From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0FE1C1C6AB; Mon, 4 Mar 2024 21:52:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709589143; cv=none; b=SwW9J3CEdrDDWd5p3x5GftPdnbduZpgk2vBF7SogpEsR/bpTprx3bHvkXjTZU41CHkhYTymwbKEB1eXj9ZmkMPuOMuUKDeisPs1rCy9sCd28lh3qcqzFUPi7Y/NGLhxKWLFc0vWyZKjz90ufZSXojiIXKccMaU350S49l3k6FZw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709589143; c=relaxed/simple; bh=OZF6LD3usQ2OKU2ho360fAoTgOoR+vT1JDSHRg1jsF0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FOtWApGfbmHt+WkV7NSzC5yXyrsxm0m8C/AdAM6K6WLnlI4e/twudJ9HXMCmT44ms+561KV46AnsmJ7GIb7CJbHDyqKAACoxRc7nI6f9WepuR+YWazQ86Q7Ap7aPyA+2/2iINmwptpvt/CtVKCTlbu4hY8Xjstry9ob1RcjZ8lA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=RkuApbcU; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="RkuApbcU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8E05EC433C7; Mon, 4 Mar 2024 21:52:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1709589142; bh=OZF6LD3usQ2OKU2ho360fAoTgOoR+vT1JDSHRg1jsF0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RkuApbcUxWZP/zLhyf3bvTR+wOTd9LvYlTDW62bIYqVyikfdiHo3mLG62zjFLzpKc rQlQQQLIlMy7ctNJkCElD+6ceeLbSCOBVXBakZtbdquL/o17XqeZ5njByvemT18V6R Q7ebR+f+cfmZbCCoXEKu+rrHmW9jyJsj0msakAlg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Louis DeLosSantos , Daniel Borkmann Subject: [PATCH 6.1 212/215] bpf: Add table ID to bpf_fib_lookup BPF helper Date: Mon, 4 Mar 2024 21:24:35 +0000 Message-ID: <20240304211603.711180329@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240304211556.993132804@linuxfoundation.org> References: <20240304211556.993132804@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Louis DeLosSantos commit 8ad77e72caae22a1ddcfd0c03f2884929e93b7a4 upstream. Add ability to specify routing table ID to the `bpf_fib_lookup` BPF helper. A new field `tbid` is added to `struct bpf_fib_lookup` used as parameters to the `bpf_fib_lookup` BPF helper. When the helper is called with the `BPF_FIB_LOOKUP_DIRECT` and `BPF_FIB_LOOKUP_TBID` flags the `tbid` field in `struct bpf_fib_lookup` will be used as the table ID for the fib lookup. If the `tbid` does not exist the fib lookup will fail with `BPF_FIB_LKUP_RET_NOT_FWDED`. The `tbid` field becomes a union over the vlan related output fields in `struct bpf_fib_lookup` and will be zeroed immediately after usage. This functionality is useful in containerized environments. For instance, if a CNI wants to dictate the next-hop for traffic leaving a container it can create a container-specific routing table and perform a fib lookup against this table in a "host-net-namespace-side" TC program. This functionality also allows `ip rule` like functionality at the TC layer, allowing an eBPF program to pick a routing table based on some aspect of the sk_buff. As a concrete use case, this feature will be used in Cilium's SRv6 L3VPN datapath. When egress traffic leaves a Pod an eBPF program attached by Cilium will determine which VRF the egress traffic should target, and then perform a FIB lookup in a specific table representing this VRF's FIB. Signed-off-by: Louis DeLosSantos Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20230505-bpf-add-tbid-fib-lookup-v2-1-0a31c22c748c@gmail.com Signed-off-by: Greg Kroah-Hartman --- include/uapi/linux/bpf.h | 21 ++++++++++++++++++--- net/core/filter.c | 14 +++++++++++++- tools/include/uapi/linux/bpf.h | 21 ++++++++++++++++++--- 3 files changed, 49 insertions(+), 7 deletions(-) --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -3109,6 +3109,10 @@ union bpf_attr { * **BPF_FIB_LOOKUP_DIRECT** * Do a direct table lookup vs full lookup using FIB * rules. + * **BPF_FIB_LOOKUP_TBID** + * Used with BPF_FIB_LOOKUP_DIRECT. + * Use the routing table ID present in *params*->tbid + * for the fib lookup. * **BPF_FIB_LOOKUP_OUTPUT** * Perform lookup from an egress perspective (default is * ingress). @@ -6687,6 +6691,7 @@ enum { BPF_FIB_LOOKUP_DIRECT = (1U << 0), BPF_FIB_LOOKUP_OUTPUT = (1U << 1), BPF_FIB_LOOKUP_SKIP_NEIGH = (1U << 2), + BPF_FIB_LOOKUP_TBID = (1U << 3), }; enum { @@ -6747,9 +6752,19 @@ struct bpf_fib_lookup { __u32 ipv6_dst[4]; /* in6_addr; network order */ }; - /* output */ - __be16 h_vlan_proto; - __be16 h_vlan_TCI; + union { + struct { + /* output */ + __be16 h_vlan_proto; + __be16 h_vlan_TCI; + }; + /* input: when accompanied with the + * 'BPF_FIB_LOOKUP_DIRECT | BPF_FIB_LOOKUP_TBID` flags, a + * specific routing table to use for the fib lookup. + */ + __u32 tbid; + }; + __u8 smac[6]; /* ETH_ALEN */ __u8 dmac[6]; /* ETH_ALEN */ }; --- a/net/core/filter.c +++ b/net/core/filter.c @@ -5752,6 +5752,12 @@ static int bpf_ipv4_fib_lookup(struct ne u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN; struct fib_table *tb; + if (flags & BPF_FIB_LOOKUP_TBID) { + tbid = params->tbid; + /* zero out for vlan output */ + params->tbid = 0; + } + tb = fib_get_table(net, tbid); if (unlikely(!tb)) return BPF_FIB_LKUP_RET_NOT_FWDED; @@ -5885,6 +5891,12 @@ static int bpf_ipv6_fib_lookup(struct ne u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN; struct fib6_table *tb; + if (flags & BPF_FIB_LOOKUP_TBID) { + tbid = params->tbid; + /* zero out for vlan output */ + params->tbid = 0; + } + tb = ipv6_stub->fib6_get_table(net, tbid); if (unlikely(!tb)) return BPF_FIB_LKUP_RET_NOT_FWDED; @@ -5957,7 +5969,7 @@ set_fwd_params: #endif #define BPF_FIB_LOOKUP_MASK (BPF_FIB_LOOKUP_DIRECT | BPF_FIB_LOOKUP_OUTPUT | \ - BPF_FIB_LOOKUP_SKIP_NEIGH) + BPF_FIB_LOOKUP_SKIP_NEIGH | BPF_FIB_LOOKUP_TBID) BPF_CALL_4(bpf_xdp_fib_lookup, struct xdp_buff *, ctx, struct bpf_fib_lookup *, params, int, plen, u32, flags) --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3109,6 +3109,10 @@ union bpf_attr { * **BPF_FIB_LOOKUP_DIRECT** * Do a direct table lookup vs full lookup using FIB * rules. + * **BPF_FIB_LOOKUP_TBID** + * Used with BPF_FIB_LOOKUP_DIRECT. + * Use the routing table ID present in *params*->tbid + * for the fib lookup. * **BPF_FIB_LOOKUP_OUTPUT** * Perform lookup from an egress perspective (default is * ingress). @@ -6687,6 +6691,7 @@ enum { BPF_FIB_LOOKUP_DIRECT = (1U << 0), BPF_FIB_LOOKUP_OUTPUT = (1U << 1), BPF_FIB_LOOKUP_SKIP_NEIGH = (1U << 2), + BPF_FIB_LOOKUP_TBID = (1U << 3), }; enum { @@ -6747,9 +6752,19 @@ struct bpf_fib_lookup { __u32 ipv6_dst[4]; /* in6_addr; network order */ }; - /* output */ - __be16 h_vlan_proto; - __be16 h_vlan_TCI; + union { + struct { + /* output */ + __be16 h_vlan_proto; + __be16 h_vlan_TCI; + }; + /* input: when accompanied with the + * 'BPF_FIB_LOOKUP_DIRECT | BPF_FIB_LOOKUP_TBID` flags, a + * specific routing table to use for the fib lookup. + */ + __u32 tbid; + }; + __u8 smac[6]; /* ETH_ALEN */ __u8 dmac[6]; /* ETH_ALEN */ };