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  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/nospec.h>
  9#include <linux/xfrm.h>
 10#include <net/xfrm.h>
 11
 12struct compat_xfrm_lifetime_cfg {
 13	compat_u64 soft_byte_limit, hard_byte_limit;
 14	compat_u64 soft_packet_limit, hard_packet_limit;
 15	compat_u64 soft_add_expires_seconds, hard_add_expires_seconds;
 16	compat_u64 soft_use_expires_seconds, hard_use_expires_seconds;
 17}; /* same size on 32bit, but only 4 byte alignment required */
 18
 19struct compat_xfrm_lifetime_cur {
 20	compat_u64 bytes, packets, add_time, use_time;
 21}; /* same size on 32bit, but only 4 byte alignment required */
 22
 23struct compat_xfrm_userpolicy_info {
 24	struct xfrm_selector sel;
 25	struct compat_xfrm_lifetime_cfg lft;
 26	struct compat_xfrm_lifetime_cur curlft;
 27	__u32 priority, index;
 28	u8 dir, action, flags, share;
 29	/* 4 bytes additional padding on 64bit */
 30};
 31
 32struct compat_xfrm_usersa_info {
 33	struct xfrm_selector sel;
 34	struct xfrm_id id;
 35	xfrm_address_t saddr;
 36	struct compat_xfrm_lifetime_cfg lft;
 37	struct compat_xfrm_lifetime_cur curlft;
 38	struct xfrm_stats stats;
 39	__u32 seq, reqid;
 40	u16 family;
 41	u8 mode, replay_window, flags;
 42	/* 4 bytes additional padding on 64bit */
 43};
 44
 45struct compat_xfrm_user_acquire {
 46	struct xfrm_id id;
 47	xfrm_address_t saddr;
 48	struct xfrm_selector sel;
 49	struct compat_xfrm_userpolicy_info policy;
 50	/* 4 bytes additional padding on 64bit */
 51	__u32 aalgos, ealgos, calgos, seq;
 52};
 53
 54struct compat_xfrm_userspi_info {
 55	struct compat_xfrm_usersa_info info;
 56	/* 4 bytes additional padding on 64bit */
 57	__u32 min, max;
 58};
 59
 60struct compat_xfrm_user_expire {
 61	struct compat_xfrm_usersa_info state;
 62	/* 8 bytes additional padding on 64bit */
 63	u8 hard;
 64};
 65
 66struct compat_xfrm_user_polexpire {
 67	struct compat_xfrm_userpolicy_info pol;
 68	/* 8 bytes additional padding on 64bit */
 69	u8 hard;
 70};
 71
 72#define XMSGSIZE(type) sizeof(struct type)
 73
 74static const int compat_msg_min[XFRM_NR_MSGTYPES] = {
 75	[XFRM_MSG_NEWSA       - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_usersa_info),
 76	[XFRM_MSG_DELSA       - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_id),
 77	[XFRM_MSG_GETSA       - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_id),
 78	[XFRM_MSG_NEWPOLICY   - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_userpolicy_info),
 79	[XFRM_MSG_DELPOLICY   - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_id),
 80	[XFRM_MSG_GETPOLICY   - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_id),
 81	[XFRM_MSG_ALLOCSPI    - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_userspi_info),
 82	[XFRM_MSG_ACQUIRE     - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_user_acquire),
 83	[XFRM_MSG_EXPIRE      - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_user_expire),
 84	[XFRM_MSG_UPDPOLICY   - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_userpolicy_info),
 85	[XFRM_MSG_UPDSA       - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_usersa_info),
 86	[XFRM_MSG_POLEXPIRE   - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_user_polexpire),
 87	[XFRM_MSG_FLUSHSA     - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_flush),
 88	[XFRM_MSG_FLUSHPOLICY - XFRM_MSG_BASE] = 0,
 89	[XFRM_MSG_NEWAE       - XFRM_MSG_BASE] = XMSGSIZE(xfrm_aevent_id),
 90	[XFRM_MSG_GETAE       - XFRM_MSG_BASE] = XMSGSIZE(xfrm_aevent_id),
 91	[XFRM_MSG_REPORT      - XFRM_MSG_BASE] = XMSGSIZE(xfrm_user_report),
 92	[XFRM_MSG_MIGRATE     - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_id),
 93	[XFRM_MSG_NEWSADINFO  - XFRM_MSG_BASE] = sizeof(u32),
 94	[XFRM_MSG_GETSADINFO  - XFRM_MSG_BASE] = sizeof(u32),
 95	[XFRM_MSG_NEWSPDINFO  - XFRM_MSG_BASE] = sizeof(u32),
 96	[XFRM_MSG_GETSPDINFO  - XFRM_MSG_BASE] = sizeof(u32),
 97	[XFRM_MSG_MAPPING     - XFRM_MSG_BASE] = XMSGSIZE(xfrm_user_mapping)
 98};
 99
100static const struct nla_policy compat_policy[XFRMA_MAX+1] = {
101	[XFRMA_UNSPEC]          = { .strict_start_type = XFRMA_SA_DIR },
102	[XFRMA_SA]		= { .len = XMSGSIZE(compat_xfrm_usersa_info)},
103	[XFRMA_POLICY]		= { .len = XMSGSIZE(compat_xfrm_userpolicy_info)},
104	[XFRMA_LASTUSED]	= { .type = NLA_U64},
105	[XFRMA_ALG_AUTH_TRUNC]	= { .len = sizeof(struct xfrm_algo_auth)},
106	[XFRMA_ALG_AEAD]	= { .len = sizeof(struct xfrm_algo_aead) },
107	[XFRMA_ALG_AUTH]	= { .len = sizeof(struct xfrm_algo) },
108	[XFRMA_ALG_CRYPT]	= { .len = sizeof(struct xfrm_algo) },
109	[XFRMA_ALG_COMP]	= { .len = sizeof(struct xfrm_algo) },
110	[XFRMA_ENCAP]		= { .len = sizeof(struct xfrm_encap_tmpl) },
111	[XFRMA_TMPL]		= { .len = sizeof(struct xfrm_user_tmpl) },
112	[XFRMA_SEC_CTX]		= { .len = sizeof(struct xfrm_user_sec_ctx) },
113	[XFRMA_LTIME_VAL]	= { .len = sizeof(struct xfrm_lifetime_cur) },
114	[XFRMA_REPLAY_VAL]	= { .len = sizeof(struct xfrm_replay_state) },
115	[XFRMA_REPLAY_THRESH]	= { .type = NLA_U32 },
116	[XFRMA_ETIMER_THRESH]	= { .type = NLA_U32 },
117	[XFRMA_SRCADDR]		= { .len = sizeof(xfrm_address_t) },
118	[XFRMA_COADDR]		= { .len = sizeof(xfrm_address_t) },
119	[XFRMA_POLICY_TYPE]	= { .len = sizeof(struct xfrm_userpolicy_type)},
120	[XFRMA_MIGRATE]		= { .len = sizeof(struct xfrm_user_migrate) },
121	[XFRMA_KMADDRESS]	= { .len = sizeof(struct xfrm_user_kmaddress) },
122	[XFRMA_MARK]		= { .len = sizeof(struct xfrm_mark) },
123	[XFRMA_TFCPAD]		= { .type = NLA_U32 },
124	[XFRMA_REPLAY_ESN_VAL]	= { .len = sizeof(struct xfrm_replay_state_esn) },
125	[XFRMA_SA_EXTRA_FLAGS]	= { .type = NLA_U32 },
126	[XFRMA_PROTO]		= { .type = NLA_U8 },
127	[XFRMA_ADDRESS_FILTER]	= { .len = sizeof(struct xfrm_address_filter) },
128	[XFRMA_OFFLOAD_DEV]	= { .len = sizeof(struct xfrm_user_offload) },
129	[XFRMA_SET_MARK]	= { .type = NLA_U32 },
130	[XFRMA_SET_MARK_MASK]	= { .type = NLA_U32 },
131	[XFRMA_IF_ID]		= { .type = NLA_U32 },
132	[XFRMA_MTIMER_THRESH]	= { .type = NLA_U32 },
133	[XFRMA_SA_DIR]          = NLA_POLICY_RANGE(NLA_U8, XFRM_SA_DIR_IN, XFRM_SA_DIR_OUT),
134	[XFRMA_NAT_KEEPALIVE_INTERVAL]	= { .type = NLA_U32 },
135	[XFRMA_SA_PCPU]		= { .type = NLA_U32 },
136};
137
138static struct nlmsghdr *xfrm_nlmsg_put_compat(struct sk_buff *skb,
139			const struct nlmsghdr *nlh_src, u16 type)
140{
141	int payload = compat_msg_min[type];
142	int src_len = xfrm_msg_min[type];
143	struct nlmsghdr *nlh_dst;
144
145	/* Compat messages are shorter or equal to native (+padding) */
146	if (WARN_ON_ONCE(src_len < payload))
147		return ERR_PTR(-EMSGSIZE);
148
149	nlh_dst = nlmsg_put(skb, nlh_src->nlmsg_pid, nlh_src->nlmsg_seq,
150			    nlh_src->nlmsg_type, payload, nlh_src->nlmsg_flags);
151	if (!nlh_dst)
152		return ERR_PTR(-EMSGSIZE);
153
154	memset(nlmsg_data(nlh_dst), 0, payload);
155
156	switch (nlh_src->nlmsg_type) {
157	/* Compat message has the same layout as native */
158	case XFRM_MSG_DELSA:
159	case XFRM_MSG_DELPOLICY:
160	case XFRM_MSG_FLUSHSA:
161	case XFRM_MSG_FLUSHPOLICY:
162	case XFRM_MSG_NEWAE:
163	case XFRM_MSG_REPORT:
164	case XFRM_MSG_MIGRATE:
165	case XFRM_MSG_NEWSADINFO:
166	case XFRM_MSG_NEWSPDINFO:
167	case XFRM_MSG_MAPPING:
168		WARN_ON_ONCE(src_len != payload);
169		memcpy(nlmsg_data(nlh_dst), nlmsg_data(nlh_src), src_len);
170		break;
171	/* 4 byte alignment for trailing u64 on native, but not on compat */
172	case XFRM_MSG_NEWSA:
173	case XFRM_MSG_NEWPOLICY:
174	case XFRM_MSG_UPDSA:
175	case XFRM_MSG_UPDPOLICY:
176		WARN_ON_ONCE(src_len != payload + 4);
177		memcpy(nlmsg_data(nlh_dst), nlmsg_data(nlh_src), payload);
178		break;
179	case XFRM_MSG_EXPIRE: {
180		const struct xfrm_user_expire *src_ue  = nlmsg_data(nlh_src);
181		struct compat_xfrm_user_expire *dst_ue = nlmsg_data(nlh_dst);
182
183		/* compat_xfrm_user_expire has 4-byte smaller state */
184		memcpy(dst_ue, src_ue, sizeof(dst_ue->state));
185		dst_ue->hard = src_ue->hard;
186		break;
187	}
188	case XFRM_MSG_ACQUIRE: {
189		const struct xfrm_user_acquire *src_ua  = nlmsg_data(nlh_src);
190		struct compat_xfrm_user_acquire *dst_ua = nlmsg_data(nlh_dst);
191
192		memcpy(dst_ua, src_ua, offsetof(struct compat_xfrm_user_acquire, aalgos));
193		dst_ua->aalgos = src_ua->aalgos;
194		dst_ua->ealgos = src_ua->ealgos;
195		dst_ua->calgos = src_ua->calgos;
196		dst_ua->seq    = src_ua->seq;
197		break;
198	}
199	case XFRM_MSG_POLEXPIRE: {
200		const struct xfrm_user_polexpire *src_upe  = nlmsg_data(nlh_src);
201		struct compat_xfrm_user_polexpire *dst_upe = nlmsg_data(nlh_dst);
202
203		/* compat_xfrm_user_polexpire has 4-byte smaller state */
204		memcpy(dst_upe, src_upe, sizeof(dst_upe->pol));
205		dst_upe->hard = src_upe->hard;
206		break;
207	}
208	case XFRM_MSG_ALLOCSPI: {
209		const struct xfrm_userspi_info *src_usi = nlmsg_data(nlh_src);
210		struct compat_xfrm_userspi_info *dst_usi = nlmsg_data(nlh_dst);
211
212		/* compat_xfrm_user_polexpire has 4-byte smaller state */
213		memcpy(dst_usi, src_usi, sizeof(src_usi->info));
214		dst_usi->min = src_usi->min;
215		dst_usi->max = src_usi->max;
216		break;
217	}
218	/* Not being sent by kernel */
219	case XFRM_MSG_GETSA:
220	case XFRM_MSG_GETPOLICY:
221	case XFRM_MSG_GETAE:
222	case XFRM_MSG_GETSADINFO:
223	case XFRM_MSG_GETSPDINFO:
224	default:
225		pr_warn_once("unsupported nlmsg_type %d\n", nlh_src->nlmsg_type);
226		return ERR_PTR(-EOPNOTSUPP);
227	}
228
229	return nlh_dst;
230}
231
232static int xfrm_nla_cpy(struct sk_buff *dst, const struct nlattr *src, int len)
233{
234	return nla_put(dst, src->nla_type, len, nla_data(src));
235}
236
237static int xfrm_xlate64_attr(struct sk_buff *dst, const struct nlattr *src)
238{
239	switch (src->nla_type) {
240	case XFRMA_PAD:
241		/* Ignore */
242		return 0;
243	case XFRMA_UNSPEC:
244	case XFRMA_ALG_AUTH:
245	case XFRMA_ALG_CRYPT:
246	case XFRMA_ALG_COMP:
247	case XFRMA_ENCAP:
248	case XFRMA_TMPL:
249		return xfrm_nla_cpy(dst, src, nla_len(src));
250	case XFRMA_SA:
251		return xfrm_nla_cpy(dst, src, XMSGSIZE(compat_xfrm_usersa_info));
252	case XFRMA_POLICY:
253		return xfrm_nla_cpy(dst, src, XMSGSIZE(compat_xfrm_userpolicy_info));
254	case XFRMA_SEC_CTX:
255		return xfrm_nla_cpy(dst, src, nla_len(src));
256	case XFRMA_LTIME_VAL:
257		return nla_put_64bit(dst, src->nla_type, nla_len(src),
258			nla_data(src), XFRMA_PAD);
259	case XFRMA_REPLAY_VAL:
260	case XFRMA_REPLAY_THRESH:
261	case XFRMA_ETIMER_THRESH:
262	case XFRMA_SRCADDR:
263	case XFRMA_COADDR:
264		return xfrm_nla_cpy(dst, src, nla_len(src));
265	case XFRMA_LASTUSED:
266		return nla_put_64bit(dst, src->nla_type, nla_len(src),
267			nla_data(src), XFRMA_PAD);
268	case XFRMA_POLICY_TYPE:
269	case XFRMA_MIGRATE:
270	case XFRMA_ALG_AEAD:
271	case XFRMA_KMADDRESS:
272	case XFRMA_ALG_AUTH_TRUNC:
273	case XFRMA_MARK:
274	case XFRMA_TFCPAD:
275	case XFRMA_REPLAY_ESN_VAL:
276	case XFRMA_SA_EXTRA_FLAGS:
277	case XFRMA_PROTO:
278	case XFRMA_ADDRESS_FILTER:
279	case XFRMA_OFFLOAD_DEV:
280	case XFRMA_SET_MARK:
281	case XFRMA_SET_MARK_MASK:
282	case XFRMA_IF_ID:
283	case XFRMA_MTIMER_THRESH:
284	case XFRMA_SA_DIR:
285	case XFRMA_NAT_KEEPALIVE_INTERVAL:
286	case XFRMA_SA_PCPU:
287		return xfrm_nla_cpy(dst, src, nla_len(src));
288	default:
289		BUILD_BUG_ON(XFRMA_MAX != XFRMA_SA_PCPU);
290		pr_warn_once("unsupported nla_type %d\n", src->nla_type);
291		return -EOPNOTSUPP;
292	}
293}
294
295/* Take kernel-built (64bit layout) and create 32bit layout for userspace */
296static int xfrm_xlate64(struct sk_buff *dst, const struct nlmsghdr *nlh_src)
297{
298	u16 type = nlh_src->nlmsg_type - XFRM_MSG_BASE;
299	const struct nlattr *nla, *attrs;
300	struct nlmsghdr *nlh_dst;
301	int len, remaining;
302
303	nlh_dst = xfrm_nlmsg_put_compat(dst, nlh_src, type);
304	if (IS_ERR(nlh_dst))
305		return PTR_ERR(nlh_dst);
306
307	attrs = nlmsg_attrdata(nlh_src, xfrm_msg_min[type]);
308	len = nlmsg_attrlen(nlh_src, xfrm_msg_min[type]);
309
310	nla_for_each_attr(nla, attrs, len, remaining) {
311		int err;
312
313		switch (nlh_src->nlmsg_type) {
314		case XFRM_MSG_NEWSPDINFO:
315			err = xfrm_nla_cpy(dst, nla, nla_len(nla));
316			break;
317		default:
318			err = xfrm_xlate64_attr(dst, nla);
319			break;
320		}
321		if (err)
322			return err;
323	}
324
325	nlmsg_end(dst, nlh_dst);
326
327	return 0;
328}
329
330static int xfrm_alloc_compat(struct sk_buff *skb, const struct nlmsghdr *nlh_src)
331{
332	u16 type = nlh_src->nlmsg_type - XFRM_MSG_BASE;
333	struct sk_buff *new = NULL;
334	int err;
335
336	if (type >= ARRAY_SIZE(xfrm_msg_min)) {
337		pr_warn_once("unsupported nlmsg_type %d\n", nlh_src->nlmsg_type);
338		return -EOPNOTSUPP;
339	}
340
341	if (skb_shinfo(skb)->frag_list == NULL) {
342		new = alloc_skb(skb->len + skb_tailroom(skb), GFP_ATOMIC);
343		if (!new)
344			return -ENOMEM;
345		skb_shinfo(skb)->frag_list = new;
346	}
347
348	err = xfrm_xlate64(skb_shinfo(skb)->frag_list, nlh_src);
349	if (err) {
350		if (new) {
351			kfree_skb(new);
352			skb_shinfo(skb)->frag_list = NULL;
353		}
354		return err;
355	}
356
357	return 0;
358}
359
360/* Calculates len of translated 64-bit message. */
361static size_t xfrm_user_rcv_calculate_len64(const struct nlmsghdr *src,
362					    struct nlattr *attrs[XFRMA_MAX + 1],
363					    int maxtype)
364{
365	size_t len = nlmsg_len(src);
366
367	switch (src->nlmsg_type) {
368	case XFRM_MSG_NEWSA:
369	case XFRM_MSG_NEWPOLICY:
370	case XFRM_MSG_ALLOCSPI:
371	case XFRM_MSG_ACQUIRE:
372	case XFRM_MSG_UPDPOLICY:
373	case XFRM_MSG_UPDSA:
374		len += 4;
375		break;
376	case XFRM_MSG_EXPIRE:
377	case XFRM_MSG_POLEXPIRE:
378		len += 8;
379		break;
380	case XFRM_MSG_NEWSPDINFO:
381		/* attirbutes are xfrm_spdattr_type_t, not xfrm_attr_type_t */
382		return len;
383	default:
384		break;
385	}
386
387	/* Unexpected for anything, but XFRM_MSG_NEWSPDINFO, please
388	 * correct both 64=>32-bit and 32=>64-bit translators to copy
389	 * new attributes.
390	 */
391	if (WARN_ON_ONCE(maxtype))
392		return len;
393
394	if (attrs[XFRMA_SA])
395		len += 4;
396	if (attrs[XFRMA_POLICY])
397		len += 4;
398
399	/* XXX: some attrs may need to be realigned
400	 * if !CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
401	 */
402
403	return len;
404}
405
406static int xfrm_attr_cpy32(void *dst, size_t *pos, const struct nlattr *src,
407			   size_t size, int copy_len, int payload)
408{
409	struct nlmsghdr *nlmsg = dst;
410	struct nlattr *nla;
411
412	/* xfrm_user_rcv_msg_compat() relies on fact that 32-bit messages
413	 * have the same len or shorted than 64-bit ones.
414	 * 32-bit translation that is bigger than 64-bit original is unexpected.
415	 */
416	if (WARN_ON_ONCE(copy_len > payload))
417		copy_len = payload;
418
419	if (size - *pos < nla_attr_size(payload))
420		return -ENOBUFS;
421
422	nla = dst + *pos;
423
424	memcpy(nla, src, nla_attr_size(copy_len));
425	nla->nla_len = nla_attr_size(payload);
426	*pos += nla_attr_size(copy_len);
427	nlmsg->nlmsg_len += nla->nla_len;
428
429	memset(dst + *pos, 0, payload - copy_len);
430	*pos += payload - copy_len;
431
432	return 0;
433}
434
435static int xfrm_xlate32_attr(void *dst, const struct nlattr *nla,
436			     size_t *pos, size_t size,
437			     struct netlink_ext_ack *extack)
438{
439	int type = nla_type(nla);
440	u16 pol_len32, pol_len64;
441	int err;
442
443	if (type > XFRMA_MAX) {
444		BUILD_BUG_ON(XFRMA_MAX != XFRMA_SA_PCPU);
445		NL_SET_ERR_MSG(extack, "Bad attribute");
446		return -EOPNOTSUPP;
447	}
448	type = array_index_nospec(type, XFRMA_MAX + 1);
449	if (nla_len(nla) < compat_policy[type].len) {
450		NL_SET_ERR_MSG(extack, "Attribute bad length");
451		return -EOPNOTSUPP;
452	}
453
454	pol_len32 = compat_policy[type].len;
455	pol_len64 = xfrma_policy[type].len;
456
457	/* XFRMA_SA and XFRMA_POLICY - need to know how-to translate */
458	if (pol_len32 != pol_len64) {
459		if (nla_len(nla) != compat_policy[type].len) {
460			NL_SET_ERR_MSG(extack, "Attribute bad length");
461			return -EOPNOTSUPP;
462		}
463		err = xfrm_attr_cpy32(dst, pos, nla, size, pol_len32, pol_len64);
464		if (err)
465			return err;
466	}
467
468	return xfrm_attr_cpy32(dst, pos, nla, size, nla_len(nla), nla_len(nla));
469}
470
471static int xfrm_xlate32(struct nlmsghdr *dst, const struct nlmsghdr *src,
472			struct nlattr *attrs[XFRMA_MAX+1],
473			size_t size, u8 type, int maxtype,
474			struct netlink_ext_ack *extack)
475{
476	size_t pos;
477	int i;
478
479	memcpy(dst, src, NLMSG_HDRLEN);
480	dst->nlmsg_len = NLMSG_HDRLEN + xfrm_msg_min[type];
481	memset(nlmsg_data(dst), 0, xfrm_msg_min[type]);
482
483	switch (src->nlmsg_type) {
484	/* Compat message has the same layout as native */
485	case XFRM_MSG_DELSA:
486	case XFRM_MSG_GETSA:
487	case XFRM_MSG_DELPOLICY:
488	case XFRM_MSG_GETPOLICY:
489	case XFRM_MSG_FLUSHSA:
490	case XFRM_MSG_FLUSHPOLICY:
491	case XFRM_MSG_NEWAE:
492	case XFRM_MSG_GETAE:
493	case XFRM_MSG_REPORT:
494	case XFRM_MSG_MIGRATE:
495	case XFRM_MSG_NEWSADINFO:
496	case XFRM_MSG_GETSADINFO:
497	case XFRM_MSG_NEWSPDINFO:
498	case XFRM_MSG_GETSPDINFO:
499	case XFRM_MSG_MAPPING:
500		memcpy(nlmsg_data(dst), nlmsg_data(src), compat_msg_min[type]);
501		break;
502	/* 4 byte alignment for trailing u64 on native, but not on compat */
503	case XFRM_MSG_NEWSA:
504	case XFRM_MSG_NEWPOLICY:
505	case XFRM_MSG_UPDSA:
506	case XFRM_MSG_UPDPOLICY:
507		memcpy(nlmsg_data(dst), nlmsg_data(src), compat_msg_min[type]);
508		break;
509	case XFRM_MSG_EXPIRE: {
510		const struct compat_xfrm_user_expire *src_ue = nlmsg_data(src);
511		struct xfrm_user_expire *dst_ue = nlmsg_data(dst);
512
513		/* compat_xfrm_user_expire has 4-byte smaller state */
514		memcpy(dst_ue, src_ue, sizeof(src_ue->state));
515		dst_ue->hard = src_ue->hard;
516		break;
517	}
518	case XFRM_MSG_ACQUIRE: {
519		const struct compat_xfrm_user_acquire *src_ua = nlmsg_data(src);
520		struct xfrm_user_acquire *dst_ua = nlmsg_data(dst);
521
522		memcpy(dst_ua, src_ua, offsetof(struct compat_xfrm_user_acquire, aalgos));
523		dst_ua->aalgos = src_ua->aalgos;
524		dst_ua->ealgos = src_ua->ealgos;
525		dst_ua->calgos = src_ua->calgos;
526		dst_ua->seq    = src_ua->seq;
527		break;
528	}
529	case XFRM_MSG_POLEXPIRE: {
530		const struct compat_xfrm_user_polexpire *src_upe = nlmsg_data(src);
531		struct xfrm_user_polexpire *dst_upe = nlmsg_data(dst);
532
533		/* compat_xfrm_user_polexpire has 4-byte smaller state */
534		memcpy(dst_upe, src_upe, sizeof(src_upe->pol));
535		dst_upe->hard = src_upe->hard;
536		break;
537	}
538	case XFRM_MSG_ALLOCSPI: {
539		const struct compat_xfrm_userspi_info *src_usi = nlmsg_data(src);
540		struct xfrm_userspi_info *dst_usi = nlmsg_data(dst);
541
542		/* compat_xfrm_user_polexpire has 4-byte smaller state */
543		memcpy(dst_usi, src_usi, sizeof(src_usi->info));
544		dst_usi->min = src_usi->min;
545		dst_usi->max = src_usi->max;
546		break;
547	}
548	default:
549		NL_SET_ERR_MSG(extack, "Unsupported message type");
550		return -EOPNOTSUPP;
551	}
552	pos = dst->nlmsg_len;
553
554	if (maxtype) {
555		/* attirbutes are xfrm_spdattr_type_t, not xfrm_attr_type_t */
556		WARN_ON_ONCE(src->nlmsg_type != XFRM_MSG_NEWSPDINFO);
557
558		for (i = 1; i <= maxtype; i++) {
559			int err;
560
561			if (!attrs[i])
562				continue;
563
564			/* just copy - no need for translation */
565			err = xfrm_attr_cpy32(dst, &pos, attrs[i], size,
566					nla_len(attrs[i]), nla_len(attrs[i]));
567			if (err)
568				return err;
569		}
570		return 0;
571	}
572
573	for (i = 1; i < XFRMA_MAX + 1; i++) {
574		int err;
575
576		if (i == XFRMA_PAD)
577			continue;
578
579		if (!attrs[i])
580			continue;
581
582		err = xfrm_xlate32_attr(dst, attrs[i], &pos, size, extack);
583		if (err)
584			return err;
585	}
586
587	return 0;
588}
589
590static struct nlmsghdr *xfrm_user_rcv_msg_compat(const struct nlmsghdr *h32,
591			int maxtype, const struct nla_policy *policy,
592			struct netlink_ext_ack *extack)
593{
594	/* netlink_rcv_skb() checks if a message has full (struct nlmsghdr) */
595	u16 type = h32->nlmsg_type - XFRM_MSG_BASE;
596	struct nlattr *attrs[XFRMA_MAX+1];
597	struct nlmsghdr *h64;
598	size_t len;
599	int err;
600
601	BUILD_BUG_ON(ARRAY_SIZE(xfrm_msg_min) != ARRAY_SIZE(compat_msg_min));
602
603	if (type >= ARRAY_SIZE(xfrm_msg_min))
604		return ERR_PTR(-EINVAL);
605
606	/* Don't call parse: the message might have only nlmsg header */
607	if ((h32->nlmsg_type == XFRM_MSG_GETSA ||
608	     h32->nlmsg_type == XFRM_MSG_GETPOLICY) &&
609	    (h32->nlmsg_flags & NLM_F_DUMP))
610		return NULL;
611
612	err = nlmsg_parse_deprecated(h32, compat_msg_min[type], attrs,
613			maxtype ? : XFRMA_MAX, policy ? : compat_policy, extack);
614	if (err < 0)
615		return ERR_PTR(err);
616
617	len = xfrm_user_rcv_calculate_len64(h32, attrs, maxtype);
618	/* The message doesn't need translation */
619	if (len == nlmsg_len(h32))
620		return NULL;
621
622	len += NLMSG_HDRLEN;
623	h64 = kvmalloc(len, GFP_KERNEL);
624	if (!h64)
625		return ERR_PTR(-ENOMEM);
626
627	err = xfrm_xlate32(h64, h32, attrs, len, type, maxtype, extack);
628	if (err < 0) {
629		kvfree(h64);
630		return ERR_PTR(err);
631	}
632
633	return h64;
634}
635
636static int xfrm_user_policy_compat(u8 **pdata32, int optlen)
637{
638	struct compat_xfrm_userpolicy_info *p = (void *)*pdata32;
639	u8 *src_templates, *dst_templates;
640	u8 *data64;
641
642	if (optlen < sizeof(*p))
643		return -EINVAL;
644
645	data64 = kmalloc_track_caller(optlen + 4, GFP_USER | __GFP_NOWARN);
646	if (!data64)
647		return -ENOMEM;
648
649	memcpy(data64, *pdata32, sizeof(*p));
650	memset(data64 + sizeof(*p), 0, 4);
651
652	src_templates = *pdata32 + sizeof(*p);
653	dst_templates = data64 + sizeof(*p) + 4;
654	memcpy(dst_templates, src_templates, optlen - sizeof(*p));
655
656	kfree(*pdata32);
657	*pdata32 = data64;
658	return 0;
659}
660
661static struct xfrm_translator xfrm_translator = {
662	.owner				= THIS_MODULE,
663	.alloc_compat			= xfrm_alloc_compat,
664	.rcv_msg_compat			= xfrm_user_rcv_msg_compat,
665	.xlate_user_policy_sockptr	= xfrm_user_policy_compat,
666};
667
668static int __init xfrm_compat_init(void)
669{
670	return xfrm_register_translator(&xfrm_translator);
671}
672
673static void __exit xfrm_compat_exit(void)
674{
675	xfrm_unregister_translator(&xfrm_translator);
676}
677
678module_init(xfrm_compat_init);
679module_exit(xfrm_compat_exit);
680MODULE_LICENSE("GPL");
681MODULE_AUTHOR("Dmitry Safonov");
682MODULE_DESCRIPTION("XFRM 32-bit compatibility layer");