Commit 5106f4a8 authored by Dmitry Safonov's avatar Dmitry Safonov Committed by Steffen Klassert
Browse files

xfrm/compat: Add 32=>64-bit messages translator 



Provide the user-to-kernel translator under XFRM_USER_COMPAT, that
creates for 32-bit xfrm-user message a 64-bit translation.
The translation is afterwards reused by xfrm_user code just as if
userspace had sent 64-bit message.

Signed-off-by: default avatarDmitry Safonov <dima@arista.com>
Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
parent e11eb32d

include/net/xfrm.h

+6 −0
Original line number Diff line number Diff line
@@ -2001,11 +2001,17 @@ static inline int xfrm_tunnel_check(struct sk_buff *skb, struct xfrm_state *x, 
}



extern const int xfrm_msg_min[XFRM_NR_MSGTYPES];

extern const struct nla_policy xfrma_policy[XFRMA_MAX+1];



struct xfrm_translator {

	/* Allocate frag_list and put compat translation there */

	int (*alloc_compat)(struct sk_buff *skb, const struct nlmsghdr *src);



	/* Allocate nlmsg with 64-bit translaton of received 32-bit message */

	struct nlmsghdr *(*rcv_msg_compat)(const struct nlmsghdr *nlh,

			int maxtype, const struct nla_policy *policy,

			struct netlink_ext_ack *extack);



	struct module *owner;

};

net/xfrm/Kconfig

+2 −1
Original line number Diff line number Diff line
@@ -30,7 +30,8 @@ config XFRM_USER 


config XFRM_USER_COMPAT

	tristate "Compatible ABI support"

	depends on XFRM_USER && COMPAT_FOR_U64_ALIGNMENT

	depends on XFRM_USER && COMPAT_FOR_U64_ALIGNMENT && \

		HAVE_EFFICIENT_UNALIGNED_ACCESS

	select WANT_COMPAT_NETLINK_MESSAGES

	help

	  Transformation(XFRM) user configuration interface like IPsec

net/xfrm/xfrm_compat.c

+274 −0
Original line number Diff line number Diff line
@@ -96,6 +96,39 @@ static const int compat_msg_min[XFRM_NR_MSGTYPES] = { 
	[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)

{
@@ -303,9 +336,250 @@ static int xfrm_alloc_compat(struct sk_buff *skb, const struct nlmsghdr *nlh_src 
	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 struct xfrm_translator xfrm_translator = {

	.owner				= THIS_MODULE,

	.alloc_compat			= xfrm_alloc_compat,

	.rcv_msg_compat			= xfrm_user_rcv_msg_compat,

};



static int __init xfrm_compat_init(void)

net/xfrm/xfrm_user.c

+39 −18
Original line number Diff line number Diff line
@@ -1019,7 +1019,6 @@ static int xfrm_dump_sa_done(struct netlink_callback *cb) 
	return 0;

}



static const struct nla_policy xfrma_policy[XFRMA_MAX+1];

static int xfrm_dump_sa(struct sk_buff *skb, struct netlink_callback *cb)

{

	struct net *net = sock_net(skb->sk);
@@ -2610,7 +2609,7 @@ EXPORT_SYMBOL_GPL(xfrm_msg_min); 


#undef XMSGSIZE



static const struct nla_policy xfrma_policy[XFRMA_MAX+1] = {

const struct nla_policy xfrma_policy[XFRMA_MAX+1] = {

	[XFRMA_SA]		= { .len = sizeof(struct xfrm_usersa_info)},

	[XFRMA_POLICY]		= { .len = sizeof(struct xfrm_userpolicy_info)},

	[XFRMA_LASTUSED]	= { .type = NLA_U64},
@@ -2642,6 +2641,7 @@ static const struct nla_policy xfrma_policy[XFRMA_MAX+1] = { 
	[XFRMA_SET_MARK_MASK]	= { .type = NLA_U32 },

	[XFRMA_IF_ID]		= { .type = NLA_U32 },

};

EXPORT_SYMBOL_GPL(xfrma_policy);



static const struct nla_policy xfrma_spd_policy[XFRMA_SPD_MAX+1] = {

	[XFRMA_SPD_IPV4_HTHRESH] = { .len = sizeof(struct xfrmu_spdhthresh) },
@@ -2691,11 +2691,9 @@ static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, 
	struct net *net = sock_net(skb->sk);

	struct nlattr *attrs[XFRMA_MAX+1];

	const struct xfrm_link *link;

	struct nlmsghdr *nlh64 = NULL;

	int type, err;



	if (in_compat_syscall())

		return -EOPNOTSUPP;



	type = nlh->nlmsg_type;

	if (type > XFRM_MSG_MAX)

		return -EINVAL;
@@ -2707,32 +2705,55 @@ static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, 
	if (!netlink_net_capable(skb, CAP_NET_ADMIN))

		return -EPERM;



	if (in_compat_syscall()) {

		struct xfrm_translator *xtr = xfrm_get_translator();



		if (!xtr)

			return -EOPNOTSUPP;



		nlh64 = xtr->rcv_msg_compat(nlh, link->nla_max,

					    link->nla_pol, extack);

		xfrm_put_translator(xtr);

		if (IS_ERR(nlh64))

			return PTR_ERR(nlh64);

		if (nlh64)

			nlh = nlh64;

	}



	if ((type == (XFRM_MSG_GETSA - XFRM_MSG_BASE) ||

	     type == (XFRM_MSG_GETPOLICY - XFRM_MSG_BASE)) &&

	    (nlh->nlmsg_flags & NLM_F_DUMP)) {

		if (link->dump == NULL)

			return -EINVAL;



		{

		struct netlink_dump_control c = {

			.start = link->start,

			.dump = link->dump,

			.done = link->done,

		};

			return netlink_dump_start(net->xfrm.nlsk, skb, nlh, &c);



		if (link->dump == NULL) {

			err = -EINVAL;

			goto err;

		}



		err = netlink_dump_start(net->xfrm.nlsk, skb, nlh, &c);

		goto err;

	}



	err = nlmsg_parse_deprecated(nlh, xfrm_msg_min[type], attrs,

				     link->nla_max ? : XFRMA_MAX,

				     link->nla_pol ? : xfrma_policy, extack);

	if (err < 0)

		return err;

		goto err;



	if (link->doit == NULL)

		return -EINVAL;

	if (link->doit == NULL) {

		err = -EINVAL;

		goto err;

	}



	return link->doit(skb, nlh, attrs);

	err = link->doit(skb, nlh, attrs);



err:

	kvfree(nlh64);

	return err;

}



static void xfrm_netlink_rcv(struct sk_buff *skb)

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