4 files changed, 61 insertions, 44 deletions

diff --git a/include/uapi/linux/ila.h b/include/uapi/linux/ila.h
index f54853288f99..0744881dcef3 100644
--- a/include/uapi/linux/ila.h
+++ b/include/uapi/linux/ila.h
@@ -41,6 +41,7 @@ enum {
         ILA_CSUM_ADJUST_TRANSPORT,
         ILA_CSUM_NEUTRAL_MAP,
         ILA_CSUM_NO_ACTION,
+        ILA_CSUM_NEUTRAL_MAP_AUTO,
 };
 
 #endif /* _UAPI_LINUX_ILA_H */
diff --git a/net/ipv6/ila/ila_common.c b/net/ipv6/ila/ila_common.c
index f1d9248d8b86..8c88ecf29b93 100644
--- a/net/ipv6/ila/ila_common.c
+++ b/net/ipv6/ila/ila_common.c
@@ -37,8 +37,8 @@ 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,
-                                struct ila_params *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;
@@ -60,13 +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:
@@ -105,36 +115,39 @@ 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);
-                        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 */
diff --git a/net/ipv6/ila/ila_lwt.c b/net/ipv6/ila/ila_lwt.c
index 696281b4bca2..104af07d83a6 100644
--- a/net/ipv6/ila/ila_lwt.c
+++ b/net/ipv6/ila/ila_lwt.c
@@ -127,6 +127,7 @@ static int ila_build_state(struct nlattr *nla,
         struct lwtunnel_state *newts;
         const struct fib6_config *cfg6 = cfg;
         struct ila_addr *iaddr;
+        u8 csum_mode = ILA_CSUM_NO_ACTION;
         int ret;
 
         if (family != AF_INET6)
@@ -139,15 +140,6 @@ static int ila_build_state(struct nlattr *nla,
                 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)
                 return ret;
@@ -155,6 +147,19 @@ static int ila_build_state(struct nlattr *nla,
         if (!tb[ILA_ATTR_LOCATOR])
                 return -EINVAL;
 
+        iaddr = (struct ila_addr *)&cfg6->fc_dst;
+
+        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 -ENOMEM;
@@ -168,17 +173,13 @@ static int ila_build_state(struct nlattr *nla,
 
         p = ila_params_lwtunnel(newts);
 
+        p->csum_mode = csum_mode;
         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);
 
diff --git a/net/ipv6/ila/ila_xlat.c b/net/ipv6/ila/ila_xlat.c
index 3123b9de91b5..213259629e66 100644
--- a/net/ipv6/ila/ila_xlat.c
+++ b/net/ipv6/ila/ila_xlat.c
@@ -138,6 +138,8 @@ 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_IFINDEX])