net/xfrm/xfrm_compat.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * XFRM compat layer
   4  * Author: Dmitry Safonov <dima@arista.com>
   5  * Based on code and translator idea by: Florian Westphal <fw@strlen.de>
   6  */
   7 #include <linux/compat.h>
   8 #include <linux/xfrm.h>
   9 #include <net/xfrm.h>
  10
  11 struct compat_xfrm_lifetime_cfg {
  12         compat_u64 soft_byte_limit, hard_byte_limit;
  13         compat_u64 soft_packet_limit, hard_packet_limit;
  14         compat_u64 soft_add_expires_seconds, hard_add_expires_seconds;
  15         compat_u64 soft_use_expires_seconds, hard_use_expires_seconds;
  16 }; /* same size on 32bit, but only 4 byte alignment required */
  17
  18 struct compat_xfrm_lifetime_cur {
  19         compat_u64 bytes, packets, add_time, use_time;
  20 }; /* same size on 32bit, but only 4 byte alignment required */
  21
  22 struct compat_xfrm_userpolicy_info {
  23         struct xfrm_selector sel;
  24         struct compat_xfrm_lifetime_cfg lft;
  25         struct compat_xfrm_lifetime_cur curlft;
  26         __u32 priority, index;
  27         u8 dir, action, flags, share;
  28         /* 4 bytes additional padding on 64bit */
  29 };
  30
  31 struct compat_xfrm_usersa_info {
  32         struct xfrm_selector sel;
  33         struct xfrm_id id;
  34         xfrm_address_t saddr;
  35         struct compat_xfrm_lifetime_cfg lft;
  36         struct compat_xfrm_lifetime_cur curlft;
  37         struct xfrm_stats stats;
  38         __u32 seq, reqid;
  39         u16 family;
  40         u8 mode, replay_window, flags;
  41         /* 4 bytes additional padding on 64bit */
  42 };
  43
  44 struct compat_xfrm_user_acquire {
  45         struct xfrm_id id;
  46         xfrm_address_t saddr;
  47         struct xfrm_selector sel;
  48         struct compat_xfrm_userpolicy_info policy;
  49         /* 4 bytes additional padding on 64bit */
  50         __u32 aalgos, ealgos, calgos, seq;
  51 };
  52
  53 struct compat_xfrm_userspi_info {
  54         struct compat_xfrm_usersa_info info;
  55         /* 4 bytes additional padding on 64bit */
  56         __u32 min, max;
  57 };
  58
  59 struct compat_xfrm_user_expire {
  60         struct compat_xfrm_usersa_info state;
  61         /* 8 bytes additional padding on 64bit */
  62         u8 hard;
  63 };
  64
  65 struct compat_xfrm_user_polexpire {
  66         struct compat_xfrm_userpolicy_info pol;
  67         /* 8 bytes additional padding on 64bit */
  68         u8 hard;
  69 };
  70
  71 #define XMSGSIZE(type) sizeof(struct type)
  72
  73 static const int compat_msg_min[XFRM_NR_MSGTYPES] = {
  74         [XFRM_MSG_NEWSA       - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_usersa_info),
  75         [XFRM_MSG_DELSA       - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_id),
  76         [XFRM_MSG_GETSA       - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_id),
  77         [XFRM_MSG_NEWPOLICY   - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_userpolicy_info),
  78         [XFRM_MSG_DELPOLICY   - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_id),
  79         [XFRM_MSG_GETPOLICY   - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_id),
  80         [XFRM_MSG_ALLOCSPI    - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_userspi_info),
  81         [XFRM_MSG_ACQUIRE     - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_user_acquire),
  82         [XFRM_MSG_EXPIRE      - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_user_expire),
  83         [XFRM_MSG_UPDPOLICY   - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_userpolicy_info),
  84         [XFRM_MSG_UPDSA       - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_usersa_info),
  85         [XFRM_MSG_POLEXPIRE   - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_user_polexpire),
  86         [XFRM_MSG_FLUSHSA     - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_flush),
  87         [XFRM_MSG_FLUSHPOLICY - XFRM_MSG_BASE] = 0,
  88         [XFRM_MSG_NEWAE       - XFRM_MSG_BASE] = XMSGSIZE(xfrm_aevent_id),
  89         [XFRM_MSG_GETAE       - XFRM_MSG_BASE] = XMSGSIZE(xfrm_aevent_id),
  90         [XFRM_MSG_REPORT      - XFRM_MSG_BASE] = XMSGSIZE(xfrm_user_report),
  91         [XFRM_MSG_MIGRATE     - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_id),
  92         [XFRM_MSG_NEWSADINFO  - XFRM_MSG_BASE] = sizeof(u32),
  93         [XFRM_MSG_GETSADINFO  - XFRM_MSG_BASE] = sizeof(u32),
  94         [XFRM_MSG_NEWSPDINFO  - XFRM_MSG_BASE] = sizeof(u32),
  95         [XFRM_MSG_GETSPDINFO  - XFRM_MSG_BASE] = sizeof(u32),
  96         [XFRM_MSG_MAPPING     - XFRM_MSG_BASE] = XMSGSIZE(xfrm_user_mapping)
  97 };
  98
  99 static const struct nla_policy compat_policy[XFRMA_MAX+1] = {
 100         [XFRMA_SA]              = { .len = XMSGSIZE(compat_xfrm_usersa_info)},
 101         [XFRMA_POLICY]          = { .len = XMSGSIZE(compat_xfrm_userpolicy_info)},
 102         [XFRMA_LASTUSED]        = { .type = NLA_U64},
 103         [XFRMA_ALG_AUTH_TRUNC]  = { .len = sizeof(struct xfrm_algo_auth)},
 104         [XFRMA_ALG_AEAD]        = { .len = sizeof(struct xfrm_algo_aead) },
 105         [XFRMA_ALG_AUTH]        = { .len = sizeof(struct xfrm_algo) },
 106         [XFRMA_ALG_CRYPT]       = { .len = sizeof(struct xfrm_algo) },
 107         [XFRMA_ALG_COMP]        = { .len = sizeof(struct xfrm_algo) },
 108         [XFRMA_ENCAP]           = { .len = sizeof(struct xfrm_encap_tmpl) },
 109         [XFRMA_TMPL]            = { .len = sizeof(struct xfrm_user_tmpl) },
 110         [XFRMA_SEC_CTX]         = { .len = sizeof(struct xfrm_sec_ctx) },
 111         [XFRMA_LTIME_VAL]       = { .len = sizeof(struct xfrm_lifetime_cur) },
 112         [XFRMA_REPLAY_VAL]      = { .len = sizeof(struct xfrm_replay_state) },
 113         [XFRMA_REPLAY_THRESH]   = { .type = NLA_U32 },
 114         [XFRMA_ETIMER_THRESH]   = { .type = NLA_U32 },
 115         [XFRMA_SRCADDR]         = { .len = sizeof(xfrm_address_t) },
 116         [XFRMA_COADDR]          = { .len = sizeof(xfrm_address_t) },
 117         [XFRMA_POLICY_TYPE]     = { .len = sizeof(struct xfrm_userpolicy_type)},
 118         [XFRMA_MIGRATE]         = { .len = sizeof(struct xfrm_user_migrate) },
 119         [XFRMA_KMADDRESS]       = { .len = sizeof(struct xfrm_user_kmaddress) },
 120         [XFRMA_MARK]            = { .len = sizeof(struct xfrm_mark) },
 121         [XFRMA_TFCPAD]          = { .type = NLA_U32 },
 122         [XFRMA_REPLAY_ESN_VAL]  = { .len = sizeof(struct xfrm_replay_state_esn) },
 123         [XFRMA_SA_EXTRA_FLAGS]  = { .type = NLA_U32 },
 124         [XFRMA_PROTO]           = { .type = NLA_U8 },
 125         [XFRMA_ADDRESS_FILTER]  = { .len = sizeof(struct xfrm_address_filter) },
 126         [XFRMA_OFFLOAD_DEV]     = { .len = sizeof(struct xfrm_user_offload) },
 127         [XFRMA_SET_MARK]        = { .type = NLA_U32 },
 128         [XFRMA_SET_MARK_MASK]   = { .type = NLA_U32 },
 129         [XFRMA_IF_ID]           = { .type = NLA_U32 },
 130 };
 131
 132 static struct nlmsghdr *xfrm_nlmsg_put_compat(struct sk_buff *skb,
 133                         const struct nlmsghdr *nlh_src, u16 type)
 134 {
 135         int payload = compat_msg_min[type];
 136         int src_len = xfrm_msg_min[type];
 137         struct nlmsghdr *nlh_dst;
 138
 139         /* Compat messages are shorter or equal to native (+padding) */
 140         if (WARN_ON_ONCE(src_len < payload))
 141                 return ERR_PTR(-EMSGSIZE);
 142
 143         nlh_dst = nlmsg_put(skb, nlh_src->nlmsg_pid, nlh_src->nlmsg_seq,
 144                             nlh_src->nlmsg_type, payload, nlh_src->nlmsg_flags);
 145         if (!nlh_dst)
 146                 return ERR_PTR(-EMSGSIZE);
 147
 148         memset(nlmsg_data(nlh_dst), 0, payload);
 149
 150         switch (nlh_src->nlmsg_type) {
 151         /* Compat message has the same layout as native */
 152         case XFRM_MSG_DELSA:
 153         case XFRM_MSG_DELPOLICY:
 154         case XFRM_MSG_FLUSHSA:
 155         case XFRM_MSG_FLUSHPOLICY:
 156         case XFRM_MSG_NEWAE:
 157         case XFRM_MSG_REPORT:
 158         case XFRM_MSG_MIGRATE:
 159         case XFRM_MSG_NEWSADINFO:
 160         case XFRM_MSG_NEWSPDINFO:
 161         case XFRM_MSG_MAPPING:
 162                 WARN_ON_ONCE(src_len != payload);
 163                 memcpy(nlmsg_data(nlh_dst), nlmsg_data(nlh_src), src_len);
 164                 break;
 165         /* 4 byte alignment for trailing u64 on native, but not on compat */
 166         case XFRM_MSG_NEWSA:
 167         case XFRM_MSG_NEWPOLICY:
 168         case XFRM_MSG_UPDSA:
 169         case XFRM_MSG_UPDPOLICY:
 170                 WARN_ON_ONCE(src_len != payload + 4);
 171                 memcpy(nlmsg_data(nlh_dst), nlmsg_data(nlh_src), payload);
 172                 break;
 173         case XFRM_MSG_EXPIRE: {
 174                 const struct xfrm_user_expire *src_ue  = nlmsg_data(nlh_src);
 175                 struct compat_xfrm_user_expire *dst_ue = nlmsg_data(nlh_dst);
 176
 177                 /* compat_xfrm_user_expire has 4-byte smaller state */
 178                 memcpy(dst_ue, src_ue, sizeof(dst_ue->state));
 179                 dst_ue->hard = src_ue->hard;
 180                 break;
 181         }
 182         case XFRM_MSG_ACQUIRE: {
 183                 const struct xfrm_user_acquire *src_ua  = nlmsg_data(nlh_src);
 184                 struct compat_xfrm_user_acquire *dst_ua = nlmsg_data(nlh_dst);
 185
 186                 memcpy(dst_ua, src_ua, offsetof(struct compat_xfrm_user_acquire, aalgos));
 187                 dst_ua->aalgos = src_ua->aalgos;
 188                 dst_ua->ealgos = src_ua->ealgos;
 189                 dst_ua->calgos = src_ua->calgos;
 190                 dst_ua->seq    = src_ua->seq;
 191                 break;
 192         }
 193         case XFRM_MSG_POLEXPIRE: {
 194                 const struct xfrm_user_polexpire *src_upe  = nlmsg_data(nlh_src);
 195                 struct compat_xfrm_user_polexpire *dst_upe = nlmsg_data(nlh_dst);
 196
 197                 /* compat_xfrm_user_polexpire has 4-byte smaller state */
 198                 memcpy(dst_upe, src_upe, sizeof(dst_upe->pol));
 199                 dst_upe->hard = src_upe->hard;
 200                 break;
 201         }
 202         case XFRM_MSG_ALLOCSPI: {
 203                 const struct xfrm_userspi_info *src_usi = nlmsg_data(nlh_src);
 204                 struct compat_xfrm_userspi_info *dst_usi = nlmsg_data(nlh_dst);
 205
 206                 /* compat_xfrm_user_polexpire has 4-byte smaller state */
 207                 memcpy(dst_usi, src_usi, sizeof(src_usi->info));
 208                 dst_usi->min = src_usi->min;
 209                 dst_usi->max = src_usi->max;
 210                 break;
 211         }
 212         /* Not being sent by kernel */
 213         case XFRM_MSG_GETSA:
 214         case XFRM_MSG_GETPOLICY:
 215         case XFRM_MSG_GETAE:
 216         case XFRM_MSG_GETSADINFO:
 217         case XFRM_MSG_GETSPDINFO:
 218         default:
 219                 WARN_ONCE(1, "unsupported nlmsg_type %d", nlh_src->nlmsg_type);
 220                 return ERR_PTR(-EOPNOTSUPP);
 221         }
 222
 223         return nlh_dst;
 224 }
 225
 226 static int xfrm_nla_cpy(struct sk_buff *dst, const struct nlattr *src, int len)
 227 {
 228         return nla_put(dst, src->nla_type, len, nla_data(src));
 229 }
 230
 231 static int xfrm_xlate64_attr(struct sk_buff *dst, const struct nlattr *src)
 232 {
 233         switch (src->nla_type) {
 234         case XFRMA_PAD:
 235                 /* Ignore */
 236                 return 0;
 237         case XFRMA_UNSPEC:
 238         case XFRMA_ALG_AUTH:
 239         case XFRMA_ALG_CRYPT:
 240         case XFRMA_ALG_COMP:
 241         case XFRMA_ENCAP:
 242         case XFRMA_TMPL:
 243                 return xfrm_nla_cpy(dst, src, nla_len(src));
 244         case XFRMA_SA:
 245                 return xfrm_nla_cpy(dst, src, XMSGSIZE(compat_xfrm_usersa_info));
 246         case XFRMA_POLICY:
 247                 return xfrm_nla_cpy(dst, src, XMSGSIZE(compat_xfrm_userpolicy_info));
 248         case XFRMA_SEC_CTX:
 249                 return xfrm_nla_cpy(dst, src, nla_len(src));
 250         case XFRMA_LTIME_VAL:
 251                 return nla_put_64bit(dst, src->nla_type, nla_len(src),
 252                         nla_data(src), XFRMA_PAD);
 253         case XFRMA_REPLAY_VAL:
 254         case XFRMA_REPLAY_THRESH:
 255         case XFRMA_ETIMER_THRESH:
 256         case XFRMA_SRCADDR:
 257         case XFRMA_COADDR:
 258                 return xfrm_nla_cpy(dst, src, nla_len(src));
 259         case XFRMA_LASTUSED:
 260                 return nla_put_64bit(dst, src->nla_type, nla_len(src),
 261                         nla_data(src), XFRMA_PAD);
 262         case XFRMA_POLICY_TYPE:
 263         case XFRMA_MIGRATE:
 264         case XFRMA_ALG_AEAD:
 265         case XFRMA_KMADDRESS:
 266         case XFRMA_ALG_AUTH_TRUNC:
 267         case XFRMA_MARK:
 268         case XFRMA_TFCPAD:
 269         case XFRMA_REPLAY_ESN_VAL:
 270         case XFRMA_SA_EXTRA_FLAGS:
 271         case XFRMA_PROTO:
 272         case XFRMA_ADDRESS_FILTER:
 273         case XFRMA_OFFLOAD_DEV:
 274         case XFRMA_SET_MARK:
 275         case XFRMA_SET_MARK_MASK:
 276         case XFRMA_IF_ID:
 277                 return xfrm_nla_cpy(dst, src, nla_len(src));
 278         default:
 279                 BUILD_BUG_ON(XFRMA_MAX != XFRMA_IF_ID);
 280                 WARN_ONCE(1, "unsupported nla_type %d", src->nla_type);
 281                 return -EOPNOTSUPP;
 282         }
 283 }
 284
 285 /* Take kernel-built (64bit layout) and create 32bit layout for userspace */
 286 static int xfrm_xlate64(struct sk_buff *dst, const struct nlmsghdr *nlh_src)
 287 {
 288         u16 type = nlh_src->nlmsg_type - XFRM_MSG_BASE;
 289         const struct nlattr *nla, *attrs;
 290         struct nlmsghdr *nlh_dst;
 291         int len, remaining;
 292
 293         nlh_dst = xfrm_nlmsg_put_compat(dst, nlh_src, type);
 294         if (IS_ERR(nlh_dst))
 295                 return PTR_ERR(nlh_dst);
 296
 297         attrs = nlmsg_attrdata(nlh_src, xfrm_msg_min[type]);
 298         len = nlmsg_attrlen(nlh_src, xfrm_msg_min[type]);
 299
 300         nla_for_each_attr(nla, attrs, len, remaining) {
 301                 int err = xfrm_xlate64_attr(dst, nla);
 302
 303                 if (err)
 304                         return err;
 305         }
 306
 307         nlmsg_end(dst, nlh_dst);
 308
 309         return 0;
 310 }
 311
 312 static int xfrm_alloc_compat(struct sk_buff *skb, const struct nlmsghdr *nlh_src)
 313 {
 314         u16 type = nlh_src->nlmsg_type - XFRM_MSG_BASE;
 315         struct sk_buff *new = NULL;
 316         int err;
 317
 318         if (WARN_ON_ONCE(type >= ARRAY_SIZE(xfrm_msg_min)))
 319                 return -EOPNOTSUPP;
 320
 321         if (skb_shinfo(skb)->frag_list == NULL) {
 322                 new = alloc_skb(skb->len + skb_tailroom(skb), GFP_ATOMIC);
 323                 if (!new)
 324                         return -ENOMEM;
 325                 skb_shinfo(skb)->frag_list = new;
 326         }
 327
 328         err = xfrm_xlate64(skb_shinfo(skb)->frag_list, nlh_src);
 329         if (err) {
 330                 if (new) {
 331                         kfree_skb(new);
 332                         skb_shinfo(skb)->frag_list = NULL;
 333                 }
 334                 return err;
 335         }
 336
 337         return 0;
 338 }
 339
 340 /* Calculates len of translated 64-bit message. */
 341 static size_t xfrm_user_rcv_calculate_len64(const struct nlmsghdr *src,
 342                                             struct nlattr *attrs[XFRMA_MAX+1])
 343 {
 344         size_t len = nlmsg_len(src);
 345
 346         switch (src->nlmsg_type) {
 347         case XFRM_MSG_NEWSA:
 348         case XFRM_MSG_NEWPOLICY:
 349         case XFRM_MSG_ALLOCSPI:
 350         case XFRM_MSG_ACQUIRE:
 351         case XFRM_MSG_UPDPOLICY:
 352         case XFRM_MSG_UPDSA:
 353                 len += 4;
 354                 break;
 355         case XFRM_MSG_EXPIRE:
 356         case XFRM_MSG_POLEXPIRE:
 357                 len += 8;
 358                 break;
 359         default:
 360                 break;
 361         }
 362
 363         if (attrs[XFRMA_SA])
 364                 len += 4;
 365         if (attrs[XFRMA_POLICY])
 366                 len += 4;
 367
 368         /* XXX: some attrs may need to be realigned
 369          * if !CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
 370          */
 371
 372         return len;
 373 }
 374
 375 static int xfrm_attr_cpy32(void *dst, size_t *pos, const struct nlattr *src,
 376                            size_t size, int copy_len, int payload)
 377 {
 378         struct nlmsghdr *nlmsg = dst;
 379         struct nlattr *nla;
 380
 381         if (WARN_ON_ONCE(copy_len > payload))
 382                 copy_len = payload;
 383
 384         if (size - *pos < nla_attr_size(payload))
 385                 return -ENOBUFS;
 386
 387         nla = dst + *pos;
 388
 389         memcpy(nla, src, nla_attr_size(copy_len));
 390         nla->nla_len = nla_attr_size(payload);
 391         *pos += nla_attr_size(copy_len);
 392         nlmsg->nlmsg_len += nla->nla_len;
 393
 394         memset(dst + *pos, 0, payload - copy_len);
 395         *pos += payload - copy_len;
 396
 397         return 0;
 398 }
 399
 400 static int xfrm_xlate32_attr(void *dst, const struct nlattr *nla,
 401                              size_t *pos, size_t size,
 402                              struct netlink_ext_ack *extack)
 403 {
 404         int type = nla_type(nla);
 405         u16 pol_len32, pol_len64;
 406         int err;
 407
 408         if (type > XFRMA_MAX) {
 409                 BUILD_BUG_ON(XFRMA_MAX != XFRMA_IF_ID);
 410                 NL_SET_ERR_MSG(extack, "Bad attribute");
 411                 return -EOPNOTSUPP;
 412         }
 413         if (nla_len(nla) < compat_policy[type].len) {
 414                 NL_SET_ERR_MSG(extack, "Attribute bad length");
 415                 return -EOPNOTSUPP;
 416         }
 417
 418         pol_len32 = compat_policy[type].len;
 419         pol_len64 = xfrma_policy[type].len;
 420
 421         /* XFRMA_SA and XFRMA_POLICY - need to know how-to translate */
 422         if (pol_len32 != pol_len64) {
 423                 if (nla_len(nla) != compat_policy[type].len) {
 424                         NL_SET_ERR_MSG(extack, "Attribute bad length");
 425                         return -EOPNOTSUPP;
 426                 }
 427                 err = xfrm_attr_cpy32(dst, pos, nla, size, pol_len32, pol_len64);
 428                 if (err)
 429                         return err;
 430         }
 431
 432         return xfrm_attr_cpy32(dst, pos, nla, size, nla_len(nla), nla_len(nla));
 433 }
 434
 435 static int xfrm_xlate32(struct nlmsghdr *dst, const struct nlmsghdr *src,
 436                         struct nlattr *attrs[XFRMA_MAX+1],
 437                         size_t size, u8 type, struct netlink_ext_ack *extack)
 438 {
 439         size_t pos;
 440         int i;
 441
 442         memcpy(dst, src, NLMSG_HDRLEN);
 443         dst->nlmsg_len = NLMSG_HDRLEN + xfrm_msg_min[type];
 444         memset(nlmsg_data(dst), 0, xfrm_msg_min[type]);
 445
 446         switch (src->nlmsg_type) {
 447         /* Compat message has the same layout as native */
 448         case XFRM_MSG_DELSA:
 449         case XFRM_MSG_GETSA:
 450         case XFRM_MSG_DELPOLICY:
 451         case XFRM_MSG_GETPOLICY:
 452         case XFRM_MSG_FLUSHSA:
 453         case XFRM_MSG_FLUSHPOLICY:
 454         case XFRM_MSG_NEWAE:
 455         case XFRM_MSG_GETAE:
 456         case XFRM_MSG_REPORT:
 457         case XFRM_MSG_MIGRATE:
 458         case XFRM_MSG_NEWSADINFO:
 459         case XFRM_MSG_GETSADINFO:
 460         case XFRM_MSG_NEWSPDINFO:
 461         case XFRM_MSG_GETSPDINFO:
 462         case XFRM_MSG_MAPPING:
 463                 memcpy(nlmsg_data(dst), nlmsg_data(src), compat_msg_min[type]);
 464                 break;
 465         /* 4 byte alignment for trailing u64 on native, but not on compat */
 466         case XFRM_MSG_NEWSA:
 467         case XFRM_MSG_NEWPOLICY:
 468         case XFRM_MSG_UPDSA:
 469         case XFRM_MSG_UPDPOLICY:
 470                 memcpy(nlmsg_data(dst), nlmsg_data(src), compat_msg_min[type]);
 471                 break;
 472         case XFRM_MSG_EXPIRE: {
 473                 const struct compat_xfrm_user_expire *src_ue = nlmsg_data(src);
 474                 struct xfrm_user_expire *dst_ue = nlmsg_data(dst);
 475
 476                 /* compat_xfrm_user_expire has 4-byte smaller state */
 477                 memcpy(dst_ue, src_ue, sizeof(src_ue->state));
 478                 dst_ue->hard = src_ue->hard;
 479                 break;
 480         }
 481         case XFRM_MSG_ACQUIRE: {
 482                 const struct compat_xfrm_user_acquire *src_ua = nlmsg_data(src);
 483                 struct xfrm_user_acquire *dst_ua = nlmsg_data(dst);
 484
 485                 memcpy(dst_ua, src_ua, offsetof(struct compat_xfrm_user_acquire, aalgos));
 486                 dst_ua->aalgos = src_ua->aalgos;
 487                 dst_ua->ealgos = src_ua->ealgos;
 488                 dst_ua->calgos = src_ua->calgos;
 489                 dst_ua->seq    = src_ua->seq;
 490                 break;
 491         }
 492         case XFRM_MSG_POLEXPIRE: {
 493                 const struct compat_xfrm_user_polexpire *src_upe = nlmsg_data(src);
 494                 struct xfrm_user_polexpire *dst_upe = nlmsg_data(dst);
 495
 496                 /* compat_xfrm_user_polexpire has 4-byte smaller state */
 497                 memcpy(dst_upe, src_upe, sizeof(src_upe->pol));
 498                 dst_upe->hard = src_upe->hard;
 499                 break;
 500         }
 501         case XFRM_MSG_ALLOCSPI: {
 502                 const struct compat_xfrm_userspi_info *src_usi = nlmsg_data(src);
 503                 struct xfrm_userspi_info *dst_usi = nlmsg_data(dst);
 504
 505                 /* compat_xfrm_user_polexpire has 4-byte smaller state */
 506                 memcpy(dst_usi, src_usi, sizeof(src_usi->info));
 507                 dst_usi->min = src_usi->min;
 508                 dst_usi->max = src_usi->max;
 509                 break;
 510         }
 511         default:
 512                 NL_SET_ERR_MSG(extack, "Unsupported message type");
 513                 return -EOPNOTSUPP;
 514         }
 515         pos = dst->nlmsg_len;
 516
 517         for (i = 1; i < XFRMA_MAX + 1; i++) {
 518                 int err;
 519
 520                 if (i == XFRMA_PAD)
 521                         continue;
 522
 523                 if (!attrs[i])
 524                         continue;
 525
 526                 err = xfrm_xlate32_attr(dst, attrs[i], &pos, size, extack);
 527                 if (err)
 528                         return err;
 529         }
 530
 531         return 0;
 532 }
 533
 534 static struct nlmsghdr *xfrm_user_rcv_msg_compat(const struct nlmsghdr *h32,
 535                         int maxtype, const struct nla_policy *policy,
 536                         struct netlink_ext_ack *extack)
 537 {
 538         /* netlink_rcv_skb() checks if a message has full (struct nlmsghdr) */
 539         u16 type = h32->nlmsg_type - XFRM_MSG_BASE;
 540         struct nlattr *attrs[XFRMA_MAX+1];
 541         struct nlmsghdr *h64;
 542         size_t len;
 543         int err;
 544
 545         BUILD_BUG_ON(ARRAY_SIZE(xfrm_msg_min) != ARRAY_SIZE(compat_msg_min));
 546
 547         if (type >= ARRAY_SIZE(xfrm_msg_min))
 548                 return ERR_PTR(-EINVAL);
 549
 550         /* Don't call parse: the message might have only nlmsg header */
 551         if ((h32->nlmsg_type == XFRM_MSG_GETSA ||
 552              h32->nlmsg_type == XFRM_MSG_GETPOLICY) &&
 553             (h32->nlmsg_flags & NLM_F_DUMP))
 554                 return NULL;
 555
 556         err = nlmsg_parse_deprecated(h32, compat_msg_min[type], attrs,
 557                         maxtype ? : XFRMA_MAX, policy ? : compat_policy, extack);
 558         if (err < 0)
 559                 return ERR_PTR(err);
 560
 561         len = xfrm_user_rcv_calculate_len64(h32, attrs);
 562         /* The message doesn't need translation */
 563         if (len == nlmsg_len(h32))
 564                 return NULL;
 565
 566         len += NLMSG_HDRLEN;
 567         h64 = kvmalloc(len, GFP_KERNEL);
 568         if (!h64)
 569                 return ERR_PTR(-ENOMEM);
 570
 571         err = xfrm_xlate32(h64, h32, attrs, len, type, extack);
 572         if (err < 0) {
 573                 kvfree(h64);
 574                 return ERR_PTR(err);
 575         }
 576
 577         return h64;
 578 }
 579
 580 static int xfrm_user_policy_compat(u8 **pdata32, int optlen)
 581 {
 582         struct compat_xfrm_userpolicy_info *p = (void *)*pdata32;
 583         u8 *src_templates, *dst_templates;
 584         u8 *data64;
 585
 586         if (optlen < sizeof(*p))
 587                 return -EINVAL;
 588
 589         data64 = kmalloc_track_caller(optlen + 4, GFP_USER | __GFP_NOWARN);
 590         if (!data64)
 591                 return -ENOMEM;
 592
 593         memcpy(data64, *pdata32, sizeof(*p));
 594         memset(data64 + sizeof(*p), 0, 4);
 595
 596         src_templates = *pdata32 + sizeof(*p);
 597         dst_templates = data64 + sizeof(*p) + 4;
 598         memcpy(dst_templates, src_templates, optlen - sizeof(*p));
 599
 600         kfree(*pdata32);
 601         *pdata32 = data64;
 602         return 0;
 603 }
 604
 605 static struct xfrm_translator xfrm_translator = {
 606         .owner                          = THIS_MODULE,
 607         .alloc_compat                   = xfrm_alloc_compat,
 608         .rcv_msg_compat                 = xfrm_user_rcv_msg_compat,
 609         .xlate_user_policy_sockptr      = xfrm_user_policy_compat,
 610 };
 611
 612 static int __init xfrm_compat_init(void)
 613 {
 614         return xfrm_register_translator(&xfrm_translator);
 615 }
 616
 617 static void __exit xfrm_compat_exit(void)
 618 {
 619         xfrm_unregister_translator(&xfrm_translator);
 620 }
 621
 622 module_init(xfrm_compat_init);
 623 module_exit(xfrm_compat_exit);
 624 MODULE_LICENSE("GPL");
 625 MODULE_AUTHOR("Dmitry Safonov");
 626 MODULE_DESCRIPTION("XFRM 32-bit compatibility layer");