From 0379244930035b3bff95281a58fa7efd7e50dd51 Mon Sep 17 00:00:00 2001 From: Jeremy Sowden Date: Sat, 11 Dec 2021 18:55:25 +0000 Subject: evaluate: reject: support ethernet as L2 protocol for inet table When we are evaluating a `reject` statement in the `inet` family, we may have `ether` and `ip` or `ip6` as the L2 and L3 protocols in the evaluation context: table inet filter { chain input { type filter hook input priority filter; ether saddr aa:bb:cc:dd:ee:ff ip daddr 192.168.0.1 reject } } Since no `reject` option is given, nft attempts to infer one and fails: BUG: unsupported familynft: evaluate.c:2766:stmt_evaluate_reject_inet_family: Assertion `0' failed. Aborted The reason it fails is that the ethernet protocol numbers for IPv4 and IPv6 (`ETH_P_IP` and `ETH_P_IPV6`) do not match `NFPROTO_IPV4` and `NFPROTO_IPV6`. Add support for the ethernet protocol numbers. Replace the current `BUG("unsupported family")` error message with something more informative that tells the user to provide an explicit reject option. Add a Python test case. Fixes: 5fdd0b6a0600 ("nft: complete reject support") Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1001360 Signed-off-by: Jeremy Sowden Signed-off-by: Pablo Neira Ayuso --- src/evaluate.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'src/evaluate.c') diff --git a/src/evaluate.c b/src/evaluate.c index 4d4dcc2e..8edefbd1 100644 --- a/src/evaluate.c +++ b/src/evaluate.c @@ -2751,19 +2751,22 @@ static int stmt_evaluate_reject_inet_family(struct eval_ctx *ctx, protocol = proto_find_num(base, desc); switch (protocol) { case NFPROTO_IPV4: + case __constant_htons(ETH_P_IP): if (stmt->reject.family == NFPROTO_IPV4) break; return stmt_binary_error(ctx, stmt->reject.expr, &ctx->pctx.protocol[PROTO_BASE_NETWORK_HDR], "conflicting protocols specified: ip vs ip6"); case NFPROTO_IPV6: + case __constant_htons(ETH_P_IPV6): if (stmt->reject.family == NFPROTO_IPV6) break; return stmt_binary_error(ctx, stmt->reject.expr, &ctx->pctx.protocol[PROTO_BASE_NETWORK_HDR], "conflicting protocols specified: ip vs ip6"); default: - BUG("unsupported family"); + return stmt_error(ctx, stmt, + "cannot infer ICMP reject variant to use: explicit value required.\n"); } break; } @@ -2923,10 +2926,12 @@ static int stmt_evaluate_reject_default(struct eval_ctx *ctx, protocol = proto_find_num(base, desc); switch (protocol) { case NFPROTO_IPV4: + case __constant_htons(ETH_P_IP): stmt->reject.family = NFPROTO_IPV4; stmt->reject.icmp_code = ICMP_PORT_UNREACH; break; case NFPROTO_IPV6: + case __constant_htons(ETH_P_IPV6): stmt->reject.family = NFPROTO_IPV6; stmt->reject.icmp_code = ICMP6_DST_UNREACH_NOPORT; break; -- cgit v1.2.3