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author | Nick Mathewson <nickm@torproject.org> | 2017-02-07 10:39:48 -0500 |
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committer | Nick Mathewson <nickm@torproject.org> | 2017-02-07 10:39:48 -0500 |
commit | 8bcc14f62e620c4a15084449c335680096511001 (patch) | |
tree | 79ef0cfd806c443621d410ef91d3346e73dc4c53 | |
parent | 9c5ff56659fc0636adfd9f1448cc0167f53e7eec (diff) | |
parent | 85a2487f9704cfeff0255c5f660d977ec9c30cff (diff) | |
download | tor-8bcc14f62e620c4a15084449c335680096511001.tar.gz tor-8bcc14f62e620c4a15084449c335680096511001.zip |
Merge branch 'maint-0.2.4' into release-0.2.4
-rw-r--r-- | changes/bug16248 | 8 | ||||
-rw-r--r-- | src/or/main.c | 55 |
2 files changed, 59 insertions, 4 deletions
diff --git a/changes/bug16248 b/changes/bug16248 new file mode 100644 index 0000000000..399b7093cd --- /dev/null +++ b/changes/bug16248 @@ -0,0 +1,8 @@ + o Major bugfixes (dns proxy mode, crash): + - Avoid crashing when running as a DNS proxy. Closes bug 16248; bugfix on + 0.2.0.1-alpha. Patch from 'cypherpunks'. + + o Minor features (bug-resistance): + - Make Tor survive errors involving connections without a corresponding + event object. Previously we'd fail with an assertion; now we produce a + log message. Related to bug 16248. diff --git a/src/or/main.c b/src/or/main.c index bd23141b97..9e78ea04c3 100644 --- a/src/or/main.c +++ b/src/or/main.c @@ -506,6 +506,45 @@ connection_is_reading(connection_t *conn) (conn->read_event && event_pending(conn->read_event, EV_READ, NULL)); } +/** Check whether <b>conn</b> is correct in having (or not having) a + * read/write event (passed in <b>ev</b). On success, return 0. On failure, + * log a warning and return -1. */ +static int +connection_check_event(connection_t *conn, struct event *ev) +{ + int bad; + + if (conn->type == CONN_TYPE_AP && TO_EDGE_CONN(conn)->is_dns_request) { + /* DNS requests which we launch through the dnsserv.c module do not have + * any underlying socket or any underlying linked connection, so they + * shouldn't have any attached events either. + */ + bad = ev != NULL; + } else { + /* Everytyhing else should have an underlying socket, or a linked + * connection (which is also tracked with a read_event/write_event pair). + */ + bad = ev == NULL; + } + + if (bad) { + log_warn(LD_BUG, "Event missing on connection %p [%s;%s]. " + "socket=%d. linked=%d. " + "is_dns_request=%d. Marked_for_close=%s:%d", + conn, + conn_type_to_string(conn->type), + conn_state_to_string(conn->type, conn->state), + (int)conn->s, (int)conn->linked, + (conn->type == CONN_TYPE_AP && TO_EDGE_CONN(conn)->is_dns_request), + conn->marked_for_close_file ? conn->marked_for_close_file : "-", + conn->marked_for_close + ); + //log_backtrace(LOG_WARN, LD_BUG, "Backtrace attached."); + return -1; + } + return 0; +} + /** Tell the main loop to stop notifying <b>conn</b> of any read events. */ void connection_stop_reading(connection_t *conn) @@ -517,7 +556,9 @@ connection_stop_reading(connection_t *conn) return; }); - tor_assert(conn->read_event); + if (connection_check_event(conn, conn->read_event) < 0) { + return; + } if (conn->linked) { conn->reading_from_linked_conn = 0; @@ -542,7 +583,9 @@ connection_start_reading(connection_t *conn) return; }); - tor_assert(conn->read_event); + if (connection_check_event(conn, conn->read_event) < 0) { + return; + } if (conn->linked) { conn->reading_from_linked_conn = 1; @@ -582,7 +625,9 @@ connection_stop_writing(connection_t *conn) return; }); - tor_assert(conn->write_event); + if (connection_check_event(conn, conn->write_event) < 0) { + return; + } if (conn->linked) { conn->writing_to_linked_conn = 0; @@ -608,7 +653,9 @@ connection_start_writing(connection_t *conn) return; }); - tor_assert(conn->write_event); + if (connection_check_event(conn, conn->write_event) < 0) { + return; + } if (conn->linked) { conn->writing_to_linked_conn = 1; |