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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /net/xfrm/xfrm_input.c
Initial import
Diffstat (limited to 'net/xfrm/xfrm_input.c')
-rw-r--r--net/xfrm/xfrm_input.c396
1 files changed, 396 insertions, 0 deletions
diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
new file mode 100644
index 000000000..b58286ecd
--- /dev/null
+++ b/net/xfrm/xfrm_input.c
@@ -0,0 +1,396 @@
+/*
+ * xfrm_input.c
+ *
+ * Changes:
+ * YOSHIFUJI Hideaki @USAGI
+ * Split up af-specific portion
+ *
+ */
+
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <net/dst.h>
+#include <net/ip.h>
+#include <net/xfrm.h>
+#include <net/ip_tunnels.h>
+#include <net/ip6_tunnel.h>
+
+static struct kmem_cache *secpath_cachep __read_mostly;
+
+static DEFINE_SPINLOCK(xfrm_input_afinfo_lock);
+static struct xfrm_input_afinfo __rcu *xfrm_input_afinfo[NPROTO];
+
+int xfrm_input_register_afinfo(struct xfrm_input_afinfo *afinfo)
+{
+ int err = 0;
+
+ if (unlikely(afinfo == NULL))
+ return -EINVAL;
+ if (unlikely(afinfo->family >= NPROTO))
+ return -EAFNOSUPPORT;
+ spin_lock_bh(&xfrm_input_afinfo_lock);
+ if (unlikely(xfrm_input_afinfo[afinfo->family] != NULL))
+ err = -ENOBUFS;
+ else
+ rcu_assign_pointer(xfrm_input_afinfo[afinfo->family], afinfo);
+ spin_unlock_bh(&xfrm_input_afinfo_lock);
+ return err;
+}
+EXPORT_SYMBOL(xfrm_input_register_afinfo);
+
+int xfrm_input_unregister_afinfo(struct xfrm_input_afinfo *afinfo)
+{
+ int err = 0;
+
+ if (unlikely(afinfo == NULL))
+ return -EINVAL;
+ if (unlikely(afinfo->family >= NPROTO))
+ return -EAFNOSUPPORT;
+ spin_lock_bh(&xfrm_input_afinfo_lock);
+ if (likely(xfrm_input_afinfo[afinfo->family] != NULL)) {
+ if (unlikely(xfrm_input_afinfo[afinfo->family] != afinfo))
+ err = -EINVAL;
+ else
+ RCU_INIT_POINTER(xfrm_input_afinfo[afinfo->family], NULL);
+ }
+ spin_unlock_bh(&xfrm_input_afinfo_lock);
+ synchronize_rcu();
+ return err;
+}
+EXPORT_SYMBOL(xfrm_input_unregister_afinfo);
+
+static struct xfrm_input_afinfo *xfrm_input_get_afinfo(unsigned int family)
+{
+ struct xfrm_input_afinfo *afinfo;
+
+ if (unlikely(family >= NPROTO))
+ return NULL;
+ rcu_read_lock();
+ afinfo = rcu_dereference(xfrm_input_afinfo[family]);
+ if (unlikely(!afinfo))
+ rcu_read_unlock();
+ return afinfo;
+}
+
+static void xfrm_input_put_afinfo(struct xfrm_input_afinfo *afinfo)
+{
+ rcu_read_unlock();
+}
+
+static int xfrm_rcv_cb(struct sk_buff *skb, unsigned int family, u8 protocol,
+ int err)
+{
+ int ret;
+ struct xfrm_input_afinfo *afinfo = xfrm_input_get_afinfo(family);
+
+ if (!afinfo)
+ return -EAFNOSUPPORT;
+
+ ret = afinfo->callback(skb, protocol, err);
+ xfrm_input_put_afinfo(afinfo);
+
+ return ret;
+}
+
+void __secpath_destroy(struct sec_path *sp)
+{
+ int i;
+ for (i = 0; i < sp->len; i++)
+ xfrm_state_put(sp->xvec[i]);
+ kmem_cache_free(secpath_cachep, sp);
+}
+EXPORT_SYMBOL(__secpath_destroy);
+
+struct sec_path *secpath_dup(struct sec_path *src)
+{
+ struct sec_path *sp;
+
+ sp = kmem_cache_alloc(secpath_cachep, GFP_ATOMIC);
+ if (!sp)
+ return NULL;
+
+ sp->len = 0;
+ if (src) {
+ int i;
+
+ memcpy(sp, src, sizeof(*sp));
+ for (i = 0; i < sp->len; i++)
+ xfrm_state_hold(sp->xvec[i]);
+ }
+ atomic_set(&sp->refcnt, 1);
+ return sp;
+}
+EXPORT_SYMBOL(secpath_dup);
+
+/* Fetch spi and seq from ipsec header */
+
+int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq)
+{
+ int offset, offset_seq;
+ int hlen;
+
+ switch (nexthdr) {
+ case IPPROTO_AH:
+ hlen = sizeof(struct ip_auth_hdr);
+ offset = offsetof(struct ip_auth_hdr, spi);
+ offset_seq = offsetof(struct ip_auth_hdr, seq_no);
+ break;
+ case IPPROTO_ESP:
+ hlen = sizeof(struct ip_esp_hdr);
+ offset = offsetof(struct ip_esp_hdr, spi);
+ offset_seq = offsetof(struct ip_esp_hdr, seq_no);
+ break;
+ case IPPROTO_COMP:
+ if (!pskb_may_pull(skb, sizeof(struct ip_comp_hdr)))
+ return -EINVAL;
+ *spi = htonl(ntohs(*(__be16 *)(skb_transport_header(skb) + 2)));
+ *seq = 0;
+ return 0;
+ default:
+ return 1;
+ }
+
+ if (!pskb_may_pull(skb, hlen))
+ return -EINVAL;
+
+ *spi = *(__be32 *)(skb_transport_header(skb) + offset);
+ *seq = *(__be32 *)(skb_transport_header(skb) + offset_seq);
+ return 0;
+}
+
+int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb)
+{
+ struct xfrm_mode *inner_mode = x->inner_mode;
+ int err;
+
+ err = x->outer_mode->afinfo->extract_input(x, skb);
+ if (err)
+ return err;
+
+ if (x->sel.family == AF_UNSPEC) {
+ inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
+ if (inner_mode == NULL)
+ return -EAFNOSUPPORT;
+ }
+
+ skb->protocol = inner_mode->afinfo->eth_proto;
+ return inner_mode->input2(x, skb);
+}
+EXPORT_SYMBOL(xfrm_prepare_input);
+
+int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
+{
+ struct net *net = dev_net(skb->dev);
+ int err;
+ __be32 seq;
+ __be32 seq_hi;
+ struct xfrm_state *x = NULL;
+ xfrm_address_t *daddr;
+ struct xfrm_mode *inner_mode;
+ u32 mark = skb->mark;
+ unsigned int family;
+ int decaps = 0;
+ int async = 0;
+
+ /* A negative encap_type indicates async resumption. */
+ if (encap_type < 0) {
+ async = 1;
+ x = xfrm_input_state(skb);
+ seq = XFRM_SKB_CB(skb)->seq.input.low;
+ family = x->outer_mode->afinfo->family;
+ goto resume;
+ }
+
+ daddr = (xfrm_address_t *)(skb_network_header(skb) +
+ XFRM_SPI_SKB_CB(skb)->daddroff);
+ family = XFRM_SPI_SKB_CB(skb)->family;
+
+ /* if tunnel is present override skb->mark value with tunnel i_key */
+ if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4) {
+ switch (family) {
+ case AF_INET:
+ mark = be32_to_cpu(XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4->parms.i_key);
+ break;
+ case AF_INET6:
+ mark = be32_to_cpu(XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6->parms.i_key);
+ break;
+ }
+ }
+
+ /* Allocate new secpath or COW existing one. */
+ if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
+ struct sec_path *sp;
+
+ sp = secpath_dup(skb->sp);
+ if (!sp) {
+ XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
+ goto drop;
+ }
+ if (skb->sp)
+ secpath_put(skb->sp);
+ skb->sp = sp;
+ }
+
+ seq = 0;
+ if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0) {
+ XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
+ goto drop;
+ }
+
+ do {
+ if (skb->sp->len == XFRM_MAX_DEPTH) {
+ XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
+ goto drop;
+ }
+
+ x = xfrm_state_lookup(net, mark, daddr, spi, nexthdr, family);
+ if (x == NULL) {
+ XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
+ xfrm_audit_state_notfound(skb, family, spi, seq);
+ goto drop;
+ }
+
+ skb->sp->xvec[skb->sp->len++] = x;
+
+ spin_lock(&x->lock);
+ if (unlikely(x->km.state == XFRM_STATE_ACQ)) {
+ XFRM_INC_STATS(net, LINUX_MIB_XFRMACQUIREERROR);
+ goto drop_unlock;
+ }
+
+ if (unlikely(x->km.state != XFRM_STATE_VALID)) {
+ XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEINVALID);
+ goto drop_unlock;
+ }
+
+ if ((x->encap ? x->encap->encap_type : 0) != encap_type) {
+ XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
+ goto drop_unlock;
+ }
+
+ if (x->repl->check(x, skb, seq)) {
+ XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
+ goto drop_unlock;
+ }
+
+ if (xfrm_state_check_expire(x)) {
+ XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEEXPIRED);
+ goto drop_unlock;
+ }
+
+ spin_unlock(&x->lock);
+
+ if (xfrm_tunnel_check(skb, x, family)) {
+ XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
+ goto drop;
+ }
+
+ seq_hi = htonl(xfrm_replay_seqhi(x, seq));
+
+ XFRM_SKB_CB(skb)->seq.input.low = seq;
+ XFRM_SKB_CB(skb)->seq.input.hi = seq_hi;
+
+ skb_dst_force(skb);
+
+ nexthdr = x->type->input(x, skb);
+
+ if (nexthdr == -EINPROGRESS)
+ return 0;
+resume:
+ spin_lock(&x->lock);
+ if (nexthdr <= 0) {
+ if (nexthdr == -EBADMSG) {
+ xfrm_audit_state_icvfail(x, skb,
+ x->type->proto);
+ x->stats.integrity_failed++;
+ }
+ XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
+ goto drop_unlock;
+ }
+
+ /* only the first xfrm gets the encap type */
+ encap_type = 0;
+
+ if (async && x->repl->recheck(x, skb, seq)) {
+ XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
+ goto drop_unlock;
+ }
+
+ x->repl->advance(x, seq);
+
+ x->curlft.bytes += skb->len;
+ x->curlft.packets++;
+
+ spin_unlock(&x->lock);
+
+ XFRM_MODE_SKB_CB(skb)->protocol = nexthdr;
+
+ inner_mode = x->inner_mode;
+
+ if (x->sel.family == AF_UNSPEC) {
+ inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
+ if (inner_mode == NULL)
+ goto drop;
+ }
+
+ if (inner_mode->input(x, skb)) {
+ XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
+ goto drop;
+ }
+
+ if (x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) {
+ decaps = 1;
+ break;
+ }
+
+ /*
+ * We need the inner address. However, we only get here for
+ * transport mode so the outer address is identical.
+ */
+ daddr = &x->id.daddr;
+ family = x->outer_mode->afinfo->family;
+
+ err = xfrm_parse_spi(skb, nexthdr, &spi, &seq);
+ if (err < 0) {
+ XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
+ goto drop;
+ }
+ } while (!err);
+
+ err = xfrm_rcv_cb(skb, family, x->type->proto, 0);
+ if (err)
+ goto drop;
+
+ nf_reset(skb);
+
+ if (decaps) {
+ skb_dst_drop(skb);
+ netif_rx(skb);
+ return 0;
+ } else {
+ return x->inner_mode->afinfo->transport_finish(skb, async);
+ }
+
+drop_unlock:
+ spin_unlock(&x->lock);
+drop:
+ xfrm_rcv_cb(skb, family, x && x->type ? x->type->proto : nexthdr, -1);
+ kfree_skb(skb);
+ return 0;
+}
+EXPORT_SYMBOL(xfrm_input);
+
+int xfrm_input_resume(struct sk_buff *skb, int nexthdr)
+{
+ return xfrm_input(skb, nexthdr, 0, -1);
+}
+EXPORT_SYMBOL(xfrm_input_resume);
+
+void __init xfrm_input_init(void)
+{
+ secpath_cachep = kmem_cache_create("secpath_cache",
+ sizeof(struct sec_path),
+ 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
+ NULL);
+}