xfrm_user.c

linux 内核源代码

	       + nla_total_size(sizeof(struct xfrmu_spdhinfo));
}

static int build_spdinfo(struct sk_buff *skb, u32 pid, u32 seq, u32 flags)
{
	struct xfrmk_spdinfo si;
	struct xfrmu_spdinfo spc;
	struct xfrmu_spdhinfo sph;
	struct nlmsghdr *nlh;
	u32 *f;

	nlh = nlmsg_put(skb, pid, seq, XFRM_MSG_NEWSPDINFO, sizeof(u32), 0);
	if (nlh == NULL) /* shouldnt really happen ... */
		return -EMSGSIZE;

	f = nlmsg_data(nlh);
	*f = flags;
	xfrm_spd_getinfo(&si);
	spc.incnt = si.incnt;
	spc.outcnt = si.outcnt;
	spc.fwdcnt = si.fwdcnt;
	spc.inscnt = si.inscnt;
	spc.outscnt = si.outscnt;
	spc.fwdscnt = si.fwdscnt;
	sph.spdhcnt = si.spdhcnt;
	sph.spdhmcnt = si.spdhmcnt;

	NLA_PUT(skb, XFRMA_SPD_INFO, sizeof(spc), &spc);
	NLA_PUT(skb, XFRMA_SPD_HINFO, sizeof(sph), &sph);

	return nlmsg_end(skb, nlh);

nla_put_failure:
	nlmsg_cancel(skb, nlh);
	return -EMSGSIZE;
}

static int xfrm_get_spdinfo(struct sk_buff *skb, struct nlmsghdr *nlh,
		struct nlattr **attrs)
{
	struct sk_buff *r_skb;
	u32 *flags = nlmsg_data(nlh);
	u32 spid = NETLINK_CB(skb).pid;
	u32 seq = nlh->nlmsg_seq;

	r_skb = nlmsg_new(xfrm_spdinfo_msgsize(), GFP_ATOMIC);
	if (r_skb == NULL)
		return -ENOMEM;

	if (build_spdinfo(r_skb, spid, seq, *flags) < 0)
		BUG();

	return nlmsg_unicast(xfrm_nl, r_skb, spid);
}

static inline size_t xfrm_sadinfo_msgsize(void)
{
	return NLMSG_ALIGN(4)
	       + nla_total_size(sizeof(struct xfrmu_sadhinfo))
	       + nla_total_size(4); /* XFRMA_SAD_CNT */
}

static int build_sadinfo(struct sk_buff *skb, u32 pid, u32 seq, u32 flags)
{
	struct xfrmk_sadinfo si;
	struct xfrmu_sadhinfo sh;
	struct nlmsghdr *nlh;
	u32 *f;

	nlh = nlmsg_put(skb, pid, seq, XFRM_MSG_NEWSADINFO, sizeof(u32), 0);
	if (nlh == NULL) /* shouldnt really happen ... */
		return -EMSGSIZE;

	f = nlmsg_data(nlh);
	*f = flags;
	xfrm_sad_getinfo(&si);

	sh.sadhmcnt = si.sadhmcnt;
	sh.sadhcnt = si.sadhcnt;

	NLA_PUT_U32(skb, XFRMA_SAD_CNT, si.sadcnt);
	NLA_PUT(skb, XFRMA_SAD_HINFO, sizeof(sh), &sh);

	return nlmsg_end(skb, nlh);

nla_put_failure:
	nlmsg_cancel(skb, nlh);
	return -EMSGSIZE;
}

static int xfrm_get_sadinfo(struct sk_buff *skb, struct nlmsghdr *nlh,
		struct nlattr **attrs)
{
	struct sk_buff *r_skb;
	u32 *flags = nlmsg_data(nlh);
	u32 spid = NETLINK_CB(skb).pid;
	u32 seq = nlh->nlmsg_seq;

	r_skb = nlmsg_new(xfrm_sadinfo_msgsize(), GFP_ATOMIC);
	if (r_skb == NULL)
		return -ENOMEM;

	if (build_sadinfo(r_skb, spid, seq, *flags) < 0)
		BUG();

	return nlmsg_unicast(xfrm_nl, r_skb, spid);
}

static int xfrm_get_sa(struct sk_buff *skb, struct nlmsghdr *nlh,
		struct nlattr **attrs)
{
	struct xfrm_usersa_id *p = nlmsg_data(nlh);
	struct xfrm_state *x;
	struct sk_buff *resp_skb;
	int err = -ESRCH;

	x = xfrm_user_state_lookup(p, attrs, &err);
	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 = nlmsg_unicast(xfrm_nl, resp_skb, NETLINK_CB(skb).pid);
	}
	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,
		struct nlattr **attrs)
{
	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;

	err = xfrm_alloc_spi(x, p->min, p->max);
	if (err)
		goto out;

	resp_skb = xfrm_state_netlink(skb, x, nlh->nlmsg_seq);
	if (IS_ERR(resp_skb)) {
		err = PTR_ERR(resp_skb);
		goto out;
	}

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

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_policy_type(u8 type)
{
	switch (type) {
	case XFRM_POLICY_TYPE_MAIN:
#ifdef CONFIG_XFRM_SUB_POLICY
	case XFRM_POLICY_TYPE_SUB:
#endif
		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 int copy_from_user_sec_ctx(struct xfrm_policy *pol, struct nlattr **attrs)
{
	struct nlattr *rt = attrs[XFRMA_SEC_CTX];
	struct xfrm_user_sec_ctx *uctx;

	if (!rt)
		return 0;

	uctx = nla_data(rt);
	return security_xfrm_policy_alloc(pol, uctx);
}

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;
		t->encap_family = ut->family;
	}
}

static int validate_tmpl(int nr, struct xfrm_user_tmpl *ut, u16 family)
{
	int i;

	if (nr > XFRM_MAX_DEPTH)
		return -EINVAL;

	for (i = 0; i < nr; i++) {
		/* We never validated the ut->family value, so many
		 * applications simply leave it at zero.  The check was
		 * never made and ut->family was ignored because all
		 * templates could be assumed to have the same family as
		 * the policy itself.  Now that we will have ipv4-in-ipv6
		 * and ipv6-in-ipv4 tunnels, this is no longer true.
		 */
		if (!ut[i].family)
			ut[i].family = family;

		switch (ut[i].family) {
		case AF_INET:
			break;
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
		case AF_INET6:
			break;
#endif
		default:
			return -EINVAL;
		}
	}

	return 0;
}

static int copy_from_user_tmpl(struct xfrm_policy *pol, struct nlattr **attrs)
{
	struct nlattr *rt = attrs[XFRMA_TMPL];

	if (!rt) {
		pol->xfrm_nr = 0;
	} else {
		struct xfrm_user_tmpl *utmpl = nla_data(rt);
		int nr = nla_len(rt) / sizeof(*utmpl);
		int err;

		err = validate_tmpl(nr, utmpl, pol->family);
		if (err)
			return err;

		copy_templates(pol, utmpl, nr);
	}
	return 0;
}

static int copy_from_user_policy_type(u8 *tp, struct nlattr **attrs)
{
	struct nlattr *rt = attrs[XFRMA_POLICY_TYPE];
	struct xfrm_userpolicy_type *upt;
	u8 type = XFRM_POLICY_TYPE_MAIN;
	int err;

	if (rt) {
		upt = nla_data(rt);
		type = upt->type;
	}

	err = verify_policy_type(type);
	if (err)
		return err;

	*tp = type;
	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;
	memcpy(&xp->selector, &p->sel, sizeof(xp->selector));
	memcpy(&xp->lft, &p->lft, sizeof(xp->lft));
	xp->action = p->action;
	xp->flags = p->flags;
	xp->family = p->sel.family;
	/* XXX xp->share = p->share; */
}

static void copy_to_user_policy(struct xfrm_policy *xp, struct xfrm_userpolicy_info *p, int dir)
{
	memcpy(&p->sel, &xp->selector, sizeof(p->sel));
	memcpy(&p->lft, &xp->lft, sizeof(p->lft));
	memcpy(&p->curlft, &xp->curlft, sizeof(p->curlft));
	p->priority = xp->priority;
	p->index = xp->index;
	p->sel.family = xp->family;
	p->dir = dir;
	p->action = xp->action;
	p->flags = xp->flags;
	p->share = XFRM_SHARE_ANY; /* XXX xp->share */
}

static struct xfrm_policy *xfrm_policy_construct(struct xfrm_userpolicy_info *p, struct nlattr **attrs, int *errp)
{
	struct xfrm_policy *xp = xfrm_policy_alloc(GFP_KERNEL);
	int err;

	if (!xp) {
		*errp = -ENOMEM;
		return NULL;
	}

	copy_from_user_policy(xp, p);

	err = copy_from_user_policy_type(&xp->type, attrs);
	if (err)
		goto error;

	if (!(err = copy_from_user_tmpl(xp, attrs)))
		err = copy_from_user_sec_ctx(xp, attrs);
	if (err)
		goto error;

	return xp;
 error:
	*errp = err;
	kfree(xp);
	return NULL;
}

static int xfrm_add_policy(struct sk_buff *skb, struct nlmsghdr *nlh,
		struct nlattr **attrs)
{
	struct xfrm_userpolicy_info *p = nlmsg_data(nlh);
	struct xfrm_policy *xp;
	struct km_event c;
	int err;
	int excl;

	err = verify_newpolicy_info(p);
	if (err)
		return err;
	err = verify_sec_ctx_len(attrs);
	if (err)
		return err;

	xp = xfrm_policy_construct(p, attrs, &err);
	if (!xp)
		return err;

	/* shouldnt excl be based on nlh flags??
	 * Aha! this is anti-netlink really i.e  more pfkey derived
	 * in netlink excl is a flag and you wouldnt need
	 * a type XFRM_MSG_UPDPOLICY - JHS */
	excl = nlh->nlmsg_type == XFRM_MSG_NEWPOLICY;
	err = xfrm_policy_insert(p->dir, xp, excl);
	xfrm_audit_policy_add(xp, err ? 0 : 1, NETLINK_CB(skb).loginuid,
			      NETLINK_CB(skb).sid);

	if (err) {
		security_xfrm_policy_free(xp);
		kfree(xp);
		return err;
	}

	c.event = nlh->nlmsg_type;
	c.seq = nlh->nlmsg_seq;
	c.pid = nlh->nlmsg_pid;
	km_policy_notify(xp, p->dir, &c);

	xfrm_pol_put(xp);

	return 0;
}

static int copy_to_user_tmpl(struct xfrm_policy *xp, struct sk_buff *skb)
{
	struct xfrm_user_tmpl vec[XFRM_MAX_DEPTH];
	int i;

	if (xp->xfrm_nr == 0)
		return 0;

	for (i = 0; i < xp->xfrm_nr; i++) {
		struct xfrm_user_tmpl *up = &vec[i];
		struct xfrm_tmpl *kp = &xp->xfrm_vec[i];

		memcpy(&up->id, &kp->id, sizeof(up->id));
		up->family = kp->encap_family;
		memcpy(&up->saddr, &kp->saddr, sizeof(up->saddr));
		up->reqid = kp->reqid;
		up->mode = kp->mode;
		up->share = kp->share;
		up->optional = kp->optional;
		up->aalgos = kp->aalgos;
		up->ealgos = kp->ealgos;
		up->calgos = kp->calgos;
	}

	return nla_put(skb, XFRMA_TMPL,
		       sizeof(struct xfrm_user_tmpl) * xp->xfrm_nr, vec);
}

static inline int copy_to_user_state_sec_ctx(struct xfrm_state *x, struct sk_buff *skb)
{
	if (x->security) {
		return copy_sec_ctx(x->security, skb);
	}
	return 0;
}

static inline int copy_to_user_sec_ctx(struct xfrm_policy *xp, struct sk_buff *skb)
{
	if (xp->security) {
		return copy_sec_ctx(xp->security, skb);
	}
	return 0;
}
static inline size_t userpolicy_type_attrsize(void)
{
#ifdef CONFIG_XFRM_SUB_POLICY
	return nla_total_size(sizeof(struct xfrm_userpolicy_type));
#else
	return 0;
#endif
}

#ifdef CONFIG_XFRM_SUB_POLICY
static int copy_to_user_policy_type(u8 type, struct sk_buff *skb)
{
	struct xfrm_userpolicy_type upt = {
		.type = type,
	};

	return nla_put(skb, XFRMA_POLICY_TYPE, sizeof(upt), &upt);
}

#else
static inline int copy_to_user_policy_type(u8 type, struct sk_buff *skb)
{
	return 0;
}
#endif

static int dump_one_policy(struct xfrm_policy *xp, int dir, int count, void *ptr)
{
	struct xfrm_dump_info *sp = ptr;
	struct xfrm_userpolicy_info *p;
	struct sk_buff *in_skb = sp->in_skb;
	struct sk_buff *skb = sp->out_skb;
	struct nlmsghdr *nlh;

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

	nlh = nlmsg_put(skb, NETLINK_CB(in_skb).pid, sp->nlmsg_seq,
			XFRM_MSG_NEWPOLICY, sizeof(*p), sp->nlmsg_flags);
	if (nlh == NULL)
		return -EMSGSIZE;

	p = nlmsg_data(nlh);
	copy_to_user_policy(xp, p, dir);
	if (copy_to_user_tmpl(xp, skb) < 0)
		goto nlmsg_failure;
	if (copy_to_user_sec_ctx(xp, skb))
		goto nlmsg_failure;
	if (copy_to_user_policy_type(xp->type, skb) < 0)
		goto nlmsg_failure;

	nlmsg_end(skb, nlh);
out:
	sp->this_idx++;
	return 0;

nlmsg_failure:
	nlmsg_cancel(skb, nlh);
	return -EMSGSIZE;
}

static int xfrm_dump_policy(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.nlmsg_flags = NLM_F_MULTI;
	info.this_idx = 0;
	info.start_idx = cb->args[0];
	(void) xfrm_policy_walk(XFRM_POLICY_TYPE_MAIN, dump_one_policy, &info);
#ifdef CONFIG_XFRM_SUB_POLICY
	(void) xfrm_policy_walk(XFRM_POLICY_TYPE_SUB, dump_one_policy, &info);
#endif
	cb->args[0] = info.this_idx;

	return skb->len;
}