From patchwork Tue Apr 14 09:09:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?TGXFn2UgRG9ydSBDxINsaW4=?= X-Patchwork-Id: 221215 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 36DF5C2BB85 for ; Tue, 14 Apr 2020 09:09:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0FB432076A for ; Tue, 14 Apr 2020 09:09:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="PpI2smU4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437421AbgDNJJh (ORCPT ); Tue, 14 Apr 2020 05:09:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2437410AbgDNJJd (ORCPT ); Tue, 14 Apr 2020 05:09:33 -0400 Received: from mail-wm1-x344.google.com (mail-wm1-x344.google.com [IPv6:2a00:1450:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C8D2C008769 for ; Tue, 14 Apr 2020 02:09:31 -0700 (PDT) Received: by mail-wm1-x344.google.com with SMTP id a81so13055202wmf.5 for ; Tue, 14 Apr 2020 02:09:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:mime-version:content-disposition :user-agent; bh=QwfKGdqam9RIuBIMLZ/S/DFAHpLMsKb4kuHzoefPgZA=; b=PpI2smU4Q7O7yGn29QKLR5E6hM2tJGmjffnfP7dOyNCNAFoNTNNGABUFekttfgkYiP hadODThe0lRT7x7HGgHEn9QEBULOXlWQqAmKyFjfJ0QJ7ZlEVAtdHyyrTTehKFKOVMRG r2H+OL/yuKyiI6HbKsKl7VSrk4FsZM3fPQuMSQbqQpjgN49YRQyNUXk/Gv4E+stmJkIr j8U2+nxQX03RAZI/r8P2y3TR3JqWLWX6vUTmNA0DRO/DHR4CZ4jK+mY8ENxSS0/jjSfh zV51qklLAsev4Bi88dM6/+qdLYfOVf+RpiYV3e0mgLya5vpcsveEdLRsrIue1uUvPxC9 +biQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition:user-agent; bh=QwfKGdqam9RIuBIMLZ/S/DFAHpLMsKb4kuHzoefPgZA=; b=lOQlWDIEafT8UCNSC5rm6MorSImZ6b79hz5b3UGRMj8iohKVAwy+y49n87ZdrDBM+r RiLmJDRAn8ATVOcj06G12d+pG6xo+2xInKZReG2BmV21UQV74YUFgERAMSrgLCLjvxnV 2MJxXoJbswcTYx2ZWivExsfgUqpjsFk5kBPM1aDtQs0HCwzZclWcVVR2Puz5g7DjZXsC 04FzHk8AAZ0RWt+lrcSCPP1L0c6CgKH9bvnIC3ove5JzFFN9nuUklXVoLv2+kDwMt85R EpZK6vBIzLCJpHLyjJY5fgcmnuUGWA4rSbEL3Q1U4pYud0Hp8hxGoCWAymr4nCBVDvlR cavw== X-Gm-Message-State: AGi0PuaHzNxVhPiNR+B4NXa4u/tx36b/qjdl1Beic5tGaJ+3VrsJXm8q VenrB1U3uk9J2h5KgeGq/hY= X-Google-Smtp-Source: APiQypLE/GfWvo5cFIPIM2QWKl6I5o86DIJtqT7i1OZu7oQiXcusw4XfKALU6y2Vue94X1qQnTCbNQ== X-Received: by 2002:a7b:c401:: with SMTP id k1mr22146271wmi.152.1586855370308; Tue, 14 Apr 2020 02:09:30 -0700 (PDT) Received: from white ([188.27.148.74]) by smtp.gmail.com with ESMTPSA id r17sm8608271wrn.43.2020.04.14.02.09.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Apr 2020 02:09:29 -0700 (PDT) Date: Tue, 14 Apr 2020 12:09:25 +0300 From: =?utf-8?b?TGXFn2UgRG9ydSBDxINsaW4=?= To: Leon Romanovsky , netdev@vger.kernel.org Cc: David Miller , Alexey Kuznetsov , Hideaki YOSHIFUJI Subject: [PATCH v3] net: UDP repair mode for retrieving the send queue of corked UDP socket Message-ID: <20200414090925.GA10402@white> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org In this year's edition of GSoC, there is a project idea for CRIU to add support for checkpoint/restore of cork-ed UDP sockets. But to add it, the kernel API needs to be extended. This is what this patch does. It adds UDP "repair mode" for UDP sockets in a similar approach to the TCP "repair mode", but only the send queue is necessary to be retrieved. So the patch extends the recv and setsockopt syscalls. Using UDP_REPAIR option in setsockopt, caller can set the socket in repair mode. If it is setted, the recv/recvfrom/recvmsg will receive the write queue and the destination of the data. As in the TCP mode, to change the repair mode requires the CAP_NET_ADMIN capability and to receive data the caller is obliged to use the MSG_PEEK flag. Signed-off-by: Lese Doru Calin --- include/linux/udp.h | 3 ++- include/uapi/linux/udp.h | 1 + net/ipv4/udp.c | 55 ++++++++++++++++++++++++++++++++++++++++ net/ipv6/udp.c | 45 ++++++++++++++++++++++++++++++++ 4 files changed, 103 insertions(+), 1 deletion(-) diff --git a/include/linux/udp.h b/include/linux/udp.h index aa84597bdc33..b22bd70118ce 100644 --- a/include/linux/udp.h +++ b/include/linux/udp.h @@ -51,7 +51,8 @@ struct udp_sock { * different encapsulation layer set * this */ - gro_enabled:1; /* Can accept GRO packets */ + gro_enabled:1, /* Can accept GRO packets */ + repair:1;/* Receive the send queue */ /* * Following member retains the information to create a UDP header * when the socket is uncorked. diff --git a/include/uapi/linux/udp.h b/include/uapi/linux/udp.h index 4828794efcf8..2fe78329d6da 100644 --- a/include/uapi/linux/udp.h +++ b/include/uapi/linux/udp.h @@ -29,6 +29,7 @@ struct udphdr { /* UDP socket options */ #define UDP_CORK 1 /* Never send partially complete segments */ +#define UDP_REPAIR 19 /* Receive the send queue */ #define UDP_ENCAP 100 /* Set the socket to accept encapsulated packets */ #define UDP_NO_CHECK6_TX 101 /* Disable sending checksum for UDP6X */ #define UDP_NO_CHECK6_RX 102 /* Disable accpeting checksum for UDP6 */ diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 32564b350823..dc9d15d564d6 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1720,6 +1720,28 @@ struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags, } EXPORT_SYMBOL(__skb_recv_udp); +static int udp_peek_sndq(struct sock *sk, struct msghdr *msg, int off, int len) +{ + int copy, copied = 0, err = 0; + struct sk_buff *skb; + + skb_queue_walk(&sk->sk_write_queue, skb) { + copy = len - copied; + if (copy > skb->len - off) + copy = skb->len - off; + + err = skb_copy_datagram_msg(skb, off, msg, copy); + if (err) + break; + + copied += copy; + + if (len <= copied) + break; + } + return err ?: copied; +} + /* * This should be easy, if there is something there we * return it, otherwise we block. @@ -1729,8 +1751,10 @@ int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, int flags, int *addr_len) { struct inet_sock *inet = inet_sk(sk); + struct udp_sock *up = udp_sk(sk); DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); struct sk_buff *skb; + struct flowi4 *fl4; unsigned int ulen, copied; int off, err, peeking = flags & MSG_PEEK; int is_udplite = IS_UDPLITE(sk); @@ -1739,6 +1763,12 @@ int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, if (flags & MSG_ERRQUEUE) return ip_recv_error(sk, msg, len, addr_len); + if (unlikely(up->repair)) { + if (!peeking) + return -EPERM; + goto recv_sndq; + } + try_again: off = sk_peek_offset(sk, flags); skb = __skb_recv_udp(sk, flags, noblock, &off, &err); @@ -1832,6 +1862,18 @@ int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, cond_resched(); msg->msg_flags &= ~MSG_TRUNC; goto try_again; + +recv_sndq: + off = sizeof(struct iphdr) + sizeof(struct udphdr); + if (sin) { + fl4 = &inet->cork.fl.u.ip4; + sin->sin_family = AF_INET; + sin->sin_port = fl4->fl4_dport; + sin->sin_addr.s_addr = fl4->daddr; + memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); + *addr_len = sizeof(*sin); + } + return udp_peek_sndq(sk, msg, off, len); } int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) @@ -2557,6 +2599,15 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname, } break; + case UDP_REPAIR: + if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) + err = -EPERM; + else if (val != 0) + up->repair = 1; + else + up->repair = 0; + break; + case UDP_ENCAP: switch (val) { case 0: @@ -2678,6 +2729,10 @@ int udp_lib_getsockopt(struct sock *sk, int level, int optname, val = up->corkflag; break; + case UDP_REPAIR: + val = up->repair; + break; + case UDP_ENCAP: val = up->encap_type; break; diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 7d4151747340..ec653f9fce2d 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -250,6 +250,28 @@ struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be EXPORT_SYMBOL_GPL(udp6_lib_lookup); #endif +static int udp6_peek_sndq(struct sock *sk, struct msghdr *msg, int off, int len) +{ + int copy, copied = 0, err = 0; + struct sk_buff *skb; + + skb_queue_walk(&sk->sk_write_queue, skb) { + copy = len - copied; + if (copy > skb->len - off) + copy = skb->len - off; + + err = skb_copy_datagram_msg(skb, off, msg, copy); + if (err) + break; + + copied += copy; + + if (len <= copied) + break; + } + return err ?: copied; +} + /* do not use the scratch area len for jumbogram: their length execeeds the * scratch area space; note that the IP6CB flags is still in the first * cacheline, so checking for jumbograms is cheap @@ -269,7 +291,9 @@ int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, { struct ipv6_pinfo *np = inet6_sk(sk); struct inet_sock *inet = inet_sk(sk); + struct udp_sock *up = udp_sk(sk); struct sk_buff *skb; + struct flowi6 *fl6; unsigned int ulen, copied; int off, err, peeking = flags & MSG_PEEK; int is_udplite = IS_UDPLITE(sk); @@ -283,6 +307,12 @@ int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, if (np->rxpmtu && np->rxopt.bits.rxpmtu) return ipv6_recv_rxpmtu(sk, msg, len, addr_len); + if (unlikely(up->repair)) { + if (!peeking) + return -EPERM; + goto recv_sndq; + } + try_again: off = sk_peek_offset(sk, flags); skb = __skb_recv_udp(sk, flags, noblock, &off, &err); @@ -394,6 +424,21 @@ int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, cond_resched(); msg->msg_flags &= ~MSG_TRUNC; goto try_again; + +recv_sndq: + off = sizeof(struct ipv6hdr) + sizeof(struct udphdr); + if (msg->msg_name) { + DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); + + fl6 = &inet->cork.fl.u.ip6; + sin6->sin6_family = AF_INET6; + sin6->sin6_port = fl6->fl6_dport; + sin6->sin6_flowinfo = 0; + sin6->sin6_addr = fl6->daddr; + sin6->sin6_scope_id = fl6->flowi6_oif; + *addr_len = sizeof(*sin6); + } + return udp6_peek_sndq(sk, msg, off, len); } DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key);