xfrm_user.c

Linux Kernel 2.6.9 for OMAP1710

/* xfrm_user.c: User interface to configure xfrm engine.
 *
 * Copyright (C) 2002 David S. Miller ([e-mail])
 *
 * Changes:
 *	Mitsuru KANDA @USAGI
 * 	Kazunori MIYAZAWA @USAGI
 * 	Kunihiro Ishiguro <[e-mail]>
 * 		IPv6 support
 * 	
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/socket.h>
#include <linux/string.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <linux/pfkeyv2.h>
#include <linux/ipsec.h>
#include <linux/init.h>
#include <linux/security.h>
#include <net/sock.h>
#include <net/xfrm.h>
#include <asm/uaccess.h>

static struct sock *xfrm_nl;

static int verify_one_alg(struct rtattr **xfrma, enum xfrm_attr_type_t type)
{
	struct rtattr *rt = xfrma[type - 1];
	struct xfrm_algo *algp;

	if (!rt)
		return 0;

	if ((rt->rta_len - sizeof(*rt)) < sizeof(*algp))
		return -EINVAL;

	algp = RTA_DATA(rt);
	switch (type) {
	case XFRMA_ALG_AUTH:
		if (!algp->alg_key_len &&
		    strcmp(algp->alg_name, "digest_null") != 0)
			return -EINVAL;
		break;

	case XFRMA_ALG_CRYPT:
		if (!algp->alg_key_len &&
		    strcmp(algp->alg_name, "cipher_null") != 0)
			return -EINVAL;
		break;

	case XFRMA_ALG_COMP:
		/* Zero length keys are legal.  */
		break;

	default:
		return -EINVAL;
	};

	algp->alg_name[CRYPTO_MAX_ALG_NAME - 1] = '\0';
	return 0;
}

static int verify_encap_tmpl(struct rtattr **xfrma)
{
	struct rtattr *rt = xfrma[XFRMA_ENCAP - 1];
	struct xfrm_encap_tmpl *encap;

	if (!rt)
		return 0;

	if ((rt->rta_len - sizeof(*rt)) < sizeof(*encap))
		return -EINVAL;

	return 0;
}

static int verify_newsa_info(struct xfrm_usersa_info *p,
			     struct rtattr **xfrma)
{
	int err;

	err = -EINVAL;
	switch (p->family) {
	case AF_INET:
		break;

	case AF_INET6:
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
		break;
#else
		err = -EAFNOSUPPORT;
		goto out;
#endif

	default:
		goto out;
	};

	err = -EINVAL;
	switch (p->id.proto) {
	case IPPROTO_AH:
		if (!xfrma[XFRMA_ALG_AUTH-1]	||
		    xfrma[XFRMA_ALG_CRYPT-1]	||
		    xfrma[XFRMA_ALG_COMP-1])
			goto out;
		break;

	case IPPROTO_ESP:
		if ((!xfrma[XFRMA_ALG_AUTH-1] &&
		     !xfrma[XFRMA_ALG_CRYPT-1])	||
		    xfrma[XFRMA_ALG_COMP-1])
			goto out;
		break;

	case IPPROTO_COMP:
		if (!xfrma[XFRMA_ALG_COMP-1]	||
		    xfrma[XFRMA_ALG_AUTH-1]	||
		    xfrma[XFRMA_ALG_CRYPT-1])
			goto out;
		break;

	default:
		goto out;
	};

	if ((err = verify_one_alg(xfrma, XFRMA_ALG_AUTH)))
		goto out;
	if ((err = verify_one_alg(xfrma, XFRMA_ALG_CRYPT)))
		goto out;
	if ((err = verify_one_alg(xfrma, XFRMA_ALG_COMP)))
		goto out;
	if ((err = verify_encap_tmpl(xfrma)))
		goto out;

	err = -EINVAL;
	switch (p->mode) {
	case 0:
	case 1:
		break;

	default:
		goto out;
	};

	err = 0;

out:
	return err;
}

static int attach_one_algo(struct xfrm_algo **algpp, u8 *props,
			   struct xfrm_algo_desc *(*get_byname)(char *),
			   struct rtattr *u_arg)
{
	struct rtattr *rta = u_arg;
	struct xfrm_algo *p, *ualg;
	struct xfrm_algo_desc *algo;

	if (!rta)
		return 0;

	ualg = RTA_DATA(rta);

	algo = get_byname(ualg->alg_name);
	if (!algo)
		return -ENOSYS;
	*props = algo->desc.sadb_alg_id;

	p = kmalloc(sizeof(*ualg) + ualg->alg_key_len, GFP_KERNEL);
	if (!p)
		return -ENOMEM;

	memcpy(p, ualg, sizeof(*ualg) + ualg->alg_key_len);
	*algpp = p;
	return 0;
}

static int attach_encap_tmpl(struct xfrm_encap_tmpl **encapp, struct rtattr *u_arg)
{
	struct rtattr *rta = u_arg;
	struct xfrm_encap_tmpl *p, *uencap;

	if (!rta)
		return 0;

	uencap = RTA_DATA(rta);
	p = kmalloc(sizeof(*p), GFP_KERNEL);
	if (!p)
		return -ENOMEM;

	memcpy(p, uencap, sizeof(*p));
	*encapp = p;
	return 0;
}

static void copy_from_user_state(struct xfrm_state *x, struct xfrm_usersa_info *p)
{
	memcpy(&x->id, &p->id, sizeof(x->id));
	memcpy(&x->sel, &p->sel, sizeof(x->sel));
	memcpy(&x->lft, &p->lft, sizeof(x->lft));
	x->props.mode = p->mode;
	x->props.replay_window = p->replay_window;
	x->props.reqid = p->reqid;
	x->props.family = p->family;
	x->props.saddr = p->saddr;
	x->props.flags = p->flags;
}

static struct xfrm_state *xfrm_state_construct(struct xfrm_usersa_info *p,
					       struct rtattr **xfrma,
					       int *errp)
{
	struct xfrm_state *x = xfrm_state_alloc();
	int err = -ENOMEM;

	if (!x)
		goto error_no_put;

	copy_from_user_state(x, p);

	if ((err = attach_one_algo(&x->aalg, &x->props.aalgo,
				   xfrm_aalg_get_byname,
				   xfrma[XFRMA_ALG_AUTH-1])))
		goto error;
	if ((err = attach_one_algo(&x->ealg, &x->props.ealgo,
				   xfrm_ealg_get_byname,
				   xfrma[XFRMA_ALG_CRYPT-1])))
		goto error;
	if ((err = attach_one_algo(&x->calg, &x->props.calgo,
				   xfrm_calg_get_byname,
				   xfrma[XFRMA_ALG_COMP-1])))
		goto error;
	if ((err = attach_encap_tmpl(&x->encap, xfrma[XFRMA_ENCAP-1])))
		goto error;

	err = -ENOENT;
	x->type = xfrm_get_type(x->id.proto, x->props.family);
	if (x->type == NULL)
		goto error;

	err = x->type->init_state(x, NULL);
	if (err)
		goto error;

	x->curlft.add_time = (unsigned long) xtime.tv_sec;
	x->km.state = XFRM_STATE_VALID;
	x->km.seq = p->seq;

	return x;

error:
	x->km.state = XFRM_STATE_DEAD;
	xfrm_state_put(x);
error_no_put:
	*errp = err;
	return NULL;
}

static int xfrm_add_sa(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
{
	struct xfrm_usersa_info *p = NLMSG_DATA(nlh);
	struct xfrm_state *x;
	int err;

	err = verify_newsa_info(p, (struct rtattr **) xfrma);
	if (err)
		return err;

	xfrm_probe_algs();

	x = xfrm_state_construct(p, (struct rtattr **) xfrma, &err);
	if (!x)
		return err;

	if (nlh->nlmsg_type == XFRM_MSG_NEWSA)
		err = xfrm_state_add(x);
	else
		err = xfrm_state_update(x);

	if (err < 0) {
		x->km.state = XFRM_STATE_DEAD;
		xfrm_state_put(x);
	}

	return err;
}

static int xfrm_del_sa(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
{
	struct xfrm_state *x;
	struct xfrm_usersa_id *p = NLMSG_DATA(nlh);

	x = xfrm_state_lookup(&p->daddr, p->spi, p->proto, p->family);
	if (x == NULL)
		return -ESRCH;

	if (xfrm_state_kern(x)) {
		xfrm_state_put(x);
		return -EPERM;
	}

	xfrm_state_delete(x);
	xfrm_state_put(x);

	return 0;
}

static void copy_to_user_state(struct xfrm_state *x, struct xfrm_usersa_info *p)
{
	memcpy(&p->id, &x->id, sizeof(p->id));
	memcpy(&p->sel, &x->sel, sizeof(p->sel));
	memcpy(&p->lft, &x->lft, sizeof(p->lft));
	memcpy(&p->curlft, &x->curlft, sizeof(p->curlft));
	memcpy(&p->stats, &x->stats, sizeof(p->stats));
	p->saddr = x->props.saddr;
	p->mode = x->props.mode;
	p->replay_window = x->props.replay_window;
	p->reqid = x->props.reqid;
	p->family = x->props.family;
	p->flags = x->props.flags;
	p->seq = x->km.seq;
}

struct xfrm_dump_info {
	struct sk_buff *in_skb;
	struct sk_buff *out_skb;
	u32 nlmsg_seq;
	int start_idx;
	int this_idx;
};

static int dump_one_state(struct xfrm_state *x, int count, void *ptr)
{
	struct xfrm_dump_info *sp = ptr;
	struct sk_buff *in_skb = sp->in_skb;
	struct sk_buff *skb = sp->out_skb;
	struct xfrm_usersa_info *p;
	struct nlmsghdr *nlh;
	unsigned char *b = skb->tail;

	if (sp->this_idx < sp->start_idx)
		goto out;

	nlh = NLMSG_PUT(skb, NETLINK_CB(in_skb).pid,
			sp->nlmsg_seq,
			XFRM_MSG_NEWSA, sizeof(*p));
	nlh->nlmsg_flags = 0;

	p = NLMSG_DATA(nlh);
	copy_to_user_state(x, p);

	if (x->aalg)
		RTA_PUT(skb, XFRMA_ALG_AUTH,
			sizeof(*(x->aalg))+(x->aalg->alg_key_len+7)/8, x->aalg);
	if (x->ealg)
		RTA_PUT(skb, XFRMA_ALG_CRYPT,
			sizeof(*(x->ealg))+(x->ealg->alg_key_len+7)/8, x->ealg);
	if (x->calg)
		RTA_PUT(skb, XFRMA_ALG_COMP, sizeof(*(x->calg)), x->calg);

	if (x->encap)
		RTA_PUT(skb, XFRMA_ENCAP, sizeof(*x->encap), x->encap);

	nlh->nlmsg_len = skb->tail - b;
out:
	sp->this_idx++;
	return 0;

nlmsg_failure:
rtattr_failure:
	skb_trim(skb, b - skb->data);
	return -1;
}

static int xfrm_dump_sa(struct sk_buff *skb, struct netlink_callback *cb)
{
	struct xfrm_dump_info info;

	info.in_skb = cb->skb;
	info.out_skb = skb;
	info.nlmsg_seq = cb->nlh->nlmsg_seq;
	info.this_idx = 0;
	info.start_idx = cb->args[0];
	(void) xfrm_state_walk(IPSEC_PROTO_ANY, dump_one_state, &info);
	cb->args[0] = info.this_idx;

	return skb->len;
}

static struct sk_buff *xfrm_state_netlink(struct sk_buff *in_skb,
					  struct xfrm_state *x, u32 seq)
{
	struct xfrm_dump_info info;
	struct sk_buff *skb;

	skb = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC);
	if (!skb)
		return ERR_PTR(-ENOMEM);

	NETLINK_CB(skb).dst_pid = NETLINK_CB(in_skb).pid;
	info.in_skb = in_skb;
	info.out_skb = skb;
	info.nlmsg_seq = seq;
	info.this_idx = info.start_idx = 0;

	if (dump_one_state(x, 0, &info)) {
		kfree_skb(skb);
		return NULL;
	}

	return skb;
}

static int xfrm_get_sa(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
{
	struct xfrm_usersa_id *p = NLMSG_DATA(nlh);
	struct xfrm_state *x;
	struct sk_buff *resp_skb;
	int err;

	x = xfrm_state_lookup(&p->daddr, p->spi, p->proto, p->family);
	err = -ESRCH;
	if (x == NULL)
		goto out_noput;

	resp_skb = xfrm_state_netlink(skb, x, nlh->nlmsg_seq);
	if (IS_ERR(resp_skb)) {
		err = PTR_ERR(resp_skb);
	} else {
		err = netlink_unicast(xfrm_nl, resp_skb,
				      NETLINK_CB(skb).pid, MSG_DONTWAIT);
	}
	xfrm_state_put(x);
out_noput:
	return err;
}

static int verify_userspi_info(struct xfrm_userspi_info *p)
{
	switch (p->info.id.proto) {
	case IPPROTO_AH:
	case IPPROTO_ESP:
		break;

	case IPPROTO_COMP:
		/* IPCOMP spi is 16-bits. */
		if (p->max >= 0x10000)
			return -EINVAL;
		break;

	default:
		return -EINVAL;
	};

	if (p->min > p->max)
		return -EINVAL;

	return 0;
}

static int xfrm_alloc_userspi(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
{
	struct xfrm_state *x;
	struct xfrm_userspi_info *p;
	struct sk_buff *resp_skb;
	xfrm_address_t *daddr;
	int family;
	int err;

	p = NLMSG_DATA(nlh);
	err = verify_userspi_info(p);
	if (err)
		goto out_noput;

	family = p->info.family;
	daddr = &p->info.id.daddr;

	x = NULL;
	if (p->info.seq) {
		x = xfrm_find_acq_byseq(p->info.seq);
		if (x && xfrm_addr_cmp(&x->id.daddr, daddr, family)) {
			xfrm_state_put(x);
			x = NULL;
		}
	}

	if (!x)
		x = xfrm_find_acq(p->info.mode, p->info.reqid,
				  p->info.id.proto, daddr,
				  &p->info.saddr, 1,
				  family);
	err = -ENOENT;
	if (x == NULL)
		goto out_noput;

	resp_skb = ERR_PTR(-ENOENT);

	spin_lock_bh(&x->lock);
	if (x->km.state != XFRM_STATE_DEAD) {
		xfrm_alloc_spi(x, htonl(p->min), htonl(p->max));
		if (x->id.spi)
			resp_skb = xfrm_state_netlink(skb, x, nlh->nlmsg_seq);
	}
	spin_unlock_bh(&x->lock);

	if (IS_ERR(resp_skb)) {
		err = PTR_ERR(resp_skb);
		goto out;
	}

	err = netlink_unicast(xfrm_nl, resp_skb,
			      NETLINK_CB(skb).pid, MSG_DONTWAIT);

out:
	xfrm_state_put(x);
out_noput:
	return err;
}

static int verify_policy_dir(__u8 dir)
{
	switch (dir) {
	case XFRM_POLICY_IN:
	case XFRM_POLICY_OUT:
	case XFRM_POLICY_FWD:
		break;

	default:
		return -EINVAL;
	};

	return 0;
}

static int verify_newpolicy_info(struct xfrm_userpolicy_info *p)
{
	switch (p->share) {
	case XFRM_SHARE_ANY:
	case XFRM_SHARE_SESSION:
	case XFRM_SHARE_USER:
	case XFRM_SHARE_UNIQUE:
		break;

	default:
		return -EINVAL;
	};

	switch (p->action) {
	case XFRM_POLICY_ALLOW:
	case XFRM_POLICY_BLOCK:
		break;

	default:
		return -EINVAL;
	};

	switch (p->sel.family) {
	case AF_INET:
		break;

	case AF_INET6:
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
		break;
#else
		return  -EAFNOSUPPORT;
#endif

	default:
		return -EINVAL;
	};

	return verify_policy_dir(p->dir);
}

static void copy_templates(struct xfrm_policy *xp, struct xfrm_user_tmpl *ut,
			   int nr)
{
	int i;

	xp->xfrm_nr = nr;
	for (i = 0; i < nr; i++, ut++) {
		struct xfrm_tmpl *t = &xp->xfrm_vec[i];

		memcpy(&t->id, &ut->id, sizeof(struct xfrm_id));
		memcpy(&t->saddr, &ut->saddr,
		       sizeof(xfrm_address_t));
		t->reqid = ut->reqid;
		t->mode = ut->mode;
		t->share = ut->share;
		t->optional = ut->optional;
		t->aalgos = ut->aalgos;
		t->ealgos = ut->ealgos;
		t->calgos = ut->calgos;
	}
}

static int copy_from_user_tmpl(struct xfrm_policy *pol, struct rtattr **xfrma)
{
	struct rtattr *rt = xfrma[XFRMA_TMPL-1];
	struct xfrm_user_tmpl *utmpl;
	int nr;

	if (!rt) {
		pol->xfrm_nr = 0;
	} else {
		nr = (rt->rta_len - sizeof(*rt)) / sizeof(*utmpl);

		if (nr > XFRM_MAX_DEPTH)
			return -EINVAL;

		copy_templates(pol, RTA_DATA(rt), nr);
	}
	return 0;
}

static void copy_from_user_policy(struct xfrm_policy *xp, struct xfrm_userpolicy_info *p)
{
	xp->priority = p->priority;
	xp->index = p->index;