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- /* Copyright (c) 2001 Matej Pfajfar.
- * Copyright (c) 2001-2004, Roger Dingledine.
- * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
- * Copyright (c) 2007-2018, The Tor Project, Inc. */
- /* See LICENSE for licensing information */
- /**
- * \file policy_parse.c
- * \brief Code to parse address policies.
- **/
- #define EXPOSE_ROUTERDESC_TOKEN_TABLE
- #include "core/or/or.h"
- #include "core/or/policies.h"
- #include "feature/dirparse/parsecommon.h"
- #include "feature/dirparse/policy_parse.h"
- #include "feature/dirparse/routerparse.h"
- #include "feature/dirparse/unparseable.h"
- #include "lib/memarea/memarea.h"
- #include "core/or/addr_policy_st.h"
- static addr_policy_t *router_parse_addr_policy_private(directory_token_t *tok);
- /** Parse the addr policy in the string <b>s</b> and return it. If
- * 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.
- *
- * Set *<b>malformed_list</b> to true if the entire policy list should be
- * discarded. Otherwise, set it to false, and only this item should be ignored
- * on error - 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,
- int *malformed_list))
- {
- directory_token_t *tok = NULL;
- const char *cp, *eos;
- /* Longest possible policy is
- * "accept6 [ffff:ffff:..255]/128:10000-65535",
- * which contains a max-length IPv6 address, plus 26 characters.
- * But note that there can be an arbitrary amount of space between the
- * accept and the address:mask/port element.
- * We don't need to multiply TOR_ADDR_BUF_LEN by 2, as there is only one
- * IPv6 address. But making the buffer shorter might cause valid long lines,
- * which parsed in previous versions, to fail to parse in new versions.
- * (These lines would have to have excessive amounts of whitespace.) */
- char line[TOR_ADDR_BUF_LEN*2 + 32];
- addr_policy_t *r;
- memarea_t *area = NULL;
- tor_assert(malformed_list);
- *malformed_list = 0;
- s = eat_whitespace(s);
- /* We can only do assume_action on []-quoted IPv6, as "a" (accept)
- * and ":" (port separator) are ambiguous */
- if ((*s == '*' || *s == '[' || TOR_ISDIGIT(*s)) && assume_action >= 0) {
- if (tor_snprintf(line, sizeof(line), "%s %s",
- assume_action == ADDR_POLICY_ACCEPT?"accept":"reject", s)<0) {
- log_warn(LD_DIR, "Policy %s is too long.", escaped(s));
- return NULL;
- }
- cp = line;
- tor_strlower(line);
- } else { /* assume an already well-formed address policy line */
- cp = s;
- }
- eos = cp + strlen(cp);
- area = memarea_new();
- tok = get_next_token(area, &cp, eos, routerdesc_token_table);
- if (tok->tp == ERR_) {
- log_warn(LD_DIR, "Error reading address policy: %s", tok->error);
- goto err;
- }
- if (tok->tp != K_ACCEPT && tok->tp != K_ACCEPT6 &&
- tok->tp != K_REJECT && tok->tp != K_REJECT6) {
- log_warn(LD_DIR, "Expected 'accept' or 'reject'.");
- 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] : "");
- addr_policy_free(r);
- r = NULL;
- goto done;
- }
- goto done;
- err:
- *malformed_list = 1;
- r = NULL;
- done:
- token_clear(tok);
- if (area) {
- DUMP_AREA(area, "policy item");
- memarea_drop_all(area);
- }
- return r;
- }
- /** Given a K_ACCEPT[6] or K_REJECT[6] token and a router, create and return
- * a new exit_policy_t corresponding to the token. If TAPMP_EXTENDED_STAR
- * is set in fmt_flags, K_ACCEPT6 and K_REJECT6 tokens followed by *
- * expand to IPv6-only policies, otherwise they expand to IPv4 and IPv6
- * policies */
- addr_policy_t *
- router_parse_addr_policy(directory_token_t *tok, unsigned fmt_flags)
- {
- addr_policy_t newe;
- char *arg;
- tor_assert(tok->tp == K_REJECT || tok->tp == K_REJECT6 ||
- tok->tp == K_ACCEPT || tok->tp == K_ACCEPT6);
- if (tok->n_args != 1)
- return NULL;
- arg = tok->args[0];
- if (!strcmpstart(arg,"private"))
- return router_parse_addr_policy_private(tok);
- memset(&newe, 0, sizeof(newe));
- if (tok->tp == K_REJECT || tok->tp == K_REJECT6)
- newe.policy_type = ADDR_POLICY_REJECT;
- else
- newe.policy_type = ADDR_POLICY_ACCEPT;
- /* accept6/reject6 * produces an IPv6 wildcard address only.
- * (accept/reject * produces rules for IPv4 and IPv6 wildcard addresses.) */
- if ((fmt_flags & TAPMP_EXTENDED_STAR)
- && (tok->tp == K_ACCEPT6 || tok->tp == K_REJECT6)) {
- fmt_flags |= TAPMP_STAR_IPV6_ONLY;
- }
- if (tor_addr_parse_mask_ports(arg, fmt_flags, &newe.addr, &newe.maskbits,
- &newe.prt_min, &newe.prt_max) < 0) {
- log_warn(LD_DIR,"Couldn't parse line %s. Dropping", escaped(arg));
- return NULL;
- }
- addr_policy_t *result = addr_policy_get_canonical_entry(&newe);
- /* It would be a nasty error to return 'newe', and sometimes
- * addr_policy_get_canonical_entry() can return its argument. But in this
- * case, it won't, since newe is *not* canonical. We assert here to make
- * sure that the compiler knows it too.
- */
- tor_assert(result != &newe);
- return result;
- }
- /** Parse an exit policy line of the format "accept[6]/reject[6] private:...".
- * This didn't exist until Tor 0.1.1.15, so nobody should generate it in
- * router descriptors until earlier versions are obsolete.
- *
- * accept/reject and accept6/reject6 private all produce rules for both
- * IPv4 and IPv6 addresses.
- */
- static addr_policy_t *
- router_parse_addr_policy_private(directory_token_t *tok)
- {
- const char *arg;
- uint16_t port_min, port_max;
- addr_policy_t result;
- arg = tok->args[0];
- if (strcmpstart(arg, "private"))
- return NULL;
- arg += strlen("private");
- arg = (char*) eat_whitespace(arg);
- if (!arg || *arg != ':')
- return NULL;
- if (parse_port_range(arg+1, &port_min, &port_max)<0)
- return NULL;
- memset(&result, 0, sizeof(result));
- if (tok->tp == K_REJECT || tok->tp == K_REJECT6)
- result.policy_type = ADDR_POLICY_REJECT;
- else
- result.policy_type = ADDR_POLICY_ACCEPT;
- result.is_private = 1;
- 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);
- }
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