static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
unsigned short id;
struct netfront_info *np = netdev_priv(dev);
struct netfront_stats *stats = this_cpu_ptr(np->stats);
struct xen_netif_tx_request *tx;
struct xen_netif_extra_info *extra;
char *data = skb->data;
RING_IDX i;
grant_ref_t ref;
unsigned long mfn;
int notify;
int slots;
unsigned int offset = offset_in_page(data);
unsigned int len = skb_headlen(skb);
unsigned long flags;
/* If skb->len is too big for wire format, drop skb and alert
* user about misconfiguration.
*/
if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
net_alert_ratelimited(
"xennet: skb->len = %u, too big for wire format\n",
skb->len);
goto drop;
}
slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) +
xennet_count_skb_frag_slots(skb);
if (unlikely(slots > MAX_SKB_FRAGS + 1)) {
net_alert_ratelimited(
"xennet: skb rides the rocket: %d slots\n", slots);
goto drop;
}
spin_lock_irqsave(&np->tx_lock, flags);
if (unlikely(!netif_carrier_ok(dev) ||
(slots > 1 && !xennet_can_sg(dev)) ||
netif_needs_gso(skb, netif_skb_features(skb)))) {
spin_unlock_irqrestore(&np->tx_lock, flags);
goto drop;
}
i = np->tx.req_prod_pvt;
id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
np->tx_skbs[id].skb = skb;
tx = RING_GET_REQUEST(&np->tx, i);
tx->id = id;
ref = gnttab_claim_grant_reference(&np->gref_tx_head);
BUG_ON((signed short)ref < 0);
mfn = virt_to_mfn(data);
gnttab_grant_foreign_access_ref(
ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly);
tx->gref = np->grant_tx_ref[id] = ref;
tx->offset = offset;
tx->size = len;
extra = NULL;
tx->flags = 0;
if (skb->ip_summed == CHECKSUM_PARTIAL)
/* local packet? */
tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
/* remote but checksummed. */
tx->flags |= XEN_NETTXF_data_validated;
if (skb_shinfo(skb)->gso_size) {
struct xen_netif_extra_info *gso;
gso = (struct xen_netif_extra_info *)
RING_GET_REQUEST(&np->tx, ++i);
if (extra)
extra->flags |= XEN_NETIF_EXTRA_FLAG_MORE;
else
tx->flags |= XEN_NETTXF_extra_info;
gso->u.gso.size = skb_shinfo(skb)->gso_size;
gso->u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4;
gso->u.gso.pad = 0;
gso->u.gso.features = 0;
gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
gso->flags = 0;
extra = gso;
}
np->tx.req_prod_pvt = i + 1;
xennet_make_frags(skb, dev, tx);
tx->size = skb->len;
RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->tx, notify);
if (notify)
notify_remote_via_irq(np->netdev->irq);
u64_stats_update_begin(&stats->syncp);
stats->tx_bytes += skb->len;
stats->tx_packets++;
u64_stats_update_end(&stats->syncp);
/* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
xennet_tx_buf_gc(dev);
if (!netfront_tx_slot_available(np))
netif_stop_queue(dev);
spin_unlock_irqrestore(&np->tx_lock, flags);
return NETDEV_TX_OK;
drop:
dev->stats.tx_dropped++;
dev_kfree_skb(skb);
return NETDEV_TX_OK;
}
static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
{
struct net_device_context *net_device_ctx = netdev_priv(net);
struct hv_netvsc_packet *packet = NULL;
int ret;
unsigned int num_data_pgs;
struct rndis_message *rndis_msg;
struct rndis_packet *rndis_pkt;
u32 rndis_msg_size;
bool isvlan;
bool linear = false;
struct rndis_per_packet_info *ppi;
struct ndis_tcp_ip_checksum_info *csum_info;
struct ndis_tcp_lso_info *lso_info;
int hdr_offset;
u32 net_trans_info;
u32 hash;
u32 skb_length;
struct hv_page_buffer page_buf[MAX_PAGE_BUFFER_COUNT];
struct hv_page_buffer *pb = page_buf;
struct netvsc_stats *tx_stats = this_cpu_ptr(net_device_ctx->tx_stats);
/* We will atmost need two pages to describe the rndis
* header. We can only transmit MAX_PAGE_BUFFER_COUNT number
* of pages in a single packet. If skb is scattered around
* more pages we try linearizing it.
*/
check_size:
skb_length = skb->len;
num_data_pgs = netvsc_get_slots(skb) + 2;
if (num_data_pgs > MAX_PAGE_BUFFER_COUNT && linear) {
net_alert_ratelimited("packet too big: %u pages (%u bytes)\n",
num_data_pgs, skb->len);
ret = -EFAULT;
goto drop;
} else if (num_data_pgs > MAX_PAGE_BUFFER_COUNT) {
if (skb_linearize(skb)) {
net_alert_ratelimited("failed to linearize skb\n");
ret = -ENOMEM;
goto drop;
}
linear = true;
goto check_size;
}
/*
* Place the rndis header in the skb head room and
* the skb->cb will be used for hv_netvsc_packet
* structure.
*/
ret = skb_cow_head(skb, RNDIS_AND_PPI_SIZE);
if (ret) {
netdev_err(net, "unable to alloc hv_netvsc_packet\n");
ret = -ENOMEM;
goto drop;
}
/* Use the skb control buffer for building up the packet */
BUILD_BUG_ON(sizeof(struct hv_netvsc_packet) >
FIELD_SIZEOF(struct sk_buff, cb));
packet = (struct hv_netvsc_packet *)skb->cb;
packet->q_idx = skb_get_queue_mapping(skb);
packet->total_data_buflen = skb->len;
rndis_msg = (struct rndis_message *)skb->head;
memset(rndis_msg, 0, RNDIS_AND_PPI_SIZE);
isvlan = skb->vlan_tci & VLAN_TAG_PRESENT;
/* Add the rndis header */
rndis_msg->ndis_msg_type = RNDIS_MSG_PACKET;
rndis_msg->msg_len = packet->total_data_buflen;
rndis_pkt = &rndis_msg->msg.pkt;
rndis_pkt->data_offset = sizeof(struct rndis_packet);
rndis_pkt->data_len = packet->total_data_buflen;
rndis_pkt->per_pkt_info_offset = sizeof(struct rndis_packet);
rndis_msg_size = RNDIS_MESSAGE_SIZE(struct rndis_packet);
hash = skb_get_hash_raw(skb);
if (hash != 0 && net->real_num_tx_queues > 1) {
rndis_msg_size += NDIS_HASH_PPI_SIZE;
ppi = init_ppi_data(rndis_msg, NDIS_HASH_PPI_SIZE,
NBL_HASH_VALUE);
*(u32 *)((void *)ppi + ppi->ppi_offset) = hash;
}
if (isvlan) {
struct ndis_pkt_8021q_info *vlan;
rndis_msg_size += NDIS_VLAN_PPI_SIZE;
ppi = init_ppi_data(rndis_msg, NDIS_VLAN_PPI_SIZE,
IEEE_8021Q_INFO);
vlan = (struct ndis_pkt_8021q_info *)((void *)ppi +
ppi->ppi_offset);
vlan->vlanid = skb->vlan_tci & VLAN_VID_MASK;
vlan->pri = (skb->vlan_tci & VLAN_PRIO_MASK) >>
VLAN_PRIO_SHIFT;
}
net_trans_info = get_net_transport_info(skb, &hdr_offset);
if (net_trans_info == TRANSPORT_INFO_NOT_IP)
goto do_send;
/*
* Setup the sendside checksum offload only if this is not a
* GSO packet.
*/
if (skb_is_gso(skb))
goto do_lso;
if ((skb->ip_summed == CHECKSUM_NONE) ||
(skb->ip_summed == CHECKSUM_UNNECESSARY))
goto do_send;
rndis_msg_size += NDIS_CSUM_PPI_SIZE;
ppi = init_ppi_data(rndis_msg, NDIS_CSUM_PPI_SIZE,
TCPIP_CHKSUM_PKTINFO);
csum_info = (struct ndis_tcp_ip_checksum_info *)((void *)ppi +
ppi->ppi_offset);
if (net_trans_info & (INFO_IPV4 << 16))
csum_info->transmit.is_ipv4 = 1;
else
csum_info->transmit.is_ipv6 = 1;
if (net_trans_info & INFO_TCP) {
csum_info->transmit.tcp_checksum = 1;
csum_info->transmit.tcp_header_offset = hdr_offset;
} else if (net_trans_info & INFO_UDP) {
/* UDP checksum offload is not supported on ws2008r2.
* Furthermore, on ws2012 and ws2012r2, there are some
* issues with udp checksum offload from Linux guests.
* (these are host issues).
* For now compute the checksum here.
*/
struct udphdr *uh;
u16 udp_len;
ret = skb_cow_head(skb, 0);
if (ret)
goto drop;
uh = udp_hdr(skb);
udp_len = ntohs(uh->len);
uh->check = 0;
uh->check = csum_tcpudp_magic(ip_hdr(skb)->saddr,
ip_hdr(skb)->daddr,
udp_len, IPPROTO_UDP,
csum_partial(uh, udp_len, 0));
if (uh->check == 0)
uh->check = CSUM_MANGLED_0;
csum_info->transmit.udp_checksum = 0;
}
goto do_send;
do_lso:
rndis_msg_size += NDIS_LSO_PPI_SIZE;
ppi = init_ppi_data(rndis_msg, NDIS_LSO_PPI_SIZE,
TCP_LARGESEND_PKTINFO);
lso_info = (struct ndis_tcp_lso_info *)((void *)ppi +
ppi->ppi_offset);
lso_info->lso_v2_transmit.type = NDIS_TCP_LARGE_SEND_OFFLOAD_V2_TYPE;
if (net_trans_info & (INFO_IPV4 << 16)) {
lso_info->lso_v2_transmit.ip_version =
NDIS_TCP_LARGE_SEND_OFFLOAD_IPV4;
ip_hdr(skb)->tot_len = 0;
ip_hdr(skb)->check = 0;
tcp_hdr(skb)->check =
~csum_tcpudp_magic(ip_hdr(skb)->saddr,
ip_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
} else {
lso_info->lso_v2_transmit.ip_version =
NDIS_TCP_LARGE_SEND_OFFLOAD_IPV6;
ipv6_hdr(skb)->payload_len = 0;
tcp_hdr(skb)->check =
~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
&ipv6_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
}
lso_info->lso_v2_transmit.tcp_header_offset = hdr_offset;
lso_info->lso_v2_transmit.mss = skb_shinfo(skb)->gso_size;
do_send:
/* Start filling in the page buffers with the rndis hdr */
rndis_msg->msg_len += rndis_msg_size;
packet->total_data_buflen = rndis_msg->msg_len;
packet->page_buf_cnt = init_page_array(rndis_msg, rndis_msg_size,
skb, packet, &pb);
/* timestamp packet in software */
skb_tx_timestamp(skb);
ret = netvsc_send(net_device_ctx->device_ctx, packet,
rndis_msg, &pb, skb);
drop:
if (ret == 0) {
u64_stats_update_begin(&tx_stats->syncp);
tx_stats->packets++;
tx_stats->bytes += skb_length;
u64_stats_update_end(&tx_stats->syncp);
} else {
if (ret != -EAGAIN) {
dev_kfree_skb_any(skb);
net->stats.tx_dropped++;
}
}
return (ret == -EAGAIN) ? NETDEV_TX_BUSY : NETDEV_TX_OK;
}
