From a7563158f77d0be4a154cab48ebaf4c515f9e4c0 Mon Sep 17 00:00:00 2001 From: Aurelien DARRAGON Date: Wed, 11 Oct 2023 09:57:35 +0200 Subject: [PATCH] MINOR: lbprm: support for the "none" hash-type function Allow the use of the "none" hash-type function so that the key resulting from the sample expression is directly used as the hash. This can be useful to do the hashing manually using available hashing converters, or even custom ones, and then inform haproxy that it can directly rely on the sample expression result which is explictly handled as an integer in this case. --- doc/configuration.txt | 4 ++++ include/haproxy/backend-t.h | 11 ++++++----- src/backend.c | 8 ++++++++ src/cfgparse-listen.c | 3 +++ 4 files changed, 21 insertions(+), 5 deletions(-) diff --git a/doc/configuration.txt b/doc/configuration.txt index d0643574b..73652aa9b 100644 --- a/doc/configuration.txt +++ b/doc/configuration.txt @@ -6060,6 +6060,10 @@ hash-type a better distribution or less predictable results especially when used on strings. + none don't hash the key, the key will be used as a hash, this can be + useful to manually hash the key using a converter for that purpose + and let haproxy use the result directly. + indicates an optional method applied after hashing the key : avalanche This directive indicates that the result from the hash diff --git a/include/haproxy/backend-t.h b/include/haproxy/backend-t.h index cce451a33..8d5973871 100644 --- a/include/haproxy/backend-t.h +++ b/include/haproxy/backend-t.h @@ -118,11 +118,12 @@ #define BE_LB_HASH_MOD 0x200000 /* get/clear hash modifier */ /* BE_LB_HFCN_* is the hash function, to be used with BE_LB_HASH_FUNC */ -#define BE_LB_HFCN_SDBM 0x000000 /* sdbm hash */ -#define BE_LB_HFCN_DJB2 0x400000 /* djb2 hash */ -#define BE_LB_HFCN_WT6 0x800000 /* wt6 hash */ -#define BE_LB_HFCN_CRC32 0xC00000 /* crc32 hash */ -#define BE_LB_HASH_FUNC 0xC00000 /* get/clear hash function */ +#define BE_LB_HFCN_SDBM 0x000000 /* sdbm hash */ +#define BE_LB_HFCN_DJB2 0x400000 /* djb2 hash */ +#define BE_LB_HFCN_WT6 0x800000 /* wt6 hash */ +#define BE_LB_HFCN_CRC32 0xC00000 /* crc32 hash */ +#define BE_LB_HFCN_NONE 0x1000000 /* none - no hash */ +#define BE_LB_HASH_FUNC 0x1C00000 /* get/clear hash function */ /* various constants */ diff --git a/src/backend.c b/src/backend.c index e0b5a5877..e7e8d29ed 100644 --- a/src/backend.c +++ b/src/backend.c @@ -84,6 +84,14 @@ static unsigned int gen_hash(const struct proxy* px, const char* key, unsigned l case BE_LB_HFCN_CRC32: hash = hash_crc32(key, len); break; + case BE_LB_HFCN_NONE: + /* use key as a hash */ + { + const char *_key = key; + + hash = read_int64(&_key, _key + len); + } + break; case BE_LB_HFCN_SDBM: /* this is the default hash function */ default: diff --git a/src/cfgparse-listen.c b/src/cfgparse-listen.c index cddb9fc79..f039a4eb3 100644 --- a/src/cfgparse-listen.c +++ b/src/cfgparse-listen.c @@ -2624,6 +2624,9 @@ int cfg_parse_listen(const char *file, int linenum, char **args, int kwm) else if (strcmp(args[2], "crc32") == 0) { curproxy->lbprm.algo |= BE_LB_HFCN_CRC32; } + else if (strcmp(args[2], "none") == 0) { + curproxy->lbprm.algo |= BE_LB_HFCN_NONE; + } else { ha_alert("parsing [%s:%d] : '%s' only supports 'sdbm', 'djb2', 'crc32', or 'wt6' hash functions.\n", file, linenum, args[0]); err_code |= ERR_ALERT | ERR_FATAL;