From 2b29ea5f3c3ed693fc0579016569a36cb3796703 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 29 Sep 2017 13:54:21 +0200 Subject: src: ct: add eval part to inject dependencies for ct saddr/daddr nft has enough context to determine if a dependeny is needed. add rule ip filter ct original ip6 saddr allows nft to generate an error due to conflicting bases (ip vs ip6). add rule inet filter ct original ip6 saddr allows nft to inject an ipv6 dependency expression. add rule inet filter ct original saddr will print an error and will suggest to add ip/ip6 keyword. Delinerize and print support will be added in followup patches. Signed-off-by: Florian Westphal --- src/evaluate.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 64 insertions(+), 6 deletions(-) (limited to 'src/evaluate.c') diff --git a/src/evaluate.c b/src/evaluate.c index c796c3c3..8735bb76 100644 --- a/src/evaluate.c +++ b/src/evaluate.c @@ -696,27 +696,85 @@ static int expr_evaluate_rt(struct eval_ctx *ctx, struct expr **expr) return expr_evaluate_primary(ctx, expr); } +static int ct_gen_nh_dependency(struct eval_ctx *ctx, struct expr *ct) +{ + const struct proto_desc *base, *base_now; + struct expr *left, *right, *dep; + struct stmt *nstmt = NULL; + + base_now = ctx->pctx.protocol[PROTO_BASE_NETWORK_HDR].desc; + + switch (ct->ct.nfproto) { + case NFPROTO_IPV4: + base = &proto_ip; + break; + case NFPROTO_IPV6: + base = &proto_ip6; + break; + default: + base = ctx->pctx.protocol[PROTO_BASE_NETWORK_HDR].desc; + if (base == &proto_ip) + ct->ct.nfproto = NFPROTO_IPV4; + else if (base == &proto_ip) + ct->ct.nfproto = NFPROTO_IPV6; + + if (base) + break; + + return expr_error(ctx->msgs, ct, + "cannot determine ip protocol version, use \"ip %1$caddr\" or \"ip6 %1$caddr\" instead", + ct->ct.key == NFT_CT_SRC ? 's' : 'd'); + } + + /* no additional dependency needed? */ + if (base == base_now) + return 0; + + if (base_now && base_now != base) + return expr_error(ctx->msgs, ct, + "conflicting dependencies: %s vs. %s\n", + base->name, + ctx->pctx.protocol[PROTO_BASE_NETWORK_HDR].desc->name); + switch (ctx->pctx.family) { + case NFPROTO_IPV4: + case NFPROTO_IPV6: + return 0; + } + + left = ct_expr_alloc(&ct->location, NFT_CT_L3PROTOCOL, ct->ct.direction, ct->ct.nfproto); + + right = constant_expr_alloc(&ct->location, left->dtype, + left->dtype->byteorder, left->len, + constant_data_ptr(ct->ct.nfproto, left->len)); + dep = relational_expr_alloc(&ct->location, OP_EQ, left, right); + + left->ops->pctx_update(&ctx->pctx, dep); + + nstmt = expr_stmt_alloc(&dep->location, dep); + + list_add_tail(&nstmt->list, &ctx->stmt->list); + return 0; +} + /* * CT expression: update the protocol dependant types bases on the protocol * context. */ static int expr_evaluate_ct(struct eval_ctx *ctx, struct expr **expr) { - const struct proto_desc *base; struct expr *ct = *expr; - ct_expr_update_type(&ctx->pctx, ct); - - base = ctx->pctx.protocol[PROTO_BASE_NETWORK_HDR].desc; switch (ct->ct.key) { case NFT_CT_SRC: case NFT_CT_DST: - if (base != &proto_ip && base != &proto_ip6) - return expr_error_base(ctx->msgs, ct); + ct_gen_nh_dependency(ctx, ct); + break; default: break; } + ct_expr_update_type(&ctx->pctx, ct); + return expr_evaluate_primary(ctx, expr); } -- cgit v1.2.3