[PATCH] knfsd: SUNRPC: Provide room in svc_rqst for larger addresses
[linux-3.10.git] / net / sunrpc / svcauth_unix.c
1 #include <linux/types.h>
2 #include <linux/sched.h>
3 #include <linux/module.h>
4 #include <linux/sunrpc/types.h>
5 #include <linux/sunrpc/xdr.h>
6 #include <linux/sunrpc/svcsock.h>
7 #include <linux/sunrpc/svcauth.h>
8 #include <linux/err.h>
9 #include <linux/seq_file.h>
10 #include <linux/hash.h>
11 #include <linux/string.h>
12 #include <net/sock.h>
13
14 #define RPCDBG_FACILITY RPCDBG_AUTH
15
16
17 /*
18  * AUTHUNIX and AUTHNULL credentials are both handled here.
19  * AUTHNULL is treated just like AUTHUNIX except that the uid/gid
20  * are always nobody (-2).  i.e. we do the same IP address checks for
21  * AUTHNULL as for AUTHUNIX, and that is done here.
22  */
23
24
25 struct unix_domain {
26         struct auth_domain      h;
27         int     addr_changes;
28         /* other stuff later */
29 };
30
31 extern struct auth_ops svcauth_unix;
32
33 struct auth_domain *unix_domain_find(char *name)
34 {
35         struct auth_domain *rv;
36         struct unix_domain *new = NULL;
37
38         rv = auth_domain_lookup(name, NULL);
39         while(1) {
40                 if (rv) {
41                         if (new && rv != &new->h)
42                                 auth_domain_put(&new->h);
43
44                         if (rv->flavour != &svcauth_unix) {
45                                 auth_domain_put(rv);
46                                 return NULL;
47                         }
48                         return rv;
49                 }
50
51                 new = kmalloc(sizeof(*new), GFP_KERNEL);
52                 if (new == NULL)
53                         return NULL;
54                 kref_init(&new->h.ref);
55                 new->h.name = kstrdup(name, GFP_KERNEL);
56                 if (new->h.name == NULL) {
57                         kfree(new);
58                         return NULL;
59                 }
60                 new->h.flavour = &svcauth_unix;
61                 new->addr_changes = 0;
62                 rv = auth_domain_lookup(name, &new->h);
63         }
64 }
65
66 static void svcauth_unix_domain_release(struct auth_domain *dom)
67 {
68         struct unix_domain *ud = container_of(dom, struct unix_domain, h);
69
70         kfree(dom->name);
71         kfree(ud);
72 }
73
74
75 /**************************************************
76  * cache for IP address to unix_domain
77  * as needed by AUTH_UNIX
78  */
79 #define IP_HASHBITS     8
80 #define IP_HASHMAX      (1<<IP_HASHBITS)
81 #define IP_HASHMASK     (IP_HASHMAX-1)
82
83 struct ip_map {
84         struct cache_head       h;
85         char                    m_class[8]; /* e.g. "nfsd" */
86         struct in_addr          m_addr;
87         struct unix_domain      *m_client;
88         int                     m_add_change;
89 };
90 static struct cache_head        *ip_table[IP_HASHMAX];
91
92 static void ip_map_put(struct kref *kref)
93 {
94         struct cache_head *item = container_of(kref, struct cache_head, ref);
95         struct ip_map *im = container_of(item, struct ip_map,h);
96
97         if (test_bit(CACHE_VALID, &item->flags) &&
98             !test_bit(CACHE_NEGATIVE, &item->flags))
99                 auth_domain_put(&im->m_client->h);
100         kfree(im);
101 }
102
103 #if IP_HASHBITS == 8
104 /* hash_long on a 64 bit machine is currently REALLY BAD for
105  * IP addresses in reverse-endian (i.e. on a little-endian machine).
106  * So use a trivial but reliable hash instead
107  */
108 static inline int hash_ip(__be32 ip)
109 {
110         int hash = (__force u32)ip ^ ((__force u32)ip>>16);
111         return (hash ^ (hash>>8)) & 0xff;
112 }
113 #endif
114 static int ip_map_match(struct cache_head *corig, struct cache_head *cnew)
115 {
116         struct ip_map *orig = container_of(corig, struct ip_map, h);
117         struct ip_map *new = container_of(cnew, struct ip_map, h);
118         return strcmp(orig->m_class, new->m_class) == 0
119                 && orig->m_addr.s_addr == new->m_addr.s_addr;
120 }
121 static void ip_map_init(struct cache_head *cnew, struct cache_head *citem)
122 {
123         struct ip_map *new = container_of(cnew, struct ip_map, h);
124         struct ip_map *item = container_of(citem, struct ip_map, h);
125
126         strcpy(new->m_class, item->m_class);
127         new->m_addr.s_addr = item->m_addr.s_addr;
128 }
129 static void update(struct cache_head *cnew, struct cache_head *citem)
130 {
131         struct ip_map *new = container_of(cnew, struct ip_map, h);
132         struct ip_map *item = container_of(citem, struct ip_map, h);
133
134         kref_get(&item->m_client->h.ref);
135         new->m_client = item->m_client;
136         new->m_add_change = item->m_add_change;
137 }
138 static struct cache_head *ip_map_alloc(void)
139 {
140         struct ip_map *i = kmalloc(sizeof(*i), GFP_KERNEL);
141         if (i)
142                 return &i->h;
143         else
144                 return NULL;
145 }
146
147 static void ip_map_request(struct cache_detail *cd,
148                                   struct cache_head *h,
149                                   char **bpp, int *blen)
150 {
151         char text_addr[20];
152         struct ip_map *im = container_of(h, struct ip_map, h);
153         __be32 addr = im->m_addr.s_addr;
154
155         snprintf(text_addr, 20, "%u.%u.%u.%u",
156                  ntohl(addr) >> 24 & 0xff,
157                  ntohl(addr) >> 16 & 0xff,
158                  ntohl(addr) >>  8 & 0xff,
159                  ntohl(addr) >>  0 & 0xff);
160
161         qword_add(bpp, blen, im->m_class);
162         qword_add(bpp, blen, text_addr);
163         (*bpp)[-1] = '\n';
164 }
165
166 static struct ip_map *ip_map_lookup(char *class, struct in_addr addr);
167 static int ip_map_update(struct ip_map *ipm, struct unix_domain *udom, time_t expiry);
168
169 static int ip_map_parse(struct cache_detail *cd,
170                           char *mesg, int mlen)
171 {
172         /* class ipaddress [domainname] */
173         /* should be safe just to use the start of the input buffer
174          * for scratch: */
175         char *buf = mesg;
176         int len;
177         int b1,b2,b3,b4;
178         char c;
179         char class[8];
180         struct in_addr addr;
181         int err;
182
183         struct ip_map *ipmp;
184         struct auth_domain *dom;
185         time_t expiry;
186
187         if (mesg[mlen-1] != '\n')
188                 return -EINVAL;
189         mesg[mlen-1] = 0;
190
191         /* class */
192         len = qword_get(&mesg, class, sizeof(class));
193         if (len <= 0) return -EINVAL;
194
195         /* ip address */
196         len = qword_get(&mesg, buf, mlen);
197         if (len <= 0) return -EINVAL;
198
199         if (sscanf(buf, "%u.%u.%u.%u%c", &b1, &b2, &b3, &b4, &c) != 4)
200                 return -EINVAL;
201
202         expiry = get_expiry(&mesg);
203         if (expiry ==0)
204                 return -EINVAL;
205
206         /* domainname, or empty for NEGATIVE */
207         len = qword_get(&mesg, buf, mlen);
208         if (len < 0) return -EINVAL;
209
210         if (len) {
211                 dom = unix_domain_find(buf);
212                 if (dom == NULL)
213                         return -ENOENT;
214         } else
215                 dom = NULL;
216
217         addr.s_addr =
218                 htonl((((((b1<<8)|b2)<<8)|b3)<<8)|b4);
219
220         ipmp = ip_map_lookup(class,addr);
221         if (ipmp) {
222                 err = ip_map_update(ipmp,
223                              container_of(dom, struct unix_domain, h),
224                              expiry);
225         } else
226                 err = -ENOMEM;
227
228         if (dom)
229                 auth_domain_put(dom);
230
231         cache_flush();
232         return err;
233 }
234
235 static int ip_map_show(struct seq_file *m,
236                        struct cache_detail *cd,
237                        struct cache_head *h)
238 {
239         struct ip_map *im;
240         struct in_addr addr;
241         char *dom = "-no-domain-";
242
243         if (h == NULL) {
244                 seq_puts(m, "#class IP domain\n");
245                 return 0;
246         }
247         im = container_of(h, struct ip_map, h);
248         /* class addr domain */
249         addr = im->m_addr;
250
251         if (test_bit(CACHE_VALID, &h->flags) &&
252             !test_bit(CACHE_NEGATIVE, &h->flags))
253                 dom = im->m_client->h.name;
254
255         seq_printf(m, "%s %d.%d.%d.%d %s\n",
256                    im->m_class,
257                    ntohl(addr.s_addr) >> 24 & 0xff,
258                    ntohl(addr.s_addr) >> 16 & 0xff,
259                    ntohl(addr.s_addr) >>  8 & 0xff,
260                    ntohl(addr.s_addr) >>  0 & 0xff,
261                    dom
262                    );
263         return 0;
264 }
265
266
267 struct cache_detail ip_map_cache = {
268         .owner          = THIS_MODULE,
269         .hash_size      = IP_HASHMAX,
270         .hash_table     = ip_table,
271         .name           = "auth.unix.ip",
272         .cache_put      = ip_map_put,
273         .cache_request  = ip_map_request,
274         .cache_parse    = ip_map_parse,
275         .cache_show     = ip_map_show,
276         .match          = ip_map_match,
277         .init           = ip_map_init,
278         .update         = update,
279         .alloc          = ip_map_alloc,
280 };
281
282 static struct ip_map *ip_map_lookup(char *class, struct in_addr addr)
283 {
284         struct ip_map ip;
285         struct cache_head *ch;
286
287         strcpy(ip.m_class, class);
288         ip.m_addr = addr;
289         ch = sunrpc_cache_lookup(&ip_map_cache, &ip.h,
290                                  hash_str(class, IP_HASHBITS) ^
291                                  hash_ip(addr.s_addr));
292
293         if (ch)
294                 return container_of(ch, struct ip_map, h);
295         else
296                 return NULL;
297 }
298
299 static int ip_map_update(struct ip_map *ipm, struct unix_domain *udom, time_t expiry)
300 {
301         struct ip_map ip;
302         struct cache_head *ch;
303
304         ip.m_client = udom;
305         ip.h.flags = 0;
306         if (!udom)
307                 set_bit(CACHE_NEGATIVE, &ip.h.flags);
308         else {
309                 ip.m_add_change = udom->addr_changes;
310                 /* if this is from the legacy set_client system call,
311                  * we need m_add_change to be one higher
312                  */
313                 if (expiry == NEVER)
314                         ip.m_add_change++;
315         }
316         ip.h.expiry_time = expiry;
317         ch = sunrpc_cache_update(&ip_map_cache,
318                                  &ip.h, &ipm->h,
319                                  hash_str(ipm->m_class, IP_HASHBITS) ^
320                                  hash_ip(ipm->m_addr.s_addr));
321         if (!ch)
322                 return -ENOMEM;
323         cache_put(ch, &ip_map_cache);
324         return 0;
325 }
326
327 int auth_unix_add_addr(struct in_addr addr, struct auth_domain *dom)
328 {
329         struct unix_domain *udom;
330         struct ip_map *ipmp;
331
332         if (dom->flavour != &svcauth_unix)
333                 return -EINVAL;
334         udom = container_of(dom, struct unix_domain, h);
335         ipmp = ip_map_lookup("nfsd", addr);
336
337         if (ipmp)
338                 return ip_map_update(ipmp, udom, NEVER);
339         else
340                 return -ENOMEM;
341 }
342
343 int auth_unix_forget_old(struct auth_domain *dom)
344 {
345         struct unix_domain *udom;
346
347         if (dom->flavour != &svcauth_unix)
348                 return -EINVAL;
349         udom = container_of(dom, struct unix_domain, h);
350         udom->addr_changes++;
351         return 0;
352 }
353
354 struct auth_domain *auth_unix_lookup(struct in_addr addr)
355 {
356         struct ip_map *ipm;
357         struct auth_domain *rv;
358
359         ipm = ip_map_lookup("nfsd", addr);
360
361         if (!ipm)
362                 return NULL;
363         if (cache_check(&ip_map_cache, &ipm->h, NULL))
364                 return NULL;
365
366         if ((ipm->m_client->addr_changes - ipm->m_add_change) >0) {
367                 if (test_and_set_bit(CACHE_NEGATIVE, &ipm->h.flags) == 0)
368                         auth_domain_put(&ipm->m_client->h);
369                 rv = NULL;
370         } else {
371                 rv = &ipm->m_client->h;
372                 kref_get(&rv->ref);
373         }
374         cache_put(&ipm->h, &ip_map_cache);
375         return rv;
376 }
377
378 void svcauth_unix_purge(void)
379 {
380         cache_purge(&ip_map_cache);
381 }
382
383 static inline struct ip_map *
384 ip_map_cached_get(struct svc_rqst *rqstp)
385 {
386         struct ip_map *ipm = rqstp->rq_sock->sk_info_authunix;
387         if (ipm != NULL) {
388                 if (!cache_valid(&ipm->h)) {
389                         /*
390                          * The entry has been invalidated since it was
391                          * remembered, e.g. by a second mount from the
392                          * same IP address.
393                          */
394                         rqstp->rq_sock->sk_info_authunix = NULL;
395                         cache_put(&ipm->h, &ip_map_cache);
396                         return NULL;
397                 }
398                 cache_get(&ipm->h);
399         }
400         return ipm;
401 }
402
403 static inline void
404 ip_map_cached_put(struct svc_rqst *rqstp, struct ip_map *ipm)
405 {
406         struct svc_sock *svsk = rqstp->rq_sock;
407
408         if (svsk->sk_sock->type == SOCK_STREAM && svsk->sk_info_authunix == NULL)
409                 svsk->sk_info_authunix = ipm;   /* newly cached, keep the reference */
410         else
411                 cache_put(&ipm->h, &ip_map_cache);
412 }
413
414 void
415 svcauth_unix_info_release(void *info)
416 {
417         struct ip_map *ipm = info;
418         cache_put(&ipm->h, &ip_map_cache);
419 }
420
421 static int
422 svcauth_unix_set_client(struct svc_rqst *rqstp)
423 {
424         struct sockaddr_in *sin = svc_addr_in(rqstp);
425         struct ip_map *ipm;
426
427         rqstp->rq_client = NULL;
428         if (rqstp->rq_proc == 0)
429                 return SVC_OK;
430
431         ipm = ip_map_cached_get(rqstp);
432         if (ipm == NULL)
433                 ipm = ip_map_lookup(rqstp->rq_server->sv_program->pg_class,
434                                     sin->sin_addr);
435
436         if (ipm == NULL)
437                 return SVC_DENIED;
438
439         switch (cache_check(&ip_map_cache, &ipm->h, &rqstp->rq_chandle)) {
440                 default:
441                         BUG();
442                 case -EAGAIN:
443                 case -ETIMEDOUT:
444                         return SVC_DROP;
445                 case -ENOENT:
446                         return SVC_DENIED;
447                 case 0:
448                         rqstp->rq_client = &ipm->m_client->h;
449                         kref_get(&rqstp->rq_client->ref);
450                         ip_map_cached_put(rqstp, ipm);
451                         break;
452         }
453         return SVC_OK;
454 }
455
456 static int
457 svcauth_null_accept(struct svc_rqst *rqstp, __be32 *authp)
458 {
459         struct kvec     *argv = &rqstp->rq_arg.head[0];
460         struct kvec     *resv = &rqstp->rq_res.head[0];
461         struct svc_cred *cred = &rqstp->rq_cred;
462
463         cred->cr_group_info = NULL;
464         rqstp->rq_client = NULL;
465
466         if (argv->iov_len < 3*4)
467                 return SVC_GARBAGE;
468
469         if (svc_getu32(argv) != 0) {
470                 dprintk("svc: bad null cred\n");
471                 *authp = rpc_autherr_badcred;
472                 return SVC_DENIED;
473         }
474         if (svc_getu32(argv) != htonl(RPC_AUTH_NULL) || svc_getu32(argv) != 0) {
475                 dprintk("svc: bad null verf\n");
476                 *authp = rpc_autherr_badverf;
477                 return SVC_DENIED;
478         }
479
480         /* Signal that mapping to nobody uid/gid is required */
481         cred->cr_uid = (uid_t) -1;
482         cred->cr_gid = (gid_t) -1;
483         cred->cr_group_info = groups_alloc(0);
484         if (cred->cr_group_info == NULL)
485                 return SVC_DROP; /* kmalloc failure - client must retry */
486
487         /* Put NULL verifier */
488         svc_putnl(resv, RPC_AUTH_NULL);
489         svc_putnl(resv, 0);
490
491         return SVC_OK;
492 }
493
494 static int
495 svcauth_null_release(struct svc_rqst *rqstp)
496 {
497         if (rqstp->rq_client)
498                 auth_domain_put(rqstp->rq_client);
499         rqstp->rq_client = NULL;
500         if (rqstp->rq_cred.cr_group_info)
501                 put_group_info(rqstp->rq_cred.cr_group_info);
502         rqstp->rq_cred.cr_group_info = NULL;
503
504         return 0; /* don't drop */
505 }
506
507
508 struct auth_ops svcauth_null = {
509         .name           = "null",
510         .owner          = THIS_MODULE,
511         .flavour        = RPC_AUTH_NULL,
512         .accept         = svcauth_null_accept,
513         .release        = svcauth_null_release,
514         .set_client     = svcauth_unix_set_client,
515 };
516
517
518 static int
519 svcauth_unix_accept(struct svc_rqst *rqstp, __be32 *authp)
520 {
521         struct kvec     *argv = &rqstp->rq_arg.head[0];
522         struct kvec     *resv = &rqstp->rq_res.head[0];
523         struct svc_cred *cred = &rqstp->rq_cred;
524         u32             slen, i;
525         int             len   = argv->iov_len;
526
527         cred->cr_group_info = NULL;
528         rqstp->rq_client = NULL;
529
530         if ((len -= 3*4) < 0)
531                 return SVC_GARBAGE;
532
533         svc_getu32(argv);                       /* length */
534         svc_getu32(argv);                       /* time stamp */
535         slen = XDR_QUADLEN(svc_getnl(argv));    /* machname length */
536         if (slen > 64 || (len -= (slen + 3)*4) < 0)
537                 goto badcred;
538         argv->iov_base = (void*)((__be32*)argv->iov_base + slen);       /* skip machname */
539         argv->iov_len -= slen*4;
540
541         cred->cr_uid = svc_getnl(argv);         /* uid */
542         cred->cr_gid = svc_getnl(argv);         /* gid */
543         slen = svc_getnl(argv);                 /* gids length */
544         if (slen > 16 || (len -= (slen + 2)*4) < 0)
545                 goto badcred;
546         cred->cr_group_info = groups_alloc(slen);
547         if (cred->cr_group_info == NULL)
548                 return SVC_DROP;
549         for (i = 0; i < slen; i++)
550                 GROUP_AT(cred->cr_group_info, i) = svc_getnl(argv);
551
552         if (svc_getu32(argv) != htonl(RPC_AUTH_NULL) || svc_getu32(argv) != 0) {
553                 *authp = rpc_autherr_badverf;
554                 return SVC_DENIED;
555         }
556
557         /* Put NULL verifier */
558         svc_putnl(resv, RPC_AUTH_NULL);
559         svc_putnl(resv, 0);
560
561         return SVC_OK;
562
563 badcred:
564         *authp = rpc_autherr_badcred;
565         return SVC_DENIED;
566 }
567
568 static int
569 svcauth_unix_release(struct svc_rqst *rqstp)
570 {
571         /* Verifier (such as it is) is already in place.
572          */
573         if (rqstp->rq_client)
574                 auth_domain_put(rqstp->rq_client);
575         rqstp->rq_client = NULL;
576         if (rqstp->rq_cred.cr_group_info)
577                 put_group_info(rqstp->rq_cred.cr_group_info);
578         rqstp->rq_cred.cr_group_info = NULL;
579
580         return 0;
581 }
582
583
584 struct auth_ops svcauth_unix = {
585         .name           = "unix",
586         .owner          = THIS_MODULE,
587         .flavour        = RPC_AUTH_UNIX,
588         .accept         = svcauth_unix_accept,
589         .release        = svcauth_unix_release,
590         .domain_release = svcauth_unix_domain_release,
591         .set_client     = svcauth_unix_set_client,
592 };
593