From 71275e3d1ed4b7a536b7ec8d13995743beccde6b Mon Sep 17 00:00:00 2001 From: Neale Ranns Date: Thu, 25 May 2017 12:38:58 -0700 Subject: MPLS hash function improvements Change-Id: I28e98f445c01493562b6196a4f5b532a51f178af Signed-off-by: Neale Ranns --- src/vnet/dpo/mpls_label_dpo.c | 2 +- src/vnet/mpls/mpls_lookup.c | 68 +++++++++++++++++++++++++++++++++++++++---- src/vnet/mpls/mpls_types.h | 1 + 3 files changed, 64 insertions(+), 7 deletions(-) (limited to 'src') diff --git a/src/vnet/dpo/mpls_label_dpo.c b/src/vnet/dpo/mpls_label_dpo.c index 18479531..1c451a51 100644 --- a/src/vnet/dpo/mpls_label_dpo.c +++ b/src/vnet/dpo/mpls_label_dpo.c @@ -356,7 +356,7 @@ mpls_label_imposition_inline (vlib_main_t * vm, } if (PREDICT_TRUE(vnet_buffer(b2)->mpls.first)) { - ASSERT(2 != vnet_buffer (b2)->mpls.ttl); + ASSERT(1 != vnet_buffer (b2)->mpls.ttl); ttl2 = vnet_buffer(b2)->mpls.ttl - 1; } diff --git a/src/vnet/mpls/mpls_lookup.c b/src/vnet/mpls/mpls_lookup.c index 322e0db0..42e5399c 100644 --- a/src/vnet/mpls/mpls_lookup.c +++ b/src/vnet/mpls/mpls_lookup.c @@ -65,14 +65,70 @@ mpls_compute_flow_hash (const mpls_unicast_header_t * hdr, flow_hash_config_t flow_hash_config) { /* - * improve this to include: - * - all labels in the stack. - * - recognise entropy labels. - * * We need to byte swap so we use the numerical value. i.e. an odd label - * leads to an odd bucket. ass opposed to a label above and below value X. + * leads to an odd bucket. as opposed to a label above and below value X. */ - return (vnet_mpls_uc_get_label(clib_net_to_host_u32(hdr->label_exp_s_ttl))); + u8 next_label_is_entropy; + mpls_label_t ho_label; + u32 hash, value; + + ho_label = clib_net_to_host_u32(hdr->label_exp_s_ttl); + hash = vnet_mpls_uc_get_label(ho_label); + next_label_is_entropy = 0; + + while (MPLS_EOS != vnet_mpls_uc_get_s(ho_label)) + { + hdr++; + ho_label = clib_net_to_host_u32(hdr->label_exp_s_ttl); + value = vnet_mpls_uc_get_label(ho_label); + + if (1 == next_label_is_entropy) + { + /* + * The label is an entropy value, use it alone as the hash + */ + return (ho_label); + } + if (MPLS_IETF_ENTROPY_LABEL == value) + { + /* + * we've met a label in the stack indicating that tha next + * label is an entropy value + */ + next_label_is_entropy = 1; + } + else + { + /* + * XOR the label values in the stack together to + * build up the hash value + */ + hash ^= value; + } + } + + /* + * check the top nibble for v4 and v6 + */ + hdr++; + + switch (((u8*)hdr)[0] >> 4) + { + case 4: + /* incorporate the v4 flow-hash */ + hash ^= ip4_compute_flow_hash ((const ip4_header_t *)hdr, + IP_FLOW_HASH_DEFAULT); + break; + case 6: + /* incorporate the v6 flow-hash */ + hash ^= ip6_compute_flow_hash ((const ip6_header_t *)hdr, + IP_FLOW_HASH_DEFAULT); + break; + default: + break; + } + + return (hash); } static inline uword diff --git a/src/vnet/mpls/mpls_types.h b/src/vnet/mpls/mpls_types.h index b1075cdd..f1c3191e 100644 --- a/src/vnet/mpls/mpls_types.h +++ b/src/vnet/mpls/mpls_types.h @@ -30,6 +30,7 @@ #define MPLS_IETF_IMPLICIT_NULL_LABEL 0x00003 #define MPLS_IETF_ELI_LABEL 0x00007 #define MPLS_IETF_GAL_LABEL 0x0000D +#define MPLS_IETF_ENTROPY_LABEL 0x0000E #define MPLS_IETF_IPV4_EXPLICIT_NULL_STRING "ip4-explicit-null" #define MPLS_IETF_IPV4_EXPLICIT_NULL_BRIEF_STRING "e-nul" -- cgit 1.2.3-korg