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