From patchwork Wed Jun 19 06:55:10 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 167216 Delivered-To: patch@linaro.org Received: by 2002:a92:4782:0:0:0:0:0 with SMTP id e2csp347247ilk; Tue, 18 Jun 2019 23:55:31 -0700 (PDT) X-Google-Smtp-Source: APXvYqyk0js9SC3VOnJ9vsRjYAct74ckjLdMXYcVa2ULkE16oo89I2ieMU5voJX/0Uc+2sR6qvMe X-Received: by 2002:a17:902:9a04:: with SMTP id v4mr21841157plp.95.1560927331019; Tue, 18 Jun 2019 23:55:31 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1560927331; cv=none; d=google.com; s=arc-20160816; b=veYt27sRdKaJDuyEb2HPiyHzsaRr1U13wjTokAtWw/VKQKezPRuFR7wIKFCiMuJfWl M1CKvTgxLkKROIyjpqIgNa/A1S6CrgXJbBD3JRsEkxLYng7NCumAfPl2inub0a/7f8o/ BNwn2n56myUUr76I5B7rhYNoSamxaOSrZ2nrKOOC5j4pW5ogJ3Kw4mF/DMMumbPvZJD0 5yfmAoWKKO8h1gwtEOXCfB2z7T5N1AYx0+OJLBwxeieBWjiGkgufODphWje6EMNiv5G3 prPCbvIsX30K86cWvuckyjH+hM1uDhzNMDeZg3715YTJEx0h27Oebk5ucf7IPmnfo9v7 vQIg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:references:in-reply-to:message-id:date :subject:cc:to:from:dkim-signature; bh=nhxfbMfaIoj5v1OpoNNqZ4rGVQ+ZNbSxJ/1xXcmdFR4=; b=ErXfb0gSknj8vihxQvUw/TRFCGJsA7O5Yx38VWwt1koS1M4RNmVMbJ0fAmL9825x/m a2BAJeYHjicu0S+ql8nNeBoecDJ2bBVTjWWcWkVCOA7k3xeaulYOZsN/omZj6CHjosXK W3dC20ZHnrfb8++nevKT6OTg1oIsHkSs6wbbND4jRlbKPe+x5jvpJ94J/rWpLycrYhJK 6aQm+BWUwLe2R8ue15pSzVnTaQ7WfWJY0KF/Ue5naNM8OHmTZmKrHYhgjVH7W83GLWyZ YjW77mU/dZfmx2Q6GVYkRweASNfcymhbH4umcVKul23t0Nqr/Ip6fZ9YkYMr35wyfb5F R45g== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=uEobiQ01; spf=pass (google.com: best guess record for domain of linux-crypto-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-crypto-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id j1si2340312pgi.271.2019.06.18.23.55.30; Tue, 18 Jun 2019 23:55:31 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-crypto-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=uEobiQ01; spf=pass (google.com: best guess record for domain of linux-crypto-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-crypto-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730979AbfFSGza (ORCPT + 3 others); Wed, 19 Jun 2019 02:55:30 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:34469 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725980AbfFSGz3 (ORCPT ); Wed, 19 Jun 2019 02:55:29 -0400 Received: by mail-wr1-f67.google.com with SMTP id k11so2074183wrl.1 for ; Tue, 18 Jun 2019 23:55:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=nhxfbMfaIoj5v1OpoNNqZ4rGVQ+ZNbSxJ/1xXcmdFR4=; b=uEobiQ01syIF0hYqrwzhxTyoiBObeOEog7egkdr9S/ipYT3Xe/iMdNVnB1z8xZqK1s 4TKzafJB9mmB1M06lYTR2CYY4xg3LS5uyomq+nGhyNTLnp11yU3v59gxb39dY9IZPaeU cN4djZT2dRIBeA84lgsTYhdvYdRDq4G6w+Fp8oqM+bghe2Jetxn/BqCWU+tz/q6f8Ari r4ZHP3q+2/tFhsWI+eDdtqZk38j5v59XvscntyCwS7Vs4QcbDopGTmQsE7jwxIX9HPJr IAG3mLTjTMegT1vKlJ5QdiyU6yx36h/DSNj48MzJatHofEYluTJlNkkHvVBpdA6SJEXA biEA== 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; bh=nhxfbMfaIoj5v1OpoNNqZ4rGVQ+ZNbSxJ/1xXcmdFR4=; b=sWNDAbG1N+d3eGpb85WaTqUdfAS7bjOB38bAPPX582V4DlfLKx5xnWeVNrMD4Ke+S3 QvbIq0bRVxqRXDpnq8Y4WPMg0sq9Z8RYHrIyZ6n+ZdAsTPR++Wd2AvCKiLrztIW6v0t4 d+hNuT5S5RaHxolomqgu+how2PficYA2LG3KutPzkpp5IoU5PvHUj+Fj4rOc4lp64Zu2 fNfubEIAS/3GrqpXhmkdz/ZULf+UZfZi2rj7nkHN/tiz6STXC+3ajkgV5o8EfrmRoHJt GhjzFob5i9ScVE+qYQ2UbUoAm+PvJRTsY6MmZjoyOujM16MADww19C0svcnTEDi+sw8g iapQ== X-Gm-Message-State: APjAAAVtImXKsUnqxjbbLbYERaaP5JUJKSuNFszWdRI/zn/WSOjUp7u4 AmtPoscs+LvA9DCS+TymYF6dIw== X-Received: by 2002:adf:f442:: with SMTP id f2mr17952391wrp.275.1560927326868; Tue, 18 Jun 2019 23:55:26 -0700 (PDT) Received: from e111045-lin.arm.com (lfbn-nic-1-216-10.w2-15.abo.wanadoo.fr. [2.15.62.10]) by smtp.gmail.com with ESMTPSA id a2sm583462wmj.9.2019.06.18.23.55.25 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Tue, 18 Jun 2019 23:55:26 -0700 (PDT) From: Ard Biesheuvel To: netdev@vger.kernel.org Cc: Ard Biesheuvel , Eric Biggers , linux-crypto@vger.kernel.org, herbert@gondor.apana.org.au, edumazet@google.com, davem@davemloft.net, kuznet@ms2.inr.ac.ru, yoshfuji@linux-ipv6.org, jbaron@akamai.com, cpaasch@apple.com, David.Laight@aculab.com, ycheng@google.com Subject: [PATCH net-next v2 1/1] net: fastopen: robustness and endianness fixes for SipHash Date: Wed, 19 Jun 2019 08:55:10 +0200 Message-Id: <20190619065510.23514-2-ard.biesheuvel@linaro.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190619065510.23514-1-ard.biesheuvel@linaro.org> References: <20190619065510.23514-1-ard.biesheuvel@linaro.org> Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Some changes to the TCP fastopen code to make it more robust against future changes in the choice of key/cookie size, etc. - Instead of keeping the SipHash key in an untyped u8[] buffer and casting it to the right type upon use, use the correct type directly. This ensures that the key will appear at the correct alignment if we ever change the way these data structures are allocated. (Currently, they are only allocated via kmalloc so they always appear at the correct alignment) - Use DIV_ROUND_UP when sizing the u64[] array to hold the cookie, so it is always of sufficient size, even if TCP_FASTOPEN_COOKIE_MAX is no longer a multiple of 8. - Drop the 'len' parameter from the tcp_fastopen_reset_cipher() function, which is no longer used. - Add endian swabbing when setting the keys and calculating the hash, to ensure that cookie values are the same for a given key and source/destination address pair regardless of the endianness of the server. Note that none of these are functional changes wrt the current state of the code, with the exception of the swabbing, which only affects big endian systems. Signed-off-by: Ard Biesheuvel --- include/linux/tcp.h | 2 +- include/net/tcp.h | 8 ++-- net/ipv4/sysctl_net_ipv4.c | 3 +- net/ipv4/tcp.c | 3 +- net/ipv4/tcp_fastopen.c | 39 +++++++++++--------- 5 files changed, 28 insertions(+), 27 deletions(-) -- 2.17.1 diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 2689b0b0b68a..f3a85a7fb4b1 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -58,7 +58,7 @@ static inline unsigned int tcp_optlen(const struct sk_buff *skb) /* TCP Fast Open Cookie as stored in memory */ struct tcp_fastopen_cookie { - u64 val[TCP_FASTOPEN_COOKIE_MAX / sizeof(u64)]; + __le64 val[DIV_ROUND_UP(TCP_FASTOPEN_COOKIE_MAX, sizeof(u64))]; s8 len; bool exp; /* In RFC6994 experimental option format */ }; diff --git a/include/net/tcp.h b/include/net/tcp.h index 573c9e9b0d72..9d36cc88d043 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -43,6 +43,7 @@ #include #include #include +#include extern struct inet_hashinfo tcp_hashinfo; @@ -1612,8 +1613,7 @@ void tcp_free_fastopen_req(struct tcp_sock *tp); void tcp_fastopen_destroy_cipher(struct sock *sk); void tcp_fastopen_ctx_destroy(struct net *net); int tcp_fastopen_reset_cipher(struct net *net, struct sock *sk, - void *primary_key, void *backup_key, - unsigned int len); + void *primary_key, void *backup_key); void tcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb); struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, struct request_sock *req, @@ -1623,14 +1623,14 @@ void tcp_fastopen_init_key_once(struct net *net); bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss, struct tcp_fastopen_cookie *cookie); bool tcp_fastopen_defer_connect(struct sock *sk, int *err); -#define TCP_FASTOPEN_KEY_LENGTH 16 +#define TCP_FASTOPEN_KEY_LENGTH sizeof(siphash_key_t) #define TCP_FASTOPEN_KEY_MAX 2 #define TCP_FASTOPEN_KEY_BUF_LENGTH \ (TCP_FASTOPEN_KEY_LENGTH * TCP_FASTOPEN_KEY_MAX) /* Fastopen key context */ struct tcp_fastopen_context { - __u8 key[TCP_FASTOPEN_KEY_MAX][TCP_FASTOPEN_KEY_LENGTH]; + siphash_key_t key[TCP_FASTOPEN_KEY_MAX]; int num; struct rcu_head rcu; }; diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index 7d802acde040..7d66306b5f39 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -365,8 +365,7 @@ static int proc_tcp_fastopen_key(struct ctl_table *table, int write, } } tcp_fastopen_reset_cipher(net, NULL, key, - backup_data ? key + 4 : NULL, - TCP_FASTOPEN_KEY_LENGTH); + backup_data ? key + 4 : NULL); } bad_key: diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index efd7f2b1d1f0..47c217905864 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2822,8 +2822,7 @@ static int do_tcp_setsockopt(struct sock *sk, int level, if (optlen == TCP_FASTOPEN_KEY_BUF_LENGTH) backup_key = key + TCP_FASTOPEN_KEY_LENGTH; - return tcp_fastopen_reset_cipher(net, sk, key, backup_key, - TCP_FASTOPEN_KEY_LENGTH); + return tcp_fastopen_reset_cipher(net, sk, key, backup_key); } default: /* fallthru */ diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c index 46b67128e1ca..2f5e7b62ffe4 100644 --- a/net/ipv4/tcp_fastopen.c +++ b/net/ipv4/tcp_fastopen.c @@ -7,7 +7,6 @@ #include #include #include -#include #include #include @@ -31,7 +30,7 @@ void tcp_fastopen_init_key_once(struct net *net) * for a valid cookie, so this is an acceptable risk. */ get_random_bytes(key, sizeof(key)); - tcp_fastopen_reset_cipher(net, NULL, key, NULL, sizeof(key)); + tcp_fastopen_reset_cipher(net, NULL, key, NULL); } static void tcp_fastopen_ctx_free(struct rcu_head *head) @@ -68,8 +67,7 @@ void tcp_fastopen_ctx_destroy(struct net *net) } int tcp_fastopen_reset_cipher(struct net *net, struct sock *sk, - void *primary_key, void *backup_key, - unsigned int len) + void *primary_key, void *backup_key) { struct tcp_fastopen_context *ctx, *octx; struct fastopen_queue *q; @@ -81,9 +79,15 @@ int tcp_fastopen_reset_cipher(struct net *net, struct sock *sk, goto out; } - memcpy(ctx->key[0], primary_key, len); + ctx->key[0] = (siphash_key_t){ + get_unaligned_le64(primary_key), + get_unaligned_le64(primary_key + 8) + }; if (backup_key) { - memcpy(ctx->key[1], backup_key, len); + ctx->key[1] = (siphash_key_t){ + get_unaligned_le64(backup_key), + get_unaligned_le64(backup_key + 8) + }; ctx->num = 2; } else { ctx->num = 1; @@ -110,19 +114,18 @@ int tcp_fastopen_reset_cipher(struct net *net, struct sock *sk, static bool __tcp_fastopen_cookie_gen_cipher(struct request_sock *req, struct sk_buff *syn, - const u8 *key, + const siphash_key_t *key, struct tcp_fastopen_cookie *foc) { - BUILD_BUG_ON(TCP_FASTOPEN_KEY_LENGTH != sizeof(siphash_key_t)); BUILD_BUG_ON(TCP_FASTOPEN_COOKIE_SIZE != sizeof(u64)); if (req->rsk_ops->family == AF_INET) { const struct iphdr *iph = ip_hdr(syn); - foc->val[0] = siphash(&iph->saddr, - sizeof(iph->saddr) + - sizeof(iph->daddr), - (const siphash_key_t *)key); + foc->val[0] = cpu_to_le64(siphash(&iph->saddr, + sizeof(iph->saddr) + + sizeof(iph->daddr), + key)); foc->len = TCP_FASTOPEN_COOKIE_SIZE; return true; } @@ -130,10 +133,10 @@ static bool __tcp_fastopen_cookie_gen_cipher(struct request_sock *req, if (req->rsk_ops->family == AF_INET6) { const struct ipv6hdr *ip6h = ipv6_hdr(syn); - foc->val[0] = siphash(&ip6h->saddr, - sizeof(ip6h->saddr) + - sizeof(ip6h->daddr), - (const siphash_key_t *)key); + foc->val[0] = cpu_to_le64(siphash(&ip6h->saddr, + sizeof(ip6h->saddr) + + sizeof(ip6h->daddr), + key)); foc->len = TCP_FASTOPEN_COOKIE_SIZE; return true; } @@ -154,7 +157,7 @@ static void tcp_fastopen_cookie_gen(struct sock *sk, rcu_read_lock(); ctx = tcp_fastopen_get_ctx(sk); if (ctx) - __tcp_fastopen_cookie_gen_cipher(req, syn, ctx->key[0], foc); + __tcp_fastopen_cookie_gen_cipher(req, syn, &ctx->key[0], foc); rcu_read_unlock(); } @@ -218,7 +221,7 @@ static int tcp_fastopen_cookie_gen_check(struct sock *sk, if (!ctx) goto out; for (i = 0; i < tcp_fastopen_context_len(ctx); i++) { - __tcp_fastopen_cookie_gen_cipher(req, syn, ctx->key[i], foc); + __tcp_fastopen_cookie_gen_cipher(req, syn, &ctx->key[i], foc); if (tcp_fastopen_cookie_match(foc, orig)) { ret = i + 1; goto out;