address_set.c (1883B)
1 /* Copyright (c) 2018-2021, The Tor Project, Inc. */ 2 /* See LICENSE for licensing information */ 3 4 /** 5 * \file address_set.c 6 * \brief Implementation for a set of addresses. 7 * 8 * This module was first written on a semi-emergency basis to improve the 9 * robustness of the anti-DoS module. As such, it's written in a pretty 10 * conservative way, and should be susceptible to improvement later on. 11 **/ 12 13 #include "orconfig.h" 14 #include "core/or/address_set.h" 15 #include "lib/net/address.h" 16 #include "lib/container/bloomfilt.h" 17 #include "lib/crypt_ops/crypto_rand.h" 18 19 /** Wrap our hash function to have the signature that the bloom filter 20 * needs. */ 21 static uint64_t 22 bloomfilt_addr_hash(const struct sipkey *key, 23 const void *item) 24 { 25 return tor_addr_keyed_hash(key, item); 26 } 27 28 /** 29 * Allocate and return an address_set, suitable for holding up to 30 * <b>max_address_guess</b> distinct values. 31 */ 32 address_set_t * 33 address_set_new(int max_addresses_guess) 34 { 35 uint8_t k[BLOOMFILT_KEY_LEN]; 36 crypto_rand((void*)k, sizeof(k)); 37 return bloomfilt_new(max_addresses_guess, bloomfilt_addr_hash, k); 38 } 39 40 /** 41 * Add <b>addr</b> to <b>set</b>. 42 * 43 * All future queries for <b>addr</b> in set will return true. Removing 44 * items is not possible. 45 */ 46 void 47 address_set_add(address_set_t *set, const struct tor_addr_t *addr) 48 { 49 bloomfilt_add(set, addr); 50 } 51 52 /** As address_set_add(), but take an ipv4 address in host order. */ 53 void 54 address_set_add_ipv4h(address_set_t *set, uint32_t addr) 55 { 56 tor_addr_t a; 57 tor_addr_from_ipv4h(&a, addr); 58 address_set_add(set, &a); 59 } 60 61 /** 62 * Return true if <b>addr</b> is a member of <b>set</b>. (And probably, 63 * return false if <b>addr</b> is not a member of set.) 64 */ 65 int 66 address_set_probably_contains(const address_set_t *set, 67 const struct tor_addr_t *addr) 68 { 69 return bloomfilt_probably_contains(set, addr); 70 }