382 lines
8.5 KiB
C
382 lines
8.5 KiB
C
/*
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* xfrm_input.c
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*
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* Changes:
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* YOSHIFUJI Hideaki @USAGI
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* Split up af-specific portion
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*
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*/
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/netdevice.h>
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#include <net/dst.h>
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#include <net/ip.h>
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#include <net/xfrm.h>
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static struct kmem_cache *secpath_cachep __read_mostly;
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static DEFINE_SPINLOCK(xfrm_input_afinfo_lock);
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static struct xfrm_input_afinfo __rcu *xfrm_input_afinfo[NPROTO];
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int xfrm_input_register_afinfo(struct xfrm_input_afinfo *afinfo)
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{
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int err = 0;
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if (unlikely(afinfo == NULL))
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return -EINVAL;
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if (unlikely(afinfo->family >= NPROTO))
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return -EAFNOSUPPORT;
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spin_lock_bh(&xfrm_input_afinfo_lock);
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if (unlikely(xfrm_input_afinfo[afinfo->family] != NULL))
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err = -ENOBUFS;
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else
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rcu_assign_pointer(xfrm_input_afinfo[afinfo->family], afinfo);
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spin_unlock_bh(&xfrm_input_afinfo_lock);
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return err;
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}
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EXPORT_SYMBOL(xfrm_input_register_afinfo);
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int xfrm_input_unregister_afinfo(struct xfrm_input_afinfo *afinfo)
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{
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int err = 0;
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if (unlikely(afinfo == NULL))
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return -EINVAL;
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if (unlikely(afinfo->family >= NPROTO))
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return -EAFNOSUPPORT;
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spin_lock_bh(&xfrm_input_afinfo_lock);
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if (likely(xfrm_input_afinfo[afinfo->family] != NULL)) {
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if (unlikely(xfrm_input_afinfo[afinfo->family] != afinfo))
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err = -EINVAL;
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else
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RCU_INIT_POINTER(xfrm_input_afinfo[afinfo->family], NULL);
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}
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spin_unlock_bh(&xfrm_input_afinfo_lock);
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synchronize_rcu();
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return err;
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}
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EXPORT_SYMBOL(xfrm_input_unregister_afinfo);
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static struct xfrm_input_afinfo *xfrm_input_get_afinfo(unsigned int family)
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{
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struct xfrm_input_afinfo *afinfo;
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if (unlikely(family >= NPROTO))
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return NULL;
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rcu_read_lock();
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afinfo = rcu_dereference(xfrm_input_afinfo[family]);
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if (unlikely(!afinfo))
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rcu_read_unlock();
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return afinfo;
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}
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static void xfrm_input_put_afinfo(struct xfrm_input_afinfo *afinfo)
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{
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rcu_read_unlock();
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}
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static int xfrm_rcv_cb(struct sk_buff *skb, unsigned int family, u8 protocol,
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int err)
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{
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int ret;
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struct xfrm_input_afinfo *afinfo = xfrm_input_get_afinfo(family);
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if (!afinfo)
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return -EAFNOSUPPORT;
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ret = afinfo->callback(skb, protocol, err);
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xfrm_input_put_afinfo(afinfo);
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return ret;
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}
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void __secpath_destroy(struct sec_path *sp)
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{
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int i;
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for (i = 0; i < sp->len; i++)
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xfrm_state_put(sp->xvec[i]);
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kmem_cache_free(secpath_cachep, sp);
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}
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EXPORT_SYMBOL(__secpath_destroy);
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struct sec_path *secpath_dup(struct sec_path *src)
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{
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struct sec_path *sp;
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sp = kmem_cache_alloc(secpath_cachep, GFP_ATOMIC);
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if (!sp)
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return NULL;
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sp->len = 0;
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if (src) {
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int i;
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memcpy(sp, src, sizeof(*sp));
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for (i = 0; i < sp->len; i++)
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xfrm_state_hold(sp->xvec[i]);
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}
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atomic_set(&sp->refcnt, 1);
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return sp;
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}
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EXPORT_SYMBOL(secpath_dup);
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/* Fetch spi and seq from ipsec header */
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int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq)
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{
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int offset, offset_seq;
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int hlen;
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switch (nexthdr) {
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case IPPROTO_AH:
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hlen = sizeof(struct ip_auth_hdr);
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offset = offsetof(struct ip_auth_hdr, spi);
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offset_seq = offsetof(struct ip_auth_hdr, seq_no);
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break;
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case IPPROTO_ESP:
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hlen = sizeof(struct ip_esp_hdr);
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offset = offsetof(struct ip_esp_hdr, spi);
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offset_seq = offsetof(struct ip_esp_hdr, seq_no);
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break;
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case IPPROTO_COMP:
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if (!pskb_may_pull(skb, sizeof(struct ip_comp_hdr)))
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return -EINVAL;
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*spi = htonl(ntohs(*(__be16 *)(skb_transport_header(skb) + 2)));
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*seq = 0;
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return 0;
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default:
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return 1;
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}
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if (!pskb_may_pull(skb, hlen))
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return -EINVAL;
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*spi = *(__be32 *)(skb_transport_header(skb) + offset);
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*seq = *(__be32 *)(skb_transport_header(skb) + offset_seq);
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return 0;
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}
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int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb)
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{
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struct xfrm_mode *inner_mode = x->inner_mode;
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int err;
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err = x->outer_mode->afinfo->extract_input(x, skb);
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if (err)
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return err;
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if (x->sel.family == AF_UNSPEC) {
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inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
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if (inner_mode == NULL)
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return -EAFNOSUPPORT;
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}
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skb->protocol = inner_mode->afinfo->eth_proto;
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return inner_mode->input2(x, skb);
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}
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EXPORT_SYMBOL(xfrm_prepare_input);
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int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
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{
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struct net *net = dev_net(skb->dev);
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int err;
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__be32 seq;
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__be32 seq_hi;
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struct xfrm_state *x = NULL;
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xfrm_address_t *daddr;
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struct xfrm_mode *inner_mode;
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unsigned int family;
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int decaps = 0;
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int async = 0;
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/* A negative encap_type indicates async resumption. */
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if (encap_type < 0) {
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async = 1;
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x = xfrm_input_state(skb);
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seq = XFRM_SKB_CB(skb)->seq.input.low;
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family = x->outer_mode->afinfo->family;
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goto resume;
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}
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daddr = (xfrm_address_t *)(skb_network_header(skb) +
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XFRM_SPI_SKB_CB(skb)->daddroff);
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family = XFRM_SPI_SKB_CB(skb)->family;
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/* Allocate new secpath or COW existing one. */
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if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
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struct sec_path *sp;
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sp = secpath_dup(skb->sp);
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if (!sp) {
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XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
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goto drop;
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}
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if (skb->sp)
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secpath_put(skb->sp);
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skb->sp = sp;
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}
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seq = 0;
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if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0) {
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XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
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goto drop;
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}
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do {
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if (skb->sp->len == XFRM_MAX_DEPTH) {
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XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
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goto drop;
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}
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x = xfrm_state_lookup(net, skb->mark, daddr, spi, nexthdr, family);
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if (x == NULL) {
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XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
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xfrm_audit_state_notfound(skb, family, spi, seq);
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goto drop;
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}
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skb->sp->xvec[skb->sp->len++] = x;
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if (xfrm_tunnel_check(skb, x, family)) {
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XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
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goto drop;
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}
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spin_lock(&x->lock);
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if (unlikely(x->km.state == XFRM_STATE_ACQ)) {
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XFRM_INC_STATS(net, LINUX_MIB_XFRMACQUIREERROR);
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goto drop_unlock;
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}
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if (unlikely(x->km.state != XFRM_STATE_VALID)) {
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XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEINVALID);
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goto drop_unlock;
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}
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if ((x->encap ? x->encap->encap_type : 0) != encap_type) {
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XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
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goto drop_unlock;
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}
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if (x->repl->check(x, skb, seq)) {
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XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
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goto drop_unlock;
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}
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if (xfrm_state_check_expire(x)) {
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XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEEXPIRED);
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goto drop_unlock;
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}
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spin_unlock(&x->lock);
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seq_hi = htonl(xfrm_replay_seqhi(x, seq));
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XFRM_SKB_CB(skb)->seq.input.low = seq;
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XFRM_SKB_CB(skb)->seq.input.hi = seq_hi;
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skb_dst_force(skb);
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nexthdr = x->type->input(x, skb);
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if (nexthdr == -EINPROGRESS)
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return 0;
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resume:
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spin_lock(&x->lock);
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if (nexthdr <= 0) {
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if (nexthdr == -EBADMSG) {
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xfrm_audit_state_icvfail(x, skb,
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x->type->proto);
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x->stats.integrity_failed++;
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}
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XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
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goto drop_unlock;
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}
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/* only the first xfrm gets the encap type */
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encap_type = 0;
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if (async && x->repl->recheck(x, skb, seq)) {
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XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
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goto drop_unlock;
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}
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x->repl->advance(x, seq);
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x->curlft.bytes += skb->len;
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x->curlft.packets++;
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spin_unlock(&x->lock);
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XFRM_MODE_SKB_CB(skb)->protocol = nexthdr;
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inner_mode = x->inner_mode;
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if (x->sel.family == AF_UNSPEC) {
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inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
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if (inner_mode == NULL)
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goto drop;
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}
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if (inner_mode->input(x, skb)) {
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XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
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goto drop;
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}
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if (x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) {
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decaps = 1;
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break;
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}
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/*
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* We need the inner address. However, we only get here for
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* transport mode so the outer address is identical.
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*/
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daddr = &x->id.daddr;
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family = x->outer_mode->afinfo->family;
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err = xfrm_parse_spi(skb, nexthdr, &spi, &seq);
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if (err < 0) {
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XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
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goto drop;
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}
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} while (!err);
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err = xfrm_rcv_cb(skb, family, x->type->proto, 0);
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if (err)
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goto drop;
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nf_reset(skb);
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if (decaps) {
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skb_dst_drop(skb);
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netif_rx(skb);
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return 0;
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} else {
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return x->inner_mode->afinfo->transport_finish(skb, async);
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}
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drop_unlock:
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spin_unlock(&x->lock);
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drop:
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xfrm_rcv_cb(skb, family, x && x->type ? x->type->proto : nexthdr, -1);
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kfree_skb(skb);
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return 0;
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}
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EXPORT_SYMBOL(xfrm_input);
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int xfrm_input_resume(struct sk_buff *skb, int nexthdr)
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{
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return xfrm_input(skb, nexthdr, 0, -1);
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}
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EXPORT_SYMBOL(xfrm_input_resume);
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void __init xfrm_input_init(void)
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{
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secpath_cachep = kmem_cache_create("secpath_cache",
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sizeof(struct sec_path),
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0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
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NULL);
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}
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