Ignore accept6/reject6 IPv4, warn about unexpected rule outcomes (e033d5e9) · Commits · Benjamin J. Thompson / Tor

changes/bug16069-exit-policy-rule6

0 → 100644

+16 −0

Original line number	Diff line number	Diff line
		o Minor bug fixes (torrc exit policies):
		- When parsing torrc ExitPolicies, we now warn if:
		* an IPv4 address is used on an accept6 or reject6 line. The line is
		ignored, but the rest of the policy items in the list are used.
		(accept/reject continue to allow both IPv4 and IPv6 addresses in
		torrcs.)
		* a "private" address alias is used on an accept6 or reject6 line.
		The line filters both IPv4 and IPv6 private addresses, disregarding
		the 6 in accept6/reject6.
		- When parsing torrc ExitPolicies, we now issue an info-level message:
		* when expanding an accept/reject * line to include both IPv4 and IPv6
		wildcard addresses.
		- In each instance, usage advice is provided to avoid the message.
		Partial fix for ticket 16069. Patch by "teor".
		Patch on 2eb7eafc9d78 and a96c0affcb4c (25 Oct 2012),
		released in 0.2.4.7-alpha.

src/common/address.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -690,6 +690,10 @@ tor_addr_parse_mask_ports(const char *s,
		if (flags & TAPMP_EXTENDED_STAR) {
		family = AF_UNSPEC;
		tor_addr_make_unspec(addr_out);
		log_info(LD_GENERAL,
		"'%s' expands into rules which apply to all IPv4 and IPv6 "
		"addresses. (Use accept/reject 4: for IPv4 or "
		"accept[6]/reject[6] 6: for IPv6.)", s);
		} else {
		family = AF_INET;
		tor_addr_from_ipv4h(addr_out, 0);

src/or/policies.c

+16 −3

Original line number	Diff line number	Diff line
		@@ -167,6 +167,7 @@ parse_addr_policy(config_line_t cfg, smartlist_t *dest,
		smartlist_t *result;
		smartlist_t *entries;
		addr_policy_t *item;
		int malformed_list;
		int r = 0;

		if (!cfg)
		@@ -179,12 +180,22 @@ parse_addr_policy(config_line_t cfg, smartlist_t *dest,
		SPLIT_SKIP_SPACE\|SPLIT_IGNORE_BLANK, 0);
		SMARTLIST_FOREACH_BEGIN(entries, const char *, ent) {
		log_debug(LD_CONFIG,"Adding new entry '%s'",ent);
		item = router_parse_addr_policy_item_from_string(ent, assume_action);
		malformed_list = 0;
		item = router_parse_addr_policy_item_from_string(ent, assume_action,
		&malformed_list);
		if (item) {
		smartlist_add(result, item);
		} else {
		log_warn(LD_CONFIG,"Malformed policy '%s'.", ent);
		} else if (malformed_list) {
		/* the error is so severe the entire list should be discarded */
		log_warn(LD_CONFIG, "Malformed policy '%s'. Discarding entire policy "
		"list.", ent);
		r = -1;
		} else {
		/* the error is minor: don't add the item, but keep processing the
		* rest of the policies in the list */
		log_debug(LD_CONFIG, "Ignored policy '%s' due to non-fatal error. "
		"The remainder of the policy list will be used.",
		ent);
		}
		} SMARTLIST_FOREACH_END(ent);
		SMARTLIST_FOREACH(entries, char *, ent, tor_free(ent));
		@@ -568,6 +579,8 @@ cmp_single_addr_policy(addr_policy_t a, addr_policy_t b)
		return r;
		if ((r=((int)a->is_private - (int)b->is_private)))
		return r;
		/* refcnt and is_canonical are irrelevant to equality,
		* they are hash table implementation details */
		if ((r=tor_addr_compare(&a->addr, &b->addr, CMP_EXACT)))
		return r;
		if ((r=((int)a->maskbits - (int)b->maskbits)))

src/or/routerparse.c

+49 −2

Original line number	Diff line number	Diff line
		@@ -3666,12 +3666,20 @@ networkstatus_parse_detached_signatures(const char s, const char eos)
		* assume_action is nonnegative, then insert its action (ADDR_POLICY_ACCEPT or
		* ADDR_POLICY_REJECT) for items that specify no action.
		*
		* Returns NULL on policy errors.
		*
		* If there is a policy error, malformed_list is set to true if the entire
		* policy list should be discarded. Otherwise, it is set to false, and only
		* this item should be ignored - the rest of the policy list can continue to
		* be processed and used.
		*
		* The addr_policy_t returned by this function can have its address set to
		* AF_UNSPEC for '*'. Use policy_expand_unspec() to turn this into a pair
		* of AF_INET and AF_INET6 items.
		*/
		MOCK_IMPL(addr_policy_t *,
		router_parse_addr_policy_item_from_string,(const char *s, int assume_action))
		router_parse_addr_policy_item_from_string,(const char *s, int assume_action,
		int *malformed_list))
		{
		directory_token_t *tok = NULL;
		const char cp, eos;
		@@ -3688,6 +3696,8 @@ router_parse_addr_policy_item_from_string,(const char *s, int assume_action))
		addr_policy_t *r;
		memarea_t *area = NULL;

		tor_assert(malformed_list);

		s = eat_whitespace(s);
		if ((s == '' \|\| TOR_ISDIGIT(*s)) && assume_action >= 0) {
		if (tor_snprintf(line, sizeof(line), "%s %s",
		@@ -3714,9 +3724,32 @@ router_parse_addr_policy_item_from_string,(const char *s, int assume_action))
		goto err;
		}

		/* Use the extended interpretation of accept/reject *,
		* expanding it into an IPv4 wildcard and an IPv6 wildcard.
		* Also permit 4 and 6 for IPv4 and IPv6 only wildcards. */
		r = router_parse_addr_policy(tok, TAPMP_EXTENDED_STAR);
		if (!r) {
		goto err;
		}

		/* Ensure that accept6/reject6 fields are followed by IPv6 addresses.
		* AF_UNSPEC addresses are only permitted on the accept/reject field type.
		* Unlike descriptors, torrcs exit policy accept/reject can be followed by
		* either an IPv4 or IPv6 address. */
		if ((tok->tp == K_ACCEPT6 \|\| tok->tp == K_REJECT6) &&
		tor_addr_family(&r->addr) != AF_INET6) {
		/* This is a non-fatal error, just ignore this one entry. */
		*malformed_list = 0;
		log_warn(LD_DIR, "IPv4 address '%s' with accept6/reject6 field type in "
		"exit policy. Ignoring, but continuing to parse rules. (Use "
		"accept/reject with IPv4 addresses.)",
		tok->n_args == 1 ? tok->args[0] : "");
		return NULL;
		}

		goto done;
		err:
		*malformed_list = 1;
		r = NULL;
		done:
		token_clear(tok);
		@@ -3733,19 +3766,26 @@ static int
		router_add_exit_policy(routerinfo_t router, directory_token_t tok)
		{
		addr_policy_t *newe;
		/* Use the standard interpretation of accept/reject , an IPv4 wildcard. /
		newe = router_parse_addr_policy(tok, 0);
		if (!newe)
		return -1;
		if (! router->exit_policy)
		router->exit_policy = smartlist_new();

		/* Ensure that in descriptors, accept/reject fields are followed by
		* IPv4 addresses, and accept6/reject6 fields are followed by
		* IPv6 addresses. Unlike torrcs, descriptor exit policies do not permit
		* accept/reject followed by IPv6. */
		if (((tok->tp == K_ACCEPT6 \|\| tok->tp == K_REJECT6) &&
		tor_addr_family(&newe->addr) == AF_INET)
		\|\|
		((tok->tp == K_ACCEPT \|\| tok->tp == K_REJECT) &&
		tor_addr_family(&newe->addr) == AF_INET6)) {
		/* There's nothing the user can do about other relays' descriptors,
		* so we don't provide usage advice here. */
		log_warn(LD_DIR, "Mismatch between field type and address type in exit "
		"policy");
		"policy '%s'. Ignoring.", tok->n_args == 1 ? tok->args[0] : "");
		addr_policy_free(newe);
		return -1;
		}
		@@ -3821,6 +3861,13 @@ router_parse_addr_policy_private(directory_token_t *tok)
		result.prt_min = port_min;
		result.prt_max = port_max;

		if (tok->tp == K_ACCEPT6 \|\| tok->tp == K_REJECT6) {
		log_warn(LD_GENERAL,
		"'%s' expands into rules which apply to all private IPv4 and "
		"IPv6 addresses. (Use accept/reject private:* for IPv4 and "
		"IPv6.)", tok->n_args == 1 ? tok->args[0] : "");
		}

		return addr_policy_get_canonical_entry(&result);
		}

src/or/routerparse.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -41,7 +41,7 @@ extrainfo_t extrainfo_parse_entry_from_string(const char s, const char *end,
		int cache_copy, struct digest_ri_map_t *routermap,
		int *can_dl_again_out);
		MOCK_DECL(addr_policy_t *, router_parse_addr_policy_item_from_string,
		(const char *s, int assume_action));
		(const char s, int assume_action, int malformed_list));
		version_status_t tor_version_is_obsolete(const char *myversion,
		const char *versionlist);
		int tor_version_as_new_as(const char platform, const char cutoff);