Merge branch 'for-linus' of git://brick.kernel.dk/data/git/linux-2.6-block
[linux-2.6] / 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
13 #define RPCDBG_FACILITY RPCDBG_AUTH
14
15
16 /*
17  * AUTHUNIX and AUTHNULL credentials are both handled here.
18  * AUTHNULL is treated just like AUTHUNIX except that the uid/gid
19  * are always nobody (-2).  i.e. we do the same IP address checks for
20  * AUTHNULL as for AUTHUNIX, and that is done here.
21  */
22
23
24 struct unix_domain {
25         struct auth_domain      h;
26         int     addr_changes;
27         /* other stuff later */
28 };
29
30 extern struct auth_ops svcauth_unix;
31
32 struct auth_domain *unix_domain_find(char *name)
33 {
34         struct auth_domain *rv;
35         struct unix_domain *new = NULL;
36
37         rv = auth_domain_lookup(name, NULL);
38         while(1) {
39                 if (rv) {
40                         if (new && rv != &new->h)
41                                 auth_domain_put(&new->h);
42
43                         if (rv->flavour != &svcauth_unix) {
44                                 auth_domain_put(rv);
45                                 return NULL;
46                         }
47                         return rv;
48                 }
49
50                 new = kmalloc(sizeof(*new), GFP_KERNEL);
51                 if (new == NULL)
52                         return NULL;
53                 kref_init(&new->h.ref);
54                 new->h.name = kstrdup(name, GFP_KERNEL);
55                 new->h.flavour = &svcauth_unix;
56                 new->addr_changes = 0;
57                 rv = auth_domain_lookup(name, &new->h);
58         }
59 }
60
61 static void svcauth_unix_domain_release(struct auth_domain *dom)
62 {
63         struct unix_domain *ud = container_of(dom, struct unix_domain, h);
64
65         kfree(dom->name);
66         kfree(ud);
67 }
68
69
70 /**************************************************
71  * cache for IP address to unix_domain
72  * as needed by AUTH_UNIX
73  */
74 #define IP_HASHBITS     8
75 #define IP_HASHMAX      (1<<IP_HASHBITS)
76 #define IP_HASHMASK     (IP_HASHMAX-1)
77
78 struct ip_map {
79         struct cache_head       h;
80         char                    m_class[8]; /* e.g. "nfsd" */
81         struct in_addr          m_addr;
82         struct unix_domain      *m_client;
83         int                     m_add_change;
84 };
85 static struct cache_head        *ip_table[IP_HASHMAX];
86
87 static void ip_map_put(struct kref *kref)
88 {
89         struct cache_head *item = container_of(kref, struct cache_head, ref);
90         struct ip_map *im = container_of(item, struct ip_map,h);
91
92         if (test_bit(CACHE_VALID, &item->flags) &&
93             !test_bit(CACHE_NEGATIVE, &item->flags))
94                 auth_domain_put(&im->m_client->h);
95         kfree(im);
96 }
97
98 #if IP_HASHBITS == 8
99 /* hash_long on a 64 bit machine is currently REALLY BAD for
100  * IP addresses in reverse-endian (i.e. on a little-endian machine).
101  * So use a trivial but reliable hash instead
102  */
103 static inline int hash_ip(unsigned long ip)
104 {
105         int hash = ip ^ (ip>>16);
106         return (hash ^ (hash>>8)) & 0xff;
107 }
108 #endif
109 static int ip_map_match(struct cache_head *corig, struct cache_head *cnew)
110 {
111         struct ip_map *orig = container_of(corig, struct ip_map, h);
112         struct ip_map *new = container_of(cnew, struct ip_map, h);
113         return strcmp(orig->m_class, new->m_class) == 0
114                 && orig->m_addr.s_addr == new->m_addr.s_addr;
115 }
116 static void ip_map_init(struct cache_head *cnew, struct cache_head *citem)
117 {
118         struct ip_map *new = container_of(cnew, struct ip_map, h);
119         struct ip_map *item = container_of(citem, struct ip_map, h);
120
121         strcpy(new->m_class, item->m_class);
122         new->m_addr.s_addr = item->m_addr.s_addr;
123 }
124 static void update(struct cache_head *cnew, struct cache_head *citem)
125 {
126         struct ip_map *new = container_of(cnew, struct ip_map, h);
127         struct ip_map *item = container_of(citem, struct ip_map, h);
128
129         kref_get(&item->m_client->h.ref);
130         new->m_client = item->m_client;
131         new->m_add_change = item->m_add_change;
132 }
133 static struct cache_head *ip_map_alloc(void)
134 {
135         struct ip_map *i = kmalloc(sizeof(*i), GFP_KERNEL);
136         if (i)
137                 return &i->h;
138         else
139                 return NULL;
140 }
141
142 static void ip_map_request(struct cache_detail *cd,
143                                   struct cache_head *h,
144                                   char **bpp, int *blen)
145 {
146         char text_addr[20];
147         struct ip_map *im = container_of(h, struct ip_map, h);
148         __u32 addr = im->m_addr.s_addr;
149         
150         snprintf(text_addr, 20, "%u.%u.%u.%u",
151                  ntohl(addr) >> 24 & 0xff,
152                  ntohl(addr) >> 16 & 0xff,
153                  ntohl(addr) >>  8 & 0xff,
154                  ntohl(addr) >>  0 & 0xff);
155
156         qword_add(bpp, blen, im->m_class);
157         qword_add(bpp, blen, text_addr);
158         (*bpp)[-1] = '\n';
159 }
160
161 static struct ip_map *ip_map_lookup(char *class, struct in_addr addr);
162 static int ip_map_update(struct ip_map *ipm, struct unix_domain *udom, time_t expiry);
163
164 static int ip_map_parse(struct cache_detail *cd,
165                           char *mesg, int mlen)
166 {
167         /* class ipaddress [domainname] */
168         /* should be safe just to use the start of the input buffer
169          * for scratch: */
170         char *buf = mesg;
171         int len;
172         int b1,b2,b3,b4;
173         char c;
174         char class[8];
175         struct in_addr addr;
176         int err;
177
178         struct ip_map *ipmp;
179         struct auth_domain *dom;
180         time_t expiry;
181
182         if (mesg[mlen-1] != '\n')
183                 return -EINVAL;
184         mesg[mlen-1] = 0;
185
186         /* class */
187         len = qword_get(&mesg, class, sizeof(class));
188         if (len <= 0) return -EINVAL;
189
190         /* ip address */
191         len = qword_get(&mesg, buf, mlen);
192         if (len <= 0) return -EINVAL;
193
194         if (sscanf(buf, "%u.%u.%u.%u%c", &b1, &b2, &b3, &b4, &c) != 4)
195                 return -EINVAL;
196         
197         expiry = get_expiry(&mesg);
198         if (expiry ==0)
199                 return -EINVAL;
200
201         /* domainname, or empty for NEGATIVE */
202         len = qword_get(&mesg, buf, mlen);
203         if (len < 0) return -EINVAL;
204
205         if (len) {
206                 dom = unix_domain_find(buf);
207                 if (dom == NULL)
208                         return -ENOENT;
209         } else
210                 dom = NULL;
211
212         addr.s_addr =
213                 htonl((((((b1<<8)|b2)<<8)|b3)<<8)|b4);
214
215         ipmp = ip_map_lookup(class,addr);
216         if (ipmp) {
217                 err = ip_map_update(ipmp,
218                              container_of(dom, struct unix_domain, h),
219                              expiry);
220         } else
221                 err = -ENOMEM;
222
223         if (dom)
224                 auth_domain_put(dom);
225
226         cache_flush();
227         return err;
228 }
229
230 static int ip_map_show(struct seq_file *m,
231                        struct cache_detail *cd,
232                        struct cache_head *h)
233 {
234         struct ip_map *im;
235         struct in_addr addr;
236         char *dom = "-no-domain-";
237
238         if (h == NULL) {
239                 seq_puts(m, "#class IP domain\n");
240                 return 0;
241         }
242         im = container_of(h, struct ip_map, h);
243         /* class addr domain */
244         addr = im->m_addr;
245
246         if (test_bit(CACHE_VALID, &h->flags) && 
247             !test_bit(CACHE_NEGATIVE, &h->flags))
248                 dom = im->m_client->h.name;
249
250         seq_printf(m, "%s %d.%d.%d.%d %s\n",
251                    im->m_class,
252                    htonl(addr.s_addr) >> 24 & 0xff,
253                    htonl(addr.s_addr) >> 16 & 0xff,
254                    htonl(addr.s_addr) >>  8 & 0xff,
255                    htonl(addr.s_addr) >>  0 & 0xff,
256                    dom
257                    );
258         return 0;
259 }
260         
261
262 struct cache_detail ip_map_cache = {
263         .owner          = THIS_MODULE,
264         .hash_size      = IP_HASHMAX,
265         .hash_table     = ip_table,
266         .name           = "auth.unix.ip",
267         .cache_put      = ip_map_put,
268         .cache_request  = ip_map_request,
269         .cache_parse    = ip_map_parse,
270         .cache_show     = ip_map_show,
271         .match          = ip_map_match,
272         .init           = ip_map_init,
273         .update         = update,
274         .alloc          = ip_map_alloc,
275 };
276
277 static struct ip_map *ip_map_lookup(char *class, struct in_addr addr)
278 {
279         struct ip_map ip;
280         struct cache_head *ch;
281
282         strcpy(ip.m_class, class);
283         ip.m_addr = addr;
284         ch = sunrpc_cache_lookup(&ip_map_cache, &ip.h,
285                                  hash_str(class, IP_HASHBITS) ^
286                                  hash_ip((unsigned long)addr.s_addr));
287
288         if (ch)
289                 return container_of(ch, struct ip_map, h);
290         else
291                 return NULL;
292 }
293
294 static int ip_map_update(struct ip_map *ipm, struct unix_domain *udom, time_t expiry)
295 {
296         struct ip_map ip;
297         struct cache_head *ch;
298
299         ip.m_client = udom;
300         ip.h.flags = 0;
301         if (!udom)
302                 set_bit(CACHE_NEGATIVE, &ip.h.flags);
303         else {
304                 ip.m_add_change = udom->addr_changes;
305                 /* if this is from the legacy set_client system call,
306                  * we need m_add_change to be one higher
307                  */
308                 if (expiry == NEVER)
309                         ip.m_add_change++;
310         }
311         ip.h.expiry_time = expiry;
312         ch = sunrpc_cache_update(&ip_map_cache,
313                                  &ip.h, &ipm->h,
314                                  hash_str(ipm->m_class, IP_HASHBITS) ^
315                                  hash_ip((unsigned long)ipm->m_addr.s_addr));
316         if (!ch)
317                 return -ENOMEM;
318         cache_put(ch, &ip_map_cache);
319         return 0;
320 }
321
322 int auth_unix_add_addr(struct in_addr addr, struct auth_domain *dom)
323 {
324         struct unix_domain *udom;
325         struct ip_map *ipmp;
326
327         if (dom->flavour != &svcauth_unix)
328                 return -EINVAL;
329         udom = container_of(dom, struct unix_domain, h);
330         ipmp = ip_map_lookup("nfsd", addr);
331
332         if (ipmp)
333                 return ip_map_update(ipmp, udom, NEVER);
334         else
335                 return -ENOMEM;
336 }
337
338 int auth_unix_forget_old(struct auth_domain *dom)
339 {
340         struct unix_domain *udom;
341         
342         if (dom->flavour != &svcauth_unix)
343                 return -EINVAL;
344         udom = container_of(dom, struct unix_domain, h);
345         udom->addr_changes++;
346         return 0;
347 }
348
349 struct auth_domain *auth_unix_lookup(struct in_addr addr)
350 {
351         struct ip_map key, *ipm;
352         struct auth_domain *rv;
353
354         strcpy(key.m_class, "nfsd");
355         key.m_addr = addr;
356
357         ipm = ip_map_lookup("nfsd", addr);
358
359         if (!ipm)
360                 return NULL;
361         if (cache_check(&ip_map_cache, &ipm->h, NULL))
362                 return NULL;
363
364         if ((ipm->m_client->addr_changes - ipm->m_add_change) >0) {
365                 if (test_and_set_bit(CACHE_NEGATIVE, &ipm->h.flags) == 0)
366                         auth_domain_put(&ipm->m_client->h);
367                 rv = NULL;
368         } else {
369                 rv = &ipm->m_client->h;
370                 kref_get(&rv->ref);
371         }
372         cache_put(&ipm->h, &ip_map_cache);
373         return rv;
374 }
375
376 void svcauth_unix_purge(void)
377 {
378         cache_purge(&ip_map_cache);
379 }
380
381 static int
382 svcauth_unix_set_client(struct svc_rqst *rqstp)
383 {
384         struct ip_map *ipm;
385
386         rqstp->rq_client = NULL;
387         if (rqstp->rq_proc == 0)
388                 return SVC_OK;
389
390         ipm = ip_map_lookup(rqstp->rq_server->sv_program->pg_class,
391                             rqstp->rq_addr.sin_addr);
392
393         if (ipm == NULL)
394                 return SVC_DENIED;
395
396         switch (cache_check(&ip_map_cache, &ipm->h, &rqstp->rq_chandle)) {
397                 default:
398                         BUG();
399                 case -EAGAIN:
400                         return SVC_DROP;
401                 case -ENOENT:
402                         return SVC_DENIED;
403                 case 0:
404                         rqstp->rq_client = &ipm->m_client->h;
405                         kref_get(&rqstp->rq_client->ref);
406                         cache_put(&ipm->h, &ip_map_cache);
407                         break;
408         }
409         return SVC_OK;
410 }
411
412 static int
413 svcauth_null_accept(struct svc_rqst *rqstp, u32 *authp)
414 {
415         struct kvec     *argv = &rqstp->rq_arg.head[0];
416         struct kvec     *resv = &rqstp->rq_res.head[0];
417         struct svc_cred *cred = &rqstp->rq_cred;
418
419         cred->cr_group_info = NULL;
420         rqstp->rq_client = NULL;
421
422         if (argv->iov_len < 3*4)
423                 return SVC_GARBAGE;
424
425         if (svc_getu32(argv) != 0) { 
426                 dprintk("svc: bad null cred\n");
427                 *authp = rpc_autherr_badcred;
428                 return SVC_DENIED;
429         }
430         if (svc_getu32(argv) != RPC_AUTH_NULL || svc_getu32(argv) != 0) {
431                 dprintk("svc: bad null verf\n");
432                 *authp = rpc_autherr_badverf;
433                 return SVC_DENIED;
434         }
435
436         /* Signal that mapping to nobody uid/gid is required */
437         cred->cr_uid = (uid_t) -1;
438         cred->cr_gid = (gid_t) -1;
439         cred->cr_group_info = groups_alloc(0);
440         if (cred->cr_group_info == NULL)
441                 return SVC_DROP; /* kmalloc failure - client must retry */
442
443         /* Put NULL verifier */
444         svc_putu32(resv, RPC_AUTH_NULL);
445         svc_putu32(resv, 0);
446
447         return SVC_OK;
448 }
449
450 static int
451 svcauth_null_release(struct svc_rqst *rqstp)
452 {
453         if (rqstp->rq_client)
454                 auth_domain_put(rqstp->rq_client);
455         rqstp->rq_client = NULL;
456         if (rqstp->rq_cred.cr_group_info)
457                 put_group_info(rqstp->rq_cred.cr_group_info);
458         rqstp->rq_cred.cr_group_info = NULL;
459
460         return 0; /* don't drop */
461 }
462
463
464 struct auth_ops svcauth_null = {
465         .name           = "null",
466         .owner          = THIS_MODULE,
467         .flavour        = RPC_AUTH_NULL,
468         .accept         = svcauth_null_accept,
469         .release        = svcauth_null_release,
470         .set_client     = svcauth_unix_set_client,
471 };
472
473
474 static int
475 svcauth_unix_accept(struct svc_rqst *rqstp, u32 *authp)
476 {
477         struct kvec     *argv = &rqstp->rq_arg.head[0];
478         struct kvec     *resv = &rqstp->rq_res.head[0];
479         struct svc_cred *cred = &rqstp->rq_cred;
480         u32             slen, i;
481         int             len   = argv->iov_len;
482
483         cred->cr_group_info = NULL;
484         rqstp->rq_client = NULL;
485
486         if ((len -= 3*4) < 0)
487                 return SVC_GARBAGE;
488
489         svc_getu32(argv);                       /* length */
490         svc_getu32(argv);                       /* time stamp */
491         slen = XDR_QUADLEN(ntohl(svc_getu32(argv)));    /* machname length */
492         if (slen > 64 || (len -= (slen + 3)*4) < 0)
493                 goto badcred;
494         argv->iov_base = (void*)((u32*)argv->iov_base + slen);  /* skip machname */
495         argv->iov_len -= slen*4;
496
497         cred->cr_uid = ntohl(svc_getu32(argv));         /* uid */
498         cred->cr_gid = ntohl(svc_getu32(argv));         /* gid */
499         slen = ntohl(svc_getu32(argv));                 /* gids length */
500         if (slen > 16 || (len -= (slen + 2)*4) < 0)
501                 goto badcred;
502         cred->cr_group_info = groups_alloc(slen);
503         if (cred->cr_group_info == NULL)
504                 return SVC_DROP;
505         for (i = 0; i < slen; i++)
506                 GROUP_AT(cred->cr_group_info, i) = ntohl(svc_getu32(argv));
507
508         if (svc_getu32(argv) != RPC_AUTH_NULL || svc_getu32(argv) != 0) {
509                 *authp = rpc_autherr_badverf;
510                 return SVC_DENIED;
511         }
512
513         /* Put NULL verifier */
514         svc_putu32(resv, RPC_AUTH_NULL);
515         svc_putu32(resv, 0);
516
517         return SVC_OK;
518
519 badcred:
520         *authp = rpc_autherr_badcred;
521         return SVC_DENIED;
522 }
523
524 static int
525 svcauth_unix_release(struct svc_rqst *rqstp)
526 {
527         /* Verifier (such as it is) is already in place.
528          */
529         if (rqstp->rq_client)
530                 auth_domain_put(rqstp->rq_client);
531         rqstp->rq_client = NULL;
532         if (rqstp->rq_cred.cr_group_info)
533                 put_group_info(rqstp->rq_cred.cr_group_info);
534         rqstp->rq_cred.cr_group_info = NULL;
535
536         return 0;
537 }
538
539
540 struct auth_ops svcauth_unix = {
541         .name           = "unix",
542         .owner          = THIS_MODULE,
543         .flavour        = RPC_AUTH_UNIX,
544         .accept         = svcauth_unix_accept,
545         .release        = svcauth_unix_release,
546         .domain_release = svcauth_unix_domain_release,
547         .set_client     = svcauth_unix_set_client,
548 };
549