1 /* 2 * linux/fs/nfs/callback_xdr.c 3 * 4 * Copyright (C) 2004 Trond Myklebust 5 * 6 * NFSv4 callback encode/decode procedures 7 */ 8 #include <linux/config.h> 9 #include <linux/kernel.h> 10 #include <linux/sunrpc/svc.h> 11 #include <linux/nfs4.h> 12 #include <linux/nfs_fs.h> 13 #include "nfs4_fs.h" 14 #include "callback.h" 15 16 #define CB_OP_TAGLEN_MAXSZ (512) 17 #define CB_OP_HDR_RES_MAXSZ (2 + CB_OP_TAGLEN_MAXSZ) 18 #define CB_OP_GETATTR_BITMAP_MAXSZ (4) 19 #define CB_OP_GETATTR_RES_MAXSZ (CB_OP_HDR_RES_MAXSZ + \ 20 CB_OP_GETATTR_BITMAP_MAXSZ + \ 21 2 + 2 + 3 + 3) 22 #define CB_OP_RECALL_RES_MAXSZ (CB_OP_HDR_RES_MAXSZ) 23 24 #define NFSDBG_FACILITY NFSDBG_CALLBACK 25 26 typedef unsigned (*callback_process_op_t)(void *, void *); 27 typedef unsigned (*callback_decode_arg_t)(struct svc_rqst *, struct xdr_stream *, void *); 28 typedef unsigned (*callback_encode_res_t)(struct svc_rqst *, struct xdr_stream *, void *); 29 30 31 struct callback_op { 32 callback_process_op_t process_op; 33 callback_decode_arg_t decode_args; 34 callback_encode_res_t encode_res; 35 long res_maxsize; 36 }; 37 38 static struct callback_op callback_ops[]; 39 40 static int nfs4_callback_null(struct svc_rqst *rqstp, void *argp, void *resp) 41 { 42 return htonl(NFS4_OK); 43 } 44 45 static int nfs4_decode_void(struct svc_rqst *rqstp, uint32_t *p, void *dummy) 46 { 47 return xdr_argsize_check(rqstp, p); 48 } 49 50 static int nfs4_encode_void(struct svc_rqst *rqstp, uint32_t *p, void *dummy) 51 { 52 return xdr_ressize_check(rqstp, p); 53 } 54 55 static uint32_t *read_buf(struct xdr_stream *xdr, int nbytes) 56 { 57 uint32_t *p; 58 59 p = xdr_inline_decode(xdr, nbytes); 60 if (unlikely(p == NULL)) 61 printk(KERN_WARNING "NFSv4 callback reply buffer overflowed!\n"); 62 return p; 63 } 64 65 static unsigned decode_string(struct xdr_stream *xdr, unsigned int *len, const char **str) 66 { 67 uint32_t *p; 68 69 p = read_buf(xdr, 4); 70 if (unlikely(p == NULL)) 71 return htonl(NFS4ERR_RESOURCE); 72 *len = ntohl(*p); 73 74 if (*len != 0) { 75 p = read_buf(xdr, *len); 76 if (unlikely(p == NULL)) 77 return htonl(NFS4ERR_RESOURCE); 78 *str = (const char *)p; 79 } else 80 *str = NULL; 81 82 return 0; 83 } 84 85 static unsigned decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh) 86 { 87 uint32_t *p; 88 89 p = read_buf(xdr, 4); 90 if (unlikely(p == NULL)) 91 return htonl(NFS4ERR_RESOURCE); 92 fh->size = ntohl(*p); 93 if (fh->size > NFS4_FHSIZE) 94 return htonl(NFS4ERR_BADHANDLE); 95 p = read_buf(xdr, fh->size); 96 if (unlikely(p == NULL)) 97 return htonl(NFS4ERR_RESOURCE); 98 memcpy(&fh->data[0], p, fh->size); 99 memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size); 100 return 0; 101 } 102 103 static unsigned decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap) 104 { 105 uint32_t *p; 106 unsigned int attrlen; 107 108 p = read_buf(xdr, 4); 109 if (unlikely(p == NULL)) 110 return htonl(NFS4ERR_RESOURCE); 111 attrlen = ntohl(*p); 112 p = read_buf(xdr, attrlen << 2); 113 if (unlikely(p == NULL)) 114 return htonl(NFS4ERR_RESOURCE); 115 if (likely(attrlen > 0)) 116 bitmap[0] = ntohl(*p++); 117 if (attrlen > 1) 118 bitmap[1] = ntohl(*p); 119 return 0; 120 } 121 122 static unsigned decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid) 123 { 124 uint32_t *p; 125 126 p = read_buf(xdr, 16); 127 if (unlikely(p == NULL)) 128 return htonl(NFS4ERR_RESOURCE); 129 memcpy(stateid->data, p, 16); 130 return 0; 131 } 132 133 static unsigned decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr) 134 { 135 uint32_t *p; 136 unsigned int minor_version; 137 unsigned status; 138 139 status = decode_string(xdr, &hdr->taglen, &hdr->tag); 140 if (unlikely(status != 0)) 141 return status; 142 /* We do not like overly long tags! */ 143 if (hdr->taglen > CB_OP_TAGLEN_MAXSZ-12 || hdr->taglen < 0) { 144 printk("NFSv4 CALLBACK %s: client sent tag of length %u\n", 145 __FUNCTION__, hdr->taglen); 146 return htonl(NFS4ERR_RESOURCE); 147 } 148 p = read_buf(xdr, 12); 149 if (unlikely(p == NULL)) 150 return htonl(NFS4ERR_RESOURCE); 151 minor_version = ntohl(*p++); 152 /* Check minor version is zero. */ 153 if (minor_version != 0) { 154 printk(KERN_WARNING "%s: NFSv4 server callback with illegal minor version %u!\n", 155 __FUNCTION__, minor_version); 156 return htonl(NFS4ERR_MINOR_VERS_MISMATCH); 157 } 158 hdr->callback_ident = ntohl(*p++); 159 hdr->nops = ntohl(*p); 160 return 0; 161 } 162 163 static unsigned decode_op_hdr(struct xdr_stream *xdr, unsigned int *op) 164 { 165 uint32_t *p; 166 p = read_buf(xdr, 4); 167 if (unlikely(p == NULL)) 168 return htonl(NFS4ERR_RESOURCE); 169 *op = ntohl(*p); 170 return 0; 171 } 172 173 static unsigned decode_getattr_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_getattrargs *args) 174 { 175 unsigned status; 176 177 status = decode_fh(xdr, &args->fh); 178 if (unlikely(status != 0)) 179 goto out; 180 args->addr = &rqstp->rq_addr; 181 status = decode_bitmap(xdr, args->bitmap); 182 out: 183 dprintk("%s: exit with status = %d\n", __FUNCTION__, status); 184 return status; 185 } 186 187 static unsigned decode_recall_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_recallargs *args) 188 { 189 uint32_t *p; 190 unsigned status; 191 192 args->addr = &rqstp->rq_addr; 193 status = decode_stateid(xdr, &args->stateid); 194 if (unlikely(status != 0)) 195 goto out; 196 p = read_buf(xdr, 4); 197 if (unlikely(p == NULL)) { 198 status = htonl(NFS4ERR_RESOURCE); 199 goto out; 200 } 201 args->truncate = ntohl(*p); 202 status = decode_fh(xdr, &args->fh); 203 out: 204 dprintk("%s: exit with status = %d\n", __FUNCTION__, status); 205 return 0; 206 } 207 208 static unsigned encode_string(struct xdr_stream *xdr, unsigned int len, const char *str) 209 { 210 uint32_t *p; 211 212 p = xdr_reserve_space(xdr, 4 + len); 213 if (unlikely(p == NULL)) 214 return htonl(NFS4ERR_RESOURCE); 215 xdr_encode_opaque(p, str, len); 216 return 0; 217 } 218 219 #define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE) 220 #define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY) 221 static unsigned encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, uint32_t **savep) 222 { 223 uint32_t bm[2]; 224 uint32_t *p; 225 226 bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0); 227 bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1); 228 if (bm[1] != 0) { 229 p = xdr_reserve_space(xdr, 16); 230 if (unlikely(p == NULL)) 231 return htonl(NFS4ERR_RESOURCE); 232 *p++ = htonl(2); 233 *p++ = bm[0]; 234 *p++ = bm[1]; 235 } else if (bm[0] != 0) { 236 p = xdr_reserve_space(xdr, 12); 237 if (unlikely(p == NULL)) 238 return htonl(NFS4ERR_RESOURCE); 239 *p++ = htonl(1); 240 *p++ = bm[0]; 241 } else { 242 p = xdr_reserve_space(xdr, 8); 243 if (unlikely(p == NULL)) 244 return htonl(NFS4ERR_RESOURCE); 245 *p++ = htonl(0); 246 } 247 *savep = p; 248 return 0; 249 } 250 251 static unsigned encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change) 252 { 253 uint32_t *p; 254 255 if (!(bitmap[0] & FATTR4_WORD0_CHANGE)) 256 return 0; 257 p = xdr_reserve_space(xdr, 8); 258 if (unlikely(p == 0)) 259 return htonl(NFS4ERR_RESOURCE); 260 p = xdr_encode_hyper(p, change); 261 return 0; 262 } 263 264 static unsigned encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size) 265 { 266 uint32_t *p; 267 268 if (!(bitmap[0] & FATTR4_WORD0_SIZE)) 269 return 0; 270 p = xdr_reserve_space(xdr, 8); 271 if (unlikely(p == 0)) 272 return htonl(NFS4ERR_RESOURCE); 273 p = xdr_encode_hyper(p, size); 274 return 0; 275 } 276 277 static unsigned encode_attr_time(struct xdr_stream *xdr, const struct timespec *time) 278 { 279 uint32_t *p; 280 281 p = xdr_reserve_space(xdr, 12); 282 if (unlikely(p == 0)) 283 return htonl(NFS4ERR_RESOURCE); 284 p = xdr_encode_hyper(p, time->tv_sec); 285 *p = htonl(time->tv_nsec); 286 return 0; 287 } 288 289 static unsigned encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time) 290 { 291 if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA)) 292 return 0; 293 return encode_attr_time(xdr,time); 294 } 295 296 static unsigned encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time) 297 { 298 if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY)) 299 return 0; 300 return encode_attr_time(xdr,time); 301 } 302 303 static unsigned encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr) 304 { 305 unsigned status; 306 307 hdr->status = xdr_reserve_space(xdr, 4); 308 if (unlikely(hdr->status == NULL)) 309 return htonl(NFS4ERR_RESOURCE); 310 status = encode_string(xdr, hdr->taglen, hdr->tag); 311 if (unlikely(status != 0)) 312 return status; 313 hdr->nops = xdr_reserve_space(xdr, 4); 314 if (unlikely(hdr->nops == NULL)) 315 return htonl(NFS4ERR_RESOURCE); 316 return 0; 317 } 318 319 static unsigned encode_op_hdr(struct xdr_stream *xdr, uint32_t op, uint32_t res) 320 { 321 uint32_t *p; 322 323 p = xdr_reserve_space(xdr, 8); 324 if (unlikely(p == NULL)) 325 return htonl(NFS4ERR_RESOURCE); 326 *p++ = htonl(op); 327 *p = res; 328 return 0; 329 } 330 331 static unsigned encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr, const struct cb_getattrres *res) 332 { 333 uint32_t *savep; 334 unsigned status = res->status; 335 336 if (unlikely(status != 0)) 337 goto out; 338 status = encode_attr_bitmap(xdr, res->bitmap, &savep); 339 if (unlikely(status != 0)) 340 goto out; 341 status = encode_attr_change(xdr, res->bitmap, res->change_attr); 342 if (unlikely(status != 0)) 343 goto out; 344 status = encode_attr_size(xdr, res->bitmap, res->size); 345 if (unlikely(status != 0)) 346 goto out; 347 status = encode_attr_ctime(xdr, res->bitmap, &res->ctime); 348 if (unlikely(status != 0)) 349 goto out; 350 status = encode_attr_mtime(xdr, res->bitmap, &res->mtime); 351 *savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1))); 352 out: 353 dprintk("%s: exit with status = %d\n", __FUNCTION__, status); 354 return status; 355 } 356 357 static unsigned process_op(struct svc_rqst *rqstp, 358 struct xdr_stream *xdr_in, void *argp, 359 struct xdr_stream *xdr_out, void *resp) 360 { 361 struct callback_op *op; 362 unsigned int op_nr; 363 unsigned int status = 0; 364 long maxlen; 365 unsigned res; 366 367 dprintk("%s: start\n", __FUNCTION__); 368 status = decode_op_hdr(xdr_in, &op_nr); 369 if (unlikely(status != 0)) { 370 op_nr = OP_CB_ILLEGAL; 371 op = &callback_ops[0]; 372 } else if (unlikely(op_nr != OP_CB_GETATTR && op_nr != OP_CB_RECALL)) { 373 op_nr = OP_CB_ILLEGAL; 374 op = &callback_ops[0]; 375 status = htonl(NFS4ERR_OP_ILLEGAL); 376 } else 377 op = &callback_ops[op_nr]; 378 379 maxlen = xdr_out->end - xdr_out->p; 380 if (maxlen > 0 && maxlen < PAGE_SIZE) { 381 if (likely(status == 0 && op->decode_args != NULL)) 382 status = op->decode_args(rqstp, xdr_in, argp); 383 if (likely(status == 0 && op->process_op != NULL)) 384 status = op->process_op(argp, resp); 385 } else 386 status = htonl(NFS4ERR_RESOURCE); 387 388 res = encode_op_hdr(xdr_out, op_nr, status); 389 if (status == 0) 390 status = res; 391 if (op->encode_res != NULL && status == 0) 392 status = op->encode_res(rqstp, xdr_out, resp); 393 dprintk("%s: done, status = %d\n", __FUNCTION__, status); 394 return status; 395 } 396 397 /* 398 * Decode, process and encode a COMPOUND 399 */ 400 static int nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *resp) 401 { 402 struct cb_compound_hdr_arg hdr_arg; 403 struct cb_compound_hdr_res hdr_res; 404 struct xdr_stream xdr_in, xdr_out; 405 uint32_t *p; 406 unsigned int status; 407 unsigned int nops = 1; 408 409 dprintk("%s: start\n", __FUNCTION__); 410 411 xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base); 412 413 p = (uint32_t*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len); 414 xdr_init_encode(&xdr_out, &rqstp->rq_res, p); 415 416 decode_compound_hdr_arg(&xdr_in, &hdr_arg); 417 hdr_res.taglen = hdr_arg.taglen; 418 hdr_res.tag = hdr_arg.tag; 419 encode_compound_hdr_res(&xdr_out, &hdr_res); 420 421 for (;;) { 422 status = process_op(rqstp, &xdr_in, argp, &xdr_out, resp); 423 if (status != 0) 424 break; 425 if (nops == hdr_arg.nops) 426 break; 427 nops++; 428 } 429 *hdr_res.status = status; 430 *hdr_res.nops = htonl(nops); 431 dprintk("%s: done, status = %u\n", __FUNCTION__, status); 432 return rpc_success; 433 } 434 435 /* 436 * Define NFS4 callback COMPOUND ops. 437 */ 438 static struct callback_op callback_ops[] = { 439 [0] = { 440 .res_maxsize = CB_OP_HDR_RES_MAXSZ, 441 }, 442 [OP_CB_GETATTR] = { 443 .process_op = (callback_process_op_t)nfs4_callback_getattr, 444 .decode_args = (callback_decode_arg_t)decode_getattr_args, 445 .encode_res = (callback_encode_res_t)encode_getattr_res, 446 .res_maxsize = CB_OP_GETATTR_RES_MAXSZ, 447 }, 448 [OP_CB_RECALL] = { 449 .process_op = (callback_process_op_t)nfs4_callback_recall, 450 .decode_args = (callback_decode_arg_t)decode_recall_args, 451 .res_maxsize = CB_OP_RECALL_RES_MAXSZ, 452 } 453 }; 454 455 /* 456 * Define NFS4 callback procedures 457 */ 458 static struct svc_procedure nfs4_callback_procedures1[] = { 459 [CB_NULL] = { 460 .pc_func = nfs4_callback_null, 461 .pc_decode = (kxdrproc_t)nfs4_decode_void, 462 .pc_encode = (kxdrproc_t)nfs4_encode_void, 463 .pc_xdrressize = 1, 464 }, 465 [CB_COMPOUND] = { 466 .pc_func = nfs4_callback_compound, 467 .pc_encode = (kxdrproc_t)nfs4_encode_void, 468 .pc_argsize = 256, 469 .pc_ressize = 256, 470 .pc_xdrressize = NFS4_CALLBACK_BUFSIZE, 471 } 472 }; 473 474 struct svc_version nfs4_callback_version1 = { 475 .vs_vers = 1, 476 .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1), 477 .vs_proc = nfs4_callback_procedures1, 478 .vs_xdrsize = NFS4_CALLBACK_XDRSIZE, 479 .vs_dispatch = NULL, 480 }; 481 482