Commit 5488bc3e authored by Nick Mathewson's avatar Nick Mathewson
Browse files

r17231@catbus: nickm | 2007-12-18 16:21:55 -0500

 Document and clean-up geoip code; give it some unit tests.


svn:r12856
parent b8ac050e
......@@ -192,7 +192,7 @@ static config_var_t _option_vars[] = {
V(FetchServerDescriptors, BOOL, "1"),
V(FetchHidServDescriptors, BOOL, "1"),
V(FetchUselessDescriptors, BOOL, "0"),
V(GEOIPFile, STRING, NULL),
V(GeoIPFile, STRING, NULL),
V(Group, STRING, NULL),
V(HardwareAccel, BOOL, "0"),
V(HashedControlPassword, LINELIST, NULL),
......@@ -1217,10 +1217,10 @@ options_act(or_options_t *old_options)
}
/* Maybe load geoip file */
if (options->GEOIPFile &&
((!old_options || !opt_streq(old_options->GEOIPFile, options->GEOIPFile))
if (options->GeoIPFile &&
((!old_options || !opt_streq(old_options->GeoIPFile, options->GeoIPFile))
|| !geoip_is_loaded())) {
geoip_load_file(options->GEOIPFile);
geoip_load_file(options->GeoIPFile);
}
/* Check if we need to parse and add the EntryNodes config option. */
if (options->EntryNodes &&
......
......@@ -4,28 +4,48 @@
const char geoip_c_id[] =
"$Id: /tor/trunk/src/or/networkstatus.c 15493 2007-12-16T18:33:25.055570Z nickm $";
/**
* \file geoip.c
* \brief Functions related to maintaining an IP-to-country database and to
* summarizing client connections by country.
*/
#define GEOIP_PRIVATE
#include "or.h"
#include "ht.h"
/** DOCDOC this whole file */
static void clear_geoip_db(void);
/** An entry from the GeoIP file: maps an IP range to a country. */
typedef struct geoip_entry_t {
uint32_t ip_low;
uint32_t ip_high;
int country;
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 */
int country; /**< An index into geoip_countries */
} geoip_entry_t;
/** A list of lowercased two-letter country codes. */
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;
/** A list of all known geoip_entry_t, sorted by ip_low. */
static smartlist_t *geoip_entries = NULL;
void
/** Add an entry to the GeoIP table, mapping all IPs between <b>low</b> and
* <b>high</b>, inclusive, to the 2-letter country code <b>country</b>.
*/
static void
geoip_add_entry(uint32_t low, uint32_t high, const char *country)
{
uintptr_t idx;
geoip_entry_t *ent;
void *_idxplus1 = strmap_get_lc(country_idxplus1_by_lc_code, country);
void *_idxplus1;
if (high < low)
return;
_idxplus1 = strmap_get_lc(country_idxplus1_by_lc_code, country);
if (!_idxplus1) {
char *c = tor_strdup(country);
......@@ -44,6 +64,33 @@ geoip_add_entry(uint32_t low, uint32_t high, const char *country)
smartlist_add(geoip_entries, ent);
}
/** Add an entry to the GeoIP table, parsing it from <b>line</b>. The
* format is as for geoip_load_file. */
/*private*/ int
geoip_parse_entry(const char *line)
{
unsigned int low, high;
char b[3];
if (!geoip_countries) {
geoip_countries = smartlist_create();
geoip_entries = smartlist_create();
country_idxplus1_by_lc_code = strmap_new();
}
if (sscanf(line,"%u,%u,%2s", &low, &high, b) == 3) {
geoip_add_entry(low, high, b);
return 0;
} else if (sscanf(line,"\"%u\",\"%u\",\"%2s\",", &low, &high, b) == 3) {
geoip_add_entry(low, high, b);
return 0;
} else {
log_warn(LD_GENERAL, "Unable to parse line from GEOIP file: %s",
escaped(line));
return -1;
}
}
/** Sorting helper: return -1, 1, or 0 based on comparison of two
* geoip_entry_t */
static int
_geoip_compare_entries(const void **_a, const void **_b)
{
......@@ -56,6 +103,8 @@ _geoip_compare_entries(const void **_a, const void **_b)
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_entry_t */
static int
_geoip_compare_key_to_entry(const void *_key, const void **_member)
{
......@@ -69,11 +118,21 @@ _geoip_compare_key_to_entry(const void *_key, const void **_member)
return 0;
}
/** Clear the GeoIP database and reload it from the file
* <b>filename</b>. Return 0 on success, -1 on failure.
*
* Recognized line formats 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.
*/
int
geoip_load_file(const char *filename)
{
FILE *f;
geoip_free_all();
clear_geoip_db();
if (!(f = fopen(filename, "r"))) {
log_warn(LD_GENERAL, "Failed to open GEOIP file %s.", filename);
return -1;
......@@ -84,19 +143,10 @@ geoip_load_file(const char *filename)
log_info(LD_GENERAL, "Parsing GEOIP file.");
while (!feof(f)) {
char buf[512];
unsigned int low, high;
char b[3];
if (fgets(buf, sizeof(buf), f) == NULL)
break;
/* XXXX020 track full country name. */
if (sscanf(buf,"%u,%u,%2s", &low, &high, b) == 3) {
geoip_add_entry(low, high, b);
} else if (sscanf(buf,"\"%u\",\"%u\",\"%2s\",", &low, &high, b) == 3) {
geoip_add_entry(low, high, b);
} else {
log_warn(LD_GENERAL, "Unable to parse line from GEOIP file: %s",
escaped(buf));
}
geoip_parse_entry(buf);
}
/*XXXX020 abort and return -1 if no entries/illformed?*/
fclose(f);
......@@ -105,6 +155,11 @@ geoip_load_file(const char *filename)
return 0;
}
/** Given an IP address in host order, return a number representing the
* country to which that address belongs, or -1 for unknown. 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_ip(uint32_t ipaddr)
{
......@@ -115,12 +170,15 @@ geoip_get_country_by_ip(uint32_t ipaddr)
return ent ? ent->country : -1;
}
/** Return the number of countries recognized by the GEOIP database. */
int
geoip_get_n_countries(void)
{
return 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(int num)
{
......@@ -130,28 +188,35 @@ geoip_get_country_name(int num)
return "??";
}
/** Return true iff we have loaded a GeoIP database.*/
int
geoip_is_loaded(void)
{
return geoip_countries != NULL && geoip_entries != NULL;
}
/** DOCDOC */
/** Entry in a map from IP address to the last time we've seen an incoming
* connection from that IP address. Used by bridges only, to track which
* countries have them blocked. */
typedef struct clientmap_entry_t {
HT_ENTRY(clientmap_entry_t) node;
uint32_t ipaddr;
time_t last_seen;
} clientmap_entry_t;
/** Map from client IP address to last time seen. */
static HT_HEAD(clientmap, clientmap_entry_t) client_history =
HT_INITIALIZER();
/** Time at which we started tracking client history. */
static time_t client_history_starts = 0;
/** Hashtable helper: compute a hash of a clientmap_entry_t. */
static INLINE unsigned
clientmap_entry_hash(const clientmap_entry_t *a)
{
return ht_improve_hash((unsigned) a->ipaddr);
}
/** Hashtable helper: compare two clientmap_entry_t values for equality. */
static INLINE int
clientmap_entries_eq(const clientmap_entry_t *a, const clientmap_entry_t *b)
{
......@@ -163,7 +228,8 @@ HT_PROTOTYPE(clientmap, clientmap_entry_t, node, clientmap_entry_hash,
HT_GENERATE(clientmap, clientmap_entry_t, node, clientmap_entry_hash,
clientmap_entries_eq, 0.6, malloc, realloc, free);
/** DOCDOC */
/** Note that we've seen a client connect from the IP <b>addr</b> (host order)
* at time <b>now</b>. Ignored by all but bridges. */
void
geoip_note_client_seen(uint32_t addr, time_t now)
{
......@@ -185,6 +251,8 @@ geoip_note_client_seen(uint32_t addr, time_t now)
client_history_starts = now;
}
/** HT_FOREACH helper: remove a clientmap_entry_t from the hashtable if it's
* older than a certain time. */
static int
_remove_old_client_helper(struct clientmap_entry_t *ent, void *_cutoff)
{
......@@ -197,6 +265,7 @@ _remove_old_client_helper(struct clientmap_entry_t *ent, void *_cutoff)
}
}
/** Forget about all clients that haven't connected since <b>cutoff</b>. */
void
geoip_remove_old_clients(time_t cutoff)
{
......@@ -207,16 +276,29 @@ geoip_remove_old_clients(time_t cutoff)
client_history_starts = cutoff;
}
/** Do not mention any country from which fewer than this number of IPs have
* connected. This avoids reporting information that could deanonymize
* users. */
#define MIN_IPS_TO_NOTE_COUNTRY 8
/** Do not report any geoip data at all if we have fewer than this number of
* IPs to report about. */
#define MIN_IPS_TO_NOTE_ANYTHING 16
/** When reporting geoip data about countries, round down to the nearest
* multiple of this value. */
#define IP_GRANULARITY 8
/** Return the time at which we started recording geoip data. */
time_t
geoip_get_history_start(void)
{
return client_history_starts;
}
/** Return a newly allocated comma-separated string containing entries for all
* the countries from which we've seen enough clients connect. The entry
* format is cc=num where num is the number of IPs we've seen connecting from
* that country, and cc is a lowercased country code. Returns NULL if we don't
* want to export geoip data yet. */
char *
geoip_get_client_history(time_t now)
{
......@@ -263,6 +345,7 @@ geoip_get_client_history(time_t now)
return result;
}
/** Helper used to implement GETINFO ip-to-country/... controller command. */
int
getinfo_helper_geoip(control_connection_t *control_conn,
const char *question, char **answer)
......@@ -282,8 +365,9 @@ getinfo_helper_geoip(control_connection_t *control_conn,
return 0;
}
void
geoip_free_all(void)
/** Release all storage held by the GeoIP database. */
static void
clear_geoip_db(void)
{
if (geoip_countries) {
SMARTLIST_FOREACH(geoip_countries, char *, cp, tor_free(cp));
......@@ -295,17 +379,23 @@ geoip_free_all(void)
SMARTLIST_FOREACH(geoip_entries, geoip_entry_t *, ent, tor_free(ent));
smartlist_free(geoip_entries);
}
{
clientmap_entry_t **ent, **next, *this;
for (ent = HT_START(clientmap, &client_history); ent != NULL; ent = next) {
this = *ent;
next = HT_NEXT_RMV(clientmap, &client_history, ent);
tor_free(this);
}
HT_CLEAR(clientmap, &client_history);
}
geoip_countries = NULL;
country_idxplus1_by_lc_code = NULL;
geoip_entries = NULL;
}
/** Release all storage held in this file. */
void
geoip_free_all(void)
{
clientmap_entry_t **ent, **next, *this;
for (ent = HT_START(clientmap, &client_history); ent != NULL; ent = next) {
this = *ent;
next = HT_NEXT_RMV(clientmap, &client_history, ent);
tor_free(this);
}
HT_CLEAR(clientmap, &client_history);
clear_geoip_db();
}
......@@ -2317,7 +2317,7 @@ typedef struct {
/** DOCDOC here and in tor.1 */
int BridgeRecordUsageByCountry;
char *GEOIPFile;
char *GeoIPFile;
} or_options_t;
......@@ -3199,7 +3199,7 @@ void dnsserv_launch_request(const char *name, int is_reverse);
/********************************* geoip.c **************************/
#ifdef GEOIP_PRIVATE
void geoip_add_entry(uint32_t low, uint32_t high, const char *country);
int geoip_parse_entry(const char *line);
#endif
int geoip_load_file(const char *filename);
int geoip_get_country_by_ip(uint32_t ipaddr);
......
......@@ -33,6 +33,7 @@ const char tor_svn_revision[] = "";
#define CRYPTO_PRIVATE
#define DIRSERV_PRIVATE
#define DIRVOTE_PRIVATE
#define GEOIP_PRIVATE
#define MEMPOOL_PRIVATE
#define ROUTER_PRIVATE
......@@ -3369,6 +3370,66 @@ test_rend_fns_v2(void)
rend_service_descriptor_free(generated);
}
static void
test_geoip(void)
{
int i, j;
time_t now = time(NULL);
char *s;
/* Populate the DB a bit. Add these in order, since we can't do the final
* 'sort' step. These aren't very good IP addresses, but they're perfectly
* fine uint32_t values. */
test_eq(0, geoip_parse_entry("10,50,AB"));
test_eq(0, geoip_parse_entry("52,90,XY"));
test_eq(0, geoip_parse_entry("95,100,AB"));
test_eq(0, geoip_parse_entry("\"105\",\"140\",\"ZZ\""));
test_eq(0, geoip_parse_entry("\"150\",\"190\",\"XY\""));
test_eq(0, geoip_parse_entry("\"200\",\"250\",\"AB\""));
/* We should have 3 countries: ab, xy, zz. */
test_eq(3, geoip_get_n_countries());
/* Make sure that country ID actually works. */
#define NAMEFOR(x) geoip_get_country_name(geoip_get_country_by_ip(x))
test_streq("ab", NAMEFOR(32));
test_streq("??", NAMEFOR(5));
test_streq("??", NAMEFOR(51));
test_streq("xy", NAMEFOR(150));
test_streq("xy", NAMEFOR(190));
test_streq("??", NAMEFOR(2000));
#undef NAMEFOR
get_options()->BridgeRelay = 1;
get_options()->BridgeRecordUsageByCountry = 1;
/* Put 9 observations in AB... */
for (i=32; i < 40; ++i)
geoip_note_client_seen(i, now);
geoip_note_client_seen(225, now);
/* and 3 observations in XY, several times. */
for (j=0; j < 10; ++j)
for (i=52; i < 55; ++i)
geoip_note_client_seen(i, now-3600);
/* and 17 observations in ZZ... */
for (i=110; i < 127; ++i)
geoip_note_client_seen(i, now-7200);
s = geoip_get_client_history(now+5*24*60*60);
test_assert(s);
test_streq("ab=8,zz=16", s);
tor_free(s);
/* Now clear out all the zz observations. */
geoip_remove_old_clients(now-6000);
s = geoip_get_client_history(now+5*24*60*60);
test_assert(! s); /* There are only 12 observations left. Not enough to
build an answer. Add 4 more in XY... */
for (i=55; i < 59; ++i)
geoip_note_client_seen(i, now-3600);
s = geoip_get_client_history(now+5*24*60*60);
test_assert(s);
test_streq("ab=8", s);
tor_free(s);
}
#define ENT(x) { #x, test_ ## x, 0, 0 }
#define SUBENT(x,y) { #x "/" #y, test_ ## x ## _ ## y, 1, 0 }
......@@ -3403,6 +3464,7 @@ static struct {
ENT(policies),
ENT(rend_fns),
SUBENT(rend_fns, v2),
ENT(geoip),
{ NULL, NULL, 0, 0 },
};
......
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