diff options
Diffstat (limited to 'drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c')
| -rw-r--r-- | drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c new file mode 100644 index 000000000..a313242a7 --- /dev/null +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c @@ -0,0 +1,261 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2013-2018, 2021, The Linux Foundation. All rights reserved. + * + * RMNET Data ingress/egress handler + */ + +#include <linux/netdevice.h> +#include <linux/netdev_features.h> +#include <linux/if_arp.h> +#include <net/sock.h> +#include "rmnet_private.h" +#include "rmnet_config.h" +#include "rmnet_vnd.h" +#include "rmnet_map.h" +#include "rmnet_handlers.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 (skb->data[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_priv *priv = netdev_priv(skb->dev); + + skb_reset_transport_header(skb); + skb_reset_network_header(skb); + rmnet_vnd_rx_fixup(skb, skb->dev); + + skb->pkt_type = PACKET_HOST; + skb_set_mac_header(skb, 0); + gro_cells_receive(&priv->gro_cells, skb); +} + +/* MAP handler */ + +static void +__rmnet_map_ingress_handler(struct sk_buff *skb, + struct rmnet_port *port) +{ + struct rmnet_map_header *map_header = (void *)skb->data; + struct rmnet_endpoint *ep; + u16 len, pad; + u8 mux_id; + + if (map_header->flags & MAP_CMD_FLAG) { + /* Packet contains a MAP command (not data) */ + if (port->data_format & RMNET_FLAGS_INGRESS_MAP_COMMANDS) + return rmnet_map_command(skb, port); + + goto free_skb; + } + + mux_id = map_header->mux_id; + pad = map_header->flags & MAP_PAD_LEN_MASK; + len = ntohs(map_header->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; + + if ((port->data_format & RMNET_FLAGS_INGRESS_MAP_CKSUMV5) && + (map_header->flags & MAP_NEXT_HEADER_FLAG)) { + if (rmnet_map_process_next_hdr_packet(skb, len)) + goto free_skb; + skb_pull(skb, sizeof(*map_header)); + rmnet_set_skb_proto(skb); + } else { + /* Subtract MAP header */ + skb_pull(skb, sizeof(*map_header)); + rmnet_set_skb_proto(skb); + if (port->data_format & RMNET_FLAGS_INGRESS_MAP_CKSUMV4 && + !rmnet_map_checksum_downlink_packet(skb, len + pad)) + skb->ip_summed = CHECKSUM_UNNECESSARY; + } + + skb_trim(skb, len); + rmnet_deliver_skb(skb); + 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 (skb->dev->type == ARPHRD_ETHER) { + 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; + + 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; + + if (!skb) + goto done; + + if (skb_linearize(skb)) { + kfree_skb(skb); + goto done; + } + + if (skb->pkt_type == PACKET_LOOPBACK) + return RX_HANDLER_PASS; + + dev = skb->dev; + port = rmnet_get_port_rcu(dev); + if (unlikely(!port)) { + dev_core_stats_rx_nohandler_inc(skb->dev); + kfree_skb(skb); + goto done; + } + + 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; +} + +/* 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. + */ +void rmnet_egress_handler(struct sk_buff *skb) +{ + struct net_device *orig_dev; + struct rmnet_port *port; + struct rmnet_priv *priv; + u8 mux_id; + + sk_pacing_shift_update(skb->sk, 8); + + orig_dev = skb->dev; + priv = netdev_priv(orig_dev); + skb->dev = priv->real_dev; + mux_id = priv->mux_id; + + port = rmnet_get_port_rcu(skb->dev); + if (!port) + goto drop; + + if (rmnet_map_egress_handler(skb, port, mux_id, orig_dev)) + goto drop; + + rmnet_vnd_tx_fixup(skb, orig_dev); + + dev_queue_xmit(skb); + return; + +drop: + this_cpu_inc(priv->pcpu_stats->stats.tx_drops); + kfree_skb(skb); +} |