[v2] ip_frag: add IPv4 fragment copy packet API

Message ID 1654784398-11315-1-git-send-email-chcchc88@163.com (mailing list archive)
State Superseded, archived
Delegated to: Thomas Monjalon
Headers
Series [v2] ip_frag: add IPv4 fragment copy packet API |

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Commit Message

Huichao Cai June 9, 2022, 2:19 p.m. UTC
  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 <chcchc88@163.com>
---
 app/test/test_ipfrag.c               |   8 +-
 lib/ip_frag/rte_ip_frag.h            |  26 ++++++
 lib/ip_frag/rte_ipv4_fragmentation.c | 165 +++++++++++++++++++++++++++++++++++
 lib/ip_frag/version.map              |   1 +
 4 files changed, 199 insertions(+), 1 deletion(-)
  

Comments

Konstantin Ananyev July 10, 2022, 11:35 p.m. UTC | #1
> 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 <chcchc88@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)
 > +{
 > +    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;
 >   };
  
Konstantin Ananyev July 11, 2022, 9:14 a.m. UTC | #2
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 <chcchc88@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;
>  >   };
  
Huichao Cai July 15, 2022, 8:05 a.m. UTC | #3
Hi Konstantin,


    I've been busy lately, sorry to reply to you late.


    > 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 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.
reply: Thanks for the reminder, I will use explicit parameters and rte_pktmbuf_copy();
> Forgot to mention, new API has to be experimental.
reply: Does this mean adding _rte_experimental when declaring a function?


Huichao,Cai
  
Konstantin Ananyev July 19, 2022, 8:19 a.m. UTC | #4
Hi Huichao,


> 
>      I've been busy lately, sorry to reply to you late.

No worries at all.

> 
>> 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 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.
> 
> reply: Thanks for the reminder, I will use explicit parameters and rte_pktmbuf_copy();
>> Forgot to mention, new API has to be experimental.
> 
> reply: Does this mean adding _rte_experimental when declaring a function?
> 

Yes, I meant _rte_experimental tag.
Thanks
Konstantin
  

Patch

diff --git a/app/test/test_ipfrag.c b/app/test/test_ipfrag.c
index 610a86b..e565e86 100644
--- a/app/test/test_ipfrag.c
+++ b/app/test/test_ipfrag.c
@@ -408,10 +408,16 @@  static void ut_teardown(void)
 		}
 
 		if (tests[i].ipv == 4)
-			len = rte_ipv4_fragment_packet(b, pkts_out, BURST,
+			if (i % 2)
+				len = rte_ipv4_fragment_packet(b, pkts_out,
+						       BURST,
 						       tests[i].mtu_size,
 						       direct_pool,
 						       indirect_pool);
+			else
+				len = rte_ipv4_fragment_copy_packet(b, pkts_out,
+							   BURST,
+							   tests[i].mtu_size);
 		else if (tests[i].ipv == 6)
 			len = rte_ipv6_fragment_packet(b, pkts_out, BURST,
 						       tests[i].mtu_size,
diff --git a/lib/ip_frag/rte_ip_frag.h b/lib/ip_frag/rte_ip_frag.h
index 7d2abe1..3e1a9ac 100644
--- 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)
+{
+	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);
+		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)) {
+			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;
 };