LXR linux/fs/lockd/xdr4.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * linux/fs/lockd/xdr4.c
   4 *
   5 * XDR support for lockd and the lock client.
   6 *
   7 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   8 * Copyright (C) 1999, Trond Myklebust <trond.myklebust@fys.uio.no>
   9 */
  10
  11#include <linux/types.h>
  12#include <linux/sched.h>
  13#include <linux/nfs.h>
  14
  15#include <linux/sunrpc/xdr.h>
  16#include <linux/sunrpc/clnt.h>
  17#include <linux/sunrpc/svc.h>
  18#include <linux/sunrpc/stats.h>
  19#include <linux/lockd/lockd.h>
  20
  21#include "svcxdr.h"
  22
  23static inline loff_t
  24s64_to_loff_t(__s64 offset)
  25{
  26        return (loff_t)offset;
  27}
  28
  29
  30static inline s64
  31loff_t_to_s64(loff_t offset)
  32{
  33        s64 res;
  34        if (offset > NLM4_OFFSET_MAX)
  35                res = NLM4_OFFSET_MAX;
  36        else if (offset < -NLM4_OFFSET_MAX)
  37                res = -NLM4_OFFSET_MAX;
  38        else
  39                res = offset;
  40        return res;
  41}
  42
  43/*
  44 * NLM file handles are defined by specification to be a variable-length
  45 * XDR opaque no longer than 1024 bytes. However, this implementation
  46 * limits their length to the size of an NFSv3 file handle.
  47 */
  48static bool
  49svcxdr_decode_fhandle(struct xdr_stream *xdr, struct nfs_fh *fh)
  50{
  51        __be32 *p;
  52        u32 len;
  53
  54        if (xdr_stream_decode_u32(xdr, &len) < 0)
  55                return false;
  56        if (len > NFS_MAXFHSIZE)
  57                return false;
  58
  59        p = xdr_inline_decode(xdr, len);
  60        if (!p)
  61                return false;
  62        fh->size = len;
  63        memcpy(fh->data, p, len);
  64        memset(fh->data + len, 0, sizeof(fh->data) - len);
  65
  66        return true;
  67}
  68
  69static bool
  70svcxdr_decode_lock(struct xdr_stream *xdr, struct nlm_lock *lock)
  71{
  72        struct file_lock *fl = &lock->fl;
  73        u64 len, start;
  74        s64 end;
  75
  76        if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
  77                return false;
  78        if (!svcxdr_decode_fhandle(xdr, &lock->fh))
  79                return false;
  80        if (!svcxdr_decode_owner(xdr, &lock->oh))
  81                return false;
  82        if (xdr_stream_decode_u32(xdr, &lock->svid) < 0)
  83                return false;
  84        if (xdr_stream_decode_u64(xdr, &start) < 0)
  85                return false;
  86        if (xdr_stream_decode_u64(xdr, &len) < 0)
  87                return false;
  88
  89        locks_init_lock(fl);
  90        fl->fl_flags = FL_POSIX;
  91        fl->fl_type  = F_RDLCK;
  92        end = start + len - 1;
  93        fl->fl_start = s64_to_loff_t(start);
  94        if (len == 0 || end < 0)
  95                fl->fl_end = OFFSET_MAX;
  96        else
  97                fl->fl_end = s64_to_loff_t(end);
  98
  99        return true;
 100}
 101
 102static bool
 103svcxdr_encode_holder(struct xdr_stream *xdr, const struct nlm_lock *lock)
 104{
 105        const struct file_lock *fl = &lock->fl;
 106        s64 start, len;
 107
 108        /* exclusive */
 109        if (xdr_stream_encode_bool(xdr, fl->fl_type != F_RDLCK) < 0)
 110                return false;
 111        if (xdr_stream_encode_u32(xdr, lock->svid) < 0)
 112                return false;
 113        if (!svcxdr_encode_owner(xdr, &lock->oh))
 114                return false;
 115        start = loff_t_to_s64(fl->fl_start);
 116        if (fl->fl_end == OFFSET_MAX)
 117                len = 0;
 118        else
 119                len = loff_t_to_s64(fl->fl_end - fl->fl_start + 1);
 120        if (xdr_stream_encode_u64(xdr, start) < 0)
 121                return false;
 122        if (xdr_stream_encode_u64(xdr, len) < 0)
 123                return false;
 124
 125        return true;
 126}
 127
 128static bool
 129svcxdr_encode_testrply(struct xdr_stream *xdr, const struct nlm_res *resp)
 130{
 131        if (!svcxdr_encode_stats(xdr, resp->status))
 132                return false;
 133        switch (resp->status) {
 134        case nlm_lck_denied:
 135                if (!svcxdr_encode_holder(xdr, &resp->lock))
 136                        return false;
 137        }
 138
 139        return true;
 140}
 141
 142
 143/*
 144 * Decode Call arguments
 145 */
 146
 147int
 148nlm4svc_decode_void(struct svc_rqst *rqstp, __be32 *p)
 149{
 150        return 1;
 151}
 152
 153int
 154nlm4svc_decode_testargs(struct svc_rqst *rqstp, __be32 *p)
 155{
 156        struct xdr_stream *xdr = &rqstp->rq_arg_stream;
 157        struct nlm_args *argp = rqstp->rq_argp;
 158        u32 exclusive;
 159
 160        if (!svcxdr_decode_cookie(xdr, &argp->cookie))
 161                return 0;
 162        if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
 163                return 0;
 164        if (!svcxdr_decode_lock(xdr, &argp->lock))
 165                return 0;
 166        if (exclusive)
 167                argp->lock.fl.fl_type = F_WRLCK;
 168
 169        return 1;
 170}
 171
 172int
 173nlm4svc_decode_lockargs(struct svc_rqst *rqstp, __be32 *p)
 174{
 175        struct xdr_stream *xdr = &rqstp->rq_arg_stream;
 176        struct nlm_args *argp = rqstp->rq_argp;
 177        u32 exclusive;
 178
 179        if (!svcxdr_decode_cookie(xdr, &argp->cookie))
 180                return 0;
 181        if (xdr_stream_decode_bool(xdr, &argp->block) < 0)
 182                return 0;
 183        if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
 184                return 0;
 185        if (!svcxdr_decode_lock(xdr, &argp->lock))
 186                return 0;
 187        if (exclusive)
 188                argp->lock.fl.fl_type = F_WRLCK;
 189        if (xdr_stream_decode_bool(xdr, &argp->reclaim) < 0)
 190                return 0;
 191        if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
 192                return 0;
 193        argp->monitor = 1;              /* monitor client by default */
 194
 195        return 1;
 196}
 197
 198int
 199nlm4svc_decode_cancargs(struct svc_rqst *rqstp, __be32 *p)
 200{
 201        struct xdr_stream *xdr = &rqstp->rq_arg_stream;
 202        struct nlm_args *argp = rqstp->rq_argp;
 203        u32 exclusive;
 204
 205        if (!svcxdr_decode_cookie(xdr, &argp->cookie))
 206                return 0;
 207        if (xdr_stream_decode_bool(xdr, &argp->block) < 0)
 208                return 0;
 209        if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
 210                return 0;
 211        if (!svcxdr_decode_lock(xdr, &argp->lock))
 212                return 0;
 213        if (exclusive)
 214                argp->lock.fl.fl_type = F_WRLCK;
 215        return 1;
 216}
 217
 218int
 219nlm4svc_decode_unlockargs(struct svc_rqst *rqstp, __be32 *p)
 220{
 221        struct xdr_stream *xdr = &rqstp->rq_arg_stream;
 222        struct nlm_args *argp = rqstp->rq_argp;
 223
 224        if (!svcxdr_decode_cookie(xdr, &argp->cookie))
 225                return 0;
 226        if (!svcxdr_decode_lock(xdr, &argp->lock))
 227                return 0;
 228        argp->lock.fl.fl_type = F_UNLCK;
 229
 230        return 1;
 231}
 232
 233int
 234nlm4svc_decode_res(struct svc_rqst *rqstp, __be32 *p)
 235{
 236        struct xdr_stream *xdr = &rqstp->rq_arg_stream;
 237        struct nlm_res *resp = rqstp->rq_argp;
 238
 239        if (!svcxdr_decode_cookie(xdr, &resp->cookie))
 240                return 0;
 241        if (!svcxdr_decode_stats(xdr, &resp->status))
 242                return 0;
 243
 244        return 1;
 245}
 246
 247int
 248nlm4svc_decode_reboot(struct svc_rqst *rqstp, __be32 *p)
 249{
 250        struct xdr_stream *xdr = &rqstp->rq_arg_stream;
 251        struct nlm_reboot *argp = rqstp->rq_argp;
 252        u32 len;
 253
 254        if (xdr_stream_decode_u32(xdr, &len) < 0)
 255                return 0;
 256        if (len > SM_MAXSTRLEN)
 257                return 0;
 258        p = xdr_inline_decode(xdr, len);
 259        if (!p)
 260                return 0;
 261        argp->len = len;
 262        argp->mon = (char *)p;
 263        if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
 264                return 0;
 265        p = xdr_inline_decode(xdr, SM_PRIV_SIZE);
 266        if (!p)
 267                return 0;
 268        memcpy(&argp->priv.data, p, sizeof(argp->priv.data));
 269
 270        return 1;
 271}
 272
 273int
 274nlm4svc_decode_shareargs(struct svc_rqst *rqstp, __be32 *p)
 275{
 276        struct xdr_stream *xdr = &rqstp->rq_arg_stream;
 277        struct nlm_args *argp = rqstp->rq_argp;
 278        struct nlm_lock *lock = &argp->lock;
 279
 280        memset(lock, 0, sizeof(*lock));
 281        locks_init_lock(&lock->fl);
 282        lock->svid = ~(u32)0;
 283
 284        if (!svcxdr_decode_cookie(xdr, &argp->cookie))
 285                return 0;
 286        if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
 287                return 0;
 288        if (!svcxdr_decode_fhandle(xdr, &lock->fh))
 289                return 0;
 290        if (!svcxdr_decode_owner(xdr, &lock->oh))
 291                return 0;
 292        /* XXX: Range checks are missing in the original code */
 293        if (xdr_stream_decode_u32(xdr, &argp->fsm_mode) < 0)
 294                return 0;
 295        if (xdr_stream_decode_u32(xdr, &argp->fsm_access) < 0)
 296                return 0;
 297
 298        return 1;
 299}
 300
 301int
 302nlm4svc_decode_notify(struct svc_rqst *rqstp, __be32 *p)
 303{
 304        struct xdr_stream *xdr = &rqstp->rq_arg_stream;
 305        struct nlm_args *argp = rqstp->rq_argp;
 306        struct nlm_lock *lock = &argp->lock;
 307
 308        if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
 309                return 0;
 310        if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
 311                return 0;
 312
 313        return 1;
 314}
 315
 316
 317/*
 318 * Encode Reply results
 319 */
 320
 321int
 322nlm4svc_encode_void(struct svc_rqst *rqstp, __be32 *p)
 323{
 324        return 1;
 325}
 326
 327int
 328nlm4svc_encode_testres(struct svc_rqst *rqstp, __be32 *p)
 329{
 330        struct xdr_stream *xdr = &rqstp->rq_res_stream;
 331        struct nlm_res *resp = rqstp->rq_resp;
 332
 333        return svcxdr_encode_cookie(xdr, &resp->cookie) &&
 334                svcxdr_encode_testrply(xdr, resp);
 335}
 336
 337int
 338nlm4svc_encode_res(struct svc_rqst *rqstp, __be32 *p)
 339{
 340        struct xdr_stream *xdr = &rqstp->rq_res_stream;
 341        struct nlm_res *resp = rqstp->rq_resp;
 342
 343        return svcxdr_encode_cookie(xdr, &resp->cookie) &&
 344                svcxdr_encode_stats(xdr, resp->status);
 345}
 346
 347int
 348nlm4svc_encode_shareres(struct svc_rqst *rqstp, __be32 *p)
 349{
 350        struct xdr_stream *xdr = &rqstp->rq_res_stream;
 351        struct nlm_res *resp = rqstp->rq_resp;
 352
 353        if (!svcxdr_encode_cookie(xdr, &resp->cookie))
 354                return 0;
 355        if (!svcxdr_encode_stats(xdr, resp->status))
 356                return 0;
 357        /* sequence */
 358        if (xdr_stream_encode_u32(xdr, 0) < 0)
 359                return 0;
 360
 361        return 1;
 362}
 363