[tor-commits] [tor/master] Better policy support for IPv6
nickm at torproject.org
nickm at torproject.org
Thu Nov 15 19:47:52 UTC 2012
commit a96c0affcb4cda1a2e0d83d123993d10efc6e396
Author: Nick Mathewson <nickm at torproject.org>
Date: Wed Oct 24 15:03:29 2012 -0400
Better policy support for IPv6
Now, "accept *:80" means "accept all addresses on port 80", and not
just IPv4. For just v4, say "accept *4:80"; for just v6 say "accept
*6:80".
We can parse these policies from torrc just fine, and we should be
successfully keeping them out of descriptors for now.
We also now include appropriate IPv6 addresses in "reject private:*"
---
src/or/dirserv.c | 2 +-
src/or/dirvote.c | 2 +-
src/or/or.h | 10 +++-
src/or/policies.c | 135 ++++++++++++++++++++++++++++++++++++++++---------
src/or/policies.h | 3 +-
src/or/router.c | 6 +-
src/or/routerparse.c | 15 ++++--
src/or/routerset.c | 1 +
src/test/test.c | 4 +-
9 files changed, 139 insertions(+), 39 deletions(-)
diff --git a/src/or/dirserv.c b/src/or/dirserv.c
index e7aa582..1d63be0 100644
--- a/src/or/dirserv.c
+++ b/src/or/dirserv.c
@@ -2237,7 +2237,7 @@ routerstatus_format_entry(char *buf, size_t buf_len,
}
if (desc) {
- summary = policy_summarize(desc->exit_policy);
+ summary = policy_summarize(desc->exit_policy, AF_INET);
r = tor_snprintf(cp, buf_len - (cp-buf), "p %s\n", summary);
if (r<0) {
log_warn(LD_BUG, "Not enough space in buffer.");
diff --git a/src/or/dirvote.c b/src/or/dirvote.c
index 7020943..f8b8d37 100644
--- a/src/or/dirvote.c
+++ b/src/or/dirvote.c
@@ -3552,7 +3552,7 @@ dirvote_create_microdescriptor(const routerinfo_t *ri, int consensus_method)
if (crypto_pk_write_public_key_to_string(ri->onion_pkey, &key, &keylen)<0)
goto done;
- summary = policy_summarize(ri->exit_policy);
+ summary = policy_summarize(ri->exit_policy, AF_INET);
if (ri->declared_family)
family = smartlist_join_strings(ri->declared_family, " ", 0, NULL);
diff --git a/src/or/or.h b/src/or/or.h
index 6510725..42bf0a8 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -1730,7 +1730,15 @@ typedef struct addr_policy_t {
maskbits_t maskbits; /**< Accept/reject all addresses <b>a</b> such that the
* first <b>maskbits</b> bits of <b>a</b> match
* <b>addr</b>. */
- tor_addr_t addr; /**< Base address to accept or reject. */
+ /** Base address to accept or reject.
+ *
+ * Note that wildcards are treated
+ * differntly depending on address family. An AF_UNSPEC address means
+ * "All addresses, IPv4 or IPv6." An AF_INET address with maskbits==0 means
+ * "All IPv4 addresses" and an AF_INET6 address with maskbits == 0 means
+ * "All IPv6 addresses".
+ **/
+ tor_addr_t addr;
uint16_t prt_min; /**< Lowest port number to accept/reject. */
uint16_t prt_max; /**< Highest port number to accept/reject. */
} addr_policy_t;
diff --git a/src/or/policies.c b/src/or/policies.c
index 442377b..8367446 100644
--- a/src/or/policies.c
+++ b/src/or/policies.c
@@ -59,8 +59,10 @@ typedef struct policy_summary_item_t {
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",
- // "fc00::/7", "fe80::/10", "fec0::/10", "::/127",
- NULL };
+ "[::]/8",
+ "[fc00::]/7", "[fe80::]/10", "[fec0::]/10", "[ff00::]/8", "[::]/127",
+ NULL
+};
/** Replace all "private" entries in *<b>policy</b> with their expanded
* equivalents. */
@@ -101,6 +103,49 @@ policy_expand_private(smartlist_t **policy)
*policy = tmp;
}
+/** Expand each of the AF_UNSPEC elements in *<b>policy</b> (which indicate
+ * protocol-neutral wildcards) into a pair of wildcard elements: one IPv4-
+ * specific and one IPv6-specific. */
+void
+policy_expand_unspec(smartlist_t **policy)
+{
+ smartlist_t *tmp;
+ if (!*policy)
+ return;
+
+ tmp = smartlist_new();
+ SMARTLIST_FOREACH_BEGIN(*policy, addr_policy_t *, p) {
+ sa_family_t family = tor_addr_family(&p->addr);
+ if (family == AF_INET6 || family == AF_INET || p->is_private) {
+ smartlist_add(tmp, p);
+ } else if (family == AF_UNSPEC) {
+ addr_policy_t newpolicy_ipv4;
+ addr_policy_t newpolicy_ipv6;
+ memcpy(&newpolicy_ipv4, p, sizeof(addr_policy_t));
+ memcpy(&newpolicy_ipv6, p, sizeof(addr_policy_t));
+ newpolicy_ipv4.is_canonical = 0;
+ newpolicy_ipv6.is_canonical = 0;
+ if (p->maskbits != 0) {
+ log_warn(LD_BUG, "AF_UNSPEC policy with maskbits==%d", p->maskbits);
+ newpolicy_ipv4.maskbits = 0;
+ newpolicy_ipv6.maskbits = 0;
+ }
+ tor_addr_from_ipv4h(&newpolicy_ipv4.addr, 0);
+ tor_addr_from_ipv6_bytes(&newpolicy_ipv6.addr,
+ "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");
+ smartlist_add(tmp, addr_policy_get_canonical_entry(&newpolicy_ipv4));
+ smartlist_add(tmp, addr_policy_get_canonical_entry(&newpolicy_ipv6));
+ addr_policy_free(p);
+ } else {
+ log_warn(LD_BUG, "Funny-looking address policy with family %d", family);
+ smartlist_add(tmp, p);
+ }
+ } SMARTLIST_FOREACH_END(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
@@ -145,6 +190,7 @@ parse_addr_policy(config_line_t *cfg, smartlist_t **dest,
addr_policy_list_free(result);
} else {
policy_expand_private(&result);
+ policy_expand_unspec(&result);
if (*dest) {
smartlist_add_all(*dest, result);
@@ -735,6 +781,10 @@ compare_tor_addr_to_addr_policy(const tor_addr_t *addr, uint16_t port,
static int
addr_policy_covers(addr_policy_t *a, addr_policy_t *b)
{
+ if (tor_addr_family(&a->addr) != tor_addr_family(&b->addr)) {
+ /* You can't cover a different family. */
+ return 0;
+ }
/* We can ignore accept/reject, since "accept *:80, reject *:80" reduces
* to "accept *:80". */
if (a->maskbits > b->maskbits) {
@@ -790,20 +840,32 @@ append_exit_policy_string(smartlist_t **policy, const char *more)
static void
exit_policy_remove_redundancies(smartlist_t *dest)
{
- addr_policy_t *ap, *tmp, *victim;
+ addr_policy_t *ap, *tmp;
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);
+ /* Step one: kill every ipv4 thing after *4:*, every IPv6 thing after *6:*
+ */
+ {
+ int kill_v4=0, kill_v6=0;
+ for (i = 0; i < smartlist_len(dest); ++i) {
+ sa_family_t family;
+ ap = smartlist_get(dest, i);
+ family = tor_addr_family(&ap->addr);
+ if ((family == AF_INET && kill_v4) ||
+ (family == AF_INET6 && kill_v6)) {
+ smartlist_del_keeporder(dest, i--);
+ addr_policy_free(ap);
+ continue;
+ }
+
+ if (ap->maskbits == 0 && ap->prt_min <= 1 && ap->prt_max >= 65535) {
+ /* This is a catch-all line -- later lines are unreachable. */
+ if (family == AF_INET) {
+ kill_v4 = 1;
+ } else if (family == AF_INET6) {
+ kill_v6 = 1;
+ }
}
- break;
}
}
@@ -869,6 +931,10 @@ exit_policy_remove_redundancies(smartlist_t *dest)
* 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.
+ *
+ * This function is used to parse the exit policy from our torrc. For
+ * the functions used to parse the exit policy from a router descriptor,
+ * see router_add_exit_policy.
*/
int
policies_parse_exit_policy(config_line_t *cfg, smartlist_t **dest,
@@ -885,10 +951,12 @@ policies_parse_exit_policy(config_line_t *cfg, smartlist_t **dest,
}
if (parse_addr_policy(cfg, dest, -1))
return -1;
- if (add_default_policy)
+ if (add_default_policy) {
append_exit_policy_string(dest, DEFAULT_EXIT_POLICY);
- else
- append_exit_policy_string(dest, "reject *:*");
+ } else {
+ append_exit_policy_string(dest, "reject *4:*");
+ append_exit_policy_string(dest, "reject *6:*");
+ }
exit_policy_remove_redundancies(*dest);
return 0;
@@ -899,7 +967,8 @@ policies_parse_exit_policy(config_line_t *cfg, smartlist_t **dest,
void
policies_exit_policy_append_reject_star(smartlist_t **dest)
{
- append_exit_policy_string(dest, "reject *:*");
+ append_exit_policy_string(dest, "reject *4:*");
+ append_exit_policy_string(dest, "reject *6:*");
}
/** Replace the exit policy of <b>node</b> with reject *:* */
@@ -1001,17 +1070,26 @@ policy_write_item(char *buf, size_t buflen, addr_policy_t *policy,
const char *addrpart;
int result;
const int is_accept = policy->policy_type == ADDR_POLICY_ACCEPT;
- const int is_ip6 = tor_addr_family(&policy->addr) == AF_INET6;
+ const sa_family_t family = tor_addr_family(&policy->addr);
+ const int is_ip6 = (family == AF_INET6);
tor_addr_to_str(addrbuf, &policy->addr, sizeof(addrbuf), 1);
/* write accept/reject 1.2.3.4 */
- if (policy->is_private)
+ if (policy->is_private) {
addrpart = "private";
- else if (policy->maskbits == 0)
- addrpart = "*";
- else
+ } else if (policy->maskbits == 0) {
+ if (format_for_desc)
+ addrpart = "*";
+ else if (family == AF_INET6)
+ addrpart = "*6";
+ else if (family == AF_INET)
+ addrpart = "*4";
+ else
+ addrpart = "*";
+ } else {
addrpart = addrbuf;
+ }
result = tor_snprintf(buf, buflen, "%s%s %s",
is_accept ? "accept" : "reject",
@@ -1220,7 +1298,7 @@ policy_summary_add_item(smartlist_t *summary, addr_policy_t *p)
* is an exception to the shorter-representation-wins rule).
*/
char *
-policy_summarize(smartlist_t *policy)
+policy_summarize(smartlist_t *policy, sa_family_t family)
{
smartlist_t *summary = policy_summary_create();
smartlist_t *accepts, *rejects;
@@ -1232,9 +1310,16 @@ policy_summarize(smartlist_t *policy)
tor_assert(policy);
/* Create the summary list */
- SMARTLIST_FOREACH(policy, addr_policy_t *, p, {
+ SMARTLIST_FOREACH_BEGIN(policy, addr_policy_t *, p) {
+ sa_family_t f = tor_addr_family(&p->addr);
+ if (f != AF_INET && f != AF_INET6) {
+ log_warn(LD_BUG, "Weird family when summarizing address policy");
+ }
+ if (f != family)
+ continue;
+ /* XXXX-ipv6 More family work is needed */
policy_summary_add_item(summary, p);
- });
+ } SMARTLIST_FOREACH_END(p);
/* Now create two lists of strings, one for accepted and one
* for rejected ports. We take care to merge ranges so that
diff --git a/src/or/policies.h b/src/or/policies.h
index 431e69e..e9d214d 100644
--- a/src/or/policies.h
+++ b/src/or/policies.h
@@ -31,6 +31,7 @@ int authdir_policy_badexit_address(uint32_t addr, uint16_t port);
int validate_addr_policies(const or_options_t *options, char **msg);
void policy_expand_private(smartlist_t **policy);
+void policy_expand_unspec(smartlist_t **policy);
int policies_parse_from_options(const or_options_t *options);
addr_policy_t *addr_policy_get_canonical_entry(addr_policy_t *ent);
@@ -58,7 +59,7 @@ void addr_policy_list_free(smartlist_t *p);
void addr_policy_free(addr_policy_t *p);
void policies_free_all(void);
-char *policy_summarize(smartlist_t *policy);
+char *policy_summarize(smartlist_t *policy, sa_family_t family);
short_policy_t *parse_short_policy(const char *summary);
char *write_short_policy(const short_policy_t *policy);
diff --git a/src/or/router.c b/src/or/router.c
index 1cac63a..efe24d7 100644
--- a/src/or/router.c
+++ b/src/or/router.c
@@ -2001,7 +2001,6 @@ router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router,
size_t onion_pkeylen, identity_pkeylen;
size_t written;
int result=0;
- addr_policy_t *tmpe;
char *family_line;
char *extra_or_address = NULL;
const or_options_t *options = get_options();
@@ -2130,11 +2129,12 @@ router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router,
if (!router->exit_policy || !smartlist_len(router->exit_policy)) {
strlcat(s+written, "reject *:*\n", maxlen-written);
written += strlen("reject *:*\n");
- tmpe = NULL;
} else if (router->exit_policy) {
int i;
for (i = 0; i < smartlist_len(router->exit_policy); ++i) {
- tmpe = smartlist_get(router->exit_policy, i);
+ addr_policy_t *tmpe = smartlist_get(router->exit_policy, i);
+ if (tor_addr_family(&tmpe->addr) == AF_INET6)
+ continue; /* Don't include IPv6 parts of address policy */
result = policy_write_item(s+written, maxlen-written, tmpe, 1);
if (result < 0) {
log_warn(LD_BUG,"descriptor policy_write_item ran out of room!");
diff --git a/src/or/routerparse.c b/src/or/routerparse.c
index 6069c8d..7c1dd88 100644
--- a/src/or/routerparse.c
+++ b/src/or/routerparse.c
@@ -535,7 +535,8 @@ static token_rule_t microdesc_token_table[] = {
/* static function prototypes */
static int router_add_exit_policy(routerinfo_t *router,directory_token_t *tok);
-static addr_policy_t *router_parse_addr_policy(directory_token_t *tok);
+static addr_policy_t *router_parse_addr_policy(directory_token_t *tok,
+ unsigned fmt_flags);
static addr_policy_t *router_parse_addr_policy_private(directory_token_t *tok);
static int router_get_hash_impl(const char *s, size_t s_len, char *digest,
@@ -3633,6 +3634,10 @@ networkstatus_parse_detached_signatures(const char *s, const char *eos)
/** 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.
+ *
+ * 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.
*/
addr_policy_t *
router_parse_addr_policy_item_from_string(const char *s, int assume_action)
@@ -3672,7 +3677,7 @@ router_parse_addr_policy_item_from_string(const char *s, int assume_action)
goto err;
}
- r = router_parse_addr_policy(tok);
+ r = router_parse_addr_policy(tok, TAPMP_EXTENDED_STAR);
goto done;
err:
r = NULL;
@@ -3691,7 +3696,7 @@ static int
router_add_exit_policy(routerinfo_t *router, directory_token_t *tok)
{
addr_policy_t *newe;
- newe = router_parse_addr_policy(tok);
+ newe = router_parse_addr_policy(tok, 0);
if (!newe)
return -1;
if (! router->exit_policy)
@@ -3716,7 +3721,7 @@ router_add_exit_policy(routerinfo_t *router, directory_token_t *tok)
/** Given a K_ACCEPT or K_REJECT token and a router, create and return
* a new exit_policy_t corresponding to the token. */
static addr_policy_t *
-router_parse_addr_policy(directory_token_t *tok)
+router_parse_addr_policy(directory_token_t *tok, unsigned fmt_flags)
{
addr_policy_t newe;
char *arg;
@@ -3738,7 +3743,7 @@ router_parse_addr_policy(directory_token_t *tok)
else
newe.policy_type = ADDR_POLICY_ACCEPT;
- if (tor_addr_parse_mask_ports(arg, 0, &newe.addr, &newe.maskbits,
+ 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;
diff --git a/src/or/routerset.c b/src/or/routerset.c
index 8a5ff21..a495863 100644
--- a/src/or/routerset.c
+++ b/src/or/routerset.c
@@ -148,6 +148,7 @@ routerset_parse(routerset_t *target, const char *s, const char *description)
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)
diff --git a/src/test/test.c b/src/test/test.c
index fc3c36e..6652e77 100644
--- a/src/test/test.c
+++ b/src/test/test.c
@@ -1046,7 +1046,7 @@ test_policy_summary_helper(const char *policy_str,
r = policies_parse_exit_policy(&line, &policy, 0, NULL, 1);
test_eq(r, 0);
- summary = policy_summarize(policy);
+ summary = policy_summarize(policy, AF_INET);
test_assert(summary != NULL);
test_streq(summary, expected_summary);
@@ -1192,7 +1192,7 @@ test_policies(void)
test_assert(policy);
//test_streq(policy->string, "accept *:80");
//test_streq(policy->next->string, "reject *:*");
- test_eq(smartlist_len(policy), 2);
+ test_eq(smartlist_len(policy), 4);
/* test policy summaries */
/* check if we properly ignore private IP addresses */
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