/* * 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> static struct kmem_cache *secpath_cachep __read_mostly; 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) { int err; err = x->outer_mode->afinfo->extract_input(x, skb); if (err) return err; skb->protocol = x->inner_mode->afinfo->eth_proto; return x->inner_mode->input2(x, skb); } EXPORT_SYMBOL(xfrm_prepare_input); int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type) { int err; __be32 seq; struct xfrm_state *x; xfrm_address_t *daddr; 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; goto resume; } /* 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(LINUX_MIB_XFRMINERROR); goto drop; } if (skb->sp) secpath_put(skb->sp); skb->sp = sp; } daddr = (xfrm_address_t *)(skb_network_header(skb) + XFRM_SPI_SKB_CB(skb)->daddroff); family = XFRM_SPI_SKB_CB(skb)->family; seq = 0; if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0) { XFRM_INC_STATS(LINUX_MIB_XFRMINHDRERROR); goto drop; } do { if (skb->sp->len == XFRM_MAX_DEPTH) { XFRM_INC_STATS(LINUX_MIB_XFRMINBUFFERERROR); goto drop; } x = xfrm_state_lookup(daddr, spi, nexthdr, family); if (x == NULL) { XFRM_INC_STATS(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_VALID)) { XFRM_INC_STATS(LINUX_MIB_XFRMINSTATEINVALID); goto drop_unlock; } if ((x->encap ? x->encap->encap_type : 0) != encap_type) { XFRM_INC_STATS(LINUX_MIB_XFRMINSTATEMISMATCH); goto drop_unlock; } if (x->props.replay_window && xfrm_replay_check(x, skb, seq)) { XFRM_INC_STATS(LINUX_MIB_XFRMINSTATESEQERROR); goto drop_unlock; } if (xfrm_state_check_expire(x)) { XFRM_INC_STATS(LINUX_MIB_XFRMINSTATEEXPIRED); goto drop_unlock; } spin_unlock(&x->lock); XFRM_SKB_CB(skb)->seq.input = seq; 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(LINUX_MIB_XFRMINSTATEPROTOERROR); goto drop_unlock; } /* only the first xfrm gets the encap type */ encap_type = 0; if (x->props.replay_window) xfrm_replay_advance(x, seq); x->curlft.bytes += skb->len; x->curlft.packets++; spin_unlock(&x->lock); XFRM_MODE_SKB_CB(skb)->protocol = nexthdr; if (x->inner_mode->input(x, skb)) { XFRM_INC_STATS(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(LINUX_MIB_XFRMINHDRERROR); goto drop; } } while (!err); nf_reset(skb); if (decaps) { dst_release(skb->dst); skb->dst = NULL; netif_rx(skb); return 0; } else { return x->inner_mode->afinfo->transport_finish(skb, async); } drop_unlock: spin_unlock(&x->lock); drop: 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); }