1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Process version 3 NFSACL requests.
4  *
5  * Copyright (C) 2002-2003 Andreas Gruenbacher <agruen@suse.de>
6  */
7 
8 #include "nfsd.h"
9 /* FIXME: nfsacl.h is a broken header */
10 #include <linux/nfsacl.h>
11 #include <linux/gfp.h>
12 #include "cache.h"
13 #include "xdr3.h"
14 #include "vfs.h"
15 
16 #define RETURN_STATUS(st)	{ resp->status = (st); return (st); }
17 
18 /*
19  * NULL call.
20  */
21 static __be32
nfsd3_proc_null(struct svc_rqst * rqstp)22 nfsd3_proc_null(struct svc_rqst *rqstp)
23 {
24 	return nfs_ok;
25 }
26 
27 /*
28  * Get the Access and/or Default ACL of a file.
29  */
nfsd3_proc_getacl(struct svc_rqst * rqstp)30 static __be32 nfsd3_proc_getacl(struct svc_rqst *rqstp)
31 {
32 	struct nfsd3_getaclargs *argp = rqstp->rq_argp;
33 	struct nfsd3_getaclres *resp = rqstp->rq_resp;
34 	struct posix_acl *acl;
35 	struct inode *inode;
36 	svc_fh *fh;
37 	__be32 nfserr = 0;
38 
39 	fh = fh_copy(&resp->fh, &argp->fh);
40 	nfserr = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP);
41 	if (nfserr)
42 		RETURN_STATUS(nfserr);
43 
44 	inode = d_inode(fh->fh_dentry);
45 
46 	if (argp->mask & ~NFS_ACL_MASK)
47 		RETURN_STATUS(nfserr_inval);
48 	resp->mask = argp->mask;
49 
50 	if (resp->mask & (NFS_ACL|NFS_ACLCNT)) {
51 		acl = get_acl(inode, ACL_TYPE_ACCESS);
52 		if (acl == NULL) {
53 			/* Solaris returns the inode's minimum ACL. */
54 			acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
55 		}
56 		if (IS_ERR(acl)) {
57 			nfserr = nfserrno(PTR_ERR(acl));
58 			goto fail;
59 		}
60 		resp->acl_access = acl;
61 	}
62 	if (resp->mask & (NFS_DFACL|NFS_DFACLCNT)) {
63 		/* Check how Solaris handles requests for the Default ACL
64 		   of a non-directory! */
65 		acl = get_acl(inode, ACL_TYPE_DEFAULT);
66 		if (IS_ERR(acl)) {
67 			nfserr = nfserrno(PTR_ERR(acl));
68 			goto fail;
69 		}
70 		resp->acl_default = acl;
71 	}
72 
73 	/* resp->acl_{access,default} are released in nfs3svc_release_getacl. */
74 	RETURN_STATUS(0);
75 
76 fail:
77 	posix_acl_release(resp->acl_access);
78 	posix_acl_release(resp->acl_default);
79 	RETURN_STATUS(nfserr);
80 }
81 
82 /*
83  * Set the Access and/or Default ACL of a file.
84  */
nfsd3_proc_setacl(struct svc_rqst * rqstp)85 static __be32 nfsd3_proc_setacl(struct svc_rqst *rqstp)
86 {
87 	struct nfsd3_setaclargs *argp = rqstp->rq_argp;
88 	struct nfsd3_attrstat *resp = rqstp->rq_resp;
89 	struct inode *inode;
90 	svc_fh *fh;
91 	__be32 nfserr = 0;
92 	int error;
93 
94 	fh = fh_copy(&resp->fh, &argp->fh);
95 	nfserr = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_SATTR);
96 	if (nfserr)
97 		goto out;
98 
99 	inode = d_inode(fh->fh_dentry);
100 
101 	error = fh_want_write(fh);
102 	if (error)
103 		goto out_errno;
104 
105 	fh_lock(fh);
106 
107 	error = set_posix_acl(inode, ACL_TYPE_ACCESS, argp->acl_access);
108 	if (error)
109 		goto out_drop_lock;
110 	error = set_posix_acl(inode, ACL_TYPE_DEFAULT, argp->acl_default);
111 
112 out_drop_lock:
113 	fh_unlock(fh);
114 	fh_drop_write(fh);
115 out_errno:
116 	nfserr = nfserrno(error);
117 out:
118 	/* argp->acl_{access,default} may have been allocated in
119 	   nfs3svc_decode_setaclargs. */
120 	posix_acl_release(argp->acl_access);
121 	posix_acl_release(argp->acl_default);
122 	RETURN_STATUS(nfserr);
123 }
124 
125 /*
126  * XDR decode functions
127  */
nfs3svc_decode_getaclargs(struct svc_rqst * rqstp,__be32 * p)128 static int nfs3svc_decode_getaclargs(struct svc_rqst *rqstp, __be32 *p)
129 {
130 	struct nfsd3_getaclargs *args = rqstp->rq_argp;
131 
132 	p = nfs3svc_decode_fh(p, &args->fh);
133 	if (!p)
134 		return 0;
135 	args->mask = ntohl(*p); p++;
136 
137 	return xdr_argsize_check(rqstp, p);
138 }
139 
140 
nfs3svc_decode_setaclargs(struct svc_rqst * rqstp,__be32 * p)141 static int nfs3svc_decode_setaclargs(struct svc_rqst *rqstp, __be32 *p)
142 {
143 	struct nfsd3_setaclargs *args = rqstp->rq_argp;
144 	struct kvec *head = rqstp->rq_arg.head;
145 	unsigned int base;
146 	int n;
147 
148 	p = nfs3svc_decode_fh(p, &args->fh);
149 	if (!p)
150 		return 0;
151 	args->mask = ntohl(*p++);
152 	if (args->mask & ~NFS_ACL_MASK ||
153 	    !xdr_argsize_check(rqstp, p))
154 		return 0;
155 
156 	base = (char *)p - (char *)head->iov_base;
157 	n = nfsacl_decode(&rqstp->rq_arg, base, NULL,
158 			  (args->mask & NFS_ACL) ?
159 			  &args->acl_access : NULL);
160 	if (n > 0)
161 		n = nfsacl_decode(&rqstp->rq_arg, base + n, NULL,
162 				  (args->mask & NFS_DFACL) ?
163 				  &args->acl_default : NULL);
164 	return (n > 0);
165 }
166 
167 /*
168  * XDR encode functions
169  */
170 
171 /* GETACL */
nfs3svc_encode_getaclres(struct svc_rqst * rqstp,__be32 * p)172 static int nfs3svc_encode_getaclres(struct svc_rqst *rqstp, __be32 *p)
173 {
174 	struct nfsd3_getaclres *resp = rqstp->rq_resp;
175 	struct dentry *dentry = resp->fh.fh_dentry;
176 
177 	p = nfs3svc_encode_post_op_attr(rqstp, p, &resp->fh);
178 	if (resp->status == 0 && dentry && d_really_is_positive(dentry)) {
179 		struct inode *inode = d_inode(dentry);
180 		struct kvec *head = rqstp->rq_res.head;
181 		unsigned int base;
182 		int n;
183 		int w;
184 
185 		*p++ = htonl(resp->mask);
186 		if (!xdr_ressize_check(rqstp, p))
187 			return 0;
188 		base = (char *)p - (char *)head->iov_base;
189 
190 		rqstp->rq_res.page_len = w = nfsacl_size(
191 			(resp->mask & NFS_ACL)   ? resp->acl_access  : NULL,
192 			(resp->mask & NFS_DFACL) ? resp->acl_default : NULL);
193 		while (w > 0) {
194 			if (!*(rqstp->rq_next_page++))
195 				return 0;
196 			w -= PAGE_SIZE;
197 		}
198 
199 		n = nfsacl_encode(&rqstp->rq_res, base, inode,
200 				  resp->acl_access,
201 				  resp->mask & NFS_ACL, 0);
202 		if (n > 0)
203 			n = nfsacl_encode(&rqstp->rq_res, base + n, inode,
204 					  resp->acl_default,
205 					  resp->mask & NFS_DFACL,
206 					  NFS_ACL_DEFAULT);
207 		if (n <= 0)
208 			return 0;
209 	} else
210 		if (!xdr_ressize_check(rqstp, p))
211 			return 0;
212 
213 	return 1;
214 }
215 
216 /* SETACL */
nfs3svc_encode_setaclres(struct svc_rqst * rqstp,__be32 * p)217 static int nfs3svc_encode_setaclres(struct svc_rqst *rqstp, __be32 *p)
218 {
219 	struct nfsd3_attrstat *resp = rqstp->rq_resp;
220 
221 	p = nfs3svc_encode_post_op_attr(rqstp, p, &resp->fh);
222 
223 	return xdr_ressize_check(rqstp, p);
224 }
225 
226 /*
227  * XDR release functions
228  */
nfs3svc_release_getacl(struct svc_rqst * rqstp)229 static void nfs3svc_release_getacl(struct svc_rqst *rqstp)
230 {
231 	struct nfsd3_getaclres *resp = rqstp->rq_resp;
232 
233 	fh_put(&resp->fh);
234 	posix_acl_release(resp->acl_access);
235 	posix_acl_release(resp->acl_default);
236 }
237 
238 #define nfs3svc_decode_voidargs		NULL
239 #define nfs3svc_release_void		NULL
240 #define nfsd3_setaclres			nfsd3_attrstat
241 #define nfsd3_voidres			nfsd3_voidargs
242 struct nfsd3_voidargs { int dummy; };
243 
244 #define PROC(name, argt, rest, relt, cache, respsize)			\
245 {									\
246 	.pc_func	= nfsd3_proc_##name,				\
247 	.pc_decode	= nfs3svc_decode_##argt##args,			\
248 	.pc_encode	= nfs3svc_encode_##rest##res,			\
249 	.pc_release	= nfs3svc_release_##relt,			\
250 	.pc_argsize	= sizeof(struct nfsd3_##argt##args),		\
251 	.pc_ressize	= sizeof(struct nfsd3_##rest##res),		\
252 	.pc_cachetype	= cache,					\
253 	.pc_xdrressize	= respsize,					\
254 }
255 
256 #define ST 1		/* status*/
257 #define AT 21		/* attributes */
258 #define pAT (1+AT)	/* post attributes - conditional */
259 #define ACL (1+NFS_ACL_MAX_ENTRIES*3)  /* Access Control List */
260 
261 static const struct svc_procedure nfsd_acl_procedures3[] = {
262   PROC(null,	void,		void,		void,	  RC_NOCACHE, ST),
263   PROC(getacl,	getacl,		getacl,		getacl,	  RC_NOCACHE, ST+1+2*(1+ACL)),
264   PROC(setacl,	setacl,		setacl,		fhandle,  RC_NOCACHE, ST+pAT),
265 };
266 
267 static unsigned int nfsd_acl_count3[ARRAY_SIZE(nfsd_acl_procedures3)];
268 const struct svc_version nfsd_acl_version3 = {
269 	.vs_vers	= 3,
270 	.vs_nproc	= 3,
271 	.vs_proc	= nfsd_acl_procedures3,
272 	.vs_count	= nfsd_acl_count3,
273 	.vs_dispatch	= nfsd_dispatch,
274 	.vs_xdrsize	= NFS3_SVC_XDRSIZE,
275 };
276 
277