From patchwork Thu Jun 24 12:30:01 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Woodhouse X-Patchwork-Id: 12342115 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 X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 ACE32C48BDF for ; Thu, 24 Jun 2021 12:30:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 95D726054E for ; Thu, 24 Jun 2021 12:30:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231475AbhFXMdO (ORCPT ); Thu, 24 Jun 2021 08:33:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45170 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231445AbhFXMc3 (ORCPT ); Thu, 24 Jun 2021 08:32:29 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 926FCC061766 for ; Thu, 24 Jun 2021 05:30:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=zHJR80i/wZ1WVZoiPlde4xMcP5UTsoCKyhR98zMFLx8=; b=N49p3AhqENOsKT9vgspdxEA0rL ufs17K9AAOlJFhgubUbNYgTsPED1FGiSu7wammq62NSOV61Gq6dVtvIyphdlTis2IONsxYAYa3ims hT1yqE520yJHow48qL12GQXa2O8tdfFsm3t5GzyKy53qzHcysoUnWPDGmWRMRTW7tEtSsQyq63gpb 0Y6wB/JNMmnugbT1D7moIz2YiqkPhfkI1pvgMVJ4/Ovq+p5jBijOZxmaRfjFXdjwXeMKSGpn12oeu 8XfHkOCrShpr7ESXT7W56IygkC8o0ybA0xCvUMszLhyFddaSuxd5JzfauiKenAUwukRydvHmgs42N YBBxqdpw==; Received: from i7.infradead.org ([2001:8b0:10b:1:21e:67ff:fecb:7a92]) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1lwOUZ-00BEEM-31; Thu, 24 Jun 2021 12:30:08 +0000 Received: from dwoodhou by i7.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1lwOUf-005Seu-If; Thu, 24 Jun 2021 13:30:05 +0100 From: David Woodhouse To: netdev@vger.kernel.org Cc: Jason Wang , =?utf-8?q?Eugenio_P=C3=A9rez?= , Willem de Bruijn Subject: [PATCH v3 1/5] net: add header len parameter to tun_get_socket(), tap_get_socket() Date: Thu, 24 Jun 2021 13:30:01 +0100 Message-Id: <20210624123005.1301761-1-dwmw2@infradead.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <03ee62602dd7b7101f78e0802249a6e2e4c10b7f.camel@infradead.org> References: <03ee62602dd7b7101f78e0802249a6e2e4c10b7f.camel@infradead.org> MIME-Version: 1.0 Sender: David Woodhouse X-SRS-Rewrite: SMTP reverse-path rewritten from by desiato.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: David Woodhouse The vhost-net driver was making wild assumptions about the header length of the underlying tun/tap socket. Then it was discarding packets if the number of bytes it got from sock_recvmsg() didn't precisely match its guess. Fix it to get the correct information along with the socket itself. As a side-effect, this means that tun_get_socket() won't work if the tun file isn't actually connected to a device, since there's no 'tun' yet in that case to get the information from. On the receive side, where the tun device generates the virtio_net_hdr but VIRITO_NET_F_MSG_RXBUF was negotiated and vhost-net needs to fill in the 'num_buffers' field on top of the existing virtio_net_hdr, fix that to use 'sock_hlen - 2' as the location, which means that it goes in the right place regardless of whether the tun device is using an additional tun_pi header or not. In this case, the user should have configured the tun device with a vnet hdr size of 12, to make room. Fixes: 8dd014adfea6f ("vhost-net: mergeable buffers support") Signed-off-by: David Woodhouse --- drivers/net/tap.c | 5 ++++- drivers/net/tun.c | 16 +++++++++++++++- drivers/vhost/net.c | 31 +++++++++++++++---------------- include/linux/if_tap.h | 4 ++-- include/linux/if_tun.h | 4 ++-- 5 files changed, 38 insertions(+), 22 deletions(-) diff --git a/drivers/net/tap.c b/drivers/net/tap.c index 8e3a28ba6b28..2170a0d3d34c 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -1246,7 +1246,7 @@ static const struct proto_ops tap_socket_ops = { * attached to a device. The returned object works like a packet socket, it * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for * holding a reference to the file for as long as the socket is in use. */ -struct socket *tap_get_socket(struct file *file) +struct socket *tap_get_socket(struct file *file, size_t *hlen) { struct tap_queue *q; if (file->f_op != &tap_fops) @@ -1254,6 +1254,9 @@ struct socket *tap_get_socket(struct file *file) q = file->private_data; if (!q) return ERR_PTR(-EBADFD); + if (hlen) + *hlen = (q->flags & IFF_VNET_HDR) ? q->vnet_hdr_sz : 0; + return &q->sock; } EXPORT_SYMBOL_GPL(tap_get_socket); diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 4cf38be26dc9..67b406fa0881 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -3649,7 +3649,7 @@ static void tun_cleanup(void) * attached to a device. The returned object works like a packet socket, it * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for * holding a reference to the file for as long as the socket is in use. */ -struct socket *tun_get_socket(struct file *file) +struct socket *tun_get_socket(struct file *file, size_t *hlen) { struct tun_file *tfile; if (file->f_op != &tun_fops) @@ -3657,6 +3657,20 @@ struct socket *tun_get_socket(struct file *file) tfile = file->private_data; if (!tfile) return ERR_PTR(-EBADFD); + + if (hlen) { + struct tun_struct *tun = tun_get(tfile); + size_t len = 0; + + if (!tun) + return ERR_PTR(-ENOTCONN); + if (tun->flags & IFF_VNET_HDR) + len += READ_ONCE(tun->vnet_hdr_sz); + if (!(tun->flags & IFF_NO_PI)) + len += sizeof(struct tun_pi); + tun_put(tun); + *hlen = len; + } return &tfile->socket; } EXPORT_SYMBOL_GPL(tun_get_socket); diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index df82b124170e..b92a7144ed90 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -1143,7 +1143,8 @@ static void handle_rx(struct vhost_net *net) vq_log = unlikely(vhost_has_feature(vq, VHOST_F_LOG_ALL)) ? vq->log : NULL; - mergeable = vhost_has_feature(vq, VIRTIO_NET_F_MRG_RXBUF); + mergeable = vhost_has_feature(vq, VIRTIO_NET_F_MRG_RXBUF) && + (vhost_hlen || sock_hlen >= sizeof(num_buffers)); do { sock_len = vhost_net_rx_peek_head_len(net, sock->sk, @@ -1213,9 +1214,10 @@ static void handle_rx(struct vhost_net *net) } } else { /* Header came from socket; we'll need to patch - * ->num_buffers over if VIRTIO_NET_F_MRG_RXBUF + * ->num_buffers over the last two bytes if + * VIRTIO_NET_F_MRG_RXBUF is enabled. */ - iov_iter_advance(&fixup, sizeof(hdr)); + iov_iter_advance(&fixup, sock_hlen - 2); } /* TODO: Should check and handle checksum. */ @@ -1420,7 +1422,7 @@ static int vhost_net_release(struct inode *inode, struct file *f) return 0; } -static struct socket *get_raw_socket(int fd) +static struct socket *get_raw_socket(int fd, size_t *hlen) { int r; struct socket *sock = sockfd_lookup(fd, &r); @@ -1438,6 +1440,7 @@ static struct socket *get_raw_socket(int fd) r = -EPFNOSUPPORT; goto err; } + *hlen = 0; return sock; err: sockfd_put(sock); @@ -1463,33 +1466,33 @@ static struct ptr_ring *get_tap_ptr_ring(int fd) return ring; } -static struct socket *get_tap_socket(int fd) +static struct socket *get_tap_socket(int fd, size_t *hlen) { struct file *file = fget(fd); struct socket *sock; if (!file) return ERR_PTR(-EBADF); - sock = tun_get_socket(file); + sock = tun_get_socket(file, hlen); if (!IS_ERR(sock)) return sock; - sock = tap_get_socket(file); + sock = tap_get_socket(file, hlen); if (IS_ERR(sock)) fput(file); return sock; } -static struct socket *get_socket(int fd) +static struct socket *get_socket(int fd, size_t *hlen) { struct socket *sock; /* special case to disable backend */ if (fd == -1) return NULL; - sock = get_raw_socket(fd); + sock = get_raw_socket(fd, hlen); if (!IS_ERR(sock)) return sock; - sock = get_tap_socket(fd); + sock = get_tap_socket(fd, hlen); if (!IS_ERR(sock)) return sock; return ERR_PTR(-ENOTSOCK); @@ -1521,7 +1524,7 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) r = -EFAULT; goto err_vq; } - sock = get_socket(fd); + sock = get_socket(fd, &nvq->sock_hlen); if (IS_ERR(sock)) { r = PTR_ERR(sock); goto err_vq; @@ -1621,7 +1624,7 @@ static long vhost_net_reset_owner(struct vhost_net *n) static int vhost_net_set_features(struct vhost_net *n, u64 features) { - size_t vhost_hlen, sock_hlen, hdr_len; + size_t vhost_hlen, hdr_len; int i; hdr_len = (features & ((1ULL << VIRTIO_NET_F_MRG_RXBUF) | @@ -1631,11 +1634,8 @@ static int vhost_net_set_features(struct vhost_net *n, u64 features) if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) { /* vhost provides vnet_hdr */ vhost_hlen = hdr_len; - sock_hlen = 0; } else { - /* socket provides vnet_hdr */ vhost_hlen = 0; - sock_hlen = hdr_len; } mutex_lock(&n->dev.mutex); if ((features & (1 << VHOST_F_LOG_ALL)) && @@ -1651,7 +1651,6 @@ static int vhost_net_set_features(struct vhost_net *n, u64 features) mutex_lock(&n->vqs[i].vq.mutex); n->vqs[i].vq.acked_features = features; n->vqs[i].vhost_hlen = vhost_hlen; - n->vqs[i].sock_hlen = sock_hlen; mutex_unlock(&n->vqs[i].vq.mutex); } mutex_unlock(&n->dev.mutex); diff --git a/include/linux/if_tap.h b/include/linux/if_tap.h index 915a187cfabd..b460ba98f34e 100644 --- a/include/linux/if_tap.h +++ b/include/linux/if_tap.h @@ -3,14 +3,14 @@ #define _LINUX_IF_TAP_H_ #if IS_ENABLED(CONFIG_TAP) -struct socket *tap_get_socket(struct file *); +struct socket *tap_get_socket(struct file *, size_t *); struct ptr_ring *tap_get_ptr_ring(struct file *file); #else #include #include struct file; struct socket; -static inline struct socket *tap_get_socket(struct file *f) +static inline struct socket *tap_get_socket(struct file *f, size_t *) { return ERR_PTR(-EINVAL); } diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h index 2a7660843444..8a7debd3f663 100644 --- a/include/linux/if_tun.h +++ b/include/linux/if_tun.h @@ -25,7 +25,7 @@ struct tun_xdp_hdr { }; #if defined(CONFIG_TUN) || defined(CONFIG_TUN_MODULE) -struct socket *tun_get_socket(struct file *); +struct socket *tun_get_socket(struct file *, size_t *); struct ptr_ring *tun_get_tx_ring(struct file *file); static inline bool tun_is_xdp_frame(void *ptr) { @@ -45,7 +45,7 @@ void tun_ptr_free(void *ptr); #include struct file; struct socket; -static inline struct socket *tun_get_socket(struct file *f) +static inline struct socket *tun_get_socket(struct file *f, size_t *) { return ERR_PTR(-EINVAL); }