diff options
Diffstat (limited to 'src/or/channeltls.c')
| -rw-r--r-- | src/or/channeltls.c | 23 |
1 files changed, 19 insertions, 4 deletions
diff --git a/src/or/channeltls.c b/src/or/channeltls.c index 3a352d47fe..ea69792f12 100644 --- a/src/or/channeltls.c +++ b/src/or/channeltls.c @@ -1584,6 +1584,18 @@ channel_tls_process_versions_cell(var_cell_t *cell, channel_tls_t *chan) } /** + * Helper: compute the absolute value of a time_t. + * + * (we need this because labs() doesn't always work for time_t, since + * long can be shorter than time_t.) + */ +static inline time_t +time_abs(time_t val) +{ + return (val < 0) ? -val : val; +} + +/** * Process a 'netinfo' cell * * This function is called to handle an incoming NETINFO cell; read and act @@ -1601,7 +1613,7 @@ channel_tls_process_netinfo_cell(cell_t *cell, channel_tls_t *chan) uint8_t n_other_addrs; time_t now = time(NULL); - long apparent_skew = 0; + time_t apparent_skew = 0; tor_addr_t my_apparent_addr = TOR_ADDR_NULL; tor_assert(cell); @@ -1659,7 +1671,11 @@ channel_tls_process_netinfo_cell(cell_t *cell, channel_tls_t *chan) /* Decode the cell. */ timestamp = ntohl(get_uint32(cell->payload)); - if (labs(now - chan->conn->handshake_state->sent_versions_at) < 180) { + const time_t sent_versions_at = + chan->conn->handshake_state->sent_versions_at; + if (now > sent_versions_at && (now - sent_versions_at) < 180) { + /* If we have gotten the NETINFO cell reasonably soon after having + * sent our VERSIONS cell, maybe we can learn skew information from it. */ apparent_skew = now - timestamp; } @@ -1705,7 +1721,7 @@ channel_tls_process_netinfo_cell(cell_t *cell, channel_tls_t *chan) /* Act on apparent skew. */ /** Warn when we get a netinfo skew with at least this value. */ #define NETINFO_NOTICE_SKEW 3600 - if (labs(apparent_skew) > NETINFO_NOTICE_SKEW && + if (time_abs(apparent_skew) && router_get_by_id_digest(chan->conn->identity_digest)) { int trusted = router_digest_is_trusted_dir(chan->conn->identity_digest); clock_skew_warning(TO_CONN(chan->conn), apparent_skew, trusted, LD_GENERAL, @@ -2182,4 +2198,3 @@ channel_tls_process_authenticate_cell(var_cell_t *cell, channel_tls_t *chan) #undef ERR } - |