xref: /openbmc/linux/fs/nfsd/nfs2acl.c (revision aac5987a)
1 /*
2  * Process version 2 NFSACL requests.
3  *
4  * Copyright (C) 2002-2003 Andreas Gruenbacher <agruen@suse.de>
5  */
6 
7 #include "nfsd.h"
8 /* FIXME: nfsacl.h is a broken header */
9 #include <linux/nfsacl.h>
10 #include <linux/gfp.h>
11 #include "cache.h"
12 #include "xdr3.h"
13 #include "vfs.h"
14 
15 #define NFSDDBG_FACILITY		NFSDDBG_PROC
16 #define RETURN_STATUS(st)	{ resp->status = (st); return (st); }
17 
18 /*
19  * NULL call.
20  */
21 static __be32
22 nfsacld_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
23 {
24 	return nfs_ok;
25 }
26 
27 /*
28  * Get the Access and/or Default ACL of a file.
29  */
30 static __be32 nfsacld_proc_getacl(struct svc_rqst * rqstp,
31 		struct nfsd3_getaclargs *argp, struct nfsd3_getaclres *resp)
32 {
33 	struct posix_acl *acl;
34 	struct inode *inode;
35 	svc_fh *fh;
36 	__be32 nfserr = 0;
37 
38 	dprintk("nfsd: GETACL(2acl)   %s\n", SVCFH_fmt(&argp->fh));
39 
40 	fh = fh_copy(&resp->fh, &argp->fh);
41 	nfserr = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP);
42 	if (nfserr)
43 		RETURN_STATUS(nfserr);
44 
45 	inode = d_inode(fh->fh_dentry);
46 
47 	if (argp->mask & ~NFS_ACL_MASK)
48 		RETURN_STATUS(nfserr_inval);
49 	resp->mask = argp->mask;
50 
51 	nfserr = fh_getattr(fh, &resp->stat);
52 	if (nfserr)
53 		RETURN_STATUS(nfserr);
54 
55 	if (resp->mask & (NFS_ACL|NFS_ACLCNT)) {
56 		acl = get_acl(inode, ACL_TYPE_ACCESS);
57 		if (acl == NULL) {
58 			/* Solaris returns the inode's minimum ACL. */
59 			acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
60 		}
61 		if (IS_ERR(acl)) {
62 			nfserr = nfserrno(PTR_ERR(acl));
63 			goto fail;
64 		}
65 		resp->acl_access = acl;
66 	}
67 	if (resp->mask & (NFS_DFACL|NFS_DFACLCNT)) {
68 		/* Check how Solaris handles requests for the Default ACL
69 		   of a non-directory! */
70 		acl = get_acl(inode, ACL_TYPE_DEFAULT);
71 		if (IS_ERR(acl)) {
72 			nfserr = nfserrno(PTR_ERR(acl));
73 			goto fail;
74 		}
75 		resp->acl_default = acl;
76 	}
77 
78 	/* resp->acl_{access,default} are released in nfssvc_release_getacl. */
79 	RETURN_STATUS(0);
80 
81 fail:
82 	posix_acl_release(resp->acl_access);
83 	posix_acl_release(resp->acl_default);
84 	RETURN_STATUS(nfserr);
85 }
86 
87 /*
88  * Set the Access and/or Default ACL of a file.
89  */
90 static __be32 nfsacld_proc_setacl(struct svc_rqst * rqstp,
91 		struct nfsd3_setaclargs *argp,
92 		struct nfsd_attrstat *resp)
93 {
94 	struct inode *inode;
95 	svc_fh *fh;
96 	__be32 nfserr = 0;
97 	int error;
98 
99 	dprintk("nfsd: SETACL(2acl)   %s\n", SVCFH_fmt(&argp->fh));
100 
101 	fh = fh_copy(&resp->fh, &argp->fh);
102 	nfserr = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_SATTR);
103 	if (nfserr)
104 		goto out;
105 
106 	inode = d_inode(fh->fh_dentry);
107 
108 	error = fh_want_write(fh);
109 	if (error)
110 		goto out_errno;
111 
112 	fh_lock(fh);
113 
114 	error = set_posix_acl(inode, ACL_TYPE_ACCESS, argp->acl_access);
115 	if (error)
116 		goto out_drop_lock;
117 	error = set_posix_acl(inode, ACL_TYPE_DEFAULT, argp->acl_default);
118 	if (error)
119 		goto out_drop_lock;
120 
121 	fh_unlock(fh);
122 
123 	fh_drop_write(fh);
124 
125 	nfserr = fh_getattr(fh, &resp->stat);
126 
127 out:
128 	/* argp->acl_{access,default} may have been allocated in
129 	   nfssvc_decode_setaclargs. */
130 	posix_acl_release(argp->acl_access);
131 	posix_acl_release(argp->acl_default);
132 	return nfserr;
133 out_drop_lock:
134 	fh_unlock(fh);
135 	fh_drop_write(fh);
136 out_errno:
137 	nfserr = nfserrno(error);
138 	goto out;
139 }
140 
141 /*
142  * Check file attributes
143  */
144 static __be32 nfsacld_proc_getattr(struct svc_rqst * rqstp,
145 		struct nfsd_fhandle *argp, struct nfsd_attrstat *resp)
146 {
147 	__be32 nfserr;
148 	dprintk("nfsd: GETATTR  %s\n", SVCFH_fmt(&argp->fh));
149 
150 	fh_copy(&resp->fh, &argp->fh);
151 	nfserr = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP);
152 	if (nfserr)
153 		return nfserr;
154 	nfserr = fh_getattr(&resp->fh, &resp->stat);
155 	return nfserr;
156 }
157 
158 /*
159  * Check file access
160  */
161 static __be32 nfsacld_proc_access(struct svc_rqst *rqstp, struct nfsd3_accessargs *argp,
162 		struct nfsd3_accessres *resp)
163 {
164 	__be32 nfserr;
165 
166 	dprintk("nfsd: ACCESS(2acl)   %s 0x%x\n",
167 			SVCFH_fmt(&argp->fh),
168 			argp->access);
169 
170 	fh_copy(&resp->fh, &argp->fh);
171 	resp->access = argp->access;
172 	nfserr = nfsd_access(rqstp, &resp->fh, &resp->access, NULL);
173 	if (nfserr)
174 		return nfserr;
175 	nfserr = fh_getattr(&resp->fh, &resp->stat);
176 	return nfserr;
177 }
178 
179 /*
180  * XDR decode functions
181  */
182 static int nfsaclsvc_decode_getaclargs(struct svc_rqst *rqstp, __be32 *p,
183 		struct nfsd3_getaclargs *argp)
184 {
185 	p = nfs2svc_decode_fh(p, &argp->fh);
186 	if (!p)
187 		return 0;
188 	argp->mask = ntohl(*p); p++;
189 
190 	return xdr_argsize_check(rqstp, p);
191 }
192 
193 
194 static int nfsaclsvc_decode_setaclargs(struct svc_rqst *rqstp, __be32 *p,
195 		struct nfsd3_setaclargs *argp)
196 {
197 	struct kvec *head = rqstp->rq_arg.head;
198 	unsigned int base;
199 	int n;
200 
201 	p = nfs2svc_decode_fh(p, &argp->fh);
202 	if (!p)
203 		return 0;
204 	argp->mask = ntohl(*p++);
205 	if (argp->mask & ~NFS_ACL_MASK ||
206 	    !xdr_argsize_check(rqstp, p))
207 		return 0;
208 
209 	base = (char *)p - (char *)head->iov_base;
210 	n = nfsacl_decode(&rqstp->rq_arg, base, NULL,
211 			  (argp->mask & NFS_ACL) ?
212 			  &argp->acl_access : NULL);
213 	if (n > 0)
214 		n = nfsacl_decode(&rqstp->rq_arg, base + n, NULL,
215 				  (argp->mask & NFS_DFACL) ?
216 				  &argp->acl_default : NULL);
217 	return (n > 0);
218 }
219 
220 static int nfsaclsvc_decode_fhandleargs(struct svc_rqst *rqstp, __be32 *p,
221 		struct nfsd_fhandle *argp)
222 {
223 	p = nfs2svc_decode_fh(p, &argp->fh);
224 	if (!p)
225 		return 0;
226 	return xdr_argsize_check(rqstp, p);
227 }
228 
229 static int nfsaclsvc_decode_accessargs(struct svc_rqst *rqstp, __be32 *p,
230 		struct nfsd3_accessargs *argp)
231 {
232 	p = nfs2svc_decode_fh(p, &argp->fh);
233 	if (!p)
234 		return 0;
235 	argp->access = ntohl(*p++);
236 
237 	return xdr_argsize_check(rqstp, p);
238 }
239 
240 /*
241  * XDR encode functions
242  */
243 
244 /*
245  * There must be an encoding function for void results so svc_process
246  * will work properly.
247  */
248 static int nfsaclsvc_encode_voidres(struct svc_rqst *rqstp, __be32 *p, void *dummy)
249 {
250 	return xdr_ressize_check(rqstp, p);
251 }
252 
253 /* GETACL */
254 static int nfsaclsvc_encode_getaclres(struct svc_rqst *rqstp, __be32 *p,
255 		struct nfsd3_getaclres *resp)
256 {
257 	struct dentry *dentry = resp->fh.fh_dentry;
258 	struct inode *inode;
259 	struct kvec *head = rqstp->rq_res.head;
260 	unsigned int base;
261 	int n;
262 	int w;
263 
264 	/*
265 	 * Since this is version 2, the check for nfserr in
266 	 * nfsd_dispatch actually ensures the following cannot happen.
267 	 * However, it seems fragile to depend on that.
268 	 */
269 	if (dentry == NULL || d_really_is_negative(dentry))
270 		return 0;
271 	inode = d_inode(dentry);
272 
273 	p = nfs2svc_encode_fattr(rqstp, p, &resp->fh, &resp->stat);
274 	*p++ = htonl(resp->mask);
275 	if (!xdr_ressize_check(rqstp, p))
276 		return 0;
277 	base = (char *)p - (char *)head->iov_base;
278 
279 	rqstp->rq_res.page_len = w = nfsacl_size(
280 		(resp->mask & NFS_ACL)   ? resp->acl_access  : NULL,
281 		(resp->mask & NFS_DFACL) ? resp->acl_default : NULL);
282 	while (w > 0) {
283 		if (!*(rqstp->rq_next_page++))
284 			return 0;
285 		w -= PAGE_SIZE;
286 	}
287 
288 	n = nfsacl_encode(&rqstp->rq_res, base, inode,
289 			  resp->acl_access,
290 			  resp->mask & NFS_ACL, 0);
291 	if (n > 0)
292 		n = nfsacl_encode(&rqstp->rq_res, base + n, inode,
293 				  resp->acl_default,
294 				  resp->mask & NFS_DFACL,
295 				  NFS_ACL_DEFAULT);
296 	return (n > 0);
297 }
298 
299 static int nfsaclsvc_encode_attrstatres(struct svc_rqst *rqstp, __be32 *p,
300 		struct nfsd_attrstat *resp)
301 {
302 	p = nfs2svc_encode_fattr(rqstp, p, &resp->fh, &resp->stat);
303 	return xdr_ressize_check(rqstp, p);
304 }
305 
306 /* ACCESS */
307 static int nfsaclsvc_encode_accessres(struct svc_rqst *rqstp, __be32 *p,
308 		struct nfsd3_accessres *resp)
309 {
310 	p = nfs2svc_encode_fattr(rqstp, p, &resp->fh, &resp->stat);
311 	*p++ = htonl(resp->access);
312 	return xdr_ressize_check(rqstp, p);
313 }
314 
315 /*
316  * XDR release functions
317  */
318 static int nfsaclsvc_release_getacl(struct svc_rqst *rqstp, __be32 *p,
319 		struct nfsd3_getaclres *resp)
320 {
321 	fh_put(&resp->fh);
322 	posix_acl_release(resp->acl_access);
323 	posix_acl_release(resp->acl_default);
324 	return 1;
325 }
326 
327 static int nfsaclsvc_release_attrstat(struct svc_rqst *rqstp, __be32 *p,
328 		struct nfsd_attrstat *resp)
329 {
330 	fh_put(&resp->fh);
331 	return 1;
332 }
333 
334 static int nfsaclsvc_release_access(struct svc_rqst *rqstp, __be32 *p,
335                struct nfsd3_accessres *resp)
336 {
337        fh_put(&resp->fh);
338        return 1;
339 }
340 
341 #define nfsaclsvc_decode_voidargs	NULL
342 #define nfsaclsvc_release_void		NULL
343 #define nfsd3_fhandleargs	nfsd_fhandle
344 #define nfsd3_attrstatres	nfsd_attrstat
345 #define nfsd3_voidres		nfsd3_voidargs
346 struct nfsd3_voidargs { int dummy; };
347 
348 #define PROC(name, argt, rest, relt, cache, respsize)	\
349  { (svc_procfunc) nfsacld_proc_##name,		\
350    (kxdrproc_t) nfsaclsvc_decode_##argt##args,	\
351    (kxdrproc_t) nfsaclsvc_encode_##rest##res,	\
352    (kxdrproc_t) nfsaclsvc_release_##relt,		\
353    sizeof(struct nfsd3_##argt##args),		\
354    sizeof(struct nfsd3_##rest##res),		\
355    0,						\
356    cache,					\
357    respsize,					\
358  }
359 
360 #define ST 1		/* status*/
361 #define AT 21		/* attributes */
362 #define pAT (1+AT)	/* post attributes - conditional */
363 #define ACL (1+NFS_ACL_MAX_ENTRIES*3)  /* Access Control List */
364 
365 static struct svc_procedure		nfsd_acl_procedures2[] = {
366   PROC(null,	void,		void,		void,	  RC_NOCACHE, ST),
367   PROC(getacl,	getacl,		getacl,		getacl,	  RC_NOCACHE, ST+1+2*(1+ACL)),
368   PROC(setacl,	setacl,		attrstat,	attrstat, RC_NOCACHE, ST+AT),
369   PROC(getattr, fhandle,	attrstat,	attrstat, RC_NOCACHE, ST+AT),
370   PROC(access,	access,		access,		access,   RC_NOCACHE, ST+AT+1),
371 };
372 
373 struct svc_version	nfsd_acl_version2 = {
374 		.vs_vers	= 2,
375 		.vs_nproc	= 5,
376 		.vs_proc	= nfsd_acl_procedures2,
377 		.vs_dispatch	= nfsd_dispatch,
378 		.vs_xdrsize	= NFS3_SVC_XDRSIZE,
379 };
380