ip_frag: fix ipv6 when MTU sizes not aligned to 8 bytes
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Commit Message
From: Chas Williams <chas3@att.com>
The same issue was fixed on for the ipv4 version of this routine in
commit 8d4d3a4f7337 ("ip_frag: handle MTU sizes not aligned to 8 bytes").
Briefly, the size of an ipv6 header is always 40 bytes. With an MTU of
1500, this will never produce a multiple of 8 bytes for the frag_size
and this routine can never succeed. Since RTE_ASSERTS are disabled by
default, this failure is tpyically ignored.
To fix this, round down to the nearest 8 bytes and use this when
producing the fragments.
Fixes: 0aa31d7a5929 ("ip_frag: add IPv6 fragmentation support")
Signed-off-by: Chas Williams <chas3@att.com>
---
lib/librte_ip_frag/rte_ip_frag.h | 1 +
lib/librte_ip_frag/rte_ipv6_fragmentation.c | 18 +++++++++++-------
2 files changed, 12 insertions(+), 7 deletions(-)
Comments
On Mon, 2018-11-26 at 23:56 -0500, Chas Williams wrote:
> From: Chas Williams <chas3@att.com>
>
> The same issue was fixed on for the ipv4 version of this routine in
> commit 8d4d3a4f7337 ("ip_frag: handle MTU sizes not aligned to 8
> bytes").
> Briefly, the size of an ipv6 header is always 40 bytes. With an MTU
> of
> 1500, this will never produce a multiple of 8 bytes for the frag_size
> and this routine can never succeed. Since RTE_ASSERTS are disabled by
> default, this failure is tpyically ignored.
>
> To fix this, round down to the nearest 8 bytes and use this when
> producing the fragments.
>
> Fixes: 0aa31d7a5929 ("ip_frag: add IPv6 fragmentation support")
>
> Signed-off-by: Chas Williams <chas3@att.com>
> ---
> lib/librte_ip_frag/rte_ip_frag.h | 1 +
> lib/librte_ip_frag/rte_ipv6_fragmentation.c | 18 +++++++++++-------
> 2 files changed, 12 insertions(+), 7 deletions(-)
Acked-by: Luca Boccassi <bluca@debian.org>
28/11/2018 11:15, Luca Boccassi:
> On Mon, 2018-11-26 at 23:56 -0500, Chas Williams wrote:
> > From: Chas Williams <chas3@att.com>
> >
> > The same issue was fixed on for the ipv4 version of this routine in
> > commit 8d4d3a4f7337 ("ip_frag: handle MTU sizes not aligned to 8
> > bytes").
> > Briefly, the size of an ipv6 header is always 40 bytes. With an MTU
> > of
> > 1500, this will never produce a multiple of 8 bytes for the frag_size
> > and this routine can never succeed. Since RTE_ASSERTS are disabled by
> > default, this failure is tpyically ignored.
> >
> > To fix this, round down to the nearest 8 bytes and use this when
> > producing the fragments.
> >
> > Fixes: 0aa31d7a5929 ("ip_frag: add IPv6 fragmentation support")
> >
> > Signed-off-by: Chas Williams <chas3@att.com>
> > ---
> > lib/librte_ip_frag/rte_ip_frag.h | 1 +
> > lib/librte_ip_frag/rte_ipv6_fragmentation.c | 18 +++++++++++-------
> > 2 files changed, 12 insertions(+), 7 deletions(-)
>
> Acked-by: Luca Boccassi <bluca@debian.org>
Konstantin, no comment?
> -----Original Message-----
> From: Chas Williams [mailto:3chas3@gmail.com]
> Sent: Tuesday, November 27, 2018 4:56 AM
> To: dev@dpdk.org
> Cc: Ananyev, Konstantin <konstantin.ananyev@intel.com>; Chas Williams <chas3@att.com>
> Subject: [PATCH] ip_frag: fix ipv6 when MTU sizes not aligned to 8 bytes
>
> From: Chas Williams <chas3@att.com>
>
> The same issue was fixed on for the ipv4 version of this routine in
> commit 8d4d3a4f7337 ("ip_frag: handle MTU sizes not aligned to 8 bytes").
> Briefly, the size of an ipv6 header is always 40 bytes. With an MTU of
> 1500, this will never produce a multiple of 8 bytes for the frag_size
> and this routine can never succeed. Since RTE_ASSERTS are disabled by
> default, this failure is tpyically ignored.
>
> To fix this, round down to the nearest 8 bytes and use this when
> producing the fragments.
>
> Fixes: 0aa31d7a5929 ("ip_frag: add IPv6 fragmentation support")
>
> Signed-off-by: Chas Williams <chas3@att.com>
> ---
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> 2.14.4
> > The same issue was fixed on for the ipv4 version of this routine in
> > commit 8d4d3a4f7337 ("ip_frag: handle MTU sizes not aligned to 8 bytes").
> > Briefly, the size of an ipv6 header is always 40 bytes. With an MTU of
> > 1500, this will never produce a multiple of 8 bytes for the frag_size
> > and this routine can never succeed. Since RTE_ASSERTS are disabled by
> > default, this failure is tpyically ignored.
> >
> > To fix this, round down to the nearest 8 bytes and use this when
> > producing the fragments.
> >
> > Fixes: 0aa31d7a5929 ("ip_frag: add IPv6 fragmentation support")
> >
> > Signed-off-by: Chas Williams <chas3@att.com>
>
> Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Applied, thanks
@@ -115,6 +115,7 @@ struct rte_ip_frag_tbl {
#define RTE_IPV6_EHDR_MF_MASK 1
#define RTE_IPV6_EHDR_FO_SHIFT 3
#define RTE_IPV6_EHDR_FO_MASK (~((1 << RTE_IPV6_EHDR_FO_SHIFT) - 1))
+#define RTE_IPV6_EHDR_FO_ALIGN (1 << RTE_IPV6_EHDR_FO_SHIFT)
#define RTE_IPV6_FRAG_USED_MASK \
(RTE_IPV6_EHDR_MF_MASK | RTE_IPV6_EHDR_FO_MASK)
@@ -77,11 +77,14 @@ rte_ipv6_fragment_packet(struct rte_mbuf *pkt_in,
uint32_t out_pkt_pos, in_seg_data_pos;
uint32_t more_in_segs;
uint16_t fragment_offset, frag_size;
+ uint64_t frag_bytes_remaining;
- frag_size = (uint16_t)(mtu_size - sizeof(struct ipv6_hdr));
-
- /* Fragment size should be a multiple of 8. */
- RTE_ASSERT((frag_size & ~RTE_IPV6_EHDR_FO_MASK) == 0);
+ /*
+ * Ensure the IP payload length of all fragments (except the
+ * the last fragment) are a multiple of 8 bytes per RFC2460.
+ */
+ frag_size = RTE_ALIGN_FLOOR(mtu_size - sizeof(struct ipv6_hdr),
+ RTE_IPV6_EHDR_FO_ALIGN);
/* Check that pkts_out is big enough to hold all fragments */
if (unlikely (frag_size * nb_pkts_out <
@@ -111,6 +114,7 @@ rte_ipv6_fragment_packet(struct rte_mbuf *pkt_in,
/* Reserve space for the IP header that will be built later */
out_pkt->data_len = sizeof(struct ipv6_hdr) + sizeof(struct ipv6_extension_fragment);
out_pkt->pkt_len = sizeof(struct ipv6_hdr) + sizeof(struct ipv6_extension_fragment);
+ frag_bytes_remaining = frag_size;
out_seg_prev = out_pkt;
more_out_segs = 1;
@@ -130,7 +134,7 @@ rte_ipv6_fragment_packet(struct rte_mbuf *pkt_in,
/* Prepare indirect buffer */
rte_pktmbuf_attach(out_seg, in_seg);
- len = mtu_size - out_pkt->pkt_len;
+ len = frag_bytes_remaining;
if (len > (in_seg->data_len - in_seg_data_pos)) {
len = in_seg->data_len - in_seg_data_pos;
}
@@ -140,11 +144,11 @@ rte_ipv6_fragment_packet(struct rte_mbuf *pkt_in,
out_pkt->pkt_len);
out_pkt->nb_segs += 1;
in_seg_data_pos += len;
+ frag_bytes_remaining -= len;
/* Current output packet (i.e. fragment) done ? */
- if (unlikely(out_pkt->pkt_len >= mtu_size)) {
+ if (unlikely(frag_bytes_remaining == 0))
more_out_segs = 0;
- }
/* Current input segment done ? */
if (unlikely(in_seg_data_pos == in_seg->data_len)) {