Merge branch 'ila-make-identifier-format-optional-and-other-fixes'

Tom Herbert says:

====================
ila: make identifier format optional and other fixes

The identifier type and checksum neutral mapping bits are optional
in identifier formats. This patch set fixes the implementation to
make them optional and configurable.

Specific items:

- Clean up checksum diff code in ILA
- Add checksum neutral mapping auto so that checksum neutral
mapping can be configured without requiring use of the C-bit
- Add identifier type configuration and allow identifier
type to be configured so that the identifier type field does
not need to be present
- Added ILA documention: ila.txt

I have fixes for ILA in iproute2 that will be poseted separately.

Tested: Ran netperf TCP_RR on various combinations of checksum
mode and the two supported identifier types.

v2:
- Add proper sign off
- In ILA LWT, only check prefix length includes identifier type
if identifier type is enabled (ILA_ATYPE_USE_FORMAT).
- Add a hook type so that it can be specified whether ILA
translation is done on input or output route funciton in
LWT.
====================

Signed-off-by: David S. Miller <[e-mail]>

Documentation/networking/ila.txt

···
+Identifier Locator Addressing (ILA)
+
+
+Introduction
+============
+
+Identifier-locator addressing (ILA) is a technique used with IPv6 that
+differentiates between location and identity of a network node. Part of an
+address expresses the immutable identity of the node, and another part
+indicates the location of the node which can be dynamic. Identifier-locator
+addressing can be used to efficiently implement overlay networks for
+network virtualization as well as solutions for use cases in mobility.
+
+ILA can be thought of as means to implement an overlay network without
+encapsulation. This is accomplished by performing network address
+translation on destination addresses as a packet traverses a network. To
+the network, an ILA translated packet appears to be no different than any
+other IPv6 packet. For instance, if the transport protocol is TCP then an
+ILA translated packet looks like just another TCP/IPv6 packet. The
+advantage of this is that ILA is transparent to the network so that
+optimizations in the network, such as ECMP, RSS, GRO, GSO, etc., just work.
+
+The ILA protocol is described in Internet-Draft draft-herbert-intarea-ila.
+
+
+ILA terminology
+===============
+
+  - Identifier	A number that identifies an addressable node in the network
+		independent of its location. ILA identifiers are sixty-four
+		bit values.
+
+  - Locator	A network prefix that routes to a physical host. Locators
+		provide the topological location of an addressed node. ILA
+		locators are sixty-four bit prefixes.
+
+  - ILA mapping
+		A mapping of an ILA identifier to a locator (or to a
+		locator and meta data). An ILA domain maintains a database
+		that contains mappings for all destinations in the domain.
+
+  - SIR address
+		An IPv6 address composed of a SIR prefix (upper sixty-
+		four bits) and an identifier (lower sixty-four bits).
+		SIR addresses are visible to applications and provide a
+		means for them to address nodes independent of their
+		location.
+
+  - ILA address
+		An IPv6 address composed of a locator (upper sixty-four
+		bits) and an identifier (low order sixty-four bits). ILA
+		addresses are never visible to an application.
+
+  - ILA host	An end host that is capable of performing ILA translations
+		on transmit or receive.
+
+  - ILA router	A network node that performs ILA translation and forwarding
+		of translated packets.
+
+  - ILA forwarding cache
+		A type of ILA router that only maintains a working set
+		cache of mappings.
+
+  - ILA node	A network node capable of performing ILA translations. This
+		can be an ILA router, ILA forwarding cache, or ILA host.
+
+
+Operation
+=========
+
+There are two fundamental operations with ILA:
+
+  - Translate a SIR address to an ILA address. This is performed on ingress
+    to an ILA overlay.
+
+  - Translate an ILA address to a SIR address. This is performed on egress
+    from the ILA overlay.
+
+ILA can be deployed either on end hosts or intermediate devices in the
+network; these are provided by "ILA hosts" and "ILA routers" respectively.
+Configuration and datapath for these two points of deployment is somewhat
+different.
+
+The diagram below illustrates the flow of packets through ILA as well
+as showing ILA hosts and routers.
+
+    +--------+                                                +--------+
+    | Host A +-+                                         +--->| Host B |
+    |        | |              (2) ILA                   (')   |        |
+    +--------+ |            ...addressed....           (   )  +--------+
+               V  +---+--+  .  packet      .  +---+--+  (_)
+   (1) SIR     |  | ILA  |----->-------->---->| ILA  |   |   (3) SIR
+    addressed  +->|router|  .              .  |router|->-+    addressed
+    packet        +---+--+  .     IPv6     .  +---+--+        packet
+                   /        .    Network   .
+                  /         .              .   +--+-++--------+
+    +--------+   /          .              .   |ILA ||  Host  |
+    |  Host  +--+           .              .- -|host||        |
+    |        |              .              .   +--+-++--------+
+    +--------+              ................
+
+
+Transport checksum handling
+===========================
+
+When an address is translated by ILA, an encapsulated transport checksum
+that includes the translated address in a pseudo header may be rendered
+incorrect on the wire. This is a problem for intermediate devices,
+including checksum offload in NICs, that process the checksum. There are
+three options to deal with this:
+
+- no action	Allow the checksum to be incorrect on the wire. Before
+		a receiver verifies a checksum the ILA to SIR address
+		translation must be done.
+
+- adjust transport checksum
+		When ILA translation is performed the packet is parsed
+		and if a transport layer checksum is found then it is
+		adjusted to reflect the correct checksum per the
+		translated address.
+
+- checksum neutral mapping
+		When an address is translated the difference can be offset
+		elsewhere in a part of the packet that is covered by the
+		the checksum. The low order sixteen bits of the identifier
+		are used. This method is preferred since it doesn't require
+		parsing a packet beyond the IP header and in most cases the
+		adjustment can be precomputed and saved with the mapping.
+
+Note that the checksum neutral adjustment affects the low order sixteen
+bits of the identifier. When ILA to SIR address translation is done on
+egress the low order bits are restored to the original value which
+restores the identifier as it was originally sent.
+
+
+Identifier types
+================
+
+ILA defines different types of identifiers for different use cases.
+
+The defined types are:
+
+      0: interface identifier
+
+      1: locally unique identifier
+
+      2: virtual networking identifier for IPv4 address
+
+      3: virtual networking identifier for IPv6 unicast address
+
+      4: virtual networking identifier for IPv6 multicast address
+
+      5: non-local address identifier
+
+In the current implementation of kernel ILA only locally unique identifiers
+(LUID) are supported. LUID allows for a generic, unformatted 64 bit
+identifier.
+
+
+Identifier formats
+==================
+
+Kernel ILA supports two optional fields in an identifier for formatting:
+"C-bit" and "identifier type". The presence of these fields is determined
+by configuration as demonstrated below.
+
+If the identifier type is present it occupies the three highest order
+bits of an identifier. The possible values are given in the above list.
+
+If the C-bit is present,  this is used as an indication that checksum
+neutral mapping has been done. The C-bit can only be set in an
+ILA address, never a SIR address.
+
+In the simplest format the identifier types, C-bit, and checksum
+adjustment value are not present so an identifier is considered an
+unstructured sixty-four bit value.
+
+     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+     |                            Identifier                         |
+     +                                                               +
+     |                                                               |
+     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+The checksum neutral adjustment may be configured to always be
+present using neutral-map-auto. In this case there is no C-bit, but the
+checksum adjustment is in the low order 16 bits. The identifier is
+still sixty-four bits.
+
+     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+     |                            Identifier                         |
+     |                               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+     |                               |  Checksum-neutral adjustment  |
+     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+The C-bit may used to explicitly indicate that checksum neutral
+mapping has been applied to an ILA address. The format is:
+
+     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+     |     |C|                    Identifier                         |
+     |     +-+                       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+     |                               |  Checksum-neutral adjustment  |
+     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+The identifier type field may be present to indicate the identifier
+type. If it is not present then the type is inferred based on mapping
+configuration. The checksum neutral adjustment may automatically
+used with the identifier type as illustrated below.
+
+     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+     | Type|                      Identifier                         |
+     +-+-+-+                         +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+     |                               |  Checksum-neutral adjustment  |
+     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+If the identifier type and the C-bit can be present simultaneously so
+the identifier format would be:
+
+     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+     | Type|C|                    Identifier                         |
+     +-+-+-+-+                       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+     |                               |  Checksum-neutral adjustment  |
+     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+
+Configuration
+=============
+
+There are two methods to configure ILA mappings. One is by using LWT routes
+and the other is ila_xlat (called from NFHOOK PREROUTING hook). ila_xlat
+is intended to be used in the receive path for ILA hosts .
+
+An ILA router has also been implemented in XDP. Description of that is
+outside the scope of this document.
+
+The usage of for ILA LWT routes is:
+
+ip route add DEST/128 encap ila LOC csum-mode MODE ident-type TYPE via ADDR
+
+Destination (DEST) can either be a SIR address (for an ILA host or ingress
+ILA router) or an ILA address (egress ILA router). LOC is the sixty-four
+bit locator (with format W:X:Y:Z) that overwrites the upper sixty-four
+bits of the destination address.  Checksum MODE is one of "no-action",
+"adj-transport", "neutral-map", and "neutral-map-auto". If neutral-map is
+set then the C-bit will be present. Identifier TYPE one of "luid" or
+"use-format." In the case of use-format, the identifier type field is
+present and the effective type is taken from that.
+
+The usage of ila_xlat is:
+
+ip ila add loc_match MATCH loc LOC csum-mode MODE ident-type TYPE
+
+MATCH indicates the incoming locator that must be matched to apply
+a the translaiton. LOC is the locator that overwrites the upper
+sixty-four bits of the destination address. MODE and TYPE have the
+same meanings as described above.
+
+
+Some examples
+=============
+
+# Configure an ILA route that uses checksum neutral mapping as well
+# as type field. Note that the type field is set in the SIR address
+# (the 2000 implies type is 1 which is LUID).
+ip route add 3333:0:0:1:2000:0:1:87/128 encap ila 2001:0:87:0 \
+     csum-mode neutral-map ident-type use-format
+
+# Configure an ILA LWT route that uses auto checksum neutral mapping
+# (no C-bit) and configure identifier type to be LUID so that the
+# identifier type field will not be present.
+ip route add 3333:0:0:1:2000:0:2:87/128 encap ila 2001:0:87:1 \
+     csum-mode neutral-map-auto ident-type luid
+
+ila_xlat configuration
+
+# Configure an ILA to SIR mapping that matches a locator and overwrites
+# it with a SIR address (3333:0:0:1 in this example). The C-bit and
+# identifier field are used.
+ip ila add loc_match 2001:0:119:0 loc 3333:0:0:1 \
+    csum-mode neutral-map-auto ident-type use-format
+
+# Configure an ILA to SIR mapping where checksum neutral is automatically
+# set without the C-bit and the identifier type is configured to be LUID
+# so that the identifier type field is not present.
+ip ila add loc_match 2001:0:119:0 loc 3333:0:0:1 \
+    csum-mode neutral-map-auto ident-type use-format

include/uapi/linux/ila.h

···
 	ILA_ATTR_DIR,				/* u32 */
 	ILA_ATTR_PAD,
 	ILA_ATTR_CSUM_MODE,			/* u8 */
+	ILA_ATTR_IDENT_TYPE,			/* u8 */
+	ILA_ATTR_HOOK_TYPE,			/* u8 */
 
 	__ILA_ATTR_MAX,
 };
···
 	ILA_CSUM_ADJUST_TRANSPORT,
 	ILA_CSUM_NEUTRAL_MAP,
 	ILA_CSUM_NO_ACTION,
+	ILA_CSUM_NEUTRAL_MAP_AUTO,
+};
+
+enum {
+	ILA_ATYPE_IID = 0,
+	ILA_ATYPE_LUID,
+	ILA_ATYPE_VIRT_V4,
+	ILA_ATYPE_VIRT_UNI_V6,
+	ILA_ATYPE_VIRT_MULTI_V6,
+	ILA_ATYPE_NONLOCAL_ADDR,
+	ILA_ATYPE_RSVD_1,
+	ILA_ATYPE_RSVD_2,
+
+	ILA_ATYPE_USE_FORMAT = 32, /* Get type from type field in identifier */
+};
+
+enum {
+	ILA_HOOK_ROUTE_OUTPUT,
+	ILA_HOOK_ROUTE_INPUT,
 };
 
 #endif /* _UAPI_LINUX_ILA_H */

net/ipv6/ila/ila.h

···
 	};
 };
 
-enum {
-	ILA_ATYPE_IID = 0,
-	ILA_ATYPE_LUID,
-	ILA_ATYPE_VIRT_V4,
-	ILA_ATYPE_VIRT_UNI_V6,
-	ILA_ATYPE_VIRT_MULTI_V6,
-	ILA_ATYPE_RSVD_1,
-	ILA_ATYPE_RSVD_2,
-	ILA_ATYPE_RSVD_3,
-};
-
 #define CSUM_NEUTRAL_FLAG	htonl(0x10000000)
 
 struct ila_addr {
···
 	struct ila_locator locator_match;
 	__wsum csum_diff;
 	u8 csum_mode;
+	u8 ident_type;
 };
 
 static inline __wsum compute_csum_diff8(const __be32 *from, const __be32 *to)

net/ipv6/ila/ila_common.c

···
 #include <uapi/linux/ila.h>
 #include "ila.h"
 
-static __wsum get_csum_diff(struct ipv6hdr *ip6h, struct ila_params *p)
+void ila_init_saved_csum(struct ila_params *p)
 {
-	struct ila_addr *iaddr = ila_a2i(&ip6h->daddr);
+	if (!p->locator_match.v64)
+		return;
 
+	p->csum_diff = compute_csum_diff8(
+				(__be32 *)&p->locator,
+				(__be32 *)&p->locator_match);
+}
+
+static __wsum get_csum_diff_iaddr(struct ila_addr *iaddr, struct ila_params *p)
+{
 	if (p->locator_match.v64)
 		return p->csum_diff;
 	else
-		return compute_csum_diff8((__be32 *)&iaddr->loc,
-					  (__be32 *)&p->locator);
+		return compute_csum_diff8((__be32 *)&p->locator,
+					  (__be32 *)&iaddr->loc);
 }
 
-static void ila_csum_do_neutral(struct ila_addr *iaddr,
-				struct ila_params *p)
+static __wsum get_csum_diff(struct ipv6hdr *ip6h, struct ila_params *p)
+{
+	return get_csum_diff_iaddr(ila_a2i(&ip6h->daddr), p);
+}
+
+static void ila_csum_do_neutral_fmt(struct ila_addr *iaddr,
+				    struct ila_params *p)
 {
 	__sum16 *adjust = (__force __sum16 *)&iaddr->ident.v16[3];
 	__wsum diff, fval;
 
-	/* Check if checksum adjust value has been cached */
-	if (p->locator_match.v64) {
-		diff = p->csum_diff;
-	} else {
-		diff = compute_csum_diff8((__be32 *)&p->locator,
-					  (__be32 *)iaddr);
-	}
+	diff = get_csum_diff_iaddr(iaddr, p);
 
 	fval = (__force __wsum)(ila_csum_neutral_set(iaddr->ident) ?
 			CSUM_NEUTRAL_FLAG : ~CSUM_NEUTRAL_FLAG);
···
 	iaddr->ident.csum_neutral ^= 1;
 }
 
+static void ila_csum_do_neutral_nofmt(struct ila_addr *iaddr,
+				      struct ila_params *p)
+{
+	__sum16 *adjust = (__force __sum16 *)&iaddr->ident.v16[3];
+	__wsum diff;
+
+	diff = get_csum_diff_iaddr(iaddr, p);
+
+	*adjust = ~csum_fold(csum_add(diff, csum_unfold(*adjust)));
+}
+
 static void ila_csum_adjust_transport(struct sk_buff *skb,
 				      struct ila_params *p)
 {
-	__wsum diff;
-	struct ipv6hdr *ip6h = ipv6_hdr(skb);
-	struct ila_addr *iaddr = ila_a2i(&ip6h->daddr);
 	size_t nhoff = sizeof(struct ipv6hdr);
+	struct ipv6hdr *ip6h = ipv6_hdr(skb);
+	__wsum diff;
 
 	switch (ip6h->nexthdr) {
 	case NEXTHDR_TCP:
···
 		}
 		break;
 	}
-
-	/* Now change destination address */
-	iaddr->loc = p->locator;
 }
 
 void ila_update_ipv6_locator(struct sk_buff *skb, struct ila_params *p,
-			     bool set_csum_neutral)
+			     bool sir2ila)
 {
 	struct ipv6hdr *ip6h = ipv6_hdr(skb);
 	struct ila_addr *iaddr = ila_a2i(&ip6h->daddr);
 
-	/* First deal with the transport checksum */
-	if (ila_csum_neutral_set(iaddr->ident)) {
-		/* C-bit is set in the locator indicating that this
-		 * is a locator being translated to a SIR address.
-		 * Perform (receiver) checksum-neutral translation.
-		 */
-		if (!set_csum_neutral)
-			ila_csum_do_neutral(iaddr, p);
-	} else {
-		switch (p->csum_mode) {
-		case ILA_CSUM_ADJUST_TRANSPORT:
-			ila_csum_adjust_transport(skb, p);
-			break;
-		case ILA_CSUM_NEUTRAL_MAP:
-			ila_csum_do_neutral(iaddr, p);
-			break;
-		case ILA_CSUM_NO_ACTION:
+	switch (p->csum_mode) {
+	case ILA_CSUM_ADJUST_TRANSPORT:
+		ila_csum_adjust_transport(skb, p);
+		break;
+	case ILA_CSUM_NEUTRAL_MAP:
+		if (sir2ila) {
+			if (WARN_ON(ila_csum_neutral_set(iaddr->ident))) {
+				/* Checksum flag should never be
+				 * set in a formatted SIR address.
+				 */
+				break;
+			}
+		} else if (!ila_csum_neutral_set(iaddr->ident)) {
+			/* ILA to SIR translation and C-bit isn't
+			 * set so we're good.
+			 */
 			break;
 		}
+		ila_csum_do_neutral_fmt(iaddr, p);
+		break;
+	case ILA_CSUM_NEUTRAL_MAP_AUTO:
+		ila_csum_do_neutral_nofmt(iaddr, p);
+		break;
+	case ILA_CSUM_NO_ACTION:
+		break;
 	}
 
 	/* Now change destination address */
 	iaddr->loc = p->locator;
-}
-
-void ila_init_saved_csum(struct ila_params *p)
-{
-	if (!p->locator_match.v64)
-		return;
-
-	p->csum_diff = compute_csum_diff8(
-				(__be32 *)&p->locator,
-				(__be32 *)&p->locator_match);
 }
 
 static int __init ila_init(void)

net/ipv6/ila/ila_lwt.c

···
 	struct ila_params p;
 	struct dst_cache dst_cache;
 	u32 connected : 1;
+	u32 lwt_output : 1;
 };
 
 static inline struct ila_lwt *ila_lwt_lwtunnel(
···
 	if (skb->protocol != htons(ETH_P_IPV6))
 		goto drop;
 
-	ila_update_ipv6_locator(skb, ila_params_lwtunnel(orig_dst->lwtstate),
-				true);
+	if (ilwt->lwt_output)
+		ila_update_ipv6_locator(skb,
+					ila_params_lwtunnel(orig_dst->lwtstate),
+					true);
 
 	if (rt->rt6i_flags & (RTF_GATEWAY | RTF_CACHE)) {
 		/* Already have a next hop address in route, no need for
···
 static int ila_input(struct sk_buff *skb)
 {
 	struct dst_entry *dst = skb_dst(skb);
+	struct ila_lwt *ilwt = ila_lwt_lwtunnel(dst->lwtstate);
 
 	if (skb->protocol != htons(ETH_P_IPV6))
 		goto drop;
 
-	ila_update_ipv6_locator(skb, ila_params_lwtunnel(dst->lwtstate), false);
+	if (!ilwt->lwt_output)
+		ila_update_ipv6_locator(skb,
+					ila_params_lwtunnel(dst->lwtstate),
+					false);
 
 	return dst->lwtstate->orig_input(skb);
 
···
 static const struct nla_policy ila_nl_policy[ILA_ATTR_MAX + 1] = {
 	[ILA_ATTR_LOCATOR] = { .type = NLA_U64, },
 	[ILA_ATTR_CSUM_MODE] = { .type = NLA_U8, },
+	[ILA_ATTR_IDENT_TYPE] = { .type = NLA_U8, },
+	[ILA_ATTR_HOOK_TYPE] = { .type = NLA_U8, },
 };
 
 static int ila_build_state(struct nlattr *nla,
···
 	struct lwtunnel_state *newts;
 	const struct fib6_config *cfg6 = cfg;
 	struct ila_addr *iaddr;
+	u8 ident_type = ILA_ATYPE_USE_FORMAT;
+	u8 hook_type = ILA_HOOK_ROUTE_OUTPUT;
+	u8 csum_mode = ILA_CSUM_NO_ACTION;
+	bool lwt_output = true;
+	u8 eff_ident_type;
 	int ret;
 
 	if (family != AF_INET6)
 		return -EINVAL;
-
-	if (cfg6->fc_dst_len < 8 * sizeof(struct ila_locator) + 3) {
-		/* Need to have full locator and at least type field
-		 * included in destination
-		 */
-		return -EINVAL;
-	}
-
-	iaddr = (struct ila_addr *)&cfg6->fc_dst;
-
-	if (!ila_addr_is_ila(iaddr) || ila_csum_neutral_set(iaddr->ident)) {
-		/* Don't allow translation for a non-ILA address or checksum
-		 * neutral flag to be set.
-		 */
-		return -EINVAL;
-	}
 
 	ret = nla_parse_nested(tb, ILA_ATTR_MAX, nla, ila_nl_policy, extack);
 	if (ret < 0)
···
 
 	if (!tb[ILA_ATTR_LOCATOR])
 		return -EINVAL;
+
+	iaddr = (struct ila_addr *)&cfg6->fc_dst;
+
+	if (tb[ILA_ATTR_IDENT_TYPE])
+		ident_type = nla_get_u8(tb[ILA_ATTR_IDENT_TYPE]);
+
+	if (ident_type == ILA_ATYPE_USE_FORMAT) {
+		/* Infer identifier type from type field in formatted
+		 * identifier.
+		 */
+
+		if (cfg6->fc_dst_len < 8 * sizeof(struct ila_locator) + 3) {
+			/* Need to have full locator and at least type field
+			 * included in destination
+			 */
+			return -EINVAL;
+		}
+
+		eff_ident_type = iaddr->ident.type;
+	} else {
+		eff_ident_type = ident_type;
+	}
+
+	switch (eff_ident_type) {
+	case ILA_ATYPE_IID:
+		/* Don't allow ILA for IID type */
+		return -EINVAL;
+	case ILA_ATYPE_LUID:
+		break;
+	case ILA_ATYPE_VIRT_V4:
+	case ILA_ATYPE_VIRT_UNI_V6:
+	case ILA_ATYPE_VIRT_MULTI_V6:
+	case ILA_ATYPE_NONLOCAL_ADDR:
+		/* These ILA formats are not supported yet. */
+	default:
+		return -EINVAL;
+	}
+
+	if (tb[ILA_ATTR_HOOK_TYPE])
+		hook_type = nla_get_u8(tb[ILA_ATTR_HOOK_TYPE]);
+
+	switch (hook_type) {
+	case ILA_HOOK_ROUTE_OUTPUT:
+		lwt_output = true;
+		break;
+	case ILA_HOOK_ROUTE_INPUT:
+		lwt_output = false;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (tb[ILA_ATTR_CSUM_MODE])
+		csum_mode = nla_get_u8(tb[ILA_ATTR_CSUM_MODE]);
+
+	if (csum_mode == ILA_CSUM_NEUTRAL_MAP &&
+	    ila_csum_neutral_set(iaddr->ident)) {
+		/* Don't allow translation if checksum neutral bit is
+		 * configured and it's set in the SIR address.
+		 */
+		return -EINVAL;
+	}
 
 	newts = lwtunnel_state_alloc(sizeof(*ilwt));
 	if (!newts)
···
 		return ret;
 	}
 
+	ilwt->lwt_output = !!lwt_output;
+
 	p = ila_params_lwtunnel(newts);
 
+	p->csum_mode = csum_mode;
+	p->ident_type = ident_type;
 	p->locator.v64 = (__force __be64)nla_get_u64(tb[ILA_ATTR_LOCATOR]);
 
 	/* Precompute checksum difference for translation since we
 	 * know both the old locator and the new one.
 	 */
 	p->locator_match = iaddr->loc;
-	p->csum_diff = compute_csum_diff8(
-		(__be32 *)&p->locator_match, (__be32 *)&p->locator);
-
-	if (tb[ILA_ATTR_CSUM_MODE])
-		p->csum_mode = nla_get_u8(tb[ILA_ATTR_CSUM_MODE]);
 
 	ila_init_saved_csum(p);
 
···
 			       struct lwtunnel_state *lwtstate)
 {
 	struct ila_params *p = ila_params_lwtunnel(lwtstate);
+	struct ila_lwt *ilwt = ila_lwt_lwtunnel(lwtstate);
 
 	if (nla_put_u64_64bit(skb, ILA_ATTR_LOCATOR, (__force u64)p->locator.v64,
 			      ILA_ATTR_PAD))
 		goto nla_put_failure;
+
 	if (nla_put_u8(skb, ILA_ATTR_CSUM_MODE, (__force u8)p->csum_mode))
+		goto nla_put_failure;
+
+	if (nla_put_u8(skb, ILA_ATTR_IDENT_TYPE, (__force u8)p->ident_type))
+		goto nla_put_failure;
+
+	if (nla_put_u8(skb, ILA_ATTR_HOOK_TYPE,
+		       ilwt->lwt_output ? ILA_HOOK_ROUTE_OUTPUT :
+					  ILA_HOOK_ROUTE_INPUT))
 		goto nla_put_failure;
 
 	return 0;
···
 {
 	return nla_total_size_64bit(sizeof(u64)) + /* ILA_ATTR_LOCATOR */
 	       nla_total_size(sizeof(u8)) +        /* ILA_ATTR_CSUM_MODE */
+	       nla_total_size(sizeof(u8)) +        /* ILA_ATTR_IDENT_TYPE */
+	       nla_total_size(sizeof(u8)) +        /* ILA_ATTR_HOOK_TYPE */
 	       0;
 }
 

net/ipv6/ila/ila_xlat.c

···
 	[ILA_ATTR_LOCATOR_MATCH] = { .type = NLA_U64, },
 	[ILA_ATTR_IFINDEX] = { .type = NLA_U32, },
 	[ILA_ATTR_CSUM_MODE] = { .type = NLA_U8, },
+	[ILA_ATTR_IDENT_TYPE] = { .type = NLA_U8, },
 };
 
 static int parse_nl_config(struct genl_info *info,
···
 
 	if (info->attrs[ILA_ATTR_CSUM_MODE])
 		xp->ip.csum_mode = nla_get_u8(info->attrs[ILA_ATTR_CSUM_MODE]);
+	else
+		xp->ip.csum_mode = ILA_CSUM_NO_ACTION;
+
+	if (info->attrs[ILA_ATTR_IDENT_TYPE])
+		xp->ip.ident_type = nla_get_u8(
+				info->attrs[ILA_ATTR_IDENT_TYPE]);
+	else
+		xp->ip.ident_type = ILA_ATYPE_USE_FORMAT;
 
 	if (info->attrs[ILA_ATTR_IFINDEX])
 		xp->ifindex = nla_get_s32(info->attrs[ILA_ATTR_IFINDEX]);
···
 	}
 }
 
-static int ila_xlat_addr(struct sk_buff *skb, bool set_csum_neutral);
+static int ila_xlat_addr(struct sk_buff *skb, bool sir2ila);
 
 static unsigned int
 ila_nf_input(void *priv,
···
 			      (__force u64)ila->xp.ip.locator_match.v64,
 			      ILA_ATTR_PAD) ||
 	    nla_put_s32(msg, ILA_ATTR_IFINDEX, ila->xp.ifindex) ||
-	    nla_put_u32(msg, ILA_ATTR_CSUM_MODE, ila->xp.ip.csum_mode))
+	    nla_put_u8(msg, ILA_ATTR_CSUM_MODE, ila->xp.ip.csum_mode) ||
+	    nla_put_u8(msg, ILA_ATTR_IDENT_TYPE, ila->xp.ip.ident_type))
 		return -1;
 
 	return 0;
···
 	.size = sizeof(struct ila_net),
 };
 
-static int ila_xlat_addr(struct sk_buff *skb, bool set_csum_neutral)
+static int ila_xlat_addr(struct sk_buff *skb, bool sir2ila)
 {
 	struct ila_map *ila;
 	struct ipv6hdr *ip6h = ipv6_hdr(skb);
···
 
 	/* Assumes skb contains a valid IPv6 header that is pulled */
 
-	if (!ila_addr_is_ila(iaddr)) {
-		/* Type indicates this is not an ILA address */
-		return 0;
-	}
+	/* No check here that ILA type in the mapping matches what is in the
+	 * address. We assume that whatever sender gaves us can be translated.
+	 * The checksum mode however is relevant.
+	 */
 
 	rcu_read_lock();
 
 	ila = ila_lookup_wildcards(iaddr, skb->dev->ifindex, ilan);
 	if (ila)
-		ila_update_ipv6_locator(skb, &ila->xp.ip, set_csum_neutral);
+		ila_update_ipv6_locator(skb, &ila->xp.ip, sir2ila);
 
 	rcu_read_unlock();