Commit 1f3a4519 authored by Tiwei Bie's avatar Tiwei Bie Committed by Michael S. Tsirkin
Browse files

vhost-user: support receiving file descriptors in slave_read 



Signed-off-by: default avatarTiwei Bie <tiwei.bie@intel.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 703878e2

hw/virtio/vhost-user.c

+40 −1
Original line number Diff line number Diff line
@@ -852,14 +852,44 @@ static void slave_read(void *opaque) 
    VhostUserHeader hdr = { 0, };

    VhostUserPayload payload = { 0, };

    int size, ret = 0;

    struct iovec iov;

    struct msghdr msgh;

    int fd = -1;

    char control[CMSG_SPACE(sizeof(fd))];

    struct cmsghdr *cmsg;

    size_t fdsize;



    memset(&msgh, 0, sizeof(msgh));

    msgh.msg_iov = &iov;

    msgh.msg_iovlen = 1;

    msgh.msg_control = control;

    msgh.msg_controllen = sizeof(control);



    /* Read header */

    size = read(u->slave_fd, &hdr, VHOST_USER_HDR_SIZE);

    iov.iov_base = &hdr;

    iov.iov_len = VHOST_USER_HDR_SIZE;



    size = recvmsg(u->slave_fd, &msgh, 0);

    if (size != VHOST_USER_HDR_SIZE) {

        error_report("Failed to read from slave.");

        goto err;

    }



    if (msgh.msg_flags & MSG_CTRUNC) {

        error_report("Truncated message.");

        goto err;

    }



    for (cmsg = CMSG_FIRSTHDR(&msgh); cmsg != NULL;

         cmsg = CMSG_NXTHDR(&msgh, cmsg)) {

            if (cmsg->cmsg_level == SOL_SOCKET &&

                cmsg->cmsg_type == SCM_RIGHTS) {

                    fdsize = cmsg->cmsg_len - CMSG_LEN(0);

                    memcpy(&fd, CMSG_DATA(cmsg), fdsize);

                    break;

            }

    }



    if (hdr.size > VHOST_USER_PAYLOAD_SIZE) {

        error_report("Failed to read msg header."

                " Size %d exceeds the maximum %zu.", hdr.size,
@@ -883,9 +913,15 @@ static void slave_read(void *opaque) 
        break;

    default:

        error_report("Received unexpected msg type.");

        if (fd != -1) {

            close(fd);

        }

        ret = -EINVAL;

    }



    /* Message handlers need to make sure that fd will be consumed. */

    fd = -1;



    /*

     * REPLY_ACK feature handling. Other reply types has to be managed

     * directly in their request handlers.
@@ -918,6 +954,9 @@ err: 
    qemu_set_fd_handler(u->slave_fd, NULL, NULL, NULL);

    close(u->slave_fd);

    u->slave_fd = -1;

    if (fd != -1) {

        close(fd);

    }

    return;

}