From patchwork Tue Mar 22 02:52:20 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Menglong Dong X-Patchwork-Id: 12788048 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D633AC433F5 for ; Tue, 22 Mar 2022 02:53:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235690AbiCVCzW (ORCPT ); Mon, 21 Mar 2022 22:55:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235723AbiCVCzR (ORCPT ); Mon, 21 Mar 2022 22:55:17 -0400 Received: from mail-pf1-x442.google.com (mail-pf1-x442.google.com [IPv6:2607:f8b0:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 89D67227C6F; Mon, 21 Mar 2022 19:53:49 -0700 (PDT) Received: by mail-pf1-x442.google.com with SMTP id g19so17058542pfc.9; Mon, 21 Mar 2022 19:53:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=hgxTxmsnaTYyizSw4eAQyNDGLmIntCuoWZzioX+aEz8=; b=Xwcx6lqcFZu7ahSvJAXSMICOYkVwiQe0bnG9/Fpbje9rbP0XR8xLBV5WQ3Ad4VtNRu Xyg8ID+Dk6oKQgCckfsV2gJCbvD/B1aSW9x0sMluqXvodR0lBmSKWN6MziWL0ziydwdf FYM6dvXsEoR1VUKfQGOuEq0nbW1peZtfBNlHBBdkrxafAmvo3JKsnsQpMoQtJGJP9k1T PNSxWWEDeX96Atc9MebuE8y22lhg4QyIs98TwBiqfgnrLjS0ntYLtmPd/fJGEDTf/OBx ay9Fl9Sahzorjfz9gsHhCya2KNZ0zEOsFskMBNrbueZlA7qy4jtj/12QK5xVGuIIXVjV phuw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=hgxTxmsnaTYyizSw4eAQyNDGLmIntCuoWZzioX+aEz8=; b=kIDWek/WsEQN8rf9Jgk6oOgrABzT/sUn0ewDauw1L5szDaLpyPuD+qoUdX4I3axi8Z 0/aJeTfjkMYGGMBzSoqWI8FIsPAFPYC0mUXJ75q5e3P1XB2jZZGarACRwQrzNs4rlC60 ULXjrCiaODr+cAvGZzHakJLDIeucjrLolB4Y5kyr5CVFQnAbCmKLhSSTa1Zpwh6moG8B TW2ucJ9XR75brUQ8PqxxXvHZWeT5ml1wteWiDl5WM8uRvKGS0BBgUawqFGXxwIgAee7P bJwENHjLOmfRdGzkNkLgD5Hzt/s9eOEjDPEL2jVk+mm8gOSPveONkN2PDaAqyBILxji/ KWhQ== X-Gm-Message-State: AOAM532FncmZlBEZaita7RnToygcczNhjwtANZTsbioSvllBSmoEuW6E Bq7mH0KcW1MvktlTHl1sDyg= X-Google-Smtp-Source: ABdhPJyviixAHAnfhAmjEBP87ZsQbnEGmFDaQFa94lB4d1hmM9MTM6/stpS1bt0ZFqi8rviRuTjMxQ== X-Received: by 2002:a05:6a00:1990:b0:4fa:b49c:d64b with SMTP id d16-20020a056a00199000b004fab49cd64bmr3025274pfl.82.1647917628961; Mon, 21 Mar 2022 19:53:48 -0700 (PDT) Received: from localhost.localdomain ([203.205.141.114]) by smtp.gmail.com with ESMTPSA id g24-20020a17090a579800b001c60f919656sm764687pji.18.2022.03.21.19.53.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 21 Mar 2022 19:53:48 -0700 (PDT) From: menglong8.dong@gmail.com X-Google-Original-From: imagedong@tencent.com To: dsahern@kernel.org, kuba@kernel.org, pabeni@redhat.com Cc: rostedt@goodmis.org, mingo@redhat.com, xeb@mail.ru, davem@davemloft.net, yoshfuji@linux-ipv6.org, imagedong@tencent.com, edumazet@google.com, kafai@fb.com, talalahmad@google.com, keescook@chromium.org, alobakin@pm.me, flyingpeng@tencent.com, mengensun@tencent.com, dongli.zhang@oracle.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, benbjiang@tencent.com Subject: [PATCH net-next v4 4/4] net: icmp: add skb drop reasons to icmp protocol Date: Tue, 22 Mar 2022 10:52:20 +0800 Message-Id: <20220322025220.190568-5-imagedong@tencent.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220322025220.190568-1-imagedong@tencent.com> References: <20220322025220.190568-1-imagedong@tencent.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Menglong Dong Replace kfree_skb() used in icmp_rcv() and icmpv6_rcv() with kfree_skb_reason(). In order to get the reasons of the skb drops after icmp message handle, we change the return type of 'handler()' in 'struct icmp_control' from 'bool' to 'enum skb_drop_reason'. This may change its original intention, as 'false' means failure, but 'SKB_NOT_DROPPED_YET' means success now. Therefore, all 'handler' and the call of them need to be handled. Following 'handler' functions are involved: icmp_unreach() icmp_redirect() icmp_echo() icmp_timestamp() icmp_discard() And following new drop reasons are added: SKB_DROP_REASON_ICMP_CSUM SKB_DROP_REASON_RFC_1122 The reason 'RFC_1122' is introduced for the case that the packet doesn't follow rfc 1122 and is dropped. This is not a common case, and I believe we can locate the problem from the data in the packet. For now, this 'RFC_1122' is used for the icmp broadcasts with wrong types. Maybe there should be a document file for these reasons. For example, list all the case that causes the 'RFC_1122' drop reason. Therefore, users can locate their problems according to the document. Reviewed-by: Hao Peng Reviewed-by: Jiang Biao Signed-off-by: Menglong Dong --- v4: - remove SKB_DROP_REASON_ICMP_TYPE and SKB_DROP_REASON_ICMP_BROADCAST and introduce the SKB_DROP_REASON_RFC_1122 --- include/linux/skbuff.h | 2 + include/net/ping.h | 2 +- include/trace/events/skb.h | 2 + net/ipv4/icmp.c | 75 ++++++++++++++++++++++---------------- net/ipv4/ping.c | 14 ++++--- net/ipv6/icmp.c | 24 +++++++----- 6 files changed, 72 insertions(+), 47 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 10ba07892c46..3c30cc6f559e 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -442,6 +442,8 @@ enum skb_drop_reason { SKB_DROP_REASON_TAP_TXFILTER, /* dropped by tx filter implemented * at tun/tap, e.g., check_filter() */ + SKB_DROP_REASON_ICMP_CSUM, /* ICMP checksum error */ + SKB_DROP_REASON_RFC_1122, /* dropped as RFC 1122 is not followed */ SKB_DROP_REASON_MAX, }; diff --git a/include/net/ping.h b/include/net/ping.h index 2fe78874318c..b68fbfdb606f 100644 --- a/include/net/ping.h +++ b/include/net/ping.h @@ -76,7 +76,7 @@ int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, int ping_common_sendmsg(int family, struct msghdr *msg, size_t len, void *user_icmph, size_t icmph_len); int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); -bool ping_rcv(struct sk_buff *skb); +enum skb_drop_reason ping_rcv(struct sk_buff *skb); #ifdef CONFIG_PROC_FS void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family); diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h index 85abd7cbd221..52c965f3fca7 100644 --- a/include/trace/events/skb.h +++ b/include/trace/events/skb.h @@ -61,6 +61,8 @@ EM(SKB_DROP_REASON_HDR_TRUNC, HDR_TRUNC) \ EM(SKB_DROP_REASON_TAP_FILTER, TAP_FILTER) \ EM(SKB_DROP_REASON_TAP_TXFILTER, TAP_TXFILTER) \ + EM(SKB_DROP_REASON_ICMP_CSUM, ICMP_CSUM) \ + EM(SKB_DROP_REASON_RFC_1122, RFC_1122) \ EMe(SKB_DROP_REASON_MAX, MAX) #undef EM diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index 72a375c7f417..1cd6296f312c 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -186,7 +186,7 @@ EXPORT_SYMBOL(icmp_err_convert); */ struct icmp_control { - bool (*handler)(struct sk_buff *skb); + enum skb_drop_reason (*handler)(struct sk_buff *skb); short error; /* This ICMP is classed as an error message */ }; @@ -839,8 +839,9 @@ static bool icmp_tag_validation(int proto) * ICMP_PARAMETERPROB. */ -static bool icmp_unreach(struct sk_buff *skb) +static enum skb_drop_reason icmp_unreach(struct sk_buff *skb) { + enum skb_drop_reason reason = SKB_NOT_DROPPED_YET; const struct iphdr *iph; struct icmphdr *icmph; struct net *net; @@ -860,8 +861,10 @@ static bool icmp_unreach(struct sk_buff *skb) icmph = icmp_hdr(skb); iph = (const struct iphdr *)skb->data; - if (iph->ihl < 5) /* Mangled header, drop. */ + if (iph->ihl < 5) { /* Mangled header, drop. */ + reason = SKB_DROP_REASON_IP_INHDR; goto out_err; + } switch (icmph->type) { case ICMP_DEST_UNREACH: @@ -941,10 +944,10 @@ static bool icmp_unreach(struct sk_buff *skb) icmp_socket_deliver(skb, info); out: - return true; + return reason; out_err: __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); - return false; + return reason ?: SKB_DROP_REASON_NOT_SPECIFIED; } @@ -952,20 +955,20 @@ static bool icmp_unreach(struct sk_buff *skb) * Handle ICMP_REDIRECT. */ -static bool icmp_redirect(struct sk_buff *skb) +static enum skb_drop_reason icmp_redirect(struct sk_buff *skb) { if (skb->len < sizeof(struct iphdr)) { __ICMP_INC_STATS(dev_net(skb->dev), ICMP_MIB_INERRORS); - return false; + return SKB_DROP_REASON_PKT_TOO_SMALL; } if (!pskb_may_pull(skb, sizeof(struct iphdr))) { /* there aught to be a stat */ - return false; + return SKB_DROP_REASON_NOMEM; } icmp_socket_deliver(skb, ntohl(icmp_hdr(skb)->un.gateway)); - return true; + return SKB_NOT_DROPPED_YET; } /* @@ -982,7 +985,7 @@ static bool icmp_redirect(struct sk_buff *skb) * See also WRT handling of options once they are done and working. */ -static bool icmp_echo(struct sk_buff *skb) +static enum skb_drop_reason icmp_echo(struct sk_buff *skb) { struct icmp_bxm icmp_param; struct net *net; @@ -990,7 +993,7 @@ static bool icmp_echo(struct sk_buff *skb) net = dev_net(skb_dst(skb)->dev); /* should there be an ICMP stat for ignored echos? */ if (net->ipv4.sysctl_icmp_echo_ignore_all) - return true; + return SKB_NOT_DROPPED_YET; icmp_param.data.icmph = *icmp_hdr(skb); icmp_param.skb = skb; @@ -1001,10 +1004,10 @@ static bool icmp_echo(struct sk_buff *skb) if (icmp_param.data.icmph.type == ICMP_ECHO) icmp_param.data.icmph.type = ICMP_ECHOREPLY; else if (!icmp_build_probe(skb, &icmp_param.data.icmph)) - return true; + return SKB_NOT_DROPPED_YET; icmp_reply(&icmp_param, skb); - return true; + return SKB_NOT_DROPPED_YET; } /* Helper for icmp_echo and icmpv6_echo_reply. @@ -1122,7 +1125,7 @@ EXPORT_SYMBOL_GPL(icmp_build_probe); * MUST be accurate to a few minutes. * MUST be updated at least at 15Hz. */ -static bool icmp_timestamp(struct sk_buff *skb) +static enum skb_drop_reason icmp_timestamp(struct sk_buff *skb) { struct icmp_bxm icmp_param; /* @@ -1147,17 +1150,17 @@ static bool icmp_timestamp(struct sk_buff *skb) icmp_param.data_len = 0; icmp_param.head_len = sizeof(struct icmphdr) + 12; icmp_reply(&icmp_param, skb); - return true; + return SKB_NOT_DROPPED_YET; out_err: __ICMP_INC_STATS(dev_net(skb_dst(skb)->dev), ICMP_MIB_INERRORS); - return false; + return SKB_DROP_REASON_PKT_TOO_SMALL; } -static bool icmp_discard(struct sk_buff *skb) +static enum skb_drop_reason icmp_discard(struct sk_buff *skb) { /* pretend it was a success */ - return true; + return SKB_NOT_DROPPED_YET; } /* @@ -1165,18 +1168,20 @@ static bool icmp_discard(struct sk_buff *skb) */ int icmp_rcv(struct sk_buff *skb) { - struct icmphdr *icmph; + enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; struct rtable *rt = skb_rtable(skb); struct net *net = dev_net(rt->dst.dev); - bool success; + struct icmphdr *icmph; if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { struct sec_path *sp = skb_sec_path(skb); int nh; if (!(sp && sp->xvec[sp->len - 1]->props.flags & - XFRM_STATE_ICMP)) + XFRM_STATE_ICMP)) { + reason = SKB_DROP_REASON_XFRM_POLICY; goto drop; + } if (!pskb_may_pull(skb, sizeof(*icmph) + sizeof(struct iphdr))) goto drop; @@ -1184,8 +1189,11 @@ int icmp_rcv(struct sk_buff *skb) nh = skb_network_offset(skb); skb_set_network_header(skb, sizeof(*icmph)); - if (!xfrm4_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) + if (!xfrm4_policy_check_reverse(NULL, XFRM_POLICY_IN, + skb)) { + reason = SKB_DROP_REASON_XFRM_POLICY; goto drop; + } skb_set_network_header(skb, nh); } @@ -1207,13 +1215,13 @@ int icmp_rcv(struct sk_buff *skb) /* We can't use icmp_pointers[].handler() because it is an array of * size NR_ICMP_TYPES + 1 (19 elements) and PROBE has code 42. */ - success = icmp_echo(skb); - goto success_check; + reason = icmp_echo(skb); + goto reason_check; } if (icmph->type == ICMP_EXT_ECHOREPLY) { - success = ping_rcv(skb); - goto success_check; + reason = ping_rcv(skb); + goto reason_check; } /* @@ -1222,8 +1230,10 @@ int icmp_rcv(struct sk_buff *skb) * RFC 1122: 3.2.2 Unknown ICMP messages types MUST be silently * discarded. */ - if (icmph->type > NR_ICMP_TYPES) + if (icmph->type > NR_ICMP_TYPES) { + reason = SKB_DROP_REASON_UNHANDLED_PROTO; goto error; + } /* * Parse the ICMP message @@ -1239,27 +1249,30 @@ int icmp_rcv(struct sk_buff *skb) if ((icmph->type == ICMP_ECHO || icmph->type == ICMP_TIMESTAMP) && net->ipv4.sysctl_icmp_echo_ignore_broadcasts) { + reason = SKB_DROP_REASON_RFC_1122; goto error; } if (icmph->type != ICMP_ECHO && icmph->type != ICMP_TIMESTAMP && icmph->type != ICMP_ADDRESS && icmph->type != ICMP_ADDRESSREPLY) { + reason = SKB_DROP_REASON_RFC_1122; goto error; } } - success = icmp_pointers[icmph->type].handler(skb); -success_check: - if (success) { + reason = icmp_pointers[icmph->type].handler(skb); +reason_check: + if (!reason) { consume_skb(skb); return NET_RX_SUCCESS; } drop: - kfree_skb(skb); + kfree_skb_reason(skb, reason); return NET_RX_DROP; csum_error: + reason = SKB_DROP_REASON_ICMP_CSUM; __ICMP_INC_STATS(net, ICMP_MIB_CSUMERRORS); error: __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c index 877270ad17c9..b383e0393206 100644 --- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -960,12 +960,12 @@ EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); * All we need to do is get the socket. */ -bool ping_rcv(struct sk_buff *skb) +enum skb_drop_reason ping_rcv(struct sk_buff *skb) { + enum skb_drop_reason reason = SKB_DROP_REASON_NO_SOCKET; struct sock *sk; struct net *net = dev_net(skb->dev); struct icmphdr *icmph = icmp_hdr(skb); - bool rc = false; /* We assume the packet has already been checked by icmp_rcv */ @@ -980,15 +980,17 @@ bool ping_rcv(struct sk_buff *skb) struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); pr_debug("rcv on socket %p\n", sk); - if (skb2 && !ping_queue_rcv_skb(sk, skb2)) - rc = true; + if (skb2) + reason = __ping_queue_rcv_skb(sk, skb2); + else + reason = SKB_DROP_REASON_NOMEM; sock_put(sk); } - if (!rc) + if (reason) pr_debug("no socket, dropping\n"); - return rc; + return reason; } EXPORT_SYMBOL_GPL(ping_rcv); diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index e6b978ea0e87..01c8003c9fc9 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -864,21 +864,23 @@ void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info) static int icmpv6_rcv(struct sk_buff *skb) { + enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; struct net *net = dev_net(skb->dev); struct net_device *dev = icmp6_dev(skb); struct inet6_dev *idev = __in6_dev_get(dev); const struct in6_addr *saddr, *daddr; struct icmp6hdr *hdr; u8 type; - bool success = false; if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { struct sec_path *sp = skb_sec_path(skb); int nh; if (!(sp && sp->xvec[sp->len - 1]->props.flags & - XFRM_STATE_ICMP)) + XFRM_STATE_ICMP)) { + reason = SKB_DROP_REASON_XFRM_POLICY; goto drop_no_count; + } if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr))) goto drop_no_count; @@ -886,8 +888,11 @@ static int icmpv6_rcv(struct sk_buff *skb) nh = skb_network_offset(skb); skb_set_network_header(skb, sizeof(*hdr)); - if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) + if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, + skb)) { + reason = SKB_DROP_REASON_XFRM_POLICY; goto drop_no_count; + } skb_set_network_header(skb, nh); } @@ -924,11 +929,11 @@ static int icmpv6_rcv(struct sk_buff *skb) break; case ICMPV6_ECHO_REPLY: - success = ping_rcv(skb); + reason = ping_rcv(skb); break; case ICMPV6_EXT_ECHO_REPLY: - success = ping_rcv(skb); + reason = ping_rcv(skb); break; case ICMPV6_PKT_TOOBIG: @@ -994,19 +999,20 @@ static int icmpv6_rcv(struct sk_buff *skb) /* until the v6 path can be better sorted assume failure and * preserve the status quo behaviour for the rest of the paths to here */ - if (success) - consume_skb(skb); + if (reason) + kfree_skb_reason(skb, reason); else - kfree_skb(skb); + consume_skb(skb); return 0; csum_error: + reason = SKB_DROP_REASON_ICMP_CSUM; __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS); discard_it: __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INERRORS); drop_no_count: - kfree_skb(skb); + kfree_skb_reason(skb, reason); return 0; }