nfsxdr.c 14 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * XDR support for nfsd
  4. *
  5. * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
  6. */
  7. #include "vfs.h"
  8. #include "xdr.h"
  9. #include "auth.h"
  10. #define NFSDDBG_FACILITY NFSDDBG_XDR
  11. /*
  12. * Mapping of S_IF* types to NFS file types
  13. */
  14. static u32 nfs_ftypes[] = {
  15. NFNON, NFCHR, NFCHR, NFBAD,
  16. NFDIR, NFBAD, NFBLK, NFBAD,
  17. NFREG, NFBAD, NFLNK, NFBAD,
  18. NFSOCK, NFBAD, NFLNK, NFBAD,
  19. };
  20. /*
  21. * XDR functions for basic NFS types
  22. */
  23. static __be32 *
  24. decode_fh(__be32 *p, struct svc_fh *fhp)
  25. {
  26. fh_init(fhp, NFS_FHSIZE);
  27. memcpy(&fhp->fh_handle.fh_base, p, NFS_FHSIZE);
  28. fhp->fh_handle.fh_size = NFS_FHSIZE;
  29. /* FIXME: Look up export pointer here and verify
  30. * Sun Secure RPC if requested */
  31. return p + (NFS_FHSIZE >> 2);
  32. }
  33. /* Helper function for NFSv2 ACL code */
  34. __be32 *nfs2svc_decode_fh(__be32 *p, struct svc_fh *fhp)
  35. {
  36. return decode_fh(p, fhp);
  37. }
  38. static __be32 *
  39. encode_fh(__be32 *p, struct svc_fh *fhp)
  40. {
  41. memcpy(p, &fhp->fh_handle.fh_base, NFS_FHSIZE);
  42. return p + (NFS_FHSIZE>> 2);
  43. }
  44. /*
  45. * Decode a file name and make sure that the path contains
  46. * no slashes or null bytes.
  47. */
  48. static __be32 *
  49. decode_filename(__be32 *p, char **namp, unsigned int *lenp)
  50. {
  51. char *name;
  52. unsigned int i;
  53. if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXNAMLEN)) != NULL) {
  54. for (i = 0, name = *namp; i < *lenp; i++, name++) {
  55. if (*name == '\0' || *name == '/')
  56. return NULL;
  57. }
  58. }
  59. return p;
  60. }
  61. static __be32 *
  62. decode_sattr(__be32 *p, struct iattr *iap, struct user_namespace *userns)
  63. {
  64. u32 tmp, tmp1;
  65. iap->ia_valid = 0;
  66. /* Sun client bug compatibility check: some sun clients seem to
  67. * put 0xffff in the mode field when they mean 0xffffffff.
  68. * Quoting the 4.4BSD nfs server code: Nah nah nah nah na nah.
  69. */
  70. if ((tmp = ntohl(*p++)) != (u32)-1 && tmp != 0xffff) {
  71. iap->ia_valid |= ATTR_MODE;
  72. iap->ia_mode = tmp;
  73. }
  74. if ((tmp = ntohl(*p++)) != (u32)-1) {
  75. iap->ia_uid = make_kuid(userns, tmp);
  76. if (uid_valid(iap->ia_uid))
  77. iap->ia_valid |= ATTR_UID;
  78. }
  79. if ((tmp = ntohl(*p++)) != (u32)-1) {
  80. iap->ia_gid = make_kgid(userns, tmp);
  81. if (gid_valid(iap->ia_gid))
  82. iap->ia_valid |= ATTR_GID;
  83. }
  84. if ((tmp = ntohl(*p++)) != (u32)-1) {
  85. iap->ia_valid |= ATTR_SIZE;
  86. iap->ia_size = tmp;
  87. }
  88. tmp = ntohl(*p++); tmp1 = ntohl(*p++);
  89. if (tmp != (u32)-1 && tmp1 != (u32)-1) {
  90. iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
  91. iap->ia_atime.tv_sec = tmp;
  92. iap->ia_atime.tv_nsec = tmp1 * 1000;
  93. }
  94. tmp = ntohl(*p++); tmp1 = ntohl(*p++);
  95. if (tmp != (u32)-1 && tmp1 != (u32)-1) {
  96. iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
  97. iap->ia_mtime.tv_sec = tmp;
  98. iap->ia_mtime.tv_nsec = tmp1 * 1000;
  99. /*
  100. * Passing the invalid value useconds=1000000 for mtime
  101. * is a Sun convention for "set both mtime and atime to
  102. * current server time". It's needed to make permissions
  103. * checks for the "touch" program across v2 mounts to
  104. * Solaris and Irix boxes work correctly. See description of
  105. * sattr in section 6.1 of "NFS Illustrated" by
  106. * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
  107. */
  108. if (tmp1 == 1000000)
  109. iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
  110. }
  111. return p;
  112. }
  113. static __be32 *
  114. encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
  115. struct kstat *stat)
  116. {
  117. struct user_namespace *userns = nfsd_user_namespace(rqstp);
  118. struct dentry *dentry = fhp->fh_dentry;
  119. int type;
  120. struct timespec64 time;
  121. u32 f;
  122. type = (stat->mode & S_IFMT);
  123. *p++ = htonl(nfs_ftypes[type >> 12]);
  124. *p++ = htonl((u32) stat->mode);
  125. *p++ = htonl((u32) stat->nlink);
  126. *p++ = htonl((u32) from_kuid_munged(userns, stat->uid));
  127. *p++ = htonl((u32) from_kgid_munged(userns, stat->gid));
  128. if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) {
  129. *p++ = htonl(NFS_MAXPATHLEN);
  130. } else {
  131. *p++ = htonl((u32) stat->size);
  132. }
  133. *p++ = htonl((u32) stat->blksize);
  134. if (S_ISCHR(type) || S_ISBLK(type))
  135. *p++ = htonl(new_encode_dev(stat->rdev));
  136. else
  137. *p++ = htonl(0xffffffff);
  138. *p++ = htonl((u32) stat->blocks);
  139. switch (fsid_source(fhp)) {
  140. default:
  141. case FSIDSOURCE_DEV:
  142. *p++ = htonl(new_encode_dev(stat->dev));
  143. break;
  144. case FSIDSOURCE_FSID:
  145. *p++ = htonl((u32) fhp->fh_export->ex_fsid);
  146. break;
  147. case FSIDSOURCE_UUID:
  148. f = ((u32*)fhp->fh_export->ex_uuid)[0];
  149. f ^= ((u32*)fhp->fh_export->ex_uuid)[1];
  150. f ^= ((u32*)fhp->fh_export->ex_uuid)[2];
  151. f ^= ((u32*)fhp->fh_export->ex_uuid)[3];
  152. *p++ = htonl(f);
  153. break;
  154. }
  155. *p++ = htonl((u32) stat->ino);
  156. *p++ = htonl((u32) stat->atime.tv_sec);
  157. *p++ = htonl(stat->atime.tv_nsec ? stat->atime.tv_nsec / 1000 : 0);
  158. time = stat->mtime;
  159. lease_get_mtime(d_inode(dentry), &time);
  160. *p++ = htonl((u32) time.tv_sec);
  161. *p++ = htonl(time.tv_nsec ? time.tv_nsec / 1000 : 0);
  162. *p++ = htonl((u32) stat->ctime.tv_sec);
  163. *p++ = htonl(stat->ctime.tv_nsec ? stat->ctime.tv_nsec / 1000 : 0);
  164. return p;
  165. }
  166. /* Helper function for NFSv2 ACL code */
  167. __be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp, struct kstat *stat)
  168. {
  169. return encode_fattr(rqstp, p, fhp, stat);
  170. }
  171. /*
  172. * XDR decode functions
  173. */
  174. int
  175. nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p)
  176. {
  177. return xdr_argsize_check(rqstp, p);
  178. }
  179. int
  180. nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p)
  181. {
  182. struct nfsd_fhandle *args = rqstp->rq_argp;
  183. p = decode_fh(p, &args->fh);
  184. if (!p)
  185. return 0;
  186. return xdr_argsize_check(rqstp, p);
  187. }
  188. int
  189. nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p)
  190. {
  191. struct nfsd_sattrargs *args = rqstp->rq_argp;
  192. p = decode_fh(p, &args->fh);
  193. if (!p)
  194. return 0;
  195. p = decode_sattr(p, &args->attrs, nfsd_user_namespace(rqstp));
  196. return xdr_argsize_check(rqstp, p);
  197. }
  198. int
  199. nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p)
  200. {
  201. struct nfsd_diropargs *args = rqstp->rq_argp;
  202. if (!(p = decode_fh(p, &args->fh))
  203. || !(p = decode_filename(p, &args->name, &args->len)))
  204. return 0;
  205. return xdr_argsize_check(rqstp, p);
  206. }
  207. int
  208. nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p)
  209. {
  210. struct nfsd_readargs *args = rqstp->rq_argp;
  211. unsigned int len;
  212. int v;
  213. p = decode_fh(p, &args->fh);
  214. if (!p)
  215. return 0;
  216. args->offset = ntohl(*p++);
  217. len = args->count = ntohl(*p++);
  218. p++; /* totalcount - unused */
  219. len = min_t(unsigned int, len, NFSSVC_MAXBLKSIZE_V2);
  220. /* set up somewhere to store response.
  221. * We take pages, put them on reslist and include in iovec
  222. */
  223. v=0;
  224. while (len > 0) {
  225. struct page *p = *(rqstp->rq_next_page++);
  226. rqstp->rq_vec[v].iov_base = page_address(p);
  227. rqstp->rq_vec[v].iov_len = min_t(unsigned int, len, PAGE_SIZE);
  228. len -= rqstp->rq_vec[v].iov_len;
  229. v++;
  230. }
  231. args->vlen = v;
  232. return xdr_argsize_check(rqstp, p);
  233. }
  234. int
  235. nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p)
  236. {
  237. struct nfsd_writeargs *args = rqstp->rq_argp;
  238. unsigned int len, hdr, dlen;
  239. struct kvec *head = rqstp->rq_arg.head;
  240. p = decode_fh(p, &args->fh);
  241. if (!p)
  242. return 0;
  243. p++; /* beginoffset */
  244. args->offset = ntohl(*p++); /* offset */
  245. p++; /* totalcount */
  246. len = args->len = ntohl(*p++);
  247. /*
  248. * The protocol specifies a maximum of 8192 bytes.
  249. */
  250. if (len > NFSSVC_MAXBLKSIZE_V2)
  251. return 0;
  252. /*
  253. * Check to make sure that we got the right number of
  254. * bytes.
  255. */
  256. hdr = (void*)p - head->iov_base;
  257. if (hdr > head->iov_len)
  258. return 0;
  259. dlen = head->iov_len + rqstp->rq_arg.page_len - hdr;
  260. /*
  261. * Round the length of the data which was specified up to
  262. * the next multiple of XDR units and then compare that
  263. * against the length which was actually received.
  264. * Note that when RPCSEC/GSS (for example) is used, the
  265. * data buffer can be padded so dlen might be larger
  266. * than required. It must never be smaller.
  267. */
  268. if (dlen < XDR_QUADLEN(len)*4)
  269. return 0;
  270. args->first.iov_base = (void *)p;
  271. args->first.iov_len = head->iov_len - hdr;
  272. return 1;
  273. }
  274. int
  275. nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p)
  276. {
  277. struct nfsd_createargs *args = rqstp->rq_argp;
  278. if ( !(p = decode_fh(p, &args->fh))
  279. || !(p = decode_filename(p, &args->name, &args->len)))
  280. return 0;
  281. p = decode_sattr(p, &args->attrs, nfsd_user_namespace(rqstp));
  282. return xdr_argsize_check(rqstp, p);
  283. }
  284. int
  285. nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p)
  286. {
  287. struct nfsd_renameargs *args = rqstp->rq_argp;
  288. if (!(p = decode_fh(p, &args->ffh))
  289. || !(p = decode_filename(p, &args->fname, &args->flen))
  290. || !(p = decode_fh(p, &args->tfh))
  291. || !(p = decode_filename(p, &args->tname, &args->tlen)))
  292. return 0;
  293. return xdr_argsize_check(rqstp, p);
  294. }
  295. int
  296. nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p)
  297. {
  298. struct nfsd_readlinkargs *args = rqstp->rq_argp;
  299. p = decode_fh(p, &args->fh);
  300. if (!p)
  301. return 0;
  302. args->buffer = page_address(*(rqstp->rq_next_page++));
  303. return xdr_argsize_check(rqstp, p);
  304. }
  305. int
  306. nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p)
  307. {
  308. struct nfsd_linkargs *args = rqstp->rq_argp;
  309. if (!(p = decode_fh(p, &args->ffh))
  310. || !(p = decode_fh(p, &args->tfh))
  311. || !(p = decode_filename(p, &args->tname, &args->tlen)))
  312. return 0;
  313. return xdr_argsize_check(rqstp, p);
  314. }
  315. int
  316. nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p)
  317. {
  318. struct nfsd_symlinkargs *args = rqstp->rq_argp;
  319. char *base = (char *)p;
  320. size_t xdrlen;
  321. if ( !(p = decode_fh(p, &args->ffh))
  322. || !(p = decode_filename(p, &args->fname, &args->flen)))
  323. return 0;
  324. args->tlen = ntohl(*p++);
  325. if (args->tlen == 0)
  326. return 0;
  327. args->first.iov_base = p;
  328. args->first.iov_len = rqstp->rq_arg.head[0].iov_len;
  329. args->first.iov_len -= (char *)p - base;
  330. /* This request is never larger than a page. Therefore,
  331. * transport will deliver either:
  332. * 1. pathname in the pagelist -> sattr is in the tail.
  333. * 2. everything in the head buffer -> sattr is in the head.
  334. */
  335. if (rqstp->rq_arg.page_len) {
  336. if (args->tlen != rqstp->rq_arg.page_len)
  337. return 0;
  338. p = rqstp->rq_arg.tail[0].iov_base;
  339. } else {
  340. xdrlen = XDR_QUADLEN(args->tlen);
  341. if (xdrlen > args->first.iov_len - (8 * sizeof(__be32)))
  342. return 0;
  343. p += xdrlen;
  344. }
  345. decode_sattr(p, &args->attrs, nfsd_user_namespace(rqstp));
  346. return 1;
  347. }
  348. int
  349. nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p)
  350. {
  351. struct nfsd_readdirargs *args = rqstp->rq_argp;
  352. p = decode_fh(p, &args->fh);
  353. if (!p)
  354. return 0;
  355. args->cookie = ntohl(*p++);
  356. args->count = ntohl(*p++);
  357. args->count = min_t(u32, args->count, PAGE_SIZE);
  358. args->buffer = page_address(*(rqstp->rq_next_page++));
  359. return xdr_argsize_check(rqstp, p);
  360. }
  361. /*
  362. * XDR encode functions
  363. */
  364. int
  365. nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p)
  366. {
  367. return xdr_ressize_check(rqstp, p);
  368. }
  369. int
  370. nfssvc_encode_stat(struct svc_rqst *rqstp, __be32 *p)
  371. {
  372. struct nfsd_stat *resp = rqstp->rq_resp;
  373. *p++ = resp->status;
  374. return xdr_ressize_check(rqstp, p);
  375. }
  376. int
  377. nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p)
  378. {
  379. struct nfsd_attrstat *resp = rqstp->rq_resp;
  380. *p++ = resp->status;
  381. if (resp->status != nfs_ok)
  382. goto out;
  383. p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
  384. out:
  385. return xdr_ressize_check(rqstp, p);
  386. }
  387. int
  388. nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p)
  389. {
  390. struct nfsd_diropres *resp = rqstp->rq_resp;
  391. *p++ = resp->status;
  392. if (resp->status != nfs_ok)
  393. goto out;
  394. p = encode_fh(p, &resp->fh);
  395. p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
  396. out:
  397. return xdr_ressize_check(rqstp, p);
  398. }
  399. int
  400. nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p)
  401. {
  402. struct nfsd_readlinkres *resp = rqstp->rq_resp;
  403. *p++ = resp->status;
  404. if (resp->status != nfs_ok)
  405. return xdr_ressize_check(rqstp, p);
  406. *p++ = htonl(resp->len);
  407. xdr_ressize_check(rqstp, p);
  408. rqstp->rq_res.page_len = resp->len;
  409. if (resp->len & 3) {
  410. /* need to pad the tail */
  411. rqstp->rq_res.tail[0].iov_base = p;
  412. *p = 0;
  413. rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
  414. }
  415. return 1;
  416. }
  417. int
  418. nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p)
  419. {
  420. struct nfsd_readres *resp = rqstp->rq_resp;
  421. *p++ = resp->status;
  422. if (resp->status != nfs_ok)
  423. return xdr_ressize_check(rqstp, p);
  424. p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
  425. *p++ = htonl(resp->count);
  426. xdr_ressize_check(rqstp, p);
  427. /* now update rqstp->rq_res to reflect data as well */
  428. rqstp->rq_res.page_len = resp->count;
  429. if (resp->count & 3) {
  430. /* need to pad the tail */
  431. rqstp->rq_res.tail[0].iov_base = p;
  432. *p = 0;
  433. rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
  434. }
  435. return 1;
  436. }
  437. int
  438. nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p)
  439. {
  440. struct nfsd_readdirres *resp = rqstp->rq_resp;
  441. *p++ = resp->status;
  442. if (resp->status != nfs_ok)
  443. return xdr_ressize_check(rqstp, p);
  444. xdr_ressize_check(rqstp, p);
  445. p = resp->buffer;
  446. *p++ = 0; /* no more entries */
  447. *p++ = htonl((resp->common.err == nfserr_eof));
  448. rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
  449. return 1;
  450. }
  451. int
  452. nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p)
  453. {
  454. struct nfsd_statfsres *resp = rqstp->rq_resp;
  455. struct kstatfs *stat = &resp->stats;
  456. *p++ = resp->status;
  457. if (resp->status != nfs_ok)
  458. return xdr_ressize_check(rqstp, p);
  459. *p++ = htonl(NFSSVC_MAXBLKSIZE_V2); /* max transfer size */
  460. *p++ = htonl(stat->f_bsize);
  461. *p++ = htonl(stat->f_blocks);
  462. *p++ = htonl(stat->f_bfree);
  463. *p++ = htonl(stat->f_bavail);
  464. return xdr_ressize_check(rqstp, p);
  465. }
  466. int
  467. nfssvc_encode_entry(void *ccdv, const char *name,
  468. int namlen, loff_t offset, u64 ino, unsigned int d_type)
  469. {
  470. struct readdir_cd *ccd = ccdv;
  471. struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
  472. __be32 *p = cd->buffer;
  473. int buflen, slen;
  474. /*
  475. dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
  476. namlen, name, offset, ino);
  477. */
  478. if (offset > ~((u32) 0)) {
  479. cd->common.err = nfserr_fbig;
  480. return -EINVAL;
  481. }
  482. if (cd->offset)
  483. *cd->offset = htonl(offset);
  484. /* truncate filename */
  485. namlen = min(namlen, NFS2_MAXNAMLEN);
  486. slen = XDR_QUADLEN(namlen);
  487. if ((buflen = cd->buflen - slen - 4) < 0) {
  488. cd->common.err = nfserr_toosmall;
  489. return -EINVAL;
  490. }
  491. if (ino > ~((u32) 0)) {
  492. cd->common.err = nfserr_fbig;
  493. return -EINVAL;
  494. }
  495. *p++ = xdr_one; /* mark entry present */
  496. *p++ = htonl((u32) ino); /* file id */
  497. p = xdr_encode_array(p, name, namlen);/* name length & name */
  498. cd->offset = p; /* remember pointer */
  499. *p++ = htonl(~0U); /* offset of next entry */
  500. cd->buflen = buflen;
  501. cd->buffer = p;
  502. cd->common.err = nfs_ok;
  503. return 0;
  504. }
  505. /*
  506. * XDR release functions
  507. */
  508. void nfssvc_release_attrstat(struct svc_rqst *rqstp)
  509. {
  510. struct nfsd_attrstat *resp = rqstp->rq_resp;
  511. fh_put(&resp->fh);
  512. }
  513. void nfssvc_release_diropres(struct svc_rqst *rqstp)
  514. {
  515. struct nfsd_diropres *resp = rqstp->rq_resp;
  516. fh_put(&resp->fh);
  517. }
  518. void nfssvc_release_readres(struct svc_rqst *rqstp)
  519. {
  520. struct nfsd_readres *resp = rqstp->rq_resp;
  521. fh_put(&resp->fh);
  522. }