[tor-commits] [tor/master] core/or: Accurately log remote relay IPv6 addresses

[nickm at torproject.org]

commit 8c55d34e0adfd9585befd7ce1f71fb219ed63146
Author: teor <teor at torproject.org>
Date:   Tue Apr 14 12:21:49 2020 +1000

    core/or: Accurately log remote relay IPv6 addresses
    
    Log IPv6 addresses on connections where this relay is the responder.
    
    Previously, responding relays would replace the remote IPv6 address with
    the IPv4 address from the consensus.
    
    (The port is replaced with the IPv6 ORPort from the consensus, we will
    resolve this issue in 33898.)
    
    Fixes bug 33899; bugfix on 0.3.1.1-alpha.
---
 changes/bug33899            |  4 ++++
 src/core/or/connection_or.c | 14 +++++++++++---
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/changes/bug33899 b/changes/bug33899
index 319df45df..b9b7d7cf1 100644
--- a/changes/bug33899
+++ b/changes/bug33899
@@ -3,3 +3,7 @@
       In 17604, relays assumed that a remote relay could consider an IPv6
       connection canonical, but did not set the canonical flag on their side
       of the connection. Fixes bug 33899; bugfix on 0.3.1.1-alpha.
+    - Log IPv6 addresses on connections where this relay is the responder.
+      Previously, responding relays would replace the remote IPv6 address with
+      the IPv4 address from the consensus.
+      Fixes bug 33899; bugfix on 0.3.1.1-alpha.
diff --git a/src/core/or/connection_or.c b/src/core/or/connection_or.c
index 2eecbc50a..f059bae25 100644
--- a/src/core/or/connection_or.c
+++ b/src/core/or/connection_or.c
@@ -909,6 +909,13 @@ connection_or_check_canonicity(or_connection_t *conn, int started_here)
         tor_addr_eq(&conn->base_.addr, &node_ipv6_ap.addr)) {
       connection_or_set_canonical(conn, 1);
     }
+    /* Choose the correct canonical address and port. */
+    tor_addr_port_t *node_ap;
+    if (tor_addr_family(&conn->base_.addr) == AF_INET) {
+      node_ap = &node_ipv4_ap;
+    } else {
+      node_ap = &node_ipv6_ap;
+    }
     if (!started_here) {
       /* Override the addr/port, so our log messages will make sense.
        * This is dangerous, since if we ever try looking up a conn by
@@ -920,13 +927,14 @@ connection_or_check_canonicity(or_connection_t *conn, int started_here)
        * right IP address and port 56244, that wouldn't be as helpful. now we
        * log the "right" port too, so we know if it's moria1 or moria2.
        */
-      tor_addr_copy(&conn->base_.addr, &node_ap.addr);
-      conn->base_.port = node_ap.port;
+      /* See #33898 for a ticket that resolves this technical debt. */
+      tor_addr_copy(&conn->base_.addr, &node_ap->addr);
+      conn->base_.port = node_ap->port;
     }
     tor_free(conn->nickname);
     conn->nickname = tor_strdup(node_get_nickname(r));
     tor_free(conn->base_.address);
-    conn->base_.address = tor_addr_to_str_dup(&node_ap.addr);
+    conn->base_.address = tor_addr_to_str_dup(&node_ap->addr);
   } else {
     tor_free(conn->nickname);
     conn->nickname = tor_malloc(HEX_DIGEST_LEN+2);