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Linux/net/sunrpc/auth_gss/svcauth_gss.c

Version: ~ [ linux-5.15-rc5 ] ~ [ linux-5.14.11 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.72 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.152 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.210 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.250 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.286 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.288 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ 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 #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                         GROUP_AT(rsci.cred.cr_group_info, 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 
728         svc_putnl(rqstp->rq_res.head, RPC_AUTH_GSS);
729         xdr_seq = htonl(seq);
730 
731         iov.iov_base = &xdr_seq;
732         iov.iov_len = sizeof(xdr_seq);
733         xdr_buf_from_iov(&iov, &verf_data);
734         p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len;
735         mic.data = (u8 *)(p + 1);
736         maj_stat = gss_get_mic(ctx_id, &verf_data, &mic);
737         if (maj_stat != GSS_S_COMPLETE)
738                 return -1;
739         *p++ = htonl(mic.len);
740         memset((u8 *)p + mic.len, 0, round_up_to_quad(mic.len) - mic.len);
741         p += XDR_QUADLEN(mic.len);
742         if (!xdr_ressize_check(rqstp, p))
743                 return -1;
744         return 0;
745 }
746 
747 struct gss_domain {
748         struct auth_domain      h;
749         u32                     pseudoflavor;
750 };
751 
752 static struct auth_domain *
753 find_gss_auth_domain(struct gss_ctx *ctx, u32 svc)
754 {
755         char *name;
756 
757         name = gss_service_to_auth_domain_name(ctx->mech_type, svc);
758         if (!name)
759                 return NULL;
760         return auth_domain_find(name);
761 }
762 
763 static struct auth_ops svcauthops_gss;
764 
765 u32 svcauth_gss_flavor(struct auth_domain *dom)
766 {
767         struct gss_domain *gd = container_of(dom, struct gss_domain, h);
768 
769         return gd->pseudoflavor;
770 }
771 
772 EXPORT_SYMBOL_GPL(svcauth_gss_flavor);
773 
774 int
775 svcauth_gss_register_pseudoflavor(u32 pseudoflavor, char * name)
776 {
777         struct gss_domain       *new;
778         struct auth_domain      *test;
779         int                     stat = -ENOMEM;
780 
781         new = kmalloc(sizeof(*new), GFP_KERNEL);
782         if (!new)
783                 goto out;
784         kref_init(&new->h.ref);
785         new->h.name = kstrdup(name, GFP_KERNEL);
786         if (!new->h.name)
787                 goto out_free_dom;
788         new->h.flavour = &svcauthops_gss;
789         new->pseudoflavor = pseudoflavor;
790 
791         stat = 0;
792         test = auth_domain_lookup(name, &new->h);
793         if (test != &new->h) { /* Duplicate registration */
794                 auth_domain_put(test);
795                 kfree(new->h.name);
796                 goto out_free_dom;
797         }
798         return 0;
799 
800 out_free_dom:
801         kfree(new);
802 out:
803         return stat;
804 }
805 
806 EXPORT_SYMBOL_GPL(svcauth_gss_register_pseudoflavor);
807 
808 static inline int
809 read_u32_from_xdr_buf(struct xdr_buf *buf, int base, u32 *obj)
810 {
811         __be32  raw;
812         int     status;
813 
814         status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj));
815         if (status)
816                 return status;
817         *obj = ntohl(raw);
818         return 0;
819 }
820 
821 /* It would be nice if this bit of code could be shared with the client.
822  * Obstacles:
823  *      The client shouldn't malloc(), would have to pass in own memory.
824  *      The server uses base of head iovec as read pointer, while the
825  *      client uses separate pointer. */
826 static int
827 unwrap_integ_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx)
828 {
829         int stat = -EINVAL;
830         u32 integ_len, maj_stat;
831         struct xdr_netobj mic;
832         struct xdr_buf integ_buf;
833 
834         /* Did we already verify the signature on the original pass through? */
835         if (rqstp->rq_deferred)
836                 return 0;
837 
838         integ_len = svc_getnl(&buf->head[0]);
839         if (integ_len & 3)
840                 return stat;
841         if (integ_len > buf->len)
842                 return stat;
843         if (xdr_buf_subsegment(buf, &integ_buf, 0, integ_len))
844                 BUG();
845         /* copy out mic... */
846         if (read_u32_from_xdr_buf(buf, integ_len, &mic.len))
847                 BUG();
848         if (mic.len > RPC_MAX_AUTH_SIZE)
849                 return stat;
850         mic.data = kmalloc(mic.len, GFP_KERNEL);
851         if (!mic.data)
852                 return stat;
853         if (read_bytes_from_xdr_buf(buf, integ_len + 4, mic.data, mic.len))
854                 goto out;
855         maj_stat = gss_verify_mic(ctx, &integ_buf, &mic);
856         if (maj_stat != GSS_S_COMPLETE)
857                 goto out;
858         if (svc_getnl(&buf->head[0]) != seq)
859                 goto out;
860         /* trim off the mic and padding at the end before returning */
861         xdr_buf_trim(buf, round_up_to_quad(mic.len) + 4);
862         stat = 0;
863 out:
864         kfree(mic.data);
865         return stat;
866 }
867 
868 static inline int
869 total_buf_len(struct xdr_buf *buf)
870 {
871         return buf->head[0].iov_len + buf->page_len + buf->tail[0].iov_len;
872 }
873 
874 static void
875 fix_priv_head(struct xdr_buf *buf, int pad)
876 {
877         if (buf->page_len == 0) {
878                 /* We need to adjust head and buf->len in tandem in this
879                  * case to make svc_defer() work--it finds the original
880                  * buffer start using buf->len - buf->head[0].iov_len. */
881                 buf->head[0].iov_len -= pad;
882         }
883 }
884 
885 static int
886 unwrap_priv_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx)
887 {
888         u32 priv_len, maj_stat;
889         int pad, saved_len, remaining_len, offset;
890 
891         clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
892 
893         priv_len = svc_getnl(&buf->head[0]);
894         if (rqstp->rq_deferred) {
895                 /* Already decrypted last time through! The sequence number
896                  * check at out_seq is unnecessary but harmless: */
897                 goto out_seq;
898         }
899         /* buf->len is the number of bytes from the original start of the
900          * request to the end, where head[0].iov_len is just the bytes
901          * not yet read from the head, so these two values are different: */
902         remaining_len = total_buf_len(buf);
903         if (priv_len > remaining_len)
904                 return -EINVAL;
905         pad = remaining_len - priv_len;
906         buf->len -= pad;
907         fix_priv_head(buf, pad);
908 
909         /* Maybe it would be better to give gss_unwrap a length parameter: */
910         saved_len = buf->len;
911         buf->len = priv_len;
912         maj_stat = gss_unwrap(ctx, 0, buf);
913         pad = priv_len - buf->len;
914         buf->len = saved_len;
915         buf->len -= pad;
916         /* The upper layers assume the buffer is aligned on 4-byte boundaries.
917          * In the krb5p case, at least, the data ends up offset, so we need to
918          * move it around. */
919         /* XXX: This is very inefficient.  It would be better to either do
920          * this while we encrypt, or maybe in the receive code, if we can peak
921          * ahead and work out the service and mechanism there. */
922         offset = buf->head[0].iov_len % 4;
923         if (offset) {
924                 buf->buflen = RPCSVC_MAXPAYLOAD;
925                 xdr_shift_buf(buf, offset);
926                 fix_priv_head(buf, pad);
927         }
928         if (maj_stat != GSS_S_COMPLETE)
929                 return -EINVAL;
930 out_seq:
931         if (svc_getnl(&buf->head[0]) != seq)
932                 return -EINVAL;
933         return 0;
934 }
935 
936 struct gss_svc_data {
937         /* decoded gss client cred: */
938         struct rpc_gss_wire_cred        clcred;
939         /* save a pointer to the beginning of the encoded verifier,
940          * for use in encryption/checksumming in svcauth_gss_release: */
941         __be32                          *verf_start;
942         struct rsc                      *rsci;
943 };
944 
945 static int
946 svcauth_gss_set_client(struct svc_rqst *rqstp)
947 {
948         struct gss_svc_data *svcdata = rqstp->rq_auth_data;
949         struct rsc *rsci = svcdata->rsci;
950         struct rpc_gss_wire_cred *gc = &svcdata->clcred;
951         int stat;
952 
953         /*
954          * A gss export can be specified either by:
955          *      export  *(sec=krb5,rw)
956          * or by
957          *      export gss/krb5(rw)
958          * The latter is deprecated; but for backwards compatibility reasons
959          * the nfsd code will still fall back on trying it if the former
960          * doesn't work; so we try to make both available to nfsd, below.
961          */
962         rqstp->rq_gssclient = find_gss_auth_domain(rsci->mechctx, gc->gc_svc);
963         if (rqstp->rq_gssclient == NULL)
964                 return SVC_DENIED;
965         stat = svcauth_unix_set_client(rqstp);
966         if (stat == SVC_DROP || stat == SVC_CLOSE)
967                 return stat;
968         return SVC_OK;
969 }
970 
971 static inline int
972 gss_write_init_verf(struct cache_detail *cd, struct svc_rqst *rqstp,
973                 struct xdr_netobj *out_handle, int *major_status)
974 {
975         struct rsc *rsci;
976         int        rc;
977 
978         if (*major_status != GSS_S_COMPLETE)
979                 return gss_write_null_verf(rqstp);
980         rsci = gss_svc_searchbyctx(cd, out_handle);
981         if (rsci == NULL) {
982                 *major_status = GSS_S_NO_CONTEXT;
983                 return gss_write_null_verf(rqstp);
984         }
985         rc = gss_write_verf(rqstp, rsci->mechctx, GSS_SEQ_WIN);
986         cache_put(&rsci->h, cd);
987         return rc;
988 }
989 
990 static inline int
991 gss_read_common_verf(struct rpc_gss_wire_cred *gc,
992                      struct kvec *argv, __be32 *authp,
993                      struct xdr_netobj *in_handle)
994 {
995         /* Read the verifier; should be NULL: */
996         *authp = rpc_autherr_badverf;
997         if (argv->iov_len < 2 * 4)
998                 return SVC_DENIED;
999         if (svc_getnl(argv) != RPC_AUTH_NULL)
1000                 return SVC_DENIED;
1001         if (svc_getnl(argv) != 0)
1002                 return SVC_DENIED;
1003         /* Martial context handle and token for upcall: */
1004         *authp = rpc_autherr_badcred;
1005         if (gc->gc_proc == RPC_GSS_PROC_INIT && gc->gc_ctx.len != 0)
1006                 return SVC_DENIED;
1007         if (dup_netobj(in_handle, &gc->gc_ctx))
1008                 return SVC_CLOSE;
1009         *authp = rpc_autherr_badverf;
1010 
1011         return 0;
1012 }
1013 
1014 static inline int
1015 gss_read_verf(struct rpc_gss_wire_cred *gc,
1016               struct kvec *argv, __be32 *authp,
1017               struct xdr_netobj *in_handle,
1018               struct xdr_netobj *in_token)
1019 {
1020         struct xdr_netobj tmpobj;
1021         int res;
1022 
1023         res = gss_read_common_verf(gc, argv, authp, in_handle);
1024         if (res)
1025                 return res;
1026 
1027         if (svc_safe_getnetobj(argv, &tmpobj)) {
1028                 kfree(in_handle->data);
1029                 return SVC_DENIED;
1030         }
1031         if (dup_netobj(in_token, &tmpobj)) {
1032                 kfree(in_handle->data);
1033                 return SVC_CLOSE;
1034         }
1035 
1036         return 0;
1037 }
1038 
1039 /* Ok this is really heavily depending on a set of semantics in
1040  * how rqstp is set up by svc_recv and pages laid down by the
1041  * server when reading a request. We are basically guaranteed that
1042  * the token lays all down linearly across a set of pages, starting
1043  * at iov_base in rq_arg.head[0] which happens to be the first of a
1044  * set of pages stored in rq_pages[].
1045  * rq_arg.head[0].iov_base will provide us the page_base to pass
1046  * to the upcall.
1047  */
1048 static inline int
1049 gss_read_proxy_verf(struct svc_rqst *rqstp,
1050                     struct rpc_gss_wire_cred *gc, __be32 *authp,
1051                     struct xdr_netobj *in_handle,
1052                     struct gssp_in_token *in_token)
1053 {
1054         struct kvec *argv = &rqstp->rq_arg.head[0];
1055         u32 inlen;
1056         int res;
1057 
1058         res = gss_read_common_verf(gc, argv, authp, in_handle);
1059         if (res)
1060                 return res;
1061 
1062         inlen = svc_getnl(argv);
1063         if (inlen > (argv->iov_len + rqstp->rq_arg.page_len))
1064                 return SVC_DENIED;
1065 
1066         in_token->pages = rqstp->rq_pages;
1067         in_token->page_base = (ulong)argv->iov_base & ~PAGE_MASK;
1068         in_token->page_len = inlen;
1069 
1070         return 0;
1071 }
1072 
1073 static inline int
1074 gss_write_resv(struct kvec *resv, size_t size_limit,
1075                struct xdr_netobj *out_handle, struct xdr_netobj *out_token,
1076                int major_status, int minor_status)
1077 {
1078         if (resv->iov_len + 4 > size_limit)
1079                 return -1;
1080         svc_putnl(resv, RPC_SUCCESS);
1081         if (svc_safe_putnetobj(resv, out_handle))
1082                 return -1;
1083         if (resv->iov_len + 3 * 4 > size_limit)
1084                 return -1;
1085         svc_putnl(resv, major_status);
1086         svc_putnl(resv, minor_status);
1087         svc_putnl(resv, GSS_SEQ_WIN);
1088         if (svc_safe_putnetobj(resv, out_token))
1089                 return -1;
1090         return 0;
1091 }
1092 
1093 /*
1094  * Having read the cred already and found we're in the context
1095  * initiation case, read the verifier and initiate (or check the results
1096  * of) upcalls to userspace for help with context initiation.  If
1097  * the upcall results are available, write the verifier and result.
1098  * Otherwise, drop the request pending an answer to the upcall.
1099  */
1100 static int svcauth_gss_legacy_init(struct svc_rqst *rqstp,
1101                         struct rpc_gss_wire_cred *gc, __be32 *authp)
1102 {
1103         struct kvec *argv = &rqstp->rq_arg.head[0];
1104         struct kvec *resv = &rqstp->rq_res.head[0];
1105         struct rsi *rsip, rsikey;
1106         int ret;
1107         struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id);
1108 
1109         memset(&rsikey, 0, sizeof(rsikey));
1110         ret = gss_read_verf(gc, argv, authp,
1111                             &rsikey.in_handle, &rsikey.in_token);
1112         if (ret)
1113                 return ret;
1114 
1115         /* Perform upcall, or find upcall result: */
1116         rsip = rsi_lookup(sn->rsi_cache, &rsikey);
1117         rsi_free(&rsikey);
1118         if (!rsip)
1119                 return SVC_CLOSE;
1120         if (cache_check(sn->rsi_cache, &rsip->h, &rqstp->rq_chandle) < 0)
1121                 /* No upcall result: */
1122                 return SVC_CLOSE;
1123 
1124         ret = SVC_CLOSE;
1125         /* Got an answer to the upcall; use it: */
1126         if (gss_write_init_verf(sn->rsc_cache, rqstp,
1127                                 &rsip->out_handle, &rsip->major_status))
1128                 goto out;
1129         if (gss_write_resv(resv, PAGE_SIZE,
1130                            &rsip->out_handle, &rsip->out_token,
1131                            rsip->major_status, rsip->minor_status))
1132                 goto out;
1133 
1134         ret = SVC_COMPLETE;
1135 out:
1136         cache_put(&rsip->h, sn->rsi_cache);
1137         return ret;
1138 }
1139 
1140 static int gss_proxy_save_rsc(struct cache_detail *cd,
1141                                 struct gssp_upcall_data *ud,
1142                                 uint64_t *handle)
1143 {
1144         struct rsc rsci, *rscp = NULL;
1145         static atomic64_t ctxhctr;
1146         long long ctxh;
1147         struct gss_api_mech *gm = NULL;
1148         time_t expiry;
1149         int status = -EINVAL;
1150 
1151         memset(&rsci, 0, sizeof(rsci));
1152         /* context handle */
1153         status = -ENOMEM;
1154         /* the handle needs to be just a unique id,
1155          * use a static counter */
1156         ctxh = atomic64_inc_return(&ctxhctr);
1157 
1158         /* make a copy for the caller */
1159         *handle = ctxh;
1160 
1161         /* make a copy for the rsc cache */
1162         if (dup_to_netobj(&rsci.handle, (char *)handle, sizeof(uint64_t)))
1163                 goto out;
1164         rscp = rsc_lookup(cd, &rsci);
1165         if (!rscp)
1166                 goto out;
1167 
1168         /* creds */
1169         if (!ud->found_creds) {
1170                 /* userspace seem buggy, we should always get at least a
1171                  * mapping to nobody */
1172                 dprintk("RPC:       No creds found!\n");
1173                 goto out;
1174         } else {
1175 
1176                 /* steal creds */
1177                 rsci.cred = ud->creds;
1178                 memset(&ud->creds, 0, sizeof(struct svc_cred));
1179 
1180                 status = -EOPNOTSUPP;
1181                 /* get mech handle from OID */
1182                 gm = gss_mech_get_by_OID(&ud->mech_oid);
1183                 if (!gm)
1184                         goto out;
1185                 rsci.cred.cr_gss_mech = gm;
1186 
1187                 status = -EINVAL;
1188                 /* mech-specific data: */
1189                 status = gss_import_sec_context(ud->out_handle.data,
1190                                                 ud->out_handle.len,
1191                                                 gm, &rsci.mechctx,
1192                                                 &expiry, GFP_KERNEL);
1193                 if (status)
1194                         goto out;
1195         }
1196 
1197         rsci.h.expiry_time = expiry;
1198         rscp = rsc_update(cd, &rsci, rscp);
1199         status = 0;
1200 out:
1201         rsc_free(&rsci);
1202         if (rscp)
1203                 cache_put(&rscp->h, cd);
1204         else
1205                 status = -ENOMEM;
1206         return status;
1207 }
1208 
1209 static int svcauth_gss_proxy_init(struct svc_rqst *rqstp,
1210                         struct rpc_gss_wire_cred *gc, __be32 *authp)
1211 {
1212         struct kvec *resv = &rqstp->rq_res.head[0];
1213         struct xdr_netobj cli_handle;
1214         struct gssp_upcall_data ud;
1215         uint64_t handle;
1216         int status;
1217         int ret;
1218         struct net *net = rqstp->rq_xprt->xpt_net;
1219         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1220 
1221         memset(&ud, 0, sizeof(ud));
1222         ret = gss_read_proxy_verf(rqstp, gc, authp,
1223                                   &ud.in_handle, &ud.in_token);
1224         if (ret)
1225                 return ret;
1226 
1227         ret = SVC_CLOSE;
1228 
1229         /* Perform synchronous upcall to gss-proxy */
1230         status = gssp_accept_sec_context_upcall(net, &ud);
1231         if (status)
1232                 goto out;
1233 
1234         dprintk("RPC:       svcauth_gss: gss major status = %d\n",
1235                         ud.major_status);
1236 
1237         switch (ud.major_status) {
1238         case GSS_S_CONTINUE_NEEDED:
1239                 cli_handle = ud.out_handle;
1240                 break;
1241         case GSS_S_COMPLETE:
1242                 status = gss_proxy_save_rsc(sn->rsc_cache, &ud, &handle);
1243                 if (status)
1244                         goto out;
1245                 cli_handle.data = (u8 *)&handle;
1246                 cli_handle.len = sizeof(handle);
1247                 break;
1248         default:
1249                 ret = SVC_CLOSE;
1250                 goto out;
1251         }
1252 
1253         /* Got an answer to the upcall; use it: */
1254         if (gss_write_init_verf(sn->rsc_cache, rqstp,
1255                                 &cli_handle, &ud.major_status))
1256                 goto out;
1257         if (gss_write_resv(resv, PAGE_SIZE,
1258                            &cli_handle, &ud.out_token,
1259                            ud.major_status, ud.minor_status))
1260                 goto out;
1261 
1262         ret = SVC_COMPLETE;
1263 out:
1264         gssp_free_upcall_data(&ud);
1265         return ret;
1266 }
1267 
1268 /*
1269  * Try to set the sn->use_gss_proxy variable to a new value. We only allow
1270  * it to be changed if it's currently undefined (-1). If it's any other value
1271  * then return -EBUSY unless the type wouldn't have changed anyway.
1272  */
1273 static int set_gss_proxy(struct net *net, int type)
1274 {
1275         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1276         int ret;
1277 
1278         WARN_ON_ONCE(type != 0 && type != 1);
1279         ret = cmpxchg(&sn->use_gss_proxy, -1, type);
1280         if (ret != -1 && ret != type)
1281                 return -EBUSY;
1282         return 0;
1283 }
1284 
1285 static bool use_gss_proxy(struct net *net)
1286 {
1287         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1288 
1289         /* If use_gss_proxy is still undefined, then try to disable it */
1290         if (sn->use_gss_proxy == -1)
1291                 set_gss_proxy(net, 0);
1292         return sn->use_gss_proxy;
1293 }
1294 
1295 #ifdef CONFIG_PROC_FS
1296 
1297 static ssize_t write_gssp(struct file *file, const char __user *buf,
1298                          size_t count, loff_t *ppos)
1299 {
1300         struct net *net = PDE_DATA(file_inode(file));
1301         char tbuf[20];
1302         unsigned long i;
1303         int res;
1304 
1305         if (*ppos || count > sizeof(tbuf)-1)
1306                 return -EINVAL;
1307         if (copy_from_user(tbuf, buf, count))
1308                 return -EFAULT;
1309 
1310         tbuf[count] = 0;
1311         res = kstrtoul(tbuf, 0, &i);
1312         if (res)
1313                 return res;
1314         if (i != 1)
1315                 return -EINVAL;
1316         res = set_gssp_clnt(net);
1317         if (res)
1318                 return res;
1319         res = set_gss_proxy(net, 1);
1320         if (res)
1321                 return res;
1322         return count;
1323 }
1324 
1325 static ssize_t read_gssp(struct file *file, char __user *buf,
1326                          size_t count, loff_t *ppos)
1327 {
1328         struct net *net = PDE_DATA(file_inode(file));
1329         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1330         unsigned long p = *ppos;
1331         char tbuf[10];
1332         size_t len;
1333 
1334         snprintf(tbuf, sizeof(tbuf), "%d\n", sn->use_gss_proxy);
1335         len = strlen(tbuf);
1336         if (p >= len)
1337                 return 0;
1338         len -= p;
1339         if (len > count)
1340                 len = count;
1341         if (copy_to_user(buf, (void *)(tbuf+p), len))
1342                 return -EFAULT;
1343         *ppos += len;
1344         return len;
1345 }
1346 
1347 static const struct file_operations use_gss_proxy_ops = {
1348         .open = nonseekable_open,
1349         .write = write_gssp,
1350         .read = read_gssp,
1351 };
1352 
1353 static int create_use_gss_proxy_proc_entry(struct net *net)
1354 {
1355         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1356         struct proc_dir_entry **p = &sn->use_gssp_proc;
1357 
1358         sn->use_gss_proxy = -1;
1359         *p = proc_create_data("use-gss-proxy", S_IFREG|S_IRUSR|S_IWUSR,
1360                               sn->proc_net_rpc,
1361                               &use_gss_proxy_ops, net);
1362         if (!*p)
1363                 return -ENOMEM;
1364         init_gssp_clnt(sn);
1365         return 0;
1366 }
1367 
1368 static void destroy_use_gss_proxy_proc_entry(struct net *net)
1369 {
1370         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1371 
1372         if (sn->use_gssp_proc) {
1373                 remove_proc_entry("use-gss-proxy", sn->proc_net_rpc); 
1374                 clear_gssp_clnt(sn);
1375         }
1376 }
1377 #else /* CONFIG_PROC_FS */
1378 
1379 static int create_use_gss_proxy_proc_entry(struct net *net)
1380 {
1381         return 0;
1382 }
1383 
1384 static void destroy_use_gss_proxy_proc_entry(struct net *net) {}
1385 
1386 #endif /* CONFIG_PROC_FS */
1387 
1388 /*
1389  * Accept an rpcsec packet.
1390  * If context establishment, punt to user space
1391  * If data exchange, verify/decrypt
1392  * If context destruction, handle here
1393  * In the context establishment and destruction case we encode
1394  * response here and return SVC_COMPLETE.
1395  */
1396 static int
1397 svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
1398 {
1399         struct kvec     *argv = &rqstp->rq_arg.head[0];
1400         struct kvec     *resv = &rqstp->rq_res.head[0];
1401         u32             crlen;
1402         struct gss_svc_data *svcdata = rqstp->rq_auth_data;
1403         struct rpc_gss_wire_cred *gc;
1404         struct rsc      *rsci = NULL;
1405         __be32          *rpcstart;
1406         __be32          *reject_stat = resv->iov_base + resv->iov_len;
1407         int             ret;
1408         struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id);
1409 
1410         dprintk("RPC:       svcauth_gss: argv->iov_len = %zd\n",
1411                         argv->iov_len);
1412 
1413         *authp = rpc_autherr_badcred;
1414         if (!svcdata)
1415                 svcdata = kmalloc(sizeof(*svcdata), GFP_KERNEL);
1416         if (!svcdata)
1417                 goto auth_err;
1418         rqstp->rq_auth_data = svcdata;
1419         svcdata->verf_start = NULL;
1420         svcdata->rsci = NULL;
1421         gc = &svcdata->clcred;
1422 
1423         /* start of rpc packet is 7 u32's back from here:
1424          * xid direction rpcversion prog vers proc flavour
1425          */
1426         rpcstart = argv->iov_base;
1427         rpcstart -= 7;
1428 
1429         /* credential is:
1430          *   version(==1), proc(0,1,2,3), seq, service (1,2,3), handle
1431          * at least 5 u32s, and is preceded by length, so that makes 6.
1432          */
1433 
1434         if (argv->iov_len < 5 * 4)
1435                 goto auth_err;
1436         crlen = svc_getnl(argv);
1437         if (svc_getnl(argv) != RPC_GSS_VERSION)
1438                 goto auth_err;
1439         gc->gc_proc = svc_getnl(argv);
1440         gc->gc_seq = svc_getnl(argv);
1441         gc->gc_svc = svc_getnl(argv);
1442         if (svc_safe_getnetobj(argv, &gc->gc_ctx))
1443                 goto auth_err;
1444         if (crlen != round_up_to_quad(gc->gc_ctx.len) + 5 * 4)
1445                 goto auth_err;
1446 
1447         if ((gc->gc_proc != RPC_GSS_PROC_DATA) && (rqstp->rq_proc != 0))
1448                 goto auth_err;
1449 
1450         *authp = rpc_autherr_badverf;
1451         switch (gc->gc_proc) {
1452         case RPC_GSS_PROC_INIT:
1453         case RPC_GSS_PROC_CONTINUE_INIT:
1454                 if (use_gss_proxy(SVC_NET(rqstp)))
1455                         return svcauth_gss_proxy_init(rqstp, gc, authp);
1456                 else
1457                         return svcauth_gss_legacy_init(rqstp, gc, authp);
1458         case RPC_GSS_PROC_DATA:
1459         case RPC_GSS_PROC_DESTROY:
1460                 /* Look up the context, and check the verifier: */
1461                 *authp = rpcsec_gsserr_credproblem;
1462                 rsci = gss_svc_searchbyctx(sn->rsc_cache, &gc->gc_ctx);
1463                 if (!rsci)
1464                         goto auth_err;
1465                 switch (gss_verify_header(rqstp, rsci, rpcstart, gc, authp)) {
1466                 case SVC_OK:
1467                         break;
1468                 case SVC_DENIED:
1469                         goto auth_err;
1470                 case SVC_DROP:
1471                         goto drop;
1472                 }
1473                 break;
1474         default:
1475                 *authp = rpc_autherr_rejectedcred;
1476                 goto auth_err;
1477         }
1478 
1479         /* now act upon the command: */
1480         switch (gc->gc_proc) {
1481         case RPC_GSS_PROC_DESTROY:
1482                 if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq))
1483                         goto auth_err;
1484                 rsci->h.expiry_time = get_seconds();
1485                 set_bit(CACHE_NEGATIVE, &rsci->h.flags);
1486                 if (resv->iov_len + 4 > PAGE_SIZE)
1487                         goto drop;
1488                 svc_putnl(resv, RPC_SUCCESS);
1489                 goto complete;
1490         case RPC_GSS_PROC_DATA:
1491                 *authp = rpcsec_gsserr_ctxproblem;
1492                 svcdata->verf_start = resv->iov_base + resv->iov_len;
1493                 if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq))
1494                         goto auth_err;
1495                 rqstp->rq_cred = rsci->cred;
1496                 get_group_info(rsci->cred.cr_group_info);
1497                 *authp = rpc_autherr_badcred;
1498                 switch (gc->gc_svc) {
1499                 case RPC_GSS_SVC_NONE:
1500                         break;
1501                 case RPC_GSS_SVC_INTEGRITY:
1502                         /* placeholders for length and seq. number: */
1503                         svc_putnl(resv, 0);
1504                         svc_putnl(resv, 0);
1505                         if (unwrap_integ_data(rqstp, &rqstp->rq_arg,
1506                                         gc->gc_seq, rsci->mechctx))
1507                                 goto garbage_args;
1508                         rqstp->rq_auth_slack = RPC_MAX_AUTH_SIZE;
1509                         break;
1510                 case RPC_GSS_SVC_PRIVACY:
1511                         /* placeholders for length and seq. number: */
1512                         svc_putnl(resv, 0);
1513                         svc_putnl(resv, 0);
1514                         if (unwrap_priv_data(rqstp, &rqstp->rq_arg,
1515                                         gc->gc_seq, rsci->mechctx))
1516                                 goto garbage_args;
1517                         rqstp->rq_auth_slack = RPC_MAX_AUTH_SIZE * 2;
1518                         break;
1519                 default:
1520                         goto auth_err;
1521                 }
1522                 svcdata->rsci = rsci;
1523                 cache_get(&rsci->h);
1524                 rqstp->rq_cred.cr_flavor = gss_svc_to_pseudoflavor(
1525                                         rsci->mechctx->mech_type,
1526                                         GSS_C_QOP_DEFAULT,
1527                                         gc->gc_svc);
1528                 ret = SVC_OK;
1529                 goto out;
1530         }
1531 garbage_args:
1532         ret = SVC_GARBAGE;
1533         goto out;
1534 auth_err:
1535         /* Restore write pointer to its original value: */
1536         xdr_ressize_check(rqstp, reject_stat);
1537         ret = SVC_DENIED;
1538         goto out;
1539 complete:
1540         ret = SVC_COMPLETE;
1541         goto out;
1542 drop:
1543         ret = SVC_DROP;
1544 out:
1545         if (rsci)
1546                 cache_put(&rsci->h, sn->rsc_cache);
1547         return ret;
1548 }
1549 
1550 static __be32 *
1551 svcauth_gss_prepare_to_wrap(struct xdr_buf *resbuf, struct gss_svc_data *gsd)
1552 {
1553         __be32 *p;
1554         u32 verf_len;
1555 
1556         p = gsd->verf_start;
1557         gsd->verf_start = NULL;
1558 
1559         /* If the reply stat is nonzero, don't wrap: */
1560         if (*(p-1) != rpc_success)
1561                 return NULL;
1562         /* Skip the verifier: */
1563         p += 1;
1564         verf_len = ntohl(*p++);
1565         p += XDR_QUADLEN(verf_len);
1566         /* move accept_stat to right place: */
1567         memcpy(p, p + 2, 4);
1568         /* Also don't wrap if the accept stat is nonzero: */
1569         if (*p != rpc_success) {
1570                 resbuf->head[0].iov_len -= 2 * 4;
1571                 return NULL;
1572         }
1573         p++;
1574         return p;
1575 }
1576 
1577 static inline int
1578 svcauth_gss_wrap_resp_integ(struct svc_rqst *rqstp)
1579 {
1580         struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
1581         struct rpc_gss_wire_cred *gc = &gsd->clcred;
1582         struct xdr_buf *resbuf = &rqstp->rq_res;
1583         struct xdr_buf integ_buf;
1584         struct xdr_netobj mic;
1585         struct kvec *resv;
1586         __be32 *p;
1587         int integ_offset, integ_len;
1588         int stat = -EINVAL;
1589 
1590         p = svcauth_gss_prepare_to_wrap(resbuf, gsd);
1591         if (p == NULL)
1592                 goto out;
1593         integ_offset = (u8 *)(p + 1) - (u8 *)resbuf->head[0].iov_base;
1594         integ_len = resbuf->len - integ_offset;
1595         BUG_ON(integ_len % 4);
1596         *p++ = htonl(integ_len);
1597         *p++ = htonl(gc->gc_seq);
1598         if (xdr_buf_subsegment(resbuf, &integ_buf, integ_offset, integ_len))
1599                 BUG();
1600         if (resbuf->tail[0].iov_base == NULL) {
1601                 if (resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE > PAGE_SIZE)
1602                         goto out_err;
1603                 resbuf->tail[0].iov_base = resbuf->head[0].iov_base
1604                                                 + resbuf->head[0].iov_len;
1605                 resbuf->tail[0].iov_len = 0;
1606         }
1607         resv = &resbuf->tail[0];
1608         mic.data = (u8 *)resv->iov_base + resv->iov_len + 4;
1609         if (gss_get_mic(gsd->rsci->mechctx, &integ_buf, &mic))
1610                 goto out_err;
1611         svc_putnl(resv, mic.len);
1612         memset(mic.data + mic.len, 0,
1613                         round_up_to_quad(mic.len) - mic.len);
1614         resv->iov_len += XDR_QUADLEN(mic.len) << 2;
1615         /* not strictly required: */
1616         resbuf->len += XDR_QUADLEN(mic.len) << 2;
1617         BUG_ON(resv->iov_len > PAGE_SIZE);
1618 out:
1619         stat = 0;
1620 out_err:
1621         return stat;
1622 }
1623 
1624 static inline int
1625 svcauth_gss_wrap_resp_priv(struct svc_rqst *rqstp)
1626 {
1627         struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
1628         struct rpc_gss_wire_cred *gc = &gsd->clcred;
1629         struct xdr_buf *resbuf = &rqstp->rq_res;
1630         struct page **inpages = NULL;
1631         __be32 *p, *len;
1632         int offset;
1633         int pad;
1634 
1635         p = svcauth_gss_prepare_to_wrap(resbuf, gsd);
1636         if (p == NULL)
1637                 return 0;
1638         len = p++;
1639         offset = (u8 *)p - (u8 *)resbuf->head[0].iov_base;
1640         *p++ = htonl(gc->gc_seq);
1641         inpages = resbuf->pages;
1642         /* XXX: Would be better to write some xdr helper functions for
1643          * nfs{2,3,4}xdr.c that place the data right, instead of copying: */
1644 
1645         /*
1646          * If there is currently tail data, make sure there is
1647          * room for the head, tail, and 2 * RPC_MAX_AUTH_SIZE in
1648          * the page, and move the current tail data such that
1649          * there is RPC_MAX_AUTH_SIZE slack space available in
1650          * both the head and tail.
1651          */
1652         if (resbuf->tail[0].iov_base) {
1653                 BUG_ON(resbuf->tail[0].iov_base >= resbuf->head[0].iov_base
1654                                                         + PAGE_SIZE);
1655                 BUG_ON(resbuf->tail[0].iov_base < resbuf->head[0].iov_base);
1656                 if (resbuf->tail[0].iov_len + resbuf->head[0].iov_len
1657                                 + 2 * RPC_MAX_AUTH_SIZE > PAGE_SIZE)
1658                         return -ENOMEM;
1659                 memmove(resbuf->tail[0].iov_base + RPC_MAX_AUTH_SIZE,
1660                         resbuf->tail[0].iov_base,
1661                         resbuf->tail[0].iov_len);
1662                 resbuf->tail[0].iov_base += RPC_MAX_AUTH_SIZE;
1663         }
1664         /*
1665          * If there is no current tail data, make sure there is
1666          * room for the head data, and 2 * RPC_MAX_AUTH_SIZE in the
1667          * allotted page, and set up tail information such that there
1668          * is RPC_MAX_AUTH_SIZE slack space available in both the
1669          * head and tail.
1670          */
1671         if (resbuf->tail[0].iov_base == NULL) {
1672                 if (resbuf->head[0].iov_len + 2*RPC_MAX_AUTH_SIZE > PAGE_SIZE)
1673                         return -ENOMEM;
1674                 resbuf->tail[0].iov_base = resbuf->head[0].iov_base
1675                         + resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE;
1676                 resbuf->tail[0].iov_len = 0;
1677         }
1678         if (gss_wrap(gsd->rsci->mechctx, offset, resbuf, inpages))
1679                 return -ENOMEM;
1680         *len = htonl(resbuf->len - offset);
1681         pad = 3 - ((resbuf->len - offset - 1)&3);
1682         p = (__be32 *)(resbuf->tail[0].iov_base + resbuf->tail[0].iov_len);
1683         memset(p, 0, pad);
1684         resbuf->tail[0].iov_len += pad;
1685         resbuf->len += pad;
1686         return 0;
1687 }
1688 
1689 static int
1690 svcauth_gss_release(struct svc_rqst *rqstp)
1691 {
1692         struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
1693         struct rpc_gss_wire_cred *gc = &gsd->clcred;
1694         struct xdr_buf *resbuf = &rqstp->rq_res;
1695         int stat = -EINVAL;
1696         struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id);
1697 
1698         if (gc->gc_proc != RPC_GSS_PROC_DATA)
1699                 goto out;
1700         /* Release can be called twice, but we only wrap once. */
1701         if (gsd->verf_start == NULL)
1702                 goto out;
1703         /* normally not set till svc_send, but we need it here: */
1704         /* XXX: what for?  Do we mess it up the moment we call svc_putu32
1705          * or whatever? */
1706         resbuf->len = total_buf_len(resbuf);
1707         switch (gc->gc_svc) {
1708         case RPC_GSS_SVC_NONE:
1709                 break;
1710         case RPC_GSS_SVC_INTEGRITY:
1711                 stat = svcauth_gss_wrap_resp_integ(rqstp);
1712                 if (stat)
1713                         goto out_err;
1714                 break;
1715         case RPC_GSS_SVC_PRIVACY:
1716                 stat = svcauth_gss_wrap_resp_priv(rqstp);
1717                 if (stat)
1718                         goto out_err;
1719                 break;
1720         /*
1721          * For any other gc_svc value, svcauth_gss_accept() already set
1722          * the auth_error appropriately; just fall through:
1723          */
1724         }
1725 
1726 out:
1727         stat = 0;
1728 out_err:
1729         if (rqstp->rq_client)
1730                 auth_domain_put(rqstp->rq_client);
1731         rqstp->rq_client = NULL;
1732         if (rqstp->rq_gssclient)
1733                 auth_domain_put(rqstp->rq_gssclient);
1734         rqstp->rq_gssclient = NULL;
1735         if (rqstp->rq_cred.cr_group_info)
1736                 put_group_info(rqstp->rq_cred.cr_group_info);
1737         rqstp->rq_cred.cr_group_info = NULL;
1738         if (gsd->rsci)
1739                 cache_put(&gsd->rsci->h, sn->rsc_cache);
1740         gsd->rsci = NULL;
1741 
1742         return stat;
1743 }
1744 
1745 static void
1746 svcauth_gss_domain_release(struct auth_domain *dom)
1747 {
1748         struct gss_domain *gd = container_of(dom, struct gss_domain, h);
1749 
1750         kfree(dom->name);
1751         kfree(gd);
1752 }
1753 
1754 static struct auth_ops svcauthops_gss = {
1755         .name           = "rpcsec_gss",
1756         .owner          = THIS_MODULE,
1757         .flavour        = RPC_AUTH_GSS,
1758         .accept         = svcauth_gss_accept,
1759         .release        = svcauth_gss_release,
1760         .domain_release = svcauth_gss_domain_release,
1761         .set_client     = svcauth_gss_set_client,
1762 };
1763 
1764 static int rsi_cache_create_net(struct net *net)
1765 {
1766         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1767         struct cache_detail *cd;
1768         int err;
1769 
1770         cd = cache_create_net(&rsi_cache_template, net);
1771         if (IS_ERR(cd))
1772                 return PTR_ERR(cd);
1773         err = cache_register_net(cd, net);
1774         if (err) {
1775                 cache_destroy_net(cd, net);
1776                 return err;
1777         }
1778         sn->rsi_cache = cd;
1779         return 0;
1780 }
1781 
1782 static void rsi_cache_destroy_net(struct net *net)
1783 {
1784         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1785         struct cache_detail *cd = sn->rsi_cache;
1786 
1787         sn->rsi_cache = NULL;
1788         cache_purge(cd);
1789         cache_unregister_net(cd, net);
1790         cache_destroy_net(cd, net);
1791 }
1792 
1793 static int rsc_cache_create_net(struct net *net)
1794 {
1795         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1796         struct cache_detail *cd;
1797         int err;
1798 
1799         cd = cache_create_net(&rsc_cache_template, net);
1800         if (IS_ERR(cd))
1801                 return PTR_ERR(cd);
1802         err = cache_register_net(cd, net);
1803         if (err) {
1804                 cache_destroy_net(cd, net);
1805                 return err;
1806         }
1807         sn->rsc_cache = cd;
1808         return 0;
1809 }
1810 
1811 static void rsc_cache_destroy_net(struct net *net)
1812 {
1813         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1814         struct cache_detail *cd = sn->rsc_cache;
1815 
1816         sn->rsc_cache = NULL;
1817         cache_purge(cd);
1818         cache_unregister_net(cd, net);
1819         cache_destroy_net(cd, net);
1820 }
1821 
1822 int
1823 gss_svc_init_net(struct net *net)
1824 {
1825         int rv;
1826 
1827         rv = rsc_cache_create_net(net);
1828         if (rv)
1829                 return rv;
1830         rv = rsi_cache_create_net(net);
1831         if (rv)
1832                 goto out1;
1833         rv = create_use_gss_proxy_proc_entry(net);
1834         if (rv)
1835                 goto out2;
1836         return 0;
1837 out2:
1838         destroy_use_gss_proxy_proc_entry(net);
1839 out1:
1840         rsc_cache_destroy_net(net);
1841         return rv;
1842 }
1843 
1844 void
1845 gss_svc_shutdown_net(struct net *net)
1846 {
1847         destroy_use_gss_proxy_proc_entry(net);
1848         rsi_cache_destroy_net(net);
1849         rsc_cache_destroy_net(net);
1850 }
1851 
1852 int
1853 gss_svc_init(void)
1854 {
1855         return svc_auth_register(RPC_AUTH_GSS, &svcauthops_gss);
1856 }
1857 
1858 void
1859 gss_svc_shutdown(void)
1860 {
1861         svc_auth_unregister(RPC_AUTH_GSS);
1862 }
1863 

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