                  * (export-specific) anonymous id by nfsd_setuser.
451                  *
452                  * (But supplementary gid's get no such special
453                  * treatment so are checked for validity here.)
454                  */
455                 /* uid */
456                 rsci.cred.cr_uid = make_kuid(&init_user_ns, id);
457 
458                 /* gid */
459                 if (get_int(&mesg, &id))
460                         goto out;
461                 rsci.cred.cr_gid = make_kgid(&init_user_ns, id);
462 
463                 /* number of additional gid's */
464                 if (get_int(&mesg, &N))
465                         goto out;
466                 if (N < 0 || N > NGROUPS_MAX)
467                         goto out;
468                 status = -ENOMEM;
469                 rsci.cred.cr_group_info = groups_alloc(N);
470                 if (rsci.cred.cr_group_info == NULL)
471                         goto out;
472 
473                 /* gid's */
474                 status = -EINVAL;
475                 for (i=0; i<N; i++) {
476                         kgid_t kgid;
477                         if (get_int(&mesg, &id))
478                                 goto out;
479                         kgid = make_kgid(&init_user_ns, id);
480                         if (!gid_valid(kgid))
481                                 goto out;
482                         rsci.cred.cr_group_info->gid[i] = kgid;
483                 }
484                 groups_sort(rsci.cred.cr_group_info);
485 
486                 /* mech name */
487                 len = qword_get(&mesg, buf, mlen);
488                 if (len < 0)
489                         goto out;
490                 gm = rsci.cred.cr_gss_mech = gss_mech_get_by_name(buf);
491                 status = -EOPNOTSUPP;
492                 if (!gm)
493                         goto out;
494 
495                 status = -EINVAL;
496                 /* mech-specific data: */
497                 len = qword_get(&mesg, buf, mlen);
498                 if (len < 0)
499                         goto out;
500                 status = gss_import_sec_context(buf, len, gm, &rsci.mechctx,
501                                                 NULL, GFP_KERNEL);
502                 if (status)
503                         goto out;
504 
505                 /* get client name */
506                 len = qword_get(&mesg, buf, mlen);
507                 if (len > 0) {
508                         rsci.cred.cr_principal = kstrdup(buf, GFP_KERNEL);
509                         if (!rsci.cred.cr_principal) {
510                                 status = -ENOMEM;
511                                 goto out;
512                         }
513                 }
514 
515         }
516         rsci.h.expiry_time = expiry;
517         rscp = rsc_update(cd, &rsci, rscp);
518         status = 0;
519 out:
520         rsc_free(&rsci);
521         if (rscp)
522                 cache_put(&rscp->h, cd);
523         else
524                 status = -ENOMEM;
525         return status;
526 }
527 
528 static const struct cache_detail rsc_cache_template = {
529         .owner          = THIS_MODULE,
530         .hash_size      = RSC_HASHMAX,
531         .name           = "auth.rpcsec.context",
532         .cache_put      = rsc_put,
533         .cache_parse    = rsc_parse,
534         .match          = rsc_match,
535         .init           = rsc_init,
536         .update         = update_rsc,
537         .alloc          = rsc_alloc,
538 };
539 
540 static struct rsc *rsc_lookup(struct cache_detail *cd, struct rsc *item)
541 {
542         struct cache_head *ch;
543         int hash = rsc_hash(item);
544 
545         ch = sunrpc_cache_lookup(cd, &item->h, hash);
546         if (ch)
547                 return container_of(ch, struct rsc, h);
548         else
549                 return NULL;
550 }
551 
552 static struct rsc *rsc_update(struct cache_detail *cd, struct rsc *new, struct rsc *old)
553 {
554         struct cache_head *ch;
555         int hash = rsc_hash(new);
556 
557         ch = sunrpc_cache_update(cd, &new->h,
558                                  &old->h, hash);
559         if (ch)
560                 return container_of(ch, struct rsc, h);
561         else
562                 return NULL;
563 }
564 
565 
566 static struct rsc *
567 gss_svc_searchbyctx(struct cache_detail *cd, struct xdr_netobj *handle)
568 {
569         struct rsc rsci;
570         struct rsc *found;
571 
572         memset(&rsci, 0, sizeof(rsci));
573         if (dup_to_netobj(&rsci.handle, handle->data, handle->len))
574                 return NULL;
575         found = rsc_lookup(cd, &rsci);
576         rsc_free(&rsci);
577         if (!found)
578                 return NULL;
579         if (cache_check(cd, &found->h, NULL))
580                 return NULL;
581         return found;
582 }
583 
584 /* Implements sequence number algorithm as specified in RFC 2203. */
585 static int
586 gss_check_seq_num(struct rsc *rsci, int seq_num)
587 {
588         struct gss_svc_seq_data *sd = &rsci->seqdata;
589 
590         spin_lock(&sd->sd_lock);
591         if (seq_num > sd->sd_max) {
592                 if (seq_num >= sd->sd_max + GSS_SEQ_WIN) {
593                         memset(sd->sd_win,0,sizeof(sd->sd_win));
594                         sd->sd_max = seq_num;
595                 } else while (sd->sd_max < seq_num) {
596                         sd->sd_max++;
597                         __clear_bit(sd->sd_max % GSS_SEQ_WIN, sd->sd_win);
598                 }
599                 __set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win);
600                 goto ok;
601         } else if (seq_num <= sd->sd_max - GSS_SEQ_WIN) {
602                 goto drop;
603         }
604         /* sd_max - GSS_SEQ_WIN < seq_num <= sd_max */
605         if (__test_and_set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win))
606                 goto drop;
607 ok:
608         spin_unlock(&sd->sd_lock);
609         return 1;
610 drop:
611         spin_unlock(&sd->sd_lock);
612         return 0;
613 }
614 
615 static inline u32 round_up_to_quad(u32 i)
616 {
617         return (i + 3 ) & ~3;
618 }
619 
620 static inline int
621 svc_safe_getnetobj(struct kvec *argv, struct xdr_netobj *o)
622 {
623         int l;
624 
625         if (argv->iov_len < 4)
626                 return -1;
627         o->len = svc_getnl(argv);
628         l = round_up_to_quad(o->len);
629         if (argv->iov_len < l)
630                 return -1;
631         o->data = argv->iov_base;
632         argv->iov_base += l;
633         argv->iov_len -= l;
634         return 0;
635 }
636 
637 static inline int
638 svc_safe_putnetobj(struct kvec *resv, struct xdr_netobj *o)
639 {
640         u8 *p;
641 
642         if (resv->iov_len + 4 > PAGE_SIZE)
643                 return -1;
644         svc_putnl(resv, o->len);
645         p = resv->iov_base + resv->iov_len;
646         resv->iov_len += round_up_to_quad(o->len);
647         if (resv->iov_len > PAGE_SIZE)
648                 return -1;
649         memcpy(p, o->data, o->len);
650         memset(p + o->len, 0, round_up_to_quad(o->len) - o->len);
651         return 0;
652 }
653 
654 /*
655  * Verify the checksum on the header and return SVC_OK on success.
656  * Otherwise, return SVC_DROP (in the case of a bad sequence number)
657  * or return SVC_DENIED and indicate error in authp.
658  */
659 static int
660 gss_verify_header(struct svc_rqst *rqstp, struct rsc *rsci,
661                   __be32 *rpcstart, struct rpc_gss_wire_cred *gc, __be32 *authp)
662 {
663         struct gss_ctx          *ctx_id = rsci->mechctx;
664         struct xdr_buf          rpchdr;
665         struct xdr_netobj       checksum;
666         u32                     flavor = 0;
667         struct kvec             *argv = &rqstp->rq_arg.head[0];
668         struct kvec             iov;
669 
670         /* data to compute the checksum over: */
671         iov.iov_base = rpcstart;
672         iov.iov_len = (u8 *)argv->iov_base - (u8 *)rpcstart;
673         xdr_buf_from_iov(&iov, &rpchdr);
674 
675         *authp = rpc_autherr_badverf;
676         if (argv->iov_len < 4)
677                 return SVC_DENIED;
678         flavor = svc_getnl(argv);
679         if (flavor != RPC_AUTH_GSS)
680                 return SVC_DENIED;
681         if (svc_safe_getnetobj(argv, &checksum))
682                 return SVC_DENIED;
683 
684         if (rqstp->rq_deferred) /* skip verification of revisited request */
685                 return SVC_OK;
686         if (gss_verify_mic(ctx_id, &rpchdr, &checksum) != GSS_S_COMPLETE) {
687                 *authp = rpcsec_gsserr_credproblem;
688                 return SVC_DENIED;
689         }
690 
691         if (gc->gc_seq > MAXSEQ) {
692                 dprintk("RPC:       svcauth_gss: discarding request with "
693                                 "large sequence number %d\n", gc->gc_seq);
694                 *authp = rpcsec_gsserr_ctxproblem;
695                 return SVC_DENIED;
696         }
697         if (!gss_check_seq_num(rsci, gc->gc_seq)) {
698                 dprintk("RPC:       svcauth_gss: discarding request with "
699                                 "old sequence number %d\n", gc->gc_seq);
700                 return SVC_DROP;
701         }
702         return SVC_OK;
703 }
704 
705 static int
706 gss_write_null_verf(struct svc_rqst *rqstp)
707 {
708         __be32     *p;
709 
710         svc_putnl(rqstp->rq_res.head, RPC_AUTH_NULL);
711         p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len;
712         /* don't really need to check if head->iov_len > PAGE_SIZE ... */
713         *p++ = 0;
714         if (!xdr_ressize_check(rqstp, p))
715                 return -1;
716         return 0;
717 }
718 
719 static int
720 gss_write_verf(struct svc_rqst *rqstp, struct gss_ctx *ctx_id, u32 seq)
721 {
722         __be32                  *xdr_seq;
723         u32                     maj_stat;
724         struct xdr_buf          verf_data;
725         struct xdr_netobj       mic;
726         __be32                  *p;
727         struct kvec             iov;
728         int err = -1;
729 
730         svc_putnl(rqstp->rq_res.head, RPC_AUTH_GSS);
731         xdr_seq = kmalloc(4, GFP_KERNEL);
732         if (!xdr_seq)
733                 return -1;
734         *xdr_seq = htonl(seq);
735 
736         iov.iov_base = xdr_seq;
737         iov.iov_len = 4;
738         xdr_buf_from_iov(&iov, &verf_data);
739         p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len;
740         mic.data = (u8 *)(p + 1);
741         maj_stat = gss_get_mic(ctx_id, &verf_data, &mic);
742         if (maj_stat != GSS_S_COMPLETE)
743                 goto out;
744         *p++ = htonl(mic.len);
745         memset((u8 *)p + mic.len, 0, round_up_to_quad(mic.len) - mic.len);
746         p += XDR_QUADLEN(mic.len);
747         if (!xdr_ressize_check(rqstp, p))
748                 goto out;
749         err = 0;
750 out:
751         kfree(xdr_seq);
752         return err;
753 }
754 
755 struct gss_domain {
756         struct auth_domain      h;
757         u32                     pseudoflavor;
758 };
759 
760 static struct auth_domain *
761 find_gss_auth_domain(struct gss_ctx *ctx, u32 svc)
762 {
763         char *name;
764 
765         name = gss_service_to_auth_domain_name(ctx->mech_type, svc);
766         if (!name)
767                 return NULL;
768         return auth_domain_find(name);
769 }
770 
771 static struct auth_ops svcauthops_gss;
772 
773 u32 svcauth_gss_flavor(struct auth_domain *dom)
774 {
775         struct gss_domain *gd = container_of(dom, struct gss_domain, h);
776 
777         return gd->pseudoflavor;
778 }
779 
780 EXPORT_SYMBOL_GPL(svcauth_gss_flavor);
781 
782 int
783 svcauth_gss_register_pseudoflavor(u32 pseudoflavor, char * name)
784 {
785         struct gss_domain       *new;
786         struct auth_domain      *test;
787         int                     stat = -ENOMEM;
788 
789         new = kmalloc(sizeof(*new), GFP_KERNEL);
790         if (!new)
791                 goto out;
792         kref_init(&new->h.ref);
793         new->h.name = kstrdup(name, GFP_KERNEL);
794         if (!new->h.name)
795                 goto out_free_dom;
796         new->h.flavour = &svcauthops_gss;
797         new->pseudoflavor = pseudoflavor;
798 
799         stat = 0;
800         test = auth_domain_lookup(name, &new->h);
801         if (test != &new->h) { /* Duplicate registration */
802                 auth_domain_put(test);
803                 kfree(new->h.name);
804                 goto out_free_dom;
805         }
806         return 0;
807 
808 out_free_dom:
809         kfree(new);
810 out:
811         return stat;
812 }
813 
814 EXPORT_SYMBOL_GPL(svcauth_gss_register_pseudoflavor);
815 
816 static inline int
817 read_u32_from_xdr_buf(struct xdr_buf *buf, int base, u32 *obj)
818 {
819         __be32  raw;
820         int     status;
821 
822         status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj));
823         if (status)
824                 return status;
825         *obj = ntohl(raw);
826         return 0;
827 }
828 
829 /* It would be nice if this bit of code could be shared with the client.
830  * Obstacles:
831  *      The client shouldn't malloc(), would have to pass in own memory.
832  *      The server uses base of head iovec as read pointer, while the
833  *      client uses separate pointer. */
834 static int
835 unwrap_integ_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx)
836 {
837         int stat = -EINVAL;
838         u32 integ_len, maj_stat;
839         struct xdr_netobj mic;
840         struct xdr_buf integ_buf;
841 
842         /* NFS READ normally uses splice to send data in-place. However
843          * the data in cache can change after the reply's MIC is computed
844          * but before the RPC reply is sent. To prevent the client from
845          * rejecting the server-computed MIC in this somewhat rare case,
846          * do not use splice with the GSS integrity service.
847          */
848         clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
849 
850         /* Did we already verify the signature on the original pass through? */
851         if (rqstp->rq_deferred)
852                 return 0;
853 
854         integ_len = svc_getnl(&buf->head[0]);
855         if (integ_len & 3)
856                 return stat;
857         if (integ_len > buf->len)
858                 return stat;
859         if (xdr_buf_subsegment(buf, &integ_buf, 0, integ_len)) {
860                 WARN_ON_ONCE(1);
861                 return stat;
862         }
863         /* copy out mic... */
864         if (read_u32_from_xdr_buf(buf, integ_len, &mic.len))
865                 return stat;
866         if (mic.len > RPC_MAX_AUTH_SIZE)
867                 return stat;
868         mic.data = kmalloc(mic.len, GFP_KERNEL);
869         if (!mic.data)
870                 return stat;
871         if (read_bytes_from_xdr_buf(buf, integ_len + 4, mic.data, mic.len))
872                 goto out;
873         maj_stat = gss_verify_mic(ctx, &integ_buf, &mic);
874         if (maj_stat != GSS_S_COMPLETE)
875                 goto out;
876         if (svc_getnl(&buf->head[0]) != seq)
877                 goto out;
878         /* trim off the mic and padding at the end before returning */
879         xdr_buf_trim(buf, round_up_to_quad(mic.len) + 4);
880         stat = 0;
881 out:
882         kfree(mic.data);
883         return stat;
884 }
885 
886 static inline int
887 total_buf_len(struct xdr_buf *buf)
888 {
889         return buf->head[0].iov_len + buf->page_len + buf->tail[0].iov_len;
890 }
891 
892 static void
893 fix_priv_head(struct xdr_buf *buf, int pad)
894 {
895         if (buf->page_len == 0) {
896                 /* We need to adjust head and buf->len in tandem in this
897                  * case to make svc_defer() work--it finds the original
898                  * buffer start using buf->len - buf->head[0].iov_len. */
899                 buf->head[0].iov_len -= pad;
900         }
901 }
902 
903 static int
904 unwrap_priv_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx)
905 {
906         u32 priv_len, maj_stat;
907         int pad, saved_len, remaining_len, offset;
908 
909         clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
910 
911         priv_len = svc_getnl(&buf->head[0]);
912         if (rqstp->rq_deferred) {
913                 /* Already decrypted last time through! The sequence number
914                  * check at out_seq is unnecessary but harmless: */
915                 goto out_seq;
916         }
917         /* buf->len is the number of bytes from the original start of the
918          * request to the end, where head[0].iov_len is just the bytes
919          * not yet read from the head, so these two values are different: */
920         remaining_len = total_buf_len(buf);
921         if (priv_len > remaining_len)
922                 return -EINVAL;
923         pad = remaining_len - priv_len;
924         buf->len -= pad;
925         fix_priv_head(buf, pad);
926 
927         /* Maybe it would be better to give gss_unwrap a length parameter: */
928         saved_len = buf->len;
929         buf->len = priv_len;
930         maj_stat = gss_unwrap(ctx, 0, buf);
931         pad = priv_len - buf->len;
932         buf->len = saved_len;
933         buf->len -= pad;
934         /* The upper layers assume the buffer is aligned on 4-byte boundaries.
935          * In the krb5p case, at least, the data ends up offset, so we need to
936          * move it around. */
937         /* XXX: This is very inefficient.  It would be better to either do
938          * this while we encrypt, or maybe in the receive code, if we can peak
939          * ahead and work out the service and mechanism there. */
940         offset = buf->head[0].iov_len % 4;
941         if (offset) {
942                 buf->buflen = RPCSVC_MAXPAYLOAD;
943                 xdr_shift_buf(buf, offset);
944                 fix_priv_head(buf, pad);
945         }
946         if (maj_stat != GSS_S_COMPLETE)
947                 return -EINVAL;
948 out_seq:
949         if (svc_getnl(&buf->head[0]) != seq)
950                 return -EINVAL;
951         return 0;
952 }
953 
954 struct gss_svc_data {
955         /* decoded gss client cred: */
956         struct rpc_gss_wire_cred        clcred;
957         /* save a pointer to the beginning of the encoded verifier,
958          * for use in encryption/checksumming in svcauth_gss_release: */
959         __be32                          *verf_start;
960         struct rsc                      *rsci;
961 };
962 
963 static int
964 svcauth_gss_set_client(struct svc_rqst *rqstp)
965 {
966         struct gss_svc_data *svcdata = rqstp->rq_auth_data;
967         struct rsc *rsci = svcdata->rsci;
968         struct rpc_gss_wire_cred *gc = &svcdata->clcred;
969         int stat;
970 
971         /*
972          * A gss export can be specified either by:
973          *      export  *(sec=krb5,rw)
974          * or by
975          *      export gss/krb5(rw)
976          * The latter is deprecated; but for backwards compatibility reasons
977          * the nfsd code will still fall back on trying it if the former
978          * doesn't work; so we try to make both available to nfsd, below.
979          */
980         rqstp->rq_gssclient = find_gss_auth_domain(rsci->mechctx, gc->gc_svc);
981         if (rqstp->rq_gssclient == NULL)
982                 return SVC_DENIED;
983         stat = svcauth_unix_set_client(rqstp);
984         if (stat == SVC_DROP || stat == SVC_CLOSE)
985                 return stat;
986         return SVC_OK;
987 }
988 
989 static inline int
990 gss_write_init_verf(struct cache_detail *cd, struct svc_rqst *rqstp,
991                 struct xdr_netobj *out_handle, int *major_status)
992 {
993         struct rsc *rsci;
994         int        rc;
995 
996         if (*major_status != GSS_S_COMPLETE)
997                 return gss_write_null_verf(rqstp);
998         rsci = gss_svc_searchbyctx(cd, out_handle);
999         if (rsci == NULL) {
1000                 *major_status = GSS_S_NO_CONTEXT;
1001                 return gss_write_null_verf(rqstp);
1002         }
1003         rc = gss_write_verf(rqstp, rsci->mechctx, GSS_SEQ_WIN);
1004         cache_put(&rsci->h, cd);
1005         return rc;
1006 }
1007 
1008 static inline int
1009 gss_read_common_verf(struct rpc_gss_wire_cred *gc,
1010                      struct kvec *argv, __be32 *authp,
1011                      struct xdr_netobj *in_handle)
1012 {
1013         /* Read the verifier; should be NULL: */
1014         *authp = rpc_autherr_badverf;
1015         if (argv->iov_len < 2 * 4)
1016                 return SVC_DENIED;
1017         if (svc_getnl(argv) != RPC_AUTH_NULL)
1018                 return SVC_DENIED;
1019         if (svc_getnl(argv) != 0)
1020                 return SVC_DENIED;
1021         /* Martial context handle and token for upcall: */
1022         *authp = rpc_autherr_badcred;
1023         if (gc->gc_proc == RPC_GSS_PROC_INIT && gc->gc_ctx.len != 0)
1024                 return SVC_DENIED;
1025         if (dup_netobj(in_handle, &gc->gc_ctx))
1026                 return SVC_CLOSE;
1027         *authp = rpc_autherr_badverf;
1028 
1029         return 0;
1030 }
1031 
1032 static inline int
1033 gss_read_verf(struct rpc_gss_wire_cred *gc,
1034               struct kvec *argv, __be32 *authp,
1035               struct xdr_netobj *in_handle,
1036               struct xdr_netobj *in_token)
1037 {
1038         struct xdr_netobj tmpobj;
1039         int res;
1040 
1041         res = gss_read_common_verf(gc, argv, authp, in_handle);
1042         if (res)
1043                 return res;
1044 
1045         if (svc_safe_getnetobj(argv, &tmpobj)) {
1046                 kfree(in_handle->data);
1047                 return SVC_DENIED;
1048         }
1049         if (dup_netobj(in_token, &tmpobj)) {
1050                 kfree(in_handle->data);
1051                 return SVC_CLOSE;
1052         }
1053 
1054         return 0;
1055 }
1056 
1057 /* Ok this is really heavily depending on a set of semantics in
1058  * how rqstp is set up by svc_recv and pages laid down by the
1059  * server when reading a request. We are basically guaranteed that
1060  * the token lays all down linearly across a set of pages, starting
1061  * at iov_base in rq_arg.head[0] which happens to be the first of a
1062  * set of pages stored in rq_pages[].
1063  * rq_arg.head[0].iov_base will provide us the page_base to pass
1064  * to the upcall.
1065  */
1066 static inline int
1067 gss_read_proxy_verf(struct svc_rqst *rqstp,
1068                     struct rpc_gss_wire_cred *gc, __be32 *authp,
1069                     struct xdr_netobj *in_handle,
1070                     struct gssp_in_token *in_token)
1071 {
1072         struct kvec *argv = &rqstp->rq_arg.head[0];
1073         u32 inlen;
1074         int res;
1075 
1076         res = gss_read_common_verf(gc, argv, authp, in_handle);
1077         if (res)
1078                 return res;
1079 
1080         inlen = svc_getnl(argv);
1081         if (inlen > (argv->iov_len + rqstp->rq_arg.page_len))
1082                 return SVC_DENIED;
1083 
1084         in_token->pages = rqstp->rq_pages;
1085         in_token->page_base = (ulong)argv->iov_base & ~PAGE_MASK;
1086         in_token->page_len = inlen;
1087 
1088         return 0;
1089 }
1090 
1091 static inline int
1092 gss_write_resv(struct kvec *resv, size_t size_limit,
1093                struct xdr_netobj *out_handle, struct xdr_netobj *out_token,
1094                int major_status, int minor_status)
1095 {
1096         if (resv->iov_len + 4 > size_limit)
1097                 return -1;
1098         svc_putnl(resv, RPC_SUCCESS);
1099         if (svc_safe_putnetobj(resv, out_handle))
1100                 return -1;
1101         if (resv->iov_len + 3 * 4 > size_limit)
1102                 return -1;
1103         svc_putnl(resv, major_status);
1104         svc_putnl(resv, minor_status);
1105         svc_putnl(resv, GSS_SEQ_WIN);
1106         if (svc_safe_putnetobj(resv, out_token))
1107                 return -1;
1108         return 0;
1109 }
1110 
1111 /*
1112  * Having read the cred already and found we're in the context
1113  * initiation case, read the verifier and initiate (or check the results
1114  * of) upcalls to userspace for help with context initiation.  If
1115  * the upcall results are available, write the verifier and result.
1116  * Otherwise, drop the request pending an answer to the upcall.
1117  */
1118 static int svcauth_gss_legacy_init(struct svc_rqst *rqstp,
1119                         struct rpc_gss_wire_cred *gc, __be32 *authp)
1120 {
1121         struct kvec *argv = &rqstp->rq_arg.head[0];
1122         struct kvec *resv = &rqstp->rq_res.head[0];
1123         struct rsi *rsip, rsikey;
1124         int ret;
1125         struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id);
1126 
1127         memset(&rsikey, 0, sizeof(rsikey));
1128         ret = gss_read_verf(gc, argv, authp,
1129                             &rsikey.in_handle, &rsikey.in_token);
1130         if (ret)
1131                 return ret;
1132 
1133         /* Perform upcall, or find upcall result: */
1134         rsip = rsi_lookup(sn->rsi_cache, &rsikey);
1135         rsi_free(&rsikey);
1136         if (!rsip)
1137                 return SVC_CLOSE;
1138         if (cache_check(sn->rsi_cache, &rsip->h, &rqstp->rq_chandle) < 0)
1139                 /* No upcall result: */
1140                 return SVC_CLOSE;
1141 
1142         ret = SVC_CLOSE;
1143         /* Got an answer to the upcall; use it: */
1144         if (gss_write_init_verf(sn->rsc_cache, rqstp,
1145                                 &rsip->out_handle, &rsip->major_status))
1146                 goto out;
1147         if (gss_write_resv(resv, PAGE_SIZE,
1148                            &rsip->out_handle, &rsip->out_token,
1149                            rsip->major_status, rsip->minor_status))
1150                 goto out;
1151 
1152         ret = SVC_COMPLETE;
1153 out:
1154         cache_put(&rsip->h, sn->rsi_cache);
1155         return ret;
1156 }
1157 
1158 static int gss_proxy_save_rsc(struct cache_detail *cd,
1159                                 struct gssp_upcall_data *ud,
1160                                 uint64_t *handle)
1161 {
1162         struct rsc rsci, *rscp = NULL;
1163         static atomic64_t ctxhctr;
1164         long long ctxh;
1165         struct gss_api_mech *gm = NULL;
1166         time_t expiry;
1167         int status = -EINVAL;
1168 
1169         memset(&rsci, 0, sizeof(rsci));
1170         /* context handle */
1171         status = -ENOMEM;
1172         /* the handle needs to be just a unique id,
1173          * use a static counter */
1174         ctxh = atomic64_inc_return(&ctxhctr);
1175 
1176         /* make a copy for the caller */
1177         *handle = ctxh;
1178 
1179         /* make a copy for the rsc cache */
1180         if (dup_to_netobj(&rsci.handle, (char *)handle, sizeof(uint64_t)))
1181                 goto out;
1182         rscp = rsc_lookup(cd, &rsci);
1183         if (!rscp)
1184                 goto out;
1185 
1186         /* creds */
1187         if (!ud->found_creds) {
1188                 /* userspace seem buggy, we should always get at least a
1189                  * mapping to nobody */
1190                 dprintk("RPC:       No creds found!\n");
1191                 goto out;
1192         } else {
1193 
1194                 /* steal creds */
1195                 rsci.cred = ud->creds;
1196                 memset(&ud->creds, 0, sizeof(struct svc_cred));
1197 
1198                 status = -EOPNOTSUPP;
1199                 /* get mech handle from OID */
1200                 gm = gss_mech_get_by_OID(&ud->mech_oid);
1201                 if (!gm)
1202                         goto out;
1203                 rsci.cred.cr_gss_mech = gm;
1204 
1205                 status = -EINVAL;
1206                 /* mech-specific data: */
1207                 status = gss_import_sec_context(ud->out_handle.data,
1208                                                 ud->out_handle.len,
1209                                                 gm, &rsci.mechctx,
1210                                                 &expiry, GFP_KERNEL);
1211                 if (status)
1212                         goto out;
1213         }
1214 
1215         rsci.h.expiry_time = expiry;
1216         rscp = rsc_update(cd, &rsci, rscp);
1217         status = 0;
1218 out:
1219         rsc_free(&rsci);
1220         if (rscp)
1221                 cache_put(&rscp->h, cd);
1222         else
1223                 status = -ENOMEM;
1224         return status;
1225 }
1226 
1227 static int svcauth_gss_proxy_init(struct svc_rqst *rqstp,
1228                         struct rpc_gss_wire_cred *gc, __be32 *authp)
1229 {
1230         struct kvec *resv = &rqstp->rq_res.head[0];
1231         struct xdr_netobj cli_handle;
1232         struct gssp_upcall_data ud;
1233         uint64_t handle;
1234         int status;
1235         int ret;
1236         struct net *net = rqstp->rq_xprt->xpt_net;
1237         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1238 
1239         memset(&ud, 0, sizeof(ud));
1240         ret = gss_read_proxy_verf(rqstp, gc, authp,
1241                                   &ud.in_handle, &ud.in_token);
1242         if (ret)
1243                 return ret;
1244 
1245         ret = SVC_CLOSE;
1246 
1247         /* Perform synchronous upcall to gss-proxy */
1248         status = gssp_accept_sec_context_upcall(net, &ud);
1249         if (status)
1250                 goto out;
1251 
1252         dprintk("RPC:       svcauth_gss: gss major status = %d "
1253                         "minor status = %d\n",
1254                         ud.major_status, ud.minor_status);
1255 
1256         switch (ud.major_status) {
1257         case GSS_S_CONTINUE_NEEDED:
1258                 cli_handle = ud.out_handle;
1259                 break;
1260         case GSS_S_COMPLETE:
1261                 status = gss_proxy_save_rsc(sn->rsc_cache, &ud, &handle);
1262                 if (status)
1263                         goto out;
1264                 cli_handle.data = (u8 *)&handle;
1265                 cli_handle.len = sizeof(handle);
1266                 break;
1267         default:
1268                 ret = SVC_CLOSE;
1269                 goto out;
1270         }
1271 
1272         /* Got an answer to the upcall; use it: */
1273         if (gss_write_init_verf(sn->rsc_cache, rqstp,
1274                                 &cli_handle, &ud.major_status))
1275                 goto out;
1276         if (gss_write_resv(resv, PAGE_SIZE,
1277                            &cli_handle, &ud.out_token,
1278                            ud.major_status, ud.minor_status))
1279                 goto out;
1280 
1281         ret = SVC_COMPLETE;
1282 out:
1283         gssp_free_upcall_data(&ud);
1284         return ret;
1285 }
1286 
1287 /*
1288  * Try to set the sn->use_gss_proxy variable to a new value. We only allow
1289  * it to be changed if it's currently undefined (-1). If it's any other value
1290  * then return -EBUSY unless the type wouldn't have changed anyway.
1291  */
1292 static int set_gss_proxy(struct net *net, int type)
1293 {
1294         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1295         int ret;
1296 
1297         WARN_ON_ONCE(type != 0 && type != 1);
1298         ret = cmpxchg(&sn->use_gss_proxy, -1, type);
1299         if (ret != -1 && ret != type)
1300                 return -EBUSY;
1301         return 0;
1302 }
1303 
1304 static bool use_gss_proxy(struct net *net)
1305 {
1306         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1307 
1308         /* If use_gss_proxy is still undefined, then try to disable it */
1309         if (sn->use_gss_proxy == -1)
1310                 set_gss_proxy(net, 0);
1311         return sn->use_gss_proxy;
1312 }
1313 
1314 #ifdef CONFIG_PROC_FS
1315 
1316 static ssize_t write_gssp(struct file *file, const char __user *buf,
1317                          size_t count, loff_t *ppos)
1318 {
1319         struct net *net = PDE_DATA(file_inode(file));
1320         char tbuf[20];
1321         unsigned long i;
1322         int res;
1323 
1324         if (*ppos || count > sizeof(tbuf)-1)
1325                 return -EINVAL;
1326         if (copy_from_user(tbuf, buf, count))
1327                 return -EFAULT;
1328 
1329         tbuf[count] = 0;
1330         res = kstrtoul(tbuf, 0, &i);
1331         if (res)
1332                 return res;
1333         if (i != 1)
1334                 return -EINVAL;
1335         res = set_gssp_clnt(net);
1336         if (res)
1337                 return res;
1338         res = set_gss_proxy(net, 1);
1339         if (res)
1340                 return res;
1341         return count;
1342 }
1343 
1344 static ssize_t read_gssp(struct file *file, char __user *buf,
1345                          size_t count, loff_t *ppos)
1346 {
1347         struct net *net = PDE_DATA(file_inode(file));
1348         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1349         unsigned long p = *ppos;
1350         char tbuf[10];
1351         size_t len;
1352 
1353         snprintf(tbuf, sizeof(tbuf), "%d\n", sn->use_gss_proxy);
1354         len = strlen(tbuf);
1355         if (p >= len)
1356                 return 0;
1357         len -= p;
1358         if (len > count)
1359                 len = count;
1360         if (copy_to_user(buf, (void *)(tbuf+p), len))
1361                 return -EFAULT;
1362         *ppos += len;
1363         return len;
1364 }
1365 
1366 static const struct file_operations use_gss_proxy_ops = {
1367         .open = nonseekable_open,
1368         .write = write_gssp,
1369         .read = read_gssp,
1370 };
1371 
1372 static int create_use_gss_proxy_proc_entry(struct net *net)
1373 {
1374         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1375         struct proc_dir_entry **p = &sn->use_gssp_proc;
1376 
1377         sn->use_gss_proxy = -1;
1378         *p = proc_create_data("use-gss-proxy", S_IFREG|S_IRUSR|S_IWUSR,
1379                               sn->proc_net_rpc,
1380                               &use_gss_proxy_ops, net);
1381         if (!*p)
1382                 return -ENOMEM;
1383         init_gssp_clnt(sn);
1384         return 0;
1385 }
1386 
1387 static void destroy_use_gss_proxy_proc_entry(struct net *net)
1388 {
1389         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1390 
1391         if (sn->use_gssp_proc) {
1392                 remove_proc_entry("use-gss-proxy", sn->proc_net_rpc); 
1393                 clear_gssp_clnt(sn);
1394         }
1395 }
1396 #else /* CONFIG_PROC_FS */
1397 
1398 static int create_use_gss_proxy_proc_entry(struct net *net)
1399 {
1400         return 0;
1401 }
1402 
1403 static void destroy_use_gss_proxy_proc_entry(struct net *net) {}
1404 
1405 #endif /* CONFIG_PROC_FS */
1406 
1407 /*
1408  * Accept an rpcsec packet.
1409  * If context establishment, punt to user space
1410  * If data exchange, verify/decrypt
1411  * If context destruction, handle here
1412  * In the context establishment and destruction case we encode
1413  * response here and return SVC_COMPLETE.
1414  */
1415 static int
1416 svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
1417 {
1418         struct kvec     *argv = &rqstp->rq_arg.head[0];
1419         struct kvec     *resv = &rqstp->rq_res.head[0];
1420         u32             crlen;
1421         struct gss_svc_data *svcdata = rqstp->rq_auth_data;
1422         struct rpc_gss_wire_cred *gc;
1423         struct rsc      *rsci = NULL;
1424         __be32          *rpcstart;
1425         __be32          *reject_stat = resv->iov_base + resv->iov_len;
1426         int             ret;
1427         struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id);
1428 
1429         dprintk("RPC:       svcauth_gss: argv->iov_len = %zd\n",
1430                         argv->iov_len);
1431 
1432         *authp = rpc_autherr_badcred;
1433         if (!svcdata)
1434                 svcdata = kmalloc(sizeof(*svcdata), GFP_KERNEL);
1435         if (!svcdata)
1436                 goto auth_err;
1437         rqstp->rq_auth_data = svcdata;
1438         svcdata->verf_start = NULL;
1439         svcdata->rsci = NULL;
1440         gc = &svcdata->clcred;
1441 
1442         /* start of rpc packet is 7 u32's back from here:
1443          * xid direction rpcversion prog vers proc flavour
1444          */
1445         rpcstart = argv->iov_base;
1446         rpcstart -= 7;
1447 
1448         /* credential is:
1449          *   version(==1), proc(0,1,2,3), seq, service (1,2,3), handle
1450          * at least 5 u32s, and is preceded by length, so that makes 6.
1451          */
1452 
1453         if (argv->iov_len < 5 * 4)
1454                 goto auth_err;
1455         crlen = svc_getnl(argv);
1456         if (svc_getnl(argv) != RPC_GSS_VERSION)
1457                 goto auth_err;
1458         gc->gc_proc = svc_getnl(argv);
1459         gc->gc_seq = svc_getnl(argv);
1460         gc->gc_svc = svc_getnl(argv);
1461         if (svc_safe_getnetobj(argv, &gc->gc_ctx))
1462                 goto auth_err;
1463         if (crlen != round_up_to_quad(gc->gc_ctx.len) + 5 * 4)
1464                 goto auth_err;
1465 
1466         if ((gc->gc_proc != RPC_GSS_PROC_DATA) && (rqstp->rq_proc != 0))
1467                 goto auth_err;
1468 
1469         *authp = rpc_autherr_badverf;
1470         switch (gc->gc_proc) {
1471         case RPC_GSS_PROC_INIT:
1472         case RPC_GSS_PROC_CONTINUE_INIT:
1473                 if (use_gss_proxy(SVC_NET(rqstp)))
1474                         return svcauth_gss_proxy_init(rqstp, gc, authp);
1475                 else
1476                         return svcauth_gss_legacy_init(rqstp, gc, authp);
1477         case RPC_GSS_PROC_DATA:
1478         case RPC_GSS_PROC_DESTROY:
1479                 /* Look up the context, and check the verifier: */
1480                 *authp = rpcsec_gsserr_credproblem;
1481                 rsci = gss_svc_searchbyctx(sn->rsc_cache, &gc->gc_ctx);
1482                 if (!rsci)
1483                         goto auth_err;
1484                 switch (gss_verify_header(rqstp, rsci, rpcstart, gc, authp)) {
1485                 case SVC_OK:
1486                         break;
1487                 case SVC_DENIED:
1488                         goto auth_err;
1489                 case SVC_DROP:
1490                         goto drop;
1491                 }
1492                 break;
1493         default:
1494                 *authp = rpc_autherr_rejectedcred;
1495                 goto auth_err;
1496         }
1497 
1498         /* now act upon the command: */
1499         switch (gc->gc_proc) {
1500         case RPC_GSS_PROC_DESTROY:
1501                 if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq))
1502                         goto auth_err;
1503                 /* Delete the entry from the cache_list and call cache_put */
1504                 sunrpc_cache_unhash(sn->rsc_cache, &rsci->h);
1505                 if (resv->iov_len + 4 > PAGE_SIZE)
1506                         goto drop;
1507                 svc_putnl(resv, RPC_SUCCESS);
1508                 goto complete;
1509         case RPC_GSS_PROC_DATA:
1510                 *authp = rpcsec_gsserr_ctxproblem;
1511                 svcdata->verf_start = resv->iov_base + resv->iov_len;
1512                 if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq))
1513                         goto auth_err;
1514                 rqstp->rq_cred = rsci->cred;
1515                 get_group_info(rsci->cred.cr_group_info);
1516                 *authp = rpc_autherr_badcred;
1517                 switch (gc->gc_svc) {
1518                 case RPC_GSS_SVC_NONE:
1519                         break;
1520                 case RPC_GSS_SVC_INTEGRITY:
1521                         /* placeholders for length and seq. number: */
1522                         svc_putnl(resv, 0);
1523                         svc_putnl(resv, 0);
1524                         if (unwrap_integ_data(rqstp, &rqstp->rq_arg,
1525                                         gc->gc_seq, rsci->mechctx))
1526                                 goto garbage_args;
1527                         rqstp->rq_auth_slack = RPC_MAX_AUTH_SIZE;
1528                         break;
1529                 case RPC_GSS_SVC_PRIVACY:
1530                         /* placeholders for length and seq. number: */
1531                         svc_putnl(resv, 0);
1532                         svc_putnl(resv, 0);
1533                         if (unwrap_priv_data(rqstp, &rqstp->rq_arg,
1534                                         gc->gc_seq, rsci->mechctx))
1535                                 goto garbage_args;
1536                         rqstp->rq_auth_slack = RPC_MAX_AUTH_SIZE * 2;
1537                         break;
1538                 default:
1539                         goto auth_err;
1540                 }
1541                 svcdata->rsci = rsci;
1542                 cache_get(&rsci->h);
1543                 rqstp->rq_cred.cr_flavor = gss_svc_to_pseudoflavor(
1544                                         rsci->mechctx->mech_type,
1545                                         GSS_C_QOP_DEFAULT,
1546                                         gc->gc_svc);
1547                 ret = SVC_OK;
1548                 goto out;
1549         }
1550 garbage_args:
1551         ret = SVC_GARBAGE;
1552         goto out;
1553 auth_err:
1554         /* Restore write pointer to its original value: */
1555         xdr_ressize_check(rqstp, reject_stat);
1556         ret = SVC_DENIED;
1557         goto out;
1558 complete:
1559         ret = SVC_COMPLETE;
1560         goto out;
1561 drop:
1562         ret = SVC_CLOSE;
1563 out:
1564         if (rsci)
1565                 cache_put(&rsci->h, sn->rsc_cache);
1566         return ret;
1567 }
1568 
1569 static __be32 *
1570 svcauth_gss_prepare_to_wrap(struct xdr_buf *resbuf, struct gss_svc_data *gsd)
1571 {
1572         __be32 *p;
1573         u32 verf_len;
1574 
1575         p = gsd->verf_start;
1576         gsd->verf_start = NULL;
1577 
1578         /* If the reply stat is nonzero, don't wrap: */
1579         if (*(p-1) != rpc_success)
1580                 return NULL;
1581         /* Skip the verifier: */
1582         p += 1;
1583         verf_len = ntohl(*p++);
1584         p += XDR_QUADLEN(verf_len);
1585         /* move accept_stat to right place: */
1586         memcpy(p, p + 2, 4);
1587         /* Also don't wrap if the accept stat is nonzero: */
1588         if (*p != rpc_success) {
1589                 resbuf->head[0].iov_len -= 2 * 4;
1590                 return NULL;
1591         }
1592         p++;
1593         return p;
1594 }
1595 
1596 static inline int
1597 svcauth_gss_wrap_resp_integ(struct svc_rqst *rqstp)
1598 {
1599         struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
1600         struct rpc_gss_wire_cred *gc = &gsd->clcred;
1601         struct xdr_buf *resbuf = &rqstp->rq_res;
1602         struct xdr_buf integ_buf;
1603         struct xdr_netobj mic;
1604         struct kvec *resv;
1605         __be32 *p;
1606         int integ_offset, integ_len;
1607         int stat = -EINVAL;
1608 
1609         p = svcauth_gss_prepare_to_wrap(resbuf, gsd);
1610         if (p == NULL)
1611                 goto out;
1612         integ_offset = (u8 *)(p + 1) - (u8 *)resbuf->head[0].iov_base;
1613         integ_len = resbuf->len - integ_offset;
1614         BUG_ON(integ_len % 4);
1615         *p++ = htonl(integ_len);
1616         *p++ = htonl(gc->gc_seq);
1617         if (xdr_buf_subsegment(resbuf, &integ_buf, integ_offset, integ_len)) {
1618                 WARN_ON_ONCE(1);
1619                 goto out_err;
1620         }
1621         if (resbuf->tail[0].iov_base == NULL) {
1622                 if (resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE > PAGE_SIZE)
1623                         goto out_err;
1624                 resbuf->tail[0].iov_base = resbuf->head[0].iov_base
1625                                                 + resbuf->head[0].iov_len;
1626                 resbuf->tail[0].iov_len = 0;
1627         }
1628         resv = &resbuf->tail[0];
1629         mic.data = (u8 *)resv->iov_base + resv->iov_len + 4;
1630         if (gss_get_mic(gsd->rsci->mechctx, &integ_buf, &mic))
1631                 goto out_err;
1632         svc_putnl(resv, mic.len);
1633         memset(mic.data + mic.len, 0,
1634                         round_up_to_quad(mic.len) - mic.len);
1635         resv->iov_len += XDR_QUADLEN(mic.len) << 2;
1636         /* not strictly required: */
1637         resbuf->len += XDR_QUADLEN(mic.len) << 2;
1638         BUG_ON(resv->iov_len > PAGE_SIZE);
1639 out:
1640         stat = 0;
1641 out_err:
1642         return stat;
1643 }
1644 
1645 static inline int
1646 svcauth_gss_wrap_resp_priv(struct svc_rqst *rqstp)
1647 {
1648         struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
1649         struct rpc_gss_wire_cred *gc = &gsd->clcred;
1650         struct xdr_buf *resbuf = &rqstp->rq_res;
1651         struct page **inpages = NULL;
1652         __be32 *p, *len;
1653         int offset;
1654         int pad;
1655 
1656         p = svcauth_gss_prepare_to_wrap(resbuf, gsd);
1657         if (p == NULL)
1658                 return 0;
1659         len = p++;
1660         offset = (u8 *)p - (u8 *)resbuf->head[0].iov_base;
1661         *p++ = htonl(gc->gc_seq);
1662         inpages = resbuf->pages;
1663         /* XXX: Would be better to write some xdr helper functions for
1664          * nfs{2,3,4}xdr.c that place the data right, instead of copying: */
1665 
1666         /*
1667          * If there is currently tail data, make sure there is
1668          * room for the head, tail, and 2 * RPC_MAX_AUTH_SIZE in
1669          * the page, and move the current tail data such that
1670          * there is RPC_MAX_AUTH_SIZE slack space available in
1671          * both the head and tail.
1672          */
1673         if (resbuf->tail[0].iov_base) {
1674                 BUG_ON(resbuf->tail[0].iov_base >= resbuf->head[0].iov_base
1675                                                         + PAGE_SIZE);
1676                 BUG_ON(resbuf->tail[0].iov_base < resbuf->head[0].iov_base);
1677                 if (resbuf->tail[0].iov_len + resbuf->head[0].iov_len
1678                                 + 2 * RPC_MAX_AUTH_SIZE > PAGE_SIZE)
1679                         return -ENOMEM;
1680                 memmove(resbuf->tail[0].iov_base + RPC_MAX_AUTH_SIZE,
1681                         resbuf->tail[0].iov_base,
1682                         resbuf->tail[0].iov_len);
1683                 resbuf->tail[0].iov_base += RPC_MAX_AUTH_SIZE;
1684         }
1685         /*
1686          * If there is no current tail data, make sure there is
1687          * room for the head data, and 2 * RPC_MAX_AUTH_SIZE in the
1688          * allotted page, and set up tail information such that there
1689          * is RPC_MAX_AUTH_SIZE slack space available in both the
1690          * head and tail.
1691          */
1692         if (resbuf->tail[0].iov_base == NULL) {
1693                 if (resbuf->head[0].iov_len + 2*RPC_MAX_AUTH_SIZE > PAGE_SIZE)
1694                         return -ENOMEM;
1695                 resbuf->tail[0].iov_base = resbuf->head[0].iov_base
1696                         + resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE;
1697                 resbuf->tail[0].iov_len = 0;
1698         }
1699         if (gss_wrap(gsd->rsci->mechctx, offset, resbuf, inpages))
1700                 return -ENOMEM;
1701         *len = htonl(resbuf->len - offset);
1702         pad = 3 - ((resbuf->len - offset - 1)&3);
1703         p = (__be32 *)(resbuf->tail[0].iov_base + resbuf->tail[0].iov_len);
1704         memset(p, 0, pad);
1705         resbuf->tail[0].iov_len += pad;
1706         resbuf->len += pad;
1707         return 0;
1708 }
1709 
1710 static int
1711 svcauth_gss_release(struct svc_rqst *rqstp)
1712 {
1713         struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
1714         struct rpc_gss_wire_cred *gc = &gsd->clcred;
1715         struct xdr_buf *resbuf = &rqstp->rq_res;
1716         int stat = -EINVAL;
1717         struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id);
1718 
1719         if (gc->gc_proc != RPC_GSS_PROC_DATA)
1720                 goto out;
1721         /* Release can be called twice, but we only wrap once. */
1722         if (gsd->verf_start == NULL)
1723                 goto out;
1724         /* normally not set till svc_send, but we need it here: */
1725         /* XXX: what for?  Do we mess it up the moment we call svc_putu32
1726          * or whatever? */
1727         resbuf->len = total_buf_len(resbuf);
1728         switch (gc->gc_svc) {
1729         case RPC_GSS_SVC_NONE:
1730                 break;
1731         case RPC_GSS_SVC_INTEGRITY:
1732                 stat = svcauth_gss_wrap_resp_integ(rqstp);
1733                 if (stat)
1734                         goto out_err;
1735                 break;
1736         case RPC_GSS_SVC_PRIVACY:
1737                 stat = svcauth_gss_wrap_resp_priv(rqstp);
1738                 if (stat)
1739                         goto out_err;
1740                 break;
1741         /*
1742          * For any other gc_svc value, svcauth_gss_accept() already set
1743          * the auth_error appropriately; just fall through:
1744          */
1745         }
1746 
1747 out:
1748         stat = 0;
1749 out_err:
1750         if (rqstp->rq_client)
1751                 auth_domain_put(rqstp->rq_client);
1752         rqstp->rq_client = NULL;
1753         if (rqstp->rq_gssclient)
1754                 auth_domain_put(rqstp->rq_gssclient);
1755         rqstp->rq_gssclient = NULL;
1756         if (rqstp->rq_cred.cr_group_info)
1757                 put_group_info(rqstp->rq_cred.cr_group_info);
1758         rqstp->rq_cred.cr_group_info = NULL;
1759         if (gsd->rsci)
1760                 cache_put(&gsd->rsci->h, sn->rsc_cache);
1761         gsd->rsci = NULL;
1762 
1763         return stat;
1764 }
1765 
1766 static void
1767 svcauth_gss_domain_release(struct auth_domain *dom)
1768 {
1769         struct gss_domain *gd = container_of(dom, struct gss_domain, h);
1770 
1771         kfree(dom->name);
1772         kfree(gd);
1773 }
1774 
1775 static struct auth_ops svcauthops_gss = {
1776         .name           = "rpcsec_gss",
1777         .owner          = THIS_MODULE,
1778         .flavour        = RPC_AUTH_GSS,
1779         .accept         = svcauth_gss_accept,
1780         .release        = svcauth_gss_release,
1781         .domain_release = svcauth_gss_domain_release,
1782         .set_client     = svcauth_gss_set_client,
1783 };
1784 
1785 static int rsi_cache_create_net(struct net *net)
1786 {
1787         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1788         struct cache_detail *cd;
1789         int err;
1790 
1791         cd = cache_create_net(&rsi_cache_template, net);
1792         if (IS_ERR(cd))
1793                 return PTR_ERR(cd);
1794         err = cache_register_net(cd, net);
1795         if (err) {
1796                 cache_destroy_net(cd, net);
1797                 return err;
1798         }
1799         sn->rsi_cache = cd;
1800         return 0;
1801 }
1802 
1803 static void rsi_cache_destroy_net(struct net *net)
1804 {
1805         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1806         struct cache_detail *cd = sn->rsi_cache;
1807 
1808         sn->rsi_cache = NULL;
1809         cache_purge(cd);
1810         cache_unregister_net(cd, net);
1811         cache_destroy_net(cd, net);
1812 }
1813 
1814 static int rsc_cache_create_net(struct net *net)
1815 {
1816         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1817         struct cache_detail *cd;
1818         int err;
1819 
1820         cd = cache_create_net(&rsc_cache_template, net);
1821         if (IS_ERR(cd))
1822                 return PTR_ERR(cd);
1823         err = cache_register_net(cd, net);
1824         if (err) {
1825                 cache_destroy_net(cd, net);
1826                 return err;
1827         }
1828         sn->rsc_cache = cd;
1829         return 0;
1830 }
1831 
1832 static void rsc_cache_destroy_net(struct net *net)
1833 {
1834         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1835         struct cache_detail *cd = sn->rsc_cache;
1836 
1837         sn->rsc_cache = NULL;
1838         cache_purge(cd);
1839         cache_unregister_net(cd, net);
1840         cache_destroy_net(cd, net);
1841 }
1842 
1843 int
1844 gss_svc_init_net(struct net *net)
1845 {
1846         int rv;
1847 
1848         rv = rsc_cache_create_net(net);
1849         if (rv)
1850                 return rv;
1851         rv = rsi_cache_create_net(net);
1852         if (rv)
1853                 goto out1;
1854         rv = create_use_gss_proxy_proc_entry(net);
1855         if (rv)
1856                 goto out2;
1857         return 0;
1858 out2:
1859         destroy_use_gss_proxy_proc_entry(net);
1860 out1:
1861         rsc_cache_destroy_net(net);
1862         return rv;
1863 }
1864 
1865 void
1866 gss_svc_shutdown_net(struct net *net)
1867 {
1868         destroy_use_gss_proxy_proc_entry(net);
1869         rsi_cache_destroy_net(net);
1870         rsc_cache_destroy_net(net);
1871 }
1872 
1873 int
1874 gss_svc_init(void)
1875 {
1876         return svc_auth_register(RPC_AUTH_GSS, &svcauthops_gss);
1877 }
1878 
1879 void
1880 gss_svc_shutdown(void)
1881 {
1882         svc_auth_unregister(RPC_AUTH_GSS);
1883 }
1884 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp