drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c

Source file repositories/reference/linux-study-clean/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c

File Facts

System
Linux kernel
Corpus path
drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
Extension
.c
Size
6272 bytes
Lines
276
Domain
Driver Families
Bucket
drivers/net
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

if (pskb_expand_head(skb, ETH_HLEN, 0, GFP_ATOMIC)) {
			kfree_skb(skb);
			return;
		}

		skb_push(skb, ETH_HLEN);
	}

	if (port->data_format & RMNET_FLAGS_INGRESS_DEAGGREGATION) {
		while ((skbn = rmnet_map_deaggregate(skb, port)) != NULL)
			__rmnet_map_ingress_handler(skbn, port);

		consume_skb(skb);
	} else {
		__rmnet_map_ingress_handler(skb, port);
	}
}

static int rmnet_map_egress_handler(struct sk_buff *skb,
				    struct rmnet_port *port, u8 mux_id,
				    struct net_device *orig_dev)
{
	int required_headroom, additional_header_len, csum_type = 0;
	struct rmnet_map_header *map_header;

	additional_header_len = 0;
	required_headroom = sizeof(struct rmnet_map_header);

	if (port->data_format & RMNET_FLAGS_EGRESS_MAP_CKSUMV4) {
		additional_header_len = sizeof(struct rmnet_map_ul_csum_header);
		csum_type = RMNET_FLAGS_EGRESS_MAP_CKSUMV4;
	} else if (port->data_format & RMNET_FLAGS_EGRESS_MAP_CKSUMV5) {
		additional_header_len = sizeof(struct rmnet_map_v5_csum_header);
		csum_type = RMNET_FLAGS_EGRESS_MAP_CKSUMV5;
	}

	required_headroom += additional_header_len;

	if (skb_cow_head(skb, required_headroom) < 0)
		return -ENOMEM;

	if (csum_type)
		rmnet_map_checksum_uplink_packet(skb, port, orig_dev,
						 csum_type);

	map_header = rmnet_map_add_map_header(skb, additional_header_len,
					      port, 0);
	if (!map_header)
		return -ENOMEM;

	map_header->mux_id = mux_id;

	if (READ_ONCE(port->egress_agg_params.count) > 1) {
		unsigned int len;

		len = rmnet_map_tx_aggregate(skb, port, orig_dev);
		if (likely(len)) {
			rmnet_vnd_tx_fixup_len(len, orig_dev);
			return -EINPROGRESS;
		}
		return -ENOMEM;
	}

	skb->protocol = htons(ETH_P_MAP);
	return 0;
}

static void
rmnet_bridge_handler(struct sk_buff *skb, struct net_device *bridge_dev)
{
	if (skb_mac_header_was_set(skb))
		skb_push(skb, skb->mac_len);

	if (bridge_dev) {
		skb->dev = bridge_dev;
		dev_queue_xmit(skb);
	}
}

/* Ingress / Egress Entry Points */

/* Processes packet as per ingress data format for receiving device. Logical
 * endpoint is determined from packet inspection. Packet is then sent to the
 * egress device listed in the logical endpoint configuration.
 */
rx_handler_result_t rmnet_rx_handler(struct sk_buff **pskb)
{
	struct sk_buff *skb = *pskb;
	struct rmnet_port *port;
	struct net_device *dev;

Annotation

Implementation Notes