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- /* Copyright (c) 2001-2004, Roger Dingledine.
- * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
- * Copyright (c) 2007-2008, The Tor Project, Inc. */
- /* See LICENSE for licensing information */
- /* $Id$ */
- const char policies_c_id[] = \
- "$Id$";
- /**
- * \file policies.c
- * \brief Code to parse and use address policies and exit policies.
- **/
- #include "or.h"
- #include "ht.h"
- /** Policy that addresses for incoming SOCKS connections must match. */
- static smartlist_t *socks_policy = NULL;
- /** Policy that addresses for incoming directory connections must match. */
- static smartlist_t *dir_policy = NULL;
- /** Policy that addresses for incoming router descriptors must match in order
- * to be published by us. */
- static smartlist_t *authdir_reject_policy = NULL;
- /** Policy that addresses for incoming router descriptors must match in order
- * to be marked as valid in our networkstatus. */
- static smartlist_t *authdir_invalid_policy = NULL;
- /** Policy that addresses for incoming router descriptors must <b>not</b>
- * match in order to not be marked as BadDirectory. */
- static smartlist_t *authdir_baddir_policy = NULL;
- /** Policy that addresses for incoming router descriptors must <b>not</b>
- * match in order to not be marked as BadExit. */
- static smartlist_t *authdir_badexit_policy = NULL;
- /** Parsed addr_policy_t describing which addresses we believe we can start
- * circuits at. */
- static smartlist_t *reachable_or_addr_policy = NULL;
- /** Parsed addr_policy_t describing which addresses we believe we can connect
- * to directories at. */
- static smartlist_t *reachable_dir_addr_policy = NULL;
- /** Replace all "private" entries in *<b>policy</b> with their expanded
- * equivalents. */
- void
- policy_expand_private(smartlist_t **policy)
- {
- static const char *private_nets[] = {
- "0.0.0.0/8", "169.254.0.0/16",
- "127.0.0.0/8", "192.168.0.0/16", "10.0.0.0/8", "172.16.0.0/12", NULL };
- uint16_t port_min, port_max;
- int i;
- smartlist_t *tmp;
- if (!*policy)
- return;
- tmp = smartlist_create();
- SMARTLIST_FOREACH(*policy, addr_policy_t *, p,
- {
- if (! p->is_private) {
- smartlist_add(tmp, p);
- continue;
- }
- for (i = 0; private_nets[i]; ++i) {
- addr_policy_t policy;
- memcpy(&policy, p, sizeof(addr_policy_t));
- policy.is_private = 0;
- policy.is_canonical = 0;
- if (parse_addr_and_port_range(private_nets[i],
- &policy.addr,
- &policy.maskbits, &port_min, &port_max)) {
- tor_assert(0);
- }
- smartlist_add(tmp, addr_policy_get_canonical_entry(&policy));
- }
- addr_policy_free(p);
- });
- smartlist_free(*policy);
- *policy = tmp;
- }
- /**
- * Given a linked list of config lines containing "allow" and "deny"
- * tokens, parse them and append the result to <b>dest</b>. Return -1
- * if any tokens are malformed (and don't append any), else return 0.
- */
- static int
- parse_addr_policy(config_line_t *cfg, smartlist_t **dest,
- int assume_action)
- {
- smartlist_t *result;
- smartlist_t *entries;
- addr_policy_t *item;
- int r = 0;
- if (!cfg)
- return 0;
- result = smartlist_create();
- entries = smartlist_create();
- for (; cfg; cfg = cfg->next) {
- smartlist_split_string(entries, cfg->value, ",",
- SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0);
- SMARTLIST_FOREACH(entries, const char *, ent,
- {
- log_debug(LD_CONFIG,"Adding new entry '%s'",ent);
- item = router_parse_addr_policy_item_from_string(ent, assume_action);
- if (item) {
- smartlist_add(result, item);
- } else {
- log_warn(LD_CONFIG,"Malformed policy '%s'.", ent);
- r = -1;
- }
- });
- SMARTLIST_FOREACH(entries, char *, ent, tor_free(ent));
- smartlist_clear(entries);
- }
- smartlist_free(entries);
- if (r == -1) {
- addr_policy_list_free(result);
- } else {
- policy_expand_private(&result);
- if (*dest) {
- smartlist_add_all(*dest, result);
- smartlist_free(result);
- } else {
- *dest = result;
- }
- }
- return r;
- }
- /** Helper: parse the Reachable(Dir|OR)?Addresses fields into
- * reachable_(or|dir)_addr_policy. The options should already have
- * been validated by validate_addr_policies.
- */
- static int
- parse_reachable_addresses(void)
- {
- or_options_t *options = get_options();
- int ret = 0;
- if (options->ReachableDirAddresses &&
- options->ReachableORAddresses &&
- options->ReachableAddresses) {
- log_warn(LD_CONFIG,
- "Both ReachableDirAddresses and ReachableORAddresses are set. "
- "ReachableAddresses setting will be ignored.");
- }
- addr_policy_list_free(reachable_or_addr_policy);
- reachable_or_addr_policy = NULL;
- if (!options->ReachableORAddresses && options->ReachableAddresses)
- log_info(LD_CONFIG,
- "Using ReachableAddresses as ReachableORAddresses.");
- if (parse_addr_policy(options->ReachableORAddresses ?
- options->ReachableORAddresses :
- options->ReachableAddresses,
- &reachable_or_addr_policy, ADDR_POLICY_ACCEPT)) {
- log_warn(LD_CONFIG,
- "Error parsing Reachable%sAddresses entry; ignoring.",
- options->ReachableORAddresses ? "OR" : "");
- ret = -1;
- }
- addr_policy_list_free(reachable_dir_addr_policy);
- reachable_dir_addr_policy = NULL;
- if (!options->ReachableDirAddresses && options->ReachableAddresses)
- log_info(LD_CONFIG,
- "Using ReachableAddresses as ReachableDirAddresses");
- if (parse_addr_policy(options->ReachableDirAddresses ?
- options->ReachableDirAddresses :
- options->ReachableAddresses,
- &reachable_dir_addr_policy, ADDR_POLICY_ACCEPT)) {
- if (options->ReachableDirAddresses)
- log_warn(LD_CONFIG,
- "Error parsing ReachableDirAddresses entry; ignoring.");
- ret = -1;
- }
- return ret;
- }
- /** Return true iff the firewall options might block any address:port
- * combination.
- */
- int
- firewall_is_fascist_or(void)
- {
- return reachable_or_addr_policy != NULL;
- }
- /** Return true iff <b>policy</b> (possibly NULL) will allow a
- * connection to <b>addr</b>:<b>port</b>.
- */
- static int
- addr_policy_permits_address(uint32_t addr, uint16_t port,
- smartlist_t *policy)
- {
- addr_policy_result_t p;
- p = compare_addr_to_addr_policy(addr, port, policy);
- switch (p) {
- case ADDR_POLICY_PROBABLY_ACCEPTED:
- case ADDR_POLICY_ACCEPTED:
- return 1;
- case ADDR_POLICY_PROBABLY_REJECTED:
- case ADDR_POLICY_REJECTED:
- return 0;
- default:
- log_warn(LD_BUG, "Unexpected result: %d", (int)p);
- return 0;
- }
- }
- /** Return true iff we think our firewall will let us make an OR connection to
- * addr:port. */
- int
- fascist_firewall_allows_address_or(uint32_t addr, uint16_t port)
- {
- return addr_policy_permits_address(addr, port,
- reachable_or_addr_policy);
- }
- /** Return true iff we think our firewall will let us make a directory
- * connection to addr:port. */
- int
- fascist_firewall_allows_address_dir(uint32_t addr, uint16_t port)
- {
- return addr_policy_permits_address(addr, port,
- reachable_dir_addr_policy);
- }
- /** Return 1 if <b>addr</b> is permitted to connect to our dir port,
- * based on <b>dir_policy</b>. Else return 0.
- */
- int
- dir_policy_permits_address(uint32_t addr)
- {
- return addr_policy_permits_address(addr, 1, dir_policy);
- }
- /** Return 1 if <b>addr</b> is permitted to connect to our socks port,
- * based on <b>socks_policy</b>. Else return 0.
- */
- int
- socks_policy_permits_address(uint32_t addr)
- {
- return addr_policy_permits_address(addr, 1, socks_policy);
- }
- /** Return 1 if <b>addr</b>:<b>port</b> is permitted to publish to our
- * directory, based on <b>authdir_reject_policy</b>. Else return 0.
- */
- int
- authdir_policy_permits_address(uint32_t addr, uint16_t port)
- {
- return addr_policy_permits_address(addr, port, authdir_reject_policy);
- }
- /** Return 1 if <b>addr</b>:<b>port</b> is considered valid in our
- * directory, based on <b>authdir_invalid_policy</b>. Else return 0.
- */
- int
- authdir_policy_valid_address(uint32_t addr, uint16_t port)
- {
- return addr_policy_permits_address(addr, port, authdir_invalid_policy);
- }
- /** Return 1 if <b>addr</b>:<b>port</b> should be marked as a bad dir,
- * based on <b>authdir_baddir_policy</b>. Else return 0.
- */
- int
- authdir_policy_baddir_address(uint32_t addr, uint16_t port)
- {
- return ! addr_policy_permits_address(addr, port, authdir_baddir_policy);
- }
- /** Return 1 if <b>addr</b>:<b>port</b> should be marked as a bad exit,
- * based on <b>authdir_badexit_policy</b>. Else return 0.
- */
- int
- authdir_policy_badexit_address(uint32_t addr, uint16_t port)
- {
- return ! addr_policy_permits_address(addr, port, authdir_badexit_policy);
- }
- #define REJECT(arg) \
- STMT_BEGIN *msg = tor_strdup(arg); goto err; STMT_END
- /** Config helper: If there's any problem with the policy configuration
- * options in <b>options</b>, return -1 and set <b>msg</b> to a newly
- * allocated description of the error. Else return 0. */
- int
- validate_addr_policies(or_options_t *options, char **msg)
- {
- /* XXXX Maybe merge this into parse_policies_from_options, to make sure
- * that the two can't go out of sync. */
- smartlist_t *addr_policy=NULL;
- *msg = NULL;
- if (policies_parse_exit_policy(options->ExitPolicy, &addr_policy,
- options->ExitPolicyRejectPrivate, NULL))
- REJECT("Error in ExitPolicy entry.");
- /* The rest of these calls *append* to addr_policy. So don't actually
- * use the results for anything other than checking if they parse! */
- if (parse_addr_policy(options->DirPolicy, &addr_policy, -1))
- REJECT("Error in DirPolicy entry.");
- if (parse_addr_policy(options->SocksPolicy, &addr_policy, -1))
- REJECT("Error in SocksPolicy entry.");
- if (parse_addr_policy(options->AuthDirReject, &addr_policy,
- ADDR_POLICY_REJECT))
- REJECT("Error in AuthDirReject entry.");
- if (parse_addr_policy(options->AuthDirInvalid, &addr_policy,
- ADDR_POLICY_REJECT))
- REJECT("Error in AuthDirInvalid entry.");
- if (parse_addr_policy(options->AuthDirBadDir, &addr_policy,
- ADDR_POLICY_REJECT))
- REJECT("Error in AuthDirBadDir entry.");
- if (parse_addr_policy(options->AuthDirBadExit, &addr_policy,
- ADDR_POLICY_REJECT))
- REJECT("Error in AuthDirBadExit entry.");
- if (parse_addr_policy(options->ReachableAddresses, &addr_policy,
- ADDR_POLICY_ACCEPT))
- REJECT("Error in ReachableAddresses entry.");
- if (parse_addr_policy(options->ReachableORAddresses, &addr_policy,
- ADDR_POLICY_ACCEPT))
- REJECT("Error in ReachableORAddresses entry.");
- if (parse_addr_policy(options->ReachableDirAddresses, &addr_policy,
- ADDR_POLICY_ACCEPT))
- REJECT("Error in ReachableDirAddresses entry.");
- if (parse_addr_policy(options->AuthDirReject, &addr_policy,
- ADDR_POLICY_REJECT))
- REJECT("Error in AuthDirReject entry.");
- if (parse_addr_policy(options->AuthDirInvalid, &addr_policy,
- ADDR_POLICY_REJECT))
- REJECT("Error in AuthDirInvalid entry.");
- err:
- addr_policy_list_free(addr_policy);
- return *msg ? -1 : 0;
- #undef REJECT
- }
- /** Parse <b>string</b> in the same way that the exit policy
- * is parsed, and put the processed version in *<b>policy</b>.
- * Ignore port specifiers.
- */
- static int
- load_policy_from_option(config_line_t *config, smartlist_t **policy,
- int assume_action)
- {
- int r;
- addr_policy_list_free(*policy);
- *policy = NULL;
- r = parse_addr_policy(config, policy, assume_action);
- if (r < 0) {
- return -1;
- }
- if (*policy) {
- SMARTLIST_FOREACH(*policy, addr_policy_t *, n, {
- /* ports aren't used. */
- n->prt_min = 1;
- n->prt_max = 65535;
- });
- }
- return 0;
- }
- /** Set all policies based on <b>options</b>, which should have been validated
- * first by validate_addr_policies. */
- int
- policies_parse_from_options(or_options_t *options)
- {
- int ret = 0;
- if (load_policy_from_option(options->SocksPolicy, &socks_policy, -1) < 0)
- ret = -1;
- if (load_policy_from_option(options->DirPolicy, &dir_policy, -1) < 0)
- ret = -1;
- if (load_policy_from_option(options->AuthDirReject,
- &authdir_reject_policy, ADDR_POLICY_REJECT) < 0)
- ret = -1;
- if (load_policy_from_option(options->AuthDirInvalid,
- &authdir_invalid_policy, ADDR_POLICY_REJECT) < 0)
- ret = -1;
- if (load_policy_from_option(options->AuthDirBadDir,
- &authdir_baddir_policy, ADDR_POLICY_REJECT) < 0)
- ret = -1;
- if (load_policy_from_option(options->AuthDirBadExit,
- &authdir_badexit_policy, ADDR_POLICY_REJECT) < 0)
- ret = -1;
- if (parse_reachable_addresses() < 0)
- ret = -1;
- return ret;
- }
- /** Compare two provided address policy items, and return -1, 0, or 1
- * if the first is less than, equal to, or greater than the second. */
- static int
- cmp_single_addr_policy(addr_policy_t *a, addr_policy_t *b)
- {
- int r;
- if ((r=((int)a->policy_type - (int)b->policy_type)))
- return r;
- if ((r=((int)a->is_private - (int)b->is_private)))
- return r;
- if ((r=((int)a->addr - (int)b->addr)))
- return r;
- if ((r=((int)a->maskbits - (int)b->maskbits)))
- return r;
- if ((r=((int)a->prt_min - (int)b->prt_min)))
- return r;
- if ((r=((int)a->prt_max - (int)b->prt_max)))
- return r;
- return 0;
- }
- /** Like cmp_single_addr_policy() above, but looks at the
- * whole set of policies in each case. */
- int
- cmp_addr_policies(smartlist_t *a, smartlist_t *b)
- {
- int r, i;
- int len_a = a ? smartlist_len(a) : 0;
- int len_b = b ? smartlist_len(b) : 0;
- for (i = 0; i < len_a && i < len_b; ++i) {
- if ((r = cmp_single_addr_policy(smartlist_get(a, i), smartlist_get(b, i))))
- return r;
- }
- if (i == len_a && i == len_b)
- return 0;
- if (i < len_a)
- return -1;
- else
- return 1;
- }
- /** Node in hashtable used to store address policy entries. */
- typedef struct policy_map_ent_t {
- HT_ENTRY(policy_map_ent_t) node;
- addr_policy_t *policy;
- } policy_map_ent_t;
- static HT_HEAD(policy_map, policy_map_ent_t) policy_root;
- /** Return true iff a and b are equal. */
- static INLINE int
- policy_eq(policy_map_ent_t *a, policy_map_ent_t *b)
- {
- return cmp_single_addr_policy(a->policy, b->policy) == 0;
- }
- /** Return a hashcode for <b>ent</b> */
- static unsigned int
- policy_hash(policy_map_ent_t *ent)
- {
- addr_policy_t *a = ent->policy;
- unsigned int r;
- if (a->is_private)
- r = 0x1234abcd;
- else
- r = (unsigned int)a->addr;
- r += a->prt_min << 8;
- r += a->prt_max << 16;
- r += a->maskbits;
- if (a->policy_type == ADDR_POLICY_REJECT)
- r ^= 0xffffffff;
- return r;
- }
- HT_PROTOTYPE(policy_map, policy_map_ent_t, node, policy_hash,
- policy_eq)
- HT_GENERATE(policy_map, policy_map_ent_t, node, policy_hash,
- policy_eq, 0.6, malloc, realloc, free)
- /** Given a pointer to an addr_policy_t, return a copy of the pointer to the
- * "canonical" copy of that addr_policy_t; the canonical copy is a single
- * reference-counted object. */
- addr_policy_t *
- addr_policy_get_canonical_entry(addr_policy_t *e)
- {
- policy_map_ent_t search, *found;
- if (e->is_canonical)
- return e;
- search.policy = e;
- found = HT_FIND(policy_map, &policy_root, &search);
- if (!found) {
- found = tor_malloc_zero(sizeof(policy_map_ent_t));
- found->policy = tor_memdup(e, sizeof(addr_policy_t));
- found->policy->is_canonical = 1;
- found->policy->refcnt = 1;
- HT_INSERT(policy_map, &policy_root, found);
- }
- tor_assert(!cmp_single_addr_policy(found->policy, e));
- ++found->policy->refcnt;
- return found->policy;
- }
- /** Decide whether a given addr:port is definitely accepted,
- * definitely rejected, probably accepted, or probably rejected by a
- * given policy. If <b>addr</b> is 0, we don't know the IP of the
- * target address. If <b>port</b> is 0, we don't know the port of the
- * target address.
- *
- * For now, the algorithm is pretty simple: we look for definite and
- * uncertain matches. The first definite match is what we guess; if
- * it was preceded by no uncertain matches of the opposite policy,
- * then the guess is definite; otherwise it is probable. (If we
- * have a known addr and port, all matches are definite; if we have an
- * unknown addr/port, any address/port ranges other than "all" are
- * uncertain.)
- *
- * We could do better by assuming that some ranges never match typical
- * addresses (127.0.0.1, and so on). But we'll try this for now.
- */
- addr_policy_result_t
- compare_addr_to_addr_policy(uint32_t addr, uint16_t port,
- smartlist_t *policy)
- {
- int maybe_reject = 0;
- int maybe_accept = 0;
- int match = 0;
- int maybe = 0;
- int i, len;
- len = policy ? smartlist_len(policy) : 0;
- for (i = 0; i < len; ++i) {
- addr_policy_t *tmpe = smartlist_get(policy, i);
- maybe = 0;
- if (!addr) {
- /* Address is unknown. */
- if ((port >= tmpe->prt_min && port <= tmpe->prt_max) ||
- (!port && tmpe->prt_min<=1 && tmpe->prt_max>=65535)) {
- /* The port definitely matches. */
- if (tmpe->maskbits == 0) {
- match = 1;
- } else {
- maybe = 1;
- }
- } else if (!port) {
- /* The port maybe matches. */
- maybe = 1;
- }
- } else {
- /* Address is known */
- if (!addr_mask_cmp_bits(addr, tmpe->addr, tmpe->maskbits)) {
- if (port >= tmpe->prt_min && port <= tmpe->prt_max) {
- /* Exact match for the policy */
- match = 1;
- } else if (!port) {
- maybe = 1;
- }
- }
- }
- if (maybe) {
- if (tmpe->policy_type == ADDR_POLICY_REJECT)
- maybe_reject = 1;
- else
- maybe_accept = 1;
- }
- if (match) {
- if (tmpe->policy_type == ADDR_POLICY_ACCEPT) {
- /* If we already hit a clause that might trigger a 'reject', than we
- * can't be sure of this certain 'accept'.*/
- return maybe_reject ? ADDR_POLICY_PROBABLY_ACCEPTED :
- ADDR_POLICY_ACCEPTED;
- } else {
- return maybe_accept ? ADDR_POLICY_PROBABLY_REJECTED :
- ADDR_POLICY_REJECTED;
- }
- }
- }
- /* accept all by default. */
- return maybe_reject ? ADDR_POLICY_PROBABLY_ACCEPTED : ADDR_POLICY_ACCEPTED;
- }
- /** Return true iff the address policy <b>a</b> covers every case that
- * would be covered by <b>b</b>, so that a,b is redundant. */
- static int
- addr_policy_covers(addr_policy_t *a, addr_policy_t *b)
- {
- /* We can ignore accept/reject, since "accept *:80, reject *:80" reduces
- * to "accept *:80". */
- if (a->maskbits > b->maskbits) {
- /* a has more fixed bits than b; it can't possibly cover b. */
- return 0;
- }
- if (addr_mask_cmp_bits(a->addr, b->addr, a->maskbits)) {
- /* There's a fixed bit in a that's set differently in b. */
- return 0;
- }
- return (a->prt_min <= b->prt_min && a->prt_max >= b->prt_max);
- }
- /** Return true iff the address policies <b>a</b> and <b>b</b> intersect,
- * that is, there exists an address/port that is covered by <b>a</b> that
- * is also covered by <b>b</b>.
- */
- static int
- addr_policy_intersects(addr_policy_t *a, addr_policy_t *b)
- {
- maskbits_t minbits;
- /* All the bits we care about are those that are set in both
- * netmasks. If they are equal in a and b's networkaddresses
- * then the networks intersect. If there is a difference,
- * then they do not. */
- if (a->maskbits < b->maskbits)
- minbits = a->maskbits;
- else
- minbits = b->maskbits;
- if (addr_mask_cmp_bits(a->addr, b->addr, minbits))
- return 0;
- if (a->prt_max < b->prt_min || b->prt_max < a->prt_min)
- return 0;
- return 1;
- }
- /** Add the exit policy described by <b>more</b> to <b>policy</b>.
- */
- static void
- append_exit_policy_string(smartlist_t **policy, const char *more)
- {
- config_line_t tmp;
- tmp.key = NULL;
- tmp.value = (char*) more;
- tmp.next = NULL;
- if (parse_addr_policy(&tmp, policy, -1)<0) {
- log_warn(LD_BUG, "Unable to parse internally generated policy %s",more);
- }
- }
- /** Detect and excise "dead code" from the policy *<b>dest</b>. */
- static void
- exit_policy_remove_redundancies(smartlist_t *dest)
- {
- addr_policy_t *ap, *tmp, *victim;
- int i, j;
- /* Step one: find a *:* entry and cut off everything after it. */
- for (i = 0; i < smartlist_len(dest); ++i) {
- ap = smartlist_get(dest, i);
- if (ap->maskbits == 0 && ap->prt_min <= 1 && ap->prt_max >= 65535) {
- /* This is a catch-all line -- later lines are unreachable. */
- while (i+1 < smartlist_len(dest)) {
- victim = smartlist_get(dest, i+1);
- smartlist_del(dest, i+1);
- addr_policy_free(victim);
- }
- break;
- }
- }
- /* Step two: for every entry, see if there's a redundant entry
- * later on, and remove it. */
- for (i = 0; i < smartlist_len(dest)-1; ++i) {
- ap = smartlist_get(dest, i);
- for (j = i+1; j < smartlist_len(dest); ++j) {
- tmp = smartlist_get(dest, j);
- tor_assert(j > i);
- if (addr_policy_covers(ap, tmp)) {
- char p1[POLICY_BUF_LEN], p2[POLICY_BUF_LEN];
- policy_write_item(p1, sizeof(p1), tmp);
- policy_write_item(p2, sizeof(p2), ap);
- log(LOG_DEBUG, LD_CONFIG, "Removing exit policy %s (%d). It is made "
- "redundant by %s (%d).", p1, j, p2, i);
- smartlist_del_keeporder(dest, j--);
- addr_policy_free(tmp);
- }
- }
- }
- /* Step three: for every entry A, see if there's an entry B making this one
- * redundant later on. This is the case if A and B are of the same type
- * (accept/reject), A is a subset of B, and there is no other entry of
- * different type in between those two that intersects with A.
- *
- * Anybody want to doublecheck the logic here? XXX
- */
- for (i = 0; i < smartlist_len(dest)-1; ++i) {
- ap = smartlist_get(dest, i);
- for (j = i+1; j < smartlist_len(dest); ++j) {
- // tor_assert(j > i); // j starts out at i+1; j only increases; i only
- // // decreases.
- tmp = smartlist_get(dest, j);
- if (ap->policy_type != tmp->policy_type) {
- if (addr_policy_intersects(ap, tmp))
- break;
- } else { /* policy_types are equal. */
- if (addr_policy_covers(tmp, ap)) {
- char p1[POLICY_BUF_LEN], p2[POLICY_BUF_LEN];
- policy_write_item(p1, sizeof(p1), ap);
- policy_write_item(p2, sizeof(p2), tmp);
- log(LOG_DEBUG, LD_CONFIG, "Removing exit policy %s. It is already "
- "covered by %s.", p1, p2);
- smartlist_del_keeporder(dest, i--);
- addr_policy_free(ap);
- break;
- }
- }
- }
- }
- }
- #define DEFAULT_EXIT_POLICY \
- "reject *:25,reject *:119,reject *:135-139,reject *:445," \
- "reject *:465,reject *:563,reject *:587," \
- "reject *:1214,reject *:4661-4666," \
- "reject *:6346-6429,reject *:6699,reject *:6881-6999,accept *:*"
- /** Parse the exit policy <b>cfg</b> into the linked list *<b>dest</b>. If
- * cfg doesn't end in an absolute accept or reject, add the default exit
- * policy afterwards. If <b>rejectprivate</b> is true, prepend
- * "reject private:*" to the policy. Return -1 if we can't parse cfg,
- * else return 0.
- */
- int
- policies_parse_exit_policy(config_line_t *cfg, smartlist_t **dest,
- int rejectprivate, const char *local_address)
- {
- if (rejectprivate) {
- append_exit_policy_string(dest, "reject private:*");
- if (local_address) {
- char buf[POLICY_BUF_LEN];
- tor_snprintf(buf, sizeof(buf), "reject %s:*", local_address);
- append_exit_policy_string(dest, buf);
- }
- }
- if (parse_addr_policy(cfg, dest, -1))
- return -1;
- append_exit_policy_string(dest, DEFAULT_EXIT_POLICY);
- exit_policy_remove_redundancies(*dest);
- return 0;
- }
- /** Replace the exit policy of <b>r</b> with reject *:*. */
- void
- policies_set_router_exitpolicy_to_reject_all(routerinfo_t *r)
- {
- addr_policy_t *item;
- addr_policy_list_free(r->exit_policy);
- r->exit_policy = smartlist_create();
- item = router_parse_addr_policy_item_from_string("reject *:*", -1);
- smartlist_add(r->exit_policy, item);
- }
- /** Return true iff <b>ri</b> is "useful as an exit node", meaning
- * it allows exit to at least one /8 address space for at least
- * two of ports 80, 443, and 6667. */
- int
- exit_policy_is_general_exit(smartlist_t *policy)
- {
- static const int ports[] = { 80, 443, 6667 };
- int n_allowed = 0;
- int i;
- for (i = 0; i < 3; ++i) {
- SMARTLIST_FOREACH(policy, addr_policy_t *, p, {
- if (p->prt_min > ports[i] || p->prt_max < ports[i])
- continue; /* Doesn't cover our port. */
- if (p->maskbits > 8)
- continue; /* Narrower than a /8. */
- if ((p->addr & 0xff000000ul) == 0x7f000000ul)
- continue; /* 127.x */
- /* We have a match that is at least a /8. */
- if (p->policy_type == ADDR_POLICY_ACCEPT) {
- ++n_allowed;
- break; /* stop considering this port */
- }
- });
- }
- return n_allowed >= 2;
- }
- /** Return false if <b>policy</b> might permit access to some addr:port;
- * otherwise if we are certain it rejects everything, return true. */
- int
- policy_is_reject_star(smartlist_t *policy)
- {
- SMARTLIST_FOREACH(policy, addr_policy_t *, p, {
- if (p->policy_type == ADDR_POLICY_ACCEPT)
- return 0;
- else if (p->policy_type == ADDR_POLICY_REJECT &&
- p->prt_min <= 1 && p->prt_max == 65535 &&
- p->maskbits == 0)
- return 1;
- });
- return 1;
- }
- /** Write a single address policy to the buf_len byte buffer at buf. Return
- * the number of characters written, or -1 on failure. */
- int
- policy_write_item(char *buf, size_t buflen, addr_policy_t *policy)
- {
- struct in_addr in;
- size_t written = 0;
- char addrbuf[INET_NTOA_BUF_LEN];
- const char *addrpart;
- int result;
- in.s_addr = htonl(policy->addr);
- tor_inet_ntoa(&in, addrbuf, sizeof(addrbuf));
- /* write accept/reject 1.2.3.4 */
- if (policy->is_private)
- addrpart = "private";
- else if (policy->maskbits == 0)
- addrpart = "*";
- else
- addrpart = addrbuf;
- result = tor_snprintf(buf, buflen, "%s %s",
- policy->policy_type == ADDR_POLICY_ACCEPT ? "accept" : "reject",
- addrpart);
- if (result < 0)
- return -1;
- written += strlen(buf);
- /* If the maskbits is 32 we don't need to give it. If the mask is 0,
- * we already wrote "*". */
- if (policy->maskbits < 32 && policy->maskbits > 0) {
- if (tor_snprintf(buf+written, buflen-written, "/%d", policy->maskbits)<0)
- return -1;
- written += strlen(buf+written);
- }
- if (policy->prt_min <= 1 && policy->prt_max == 65535) {
- /* There is no port set; write ":*" */
- if (written+4 > buflen)
- return -1;
- strlcat(buf+written, ":*", buflen-written);
- written += 2;
- } else if (policy->prt_min == policy->prt_max) {
- /* There is only one port; write ":80". */
- result = tor_snprintf(buf+written, buflen-written, ":%d", policy->prt_min);
- if (result<0)
- return -1;
- written += result;
- } else {
- /* There is a range of ports; write ":79-80". */
- result = tor_snprintf(buf+written, buflen-written, ":%d-%d",
- policy->prt_min, policy->prt_max);
- if (result<0)
- return -1;
- written += result;
- }
- if (written < buflen)
- buf[written] = '\0';
- else
- return -1;
- return (int)written;
- }
- /** Implementation for GETINFO control command: knows the answer for questions
- * about "exit-policy/..." */
- int
- getinfo_helper_policies(control_connection_t *conn,
- const char *question, char **answer)
- {
- (void) conn;
- if (!strcmp(question, "exit-policy/default")) {
- *answer = tor_strdup(DEFAULT_EXIT_POLICY);
- }
- return 0;
- }
- /** Release all storage held by <b>p</b>. */
- void
- addr_policy_list_free(smartlist_t *lst)
- {
- if (!lst) return;
- SMARTLIST_FOREACH(lst, addr_policy_t *, policy, addr_policy_free(policy));
- smartlist_free(lst);
- }
- /** Release all storage held by <b>p</b>. */
- void
- addr_policy_free(addr_policy_t *p)
- {
- if (p) {
- if (--p->refcnt <= 0) {
- if (p->is_canonical) {
- policy_map_ent_t search, *found;
- search.policy = p;
- found = HT_REMOVE(policy_map, &policy_root, &search);
- if (found) {
- tor_assert(p == found->policy);
- tor_free(found);
- }
- }
- tor_free(p);
- }
- }
- }
- /** Release all storage held by policy variables. */
- void
- policies_free_all(void)
- {
- addr_policy_list_free(reachable_or_addr_policy);
- reachable_or_addr_policy = NULL;
- addr_policy_list_free(reachable_dir_addr_policy);
- reachable_dir_addr_policy = NULL;
- addr_policy_list_free(socks_policy);
- socks_policy = NULL;
- addr_policy_list_free(dir_policy);
- dir_policy = NULL;
- addr_policy_list_free(authdir_reject_policy);
- authdir_reject_policy = NULL;
- addr_policy_list_free(authdir_invalid_policy);
- authdir_invalid_policy = NULL;
- }
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