Parse *Port flags NoDNSRequest, NoOnionTraffic & OnionTrafficOnly

OnionTrafficOnly is equivalent to NoDNSRequest, NoIPv4Traffic,
and NoIPv6Traffic.

Add unit tests for parsing and checking option validity.
Add documentation for each flag to the man page.

Add changes file for all of #18693.

Parsing only: the flags do not change client behaviour (yet!)

1 files changed, 44 insertions, 6 deletions

diff --git a/src/or/config.c b/src/or/config.c
index 541025de16..10002ff620 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -6025,6 +6025,8 @@ port_cfg_new(size_t namelen)
   tor_assert(namelen <= SIZE_T_CEILING - sizeof(port_cfg_t) - 1);
   port_cfg_t *cfg = tor_malloc_zero(sizeof(port_cfg_t) + namelen + 1);
   cfg->entry_cfg.ipv4_traffic = 1;
+  cfg->entry_cfg.dns_request = 1;
+  cfg->entry_cfg.onion_traffic = 1;
   cfg->entry_cfg.cache_ipv4_answers = 1;
   cfg->entry_cfg.prefer_ipv6_virtaddr = 1;
   return cfg;
@@ -6295,8 +6297,7 @@ parse_port_config(smartlist_t *out,
       tor_addr_make_unspec(&cfg->addr); /* Server ports default to 0.0.0.0 */
       cfg->server_cfg.no_listen = 1;
       cfg->server_cfg.bind_ipv4_only = 1;
-      cfg->entry_cfg.ipv4_traffic = 1;
-      cfg->entry_cfg.prefer_ipv6_virtaddr = 1;
+      /* cfg->entry_cfg defaults are already set by port_cfg_new */
       smartlist_add(out, cfg);
     }
 
@@ -6367,9 +6368,11 @@ parse_port_config(smartlist_t *out,
     char *addrport;
     uint16_t ptmp=0;
     int ok;
+    /* This must be kept in sync with port_cfg_new's defaults */
     int no_listen = 0, no_advertise = 0, all_addrs = 0,
       bind_ipv4_only = 0, bind_ipv6_only = 0,
-      ipv4_traffic = 1, ipv6_traffic = 0, prefer_ipv6 = 0,
+      ipv4_traffic = 1, ipv6_traffic = 0, prefer_ipv6 = 0, dns_request = 1,
+      onion_traffic = 1,
       cache_ipv4 = 1, use_cached_ipv4 = 0,
       cache_ipv6 = 0, use_cached_ipv6 = 0,
       prefer_ipv6_automap = 1, world_writable = 0, group_writable = 0,
@@ -6555,6 +6558,24 @@ parse_port_config(smartlist_t *out,
           } else if (!strcasecmp(elt, "PreferIPv6")) {
             prefer_ipv6 = ! no;
             continue;
+          } else if (!strcasecmp(elt, "DNSRequest")) {
+            dns_request = ! no;
+            continue;
+          } else if (!strcasecmp(elt, "OnionTraffic")) {
+            onion_traffic = ! no;
+            continue;
+          } else if (!strcasecmp(elt, "OnionTrafficOnly")) {
+            /* Only connect to .onion addresses.  Equivalent to
+             * NoDNSRequest, NoIPv4Traffic, NoIPv6Traffic. The option
+             * NoOnionTrafficOnly is not supported, it's too confusing. */
+            if (no) {
+              log_warn(LD_CONFIG, "Unsupported %sPort option 'No%s'. Use "
+                       "DNSRequest, IPv4Traffic, and/or IPv6Traffic instead.",
+                       portname, escaped(elt));
+            } else {
+              ipv4_traffic = ipv6_traffic = dns_request = 0;
+            }
+            continue;
           }
         }
         if (!strcasecmp(elt, "CacheIPv4DNS")) {
@@ -6623,9 +6644,24 @@ parse_port_config(smartlist_t *out,
     else
       got_zero_port = 1;
 
-    if (ipv4_traffic == 0 && ipv6_traffic == 0) {
-      log_warn(LD_CONFIG, "You have a %sPort entry with both IPv4 and "
-               "IPv6 disabled; that won't work.", portname);
+    if (dns_request == 0 && listener_type == CONN_TYPE_AP_DNS_LISTENER) {
+      log_warn(LD_CONFIG, "You have a %sPort entry with DNS disabled; that "
+               "won't work.", portname);
+      goto err;
+    }
+
+    if (ipv4_traffic == 0 && ipv6_traffic == 0 && onion_traffic == 0
+        && listener_type != CONN_TYPE_AP_DNS_LISTENER) {
+      log_warn(LD_CONFIG, "You have a %sPort entry with all of IPv4 and "
+               "IPv6 and .onion disabled; that won't work.", portname);
+      goto err;
+    }
+
+    if (dns_request == 1 && ipv4_traffic == 0 && ipv6_traffic == 0
+        && listener_type != CONN_TYPE_AP_DNS_LISTENER) {
+      log_warn(LD_CONFIG, "You have a %sPort entry with DNSRequest enabled, "
+               "but IPv4 and IPv6 disabled; DNS-based sites won't work.",
+               portname);
       goto err;
     }
 
@@ -6669,6 +6705,8 @@ parse_port_config(smartlist_t *out,
       cfg->entry_cfg.ipv4_traffic = ipv4_traffic;
       cfg->entry_cfg.ipv6_traffic = ipv6_traffic;
       cfg->entry_cfg.prefer_ipv6 = prefer_ipv6;
+      cfg->entry_cfg.dns_request = dns_request;
+      cfg->entry_cfg.onion_traffic = onion_traffic;
       cfg->entry_cfg.cache_ipv4_answers = cache_ipv4;
       cfg->entry_cfg.cache_ipv6_answers = cache_ipv6;
       cfg->entry_cfg.use_cached_ipv4_answers = use_cached_ipv4;