net/dsa/tag.c
Source file repositories/reference/linux-study-clean/net/dsa/tag.c
File Facts
- System
- Linux kernel
- Corpus path
net/dsa/tag.c- Extension
.c- Size
- 5821 bytes
- Lines
- 245
- Domain
- Networking Core
- Bucket
- Sockets, Protocols, Packet Path, And Network Policy
- Inferred role
- Networking Core: exported/initcall integration point
- Status
- integration implementation candidate
Why This File Exists
Networking stack implementation surface: socket APIs, protocol dispatch, packet flow, routing, filtering, and network namespaces.
- Networking stack implementation surface: socket APIs, protocol dispatch, packet flow, routing, filtering, and network namespaces.
- Exports symbols or registers init work; inspect boot/module ordering and who consumes the exported contract.
- Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
linux/netdevice.hlinux/ptp_classify.hlinux/skbuff.hnet/dsa.hnet/dst_metadata.htag.huser.h
Detected Declarations
function dsa_skb_defer_rx_timestampfunction dsa_switch_rcvfunction dsa_tag_driver_registerfunction dsa_tag_drivers_registerfunction dsa_tag_driver_unregisterfunction dsa_tag_drivers_unregisterfunction dsa_tag_driver_putexport dsa_tag_drivers_registerexport dsa_tag_drivers_unregister
Annotated Snippet
if (likely(skb->dev)) {
dsa_default_offload_fwd_mark(skb);
nskb = skb;
}
} else {
nskb = cpu_dp->rcv(skb, dev);
}
if (!nskb) {
kfree_skb(skb);
return 0;
}
skb = nskb;
skb_push(skb, ETH_HLEN);
skb->pkt_type = PACKET_HOST;
skb->protocol = eth_type_trans(skb, skb->dev);
if (unlikely(!dsa_user_dev_check(skb->dev))) {
/* Packet is to be injected directly on an upper
* device, e.g. a team/bond, so skip all DSA-port
* specific actions.
*/
netif_rx(skb);
return 0;
}
p = netdev_priv(skb->dev);
if (unlikely(cpu_dp->ds->untag_bridge_pvid ||
cpu_dp->ds->untag_vlan_aware_bridge_pvid)) {
nskb = dsa_software_vlan_untag(skb);
if (!nskb) {
kfree_skb(skb);
return 0;
}
skb = nskb;
}
dev_sw_netstats_rx_add(skb->dev, skb->len + ETH_HLEN);
if (dsa_skb_defer_rx_timestamp(p, skb))
return 0;
gro_cells_receive(&p->gcells, skb);
return 0;
}
struct packet_type dsa_pack_type __read_mostly = {
.type = cpu_to_be16(ETH_P_XDSA),
.func = dsa_switch_rcv,
};
static void dsa_tag_driver_register(struct dsa_tag_driver *dsa_tag_driver,
struct module *owner)
{
dsa_tag_driver->owner = owner;
mutex_lock(&dsa_tag_drivers_lock);
list_add_tail(&dsa_tag_driver->list, &dsa_tag_drivers_list);
mutex_unlock(&dsa_tag_drivers_lock);
}
void dsa_tag_drivers_register(struct dsa_tag_driver *dsa_tag_driver_array[],
unsigned int count, struct module *owner)
{
unsigned int i;
for (i = 0; i < count; i++)
dsa_tag_driver_register(dsa_tag_driver_array[i], owner);
}
static void dsa_tag_driver_unregister(struct dsa_tag_driver *dsa_tag_driver)
{
mutex_lock(&dsa_tag_drivers_lock);
list_del(&dsa_tag_driver->list);
mutex_unlock(&dsa_tag_drivers_lock);
}
EXPORT_SYMBOL_GPL(dsa_tag_drivers_register);
void dsa_tag_drivers_unregister(struct dsa_tag_driver *dsa_tag_driver_array[],
unsigned int count)
{
unsigned int i;
for (i = 0; i < count; i++)
dsa_tag_driver_unregister(dsa_tag_driver_array[i]);
}
EXPORT_SYMBOL_GPL(dsa_tag_drivers_unregister);
Annotation
- Immediate include surface: `linux/netdevice.h`, `linux/ptp_classify.h`, `linux/skbuff.h`, `net/dsa.h`, `net/dst_metadata.h`, `tag.h`, `user.h`.
- Detected declarations: `function dsa_skb_defer_rx_timestamp`, `function dsa_switch_rcv`, `function dsa_tag_driver_register`, `function dsa_tag_drivers_register`, `function dsa_tag_driver_unregister`, `function dsa_tag_drivers_unregister`, `function dsa_tag_driver_put`, `export dsa_tag_drivers_register`, `export dsa_tag_drivers_unregister`.
- Atlas domain: Networking Core / Sockets, Protocols, Packet Path, And Network Policy.
- Implementation status: integration implementation candidate.
- Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.