commit d68b7fd4422f6ea1cad18a26b6a46b61bc182285 Author: Arlo Breault <arlolra@gmail.com> Date: Tue Dec 8 11:32:29 2015 -0800 Refactor clock skew warning code to avoid duplication --- src/or/channeltls.c | 27 +++------------------------ src/or/connection.c | 30 ++++++++++++++++++++++++++++++ src/or/connection.h | 4 ++++ src/or/directory.c | 25 ++++++------------------- src/or/statefile.c | 16 +++++----------- 5 files changed, 48 insertions(+), 54 deletions(-) diff --git a/src/or/channeltls.c b/src/or/channeltls.c index c90f569..f0333e8 100644 --- a/src/or/channeltls.c +++ b/src/or/channeltls.c @@ -1663,30 +1663,9 @@ channel_tls_process_netinfo_cell(cell_t *cell, channel_tls_t *chan) #define NETINFO_NOTICE_SKEW 3600 if (labs(apparent_skew) > NETINFO_NOTICE_SKEW && router_get_by_id_digest(chan->conn->identity_digest)) { - char dbuf[64]; - int severity; - /*XXXX be smarter about when everybody says we are skewed. */ - if (router_digest_is_trusted_dir(chan->conn->identity_digest)) - severity = LOG_WARN; - else - severity = LOG_INFO; - format_time_interval(dbuf, sizeof(dbuf), apparent_skew); - log_fn(severity, LD_GENERAL, - "Received NETINFO cell with skewed time from " - "server at %s:%d. It seems that our clock is %s by %s, or " - "that theirs is %s. Tor requires an accurate clock to work: " - "please check your time and date settings.", - chan->conn->base_.address, - (int)(chan->conn->base_.port), - apparent_skew > 0 ? "ahead" : "behind", - dbuf, - apparent_skew > 0 ? "behind" : "ahead"); - if (severity == LOG_WARN) /* only tell the controller if an authority */ - control_event_general_status(LOG_WARN, - "CLOCK_SKEW SKEW=%ld SOURCE=OR:%s:%d", - apparent_skew, - chan->conn->base_.address, - chan->conn->base_.port); + int trusted = router_digest_is_trusted_dir(chan->conn->identity_digest); + clock_skew_warning(TO_CONN(chan->conn), apparent_skew, trusted, LD_GENERAL, + "NETINFO cell", "OR"); } /* XXX maybe act on my_apparent_addr, if the source is sufficiently diff --git a/src/or/connection.c b/src/or/connection.c index 4e39832..7b8cc6b 100644 --- a/src/or/connection.c +++ b/src/or/connection.c @@ -5018,3 +5018,33 @@ connection_free_all(void) #endif } +/** Log a warning, and possibly emit a control event, that <b>received</b> came + * at a skewed time. <b>trusted</b> indicates that the <b>source</b> was one + * that we had more faith in and therefore the warning level should have higher + * severity. + */ +void +clock_skew_warning(const connection_t *conn, long apparent_skew, int trusted, + log_domain_mask_t domain, const char *received, + const char *source) +{ + char dbuf[64]; + char *ext_source = NULL; + format_time_interval(dbuf, sizeof(dbuf), apparent_skew); + if (conn) + tor_asprintf(&ext_source, "%s:%s:%d", source, conn->address, conn->port); + else + ext_source = tor_strdup(source); + log_fn(trusted ? LOG_WARN : LOG_INFO, domain, + "Received %s with skewed time (%s): " + "It seems that our clock is %s by %s, or that theirs is %s%s. " + "Tor requires an accurate clock to work: please check your time, " + "timezone, and date settings.", received, ext_source, + apparent_skew > 0 ? "ahead" : "behind", dbuf, + apparent_skew > 0 ? "behind" : "ahead", + (!conn || trusted) ? "" : ", or they are sending us the wrong time"); + if (trusted) + control_event_general_status(LOG_WARN, "CLOCK_SKEW SKEW=%ld SOURCE=%s", + apparent_skew, ext_source); + tor_free(ext_source); +} diff --git a/src/or/connection.h b/src/or/connection.h index b6ff3d7..48929c3 100644 --- a/src/or/connection.h +++ b/src/or/connection.h @@ -210,6 +210,10 @@ int connection_or_nonopen_was_started_here(or_connection_t *conn); void connection_dump_buffer_mem_stats(int severity); void remove_file_if_very_old(const char *fname, time_t now); +void clock_skew_warning(const connection_t *conn, long apparent_skew, + int trusted, log_domain_mask_t domain, + const char *received, const char *source); + #ifdef USE_BUFFEREVENTS int connection_type_uses_bufferevent(connection_t *conn); void connection_configure_bufferevent_callbacks(connection_t *conn); diff --git a/src/or/directory.c b/src/or/directory.c index 0a09e83..4e5644b 100644 --- a/src/or/directory.c +++ b/src/or/directory.c @@ -1595,7 +1595,7 @@ connection_dir_client_reached_eof(dir_connection_t *conn) size_t body_len = 0, orig_len = 0; int status_code; time_t date_header = 0; - long delta; + long apparent_skew; compress_method_t compression; int plausible; int skewed = 0; @@ -1654,28 +1654,15 @@ connection_dir_client_reached_eof(dir_connection_t *conn) * and the date header. (We used to check now-date_header, but that's * inaccurate if we spend a lot of time downloading.) */ - delta = conn->base_.timestamp_lastwritten - date_header; - if (labs(delta)>ALLOW_DIRECTORY_TIME_SKEW) { - char dbuf[64]; + apparent_skew = conn->base_.timestamp_lastwritten - date_header; + if (labs(apparent_skew)>ALLOW_DIRECTORY_TIME_SKEW) { int trusted = router_digest_is_trusted_dir(conn->identity_digest); - format_time_interval(dbuf, sizeof(dbuf), delta); - log_fn(trusted ? LOG_WARN : LOG_INFO, - LD_HTTP, - "Received directory with skewed time (server '%s:%d'): " - "It seems that our clock is %s by %s, or that theirs is %s. " - "Tor requires an accurate clock to work: please check your time, " - "timezone, and date settings.", - conn->base_.address, conn->base_.port, - delta>0 ? "ahead" : "behind", dbuf, - delta>0 ? "behind" : "ahead"); + clock_skew_warning(TO_CONN(conn), apparent_skew, trusted, LD_HTTP, + "directory", "DIRSERV"); skewed = 1; /* don't check the recommended-versions line */ - if (trusted) - control_event_general_status(LOG_WARN, - "CLOCK_SKEW SKEW=%ld SOURCE=DIRSERV:%s:%d", - delta, conn->base_.address, conn->base_.port); } else { log_debug(LD_HTTP, "Time on received directory is within tolerance; " - "we are %ld seconds skewed. (That's okay.)", delta); + "we are %ld seconds skewed. (That's okay.)", apparent_skew); } } (void) skewed; /* skewed isn't used yet. */ diff --git a/src/or/statefile.c b/src/or/statefile.c index 7481cd7..7fe8dc5 100644 --- a/src/or/statefile.c +++ b/src/or/statefile.c @@ -9,6 +9,7 @@ #include "circuitstats.h" #include "config.h" #include "confparse.h" +#include "connection.h" #include "entrynodes.h" #include "hibernate.h" #include "rephist.h" @@ -374,17 +375,10 @@ or_state_load(void) log_info(LD_GENERAL, "Loaded state from \"%s\"", fname); /* Warn the user if their clock has been set backwards, * they could be tricked into using old consensuses */ - if (new_state->LastWritten > time(NULL)) { - char last_written_str[ISO_TIME_LEN+1]; - char now_str[ISO_TIME_LEN+1]; - format_iso_time(last_written_str, new_state->LastWritten), - format_iso_time(now_str, time(NULL)); - log_warn(LD_GENERAL, "Your system clock has been set back in time. " - "Tor needs an accurate clock to know when the consensus " - "expires. You might have an empty clock battery or bad NTP " - "server. Clock time is %s, state file time is %s.", - now_str, last_written_str); - } + time_t apparent_skew = new_state->LastWritten - time(NULL); + if (apparent_skew > 0) + clock_skew_warning(NULL, (long)apparent_skew, 1, LD_GENERAL, + "local state file", fname); } else { log_info(LD_GENERAL, "Initialized state"); }