commit 7197c9f14a60cd9e496fcd432a2fecb12b20f4dc Author: Nick Mathewson nickm@torproject.org Date: Wed Nov 14 10:14:23 2012 -0500
Repair DNS NEXIST hijacking workaround
The code previously detected wildcarding and replaced wildcarded answers with DNS_STATUS_FAILED_PERMANENT. But that status variable was no longer used! Remove the status variable, and instead change the value of 'result' in evdns_callback.
Thank goodness for compiler warnings. In this case, unused-but-set-variable.
Thanks to Linus for finding this one. --- src/or/dns.c | 11 ++--------- 1 files changed, 2 insertions(+), 9 deletions(-)
diff --git a/src/or/dns.c b/src/or/dns.c index 2804a0f..5a7f07c 100644 --- a/src/or/dns.c +++ b/src/or/dns.c @@ -1530,7 +1530,6 @@ evdns_callback(int result, char type, int count, int ttl, void *addresses, char *arg_ = arg; uint8_t orig_query_type = arg_[0]; char *string_address = arg_ + 1; - int status = DNS_RESOLVE_FAILED_PERMANENT; tor_addr_t addr; const char *hostname = NULL; int was_wildcarded = 0; @@ -1560,7 +1559,6 @@ evdns_callback(int result, char type, int count, int ttl, void *addresses, char *escaped_address; uint32_t *addrs = addresses; tor_addr_from_ipv4n(&addr, addrs[0]); - status = DNS_RESOLVE_SUCCEEDED;
tor_addr_to_str(answer_buf, &addr, sizeof(answer_buf), 0); escaped_address = esc_for_log(string_address); @@ -1572,7 +1570,7 @@ evdns_callback(int result, char type, int count, int ttl, void *addresses, escaped_safe_str(answer_buf)); was_wildcarded = 1; tor_addr_make_null(&addr, AF_INET); /* ???? */ - status = DNS_RESOLVE_FAILED_PERMANENT; + result = DNS_ERR_NOTEXIST; } else { log_debug(LD_EXIT, "eventdns said that %s resolves to %s", safe_str(escaped_address), @@ -1584,7 +1582,6 @@ evdns_callback(int result, char type, int count, int ttl, void *addresses, char *escaped_address; struct in6_addr *addrs = addresses; tor_addr_from_in6(&addr, &addrs[0]); - status = DNS_RESOLVE_SUCCEEDED; tor_inet_ntop(AF_INET6, &addrs[0], answer_buf, sizeof(answer_buf)); escaped_address = esc_for_log(string_address);
@@ -1595,7 +1592,7 @@ evdns_callback(int result, char type, int count, int ttl, void *addresses, escaped_safe_str(answer_buf)); was_wildcarded = 1; tor_addr_make_unspec(&addr); /* WRONG WRONG ETC XXXXXXXX */ - status = DNS_RESOLVE_FAILED_PERMANENT; + result = DNS_ERR_NOTEXIST; } else { log_debug(LD_EXIT, "eventdns said that %s resolves to %s", safe_str(escaped_address), @@ -1605,7 +1602,6 @@ evdns_callback(int result, char type, int count, int ttl, void *addresses, } else if (type == DNS_PTR && count) { char *escaped_address; hostname = ((char**)addresses)[0]; - status = DNS_RESOLVE_SUCCEEDED; escaped_address = esc_for_log(string_address); log_debug(LD_EXIT, "eventdns said that %s resolves to %s", safe_str(escaped_address), @@ -1618,9 +1614,6 @@ evdns_callback(int result, char type, int count, int ttl, void *addresses, log_warn(LD_BUG, "eventdns returned no addresses or error for %s!", escaped_safe_str(string_address)); } - } else { - if (evdns_err_is_transient(result)) - status = DNS_RESOLVE_FAILED_TRANSIENT; } if (was_wildcarded) { if (is_test_address(string_address)) {