Root/fs/nfsd/nfsxdr.c

1/*
2 * XDR support for nfsd
3 *
4 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
5 */
6
7#include "xdr.h"
8#include "auth.h"
9
10#define NFSDDBG_FACILITY NFSDDBG_XDR
11
12/*
13 * Mapping of S_IF* types to NFS file types
14 */
15static u32 nfs_ftypes[] = {
16    NFNON, NFCHR, NFCHR, NFBAD,
17    NFDIR, NFBAD, NFBLK, NFBAD,
18    NFREG, NFBAD, NFLNK, NFBAD,
19    NFSOCK, NFBAD, NFLNK, NFBAD,
20};
21
22
23/*
24 * XDR functions for basic NFS types
25 */
26static __be32 *
27decode_fh(__be32 *p, struct svc_fh *fhp)
28{
29    fh_init(fhp, NFS_FHSIZE);
30    memcpy(&fhp->fh_handle.fh_base, p, NFS_FHSIZE);
31    fhp->fh_handle.fh_size = NFS_FHSIZE;
32
33    /* FIXME: Look up export pointer here and verify
34     * Sun Secure RPC if requested */
35    return p + (NFS_FHSIZE >> 2);
36}
37
38/* Helper function for NFSv2 ACL code */
39__be32 *nfs2svc_decode_fh(__be32 *p, struct svc_fh *fhp)
40{
41    return decode_fh(p, fhp);
42}
43
44static __be32 *
45encode_fh(__be32 *p, struct svc_fh *fhp)
46{
47    memcpy(p, &fhp->fh_handle.fh_base, NFS_FHSIZE);
48    return p + (NFS_FHSIZE>> 2);
49}
50
51/*
52 * Decode a file name and make sure that the path contains
53 * no slashes or null bytes.
54 */
55static __be32 *
56decode_filename(__be32 *p, char **namp, unsigned int *lenp)
57{
58    char *name;
59    unsigned int i;
60
61    if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXNAMLEN)) != NULL) {
62        for (i = 0, name = *namp; i < *lenp; i++, name++) {
63            if (*name == '\0' || *name == '/')
64                return NULL;
65        }
66    }
67
68    return p;
69}
70
71static __be32 *
72decode_pathname(__be32 *p, char **namp, unsigned int *lenp)
73{
74    char *name;
75    unsigned int i;
76
77    if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXPATHLEN)) != NULL) {
78        for (i = 0, name = *namp; i < *lenp; i++, name++) {
79            if (*name == '\0')
80                return NULL;
81        }
82    }
83
84    return p;
85}
86
87static __be32 *
88decode_sattr(__be32 *p, struct iattr *iap)
89{
90    u32 tmp, tmp1;
91
92    iap->ia_valid = 0;
93
94    /* Sun client bug compatibility check: some sun clients seem to
95     * put 0xffff in the mode field when they mean 0xffffffff.
96     * Quoting the 4.4BSD nfs server code: Nah nah nah nah na nah.
97     */
98    if ((tmp = ntohl(*p++)) != (u32)-1 && tmp != 0xffff) {
99        iap->ia_valid |= ATTR_MODE;
100        iap->ia_mode = tmp;
101    }
102    if ((tmp = ntohl(*p++)) != (u32)-1) {
103        iap->ia_valid |= ATTR_UID;
104        iap->ia_uid = tmp;
105    }
106    if ((tmp = ntohl(*p++)) != (u32)-1) {
107        iap->ia_valid |= ATTR_GID;
108        iap->ia_gid = tmp;
109    }
110    if ((tmp = ntohl(*p++)) != (u32)-1) {
111        iap->ia_valid |= ATTR_SIZE;
112        iap->ia_size = tmp;
113    }
114    tmp = ntohl(*p++); tmp1 = ntohl(*p++);
115    if (tmp != (u32)-1 && tmp1 != (u32)-1) {
116        iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
117        iap->ia_atime.tv_sec = tmp;
118        iap->ia_atime.tv_nsec = tmp1 * 1000;
119    }
120    tmp = ntohl(*p++); tmp1 = ntohl(*p++);
121    if (tmp != (u32)-1 && tmp1 != (u32)-1) {
122        iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
123        iap->ia_mtime.tv_sec = tmp;
124        iap->ia_mtime.tv_nsec = tmp1 * 1000;
125        /*
126         * Passing the invalid value useconds=1000000 for mtime
127         * is a Sun convention for "set both mtime and atime to
128         * current server time". It's needed to make permissions
129         * checks for the "touch" program across v2 mounts to
130         * Solaris and Irix boxes work correctly. See description of
131         * sattr in section 6.1 of "NFS Illustrated" by
132         * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
133         */
134        if (tmp1 == 1000000)
135            iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
136    }
137    return p;
138}
139
140static __be32 *
141encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
142         struct kstat *stat)
143{
144    struct dentry *dentry = fhp->fh_dentry;
145    int type;
146    struct timespec time;
147    u32 f;
148
149    type = (stat->mode & S_IFMT);
150
151    *p++ = htonl(nfs_ftypes[type >> 12]);
152    *p++ = htonl((u32) stat->mode);
153    *p++ = htonl((u32) stat->nlink);
154    *p++ = htonl((u32) nfsd_ruid(rqstp, stat->uid));
155    *p++ = htonl((u32) nfsd_rgid(rqstp, stat->gid));
156
157    if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) {
158        *p++ = htonl(NFS_MAXPATHLEN);
159    } else {
160        *p++ = htonl((u32) stat->size);
161    }
162    *p++ = htonl((u32) stat->blksize);
163    if (S_ISCHR(type) || S_ISBLK(type))
164        *p++ = htonl(new_encode_dev(stat->rdev));
165    else
166        *p++ = htonl(0xffffffff);
167    *p++ = htonl((u32) stat->blocks);
168    switch (fsid_source(fhp)) {
169    default:
170    case FSIDSOURCE_DEV:
171        *p++ = htonl(new_encode_dev(stat->dev));
172        break;
173    case FSIDSOURCE_FSID:
174        *p++ = htonl((u32) fhp->fh_export->ex_fsid);
175        break;
176    case FSIDSOURCE_UUID:
177        f = ((u32*)fhp->fh_export->ex_uuid)[0];
178        f ^= ((u32*)fhp->fh_export->ex_uuid)[1];
179        f ^= ((u32*)fhp->fh_export->ex_uuid)[2];
180        f ^= ((u32*)fhp->fh_export->ex_uuid)[3];
181        *p++ = htonl(f);
182        break;
183    }
184    *p++ = htonl((u32) stat->ino);
185    *p++ = htonl((u32) stat->atime.tv_sec);
186    *p++ = htonl(stat->atime.tv_nsec ? stat->atime.tv_nsec / 1000 : 0);
187    lease_get_mtime(dentry->d_inode, &time);
188    *p++ = htonl((u32) time.tv_sec);
189    *p++ = htonl(time.tv_nsec ? time.tv_nsec / 1000 : 0);
190    *p++ = htonl((u32) stat->ctime.tv_sec);
191    *p++ = htonl(stat->ctime.tv_nsec ? stat->ctime.tv_nsec / 1000 : 0);
192
193    return p;
194}
195
196/* Helper function for NFSv2 ACL code */
197__be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
198{
199    struct kstat stat;
200    vfs_getattr(fhp->fh_export->ex_path.mnt, fhp->fh_dentry, &stat);
201    return encode_fattr(rqstp, p, fhp, &stat);
202}
203
204/*
205 * XDR decode functions
206 */
207int
208nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
209{
210    return xdr_argsize_check(rqstp, p);
211}
212
213int
214nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p, struct nfsd_fhandle *args)
215{
216    if (!(p = decode_fh(p, &args->fh)))
217        return 0;
218    return xdr_argsize_check(rqstp, p);
219}
220
221int
222nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,
223                    struct nfsd_sattrargs *args)
224{
225    p = decode_fh(p, &args->fh);
226    if (!p)
227        return 0;
228    p = decode_sattr(p, &args->attrs);
229
230    return xdr_argsize_check(rqstp, p);
231}
232
233int
234nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p,
235                    struct nfsd_diropargs *args)
236{
237    if (!(p = decode_fh(p, &args->fh))
238     || !(p = decode_filename(p, &args->name, &args->len)))
239        return 0;
240
241     return xdr_argsize_check(rqstp, p);
242}
243
244int
245nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p,
246                    struct nfsd_readargs *args)
247{
248    unsigned int len;
249    int v,pn;
250    if (!(p = decode_fh(p, &args->fh)))
251        return 0;
252
253    args->offset = ntohl(*p++);
254    len = args->count = ntohl(*p++);
255    p++; /* totalcount - unused */
256
257    if (len > NFSSVC_MAXBLKSIZE_V2)
258        len = NFSSVC_MAXBLKSIZE_V2;
259
260    /* set up somewhere to store response.
261     * We take pages, put them on reslist and include in iovec
262     */
263    v=0;
264    while (len > 0) {
265        pn = rqstp->rq_resused++;
266        rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_respages[pn]);
267        rqstp->rq_vec[v].iov_len = len < PAGE_SIZE?len:PAGE_SIZE;
268        len -= rqstp->rq_vec[v].iov_len;
269        v++;
270    }
271    args->vlen = v;
272    return xdr_argsize_check(rqstp, p);
273}
274
275int
276nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
277                    struct nfsd_writeargs *args)
278{
279    unsigned int len, hdr, dlen;
280    int v;
281
282    if (!(p = decode_fh(p, &args->fh)))
283        return 0;
284
285    p++; /* beginoffset */
286    args->offset = ntohl(*p++); /* offset */
287    p++; /* totalcount */
288    len = args->len = ntohl(*p++);
289    /*
290     * The protocol specifies a maximum of 8192 bytes.
291     */
292    if (len > NFSSVC_MAXBLKSIZE_V2)
293        return 0;
294
295    /*
296     * Check to make sure that we got the right number of
297     * bytes.
298     */
299    hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
300    dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
301        - hdr;
302
303    /*
304     * Round the length of the data which was specified up to
305     * the next multiple of XDR units and then compare that
306     * against the length which was actually received.
307     * Note that when RPCSEC/GSS (for example) is used, the
308     * data buffer can be padded so dlen might be larger
309     * than required. It must never be smaller.
310     */
311    if (dlen < XDR_QUADLEN(len)*4)
312        return 0;
313
314    rqstp->rq_vec[0].iov_base = (void*)p;
315    rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
316    v = 0;
317    while (len > rqstp->rq_vec[v].iov_len) {
318        len -= rqstp->rq_vec[v].iov_len;
319        v++;
320        rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
321        rqstp->rq_vec[v].iov_len = PAGE_SIZE;
322    }
323    rqstp->rq_vec[v].iov_len = len;
324    args->vlen = v + 1;
325    return 1;
326}
327
328int
329nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
330                    struct nfsd_createargs *args)
331{
332    if ( !(p = decode_fh(p, &args->fh))
333        || !(p = decode_filename(p, &args->name, &args->len)))
334        return 0;
335    p = decode_sattr(p, &args->attrs);
336
337    return xdr_argsize_check(rqstp, p);
338}
339
340int
341nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
342                    struct nfsd_renameargs *args)
343{
344    if (!(p = decode_fh(p, &args->ffh))
345     || !(p = decode_filename(p, &args->fname, &args->flen))
346     || !(p = decode_fh(p, &args->tfh))
347     || !(p = decode_filename(p, &args->tname, &args->tlen)))
348        return 0;
349
350    return xdr_argsize_check(rqstp, p);
351}
352
353int
354nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p, struct nfsd_readlinkargs *args)
355{
356    if (!(p = decode_fh(p, &args->fh)))
357        return 0;
358    args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused++]);
359
360    return xdr_argsize_check(rqstp, p);
361}
362
363int
364nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
365                    struct nfsd_linkargs *args)
366{
367    if (!(p = decode_fh(p, &args->ffh))
368     || !(p = decode_fh(p, &args->tfh))
369     || !(p = decode_filename(p, &args->tname, &args->tlen)))
370        return 0;
371
372    return xdr_argsize_check(rqstp, p);
373}
374
375int
376nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
377                    struct nfsd_symlinkargs *args)
378{
379    if ( !(p = decode_fh(p, &args->ffh))
380        || !(p = decode_filename(p, &args->fname, &args->flen))
381        || !(p = decode_pathname(p, &args->tname, &args->tlen)))
382        return 0;
383    p = decode_sattr(p, &args->attrs);
384
385    return xdr_argsize_check(rqstp, p);
386}
387
388int
389nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
390                    struct nfsd_readdirargs *args)
391{
392    if (!(p = decode_fh(p, &args->fh)))
393        return 0;
394    args->cookie = ntohl(*p++);
395    args->count = ntohl(*p++);
396    if (args->count > PAGE_SIZE)
397        args->count = PAGE_SIZE;
398
399    args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused++]);
400
401    return xdr_argsize_check(rqstp, p);
402}
403
404/*
405 * XDR encode functions
406 */
407int
408nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
409{
410    return xdr_ressize_check(rqstp, p);
411}
412
413int
414nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
415                    struct nfsd_attrstat *resp)
416{
417    p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
418    return xdr_ressize_check(rqstp, p);
419}
420
421int
422nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
423                    struct nfsd_diropres *resp)
424{
425    p = encode_fh(p, &resp->fh);
426    p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
427    return xdr_ressize_check(rqstp, p);
428}
429
430int
431nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
432                    struct nfsd_readlinkres *resp)
433{
434    *p++ = htonl(resp->len);
435    xdr_ressize_check(rqstp, p);
436    rqstp->rq_res.page_len = resp->len;
437    if (resp->len & 3) {
438        /* need to pad the tail */
439        rqstp->rq_res.tail[0].iov_base = p;
440        *p = 0;
441        rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
442    }
443    return 1;
444}
445
446int
447nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
448                    struct nfsd_readres *resp)
449{
450    p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
451    *p++ = htonl(resp->count);
452    xdr_ressize_check(rqstp, p);
453
454    /* now update rqstp->rq_res to reflect data as well */
455    rqstp->rq_res.page_len = resp->count;
456    if (resp->count & 3) {
457        /* need to pad the tail */
458        rqstp->rq_res.tail[0].iov_base = p;
459        *p = 0;
460        rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
461    }
462    return 1;
463}
464
465int
466nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
467                    struct nfsd_readdirres *resp)
468{
469    xdr_ressize_check(rqstp, p);
470    p = resp->buffer;
471    *p++ = 0; /* no more entries */
472    *p++ = htonl((resp->common.err == nfserr_eof));
473    rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
474
475    return 1;
476}
477
478int
479nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p,
480                    struct nfsd_statfsres *resp)
481{
482    struct kstatfs *stat = &resp->stats;
483
484    *p++ = htonl(NFSSVC_MAXBLKSIZE_V2); /* max transfer size */
485    *p++ = htonl(stat->f_bsize);
486    *p++ = htonl(stat->f_blocks);
487    *p++ = htonl(stat->f_bfree);
488    *p++ = htonl(stat->f_bavail);
489    return xdr_ressize_check(rqstp, p);
490}
491
492int
493nfssvc_encode_entry(void *ccdv, const char *name,
494            int namlen, loff_t offset, u64 ino, unsigned int d_type)
495{
496    struct readdir_cd *ccd = ccdv;
497    struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
498    __be32 *p = cd->buffer;
499    int buflen, slen;
500
501    /*
502    dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
503            namlen, name, offset, ino);
504     */
505
506    if (offset > ~((u32) 0)) {
507        cd->common.err = nfserr_fbig;
508        return -EINVAL;
509    }
510    if (cd->offset)
511        *cd->offset = htonl(offset);
512    if (namlen > NFS2_MAXNAMLEN)
513        namlen = NFS2_MAXNAMLEN;/* truncate filename */
514
515    slen = XDR_QUADLEN(namlen);
516    if ((buflen = cd->buflen - slen - 4) < 0) {
517        cd->common.err = nfserr_toosmall;
518        return -EINVAL;
519    }
520    if (ino > ~((u32) 0)) {
521        cd->common.err = nfserr_fbig;
522        return -EINVAL;
523    }
524    *p++ = xdr_one; /* mark entry present */
525    *p++ = htonl((u32) ino); /* file id */
526    p = xdr_encode_array(p, name, namlen);/* name length & name */
527    cd->offset = p; /* remember pointer */
528    *p++ = htonl(~0U); /* offset of next entry */
529
530    cd->buflen = buflen;
531    cd->buffer = p;
532    cd->common.err = nfs_ok;
533    return 0;
534}
535
536/*
537 * XDR release functions
538 */
539int
540nfssvc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
541                    struct nfsd_fhandle *resp)
542{
543    fh_put(&resp->fh);
544    return 1;
545}
546

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