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Diffstat (limited to 'src/lib/geoip/geoip.c')
| -rw-r--r-- | src/lib/geoip/geoip.c | 510 |
1 files changed, 510 insertions, 0 deletions
diff --git a/src/lib/geoip/geoip.c b/src/lib/geoip/geoip.c new file mode 100644 index 0000000000..70b1c2dc8c --- /dev/null +++ b/src/lib/geoip/geoip.c @@ -0,0 +1,510 @@ +/* Copyright (c) 2007-2019, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file geoip.c + * \brief Functions related to maintaining an IP-to-country database; + * to summarizing client connections by country to entry guards, bridges, + * and directory servers; and for statistics on answering network status + * requests. + * + * There are two main kinds of functions in this module: geoip functions, + * which map groups of IPv4 and IPv6 addresses to country codes, and + * statistical functions, which collect statistics about different kinds of + * per-country usage. + * + * The geoip lookup tables are implemented as sorted lists of disjoint address + * ranges, each mapping to a singleton geoip_country_t. These country objects + * are also indexed by their names in a hashtable. + * + * The tables are populated from disk at startup by the geoip_load_file() + * function. For more information on the file format they read, see that + * function. See the scripts and the README file in src/config for more + * information about how those files are generated. + * + * Tor uses GeoIP information in order to implement user requests (such as + * ExcludeNodes {cc}), and to keep track of how much usage relays are getting + * for each country. + */ + +#define GEOIP_PRIVATE +#include "lib/geoip/geoip.h" +#include "lib/container/map.h" +#include "lib/container/order.h" +#include "lib/container/smartlist.h" +#include "lib/crypt_ops/crypto_digest.h" +#include "lib/ctime/di_ops.h" +#include "lib/encoding/binascii.h" +#include "lib/fs/files.h" +#include "lib/log/escape.h" +#include "lib/malloc/malloc.h" +#include "lib/net/address.h" //???? +#include "lib/net/inaddr.h" +#include "lib/string/compat_ctype.h" +#include "lib/string/compat_string.h" +#include "lib/string/scanf.h" +#include "lib/string/util_string.h" + +#include <stdio.h> +#include <string.h> + +static void init_geoip_countries(void); + +/** An entry from the GeoIP IPv4 file: maps an IPv4 range to a country. */ +typedef struct geoip_ipv4_entry_t { + uint32_t ip_low; /**< The lowest IP in the range, in host order */ + uint32_t ip_high; /**< The highest IP in the range, in host order */ + intptr_t country; /**< An index into geoip_countries */ +} geoip_ipv4_entry_t; + +/** An entry from the GeoIP IPv6 file: maps an IPv6 range to a country. */ +typedef struct geoip_ipv6_entry_t { + struct in6_addr ip_low; /**< The lowest IP in the range, in host order */ + struct in6_addr ip_high; /**< The highest IP in the range, in host order */ + intptr_t country; /**< An index into geoip_countries */ +} geoip_ipv6_entry_t; + +/** A list of geoip_country_t */ +static smartlist_t *geoip_countries = NULL; +/** A map from lowercased country codes to their position in geoip_countries. + * The index is encoded in the pointer, and 1 is added so that NULL can mean + * not found. */ +static strmap_t *country_idxplus1_by_lc_code = NULL; +/** Lists of all known geoip_ipv4_entry_t and geoip_ipv6_entry_t, sorted + * by their respective ip_low. */ +static smartlist_t *geoip_ipv4_entries = NULL, *geoip_ipv6_entries = NULL; + +/** SHA1 digest of the GeoIP files to include in extra-info descriptors. */ +static char geoip_digest[DIGEST_LEN]; +static char geoip6_digest[DIGEST_LEN]; + +/** Return a list of geoip_country_t for all known countries. */ +const smartlist_t * +geoip_get_countries(void) +{ + if (geoip_countries == NULL) { + init_geoip_countries(); + } + return geoip_countries; +} + +/** Return the index of the <b>country</b>'s entry in the GeoIP + * country list if it is a valid 2-letter country code, otherwise + * return -1. */ +MOCK_IMPL(country_t, +geoip_get_country,(const char *country)) +{ + void *idxplus1_; + intptr_t idx; + + idxplus1_ = strmap_get_lc(country_idxplus1_by_lc_code, country); + if (!idxplus1_) + return -1; + + idx = ((uintptr_t)idxplus1_)-1; + return (country_t)idx; +} + +/** Add an entry to a GeoIP table, mapping all IP addresses between <b>low</b> + * and <b>high</b>, inclusive, to the 2-letter country code <b>country</b>. */ +static void +geoip_add_entry(const tor_addr_t *low, const tor_addr_t *high, + const char *country) +{ + intptr_t idx; + void *idxplus1_; + + IF_BUG_ONCE(tor_addr_family(low) != tor_addr_family(high)) + return; + IF_BUG_ONCE(tor_addr_compare(high, low, CMP_EXACT) < 0) + return; + + idxplus1_ = strmap_get_lc(country_idxplus1_by_lc_code, country); + + if (!idxplus1_) { + geoip_country_t *c = tor_malloc_zero(sizeof(geoip_country_t)); + strlcpy(c->countrycode, country, sizeof(c->countrycode)); + tor_strlower(c->countrycode); + smartlist_add(geoip_countries, c); + idx = smartlist_len(geoip_countries) - 1; + strmap_set_lc(country_idxplus1_by_lc_code, country, (void*)(idx+1)); + } else { + idx = ((uintptr_t)idxplus1_)-1; + } + { + geoip_country_t *c = smartlist_get(geoip_countries, (int)idx); + tor_assert(!strcasecmp(c->countrycode, country)); + } + + if (tor_addr_family(low) == AF_INET) { + geoip_ipv4_entry_t *ent = tor_malloc_zero(sizeof(geoip_ipv4_entry_t)); + ent->ip_low = tor_addr_to_ipv4h(low); + ent->ip_high = tor_addr_to_ipv4h(high); + ent->country = idx; + smartlist_add(geoip_ipv4_entries, ent); + } else if (tor_addr_family(low) == AF_INET6) { + geoip_ipv6_entry_t *ent = tor_malloc_zero(sizeof(geoip_ipv6_entry_t)); + ent->ip_low = *tor_addr_to_in6_assert(low); + ent->ip_high = *tor_addr_to_in6_assert(high); + ent->country = idx; + smartlist_add(geoip_ipv6_entries, ent); + } +} + +/** Add an entry to the GeoIP table indicated by <b>family</b>, + * parsing it from <b>line</b>. The format is as for geoip_load_file(). */ +STATIC int +geoip_parse_entry(const char *line, sa_family_t family) +{ + tor_addr_t low_addr, high_addr; + char c[3]; + char *country = NULL; + + if (!geoip_countries) + init_geoip_countries(); + if (family == AF_INET) { + if (!geoip_ipv4_entries) + geoip_ipv4_entries = smartlist_new(); + } else if (family == AF_INET6) { + if (!geoip_ipv6_entries) + geoip_ipv6_entries = smartlist_new(); + } else { + log_warn(LD_GENERAL, "Unsupported family: %d", family); + return -1; + } + + while (TOR_ISSPACE(*line)) + ++line; + if (*line == '#') + return 0; + + char buf[512]; + if (family == AF_INET) { + unsigned int low, high; + if (tor_sscanf(line,"%u,%u,%2s", &low, &high, c) == 3 || + tor_sscanf(line,"\"%u\",\"%u\",\"%2s\",", &low, &high, c) == 3) { + tor_addr_from_ipv4h(&low_addr, low); + tor_addr_from_ipv4h(&high_addr, high); + } else + goto fail; + country = c; + } else { /* AF_INET6 */ + char *low_str, *high_str; + struct in6_addr low, high; + char *strtok_state; + strlcpy(buf, line, sizeof(buf)); + low_str = tor_strtok_r(buf, ",", &strtok_state); + if (!low_str) + goto fail; + high_str = tor_strtok_r(NULL, ",", &strtok_state); + if (!high_str) + goto fail; + country = tor_strtok_r(NULL, "\n", &strtok_state); + if (!country) + goto fail; + if (strlen(country) != 2) + goto fail; + if (tor_inet_pton(AF_INET6, low_str, &low) <= 0) + goto fail; + tor_addr_from_in6(&low_addr, &low); + if (tor_inet_pton(AF_INET6, high_str, &high) <= 0) + goto fail; + tor_addr_from_in6(&high_addr, &high); + } + geoip_add_entry(&low_addr, &high_addr, country); + return 0; + + fail: + log_warn(LD_GENERAL, "Unable to parse line from GEOIP %s file: %s", + family == AF_INET ? "IPv4" : "IPv6", escaped(line)); + return -1; +} + +/** Sorting helper: return -1, 1, or 0 based on comparison of two + * geoip_ipv4_entry_t */ +static int +geoip_ipv4_compare_entries_(const void **_a, const void **_b) +{ + const geoip_ipv4_entry_t *a = *_a, *b = *_b; + if (a->ip_low < b->ip_low) + return -1; + else if (a->ip_low > b->ip_low) + return 1; + else + return 0; +} + +/** bsearch helper: return -1, 1, or 0 based on comparison of an IP (a pointer + * to a uint32_t in host order) to a geoip_ipv4_entry_t */ +static int +geoip_ipv4_compare_key_to_entry_(const void *_key, const void **_member) +{ + /* No alignment issue here, since _key really is a pointer to uint32_t */ + const uint32_t addr = *(uint32_t *)_key; + const geoip_ipv4_entry_t *entry = *_member; + if (addr < entry->ip_low) + return -1; + else if (addr > entry->ip_high) + return 1; + else + return 0; +} + +/** Sorting helper: return -1, 1, or 0 based on comparison of two + * geoip_ipv6_entry_t */ +static int +geoip_ipv6_compare_entries_(const void **_a, const void **_b) +{ + const geoip_ipv6_entry_t *a = *_a, *b = *_b; + return fast_memcmp(a->ip_low.s6_addr, b->ip_low.s6_addr, + sizeof(struct in6_addr)); +} + +/** bsearch helper: return -1, 1, or 0 based on comparison of an IPv6 + * (a pointer to a in6_addr) to a geoip_ipv6_entry_t */ +static int +geoip_ipv6_compare_key_to_entry_(const void *_key, const void **_member) +{ + const struct in6_addr *addr = (struct in6_addr *)_key; + const geoip_ipv6_entry_t *entry = *_member; + + if (fast_memcmp(addr->s6_addr, entry->ip_low.s6_addr, + sizeof(struct in6_addr)) < 0) + return -1; + else if (fast_memcmp(addr->s6_addr, entry->ip_high.s6_addr, + sizeof(struct in6_addr)) > 0) + return 1; + else + return 0; +} + +/** Set up a new list of geoip countries with no countries (yet) set in it, + * except for the unknown country. + */ +static void +init_geoip_countries(void) +{ + geoip_country_t *geoip_unresolved; + geoip_countries = smartlist_new(); + /* Add a geoip_country_t for requests that could not be resolved to a + * country as first element (index 0) to geoip_countries. */ + geoip_unresolved = tor_malloc_zero(sizeof(geoip_country_t)); + strlcpy(geoip_unresolved->countrycode, "??", + sizeof(geoip_unresolved->countrycode)); + smartlist_add(geoip_countries, geoip_unresolved); + country_idxplus1_by_lc_code = strmap_new(); + strmap_set_lc(country_idxplus1_by_lc_code, "??", (void*)(1)); +} + +/** Clear appropriate GeoIP database, based on <b>family</b>, and + * reload it from the file <b>filename</b>. Return 0 on success, -1 on + * failure. + * + * Recognized line formats for IPv4 are: + * INTIPLOW,INTIPHIGH,CC + * and + * "INTIPLOW","INTIPHIGH","CC","CC3","COUNTRY NAME" + * where INTIPLOW and INTIPHIGH are IPv4 addresses encoded as 4-byte unsigned + * integers, and CC is a country code. + * + * Recognized line format for IPv6 is: + * IPV6LOW,IPV6HIGH,CC + * where IPV6LOW and IPV6HIGH are IPv6 addresses and CC is a country code. + * + * It also recognizes, and skips over, blank lines and lines that start + * with '#' (comments). + */ +int +geoip_load_file(sa_family_t family, const char *filename, int severity) +{ + FILE *f; + crypto_digest_t *geoip_digest_env = NULL; + + tor_assert(family == AF_INET || family == AF_INET6); + + if (!(f = tor_fopen_cloexec(filename, "r"))) { + log_fn(severity, LD_GENERAL, "Failed to open GEOIP file %s.", + filename); + return -1; + } + if (!geoip_countries) + init_geoip_countries(); + + if (family == AF_INET) { + if (geoip_ipv4_entries) { + SMARTLIST_FOREACH(geoip_ipv4_entries, geoip_ipv4_entry_t *, e, + tor_free(e)); + smartlist_free(geoip_ipv4_entries); + } + geoip_ipv4_entries = smartlist_new(); + } else { /* AF_INET6 */ + if (geoip_ipv6_entries) { + SMARTLIST_FOREACH(geoip_ipv6_entries, geoip_ipv6_entry_t *, e, + tor_free(e)); + smartlist_free(geoip_ipv6_entries); + } + geoip_ipv6_entries = smartlist_new(); + } + geoip_digest_env = crypto_digest_new(); + + log_notice(LD_GENERAL, "Parsing GEOIP %s file %s.", + (family == AF_INET) ? "IPv4" : "IPv6", filename); + while (!feof(f)) { + char buf[512]; + if (fgets(buf, (int)sizeof(buf), f) == NULL) + break; + crypto_digest_add_bytes(geoip_digest_env, buf, strlen(buf)); + /* FFFF track full country name. */ + geoip_parse_entry(buf, family); + } + /*XXXX abort and return -1 if no entries/illformed?*/ + fclose(f); + + /* Sort list and remember file digests so that we can include it in + * our extra-info descriptors. */ + if (family == AF_INET) { + smartlist_sort(geoip_ipv4_entries, geoip_ipv4_compare_entries_); + crypto_digest_get_digest(geoip_digest_env, geoip_digest, DIGEST_LEN); + } else { + /* AF_INET6 */ + smartlist_sort(geoip_ipv6_entries, geoip_ipv6_compare_entries_); + crypto_digest_get_digest(geoip_digest_env, geoip6_digest, DIGEST_LEN); + } + crypto_digest_free(geoip_digest_env); + + return 0; +} + +/** Given an IP address in host order, return a number representing the + * country to which that address belongs, -1 for "No geoip information + * available", or 0 for the 'unknown country'. The return value will always + * be less than geoip_get_n_countries(). To decode it, call + * geoip_get_country_name(). + */ +int +geoip_get_country_by_ipv4(uint32_t ipaddr) +{ + geoip_ipv4_entry_t *ent; + if (!geoip_ipv4_entries) + return -1; + ent = smartlist_bsearch(geoip_ipv4_entries, &ipaddr, + geoip_ipv4_compare_key_to_entry_); + return ent ? (int)ent->country : 0; +} + +/** Given an IPv6 address, return a number representing the country to + * which that address belongs, -1 for "No geoip information available", or + * 0 for the 'unknown country'. The return value will always be less than + * geoip_get_n_countries(). To decode it, call geoip_get_country_name(). + */ +int +geoip_get_country_by_ipv6(const struct in6_addr *addr) +{ + geoip_ipv6_entry_t *ent; + + if (!geoip_ipv6_entries) + return -1; + ent = smartlist_bsearch(geoip_ipv6_entries, addr, + geoip_ipv6_compare_key_to_entry_); + return ent ? (int)ent->country : 0; +} + +/** Given an IP address, return a number representing the country to which + * that address belongs, -1 for "No geoip information available", or 0 for + * the 'unknown country'. The return value will always be less than + * geoip_get_n_countries(). To decode it, call geoip_get_country_name(). + */ +MOCK_IMPL(int, +geoip_get_country_by_addr,(const tor_addr_t *addr)) +{ + if (tor_addr_family(addr) == AF_INET) { + return geoip_get_country_by_ipv4(tor_addr_to_ipv4h(addr)); + } else if (tor_addr_family(addr) == AF_INET6) { + return geoip_get_country_by_ipv6(tor_addr_to_in6(addr)); + } else { + return -1; + } +} + +/** Return the number of countries recognized by the GeoIP country list. */ +MOCK_IMPL(int, +geoip_get_n_countries,(void)) +{ + if (!geoip_countries) + init_geoip_countries(); + return (int) smartlist_len(geoip_countries); +} + +/** Return the two-letter country code associated with the number <b>num</b>, + * or "??" for an unknown value. */ +const char * +geoip_get_country_name(country_t num) +{ + if (geoip_countries && num >= 0 && num < smartlist_len(geoip_countries)) { + geoip_country_t *c = smartlist_get(geoip_countries, num); + return c->countrycode; + } else + return "??"; +} + +/** Return true iff we have loaded a GeoIP database.*/ +MOCK_IMPL(int, +geoip_is_loaded,(sa_family_t family)) +{ + tor_assert(family == AF_INET || family == AF_INET6); + if (geoip_countries == NULL) + return 0; + if (family == AF_INET) + return geoip_ipv4_entries != NULL; + else /* AF_INET6 */ + return geoip_ipv6_entries != NULL; +} + +/** Return the hex-encoded SHA1 digest of the loaded GeoIP file. The + * result does not need to be deallocated, but will be overwritten by the + * next call of hex_str(). */ +const char * +geoip_db_digest(sa_family_t family) +{ + tor_assert(family == AF_INET || family == AF_INET6); + if (family == AF_INET) + return hex_str(geoip_digest, DIGEST_LEN); + else /* AF_INET6 */ + return hex_str(geoip6_digest, DIGEST_LEN); +} + +/** Release all storage held by the GeoIP databases and country list. */ +STATIC void +clear_geoip_db(void) +{ + if (geoip_countries) { + SMARTLIST_FOREACH(geoip_countries, geoip_country_t *, c, tor_free(c)); + smartlist_free(geoip_countries); + } + + strmap_free(country_idxplus1_by_lc_code, NULL); + if (geoip_ipv4_entries) { + SMARTLIST_FOREACH(geoip_ipv4_entries, geoip_ipv4_entry_t *, ent, + tor_free(ent)); + smartlist_free(geoip_ipv4_entries); + } + if (geoip_ipv6_entries) { + SMARTLIST_FOREACH(geoip_ipv6_entries, geoip_ipv6_entry_t *, ent, + tor_free(ent)); + smartlist_free(geoip_ipv6_entries); + } + geoip_countries = NULL; + country_idxplus1_by_lc_code = NULL; + geoip_ipv4_entries = NULL; + geoip_ipv6_entries = NULL; +} + +/** Release all storage held in this file. */ +void +geoip_free_all(void) +{ + clear_geoip_db(); + + memset(geoip_digest, 0, sizeof(geoip_digest)); + memset(geoip6_digest, 0, sizeof(geoip6_digest)); +} |