diff options
Diffstat (limited to 'src/include/xen/io/netif.h')
| -rw-r--r-- | src/include/xen/io/netif.h | 942 |
1 files changed, 864 insertions, 78 deletions
diff --git a/src/include/xen/io/netif.h b/src/include/xen/io/netif.h index ae12eab73..bec61ab3e 100644 --- a/src/include/xen/io/netif.h +++ b/src/include/xen/io/netif.h @@ -1,26 +1,9 @@ +/* SPDX-License-Identifier: MIT */ /****************************************************************************** * 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 */ @@ -138,14 +121,839 @@ FILE_LICENCE ( MIT ); */ /* - * 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 + * "feature-multicast-control" and "feature-dynamic-multicast-control" + * advertise the capability to filter ethernet multicast packets in the + * backend. If the frontend wishes to take advantage of this feature then + * it may set "request-multicast-control". If the backend only advertises + * "feature-multicast-control" then "request-multicast-control" must be set + * before the frontend moves into the connected state. The backend will + * sample the value on this state transition and any subsequent change in + * value will have no effect. However, if the backend also advertises + * "feature-dynamic-multicast-control" then "request-multicast-control" + * may be set by the frontend at any time. In this case, the backend will + * watch the value and re-sample on watch events. + * + * If the sampled value of "request-multicast-control" is set then the + * backend transmit side should no longer flood multicast packets to the + * frontend, it should instead drop any multicast packet that does not + * match in a filter list. + * The list is amended by the frontend by sending dummy transmit requests + * containing XEN_NETIF_EXTRA_TYPE_MCAST_{ADD,DEL} extra-info fragments as + * specified below. + * Note that the filter list may be amended even if the sampled value of + * "request-multicast-control" is not set, however the filter should only + * be applied if it is set. + */ + +/* + * The setting of "trusted" node to "0" in the frontend path signals that the + * frontend should not trust the backend, and should deploy whatever measures + * available to protect from a malicious backend on the other end. + */ + +/* + * Control ring + * ============ + * + * Some features, such as hashing (detailed below), require a + * significant amount of out-of-band data to be passed from frontend to + * backend. Use of xenstore is not suitable for large quantities of data + * because of quota limitations and so a dedicated 'control ring' is used. + * The ability of the backend to use a control ring is advertised by + * setting: + * + * /local/domain/X/backend/vif/<domid>/<vif>/feature-ctrl-ring = "1" + * + * The frontend provides a control ring to the backend by setting: + * + * /local/domain/<domid>/device/vif/<vif>/ctrl-ring-ref = <gref> + * /local/domain/<domid>/device/vif/<vif>/event-channel-ctrl = <port> + * + * where <gref> is the grant reference of the shared page used to + * implement the control ring and <port> is an event channel to be used + * as a mailbox interrupt. These keys must be set before the frontend + * moves into the connected state. + * + * The control ring uses a fixed request/response message size and is + * balanced (i.e. one request to one response), so operationally it is much + * the same as a transmit or receive ring. + * Note that there is no requirement that responses are issued in the same + * order as requests. + */ + +/* + * Link state + * ========== + * + * The backend can advertise its current link (carrier) state to the + * frontend using the /local/domain/X/backend/vif/<domid>/<vif>/carrier + * node. If this node is not present, then the frontend should assume that + * the link is up (for compatibility with backends that do not implement + * this feature). If this node is present, then a value of "0" should be + * interpreted by the frontend as the link being down (no carrier) and a + * value of "1" should be interpreted as the link being up (carrier + * present). + */ + +/* + * MTU + * === + * + * The toolstack may set a value of MTU for the frontend by setting the + * /local/domain/<domid>/device/vif/<vif>/mtu node with the MTU value in + * octets. If this node is absent the frontend should assume an MTU value + * of 1500 octets. A frontend is also at liberty to ignore this value so + * it is only suitable for informing the frontend that a packet payload + * >1500 octets is permitted. + */ + +/* + * Hash types + * ========== + * + * For the purposes of the definitions below, 'Packet[]' is an array of + * octets containing an IP packet without options, 'Array[X..Y]' means a + * sub-array of 'Array' containing bytes X thru Y inclusive, and '+' is + * used to indicate concatenation of arrays. + */ + +/* + * A hash calculated over an IP version 4 header as follows: + * + * Buffer[0..8] = Packet[12..15] (source address) + + * Packet[16..19] (destination address) + * + * Result = Hash(Buffer, 8) + */ +#define _XEN_NETIF_CTRL_HASH_TYPE_IPV4 0 +#define XEN_NETIF_CTRL_HASH_TYPE_IPV4 \ + (1 << _XEN_NETIF_CTRL_HASH_TYPE_IPV4) + +/* + * A hash calculated over an IP version 4 header and TCP header as + * follows: + * + * Buffer[0..12] = Packet[12..15] (source address) + + * Packet[16..19] (destination address) + + * Packet[20..21] (source port) + + * Packet[22..23] (destination port) + * + * Result = Hash(Buffer, 12) + */ +#define _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP 1 +#define XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP \ + (1 << _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP) + +/* + * A hash calculated over an IP version 6 header as follows: + * + * Buffer[0..32] = Packet[8..23] (source address ) + + * Packet[24..39] (destination address) + * + * Result = Hash(Buffer, 32) + */ +#define _XEN_NETIF_CTRL_HASH_TYPE_IPV6 2 +#define XEN_NETIF_CTRL_HASH_TYPE_IPV6 \ + (1 << _XEN_NETIF_CTRL_HASH_TYPE_IPV6) + +/* + * A hash calculated over an IP version 6 header and TCP header as + * follows: + * + * Buffer[0..36] = Packet[8..23] (source address) + + * Packet[24..39] (destination address) + + * Packet[40..41] (source port) + + * Packet[42..43] (destination port) + * + * Result = Hash(Buffer, 36) + */ +#define _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP 3 +#define XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP \ + (1 << _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP) + +/* + * Hash algorithms + * =============== + */ + +#define XEN_NETIF_CTRL_HASH_ALGORITHM_NONE 0 + +/* + * Toeplitz hash: + */ + +#define XEN_NETIF_CTRL_HASH_ALGORITHM_TOEPLITZ 1 + +/* + * This algorithm uses a 'key' as well as the data buffer itself. + * (Buffer[] and Key[] are treated as shift-registers where the MSB of + * Buffer/Key[0] is considered 'left-most' and the LSB of Buffer/Key[N-1] + * is the 'right-most'). + * + * Value = 0 + * For number of bits in Buffer[] + * If (left-most bit of Buffer[] is 1) + * Value ^= left-most 32 bits of Key[] + * Key[] << 1 + * Buffer[] << 1 + * + * The code below is provided for convenience where an operating system + * does not already provide an implementation. + */ +#ifdef XEN_NETIF_DEFINE_TOEPLITZ +static uint32_t xen_netif_toeplitz_hash(const uint8_t *key, + unsigned int keylen, + const uint8_t *buf, + unsigned int buflen) +{ + unsigned int keyi, bufi; + uint64_t prefix = 0; + uint64_t hash = 0; + + /* Pre-load prefix with the first 8 bytes of the key */ + for (keyi = 0; keyi < 8; keyi++) { + prefix <<= 8; + prefix |= (keyi < keylen) ? key[keyi] : 0; + } + + for (bufi = 0; bufi < buflen; bufi++) { + uint8_t byte = buf[bufi]; + unsigned int bit; + + for (bit = 0; bit < 8; bit++) { + if (byte & 0x80) + hash ^= prefix; + prefix <<= 1; + byte <<=1; + } + + /* + * 'prefix' has now been left-shifted by 8, so + * OR in the next byte. + */ + prefix |= (keyi < keylen) ? key[keyi] : 0; + keyi++; + } + + /* The valid part of the hash is in the upper 32 bits. */ + return hash >> 32; +} +#endif /* XEN_NETIF_DEFINE_TOEPLITZ */ + +/* + * Control requests (struct xen_netif_ctrl_request) + * ================================================ + * + * All requests have the following format: + * + * 0 1 2 3 4 5 6 7 octet + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * | id | type | data[0] | + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * | data[1] | data[2] | + * +-----+-----+-----+-----+-----------------------+ + * + * id: the request identifier, echoed in response. + * type: the type of request (see below) + * data[]: any data associated with the request (determined by type) + */ + +struct xen_netif_ctrl_request { + uint16_t id; + uint16_t type; + +#define XEN_NETIF_CTRL_TYPE_INVALID 0 +#define XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS 1 +#define XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS 2 +#define XEN_NETIF_CTRL_TYPE_SET_HASH_KEY 3 +#define XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE 4 +#define XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE 5 +#define XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING 6 +#define XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM 7 +#define XEN_NETIF_CTRL_TYPE_GET_GREF_MAPPING_SIZE 8 +#define XEN_NETIF_CTRL_TYPE_ADD_GREF_MAPPING 9 +#define XEN_NETIF_CTRL_TYPE_DEL_GREF_MAPPING 10 + + uint32_t data[3]; +}; + +/* + * Control responses (struct xen_netif_ctrl_response) + * ================================================== + * + * All responses have the following format: + * + * 0 1 2 3 4 5 6 7 octet + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * | id | type | status | + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * | data | + * +-----+-----+-----+-----+ + * + * id: the corresponding request identifier + * type: the type of the corresponding request + * status: the status of request processing + * data: any data associated with the response (determined by type and + * status) + */ + +struct xen_netif_ctrl_response { + uint16_t id; + uint16_t type; + uint32_t status; + +#define XEN_NETIF_CTRL_STATUS_SUCCESS 0 +#define XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED 1 +#define XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER 2 +#define XEN_NETIF_CTRL_STATUS_BUFFER_OVERFLOW 3 + + uint32_t data; +}; + +/* + * Static Grants (struct xen_netif_gref) + * ===================================== + * + * A frontend may provide a fixed set of grant references to be mapped on + * the backend. The message of type XEN_NETIF_CTRL_TYPE_ADD_GREF_MAPPING + * prior its usage in the command ring allows for creation of these mappings. + * The backend will maintain a fixed amount of these mappings. + * + * XEN_NETIF_CTRL_TYPE_GET_GREF_MAPPING_SIZE lets a frontend query how many + * of these mappings can be kept. + * + * Each entry in the XEN_NETIF_CTRL_TYPE_{ADD,DEL}_GREF_MAPPING input table has + * the following format: + * + * 0 1 2 3 4 5 6 7 octet + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * | grant ref | flags | status | + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * + * grant ref: grant reference (IN) + * flags: flags describing the control operation (IN) + * status: XEN_NETIF_CTRL_STATUS_* (OUT) + * + * 'status' is an output parameter which does not require to be set to zero + * prior to its usage in the corresponding control messages. + */ + +struct xen_netif_gref { + grant_ref_t ref; + uint16_t flags; + +#define _XEN_NETIF_CTRLF_GREF_readonly 0 +#define XEN_NETIF_CTRLF_GREF_readonly (1U<<_XEN_NETIF_CTRLF_GREF_readonly) + + uint16_t status; +}; + +/* + * Control messages + * ================ + * + * XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM + * -------------------------------------- + * + * This is sent by the frontend to set the desired hash algorithm. + * + * Request: + * + * type = XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM + * data[0] = a XEN_NETIF_CTRL_HASH_ALGORITHM_* value + * data[1] = 0 + * data[2] = 0 + * + * Response: + * + * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not + * supported + * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - The algorithm is not + * supported + * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful + * + * NOTE: Setting data[0] to XEN_NETIF_CTRL_HASH_ALGORITHM_NONE disables + * hashing and the backend is free to choose how it steers packets + * to queues (which is the default behaviour). + * + * XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS + * ---------------------------------- + * + * This is sent by the frontend to query the types of hash supported by + * the backend. + * + * Request: + * + * type = XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS + * data[0] = 0 + * data[1] = 0 + * data[2] = 0 + * + * Response: + * + * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not supported + * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful + * data = supported hash types (if operation was successful) + * + * NOTE: A valid hash algorithm must be selected before this operation can + * succeed. + * + * XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS + * ---------------------------------- + * + * This is sent by the frontend to set the types of hash that the backend + * should calculate. (See above for hash type definitions). + * Note that the 'maximal' type of hash should always be chosen. For + * example, if the frontend sets both IPV4 and IPV4_TCP hash types then + * the latter hash type should be calculated for any TCP packet and the + * former only calculated for non-TCP packets. + * + * Request: + * + * type = XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS + * data[0] = bitwise OR of XEN_NETIF_CTRL_HASH_TYPE_* values + * data[1] = 0 + * data[2] = 0 + * + * Response: + * + * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not + * supported + * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - One or more flag + * value is invalid or + * unsupported + * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful + * data = 0 + * + * NOTE: A valid hash algorithm must be selected before this operation can + * succeed. + * Also, setting data[0] to zero disables hashing and the backend + * is free to choose how it steers packets to queues. + * + * XEN_NETIF_CTRL_TYPE_SET_HASH_KEY + * -------------------------------- + * + * This is sent by the frontend to set the key of the hash if the algorithm + * requires it. (See hash algorithms above). + * + * Request: + * + * type = XEN_NETIF_CTRL_TYPE_SET_HASH_KEY + * data[0] = grant reference of page containing the key (assumed to + * start at beginning of grant) + * data[1] = size of key in octets + * data[2] = 0 + * + * Response: + * + * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not + * supported + * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - Key size is invalid + * XEN_NETIF_CTRL_STATUS_BUFFER_OVERFLOW - Key size is larger + * than the backend + * supports + * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful + * data = 0 + * + * NOTE: Any key octets not specified are assumed to be zero (the key + * is assumed to be empty by default) and specifying a new key + * invalidates any previous key, hence specifying a key size of + * zero will clear the key (which ensures that the calculated hash + * will always be zero). + * The maximum size of key is algorithm and backend specific, but + * is also limited by the single grant reference. + * The grant reference may be read-only and must remain valid until + * the response has been processed. + * + * XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE + * ----------------------------------------- + * + * This is sent by the frontend to query the maximum size of mapping + * table supported by the backend. The size is specified in terms of + * table entries. + * + * Request: + * + * type = XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE + * data[0] = 0 + * data[1] = 0 + * data[2] = 0 + * + * Response: + * + * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not supported + * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful + * data = maximum number of entries allowed in the mapping table + * (if operation was successful) or zero if a mapping table is + * not supported (i.e. hash mapping is done only by modular + * arithmetic). + * + * XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE + * ------------------------------------- + * + * This is sent by the frontend to set the actual size of the mapping + * table to be used by the backend. The size is specified in terms of + * table entries. + * Any previous table is invalidated by this message and any new table + * is assumed to be zero filled. + * + * Request: + * + * type = XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE + * data[0] = number of entries in mapping table + * data[1] = 0 + * data[2] = 0 + * + * Response: + * + * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not + * supported + * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - Table size is invalid + * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful + * data = 0 + * + * NOTE: Setting data[0] to 0 means that hash mapping should be done + * using modular arithmetic. + * + * XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING + * ------------------------------------ + * + * This is sent by the frontend to set the content of the table mapping + * hash value to queue number. The backend should calculate the hash from + * the packet header, use it as an index into the table (modulo the size + * of the table) and then steer the packet to the queue number found at + * that index. + * + * Request: + * + * type = XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING + * data[0] = grant reference of page containing the mapping (sub-)table + * (assumed to start at beginning of grant) + * data[1] = size of (sub-)table in entries + * data[2] = offset, in entries, of sub-table within overall table + * + * Response: + * + * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not + * supported + * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - Table size or content + * is invalid + * XEN_NETIF_CTRL_STATUS_BUFFER_OVERFLOW - Table size is larger + * than the backend + * supports + * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful + * data = 0 + * + * NOTE: The overall table has the following format: + * + * 0 1 2 3 4 5 6 7 octet + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * | mapping[0] | mapping[1] | + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * | . | + * | . | + * | . | + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * | mapping[N-2] | mapping[N-1] | + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * + * where N is specified by a XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE + * message and each mapping must specifies a queue between 0 and + * "multi-queue-num-queues" (see above). + * The backend may support a mapping table larger than can be + * mapped by a single grant reference. Thus sub-tables within a + * larger table can be individually set by sending multiple messages + * with differing offset values. Specifying a new sub-table does not + * invalidate any table data outside that range. + * The grant reference may be read-only and must remain valid until + * the response has been processed. + * + * XEN_NETIF_CTRL_TYPE_GET_GREF_MAPPING_SIZE + * ----------------------------------------- + * + * This is sent by the frontend to fetch the number of grefs that can be kept + * mapped in the backend. + * + * Request: + * + * type = XEN_NETIF_CTRL_TYPE_GET_GREF_MAPPING_SIZE + * data[0] = queue index (assumed 0 for single queue) + * data[1] = 0 + * data[2] = 0 + * + * Response: + * + * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not + * supported + * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - The queue index is + * out of range + * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful + * data = maximum number of entries allowed in the gref mapping table + * (if operation was successful) or zero if it is not supported. + * + * XEN_NETIF_CTRL_TYPE_ADD_GREF_MAPPING + * ------------------------------------ + * + * This is sent by the frontend for backend to map a list of grant + * references. + * + * Request: + * + * type = XEN_NETIF_CTRL_TYPE_ADD_GREF_MAPPING + * data[0] = queue index + * data[1] = grant reference of page containing the mapping list + * (r/w and assumed to start at beginning of page) + * data[2] = size of list in entries + * + * Response: + * + * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not + * supported + * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - Operation failed + * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful + * + * NOTE: Each entry in the input table has the format outlined + * in struct xen_netif_gref. + * Contrary to XEN_NETIF_CTRL_TYPE_DEL_GREF_MAPPING, the struct + * xen_netif_gref 'status' field is not used and therefore the response + * 'status' determines the success of this operation. In case of + * failure none of grants mappings get added in the backend. + * + * XEN_NETIF_CTRL_TYPE_DEL_GREF_MAPPING + * ------------------------------------ + * + * This is sent by the frontend for backend to unmap a list of grant + * references. + * + * Request: + * + * type = XEN_NETIF_CTRL_TYPE_DEL_GREF_MAPPING + * data[0] = queue index + * data[1] = grant reference of page containing the mapping list + * (r/w and assumed to start at beginning of page) + * data[2] = size of list in entries + * + * Response: + * + * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not + * supported + * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - Operation failed + * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful + * data = number of entries that were unmapped + * + * NOTE: Each entry in the input table has the format outlined in struct + * xen_netif_gref. + * The struct xen_netif_gref 'status' field determines if the entry + * was successfully removed. + * The entries used are only the ones representing grant references that + * were previously the subject of a XEN_NETIF_CTRL_TYPE_ADD_GREF_MAPPING + * operation. Any other entries will have their status set to + * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER upon completion. + */ + +DEFINE_RING_TYPES(xen_netif_ctrl, + struct xen_netif_ctrl_request, + struct xen_netif_ctrl_response); + +/* + * Guest transmit + * ============== + * + * This is the 'wire' format for transmit (frontend -> backend) packets: + * + * Fragment 1: netif_tx_request_t - flags = NETTXF_* + * size = total packet size + * [Extra 1: netif_extra_info_t] - (only if fragment 1 flags include + * NETTXF_extra_info) + * ... + * [Extra N: netif_extra_info_t] - (only if extra N-1 flags include + * XEN_NETIF_EXTRA_MORE) + * ... + * Fragment N: netif_tx_request_t - (only if fragment N-1 flags include + * NETTXF_more_data - flags on preceding + * extras are not relevant here) + * flags = 0 + * size = fragment size + * + * NOTE: + * + * This format slightly is different from that used for receive + * (backend -> frontend) packets. Specifically, in a multi-fragment + * packet the actual size of fragment 1 can only be determined by + * subtracting the sizes of fragments 2..N from the total packet size. + * + * Ring slot size is 12 octets, however not all request/response + * structs use the full size. + * + * tx request data (netif_tx_request_t) + * ------------------------------------ + * + * 0 1 2 3 4 5 6 7 octet + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * | grant ref | offset | flags | + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * | id | size | + * +-----+-----+-----+-----+ + * + * grant ref: Reference to buffer page. + * offset: Offset within buffer page. + * flags: NETTXF_*. + * id: request identifier, echoed in response. + * size: packet size in bytes. + * + * tx response (netif_tx_response_t) + * --------------------------------- + * + * 0 1 2 3 4 5 6 7 octet + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * | id | status | unused | + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * | unused | + * +-----+-----+-----+-----+ + * + * id: reflects id in transmit request + * status: NETIF_RSP_* + * + * Guest receive + * ============= + * + * This is the 'wire' format for receive (backend -> frontend) packets: + * + * Fragment 1: netif_rx_request_t - flags = NETRXF_* + * size = fragment size + * [Extra 1: netif_extra_info_t] - (only if fragment 1 flags include + * NETRXF_extra_info) * ... - * Request N: netif_tx_request -- 0 + * [Extra N: netif_extra_info_t] - (only if extra N-1 flags include + * XEN_NETIF_EXTRA_MORE) + * ... + * Fragment N: netif_rx_request_t - (only if fragment N-1 flags include + * NETRXF_more_data - flags on preceding + * extras are not relevant here) + * flags = 0 + * size = fragment size + * + * NOTE: + * + * This format slightly is different from that used for transmit + * (frontend -> backend) packets. Specifically, in a multi-fragment + * packet the size of the packet can only be determined by summing the + * sizes of fragments 1..N. + * + * Ring slot size is 8 octets. + * + * rx request (netif_rx_request_t) + * ------------------------------- + * + * 0 1 2 3 4 5 6 7 octet + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * | id | pad | gref | + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * + * id: request identifier, echoed in response. + * gref: reference to incoming granted frame. + * + * rx response (netif_rx_response_t) + * --------------------------------- + * + * 0 1 2 3 4 5 6 7 octet + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * | id | offset | flags | status | + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * + * id: reflects id in receive request + * offset: offset in page of start of received packet + * flags: NETRXF_* + * status: -ve: NETIF_RSP_*; +ve: Rx'ed pkt size. + * + * NOTE: Historically, to support GSO on the frontend receive side, Linux + * netfront does not make use of the rx response id (because, as + * described below, extra info structures overlay the id field). + * Instead it assumes that responses always appear in the same ring + * slot as their corresponding request. Thus, to maintain + * compatibility, backends must make sure this is the case. + * + * Extra Info + * ========== + * + * Can be present if initial request or response has NET{T,R}XF_extra_info, + * or previous extra request has XEN_NETIF_EXTRA_MORE. + * + * The struct therefore needs to fit into either a tx or rx slot and + * is therefore limited to 8 octets. + * + * NOTE: Because extra info data overlays the usual request/response + * structures, there is no id information in the opposite direction. + * So, if an extra info overlays an rx response the frontend can + * assume that it is in the same ring slot as the request that was + * consumed to make the slot available, and the backend must ensure + * this assumption is true. + * + * extra info (netif_extra_info_t) + * ------------------------------- + * + * General format: + * + * 0 1 2 3 4 5 6 7 octet + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * |type |flags| type specific data | + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * | padding for tx | + * +-----+-----+-----+-----+ + * + * type: XEN_NETIF_EXTRA_TYPE_* + * flags: XEN_NETIF_EXTRA_FLAG_* + * padding for tx: present only in the tx case due to 8 octet limit + * from rx case. Not shown in type specific entries + * below. + * + * XEN_NETIF_EXTRA_TYPE_GSO: + * + * 0 1 2 3 4 5 6 7 octet + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * |type |flags| size |type | pad | features | + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * + * type: Must be XEN_NETIF_EXTRA_TYPE_GSO + * flags: XEN_NETIF_EXTRA_FLAG_* + * size: Maximum payload size of each segment. For example, + * for TCP this is just the path MSS. + * type: XEN_NETIF_GSO_TYPE_*: This determines the protocol of + * the packet and any extra features required to segment the + * packet properly. + * features: EN_NETIF_GSO_FEAT_*: This specifies any extra GSO + * features required to process this packet, such as ECN + * support for TCPv4. + * + * XEN_NETIF_EXTRA_TYPE_MCAST_{ADD,DEL}: + * + * 0 1 2 3 4 5 6 7 octet + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * |type |flags| addr | + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * + * type: Must be XEN_NETIF_EXTRA_TYPE_MCAST_{ADD,DEL} + * flags: XEN_NETIF_EXTRA_FLAG_* + * addr: address to add/remove + * + * XEN_NETIF_EXTRA_TYPE_HASH: + * + * A backend that supports teoplitz hashing is assumed to accept + * this type of extra info in transmit packets. + * A frontend that enables hashing is assumed to accept + * this type of extra info in receive packets. + * + * 0 1 2 3 4 5 6 7 octet + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * |type |flags|htype| alg |LSB ---- value ---- MSB| + * +-----+-----+-----+-----+-----+-----+-----+-----+ + * + * type: Must be XEN_NETIF_EXTRA_TYPE_HASH + * flags: XEN_NETIF_EXTRA_FLAG_* + * htype: Hash type (one of _XEN_NETIF_CTRL_HASH_TYPE_* - see above) + * alg: The algorithm used to calculate the hash (one of + * XEN_NETIF_CTRL_HASH_TYPE_ALGORITHM_* - see above) + * value: Hash value */ /* Protocol checksum field is blank in the packet (hardware offload)? */ @@ -166,11 +974,11 @@ FILE_LICENCE ( MIT ); #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. */ + grant_ref_t gref; + uint16_t offset; + uint16_t flags; + uint16_t id; + uint16_t size; }; typedef struct netif_tx_request netif_tx_request_t; @@ -179,9 +987,10 @@ typedef struct netif_tx_request netif_tx_request_t; #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) +#define XEN_NETIF_EXTRA_TYPE_HASH (4) /* u.hash */ +#define XEN_NETIF_EXTRA_TYPE_MAX (5) -/* netif_extra_info flags. */ +/* netif_extra_info_t flags. */ #define _XEN_NETIF_EXTRA_FLAG_MORE (0) #define XEN_NETIF_EXTRA_FLAG_MORE (1U<<_XEN_NETIF_EXTRA_FLAG_MORE) @@ -191,55 +1000,27 @@ typedef struct netif_tx_request netif_tx_request_t; #define XEN_NETIF_GSO_TYPE_TCPV6 (2) /* - * This structure needs to fit within both netif_tx_request and - * netif_rx_response for compatibility. + * This structure needs to fit within both netif_tx_request_t and + * netif_rx_response_t for compatibility. */ struct netif_extra_info { - uint8_t type; /* XEN_NETIF_EXTRA_TYPE_* */ - uint8_t flags; /* XEN_NETIF_EXTRA_FLAG_* */ - + uint8_t type; + uint8_t flags; 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 type; 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_* */ + uint16_t features; } 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. */ + uint8_t addr[6]; } mcast; - + struct { + uint8_t type; + uint8_t algorithm; + uint8_t value[4]; + } hash; uint16_t pad[3]; } u; }; @@ -247,13 +1028,14 @@ typedef struct netif_extra_info netif_extra_info_t; struct netif_tx_response { uint16_t id; - int16_t status; /* NETIF_RSP_* */ + int16_t status; }; 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 */ + uint16_t pad; + grant_ref_t gref; }; typedef struct netif_rx_request netif_rx_request_t; @@ -273,11 +1055,15 @@ typedef struct netif_rx_request netif_rx_request_t; #define _NETRXF_extra_info (3) #define NETRXF_extra_info (1U<<_NETRXF_extra_info) +/* Packet has GSO prefix. Deprecated but included for compatibility */ +#define _NETRXF_gso_prefix (4) +#define NETRXF_gso_prefix (1U<<_NETRXF_gso_prefix) + 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: NETIF_RSP_* ; +ve: Rx'ed pkt size. */ + uint16_t offset; + uint16_t flags; + int16_t status; }; typedef struct netif_rx_response netif_rx_response_t; @@ -291,7 +1077,7 @@ 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). */ +/* No response: used for auxiliary requests (e.g., netif_extra_info_t). */ #define NETIF_RSP_NULL 1 #endif |