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

Version: ~ [ linux-5.7-rc7 ] ~ [ linux-5.6.14 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.42 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.124 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.181 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.224 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.224 ] ~ [ 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-3.16.84 ] ~ [ 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 ] ~
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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 #ifdef RPC_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                 status = -ENOMEM;
467                 rsci.cred.cr_group_info = groups_alloc(N);
468                 if (rsci.cred.cr_group_info == NULL)
469                         goto out;
470 
471                 /* gid's */
472                 status = -EINVAL;
473                 for (i=0; i<N; i++) {
474                         kgid_t kgid;
475                         if (get_int(&mesg, &id))
476                                 goto out;
477                         kgid = make_kgid(&init_user_ns, id);
478                         if (!gid_valid(kgid))
479                                 goto out;
480                         GROUP_AT(rsci.cred.cr_group_info, i) = kgid;
481                 }
482 
483                 /* mech name */
484                 len = qword_get(&mesg, buf, mlen);
485                 if (len < 0)
486                         goto out;
487                 gm = rsci.cred.cr_gss_mech = gss_mech_get_by_name(buf);
488                 status = -EOPNOTSUPP;
489                 if (!gm)
490                         goto out;
491 
492                 status = -EINVAL;
493                 /* mech-specific data: */
494                 len = qword_get(&mesg, buf, mlen);
495                 if (len < 0)
496                         goto out;
497                 status = gss_import_sec_context(buf, len, gm, &rsci.mechctx,
498                                                 NULL, GFP_KERNEL);
499                 if (status)
500                         goto out;
501 
502                 /* get client name */
503                 len = qword_get(&mesg, buf, mlen);
504                 if (len > 0) {
505                         rsci.cred.cr_principal = kstrdup(buf, GFP_KERNEL);
506                         if (!rsci.cred.cr_principal) {
507                                 status = -ENOMEM;
508                                 goto out;
509                         }
510                 }
511 
512         }
513         rsci.h.expiry_time = expiry;
514         rscp = rsc_update(cd, &rsci, rscp);
515         status = 0;
516 out:
517         rsc_free(&rsci);
518         if (rscp)
519                 cache_put(&rscp->h, cd);
520         else
521                 status = -ENOMEM;
522         return status;
523 }
524 
525 static struct cache_detail rsc_cache_template = {
526         .owner          = THIS_MODULE,
527         .hash_size      = RSC_HASHMAX,
528         .name           = "auth.rpcsec.context",
529         .cache_put      = rsc_put,
530         .cache_parse    = rsc_parse,
531         .match          = rsc_match,
532         .init           = rsc_init,
533         .update         = update_rsc,
534         .alloc          = rsc_alloc,
535 };
536 
537 static struct rsc *rsc_lookup(struct cache_detail *cd, struct rsc *item)
538 {
539         struct cache_head *ch;
540         int hash = rsc_hash(item);
541 
542         ch = sunrpc_cache_lookup(cd, &item->h, hash);
543         if (ch)
544                 return container_of(ch, struct rsc, h);
545         else
546                 return NULL;
547 }
548 
549 static struct rsc *rsc_update(struct cache_detail *cd, struct rsc *new, struct rsc *old)
550 {
551         struct cache_head *ch;
552         int hash = rsc_hash(new);
553 
554         ch = sunrpc_cache_update(cd, &new->h,
555                                  &old->h, hash);
556         if (ch)
557                 return container_of(ch, struct rsc, h);
558         else
559                 return NULL;
560 }
561 
562 
563 static struct rsc *
564 gss_svc_searchbyctx(struct cache_detail *cd, struct xdr_netobj *handle)
565 {
566         struct rsc rsci;
567         struct rsc *found;
568 
569         memset(&rsci, 0, sizeof(rsci));
570         if (dup_to_netobj(&rsci.handle, handle->data, handle->len))
571                 return NULL;
572         found = rsc_lookup(cd, &rsci);
573         rsc_free(&rsci);
574         if (!found)
575                 return NULL;
576         if (cache_check(cd, &found->h, NULL))
577                 return NULL;
578         return found;
579 }
580 
581 /* Implements sequence number algorithm as specified in RFC 2203. */
582 static int
583 gss_check_seq_num(struct rsc *rsci, int seq_num)
584 {
585         struct gss_svc_seq_data *sd = &rsci->seqdata;
586 
587         spin_lock(&sd->sd_lock);
588         if (seq_num > sd->sd_max) {
589                 if (seq_num >= sd->sd_max + GSS_SEQ_WIN) {
590                         memset(sd->sd_win,0,sizeof(sd->sd_win));
591                         sd->sd_max = seq_num;
592                 } else while (sd->sd_max < seq_num) {
593                         sd->sd_max++;
594                         __clear_bit(sd->sd_max % GSS_SEQ_WIN, sd->sd_win);
595                 }
596                 __set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win);
597                 goto ok;
598         } else if (seq_num <= sd->sd_max - GSS_SEQ_WIN) {
599                 goto drop;
600         }
601         /* sd_max - GSS_SEQ_WIN < seq_num <= sd_max */
602         if (__test_and_set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win))
603                 goto drop;
604 ok:
605         spin_unlock(&sd->sd_lock);
606         return 1;
607 drop:
608         spin_unlock(&sd->sd_lock);
609         return 0;
610 }
611 
612 static inline u32 round_up_to_quad(u32 i)
613 {
614         return (i + 3 ) & ~3;
615 }
616 
617 static inline int
618 svc_safe_getnetobj(struct kvec *argv, struct xdr_netobj *o)
619 {
620         int l;
621 
622         if (argv->iov_len < 4)
623                 return -1;
624         o->len = svc_getnl(argv);
625         l = round_up_to_quad(o->len);
626         if (argv->iov_len < l)
627                 return -1;
628         o->data = argv->iov_base;
629         argv->iov_base += l;
630         argv->iov_len -= l;
631         return 0;
632 }
633 
634 static inline int
635 svc_safe_putnetobj(struct kvec *resv, struct xdr_netobj *o)
636 {
637         u8 *p;
638 
639         if (resv->iov_len + 4 > PAGE_SIZE)
640                 return -1;
641         svc_putnl(resv, o->len);
642         p = resv->iov_base + resv->iov_len;
643         resv->iov_len += round_up_to_quad(o->len);
644         if (resv->iov_len > PAGE_SIZE)
645                 return -1;
646         memcpy(p, o->data, o->len);
647         memset(p + o->len, 0, round_up_to_quad(o->len) - o->len);
648         return 0;
649 }
650 
651 /*
652  * Verify the checksum on the header and return SVC_OK on success.
653  * Otherwise, return SVC_DROP (in the case of a bad sequence number)
654  * or return SVC_DENIED and indicate error in authp.
655  */
656 static int
657 gss_verify_header(struct svc_rqst *rqstp, struct rsc *rsci,
658                   __be32 *rpcstart, struct rpc_gss_wire_cred *gc, __be32 *authp)
659 {
660         struct gss_ctx          *ctx_id = rsci->mechctx;
661         struct xdr_buf          rpchdr;
662         struct xdr_netobj       checksum;
663         u32                     flavor = 0;
664         struct kvec             *argv = &rqstp->rq_arg.head[0];
665         struct kvec             iov;
666 
667         /* data to compute the checksum over: */
668         iov.iov_base = rpcstart;
669         iov.iov_len = (u8 *)argv->iov_base - (u8 *)rpcstart;
670         xdr_buf_from_iov(&iov, &rpchdr);
671 
672         *authp = rpc_autherr_badverf;
673         if (argv->iov_len < 4)
674                 return SVC_DENIED;
675         flavor = svc_getnl(argv);
676         if (flavor != RPC_AUTH_GSS)
677                 return SVC_DENIED;
678         if (svc_safe_getnetobj(argv, &checksum))
679                 return SVC_DENIED;
680 
681         if (rqstp->rq_deferred) /* skip verification of revisited request */
682                 return SVC_OK;
683         if (gss_verify_mic(ctx_id, &rpchdr, &checksum) != GSS_S_COMPLETE) {
684                 *authp = rpcsec_gsserr_credproblem;
685                 return SVC_DENIED;
686         }
687 
688         if (gc->gc_seq > MAXSEQ) {
689                 dprintk("RPC:       svcauth_gss: discarding request with "
690                                 "large sequence number %d\n", gc->gc_seq);
691                 *authp = rpcsec_gsserr_ctxproblem;
692                 return SVC_DENIED;
693         }
694         if (!gss_check_seq_num(rsci, gc->gc_seq)) {
695                 dprintk("RPC:       svcauth_gss: discarding request with "
696                                 "old sequence number %d\n", gc->gc_seq);
697                 return SVC_DROP;
698         }
699         return SVC_OK;
700 }
701 
702 static int
703 gss_write_null_verf(struct svc_rqst *rqstp)
704 {
705         __be32     *p;
706 
707         svc_putnl(rqstp->rq_res.head, RPC_AUTH_NULL);
708         p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len;
709         /* don't really need to check if head->iov_len > PAGE_SIZE ... */
710         *p++ = 0;
711         if (!xdr_ressize_check(rqstp, p))
712                 return -1;
713         return 0;
714 }
715 
716 static int
717 gss_write_verf(struct svc_rqst *rqstp, struct gss_ctx *ctx_id, u32 seq)
718 {
719         __be32                  xdr_seq;
720         u32                     maj_stat;
721         struct xdr_buf          verf_data;
722         struct xdr_netobj       mic;
723         __be32                  *p;
724         struct kvec             iov;
725 
726         svc_putnl(rqstp->rq_res.head, RPC_AUTH_GSS);
727         xdr_seq = htonl(seq);
728 
729         iov.iov_base = &xdr_seq;
730         iov.iov_len = sizeof(xdr_seq);
731         xdr_buf_from_iov(&iov, &verf_data);
732         p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len;
733         mic.data = (u8 *)(p + 1);
734         maj_stat = gss_get_mic(ctx_id, &verf_data, &mic);
735         if (maj_stat != GSS_S_COMPLETE)
736                 return -1;
737         *p++ = htonl(mic.len);
738         memset((u8 *)p + mic.len, 0, round_up_to_quad(mic.len) - mic.len);
739         p += XDR_QUADLEN(mic.len);
740         if (!xdr_ressize_check(rqstp, p))
741                 return -1;
742         return 0;
743 }
744 
745 struct gss_domain {
746         struct auth_domain      h;
747         u32                     pseudoflavor;
748 };
749 
750 static struct auth_domain *
751 find_gss_auth_domain(struct gss_ctx *ctx, u32 svc)
752 {
753         char *name;
754 
755         name = gss_service_to_auth_domain_name(ctx->mech_type, svc);
756         if (!name)
757                 return NULL;
758         return auth_domain_find(name);
759 }
760 
761 static struct auth_ops svcauthops_gss;
762 
763 u32 svcauth_gss_flavor(struct auth_domain *dom)
764 {
765         struct gss_domain *gd = container_of(dom, struct gss_domain, h);
766 
767         return gd->pseudoflavor;
768 }
769 
770 EXPORT_SYMBOL_GPL(svcauth_gss_flavor);
771 
772 int
773 svcauth_gss_register_pseudoflavor(u32 pseudoflavor, char * name)
774 {
775         struct gss_domain       *new;
776         struct auth_domain      *test;
777         int                     stat = -ENOMEM;
778 
779         new = kmalloc(sizeof(*new), GFP_KERNEL);
780         if (!new)
781                 goto out;
782         kref_init(&new->h.ref);
783         new->h.name = kstrdup(name, GFP_KERNEL);
784         if (!new->h.name)
785                 goto out_free_dom;
786         new->h.flavour = &svcauthops_gss;
787         new->pseudoflavor = pseudoflavor;
788 
789         stat = 0;
790         test = auth_domain_lookup(name, &new->h);
791         if (test != &new->h) { /* Duplicate registration */
792                 auth_domain_put(test);
793                 kfree(new->h.name);
794                 goto out_free_dom;
795         }
796         return 0;
797 
798 out_free_dom:
799         kfree(new);
800 out:
801         return stat;
802 }
803 
804 EXPORT_SYMBOL_GPL(svcauth_gss_register_pseudoflavor);
805 
806 static inline int
807 read_u32_from_xdr_buf(struct xdr_buf *buf, int base, u32 *obj)
808 {
809         __be32  raw;
810         int     status;
811 
812         status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj));
813         if (status)
814                 return status;
815         *obj = ntohl(raw);
816         return 0;
817 }
818 
819 /* It would be nice if this bit of code could be shared with the client.
820  * Obstacles:
821  *      The client shouldn't malloc(), would have to pass in own memory.
822  *      The server uses base of head iovec as read pointer, while the
823  *      client uses separate pointer. */
824 static int
825 unwrap_integ_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx)
826 {
827         int stat = -EINVAL;
828         u32 integ_len, maj_stat;
829         struct xdr_netobj mic;
830         struct xdr_buf integ_buf;
831 
832         /* Did we already verify the signature on the original pass through? */
833         if (rqstp->rq_deferred)
834                 return 0;
835 
836         integ_len = svc_getnl(&buf->head[0]);
837         if (integ_len & 3)
838                 return stat;
839         if (integ_len > buf->len)
840                 return stat;
841         if (xdr_buf_subsegment(buf, &integ_buf, 0, integ_len))
842                 BUG();
843         /* copy out mic... */
844         if (read_u32_from_xdr_buf(buf, integ_len, &mic.len))
845                 BUG();
846         if (mic.len > RPC_MAX_AUTH_SIZE)
847                 return stat;
848         mic.data = kmalloc(mic.len, GFP_KERNEL);
849         if (!mic.data)
850                 return stat;
851         if (read_bytes_from_xdr_buf(buf, integ_len + 4, mic.data, mic.len))
852                 goto out;
853         maj_stat = gss_verify_mic(ctx, &integ_buf, &mic);
854         if (maj_stat != GSS_S_COMPLETE)
855                 goto out;
856         if (svc_getnl(&buf->head[0]) != seq)
857                 goto out;
858         /* trim off the mic at the end before returning */
859         xdr_buf_trim(buf, mic.len + 4);
860         stat = 0;
861 out:
862         kfree(mic.data);
863         return stat;
864 }
865 
866 static inline int
867 total_buf_len(struct xdr_buf *buf)
868 {
869         return buf->head[0].iov_len + buf->page_len + buf->tail[0].iov_len;
870 }
871 
872 static void
873 fix_priv_head(struct xdr_buf *buf, int pad)
874 {
875         if (buf->page_len == 0) {
876                 /* We need to adjust head and buf->len in tandem in this
877                  * case to make svc_defer() work--it finds the original
878                  * buffer start using buf->len - buf->head[0].iov_len. */
879                 buf->head[0].iov_len -= pad;
880         }
881 }
882 
883 static int
884 unwrap_priv_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx)
885 {
886         u32 priv_len, maj_stat;
887         int pad, saved_len, remaining_len, offset;
888 
889         rqstp->rq_splice_ok = 0;
890 
891         priv_len = svc_getnl(&buf->head[0]);
892         if (rqstp->rq_deferred) {
893                 /* Already decrypted last time through! The sequence number
894                  * check at out_seq is unnecessary but harmless: */
895                 goto out_seq;
896         }
897         /* buf->len is the number of bytes from the original start of the
898          * request to the end, where head[0].iov_len is just the bytes
899          * not yet read from the head, so these two values are different: */
900         remaining_len = total_buf_len(buf);
901         if (priv_len > remaining_len)
902                 return -EINVAL;
903         pad = remaining_len - priv_len;
904         buf->len -= pad;
905         fix_priv_head(buf, pad);
906 
907         /* Maybe it would be better to give gss_unwrap a length parameter: */
908         saved_len = buf->len;
909         buf->len = priv_len;
910         maj_stat = gss_unwrap(ctx, 0, buf);
911         pad = priv_len - buf->len;
912         buf->len = saved_len;
913         buf->len -= pad;
914         /* The upper layers assume the buffer is aligned on 4-byte boundaries.
915          * In the krb5p case, at least, the data ends up offset, so we need to
916          * move it around. */
917         /* XXX: This is very inefficient.  It would be better to either do
918          * this while we encrypt, or maybe in the receive code, if we can peak
919          * ahead and work out the service and mechanism there. */
920         offset = buf->head[0].iov_len % 4;
921         if (offset) {
922                 buf->buflen = RPCSVC_MAXPAYLOAD;
923                 xdr_shift_buf(buf, offset);
924                 fix_priv_head(buf, pad);
925         }
926         if (maj_stat != GSS_S_COMPLETE)
927                 return -EINVAL;
928 out_seq:
929         if (svc_getnl(&buf->head[0]) != seq)
930                 return -EINVAL;
931         return 0;
932 }
933 
934 struct gss_svc_data {
935         /* decoded gss client cred: */
936         struct rpc_gss_wire_cred        clcred;
937         /* save a pointer to the beginning of the encoded verifier,
938          * for use in encryption/checksumming in svcauth_gss_release: */
939         __be32                          *verf_start;
940         struct rsc                      *rsci;
941 };
942 
943 static int
944 svcauth_gss_set_client(struct svc_rqst *rqstp)
945 {
946         struct gss_svc_data *svcdata = rqstp->rq_auth_data;
947         struct rsc *rsci = svcdata->rsci;
948         struct rpc_gss_wire_cred *gc = &svcdata->clcred;
949         int stat;
950 
951         /*
952          * A gss export can be specified either by:
953          *      export  *(sec=krb5,rw)
954          * or by
955          *      export gss/krb5(rw)
956          * The latter is deprecated; but for backwards compatibility reasons
957          * the nfsd code will still fall back on trying it if the former
958          * doesn't work; so we try to make both available to nfsd, below.
959          */
960         rqstp->rq_gssclient = find_gss_auth_domain(rsci->mechctx, gc->gc_svc);
961         if (rqstp->rq_gssclient == NULL)
962                 return SVC_DENIED;
963         stat = svcauth_unix_set_client(rqstp);
964         if (stat == SVC_DROP || stat == SVC_CLOSE)
965                 return stat;
966         return SVC_OK;
967 }
968 
969 static inline int
970 gss_write_init_verf(struct cache_detail *cd, struct svc_rqst *rqstp,
971                 struct xdr_netobj *out_handle, int *major_status)
972 {
973         struct rsc *rsci;
974         int        rc;
975 
976         if (*major_status != GSS_S_COMPLETE)
977                 return gss_write_null_verf(rqstp);
978         rsci = gss_svc_searchbyctx(cd, out_handle);
979         if (rsci == NULL) {
980                 *major_status = GSS_S_NO_CONTEXT;
981                 return gss_write_null_verf(rqstp);
982         }
983         rc = gss_write_verf(rqstp, rsci->mechctx, GSS_SEQ_WIN);
984         cache_put(&rsci->h, cd);
985         return rc;
986 }
987 
988 static inline int
989 gss_read_common_verf(struct rpc_gss_wire_cred *gc,
990                      struct kvec *argv, __be32 *authp,
991                      struct xdr_netobj *in_handle)
992 {
993         /* Read the verifier; should be NULL: */
994         *authp = rpc_autherr_badverf;
995         if (argv->iov_len < 2 * 4)
996                 return SVC_DENIED;
997         if (svc_getnl(argv) != RPC_AUTH_NULL)
998                 return SVC_DENIED;
999         if (svc_getnl(argv) != 0)
1000                 return SVC_DENIED;
1001         /* Martial context handle and token for upcall: */
1002         *authp = rpc_autherr_badcred;
1003         if (gc->gc_proc == RPC_GSS_PROC_INIT && gc->gc_ctx.len != 0)
1004                 return SVC_DENIED;
1005         if (dup_netobj(in_handle, &gc->gc_ctx))
1006                 return SVC_CLOSE;
1007         *authp = rpc_autherr_badverf;
1008 
1009         return 0;
1010 }
1011 
1012 static inline int
1013 gss_read_verf(struct rpc_gss_wire_cred *gc,
1014               struct kvec *argv, __be32 *authp,
1015               struct xdr_netobj *in_handle,
1016               struct xdr_netobj *in_token)
1017 {
1018         struct xdr_netobj tmpobj;
1019         int res;
1020 
1021         res = gss_read_common_verf(gc, argv, authp, in_handle);
1022         if (res)
1023                 return res;
1024 
1025         if (svc_safe_getnetobj(argv, &tmpobj)) {
1026                 kfree(in_handle->data);
1027                 return SVC_DENIED;
1028         }
1029         if (dup_netobj(in_token, &tmpobj)) {
1030                 kfree(in_handle->data);
1031                 return SVC_CLOSE;
1032         }
1033 
1034         return 0;
1035 }
1036 
1037 /* Ok this is really heavily depending on a set of semantics in
1038  * how rqstp is set up by svc_recv and pages laid down by the
1039  * server when reading a request. We are basically guaranteed that
1040  * the token lays all down linearly across a set of pages, starting
1041  * at iov_base in rq_arg.head[0] which happens to be the first of a
1042  * set of pages stored in rq_pages[].
1043  * rq_arg.head[0].iov_base will provide us the page_base to pass
1044  * to the upcall.
1045  */
1046 static inline int
1047 gss_read_proxy_verf(struct svc_rqst *rqstp,
1048                     struct rpc_gss_wire_cred *gc, __be32 *authp,
1049                     struct xdr_netobj *in_handle,
1050                     struct gssp_in_token *in_token)
1051 {
1052         struct kvec *argv = &rqstp->rq_arg.head[0];
1053         u32 inlen;
1054         int res;
1055 
1056         res = gss_read_common_verf(gc, argv, authp, in_handle);
1057         if (res)
1058                 return res;
1059 
1060         inlen = svc_getnl(argv);
1061         if (inlen > (argv->iov_len + rqstp->rq_arg.page_len))
1062                 return SVC_DENIED;
1063 
1064         in_token->pages = rqstp->rq_pages;
1065         in_token->page_base = (ulong)argv->iov_base & ~PAGE_MASK;
1066         in_token->page_len = inlen;
1067 
1068         return 0;
1069 }
1070 
1071 static inline int
1072 gss_write_resv(struct kvec *resv, size_t size_limit,
1073                struct xdr_netobj *out_handle, struct xdr_netobj *out_token,
1074                int major_status, int minor_status)
1075 {
1076         if (resv->iov_len + 4 > size_limit)
1077                 return -1;
1078         svc_putnl(resv, RPC_SUCCESS);
1079         if (svc_safe_putnetobj(resv, out_handle))
1080                 return -1;
1081         if (resv->iov_len + 3 * 4 > size_limit)
1082                 return -1;
1083         svc_putnl(resv, major_status);
1084         svc_putnl(resv, minor_status);
1085         svc_putnl(resv, GSS_SEQ_WIN);
1086         if (svc_safe_putnetobj(resv, out_token))
1087                 return -1;
1088         return 0;
1089 }
1090 
1091 /*
1092  * Having read the cred already and found we're in the context
1093  * initiation case, read the verifier and initiate (or check the results
1094  * of) upcalls to userspace for help with context initiation.  If
1095  * the upcall results are available, write the verifier and result.
1096  * Otherwise, drop the request pending an answer to the upcall.
1097  */
1098 static int svcauth_gss_legacy_init(struct svc_rqst *rqstp,
1099                         struct rpc_gss_wire_cred *gc, __be32 *authp)
1100 {
1101         struct kvec *argv = &rqstp->rq_arg.head[0];
1102         struct kvec *resv = &rqstp->rq_res.head[0];
1103         struct rsi *rsip, rsikey;
1104         int ret;
1105         struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id);
1106 
1107         memset(&rsikey, 0, sizeof(rsikey));
1108         ret = gss_read_verf(gc, argv, authp,
1109                             &rsikey.in_handle, &rsikey.in_token);
1110         if (ret)
1111                 return ret;
1112 
1113         /* Perform upcall, or find upcall result: */
1114         rsip = rsi_lookup(sn->rsi_cache, &rsikey);
1115         rsi_free(&rsikey);
1116         if (!rsip)
1117                 return SVC_CLOSE;
1118         if (cache_check(sn->rsi_cache, &rsip->h, &rqstp->rq_chandle) < 0)
1119                 /* No upcall result: */
1120                 return SVC_CLOSE;
1121 
1122         ret = SVC_CLOSE;
1123         /* Got an answer to the upcall; use it: */
1124         if (gss_write_init_verf(sn->rsc_cache, rqstp,
1125                                 &rsip->out_handle, &rsip->major_status))
1126                 goto out;
1127         if (gss_write_resv(resv, PAGE_SIZE,
1128                            &rsip->out_handle, &rsip->out_token,
1129                            rsip->major_status, rsip->minor_status))
1130                 goto out;
1131 
1132         ret = SVC_COMPLETE;
1133 out:
1134         cache_put(&rsip->h, sn->rsi_cache);
1135         return ret;
1136 }
1137 
1138 static int gss_proxy_save_rsc(struct cache_detail *cd,
1139                                 struct gssp_upcall_data *ud,
1140                                 uint64_t *handle)
1141 {
1142         struct rsc rsci, *rscp = NULL;
1143         static atomic64_t ctxhctr;
1144         long long ctxh;
1145         struct gss_api_mech *gm = NULL;
1146         time_t expiry;
1147         int status = -EINVAL;
1148 
1149         memset(&rsci, 0, sizeof(rsci));
1150         /* context handle */
1151         status = -ENOMEM;
1152         /* the handle needs to be just a unique id,
1153          * use a static counter */
1154         ctxh = atomic64_inc_return(&ctxhctr);
1155 
1156         /* make a copy for the caller */
1157         *handle = ctxh;
1158 
1159         /* make a copy for the rsc cache */
1160         if (dup_to_netobj(&rsci.handle, (char *)handle, sizeof(uint64_t)))
1161                 goto out;
1162         rscp = rsc_lookup(cd, &rsci);
1163         if (!rscp)
1164                 goto out;
1165 
1166         /* creds */
1167         if (!ud->found_creds) {
1168                 /* userspace seem buggy, we should always get at least a
1169                  * mapping to nobody */
1170                 dprintk("RPC:       No creds found!\n");
1171                 goto out;
1172         } else {
1173 
1174                 /* steal creds */
1175                 rsci.cred = ud->creds;
1176                 memset(&ud->creds, 0, sizeof(struct svc_cred));
1177 
1178                 status = -EOPNOTSUPP;
1179                 /* get mech handle from OID */
1180                 gm = gss_mech_get_by_OID(&ud->mech_oid);
1181                 if (!gm)
1182                         goto out;
1183                 rsci.cred.cr_gss_mech = gm;
1184 
1185                 status = -EINVAL;
1186                 /* mech-specific data: */
1187                 status = gss_import_sec_context(ud->out_handle.data,
1188                                                 ud->out_handle.len,
1189                                                 gm, &rsci.mechctx,
1190                                                 &expiry, GFP_KERNEL);
1191                 if (status)
1192                         goto out;
1193         }
1194 
1195         rsci.h.expiry_time = expiry;
1196         rscp = rsc_update(cd, &rsci, rscp);
1197         status = 0;
1198 out:
1199         rsc_free(&rsci);
1200         if (rscp)
1201                 cache_put(&rscp->h, cd);
1202         else
1203                 status = -ENOMEM;
1204         return status;
1205 }
1206 
1207 static int svcauth_gss_proxy_init(struct svc_rqst *rqstp,
1208                         struct rpc_gss_wire_cred *gc, __be32 *authp)
1209 {
1210         struct kvec *resv = &rqstp->rq_res.head[0];
1211         struct xdr_netobj cli_handle;
1212         struct gssp_upcall_data ud;
1213         uint64_t handle;
1214         int status;
1215         int ret;
1216         struct net *net = rqstp->rq_xprt->xpt_net;
1217         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1218 
1219         memset(&ud, 0, sizeof(ud));
1220         ret = gss_read_proxy_verf(rqstp, gc, authp,
1221                                   &ud.in_handle, &ud.in_token);
1222         if (ret)
1223                 return ret;
1224 
1225         ret = SVC_CLOSE;
1226 
1227         /* Perform synchronous upcall to gss-proxy */
1228         status = gssp_accept_sec_context_upcall(net, &ud);
1229         if (status)
1230                 goto out;
1231 
1232         dprintk("RPC:       svcauth_gss: gss major status = %d\n",
1233                         ud.major_status);
1234 
1235         switch (ud.major_status) {
1236         case GSS_S_CONTINUE_NEEDED:
1237                 cli_handle = ud.out_handle;
1238                 break;
1239         case GSS_S_COMPLETE:
1240                 status = gss_proxy_save_rsc(sn->rsc_cache, &ud, &handle);
1241                 if (status)
1242                         goto out;
1243                 cli_handle.data = (u8 *)&handle;
1244                 cli_handle.len = sizeof(handle);
1245                 break;
1246         default:
1247                 ret = SVC_CLOSE;
1248                 goto out;
1249         }
1250 
1251         /* Got an answer to the upcall; use it: */
1252         if (gss_write_init_verf(sn->rsc_cache, rqstp,
1253                                 &cli_handle, &ud.major_status))
1254                 goto out;
1255         if (gss_write_resv(resv, PAGE_SIZE,
1256                            &cli_handle, &ud.out_token,
1257                            ud.major_status, ud.minor_status))
1258                 goto out;
1259 
1260         ret = SVC_COMPLETE;
1261 out:
1262         gssp_free_upcall_data(&ud);
1263         return ret;
1264 }
1265 
1266 DEFINE_SPINLOCK(use_gssp_lock);
1267 
1268 static bool use_gss_proxy(struct net *net)
1269 {
1270         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1271 
1272         if (sn->use_gss_proxy != -1)
1273                 return sn->use_gss_proxy;
1274         spin_lock(&use_gssp_lock);
1275         /*
1276          * If you wanted gss-proxy, you should have said so before
1277          * starting to accept requests:
1278          */
1279         sn->use_gss_proxy = 0;
1280         spin_unlock(&use_gssp_lock);
1281         return 0;
1282 }
1283 
1284 #ifdef CONFIG_PROC_FS
1285 
1286 static int set_gss_proxy(struct net *net, int type)
1287 {
1288         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1289         int ret = 0;
1290 
1291         WARN_ON_ONCE(type != 0 && type != 1);
1292         spin_lock(&use_gssp_lock);
1293         if (sn->use_gss_proxy == -1 || sn->use_gss_proxy == type)
1294                 sn->use_gss_proxy = type;
1295         else
1296                 ret = -EBUSY;
1297         spin_unlock(&use_gssp_lock);
1298         return ret;
1299 }
1300 
1301 static ssize_t write_gssp(struct file *file, const char __user *buf,
1302                          size_t count, loff_t *ppos)
1303 {
1304         struct net *net = PDE_DATA(file_inode(file));
1305         char tbuf[20];
1306         unsigned long i;
1307         int res;
1308 
1309         if (*ppos || count > sizeof(tbuf)-1)
1310                 return -EINVAL;
1311         if (copy_from_user(tbuf, buf, count))
1312                 return -EFAULT;
1313 
1314         tbuf[count] = 0;
1315         res = kstrtoul(tbuf, 0, &i);
1316         if (res)
1317                 return res;
1318         if (i != 1)
1319                 return -EINVAL;
1320         res = set_gss_proxy(net, 1);
1321         if (res)
1322                 return res;
1323         res = set_gssp_clnt(net);
1324         if (res)
1325                 return res;
1326         return count;
1327 }
1328 
1329 static ssize_t read_gssp(struct file *file, char __user *buf,
1330                          size_t count, loff_t *ppos)
1331 {
1332         struct net *net = PDE_DATA(file_inode(file));
1333         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1334         unsigned long p = *ppos;
1335         char tbuf[10];
1336         size_t len;
1337 
1338         snprintf(tbuf, sizeof(tbuf), "%d\n", sn->use_gss_proxy);
1339         len = strlen(tbuf);
1340         if (p >= len)
1341                 return 0;
1342         len -= p;
1343         if (len > count)
1344                 len = count;
1345         if (copy_to_user(buf, (void *)(tbuf+p), len))
1346                 return -EFAULT;
1347         *ppos += len;
1348         return len;
1349 }
1350 
1351 static const struct file_operations use_gss_proxy_ops = {
1352         .open = nonseekable_open,
1353         .write = write_gssp,
1354         .read = read_gssp,
1355 };
1356 
1357 static int create_use_gss_proxy_proc_entry(struct net *net)
1358 {
1359         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1360         struct proc_dir_entry **p = &sn->use_gssp_proc;
1361 
1362         sn->use_gss_proxy = -1;
1363         *p = proc_create_data("use-gss-proxy", S_IFREG|S_IRUSR|S_IWUSR,
1364                               sn->proc_net_rpc,
1365                               &use_gss_proxy_ops, net);
1366         if (!*p)
1367                 return -ENOMEM;
1368         init_gssp_clnt(sn);
1369         return 0;
1370 }
1371 
1372 static void destroy_use_gss_proxy_proc_entry(struct net *net)
1373 {
1374         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1375 
1376         if (sn->use_gssp_proc) {
1377                 remove_proc_entry("use-gss-proxy", sn->proc_net_rpc); 
1378                 clear_gssp_clnt(sn);
1379         }
1380 }
1381 #else /* CONFIG_PROC_FS */
1382 
1383 static int create_use_gss_proxy_proc_entry(struct net *net)
1384 {
1385         return 0;
1386 }
1387 
1388 static void destroy_use_gss_proxy_proc_entry(struct net *net) {}
1389 
1390 #endif /* CONFIG_PROC_FS */
1391 
1392 /*
1393  * Accept an rpcsec packet.
1394  * If context establishment, punt to user space
1395  * If data exchange, verify/decrypt
1396  * If context destruction, handle here
1397  * In the context establishment and destruction case we encode
1398  * response here and return SVC_COMPLETE.
1399  */
1400 static int
1401 svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
1402 {
1403         struct kvec     *argv = &rqstp->rq_arg.head[0];
1404         struct kvec     *resv = &rqstp->rq_res.head[0];
1405         u32             crlen;
1406         struct gss_svc_data *svcdata = rqstp->rq_auth_data;
1407         struct rpc_gss_wire_cred *gc;
1408         struct rsc      *rsci = NULL;
1409         __be32          *rpcstart;
1410         __be32          *reject_stat = resv->iov_base + resv->iov_len;
1411         int             ret;
1412         struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id);
1413 
1414         dprintk("RPC:       svcauth_gss: argv->iov_len = %zd\n",
1415                         argv->iov_len);
1416 
1417         *authp = rpc_autherr_badcred;
1418         if (!svcdata)
1419                 svcdata = kmalloc(sizeof(*svcdata), GFP_KERNEL);
1420         if (!svcdata)
1421                 goto auth_err;
1422         rqstp->rq_auth_data = svcdata;
1423         svcdata->verf_start = NULL;
1424         svcdata->rsci = NULL;
1425         gc = &svcdata->clcred;
1426 
1427         /* start of rpc packet is 7 u32's back from here:
1428          * xid direction rpcversion prog vers proc flavour
1429          */
1430         rpcstart = argv->iov_base;
1431         rpcstart -= 7;
1432 
1433         /* credential is:
1434          *   version(==1), proc(0,1,2,3), seq, service (1,2,3), handle
1435          * at least 5 u32s, and is preceded by length, so that makes 6.
1436          */
1437 
1438         if (argv->iov_len < 5 * 4)
1439                 goto auth_err;
1440         crlen = svc_getnl(argv);
1441         if (svc_getnl(argv) != RPC_GSS_VERSION)
1442                 goto auth_err;
1443         gc->gc_proc = svc_getnl(argv);
1444         gc->gc_seq = svc_getnl(argv);
1445         gc->gc_svc = svc_getnl(argv);
1446         if (svc_safe_getnetobj(argv, &gc->gc_ctx))
1447                 goto auth_err;
1448         if (crlen != round_up_to_quad(gc->gc_ctx.len) + 5 * 4)
1449                 goto auth_err;
1450 
1451         if ((gc->gc_proc != RPC_GSS_PROC_DATA) && (rqstp->rq_proc != 0))
1452                 goto auth_err;
1453 
1454         *authp = rpc_autherr_badverf;
1455         switch (gc->gc_proc) {
1456         case RPC_GSS_PROC_INIT:
1457         case RPC_GSS_PROC_CONTINUE_INIT:
1458                 if (use_gss_proxy(SVC_NET(rqstp)))
1459                         return svcauth_gss_proxy_init(rqstp, gc, authp);
1460                 else
1461                         return svcauth_gss_legacy_init(rqstp, gc, authp);
1462         case RPC_GSS_PROC_DATA:
1463         case RPC_GSS_PROC_DESTROY:
1464                 /* Look up the context, and check the verifier: */
1465                 *authp = rpcsec_gsserr_credproblem;
1466                 rsci = gss_svc_searchbyctx(sn->rsc_cache, &gc->gc_ctx);
1467                 if (!rsci)
1468                         goto auth_err;
1469                 switch (gss_verify_header(rqstp, rsci, rpcstart, gc, authp)) {
1470                 case SVC_OK:
1471                         break;
1472                 case SVC_DENIED:
1473                         goto auth_err;
1474                 case SVC_DROP:
1475                         goto drop;
1476                 }
1477                 break;
1478         default:
1479                 *authp = rpc_autherr_rejectedcred;
1480                 goto auth_err;
1481         }
1482 
1483         /* now act upon the command: */
1484         switch (gc->gc_proc) {
1485         case RPC_GSS_PROC_DESTROY:
1486                 if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq))
1487                         goto auth_err;
1488                 rsci->h.expiry_time = get_seconds();
1489                 set_bit(CACHE_NEGATIVE, &rsci->h.flags);
1490                 if (resv->iov_len + 4 > PAGE_SIZE)
1491                         goto drop;
1492                 svc_putnl(resv, RPC_SUCCESS);
1493                 goto complete;
1494         case RPC_GSS_PROC_DATA:
1495                 *authp = rpcsec_gsserr_ctxproblem;
1496                 svcdata->verf_start = resv->iov_base + resv->iov_len;
1497                 if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq))
1498                         goto auth_err;
1499                 rqstp->rq_cred = rsci->cred;
1500                 get_group_info(rsci->cred.cr_group_info);
1501                 *authp = rpc_autherr_badcred;
1502                 switch (gc->gc_svc) {
1503                 case RPC_GSS_SVC_NONE:
1504                         break;
1505                 case RPC_GSS_SVC_INTEGRITY:
1506                         /* placeholders for length and seq. number: */
1507                         svc_putnl(resv, 0);
1508                         svc_putnl(resv, 0);
1509                         if (unwrap_integ_data(rqstp, &rqstp->rq_arg,
1510                                         gc->gc_seq, rsci->mechctx))
1511                                 goto garbage_args;
1512                         break;
1513                 case RPC_GSS_SVC_PRIVACY:
1514                         /* placeholders for length and seq. number: */
1515                         svc_putnl(resv, 0);
1516                         svc_putnl(resv, 0);
1517                         if (unwrap_priv_data(rqstp, &rqstp->rq_arg,
1518                                         gc->gc_seq, rsci->mechctx))
1519                                 goto garbage_args;
1520                         break;
1521                 default:
1522                         goto auth_err;
1523                 }
1524                 svcdata->rsci = rsci;
1525                 cache_get(&rsci->h);
1526                 rqstp->rq_cred.cr_flavor = gss_svc_to_pseudoflavor(
1527                                         rsci->mechctx->mech_type,
1528                                         GSS_C_QOP_DEFAULT,
1529                                         gc->gc_svc);
1530                 ret = SVC_OK;
1531                 goto out;
1532         }
1533 garbage_args:
1534         ret = SVC_GARBAGE;
1535         goto out;
1536 auth_err:
1537         /* Restore write pointer to its original value: */
1538         xdr_ressize_check(rqstp, reject_stat);
1539         ret = SVC_DENIED;
1540         goto out;
1541 complete:
1542         ret = SVC_COMPLETE;
1543         goto out;
1544 drop:
1545         ret = SVC_DROP;
1546 out:
1547         if (rsci)
1548                 cache_put(&rsci->h, sn->rsc_cache);
1549         return ret;
1550 }
1551 
1552 static __be32 *
1553 svcauth_gss_prepare_to_wrap(struct xdr_buf *resbuf, struct gss_svc_data *gsd)
1554 {
1555         __be32 *p;
1556         u32 verf_len;
1557 
1558         p = gsd->verf_start;
1559         gsd->verf_start = NULL;
1560 
1561         /* If the reply stat is nonzero, don't wrap: */
1562         if (*(p-1) != rpc_success)
1563                 return NULL;
1564         /* Skip the verifier: */
1565         p += 1;
1566         verf_len = ntohl(*p++);
1567         p += XDR_QUADLEN(verf_len);
1568         /* move accept_stat to right place: */
1569         memcpy(p, p + 2, 4);
1570         /* Also don't wrap if the accept stat is nonzero: */
1571         if (*p != rpc_success) {
1572                 resbuf->head[0].iov_len -= 2 * 4;
1573                 return NULL;
1574         }
1575         p++;
1576         return p;
1577 }
1578 
1579 static inline int
1580 svcauth_gss_wrap_resp_integ(struct svc_rqst *rqstp)
1581 {
1582         struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
1583         struct rpc_gss_wire_cred *gc = &gsd->clcred;
1584         struct xdr_buf *resbuf = &rqstp->rq_res;
1585         struct xdr_buf integ_buf;
1586         struct xdr_netobj mic;
1587         struct kvec *resv;
1588         __be32 *p;
1589         int integ_offset, integ_len;
1590         int stat = -EINVAL;
1591 
1592         p = svcauth_gss_prepare_to_wrap(resbuf, gsd);
1593         if (p == NULL)
1594                 goto out;
1595         integ_offset = (u8 *)(p + 1) - (u8 *)resbuf->head[0].iov_base;
1596         integ_len = resbuf->len - integ_offset;
1597         BUG_ON(integ_len % 4);
1598         *p++ = htonl(integ_len);
1599         *p++ = htonl(gc->gc_seq);
1600         if (xdr_buf_subsegment(resbuf, &integ_buf, integ_offset,
1601                                 integ_len))
1602                 BUG();
1603         if (resbuf->tail[0].iov_base == NULL) {
1604                 if (resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE > PAGE_SIZE)
1605                         goto out_err;
1606                 resbuf->tail[0].iov_base = resbuf->head[0].iov_base
1607                                                 + resbuf->head[0].iov_len;
1608                 resbuf->tail[0].iov_len = 0;
1609                 resv = &resbuf->tail[0];
1610         } else {
1611                 resv = &resbuf->tail[0];
1612         }
1613         mic.data = (u8 *)resv->iov_base + resv->iov_len + 4;
1614         if (gss_get_mic(gsd->rsci->mechctx, &integ_buf, &mic))
1615                 goto out_err;
1616         svc_putnl(resv, mic.len);
1617         memset(mic.data + mic.len, 0,
1618                         round_up_to_quad(mic.len) - mic.len);
1619         resv->iov_len += XDR_QUADLEN(mic.len) << 2;
1620         /* not strictly required: */
1621         resbuf->len += XDR_QUADLEN(mic.len) << 2;
1622         BUG_ON(resv->iov_len > PAGE_SIZE);
1623 out:
1624         stat = 0;
1625 out_err:
1626         return stat;
1627 }
1628 
1629 static inline int
1630 svcauth_gss_wrap_resp_priv(struct svc_rqst *rqstp)
1631 {
1632         struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
1633         struct rpc_gss_wire_cred *gc = &gsd->clcred;
1634         struct xdr_buf *resbuf = &rqstp->rq_res;
1635         struct page **inpages = NULL;
1636         __be32 *p, *len;
1637         int offset;
1638         int pad;
1639 
1640         p = svcauth_gss_prepare_to_wrap(resbuf, gsd);
1641         if (p == NULL)
1642                 return 0;
1643         len = p++;
1644         offset = (u8 *)p - (u8 *)resbuf->head[0].iov_base;
1645         *p++ = htonl(gc->gc_seq);
1646         inpages = resbuf->pages;
1647         /* XXX: Would be better to write some xdr helper functions for
1648          * nfs{2,3,4}xdr.c that place the data right, instead of copying: */
1649 
1650         /*
1651          * If there is currently tail data, make sure there is
1652          * room for the head, tail, and 2 * RPC_MAX_AUTH_SIZE in
1653          * the page, and move the current tail data such that
1654          * there is RPC_MAX_AUTH_SIZE slack space available in
1655          * both the head and tail.
1656          */
1657         if (resbuf->tail[0].iov_base) {
1658                 BUG_ON(resbuf->tail[0].iov_base >= resbuf->head[0].iov_base
1659                                                         + PAGE_SIZE);
1660                 BUG_ON(resbuf->tail[0].iov_base < resbuf->head[0].iov_base);
1661                 if (resbuf->tail[0].iov_len + resbuf->head[0].iov_len
1662                                 + 2 * RPC_MAX_AUTH_SIZE > PAGE_SIZE)
1663                         return -ENOMEM;
1664                 memmove(resbuf->tail[0].iov_base + RPC_MAX_AUTH_SIZE,
1665                         resbuf->tail[0].iov_base,
1666                         resbuf->tail[0].iov_len);
1667                 resbuf->tail[0].iov_base += RPC_MAX_AUTH_SIZE;
1668         }
1669         /*
1670          * If there is no current tail data, make sure there is
1671          * room for the head data, and 2 * RPC_MAX_AUTH_SIZE in the
1672          * allotted page, and set up tail information such that there
1673          * is RPC_MAX_AUTH_SIZE slack space available in both the
1674          * head and tail.
1675          */
1676         if (resbuf->tail[0].iov_base == NULL) {
1677                 if (resbuf->head[0].iov_len + 2*RPC_MAX_AUTH_SIZE > PAGE_SIZE)
1678                         return -ENOMEM;
1679                 resbuf->tail[0].iov_base = resbuf->head[0].iov_base
1680                         + resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE;
1681                 resbuf->tail[0].iov_len = 0;
1682         }
1683         if (gss_wrap(gsd->rsci->mechctx, offset, resbuf, inpages))
1684                 return -ENOMEM;
1685         *len = htonl(resbuf->len - offset);
1686         pad = 3 - ((resbuf->len - offset - 1)&3);
1687         p = (__be32 *)(resbuf->tail[0].iov_base + resbuf->tail[0].iov_len);
1688         memset(p, 0, pad);
1689         resbuf->tail[0].iov_len += pad;
1690         resbuf->len += pad;
1691         return 0;
1692 }
1693 
1694 static int
1695 svcauth_gss_release(struct svc_rqst *rqstp)
1696 {
1697         struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
1698         struct rpc_gss_wire_cred *gc = &gsd->clcred;
1699         struct xdr_buf *resbuf = &rqstp->rq_res;
1700         int stat = -EINVAL;
1701         struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id);
1702 
1703         if (gc->gc_proc != RPC_GSS_PROC_DATA)
1704                 goto out;
1705         /* Release can be called twice, but we only wrap once. */
1706         if (gsd->verf_start == NULL)
1707                 goto out;
1708         /* normally not set till svc_send, but we need it here: */
1709         /* XXX: what for?  Do we mess it up the moment we call svc_putu32
1710          * or whatever? */
1711         resbuf->len = total_buf_len(resbuf);
1712         switch (gc->gc_svc) {
1713         case RPC_GSS_SVC_NONE:
1714                 break;
1715         case RPC_GSS_SVC_INTEGRITY:
1716                 stat = svcauth_gss_wrap_resp_integ(rqstp);
1717                 if (stat)
1718                         goto out_err;
1719                 break;
1720         case RPC_GSS_SVC_PRIVACY:
1721                 stat = svcauth_gss_wrap_resp_priv(rqstp);
1722                 if (stat)
1723                         goto out_err;
1724                 break;
1725         /*
1726          * For any other gc_svc value, svcauth_gss_accept() already set
1727          * the auth_error appropriately; just fall through:
1728          */
1729         }
1730 
1731 out:
1732         stat = 0;
1733 out_err:
1734         if (rqstp->rq_client)
1735                 auth_domain_put(rqstp->rq_client);
1736         rqstp->rq_client = NULL;
1737         if (rqstp->rq_gssclient)
1738                 auth_domain_put(rqstp->rq_gssclient);
1739         rqstp->rq_gssclient = NULL;
1740         if (rqstp->rq_cred.cr_group_info)
1741                 put_group_info(rqstp->rq_cred.cr_group_info);
1742         rqstp->rq_cred.cr_group_info = NULL;
1743         if (gsd->rsci)
1744                 cache_put(&gsd->rsci->h, sn->rsc_cache);
1745         gsd->rsci = NULL;
1746 
1747         return stat;
1748 }
1749 
1750 static void
1751 svcauth_gss_domain_release(struct auth_domain *dom)
1752 {
1753         struct gss_domain *gd = container_of(dom, struct gss_domain, h);
1754 
1755         kfree(dom->name);
1756         kfree(gd);
1757 }
1758 
1759 static struct auth_ops svcauthops_gss = {
1760         .name           = "rpcsec_gss",
1761         .owner          = THIS_MODULE,
1762         .flavour        = RPC_AUTH_GSS,
1763         .accept         = svcauth_gss_accept,
1764         .release        = svcauth_gss_release,
1765         .domain_release = svcauth_gss_domain_release,
1766         .set_client     = svcauth_gss_set_client,
1767 };
1768 
1769 static int rsi_cache_create_net(struct net *net)
1770 {
1771         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1772         struct cache_detail *cd;
1773         int err;
1774 
1775         cd = cache_create_net(&rsi_cache_template, net);
1776         if (IS_ERR(cd))
1777                 return PTR_ERR(cd);
1778         err = cache_register_net(cd, net);
1779         if (err) {
1780                 cache_destroy_net(cd, net);
1781                 return err;
1782         }
1783         sn->rsi_cache = cd;
1784         return 0;
1785 }
1786 
1787 static void rsi_cache_destroy_net(struct net *net)
1788 {
1789         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1790         struct cache_detail *cd = sn->rsi_cache;
1791 
1792         sn->rsi_cache = NULL;
1793         cache_purge(cd);
1794         cache_unregister_net(cd, net);
1795         cache_destroy_net(cd, net);
1796 }
1797 
1798 static int rsc_cache_create_net(struct net *net)
1799 {
1800         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1801         struct cache_detail *cd;
1802         int err;
1803 
1804         cd = cache_create_net(&rsc_cache_template, net);
1805         if (IS_ERR(cd))
1806                 return PTR_ERR(cd);
1807         err = cache_register_net(cd, net);
1808         if (err) {
1809                 cache_destroy_net(cd, net);
1810                 return err;
1811         }
1812         sn->rsc_cache = cd;
1813         return 0;
1814 }
1815 
1816 static void rsc_cache_destroy_net(struct net *net)
1817 {
1818         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1819         struct cache_detail *cd = sn->rsc_cache;
1820 
1821         sn->rsc_cache = NULL;
1822         cache_purge(cd);
1823         cache_unregister_net(cd, net);
1824         cache_destroy_net(cd, net);
1825 }
1826 
1827 int
1828 gss_svc_init_net(struct net *net)
1829 {
1830         int rv;
1831 
1832         rv = rsc_cache_create_net(net);
1833         if (rv)
1834                 return rv;
1835         rv = rsi_cache_create_net(net);
1836         if (rv)
1837                 goto out1;
1838         rv = create_use_gss_proxy_proc_entry(net);
1839         if (rv)
1840                 goto out2;
1841         return 0;
1842 out2:
1843         destroy_use_gss_proxy_proc_entry(net);
1844 out1:
1845         rsc_cache_destroy_net(net);
1846         return rv;
1847 }
1848 
1849 void
1850 gss_svc_shutdown_net(struct net *net)
1851 {
1852         destroy_use_gss_proxy_proc_entry(net);
1853         rsi_cache_destroy_net(net);
1854         rsc_cache_destroy_net(net);
1855 }
1856 
1857 int
1858 gss_svc_init(void)
1859 {
1860         return svc_auth_register(RPC_AUTH_GSS, &svcauthops_gss);
1861 }
1862 
1863 void
1864 gss_svc_shutdown(void)
1865 {
1866         svc_auth_unregister(RPC_AUTH_GSS);
1867 }
1868 

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