commit 38e9d9b465f5ae825d054b7baf06a851ad6b371a Author: David Goulet <dgoulet@torproject.org> Date: Thu Feb 3 21:06:28 2022 +0000 hs: Build INTRODUCE extension in the encrypted section Signed-off-by: David Goulet <dgoulet@torproject.org> --- src/feature/hs/hs_cell.c | 28 ++++++++++++++++++++++++++-- src/feature/hs/hs_cell.h | 2 ++ src/feature/hs/hs_circuit.c | 8 ++++++++ 3 files changed, 36 insertions(+), 2 deletions(-) diff --git a/src/feature/hs/hs_cell.c b/src/feature/hs/hs_cell.c index 116395b3c8..4b961a6add 100644 --- a/src/feature/hs/hs_cell.c +++ b/src/feature/hs/hs_cell.c @@ -18,6 +18,7 @@ #include "core/or/origin_circuit_st.h" /* Trunnel. */ +#include "trunnel/congestion_control.h" #include "trunnel/ed25519_cert.h" #include "trunnel/extension.h" #include "trunnel/hs/cell_establish_intro.h" @@ -372,6 +373,26 @@ introduce1_encrypt_and_encode(trn_cell_introduce1_t *cell, tor_free(encrypted); } +/** Build and set the INTRODUCE congestion control extension in the given + * extensions. */ +static void +build_introduce_cc_extension(trn_extension_t *extensions) +{ + trn_extension_field_t *field = NULL; + + /* Build CC request extension. */ + field = trn_extension_field_new(); + trn_extension_field_set_field_type(field, + TRUNNEL_EXT_TYPE_CC_FIELD_REQUEST); + + /* No payload indicating a request to use congestion control. */ + trn_extension_field_set_field_len(field, 0); + + /* Build final extension. */ + trn_extension_add_fields(extensions, field); + trn_extension_set_num(extensions, trn_extension_get_num(extensions) + 1); +} + /** Using the INTRODUCE1 data, setup the ENCRYPTED section in cell. This means * set it, encrypt it and encode it. */ static void @@ -387,10 +408,13 @@ introduce1_set_encrypted(trn_cell_introduce1_t *cell, enc_cell = trn_cell_introduce_encrypted_new(); tor_assert(enc_cell); - /* Set extension data. None are used. */ + /* Setup extension(s) if any. */ ext = trn_extension_new(); tor_assert(ext); - trn_extension_set_num(ext, 0); + /* Build congestion control extension is enabled. */ + if (data->cc_enabled) { + build_introduce_cc_extension(ext); + } trn_cell_introduce_encrypted_set_extensions(enc_cell, ext); /* Set the rendezvous cookie. */ diff --git a/src/feature/hs/hs_cell.h b/src/feature/hs/hs_cell.h index c25fd45567..43be038a93 100644 --- a/src/feature/hs/hs_cell.h +++ b/src/feature/hs/hs_cell.h @@ -40,6 +40,8 @@ typedef struct hs_cell_introduce1_data_t { const curve25519_keypair_t *client_kp; /** Rendezvous point link specifiers. */ smartlist_t *link_specifiers; + /** Congestion control parameters. */ + unsigned int cc_enabled : 1; } hs_cell_introduce1_data_t; /** This data structure contains data that we need to parse an INTRODUCE2 cell diff --git a/src/feature/hs/hs_circuit.c b/src/feature/hs/hs_circuit.c index 3347bdca07..10a6f51eb3 100644 --- a/src/feature/hs/hs_circuit.c +++ b/src/feature/hs/hs_circuit.c @@ -37,6 +37,7 @@ #include "trunnel/ed25519_cert.h" #include "trunnel/hs/cell_establish_intro.h" +#include "core/or/congestion_control_st.h" #include "core/or/cpath_build_state_st.h" #include "core/or/crypt_path_st.h" #include "feature/nodelist/node_st.h" @@ -549,6 +550,7 @@ setup_introduce1_data(const hs_desc_intro_point_t *ip, /* We can't rendezvous without the curve25519 onion key. */ goto end; } + /* Success, we have valid introduce data. */ ret = 0; @@ -1072,6 +1074,12 @@ hs_circ_send_introduce1(origin_circuit_t *intro_circ, goto close; } + /* If the rend circ was set up for congestion control, add that to the + * intro data, to signal it in an extension */ + if (TO_CIRCUIT(rend_circ)->ccontrol) { + intro1_data.cc_enabled = 1; + } + /* Final step before we encode a cell, we setup the circuit identifier which * will generate both the rendezvous cookie and client keypair for this * connection. Those are put in the ident. */