From patchwork Fri Nov 30 00:29:33 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joe Stringer X-Patchwork-Id: 1005743 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=wand.net.nz Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="ul5DR6fQ"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 435b055n2Cz9s9J for ; Fri, 30 Nov 2018 11:30:45 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727030AbeK3LiG (ORCPT ); Fri, 30 Nov 2018 06:38:06 -0500 Received: from mail-ot1-f65.google.com ([209.85.210.65]:42024 "EHLO mail-ot1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726451AbeK3LiG (ORCPT ); Fri, 30 Nov 2018 06:38:06 -0500 Received: by mail-ot1-f65.google.com with SMTP id v23so3576808otk.9 for ; Thu, 29 Nov 2018 16:30:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id; bh=//yfGSBqGwvU7jzl5N7YBDdjyaiZTwNFNj5bp513SuM=; b=ul5DR6fQdiCUdmsu2IRJieRUFyncech6MtMWMY9hY0ufwS/qyQ9GoM2n0a2oC77Ooo S6xLFH9WX/VumBSk+LuoGPnDhDczQlyEdvoc0b/+vtqmt3sdKoLJbMrHgh+ckQdcYjCQ 3LBuNfiSDiYAsCK8cKf2dfOCJUclyDINAGWRbVb1aUJ+YvaTF2NqwgPH0bChg6KbHDuc X7wwP8n4Ja57J5TYtLF7EnOz917dqe51dLpHVuoOYHY4av/Sb0Mqju1Cw77ogJsL3v3Y rncAmyNPqSyXomKaTX15lQwCUFhJqE/0BfJB2eXr8m1C6wWr6FupjoxFWd8wZZoYY2ie JHLQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id; bh=//yfGSBqGwvU7jzl5N7YBDdjyaiZTwNFNj5bp513SuM=; b=j9vglkE/14OdMDRyADuthcBsUD6MiRdwnDLe5jZddJzpIb7iez9pbpTyGPnNbJl3ql 8n2fp5k2qrXZ8isq37vD2xcRGmxV16WJQPCUM75dPtSIeQab014wwTPx1+FbdfTx+lvM oXB2/W1105MfS9wuJpiDh9SREyjO7RJ7iLvY2/hIFZa8zPIOgGrJu6ec/acb+850Z5TC 0KcDoIovJw69OyQrTxINtqCrfQ8QSKjkoTeje9IcroaJkpeJau6Dvd0vdqXO/1FJOjka MmkIPzRfSza1FtXaliHbEgoqtBvqYZpN+aj5bxFN8XFpUal1G6VperuqlYtbH8D4iXyw 1cQg== X-Gm-Message-State: AA+aEWbHEAPfplrrNUDYI+043aYrXP9t6gPS/P8zG6y2zv9D4kzlVpsB uTxDHZ3DNKx5QmcdxB8yIXc= X-Google-Smtp-Source: AFSGD/W3PfeBCo396iYhkLV7kfPChFPZS5LR5Hs4vH1qFRGXEr1mCeQwdBEN5UbaXxkggEzn5Cdbrg== X-Received: by 2002:a9d:67ce:: with SMTP id c14mr2135576otn.341.1543537842598; Thu, 29 Nov 2018 16:30:42 -0800 (PST) Received: from localhost.localdomain ([99.0.85.34]) by smtp.gmail.com with ESMTPSA id k207sm2112733oih.58.2018.11.29.16.30.41 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 29 Nov 2018 16:30:41 -0800 (PST) From: Joe Stringer To: daniel@iogearbox.net, ast@kernel.org Cc: netdev@vger.kernel.org, dsahern@gmail.com, nicolas.dichtel@6wind.com Subject: [PATCHv2 bpf 1/2] bpf: Support sk lookup in netns with id 0 Date: Thu, 29 Nov 2018 16:29:33 -0800 Message-Id: <20181130002934.21627-1-joe@wand.net.nz> X-Mailer: git-send-email 2.17.1 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org David Ahern and Nicolas Dichtel report that the handling of the netns id 0 is incorrect for the BPF socket lookup helpers: rather than finding the netns with id 0, it is resolving to the current netns. This renders the netns_id 0 inaccessible. To fix this, adjust the API for the netns to treat all negative s32 values as a lookup in the current netns, while any values with a positive value in the signed 32-bit integer space would result in a lookup for a socket in the netns corresponding to that id. As before, if the netns with that ID does not exist, no socket will be found. Furthermore, if any bits are set in the upper 32-bits, then no socket will be found. Signed-off-by: Joe Stringer Acked-by: Nicolas Dichtel --- include/uapi/linux/bpf.h | 35 ++++++++++------- net/core/filter.c | 11 +++--- tools/include/uapi/linux/bpf.h | 39 ++++++++++++------- tools/testing/selftests/bpf/bpf_helpers.h | 4 +- .../selftests/bpf/test_sk_lookup_kern.c | 18 ++++----- 5 files changed, 63 insertions(+), 44 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 852dc17ab47a..38924b306e9f 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -2170,7 +2170,7 @@ union bpf_attr { * Return * 0 on success, or a negative error in case of failure. * - * struct bpf_sock *bpf_sk_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u32 netns, u64 flags) + * struct bpf_sock *bpf_sk_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags) * Description * Look for TCP socket matching *tuple*, optionally in a child * network namespace *netns*. The return value must be checked, @@ -2187,12 +2187,14 @@ union bpf_attr { * **sizeof**\ (*tuple*\ **->ipv6**) * Look for an IPv6 socket. * - * If the *netns* is zero, then the socket lookup table in the - * netns associated with the *ctx* will be used. For the TC hooks, - * this in the netns of the device in the skb. For socket hooks, - * this in the netns of the socket. If *netns* is non-zero, then - * it specifies the ID of the netns relative to the netns - * associated with the *ctx*. + * If the *netns* is a negative signed 32-bit integer, then the + * socket lookup table in the netns associated with the *ctx* will + * will be used. For the TC hooks, this is the netns of the device + * in the skb. For socket hooks, this is the netns of the socket. + * If *netns* is any other signed 32-bit value greater than or + * equal to zero then it specifies the ID of the netns relative to + * the netns associated with the *ctx*. *netns* values beyond the + * range of 32-bit integers are reserved for future use. * * All values for *flags* are reserved for future usage, and must * be left at zero. @@ -2202,7 +2204,7 @@ union bpf_attr { * Return * Pointer to *struct bpf_sock*, or NULL in case of failure. * - * struct bpf_sock *bpf_sk_lookup_udp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u32 netns, u64 flags) + * struct bpf_sock *bpf_sk_lookup_udp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags) * Description * Look for UDP socket matching *tuple*, optionally in a child * network namespace *netns*. The return value must be checked, @@ -2219,12 +2221,14 @@ union bpf_attr { * **sizeof**\ (*tuple*\ **->ipv6**) * Look for an IPv6 socket. * - * If the *netns* is zero, then the socket lookup table in the - * netns associated with the *ctx* will be used. For the TC hooks, - * this in the netns of the device in the skb. For socket hooks, - * this in the netns of the socket. If *netns* is non-zero, then - * it specifies the ID of the netns relative to the netns - * associated with the *ctx*. + * If the *netns* is a negative signed 32-bit integer, then the + * socket lookup table in the netns associated with the *ctx* will + * will be used. For the TC hooks, this is the netns of the device + * in the skb. For socket hooks, this is the netns of the socket. + * If *netns* is any other signed 32-bit value greater than or + * equal to zero then it specifies the ID of the netns relative to + * the netns associated with the *ctx*. *netns* values beyond the + * range of 32-bit integers are reserved for future use. * * All values for *flags* are reserved for future usage, and must * be left at zero. @@ -2405,6 +2409,9 @@ enum bpf_func_id { /* BPF_FUNC_perf_event_output for sk_buff input context. */ #define BPF_F_CTXLEN_MASK (0xfffffULL << 32) +/* Current network namespace */ +#define BPF_CURRENT_NETNS (-1L) + /* Mode for BPF_FUNC_skb_adjust_room helper. */ enum bpf_adj_room_mode { BPF_ADJ_ROOM_NET, diff --git a/net/core/filter.c b/net/core/filter.c index 9a1327eb25fa..d00b55929ab8 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4890,22 +4890,23 @@ bpf_sk_lookup(struct sk_buff *skb, struct bpf_sock_tuple *tuple, u32 len, struct net *net; family = len == sizeof(tuple->ipv4) ? AF_INET : AF_INET6; - if (unlikely(family == AF_UNSPEC || netns_id > U32_MAX || flags)) + if (unlikely(family == AF_UNSPEC || flags || + !((s32)netns_id < 0 || netns_id <= S32_MAX))) goto out; if (skb->dev) caller_net = dev_net(skb->dev); else caller_net = sock_net(skb->sk); - if (netns_id) { + if ((s32)netns_id < 0) { + net = caller_net; + sk = sk_lookup(net, tuple, skb, family, proto); + } else { net = get_net_ns_by_id(caller_net, netns_id); if (unlikely(!net)) goto out; sk = sk_lookup(net, tuple, skb, family, proto); put_net(net); - } else { - net = caller_net; - sk = sk_lookup(net, tuple, skb, family, proto); } if (sk) diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 852dc17ab47a..465ad585c836 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -2170,7 +2170,7 @@ union bpf_attr { * Return * 0 on success, or a negative error in case of failure. * - * struct bpf_sock *bpf_sk_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u32 netns, u64 flags) + * struct bpf_sock *bpf_sk_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags) * Description * Look for TCP socket matching *tuple*, optionally in a child * network namespace *netns*. The return value must be checked, @@ -2187,12 +2187,14 @@ union bpf_attr { * **sizeof**\ (*tuple*\ **->ipv6**) * Look for an IPv6 socket. * - * If the *netns* is zero, then the socket lookup table in the - * netns associated with the *ctx* will be used. For the TC hooks, - * this in the netns of the device in the skb. For socket hooks, - * this in the netns of the socket. If *netns* is non-zero, then - * it specifies the ID of the netns relative to the netns - * associated with the *ctx*. + * If the *netns* is a negative signed 32-bit integer, then the + * socket lookup table in the netns associated with the *ctx* will + * will be used. For the TC hooks, this is the netns of the device + * in the skb. For socket hooks, this is the netns of the socket. + * If *netns* is any other signed 32-bit value greater than or + * equal to zero then it specifies the ID of the netns relative to + * the netns associated with the *ctx*. *netns* values beyond the + * range of 32-bit integers are reserved for future use. * * All values for *flags* are reserved for future usage, and must * be left at zero. @@ -2201,8 +2203,10 @@ union bpf_attr { * **CONFIG_NET** configuration option. * Return * Pointer to *struct bpf_sock*, or NULL in case of failure. + * For sockets with reuseport option, *struct bpf_sock* + * return is from reuse->socks[] using hash of the packet. * - * struct bpf_sock *bpf_sk_lookup_udp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u32 netns, u64 flags) + * struct bpf_sock *bpf_sk_lookup_udp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags) * Description * Look for UDP socket matching *tuple*, optionally in a child * network namespace *netns*. The return value must be checked, @@ -2219,12 +2223,14 @@ union bpf_attr { * **sizeof**\ (*tuple*\ **->ipv6**) * Look for an IPv6 socket. * - * If the *netns* is zero, then the socket lookup table in the - * netns associated with the *ctx* will be used. For the TC hooks, - * this in the netns of the device in the skb. For socket hooks, - * this in the netns of the socket. If *netns* is non-zero, then - * it specifies the ID of the netns relative to the netns - * associated with the *ctx*. + * If the *netns* is a negative signed 32-bit integer, then the + * socket lookup table in the netns associated with the *ctx* will + * will be used. For the TC hooks, this is the netns of the device + * in the skb. For socket hooks, this is the netns of the socket. + * If *netns* is any other signed 32-bit value greater than or + * equal to zero then it specifies the ID of the netns relative to + * the netns associated with the *ctx*. *netns* values beyond the + * range of 32-bit integers are reserved for future use. * * All values for *flags* are reserved for future usage, and must * be left at zero. @@ -2233,6 +2239,8 @@ union bpf_attr { * **CONFIG_NET** configuration option. * Return * Pointer to *struct bpf_sock*, or NULL in case of failure. + * For sockets with reuseport option, *struct bpf_sock* + * return is from reuse->socks[] using hash of the packet. * * int bpf_sk_release(struct bpf_sock *sk) * Description @@ -2405,6 +2413,9 @@ enum bpf_func_id { /* BPF_FUNC_perf_event_output for sk_buff input context. */ #define BPF_F_CTXLEN_MASK (0xfffffULL << 32) +/* Current network namespace */ +#define BPF_CURRENT_NETNS (-1L) + /* Mode for BPF_FUNC_skb_adjust_room helper. */ enum bpf_adj_room_mode { BPF_ADJ_ROOM_NET, diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h index 686e57ce40f4..efb6c13ab0de 100644 --- a/tools/testing/selftests/bpf/bpf_helpers.h +++ b/tools/testing/selftests/bpf/bpf_helpers.h @@ -154,12 +154,12 @@ static unsigned long long (*bpf_skb_ancestor_cgroup_id)(void *ctx, int level) = (void *) BPF_FUNC_skb_ancestor_cgroup_id; static struct bpf_sock *(*bpf_sk_lookup_tcp)(void *ctx, struct bpf_sock_tuple *tuple, - int size, unsigned int netns_id, + int size, unsigned long long netns_id, unsigned long long flags) = (void *) BPF_FUNC_sk_lookup_tcp; static struct bpf_sock *(*bpf_sk_lookup_udp)(void *ctx, struct bpf_sock_tuple *tuple, - int size, unsigned int netns_id, + int size, unsigned long long netns_id, unsigned long long flags) = (void *) BPF_FUNC_sk_lookup_udp; static int (*bpf_sk_release)(struct bpf_sock *sk) = diff --git a/tools/testing/selftests/bpf/test_sk_lookup_kern.c b/tools/testing/selftests/bpf/test_sk_lookup_kern.c index b745bdc08c2b..78290e0daa36 100644 --- a/tools/testing/selftests/bpf/test_sk_lookup_kern.c +++ b/tools/testing/selftests/bpf/test_sk_lookup_kern.c @@ -72,7 +72,7 @@ int bpf_sk_lookup_test0(struct __sk_buff *skb) return TC_ACT_SHOT; tuple_len = ipv4 ? sizeof(tuple->ipv4) : sizeof(tuple->ipv6); - sk = bpf_sk_lookup_tcp(skb, tuple, tuple_len, 0, 0); + sk = bpf_sk_lookup_tcp(skb, tuple, tuple_len, BPF_CURRENT_NETNS, 0); if (sk) bpf_sk_release(sk); return sk ? TC_ACT_OK : TC_ACT_UNSPEC; @@ -84,7 +84,7 @@ int bpf_sk_lookup_test1(struct __sk_buff *skb) struct bpf_sock_tuple tuple = {}; struct bpf_sock *sk; - sk = bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), 0, 0); + sk = bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), BPF_CURRENT_NETNS, 0); if (sk) bpf_sk_release(sk); return 0; @@ -97,7 +97,7 @@ int bpf_sk_lookup_uaf(struct __sk_buff *skb) struct bpf_sock *sk; __u32 family = 0; - sk = bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), 0, 0); + sk = bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), BPF_CURRENT_NETNS, 0); if (sk) { bpf_sk_release(sk); family = sk->family; @@ -112,7 +112,7 @@ int bpf_sk_lookup_modptr(struct __sk_buff *skb) struct bpf_sock *sk; __u32 family; - sk = bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), 0, 0); + sk = bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), BPF_CURRENT_NETNS, 0); if (sk) { sk += 1; bpf_sk_release(sk); @@ -127,7 +127,7 @@ int bpf_sk_lookup_modptr_or_null(struct __sk_buff *skb) struct bpf_sock *sk; __u32 family; - sk = bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), 0, 0); + sk = bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), BPF_CURRENT_NETNS, 0); sk += 1; if (sk) bpf_sk_release(sk); @@ -139,7 +139,7 @@ int bpf_sk_lookup_test2(struct __sk_buff *skb) { struct bpf_sock_tuple tuple = {}; - bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), 0, 0); + bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), BPF_CURRENT_NETNS, 0); return 0; } @@ -149,7 +149,7 @@ int bpf_sk_lookup_test3(struct __sk_buff *skb) struct bpf_sock_tuple tuple = {}; struct bpf_sock *sk; - sk = bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), 0, 0); + sk = bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), BPF_CURRENT_NETNS, 0); bpf_sk_release(sk); bpf_sk_release(sk); return 0; @@ -161,7 +161,7 @@ int bpf_sk_lookup_test4(struct __sk_buff *skb) struct bpf_sock_tuple tuple = {}; struct bpf_sock *sk; - sk = bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), 0, 0); + sk = bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), BPF_CURRENT_NETNS, 0); bpf_sk_release(sk); return 0; } @@ -169,7 +169,7 @@ int bpf_sk_lookup_test4(struct __sk_buff *skb) void lookup_no_release(struct __sk_buff *skb) { struct bpf_sock_tuple tuple = {}; - bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), 0, 0); + bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), BPF_CURRENT_NETNS, 0); } SEC("fail_no_release_subcall")