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

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  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 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 
485                 /* mech name */
486                 len = qword_get(&mesg, buf, mlen);
487                 if (len < 0)
488                         goto out;
489                 gm = rsci.cred.cr_gss_mech = gss_mech_get_by_name(buf);
490                 status = -EOPNOTSUPP;
491                 if (!gm)
492                         goto out;
493 
494                 status = -EINVAL;
495                 /* mech-specific data: */
496                 len = qword_get(&mesg, buf, mlen);
497                 if (len < 0)
498                         goto out;
499                 status = gss_import_sec_context(buf, len, gm, &rsci.mechctx,
500                                                 NULL, GFP_KERNEL);
501                 if (status)
502                         goto out;
503 
504                 /* get client name */
505                 len = qword_get(&mesg, buf, mlen);
506                 if (len > 0) {
507                         rsci.cred.cr_principal = kstrdup(buf, GFP_KERNEL);
508                         if (!rsci.cred.cr_principal) {
509                                 status = -ENOMEM;
510                                 goto out;
511                         }
512                 }
513 
514         }
515         rsci.h.expiry_time = expiry;
516         rscp = rsc_update(cd, &rsci, rscp);
517         status = 0;
518 out:
519         rsc_free(&rsci);
520         if (rscp)
521                 cache_put(&rscp->h, cd);
522         else
523                 status = -ENOMEM;
524         return status;
525 }
526 
527 static struct cache_detail rsc_cache_template = {
528         .owner          = THIS_MODULE,
529         .hash_size      = RSC_HASHMAX,
530         .name           = "auth.rpcsec.context",
531         .cache_put      = rsc_put,
532         .cache_parse    = rsc_parse,
533         .match          = rsc_match,
534         .init           = rsc_init,
535         .update         = update_rsc,
536         .alloc          = rsc_alloc,
537 };
538 
539 static struct rsc *rsc_lookup(struct cache_detail *cd, struct rsc *item)
540 {
541         struct cache_head *ch;
542         int hash = rsc_hash(item);
543 
544         ch = sunrpc_cache_lookup(cd, &item->h, hash);
545         if (ch)
546                 return container_of(ch, struct rsc, h);
547         else
548                 return NULL;
549 }
550 
551 static struct rsc *rsc_update(struct cache_detail *cd, struct rsc *new, struct rsc *old)
552 {
553         struct cache_head *ch;
554         int hash = rsc_hash(new);
555 
556         ch = sunrpc_cache_update(cd, &new->h,
557                                  &old->h, hash);
558         if (ch)
559                 return container_of(ch, struct rsc, h);
560         else
561                 return NULL;
562 }
563 
564 
565 static struct rsc *
566 gss_svc_searchbyctx(struct cache_detail *cd, struct xdr_netobj *handle)
567 {
568         struct rsc rsci;
569         struct rsc *found;
570 
571         memset(&rsci, 0, sizeof(rsci));
572         if (dup_to_netobj(&rsci.handle, handle->data, handle->len))
573                 return NULL;
574         found = rsc_lookup(cd, &rsci);
575         rsc_free(&rsci);
576         if (!found)
577                 return NULL;
578         if (cache_check(cd, &found->h, NULL))
579                 return NULL;
580         return found;
581 }
582 
583 /* Implements sequence number algorithm as specified in RFC 2203. */
584 static int
585 gss_check_seq_num(struct rsc *rsci, int seq_num)
586 {
587         struct gss_svc_seq_data *sd = &rsci->seqdata;
588 
589         spin_lock(&sd->sd_lock);
590         if (seq_num > sd->sd_max) {
591                 if (seq_num >= sd->sd_max + GSS_SEQ_WIN) {
592                         memset(sd->sd_win,0,sizeof(sd->sd_win));
593                         sd->sd_max = seq_num;
594                 } else while (sd->sd_max < seq_num) {
595                         sd->sd_max++;
596                         __clear_bit(sd->sd_max % GSS_SEQ_WIN, sd->sd_win);
597                 }
598                 __set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win);
599                 goto ok;
600         } else if (seq_num <= sd->sd_max - GSS_SEQ_WIN) {
601                 goto drop;
602         }
603         /* sd_max - GSS_SEQ_WIN < seq_num <= sd_max */
604         if (__test_and_set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win))
605                 goto drop;
606 ok:
607         spin_unlock(&sd->sd_lock);
608         return 1;
609 drop:
610         spin_unlock(&sd->sd_lock);
611         return 0;
612 }
613 
614 static inline u32 round_up_to_quad(u32 i)
615 {
616         return (i + 3 ) & ~3;
617 }
618 
619 static inline int
620 svc_safe_getnetobj(struct kvec *argv, struct xdr_netobj *o)
621 {
622         int l;
623 
624         if (argv->iov_len < 4)
625                 return -1;
626         o->len = svc_getnl(argv);
627         l = round_up_to_quad(o->len);
628         if (argv->iov_len < l)
629                 return -1;
630         o->data = argv->iov_base;
631         argv->iov_base += l;
632         argv->iov_len -= l;
633         return 0;
634 }
635 
636 static inline int
637 svc_safe_putnetobj(struct kvec *resv, struct xdr_netobj *o)
638 {
639         u8 *p;
640 
641         if (resv->iov_len + 4 > PAGE_SIZE)
642                 return -1;
643         svc_putnl(resv, o->len);
644         p = resv->iov_base + resv->iov_len;
645         resv->iov_len += round_up_to_quad(o->len);
646         if (resv->iov_len > PAGE_SIZE)
647                 return -1;
648         memcpy(p, o->data, o->len);
649         memset(p + o->len, 0, round_up_to_quad(o->len) - o->len);
650         return 0;
651 }
652 
653 /*
654  * Verify the checksum on the header and return SVC_OK on success.
655  * Otherwise, return SVC_DROP (in the case of a bad sequence number)
656  * or return SVC_DENIED and indicate error in authp.
657  */
658 static int
659 gss_verify_header(struct svc_rqst *rqstp, struct rsc *rsci,
660                   __be32 *rpcstart, struct rpc_gss_wire_cred *gc, __be32 *authp)
661 {
662         struct gss_ctx          *ctx_id = rsci->mechctx;
663         struct xdr_buf          rpchdr;
664         struct xdr_netobj       checksum;
665         u32                     flavor = 0;
666         struct kvec             *argv = &rqstp->rq_arg.head[0];
667         struct kvec             iov;
668 
669         /* data to compute the checksum over: */
670         iov.iov_base = rpcstart;
671         iov.iov_len = (u8 *)argv->iov_base - (u8 *)rpcstart;
672         xdr_buf_from_iov(&iov, &rpchdr);
673 
674         *authp = rpc_autherr_badverf;
675         if (argv->iov_len < 4)
676                 return SVC_DENIED;
677         flavor = svc_getnl(argv);
678         if (flavor != RPC_AUTH_GSS)
679                 return SVC_DENIED;
680         if (svc_safe_getnetobj(argv, &checksum))
681                 return SVC_DENIED;
682 
683         if (rqstp->rq_deferred) /* skip verification of revisited request */
684                 return SVC_OK;
685         if (gss_verify_mic(ctx_id, &rpchdr, &checksum) != GSS_S_COMPLETE) {
686                 *authp = rpcsec_gsserr_credproblem;
687                 return SVC_DENIED;
688         }
689 
690         if (gc->gc_seq > MAXSEQ) {
691                 dprintk("RPC:       svcauth_gss: discarding request with "
692                                 "large sequence number %d\n", gc->gc_seq);
693                 *authp = rpcsec_gsserr_ctxproblem;
694                 return SVC_DENIED;
695         }
696         if (!gss_check_seq_num(rsci, gc->gc_seq)) {
697                 dprintk("RPC:       svcauth_gss: discarding request with "
698                                 "old sequence number %d\n", gc->gc_seq);
699                 return SVC_DROP;
700         }
701         return SVC_OK;
702 }
703 
704 static int
705 gss_write_null_verf(struct svc_rqst *rqstp)
706 {
707         __be32     *p;
708 
709         svc_putnl(rqstp->rq_res.head, RPC_AUTH_NULL);
710         p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len;
711         /* don't really need to check if head->iov_len > PAGE_SIZE ... */
712         *p++ = 0;
713         if (!xdr_ressize_check(rqstp, p))
714                 return -1;
715         return 0;
716 }
717 
718 static int
719 gss_write_verf(struct svc_rqst *rqstp, struct gss_ctx *ctx_id, u32 seq)
720 {
721         __be32                  *xdr_seq;
722         u32                     maj_stat;
723         struct xdr_buf          verf_data;
724         struct xdr_netobj       mic;
725         __be32                  *p;
726         struct kvec             iov;
727         int err = -1;
728 
729         svc_putnl(rqstp->rq_res.head, RPC_AUTH_GSS);
730         xdr_seq = kmalloc(4, GFP_KERNEL);
731         if (!xdr_seq)
732                 return -1;
733         *xdr_seq = htonl(seq);
734 
735         iov.iov_base = xdr_seq;
736         iov.iov_len = 4;
737         xdr_buf_from_iov(&iov, &verf_data);
738         p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len;
739         mic.data = (u8 *)(p + 1);
740         maj_stat = gss_get_mic(ctx_id, &verf_data, &mic);
741         if (maj_stat != GSS_S_COMPLETE)
742                 goto out;
743         *p++ = htonl(mic.len);
744         memset((u8 *)p + mic.len, 0, round_up_to_quad(mic.len) - mic.len);
745         p += XDR_QUADLEN(mic.len);
746         if (!xdr_ressize_check(rqstp, p))
747                 goto out;
748         err = 0;
749 out:
750         kfree(xdr_seq);
751         return err;
752 }
753 
754 struct gss_domain {
755         struct auth_domain      h;
756         u32                     pseudoflavor;
757 };
758 
759 static struct auth_domain *
760 find_gss_auth_domain(struct gss_ctx *ctx, u32 svc)
761 {
762         char *name;
763 
764         name = gss_service_to_auth_domain_name(ctx->mech_type, svc);
765         if (!name)
766                 return NULL;
767         return auth_domain_find(name);
768 }
769 
770 static struct auth_ops svcauthops_gss;
771 
772 u32 svcauth_gss_flavor(struct auth_domain *dom)
773 {
774         struct gss_domain *gd = container_of(dom, struct gss_domain, h);
775 
776         return gd->pseudoflavor;
777 }
778 
779 EXPORT_SYMBOL_GPL(svcauth_gss_flavor);
780 
781 int
782 svcauth_gss_register_pseudoflavor(u32 pseudoflavor, char * name)
783 {
784         struct gss_domain       *new;
785         struct auth_domain      *test;
786         int                     stat = -ENOMEM;
787 
788         new = kmalloc(sizeof(*new), GFP_KERNEL);
789         if (!new)
790                 goto out;
791         kref_init(&new->h.ref);
792         new->h.name = kstrdup(name, GFP_KERNEL);
793         if (!new->h.name)
794                 goto out_free_dom;
795         new->h.flavour = &svcauthops_gss;
796         new->pseudoflavor = pseudoflavor;
797 
798         stat = 0;
799         test = auth_domain_lookup(name, &new->h);
800         if (test != &new->h) { /* Duplicate registration */
801                 auth_domain_put(test);
802                 kfree(new->h.name);
803                 goto out_free_dom;
804         }
805         return 0;
806 
807 out_free_dom:
808         kfree(new);
809 out:
810         return stat;
811 }
812 
813 EXPORT_SYMBOL_GPL(svcauth_gss_register_pseudoflavor);
814 
815 static inline int
816 read_u32_from_xdr_buf(struct xdr_buf *buf, int base, u32 *obj)
817 {
818         __be32  raw;
819         int     status;
820 
821         status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj));
822         if (status)
823                 return status;
824         *obj = ntohl(raw);
825         return 0;
826 }
827 
828 /* It would be nice if this bit of code could be shared with the client.
829  * Obstacles:
830  *      The client shouldn't malloc(), would have to pass in own memory.
831  *      The server uses base of head iovec as read pointer, while the
832  *      client uses separate pointer. */
833 static int
834 unwrap_integ_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx)
835 {
836         int stat = -EINVAL;
837         u32 integ_len, maj_stat;
838         struct xdr_netobj mic;
839         struct xdr_buf integ_buf;
840 
841         /* NFS READ normally uses splice to send data in-place. However
842          * the data in cache can change after the reply's MIC is computed
843          * but before the RPC reply is sent. To prevent the client from
844          * rejecting the server-computed MIC in this somewhat rare case,
845          * do not use splice with the GSS integrity service.
846          */
847         clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
848 
849         /* Did we already verify the signature on the original pass through? */
850         if (rqstp->rq_deferred)
851                 return 0;
852 
853         integ_len = svc_getnl(&buf->head[0]);
854         if (integ_len & 3)
855                 return stat;
856         if (integ_len > buf->len)
857                 return stat;
858         if (xdr_buf_subsegment(buf, &integ_buf, 0, integ_len))
859                 BUG();
860         /* copy out mic... */
861         if (read_u32_from_xdr_buf(buf, integ_len, &mic.len))
862                 BUG();
863         if (mic.len > RPC_MAX_AUTH_SIZE)
864                 return stat;
865         mic.data = kmalloc(mic.len, GFP_KERNEL);
866         if (!mic.data)
867                 return stat;
868         if (read_bytes_from_xdr_buf(buf, integ_len + 4, mic.data, mic.len))
869                 goto out;
870         maj_stat = gss_verify_mic(ctx, &integ_buf, &mic);
871         if (maj_stat != GSS_S_COMPLETE)
872                 goto out;
873         if (svc_getnl(&buf->head[0]) != seq)
874                 goto out;
875         /* trim off the mic and padding at the end before returning */
876         xdr_buf_trim(buf, round_up_to_quad(mic.len) + 4);
877         stat = 0;
878 out:
879         kfree(mic.data);
880         return stat;
881 }
882 
883 static inline int
884 total_buf_len(struct xdr_buf *buf)
885 {
886         return buf->head[0].iov_len + buf->page_len + buf->tail[0].iov_len;
887 }
888 
889 static void
890 fix_priv_head(struct xdr_buf *buf, int pad)
891 {
892         if (buf->page_len == 0) {
893                 /* We need to adjust head and buf->len in tandem in this
894                  * case to make svc_defer() work--it finds the original
895                  * buffer start using buf->len - buf->head[0].iov_len. */
896                 buf->head[0].iov_len -= pad;
897         }
898 }
899 
900 static int
901 unwrap_priv_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx)
902 {
903         u32 priv_len, maj_stat;
904         int pad, saved_len, remaining_len, offset;
905 
906         clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
907 
908         priv_len = svc_getnl(&buf->head[0]);
909         if (rqstp->rq_deferred) {
910                 /* Already decrypted last time through! The sequence number
911                  * check at out_seq is unnecessary but harmless: */
912                 goto out_seq;
913         }
914         /* buf->len is the number of bytes from the original start of the
915          * request to the end, where head[0].iov_len is just the bytes
916          * not yet read from the head, so these two values are different: */
917         remaining_len = total_buf_len(buf);
918         if (priv_len > remaining_len)
919                 return -EINVAL;
920         pad = remaining_len - priv_len;
921         buf->len -= pad;
922         fix_priv_head(buf, pad);
923 
924         /* Maybe it would be better to give gss_unwrap a length parameter: */
925         saved_len = buf->len;
926         buf->len = priv_len;
927         maj_stat = gss_unwrap(ctx, 0, buf);
928         pad = priv_len - buf->len;
929         buf->len = saved_len;
930         buf->len -= pad;
931         /* The upper layers assume the buffer is aligned on 4-byte boundaries.
932          * In the krb5p case, at least, the data ends up offset, so we need to
933          * move it around. */
934         /* XXX: This is very inefficient.  It would be better to either do
935          * this while we encrypt, or maybe in the receive code, if we can peak
936          * ahead and work out the service and mechanism there. */
937         offset = buf->head[0].iov_len % 4;
938         if (offset) {
939                 buf->buflen = RPCSVC_MAXPAYLOAD;
940                 xdr_shift_buf(buf, offset);
941                 fix_priv_head(buf, pad);
942         }
943         if (maj_stat != GSS_S_COMPLETE)
944                 return -EINVAL;
945 out_seq:
946         if (svc_getnl(&buf->head[0]) != seq)
947                 return -EINVAL;
948         return 0;
949 }
950 
951 struct gss_svc_data {
952         /* decoded gss client cred: */
953         struct rpc_gss_wire_cred        clcred;
954         /* save a pointer to the beginning of the encoded verifier,
955          * for use in encryption/checksumming in svcauth_gss_release: */
956         __be32                          *verf_start;
957         struct rsc                      *rsci;
958 };
959 
960 static int
961 svcauth_gss_set_client(struct svc_rqst *rqstp)
962 {
963         struct gss_svc_data *svcdata = rqstp->rq_auth_data;
964         struct rsc *rsci = svcdata->rsci;
965         struct rpc_gss_wire_cred *gc = &svcdata->clcred;
966         int stat;
967 
968         /*
969          * A gss export can be specified either by:
970          *      export  *(sec=krb5,rw)
971          * or by
972          *      export gss/krb5(rw)
973          * The latter is deprecated; but for backwards compatibility reasons
974          * the nfsd code will still fall back on trying it if the former
975          * doesn't work; so we try to make both available to nfsd, below.
976          */
977         rqstp->rq_gssclient = find_gss_auth_domain(rsci->mechctx, gc->gc_svc);
978         if (rqstp->rq_gssclient == NULL)
979                 return SVC_DENIED;
980         stat = svcauth_unix_set_client(rqstp);
981         if (stat == SVC_DROP || stat == SVC_CLOSE)
982                 return stat;
983         return SVC_OK;
984 }
985 
986 static inline int
987 gss_write_init_verf(struct cache_detail *cd, struct svc_rqst *rqstp,
988                 struct xdr_netobj *out_handle, int *major_status)
989 {
990         struct rsc *rsci;
991         int        rc;
992 
993         if (*major_status != GSS_S_COMPLETE)
994                 return gss_write_null_verf(rqstp);
995         rsci = gss_svc_searchbyctx(cd, out_handle);
996         if (rsci == NULL) {
997                 *major_status = GSS_S_NO_CONTEXT;
998                 return gss_write_null_verf(rqstp);
999         }
1000         rc = gss_write_verf(rqstp, rsci->mechctx, GSS_SEQ_WIN);
1001         cache_put(&rsci->h, cd);
1002         return rc;
1003 }
1004 
1005 static inline int
1006 gss_read_common_verf(struct rpc_gss_wire_cred *gc,
1007                      struct kvec *argv, __be32 *authp,
1008                      struct xdr_netobj *in_handle)
1009 {
1010         /* Read the verifier; should be NULL: */
1011         *authp = rpc_autherr_badverf;
1012         if (argv->iov_len < 2 * 4)
1013                 return SVC_DENIED;
1014         if (svc_getnl(argv) != RPC_AUTH_NULL)
1015                 return SVC_DENIED;
1016         if (svc_getnl(argv) != 0)
1017                 return SVC_DENIED;
1018         /* Martial context handle and token for upcall: */
1019         *authp = rpc_autherr_badcred;
1020         if (gc->gc_proc == RPC_GSS_PROC_INIT && gc->gc_ctx.len != 0)
1021                 return SVC_DENIED;
1022         if (dup_netobj(in_handle, &gc->gc_ctx))
1023                 return SVC_CLOSE;
1024         *authp = rpc_autherr_badverf;
1025 
1026         return 0;
1027 }
1028 
1029 static inline int
1030 gss_read_verf(struct rpc_gss_wire_cred *gc,
1031               struct kvec *argv, __be32 *authp,
1032               struct xdr_netobj *in_handle,
1033               struct xdr_netobj *in_token)
1034 {
1035         struct xdr_netobj tmpobj;
1036         int res;
1037 
1038         res = gss_read_common_verf(gc, argv, authp, in_handle);
1039         if (res)
1040                 return res;
1041 
1042         if (svc_safe_getnetobj(argv, &tmpobj)) {
1043                 kfree(in_handle->data);
1044                 return SVC_DENIED;
1045         }
1046         if (dup_netobj(in_token, &tmpobj)) {
1047                 kfree(in_handle->data);
1048                 return SVC_CLOSE;
1049         }
1050 
1051         return 0;
1052 }
1053 
1054 /* Ok this is really heavily depending on a set of semantics in
1055  * how rqstp is set up by svc_recv and pages laid down by the
1056  * server when reading a request. We are basically guaranteed that
1057  * the token lays all down linearly across a set of pages, starting
1058  * at iov_base in rq_arg.head[0] which happens to be the first of a
1059  * set of pages stored in rq_pages[].
1060  * rq_arg.head[0].iov_base will provide us the page_base to pass
1061  * to the upcall.
1062  */
1063 static inline int
1064 gss_read_proxy_verf(struct svc_rqst *rqstp,
1065                     struct rpc_gss_wire_cred *gc, __be32 *authp,
1066                     struct xdr_netobj *in_handle,
1067                     struct gssp_in_token *in_token)
1068 {
1069         struct kvec *argv = &rqstp->rq_arg.head[0];
1070         u32 inlen;
1071         int res;
1072 
1073         res = gss_read_common_verf(gc, argv, authp, in_handle);
1074         if (res)
1075                 return res;
1076 
1077         inlen = svc_getnl(argv);
1078         if (inlen > (argv->iov_len + rqstp->rq_arg.page_len))
1079                 return SVC_DENIED;
1080 
1081         in_token->pages = rqstp->rq_pages;
1082         in_token->page_base = (ulong)argv->iov_base & ~PAGE_MASK;
1083         in_token->page_len = inlen;
1084 
1085         return 0;
1086 }
1087 
1088 static inline int
1089 gss_write_resv(struct kvec *resv, size_t size_limit,
1090                struct xdr_netobj *out_handle, struct xdr_netobj *out_token,
1091                int major_status, int minor_status)
1092 {
1093         if (resv->iov_len + 4 > size_limit)
1094                 return -1;
1095         svc_putnl(resv, RPC_SUCCESS);
1096         if (svc_safe_putnetobj(resv, out_handle))
1097                 return -1;
1098         if (resv->iov_len + 3 * 4 > size_limit)
1099                 return -1;
1100         svc_putnl(resv, major_status);
1101         svc_putnl(resv, minor_status);
1102         svc_putnl(resv, GSS_SEQ_WIN);
1103         if (svc_safe_putnetobj(resv, out_token))
1104                 return -1;
1105         return 0;
1106 }
1107 
1108 /*
1109  * Having read the cred already and found we're in the context
1110  * initiation case, read the verifier and initiate (or check the results
1111  * of) upcalls to userspace for help with context initiation.  If
1112  * the upcall results are available, write the verifier and result.
1113  * Otherwise, drop the request pending an answer to the upcall.
1114  */
1115 static int svcauth_gss_legacy_init(struct svc_rqst *rqstp,
1116                         struct rpc_gss_wire_cred *gc, __be32 *authp)
1117 {
1118         struct kvec *argv = &rqstp->rq_arg.head[0];
1119         struct kvec *resv = &rqstp->rq_res.head[0];
1120         struct rsi *rsip, rsikey;
1121         int ret;
1122         struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id);
1123 
1124         memset(&rsikey, 0, sizeof(rsikey));
1125         ret = gss_read_verf(gc, argv, authp,
1126                             &rsikey.in_handle, &rsikey.in_token);
1127         if (ret)
1128                 return ret;
1129 
1130         /* Perform upcall, or find upcall result: */
1131         rsip = rsi_lookup(sn->rsi_cache, &rsikey);
1132         rsi_free(&rsikey);
1133         if (!rsip)
1134                 return SVC_CLOSE;
1135         if (cache_check(sn->rsi_cache, &rsip->h, &rqstp->rq_chandle) < 0)
1136                 /* No upcall result: */
1137                 return SVC_CLOSE;
1138 
1139         ret = SVC_CLOSE;
1140         /* Got an answer to the upcall; use it: */
1141         if (gss_write_init_verf(sn->rsc_cache, rqstp,
1142                                 &rsip->out_handle, &rsip->major_status))
1143                 goto out;
1144         if (gss_write_resv(resv, PAGE_SIZE,
1145                            &rsip->out_handle, &rsip->out_token,
1146                            rsip->major_status, rsip->minor_status))
1147                 goto out;
1148 
1149         ret = SVC_COMPLETE;
1150 out:
1151         cache_put(&rsip->h, sn->rsi_cache);
1152         return ret;
1153 }
1154 
1155 static int gss_proxy_save_rsc(struct cache_detail *cd,
1156                                 struct gssp_upcall_data *ud,
1157                                 uint64_t *handle)
1158 {
1159         struct rsc rsci, *rscp = NULL;
1160         static atomic64_t ctxhctr;
1161         long long ctxh;
1162         struct gss_api_mech *gm = NULL;
1163         time_t expiry;
1164         int status = -EINVAL;
1165 
1166         memset(&rsci, 0, sizeof(rsci));
1167         /* context handle */
1168         status = -ENOMEM;
1169         /* the handle needs to be just a unique id,
1170          * use a static counter */
1171         ctxh = atomic64_inc_return(&ctxhctr);
1172 
1173         /* make a copy for the caller */
1174         *handle = ctxh;
1175 
1176         /* make a copy for the rsc cache */
1177         if (dup_to_netobj(&rsci.handle, (char *)handle, sizeof(uint64_t)))
1178                 goto out;
1179         rscp = rsc_lookup(cd, &rsci);
1180         if (!rscp)
1181                 goto out;
1182 
1183         /* creds */
1184         if (!ud->found_creds) {
1185                 /* userspace seem buggy, we should always get at least a
1186                  * mapping to nobody */
1187                 dprintk("RPC:       No creds found!\n");
1188                 goto out;
1189         } else {
1190 
1191                 /* steal creds */
1192                 rsci.cred = ud->creds;
1193                 memset(&ud->creds, 0, sizeof(struct svc_cred));
1194 
1195                 status = -EOPNOTSUPP;
1196                 /* get mech handle from OID */
1197                 gm = gss_mech_get_by_OID(&ud->mech_oid);
1198                 if (!gm)
1199                         goto out;
1200                 rsci.cred.cr_gss_mech = gm;
1201 
1202                 status = -EINVAL;
1203                 /* mech-specific data: */
1204                 status = gss_import_sec_context(ud->out_handle.data,
1205                                                 ud->out_handle.len,
1206                                                 gm, &rsci.mechctx,
1207                                                 &expiry, GFP_KERNEL);
1208                 if (status)
1209                         goto out;
1210         }
1211 
1212         rsci.h.expiry_time = expiry;
1213         rscp = rsc_update(cd, &rsci, rscp);
1214         status = 0;
1215 out:
1216         rsc_free(&rsci);
1217         if (rscp)
1218                 cache_put(&rscp->h, cd);
1219         else
1220                 status = -ENOMEM;
1221         return status;
1222 }
1223 
1224 static int svcauth_gss_proxy_init(struct svc_rqst *rqstp,
1225                         struct rpc_gss_wire_cred *gc, __be32 *authp)
1226 {
1227         struct kvec *resv = &rqstp->rq_res.head[0];
1228         struct xdr_netobj cli_handle;
1229         struct gssp_upcall_data ud;
1230         uint64_t handle;
1231         int status;
1232         int ret;
1233         struct net *net = rqstp->rq_xprt->xpt_net;
1234         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1235 
1236         memset(&ud, 0, sizeof(ud));
1237         ret = gss_read_proxy_verf(rqstp, gc, authp,
1238                                   &ud.in_handle, &ud.in_token);
1239         if (ret)
1240                 return ret;
1241 
1242         ret = SVC_CLOSE;
1243 
1244         /* Perform synchronous upcall to gss-proxy */
1245         status = gssp_accept_sec_context_upcall(net, &ud);
1246         if (status)
1247                 goto out;
1248 
1249         dprintk("RPC:       svcauth_gss: gss major status = %d "
1250                         "minor status = %d\n",
1251                         ud.major_status, ud.minor_status);
1252 
1253         switch (ud.major_status) {
1254         case GSS_S_CONTINUE_NEEDED:
1255                 cli_handle = ud.out_handle;
1256                 break;
1257         case GSS_S_COMPLETE:
1258                 status = gss_proxy_save_rsc(sn->rsc_cache, &ud, &handle);
1259                 if (status)
1260                         goto out;
1261                 cli_handle.data = (u8 *)&handle;
1262                 cli_handle.len = sizeof(handle);
1263                 break;
1264         default:
1265                 ret = SVC_CLOSE;
1266                 goto out;
1267         }
1268 
1269         /* Got an answer to the upcall; use it: */
1270         if (gss_write_init_verf(sn->rsc_cache, rqstp,
1271                                 &cli_handle, &ud.major_status))
1272                 goto out;
1273         if (gss_write_resv(resv, PAGE_SIZE,
1274                            &cli_handle, &ud.out_token,
1275                            ud.major_status, ud.minor_status))
1276                 goto out;
1277 
1278         ret = SVC_COMPLETE;
1279 out:
1280         gssp_free_upcall_data(&ud);
1281         return ret;
1282 }
1283 
1284 /*
1285  * Try to set the sn->use_gss_proxy variable to a new value. We only allow
1286  * it to be changed if it's currently undefined (-1). If it's any other value
1287  * then return -EBUSY unless the type wouldn't have changed anyway.
1288  */
1289 static int set_gss_proxy(struct net *net, int type)
1290 {
1291         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1292         int ret;
1293 
1294         WARN_ON_ONCE(type != 0 && type != 1);
1295         ret = cmpxchg(&sn->use_gss_proxy, -1, type);
1296         if (ret != -1 && ret != type)
1297                 return -EBUSY;
1298         return 0;
1299 }
1300 
1301 static bool use_gss_proxy(struct net *net)
1302 {
1303         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1304 
1305         /* If use_gss_proxy is still undefined, then try to disable it */
1306         if (sn->use_gss_proxy == -1)
1307                 set_gss_proxy(net, 0);
1308         return sn->use_gss_proxy;
1309 }
1310 
1311 #ifdef CONFIG_PROC_FS
1312 
1313 static ssize_t write_gssp(struct file *file, const char __user *buf,
1314                          size_t count, loff_t *ppos)
1315 {
1316         struct net *net = PDE_DATA(file_inode(file));
1317         char tbuf[20];
1318         unsigned long i;
1319         int res;
1320 
1321         if (*ppos || count > sizeof(tbuf)-1)
1322                 return -EINVAL;
1323         if (copy_from_user(tbuf, buf, count))
1324                 return -EFAULT;
1325 
1326         tbuf[count] = 0;
1327         res = kstrtoul(tbuf, 0, &i);
1328         if (res)
1329                 return res;
1330         if (i != 1)
1331                 return -EINVAL;
1332         res = set_gssp_clnt(net);
1333         if (res)
1334                 return res;
1335         res = set_gss_proxy(net, 1);
1336         if (res)
1337                 return res;
1338         return count;
1339 }
1340 
1341 static ssize_t read_gssp(struct file *file, char __user *buf,
1342                          size_t count, loff_t *ppos)
1343 {
1344         struct net *net = PDE_DATA(file_inode(file));
1345         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1346         unsigned long p = *ppos;
1347         char tbuf[10];
1348         size_t len;
1349 
1350         snprintf(tbuf, sizeof(tbuf), "%d\n", sn->use_gss_proxy);
1351         len = strlen(tbuf);
1352         if (p >= len)
1353                 return 0;
1354         len -= p;
1355         if (len > count)
1356                 len = count;
1357         if (copy_to_user(buf, (void *)(tbuf+p), len))
1358                 return -EFAULT;
1359         *ppos += len;
1360         return len;
1361 }
1362 
1363 static const struct file_operations use_gss_proxy_ops = {
1364         .open = nonseekable_open,
1365         .write = write_gssp,
1366         .read = read_gssp,
1367 };
1368 
1369 static int create_use_gss_proxy_proc_entry(struct net *net)
1370 {
1371         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1372         struct proc_dir_entry **p = &sn->use_gssp_proc;
1373 
1374         sn->use_gss_proxy = -1;
1375         *p = proc_create_data("use-gss-proxy", S_IFREG|S_IRUSR|S_IWUSR,
1376                               sn->proc_net_rpc,
1377                               &use_gss_proxy_ops, net);
1378         if (!*p)
1379                 return -ENOMEM;
1380         init_gssp_clnt(sn);
1381         return 0;
1382 }
1383 
1384 static void destroy_use_gss_proxy_proc_entry(struct net *net)
1385 {
1386         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1387 
1388         if (sn->use_gssp_proc) {
1389                 remove_proc_entry("use-gss-proxy", sn->proc_net_rpc); 
1390                 clear_gssp_clnt(sn);
1391         }
1392 }
1393 #else /* CONFIG_PROC_FS */
1394 
1395 static int create_use_gss_proxy_proc_entry(struct net *net)
1396 {
1397         return 0;
1398 }
1399 
1400 static void destroy_use_gss_proxy_proc_entry(struct net *net) {}
1401 
1402 #endif /* CONFIG_PROC_FS */
1403 
1404 /*
1405  * Accept an rpcsec packet.
1406  * If context establishment, punt to user space
1407  * If data exchange, verify/decrypt
1408  * If context destruction, handle here
1409  * In the context establishment and destruction case we encode
1410  * response here and return SVC_COMPLETE.
1411  */
1412 static int
1413 svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
1414 {
1415         struct kvec     *argv = &rqstp->rq_arg.head[0];
1416         struct kvec     *resv = &rqstp->rq_res.head[0];
1417         u32             crlen;
1418         struct gss_svc_data *svcdata = rqstp->rq_auth_data;
1419         struct rpc_gss_wire_cred *gc;
1420         struct rsc      *rsci = NULL;
1421         __be32          *rpcstart;
1422         __be32          *reject_stat = resv->iov_base + resv->iov_len;
1423         int             ret;
1424         struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id);
1425 
1426         dprintk("RPC:       svcauth_gss: argv->iov_len = %zd\n",
1427                         argv->iov_len);
1428 
1429         *authp = rpc_autherr_badcred;
1430         if (!svcdata)
1431                 svcdata = kmalloc(sizeof(*svcdata), GFP_KERNEL);
1432         if (!svcdata)
1433                 goto auth_err;
1434         rqstp->rq_auth_data = svcdata;
1435         svcdata->verf_start = NULL;
1436         svcdata->rsci = NULL;
1437         gc = &svcdata->clcred;
1438 
1439         /* start of rpc packet is 7 u32's back from here:
1440          * xid direction rpcversion prog vers proc flavour
1441          */
1442         rpcstart = argv->iov_base;
1443         rpcstart -= 7;
1444 
1445         /* credential is:
1446          *   version(==1), proc(0,1,2,3), seq, service (1,2,3), handle
1447          * at least 5 u32s, and is preceded by length, so that makes 6.
1448          */
1449 
1450         if (argv->iov_len < 5 * 4)
1451                 goto auth_err;
1452         crlen = svc_getnl(argv);
1453         if (svc_getnl(argv) != RPC_GSS_VERSION)
1454                 goto auth_err;
1455         gc->gc_proc = svc_getnl(argv);
1456         gc->gc_seq = svc_getnl(argv);
1457         gc->gc_svc = svc_getnl(argv);
1458         if (svc_safe_getnetobj(argv, &gc->gc_ctx))
1459                 goto auth_err;
1460         if (crlen != round_up_to_quad(gc->gc_ctx.len) + 5 * 4)
1461                 goto auth_err;
1462 
1463         if ((gc->gc_proc != RPC_GSS_PROC_DATA) && (rqstp->rq_proc != 0))
1464                 goto auth_err;
1465 
1466         *authp = rpc_autherr_badverf;
1467         switch (gc->gc_proc) {
1468         case RPC_GSS_PROC_INIT:
1469         case RPC_GSS_PROC_CONTINUE_INIT:
1470                 if (use_gss_proxy(SVC_NET(rqstp)))
1471                         return svcauth_gss_proxy_init(rqstp, gc, authp);
1472                 else
1473                         return svcauth_gss_legacy_init(rqstp, gc, authp);
1474         case RPC_GSS_PROC_DATA:
1475         case RPC_GSS_PROC_DESTROY:
1476                 /* Look up the context, and check the verifier: */
1477                 *authp = rpcsec_gsserr_credproblem;
1478                 rsci = gss_svc_searchbyctx(sn->rsc_cache, &gc->gc_ctx);
1479                 if (!rsci)
1480                         goto auth_err;
1481                 switch (gss_verify_header(rqstp, rsci, rpcstart, gc, authp)) {
1482                 case SVC_OK:
1483                         break;
1484                 case SVC_DENIED:
1485                         goto auth_err;
1486                 case SVC_DROP:
1487                         goto drop;
1488                 }
1489                 break;
1490         default:
1491                 *authp = rpc_autherr_rejectedcred;
1492                 goto auth_err;
1493         }
1494 
1495         /* now act upon the command: */
1496         switch (gc->gc_proc) {
1497         case RPC_GSS_PROC_DESTROY:
1498                 if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq))
1499                         goto auth_err;
1500                 /* Delete the entry from the cache_list and call cache_put */
1501                 sunrpc_cache_unhash(sn->rsc_cache, &rsci->h);
1502                 if (resv->iov_len + 4 > PAGE_SIZE)
1503                         goto drop;
1504                 svc_putnl(resv, RPC_SUCCESS);
1505                 goto complete;
1506         case RPC_GSS_PROC_DATA:
1507                 *authp = rpcsec_gsserr_ctxproblem;
1508                 svcdata->verf_start = resv->iov_base + resv->iov_len;
1509                 if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq))
1510                         goto auth_err;
1511                 rqstp->rq_cred = rsci->cred;
1512                 get_group_info(rsci->cred.cr_group_info);
1513                 *authp = rpc_autherr_badcred;
1514                 switch (gc->gc_svc) {
1515                 case RPC_GSS_SVC_NONE:
1516                         break;
1517                 case RPC_GSS_SVC_INTEGRITY:
1518                         /* placeholders for length and seq. number: */
1519                         svc_putnl(resv, 0);
1520                         svc_putnl(resv, 0);
1521                         if (unwrap_integ_data(rqstp, &rqstp->rq_arg,
1522                                         gc->gc_seq, rsci->mechctx))
1523                                 goto garbage_args;
1524                         rqstp->rq_auth_slack = RPC_MAX_AUTH_SIZE;
1525                         break;
1526                 case RPC_GSS_SVC_PRIVACY:
1527                         /* placeholders for length and seq. number: */
1528                         svc_putnl(resv, 0);
1529                         svc_putnl(resv, 0);
1530                         if (unwrap_priv_data(rqstp, &rqstp->rq_arg,
1531                                         gc->gc_seq, rsci->mechctx))
1532                                 goto garbage_args;
1533                         rqstp->rq_auth_slack = RPC_MAX_AUTH_SIZE * 2;
1534                         break;
1535                 default:
1536                         goto auth_err;
1537                 }
1538                 svcdata->rsci = rsci;
1539                 cache_get(&rsci->h);
1540                 rqstp->rq_cred.cr_flavor = gss_svc_to_pseudoflavor(
1541                                         rsci->mechctx->mech_type,
1542                                         GSS_C_QOP_DEFAULT,
1543                                         gc->gc_svc);
1544                 ret = SVC_OK;
1545                 goto out;
1546         }
1547 garbage_args:
1548         ret = SVC_GARBAGE;
1549         goto out;
1550 auth_err:
1551         /* Restore write pointer to its original value: */
1552         xdr_ressize_check(rqstp, reject_stat);
1553         ret = SVC_DENIED;
1554         goto out;
1555 complete:
1556         ret = SVC_COMPLETE;
1557         goto out;
1558 drop:
1559         ret = SVC_CLOSE;
1560 out:
1561         if (rsci)
1562                 cache_put(&rsci->h, sn->rsc_cache);
1563         return ret;
1564 }
1565 
1566 static __be32 *
1567 svcauth_gss_prepare_to_wrap(struct xdr_buf *resbuf, struct gss_svc_data *gsd)
1568 {
1569         __be32 *p;
1570         u32 verf_len;
1571 
1572         p = gsd->verf_start;
1573         gsd->verf_start = NULL;
1574 
1575         /* If the reply stat is nonzero, don't wrap: */
1576         if (*(p-1) != rpc_success)
1577                 return NULL;
1578         /* Skip the verifier: */
1579         p += 1;
1580         verf_len = ntohl(*p++);
1581         p += XDR_QUADLEN(verf_len);
1582         /* move accept_stat to right place: */
1583         memcpy(p, p + 2, 4);
1584         /* Also don't wrap if the accept stat is nonzero: */
1585         if (*p != rpc_success) {
1586                 resbuf->head[0].iov_len -= 2 * 4;
1587                 return NULL;
1588         }
1589         p++;
1590         return p;
1591 }
1592 
1593 static inline int
1594 svcauth_gss_wrap_resp_integ(struct svc_rqst *rqstp)
1595 {
1596         struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
1597         struct rpc_gss_wire_cred *gc = &gsd->clcred;
1598         struct xdr_buf *resbuf = &rqstp->rq_res;
1599         struct xdr_buf integ_buf;
1600         struct xdr_netobj mic;
1601         struct kvec *resv;
1602         __be32 *p;
1603         int integ_offset, integ_len;
1604         int stat = -EINVAL;
1605 
1606         p = svcauth_gss_prepare_to_wrap(resbuf, gsd);
1607         if (p == NULL)
1608                 goto out;
1609         integ_offset = (u8 *)(p + 1) - (u8 *)resbuf->head[0].iov_base;
1610         integ_len = resbuf->len - integ_offset;
1611         BUG_ON(integ_len % 4);
1612         *p++ = htonl(integ_len);
1613         *p++ = htonl(gc->gc_seq);
1614         if (xdr_buf_subsegment(resbuf, &integ_buf, integ_offset, integ_len))
1615                 BUG();
1616         if (resbuf->tail[0].iov_base == NULL) {
1617                 if (resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE > PAGE_SIZE)
1618                         goto out_err;
1619                 resbuf->tail[0].iov_base = resbuf->head[0].iov_base
1620                                                 + resbuf->head[0].iov_len;
1621                 resbuf->tail[0].iov_len = 0;
1622         }
1623         resv = &resbuf->tail[0];
1624         mic.data = (u8 *)resv->iov_base + resv->iov_len + 4;
1625         if (gss_get_mic(gsd->rsci->mechctx, &integ_buf, &mic))
1626                 goto out_err;
1627         svc_putnl(resv, mic.len);
1628         memset(mic.data + mic.len, 0,
1629                         round_up_to_quad(mic.len) - mic.len);
1630         resv->iov_len += XDR_QUADLEN(mic.len) << 2;
1631         /* not strictly required: */
1632         resbuf->len += XDR_QUADLEN(mic.len) << 2;
1633         BUG_ON(resv->iov_len > PAGE_SIZE);
1634 out:
1635         stat = 0;
1636 out_err:
1637         return stat;
1638 }
1639 
1640 static inline int
1641 svcauth_gss_wrap_resp_priv(struct svc_rqst *rqstp)
1642 {
1643         struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
1644         struct rpc_gss_wire_cred *gc = &gsd->clcred;
1645         struct xdr_buf *resbuf = &rqstp->rq_res;
1646         struct page **inpages = NULL;
1647         __be32 *p, *len;
1648         int offset;
1649         int pad;
1650 
1651         p = svcauth_gss_prepare_to_wrap(resbuf, gsd);
1652         if (p == NULL)
1653                 return 0;
1654         len = p++;
1655         offset = (u8 *)p - (u8 *)resbuf->head[0].iov_base;
1656         *p++ = htonl(gc->gc_seq);
1657         inpages = resbuf->pages;
1658         /* XXX: Would be better to write some xdr helper functions for
1659          * nfs{2,3,4}xdr.c that place the data right, instead of copying: */
1660 
1661         /*
1662          * If there is currently tail data, make sure there is
1663          * room for the head, tail, and 2 * RPC_MAX_AUTH_SIZE in
1664          * the page, and move the current tail data such that
1665          * there is RPC_MAX_AUTH_SIZE slack space available in
1666          * both the head and tail.
1667          */
1668         if (resbuf->tail[0].iov_base) {
1669                 BUG_ON(resbuf->tail[0].iov_base >= resbuf->head[0].iov_base
1670                                                         + PAGE_SIZE);
1671                 BUG_ON(resbuf->tail[0].iov_base < resbuf->head[0].iov_base);
1672                 if (resbuf->tail[0].iov_len + resbuf->head[0].iov_len
1673                                 + 2 * RPC_MAX_AUTH_SIZE > PAGE_SIZE)
1674                         return -ENOMEM;
1675                 memmove(resbuf->tail[0].iov_base + RPC_MAX_AUTH_SIZE,
1676                         resbuf->tail[0].iov_base,
1677                         resbuf->tail[0].iov_len);
1678                 resbuf->tail[0].iov_base += RPC_MAX_AUTH_SIZE;
1679         }
1680         /*
1681          * If there is no current tail data, make sure there is
1682          * room for the head data, and 2 * RPC_MAX_AUTH_SIZE in the
1683          * allotted page, and set up tail information such that there
1684          * is RPC_MAX_AUTH_SIZE slack space available in both the
1685          * head and tail.
1686          */
1687         if (resbuf->tail[0].iov_base == NULL) {
1688                 if (resbuf->head[0].iov_len + 2*RPC_MAX_AUTH_SIZE > PAGE_SIZE)
1689                         return -ENOMEM;
1690                 resbuf->tail[0].iov_base = resbuf->head[0].iov_base
1691                         + resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE;
1692                 resbuf->tail[0].iov_len = 0;
1693         }
1694         if (gss_wrap(gsd->rsci->mechctx, offset, resbuf, inpages))
1695                 return -ENOMEM;
1696         *len = htonl(resbuf->len - offset);
1697         pad = 3 - ((resbuf->len - offset - 1)&3);
1698         p = (__be32 *)(resbuf->tail[0].iov_base + resbuf->tail[0].iov_len);
1699         memset(p, 0, pad);
1700         resbuf->tail[0].iov_len += pad;
1701         resbuf->len += pad;
1702         return 0;
1703 }
1704 
1705 static int
1706 svcauth_gss_release(struct svc_rqst *rqstp)
1707 {
1708         struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
1709         struct rpc_gss_wire_cred *gc = &gsd->clcred;
1710         struct xdr_buf *resbuf = &rqstp->rq_res;
1711         int stat = -EINVAL;
1712         struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id);
1713 
1714         if (gc->gc_proc != RPC_GSS_PROC_DATA)
1715                 goto out;
1716         /* Release can be called twice, but we only wrap once. */
1717         if (gsd->verf_start == NULL)
1718                 goto out;
1719         /* normally not set till svc_send, but we need it here: */
1720         /* XXX: what for?  Do we mess it up the moment we call svc_putu32
1721          * or whatever? */
1722         resbuf->len = total_buf_len(resbuf);
1723         switch (gc->gc_svc) {
1724         case RPC_GSS_SVC_NONE:
1725                 break;
1726         case RPC_GSS_SVC_INTEGRITY:
1727                 stat = svcauth_gss_wrap_resp_integ(rqstp);
1728                 if (stat)
1729                         goto out_err;
1730                 break;
1731         case RPC_GSS_SVC_PRIVACY:
1732                 stat = svcauth_gss_wrap_resp_priv(rqstp);
1733                 if (stat)
1734                         goto out_err;
1735                 break;
1736         /*
1737          * For any other gc_svc value, svcauth_gss_accept() already set
1738          * the auth_error appropriately; just fall through:
1739          */
1740         }
1741 
1742 out:
1743         stat = 0;
1744 out_err:
1745         if (rqstp->rq_client)
1746                 auth_domain_put(rqstp->rq_client);
1747         rqstp->rq_client = NULL;
1748         if (rqstp->rq_gssclient)
1749                 auth_domain_put(rqstp->rq_gssclient);
1750         rqstp->rq_gssclient = NULL;
1751         if (rqstp->rq_cred.cr_group_info)
1752                 put_group_info(rqstp->rq_cred.cr_group_info);
1753         rqstp->rq_cred.cr_group_info = NULL;
1754         if (gsd->rsci)
1755                 cache_put(&gsd->rsci->h, sn->rsc_cache);
1756         gsd->rsci = NULL;
1757 
1758         return stat;
1759 }
1760 
1761 static void
1762 svcauth_gss_domain_release(struct auth_domain *dom)
1763 {
1764         struct gss_domain *gd = container_of(dom, struct gss_domain, h);
1765 
1766         kfree(dom->name);
1767         kfree(gd);
1768 }
1769 
1770 static struct auth_ops svcauthops_gss = {
1771         .name           = "rpcsec_gss",
1772         .owner          = THIS_MODULE,
1773         .flavour        = RPC_AUTH_GSS,
1774         .accept         = svcauth_gss_accept,
1775         .release        = svcauth_gss_release,
1776         .domain_release = svcauth_gss_domain_release,
1777         .set_client     = svcauth_gss_set_client,
1778 };
1779 
1780 static int rsi_cache_create_net(struct net *net)
1781 {
1782         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1783         struct cache_detail *cd;
1784         int err;
1785 
1786         cd = cache_create_net(&rsi_cache_template, net);
1787         if (IS_ERR(cd))
1788                 return PTR_ERR(cd);
1789         err = cache_register_net(cd, net);
1790         if (err) {
1791                 cache_destroy_net(cd, net);
1792                 return err;
1793         }
1794         sn->rsi_cache = cd;
1795         return 0;
1796 }
1797 
1798 static void rsi_cache_destroy_net(struct net *net)
1799 {
1800         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1801         struct cache_detail *cd = sn->rsi_cache;
1802 
1803         sn->rsi_cache = NULL;
1804         cache_purge(cd);
1805         cache_unregister_net(cd, net);
1806         cache_destroy_net(cd, net);
1807 }
1808 
1809 static int rsc_cache_create_net(struct net *net)
1810 {
1811         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1812         struct cache_detail *cd;
1813         int err;
1814 
1815         cd = cache_create_net(&rsc_cache_template, net);
1816         if (IS_ERR(cd))
1817                 return PTR_ERR(cd);
1818         err = cache_register_net(cd, net);
1819         if (err) {
1820                 cache_destroy_net(cd, net);
1821                 return err;
1822         }
1823         sn->rsc_cache = cd;
1824         return 0;
1825 }
1826 
1827 static void rsc_cache_destroy_net(struct net *net)
1828 {
1829         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1830         struct cache_detail *cd = sn->rsc_cache;
1831 
1832         sn->rsc_cache = NULL;
1833         cache_purge(cd);
1834         cache_unregister_net(cd, net);
1835         cache_destroy_net(cd, net);
1836 }
1837 
1838 int
1839 gss_svc_init_net(struct net *net)
1840 {
1841         int rv;
1842 
1843         rv = rsc_cache_create_net(net);
1844         if (rv)
1845                 return rv;
1846         rv = rsi_cache_create_net(net);
1847         if (rv)
1848                 goto out1;
1849         rv = create_use_gss_proxy_proc_entry(net);
1850         if (rv)
1851                 goto out2;
1852         return 0;
1853 out2:
1854         destroy_use_gss_proxy_proc_entry(net);
1855 out1:
1856         rsc_cache_destroy_net(net);
1857         return rv;
1858 }
1859 
1860 void
1861 gss_svc_shutdown_net(struct net *net)
1862 {
1863         destroy_use_gss_proxy_proc_entry(net);
1864         rsi_cache_destroy_net(net);
1865         rsc_cache_destroy_net(net);
1866 }
1867 
1868 int
1869 gss_svc_init(void)
1870 {
1871         return svc_auth_register(RPC_AUTH_GSS, &svcauthops_gss);
1872 }
1873 
1874 void
1875 gss_svc_shutdown(void)
1876 {
1877         svc_auth_unregister(RPC_AUTH_GSS);
1878 }
1879 

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