android13/kernel-5.10/drivers/pcie_mhi/devices/rmnet/rmnet_handlers.c

375 lines
8.5 KiB
C
Executable File

/* Copyright (c) 2013-2019, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* RMNET Data ingress/egress handler
*
*/
#include <linux/netdevice.h>
#include <linux/netdev_features.h>
#include <linux/if_arp.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <net/sock.h>
#include <linux/tracepoint.h>
#include "rmnet_private.h"
#include "rmnet_config.h"
#include "rmnet_vnd.h"
#include "rmnet_map.h"
#include "rmnet_handlers.h"
#include "rmnet_descriptor.h"
#define RMNET_IP_VERSION_4 0x40
#define RMNET_IP_VERSION_6 0x60
/* Helper Functions */
static void rmnet_set_skb_proto(struct sk_buff *skb)
{
switch (rmnet_map_data_ptr(skb)[0] & 0xF0) {
case RMNET_IP_VERSION_4:
skb->protocol = htons(ETH_P_IP);
break;
case RMNET_IP_VERSION_6:
skb->protocol = htons(ETH_P_IPV6);
break;
default:
skb->protocol = htons(ETH_P_MAP);
break;
}
}
/* Generic handler */
static void
rmnet_deliver_skb(struct sk_buff *skb, struct rmnet_port *port)
{
struct rmnet_nss_cb *nss_cb;
rmnet_vnd_rx_fixup(skb->dev, skb->len);
/* Pass off the packet to NSS driver if we can */
nss_cb = rcu_dereference(rmnet_nss_callbacks);
if (nss_cb) {
if (!port->chain_head)
port->chain_head = skb;
else
skb_shinfo(port->chain_tail)->frag_list = skb;
port->chain_tail = skb;
return;
}
skb_reset_transport_header(skb);
skb_reset_network_header(skb);
skb->pkt_type = PACKET_HOST;
skb_set_mac_header(skb, 0);
//if (port->data_format & RMNET_INGRESS_FORMAT_DL_MARKER) {
//} else {
//if (!rmnet_check_skb_can_gro(skb))
// gro_cells_receive(&priv->gro_cells, skb);
//else
netif_receive_skb(skb);
//}
}
/* Deliver a list of skbs after undoing coalescing */
static void rmnet_deliver_skb_list(struct sk_buff_head *head,
struct rmnet_port *port)
{
struct sk_buff *skb;
while ((skb = __skb_dequeue(head))) {
rmnet_set_skb_proto(skb);
rmnet_deliver_skb(skb, port);
}
}
/* MAP handler */
static void
_rmnet_map_ingress_handler(struct sk_buff *skb,
struct rmnet_port *port)
{
struct rmnet_map_header *qmap;
struct rmnet_endpoint *ep;
struct sk_buff_head list;
u16 len, pad;
u8 mux_id;
/* We don't need the spinlock since only we touch this */
__skb_queue_head_init(&list);
qmap = (struct rmnet_map_header *)rmnet_map_data_ptr(skb);
if (qmap->cd_bit) {
if (port->data_format & RMNET_INGRESS_FORMAT_DL_MARKER) {
//if (!rmnet_map_flow_command(skb, port, false))
return;
}
if (port->data_format & RMNET_FLAGS_INGRESS_MAP_COMMANDS)
return rmnet_map_command(skb, port);
goto free_skb;
}
mux_id = qmap->mux_id;
pad = qmap->pad_len;
len = ntohs(qmap->pkt_len) - pad;
if (mux_id >= RMNET_MAX_LOGICAL_EP)
goto free_skb;
ep = rmnet_get_endpoint(port, mux_id);
if (!ep)
goto free_skb;
skb->dev = ep->egress_dev;
/* Handle QMAPv5 packet */
if (qmap->next_hdr &&
(port->data_format & (RMNET_FLAGS_INGRESS_COALESCE |
RMNET_FLAGS_INGRESS_MAP_CKSUMV5))) {
if (rmnet_map_process_next_hdr_packet(skb, &list, len))
goto free_skb;
} else {
/* We only have the main QMAP header to worry about */
pskb_pull(skb, sizeof(*qmap));
rmnet_set_skb_proto(skb);
if (port->data_format & RMNET_FLAGS_INGRESS_MAP_CKSUMV4) {
//if (!rmnet_map_checksum_downlink_packet(skb, len + pad))
// skb->ip_summed = CHECKSUM_UNNECESSARY;
}
pskb_trim(skb, len);
/* Push the single packet onto the list */
__skb_queue_tail(&list, skb);
}
rmnet_deliver_skb_list(&list, port);
return;
free_skb:
kfree_skb(skb);
}
static void
rmnet_map_ingress_handler(struct sk_buff *skb,
struct rmnet_port *port)
{
struct sk_buff *skbn;
if (port->data_format & (RMNET_FLAGS_INGRESS_COALESCE |
RMNET_FLAGS_INGRESS_MAP_CKSUMV5)) {
if (skb_is_nonlinear(skb)) {
rmnet_frag_ingress_handler(skb, port);
return;
}
}
/* Deaggregation and freeing of HW originating
* buffers is done within here
*/
while (skb) {
struct sk_buff *skb_frag = skb_shinfo(skb)->frag_list;
skb_shinfo(skb)->frag_list = NULL;
while ((skbn = rmnet_map_deaggregate(skb, port)) != NULL) {
_rmnet_map_ingress_handler(skbn, port);
if (skbn == skb)
goto next_skb;
}
consume_skb(skb);
next_skb:
skb = skb_frag;
}
}
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;
struct rmnet_map_header *map_header;
additional_header_len = 0;
required_headroom = sizeof(struct rmnet_map_header);
csum_type = 0;
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_headroom(skb) < required_headroom) {
if (pskb_expand_head(skb, required_headroom, 0, GFP_ATOMIC))
return -ENOMEM;
}
if (csum_type)
rmnet_map_checksum_uplink_packet(skb, orig_dev, csum_type);
map_header = rmnet_map_add_map_header(skb, additional_header_len, 0,
port);
if (!map_header)
return -ENOMEM;
map_header->mux_id = mux_id;
if (port->data_format & RMNET_EGRESS_FORMAT_AGGREGATION) {
if (rmnet_map_tx_agg_skip(skb, required_headroom))
goto done;
rmnet_map_tx_aggregate(skb, port);
return -EINPROGRESS;
}
done:
skb->protocol = htons(ETH_P_MAP);
return 0;
}
static void
rmnet_bridge_handler(struct sk_buff *skb, struct net_device *bridge_dev)
{
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.
*/
static rx_handler_result_t rmnet_rx_handler(struct sk_buff **pskb)
{
struct sk_buff *skb = *pskb;
struct rmnet_port *port;
struct net_device *dev;
if (!skb)
goto done;
if (skb->pkt_type == PACKET_LOOPBACK)
return RX_HANDLER_PASS;
dev = skb->dev;
port = rmnet_get_port(dev);
port->chain_head = NULL;
port->chain_tail = NULL;
switch (port->rmnet_mode) {
case RMNET_EPMODE_VND:
rmnet_map_ingress_handler(skb, port);
break;
case RMNET_EPMODE_BRIDGE:
rmnet_bridge_handler(skb, port->bridge_ep);
break;
}
done:
return RX_HANDLER_CONSUMED;
}
static rx_handler_result_t rmnet_rx_priv_handler(struct sk_buff **pskb)
{
struct sk_buff *skb = *pskb;
struct rmnet_nss_cb *nss_cb;
if (!skb)
return RX_HANDLER_CONSUMED;
if (nss_debug) printk("%s skb=%p, len=%d, protocol=%x, hdr_len=%d\n", __func__, skb, skb->len, skb->protocol, skb->hdr_len);
if (skb->pkt_type == PACKET_LOOPBACK)
return RX_HANDLER_PASS;
/* Check this so that we dont loop around netif_receive_skb */
if (skb->cb[0] == 1) {
skb->cb[0] = 0;
skb->dev->stats.rx_packets++;
return RX_HANDLER_PASS;
}
while (skb) {
struct sk_buff *skb_frag = skb_shinfo(skb)->frag_list;
skb_shinfo(skb)->frag_list = NULL;
nss_cb = rcu_dereference(rmnet_nss_callbacks);
if (nss_cb)
nss_cb->nss_tx(skb);
skb = skb_frag;
}
return RX_HANDLER_CONSUMED;
}
/* Modifies packet as per logical endpoint configuration and egress data format
* for egress device configured in logical endpoint. Packet is then transmitted
* on the egress device.
*/
static void rmnet_egress_handler(struct sk_buff *skb)
{
struct net_device *orig_dev;
struct rmnet_port *port;
struct rmnet_priv *priv;
u8 mux_id;
int err;
u32 skb_len;
skb_orphan(skb);
orig_dev = skb->dev;
priv = netdev_priv(orig_dev);
skb->dev = priv->real_dev;
mux_id = priv->mux_id;
port = rmnet_get_port(skb->dev);
if (!port)
goto drop;
skb_len = skb->len;
err = rmnet_map_egress_handler(skb, port, mux_id, orig_dev);
if (err == -ENOMEM)
goto drop;
else if (err == -EINPROGRESS) {
rmnet_vnd_tx_fixup(orig_dev, skb_len);
return;
}
rmnet_vnd_tx_fixup(orig_dev, skb_len);
dev_queue_xmit(skb);
return;
drop:
this_cpu_inc(priv->pcpu_stats->stats.tx_drops);
kfree_skb(skb);
}