From 8f85d9f4469e50ade883b652ab3c112c90d477c3 Mon Sep 17 00:00:00 2001 From: Jeremy Sowden Date: Sat, 15 Jan 2022 18:27:06 +0000 Subject: 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 Signed-off-by: Florian Westphal --- include/payload.h | 2 ++ src/netlink_delinearize.c | 4 ++-- src/payload.c | 31 +++++++++++++++++++++++++++---- 3 files changed, 31 insertions(+), 6 deletions(-) diff --git a/include/payload.h b/include/payload.h index 8bc3fb9a..af6fa478 100644 --- 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 87316429..068d305b 100644 --- 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 576eb149..accbe0ab 100644 --- 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 -- cgit v1.2.3