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 <davem@davemloft.net>

include/uapi/linux/ila.h

@@ -17,6 +17,8 @@ enum {
 	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,
 };
@@ -41,6 +43,25 @@ enum {
 	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

@@ -55,17 +55,6 @@ struct ila_identifier {
 	};
 };
 
-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 {
@@ -93,6 +82,7 @@ struct ila_params {
 	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

@@ -13,30 +13,37 @@
 #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 __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(struct ila_addr *iaddr,
+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);
@@ -53,13 +60,23 @@ static void ila_csum_do_neutral(struct ila_addr *iaddr,
 	iaddr->ident.csum_neutral ^= 1;
 }
 
-static void ila_csum_adjust_transport(struct sk_buff *skb,
+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;
-	struct ipv6hdr *ip6h = ipv6_hdr(skb);
-	struct ila_addr *iaddr = ila_a2i(&ip6h->daddr);
+
+	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)
+{
 	size_t nhoff = sizeof(struct ipv6hdr);
+	struct ipv6hdr *ip6h = ipv6_hdr(skb);
+	__wsum diff;
 
 	switch (ip6h->nexthdr) {
 	case NEXTHDR_TCP:
@@ -98,52 +115,45 @@ static void ila_csum_adjust_transport(struct sk_buff *skb,
 		}
 		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);
+		if (sir2ila) {
+			if (WARN_ON(ila_csum_neutral_set(iaddr->ident))) {
+				/* Checksum flag should never be
+				 * set in a formatted SIR address.
+				 */
 				break;
-		case ILA_CSUM_NO_ACTION:
+			}
+		} 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)
 {
 	int ret;

net/ipv6/ila/ila_lwt.c

@@ -20,6 +20,7 @@ struct ila_lwt {
 	struct ila_params p;
 	struct dst_cache dst_cache;
 	u32 connected : 1;
+	u32 lwt_output : 1;
 };
 
 static inline struct ila_lwt *ila_lwt_lwtunnel(
@@ -45,7 +46,9 @@ static int ila_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 	if (skb->protocol != htons(ETH_P_IPV6))
 		goto drop;
 
-	ila_update_ipv6_locator(skb, ila_params_lwtunnel(orig_dst->lwtstate),
+	if (ilwt->lwt_output)
+		ila_update_ipv6_locator(skb,
+					ila_params_lwtunnel(orig_dst->lwtstate),
 					true);
 
 	if (rt->rt6i_flags & (RTF_GATEWAY | RTF_CACHE)) {
@@ -98,11 +101,15 @@ static int ila_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 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);
 
@@ -114,6 +121,8 @@ static int ila_input(struct sk_buff *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,
@@ -127,11 +136,33 @@ 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;
 
+	ret = nla_parse_nested(tb, ILA_ATTR_MAX, nla, ila_nl_policy, extack);
+	if (ret < 0)
+		return ret;
+
+	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
@@ -139,21 +170,50 @@ static int ila_build_state(struct nlattr *nla,
 			return -EINVAL;
 		}
 
-	iaddr = (struct ila_addr *)&cfg6->fc_dst;
+		eff_ident_type = iaddr->ident.type;
+	} else {
+		eff_ident_type = ident_type;
+	}
 
-	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.
-		 */
+	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;
 	}
 
-	ret = nla_parse_nested(tb, ILA_ATTR_MAX, nla, ila_nl_policy, extack);
-	if (ret < 0)
-		return ret;
+	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_LOCATOR])
+	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)
@@ -166,19 +226,18 @@ static int ila_build_state(struct nlattr *nla,
 		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);
 
@@ -203,13 +262,23 @@ static int ila_fill_encap_info(struct sk_buff *skb,
 			       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;
 
 nla_put_failure:
@@ -220,6 +289,8 @@ static int ila_encap_nlsize(struct lwtunnel_state *lwtstate)
 {
 	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

@@ -121,6 +121,7 @@ static const struct nla_policy ila_nl_policy[ILA_ATTR_MAX + 1] = {
 	[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,
@@ -138,6 +139,14 @@ 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]);
@@ -198,7 +207,7 @@ static void ila_free_cb(void *ptr, void *arg)
 	}
 }
 
-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,
@@ -396,7 +405,8 @@ static int ila_fill_info(struct ila_map *ila, struct sk_buff *msg)
 			      (__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;
@@ -607,7 +617,7 @@ static struct pernet_operations ila_net_ops = {
 	.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);
@@ -617,16 +627,16 @@ static int ila_xlat_addr(struct sk_buff *skb, bool set_csum_neutral)
 
 	/* 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();