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|
/* Copyright (C) 2023 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#include <assert.h>
#include <gnutls/gnutls.h>
#include <gnutls/crypto.h>
#include <gnutls/x509.h>
#include <ngtcp2/ngtcp2.h>
#include <ngtcp2/ngtcp2_crypto.h>
#include <ngtcp2/ngtcp2_crypto_gnutls.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include "libknot/xdp/quic.h"
#include "contrib/macros.h"
#include "contrib/sockaddr.h"
#include "contrib/ucw/lists.h"
#include "libknot/endian.h"
#include "libdnssec/error.h"
#include "libdnssec/random.h"
#include "libknot/attribute.h"
#include "libknot/endian.h"
#include "libknot/error.h"
#include "libknot/wire.h"
#define SERVER_DEFAULT_SCIDLEN 18
#define QUIC_DEFAULT_VERSION "-VERS-ALL:+VERS-TLS1.3"
#define QUIC_DEFAULT_CIPHERS "-CIPHER-ALL:+AES-128-GCM:+AES-256-GCM:+CHACHA20-POLY1305:+AES-128-CCM"
#define QUIC_DEFAULT_GROUPS "-GROUP-ALL:+GROUP-SECP256R1:+GROUP-X25519:+GROUP-SECP384R1:+GROUP-SECP521R1"
#define QUIC_PRIORITIES "%DISABLE_TLS13_COMPAT_MODE:NORMAL:"QUIC_DEFAULT_VERSION":"QUIC_DEFAULT_CIPHERS":"QUIC_DEFAULT_GROUPS
#define XQUIC_SEND_VERSION_NEGOTIATION NGTCP2_ERR_VERSION_NEGOTIATION
#define XQUIC_SEND_RETRY NGTCP2_ERR_RETRY
#define XQUIC_SEND_STATELESS_RESET (-NGTCP2_STATELESS_RESET_TOKENLEN)
#define TLS_CALLBACK_ERR (-1)
typedef struct knot_quic_creds {
gnutls_certificate_credentials_t tls_cert;
gnutls_anti_replay_t tls_anti_replay;
gnutls_datum_t tls_ticket_key;
bool is_clone;
} knot_xquic_creds_t;
typedef struct knot_quic_session {
node_t n;
gnutls_datum_t tls_session;
ngtcp2_transport_params quic_params;
} knot_xquic_session_t;
static unsigned addr_len(const struct sockaddr_in6 *ss)
{
return (ss->sin6_family == AF_INET6 ?
sizeof(struct sockaddr_in6) : sizeof(struct sockaddr));
}
_public_
struct knot_quic_session *knot_xquic_session_save(knot_xquic_conn_t *conn)
{
const ngtcp2_transport_params *tmp = ngtcp2_conn_get_remote_transport_params(conn->conn);
if (tmp == NULL) {
return NULL;
}
knot_xquic_session_t *session = calloc(1, sizeof(*session));
if (session == NULL) {
return NULL;
}
int ret = gnutls_session_get_data2(conn->tls_session, &session->tls_session);
if (ret != GNUTLS_E_SUCCESS) {
free(session);
return NULL;
}
memcpy(&session->quic_params, tmp, sizeof(session->quic_params));
return session;
}
_public_
int knot_xquic_session_load(knot_xquic_conn_t *conn, struct knot_quic_session *session)
{
if (session == NULL) {
return KNOT_EINVAL;
}
int ret = KNOT_EOK;
if (conn == NULL) {
goto session_free;
}
ret = gnutls_session_set_data(conn->tls_session, session->tls_session.data, session->tls_session.size);
if (ret != KNOT_EOK) {
goto session_free;
}
ngtcp2_conn_set_early_remote_transport_params(conn->conn, &session->quic_params);
session_free:
gnutls_free(session->tls_session.data);
free(session);
return ret;
}
static int tls_anti_replay_db_add_func(void *dbf, time_t exp_time,
const gnutls_datum_t *key,
const gnutls_datum_t *data)
{
return 0;
}
static void tls_session_ticket_key_free(gnutls_datum_t *ticket)
{
gnutls_memset(ticket->data, 0, ticket->size);
gnutls_free(ticket->data);
}
static int self_signed_cert(gnutls_certificate_credentials_t tls_cert)
{
gnutls_x509_privkey_t privkey = NULL;
gnutls_x509_crt_t cert = NULL;
char *hostname = sockaddr_hostname();
if (hostname == NULL) {
return -ENOMEM;
}
int ret = gnutls_x509_privkey_init(&privkey);
if (ret < 0) {
free(hostname);
return ret;
}
uint8_t serial[16];
gnutls_rnd(GNUTLS_RND_NONCE, serial, sizeof(serial));
/* clear the left-most bit to avoid signedness confusion: */
serial[0] &= 0x8f;
#define CHK(cmd) \
ret = (cmd); \
if (ret < 0) { goto finish; }
#define now_years(years) (time(NULL) + 365 * 24 * 3600 * (years))
CHK(gnutls_x509_privkey_generate(privkey, GNUTLS_PK_ECDSA, GNUTLS_CURVE_TO_BITS(GNUTLS_ECC_CURVE_SECP256R1), 0));
CHK(gnutls_x509_crt_init(&cert));
//CHK(gnutls_x509_crt_set_ca_status(cert, 0)); // TODO needed ?
CHK(gnutls_x509_crt_set_activation_time(cert, now_years(-1)));
CHK(gnutls_x509_crt_set_expiration_time(cert, now_years(20)));
CHK(gnutls_x509_crt_set_dn(cert, "CN=DoQ Self-Signed Server Certificate", NULL));
CHK(gnutls_x509_crt_set_key(cert, privkey));
CHK(gnutls_x509_crt_set_serial(cert, serial, sizeof(serial)));
CHK(gnutls_x509_crt_set_subject_alt_name(cert, GNUTLS_SAN_DNSNAME, hostname, strlen(hostname), GNUTLS_FSAN_SET));
CHK(gnutls_x509_crt_set_version(cert, 3));
CHK(gnutls_x509_crt_sign2(cert, cert, privkey, GNUTLS_DIG_SHA256, 0));
ret = gnutls_certificate_set_x509_key(tls_cert, &cert, 1, privkey);
finish:
free(hostname);
gnutls_x509_privkey_deinit(privkey);
gnutls_x509_crt_deinit(cert);
return ret;
}
_public_
struct knot_quic_creds *knot_xquic_init_creds(bool server, const char *tls_cert,
const char *tls_key)
{
knot_xquic_creds_t *creds = calloc(1, sizeof(*creds));
if (creds == NULL) {
return NULL;
}
int ret = gnutls_anti_replay_init(&creds->tls_anti_replay);
if (ret != GNUTLS_E_SUCCESS) {
goto fail;
}
gnutls_anti_replay_set_add_function(creds->tls_anti_replay, tls_anti_replay_db_add_func);
gnutls_anti_replay_set_ptr(creds->tls_anti_replay, NULL);
ret = gnutls_certificate_allocate_credentials(&creds->tls_cert);
if (ret != GNUTLS_E_SUCCESS) {
gnutls_anti_replay_deinit(creds->tls_anti_replay);
goto fail;
}
ret = gnutls_certificate_set_x509_system_trust(creds->tls_cert);
if (ret < 0) {
goto fail2;
}
if ((bool)(tls_cert == NULL) != (bool)(tls_key == NULL) ||
(tls_cert != NULL && !server)) {
goto fail2;
}
if (tls_cert != NULL) {
ret = gnutls_certificate_set_x509_key_file(creds->tls_cert, tls_cert, tls_key, GNUTLS_X509_FMT_PEM);
} else if (server) {
ret = self_signed_cert(creds->tls_cert);
}
if (ret < 0) {
goto fail2;
}
ret = gnutls_session_ticket_key_generate(&creds->tls_ticket_key);
if (ret != GNUTLS_E_SUCCESS) {
goto fail2;
}
return creds;
fail:
free(creds);
return NULL;
fail2:
knot_xquic_free_creds(creds);
return NULL;
}
_public_
void knot_xquic_free_creds(struct knot_quic_creds *creds)
{
if (creds == NULL) {
return;
}
if (!creds->is_clone) {
gnutls_certificate_free_credentials(creds->tls_cert);
if (creds->tls_ticket_key.data != NULL) {
tls_session_ticket_key_free(&creds->tls_ticket_key);
}
}
gnutls_anti_replay_deinit(creds->tls_anti_replay);
free(creds);
}
#define ALPN "\03""doq"
#define ALPN_TMP1 "\07""doq-i11"
#define ALPN_TMP2 "\07""doq-i03"
static int tls_client_hello_cb(gnutls_session_t session, unsigned int htype,
unsigned when, unsigned int incoming,
const gnutls_datum_t *msg)
{
assert(htype == GNUTLS_HANDSHAKE_CLIENT_HELLO);
assert(when == GNUTLS_HOOK_POST);
if (!incoming) {
return 0;
}
gnutls_datum_t alpn;
int ret = gnutls_alpn_get_selected_protocol(session, &alpn);
if (ret != 0) {
return ret;
}
const char *dq = (const char *)&ALPN[1];
if (((unsigned int)ALPN[0] != alpn.size ||
memcmp(dq, alpn.data, alpn.size) != 0) &&
((unsigned int)ALPN_TMP1[0] != alpn.size ||
memcmp((const char *)&ALPN_TMP1[1], alpn.data, alpn.size) != 0) &&
((unsigned int)ALPN_TMP1[0] != alpn.size ||
memcmp((const char *)&ALPN_TMP2[1], alpn.data, alpn.size) != 0)) {
return TLS_CALLBACK_ERR;
}
return 0;
}
static ngtcp2_conn *get_conn(ngtcp2_crypto_conn_ref *conn_ref)
{
return ((knot_xquic_conn_t *)conn_ref->user_data)->conn;
}
static int tls_init_conn_session(knot_xquic_conn_t *conn, bool server)
{
if (gnutls_init(&conn->tls_session, (server ? GNUTLS_SERVER : GNUTLS_CLIENT) |
GNUTLS_ENABLE_EARLY_DATA | GNUTLS_NO_AUTO_SEND_TICKET |
GNUTLS_NO_END_OF_EARLY_DATA) != GNUTLS_E_SUCCESS) {
return TLS_CALLBACK_ERR;
}
if (gnutls_priority_set_direct(conn->tls_session, QUIC_PRIORITIES,
NULL) != GNUTLS_E_SUCCESS) {
return TLS_CALLBACK_ERR;
}
if (server && gnutls_session_ticket_enable_server(conn->tls_session,
&conn->xquic_table->creds->tls_ticket_key) != GNUTLS_E_SUCCESS) {
return TLS_CALLBACK_ERR;
}
gnutls_handshake_set_hook_function(conn->tls_session,
GNUTLS_HANDSHAKE_CLIENT_HELLO,
GNUTLS_HOOK_POST, tls_client_hello_cb);
int ret = ngtcp2_crypto_gnutls_configure_server_session(conn->tls_session);
if (ret != 0) {
return TLS_CALLBACK_ERR;
}
gnutls_record_set_max_early_data_size(conn->tls_session, 0xffffffffu);
conn->conn_ref = (nc_conn_ref_placeholder_t) {
.get_conn = get_conn,
.user_data = conn
};
_Static_assert(sizeof(nc_conn_ref_placeholder_t) == sizeof(ngtcp2_crypto_conn_ref), "invalid placeholder for conn_ref");
gnutls_session_set_ptr(conn->tls_session, &conn->conn_ref);
if (server) {
gnutls_anti_replay_enable(conn->tls_session, conn->xquic_table->creds->tls_anti_replay);
}
if (gnutls_credentials_set(conn->tls_session, GNUTLS_CRD_CERTIFICATE,
conn->xquic_table->creds->tls_cert) != GNUTLS_E_SUCCESS) {
return TLS_CALLBACK_ERR;
}
gnutls_datum_t alpn[3] = {
{
.data = (uint8_t *)(&ALPN[1]),
.size = ALPN[0],
},
{
.data = (uint8_t *)(&ALPN_TMP1[1]),
.size = ALPN_TMP1[0],
},
{
.data = (uint8_t *)(&ALPN_TMP2[1]),
.size = ALPN_TMP2[0],
}
};
gnutls_alpn_set_protocols(conn->tls_session, alpn, 3, 0);
ngtcp2_conn_set_tls_native_handle(conn->conn, conn->tls_session);
return KNOT_EOK;
}
static uint64_t get_timestamp(void)
{
struct timespec ts;
if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0) {
assert(0);
}
return (uint64_t)ts.tv_sec * NGTCP2_SECONDS + (uint64_t)ts.tv_nsec;
}
uint64_t xquic_conn_get_timeout(knot_xquic_conn_t *conn)
{
// This effectively obtains the locally configured conn timeout.
// It would be possible to obey negotitated idle timeout by employing remote params,
// but this would differ per-connection and the whole idea of maintaining
// to-be-timeouted connections in simple linear list requires that
// the idle timeout is homogeneous among conns.
// Anyway, we also violate RFC9000/10.1 (Probe Timeout) for the same reason.
// TODO for the future: refactor conn table to use some tree/heap
// for to-be-timeouted conns, and use ngtcp2_conn_get_expiry() and
// ngtcp2_conn_handle_expiry() appropriately.
const ngtcp2_transport_params *params = ngtcp2_conn_get_local_transport_params(conn->conn);
return conn->last_ts + params->max_idle_timeout;
}
bool xquic_conn_timeout(knot_xquic_conn_t *conn, uint64_t *now)
{
if (*now == 0) {
*now = get_timestamp();
}
return *now > xquic_conn_get_timeout(conn);
}
_public_
uint32_t knot_xquic_conn_rtt(knot_xquic_conn_t *conn)
{
ngtcp2_conn_stat stat = { 0 };
ngtcp2_conn_get_conn_stat(conn->conn, &stat);
return stat.smoothed_rtt / 1000; // nanosec --> usec
}
static void knot_quic_rand_cb(uint8_t *dest, size_t destlen, const ngtcp2_rand_ctx *rand_ctx)
{
(void)rand_ctx;
dnssec_random_buffer(dest, destlen);
}
static void init_random_cid(ngtcp2_cid *cid, size_t len)
{
if (len == 0) {
len = SERVER_DEFAULT_SCIDLEN;
}
if (dnssec_random_buffer(cid->data, len) != DNSSEC_EOK) {
cid->datalen = 0;
} else {
cid->datalen = len;
}
}
static bool init_unique_cid(ngtcp2_cid *cid, size_t len, knot_xquic_table_t *table)
{
do {
if (init_random_cid(cid, len), cid->datalen == 0) {
return false;
}
} while (xquic_table_lookup(cid, table) != NULL);
return true;
}
static int get_new_connection_id(ngtcp2_conn *conn, ngtcp2_cid *cid,
uint8_t *token, size_t cidlen,
void *user_data)
{
knot_xquic_conn_t *ctx = (knot_xquic_conn_t *)user_data;
assert(ctx->conn == conn);
if (!init_unique_cid(cid, cidlen, ctx->xquic_table)) {
return NGTCP2_ERR_CALLBACK_FAILURE;
}
knot_xquic_cid_t **addto = xquic_table_insert(ctx, cid, ctx->xquic_table);
(void)addto;
if (token != NULL &&
ngtcp2_crypto_generate_stateless_reset_token(
token, (uint8_t *)ctx->xquic_table->hash_secret,
sizeof(ctx->xquic_table->hash_secret), cid) != 0) {
return NGTCP2_ERR_CALLBACK_FAILURE;
}
return 0;
}
static int remove_connection_id(ngtcp2_conn *conn, const ngtcp2_cid *cid,
void *user_data)
{
knot_xquic_conn_t *ctx = (knot_xquic_conn_t *)user_data;
assert(ctx->conn == conn);
knot_xquic_cid_t **torem = xquic_table_lookup2(cid, ctx->xquic_table);
if (torem != NULL) {
assert((*torem)->conn == ctx);
xquic_table_rem2(torem, ctx->xquic_table);
}
return 0;
}
static int handshake_completed_cb(ngtcp2_conn *conn, void *user_data)
{
knot_xquic_conn_t *ctx = (knot_xquic_conn_t *)user_data;
assert(ctx->conn == conn);
assert(!ctx->handshake_done);
ctx->handshake_done = true;
if (!ngtcp2_conn_is_server(conn)) {
return 0;
}
gnutls_datum_t alpn;
if (gnutls_alpn_get_selected_protocol(ctx->tls_session, &alpn) != 0) {
return NGTCP2_ERR_CALLBACK_FAILURE;
}
char alpn_str[alpn.size + 1];
alpn_str[alpn.size] = '\0';
memcpy(alpn_str, alpn.data, alpn.size);
if (gnutls_session_ticket_send(ctx->tls_session, 1, 0) != GNUTLS_E_SUCCESS) {
return TLS_CALLBACK_ERR;
}
uint8_t token[NGTCP2_CRYPTO_MAX_REGULAR_TOKENLEN];
ngtcp2_path path = *ngtcp2_conn_get_path(ctx->conn);
uint64_t ts = get_timestamp();
ngtcp2_ssize tokenlen = ngtcp2_crypto_generate_regular_token(token,
(uint8_t *)ctx->xquic_table->hash_secret,
sizeof(ctx->xquic_table->hash_secret),
path.remote.addr, path.remote.addrlen, ts);
if (tokenlen < 0) {
return NGTCP2_ERR_CALLBACK_FAILURE;
}
if (ngtcp2_conn_submit_new_token(ctx->conn, token, tokenlen) != 0) {
return NGTCP2_ERR_CALLBACK_FAILURE;
}
return 0;
}
static int recv_stream_data(ngtcp2_conn *conn, uint32_t flags,
int64_t stream_id, uint64_t offset,
const uint8_t *data, size_t datalen,
void *user_data, void *stream_user_data)
{
(void)(stream_user_data); // always NULL
(void)(offset); // QUIC shall ensure that data arrive in-order
knot_xquic_conn_t *ctx = (knot_xquic_conn_t *)user_data;
assert(ctx->conn == conn);
int ret = knot_xquic_stream_recv_data(ctx, stream_id, data, datalen, (flags & NGTCP2_STREAM_DATA_FLAG_FIN));
return ret == KNOT_EOK ? 0 : NGTCP2_ERR_CALLBACK_FAILURE;
}
static int acked_stream_data_offset_cb(ngtcp2_conn *conn, int64_t stream_id,
uint64_t offset, uint64_t datalen,
void *user_data, void *stream_user_data)
{
knot_xquic_conn_t *ctx = (knot_xquic_conn_t *)user_data;
bool keep = !ngtcp2_conn_is_server(conn); // kxdpgun: await incomming reply after query sent&acked
knot_xquic_stream_ack_data(ctx, stream_id, offset + datalen, keep);
return 0;
}
static int stream_closed(ngtcp2_conn *conn, uint32_t flags, int64_t stream_id,
uint64_t app_error_code, void *user_data, void *stream_user_data)
{
knot_xquic_conn_t *ctx = (knot_xquic_conn_t *)user_data;
assert(ctx->conn == conn);
// NOTE possible error is stored in (flags & NGTCP2_STREAM_CLOSE_FLAG_APP_ERROR_CODE_SET)
bool keep = !ngtcp2_conn_is_server(conn); // kxdpgun: process incomming reply after recvd&closed
if (!keep) {
xquic_stream_free(ctx, stream_id);
}
return 0;
}
static int recv_stateless_rst(ngtcp2_conn *conn, const ngtcp2_pkt_stateless_reset *sr, void *user_data)
{
// NOTE server can't receive stateless resets, only client
// ngtcp2 verified stateless reset token already
(void)(sr);
knot_xquic_conn_t *ctx = (knot_xquic_conn_t *)user_data;
assert(ctx->conn == conn);
knot_xquic_table_rem(ctx, ctx->xquic_table);
return 0;
}
static int recv_stream_rst(ngtcp2_conn *conn, int64_t stream_id, uint64_t final_size,
uint64_t app_error_code, void *user_data, void *stream_user_data)
{
(void)final_size;
return stream_closed(conn, NGTCP2_STREAM_CLOSE_FLAG_APP_ERROR_CODE_SET,
stream_id, app_error_code, user_data, stream_user_data);
}
static void user_printf(void *user_data, const char *format, ...)
{
knot_xquic_conn_t *ctx = (knot_xquic_conn_t *)user_data;
if (ctx->xquic_table->log_cb != NULL) {
char buf[256];
va_list args;
va_start(args, format);
vsnprintf(buf, sizeof(buf), format, args);
va_end(args);
ctx->xquic_table->log_cb(buf);
}
}
static int conn_new(ngtcp2_conn **pconn, const ngtcp2_path *path, const ngtcp2_cid *scid,
const ngtcp2_cid *dcid, const ngtcp2_cid *odcid, uint32_t version,
uint64_t now, size_t udp_pl, uint64_t idle_timeout_ns,
void *user_data, bool server, bool retry_sent)
{
// I. CALLBACKS
const ngtcp2_callbacks callbacks = {
ngtcp2_crypto_client_initial_cb,
ngtcp2_crypto_recv_client_initial_cb,
ngtcp2_crypto_recv_crypto_data_cb,
handshake_completed_cb,
NULL, // recv_version_negotiation not needed on server, nor kxdpgun
ngtcp2_crypto_encrypt_cb,
ngtcp2_crypto_decrypt_cb,
ngtcp2_crypto_hp_mask_cb,
recv_stream_data,
acked_stream_data_offset_cb,
NULL, // stream_opened
stream_closed,
recv_stateless_rst,
ngtcp2_crypto_recv_retry_cb,
NULL, // extend_max_streams_bidi
NULL, // extend_max_streams_uni
knot_quic_rand_cb,
get_new_connection_id,
remove_connection_id,
ngtcp2_crypto_update_key_cb,
NULL, // path_validation,
NULL, // select_preferred_addr
recv_stream_rst,
NULL, // extend_max_remote_streams_bidi, might be useful to some allocation optimizations?
NULL, // extend_max_remote_streams_uni
NULL, // extend_max_stream_data,
NULL, // dcid_status
NULL, // handshake_confirmed
NULL, // recv_new_token
ngtcp2_crypto_delete_crypto_aead_ctx_cb,
ngtcp2_crypto_delete_crypto_cipher_ctx_cb,
NULL, // recv_datagram
NULL, // ack_datagram
NULL, // lost_datagram
ngtcp2_crypto_get_path_challenge_data_cb,
NULL, // stream_stop_sending
ngtcp2_crypto_version_negotiation_cb,
NULL, // recv_rx_key
NULL // recv_tx_key
};
// II. SETTINGS
ngtcp2_settings settings;
ngtcp2_settings_default(&settings);
settings.initial_ts = now;
settings.log_printf = user_printf;
settings.max_tx_udp_payload_size = udp_pl;
settings.qlog.odcid = *odcid;
settings.handshake_timeout = idle_timeout_ns; // NOTE setting handshake timeout to idle_timeout for simplicity
settings.no_pmtud = true;
// III. PARAMS
ngtcp2_transport_params params;
ngtcp2_transport_params_default(¶ms);
params.initial_max_data = 786432;
params.initial_max_stream_data_bidi_local = 524288;
params.initial_max_stream_data_bidi_remote = 524288;
params.initial_max_stream_data_uni = 524288;
// params.initial_max_stream_data_bidi_local = config.max_stream_data_bidi_local;
// params.initial_max_stream_data_bidi_remote = config.max_stream_data_bidi_remote;
// params.initial_max_stream_data_uni = config.max_stream_data_uni;
// params.initial_max_data = config.max_data;
params.initial_max_streams_bidi = 100;
params.initial_max_streams_uni = 3;
params.max_idle_timeout = idle_timeout_ns;
// params.stateless_reset_token_present = 1;
// params.active_connection_id_limit = 7;
if (odcid) {
params.original_dcid = *odcid;
} else {
params.original_dcid = *scid;
}
if (retry_sent) {
params.retry_scid_present = 1;
params.retry_scid = *scid;
}
if (dnssec_random_buffer(params.stateless_reset_token, NGTCP2_STATELESS_RESET_TOKENLEN) != DNSSEC_EOK) {
return KNOT_ERROR;
}
if (server) {
return ngtcp2_conn_server_new(pconn, dcid, scid, path, version, &callbacks, &settings, ¶ms, NULL, user_data);
} else {
return ngtcp2_conn_client_new(pconn, dcid, scid, path, version, &callbacks, &settings, ¶ms, NULL, user_data);
}
}
_public_
int knot_xquic_client(knot_xquic_table_t *table, struct sockaddr_in6 *dest,
struct sockaddr_in6 *via, knot_xquic_conn_t **out_conn)
{
ngtcp2_cid scid = { 0 }, dcid = { 0 };
uint64_t now = get_timestamp();
init_random_cid(&scid, 0);
init_random_cid(&dcid, 0);
knot_xquic_conn_t *xconn = xquic_table_add(NULL, &dcid, table);
if (xconn == NULL) {
return ENOMEM;
}
xquic_conn_mark_used(xconn, table, now);
ngtcp2_path path;
path.remote.addr = (struct sockaddr *)dest;
path.remote.addrlen = addr_len((const struct sockaddr_in6 *)dest);
path.local.addr = (struct sockaddr *)via;
path.local.addrlen = addr_len((const struct sockaddr_in6 *)via);
int ret = conn_new(&xconn->conn, &path, &dcid, &scid, &dcid, NGTCP2_PROTO_VER_V1, now,
table->udp_payload_limit, 5000000000L, xconn, false, false);
if (ret == KNOT_EOK) {
ret = tls_init_conn_session(xconn, false);
}
if (ret == KNOT_EOK) {
char *hostname = sockaddr_hostname();
if (hostname == NULL) {
ret = KNOT_ENOMEM;
} else {
ret = gnutls_server_name_set(xconn->tls_session, GNUTLS_NAME_DNS,
hostname, strlen(hostname));
free(hostname);
}
}
if (ret != KNOT_EOK) {
knot_xquic_table_rem(xconn, table);
return ret;
}
*out_conn = xconn;
return KNOT_EOK;
}
_public_
int knot_xquic_handle(knot_xquic_table_t *table, knot_xdp_msg_t *msg, uint64_t idle_timeout, knot_xquic_conn_t **out_conn)
{
*out_conn = NULL;
ngtcp2_version_cid decoded_cids = { 0 };
ngtcp2_cid scid = { 0 }, dcid = { 0 }, odcid = { 0 };
uint64_t now = get_timestamp();
int ret = ngtcp2_pkt_decode_version_cid(&decoded_cids,
msg->payload.iov_base,
msg->payload.iov_len,
SERVER_DEFAULT_SCIDLEN);
if (ret == NGTCP2_ERR_VERSION_NEGOTIATION) {
return -XQUIC_SEND_VERSION_NEGOTIATION;
} else if (ret != NGTCP2_NO_ERROR) {
return ret;
}
ngtcp2_cid_init(&dcid, decoded_cids.dcid, decoded_cids.dcidlen);
ngtcp2_cid_init(&scid, decoded_cids.scid, decoded_cids.scidlen);
knot_xquic_conn_t *xconn = xquic_table_lookup(&dcid, table);
if (decoded_cids.version == 0 /* short header */ && xconn == NULL) {
return KNOT_EOK; // NOOP
}
ngtcp2_path path;
path.remote.addr = (struct sockaddr *)&msg->ip_from;
path.remote.addrlen = addr_len(&msg->ip_from);
path.local.addr = (struct sockaddr *)&msg->ip_to;
path.local.addrlen = addr_len(&msg->ip_to);
if (xconn == NULL) {
// new conn
ngtcp2_pkt_hd header = { 0 };
ret = ngtcp2_accept(&header, msg->payload.iov_base, msg->payload.iov_len);
if (ret == NGTCP2_ERR_RETRY) {
return -XQUIC_SEND_RETRY;
} else if (ret != NGTCP2_NO_ERROR) { // discard packet
return KNOT_EOK;
}
assert(header.type == NGTCP2_PKT_INITIAL);
if (header.tokenlen == 0 && xquic_require_retry(table)) {
return -XQUIC_SEND_RETRY;
}
if (header.tokenlen > 0) {
ret = ngtcp2_crypto_verify_retry_token(
&odcid, header.token, header.tokenlen,
(const uint8_t *)table->hash_secret, sizeof(table->hash_secret), header.version,
(const struct sockaddr *)&msg->ip_from, addr_len(&msg->ip_from),
&dcid, idle_timeout, now // NOTE setting retry token validity to idle_timeout for simplicity
);
if (ret != 0) {
return KNOT_EOK;
}
} else {
memcpy(&odcid, &dcid, sizeof(odcid));
}
// server chooses his CID to his liking
if (!init_unique_cid(&dcid, 0, table)) {
return KNOT_ERROR;
}
xconn = xquic_table_add(NULL, &dcid, table);
if (xconn == NULL) {
return ENOMEM;
}
xquic_conn_mark_used(xconn, table, now);
ret = conn_new(&xconn->conn, &path, &dcid, &scid, &odcid, decoded_cids.version, now,
table->udp_payload_limit, idle_timeout, xconn, true, header.tokenlen > 0);
if (ret >= 0) {
ret = tls_init_conn_session(xconn, true);
}
if (ret < 0) {
knot_xquic_table_rem(xconn, table);
return ret;
}
}
ngtcp2_pkt_info pi = { .ecn = NGTCP2_ECN_NOT_ECT, };
ret = ngtcp2_conn_read_pkt(xconn->conn, &path, &pi, msg->payload.iov_base, msg->payload.iov_len, now);
*out_conn = xconn;
if (ret == NGTCP2_ERR_DRAINING) { // received CONNECTION_CLOSE from the counterpart
knot_xquic_table_rem(xconn, table);
return KNOT_EOK;
} else if(ngtcp2_err_is_fatal(ret)) { // connection doomed
knot_xquic_table_rem(xconn, table);
return KNOT_ECONN;
} else if (ret != NGTCP2_NO_ERROR) { // non-fatal error, discard packet
return KNOT_EOK;
}
xquic_conn_mark_used(xconn, table, now);
return KNOT_EOK;
}
static bool stream_exists(knot_xquic_conn_t *xconn, int64_t stream_id)
{
// TRICK, we never use stream_user_data
return (ngtcp2_conn_set_stream_user_data(xconn->conn, stream_id, NULL) == NGTCP2_NO_ERROR);
}
static int send_stream(knot_xquic_table_t *quic_table, knot_xdp_socket_t *sock,
knot_xdp_msg_t *in_msg, knot_xquic_conn_t *relay, int64_t stream_id,
uint8_t *data, size_t len, bool fin, ngtcp2_ssize *sent)
{
(void)quic_table;
assert(stream_id >= 0 || (data == NULL && len == 0));
while (stream_id >= 0 && !stream_exists(relay, stream_id)) {
int64_t opened = 0;
int ret = ngtcp2_conn_open_bidi_stream(relay->conn, &opened, NULL);
if (ret != KNOT_EOK) {
return ret;
}
assert((bool)(opened == stream_id) == stream_exists(relay, stream_id));
}
uint32_t xdp_sent = 0;
knot_xdp_msg_t out_msg = { 0 };
int ret = knot_xdp_reply_alloc(sock, in_msg, &out_msg);
if (ret != KNOT_EOK) {
return ret;
}
uint32_t fl = ((stream_id >= 0 && fin) ? NGTCP2_WRITE_STREAM_FLAG_FIN : NGTCP2_WRITE_STREAM_FLAG_NONE);
ngtcp2_vec vec = { .base = data, .len = len };
ret = ngtcp2_conn_writev_stream(relay->conn, NULL, NULL, out_msg.payload.iov_base, out_msg.payload.iov_len,
sent, fl, stream_id, &vec, (stream_id >= 0 ? 1 : 0), get_timestamp());
if (ret <= 0) {
knot_xdp_send_free(sock, &out_msg, 1);
return ret;
}
if (*sent < 0) {
*sent = 0;
}
out_msg.payload.iov_len = ret;
ret = knot_xdp_send(sock, &out_msg, 1, &xdp_sent);
if (ret == KNOT_EOK) {
assert(xdp_sent == 1);
return 1;
}
return ret;
}
static int send_special(knot_xquic_table_t *quic_table, knot_xdp_socket_t *sock,
knot_xdp_msg_t *in_msg, int handle_ret)
{
knot_xdp_msg_t out_msg;
int ret = knot_xdp_reply_alloc(sock, in_msg, &out_msg);
if (ret != KNOT_EOK) {
return ret;
}
uint64_t now = get_timestamp();
ngtcp2_version_cid decoded_cids = { 0 };
ngtcp2_cid scid = { 0 }, dcid = { 0 };
int dvc_ret = ngtcp2_pkt_decode_version_cid(&decoded_cids,
in_msg->payload.iov_base,
in_msg->payload.iov_len,
SERVER_DEFAULT_SCIDLEN);
uint8_t rnd = 0;
dnssec_random_buffer(&rnd, sizeof(rnd));
uint32_t supported_quic[1] = { NGTCP2_PROTO_VER_V1 };
ngtcp2_cid new_dcid;
uint8_t retry_token[NGTCP2_CRYPTO_MAX_RETRY_TOKENLEN];
uint8_t stateless_reset_token[NGTCP2_STATELESS_RESET_TOKENLEN];
uint8_t sreset_rand[NGTCP2_MIN_STATELESS_RESET_RANDLEN];
dnssec_random_buffer(sreset_rand, sizeof(sreset_rand));
switch (handle_ret) {
case -XQUIC_SEND_VERSION_NEGOTIATION:
if (dvc_ret != NGTCP2_ERR_VERSION_NEGOTIATION) {
return KNOT_ERROR;
}
ret = ngtcp2_pkt_write_version_negotiation(
out_msg.payload.iov_base, out_msg.payload.iov_len,
rnd, decoded_cids.scid, decoded_cids.scidlen, decoded_cids.dcid,
decoded_cids.dcidlen, supported_quic,
sizeof(supported_quic) / sizeof(*supported_quic)
);
break;
case -XQUIC_SEND_RETRY:
ngtcp2_cid_init(&dcid, decoded_cids.dcid, decoded_cids.dcidlen);
ngtcp2_cid_init(&scid, decoded_cids.scid, decoded_cids.scidlen);
init_random_cid(&new_dcid, 0);
ret = ngtcp2_crypto_generate_retry_token(
retry_token, (const uint8_t *)quic_table->hash_secret, sizeof(quic_table->hash_secret), decoded_cids.version,
(const struct sockaddr *)&in_msg->ip_from, sockaddr_len((const struct sockaddr_storage *)&in_msg->ip_from),
&new_dcid, &dcid, now
);
if (ret >= 0) {
ret = ngtcp2_crypto_write_retry(
out_msg.payload.iov_base, out_msg.payload.iov_len,
decoded_cids.version, &scid, &new_dcid, &dcid, retry_token, ret
);
}
break;
case -XQUIC_SEND_STATELESS_RESET:
ret = ngtcp2_pkt_write_stateless_reset(
out_msg.payload.iov_base, out_msg.payload.iov_len,
stateless_reset_token, sreset_rand, sizeof(sreset_rand)
);
break;
default:
ret = KNOT_EINVAL;
break;
}
if (ret < 0) {
knot_xdp_send_free(sock, &out_msg, 1);
} else {
uint32_t sent;
out_msg.payload.iov_len = ret;
ret = knot_xdp_send(sock, &out_msg, 1, &sent);
}
return ret;
}
_public_
int knot_xquic_send(knot_xquic_table_t *quic_table, knot_xquic_conn_t *relay,
knot_xdp_socket_t *sock, knot_xdp_msg_t *in_msg,
int handle_ret, unsigned max_msgs, bool ignore_lastbyte)
{
if (handle_ret < 0) {
return handle_ret;
} else if (handle_ret > 0) {
return send_special(quic_table, sock, in_msg, handle_ret);
} else if (relay == NULL) {
return KNOT_EINVAL;
} else if (relay->conn == NULL) {
return KNOT_EOK;
}
unsigned sent_msgs = 0, stream_msgs = 0;
int ret = 1;
for (int64_t si = 0; si < relay->streams_count && sent_msgs < max_msgs; /* NO INCREMENT */) {
int64_t stream_id = 4 * (relay->streams_first + si);
ngtcp2_ssize sent = 0;
size_t uf = relay->streams[si].unsent_offset;
knot_xquic_obuf_t *uo = relay->streams[si].unsent_obuf;
if (uo == NULL) {
si++;
continue;
}
bool fin = (((node_t *)uo->node.next)->next == NULL) && !ignore_lastbyte;
ret = send_stream(quic_table, sock, in_msg, relay, stream_id,
uo->buf + uf, uo->len - uf - (ignore_lastbyte ? 1 : 0),
fin, &sent);
if (ret < 0) {
return ret;
}
sent_msgs++;
stream_msgs++;
if (sent > 0 && ignore_lastbyte) {
sent++;
}
if (sent > 0) {
knot_xquic_stream_mark_sent(relay, stream_id, sent);
}
if (stream_msgs >= max_msgs / relay->streams_count) {
stream_msgs = 0;
si++; // if this stream is sending too much, give chance to other streams
}
}
while (ret == 1) {
ngtcp2_ssize unused = 0;
ret = send_stream(quic_table, sock, in_msg, relay, -1, NULL, 0, false, &unused);
}
return ret;
}
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