1 /* SPDX-License-Identifier: BSD-3-Clause 2 * Copyright(c) 2017 Intel Corporation 3 */ 4 5 #ifndef _RTE_GSO_H_ 6 #define _RTE_GSO_H_ 7 8 /** 9 * @file 10 * Interface to GSO library 11 */ 12 13 #include <stdint.h> 14 #include <rte_mbuf.h> 15 16 #ifdef __cplusplus 17 extern "C" { 18 #endif 19 20 /* Minimum GSO segment size for TCP based packets. */ 21 #define RTE_GSO_SEG_SIZE_MIN (sizeof(struct rte_ether_hdr) + \ 22 sizeof(struct rte_ipv4_hdr) + sizeof(struct rte_tcp_hdr) + 1) 23 24 /* Minimum GSO segment size for UDP based packets. */ 25 #define RTE_GSO_UDP_SEG_SIZE_MIN (sizeof(struct rte_ether_hdr) + \ 26 sizeof(struct rte_ipv4_hdr) + sizeof(struct rte_udp_hdr) + 1) 27 28 /* GSO flags for rte_gso_ctx. */ 29 #define RTE_GSO_FLAG_IPID_FIXED (1ULL << 0) 30 /**< Use fixed IP ids for output GSO segments. Setting 31 * 0 indicates using incremental IP ids. 32 */ 33 34 /** 35 * GSO context structure. 36 */ 37 struct rte_gso_ctx { 38 struct rte_mempool *direct_pool; 39 /**< MBUF pool for allocating direct buffers, which are used 40 * to store packet headers for GSO segments. 41 */ 42 struct rte_mempool *indirect_pool; 43 /**< MBUF pool for allocating indirect buffers, which are used 44 * to locate packet payloads for GSO segments. The indirect 45 * buffer doesn't contain any data, but simply points to an 46 * offset within the packet to segment. 47 */ 48 uint64_t flag; 49 /**< flag that controls specific attributes of output segments, 50 * such as the type of IP ID generated (i.e. fixed or incremental). 51 */ 52 uint32_t gso_types; 53 /**< the bit mask of required GSO types. The GSO library 54 * uses the same macros as that of describing device TX 55 * offloading capabilities (i.e. RTE_ETH_TX_OFFLOAD_*_TSO) for 56 * gso_types. 57 * 58 * For example, if applications want to segment TCP/IPv4 59 * packets, set RTE_ETH_TX_OFFLOAD_TCP_TSO in gso_types. 60 */ 61 uint16_t gso_size; 62 /**< maximum size of an output GSO segment, including packet 63 * header and payload, measured in bytes. Must exceed 64 * RTE_GSO_SEG_SIZE_MIN. 65 */ 66 }; 67 68 /** 69 * Segmentation function, which supports processing of both single- and 70 * multi- MBUF packets. 71 * 72 * Note that we refer to the packets that are segmented from the input 73 * packet as 'GSO segments'. rte_gso_segment() doesn't check if the 74 * input packet has correct checksums, and doesn't update checksums for 75 * output GSO segments. Additionally, it doesn't process IP fragment 76 * packets. 77 * 78 * Before calling rte_gso_segment(), applications must set proper ol_flags 79 * for the packet. The GSO library uses the same macros as that of TSO. 80 * For example, set RTE_MBUF_F_TX_TCP_SEG and RTE_MBUF_F_TX_IPV4 in ol_flags to segment 81 * a TCP/IPv4 packet. If rte_gso_segment() succeeds, the RTE_MBUF_F_TX_TCP_SEG 82 * flag is removed for all GSO segments and the input packet. 83 * 84 * Each of the newly-created GSO segments is organized as a two-segment 85 * MBUF, where the first segment is a standard MBUF, which stores a copy 86 * of packet header, and the second is an indirect MBUF which points to 87 * a section of data in the input packet. Since each GSO segment has 88 * multiple MBUFs (i.e. typically 2 MBUFs), the driver of the interface which 89 * the GSO segments are sent to should support transmission of multi-segment 90 * packets. 91 * 92 * If the input packet is GSO'd, all the indirect segments are attached to the 93 * input packet. 94 * 95 * rte_gso_segment() will not free the input packet no matter whether it is 96 * GSO'd or not, the application should free it after calling rte_gso_segment(). 97 * 98 * If the memory space in pkts_out or MBUF pools is insufficient, this 99 * function fails, and it returns (-1) * errno. Otherwise, GSO succeeds, 100 * and this function returns the number of output GSO segments filled in 101 * pkts_out. 102 * 103 * @param pkt 104 * The packet mbuf to segment. 105 * @param ctx 106 * GSO context object pointer. 107 * @param pkts_out 108 * Pointer array used to store the MBUF addresses of output GSO 109 * segments, when rte_gso_segment() succeeds. 110 * @param nb_pkts_out 111 * The max number of items that pkts_out can keep. 112 * 113 * @return 114 * - The number of GSO segments filled in pkts_out on success. 115 * - Return 0 if it does not need to be GSO'd. 116 * - Return -ENOMEM if run out of memory in MBUF pools. 117 * - Return -ENOTSUP for protocols that can not be segmented. 118 * - Return -EINVAL for invalid parameters. 119 */ 120 int rte_gso_segment(struct rte_mbuf *pkt, 121 const struct rte_gso_ctx *ctx, 122 struct rte_mbuf **pkts_out, 123 uint16_t nb_pkts_out); 124 #ifdef __cplusplus 125 } 126 #endif 127 128 #endif /* _RTE_GSO_H_ */ 129