Re: [dpdk-dev] [PATCH v3] ip_frag: extend rte_ipv6_frag_get_ipv6_fragment_header()

[Cody Doucette <doucette@bu.edu>]

Re-upping for review.

Thanks,
Cody

On Fri, Jul 27, 2018 at 9:52 AM, Cody Doucette <doucette@bu.edu> wrote:

> Extend rte_ipv6_frag_get_ipv6_fragment_header() to skip over any
> other IPv6 extension headers when finding the fragment header.
>
> According to RFC 8200, there is no guarantee that the IPv6
> Fragment extension header will come before any other extension
> header, even though it is recommended.
>
> Signed-off-by: Cody Doucette <doucette@bu.edu>
> Signed-off-by: Qiaobin Fu <qiaobinf@bu.edu>
> Reviewed-by: Michel Machado <michel@digirati.com.br>
> ---
> v3:
> * Removed compilation flag D_XOPEN_SOURCE=700 from the
>   failsafe driver to allow compilation on freebsd.
>
> v2:
> * Moved IPv6 extension header definitions to lib_net.
>
>  drivers/net/failsafe/Makefile               |  1 -
>  drivers/net/failsafe/meson.build            |  1 -
>  examples/ip_reassembly/main.c               |  6 ++--
>  lib/librte_ip_frag/rte_ip_frag.h            | 23 ++++++-------
>  lib/librte_ip_frag/rte_ip_frag_version.map  |  1 +
>  lib/librte_ip_frag/rte_ipv6_fragmentation.c | 38 +++++++++++++++++++++
>  lib/librte_ip_frag/rte_ipv6_reassembly.c    |  4 +--
>  lib/librte_net/rte_ip.h                     | 27 +++++++++++++++
>  lib/librte_port/rte_port_ras.c              |  6 ++--
>  9 files changed, 86 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/net/failsafe/Makefile b/drivers/net/failsafe/Makefile
> index 81802d092..eb9292425 100644
> --- a/drivers/net/failsafe/Makefile
> +++ b/drivers/net/failsafe/Makefile
> @@ -34,7 +34,6 @@ CFLAGS += -std=gnu99 -Wextra
>  CFLAGS += -O3
>  CFLAGS += -I.
>  CFLAGS += -D_DEFAULT_SOURCE
> -CFLAGS += -D_XOPEN_SOURCE=700
>  CFLAGS += $(WERROR_FLAGS)
>  CFLAGS += -Wno-strict-prototypes
>  CFLAGS += -pedantic
> diff --git a/drivers/net/failsafe/meson.build
> b/drivers/net/failsafe/meson.build
> index a249ff4af..d47a52acd 100644
> --- a/drivers/net/failsafe/meson.build
> +++ b/drivers/net/failsafe/meson.build
> @@ -3,7 +3,6 @@
>
>  cflags += '-std=gnu99'
>  cflags += '-D_DEFAULT_SOURCE'
> -cflags += '-D_XOPEN_SOURCE=700'
>  cflags += '-pedantic'
>  if host_machine.system() == 'linux'
>         cflags += '-DLINUX'
> diff --git a/examples/ip_reassembly/main.c b/examples/ip_reassembly/main.c
> index b830f67a5..58c388708 100644
> --- a/examples/ip_reassembly/main.c
> +++ b/examples/ip_reassembly/main.c
> @@ -366,12 +366,14 @@ reassemble(struct rte_mbuf *m, uint16_t portid,
> uint32_t queue,
>                 eth_hdr->ether_type = rte_be_to_cpu_16(ETHER_TYPE_IPv4);
>         } else if (RTE_ETH_IS_IPV6_HDR(m->packet_type)) {
>                 /* if packet is IPv6 */
> -               struct ipv6_extension_fragment *frag_hdr;
> +               const struct ipv6_extension_fragment *frag_hdr;
> +               struct ipv6_extension_fragment frag_hdr_buf;
>                 struct ipv6_hdr *ip_hdr;
>
>                 ip_hdr = (struct ipv6_hdr *)(eth_hdr + 1);
>
> -               frag_hdr = rte_ipv6_frag_get_ipv6_fragment_header(ip_hdr);
> +               frag_hdr = rte_ipv6_frag_get_ipv6_fragment_header(m,
> +                       ip_hdr, &frag_hdr_buf);
>
>                 if (frag_hdr != NULL) {
>                         struct rte_mbuf *mo;
> diff --git a/lib/librte_ip_frag/rte_ip_frag.h b/lib/librte_ip_frag/rte_ip_
> frag.h
> index b3f3f78df..bd6f02a16 100644
> --- a/lib/librte_ip_frag/rte_ip_frag.h
> +++ b/lib/librte_ip_frag/rte_ip_frag.h
> @@ -208,28 +208,25 @@ rte_ipv6_fragment_packet(struct rte_mbuf *pkt_in,
>  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);
> +               const 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.
>   *
> - * @param hdr
> + * @param pkt
> + *   Pointer to the mbuf of the packet.
> + * @param ip_hdr
>   *   Pointer to the IPv6 header.
> + * @param frag_hdr
> + *   A pointer to the buffer where the fragment header
> + *   will be copied if it is not contiguous in mbuf data.
>   * @return
>   *   Pointer to the IPv6 fragment extension header, or NULL if it's not
>   *   present.
>   */
> -static inline struct ipv6_extension_fragment *
> -rte_ipv6_frag_get_ipv6_fragment_header(struct ipv6_hdr *hdr)
> -{
> -       if (hdr->proto == IPPROTO_FRAGMENT) {
> -               return (struct ipv6_extension_fragment *) ++hdr;
> -       }
> -       else
> -               return NULL;
> -}
> +const struct ipv6_extension_fragment *rte_ipv6_frag_get_ipv6_
> fragment_header(
> +               struct rte_mbuf *pkt, const struct ipv6_hdr *ip_hdr,
> +               struct ipv6_extension_fragment *frag_hdr);
>
>  /**
>   * IPv4 fragmentation.
> diff --git a/lib/librte_ip_frag/rte_ip_frag_version.map
> b/lib/librte_ip_frag/rte_ip_frag_version.map
> index d1acf07cb..98fe4f2d4 100644
> --- a/lib/librte_ip_frag/rte_ip_frag_version.map
> +++ b/lib/librte_ip_frag/rte_ip_frag_version.map
> @@ -8,6 +8,7 @@ DPDK_2.0 {
>         rte_ipv4_fragment_packet;
>         rte_ipv6_frag_reassemble_packet;
>         rte_ipv6_fragment_packet;
> +       rte_ipv6_frag_get_ipv6_fragment_header;
>
>         local: *;
>  };
> diff --git a/lib/librte_ip_frag/rte_ipv6_fragmentation.c
> b/lib/librte_ip_frag/rte_ipv6_fragmentation.c
> index 62a7e4e83..bd847dd3d 100644
> --- a/lib/librte_ip_frag/rte_ipv6_fragmentation.c
> +++ b/lib/librte_ip_frag/rte_ipv6_fragmentation.c
> @@ -176,3 +176,41 @@ rte_ipv6_fragment_packet(struct rte_mbuf *pkt_in,
>
>         return out_pkt_pos;
>  }
> +
> +const struct ipv6_extension_fragment *
> +rte_ipv6_frag_get_ipv6_fragment_header(struct rte_mbuf *pkt,
> +       const struct ipv6_hdr *ip_hdr,
> +       struct ipv6_extension_fragment *frag_hdr)
> +{
> +       size_t offset = sizeof(struct ipv6_hdr);
> +       uint8_t nexthdr = ip_hdr->proto;
> +
> +       while (ipv6_ext_hdr(nexthdr)) {
> +               struct ipv6_opt_hdr opt;
> +               const struct ipv6_opt_hdr *popt = rte_pktmbuf_read(pkt,
> +                       offset, sizeof(opt), &opt);
> +               if (popt == NULL)
> +                       return NULL;
> +
> +               switch (nexthdr) {
> +               case IPPROTO_NONE:
> +                       return NULL;
> +
> +               case IPPROTO_FRAGMENT:
> +                       return rte_pktmbuf_read(pkt, offset,
> +                               sizeof(*frag_hdr), frag_hdr);
> +
> +               case IPPROTO_AH:
> +                       offset += (popt->hdrlen + 2) << 2;
> +                       break;
> +
> +               default:
> +                       offset += (popt->hdrlen + 1) << 3;
> +                       break;
> +               }
> +
> +               nexthdr = popt->nexthdr;
> +       }
> +
> +       return NULL;
> +}
> diff --git a/lib/librte_ip_frag/rte_ipv6_reassembly.c
> b/lib/librte_ip_frag/rte_ipv6_reassembly.c
> index db249fe60..b2d67a3f0 100644
> --- a/lib/librte_ip_frag/rte_ipv6_reassembly.c
> +++ b/lib/librte_ip_frag/rte_ipv6_reassembly.c
> @@ -135,8 +135,8 @@ ipv6_frag_reassemble(struct ip_frag_pkt *fp)
>  #define FRAG_OFFSET(x) (rte_cpu_to_be_16(x) >> 3)
>  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)
> +       struct rte_ip_frag_death_row *dr, struct rte_mbuf *mb, uint64_t
> tms,
> +       struct ipv6_hdr *ip_hdr, const struct ipv6_extension_fragment
> *frag_hdr)
>  {
>         struct ip_frag_pkt *fp;
>         struct ip_frag_key key;
> diff --git a/lib/librte_net/rte_ip.h b/lib/librte_net/rte_ip.h
> index f2a8904a2..edcbdb67a 100644
> --- a/lib/librte_net/rte_ip.h
> +++ b/lib/librte_net/rte_ip.h
> @@ -350,6 +350,14 @@ struct ipv6_hdr {
>  #define IPV6_HDR_FL_MASK ((1u << IPV6_HDR_TC_SHIFT) - 1)
>  #define IPV6_HDR_TC_MASK (0xf << IPV6_HDR_TC_SHIFT)
>
> +/**
> + * IPv6 extension header
> + */
> +struct ipv6_opt_hdr {
> +       uint8_t nexthdr;
> +       uint8_t hdrlen;
> +} __attribute__((packed));
> +
>  /**
>   * Process the pseudo-header checksum of an IPv6 header.
>   *
> @@ -421,6 +429,25 @@ rte_ipv6_udptcp_cksum(const struct ipv6_hdr
> *ipv6_hdr, const void *l4_hdr)
>         return (uint16_t)cksum;
>  }
>
> +/**
> + * Check whether an IPv6 nexthdr value is for an IPv6 extension header.
> + *
> + * @param nexthdr
> + *   The protocol/next header field from an IPv6 (extension) header.
> + * @return
> + *   Whether the nexthdr field is for an IPv6 extension header.
> + */
> +static inline int
> +ipv6_ext_hdr(uint8_t nexthdr)
> +{
> +       return (nexthdr == IPPROTO_HOPOPTS) ||
> +               (nexthdr == IPPROTO_ROUTING) ||
> +               (nexthdr == IPPROTO_FRAGMENT) ||
> +               (nexthdr == IPPROTO_AH) ||
> +               (nexthdr == IPPROTO_NONE) ||
> +               (nexthdr == IPPROTO_DSTOPTS);
> +}
> +
>  #ifdef __cplusplus
>  }
>  #endif
> diff --git a/lib/librte_port/rte_port_ras.c b/lib/librte_port/rte_port_
> ras.c
> index c8b2e19bf..28764f744 100644
> --- a/lib/librte_port/rte_port_ras.c
> +++ b/lib/librte_port/rte_port_ras.c
> @@ -184,9 +184,11 @@ process_ipv6(struct rte_port_ring_writer_ras *p,
> struct rte_mbuf *pkt)
>         /* Assume there is no ethernet header */
>         struct ipv6_hdr *pkt_hdr = rte_pktmbuf_mtod(pkt, struct ipv6_hdr
> *);
>
> -       struct ipv6_extension_fragment *frag_hdr;
> +       const struct ipv6_extension_fragment *frag_hdr;
> +       struct ipv6_extension_fragment frag_hdr_buf;
>         uint16_t frag_data = 0;
> -       frag_hdr = rte_ipv6_frag_get_ipv6_fragment_header(pkt_hdr);
> +       frag_hdr = rte_ipv6_frag_get_ipv6_fragment_header(pkt, pkt_hdr,
> +               &frag_hdr_buf);
>         if (frag_hdr != NULL)
>                 frag_data = rte_be_to_cpu_16(frag_hdr->frag_data);
>
> --
> 2.17.1
>
>