+ * Implementation of IP packet fragmentation and reassembly.
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include <stdio.h>
+
+#include <rte_malloc.h>
+#include <rte_mbuf.h>
+#include <rte_memory.h>
+#include <rte_ip.h>
+#include <rte_byteorder.h>
+
+enum {
+ IP_LAST_FRAG_IDX, /**< index of last fragment */
+ IP_FIRST_FRAG_IDX, /**< index of first fragment */
+ IP_MIN_FRAG_NUM, /**< minimum number of fragments */
+ IP_MAX_FRAG_NUM = RTE_LIBRTE_IP_FRAG_MAX_FRAG,
+ /**< maximum number of fragments per packet */
+};
+
+/** @internal fragmented mbuf */
+struct ip_frag {
+ uint16_t ofs; /**< offset into the packet */
+ uint16_t len; /**< length of fragment */
+ struct rte_mbuf *mb; /**< fragment mbuf */
+};
+
+/** @internal <src addr, dst_addr, id> to uniquely indetify fragmented datagram. */
+struct ip_frag_key {
+ uint64_t src_dst[4]; /**< src address, first 8 bytes used for IPv4 */
+ uint32_t id; /**< dst address */
+ uint32_t key_len; /**< src/dst key length */
+};
+
+/*
+ * @internal Fragmented packet to reassemble.
+ * First two entries in the frags[] array are for the last and first fragments.
+ */
+struct ip_frag_pkt {
+ TAILQ_ENTRY(ip_frag_pkt) lru; /**< LRU list */
+ struct ip_frag_key key; /**< fragmentation key */
+ uint64_t start; /**< creation timestamp */
+ uint32_t total_size; /**< expected reassembled size */
+ uint32_t frag_size; /**< size of fragments received */
+ uint32_t last_idx; /**< index of next entry to fill */
+ struct ip_frag frags[IP_MAX_FRAG_NUM]; /**< fragments */
+} __rte_cache_aligned;
+
+#define IP_FRAG_DEATH_ROW_LEN 32 /**< death row size (in packets) */
+
+/** mbuf death row (packets to be freed) */
+struct rte_ip_frag_death_row {
+ uint32_t cnt; /**< number of mbufs currently on death row */
+ struct rte_mbuf *row[IP_FRAG_DEATH_ROW_LEN * (IP_MAX_FRAG_NUM + 1)];
+ /**< mbufs to be freed */
+};
+
+TAILQ_HEAD(ip_pkt_list, ip_frag_pkt); /**< @internal fragments tailq */
+
+/** fragmentation table statistics */
+struct ip_frag_tbl_stat {
+ uint64_t find_num; /**< total # of find/insert attempts. */
+ uint64_t add_num; /**< # of add ops. */
+ uint64_t del_num; /**< # of del ops. */
+ uint64_t reuse_num; /**< # of reuse (del/add) ops. */
+ uint64_t fail_total; /**< total # of add failures. */
+ uint64_t fail_nospace; /**< # of 'no space' add failures. */
+} __rte_cache_aligned;
+
+/** fragmentation table */
+struct rte_ip_frag_tbl {
+ uint64_t max_cycles; /**< ttl for table entries. */
+ uint32_t entry_mask; /**< hash value mask. */
+ uint32_t max_entries; /**< max entries allowed. */
+ uint32_t use_entries; /**< entries in use. */
+ uint32_t bucket_entries; /**< hash assocaitivity. */
+ uint32_t nb_entries; /**< total size of the table. */
+ uint32_t nb_buckets; /**< num of associativity lines. */
+ struct ip_frag_pkt *last; /**< last used entry. */
+ struct ip_pkt_list lru; /**< LRU list for table entries. */
+ struct ip_frag_tbl_stat stat; /**< statistics counters. */
+ struct ip_frag_pkt pkt[0]; /**< hash table. */
+};
+
+/** IPv6 fragment extension header */
+struct ipv6_extension_fragment {
+ uint8_t next_header; /**< Next header type */
+ uint8_t reserved1; /**< Reserved */
+ union {
+ struct {
+ uint16_t frag_offset:13; /**< Offset from the start of the packet */
+ uint16_t reserved2:2; /**< Reserved */
+ uint16_t more_frags:1;
+ /**< 1 if more fragments left, 0 if last fragment */
+ };
+ uint16_t frag_data;
+ /**< union of all fragmentation data */
+ };
+ uint32_t id; /**< Packet ID */
+} __attribute__((__packed__));
+
+
+
+/*
+ * Create a new IP fragmentation table.
+ *
+ * @param bucket_num
+ * Number of buckets in the hash table.
+ * @param bucket_entries
+ * Number of entries per bucket (e.g. hash associativity).
+ * Should be power of two.
+ * @param max_entries
+ * Maximum number of entries that could be stored in the table.
+ * The value should be less or equal then bucket_num * bucket_entries.
+ * @param max_cycles
+ * Maximum TTL in cycles for each fragmented packet.
+ * @param socket_id
+ * The *socket_id* argument is the socket identifier in the case of
+ * NUMA. The value can be *SOCKET_ID_ANY* if there is no NUMA constraints.
+ * @return
+ * The pointer to the new allocated fragmentation table, on success. NULL on error.
+ */
+struct rte_ip_frag_tbl * rte_ip_frag_table_create(uint32_t bucket_num,
+ uint32_t bucket_entries, uint32_t max_entries,
+ uint64_t max_cycles, int socket_id);
+
+/*
+ * Free allocated IP fragmentation table.
+ *
+ * @param btl
+ * Fragmentation table to free.
+ */
+static inline void
+rte_ip_frag_table_destroy( struct rte_ip_frag_tbl *tbl)
+{
+ rte_free(tbl);
+}
+
+/**
+ * This function implements the fragmentation of IPv6 packets.
+ *
+ * @param pkt_in
+ * The input packet.
+ * @param pkts_out
+ * Array storing the output fragments.
+ * @param nb_pkts_out
+ * Number of fragments.
+ * @param mtu_size
+ * Size in bytes of the Maximum Transfer Unit (MTU) for the outgoing IPv6
+ * datagrams. This value includes the size of the IPv6 header.
+ * @param pool_direct
+ * MBUF pool used for allocating direct buffers for the output fragments.
+ * @param pool_indirect
+ * MBUF pool used for allocating indirect buffers for the output fragments.
+ * @return
+ * Upon successful completion - number of output fragments placed
+ * in the pkts_out array.
+ * Otherwise - (-1) * errno.
+ */
+int32_t
+rte_ipv6_fragment_packet(struct rte_mbuf *pkt_in,
+ struct rte_mbuf **pkts_out,
+ uint16_t nb_pkts_out,
+ uint16_t mtu_size,
+ struct rte_mempool *pool_direct,
+ struct rte_mempool *pool_indirect);
+
+/*
+ * This function implements reassembly of fragmented IPv6 packets.
+ * Incoming mbuf should have its l2_len/l3_len fields setup correctly.
+ *
+ * @param tbl
+ * Table where to lookup/add the fragmented packet.
+ * @param dr
+ * Death row to free buffers to
+ * @param mb
+ * Incoming mbuf with IPv6 fragment.
+ * @param tms
+ * Fragment arrival timestamp.
+ * @param ip_hdr
+ * Pointer to the IPv6 header.
+ * @param frag_hdr
+ * Pointer to the IPv6 fragment extension header.
+ * @return
+ * Pointer to mbuf for reassembled packet, or NULL if:
+ * - an error occured.
+ * - not all fragments of the packet are collected yet.
+ */
+struct rte_mbuf *rte_ipv6_frag_reassemble_packet(struct rte_ip_frag_tbl *tbl,
+ struct rte_ip_frag_death_row *dr,
+ struct rte_mbuf *mb, uint64_t tms, struct ipv6_hdr *ip_hdr,
+ struct ipv6_extension_fragment *frag_hdr);
+
+/*
+ * Return a pointer to the packet's fragment header, if found.
+ * It only looks at the extension header that's right after the fixed IPv6
+ * header, and doesn't follow the whole chain of extension headers.