diff options
Diffstat (limited to 'drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c')
| -rw-r--r-- | drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c | 271 |
1 files changed, 271 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 000000000000..7dab3bbfeda5 --- /dev/null +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c @@ -0,0 +1,271 @@ +/* Copyright (c) 2013-2017, 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 "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 rx_handler_result_t +rmnet_bridge_handler(struct sk_buff *skb, struct rmnet_endpoint *ep) +{ + if (!ep->egress_dev) + kfree_skb(skb); + else + rmnet_egress_handler(skb, ep); + + return RX_HANDLER_CONSUMED; +} + +static rx_handler_result_t +rmnet_deliver_skb(struct sk_buff *skb, struct rmnet_endpoint *ep) +{ + switch (ep->rmnet_mode) { + case RMNET_EPMODE_NONE: + return RX_HANDLER_PASS; + + case RMNET_EPMODE_BRIDGE: + return rmnet_bridge_handler(skb, ep); + + case RMNET_EPMODE_VND: + 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); + netif_receive_skb(skb); + return RX_HANDLER_CONSUMED; + + default: + kfree_skb(skb); + return RX_HANDLER_CONSUMED; + } +} + +static rx_handler_result_t +rmnet_ingress_deliver_packet(struct sk_buff *skb, + struct rmnet_real_dev_info *r) +{ + if (!r) { + kfree_skb(skb); + return RX_HANDLER_CONSUMED; + } + + skb->dev = r->local_ep.egress_dev; + + return rmnet_deliver_skb(skb, &r->local_ep); +} + +/* MAP handler */ + +static rx_handler_result_t +__rmnet_map_ingress_handler(struct sk_buff *skb, + struct rmnet_real_dev_info *r) +{ + struct rmnet_endpoint *ep; + u8 mux_id; + u16 len; + + if (RMNET_MAP_GET_CD_BIT(skb)) { + if (r->ingress_data_format + & RMNET_INGRESS_FORMAT_MAP_COMMANDS) + return rmnet_map_command(skb, r); + + kfree_skb(skb); + return RX_HANDLER_CONSUMED; + } + + mux_id = RMNET_MAP_GET_MUX_ID(skb); + len = RMNET_MAP_GET_LENGTH(skb) - RMNET_MAP_GET_PAD(skb); + + if (mux_id >= RMNET_MAX_LOGICAL_EP) { + kfree_skb(skb); + return RX_HANDLER_CONSUMED; + } + + ep = &r->muxed_ep[mux_id]; + + if (r->ingress_data_format & RMNET_INGRESS_FORMAT_DEMUXING) + skb->dev = ep->egress_dev; + + /* Subtract MAP header */ + skb_pull(skb, sizeof(struct rmnet_map_header)); + skb_trim(skb, len); + rmnet_set_skb_proto(skb); + return rmnet_deliver_skb(skb, ep); +} + +static rx_handler_result_t +rmnet_map_ingress_handler(struct sk_buff *skb, + struct rmnet_real_dev_info *r) +{ + struct sk_buff *skbn; + int rc; + + if (r->ingress_data_format & RMNET_INGRESS_FORMAT_DEAGGREGATION) { + while ((skbn = rmnet_map_deaggregate(skb, r)) != NULL) + __rmnet_map_ingress_handler(skbn, r); + + consume_skb(skb); + rc = RX_HANDLER_CONSUMED; + } else { + rc = __rmnet_map_ingress_handler(skb, r); + } + + return rc; +} + +static int rmnet_map_egress_handler(struct sk_buff *skb, + struct rmnet_real_dev_info *r, + struct rmnet_endpoint *ep, + struct net_device *orig_dev) +{ + int required_headroom, additional_header_len; + struct rmnet_map_header *map_header; + + additional_header_len = 0; + required_headroom = sizeof(struct rmnet_map_header); + + if (skb_headroom(skb) < required_headroom) { + if (pskb_expand_head(skb, required_headroom, 0, GFP_KERNEL)) + return RMNET_MAP_CONSUMED; + } + + map_header = rmnet_map_add_map_header(skb, additional_header_len, 0); + if (!map_header) + return RMNET_MAP_CONSUMED; + + if (r->egress_data_format & RMNET_EGRESS_FORMAT_MUXING) { + if (ep->mux_id == 0xff) + map_header->mux_id = 0; + else + map_header->mux_id = ep->mux_id; + } + + skb->protocol = htons(ETH_P_MAP); + + return RMNET_MAP_SUCCESS; +} + +/* 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 rmnet_real_dev_info *r; + struct sk_buff *skb = *pskb; + struct net_device *dev; + int rc; + + if (!skb) + return RX_HANDLER_CONSUMED; + + dev = skb->dev; + r = rmnet_get_real_dev_info(dev); + + if (r->ingress_data_format & RMNET_INGRESS_FORMAT_MAP) { + rc = rmnet_map_ingress_handler(skb, r); + } else { + switch (ntohs(skb->protocol)) { + case ETH_P_MAP: + if (r->local_ep.rmnet_mode == + RMNET_EPMODE_BRIDGE) { + rc = rmnet_ingress_deliver_packet(skb, r); + } else { + kfree_skb(skb); + rc = RX_HANDLER_CONSUMED; + } + break; + + case ETH_P_IP: + case ETH_P_IPV6: + rc = rmnet_ingress_deliver_packet(skb, r); + break; + + default: + rc = RX_HANDLER_PASS; + } + } + + return rc; +} + +/* 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 rmnet_endpoint *ep) +{ + struct rmnet_real_dev_info *r; + struct net_device *orig_dev; + + orig_dev = skb->dev; + skb->dev = ep->egress_dev; + + r = rmnet_get_real_dev_info(skb->dev); + if (!r) { + kfree_skb(skb); + return; + } + + if (r->egress_data_format & RMNET_EGRESS_FORMAT_MAP) { + switch (rmnet_map_egress_handler(skb, r, ep, orig_dev)) { + case RMNET_MAP_CONSUMED: + return; + + case RMNET_MAP_SUCCESS: + break; + + default: + kfree_skb(skb); + return; + } + } + + if (ep->rmnet_mode == RMNET_EPMODE_VND) + rmnet_vnd_tx_fixup(skb, orig_dev); + + dev_queue_xmit(skb); +} |