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: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 992396a..bd3de7b 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1960,6 +1960,64 @@
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 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 @@
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 @@
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)
+ err = packet_snd_vnet_parse(msg, &len, &vnet_hdr);
+ if (err)
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)
- goto out_unlock;
-
- }
}
if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
@@ -2744,7 +2833,8 @@
}
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 @@
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 @@
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;
- 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;
+ err = packet_snd_vnet_gso(skb, &vnet_hdr);
+ if (err)
+ goto out_free;
+ len += sizeof(vnet_hdr);
}
skb_probe_transport_header(skb, reserve);
@@ -3177,51 +3253,10 @@
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)
+ err = packet_rcv_vnet(msg, skb, &len);
+ if (err)
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)
- goto out_free;
+ vnet_hdr_len = sizeof(struct virtio_net_hdr);
}
/* You lose any data beyond the buffer you gave. If it worries