commit 0ccdf05dc54bf956348b0647414732b6a497d17a Author: Nick Mathewson nickm@torproject.org Date: Tue Jul 14 13:53:27 2020 -0400
Minor refactoring on channel_get_remote_addr_if_possible()
* We no longer call this an optional method * We document that it returns the real address, not a canonical one. * We have it try harder if the real address hasn't been set yet. --- src/core/or/channel.c | 14 ++++++++------ src/core/or/channel.h | 8 +++----- src/core/or/channeltls.c | 32 +++++++++++++++++++++----------- src/test/test_channel.c | 11 ++++++++++- 4 files changed, 42 insertions(+), 23 deletions(-)
diff --git a/src/core/or/channel.c b/src/core/or/channel.c index 20ccf41306..deb27a4d78 100644 --- a/src/core/or/channel.c +++ b/src/core/or/channel.c @@ -2835,22 +2835,24 @@ channel_get_canonical_remote_descr,(channel_t *chan)) }
/** - * Get remote address if possible. + * Get the remote address for this channel, if possible. * * Write the remote address out to a tor_addr_t if the underlying transport * supports this operation, and return 1. Return 0 if the underlying transport * doesn't let us do this. + * + * Always returns the "real" address of the peer -- the one we're connected to + * on the internet. */ MOCK_IMPL(int, -channel_get_addr_if_possible,(const channel_t *chan, tor_addr_t *addr_out)) +channel_get_addr_if_possible,(const channel_t *chan, + tor_addr_t *addr_out)) { tor_assert(chan); tor_assert(addr_out); + tor_assert(chan->get_remote_addr);
- if (chan->get_remote_addr) - return chan->get_remote_addr(chan, addr_out); - /* Else no support, method not implemented */ - else return 0; + return chan->get_remote_addr(chan, addr_out); }
/** diff --git a/src/core/or/channel.h b/src/core/or/channel.h index 5fe1fb9cc4..9aa59da2cb 100644 --- a/src/core/or/channel.h +++ b/src/core/or/channel.h @@ -329,11 +329,9 @@ struct channel_t { */ double (*get_overhead_estimate)(channel_t *); /* - * Ask the underlying transport what the remote endpoint address is, in - * a tor_addr_t. This is optional and subclasses may leave this NULL. - * If they implement it, they should write the address out to the - * provided tor_addr_t *, and return 1 if successful or 0 if no address - * available. + * Ask the underlying transport what the remote endpoint address is, in a + * tor_addr_t. Write the address out to the provided tor_addr_t *, and + * return 1 if successful or 0 if no address available. */ int (*get_remote_addr)(const channel_t *, tor_addr_t *); int (*get_transport_name)(channel_t *chan, char **transport_out); diff --git a/src/core/or/channeltls.c b/src/core/or/channeltls.c index e4dbdda7db..8273235efb 100644 --- a/src/core/or/channeltls.c +++ b/src/core/or/channeltls.c @@ -103,9 +103,8 @@ static void channel_tls_close_method(channel_t *chan); static const char * channel_tls_describe_transport_method(channel_t *chan); static void channel_tls_free_method(channel_t *chan); static double channel_tls_get_overhead_estimate_method(channel_t *chan); -static int -channel_tls_get_remote_addr_method(const channel_t *chan, - tor_addr_t *addr_out); +static int channel_tls_get_remote_addr_method(const channel_t *chan, + tor_addr_t *addr_out); static int channel_tls_get_transport_name_method(channel_t *chan, char **transport_out); static const char * @@ -512,24 +511,35 @@ channel_tls_get_overhead_estimate_method(channel_t *chan) * Get the remote address of a channel_tls_t. * * This implements the get_remote_addr method for channel_tls_t; copy the - * remote endpoint of the channel to addr_out and return 1 (always - * succeeds for this transport). + * remote endpoint of the channel to addr_out and return 1. (Always + * succeeds if this channel is attached to an OR connection.) + * + * Always returns the real address of the peer, not the canonical address. */ static int -channel_tls_get_remote_addr_method(const channel_t *chan, tor_addr_t *addr_out) +channel_tls_get_remote_addr_method(const channel_t *chan, + tor_addr_t *addr_out) { - int rv = 0; const channel_tls_t *tlschan = BASE_CHAN_TO_TLS((channel_t*) chan);
tor_assert(tlschan); tor_assert(addr_out);
- if (tlschan->conn) { + if (tlschan->conn == NULL) { + tor_addr_make_unspec(addr_out); + return 0; + } + + if (! tor_addr_is_null(&tlschan->conn->real_addr)) { + /* They want the real address, and real_addr is set. */ tor_addr_copy(addr_out, &(tlschan->conn->real_addr)); - rv = 1; - } else tor_addr_make_unspec(addr_out); + } else { + /* We'll have to give them the nominal address, which hopefully has + * not been overwritten yet. */ + tor_addr_copy(addr_out, &TO_CONN(tlschan->conn)->addr); + }
- return rv; + return 1; }
/** diff --git a/src/test/test_channel.c b/src/test/test_channel.c index 2b723b4a8d..efe195eac4 100644 --- a/src/test/test_channel.c +++ b/src/test/test_channel.c @@ -166,12 +166,20 @@ static const char * chan_test_get_remote_descr(channel_t *ch, int flags) { tt_assert(ch); - tt_int_op(flags & ~(GRD_FLAG_ORIGINAL | GRD_FLAG_ADDR_ONLY), OP_EQ, 0); + tt_int_op(flags & ~(GRD_FLAG_ORIGINAL), OP_EQ, 0);
done: return "Fake channel for unit tests; no real endpoint"; }
+static int +chan_test_get_remote_addr(const channel_t *ch, tor_addr_t *out) +{ + (void)ch; + tor_addr_from_ipv4h(out, 0x7f000001); + return 1; +} + static int chan_test_num_cells_writeable(channel_t *ch) { @@ -269,6 +277,7 @@ new_fake_channel(void) chan->close = chan_test_close; chan->num_cells_writeable = chan_test_num_cells_writeable; chan->get_remote_descr = chan_test_get_remote_descr; + chan->get_remote_addr = chan_test_get_remote_addr; chan->write_packed_cell = chan_test_write_packed_cell; chan->write_var_cell = chan_test_write_var_cell; chan->state = CHANNEL_STATE_OPEN;