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net: move vlan pop/push functions into common code
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So it can be used from out of openvswitch code.
Did couple of cosmetic changes on the way, namely variable naming and
adding support for 8021AD proto.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Jiri Pirko authored and David S. Miller committed Nov 21, 2014
1 parent e219512 commit 93515d5
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Showing 3 changed files with 106 additions and 77 deletions.
2 changes: 2 additions & 0 deletions include/linux/skbuff.h
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Original file line number Diff line number Diff line change
Expand Up @@ -2679,6 +2679,8 @@ unsigned int skb_gso_transport_seglen(const struct sk_buff *skb);
struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
struct sk_buff *skb_vlan_untag(struct sk_buff *skb);
int skb_ensure_writable(struct sk_buff *skb, int write_len);
int skb_vlan_pop(struct sk_buff *skb);
int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci);

struct skb_checksum_ops {
__wsum (*update)(const void *mem, int len, __wsum wsum);
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95 changes: 95 additions & 0 deletions net/core/skbuff.c
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Original file line number Diff line number Diff line change
Expand Up @@ -4163,6 +4163,101 @@ int skb_ensure_writable(struct sk_buff *skb, int write_len)
}
EXPORT_SYMBOL(skb_ensure_writable);

/* remove VLAN header from packet and update csum accordingly. */
static int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci)
{
struct vlan_hdr *vhdr;
unsigned int offset = skb->data - skb_mac_header(skb);
int err;

__skb_push(skb, offset);
err = skb_ensure_writable(skb, VLAN_ETH_HLEN);
if (unlikely(err))
goto pull;

skb_postpull_rcsum(skb, skb->data + (2 * ETH_ALEN), VLAN_HLEN);

vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
*vlan_tci = ntohs(vhdr->h_vlan_TCI);

memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
__skb_pull(skb, VLAN_HLEN);

vlan_set_encap_proto(skb, vhdr);
skb->mac_header += VLAN_HLEN;

if (skb_network_offset(skb) < ETH_HLEN)
skb_set_network_header(skb, ETH_HLEN);

skb_reset_mac_len(skb);
pull:
__skb_pull(skb, offset);

return err;
}

int skb_vlan_pop(struct sk_buff *skb)
{
u16 vlan_tci;
__be16 vlan_proto;
int err;

if (likely(vlan_tx_tag_present(skb))) {
skb->vlan_tci = 0;
} else {
if (unlikely((skb->protocol != htons(ETH_P_8021Q) &&
skb->protocol != htons(ETH_P_8021AD)) ||
skb->len < VLAN_ETH_HLEN))
return 0;

err = __skb_vlan_pop(skb, &vlan_tci);
if (err)
return err;
}
/* move next vlan tag to hw accel tag */
if (likely((skb->protocol != htons(ETH_P_8021Q) &&
skb->protocol != htons(ETH_P_8021AD)) ||
skb->len < VLAN_ETH_HLEN))
return 0;

vlan_proto = skb->protocol;
err = __skb_vlan_pop(skb, &vlan_tci);
if (unlikely(err))
return err;

__vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci);
return 0;
}
EXPORT_SYMBOL(skb_vlan_pop);

int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci)
{
if (vlan_tx_tag_present(skb)) {
unsigned int offset = skb->data - skb_mac_header(skb);
int err;

/* __vlan_insert_tag expect skb->data pointing to mac header.
* So change skb->data before calling it and change back to
* original position later
*/
__skb_push(skb, offset);
err = __vlan_insert_tag(skb, skb->vlan_proto,
vlan_tx_tag_get(skb));
if (err)
return err;
skb->protocol = skb->vlan_proto;
skb->mac_len += VLAN_HLEN;
__skb_pull(skb, offset);

if (skb->ip_summed == CHECKSUM_COMPLETE)
skb->csum = csum_add(skb->csum, csum_partial(skb->data
+ (2 * ETH_ALEN), VLAN_HLEN, 0));
}
__vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci);
return 0;
}
EXPORT_SYMBOL(skb_vlan_push);

/**
* alloc_skb_with_frags - allocate skb with page frags
*
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86 changes: 9 additions & 77 deletions net/openvswitch/actions.c
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Original file line number Diff line number Diff line change
Expand Up @@ -206,93 +206,27 @@ static int set_mpls(struct sk_buff *skb, struct sw_flow_key *key,
return 0;
}

/* remove VLAN header from packet and update csum accordingly. */
static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci)
{
struct vlan_hdr *vhdr;
int err;

err = skb_ensure_writable(skb, VLAN_ETH_HLEN);
if (unlikely(err))
return err;

skb_postpull_rcsum(skb, skb->data + (2 * ETH_ALEN), VLAN_HLEN);

vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
*current_tci = vhdr->h_vlan_TCI;

memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
__skb_pull(skb, VLAN_HLEN);

vlan_set_encap_proto(skb, vhdr);
skb->mac_header += VLAN_HLEN;

if (skb_network_offset(skb) < ETH_HLEN)
skb_set_network_header(skb, ETH_HLEN);

/* Update mac_len for subsequent MPLS actions */
skb_reset_mac_len(skb);
return 0;
}

static int pop_vlan(struct sk_buff *skb, struct sw_flow_key *key)
{
__be16 tci;
int err;

if (likely(vlan_tx_tag_present(skb))) {
skb->vlan_tci = 0;
} else {
if (unlikely(skb->protocol != htons(ETH_P_8021Q) ||
skb->len < VLAN_ETH_HLEN))
return 0;

err = __pop_vlan_tci(skb, &tci);
if (err)
return err;
}
/* move next vlan tag to hw accel tag */
if (likely(skb->protocol != htons(ETH_P_8021Q) ||
skb->len < VLAN_ETH_HLEN)) {
err = skb_vlan_pop(skb);
if (vlan_tx_tag_present(skb))
invalidate_flow_key(key);
else
key->eth.tci = 0;
return 0;
}

invalidate_flow_key(key);
err = __pop_vlan_tci(skb, &tci);
if (unlikely(err))
return err;

__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), ntohs(tci));
return 0;
return err;
}

static int push_vlan(struct sk_buff *skb, struct sw_flow_key *key,
const struct ovs_action_push_vlan *vlan)
{
if (unlikely(vlan_tx_tag_present(skb))) {
u16 current_tag;

/* push down current VLAN tag */
current_tag = vlan_tx_tag_get(skb);

skb = vlan_insert_tag_set_proto(skb, skb->vlan_proto,
current_tag);
if (!skb)
return -ENOMEM;
/* Update mac_len for subsequent MPLS actions */
skb->mac_len += VLAN_HLEN;

if (skb->ip_summed == CHECKSUM_COMPLETE)
skb->csum = csum_add(skb->csum, csum_partial(skb->data
+ (2 * ETH_ALEN), VLAN_HLEN, 0));

if (vlan_tx_tag_present(skb))
invalidate_flow_key(key);
} else {
else
key->eth.tci = vlan->vlan_tci;
}
__vlan_hwaccel_put_tag(skb, vlan->vlan_tpid, ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
return 0;
return skb_vlan_push(skb, vlan->vlan_tpid,
ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
}

static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *key,
Expand Down Expand Up @@ -858,8 +792,6 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,

case OVS_ACTION_ATTR_PUSH_VLAN:
err = push_vlan(skb, key, nla_data(a));
if (unlikely(err)) /* skb already freed. */
return err;
break;

case OVS_ACTION_ATTR_POP_VLAN:
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