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Merge branch 'ticket31343_029' into ticket31343_035

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This commit is contained in:
Nick Mathewson 2019-08-06 11:15:20 -04:00
commit bc9492a938
2 changed files with 29 additions and 4 deletions
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9
changes/bug31343 Normal file
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@ -0,0 +1,9 @@
o Minor bugfixes (compilation):
- Avoid using labs() on time_t, which can cause compilation warnings
on 64-bit Windows builds. Fixes bug 31343; bugfix on 0.2.4.4-alpha.
o Minor bugfixes (clock skew detection):
- Don't believe clock skew results from NETINFO cells that appear to
arrive before the VERSIONS cells they are responding to were sent.
Previously, we would accept them up to 3 minutes "in the past".
Fixes bug 31343; bugfix on 0.2.4.4-alpha.

24
src/core/or/channeltls.c
View file

@ -1637,7 +1637,19 @@ channel_tls_process_padding_negotiate_cell(cell_t *cell, channel_tls_t *chan)
} }
/** /**
* Process a 'netinfo' cell. * 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 * This function is called to handle an incoming NETINFO cell; read and act
* on its contents, and set the connection state to "open". * on its contents, and set the connection state to "open".
@ -1654,7 +1666,7 @@ channel_tls_process_netinfo_cell(cell_t *cell, channel_tls_t *chan)
time_t now = time(NULL); time_t now = time(NULL);
const routerinfo_t *me = router_get_my_routerinfo(); const routerinfo_t *me = router_get_my_routerinfo();
long apparent_skew = 0; time_t apparent_skew = 0;
tor_addr_t my_apparent_addr = TOR_ADDR_NULL; tor_addr_t my_apparent_addr = TOR_ADDR_NULL;
int started_here = 0; int started_here = 0;
const char *identity_digest = NULL; const char *identity_digest = NULL;
@ -1721,7 +1733,11 @@ channel_tls_process_netinfo_cell(cell_t *cell, channel_tls_t *chan)
/* Decode the cell. */ /* Decode the cell. */
timestamp = ntohl(get_uint32(cell->payload)); 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; apparent_skew = now - timestamp;
} }
@ -1801,7 +1817,7 @@ channel_tls_process_netinfo_cell(cell_t *cell, channel_tls_t *chan)
/* Act on apparent skew. */ /* Act on apparent skew. */
/** Warn when we get a netinfo skew with at least this value. */ /** Warn when we get a netinfo skew with at least this value. */
#define NETINFO_NOTICE_SKEW 3600 #define NETINFO_NOTICE_SKEW 3600
if (labs(apparent_skew) > NETINFO_NOTICE_SKEW && if (time_abs(apparent_skew) > NETINFO_NOTICE_SKEW &&
(started_here || (started_here ||
connection_or_digest_is_known_relay(chan->conn->identity_digest))) { connection_or_digest_is_known_relay(chan->conn->identity_digest))) {
int trusted = router_digest_is_trusted_dir(chan->conn->identity_digest); int trusted = router_digest_is_trusted_dir(chan->conn->identity_digest);