[linux-2.6-block.git] / net / xfrm / xfrm_compat.c

// SPDX-License-Identifier: GPL-2.0
/*
 * XFRM compat layer
 * Author: Dmitry Safonov <dima@arista.com>
 * Based on code and translator idea by: Florian Westphal <fw@strlen.de>
 */
#include <linux/compat.h>
#include <linux/xfrm.h>
#include <net/xfrm.h>

struct compat_xfrm_lifetime_cfg {
	compat_u64 soft_byte_limit, hard_byte_limit;
	compat_u64 soft_packet_limit, hard_packet_limit;
	compat_u64 soft_add_expires_seconds, hard_add_expires_seconds;
	compat_u64 soft_use_expires_seconds, hard_use_expires_seconds;
}; /* same size on 32bit, but only 4 byte alignment required */

struct compat_xfrm_lifetime_cur {
	compat_u64 bytes, packets, add_time, use_time;
}; /* same size on 32bit, but only 4 byte alignment required */

struct compat_xfrm_userpolicy_info {
	struct xfrm_selector sel;
	struct compat_xfrm_lifetime_cfg lft;
	struct compat_xfrm_lifetime_cur curlft;
	__u32 priority, index;
	u8 dir, action, flags, share;
	/* 4 bytes additional padding on 64bit */
};

struct compat_xfrm_usersa_info {
	struct xfrm_selector sel;
	struct xfrm_id id;
	xfrm_address_t saddr;
	struct compat_xfrm_lifetime_cfg lft;
	struct compat_xfrm_lifetime_cur curlft;
	struct xfrm_stats stats;
	__u32 seq, reqid;
	u16 family;
	u8 mode, replay_window, flags;
	/* 4 bytes additional padding on 64bit */
};

struct compat_xfrm_user_acquire {
	struct xfrm_id id;
	xfrm_address_t saddr;
	struct xfrm_selector sel;
	struct compat_xfrm_userpolicy_info policy;
	/* 4 bytes additional padding on 64bit */
	__u32 aalgos, ealgos, calgos, seq;
};

struct compat_xfrm_userspi_info {
	struct compat_xfrm_usersa_info info;
	/* 4 bytes additional padding on 64bit */
	__u32 min, max;
};

struct compat_xfrm_user_expire {
	struct compat_xfrm_usersa_info state;
	/* 8 bytes additional padding on 64bit */
	u8 hard;
};

struct compat_xfrm_user_polexpire {
	struct compat_xfrm_userpolicy_info pol;
	/* 8 bytes additional padding on 64bit */
	u8 hard;
};

#define XMSGSIZE(type) sizeof(struct type)

static const int compat_msg_min[XFRM_NR_MSGTYPES] = {
	[XFRM_MSG_NEWSA       - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_usersa_info),
	[XFRM_MSG_DELSA       - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_id),
	[XFRM_MSG_GETSA       - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_id),
	[XFRM_MSG_NEWPOLICY   - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_userpolicy_info),
	[XFRM_MSG_DELPOLICY   - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_id),
	[XFRM_MSG_GETPOLICY   - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_id),
	[XFRM_MSG_ALLOCSPI    - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_userspi_info),
	[XFRM_MSG_ACQUIRE     - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_user_acquire),
	[XFRM_MSG_EXPIRE      - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_user_expire),
	[XFRM_MSG_UPDPOLICY   - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_userpolicy_info),
	[XFRM_MSG_UPDSA       - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_usersa_info),
	[XFRM_MSG_POLEXPIRE   - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_user_polexpire),
	[XFRM_MSG_FLUSHSA     - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_flush),
	[XFRM_MSG_FLUSHPOLICY - XFRM_MSG_BASE] = 0,
	[XFRM_MSG_NEWAE       - XFRM_MSG_BASE] = XMSGSIZE(xfrm_aevent_id),
	[XFRM_MSG_GETAE       - XFRM_MSG_BASE] = XMSGSIZE(xfrm_aevent_id),
	[XFRM_MSG_REPORT      - XFRM_MSG_BASE] = XMSGSIZE(xfrm_user_report),
	[XFRM_MSG_MIGRATE     - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_id),
	[XFRM_MSG_NEWSADINFO  - XFRM_MSG_BASE] = sizeof(u32),
	[XFRM_MSG_GETSADINFO  - XFRM_MSG_BASE] = sizeof(u32),
	[XFRM_MSG_NEWSPDINFO  - XFRM_MSG_BASE] = sizeof(u32),
	[XFRM_MSG_GETSPDINFO  - XFRM_MSG_BASE] = sizeof(u32),
	[XFRM_MSG_MAPPING     - XFRM_MSG_BASE] = XMSGSIZE(xfrm_user_mapping)
};

static const struct nla_policy compat_policy[XFRMA_MAX+1] = {
	[XFRMA_SA]		= { .len = XMSGSIZE(compat_xfrm_usersa_info)},
	[XFRMA_POLICY]		= { .len = XMSGSIZE(compat_xfrm_userpolicy_info)},
	[XFRMA_LASTUSED]	= { .type = NLA_U64},
	[XFRMA_ALG_AUTH_TRUNC]	= { .len = sizeof(struct xfrm_algo_auth)},
	[XFRMA_ALG_AEAD]	= { .len = sizeof(struct xfrm_algo_aead) },
	[XFRMA_ALG_AUTH]	= { .len = sizeof(struct xfrm_algo) },
	[XFRMA_ALG_CRYPT]	= { .len = sizeof(struct xfrm_algo) },
	[XFRMA_ALG_COMP]	= { .len = sizeof(struct xfrm_algo) },
	[XFRMA_ENCAP]		= { .len = sizeof(struct xfrm_encap_tmpl) },
	[XFRMA_TMPL]		= { .len = sizeof(struct xfrm_user_tmpl) },
	[XFRMA_SEC_CTX]		= { .len = sizeof(struct xfrm_sec_ctx) },
	[XFRMA_LTIME_VAL]	= { .len = sizeof(struct xfrm_lifetime_cur) },
	[XFRMA_REPLAY_VAL]	= { .len = sizeof(struct xfrm_replay_state) },
	[XFRMA_REPLAY_THRESH]	= { .type = NLA_U32 },
	[XFRMA_ETIMER_THRESH]	= { .type = NLA_U32 },
	[XFRMA_SRCADDR]		= { .len = sizeof(xfrm_address_t) },
	[XFRMA_COADDR]		= { .len = sizeof(xfrm_address_t) },
	[XFRMA_POLICY_TYPE]	= { .len = sizeof(struct xfrm_userpolicy_type)},
	[XFRMA_MIGRATE]		= { .len = sizeof(struct xfrm_user_migrate) },
	[XFRMA_KMADDRESS]	= { .len = sizeof(struct xfrm_user_kmaddress) },
	[XFRMA_MARK]		= { .len = sizeof(struct xfrm_mark) },
	[XFRMA_TFCPAD]		= { .type = NLA_U32 },
	[XFRMA_REPLAY_ESN_VAL]	= { .len = sizeof(struct xfrm_replay_state_esn) },
	[XFRMA_SA_EXTRA_FLAGS]	= { .type = NLA_U32 },
	[XFRMA_PROTO]		= { .type = NLA_U8 },
	[XFRMA_ADDRESS_FILTER]	= { .len = sizeof(struct xfrm_address_filter) },
	[XFRMA_OFFLOAD_DEV]	= { .len = sizeof(struct xfrm_user_offload) },
	[XFRMA_SET_MARK]	= { .type = NLA_U32 },
	[XFRMA_SET_MARK_MASK]	= { .type = NLA_U32 },
	[XFRMA_IF_ID]		= { .type = NLA_U32 },
};

static struct nlmsghdr *xfrm_nlmsg_put_compat(struct sk_buff *skb,
			const struct nlmsghdr *nlh_src, u16 type)
{
	int payload = compat_msg_min[type];
	int src_len = xfrm_msg_min[type];
	struct nlmsghdr *nlh_dst;

	/* Compat messages are shorter or equal to native (+padding) */
	if (WARN_ON_ONCE(src_len < payload))
		return ERR_PTR(-EMSGSIZE);

	nlh_dst = nlmsg_put(skb, nlh_src->nlmsg_pid, nlh_src->nlmsg_seq,
			    nlh_src->nlmsg_type, payload, nlh_src->nlmsg_flags);
	if (!nlh_dst)
		return ERR_PTR(-EMSGSIZE);

	memset(nlmsg_data(nlh_dst), 0, payload);

	switch (nlh_src->nlmsg_type) {
	/* Compat message has the same layout as native */
	case XFRM_MSG_DELSA:
	case XFRM_MSG_DELPOLICY:
	case XFRM_MSG_FLUSHSA:
	case XFRM_MSG_FLUSHPOLICY:
	case XFRM_MSG_NEWAE:
	case XFRM_MSG_REPORT:
	case XFRM_MSG_MIGRATE:
	case XFRM_MSG_NEWSADINFO:
	case XFRM_MSG_NEWSPDINFO:
	case XFRM_MSG_MAPPING:
		WARN_ON_ONCE(src_len != payload);
		memcpy(nlmsg_data(nlh_dst), nlmsg_data(nlh_src), src_len);
		break;
	/* 4 byte alignment for trailing u64 on native, but not on compat */
	case XFRM_MSG_NEWSA:
	case XFRM_MSG_NEWPOLICY:
	case XFRM_MSG_UPDSA:
	case XFRM_MSG_UPDPOLICY:
		WARN_ON_ONCE(src_len != payload + 4);
		memcpy(nlmsg_data(nlh_dst), nlmsg_data(nlh_src), payload);
		break;
	case XFRM_MSG_EXPIRE: {
		const struct xfrm_user_expire *src_ue  = nlmsg_data(nlh_src);
		struct compat_xfrm_user_expire *dst_ue = nlmsg_data(nlh_dst);

		/* compat_xfrm_user_expire has 4-byte smaller state */
		memcpy(dst_ue, src_ue, sizeof(dst_ue->state));
		dst_ue->hard = src_ue->hard;
		break;
	}
	case XFRM_MSG_ACQUIRE: {
		const struct xfrm_user_acquire *src_ua  = nlmsg_data(nlh_src);
		struct compat_xfrm_user_acquire *dst_ua = nlmsg_data(nlh_dst);

		memcpy(dst_ua, src_ua, offsetof(struct compat_xfrm_user_acquire, aalgos));
		dst_ua->aalgos = src_ua->aalgos;
		dst_ua->ealgos = src_ua->ealgos;
		dst_ua->calgos = src_ua->calgos;
		dst_ua->seq    = src_ua->seq;
		break;
	}
	case XFRM_MSG_POLEXPIRE: {
		const struct xfrm_user_polexpire *src_upe  = nlmsg_data(nlh_src);
		struct compat_xfrm_user_polexpire *dst_upe = nlmsg_data(nlh_dst);

		/* compat_xfrm_user_polexpire has 4-byte smaller state */
		memcpy(dst_upe, src_upe, sizeof(dst_upe->pol));
		dst_upe->hard = src_upe->hard;
		break;
	}
	case XFRM_MSG_ALLOCSPI: {
		const struct xfrm_userspi_info *src_usi = nlmsg_data(nlh_src);
		struct compat_xfrm_userspi_info *dst_usi = nlmsg_data(nlh_dst);

		/* compat_xfrm_user_polexpire has 4-byte smaller state */
		memcpy(dst_usi, src_usi, sizeof(src_usi->info));
		dst_usi->min = src_usi->min;
		dst_usi->max = src_usi->max;
		break;
	}
	/* Not being sent by kernel */
	case XFRM_MSG_GETSA:
	case XFRM_MSG_GETPOLICY:
	case XFRM_MSG_GETAE:
	case XFRM_MSG_GETSADINFO:
	case XFRM_MSG_GETSPDINFO:
	default:
		WARN_ONCE(1, "unsupported nlmsg_type %d", nlh_src->nlmsg_type);
		return ERR_PTR(-EOPNOTSUPP);
	}

	return nlh_dst;
}

static int xfrm_nla_cpy(struct sk_buff *dst, const struct nlattr *src, int len)
{
	return nla_put(dst, src->nla_type, len, nla_data(src));
}

static int xfrm_xlate64_attr(struct sk_buff *dst, const struct nlattr *src)
{
	switch (src->nla_type) {
	case XFRMA_PAD:
		/* Ignore */
		return 0;
	case XFRMA_ALG_AUTH:
	case XFRMA_ALG_CRYPT:
	case XFRMA_ALG_COMP:
	case XFRMA_ENCAP:
	case XFRMA_TMPL:
		return xfrm_nla_cpy(dst, src, nla_len(src));
	case XFRMA_SA:
		return xfrm_nla_cpy(dst, src, XMSGSIZE(compat_xfrm_usersa_info));
	case XFRMA_POLICY:
		return xfrm_nla_cpy(dst, src, XMSGSIZE(compat_xfrm_userpolicy_info));
	case XFRMA_SEC_CTX:
		return xfrm_nla_cpy(dst, src, nla_len(src));
	case XFRMA_LTIME_VAL:
		return nla_put_64bit(dst, src->nla_type, nla_len(src),
			nla_data(src), XFRMA_PAD);
	case XFRMA_REPLAY_VAL:
	case XFRMA_REPLAY_THRESH:
	case XFRMA_ETIMER_THRESH:
	case XFRMA_SRCADDR:
	case XFRMA_COADDR:
		return xfrm_nla_cpy(dst, src, nla_len(src));
	case XFRMA_LASTUSED:
		return nla_put_64bit(dst, src->nla_type, nla_len(src),
			nla_data(src), XFRMA_PAD);
	case XFRMA_POLICY_TYPE:
	case XFRMA_MIGRATE:
	case XFRMA_ALG_AEAD:
	case XFRMA_KMADDRESS:
	case XFRMA_ALG_AUTH_TRUNC:
	case XFRMA_MARK:
	case XFRMA_TFCPAD:
	case XFRMA_REPLAY_ESN_VAL:
	case XFRMA_SA_EXTRA_FLAGS:
	case XFRMA_PROTO:
	case XFRMA_ADDRESS_FILTER:
	case XFRMA_OFFLOAD_DEV:
	case XFRMA_SET_MARK:
	case XFRMA_SET_MARK_MASK:
	case XFRMA_IF_ID:
		return xfrm_nla_cpy(dst, src, nla_len(src));
	default:
		BUILD_BUG_ON(XFRMA_MAX != XFRMA_IF_ID);
		WARN_ONCE(1, "unsupported nla_type %d", src->nla_type);
		return -EOPNOTSUPP;
	}
}

/* Take kernel-built (64bit layout) and create 32bit layout for userspace */
static int xfrm_xlate64(struct sk_buff *dst, const struct nlmsghdr *nlh_src)
{
	u16 type = nlh_src->nlmsg_type - XFRM_MSG_BASE;
	const struct nlattr *nla, *attrs;
	struct nlmsghdr *nlh_dst;
	int len, remaining;

	nlh_dst = xfrm_nlmsg_put_compat(dst, nlh_src, type);
	if (IS_ERR(nlh_dst))
		return PTR_ERR(nlh_dst);

	attrs = nlmsg_attrdata(nlh_src, xfrm_msg_min[type]);
	len = nlmsg_attrlen(nlh_src, xfrm_msg_min[type]);

	nla_for_each_attr(nla, attrs, len, remaining) {
		int err = xfrm_xlate64_attr(dst, nla);

		if (err)
			return err;
	}

	nlmsg_end(dst, nlh_dst);

	return 0;
}

static int xfrm_alloc_compat(struct sk_buff *skb, const struct nlmsghdr *nlh_src)
{
	u16 type = nlh_src->nlmsg_type - XFRM_MSG_BASE;
	struct sk_buff *new = NULL;
	int err;

	if (WARN_ON_ONCE(type >= ARRAY_SIZE(xfrm_msg_min)))
		return -EOPNOTSUPP;

	if (skb_shinfo(skb)->frag_list == NULL) {
		new = alloc_skb(skb->len + skb_tailroom(skb), GFP_ATOMIC);
		if (!new)
			return -ENOMEM;
		skb_shinfo(skb)->frag_list = new;
	}

	err = xfrm_xlate64(skb_shinfo(skb)->frag_list, nlh_src);
	if (err) {
		if (new) {
			kfree_skb(new);
			skb_shinfo(skb)->frag_list = NULL;
		}
		return err;
	}

	return 0;
}

/* Calculates len of translated 64-bit message. */
static size_t xfrm_user_rcv_calculate_len64(const struct nlmsghdr *src,
					    struct nlattr *attrs[XFRMA_MAX+1])
{
	size_t len = nlmsg_len(src);

	switch (src->nlmsg_type) {
	case XFRM_MSG_NEWSA:
	case XFRM_MSG_NEWPOLICY:
	case XFRM_MSG_ALLOCSPI:
	case XFRM_MSG_ACQUIRE:
	case XFRM_MSG_UPDPOLICY:
	case XFRM_MSG_UPDSA:
		len += 4;
		break;
	case XFRM_MSG_EXPIRE:
	case XFRM_MSG_POLEXPIRE:
		len += 8;
		break;
	default:
		break;
	}

	if (attrs[XFRMA_SA])
		len += 4;
	if (attrs[XFRMA_POLICY])
		len += 4;

	/* XXX: some attrs may need to be realigned
	 * if !CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
	 */

	return len;
}

static int xfrm_attr_cpy32(void *dst, size_t *pos, const struct nlattr *src,
			   size_t size, int copy_len, int payload)
{
	struct nlmsghdr *nlmsg = dst;
	struct nlattr *nla;

	if (WARN_ON_ONCE(copy_len > payload))
		copy_len = payload;

	if (size - *pos < nla_attr_size(payload))
		return -ENOBUFS;

	nla = dst + *pos;

	memcpy(nla, src, nla_attr_size(copy_len));
	nla->nla_len = nla_attr_size(payload);
	*pos += nla_attr_size(payload);
	nlmsg->nlmsg_len += nla->nla_len;

	memset(dst + *pos, 0, payload - copy_len);
	*pos += payload - copy_len;

	return 0;
}

static int xfrm_xlate32_attr(void *dst, const struct nlattr *nla,
			     size_t *pos, size_t size,
			     struct netlink_ext_ack *extack)
{
	int type = nla_type(nla);
	u16 pol_len32, pol_len64;
	int err;

	if (type > XFRMA_MAX) {
		BUILD_BUG_ON(XFRMA_MAX != XFRMA_IF_ID);
		NL_SET_ERR_MSG(extack, "Bad attribute");
		return -EOPNOTSUPP;
	}
	if (nla_len(nla) < compat_policy[type].len) {
		NL_SET_ERR_MSG(extack, "Attribute bad length");
		return -EOPNOTSUPP;
	}

	pol_len32 = compat_policy[type].len;
	pol_len64 = xfrma_policy[type].len;

	/* XFRMA_SA and XFRMA_POLICY - need to know how-to translate */
	if (pol_len32 != pol_len64) {
		if (nla_len(nla) != compat_policy[type].len) {
			NL_SET_ERR_MSG(extack, "Attribute bad length");
			return -EOPNOTSUPP;
		}
		err = xfrm_attr_cpy32(dst, pos, nla, size, pol_len32, pol_len64);
		if (err)
			return err;
	}

	return xfrm_attr_cpy32(dst, pos, nla, size, nla_len(nla), nla_len(nla));
}

static int xfrm_xlate32(struct nlmsghdr *dst, const struct nlmsghdr *src,
			struct nlattr *attrs[XFRMA_MAX+1],
			size_t size, u8 type, struct netlink_ext_ack *extack)
{
	size_t pos;
	int i;

	memcpy(dst, src, NLMSG_HDRLEN);
	dst->nlmsg_len = NLMSG_HDRLEN + xfrm_msg_min[type];
	memset(nlmsg_data(dst), 0, xfrm_msg_min[type]);

	switch (src->nlmsg_type) {
	/* Compat message has the same layout as native */
	case XFRM_MSG_DELSA:
	case XFRM_MSG_GETSA:
	case XFRM_MSG_DELPOLICY:
	case XFRM_MSG_GETPOLICY:
	case XFRM_MSG_FLUSHSA:
	case XFRM_MSG_FLUSHPOLICY:
	case XFRM_MSG_NEWAE:
	case XFRM_MSG_GETAE:
	case XFRM_MSG_REPORT:
	case XFRM_MSG_MIGRATE:
	case XFRM_MSG_NEWSADINFO:
	case XFRM_MSG_GETSADINFO:
	case XFRM_MSG_NEWSPDINFO:
	case XFRM_MSG_GETSPDINFO:
	case XFRM_MSG_MAPPING:
		memcpy(nlmsg_data(dst), nlmsg_data(src), compat_msg_min[type]);
		break;
	/* 4 byte alignment for trailing u64 on native, but not on compat */
	case XFRM_MSG_NEWSA:
	case XFRM_MSG_NEWPOLICY:
	case XFRM_MSG_UPDSA:
	case XFRM_MSG_UPDPOLICY:
		memcpy(nlmsg_data(dst), nlmsg_data(src), compat_msg_min[type]);
		break;
	case XFRM_MSG_EXPIRE: {
		const struct compat_xfrm_user_expire *src_ue = nlmsg_data(src);
		struct xfrm_user_expire *dst_ue = nlmsg_data(dst);

		/* compat_xfrm_user_expire has 4-byte smaller state */
		memcpy(dst_ue, src_ue, sizeof(src_ue->state));
		dst_ue->hard = src_ue->hard;
		break;
	}
	case XFRM_MSG_ACQUIRE: {
		const struct compat_xfrm_user_acquire *src_ua = nlmsg_data(src);
		struct xfrm_user_acquire *dst_ua = nlmsg_data(dst);

		memcpy(dst_ua, src_ua, offsetof(struct compat_xfrm_user_acquire, aalgos));
		dst_ua->aalgos = src_ua->aalgos;
		dst_ua->ealgos = src_ua->ealgos;
		dst_ua->calgos = src_ua->calgos;
		dst_ua->seq    = src_ua->seq;
		break;
	}
	case XFRM_MSG_POLEXPIRE: {
		const struct compat_xfrm_user_polexpire *src_upe = nlmsg_data(src);
		struct xfrm_user_polexpire *dst_upe = nlmsg_data(dst);

		/* compat_xfrm_user_polexpire has 4-byte smaller state */
		memcpy(dst_upe, src_upe, sizeof(src_upe->pol));
		dst_upe->hard = src_upe->hard;
		break;
	}
	case XFRM_MSG_ALLOCSPI: {
		const struct compat_xfrm_userspi_info *src_usi = nlmsg_data(src);
		struct xfrm_userspi_info *dst_usi = nlmsg_data(dst);

		/* compat_xfrm_user_polexpire has 4-byte smaller state */
		memcpy(dst_usi, src_usi, sizeof(src_usi->info));
		dst_usi->min = src_usi->min;
		dst_usi->max = src_usi->max;
		break;
	}
	default:
		NL_SET_ERR_MSG(extack, "Unsupported message type");
		return -EOPNOTSUPP;
	}
	pos = dst->nlmsg_len;

	for (i = 1; i < XFRMA_MAX + 1; i++) {
		int err;

		if (i == XFRMA_PAD)
			continue;

		if (!attrs[i])
			continue;

		err = xfrm_xlate32_attr(dst, attrs[i], &pos, size, extack);
		if (err)
			return err;
	}

	return 0;
}

static struct nlmsghdr *xfrm_user_rcv_msg_compat(const struct nlmsghdr *h32,
			int maxtype, const struct nla_policy *policy,
			struct netlink_ext_ack *extack)
{
	/* netlink_rcv_skb() checks if a message has full (struct nlmsghdr) */
	u16 type = h32->nlmsg_type - XFRM_MSG_BASE;
	struct nlattr *attrs[XFRMA_MAX+1];
	struct nlmsghdr *h64;
	size_t len;
	int err;

	BUILD_BUG_ON(ARRAY_SIZE(xfrm_msg_min) != ARRAY_SIZE(compat_msg_min));

	if (type >= ARRAY_SIZE(xfrm_msg_min))
		return ERR_PTR(-EINVAL);

	/* Don't call parse: the message might have only nlmsg header */
	if ((h32->nlmsg_type == XFRM_MSG_GETSA ||
	     h32->nlmsg_type == XFRM_MSG_GETPOLICY) &&
	    (h32->nlmsg_flags & NLM_F_DUMP))
		return NULL;

	err = nlmsg_parse_deprecated(h32, compat_msg_min[type], attrs,
			maxtype ? : XFRMA_MAX, policy ? : compat_policy, extack);
	if (err < 0)
		return ERR_PTR(err);

	len = xfrm_user_rcv_calculate_len64(h32, attrs);
	/* The message doesn't need translation */
	if (len == nlmsg_len(h32))
		return NULL;

	len += NLMSG_HDRLEN;
	h64 = kvmalloc(len, GFP_KERNEL | __GFP_ZERO);
	if (!h64)
		return ERR_PTR(-ENOMEM);

	err = xfrm_xlate32(h64, h32, attrs, len, type, extack);
	if (err < 0) {
		kvfree(h64);
		return ERR_PTR(err);
	}

	return h64;
}

static int xfrm_user_policy_compat(u8 **pdata32, int optlen)
{
	struct compat_xfrm_userpolicy_info *p = (void *)*pdata32;
	u8 *src_templates, *dst_templates;
	u8 *data64;

	if (optlen < sizeof(*p))
		return -EINVAL;

	data64 = kmalloc_track_caller(optlen + 4, GFP_USER | __GFP_NOWARN);
	if (!data64)
		return -ENOMEM;

	memcpy(data64, *pdata32, sizeof(*p));
	memset(data64 + sizeof(*p), 0, 4);

	src_templates = *pdata32 + sizeof(*p);
	dst_templates = data64 + sizeof(*p) + 4;
	memcpy(dst_templates, src_templates, optlen - sizeof(*p));

	kfree(*pdata32);
	*pdata32 = data64;
	return 0;
}

static struct xfrm_translator xfrm_translator = {
	.owner				= THIS_MODULE,
	.alloc_compat			= xfrm_alloc_compat,
	.rcv_msg_compat			= xfrm_user_rcv_msg_compat,
	.xlate_user_policy_sockptr	= xfrm_user_policy_compat,
};

static int __init xfrm_compat_init(void)
{
	return xfrm_register_translator(&xfrm_translator);
}

static void __exit xfrm_compat_exit(void)
{
	xfrm_unregister_translator(&xfrm_translator);
}

module_init(xfrm_compat_init);
module_exit(xfrm_compat_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Dmitry Safonov");
MODULE_DESCRIPTION("XFRM 32-bit compatibility layer");
Commit	Line	Data
c9e7c76d DS	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
5461fc0c DS	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
5106f4a8 DS	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
5461fc0c DS	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_ALG_AUTH:
238	case XFRMA_ALG_CRYPT:
239	case XFRMA_ALG_COMP:
240	case XFRMA_ENCAP:
241	case XFRMA_TMPL:
242	return xfrm_nla_cpy(dst, src, nla_len(src));
243	case XFRMA_SA:
244	return xfrm_nla_cpy(dst, src, XMSGSIZE(compat_xfrm_usersa_info));
245	case XFRMA_POLICY:
246	return xfrm_nla_cpy(dst, src, XMSGSIZE(compat_xfrm_userpolicy_info));
247	case XFRMA_SEC_CTX:
248	return xfrm_nla_cpy(dst, src, nla_len(src));
249	case XFRMA_LTIME_VAL:
250	return nla_put_64bit(dst, src->nla_type, nla_len(src),
251	nla_data(src), XFRMA_PAD);
252	case XFRMA_REPLAY_VAL:
253	case XFRMA_REPLAY_THRESH:
254	case XFRMA_ETIMER_THRESH:
255	case XFRMA_SRCADDR:
256	case XFRMA_COADDR:
257	return xfrm_nla_cpy(dst, src, nla_len(src));
258	case XFRMA_LASTUSED:
259	return nla_put_64bit(dst, src->nla_type, nla_len(src),
260	nla_data(src), XFRMA_PAD);
261	case XFRMA_POLICY_TYPE:
262	case XFRMA_MIGRATE:
263	case XFRMA_ALG_AEAD:
264	case XFRMA_KMADDRESS:
265	case XFRMA_ALG_AUTH_TRUNC:
266	case XFRMA_MARK:
267	case XFRMA_TFCPAD:
268	case XFRMA_REPLAY_ESN_VAL:
269	case XFRMA_SA_EXTRA_FLAGS:
270	case XFRMA_PROTO:
271	case XFRMA_ADDRESS_FILTER:
272	case XFRMA_OFFLOAD_DEV:
273	case XFRMA_SET_MARK:
274	case XFRMA_SET_MARK_MASK:
275	case XFRMA_IF_ID:
276	return xfrm_nla_cpy(dst, src, nla_len(src));
277	default:
278	BUILD_BUG_ON(XFRMA_MAX != XFRMA_IF_ID);
279	WARN_ONCE(1, "unsupported nla_type %d", src->nla_type);
280	return -EOPNOTSUPP;
281	}
282	}
283
284	/* Take kernel-built (64bit layout) and create 32bit layout for userspace */
285	static int xfrm_xlate64(struct sk_buff dst, const struct nlmsghdr nlh_src)
286	{
287	u16 type = nlh_src->nlmsg_type - XFRM_MSG_BASE;
288	const struct nlattr nla, attrs;
289	struct nlmsghdr *nlh_dst;
290	int len, remaining;
291
292	nlh_dst = xfrm_nlmsg_put_compat(dst, nlh_src, type);
293	if (IS_ERR(nlh_dst))
294	return PTR_ERR(nlh_dst);
295
296	attrs = nlmsg_attrdata(nlh_src, xfrm_msg_min[type]);
297	len = nlmsg_attrlen(nlh_src, xfrm_msg_min[type]);
298
299	nla_for_each_attr(nla, attrs, len, remaining) {
300	int err = xfrm_xlate64_attr(dst, nla);
301
302	if (err)
303	return err;
304	}
305
306	nlmsg_end(dst, nlh_dst);
307
308	return 0;
309	}
310
311	static int xfrm_alloc_compat(struct sk_buff skb, const struct nlmsghdr nlh_src)
312	{
313	u16 type = nlh_src->nlmsg_type - XFRM_MSG_BASE;
314	struct sk_buff *new = NULL;
315	int err;
316
317	if (WARN_ON_ONCE(type >= ARRAY_SIZE(xfrm_msg_min)))
318	return -EOPNOTSUPP;
319
320	if (skb_shinfo(skb)->frag_list == NULL) {
321	new = alloc_skb(skb->len + skb_tailroom(skb), GFP_ATOMIC);
322	if (!new)
323	return -ENOMEM;
324	skb_shinfo(skb)->frag_list = new;
325	}
326
327	err = xfrm_xlate64(skb_shinfo(skb)->frag_list, nlh_src);
328	if (err) {
329	if (new) {
330	kfree_skb(new);
331	skb_shinfo(skb)->frag_list = NULL;
332	}
333	return err;
334	}
335
336	return 0;
337	}
338
5106f4a8 DS	339	/* Calculates len of translated 64-bit message. */
	340	static size_t xfrm_user_rcv_calculate_len64(const struct nlmsghdr *src,
	341	struct nlattr *attrs[XFRMA_MAX+1])
	342	{
	343	size_t len = nlmsg_len(src);
	344
	345	switch (src->nlmsg_type) {
	346	case XFRM_MSG_NEWSA:
	347	case XFRM_MSG_NEWPOLICY:
	348	case XFRM_MSG_ALLOCSPI:
	349	case XFRM_MSG_ACQUIRE:
	350	case XFRM_MSG_UPDPOLICY:
	351	case XFRM_MSG_UPDSA:
	352	len += 4;
	353	break;
	354	case XFRM_MSG_EXPIRE:
	355	case XFRM_MSG_POLEXPIRE:
	356	len += 8;
	357	break;
	358	default:
	359	break;
	360	}
	361
	362	if (attrs[XFRMA_SA])
	363	len += 4;
	364	if (attrs[XFRMA_POLICY])
	365	len += 4;
	366
	367	/* XXX: some attrs may need to be realigned
	368	* if !CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
	369	*/
	370
	371	return len;
	372	}
	373
	374	static int xfrm_attr_cpy32(void dst, size_t pos, const struct nlattr *src,
	375	size_t size, int copy_len, int payload)
	376	{
	377	struct nlmsghdr *nlmsg = dst;
	378	struct nlattr *nla;
	379
	380	if (WARN_ON_ONCE(copy_len > payload))
	381	copy_len = payload;
	382
	383	if (size - *pos < nla_attr_size(payload))
	384	return -ENOBUFS;
	385
	386	nla = dst + *pos;
	387
	388	memcpy(nla, src, nla_attr_size(copy_len));
	389	nla->nla_len = nla_attr_size(payload);
	390	*pos += nla_attr_size(payload);
	391	nlmsg->nlmsg_len += nla->nla_len;
	392
	393	memset(dst + *pos, 0, payload - copy_len);
	394	*pos += payload - copy_len;
	395
	396	return 0;
	397	}
	398
	399	static int xfrm_xlate32_attr(void dst, const struct nlattr nla,
	400	size_t *pos, size_t size,
	401	struct netlink_ext_ack *extack)
	402	{
403	int type = nla_type(nla);
404	u16 pol_len32, pol_len64;
405	int err;
406
407	if (type > XFRMA_MAX) {
408	BUILD_BUG_ON(XFRMA_MAX != XFRMA_IF_ID);
409	NL_SET_ERR_MSG(extack, "Bad attribute");
410	return -EOPNOTSUPP;
411	}
412	if (nla_len(nla) < compat_policy[type].len) {
413	NL_SET_ERR_MSG(extack, "Attribute bad length");
414	return -EOPNOTSUPP;
415	}
416
417	pol_len32 = compat_policy[type].len;
418	pol_len64 = xfrma_policy[type].len;
419
420	/* XFRMA_SA and XFRMA_POLICY - need to know how-to translate */
421	if (pol_len32 != pol_len64) {
422	if (nla_len(nla) != compat_policy[type].len) {
423	NL_SET_ERR_MSG(extack, "Attribute bad length");
424	return -EOPNOTSUPP;
425	}
426	err = xfrm_attr_cpy32(dst, pos, nla, size, pol_len32, pol_len64);
427	if (err)
428	return err;
429	}
430
431	return xfrm_attr_cpy32(dst, pos, nla, size, nla_len(nla), nla_len(nla));
432	}
433
434	static int xfrm_xlate32(struct nlmsghdr dst, const struct nlmsghdr src,
435	struct nlattr *attrs[XFRMA_MAX+1],
436	size_t size, u8 type, struct netlink_ext_ack *extack)
437	{
438	size_t pos;
439	int i;
440
441	memcpy(dst, src, NLMSG_HDRLEN);
442	dst->nlmsg_len = NLMSG_HDRLEN + xfrm_msg_min[type];
443	memset(nlmsg_data(dst), 0, xfrm_msg_min[type]);
444
445	switch (src->nlmsg_type) {
446	/* Compat message has the same layout as native */
447	case XFRM_MSG_DELSA:
448	case XFRM_MSG_GETSA:
449	case XFRM_MSG_DELPOLICY:
450	case XFRM_MSG_GETPOLICY:
451	case XFRM_MSG_FLUSHSA:
452	case XFRM_MSG_FLUSHPOLICY:
453	case XFRM_MSG_NEWAE:
454	case XFRM_MSG_GETAE:
455	case XFRM_MSG_REPORT:
456	case XFRM_MSG_MIGRATE:
457	case XFRM_MSG_NEWSADINFO:
458	case XFRM_MSG_GETSADINFO:
459	case XFRM_MSG_NEWSPDINFO:
460	case XFRM_MSG_GETSPDINFO:
461	case XFRM_MSG_MAPPING:
462	memcpy(nlmsg_data(dst), nlmsg_data(src), compat_msg_min[type]);
463	break;
464	/* 4 byte alignment for trailing u64 on native, but not on compat */
465	case XFRM_MSG_NEWSA:
466	case XFRM_MSG_NEWPOLICY:
467	case XFRM_MSG_UPDSA:
468	case XFRM_MSG_UPDPOLICY:
469	memcpy(nlmsg_data(dst), nlmsg_data(src), compat_msg_min[type]);
470	break;
471	case XFRM_MSG_EXPIRE: {
472	const struct compat_xfrm_user_expire *src_ue = nlmsg_data(src);
473	struct xfrm_user_expire *dst_ue = nlmsg_data(dst);
474
475	/* compat_xfrm_user_expire has 4-byte smaller state */
476	memcpy(dst_ue, src_ue, sizeof(src_ue->state));
477	dst_ue->hard = src_ue->hard;
478	break;
479	}
480	case XFRM_MSG_ACQUIRE: {
481	const struct compat_xfrm_user_acquire *src_ua = nlmsg_data(src);
482	struct xfrm_user_acquire *dst_ua = nlmsg_data(dst);
483
484	memcpy(dst_ua, src_ua, offsetof(struct compat_xfrm_user_acquire, aalgos));
485	dst_ua->aalgos = src_ua->aalgos;
486	dst_ua->ealgos = src_ua->ealgos;
487	dst_ua->calgos = src_ua->calgos;
488	dst_ua->seq = src_ua->seq;
489	break;
490	}
491	case XFRM_MSG_POLEXPIRE: {
492	const struct compat_xfrm_user_polexpire *src_upe = nlmsg_data(src);
493	struct xfrm_user_polexpire *dst_upe = nlmsg_data(dst);
494
495	/* compat_xfrm_user_polexpire has 4-byte smaller state */
496	memcpy(dst_upe, src_upe, sizeof(src_upe->pol));
497	dst_upe->hard = src_upe->hard;
498	break;
499	}
500	case XFRM_MSG_ALLOCSPI: {
501	const struct compat_xfrm_userspi_info *src_usi = nlmsg_data(src);
502	struct xfrm_userspi_info *dst_usi = nlmsg_data(dst);
503
504	/* compat_xfrm_user_polexpire has 4-byte smaller state */
505	memcpy(dst_usi, src_usi, sizeof(src_usi->info));
506	dst_usi->min = src_usi->min;
507	dst_usi->max = src_usi->max;
508	break;
509	}
510	default:
511	NL_SET_ERR_MSG(extack, "Unsupported message type");
512	return -EOPNOTSUPP;
513	}
514	pos = dst->nlmsg_len;
515
516	for (i = 1; i < XFRMA_MAX + 1; i++) {
517	int err;
518
519	if (i == XFRMA_PAD)
520	continue;
521
522	if (!attrs[i])
523	continue;
524
525	err = xfrm_xlate32_attr(dst, attrs[i], &pos, size, extack);
526	if (err)
527	return err;
528	}
529
530	return 0;
531	}
532
533	static struct nlmsghdr xfrm_user_rcv_msg_compat(const struct nlmsghdr h32,
534	int maxtype, const struct nla_policy *policy,
535	struct netlink_ext_ack *extack)
536	{
537	/* netlink_rcv_skb() checks if a message has full (struct nlmsghdr) */
538	u16 type = h32->nlmsg_type - XFRM_MSG_BASE;
539	struct nlattr *attrs[XFRMA_MAX+1];
540	struct nlmsghdr *h64;
541	size_t len;
542	int err;
543
544	BUILD_BUG_ON(ARRAY_SIZE(xfrm_msg_min) != ARRAY_SIZE(compat_msg_min));
545
546	if (type >= ARRAY_SIZE(xfrm_msg_min))
547	return ERR_PTR(-EINVAL);
548
549	/* Don't call parse: the message might have only nlmsg header */
550	if ((h32->nlmsg_type == XFRM_MSG_GETSA \|\|
551	h32->nlmsg_type == XFRM_MSG_GETPOLICY) &&
552	(h32->nlmsg_flags & NLM_F_DUMP))
553	return NULL;
554
555	err = nlmsg_parse_deprecated(h32, compat_msg_min[type], attrs,
556	maxtype ? : XFRMA_MAX, policy ? : compat_policy, extack);
557	if (err < 0)
558	return ERR_PTR(err);
559
560	len = xfrm_user_rcv_calculate_len64(h32, attrs);
561	/* The message doesn't need translation */
562	if (len == nlmsg_len(h32))
563	return NULL;
564
565	len += NLMSG_HDRLEN;
566	h64 = kvmalloc(len, GFP_KERNEL \| __GFP_ZERO);
567	if (!h64)
568	return ERR_PTR(-ENOMEM);
569
570	err = xfrm_xlate32(h64, h32, attrs, len, type, extack);
571	if (err < 0) {
572	kvfree(h64);
573	return ERR_PTR(err);
574	}
575
576	return h64;
577	}
578
96392ee5 DS	579	static int xfrm_user_policy_compat(u8 **pdata32, int optlen)
	580	{
	581	struct compat_xfrm_userpolicy_info p = (void )*pdata32;
	582	u8 src_templates, dst_templates;
	583	u8 *data64;
	584
	585	if (optlen < sizeof(*p))
	586	return -EINVAL;
	587
	588	data64 = kmalloc_track_caller(optlen + 4, GFP_USER \| __GFP_NOWARN);
	589	if (!data64)
	590	return -ENOMEM;
	591
	592	memcpy(data64, pdata32, sizeof(p));
	593	memset(data64 + sizeof(*p), 0, 4);
	594
	595	src_templates = pdata32 + sizeof(p);
	596	dst_templates = data64 + sizeof(*p) + 4;
	597	memcpy(dst_templates, src_templates, optlen - sizeof(*p));
	598
	599	kfree(*pdata32);
	600	*pdata32 = data64;
	601	return 0;
	602	}
	603
c9e7c76d DS	604	static struct xfrm_translator xfrm_translator = {
c9e7c76d DS	605	.owner = THIS_MODULE,
5461fc0c	606	.alloc_compat = xfrm_alloc_compat,
5106f4a8	607	.rcv_msg_compat = xfrm_user_rcv_msg_compat,
96392ee5	608	.xlate_user_policy_sockptr = xfrm_user_policy_compat,
c9e7c76d DS	609	};
	610
	611	static int __init xfrm_compat_init(void)
	612	{
	613	return xfrm_register_translator(&xfrm_translator);
	614	}
	615
	616	static void __exit xfrm_compat_exit(void)
	617	{
	618	xfrm_unregister_translator(&xfrm_translator);
	619	}
	620
	621	module_init(xfrm_compat_init);
	622	module_exit(xfrm_compat_exit);
	623	MODULE_LICENSE("GPL");
	624	MODULE_AUTHOR("Dmitry Safonov");
	625	MODULE_DESCRIPTION("XFRM 32-bit compatibility layer");