11/07/2022 00:35, Konstantin Ananyev пишет:
> Some NIC drivers support MBUF_FAST_FREE(Device supports optimization
> for fast release of mbufs. When set application must guarantee that
> per-queue all mbufs comes from the same mempool and has refcnt = 1)
> offload. In order to adapt to this offload function, add this API.
> Add some test data for this API.
>
> Signed-off-by: Huichao Cai <chcch...@163.com>
> ---
...
> --- a/lib/ip_frag/rte_ip_frag.h
> +++ b/lib/ip_frag/rte_ip_frag.h
> @@ -179,6 +179,32 @@ int32_t rte_ipv4_fragment_packet(struct rte_mbuf
> *pkt_in,
> struct rte_mempool *pool_indirect);
>
> /**
> + * IPv4 fragmentation by copy.
> + *
> + * This function implements the fragmentation of IPv4 packets by copy.
> + *
> + * @param pkt_in
> + * The input packet.
> + * @param pkts_out
> + * Array storing the output fragments.
> + * @param nb_pkts_out
> + * The size of the array that stores the output fragments.
> + * @param mtu_size
> + * Size in bytes of the Maximum Transfer Unit (MTU) for the outgoing
> IPv4
> + * datagrams. This value includes the size of the IPv4 header.
> + * @return
> + * Upon successful completion - number of output fragments placed
> + * in the pkts_out array.
> + * Otherwise - (-1) * errno.
> + */
> +__rte_experimental
> +int32_t
> +rte_ipv4_fragment_copy_packet(struct rte_mbuf *pkt_in,
> + struct rte_mbuf **pkts_out,
> + uint16_t nb_pkts_out,
> + uint16_t mtu_size);
> +
> +/**
> * This function implements reassembly of fragmented IPv4 packets.
> * Incoming mbufs should have its l2_len/l3_len fields setup
correctly.
> *
> diff --git a/lib/ip_frag/rte_ipv4_fragmentation.c
> b/lib/ip_frag/rte_ipv4_fragmentation.c
> index a562424..9e050cc 100644
> --- a/lib/ip_frag/rte_ipv4_fragmentation.c
> +++ b/lib/ip_frag/rte_ipv4_fragmentation.c
> @@ -262,3 +262,168 @@ static inline uint16_t
> __create_ipopt_frag_hdr(uint8_t *iph,
>
> return out_pkt_pos;
> }
> +
> +/**
> + * IPv4 fragmentation by copy.
> + *
> + * This function implements the fragmentation of IPv4 packets by copy.
> + *
> + * @param pkt_in
> + * The input packet.
> + * @param pkts_out
> + * Array storing the output fragments.
> + * @param nb_pkts_out
> + * The size of the array that stores the output fragments.
> + * @param mtu_size
> + * Size in bytes of the Maximum Transfer Unit (MTU) for the outgoing
> IPv4
> + * datagrams. This value includes the size of the IPv4 header.
> + * @return
> + * Upon successful completion - number of output fragments placed
> + * in the pkts_out array.
> + * Otherwise - (-1) * errno.
> + */
> +int32_t
> +rte_ipv4_fragment_copy_packet(struct rte_mbuf *pkt_in,
> + struct rte_mbuf **pkts_out,
> + uint16_t nb_pkts_out,
> + uint16_t mtu_size)
Forgot to mention, new API has to be experimental.
> +{
> + struct rte_mbuf *in_seg = NULL;
> + struct rte_ipv4_hdr *in_hdr;
> + uint32_t out_pkt_pos, in_seg_data_pos;
> + uint32_t more_in_segs;
> + uint16_t fragment_offset, flag_offset, frag_size, header_len;
> + uint16_t frag_bytes_remaining;
> + uint8_t ipopt_frag_hdr[IPV4_HDR_MAX_LEN];
> + uint16_t ipopt_len;
> +
> + /*
> + * Formal parameter checking.
> + */
> + if (unlikely(pkt_in == NULL) || unlikely(pkts_out == NULL) ||
> + unlikely(nb_pkts_out == 0) ||
> + unlikely(pkt_in->pool == NULL) ||
> + unlikely(mtu_size < RTE_ETHER_MIN_MTU))
> + return -EINVAL;
> +
> + in_hdr = rte_pktmbuf_mtod(pkt_in, struct rte_ipv4_hdr *);
> + header_len = (in_hdr->version_ihl & RTE_IPV4_HDR_IHL_MASK) *
> + RTE_IPV4_IHL_MULTIPLIER;
> +
> + /* Check IP header length */
> + if (unlikely(pkt_in->data_len < header_len) ||
> + unlikely(mtu_size < header_len))
> + return -EINVAL;
> +
> + /*
> + * Ensure the IP payload length of all fragments is aligned to a
> + * multiple of 8 bytes as per RFC791 section 2.3.
> + */
> + frag_size = RTE_ALIGN_FLOOR((mtu_size - header_len),
> + IPV4_HDR_FO_ALIGN);
> +
> + flag_offset = rte_cpu_to_be_16(in_hdr->fragment_offset);
> +
> + /* If Don't Fragment flag is set */
> + if (unlikely((flag_offset & IPV4_HDR_DF_MASK) != 0))
> + return -ENOTSUP;
> +
> + /* Check that pkts_out is big enough to hold all fragments */
> + if (unlikely(frag_size * nb_pkts_out <
> + (uint16_t)(pkt_in->pkt_len - header_len)))
> + return -EINVAL;
> +
> + in_seg = pkt_in;
> + in_seg_data_pos = header_len;
> + out_pkt_pos = 0;
> + fragment_offset = 0;
> +
> + ipopt_len = header_len - sizeof(struct rte_ipv4_hdr);
> + if (unlikely(ipopt_len > RTE_IPV4_HDR_OPT_MAX_LEN))
> + return -EINVAL;
> +
> + more_in_segs = 1;
> + while (likely(more_in_segs)) {
> + struct rte_mbuf *out_pkt = NULL;
> + uint32_t more_out_segs;
> + struct rte_ipv4_hdr *out_hdr;
> +
> + /* Allocate buffer from pkt_in->pool*/
> + out_pkt = rte_pktmbuf_alloc(pkt_in->pool);
Instead of implicitly assuming that output mbufs will be allocated
from pkt_in pool, it would be better to have output_pool as explicit
parameter for that function.
In a same way we have it for rte_ipv4_fragment_packet().
> + if (unlikely(out_pkt == NULL)) {
> + __free_fragments(pkts_out, out_pkt_pos);
> + return -ENOMEM;
> + }
> +
> + /* Reserve space for the IP header that will be built later */
> + out_pkt->data_len = header_len;
> + out_pkt->pkt_len = header_len;
> + frag_bytes_remaining = frag_size;
> +
> + more_out_segs = 1;
> + while (likely(more_out_segs && more_in_segs)) {
If I understand correctly, here you assume that out_pkt will always
be big enough to hold entire fragment, right?
But that can not always be the case and probably we shouldn't assume
that for generic function.
I suppose safest way would be either use rte_pktmbuf_copy() here
directly or do something similar to what that function doing ourselves
here.
> + uint32_t len;
> +
> + len = frag_bytes_remaining;
> + if (len > (in_seg->data_len - in_seg_data_pos))
> + len = in_seg->data_len - in_seg_data_pos;
> +
> + rte_memcpy(
> + rte_pktmbuf_mtod_offset(
> + out_pkt, char *, out_pkt->pkt_len),
> + rte_pktmbuf_mtod_offset(
> + in_seg, char *, in_seg_data_pos),
> + len);
> + out_pkt->data_len = (uint16_t)(len +
> + out_pkt->data_len);
> +
> + out_pkt->pkt_len = (uint16_t)(len +
> + out_pkt->pkt_len);
> + in_seg_data_pos += len;
> + frag_bytes_remaining -= len;
> +
> + /* Current output packet (i.e. fragment) done ? */
> + if (unlikely(frag_bytes_remaining == 0))
> + more_out_segs = 0;
> +
> + /* Current input segment done ? */
> + if (unlikely(in_seg_data_pos == in_seg->data_len)) {
> + in_seg = in_seg->next;
> + in_seg_data_pos = 0;
> +
> + if (unlikely(in_seg == NULL))
> + more_in_segs = 0;
> + }
> + }
> +
> + /* Build the IP header */
> +
> + out_hdr = rte_pktmbuf_mtod(out_pkt, struct rte_ipv4_hdr *);
> +
> + __fill_ipv4hdr_frag(out_hdr, in_hdr, header_len,
> + (uint16_t)out_pkt->pkt_len,
> + flag_offset, fragment_offset, more_in_segs);
> +
> + if (unlikely((fragment_offset == 0) && (ipopt_len) &&
> + ((flag_offset & RTE_IPV4_HDR_OFFSET_MASK) == 0))) {
> + ipopt_len = __create_ipopt_frag_hdr((uint8_t *)in_hdr,
> + ipopt_len, ipopt_frag_hdr);
> + fragment_offset = (uint16_t)(fragment_offset +
> + out_pkt->pkt_len - header_len);
> + out_pkt->l3_len = header_len;
> +
> + header_len = sizeof(struct rte_ipv4_hdr) + ipopt_len;
> + in_hdr = (struct rte_ipv4_hdr *)ipopt_frag_hdr;
> + } else {
> + fragment_offset = (uint16_t)(fragment_offset +
> + out_pkt->pkt_len - header_len);
> + out_pkt->l3_len = header_len;
> + }
> +
> + /* Write the fragment to the output list */
> + pkts_out[out_pkt_pos] = out_pkt;
> + out_pkt_pos++;
> + }
> +
> + return out_pkt_pos;
> +}
> diff --git a/lib/ip_frag/version.map b/lib/ip_frag/version.map
> index e537224..4aa66bc 100644
> --- a/lib/ip_frag/version.map
> +++ b/lib/ip_frag/version.map
> @@ -17,4 +17,5 @@ EXPERIMENTAL {
> global:
>
> rte_ip_frag_table_del_expired_entries;
> + rte_ipv4_fragment_copy_packet;
> };
