commit 85659d3964669f9f419123c648e517f4ba539462 Author: Nick Mathewson nickm@torproject.org Date: Mon Oct 22 17:34:05 2012 -0400
Fix parse_short_policy (bug 7192.)
Our implementation of parse_short_policy was screwed up: it would ignore the last character of every short policy. Obviously, that's broken.
This patch fixes the busted behavior, and adds a bunch of unit tests to make sure the rest of that function is okay.
Fixes bug 7192; fix on 0.2.3.1-alpha. --- changes/bug7192 | 10 ++++++++ src/or/policies.c | 18 +++++++++----- src/or/policies.h | 2 +- src/test/test.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++- 4 files changed, 85 insertions(+), 9 deletions(-)
diff --git a/changes/bug7192 b/changes/bug7192 new file mode 100644 index 0000000..10cbc24 --- /dev/null +++ b/changes/bug7192 @@ -0,0 +1,10 @@ + o Major bugfixes: + - When parsing exit policy summaries from microdescriptors, we had + previously been ignoring the last character in each one, so that + "accept 80,443,8080" would be treated by clients as indicating a + node that allows access to ports 80, 443, and 808. That would lead + to clients attempting connections that could never work, and + ignoring exit nodes that would support their connections. Now clients + parse these exit policy summaries correctly. Fixes bug 7192; + bugfix on 0.2.3.1-alpha. + diff --git a/src/or/policies.c b/src/or/policies.c index 486c264..bbd6816 100644 --- a/src/or/policies.c +++ b/src/or/policies.c @@ -1348,8 +1348,10 @@ parse_short_policy(const char *summary) unsigned low, high; char dummy; char ent_buf[32]; + size_t len;
next = comma ? comma+1 : strchr(summary, '\0'); + len = comma ? (size_t)(comma - summary) : strlen(summary);
if (n_entries == MAX_EXITPOLICY_SUMMARY_LEN) { log_fn(LOG_PROTOCOL_WARN, LD_DIR, "Impossibly long policy summary %s", @@ -1357,20 +1359,22 @@ parse_short_policy(const char *summary) return NULL; }
- if (! TOR_ISDIGIT(*summary) || next-summary > (int)(sizeof(ent_buf)-1)) { + if (! TOR_ISDIGIT(*summary) || len > (sizeof(ent_buf)-1)) { /* unrecognized entry format. skip it. */ continue; } - if (next-summary < 2) { + if (len < 1) { /* empty; skip it. */ + /* XXX This happens to be unreachable, since if len==0, then *summary is + * ',' or '\0', and the TOR_ISDIGIT test above would have failed. */ continue; }
- memcpy(ent_buf, summary, next-summary-1); - ent_buf[next-summary-1] = '\0'; + memcpy(ent_buf, summary, len); + ent_buf[len] = '\0';
if (tor_sscanf(ent_buf, "%u-%u%c", &low, &high, &dummy) == 2) { - if (low<1 || low>65535 || high<1 || high>65535) { + if (low<1 || low>65535 || high<1 || high>65535 || low>high) { log_fn(LOG_PROTOCOL_WARN, LD_DIR, "Found bad entry in policy summary %s", escaped(orig_summary)); return NULL; @@ -1415,7 +1419,7 @@ parse_short_policy(const char *summary)
/** Write <b>policy</b> back out into a string. Used only for unit tests * currently. */ -const char * +char * write_short_policy(const short_policy_t *policy) { int i; @@ -1424,7 +1428,7 @@ write_short_policy(const short_policy_t *policy)
smartlist_add_asprintf(sl, "%s", policy->is_accept ? "accept " : "reject ");
- for(i=0; i < policy->n_entries; i++) { + for (i=0; i < policy->n_entries; i++) { const short_policy_entry_t *e = &policy->entries[i]; if (e->min_port == e->max_port) { smartlist_add_asprintf(sl, "%d", e->min_port); diff --git a/src/or/policies.h b/src/or/policies.h index b385d8e..f00d829 100644 --- a/src/or/policies.h +++ b/src/or/policies.h @@ -61,7 +61,7 @@ void policies_free_all(void); char *policy_summarize(smartlist_t *policy);
short_policy_t *parse_short_policy(const char *summary); -const char *write_short_policy(const short_policy_t *policy); +char *write_short_policy(const short_policy_t *policy); void short_policy_free(short_policy_t *policy); int short_policy_is_reject_star(const short_policy_t *policy); addr_policy_result_t compare_tor_addr_to_short_policy( diff --git a/src/test/test.c b/src/test/test.c index 9b510d2..ddfd633 100644 --- a/src/test/test.c +++ b/src/test/test.c @@ -1004,6 +1004,28 @@ test_circuit_timeout(void) return; }
+/* Helper: assert that short_policy parses and writes back out as itself, + or as <b>expected</b> if that's provided. */ +static void +test_short_policy_parse(const char *input, + const char *expected) +{ + short_policy_t *short_policy = NULL; + char *out = NULL; + + if (expected == NULL) + expected = input; + + short_policy = parse_short_policy(input); + tt_assert(short_policy); + out = write_short_policy(short_policy); + tt_str_op(out, ==, expected); + + done: + tor_free(out); + short_policy_free(short_policy); +} + /** Helper: Parse the exit policy string in <b>policy_str</b>, and make sure * that policies_summarize() produces the string <b>expected_summary</b> from * it. */ @@ -1014,7 +1036,7 @@ test_policy_summary_helper(const char *policy_str, config_line_t line; smartlist_t *policy = smartlist_new(); char *summary = NULL; - const char *summary_after; + char *summary_after = NULL; int r; short_policy_t *short_policy = NULL;
@@ -1231,6 +1253,46 @@ test_policies(void) "accept *:*", "reject 1,3,5,7");
+ /* Short policies with unrecognized formats should get accepted. */ + test_short_policy_parse("accept fred,2,3-5", "accept 2,3-5"); + test_short_policy_parse("accept 2,fred,3", "accept 2,3"); + test_short_policy_parse("accept 2,fred,3,bob", "accept 2,3"); + test_short_policy_parse("accept 2,-3,500-600", "accept 2,500-600"); + /* Short policies with nil entries are accepted too. */ + test_short_policy_parse("accept 1,,3", "accept 1,3"); + test_short_policy_parse("accept 100-200,,", "accept 100-200"); + test_short_policy_parse("reject ,1-10,,,,30-40", "reject 1-10,30-40"); + + /* Try parsing various broken short policies */ + tt_ptr_op(NULL, ==, parse_short_policy("accept 200-199")); + tt_ptr_op(NULL, ==, parse_short_policy("")); + tt_ptr_op(NULL, ==, parse_short_policy("rejekt 1,2,3")); + tt_ptr_op(NULL, ==, parse_short_policy("reject ")); + tt_ptr_op(NULL, ==, parse_short_policy("reject")); + tt_ptr_op(NULL, ==, parse_short_policy("rej")); + tt_ptr_op(NULL, ==, parse_short_policy("accept 2,3,100000")); + tt_ptr_op(NULL, ==, parse_short_policy("accept 2,3x,4")); + tt_ptr_op(NULL, ==, parse_short_policy("accept 2,3x,4")); + tt_ptr_op(NULL, ==, parse_short_policy("accept 2-")); + tt_ptr_op(NULL, ==, parse_short_policy("accept 2-x")); + tt_ptr_op(NULL, ==, parse_short_policy("accept 1-,3")); + tt_ptr_op(NULL, ==, parse_short_policy("accept 1-,3")); + /* Test a too-long policy. */ + { + int i; + char *policy = NULL; + smartlist_t *chunks = smartlist_new(); + smartlist_add(chunks, tor_strdup("accept ")); + for (i=1; i<10000; ++i) + smartlist_add_asprintf(chunks, "%d,", i); + smartlist_add(chunks, tor_strdup("20000")); + policy = smartlist_join_strings(chunks, "", 0, NULL); + SMARTLIST_FOREACH(chunks, char *, ch, tor_free(ch)); + smartlist_free(chunks); + tt_ptr_op(NULL, ==, parse_short_policy(policy));/* shouldn't be accepted */ + tor_free(policy); /* could leak. */ + } + /* truncation ports */ sm = smartlist_new(); for (i=1; i<2000; i+=2) {