tor/src/or/routerset.c
2017-03-15 16:13:17 -04:00

459 lines
14 KiB
C

/* Copyright (c) 2001 Matej Pfajfar.
* Copyright (c) 2001-2004, Roger Dingledine.
* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2017, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/**
* \file routerset.c
*
* \brief Functions and structures to handle set-type selection of routers
* by name, ID, address, etc.
*
* This module implements the routerset_t data structure, whose purpose
* is to specify a set of relays based on a list of their identities or
* properties. Routersets can restrict relays by IP address mask,
* identity fingerprint, country codes, and nicknames (deprecated).
*
* Routersets are typically used for user-specified restrictions, and
* are created by invoking routerset_new and routerset_parse from
* config.c and confparse.c. To use a routerset, invoke one of
* routerset_contains_...() functions , or use
* routerstatus_get_all_nodes() / routerstatus_subtract_nodes() to
* manipulate a smartlist of node_t pointers.
*
* Country-code restrictions are implemented in geoip.c.
*/
#define ROUTERSET_PRIVATE
#include "or.h"
#include "bridges.h"
#include "geoip.h"
#include "nodelist.h"
#include "policies.h"
#include "router.h"
#include "routerparse.h"
#include "routerset.h"
/** Return a new empty routerset. */
routerset_t *
routerset_new(void)
{
routerset_t *result = tor_malloc_zero(sizeof(routerset_t));
result->list = smartlist_new();
result->names = strmap_new();
result->digests = digestmap_new();
result->policies = smartlist_new();
result->country_names = smartlist_new();
return result;
}
/** If <b>c</b> is a country code in the form {cc}, return a newly allocated
* string holding the "cc" part. Else, return NULL. */
STATIC char *
routerset_get_countryname(const char *c)
{
char *country;
if (strlen(c) < 4 || c[0] !='{' || c[3] !='}')
return NULL;
country = tor_strndup(c+1, 2);
tor_strlower(country);
return country;
}
/** Update the routerset's <b>countries</b> bitarray_t. Called whenever
* the GeoIP IPv4 database is reloaded.
*/
void
routerset_refresh_countries(routerset_t *target)
{
int cc;
bitarray_free(target->countries);
if (!geoip_is_loaded(AF_INET)) {
target->countries = NULL;
target->n_countries = 0;
return;
}
target->n_countries = geoip_get_n_countries();
target->countries = bitarray_init_zero(target->n_countries);
SMARTLIST_FOREACH_BEGIN(target->country_names, const char *, country) {
cc = geoip_get_country(country);
if (cc >= 0) {
tor_assert(cc < target->n_countries);
bitarray_set(target->countries, cc);
} else {
log_warn(LD_CONFIG, "Country code '%s' is not recognized.",
country);
}
} SMARTLIST_FOREACH_END(country);
}
/** Parse the string <b>s</b> to create a set of routerset entries, and add
* them to <b>target</b>. In log messages, refer to the string as
* <b>description</b>. Return 0 on success, -1 on failure.
*
* Three kinds of elements are allowed in routersets: nicknames, IP address
* patterns, and fingerprints. They may be surrounded by optional space, and
* must be separated by commas.
*/
int
routerset_parse(routerset_t *target, const char *s, const char *description)
{
int r = 0;
int added_countries = 0;
char *countryname;
smartlist_t *list = smartlist_new();
int malformed_list;
smartlist_split_string(list, s, ",",
SPLIT_SKIP_SPACE | SPLIT_IGNORE_BLANK, 0);
SMARTLIST_FOREACH_BEGIN(list, char *, nick) {
addr_policy_t *p;
/* if it doesn't pass our validation, assume it's malformed */
malformed_list = 1;
if (is_legal_hexdigest(nick)) {
char d[DIGEST_LEN];
if (*nick == '$')
++nick;
log_debug(LD_CONFIG, "Adding identity %s to %s", nick, description);
base16_decode(d, sizeof(d), nick, HEX_DIGEST_LEN);
digestmap_set(target->digests, d, (void*)1);
} else if (is_legal_nickname(nick)) {
log_debug(LD_CONFIG, "Adding nickname %s to %s", nick, description);
strmap_set_lc(target->names, nick, (void*)1);
} else if ((countryname = routerset_get_countryname(nick)) != NULL) {
log_debug(LD_CONFIG, "Adding country %s to %s", nick,
description);
smartlist_add(target->country_names, countryname);
added_countries = 1;
} else if ((strchr(nick,'.') || strchr(nick, ':') || strchr(nick, '*'))
&& (p = router_parse_addr_policy_item_from_string(
nick, ADDR_POLICY_REJECT,
&malformed_list))) {
/* IPv4 addresses contain '.', IPv6 addresses contain ':',
* and wildcard addresses contain '*'. */
log_debug(LD_CONFIG, "Adding address %s to %s", nick, description);
smartlist_add(target->policies, p);
} else if (malformed_list) {
log_warn(LD_CONFIG, "Entry '%s' in %s is malformed. Discarding entire"
" list.", nick, description);
r = -1;
tor_free(nick);
SMARTLIST_DEL_CURRENT(list, nick);
} else {
log_notice(LD_CONFIG, "Entry '%s' in %s is ignored. Using the"
" remainder of the list.", nick, description);
tor_free(nick);
SMARTLIST_DEL_CURRENT(list, nick);
}
} SMARTLIST_FOREACH_END(nick);
policy_expand_unspec(&target->policies);
smartlist_add_all(target->list, list);
smartlist_free(list);
if (added_countries)
routerset_refresh_countries(target);
return r;
}
/** Add all members of the set <b>source</b> to <b>target</b>. */
void
routerset_union(routerset_t *target, const routerset_t *source)
{
char *s;
tor_assert(target);
if (!source || !source->list)
return;
s = routerset_to_string(source);
routerset_parse(target, s, "other routerset");
tor_free(s);
}
/** Return true iff <b>set</b> lists only nicknames and digests, and includes
* no IP ranges or countries. */
int
routerset_is_list(const routerset_t *set)
{
return smartlist_len(set->country_names) == 0 &&
smartlist_len(set->policies) == 0;
}
/** Return true iff we need a GeoIP IP-to-country database to make sense of
* <b>set</b>. */
int
routerset_needs_geoip(const routerset_t *set)
{
return set && smartlist_len(set->country_names);
}
/** Return true iff there are no entries in <b>set</b>. */
int
routerset_is_empty(const routerset_t *set)
{
return !set || smartlist_len(set->list) == 0;
}
/** Return the number of entries in <b>set</b>. This does NOT return a
* negative value. */
int
routerset_len(const routerset_t *set)
{
if (!set) {
return 0;
}
return smartlist_len(set->list);
}
/** Helper. Return true iff <b>set</b> contains a router based on the other
* provided fields. Return higher values for more specific subentries: a
* single router is more specific than an address range of routers, which is
* more specific in turn than a country code.
*
* (If country is -1, then we take the country
* from addr.) */
STATIC int
routerset_contains(const routerset_t *set, const tor_addr_t *addr,
uint16_t orport,
const char *nickname, const char *id_digest,
country_t country)
{
if (!set || !set->list)
return 0;
if (nickname && strmap_get_lc(set->names, nickname))
return 4;
if (id_digest && digestmap_get(set->digests, id_digest))
return 4;
if (addr && compare_tor_addr_to_addr_policy(addr, orport, set->policies)
== ADDR_POLICY_REJECTED)
return 3;
if (set->countries) {
if (country < 0 && addr)
country = geoip_get_country_by_addr(addr);
if (country >= 0 && country < set->n_countries &&
bitarray_is_set(set->countries, country))
return 2;
}
return 0;
}
/** If *<b>setp</b> includes at least one country code, or if
* <b>only_some_cc_set</b> is 0, add the ?? and A1 country codes to
* *<b>setp</b>, creating it as needed. Return true iff *<b>setp</b> changed.
*/
int
routerset_add_unknown_ccs(routerset_t **setp, int only_if_some_cc_set)
{
routerset_t *set;
int add_unknown, add_a1;
if (only_if_some_cc_set) {
if (!*setp || smartlist_len((*setp)->country_names) == 0)
return 0;
}
if (!*setp)
*setp = routerset_new();
set = *setp;
add_unknown = ! smartlist_contains_string_case(set->country_names, "??") &&
geoip_get_country("??") >= 0;
add_a1 = ! smartlist_contains_string_case(set->country_names, "a1") &&
geoip_get_country("A1") >= 0;
if (add_unknown) {
smartlist_add_strdup(set->country_names, "??");
smartlist_add_strdup(set->list, "{??}");
}
if (add_a1) {
smartlist_add_strdup(set->country_names, "a1");
smartlist_add_strdup(set->list, "{a1}");
}
if (add_unknown || add_a1) {
routerset_refresh_countries(set);
return 1;
}
return 0;
}
/** Return true iff we can tell that <b>ei</b> is a member of <b>set</b>. */
int
routerset_contains_extendinfo(const routerset_t *set, const extend_info_t *ei)
{
return routerset_contains(set,
&ei->addr,
ei->port,
ei->nickname,
ei->identity_digest,
-1 /*country*/);
}
/** Return true iff <b>ri</b> is in <b>set</b>. If country is <b>-1</b>, we
* look up the country. */
int
routerset_contains_router(const routerset_t *set, const routerinfo_t *ri,
country_t country)
{
tor_addr_t addr;
tor_addr_from_ipv4h(&addr, ri->addr);
return routerset_contains(set,
&addr,
ri->or_port,
ri->nickname,
ri->cache_info.identity_digest,
country);
}
/** Return true iff <b>rs</b> is in <b>set</b>. If country is <b>-1</b>, we
* look up the country. */
int
routerset_contains_routerstatus(const routerset_t *set,
const routerstatus_t *rs,
country_t country)
{
tor_addr_t addr;
tor_addr_from_ipv4h(&addr, rs->addr);
return routerset_contains(set,
&addr,
rs->or_port,
rs->nickname,
rs->identity_digest,
country);
}
/** Return true iff <b>node</b> is in <b>set</b>. */
int
routerset_contains_node(const routerset_t *set, const node_t *node)
{
if (node->rs)
return routerset_contains_routerstatus(set, node->rs, node->country);
else if (node->ri)
return routerset_contains_router(set, node->ri, node->country);
else
return 0;
}
/** Return true iff <b>routerset</b> contains the bridge <b>bridge</b>. */
int
routerset_contains_bridge(const routerset_t *set, const bridge_info_t *bridge)
{
const char *id = (const char*)bridge_get_rsa_id_digest(bridge);
const tor_addr_port_t *addrport = bridge_get_addr_port(bridge);
tor_assert(addrport);
return routerset_contains(set, &addrport->addr, addrport->port,
NULL, id, -1);
}
/** Add every known node_t that is a member of <b>routerset</b> to
* <b>out</b>, but never add any that are part of <b>excludeset</b>.
* If <b>running_only</b>, only add the running ones. */
void
routerset_get_all_nodes(smartlist_t *out, const routerset_t *routerset,
const routerset_t *excludeset, int running_only)
{
tor_assert(out);
if (!routerset || !routerset->list)
return;
if (routerset_is_list(routerset)) {
/* No routers are specified by type; all are given by name or digest.
* we can do a lookup in O(len(routerset)). */
SMARTLIST_FOREACH(routerset->list, const char *, name, {
const node_t *node = node_get_by_nickname(name, 1);
if (node) {
if (!running_only || node->is_running)
if (!routerset_contains_node(excludeset, node))
smartlist_add(out, (void*)node);
}
});
} else {
/* We need to iterate over the routerlist to get all the ones of the
* right kind. */
smartlist_t *nodes = nodelist_get_list();
SMARTLIST_FOREACH(nodes, const node_t *, node, {
if (running_only && !node->is_running)
continue;
if (routerset_contains_node(routerset, node) &&
!routerset_contains_node(excludeset, node))
smartlist_add(out, (void*)node);
});
}
}
/** Remove every node_t from <b>lst</b> that is in <b>routerset</b>. */
void
routerset_subtract_nodes(smartlist_t *lst, const routerset_t *routerset)
{
tor_assert(lst);
if (!routerset)
return;
SMARTLIST_FOREACH(lst, const node_t *, node, {
if (routerset_contains_node(routerset, node)) {
//log_debug(LD_DIR, "Subtracting %s",r->nickname);
SMARTLIST_DEL_CURRENT(lst, node);
}
});
}
/** Return a new string that when parsed by routerset_parse_string() will
* yield <b>set</b>. */
char *
routerset_to_string(const routerset_t *set)
{
if (!set || !set->list)
return tor_strdup("");
return smartlist_join_strings(set->list, ",", 0, NULL);
}
/** Helper: return true iff old and new are both NULL, or both non-NULL
* equal routersets. */
int
routerset_equal(const routerset_t *old, const routerset_t *new)
{
if (routerset_is_empty(old) && routerset_is_empty(new)) {
/* Two empty sets are equal */
return 1;
} else if (routerset_is_empty(old) || routerset_is_empty(new)) {
/* An empty set is equal to nothing else. */
return 0;
}
tor_assert(old != NULL);
tor_assert(new != NULL);
if (smartlist_len(old->list) != smartlist_len(new->list))
return 0;
SMARTLIST_FOREACH(old->list, const char *, cp1, {
const char *cp2 = smartlist_get(new->list, cp1_sl_idx);
if (strcmp(cp1, cp2))
return 0;
});
return 1;
}
/** Free all storage held in <b>routerset</b>. */
void
routerset_free(routerset_t *routerset)
{
if (!routerset)
return;
SMARTLIST_FOREACH(routerset->list, char *, cp, tor_free(cp));
smartlist_free(routerset->list);
SMARTLIST_FOREACH(routerset->policies, addr_policy_t *, p,
addr_policy_free(p));
smartlist_free(routerset->policies);
SMARTLIST_FOREACH(routerset->country_names, char *, cp, tor_free(cp));
smartlist_free(routerset->country_names);
strmap_free(routerset->names, NULL);
digestmap_free(routerset->digests, NULL);
bitarray_free(routerset->countries);
tor_free(routerset);
}