[tor-commits] [tor/master] Don't check create cells too much when we're relaying them
nickm at torproject.org
nickm at torproject.org
Thu Jan 3 16:52:58 UTC 2013
commit 5c68a1efaa9511baf2a2af0a49946e0a2de9e246
Author: Nick Mathewson <nickm at torproject.org>
Date: Thu Dec 6 00:21:24 2012 -0500
Don't check create cells too much when we're relaying them
We want to sanity-check our own create cells carefully, and other
people's loosely.
---
src/or/circuitbuild.c | 21 ++++++++++++---------
src/or/onion.c | 21 +++++++++++++++++----
src/or/onion.h | 1 +
src/test/test_cell_formats.c | 3 ++-
4 files changed, 32 insertions(+), 14 deletions(-)
diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c
index 43ad9f4..b7ab47f 100644
--- a/src/or/circuitbuild.c
+++ b/src/or/circuitbuild.c
@@ -55,7 +55,8 @@ static channel_t * channel_connect_for_circuit(const tor_addr_t *addr,
uint16_t port,
const char *id_digest);
static int circuit_deliver_create_cell(circuit_t *circ,
- const create_cell_t *create_cell);
+ const create_cell_t *create_cell,
+ int relayed);
static int onion_pick_cpath_exit(origin_circuit_t *circ, extend_info_t *exit);
static crypt_path_t *onion_next_hop_in_cpath(crypt_path_t *cpath);
static int onion_extend_cpath(origin_circuit_t *circ);
@@ -474,7 +475,7 @@ circuit_n_chan_done(channel_t *chan, int status)
} else {
/* pull the create cell out of circ->n_chan_create_cell, and send it */
tor_assert(circ->n_chan_create_cell);
- if (circuit_deliver_create_cell(circ, circ->n_chan_create_cell)<0) {
+ if (circuit_deliver_create_cell(circ, circ->n_chan_create_cell, 1)<0) {
circuit_mark_for_close(circ, END_CIRC_REASON_RESOURCELIMIT);
continue;
}
@@ -491,14 +492,16 @@ circuit_n_chan_done(channel_t *chan, int status)
* for the outgoing
* circuit <b>circ</b>, and deliver a cell of type <b>cell_type</b>
* (either CELL_CREATE or CELL_CREATE_FAST) with payload <b>payload</b>
- * to this circuit. DOCDOC payload_len
+ * to this circuit. DOCDOC new arguments
* Return -1 if we failed to find a suitable circid, else return 0.
*/
static int
-circuit_deliver_create_cell(circuit_t *circ, const create_cell_t *create_cell)
+circuit_deliver_create_cell(circuit_t *circ, const create_cell_t *create_cell,
+ int relayed)
{
cell_t cell;
circid_t id;
+ int r;
tor_assert(circ);
tor_assert(circ->n_chan);
@@ -516,7 +519,9 @@ circuit_deliver_create_cell(circuit_t *circ, const create_cell_t *create_cell)
circuit_set_n_circid_chan(circ, id, circ->n_chan);
memset(&cell, 0, sizeof(cell_t));
- if (create_cell_format(&cell, create_cell) < 0) {
+ r = relayed ? create_cell_format_relayed(&cell, create_cell)
+ : create_cell_format(&cell, create_cell);
+ if (r < 0) {
log_warn(LD_CIRC,"Couldn't format create cell");
return -1;
}
@@ -657,7 +662,7 @@ circuit_send_next_onion_skin(origin_circuit_t *circ)
}
cc.handshake_len = len;
- if (circuit_deliver_create_cell(TO_CIRCUIT(circ), &cc) < 0)
+ if (circuit_deliver_create_cell(TO_CIRCUIT(circ), &cc, 0) < 0)
return - END_CIRC_REASON_RESOURCELIMIT;
circ->cpath->state = CPATH_STATE_AWAITING_KEYS;
@@ -901,8 +906,6 @@ circuit_extend(cell_t *cell, circuit_t *circ)
&ec.orport_ipv4.addr,
ec.orport_ipv4.port);
- /* XXXX Make sure we can eventually deliver create cell with weird
- * content */
circ->n_chan_create_cell = tor_memdup(&ec.create_cell,
sizeof(ec.create_cell));
@@ -933,7 +936,7 @@ circuit_extend(cell_t *cell, circuit_t *circ)
"n_chan is %s",
channel_get_canonical_remote_descr(n_chan));
- if (circuit_deliver_create_cell(circ, &ec.create_cell) < 0)
+ if (circuit_deliver_create_cell(circ, &ec.create_cell, 1) < 0)
return -1;
return 0;
}
diff --git a/src/or/onion.c b/src/or/onion.c
index 753ddcf..b42a66c 100644
--- a/src/or/onion.c
+++ b/src/or/onion.c
@@ -808,13 +808,14 @@ extended_cell_parse(extended_cell_t *cell_out,
/** Fill <b>cell_out</b> with a correctly formatted version of the
* CREATE{,_FAST,2} cell in <b>cell_in</b>. Return 0 on success, -1 on
- * failure. */
-int
-create_cell_format(cell_t *cell_out, const create_cell_t *cell_in)
+ * failure. This is a cell we didn't originate if <b>relayed</b> is true. */
+static int
+create_cell_format_impl(cell_t *cell_out, const create_cell_t *cell_in,
+ int relayed)
{
uint8_t *p;
size_t space;
- if (check_create_cell(cell_in, 0) < 0)
+ if (check_create_cell(cell_in, relayed) < 0)
return -1;
memset(cell_out->payload, 0, sizeof(cell_out->payload));
@@ -848,6 +849,18 @@ create_cell_format(cell_t *cell_out, const create_cell_t *cell_in)
return 0;
}
+int
+create_cell_format(cell_t *cell_out, const create_cell_t *cell_in)
+{
+ return create_cell_format_impl(cell_out, cell_in, 0);
+}
+
+int
+create_cell_format_relayed(cell_t *cell_out, const create_cell_t *cell_in)
+{
+ return create_cell_format_impl(cell_out, cell_in, 1);
+}
+
/** Fill <b>cell_out</b> with a correctly formatted version of the
* CREATED{,_FAST,2} cell in <b>cell_in</b>. Return 0 on success, -1 on
* failure. */
diff --git a/src/or/onion.h b/src/or/onion.h
index 36cb761..e408139 100644
--- a/src/or/onion.h
+++ b/src/or/onion.h
@@ -106,6 +106,7 @@ int extended_cell_parse(extended_cell_t *cell_out, uint8_t command,
const uint8_t *payload_in, size_t payload_len);
int create_cell_format(cell_t *cell_out, const create_cell_t *cell_in);
+int create_cell_format_relayed(cell_t *cell_out, const create_cell_t *cell_in);
int created_cell_format(cell_t *cell_out, const created_cell_t *cell_in);
int extend_cell_format(uint8_t *command_out, uint16_t *len_out,
uint8_t *payload_out, const extend_cell_t *cell_in);
diff --git a/src/test/test_cell_formats.c b/src/test/test_cell_formats.c
index bdbc555..932124c 100644
--- a/src/test/test_cell_formats.c
+++ b/src/test/test_cell_formats.c
@@ -651,7 +651,7 @@ test_cfmt_extend_cells(void *arg)
tt_int_op(p2_cmd, ==, RELAY_COMMAND_EXTEND);
tt_int_op(p2_len, ==, 26+TAP_ONIONSKIN_CHALLENGE_LEN);
test_memeq(p2, p, RELAY_PAYLOAD_SIZE);
- tt_int_op(0, ==, create_cell_format(&cell, cc));
+ tt_int_op(0, ==, create_cell_format_relayed(&cell, cc));
/* Now let's do a minimal ntor EXTEND2 cell. */
memset(&ec, 0xff, sizeof(ec));
@@ -721,6 +721,7 @@ test_cfmt_extend_cells(void *arg)
/* Now the handshake prologue */
"01050063");
test_memeq(p2+1+8+22+4, b, 99+20);
+ tt_int_op(0, ==, create_cell_format_relayed(&cell, cc));
/* == Now try parsing some junk */
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