From patchwork Thu Jan 23 15:55:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jakub Sitnicki X-Patchwork-Id: 1228209 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 (no SPF record) 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=pass (p=quarantine dis=none) header.from=cloudflare.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; secure) header.d=cloudflare.com header.i=@cloudflare.com header.a=rsa-sha256 header.s=google header.b=B2Jq7Iy4; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 483Rh73frcz9sSH for ; Fri, 24 Jan 2020 02:55:51 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729074AbgAWPzu (ORCPT ); Thu, 23 Jan 2020 10:55:50 -0500 Received: from mail-wr1-f66.google.com ([209.85.221.66]:37741 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728992AbgAWPzr (ORCPT ); Thu, 23 Jan 2020 10:55:47 -0500 Received: by mail-wr1-f66.google.com with SMTP id w15so3665285wru.4 for ; Thu, 23 Jan 2020 07:55:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=VVLv1nOpcm8g71RlGNU+JDanGJ7QnKmZ4x0azYDRngs=; b=B2Jq7Iy4QUtzJrwz1A1nwILtdxg/B/16ouDihBZS+EiodNyGu6LJXbszyNZ9ht/6Gn B6V+ioOzGYwSygItm+xcVAja9c+ExfIGKO2XAMCVps4d3/YZB8+aMXyyydxpqy39Mn0h 198Fwe4GYbL7Qny/+OnPQQXNQlTVpi130r4js= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=VVLv1nOpcm8g71RlGNU+JDanGJ7QnKmZ4x0azYDRngs=; b=Bi2USlUDomzDVBIeoKOrxqCIHwomZwHkB29lZWxXVBJdiw5tGGNYvCefQFbhDvtGcv aFMC/MDRvwHlIQYYgnfS1TwC6EKHwZil+ssAyQuZlgrKHAd5NqiJOLIzXJZoMRQJP9+j qKmwGK8qpfo0gpCc5iyxZ92s+7zsgOLtVVsqTWM97BmM2NmDreEWJ2QgaCnNY9STY76D HFVNKC/NS7IqS8FcKdCD3YUsohJ3UeiHlE1AYJpJUERbxtDh+xfcaX+t1ya+BLkuBx4J And1ztj8dJ5qjat3B7Lav692cn3AWYmzztBFGTFtZAnQ7CtjgLT5uSZKb+1RwSydO3fI /pbw== X-Gm-Message-State: APjAAAWarSB3KN8GuDBuEFFup4cve1WnCSupd5npDfsN4TGGGISgBi9k eB8V26C0QKv4lNnn7Y+VgoTSEQ== X-Google-Smtp-Source: APXvYqwsGxZP/OSMOEPRohkvmQeQm4Jdsa4I0e9fADufRzS4mZO2BsuOFbeUvAfS2tnV3jgVRja2rQ== X-Received: by 2002:adf:806e:: with SMTP id 101mr18279107wrk.300.1579794944869; Thu, 23 Jan 2020 07:55:44 -0800 (PST) Received: from cloudflare.com ([176.221.114.230]) by smtp.gmail.com with ESMTPSA id p5sm3394270wrt.79.2020.01.23.07.55.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Jan 2020 07:55:44 -0800 (PST) From: Jakub Sitnicki To: bpf@vger.kernel.org Cc: netdev@vger.kernel.org, kernel-team@cloudflare.com, John Fastabend , Lorenz Bauer , Martin Lau Subject: [PATCH bpf-next v4 07/12] bpf, sockmap: Return socket cookie on lookup from syscall Date: Thu, 23 Jan 2020 16:55:29 +0100 Message-Id: <20200123155534.114313-8-jakub@cloudflare.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200123155534.114313-1-jakub@cloudflare.com> References: <20200123155534.114313-1-jakub@cloudflare.com> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Tooling that populates the SOCKMAP with sockets from user-space needs a way to inspect its contents. Returning the struct sock * that SOCKMAP holds to user-space is neither safe nor useful. An approach established by REUSEPORT_SOCKARRAY is to return a socket cookie (a unique identifier) instead. Since socket cookies are u64 values, SOCKMAP needs to support such a value size for lookup to be possible. This requires special handling on update, though. Attempts to do a lookup on SOCKMAP holding u32 values will be met with ENOSPC error. Acked-by: John Fastabend Acked-by: Martin KaFai Lau Signed-off-by: Jakub Sitnicki --- net/core/sock_map.c | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) diff --git a/net/core/sock_map.c b/net/core/sock_map.c index 2ff545e04f6e..441f213bd4c5 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -10,6 +10,7 @@ #include #include #include +#include struct bpf_stab { struct bpf_map map; @@ -31,7 +32,8 @@ static struct bpf_map *sock_map_alloc(union bpf_attr *attr) return ERR_PTR(-EPERM); if (attr->max_entries == 0 || attr->key_size != 4 || - attr->value_size != 4 || + (attr->value_size != sizeof(u32) && + attr->value_size != sizeof(u64)) || attr->map_flags & ~SOCK_CREATE_FLAG_MASK) return ERR_PTR(-EINVAL); @@ -298,6 +300,21 @@ static void *sock_map_lookup(struct bpf_map *map, void *key) return ERR_PTR(-EOPNOTSUPP); } +static void *sock_map_lookup_sys(struct bpf_map *map, void *key) +{ + struct sock *sk; + + if (map->value_size != sizeof(u64)) + return ERR_PTR(-ENOSPC); + + sk = __sock_map_lookup_elem(map, *(u32 *)key); + if (!sk) + return ERR_PTR(-ENOENT); + + sock_gen_cookie(sk); + return &sk->sk_cookie; +} + static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test, struct sock **psk) { @@ -459,12 +476,19 @@ static bool sock_hash_sk_is_suitable(const struct sock *sk) static int sock_map_update_elem(struct bpf_map *map, void *key, void *value, u64 flags) { - u32 ufd = *(u32 *)value; u32 idx = *(u32 *)key; struct socket *sock; struct sock *sk; + u64 ufd; int ret; + if (map->value_size == sizeof(u64)) + ufd = *(u64 *)value; + else + ufd = *(u32 *)value; + if (ufd > S32_MAX) + return -EINVAL; + sock = sockfd_lookup(ufd, &ret); if (!sock) return ret; @@ -568,6 +592,7 @@ const struct bpf_map_ops sock_map_ops = { .map_alloc = sock_map_alloc, .map_free = sock_map_free, .map_get_next_key = sock_map_get_next_key, + .map_lookup_elem_sys_only = sock_map_lookup_sys, .map_update_elem = sock_map_update_elem, .map_delete_elem = sock_map_delete_elem, .map_lookup_elem = sock_map_lookup,