From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id 686301B450; Fri, 12 Oct 2018 11:52:28 +0200 (CEST) Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B2DD23D970; Fri, 12 Oct 2018 09:52:27 +0000 (UTC) Received: from [10.36.112.48] (ovpn-112-48.ams2.redhat.com [10.36.112.48]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 52E766E415; Fri, 12 Oct 2018 09:52:21 +0000 (UTC) To: Ilya Maximets , dev@dpdk.org, tiwei.bie@intel.com, zhihong.wang@intel.com, jfreimann@redhat.com, nicknickolaev@gmail.com, bruce.richardson@intel.com, alejandro.lucero@netronome.com, dgilbert@redhat.com Cc: stable@dpdk.org References: <20181011092432.22275-1-maxime.coquelin@redhat.com> <20181011092432.22275-8-maxime.coquelin@redhat.com> <20181011155709eucas1p20da3d82e3f74a0f8b8bd06eae4baa0c5~cmQddRjzg2527125271eucas1p2_@eucas1p2.samsung.com> <377e0ee1-562d-e5cb-e411-e041f8c60ba5@redhat.com> <7df5b8ea-6570-e2ab-1983-e74d316e530d@redhat.com> <72d63d93-ba13-d228-d67a-0bbdbebeceaf@redhat.com> <20181012095039eucas1p12ad20f88162a3e0eed0464d05acc8a08~c05vvgLoP1463314633eucas1p1l@eucas1p1.samsung.com> From: Maxime Coquelin Message-ID: Date: Fri, 12 Oct 2018 11:52:18 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20181012095039eucas1p12ad20f88162a3e0eed0464d05acc8a08~c05vvgLoP1463314633eucas1p1l@eucas1p1.samsung.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Fri, 12 Oct 2018 09:52:27 +0000 (UTC) Subject: Re: [dpdk-dev] [PATCH v6 07/19] vhost: add number of fds to vhost-user messages and use it X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 12 Oct 2018 09:52:28 -0000 On 10/12/2018 11:53 AM, Ilya Maximets wrote: > On 12.10.2018 11:57, Maxime Coquelin wrote: >> >> >> On 10/12/2018 10:45 AM, Maxime Coquelin wrote: >>> >>> >>> On 10/12/2018 10:43 AM, Maxime Coquelin wrote: >>>> >>>> >>>> On 10/11/2018 05:59 PM, Ilya Maximets wrote: >>>>> On 11.10.2018 12:24, Maxime Coquelin wrote: >>>>>> As soon as some ancillary data (fds) are received, it is copied >>>>>> without checking its length. >>>>>> >>>>>> This patch adds the number of fds received to the message, >>>>>> which is set in read_vhost_message(). >>>>>> >>>>>> This is preliminary work to support sending fds to Qemu. >>>>>> >>>>>> Signed-off-by: Dr. David Alan Gilbert >>>>>> Signed-off-by: Maxime Coquelin >>>>>> --- >>>>>>   lib/librte_vhost/socket.c     | 25 ++++++++++++++++++++----- >>>>>>   lib/librte_vhost/vhost_user.c |  2 +- >>>>>>   lib/librte_vhost/vhost_user.h |  4 +++- >>>>>>   3 files changed, 24 insertions(+), 7 deletions(-) >>>>>> >>>>>> diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c >>>>>> index d63031747..3b0287a26 100644 >>>>>> --- a/lib/librte_vhost/socket.c >>>>>> +++ b/lib/librte_vhost/socket.c >>>>>> @@ -94,18 +94,24 @@ static struct vhost_user vhost_user = { >>>>>>       .mutex = PTHREAD_MUTEX_INITIALIZER, >>>>>>   }; >>>>>> -/* return bytes# of read on success or negative val on failure. */ >>>>>> +/* >>>>>> + * return bytes# of read on success or negative val on failure. Update fdnum >>>>>> + * with number of fds read. >>>>>> + */ >>>>>>   int >>>>>> -read_fd_message(int sockfd, char *buf, int buflen, int *fds, int fd_num) >>>>>> +read_fd_message(int sockfd, char *buf, int buflen, int *fds, int max_fds, >>>>>> +        int *fd_num) >>>>>>   { >>>>>>       struct iovec iov; >>>>>>       struct msghdr msgh; >>>>>> -    size_t fdsize = fd_num * sizeof(int); >>>>>> -    char control[CMSG_SPACE(fdsize)]; >>>>>> +    char control[CMSG_SPACE(max_fds * sizeof(int))]; >>>>>>       struct cmsghdr *cmsg; >>>>>>       int got_fds = 0; >>>>>> +    int *tmp_fds; >>>>>>       int ret; >>>>>> +    *fd_num = 0; >>>>>> + >>>>>>       memset(&msgh, 0, sizeof(msgh)); >>>>>>       iov.iov_base = buf; >>>>>>       iov.iov_len  = buflen; >>>>>> @@ -131,13 +137,22 @@ read_fd_message(int sockfd, char *buf, int buflen, int *fds, int fd_num) >>>>>>           if ((cmsg->cmsg_level == SOL_SOCKET) && >>>>>>               (cmsg->cmsg_type == SCM_RIGHTS)) { >>>>>>               got_fds = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int); >>>>>> +            if (got_fds > max_fds) { >>>>> >>>>> Hmm. I just noticed that 'msg_controllen' is set to receive >>>>> not more than max_fds descriptors. So, this case should not >>>>> be possible. We will receive MSG_CTRUNC and return before >>>>> the loop. >>>> >>>> Maybe it is better to remove check for MSG_CTRUNC. >>> s/remove/rework/ >>> >>>> IIUC, if MSG_CTRUNC happens, we may have to close anyway the ones >>>> received. >>>> >>>> Do you agree? >> >> So it seems that other use of MSG_CTRUNC in DPDK and QEMU does care >> to close the ones that would have been received and just return an >> error. > > Did you mean 'does not care'? Yes, I meant "does not care", sorry. > 'read_msg()' in lib/librte_eal/common/eal_common_proc.c just returns -1 > and 'slave_read()' in hw/virtio/vhost-user.c does not close fds, because > 'fdsize' is not set at the time of checking the flag. > >> >> I propose to do the same for now, an remove the got_fds > max_fds part. >> >>>>> +                RTE_LOG(ERR, VHOST_CONFIG, >>>>>> +                    "Received msg contains more fds than supported\n"); >>>>>> +                tmp_fds = (int *)CMSG_DATA(cmsg); >>>>>> +                while (got_fds--) >>>>>> +                    close(tmp_fds[got_fds]); >>>>>> +                return -1; >>>>>> +            } >>>>>> +            *fd_num = got_fds; >>>>>>               memcpy(fds, CMSG_DATA(cmsg), got_fds * sizeof(int)); >>>>>>               break; >>>>>>           } >>>>>>       } >>>>>>       /* Clear out unused file descriptors */ >>>>>> -    while (got_fds < fd_num) >>>>>> +    while (got_fds < max_fds) >>>>>>           fds[got_fds++] = -1; >>>>>>       return ret; >>>>>> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c >>>>>> index 83d3e6321..c1c5f35ff 100644 >>>>>> --- a/lib/librte_vhost/vhost_user.c >>>>>> +++ b/lib/librte_vhost/vhost_user.c >>>>>> @@ -1509,7 +1509,7 @@ read_vhost_message(int sockfd, struct VhostUserMsg *msg) >>>>>>       int ret; >>>>>>       ret = read_fd_message(sockfd, (char *)msg, VHOST_USER_HDR_SIZE, >>>>>> -        msg->fds, VHOST_MEMORY_MAX_NREGIONS); >>>>>> +        msg->fds, VHOST_MEMORY_MAX_NREGIONS, &msg->fd_num); >>>>>>       if (ret <= 0) >>>>>>           return ret; >>>>>> diff --git a/lib/librte_vhost/vhost_user.h b/lib/librte_vhost/vhost_user.h >>>>>> index 62654f736..9a91d496b 100644 >>>>>> --- a/lib/librte_vhost/vhost_user.h >>>>>> +++ b/lib/librte_vhost/vhost_user.h >>>>>> @@ -132,6 +132,7 @@ typedef struct VhostUserMsg { >>>>>>           VhostUserVringArea area; >>>>>>       } payload; >>>>>>       int fds[VHOST_MEMORY_MAX_NREGIONS]; >>>>>> +    int fd_num; >>>>>>   } __attribute((packed)) VhostUserMsg; >>>>>>   #define VHOST_USER_HDR_SIZE offsetof(VhostUserMsg, payload.u64) >>>>>> @@ -155,7 +156,8 @@ int vhost_user_iotlb_miss(struct virtio_net *dev, uint64_t iova, uint8_t perm); >>>>>>   int vhost_user_host_notifier_ctrl(int vid, bool enable); >>>>>>   /* socket.c */ >>>>>> -int read_fd_message(int sockfd, char *buf, int buflen, int *fds, int fd_num); >>>>>> +int read_fd_message(int sockfd, char *buf, int buflen, int *fds, int max_fds, >>>>>> +        int *fd_num); >>>>>>   int send_fd_message(int sockfd, char *buf, int buflen, int *fds, int fd_num); >>>>>>   #endif >>>>>> >> >>