[tor-commits] [tor/master] prop289: Support sending SENDME version 1
asn at torproject.org
asn at torproject.org
Thu May 2 15:16:20 UTC 2019
commit 023a70da841182fbbbe11389929c8fbbc7490365
Author: David Goulet <dgoulet at torproject.org>
Date: Wed Jan 9 12:22:35 2019 -0500
prop289: Support sending SENDME version 1
This code will obey the consensus parameter "sendme_emit_min_version" to know
which SENDME version it should send. For now, the default is 0 and the
parameter is not yet used in the consensus.
This commit adds the support to send version 1 SENDMEs but aren't sent on the
wire at this commit.
Closes #26840
Signed-off-by: David Goulet <dgoulet at torproject.org>
---
src/core/or/relay.c | 2 +-
src/core/or/sendme.c | 106 ++++++++++++++++++++++++++++++++++++++++++++++++---
src/core/or/sendme.h | 3 +-
3 files changed, 103 insertions(+), 8 deletions(-)
diff --git a/src/core/or/relay.c b/src/core/or/relay.c
index 6ff053d8a..6f69ed999 100644
--- a/src/core/or/relay.c
+++ b/src/core/or/relay.c
@@ -1560,7 +1560,7 @@ connection_edge_process_relay_cell(cell_t *cell, circuit_t *circ,
}
/* Consider sending a circuit-level SENDME cell. */
- sendme_circuit_consider_sending(circ, layer_hint);
+ sendme_circuit_consider_sending(circ, layer_hint, NULL);
if (rh.stream_id == 0) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, "Relay data cell with zero "
diff --git a/src/core/or/sendme.c b/src/core/or/sendme.c
index bba760ae9..f22e7027d 100644
--- a/src/core/or/sendme.c
+++ b/src/core/or/sendme.c
@@ -16,6 +16,7 @@
#include "core/or/relay.h"
#include "core/or/sendme.h"
#include "feature/nodelist/networkstatus.h"
+#include "trunnel/sendme.h"
/* The cell version constants for when emitting a cell. */
#define SENDME_EMIT_MIN_VERSION_DEFAULT 0
@@ -38,6 +39,7 @@ get_emit_min_version(void)
SENDME_EMIT_MIN_VERSION_MAX);
}
+#if 0
/* Return the minimum version given by the consensus (if any) that should be
* accepted when receiving a SENDME cell. */
static int
@@ -48,6 +50,98 @@ get_accept_min_version(void)
SENDME_ACCEPT_MIN_VERSION_MIN,
SENDME_ACCEPT_MIN_VERSION_MAX);
}
+#endif
+
+/* Build and encode a version 1 SENDME cell into payload, which must be at
+ * least of RELAY_PAYLOAD_SIZE bytes, using the digest for the cell data.
+ *
+ * Return the size in bytes of the encoded cell in payload. A negative value
+ * is returned on encoding failure. */
+static ssize_t
+build_cell_payload_v1(crypto_digest_t *cell_digest, uint8_t *payload)
+{
+ ssize_t len = -1;
+ sendme_cell_t *cell = NULL;
+ sendme_data_v1_t *data = NULL;
+
+ tor_assert(cell_digest);
+ tor_assert(payload);
+
+ cell = sendme_cell_new();
+ data = sendme_data_v1_new();
+
+ /* Building a payload for version 1. */
+ sendme_cell_set_version(cell, 0x01);
+
+ /* Copy the digest into the data payload. */
+ crypto_digest_get_digest(cell_digest,
+ (char *) sendme_data_v1_getarray_digest(data),
+ sendme_data_v1_getlen_digest(data));
+
+ /* Set the length of the data in the cell payload. It is the encoded length
+ * of the v1 data object. */
+ sendme_cell_setlen_data(cell, sendme_data_v1_encoded_len(data));
+ /* Encode into the cell's data field using its current length just set. */
+ if (sendme_data_v1_encode(sendme_cell_getarray_data(cell),
+ sendme_cell_getlen_data(cell), data) < 0) {
+ goto end;
+ }
+ /* Set the DATA_LEN field to what we've just encoded. */
+ sendme_cell_set_data_len(cell, sendme_cell_getlen_data(cell));
+
+ /* Finally, encode the cell into the payload. */
+ len = sendme_cell_encode(payload, RELAY_PAYLOAD_SIZE, cell);
+
+ end:
+ sendme_cell_free(cell);
+ sendme_data_v1_free(data);
+ return len;
+}
+
+/* Send a circuit-level SENDME on the given circuit using the layer_hint if
+ * not NULL. The digest is only used for version 1.
+ *
+ * Return 0 on success else a negative value and the circuit will be closed
+ * because we failed to send the cell on it. */
+static int
+send_circuit_level_sendme(circuit_t *circ, crypt_path_t *layer_hint,
+ crypto_digest_t *cell_digest)
+{
+ uint8_t emit_version;
+ uint8_t payload[RELAY_PAYLOAD_SIZE];
+ ssize_t payload_len;
+
+ tor_assert(circ);
+ tor_assert(cell_digest);
+
+ emit_version = get_emit_min_version();
+ switch (emit_version) {
+ case 0x01:
+ payload_len = build_cell_payload_v1(cell_digest, payload);
+ if (BUG(payload_len < 0)) {
+ /* Unable to encode the cell, abort. We can recover from this by closing
+ * the circuit but in theory it should never happen. */
+ return -1;
+ }
+ log_debug(LD_PROTOCOL, "Emitting SENDME version 1 cell.");
+ break;
+ case 0x00:
+ /* Fallthrough because default is to use v0. */
+ default:
+ /* Unknown version, fallback to version 0 meaning no payload. */
+ payload_len = 0;
+ break;
+ }
+
+ if (relay_send_command_from_edge(0, circ, RELAY_COMMAND_SENDME,
+ (char *) payload, payload_len,
+ layer_hint) < 0) {
+ log_warn(LD_CIRC,
+ "SENDME relay_send_command_from_edge failed. Circuit's closed.");
+ return -1; /* the circuit's closed, don't continue */
+ }
+ return 0;
+}
/** Called when we've just received a relay data cell, when we've just
* finished flushing all bytes to stream <b>conn</b>, or when we've flushed
@@ -100,8 +194,11 @@ sendme_connection_edge_consider_sending(edge_connection_t *conn)
* more.
*/
void
-sendme_circuit_consider_sending(circuit_t *circ, crypt_path_t *layer_hint)
+sendme_circuit_consider_sending(circuit_t *circ, crypt_path_t *layer_hint,
+ crypto_digest_t *digest)
{
+ tor_assert(digest);
+
while ((layer_hint ? layer_hint->deliver_window : circ->deliver_window) <=
CIRCWINDOW_START - CIRCWINDOW_INCREMENT) {
log_debug(LD_CIRC,"Queuing circuit sendme.");
@@ -109,11 +206,8 @@ sendme_circuit_consider_sending(circuit_t *circ, crypt_path_t *layer_hint)
layer_hint->deliver_window += CIRCWINDOW_INCREMENT;
else
circ->deliver_window += CIRCWINDOW_INCREMENT;
- if (relay_send_command_from_edge(0, circ, RELAY_COMMAND_SENDME,
- NULL, 0, layer_hint) < 0) {
- log_warn(LD_CIRC,
- "relay_send_command_from_edge failed. Circuit's closed.");
- return; /* the circuit's closed, don't continue */
+ if (send_circuit_level_sendme(circ, layer_hint, digest) < 0) {
+ return; /* The circuit's closed, don't continue */
}
}
}
diff --git a/src/core/or/sendme.h b/src/core/or/sendme.h
index f50ccfbfe..ba01ecfaf 100644
--- a/src/core/or/sendme.h
+++ b/src/core/or/sendme.h
@@ -16,7 +16,8 @@
/* Sending SENDME cell. */
void sendme_connection_edge_consider_sending(edge_connection_t *edge_conn);
void sendme_circuit_consider_sending(circuit_t *circ,
- crypt_path_t *layer_hint);
+ crypt_path_t *layer_hint,
+ crypto_digest_t *digest);
/* Processing SENDME cell. */
int sendme_process_circuit_level(crypt_path_t *layer_hint,
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