diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/macvtap.c | 206 |
1 files changed, 182 insertions, 24 deletions
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c index e354501ab29..55ceae09738 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -17,6 +17,7 @@ #include <net/net_namespace.h> #include <net/rtnetlink.h> #include <net/sock.h> +#include <linux/virtio_net.h> /* * A macvtap queue is the central object of this driver, it connects @@ -37,6 +38,7 @@ struct macvtap_queue { struct socket sock; struct macvlan_dev *vlan; struct file *file; + unsigned int flags; }; static struct proto macvtap_proto = { @@ -276,6 +278,7 @@ static int macvtap_open(struct inode *inode, struct file *file) q->sock.ops = &macvtap_socket_ops; sock_init_data(&q->sock, &q->sk); q->sk.sk_write_space = macvtap_sock_write_space; + q->flags = IFF_VNET_HDR | IFF_NO_PI | IFF_TAP; err = macvtap_set_queue(dev, file, q); if (err) @@ -318,6 +321,111 @@ out: return mask; } +static inline struct sk_buff *macvtap_alloc_skb(struct sock *sk, size_t prepad, + size_t len, size_t linear, + int noblock, int *err) +{ + struct sk_buff *skb; + + /* Under a page? Don't bother with paged skb. */ + if (prepad + len < PAGE_SIZE || !linear) + linear = len; + + skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, + err); + if (!skb) + return NULL; + + skb_reserve(skb, prepad); + skb_put(skb, linear); + skb->data_len = len - linear; + skb->len += len - linear; + + return skb; +} + +/* + * macvtap_skb_from_vnet_hdr and macvtap_skb_to_vnet_hdr should + * be shared with the tun/tap driver. + */ +static int macvtap_skb_from_vnet_hdr(struct sk_buff *skb, + struct virtio_net_hdr *vnet_hdr) +{ + unsigned short gso_type = 0; + if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) { + switch (vnet_hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { + case VIRTIO_NET_HDR_GSO_TCPV4: + gso_type = SKB_GSO_TCPV4; + break; + case VIRTIO_NET_HDR_GSO_TCPV6: + gso_type = SKB_GSO_TCPV6; + break; + case VIRTIO_NET_HDR_GSO_UDP: + gso_type = SKB_GSO_UDP; + break; + default: + return -EINVAL; + } + + if (vnet_hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN) + gso_type |= SKB_GSO_TCP_ECN; + + if (vnet_hdr->gso_size == 0) + return -EINVAL; + } + + if (vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { + if (!skb_partial_csum_set(skb, vnet_hdr->csum_start, + vnet_hdr->csum_offset)) + return -EINVAL; + } + + if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) { + skb_shinfo(skb)->gso_size = vnet_hdr->gso_size; + skb_shinfo(skb)->gso_type = gso_type; + + /* Header must be checked, and gso_segs computed. */ + skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; + skb_shinfo(skb)->gso_segs = 0; + } + return 0; +} + +static int macvtap_skb_to_vnet_hdr(const struct sk_buff *skb, + struct virtio_net_hdr *vnet_hdr) +{ + memset(vnet_hdr, 0, sizeof(*vnet_hdr)); + + if (skb_is_gso(skb)) { + struct skb_shared_info *sinfo = skb_shinfo(skb); + + /* This is a hint as to how much should be linear. */ + vnet_hdr->hdr_len = skb_headlen(skb); + vnet_hdr->gso_size = sinfo->gso_size; + if (sinfo->gso_type & SKB_GSO_TCPV4) + vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4; + else if (sinfo->gso_type & SKB_GSO_TCPV6) + vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6; + else if (sinfo->gso_type & SKB_GSO_UDP) + vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP; + else + BUG(); + if (sinfo->gso_type & SKB_GSO_TCP_ECN) + vnet_hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN; + } else + vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE; + + if (skb->ip_summed == CHECKSUM_PARTIAL) { + vnet_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; + vnet_hdr->csum_start = skb->csum_start - + skb_headroom(skb); + vnet_hdr->csum_offset = skb->csum_offset; + } /* else everything is zero */ + + return 0; +} + + /* Get packet from user space buffer */ static ssize_t macvtap_get_user(struct macvtap_queue *q, const struct iovec *iv, size_t count, @@ -327,22 +435,53 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct macvlan_dev *vlan; size_t len = count; int err; + struct virtio_net_hdr vnet_hdr = { 0 }; + int vnet_hdr_len = 0; + + if (q->flags & IFF_VNET_HDR) { + vnet_hdr_len = sizeof(vnet_hdr); + + err = -EINVAL; + if ((len -= vnet_hdr_len) < 0) + goto err; + + err = memcpy_fromiovecend((void *)&vnet_hdr, iv, 0, + vnet_hdr_len); + if (err < 0) + goto err; + if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && + vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 > + vnet_hdr.hdr_len) + vnet_hdr.hdr_len = vnet_hdr.csum_start + + vnet_hdr.csum_offset + 2; + err = -EINVAL; + if (vnet_hdr.hdr_len > len) + goto err; + } + err = -EINVAL; if (unlikely(len < ETH_HLEN)) - return -EINVAL; + goto err; - skb = sock_alloc_send_skb(&q->sk, NET_IP_ALIGN + len, noblock, &err); + skb = macvtap_alloc_skb(&q->sk, NET_IP_ALIGN, len, vnet_hdr.hdr_len, + noblock, &err); if (!skb) goto err; - skb_reserve(skb, NET_IP_ALIGN); - skb_put(skb, count); - - err = skb_copy_datagram_from_iovec(skb, 0, iv, 0, len); + err = skb_copy_datagram_from_iovec(skb, 0, iv, vnet_hdr_len, len); if (err) - goto err; + goto err_kfree; skb_set_network_header(skb, ETH_HLEN); + skb_reset_mac_header(skb); + skb->protocol = eth_hdr(skb)->h_proto; + + if (vnet_hdr_len) { + err = macvtap_skb_from_vnet_hdr(skb, &vnet_hdr); + if (err) + goto err_kfree; + } + rcu_read_lock_bh(); vlan = rcu_dereference(q->vlan); if (vlan) @@ -353,15 +492,16 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, return count; +err_kfree: + kfree_skb(skb); + err: rcu_read_lock_bh(); vlan = rcu_dereference(q->vlan); if (vlan) - macvlan_count_rx(q->vlan, 0, false, false); + netdev_get_tx_queue(vlan->dev, 0)->tx_dropped++; rcu_read_unlock_bh(); - kfree_skb(skb); - return err; } @@ -384,10 +524,25 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q, { struct macvlan_dev *vlan; int ret; + int vnet_hdr_len = 0; + + if (q->flags & IFF_VNET_HDR) { + struct virtio_net_hdr vnet_hdr; + vnet_hdr_len = sizeof (vnet_hdr); + if ((len -= vnet_hdr_len) < 0) + return -EINVAL; + + ret = macvtap_skb_to_vnet_hdr(skb, &vnet_hdr); + if (ret) + return ret; + + if (memcpy_toiovecend(iv, (void *)&vnet_hdr, 0, vnet_hdr_len)) + return -EFAULT; + } len = min_t(int, skb->len, len); - ret = skb_copy_datagram_const_iovec(skb, 0, iv, 0, len); + ret = skb_copy_datagram_const_iovec(skb, 0, iv, vnet_hdr_len, len); rcu_read_lock_bh(); vlan = rcu_dereference(q->vlan); @@ -395,7 +550,7 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q, macvlan_count_rx(vlan, len, ret == 0, 0); rcu_read_unlock_bh(); - return ret ? ret : len; + return ret ? ret : (len + vnet_hdr_len); } static ssize_t macvtap_do_read(struct macvtap_queue *q, struct kiocb *iocb, @@ -473,9 +628,14 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd, /* ignore the name, just look at flags */ if (get_user(u, &ifr->ifr_flags)) return -EFAULT; - if (u != (IFF_TAP | IFF_NO_PI)) - return -EINVAL; - return 0; + + ret = 0; + if ((u & ~IFF_VNET_HDR) != (IFF_NO_PI | IFF_TAP)) + ret = -EINVAL; + else + q->flags = u; + + return ret; case TUNGETIFF: rcu_read_lock_bh(); @@ -489,13 +649,13 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd, ret = 0; if (copy_to_user(&ifr->ifr_name, q->vlan->dev->name, IFNAMSIZ) || - put_user((TUN_TAP_DEV | TUN_NO_PI), &ifr->ifr_flags)) + put_user(q->flags, &ifr->ifr_flags)) ret = -EFAULT; dev_put(vlan->dev); return ret; case TUNGETFEATURES: - if (put_user((IFF_TAP | IFF_NO_PI), up)) + if (put_user(IFF_TAP | IFF_NO_PI | IFF_VNET_HDR, up)) return -EFAULT; return 0; @@ -509,15 +669,13 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd, case TUNSETOFFLOAD: /* let the user check for future flags */ if (arg & ~(TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 | - TUN_F_TSO_ECN | TUN_F_UFO)) - return -EINVAL; - - /* TODO: add support for these, so far we don't - support any offload */ - if (arg & (TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 | - TUN_F_TSO_ECN | TUN_F_UFO)) + TUN_F_TSO_ECN | TUN_F_UFO)) return -EINVAL; + /* TODO: only accept frames with the features that + got enabled for forwarded frames */ + if (!(q->flags & IFF_VNET_HDR)) + return -EINVAL; return 0; default: |