1 files changed, 181 insertions, 0 deletions

diff --git a/sys/kern/uipc_mbufhash.c b/sys/kern/uipc_mbufhash.c
new file mode 100644
index 000000000000..75f4f93988f9
--- /dev/null
+++ b/sys/kern/uipc_mbufhash.c
@@ -0,0 +1,181 @@
+/*	$OpenBSD: if_trunk.c,v 1.30 2007/01/31 06:20:19 reyk Exp $	*/
+
+/*
+ * Copyright (c) 2005, 2006 Reyk Floeter <reyk@openbsd.org>
+ * Copyright (c) 2007 Andrew Thompson <thompsa@FreeBSD.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "opt_inet.h"
+#include "opt_inet6.h"
+
+#include <sys/param.h>
+#include <sys/kernel.h>
+#include <sys/mbuf.h>
+#include <sys/fnv_hash.h>
+#include <sys/socket.h>
+
+#include <net/if.h>
+#include <net/if_var.h>
+
+#include <net/ethernet.h>
+
+#if defined(INET) || defined(INET6)
+#include <netinet/in.h>
+#endif
+
+#ifdef INET
+#include <netinet/ip.h>
+#endif
+
+#ifdef INET6
+#include <netinet/ip6.h>
+#endif
+
+#include <net/if_vlan_var.h>
+
+static const void *
+m_ether_tcpip_hash_gethdr(const struct mbuf *m, const u_int off,
+    const u_int len, void *buf)
+{
+
+	if (m->m_pkthdr.len < (off + len)) {
+		return (NULL);
+	} else if (m->m_len < (off + len)) {
+		m_copydata(m, off, len, buf);
+		return (buf);
+	}
+	return (mtod(m, char *) + off);
+}
+
+uint32_t
+m_ether_tcpip_hash_init(void)
+{
+	uint32_t seed;
+
+	seed = arc4random();
+	return (fnv_32_buf(&seed, sizeof(seed), FNV1_32_INIT));
+}
+
+uint32_t
+m_ether_tcpip_hash(const uint32_t flags, const struct mbuf *m,
+    const uint32_t key)
+{
+	union {
+#ifdef INET
+		struct ip ip;
+#endif
+#ifdef INET6
+		struct ip6_hdr ip6;
+#endif
+		struct ether_vlan_header vlan;
+		uint32_t port;
+	} buf;
+	struct ether_header *eh;
+	const struct ether_vlan_header *vlan;
+#ifdef INET
+	const struct ip *ip;
+#endif
+#ifdef INET6
+	const struct ip6_hdr *ip6;
+#endif
+	uint32_t p;
+	int off;
+	uint16_t etype;
+
+	p = key;
+	off = sizeof(*eh);
+	if (m->m_len < off)
+		goto done;
+	eh = mtod(m, struct ether_header *);
+	etype = ntohs(eh->ether_type);
+	if (flags & MBUF_HASHFLAG_L2) {
+		p = fnv_32_buf(&eh->ether_shost, ETHER_ADDR_LEN, p);
+		p = fnv_32_buf(&eh->ether_dhost, ETHER_ADDR_LEN, p);
+	}
+	/* Special handling for encapsulating VLAN frames */
+	if ((m->m_flags & M_VLANTAG) && (flags & MBUF_HASHFLAG_L2)) {
+		p = fnv_32_buf(&m->m_pkthdr.ether_vtag,
+		    sizeof(m->m_pkthdr.ether_vtag), p);
+	} else if (etype == ETHERTYPE_VLAN) {
+		vlan = m_ether_tcpip_hash_gethdr(m, off, sizeof(*vlan), &buf);
+		if (vlan == NULL)
+			goto done;
+
+		if (flags & MBUF_HASHFLAG_L2)
+			p = fnv_32_buf(&vlan->evl_tag, sizeof(vlan->evl_tag), p);
+		etype = ntohs(vlan->evl_proto);
+		off += sizeof(*vlan) - sizeof(*eh);
+	}
+	switch (etype) {
+#ifdef INET
+	case ETHERTYPE_IP:
+		ip = m_ether_tcpip_hash_gethdr(m, off, sizeof(*ip), &buf);
+		if (ip == NULL)
+			break;
+		if (flags & MBUF_HASHFLAG_L3) {
+			p = fnv_32_buf(&ip->ip_src, sizeof(struct in_addr), p);
+			p = fnv_32_buf(&ip->ip_dst, sizeof(struct in_addr), p);
+		}
+		if (flags & MBUF_HASHFLAG_L4) {
+			const uint32_t *ports;
+			int iphlen;
+
+			switch (ip->ip_p) {
+			case IPPROTO_TCP:
+			case IPPROTO_UDP:
+			case IPPROTO_SCTP:
+				iphlen = ip->ip_hl << 2;
+				if (iphlen < sizeof(*ip))
+					break;
+				off += iphlen;
+				ports = m_ether_tcpip_hash_gethdr(m,
+				    off, sizeof(*ports), &buf);
+				if (ports == NULL)
+					break;
+				p = fnv_32_buf(ports, sizeof(*ports), p);
+				break;
+			default:
+				break;
+			}
+		}
+		break;
+#endif
+#ifdef INET6
+	case ETHERTYPE_IPV6:
+		ip6 = m_ether_tcpip_hash_gethdr(m, off, sizeof(*ip6), &buf);
+		if (ip6 == NULL)
+			break;
+		if (flags & MBUF_HASHFLAG_L3) {
+			p = fnv_32_buf(&ip6->ip6_src, sizeof(struct in6_addr), p);
+			p = fnv_32_buf(&ip6->ip6_dst, sizeof(struct in6_addr), p);
+		}
+		if (flags & MBUF_HASHFLAG_L4) {
+			uint32_t flow;
+
+			/* IPv6 flow label */
+			flow = ip6->ip6_flow & IPV6_FLOWLABEL_MASK;
+			p = fnv_32_buf(&flow, sizeof(flow), p);
+		}
+		break;
+#endif
+	default:
+		break;
+	}
+done:
+	return (p);
+}