Commit 16cc1400 authored by Willem de Bruijn's avatar Willem de Bruijn Committed by David S. Miller
Browse files

packet: move vnet_hdr code to helper functions 



packet_snd and packet_rcv support virtio net headers for GSO.
Move this logic into helper functions to be able to reuse it in
tpacket_snd and tpacket_rcv.

This is a straighforward code move with one exception. Instead of
creating and passing a separate gso_type variable, reuse
vnet_hdr.gso_type after conversion from virtio to kernel gso type.

Signed-off-by: default avatarWillem de Bruijn <willemb@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5ee14e6d

net/packet/af_packet.c

+148 −113
Original line number Diff line number Diff line
@@ -1960,6 +1960,64 @@ static unsigned int run_filter(struct sk_buff *skb, 
	return res;

}



static int __packet_rcv_vnet(const struct sk_buff *skb,

			     struct virtio_net_hdr *vnet_hdr)

{

	*vnet_hdr = (const struct virtio_net_hdr) { 0 };



	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 =

			__cpu_to_virtio16(vio_le(), skb_headlen(skb));

		vnet_hdr->gso_size =

			__cpu_to_virtio16(vio_le(), 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 if (sinfo->gso_type & SKB_GSO_FCOE)

			return -EINVAL;

		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 = __cpu_to_virtio16(vio_le(),

				  skb_checksum_start_offset(skb));

		vnet_hdr->csum_offset = __cpu_to_virtio16(vio_le(),

						 skb->csum_offset);

	} else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {

		vnet_hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID;

	} /* else everything is zero */



	return 0;

}



static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb,

			   size_t *len)

{

	struct virtio_net_hdr vnet_hdr;



	if (*len < sizeof(vnet_hdr))

		return -EINVAL;

	*len -= sizeof(vnet_hdr);



	if (__packet_rcv_vnet(skb, &vnet_hdr))

		return -EINVAL;



	return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr));

}



/*

 * This function makes lazy skb cloning in hope that most of packets

 * are discarded by BPF.
@@ -2347,6 +2405,84 @@ static void tpacket_set_protocol(const struct net_device *dev, 
	}

}



static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len)

{

	unsigned short gso_type = 0;



	if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&

	    (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +

	     __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 >

	      __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len)))

		vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(),

			 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +

			__virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2);



	if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len)

		return -EINVAL;



	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;

	}



	vnet_hdr->gso_type = gso_type;	/* changes type, temporary storage */

	return 0;

}



static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len,

				 struct virtio_net_hdr *vnet_hdr)

{

	int n;



	if (*len < sizeof(*vnet_hdr))

		return -EINVAL;

	*len -= sizeof(*vnet_hdr);



	n = copy_from_iter(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter);

	if (n != sizeof(*vnet_hdr))

		return -EFAULT;



	return __packet_snd_vnet_parse(vnet_hdr, *len);

}



static int packet_snd_vnet_gso(struct sk_buff *skb,

			       struct virtio_net_hdr *vnet_hdr)

{

	if (vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {

		u16 s = __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start);

		u16 o = __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset);



		if (!skb_partial_csum_set(skb, s, o))

			return -EINVAL;

	}



	skb_shinfo(skb)->gso_size =

		__virtio16_to_cpu(vio_le(), vnet_hdr->gso_size);

	skb_shinfo(skb)->gso_type = vnet_hdr->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 tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,

		void *frame, struct net_device *dev, int size_max,

		__be16 proto, unsigned char *addr, int hlen)
@@ -2643,12 +2779,9 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 
	struct sockcm_cookie sockc;

	struct virtio_net_hdr vnet_hdr = { 0 };

	int offset = 0;

	int vnet_hdr_len;

	struct packet_sock *po = pkt_sk(sk);

	unsigned short gso_type = 0;

	int hlen, tlen;

	int extra_len = 0;

	ssize_t n;



	/*

	 *	Get and verify the address.
@@ -2686,53 +2819,9 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 
	if (sock->type == SOCK_RAW)

		reserve = dev->hard_header_len;

	if (po->has_vnet_hdr) {

		vnet_hdr_len = sizeof(vnet_hdr);



		err = -EINVAL;

		if (len < vnet_hdr_len)

			goto out_unlock;



		len -= vnet_hdr_len;



		err = -EFAULT;

		n = copy_from_iter(&vnet_hdr, vnet_hdr_len, &msg->msg_iter);

		if (n != vnet_hdr_len)

			goto out_unlock;



		if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&

		    (__virtio16_to_cpu(vio_le(), vnet_hdr.csum_start) +

		     __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset) + 2 >

		      __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len)))

			vnet_hdr.hdr_len = __cpu_to_virtio16(vio_le(),

				 __virtio16_to_cpu(vio_le(), vnet_hdr.csum_start) +

				__virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset) + 2);



		err = -EINVAL;

		if (__virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len) > len)

			goto out_unlock;



		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:

				goto out_unlock;

			}



			if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)

				gso_type |= SKB_GSO_TCP_ECN;



			if (vnet_hdr.gso_size == 0)

		err = packet_snd_vnet_parse(msg, &len, &vnet_hdr);

		if (err)

			goto out_unlock;



		}

	}



	if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
@@ -2744,7 +2833,8 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 
	}



	err = -EMSGSIZE;

	if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))

	if (!vnet_hdr.gso_type &&

	    (len > dev->mtu + reserve + VLAN_HLEN + extra_len))

		goto out_unlock;



	err = -ENOBUFS;
@@ -2775,7 +2865,7 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 


	sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);



	if (!gso_type && (len > dev->mtu + reserve + extra_len) &&

	if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) &&

	    !packet_extra_vlan_len_allowed(dev, skb)) {

		err = -EMSGSIZE;

		goto out_free;
@@ -2789,24 +2879,10 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) 
	packet_pick_tx_queue(dev, skb);



	if (po->has_vnet_hdr) {

		if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {

			u16 s = __virtio16_to_cpu(vio_le(), vnet_hdr.csum_start);

			u16 o = __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset);

			if (!skb_partial_csum_set(skb, s, o)) {

				err = -EINVAL;

		err = packet_snd_vnet_gso(skb, &vnet_hdr);

		if (err)

			goto out_free;

			}

		}



		skb_shinfo(skb)->gso_size =

			__virtio16_to_cpu(vio_le(), 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;



		len += vnet_hdr_len;

		len += sizeof(vnet_hdr);

	}



	skb_probe_transport_header(skb, reserve);
@@ -3177,51 +3253,10 @@ static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 
		packet_rcv_has_room(pkt_sk(sk), NULL);



	if (pkt_sk(sk)->has_vnet_hdr) {

		struct virtio_net_hdr vnet_hdr = { 0 };



		err = -EINVAL;

		vnet_hdr_len = sizeof(vnet_hdr);

		if (len < vnet_hdr_len)

			goto out_free;



		len -= vnet_hdr_len;



		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 =

				__cpu_to_virtio16(vio_le(), skb_headlen(skb));

			vnet_hdr.gso_size =

				__cpu_to_virtio16(vio_le(), 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 if (sinfo->gso_type & SKB_GSO_FCOE)

				goto out_free;

			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 = __cpu_to_virtio16(vio_le(),

					  skb_checksum_start_offset(skb));

			vnet_hdr.csum_offset = __cpu_to_virtio16(vio_le(),

							 skb->csum_offset);

		} else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {

			vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;

		} /* else everything is zero */



		err = memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_len);

		if (err < 0)

		err = packet_rcv_vnet(msg, skb, &len);

		if (err)

			goto out_free;

		vnet_hdr_len = sizeof(struct virtio_net_hdr);

	}



	/* You lose any data beyond the buffer you gave. If it worries

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