ref: d67596f1bbdce63cd6a053cc17443fde1631ed10
dir: /sys/src/9/xen/xen-public/io/netif.h/
/****************************************************************************** * netif.h * * Unified network-device I/O interface for Xen guest OSes. * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to * deal in the Software without restriction, including without limitation the * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or * sell copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. * * Copyright (c) 2003-2004, Keir Fraser */ #ifndef __XEN_PUBLIC_IO_NETIF_H__ #define __XEN_PUBLIC_IO_NETIF_H__ #include "ring.h" #include "../grant_table.h" /* * Older implementation of Xen network frontend / backend has an * implicit dependency on the MAX_SKB_FRAGS as the maximum number of * ring slots a skb can use. Netfront / netback may not work as * expected when frontend and backend have different MAX_SKB_FRAGS. * * A better approach is to add mechanism for netfront / netback to * negotiate this value. However we cannot fix all possible * frontends, so we need to define a value which states the minimum * slots backend must support. * * The minimum value derives from older Linux kernel's MAX_SKB_FRAGS * (18), which is proved to work with most frontends. Any new backend * which doesn't negotiate with frontend should expect frontend to * send a valid packet using slots up to this value. */ #define XEN_NETIF_NR_SLOTS_MIN 18 /* * Notifications after enqueuing any type of message should be conditional on * the appropriate req_event or rsp_event field in the shared ring. * If the client sends notification for rx requests then it should specify * feature 'feature-rx-notify' via xenbus. Otherwise the backend will assume * that it cannot safely queue packets (as it may not be kicked to send them). */ /* * "feature-split-event-channels" is introduced to separate guest TX * and RX notification. Backend either doesn't support this feature or * advertises it via xenstore as 0 (disabled) or 1 (enabled). * * To make use of this feature, frontend should allocate two event * channels for TX and RX, advertise them to backend as * "event-channel-tx" and "event-channel-rx" respectively. If frontend * doesn't want to use this feature, it just writes "event-channel" * node as before. */ /* * This is the 'wire' format for packets: * Request 1: netif_tx_request -- NETTXF_* (any flags) * [Request 2: netif_tx_extra] (only if request 1 has NETTXF_extra_info) * [Request 3: netif_tx_extra] (only if request 2 has XEN_NETIF_EXTRA_MORE) * Request 4: netif_tx_request -- NETTXF_more_data * Request 5: netif_tx_request -- NETTXF_more_data * ... * Request N: netif_tx_request -- 0 */ /* Protocol checksum field is blank in the packet (hardware offload)? */ #define _NETTXF_csum_blank (0) #define NETTXF_csum_blank (1U<<_NETTXF_csum_blank) /* Packet data has been validated against protocol checksum. */ #define _NETTXF_data_validated (1) #define NETTXF_data_validated (1U<<_NETTXF_data_validated) /* Packet continues in the next request descriptor. */ #define _NETTXF_more_data (2) #define NETTXF_more_data (1U<<_NETTXF_more_data) /* Packet to be followed by extra descriptor(s). */ #define _NETTXF_extra_info (3) #define NETTXF_extra_info (1U<<_NETTXF_extra_info) #define XEN_NETIF_MAX_TX_SIZE 0xFFFF struct netif_tx_request { grant_ref_t gref; /* Reference to buffer page */ uint16_t offset; /* Offset within buffer page */ uint16_t flags; /* NETTXF_* */ uint16_t id; /* Echoed in response message. */ uint16_t size; /* Packet size in bytes. */ }; typedef struct netif_tx_request netif_tx_request_t; /* Types of netif_extra_info descriptors. */ #define XEN_NETIF_EXTRA_TYPE_NONE (0) /* Never used - invalid */ #define XEN_NETIF_EXTRA_TYPE_GSO (1) /* u.gso */ #define XEN_NETIF_EXTRA_TYPE_MCAST_ADD (2) /* u.mcast */ #define XEN_NETIF_EXTRA_TYPE_MCAST_DEL (3) /* u.mcast */ #define XEN_NETIF_EXTRA_TYPE_MAX (4) /* netif_extra_info flags. */ #define _XEN_NETIF_EXTRA_FLAG_MORE (0) #define XEN_NETIF_EXTRA_FLAG_MORE (1U<<_XEN_NETIF_EXTRA_FLAG_MORE) /* GSO types - only TCPv4 currently supported. */ #define XEN_NETIF_GSO_TYPE_TCPV4 (1) /* * This structure needs to fit within both netif_tx_request and * netif_rx_response for compatibility. */ struct netif_extra_info { uint8_t type; /* XEN_NETIF_EXTRA_TYPE_* */ uint8_t flags; /* XEN_NETIF_EXTRA_FLAG_* */ union { /* * XEN_NETIF_EXTRA_TYPE_GSO: */ struct { /* * Maximum payload size of each segment. For example, for TCP this * is just the path MSS. */ uint16_t size; /* * GSO type. This determines the protocol of the packet and any * extra features required to segment the packet properly. */ uint8_t type; /* XEN_NETIF_GSO_TYPE_* */ /* Future expansion. */ uint8_t pad; /* * GSO features. This specifies any extra GSO features required * to process this packet, such as ECN support for TCPv4. */ uint16_t features; /* XEN_NETIF_GSO_FEAT_* */ } gso; /* * XEN_NETIF_EXTRA_TYPE_MCAST_{ADD,DEL}: * Backend advertises availability via 'feature-multicast-control' * xenbus node containing value '1'. * Frontend requests this feature by advertising * 'request-multicast-control' xenbus node containing value '1'. * If multicast control is requested then multicast flooding is * disabled and the frontend must explicitly register its interest * in multicast groups using dummy transmit requests containing * MCAST_{ADD,DEL} extra-info fragments. */ struct { uint8_t addr[6]; /* Address to add/remove. */ } mcast; uint16_t pad[3]; } u; }; typedef struct netif_extra_info netif_extra_info_t; struct netif_tx_response { uint16_t id; int16_t status; /* NETIF_RSP_* */ }; typedef struct netif_tx_response netif_tx_response_t; struct netif_rx_request { uint16_t id; /* Echoed in response message. */ grant_ref_t gref; /* Reference to incoming granted frame */ }; typedef struct netif_rx_request netif_rx_request_t; /* Packet data has been validated against protocol checksum. */ #define _NETRXF_data_validated (0) #define NETRXF_data_validated (1U<<_NETRXF_data_validated) /* Protocol checksum field is blank in the packet (hardware offload)? */ #define _NETRXF_csum_blank (1) #define NETRXF_csum_blank (1U<<_NETRXF_csum_blank) /* Packet continues in the next request descriptor. */ #define _NETRXF_more_data (2) #define NETRXF_more_data (1U<<_NETRXF_more_data) /* Packet to be followed by extra descriptor(s). */ #define _NETRXF_extra_info (3) #define NETRXF_extra_info (1U<<_NETRXF_extra_info) struct netif_rx_response { uint16_t id; uint16_t offset; /* Offset in page of start of received packet */ uint16_t flags; /* NETRXF_* */ int16_t status; /* -ve: BLKIF_RSP_* ; +ve: Rx'ed pkt size. */ }; typedef struct netif_rx_response netif_rx_response_t; /* * Generate netif ring structures and types. */ DEFINE_RING_TYPES(netif_tx, struct netif_tx_request, struct netif_tx_response); DEFINE_RING_TYPES(netif_rx, struct netif_rx_request, struct netif_rx_response); #define NETIF_RSP_DROPPED -2 #define NETIF_RSP_ERROR -1 #define NETIF_RSP_OKAY 0 /* No response: used for auxiliary requests (e.g., netif_tx_extra). */ #define NETIF_RSP_NULL 1 #endif /* * Local variables: * mode: C * c-file-style: "BSD" * c-basic-offset: 4 * tab-width: 4 * indent-tabs-mode: nil * End: */