src: add a helper that returns a payload dependency for a particular base

Currently, with only one base and dependency stored this is superfluous,
but it will become more useful when the next commit adds support for
storing a payload for every base.

Remove redundant `ctx->pbase` check.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Florian Westphal <fw@strlen.de>

diff --git a/include/payload.h b/include/payload.h
index 8bc3fb9a8a5456a45180aa09d953525cae32f5d3..af6fa478270604b7802159edf5b28d572b45ae3c 100644 (file)
--- a/include/payload.h
+++ b/include/payload.h
@@ -47,6 +47,8 @@ extern void payload_dependency_store(struct payload_dep_ctx *ctx,
                                     enum proto_bases base);
 extern bool payload_dependency_exists(const struct payload_dep_ctx *ctx,
                                      enum proto_bases base);
+extern struct expr *payload_dependency_get(struct payload_dep_ctx *ctx,
+                                          enum proto_bases base);
 extern void payload_dependency_release(struct payload_dep_ctx *ctx);
 extern void payload_dependency_kill(struct payload_dep_ctx *ctx,
                                    struct expr *expr, unsigned int family);

diff --git a/src/netlink_delinearize.c b/src/netlink_delinearize.c
index 873164299c6d456d8426b5d2a80f77859420bb2b..068d305b3943b6e743e30ef99c04335755155850 100644 (file)
--- a/src/netlink_delinearize.c
+++ b/src/netlink_delinearize.c
@@ -2067,9 +2067,9 @@ static bool meta_may_dependency_kill(struct payload_dep_ctx *ctx,
                                     const struct expr *expr)
 {
        uint8_t l4proto, nfproto = NFPROTO_UNSPEC;
-       struct expr *dep = ctx->pdep->expr;
+       struct expr *dep = payload_dependency_get(ctx, PROTO_BASE_NETWORK_HDR);
 
-       if (ctx->pbase != PROTO_BASE_NETWORK_HDR)
+       if (!dep)
                return true;
 
        if (__meta_dependency_may_kill(dep, &nfproto))

diff --git a/src/payload.c b/src/payload.c
index 576eb149f71d90cb40d76d12581fb2ac68d1e159..accbe0ab6066822b6beec740e7015aed81239ae2 100644 (file)
--- a/src/payload.c
+++ b/src/payload.c
@@ -631,6 +631,27 @@ bool payload_dependency_exists(const struct payload_dep_ctx *ctx,
               (ctx->pbase == base || (base == PROTO_BASE_TRANSPORT_HDR && ctx->pbase == base + 1));
 }
 
+/**
+ * payload_dependency_get - return a payload dependency if available
+ * @ctx: payload dependency context
+ * @base: payload protocol base
+ *
+ * If we have seen a protocol key payload expression for this base, we return
+ * it.
+ */
+struct expr *payload_dependency_get(struct payload_dep_ctx *ctx,
+                                   enum proto_bases base)
+{
+       if (ctx->pbase == base)
+               return ctx->pdep->expr;
+
+       if (base == PROTO_BASE_TRANSPORT_HDR &&
+           ctx->pbase == PROTO_BASE_INNER_HDR)
+               return ctx->pdep->expr;
+
+       return NULL;
+}
+
 void payload_dependency_release(struct payload_dep_ctx *ctx)
 {
        list_del(&ctx->pdep->list);
@@ -661,7 +682,7 @@ static uint8_t icmp_dep_to_type(enum icmp_hdr_field_type t)
 
 static bool payload_may_dependency_kill_icmp(struct payload_dep_ctx *ctx, struct expr *expr)
 {
-       const struct expr *dep = ctx->pdep->expr;
+       const struct expr *dep = payload_dependency_get(ctx, expr->payload.base);
        uint8_t icmp_type;
 
        icmp_type = expr->payload.tmpl->icmp_dep;
@@ -678,9 +699,11 @@ static bool payload_may_dependency_kill_icmp(struct payload_dep_ctx *ctx, struct
 
 static bool payload_may_dependency_kill_ll(struct payload_dep_ctx *ctx, struct expr *expr)
 {
-       const struct expr *dep = ctx->pdep->expr;
+       const struct expr *dep = payload_dependency_get(ctx, expr->payload.base);
 
-       /* Never remove a 'vlan type 0x...' expression, they are never added implicitly */
+       /* Never remove a 'vlan type 0x...' expression, they are never added
+        * implicitly
+        */
        if (dep->left->payload.desc == &proto_vlan)
                return false;
 
@@ -697,7 +720,7 @@ static bool payload_may_dependency_kill_ll(struct payload_dep_ctx *ctx, struct e
 static bool payload_may_dependency_kill(struct payload_dep_ctx *ctx,
                                        unsigned int family, struct expr *expr)
 {
-       struct expr *dep = ctx->pdep->expr;
+       struct expr *dep = payload_dependency_get(ctx, expr->payload.base);
 
        /* Protocol key payload expression at network base such as 'ip6 nexthdr'
         * need to be left in place since it implicitly restricts matching to