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author | David Goulet <dgoulet@torproject.org> | 2021-01-29 14:51:38 -0500 |
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committer | David Goulet <dgoulet@torproject.org> | 2021-01-29 14:51:38 -0500 |
commit | 705fd37875c4acd61037da6a2680678ae128e4a4 (patch) | |
tree | ad5d4c14bacfda66b55e8ab4cac31c90faac5d21 /src/core/or/address_set.c | |
parent | 79cb47cfc2ed83911f78fa24ba4205bf69958105 (diff) | |
parent | 9eba65bd8b688497de139b57ac72e5b8a40bb728 (diff) | |
download | tor-705fd37875c4acd61037da6a2680678ae128e4a4.tar.gz tor-705fd37875c4acd61037da6a2680678ae128e4a4.zip |
Merge branch 'tor-gitlab/mr/284' into ticket2667_043_01
Diffstat (limited to 'src/core/or/address_set.c')
-rw-r--r-- | src/core/or/address_set.c | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/src/core/or/address_set.c b/src/core/or/address_set.c index d618ffc3d6..fcddc55e9f 100644 --- a/src/core/or/address_set.c +++ b/src/core/or/address_set.c @@ -69,3 +69,77 @@ address_set_probably_contains(const address_set_t *set, { return bloomfilt_probably_contains(set, addr); } + +/* Length of the item is an address (IPv4 or IPv6) and a 2 byte port. We use + * 16 bytes for the address here (IPv6) since we do not know which family + * the given address in the item thus in the case of IPv4, the extra bytes + * are simply zeroes to accomodate. */ +#define BLOOMFILT_ADDR_PORT_ITEM_LEN (16 + sizeof(uint16_t)) + +/** Build an item for the bloomfilter consisting of an address and port pair. + * + * If the given address is _not_ AF_INET or AF_INET6, then the item is an + * array of 0s. + * + * Return a pointer to a static buffer containing the item. Next call to this + * function invalidates its previous content. */ +static const uint8_t * +build_addr_port_item(const tor_addr_t *addr, const uint16_t port) +{ + static uint8_t data[BLOOMFILT_ADDR_PORT_ITEM_LEN]; + + memset(data, 0, sizeof(data)); + switch (tor_addr_family(addr)) { + case AF_INET: + memcpy(data, &addr->addr.in_addr.s_addr, 4); + break; + case AF_INET6: + memcpy(data, &addr->addr.in6_addr.s6_addr, 16); + break; + case AF_UNSPEC: + /* Leave the 0. */ + break; + default: + /* LCOV_EXCL_START */ + tor_fragile_assert(); + /* LCOV_EXCL_STOP */ + } + + memcpy(data + 16, &port, sizeof(port)); + return data; +} + +/** Return a hash value for the given item that the bloomfilter will use. */ +static uint64_t +bloomfilt_addr_port_hash(const struct sipkey *key, + const void *item) +{ + return siphash24(item, BLOOMFILT_ADDR_PORT_ITEM_LEN, key); +} + +/** Allocate and return an addr_port_set_t, suitable for holding up to + * max_address_guess distinct values. */ +addr_port_set_t * +addr_port_set_new(int max_addresses_guess) +{ + uint8_t k[BLOOMFILT_KEY_LEN]; + crypto_rand((void*)k, sizeof(k)); + return bloomfilt_new(max_addresses_guess, bloomfilt_addr_port_hash, k); +} + +/** Add an address and port pair to the given set. */ +void +addr_port_set_add(addr_port_set_t *set, const tor_addr_t *addr, uint16_t port) +{ + bloomfilt_add(set, build_addr_port_item(addr, port)); +} + +/** Return true if the given address and port pair are in the set. Of course, + * this is a bloomfilter and thus in rare occasion, a false positive happens + * thus the "probably". */ +bool +addr_port_set_probably_contains(const addr_port_set_t *set, + const tor_addr_t *addr, uint16_t port) +{ + return !!bloomfilt_probably_contains(set, build_addr_port_item(addr, port)); +} |