xfrm_user.c

linux 内核源代码

};

static struct xfrm_link {
	int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);
	int (*dump)(struct sk_buff *, struct netlink_callback *);
} xfrm_dispatch[XFRM_NR_MSGTYPES] = {
	[XFRM_MSG_NEWSA       - XFRM_MSG_BASE] = { .doit = xfrm_add_sa        },
	[XFRM_MSG_DELSA       - XFRM_MSG_BASE] = { .doit = xfrm_del_sa        },
	[XFRM_MSG_GETSA       - XFRM_MSG_BASE] = { .doit = xfrm_get_sa,
						   .dump = xfrm_dump_sa       },
	[XFRM_MSG_NEWPOLICY   - XFRM_MSG_BASE] = { .doit = xfrm_add_policy    },
	[XFRM_MSG_DELPOLICY   - XFRM_MSG_BASE] = { .doit = xfrm_get_policy    },
	[XFRM_MSG_GETPOLICY   - XFRM_MSG_BASE] = { .doit = xfrm_get_policy,
						   .dump = xfrm_dump_policy   },
	[XFRM_MSG_ALLOCSPI    - XFRM_MSG_BASE] = { .doit = xfrm_alloc_userspi },
	[XFRM_MSG_ACQUIRE     - XFRM_MSG_BASE] = { .doit = xfrm_add_acquire   },
	[XFRM_MSG_EXPIRE      - XFRM_MSG_BASE] = { .doit = xfrm_add_sa_expire },
	[XFRM_MSG_UPDPOLICY   - XFRM_MSG_BASE] = { .doit = xfrm_add_policy    },
	[XFRM_MSG_UPDSA       - XFRM_MSG_BASE] = { .doit = xfrm_add_sa        },
	[XFRM_MSG_POLEXPIRE   - XFRM_MSG_BASE] = { .doit = xfrm_add_pol_expire},
	[XFRM_MSG_FLUSHSA     - XFRM_MSG_BASE] = { .doit = xfrm_flush_sa      },
	[XFRM_MSG_FLUSHPOLICY - XFRM_MSG_BASE] = { .doit = xfrm_flush_policy  },
	[XFRM_MSG_NEWAE       - XFRM_MSG_BASE] = { .doit = xfrm_new_ae  },
	[XFRM_MSG_GETAE       - XFRM_MSG_BASE] = { .doit = xfrm_get_ae  },
	[XFRM_MSG_MIGRATE     - XFRM_MSG_BASE] = { .doit = xfrm_do_migrate    },
	[XFRM_MSG_GETSADINFO  - XFRM_MSG_BASE] = { .doit = xfrm_get_sadinfo   },
	[XFRM_MSG_GETSPDINFO  - XFRM_MSG_BASE] = { .doit = xfrm_get_spdinfo   },
};

static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
{
	struct nlattr *attrs[XFRMA_MAX+1];
	struct xfrm_link *link;
	int type, err;

	type = nlh->nlmsg_type;
	if (type > XFRM_MSG_MAX)
		return -EINVAL;

	type -= XFRM_MSG_BASE;
	link = &xfrm_dispatch[type];

	/* All operations require privileges, even GET */
	if (security_netlink_recv(skb, CAP_NET_ADMIN))
		return -EPERM;

	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;

		return netlink_dump_start(xfrm_nl, skb, nlh, link->dump, NULL);
	}

	err = nlmsg_parse(nlh, xfrm_msg_min[type], attrs, XFRMA_MAX,
			  xfrma_policy);
	if (err < 0)
		return err;

	if (link->doit == NULL)
		return -EINVAL;

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

static void xfrm_netlink_rcv(struct sk_buff *skb)
{
	mutex_lock(&xfrm_cfg_mutex);
	netlink_rcv_skb(skb, &xfrm_user_rcv_msg);
	mutex_unlock(&xfrm_cfg_mutex);
}

static inline size_t xfrm_expire_msgsize(void)
{
	return NLMSG_ALIGN(sizeof(struct xfrm_user_expire));
}

static int build_expire(struct sk_buff *skb, struct xfrm_state *x, struct km_event *c)
{
	struct xfrm_user_expire *ue;
	struct nlmsghdr *nlh;

	nlh = nlmsg_put(skb, c->pid, 0, XFRM_MSG_EXPIRE, sizeof(*ue), 0);
	if (nlh == NULL)
		return -EMSGSIZE;

	ue = nlmsg_data(nlh);
	copy_to_user_state(x, &ue->state);
	ue->hard = (c->data.hard != 0) ? 1 : 0;

	return nlmsg_end(skb, nlh);
}

static int xfrm_exp_state_notify(struct xfrm_state *x, struct km_event *c)
{
	struct sk_buff *skb;

	skb = nlmsg_new(xfrm_expire_msgsize(), GFP_ATOMIC);
	if (skb == NULL)
		return -ENOMEM;

	if (build_expire(skb, x, c) < 0)
		BUG();

	return nlmsg_multicast(xfrm_nl, skb, 0, XFRMNLGRP_EXPIRE, GFP_ATOMIC);
}

static int xfrm_aevent_state_notify(struct xfrm_state *x, struct km_event *c)
{
	struct sk_buff *skb;

	skb = nlmsg_new(xfrm_aevent_msgsize(), GFP_ATOMIC);
	if (skb == NULL)
		return -ENOMEM;

	if (build_aevent(skb, x, c) < 0)
		BUG();

	return nlmsg_multicast(xfrm_nl, skb, 0, XFRMNLGRP_AEVENTS, GFP_ATOMIC);
}

static int xfrm_notify_sa_flush(struct km_event *c)
{
	struct xfrm_usersa_flush *p;
	struct nlmsghdr *nlh;
	struct sk_buff *skb;
	int len = NLMSG_ALIGN(sizeof(struct xfrm_usersa_flush));

	skb = nlmsg_new(len, GFP_ATOMIC);
	if (skb == NULL)
		return -ENOMEM;

	nlh = nlmsg_put(skb, c->pid, c->seq, XFRM_MSG_FLUSHSA, sizeof(*p), 0);
	if (nlh == NULL) {
		kfree_skb(skb);
		return -EMSGSIZE;
	}

	p = nlmsg_data(nlh);
	p->proto = c->data.proto;

	nlmsg_end(skb, nlh);

	return nlmsg_multicast(xfrm_nl, skb, 0, XFRMNLGRP_SA, GFP_ATOMIC);
}

static inline size_t xfrm_sa_len(struct xfrm_state *x)
{
	size_t l = 0;
	if (x->aalg)
		l += nla_total_size(xfrm_alg_len(x->aalg));
	if (x->ealg)
		l += nla_total_size(xfrm_alg_len(x->ealg));
	if (x->calg)
		l += nla_total_size(sizeof(*x->calg));
	if (x->encap)
		l += nla_total_size(sizeof(*x->encap));
	if (x->security)
		l += nla_total_size(sizeof(struct xfrm_user_sec_ctx) +
				    x->security->ctx_len);
	if (x->coaddr)
		l += nla_total_size(sizeof(*x->coaddr));

	/* Must count this as this may become non-zero behind our back. */
	l += nla_total_size(sizeof(x->lastused));

	return l;
}

static int xfrm_notify_sa(struct xfrm_state *x, struct km_event *c)
{
	struct xfrm_usersa_info *p;
	struct xfrm_usersa_id *id;
	struct nlmsghdr *nlh;
	struct sk_buff *skb;
	int len = xfrm_sa_len(x);
	int headlen;

	headlen = sizeof(*p);
	if (c->event == XFRM_MSG_DELSA) {
		len += nla_total_size(headlen);
		headlen = sizeof(*id);
	}
	len += NLMSG_ALIGN(headlen);

	skb = nlmsg_new(len, GFP_ATOMIC);
	if (skb == NULL)
		return -ENOMEM;

	nlh = nlmsg_put(skb, c->pid, c->seq, c->event, headlen, 0);
	if (nlh == NULL)
		goto nla_put_failure;

	p = nlmsg_data(nlh);
	if (c->event == XFRM_MSG_DELSA) {
		struct nlattr *attr;

		id = nlmsg_data(nlh);
		memcpy(&id->daddr, &x->id.daddr, sizeof(id->daddr));
		id->spi = x->id.spi;
		id->family = x->props.family;
		id->proto = x->id.proto;

		attr = nla_reserve(skb, XFRMA_SA, sizeof(*p));
		if (attr == NULL)
			goto nla_put_failure;

		p = nla_data(attr);
	}

	if (copy_to_user_state_extra(x, p, skb))
		goto nla_put_failure;

	nlmsg_end(skb, nlh);

	return nlmsg_multicast(xfrm_nl, skb, 0, XFRMNLGRP_SA, GFP_ATOMIC);

nla_put_failure:
	/* Somebody screwed up with xfrm_sa_len! */
	WARN_ON(1);
	kfree_skb(skb);
	return -1;
}

static int xfrm_send_state_notify(struct xfrm_state *x, struct km_event *c)
{

	switch (c->event) {
	case XFRM_MSG_EXPIRE:
		return xfrm_exp_state_notify(x, c);
	case XFRM_MSG_NEWAE:
		return xfrm_aevent_state_notify(x, c);
	case XFRM_MSG_DELSA:
	case XFRM_MSG_UPDSA:
	case XFRM_MSG_NEWSA:
		return xfrm_notify_sa(x, c);
	case XFRM_MSG_FLUSHSA:
		return xfrm_notify_sa_flush(c);
	default:
		 printk("xfrm_user: Unknown SA event %d\n", c->event);
		 break;
	}

	return 0;

}

static inline size_t xfrm_acquire_msgsize(struct xfrm_state *x,
					  struct xfrm_policy *xp)
{
	return NLMSG_ALIGN(sizeof(struct xfrm_user_acquire))
	       + nla_total_size(sizeof(struct xfrm_user_tmpl) * xp->xfrm_nr)
	       + nla_total_size(xfrm_user_sec_ctx_size(x->security))
	       + userpolicy_type_attrsize();
}

static int build_acquire(struct sk_buff *skb, struct xfrm_state *x,
			 struct xfrm_tmpl *xt, struct xfrm_policy *xp,
			 int dir)
{
	struct xfrm_user_acquire *ua;
	struct nlmsghdr *nlh;
	__u32 seq = xfrm_get_acqseq();

	nlh = nlmsg_put(skb, 0, 0, XFRM_MSG_ACQUIRE, sizeof(*ua), 0);
	if (nlh == NULL)
		return -EMSGSIZE;

	ua = nlmsg_data(nlh);
	memcpy(&ua->id, &x->id, sizeof(ua->id));
	memcpy(&ua->saddr, &x->props.saddr, sizeof(ua->saddr));
	memcpy(&ua->sel, &x->sel, sizeof(ua->sel));
	copy_to_user_policy(xp, &ua->policy, dir);
	ua->aalgos = xt->aalgos;
	ua->ealgos = xt->ealgos;
	ua->calgos = xt->calgos;
	ua->seq = x->km.seq = seq;

	if (copy_to_user_tmpl(xp, skb) < 0)
		goto nlmsg_failure;
	if (copy_to_user_state_sec_ctx(x, skb))
		goto nlmsg_failure;
	if (copy_to_user_policy_type(xp->type, skb) < 0)
		goto nlmsg_failure;

	return nlmsg_end(skb, nlh);

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

static int xfrm_send_acquire(struct xfrm_state *x, struct xfrm_tmpl *xt,
			     struct xfrm_policy *xp, int dir)
{
	struct sk_buff *skb;

	skb = nlmsg_new(xfrm_acquire_msgsize(x, xp), GFP_ATOMIC);
	if (skb == NULL)
		return -ENOMEM;

	if (build_acquire(skb, x, xt, xp, dir) < 0)
		BUG();

	return nlmsg_multicast(xfrm_nl, skb, 0, XFRMNLGRP_ACQUIRE, GFP_ATOMIC);
}

/* User gives us xfrm_user_policy_info followed by an array of 0
 * or more templates.
 */
static struct xfrm_policy *xfrm_compile_policy(struct sock *sk, int opt,
					       u8 *data, int len, int *dir)
{
	struct xfrm_userpolicy_info *p = (struct xfrm_userpolicy_info *)data;
	struct xfrm_user_tmpl *ut = (struct xfrm_user_tmpl *) (p + 1);
	struct xfrm_policy *xp;
	int nr;

	switch (sk->sk_family) {
	case AF_INET:
		if (opt != IP_XFRM_POLICY) {
			*dir = -EOPNOTSUPP;
			return NULL;
		}
		break;
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
	case AF_INET6:
		if (opt != IPV6_XFRM_POLICY) {
			*dir = -EOPNOTSUPP;
			return NULL;
		}
		break;
#endif
	default:
		*dir = -EINVAL;
		return NULL;
	}

	*dir = -EINVAL;

	if (len < sizeof(*p) ||
	    verify_newpolicy_info(p))
		return NULL;

	nr = ((len - sizeof(*p)) / sizeof(*ut));
	if (validate_tmpl(nr, ut, p->sel.family))
		return NULL;

	if (p->dir > XFRM_POLICY_OUT)
		return NULL;

	xp = xfrm_policy_alloc(GFP_KERNEL);
	if (xp == NULL) {
		*dir = -ENOBUFS;
		return NULL;
	}

	copy_from_user_policy(xp, p);
	xp->type = XFRM_POLICY_TYPE_MAIN;
	copy_templates(xp, ut, nr);

	*dir = p->dir;

	return xp;
}

static inline size_t xfrm_polexpire_msgsize(struct xfrm_policy *xp)
{
	return NLMSG_ALIGN(sizeof(struct xfrm_user_polexpire))
	       + nla_total_size(sizeof(struct xfrm_user_tmpl) * xp->xfrm_nr)
	       + nla_total_size(xfrm_user_sec_ctx_size(xp->security))
	       + userpolicy_type_attrsize();
}

static int build_polexpire(struct sk_buff *skb, struct xfrm_policy *xp,
			   int dir, struct km_event *c)
{
	struct xfrm_user_polexpire *upe;
	struct nlmsghdr *nlh;
	int hard = c->data.hard;

	nlh = nlmsg_put(skb, c->pid, 0, XFRM_MSG_POLEXPIRE, sizeof(*upe), 0);
	if (nlh == NULL)
		return -EMSGSIZE;

	upe = nlmsg_data(nlh);
	copy_to_user_policy(xp, &upe->pol, 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;
	upe->hard = !!hard;

	return nlmsg_end(skb, nlh);

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

static int xfrm_exp_policy_notify(struct xfrm_policy *xp, int dir, struct km_event *c)
{
	struct sk_buff *skb;

	skb = nlmsg_new(xfrm_polexpire_msgsize(xp), GFP_ATOMIC);
	if (skb == NULL)
		return -ENOMEM;

	if (build_polexpire(skb, xp, dir, c) < 0)
		BUG();

	return nlmsg_multicast(xfrm_nl, skb, 0, XFRMNLGRP_EXPIRE, GFP_ATOMIC);
}

static int xfrm_notify_policy(struct xfrm_policy *xp, int dir, struct km_event *c)
{
	struct xfrm_userpolicy_info *p;
	struct xfrm_userpolicy_id *id;
	struct nlmsghdr *nlh;
	struct sk_buff *skb;
	int len = nla_total_size(sizeof(struct xfrm_user_tmpl) * xp->xfrm_nr);
	int headlen;

	headlen = sizeof(*p);
	if (c->event == XFRM_MSG_DELPOLICY) {
		len += nla_total_size(headlen);
		headlen = sizeof(*id);
	}
	len += userpolicy_type_attrsize();
	len += NLMSG_ALIGN(headlen);

	skb = nlmsg_new(len, GFP_ATOMIC);
	if (skb == NULL)
		return -ENOMEM;

	nlh = nlmsg_put(skb, c->pid, c->seq, c->event, headlen, 0);
	if (nlh == NULL)
		goto nlmsg_failure;

	p = nlmsg_data(nlh);
	if (c->event == XFRM_MSG_DELPOLICY) {
		struct nlattr *attr;

		id = nlmsg_data(nlh);
		memset(id, 0, sizeof(*id));
		id->dir = dir;
		if (c->data.byid)
			id->index = xp->index;
		else
			memcpy(&id->sel, &xp->selector, sizeof(id->sel));

		attr = nla_reserve(skb, XFRMA_POLICY, sizeof(*p));
		if (attr == NULL)
			goto nlmsg_failure;

		p = nla_data(attr);
	}

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

	nlmsg_end(skb, nlh);

	return nlmsg_multicast(xfrm_nl, skb, 0, XFRMNLGRP_POLICY, GFP_ATOMIC);

nlmsg_failure:
	kfree_skb(skb);
	return -1;
}

static int xfrm_notify_policy_flush(struct km_event *c)
{
	struct nlmsghdr *nlh;
	struct sk_buff *skb;

	skb = nlmsg_new(userpolicy_type_attrsize(), GFP_ATOMIC);
	if (skb == NULL)
		return -ENOMEM;

	nlh = nlmsg_put(skb, c->pid, c->seq, XFRM_MSG_FLUSHPOLICY, 0, 0);
	if (nlh == NULL)
		goto nlmsg_failure;
	if (copy_to_user_policy_type(c->data.type, skb) < 0)
		goto nlmsg_failure;

	nlmsg_end(skb, nlh);

	return nlmsg_multicast(xfrm_nl, skb, 0, XFRMNLGRP_POLICY, GFP_ATOMIC);

nlmsg_failure:
	kfree_skb(skb);
	return -1;
}

static int xfrm_send_policy_notify(struct xfrm_policy *xp, int dir, struct km_event *c)
{

	switch (c->event) {
	case XFRM_MSG_NEWPOLICY:
	case XFRM_MSG_UPDPOLICY:
	case XFRM_MSG_DELPOLICY:
		return xfrm_notify_policy(xp, dir, c);
	case XFRM_MSG_FLUSHPOLICY:
		return xfrm_notify_policy_flush(c);
	case XFRM_MSG_POLEXPIRE:
		return xfrm_exp_policy_notify(xp, dir, c);
	default:
		printk("xfrm_user: Unknown Policy event %d\n", c->event);
	}

	return 0;

}

static inline size_t xfrm_report_msgsize(void)
{
	return NLMSG_ALIGN(sizeof(struct xfrm_user_report));
}

static int build_report(struct sk_buff *skb, u8 proto,
			struct xfrm_selector *sel, xfrm_address_t *addr)
{
	struct xfrm_user_report *ur;
	struct nlmsghdr *nlh;

	nlh = nlmsg_put(skb, 0, 0, XFRM_MSG_REPORT, sizeof(*ur), 0);
	if (nlh == NULL)
		return -EMSGSIZE;

	ur = nlmsg_data(nlh);
	ur->proto = proto;
	memcpy(&ur->sel, sel, sizeof(ur->sel));

	if (addr)
		NLA_PUT(skb, XFRMA_COADDR, sizeof(*addr), addr);

	return nlmsg_end(skb, nlh);

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

static int xfrm_send_report(u8 proto, struct xfrm_selector *sel,
			    xfrm_address_t *addr)
{
	struct sk_buff *skb;

	skb = nlmsg_new(xfrm_report_msgsize(), GFP_ATOMIC);
	if (skb == NULL)
		return -ENOMEM;

	if (build_report(skb, proto, sel, addr) < 0)
		BUG();

	return nlmsg_multicast(xfrm_nl, skb, 0, XFRMNLGRP_REPORT, GFP_ATOMIC);
}

static struct xfrm_mgr netlink_mgr = {
	.id		= "netlink",
	.notify		= xfrm_send_state_notify,
	.acquire	= xfrm_send_acquire,
	.compile_policy	= xfrm_compile_policy,
	.notify_policy	= xfrm_send_policy_notify,
	.report		= xfrm_send_report,
	.migrate	= xfrm_send_migrate,
};

static int __init xfrm_user_init(void)
{
	struct sock *nlsk;

	printk(KERN_INFO "Initializing XFRM netlink socket\n");

	nlsk = netlink_kernel_create(&init_net, NETLINK_XFRM, XFRMNLGRP_MAX,
				     xfrm_netlink_rcv, NULL, THIS_MODULE);
	if (nlsk == NULL)
		return -ENOMEM;
	rcu_assign_pointer(xfrm_nl, nlsk);

	xfrm_register_km(&netlink_mgr);

	return 0;
}

static void __exit xfrm_user_exit(void)
{
	struct sock *nlsk = xfrm_nl;

	xfrm_unregister_km(&netlink_mgr);
	rcu_assign_pointer(xfrm_nl, NULL);
	synchronize_rcu();
	sock_release(nlsk->sk_socket);
}

module_init(xfrm_user_init);
module_exit(xfrm_user_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_XFRM);