Commit 0e97c8e2 authored by Nick Mathewson's avatar Nick Mathewson 🏃
Browse files

Siphash-2-4 is now our hash in nearly all cases.

I've made an exception for cases where I'm sure that users can't
influence the inputs.  This is likely to cause a slowdown somewhere,
but it's safer to siphash everything and *then* look for cases to
optimize.

This patch doesn't actually get us any _benefit_ from siphash yet,
since we don't really randomize the key at any point.
parent f0582053
......@@ -874,6 +874,32 @@ tor_addr_copy(tor_addr_t *dest, const tor_addr_t *src)
memcpy(dest, src, sizeof(tor_addr_t));
}
/** Copy a tor_addr_t from <b>src</b> to <b>dest</b>, taking extra case to
* copy only the well-defined portions. Used for computing hashes of
* addresses.
*/
void
tor_addr_copy_tight(tor_addr_t *dest, const tor_addr_t *src)
{
tor_assert(src != dest);
tor_assert(src);
tor_assert(dest);
memset(dest, 0, sizeof(tor_addr_t));
dest->family = src->family;
switch (tor_addr_family(src))
{
case AF_INET:
dest->addr.in_addr.s_addr = src->addr.in_addr.s_addr;
break;
case AF_INET6:
memcpy(dest->addr.in6_addr.s6_addr, src->addr.in6_addr.s6_addr, 16);
case AF_UNSPEC:
break;
default:
tor_fragile_assert();
}
}
/** Given two addresses <b>addr1</b> and <b>addr2</b>, return 0 if the two
* addresses are equivalent under the mask mbits, less than 0 if addr1
* precedes addr2, and greater than 0 otherwise.
......@@ -995,19 +1021,17 @@ tor_addr_compare_masked(const tor_addr_t *addr1, const tor_addr_t *addr2,
}
}
/** Return a hash code based on the address addr */
unsigned int
/** Return a hash code based on the address addr. DOCDOC extra */
uint64_t
tor_addr_hash(const tor_addr_t *addr)
{
switch (tor_addr_family(addr)) {
case AF_INET:
return tor_addr_to_ipv4h(addr);
return siphash24g(&addr->addr.in_addr.s_addr, 4);
case AF_UNSPEC:
return 0x4e4d5342;
case AF_INET6: {
const uint32_t *u = tor_addr_to_in6_addr32(addr);
return u[0] + u[1] + u[2] + u[3];
}
case AF_INET6:
return siphash24g(&addr->addr.in6_addr.s6_addr, 16);
default:
tor_fragile_assert();
return 0;
......
......@@ -167,7 +167,7 @@ int tor_addr_compare_masked(const tor_addr_t *addr1, const tor_addr_t *addr2,
* "exactly". */
#define tor_addr_eq(a,b) (0==tor_addr_compare((a),(b),CMP_EXACT))
unsigned int tor_addr_hash(const tor_addr_t *addr);
uint64_t tor_addr_hash(const tor_addr_t *addr);
int tor_addr_is_v4(const tor_addr_t *addr);
int tor_addr_is_internal_(const tor_addr_t *ip, int for_listening,
const char *filename, int lineno);
......@@ -192,6 +192,7 @@ const char * tor_addr_to_str(char *dest, const tor_addr_t *addr, size_t len,
int decorate);
int tor_addr_parse(tor_addr_t *addr, const char *src);
void tor_addr_copy(tor_addr_t *dest, const tor_addr_t *src);
void tor_addr_copy_tight(tor_addr_t *dest, const tor_addr_t *src);
void tor_addr_from_ipv4n(tor_addr_t *dest, uint32_t v4addr);
/** Set <b>dest</b> to the IPv4 address encoded in <b>v4addr</b> in host
* order. */
......
......@@ -1004,7 +1004,7 @@ strmap_entries_eq(const strmap_entry_t *a, const strmap_entry_t *b)
static INLINE unsigned int
strmap_entry_hash(const strmap_entry_t *a)
{
return ht_string_hash(a->key);
return (unsigned) siphash24g(a->key, strlen(a->key));
}
/** Helper: compare digestmap_entry_t objects by key value. */
......@@ -1018,13 +1018,7 @@ digestmap_entries_eq(const digestmap_entry_t *a, const digestmap_entry_t *b)
static INLINE unsigned int
digestmap_entry_hash(const digestmap_entry_t *a)
{
#if SIZEOF_INT != 8
const uint32_t *p = (const uint32_t*)a->key;
return p[0] ^ p[1] ^ p[2] ^ p[3] ^ p[4];
#else
const uint64_t *p = (const uint64_t*)a->key;
return p[0] ^ p[1];
#endif
return (unsigned) siphash24g(a->key, DIGEST_LEN);
}
HT_PROTOTYPE(strmap_impl, strmap_entry_t, node, strmap_entry_hash,
......
......@@ -7,6 +7,7 @@
#define TOR_CONTAINER_H
#include "util.h"
#include "siphash.h"
/** A resizeable list of pointers, with associated helpful functionality.
*
......@@ -610,11 +611,11 @@ typedef struct {
static INLINE void
digestset_add(digestset_t *set, const char *digest)
{
const uint32_t *p = (const uint32_t *)digest;
const uint32_t d1 = p[0] + (p[1]>>16);
const uint32_t d2 = p[1] + (p[2]>>16);
const uint32_t d3 = p[2] + (p[3]>>16);
const uint32_t d4 = p[3] + (p[0]>>16);
const uint64_t x = siphash24g(digest, 20);
const uint32_t d1 = (uint32_t) x;
const uint32_t d2 = (uint32_t)( (x>>16) + x);
const uint32_t d3 = (uint32_t)( (x>>32) + x);
const uint32_t d4 = (uint32_t)( (x>>48) + x);
bitarray_set(set->ba, BIT(d1));
bitarray_set(set->ba, BIT(d2));
bitarray_set(set->ba, BIT(d3));
......@@ -626,11 +627,11 @@ digestset_add(digestset_t *set, const char *digest)
static INLINE int
digestset_contains(const digestset_t *set, const char *digest)
{
const uint32_t *p = (const uint32_t *)digest;
const uint32_t d1 = p[0] + (p[1]>>16);
const uint32_t d2 = p[1] + (p[2]>>16);
const uint32_t d3 = p[2] + (p[3]>>16);
const uint32_t d4 = p[3] + (p[0]>>16);
const uint64_t x = siphash24g(digest, 20);
const uint32_t d1 = (uint32_t) x;
const uint32_t d2 = (uint32_t)( (x>>16) + x);
const uint32_t d3 = (uint32_t)( (x>>32) + x);
const uint32_t d4 = (uint32_t)( (x>>48) + x);
return bitarray_is_set(set->ba, BIT(d1)) &&
bitarray_is_set(set->ba, BIT(d2)) &&
bitarray_is_set(set->ba, BIT(d3)) &&
......
#ifndef SIPHASH_H
#define SIPHASH_H
struct sipkey {
uint64_t k0;
uint64_t k1;
......
......@@ -95,12 +95,7 @@ typedef struct channel_idmap_entry_s {
static INLINE unsigned
channel_idmap_hash(const channel_idmap_entry_t *ent)
{
const unsigned *a = (const unsigned *)ent->digest;
#if SIZEOF_INT == 4
return a[0] ^ a[1] ^ a[2] ^ a[3] ^ a[4];
#elif SIZEOF_INT == 8
return a[0] ^ a[1];
#endif
return (unsigned) siphash24g(ent->digest, DIGEST_LEN);
}
static INLINE int
......
......@@ -239,7 +239,7 @@ cached_resolves_eq(cached_resolve_t *a, cached_resolve_t *b)
static INLINE unsigned int
cached_resolve_hash(cached_resolve_t *a)
{
return ht_string_hash(a->address);
return (unsigned) siphash24g((const uint8_t*)a->address, strlen(a->address));
}
HT_PROTOTYPE(cache_map, cached_resolve_t, node, cached_resolve_hash,
......
......@@ -32,17 +32,8 @@ fp_pair_map_entries_eq(const fp_pair_map_entry_t *a,
static INLINE unsigned int
fp_pair_map_entry_hash(const fp_pair_map_entry_t *a)
{
const uint32_t *p;
unsigned int hash;
p = (const uint32_t *)(a->key.first);
/* Hashes are 20 bytes long, so 5 times uint32_t */
hash = p[0] ^ p[1] ^ p[2] ^ p[3] ^ p[4];
/* Now XOR in the second fingerprint */
p = (const uint32_t *)(a->key.second);
hash ^= p[0] ^ p[1] ^ p[2] ^ p[3] ^ p[4];
return hash;
tor_assert(sizeof(a->key) == DIGEST_LEN*2);
return (unsigned) siphash24g(&a->key, DIGEST_LEN*2);
}
/*
......
......@@ -486,10 +486,12 @@ static HT_HEAD(clientmap, clientmap_entry_t) client_history =
static INLINE unsigned
clientmap_entry_hash(const clientmap_entry_t *a)
{
unsigned h = tor_addr_hash(&a->addr);
unsigned h = (unsigned) tor_addr_hash(&a->addr);
if (a->transport_name)
h += ht_string_hash(a->transport_name);
return ht_improve_hash(h);
h += (unsigned) siphash24g(a->transport_name, strlen(a->transport_name));
return h;
}
/** Hashtable helper: compare two clientmap_entry_t values for equality. */
static INLINE int
......
......@@ -45,12 +45,7 @@ struct microdesc_cache_t {
static INLINE unsigned int
microdesc_hash_(microdesc_t *md)
{
unsigned *d = (unsigned*)md->digest;
#if SIZEOF_INT == 4
return d[0] ^ d[1] ^ d[2] ^ d[3] ^ d[4] ^ d[5] ^ d[6] ^ d[7];
#else
return d[0] ^ d[1] ^ d[2] ^ d[3];
#endif
return (unsigned) siphash24g(md->digest, sizeof(md->digest));
}
/** Helper: compares <b>a</b> and </b> for equality for hash-table purposes. */
......
......@@ -43,14 +43,7 @@ typedef struct nodelist_t {
static INLINE unsigned int
node_id_hash(const node_t *node)
{
#if SIZEOF_INT == 4
const uint32_t *p = (const uint32_t*)node->identity;
return p[0] ^ p[1] ^ p[2] ^ p[3] ^ p[4];
#elif SIZEOF_INT == 8
const uint64_t *p = (const uint32_t*)node->identity;
const uint32_t *p32 = (const uint32_t*)node->identity;
return p[0] ^ p[1] ^ p32[4];
#endif
return (unsigned) siphash24g(node->identity, DIGEST_LEN);
}
static INLINE unsigned int
......
......@@ -597,21 +597,25 @@ policy_eq(policy_map_ent_t *a, policy_map_ent_t *b)
/** Return a hashcode for <b>ent</b> */
static unsigned int
policy_hash(policy_map_ent_t *ent)
policy_hash(const policy_map_ent_t *ent)
{
addr_policy_t *a = ent->policy;
unsigned int r;
if (a->is_private)
r = 0x1234abcd;
else
r = tor_addr_hash(&a->addr);
r += a->prt_min << 8;
r += a->prt_max << 16;
r += a->maskbits;
if (a->policy_type == ADDR_POLICY_REJECT)
r ^= 0xffffffff;
const addr_policy_t *a = ent->policy;
addr_policy_t aa;
memset(&aa, 0, sizeof(aa));
aa.prt_min = a->prt_min;
aa.prt_max = a->prt_max;
aa.maskbits = a->maskbits;
aa.policy_type = a->policy_type;
aa.is_private = a->is_private;
if (a->is_private) {
aa.is_private = 1;
} else {
tor_addr_copy_tight(&aa.addr, &a->addr);
}
return r;
return (unsigned) siphash24g(&aa, sizeof(aa));
}
HT_PROTOTYPE(policy_map, policy_map_ent_t, node, policy_hash,
......
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