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/kernel.h> 9 #include <linux/sunrpc/svc.h> 10 #include <linux/nfs4.h> 11 #include <linux/nfs_fs.h> 12 #include "nfs4_fs.h" 13 #include "callback.h" 14 15 #define CB_OP_TAGLEN_MAXSZ (512) 16 #define CB_OP_HDR_RES_MAXSZ (2 + CB_OP_TAGLEN_MAXSZ) 17 #define CB_OP_GETATTR_BITMAP_MAXSZ (4) 18 #define CB_OP_GETATTR_RES_MAXSZ (CB_OP_HDR_RES_MAXSZ + \ 19 CB_OP_GETATTR_BITMAP_MAXSZ + \ 20 2 + 2 + 3 + 3) 21 #define CB_OP_RECALL_RES_MAXSZ (CB_OP_HDR_RES_MAXSZ) 22 23 #define NFSDBG_FACILITY NFSDBG_CALLBACK 24 25 typedef __be32 (*callback_process_op_t)(void *, void *); 26 typedef __be32 (*callback_decode_arg_t)(struct svc_rqst *, struct xdr_stream *, void *); 27 typedef __be32 (*callback_encode_res_t)(struct svc_rqst *, struct xdr_stream *, void *); 28 29 30 struct callback_op { 31 callback_process_op_t process_op; 32 callback_decode_arg_t decode_args; 33 callback_encode_res_t encode_res; 34 long res_maxsize; 35 }; 36 37 static struct callback_op callback_ops[]; 38 39 static __be32 nfs4_callback_null(struct svc_rqst *rqstp, void *argp, void *resp) 40 { 41 return htonl(NFS4_OK); 42 } 43 44 static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy) 45 { 46 return xdr_argsize_check(rqstp, p); 47 } 48 49 static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy) 50 { 51 return xdr_ressize_check(rqstp, p); 52 } 53 54 static __be32 *read_buf(struct xdr_stream *xdr, int nbytes) 55 { 56 __be32 *p; 57 58 p = xdr_inline_decode(xdr, nbytes); 59 if (unlikely(p == NULL)) 60 printk(KERN_WARNING "NFSv4 callback reply buffer overflowed!\n"); 61 return p; 62 } 63 64 static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len, const char **str) 65 { 66 __be32 *p; 67 68 p = read_buf(xdr, 4); 69 if (unlikely(p == NULL)) 70 return htonl(NFS4ERR_RESOURCE); 71 *len = ntohl(*p); 72 73 if (*len != 0) { 74 p = read_buf(xdr, *len); 75 if (unlikely(p == NULL)) 76 return htonl(NFS4ERR_RESOURCE); 77 *str = (const char *)p; 78 } else 79 *str = NULL; 80 81 return 0; 82 } 83 84 static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh) 85 { 86 __be32 *p; 87 88 p = read_buf(xdr, 4); 89 if (unlikely(p == NULL)) 90 return htonl(NFS4ERR_RESOURCE); 91 fh->size = ntohl(*p); 92 if (fh->size > NFS4_FHSIZE) 93 return htonl(NFS4ERR_BADHANDLE); 94 p = read_buf(xdr, fh->size); 95 if (unlikely(p == NULL)) 96 return htonl(NFS4ERR_RESOURCE); 97 memcpy(&fh->data[0], p, fh->size); 98 memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size); 99 return 0; 100 } 101 102 static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap) 103 { 104 __be32 *p; 105 unsigned int attrlen; 106 107 p = read_buf(xdr, 4); 108 if (unlikely(p == NULL)) 109 return htonl(NFS4ERR_RESOURCE); 110 attrlen = ntohl(*p); 111 p = read_buf(xdr, attrlen << 2); 112 if (unlikely(p == NULL)) 113 return htonl(NFS4ERR_RESOURCE); 114 if (likely(attrlen > 0)) 115 bitmap[0] = ntohl(*p++); 116 if (attrlen > 1) 117 bitmap[1] = ntohl(*p); 118 return 0; 119 } 120 121 static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid) 122 { 123 __be32 *p; 124 125 p = read_buf(xdr, 16); 126 if (unlikely(p == NULL)) 127 return htonl(NFS4ERR_RESOURCE); 128 memcpy(stateid->data, p, 16); 129 return 0; 130 } 131 132 static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr) 133 { 134 __be32 *p; 135 unsigned int minor_version; 136 __be32 status; 137 138 status = decode_string(xdr, &hdr->taglen, &hdr->tag); 139 if (unlikely(status != 0)) 140 return status; 141 /* We do not like overly long tags! */ 142 if (hdr->taglen > CB_OP_TAGLEN_MAXSZ - 12) { 143 printk("NFSv4 CALLBACK %s: client sent tag of length %u\n", 144 __func__, hdr->taglen); 145 return htonl(NFS4ERR_RESOURCE); 146 } 147 p = read_buf(xdr, 12); 148 if (unlikely(p == NULL)) 149 return htonl(NFS4ERR_RESOURCE); 150 minor_version = ntohl(*p++); 151 /* Check minor version is zero. */ 152 if (minor_version != 0) { 153 printk(KERN_WARNING "%s: NFSv4 server callback with illegal minor version %u!\n", 154 __func__, minor_version); 155 return htonl(NFS4ERR_MINOR_VERS_MISMATCH); 156 } 157 hdr->callback_ident = ntohl(*p++); 158 hdr->nops = ntohl(*p); 159 return 0; 160 } 161 162 static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op) 163 { 164 __be32 *p; 165 p = read_buf(xdr, 4); 166 if (unlikely(p == NULL)) 167 return htonl(NFS4ERR_RESOURCE); 168 *op = ntohl(*p); 169 return 0; 170 } 171 172 static __be32 decode_getattr_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_getattrargs *args) 173 { 174 __be32 status; 175 176 status = decode_fh(xdr, &args->fh); 177 if (unlikely(status != 0)) 178 goto out; 179 args->addr = svc_addr(rqstp); 180 status = decode_bitmap(xdr, args->bitmap); 181 out: 182 dprintk("%s: exit with status = %d\n", __func__, ntohl(status)); 183 return status; 184 } 185 186 static __be32 decode_recall_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_recallargs *args) 187 { 188 __be32 *p; 189 __be32 status; 190 191 args->addr = svc_addr(rqstp); 192 status = decode_stateid(xdr, &args->stateid); 193 if (unlikely(status != 0)) 194 goto out; 195 p = read_buf(xdr, 4); 196 if (unlikely(p == NULL)) { 197 status = htonl(NFS4ERR_RESOURCE); 198 goto out; 199 } 200 args->truncate = ntohl(*p); 201 status = decode_fh(xdr, &args->fh); 202 out: 203 dprintk("%s: exit with status = %d\n", __func__, ntohl(status)); 204 return status; 205 } 206 207 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str) 208 { 209 __be32 *p; 210 211 p = xdr_reserve_space(xdr, 4 + len); 212 if (unlikely(p == NULL)) 213 return htonl(NFS4ERR_RESOURCE); 214 xdr_encode_opaque(p, str, len); 215 return 0; 216 } 217 218 #define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE) 219 #define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY) 220 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, __be32 **savep) 221 { 222 __be32 bm[2]; 223 __be32 *p; 224 225 bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0); 226 bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1); 227 if (bm[1] != 0) { 228 p = xdr_reserve_space(xdr, 16); 229 if (unlikely(p == NULL)) 230 return htonl(NFS4ERR_RESOURCE); 231 *p++ = htonl(2); 232 *p++ = bm[0]; 233 *p++ = bm[1]; 234 } else if (bm[0] != 0) { 235 p = xdr_reserve_space(xdr, 12); 236 if (unlikely(p == NULL)) 237 return htonl(NFS4ERR_RESOURCE); 238 *p++ = htonl(1); 239 *p++ = bm[0]; 240 } else { 241 p = xdr_reserve_space(xdr, 8); 242 if (unlikely(p == NULL)) 243 return htonl(NFS4ERR_RESOURCE); 244 *p++ = htonl(0); 245 } 246 *savep = p; 247 return 0; 248 } 249 250 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change) 251 { 252 __be32 *p; 253 254 if (!(bitmap[0] & FATTR4_WORD0_CHANGE)) 255 return 0; 256 p = xdr_reserve_space(xdr, 8); 257 if (unlikely(!p)) 258 return htonl(NFS4ERR_RESOURCE); 259 p = xdr_encode_hyper(p, change); 260 return 0; 261 } 262 263 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size) 264 { 265 __be32 *p; 266 267 if (!(bitmap[0] & FATTR4_WORD0_SIZE)) 268 return 0; 269 p = xdr_reserve_space(xdr, 8); 270 if (unlikely(!p)) 271 return htonl(NFS4ERR_RESOURCE); 272 p = xdr_encode_hyper(p, size); 273 return 0; 274 } 275 276 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time) 277 { 278 __be32 *p; 279 280 p = xdr_reserve_space(xdr, 12); 281 if (unlikely(!p)) 282 return htonl(NFS4ERR_RESOURCE); 283 p = xdr_encode_hyper(p, time->tv_sec); 284 *p = htonl(time->tv_nsec); 285 return 0; 286 } 287 288 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time) 289 { 290 if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA)) 291 return 0; 292 return encode_attr_time(xdr,time); 293 } 294 295 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time) 296 { 297 if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY)) 298 return 0; 299 return encode_attr_time(xdr,time); 300 } 301 302 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr) 303 { 304 __be32 status; 305 306 hdr->status = xdr_reserve_space(xdr, 4); 307 if (unlikely(hdr->status == NULL)) 308 return htonl(NFS4ERR_RESOURCE); 309 status = encode_string(xdr, hdr->taglen, hdr->tag); 310 if (unlikely(status != 0)) 311 return status; 312 hdr->nops = xdr_reserve_space(xdr, 4); 313 if (unlikely(hdr->nops == NULL)) 314 return htonl(NFS4ERR_RESOURCE); 315 return 0; 316 } 317 318 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res) 319 { 320 __be32 *p; 321 322 p = xdr_reserve_space(xdr, 8); 323 if (unlikely(p == NULL)) 324 return htonl(NFS4ERR_RESOURCE); 325 *p++ = htonl(op); 326 *p = res; 327 return 0; 328 } 329 330 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr, const struct cb_getattrres *res) 331 { 332 __be32 *savep = NULL; 333 __be32 status = res->status; 334 335 if (unlikely(status != 0)) 336 goto out; 337 status = encode_attr_bitmap(xdr, res->bitmap, &savep); 338 if (unlikely(status != 0)) 339 goto out; 340 status = encode_attr_change(xdr, res->bitmap, res->change_attr); 341 if (unlikely(status != 0)) 342 goto out; 343 status = encode_attr_size(xdr, res->bitmap, res->size); 344 if (unlikely(status != 0)) 345 goto out; 346 status = encode_attr_ctime(xdr, res->bitmap, &res->ctime); 347 if (unlikely(status != 0)) 348 goto out; 349 status = encode_attr_mtime(xdr, res->bitmap, &res->mtime); 350 *savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1))); 351 out: 352 dprintk("%s: exit with status = %d\n", __func__, ntohl(status)); 353 return status; 354 } 355 356 static __be32 process_op(struct svc_rqst *rqstp, 357 struct xdr_stream *xdr_in, void *argp, 358 struct xdr_stream *xdr_out, void *resp) 359 { 360 struct callback_op *op = &callback_ops[0]; 361 unsigned int op_nr = OP_CB_ILLEGAL; 362 __be32 status = 0; 363 long maxlen; 364 __be32 res; 365 366 dprintk("%s: start\n", __func__); 367 status = decode_op_hdr(xdr_in, &op_nr); 368 if (likely(status == 0)) { 369 switch (op_nr) { 370 case OP_CB_GETATTR: 371 case OP_CB_RECALL: 372 op = &callback_ops[op_nr]; 373 break; 374 default: 375 op_nr = OP_CB_ILLEGAL; 376 op = &callback_ops[0]; 377 status = htonl(NFS4ERR_OP_ILLEGAL); 378 } 379 } 380 381 maxlen = xdr_out->end - xdr_out->p; 382 if (maxlen > 0 && maxlen < PAGE_SIZE) { 383 if (likely(status == 0 && op->decode_args != NULL)) 384 status = op->decode_args(rqstp, xdr_in, argp); 385 if (likely(status == 0 && op->process_op != NULL)) 386 status = op->process_op(argp, resp); 387 } else 388 status = htonl(NFS4ERR_RESOURCE); 389 390 res = encode_op_hdr(xdr_out, op_nr, status); 391 if (status == 0) 392 status = res; 393 if (op->encode_res != NULL && status == 0) 394 status = op->encode_res(rqstp, xdr_out, resp); 395 dprintk("%s: done, status = %d\n", __func__, ntohl(status)); 396 return status; 397 } 398 399 /* 400 * Decode, process and encode a COMPOUND 401 */ 402 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *resp) 403 { 404 struct cb_compound_hdr_arg hdr_arg = { 0 }; 405 struct cb_compound_hdr_res hdr_res = { NULL }; 406 struct xdr_stream xdr_in, xdr_out; 407 __be32 *p; 408 __be32 status; 409 unsigned int nops = 0; 410 411 dprintk("%s: start\n", __func__); 412 413 xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base); 414 415 p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len); 416 xdr_init_encode(&xdr_out, &rqstp->rq_res, p); 417 418 status = decode_compound_hdr_arg(&xdr_in, &hdr_arg); 419 if (status == __constant_htonl(NFS4ERR_RESOURCE)) 420 return rpc_garbage_args; 421 422 hdr_res.taglen = hdr_arg.taglen; 423 hdr_res.tag = hdr_arg.tag; 424 if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0) 425 return rpc_system_err; 426 427 while (status == 0 && nops != hdr_arg.nops) { 428 status = process_op(rqstp, &xdr_in, argp, &xdr_out, resp); 429 nops++; 430 } 431 432 *hdr_res.status = status; 433 *hdr_res.nops = htonl(nops); 434 dprintk("%s: done, status = %u\n", __func__, ntohl(status)); 435 return rpc_success; 436 } 437 438 /* 439 * Define NFS4 callback COMPOUND ops. 440 */ 441 static struct callback_op callback_ops[] = { 442 [0] = { 443 .res_maxsize = CB_OP_HDR_RES_MAXSZ, 444 }, 445 [OP_CB_GETATTR] = { 446 .process_op = (callback_process_op_t)nfs4_callback_getattr, 447 .decode_args = (callback_decode_arg_t)decode_getattr_args, 448 .encode_res = (callback_encode_res_t)encode_getattr_res, 449 .res_maxsize = CB_OP_GETATTR_RES_MAXSZ, 450 }, 451 [OP_CB_RECALL] = { 452 .process_op = (callback_process_op_t)nfs4_callback_recall, 453 .decode_args = (callback_decode_arg_t)decode_recall_args, 454 .res_maxsize = CB_OP_RECALL_RES_MAXSZ, 455 } 456 }; 457 458 /* 459 * Define NFS4 callback procedures 460 */ 461 static struct svc_procedure nfs4_callback_procedures1[] = { 462 [CB_NULL] = { 463 .pc_func = nfs4_callback_null, 464 .pc_decode = (kxdrproc_t)nfs4_decode_void, 465 .pc_encode = (kxdrproc_t)nfs4_encode_void, 466 .pc_xdrressize = 1, 467 }, 468 [CB_COMPOUND] = { 469 .pc_func = nfs4_callback_compound, 470 .pc_encode = (kxdrproc_t)nfs4_encode_void, 471 .pc_argsize = 256, 472 .pc_ressize = 256, 473 .pc_xdrressize = NFS4_CALLBACK_BUFSIZE, 474 } 475 }; 476 477 struct svc_version nfs4_callback_version1 = { 478 .vs_vers = 1, 479 .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1), 480 .vs_proc = nfs4_callback_procedures1, 481 .vs_xdrsize = NFS4_CALLBACK_XDRSIZE, 482 .vs_dispatch = NULL, 483 }; 484 485