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openssl/ssl/quic/quic_txp.c
Hugo Landau a73078b79f QUIC TX Packetiser and Streams Mapper 
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/19346)
2022-11-24 08:15:20 +00:00

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/*
* Copyright 2022 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include "internal/quic_txp.h"
#include "internal/quic_fifd.h"
#include "internal/quic_stream_map.h"
#include "internal/common.h"
#include <openssl/err.h>
#define MIN_CRYPTO_HDR_SIZE 3
#define MIN_FRAME_SIZE_HANDSHAKE_DONE 1
#define MIN_FRAME_SIZE_MAX_DATA 2
#define MIN_FRAME_SIZE_ACK 5
#define MIN_FRAME_SIZE_CRYPTO (MIN_CRYPTO_HDR_SIZE + 1)
#define MIN_FRAME_SIZE_STREAM 3 /* minimum useful size (for non-FIN) */
#define MIN_FRAME_SIZE_MAX_STREAMS_BIDI 2
#define MIN_FRAME_SIZE_MAX_STREAMS_UNI 2
struct ossl_quic_tx_packetiser_st {
OSSL_QUIC_TX_PACKETISER_ARGS args;
/*
* Opaque initial token blob provided by caller. TXP frees using the
* callback when it is no longer needed.
*/
const unsigned char *initial_token;
size_t initial_token_len;
ossl_quic_initial_token_free_fn *initial_token_free_cb;
void *initial_token_free_cb_arg;
/* Subcomponents of the TXP that we own. */
QUIC_FIFD fifd; /* QUIC Frame-in-Flight Dispatcher */
/* Internal state. */
uint64_t next_pn[QUIC_PN_SPACE_NUM]; /* Next PN to use in given PN space. */
OSSL_TIME last_tx_time; /* Last time a packet was generated, or 0. */
/* Internal state - frame (re)generation flags. */
unsigned int want_handshake_done : 1;
unsigned int want_max_data : 1;
unsigned int want_max_streams_bidi : 1;
unsigned int want_max_streams_uni : 1;
/* Internal state - frame (re)generation flags - per PN space. */
unsigned int want_ack : QUIC_PN_SPACE_NUM;
unsigned int force_ack_eliciting : QUIC_PN_SPACE_NUM;
/*
* Internal state - connection close terminal state.
* Once this is set, it is not unset unlike other want_ flags - we keep
* sending it in every packet.
*/
unsigned int want_conn_close : 1;
OSSL_QUIC_FRAME_CONN_CLOSE conn_close_frame;
/* Internal state - packet assembly. */
unsigned char *scratch; /* scratch buffer for packet assembly */
size_t scratch_len; /* number of bytes allocated for scratch */
OSSL_QTX_IOVEC *iovec; /* scratch iovec array for use with QTX */
size_t alloc_iovec; /* size of iovec array */
};
/*
* The TX helper records state used while generating frames into packets. It
* enables serialization into the packet to be done "transactionally" where
* serialization of a frame can be rolled back if it fails midway (e.g. if it
* does not fit).
*/
struct tx_helper {
OSSL_QUIC_TX_PACKETISER *txp;
/*
* The Maximum Packet Payload Length in bytes. This is the amount of
* space we have to generate frames into.
*/
size_t max_ppl;
/*
* Number of bytes we have generated so far.
*/
size_t bytes_appended;
/*
* Number of scratch bytes in txp->scratch we have used so far. Some iovecs
* will reference this scratch buffer. When we need to use more of it (e.g.
* when we need to put frame headers somewhere), we append to the scratch
* buffer, resizing if necessary, and increase this accordingly.
*/
size_t scratch_bytes;
/*
* Bytes reserved in the MaxPPL budget. We keep this number of bytes spare
* until reserve_allowed is set to 1. Currently this is always at most 1, as
* a PING frame takes up one byte and this mechanism is only used to ensure
* we can encode a PING frame if we have been asked to ensure a packet is
* ACK-eliciting and we are unusure if we are going to add any other
* ACK-eliciting frames before we reach our MaxPPL budget.
*/
size_t reserve;
/*
* Number of iovecs we have currently appended. This is the number of
* entries valid in txp->iovec.
*/
size_t num_iovec;
/*
* Whether we are allowed to make use of the reserve bytes in our MaxPPL
* budget. This is used to ensure we have room to append a PING frame later
* if we need to. Once we know we will not need to append a PING frame, this
* is set to 1.
*/
unsigned int reserve_allowed : 1;
/*
* Set to 1 if we have appended a STREAM frame with an implicit length. If
* this happens we should never append another frame after that frame as it
* cannot be validly encoded. This is just a safety check.
*/
unsigned int done_implicit : 1;
struct {
/*
* The fields in this structure are valid if active is set, which means
* that a serialization transaction is currently in progress.
*/
unsigned char *data;
WPACKET wpkt;
unsigned int active : 1;
} txn;
};
static void tx_helper_rollback(struct tx_helper *h);
static int txp_ensure_iovec(OSSL_QUIC_TX_PACKETISER *txp, size_t num);
/* Initialises the TX helper. */
static int tx_helper_init(struct tx_helper *h, OSSL_QUIC_TX_PACKETISER *txp,
size_t max_ppl, size_t reserve)
{
if (reserve > max_ppl)
return 0;
h->txp = txp;
h->max_ppl = max_ppl;
h->reserve = reserve;
h->num_iovec = 0;
h->bytes_appended = 0;
h->scratch_bytes = 0;
h->reserve_allowed = 0;
h->done_implicit = 0;
h->txn.data = NULL;
h->txn.active = 0;
if (max_ppl > h->txp->scratch_len) {
unsigned char *scratch;
scratch = OPENSSL_realloc(h->txp->scratch, max_ppl);
if (scratch == NULL)
return 0;
h->txp->scratch = scratch;
h->txp->scratch_len = max_ppl;
}
return 1;
}
static void tx_helper_cleanup(struct tx_helper *h)
{
if (h->txn.active)
tx_helper_rollback(h);
h->txp = NULL;
}
static void tx_helper_unrestrict(struct tx_helper *h)
{
h->reserve_allowed = 1;
}
/*
* Append an extent of memory to the iovec list. The memory must remain
* allocated until we finish generating the packet and call the QTX.
*
* In general, the buffers passed to this function will be from one of two
* ranges:
*
* - Application data contained in stream buffers managed elsewhere
* in the QUIC stack; or
*
* - Control frame data appended into txp->scratch using tx_helper_begin and
* tx_helper_commit.
*
*/
static int tx_helper_append_iovec(struct tx_helper *h,
const unsigned char *buf,
size_t buf_len)
{
if (buf_len == 0)
return 1;
if (!ossl_assert(!h->done_implicit))
return 0;
if (!txp_ensure_iovec(h->txp, h->num_iovec + 1))
return 0;
h->txp->iovec[h->num_iovec].buf = buf;
h->txp->iovec[h->num_iovec].buf_len = buf_len;
++h->num_iovec;
h->bytes_appended += buf_len;
return 1;
}
/*
* How many more bytes of space do we have left in our plaintext packet payload?
*/
static size_t tx_helper_get_space_left(struct tx_helper *h)
{
return h->max_ppl
- (h->reserve_allowed ? 0 : h->reserve) - h->bytes_appended;
}
/*
* Begin a control frame serialization transaction. This allows the
* serialization of the control frame to be backed out if it turns out it won't
* fit. Write the control frame to the returned WPACKET. Ensure you always
* call tx_helper_rollback or tx_helper_commit (or tx_helper_cleanup). Returns
* NULL on failure.
*/
static WPACKET *tx_helper_begin(struct tx_helper *h)
{
size_t space_left, len;
unsigned char *data;
if (!ossl_assert(!h->txn.active))
return NULL;
if (!ossl_assert(!h->done_implicit))
return NULL;
data = (unsigned char *)h->txp->scratch + h->scratch_bytes;
len = h->txp->scratch_len - h->scratch_bytes;
space_left = tx_helper_get_space_left(h);
if (!ossl_assert(space_left <= len))
return NULL;
if (!WPACKET_init_static_len(&h->txn.wpkt, data, len, 0))
return NULL;
if (!WPACKET_set_max_size(&h->txn.wpkt, space_left)) {
WPACKET_cleanup(&h->txn.wpkt);
return NULL;
}
h->txn.data = data;
h->txn.active = 1;
return &h->txn.wpkt;
}
static void tx_helper_end(struct tx_helper *h, int success)
{
if (success)
WPACKET_finish(&h->txn.wpkt);
else
WPACKET_cleanup(&h->txn.wpkt);
h->txn.active = 0;
h->txn.data = NULL;
}
/* Abort a control frame serialization transaction. */
static void tx_helper_rollback(struct tx_helper *h)
{
if (!h->txn.active)
return;
tx_helper_end(h, 0);
}
/* Commit a control frame. */
static int tx_helper_commit(struct tx_helper *h)
{
size_t l = 0;
if (!h->txn.active)
return 0;
if (!WPACKET_get_total_written(&h->txn.wpkt, &l)) {
tx_helper_end(h, 0);
return 0;
}
if (!tx_helper_append_iovec(h, h->txn.data, l)) {
tx_helper_end(h, 0);
return 0;
}
h->scratch_bytes += l;
tx_helper_end(h, 1);
return 1;
}
static QUIC_SSTREAM *get_sstream_by_id(uint64_t stream_id, uint32_t pn_space,
void *arg);
static void on_regen_notify(uint64_t frame_type, uint64_t stream_id,
QUIC_TXPIM_PKT *pkt, void *arg);
static int sstream_is_pending(QUIC_SSTREAM *sstream);
static int txp_el_pending(OSSL_QUIC_TX_PACKETISER *txp, uint32_t enc_level,
uint32_t archetype);
static int txp_generate_for_el(OSSL_QUIC_TX_PACKETISER *txp, uint32_t enc_level,
uint32_t archetype,
char is_last_in_dgram,
char dgram_contains_initial);
static size_t txp_determine_pn_len(OSSL_QUIC_TX_PACKETISER *txp);
static int txp_determine_ppl_from_pl(OSSL_QUIC_TX_PACKETISER *txp,
size_t pl,
uint32_t enc_level,
size_t hdr_len,
size_t *r);
static size_t txp_get_mdpl(OSSL_QUIC_TX_PACKETISER *txp);
static int txp_generate_for_el_actual(OSSL_QUIC_TX_PACKETISER *txp,
uint32_t enc_level,
uint32_t archetype,
size_t min_ppl,
size_t max_ppl,
size_t pkt_overhead,
QUIC_PKT_HDR *phdr);
OSSL_QUIC_TX_PACKETISER *ossl_quic_tx_packetiser_new(const OSSL_QUIC_TX_PACKETISER_ARGS *args)
{
OSSL_QUIC_TX_PACKETISER *txp;
if (args == NULL
|| args->qtx == NULL
|| args->txpim == NULL
|| args->cfq == NULL
|| args->ackm == NULL
|| args->qsm == NULL
|| args->conn_txfc == NULL
|| args->conn_rxfc == NULL) {
ERR_raise(ERR_LIB_SSL, ERR_R_PASSED_NULL_PARAMETER);
return NULL;
}
txp = OPENSSL_zalloc(sizeof(*txp));
if (txp == NULL)
return NULL;
txp->args = *args;
txp->last_tx_time = ossl_time_zero();
if (!ossl_quic_fifd_init(&txp->fifd,
txp->args.cfq, txp->args.ackm, txp->args.txpim,
get_sstream_by_id, txp,
on_regen_notify, txp)) {
OPENSSL_free(txp);
return NULL;
}
return txp;
}
void ossl_quic_tx_packetiser_free(OSSL_QUIC_TX_PACKETISER *txp)
{
if (txp == NULL)
return;
ossl_quic_tx_packetiser_set_initial_token(txp, NULL, 0, NULL, NULL);
ossl_quic_fifd_cleanup(&txp->fifd);
OPENSSL_free(txp->iovec);
OPENSSL_free(txp->conn_close_frame.reason);
OPENSSL_free(txp->scratch);
OPENSSL_free(txp);
}
void ossl_quic_tx_packetiser_set_initial_token(OSSL_QUIC_TX_PACKETISER *txp,
const unsigned char *token,
size_t token_len,
ossl_quic_initial_token_free_fn *free_cb,
void *free_cb_arg)
{
if (txp->initial_token != NULL && txp->initial_token_free_cb != NULL)
txp->initial_token_free_cb(txp->initial_token, txp->initial_token_len,
txp->initial_token_free_cb_arg);
txp->initial_token = token;
txp->initial_token_len = token_len;
txp->initial_token_free_cb = free_cb;
txp->initial_token_free_cb_arg = free_cb_arg;
}
int ossl_quic_tx_packetiser_set_cur_dcid(OSSL_QUIC_TX_PACKETISER *txp,
const QUIC_CONN_ID *dcid)
{
if (dcid == NULL) {
ERR_raise(ERR_LIB_SSL, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
txp->args.cur_dcid = *dcid;
return 1;
}
int ossl_quic_tx_packetiser_set_cur_scid(OSSL_QUIC_TX_PACKETISER *txp,
const QUIC_CONN_ID *scid)
{
if (scid == NULL) {
ERR_raise(ERR_LIB_SSL, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
txp->args.cur_scid = *scid;
return 1;
}
/* Change the destination L4 address the TXP uses to send datagrams. */
int ossl_quic_tx_packetiser_set_peer(OSSL_QUIC_TX_PACKETISER *txp,
const BIO_ADDR *peer)
{
if (peer == NULL) {
ERR_raise(ERR_LIB_SSL, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
txp->args.peer = *peer;
return 1;
}
int ossl_quic_tx_packetiser_discard_enc_level(OSSL_QUIC_TX_PACKETISER *txp,
uint32_t enc_level)
{
if (enc_level >= QUIC_ENC_LEVEL_NUM) {
ERR_raise(ERR_LIB_SSL, ERR_R_PASSED_INVALID_ARGUMENT);
return 0;
}
if (enc_level != QUIC_ENC_LEVEL_0RTT)
txp->args.crypto[ossl_quic_enc_level_to_pn_space(enc_level)] = NULL;
ossl_qtx_discard_enc_level(txp->args.qtx, enc_level);
return 1;
}
void ossl_quic_tx_packetiser_schedule_handshake_done(OSSL_QUIC_TX_PACKETISER *txp)
{
txp->want_handshake_done = 1;
}
void ossl_quic_tx_packetiser_schedule_ack_eliciting(OSSL_QUIC_TX_PACKETISER *txp,
uint32_t pn_space)
{
txp->force_ack_eliciting |= (1UL << pn_space);
}
#define TXP_ERR_INTERNAL 0 /* Internal (e.g. alloc) error */
#define TXP_ERR_SUCCESS 1 /* Success */
#define TXP_ERR_SPACE 2 /* Not enough room for another packet */
#define TXP_ERR_INPUT 3 /* Invalid/malformed input */
/*
* Generates a datagram by polling the various ELs to determine if they want to
* generate any frames, and generating a datagram which coalesces packets for
* any ELs which do.
*/
int ossl_quic_tx_packetiser_generate(OSSL_QUIC_TX_PACKETISER *txp,
uint32_t archetype)
{
uint32_t enc_level;
char have_pkt_for_el[QUIC_ENC_LEVEL_NUM], is_last_in_dgram;
size_t num_el_in_dgram = 0, pkts_done = 0;
int rc;
if (!txp->args.cc_method->can_send(txp->args.cc_data))
return TX_PACKETISER_RES_NO_PKT;
for (enc_level = QUIC_ENC_LEVEL_INITIAL;
enc_level < QUIC_ENC_LEVEL_NUM;
++enc_level) {
have_pkt_for_el[enc_level] = txp_el_pending(txp, enc_level, archetype);
if (have_pkt_for_el[enc_level])
++num_el_in_dgram;
}
if (num_el_in_dgram == 0)
return TX_PACKETISER_RES_NO_PKT;
/*
* Should not be needed, but a sanity check in case anyone else has been
* using the QTX.
*/
ossl_qtx_finish_dgram(txp->args.qtx);
for (enc_level = QUIC_ENC_LEVEL_INITIAL;
enc_level < QUIC_ENC_LEVEL_NUM;
++enc_level) {
if (!have_pkt_for_el[enc_level])
continue;
is_last_in_dgram = (pkts_done + 1 == num_el_in_dgram);
rc = txp_generate_for_el(txp, enc_level, archetype, is_last_in_dgram,
have_pkt_for_el[QUIC_ENC_LEVEL_INITIAL]);
if (rc != TXP_ERR_SUCCESS) {
/*
* If we already successfully did at least one, make sure we report
* this via the return code.
*/
if (pkts_done > 0)
break;
else
return TX_PACKETISER_RES_FAILURE;
}
++pkts_done;
}
ossl_qtx_finish_dgram(txp->args.qtx);
return TX_PACKETISER_RES_SENT_PKT;
}
struct archetype_data {
unsigned int allow_ack : 1;
unsigned int allow_ping : 1;
unsigned int allow_crypto : 1;
unsigned int allow_handshake_done : 1;
unsigned int allow_path_challenge : 1;
unsigned int allow_path_response : 1;
unsigned int allow_new_conn_id : 1;
unsigned int allow_retire_conn_id : 1;
unsigned int allow_stream_rel : 1;
unsigned int allow_conn_fc : 1;
unsigned int allow_conn_close : 1;
unsigned int allow_cfq_other : 1;
unsigned int allow_new_token : 1;
unsigned int allow_force_ack_eliciting : 1;
};
static const struct archetype_data archetypes[QUIC_ENC_LEVEL_NUM][TX_PACKETISER_ARCHETYPE_NUM] = {
/* EL 0(INITIAL) */
{
/* EL 0(INITIAL) - Archetype 0(NORMAL) */
{
/*allow_ack =*/ 1,
/*allow_ping =*/ 1,
/*allow_crypto =*/ 1,
/*allow_handshake_done =*/ 0,
/*allow_path_challenge =*/ 0,
/*allow_path_response =*/ 0,
/*allow_new_conn_id =*/ 0,
/*allow_retire_conn_id =*/ 0,
/*allow_stream_rel =*/ 0,
/*allow_conn_fc =*/ 0,
/*allow_conn_close =*/ 1,
/*allow_cfq_other =*/ 1,
/*allow_new_token =*/ 0,
/*allow_force_ack_eliciting =*/ 1,
},
/* EL 0(INITIAL) - Archetype 1(ACK_ONLY) */
{
/*allow_ack =*/ 1,
/*allow_ping =*/ 0,
/*allow_crypto =*/ 0,
/*allow_handshake_done =*/ 0,
/*allow_path_challenge =*/ 0,
/*allow_path_response =*/ 0,
/*allow_new_conn_id =*/ 0,
/*allow_retire_conn_id =*/ 0,
/*allow_stream_rel =*/ 0,
/*allow_conn_fc =*/ 0,
/*allow_conn_close =*/ 0,
/*allow_cfq_other =*/ 0,
/*allow_new_token =*/ 0,
/*allow_force_ack_eliciting =*/ 1,
},
},
/* EL 1(HANDSHAKE) */
{
/* EL 1(HANDSHAKE) - Archetype 0(NORMAL) */
{
/*allow_ack =*/ 1,
/*allow_ping =*/ 1,
/*allow_crypto =*/ 1,
/*allow_handshake_done =*/ 0,
/*allow_path_challenge =*/ 0,
/*allow_path_response =*/ 0,
/*allow_new_conn_id =*/ 0,
/*allow_retire_conn_id =*/ 0,
/*allow_stream_rel =*/ 0,
/*allow_conn_fc =*/ 0,
/*allow_conn_close =*/ 1,
/*allow_cfq_other =*/ 1,
/*allow_new_token =*/ 0,
/*allow_force_ack_eliciting =*/ 1,
},
/* EL 1(HANDSHAKE) - Archetype 1(ACK_ONLY) */
{
/*allow_ack =*/ 1,
/*allow_ping =*/ 0,
/*allow_crypto =*/ 0,
/*allow_handshake_done =*/ 0,
/*allow_path_challenge =*/ 0,
/*allow_path_response =*/ 0,
/*allow_new_conn_id =*/ 0,
/*allow_retire_conn_id =*/ 0,
/*allow_stream_rel =*/ 0,
/*allow_conn_fc =*/ 0,
/*allow_conn_close =*/ 0,
/*allow_cfq_other =*/ 0,
/*allow_new_token =*/ 0,
/*allow_force_ack_eliciting =*/ 1,
},
},
/* EL 2(0RTT) */
{
/* EL 2(0RTT) - Archetype 0(NORMAL) */
{
/*allow_ack =*/ 0,
/*allow_ping =*/ 1,
/*allow_crypto =*/ 0,
/*allow_handshake_done =*/ 0,
/*allow_path_challenge =*/ 0,
/*allow_path_response =*/ 0,
/*allow_new_conn_id =*/ 1,
/*allow_retire_conn_id =*/ 1,
/*allow_stream_rel =*/ 1,
/*allow_conn_fc =*/ 1,
/*allow_conn_close =*/ 1,
/*allow_cfq_other =*/ 0,
/*allow_new_token =*/ 0,
/*allow_force_ack_eliciting =*/ 0,
},
/* EL 2(0RTT) - Archetype 1(ACK_ONLY) */
{
/*allow_ack =*/ 0,
/*allow_ping =*/ 0,
/*allow_crypto =*/ 0,
/*allow_handshake_done =*/ 0,
/*allow_path_challenge =*/ 0,
/*allow_path_response =*/ 0,
/*allow_new_conn_id =*/ 0,
/*allow_retire_conn_id =*/ 0,
/*allow_stream_rel =*/ 0,
/*allow_conn_fc =*/ 0,
/*allow_conn_close =*/ 0,
/*allow_cfq_other =*/ 0,
/*allow_new_token =*/ 0,
/*allow_force_ack_eliciting =*/ 0,
},
},
/* EL 3(1RTT) */
{
/* EL 3(1RTT) - Archetype 0(NORMAL) */
{
/*allow_ack =*/ 1,
/*allow_ping =*/ 1,
/*allow_crypto =*/ 1,
/*allow_handshake_done =*/ 1,
/*allow_path_challenge =*/ 0,
/*allow_path_response =*/ 0,
/*allow_new_conn_id =*/ 1,
/*allow_retire_conn_id =*/ 1,
/*allow_stream_rel =*/ 1,
/*allow_conn_fc =*/ 1,
/*allow_conn_close =*/ 1,
/*allow_cfq_other =*/ 1,
/*allow_new_token =*/ 1,
/*allow_force_ack_eliciting =*/ 1,
},
/* EL 3(1RTT) - Archetype 1(ACK_ONLY) */
{
/*allow_ack =*/ 1,
/*allow_ping =*/ 0,
/*allow_crypto =*/ 0,
/*allow_handshake_done =*/ 0,
/*allow_path_challenge =*/ 0,
/*allow_path_response =*/ 0,
/*allow_new_conn_id =*/ 0,
/*allow_retire_conn_id =*/ 0,
/*allow_stream_rel =*/ 0,
/*allow_conn_fc =*/ 0,
/*allow_conn_close =*/ 0,
/*allow_cfq_other =*/ 0,
/*allow_new_token =*/ 0,
/*allow_force_ack_eliciting =*/ 1,
}
}
};
static int txp_get_archetype_data(uint32_t enc_level,
uint32_t archetype,
struct archetype_data *a)
{
if (enc_level >= QUIC_ENC_LEVEL_NUM
|| archetype >= TX_PACKETISER_ARCHETYPE_NUM)
return 0;
/* No need to avoid copying this as it should not exceed one int in size. */
*a = archetypes[enc_level][archetype];
return 1;
}
/*
* Returns 1 if the given EL wants to produce one or more frames.
* Always returns 0 if the given EL is discarded.
*/
static int txp_el_pending(OSSL_QUIC_TX_PACKETISER *txp, uint32_t enc_level,
uint32_t archetype)
{
struct archetype_data a;
uint32_t pn_space = ossl_quic_enc_level_to_pn_space(enc_level);
QUIC_CFQ_ITEM *cfq_item;
if (!ossl_qtx_is_enc_level_provisioned(txp->args.qtx, enc_level))
return 0;
if (!txp_get_archetype_data(enc_level, archetype, &a))
return 0;
/* Does the crypto stream for this EL want to produce anything? */
if (a.allow_crypto && sstream_is_pending(txp->args.crypto[pn_space]))
return 1;
/* Does the ACKM for this PN space want to produce anything? */
if (a.allow_ack && (ossl_ackm_is_ack_desired(txp->args.ackm, pn_space)
|| (txp->want_ack & (1UL << pn_space)) != 0))
return 1;
/* Do we need to force emission of an ACK-eliciting packet? */
if (a.allow_force_ack_eliciting
&& (txp->force_ack_eliciting & (1UL << pn_space)) != 0)
return 1;
/* Does the connection-level RXFC want to produce a frame? */
if (a.allow_conn_fc && (txp->want_max_data
|| ossl_quic_rxfc_has_cwm_changed(txp->args.conn_rxfc, 0)))
return 1;
/* Do we want to produce a MAX_STREAMS frame? */
if (a.allow_conn_fc && (txp->want_max_streams_bidi
|| txp->want_max_streams_uni))
return 1;
/* Do we want to produce a HANDSHAKE_DONE frame? */
if (a.allow_handshake_done && txp->want_handshake_done)
return 1;
/* Do we want to produce a CONNECTION_CLOSE frame? */
if (a.allow_conn_close && txp->want_conn_close)
return 1;
/* Does the CFQ have any frames queued for this PN space? */
if (enc_level != QUIC_ENC_LEVEL_0RTT)
for (cfq_item = ossl_quic_cfq_get_priority_head(txp->args.cfq, pn_space);
cfq_item != NULL;
cfq_item = ossl_quic_cfq_item_get_priority_next(cfq_item, pn_space)) {
uint64_t frame_type = ossl_quic_cfq_item_get_frame_type(cfq_item);
switch (frame_type) {
case OSSL_QUIC_FRAME_TYPE_NEW_CONN_ID:
if (a.allow_new_conn_id)
return 1;
break;
case OSSL_QUIC_FRAME_TYPE_RETIRE_CONN_ID:
if (a.allow_retire_conn_id)
return 1;
break;
case OSSL_QUIC_FRAME_TYPE_NEW_TOKEN:
if (a.allow_new_token)
return 1;
break;
default:
if (a.allow_cfq_other)
return 1;
break;
}
}
if (a.allow_stream_rel) {
QUIC_STREAM_ITER it;
/* If there are any active streams, 0/1-RTT wants to produce a packet.
* Whether a stream is on the active list is required to be precise
* (i.e., a stream is never on the active list if we cannot produce a
* frame for it), and all stream-related frames are governed by
* a.allow_stream_rel (i.e., if we can send one type of stream-related
* frame, we can send any of them), so we don't need to inspect
* individual streams on the active list, just confirm that the active
* list is non-empty.
*/
ossl_quic_stream_iter_init(&it, txp->args.qsm, 0);
if (it.stream != NULL)
return 1;
}
return 0;
}
static int sstream_is_pending(QUIC_SSTREAM *sstream)
{
OSSL_QUIC_FRAME_STREAM hdr;
OSSL_QTX_IOVEC iov[2];
size_t num_iov = OSSL_NELEM(iov);
return ossl_quic_sstream_get_stream_frame(sstream, 0, &hdr, iov, &num_iov);
}
/*
* Generates a packet for a given EL, coalescing it into the current datagram.
*
* is_last_in_dgram and dgram_contains_initial are used to determine padding
* requirements.
*
* Returns TXP_ERR_* value.
*/
static int txp_generate_for_el(OSSL_QUIC_TX_PACKETISER *txp, uint32_t enc_level,
uint32_t archetype,
char is_last_in_dgram,
char dgram_contains_initial)
{
char must_pad = dgram_contains_initial && is_last_in_dgram;
size_t min_dpl, min_pl, min_ppl, cmpl, cmppl, running_total;
size_t mdpl, hdr_len, pkt_overhead, cc_limit;
uint64_t cc_limit_;
QUIC_PKT_HDR phdr;
OSSL_TIME time_since_last;
/* Determine the limit CC imposes on what we can send. */
if (ossl_time_is_zero(txp->last_tx_time))
time_since_last = ossl_time_zero();
else
time_since_last = ossl_time_subtract(txp->args.now(txp->args.now_arg),
txp->last_tx_time);
cc_limit_ = txp->args.cc_method->get_send_allowance(txp->args.cc_data,
time_since_last,
ossl_time_is_zero(time_since_last));
cc_limit = (cc_limit_ > SIZE_MAX ? SIZE_MAX : (size_t)cc_limit_);
/* Assemble packet header. */
phdr.type = ossl_quic_enc_level_to_pkt_type(enc_level);
phdr.spin_bit = 0;
phdr.pn_len = txp_determine_pn_len(txp);
phdr.partial = 0;
phdr.fixed = 1;
phdr.version = QUIC_VERSION_1;
phdr.dst_conn_id = txp->args.cur_dcid;
phdr.src_conn_id = txp->args.cur_scid;
/*
* We need to know the length of the payload to get an accurate header
* length for non-1RTT packets, because the Length field found in
* Initial/Handshake/0-RTT packets uses a variable-length encoding. However,
* we don't have a good idea of the length of our payload, because the
* length of the payload depends on the room in the datagram after fitting
* the header, which depends on the size of the header.
*
* In general, it does not matter if a packet is slightly shorter (because
* e.g. we predicted use of a 2-byte length field, but ended up only needing
* a 1-byte length field). However this does matter for Initial packets
* which must be at least 1200 bytes, which is also the assumed default MTU;
* therefore in many cases Initial packets will be padded to 1200 bytes,
* which means if we overestimated the header size, we will be short by a
* few bytes and the server will ignore the packet for being too short. In
* this case, however, such packets always *will* be padded to meet 1200
* bytes, which requires a 2-byte length field, so we don't actually need to
* worry about this. Thus we estimate the header length assuming a 2-byte
* length field here, which should in practice work well in all cases.
*/
phdr.len = OSSL_QUIC_VLINT_2B_MAX - phdr.pn_len;
if (enc_level == QUIC_ENC_LEVEL_INITIAL) {
phdr.token = txp->initial_token;
phdr.token_len = txp->initial_token_len;
} else {
phdr.token = NULL;
phdr.token_len = 0;
}
hdr_len = ossl_quic_wire_get_encoded_pkt_hdr_len(phdr.dst_conn_id.id_len,
&phdr);
if (hdr_len == 0)
return TXP_ERR_INPUT;
/* MinDPL: Minimum total datagram payload length. */
min_dpl = must_pad ? QUIC_MIN_INITIAL_DGRAM_LEN : 0;
/* How much data is already in the current datagram? */
running_total = ossl_qtx_get_cur_dgram_len_bytes(txp->args.qtx);
/* MinPL: Minimum length of the fully encoded packet. */
min_pl = running_total < min_dpl ? min_dpl - running_total : 0;
if ((uint64_t)min_pl > cc_limit)
/*
* Congestion control does not allow us to send a packet of adequate
* size.
*/
return TXP_ERR_SPACE;
/* MinPPL: Minimum plaintext payload length needed to meet MinPL. */
if (!txp_determine_ppl_from_pl(txp, min_pl, enc_level, hdr_len, &min_ppl))
/* MinPL is less than a valid packet size, so just use a MinPPL of 0. */
min_ppl = 0;
/* MDPL: Maximum datagram payload length. */
mdpl = txp_get_mdpl(txp);
/*
* CMPL: Maximum encoded packet size we can put into this datagram given any
* previous packets coalesced into it.
*/
if (running_total > mdpl)
/* Should not be possible, but if it happens: */
cmpl = 0;
else
cmpl = mdpl - running_total;
/* Clamp CMPL based on congestion control limit. */
if (cmpl > cc_limit)
cmpl = cc_limit;
/* CMPPL: Maximum amount we can put into the current datagram payload. */
if (!txp_determine_ppl_from_pl(txp, cmpl, enc_level, hdr_len, &cmppl))
return TXP_ERR_SPACE;
/* Packet overhead (size of headers, AEAD tag, etc.) */
pkt_overhead = cmpl - cmppl;
return txp_generate_for_el_actual(txp, enc_level, archetype, min_ppl, cmppl,
pkt_overhead, &phdr);
}
/* Determine how many bytes we should use for the encoded PN. */
static size_t txp_determine_pn_len(OSSL_QUIC_TX_PACKETISER *txp)
{
return 4; /* TODO(QUIC) */
}
/* Determine plaintext packet payload length from payload length. */
static int txp_determine_ppl_from_pl(OSSL_QUIC_TX_PACKETISER *txp,
size_t pl,
uint32_t enc_level,
size_t hdr_len,
size_t *r)
{
if (pl < hdr_len)
return 0;
pl -= hdr_len;
if (!ossl_qtx_calculate_plaintext_payload_len(txp->args.qtx, enc_level,
pl, &pl))
return 0;
*r = pl;
return 1;
}
static size_t txp_get_mdpl(OSSL_QUIC_TX_PACKETISER *txp)
{
return ossl_qtx_get_mdpl(txp->args.qtx);
}
static QUIC_SSTREAM *get_sstream_by_id(uint64_t stream_id, uint32_t pn_space,
void *arg)
{
OSSL_QUIC_TX_PACKETISER *txp = arg;
QUIC_STREAM *s;
if (stream_id == UINT64_MAX)
return txp->args.crypto[pn_space];
s = ossl_quic_stream_map_get_by_id(txp->args.qsm, stream_id);
if (s == NULL)
return NULL;
return s->sstream;
}
static void on_regen_notify(uint64_t frame_type, uint64_t stream_id,
QUIC_TXPIM_PKT *pkt, void *arg)
{
OSSL_QUIC_TX_PACKETISER *txp = arg;
switch (frame_type) {
case OSSL_QUIC_FRAME_TYPE_HANDSHAKE_DONE:
txp->want_handshake_done = 1;
break;
case OSSL_QUIC_FRAME_TYPE_MAX_DATA:
txp->want_max_data = 1;
break;
case OSSL_QUIC_FRAME_TYPE_MAX_STREAMS_BIDI:
txp->want_max_streams_bidi = 1;
break;
case OSSL_QUIC_FRAME_TYPE_MAX_STREAMS_UNI:
txp->want_max_streams_uni = 1;
break;
case OSSL_QUIC_FRAME_TYPE_ACK_WITH_ECN:
txp->want_ack |= (1UL << pkt->ackm_pkt.pkt_space);
break;
case OSSL_QUIC_FRAME_TYPE_MAX_STREAM_DATA:
{
QUIC_STREAM *s
= ossl_quic_stream_map_get_by_id(txp->args.qsm, stream_id);
if (s == NULL)
return;
s->want_max_stream_data = 1;
ossl_quic_stream_map_update_state(txp->args.qsm, s);
}
break;
case OSSL_QUIC_FRAME_TYPE_STOP_SENDING:
{
QUIC_STREAM *s
= ossl_quic_stream_map_get_by_id(txp->args.qsm, stream_id);
if (s == NULL)
return;
s->want_stop_sending = 1;
ossl_quic_stream_map_update_state(txp->args.qsm, s);
}
break;
case OSSL_QUIC_FRAME_TYPE_RESET_STREAM:
{
QUIC_STREAM *s
= ossl_quic_stream_map_get_by_id(txp->args.qsm, stream_id);
if (s == NULL)
return;
s->want_reset_stream = 1;
ossl_quic_stream_map_update_state(txp->args.qsm, s);
}
break;
default:
assert(0);
break;
}
}
static int txp_generate_pre_token(OSSL_QUIC_TX_PACKETISER *txp,
struct tx_helper *h,
QUIC_TXPIM_PKT *tpkt,
uint32_t pn_space,
struct archetype_data *a)
{
const OSSL_QUIC_FRAME_ACK *ack;
OSSL_QUIC_FRAME_ACK ack2;
tpkt->ackm_pkt.largest_acked = QUIC_PN_INVALID;
/* ACK Frames (Regenerate) */
if (a->allow_ack
&& tx_helper_get_space_left(h) >= MIN_FRAME_SIZE_ACK
&& (txp->want_ack
|| ossl_ackm_is_ack_desired(txp->args.ackm, pn_space))
&& (ack = ossl_ackm_get_ack_frame(txp->args.ackm, pn_space)) != NULL) {
WPACKET *wpkt = tx_helper_begin(h);
if (wpkt == NULL)
return 0;
/* We do not currently support ECN */
ack2 = *ack;
ack2.ecn_present = 0;
if (ossl_quic_wire_encode_frame_ack(wpkt,
txp->args.ack_delay_exponent,
&ack2)) {
if (!tx_helper_commit(h))
return 0;
tpkt->had_ack_frame = 1;
if (ack->num_ack_ranges > 0)
tpkt->ackm_pkt.largest_acked = ack->ack_ranges[0].end;
} else {
tx_helper_rollback(h);
}
}
/* CONNECTION_CLOSE Frames (Regenerate) */
if (a->allow_conn_close && txp->want_conn_close) {
WPACKET *wpkt = tx_helper_begin(h);
if (wpkt == NULL)
return 0;
if (ossl_quic_wire_encode_frame_conn_close(wpkt,
&txp->conn_close_frame)) {
if (!tx_helper_commit(h))
return 0;
} else {
tx_helper_rollback(h);
}
}
return 1;
}
static int try_len(size_t space_left, size_t orig_len,
size_t base_hdr_len, size_t lenbytes,
uint64_t maxn, size_t *hdr_len, size_t *payload_len)
{
size_t n;
size_t maxn_ = maxn > SIZE_MAX ? SIZE_MAX : (size_t)maxn;
*hdr_len = base_hdr_len + lenbytes;
n = orig_len;
if (n > maxn_)
n = maxn_;
if (n + *hdr_len > space_left)
n = (space_left >= *hdr_len) ? space_left - *hdr_len : 0;
*payload_len = n;
return n > 0;
}
static void determine_len(size_t space_left, size_t orig_len,
size_t base_hdr_len,
uint64_t *hlen, uint64_t *len)
{
size_t chosen_payload_len = 0;
size_t chosen_hdr_len = 0;
size_t payload_len[4], hdr_len[4];
int i, valid[4] = {0};
valid[0] = try_len(space_left, orig_len, base_hdr_len,
1, OSSL_QUIC_VLINT_1B_MAX,
&hdr_len[0], &payload_len[0]);
valid[1] = try_len(space_left, orig_len, base_hdr_len,
2, OSSL_QUIC_VLINT_2B_MAX,
&hdr_len[1], &payload_len[1]);
valid[2] = try_len(space_left, orig_len, base_hdr_len,
4, OSSL_QUIC_VLINT_4B_MAX,
&hdr_len[2], &payload_len[2]);
valid[3] = try_len(space_left, orig_len, base_hdr_len,
8, OSSL_QUIC_VLINT_8B_MAX,
&hdr_len[3], &payload_len[3]);
for (i = OSSL_NELEM(valid) - 1; i >= 0; --i)
if (valid[i] && payload_len[i] >= chosen_payload_len) {
chosen_payload_len = payload_len[i];
chosen_hdr_len = hdr_len[i];
}
*hlen = chosen_hdr_len;
*len = chosen_payload_len;
}
/*
* Given a CRYPTO frame header with accurate chdr->len and a budget
* (space_left), try to find the optimal value of chdr->len to fill as much of
* the budget as possible. This is slightly hairy because larger values of
* chdr->len cause larger encoded sizes of the length field of the frame, which
* in turn mean less space available for payload data. We check all possible
* encodings and choose the optimal encoding.
*/
static int determine_crypto_len(struct tx_helper *h,
OSSL_QUIC_FRAME_CRYPTO *chdr,
size_t space_left,
uint64_t *hlen,
uint64_t *len)
{
size_t orig_len;
size_t base_hdr_len; /* CRYPTO header length without length field */
if (chdr->len > SIZE_MAX)
return 0;
orig_len = (size_t)chdr->len;
chdr->len = 0;
base_hdr_len = ossl_quic_wire_get_encoded_frame_len_crypto_hdr(chdr);
chdr->len = orig_len;
if (base_hdr_len == 0)
return 0;
--base_hdr_len;
determine_len(space_left, orig_len, base_hdr_len, hlen, len);
return 1;
}
static int determine_stream_len(struct tx_helper *h,
OSSL_QUIC_FRAME_STREAM *shdr,
size_t space_left,
uint64_t *hlen,
uint64_t *len)
{
size_t orig_len;
size_t base_hdr_len; /* STREAM header length without length field */
if (shdr->len > SIZE_MAX)
return 0;
orig_len = (size_t)shdr->len;
shdr->len = 0;
base_hdr_len = ossl_quic_wire_get_encoded_frame_len_stream_hdr(shdr);
shdr->len = orig_len;
if (base_hdr_len == 0)
return 0;
if (shdr->has_explicit_len)
--base_hdr_len;
determine_len(space_left, orig_len, base_hdr_len, hlen, len);
return 1;
}
static int txp_generate_crypto_frames(OSSL_QUIC_TX_PACKETISER *txp,
struct tx_helper *h,
uint32_t pn_space,
QUIC_TXPIM_PKT *tpkt,
char *have_ack_eliciting)
{
size_t num_stream_iovec;
OSSL_QUIC_FRAME_STREAM shdr = {0};
OSSL_QUIC_FRAME_CRYPTO chdr = {0};
OSSL_QTX_IOVEC iov[2];
uint64_t hdr_bytes;
WPACKET *wpkt;
QUIC_TXPIM_CHUNK chunk;
size_t i, space_left;
for (i = 0;; ++i) {
space_left = tx_helper_get_space_left(h);
if (space_left < MIN_FRAME_SIZE_CRYPTO)
return 1; /* no point trying */
/* Do we have any CRYPTO data waiting? */
num_stream_iovec = OSSL_NELEM(iov);
if (!ossl_quic_sstream_get_stream_frame(txp->args.crypto[pn_space],
i, &shdr, iov,
&num_stream_iovec))
return 1; /* nothing to do */
/* Convert STREAM frame header to CRYPTO frame header */
chdr.offset = shdr.offset;
chdr.len = shdr.len;
if (chdr.len == 0)
return 1; /* nothing to do */
/* Find best fit (header length, payload length) combination. */
if (!determine_crypto_len(h, &chdr, space_left, &hdr_bytes,
&chdr.len)
|| hdr_bytes == 0 || chdr.len == 0) {
return 1; /* can't fit anything */
}
/*
* Truncate IOVs to match our chosen length.
*
* The length cannot be more than SIZE_MAX because this length comes
* from our send stream buffer.
*/
ossl_quic_sstream_adjust_iov((size_t)chdr.len, iov, num_stream_iovec);
/*
* Ensure we have enough iovecs allocated (1 for the header, up to 2 for
* the the stream data.)
*/
if (!txp_ensure_iovec(txp, h->num_iovec + 3))
return 0; /* alloc error */
/* Encode the header. */
wpkt = tx_helper_begin(h);
if (wpkt == NULL)
return 0; /* alloc error */
if (!ossl_quic_wire_encode_frame_crypto_hdr(wpkt, &chdr)) {
tx_helper_rollback(h);
return 1; /* can't fit */
}
if (!tx_helper_commit(h))
return 0; /* alloc error */
/* Add payload iovecs to the helper (infallible). */
for (i = 0; i < num_stream_iovec; ++i)
tx_helper_append_iovec(h, iov[i].buf, iov[i].buf_len);
*have_ack_eliciting = 1;
tx_helper_unrestrict(h); /* no longer need PING */
/* Log chunk to TXPIM. */
chunk.stream_id = UINT64_MAX; /* crypto stream */
chunk.start = chdr.offset;
chunk.end = chdr.offset + chdr.len - 1;
chunk.has_fin = 0; /* Crypto stream never ends */
if (!ossl_quic_txpim_pkt_append_chunk(tpkt, &chunk))
return 0; /* alloc error */
}
}
struct chunk_info {
OSSL_QUIC_FRAME_STREAM shdr;
OSSL_QTX_IOVEC iov[2];
size_t num_stream_iovec;
char valid;
};
static int txp_plan_stream_chunk(OSSL_QUIC_TX_PACKETISER *txp,
struct tx_helper *h,
QUIC_SSTREAM *sstream,
QUIC_TXFC *stream_txfc,
size_t skip,
struct chunk_info *chunk)
{
uint64_t fc_credit, fc_swm, fc_limit;
chunk->num_stream_iovec = OSSL_NELEM(chunk->iov);
chunk->valid = ossl_quic_sstream_get_stream_frame(sstream, skip,
&chunk->shdr,
chunk->iov,
&chunk->num_stream_iovec);
if (!chunk->valid)
return 1;
if (!ossl_assert(chunk->shdr.len > 0 || chunk->shdr.is_fin))
/* Should only have 0-length chunk if FIN */
return 0;
/* Clamp according to connection and stream-level TXFC. */
fc_credit = ossl_quic_txfc_get_credit(stream_txfc);
fc_swm = ossl_quic_txfc_get_swm(stream_txfc);
fc_limit = fc_swm + fc_credit;
if (chunk->shdr.len > 0 && chunk->shdr.offset + chunk->shdr.len > fc_limit) {
chunk->shdr.len = (fc_limit <= chunk->shdr.offset)
? 0 : fc_limit - chunk->shdr.offset;
chunk->shdr.is_fin = 0;
}
if (chunk->shdr.len == 0 && !chunk->shdr.is_fin) {
/*
* Nothing to do due to TXFC. Since SSTREAM returns chunks in ascending
* order of offset we don't need to check any later chunks, so stop
* iterating here.
*/
chunk->valid = 0;
return 1;
}
return 1;
}
/*
* Returns 0 on fatal error (e.g. allocation failure), 1 on success.
* *packet_full is set to 1 if there is no longer enough room for another STREAM
* frame, and *stream_drained is set to 1 if all stream buffers have now been
* sent.
*/
static int txp_generate_stream_frames(OSSL_QUIC_TX_PACKETISER *txp,
struct tx_helper *h,
uint32_t pn_space,
QUIC_TXPIM_PKT *tpkt,
uint64_t id,
QUIC_SSTREAM *sstream,
QUIC_TXFC *stream_txfc,
QUIC_STREAM *next_stream,
size_t min_ppl,
char *have_ack_eliciting,
char *packet_full,
char *stream_drained,
uint64_t *new_credit_consumed)
{
int rc = 0;
struct chunk_info chunks[2] = {0};
OSSL_QUIC_FRAME_STREAM *shdr;
WPACKET *wpkt;
QUIC_TXPIM_CHUNK chunk;
size_t i, j, space_left;
int needs_padding_if_implicit, can_fill_payload, use_explicit_len;
int could_have_following_chunk;
uint64_t hdr_len_implicit, payload_len_implicit;
uint64_t hdr_len_explicit, payload_len_explicit;
uint64_t fc_swm, fc_new_hwm;
fc_swm = ossl_quic_txfc_get_swm(stream_txfc);
fc_new_hwm = fc_swm;
/*
* Load the first two chunks if any offered by the send stream. We retrieve
* the next chunk in advance so we can determine if we need to send any more
* chunks from the same stream after this one, which is needed when
* determining when we can use an implicit length in a STREAM frame.
*/
for (i = 0; i < 2; ++i) {
if (!txp_plan_stream_chunk(txp, h, sstream, stream_txfc, i, &chunks[i]))
goto err;
if (i == 0 && !chunks[i].valid) {
/* No chunks, nothing to do. */
*stream_drained = 1;
rc = 1;
goto err;
}
}
for (i = 0;; ++i) {
space_left = tx_helper_get_space_left(h);
if (space_left < MIN_FRAME_SIZE_STREAM) {
*packet_full = 1;
rc = 1;
goto err;
}
if (!chunks[i % 2].valid) {
/* Out of chunks; we're done. */
*stream_drained = 1;
rc = 1;
goto err;
}
if (!ossl_assert(!h->done_implicit))
/*
* Logic below should have ensured we didn't append an
* implicit-length unless we filled the packet or didn't have
* another stream to handle, so this should not be possible.
*/
goto err;
shdr = &chunks[i % 2].shdr;
if (i > 0)
/* Load next chunk for lookahead. */
if (!txp_plan_stream_chunk(txp, h, sstream, stream_txfc, i + 1,
&chunks[(i + 1) % 2]))
goto err;
/*
* Find best fit (header length, payload length) combination for if we
* use an implicit length.
*/
shdr->has_explicit_len = 0;
hdr_len_implicit = payload_len_implicit = 0;
if (!determine_stream_len(h, shdr, space_left,
&hdr_len_implicit, &payload_len_implicit)
|| hdr_len_implicit == 0 || payload_len_implicit == 0) {
*packet_full = 1;
rc = 1;
goto err; /* can't fit anything */
}
/*
* If using the implicit-length representation would need padding, we
* can't use it.
*/
needs_padding_if_implicit = (h->bytes_appended + hdr_len_implicit
+ payload_len_implicit < min_ppl);
/*
* If there is a next stream, we don't use the implicit length so we can
* add more STREAM frames after this one, unless there is enough data
* for this STREAM frame to fill the packet.
*/
can_fill_payload = (hdr_len_implicit + payload_len_implicit
>= space_left);
/*
* Is there is a stream after this one, or another chunk pending
* transmission in this stream?
*/
could_have_following_chunk
= (next_stream != NULL || chunks[(i + 1) % 2].valid);
/* Choose between explicit or implicit length representations. */
use_explicit_len = !((can_fill_payload || !could_have_following_chunk)
&& !needs_padding_if_implicit);
if (use_explicit_len) {
/*
* Find best fit (header length, payload length) combination for if
* we use an explicit length.
*/
shdr->has_explicit_len = 1;
hdr_len_explicit = payload_len_explicit = 0;
if (!determine_stream_len(h, shdr, space_left,
&hdr_len_explicit, &payload_len_explicit)
|| hdr_len_explicit == 0 || payload_len_explicit == 0) {
*packet_full = 1;
rc = 1;
goto err; /* can't fit anything */
}
shdr->len = payload_len_explicit;
} else {
shdr->has_explicit_len = 0;
shdr->len = payload_len_implicit;
}
/* Truncate IOVs to match our chosen length. */
ossl_quic_sstream_adjust_iov((size_t)shdr->len, chunks[i % 2].iov,
chunks[i % 2].num_stream_iovec);
/*
* Ensure we have enough iovecs allocated (1 for the header, up to 2 for
* the the stream data.)
*/
if (!txp_ensure_iovec(txp, h->num_iovec + 3))
goto err; /* alloc error */
/* Encode the header. */
wpkt = tx_helper_begin(h);
if (wpkt == NULL)
goto err; /* alloc error */
shdr->stream_id = id;
if (!ossl_assert(ossl_quic_wire_encode_frame_stream_hdr(wpkt, shdr))) {
/* (Should not be possible.) */
tx_helper_rollback(h);
*packet_full = 1;
rc = 1;
goto err; /* can't fit */
}
if (!tx_helper_commit(h))
goto err; /* alloc error */
/* Add payload iovecs to the helper (infallible). */
for (j = 0; j < chunks[i % 2].num_stream_iovec; ++j)
tx_helper_append_iovec(h, chunks[i % 2].iov[j].buf,
chunks[i % 2].iov[j].buf_len);
*have_ack_eliciting = 1;
tx_helper_unrestrict(h); /* no longer need PING */
if (!shdr->has_explicit_len)
h->done_implicit = 1;
/* Log new TXFC credit which was consumed. */
if (shdr->len > 0 && shdr->offset + shdr->len > fc_new_hwm)
fc_new_hwm = shdr->offset + shdr->len;
/* Log chunk to TXPIM. */
chunk.stream_id = shdr->stream_id;
chunk.start = shdr->offset;
chunk.end = shdr->offset + shdr->len - 1;
chunk.has_fin = shdr->is_fin;
chunk.has_stop_sending = 0;
chunk.has_reset_stream = 0;
if (!ossl_quic_txpim_pkt_append_chunk(tpkt, &chunk))
goto err; /* alloc error */
}
err:
*new_credit_consumed = fc_new_hwm - fc_swm;
return rc;
}
static void txp_enlink_tmp(QUIC_STREAM **tmp_head, QUIC_STREAM *stream)
{
stream->txp_next = *tmp_head;
*tmp_head = stream;
}
static int txp_generate_stream_related(OSSL_QUIC_TX_PACKETISER *txp,
struct tx_helper *h,
uint32_t pn_space,
QUIC_TXPIM_PKT *tpkt,
size_t min_ppl,
char *have_ack_eliciting,
QUIC_STREAM **tmp_head)
{
QUIC_STREAM_ITER it;
void *rstream;
WPACKET *wpkt;
uint64_t cwm;
QUIC_STREAM *stream, *snext;
for (ossl_quic_stream_iter_init(&it, txp->args.qsm, 1);
it.stream != NULL;) {
stream = it.stream;
ossl_quic_stream_iter_next(&it);
snext = it.stream;
stream->txp_sent_fc = 0;
stream->txp_sent_stop_sending = 0;
stream->txp_sent_reset_stream = 0;
stream->txp_drained = 0;
stream->txp_blocked = 0;
stream->txp_txfc_new_credit_consumed = 0;
rstream = stream->rstream;
/* Stream Abort Frames (STOP_SENDING, RESET_STREAM) */
if (stream->want_stop_sending) {
OSSL_QUIC_FRAME_STOP_SENDING f;
wpkt = tx_helper_begin(h);
if (wpkt == NULL)
return 0; /* alloc error */
f.stream_id = stream->id;
f.app_error_code = stream->stop_sending_aec;
if (!ossl_quic_wire_encode_frame_stop_sending(wpkt, &f)) {
tx_helper_rollback(h); /* can't fit */
txp_enlink_tmp(tmp_head, stream);
break;
}
if (!tx_helper_commit(h))
return 0; /* alloc error */
*have_ack_eliciting = 1;
tx_helper_unrestrict(h); /* no longer need PING */
stream->txp_sent_stop_sending = 1;
}
if (stream->want_reset_stream) {
OSSL_QUIC_FRAME_RESET_STREAM f;
wpkt = tx_helper_begin(h);
if (wpkt == NULL)
return 0; /* alloc error */
f.stream_id = stream->id;
f.app_error_code = stream->reset_stream_aec;
f.final_size = ossl_quic_sstream_get_cur_size(stream->sstream);
if (!ossl_quic_wire_encode_frame_reset_stream(wpkt, &f)) {
tx_helper_rollback(h); /* can't fit */
txp_enlink_tmp(tmp_head, stream);
break;
}
if (!tx_helper_commit(h))
return 0; /* alloc error */
*have_ack_eliciting = 1;
tx_helper_unrestrict(h); /* no longer need PING */
stream->txp_sent_reset_stream = 1;
}
/* Stream Flow Control Frames (MAX_STREAM_DATA) */
if (rstream != NULL
&& (stream->want_max_stream_data
|| ossl_quic_rxfc_has_cwm_changed(&stream->rxfc, 0))) {
wpkt = tx_helper_begin(h);
if (wpkt == NULL)
return 0; /* alloc error */
cwm = ossl_quic_rxfc_get_cwm(&stream->rxfc);
if (!ossl_quic_wire_encode_frame_max_stream_data(wpkt, stream->id,
cwm)) {
tx_helper_rollback(h); /* can't fit */
txp_enlink_tmp(tmp_head, stream);
break;
}
if (!tx_helper_commit(h))
return 0; /* alloc error */
*have_ack_eliciting = 1;
tx_helper_unrestrict(h); /* no longer need PING */
stream->txp_sent_fc = 1;
}
/* Stream Data Frames (STREAM) */
if (stream->sstream != NULL) {
char packet_full = 0, stream_drained = 0;
if (!txp_generate_stream_frames(txp, h, pn_space, tpkt,
stream->id, stream->sstream,
&stream->txfc,
snext, min_ppl,
have_ack_eliciting,
&packet_full,
&stream_drained,
&stream->txp_txfc_new_credit_consumed)) {
/* Fatal error (allocation, etc.) */
txp_enlink_tmp(tmp_head, stream);
return 0;
}
if (stream_drained)
stream->txp_drained = 1;
if (packet_full) {
txp_enlink_tmp(tmp_head, stream);
break;
}
}
txp_enlink_tmp(tmp_head, stream);
}
return 1;
}
/*
* Generates a packet for a given EL with the given minimum and maximum
* plaintext packet payload lengths. Returns TXP_ERR_* value.
*/
static int txp_generate_for_el_actual(OSSL_QUIC_TX_PACKETISER *txp,
uint32_t enc_level,
uint32_t archetype,
size_t min_ppl,
size_t max_ppl,
size_t pkt_overhead,
QUIC_PKT_HDR *phdr)
{
int rc = TXP_ERR_SUCCESS;
struct archetype_data a;
uint32_t pn_space = ossl_quic_enc_level_to_pn_space(enc_level);
struct tx_helper h;
char have_helper = 0, have_ack_eliciting = 0, done_pre_token = 0;
char require_ack_eliciting;
QUIC_CFQ_ITEM *cfq_item;
QUIC_TXPIM_PKT *tpkt = NULL;
OSSL_QTX_PKT pkt;
QUIC_STREAM *tmp_head = NULL, *stream;
if (!txp_get_archetype_data(enc_level, archetype, &a))
goto fatal_err;
require_ack_eliciting
= (a.allow_force_ack_eliciting
&& (txp->force_ack_eliciting & (1UL << pn_space)));
/* Minimum cannot be bigger than maximum. */
if (min_ppl > max_ppl)
goto fatal_err;
/* Maximum PN reached? */
if (txp->next_pn[pn_space] >= (((QUIC_PN)1) << 62))
goto fatal_err;
if ((tpkt = ossl_quic_txpim_pkt_alloc(txp->args.txpim)) == NULL)
goto fatal_err;
/*
* Initialise TX helper. If we must be ACK eliciting, reserve 1 byte for
* PING.
*/
if (!tx_helper_init(&h, txp, max_ppl, require_ack_eliciting ? 1 : 0))
goto fatal_err;
have_helper = 1;
/*
* Frame Serialization
* ===================
*
* We now serialize frames into the packet in descending order of priority.
*/
/* HANDSHAKE_DONE (Regenerate) */
if (a.allow_handshake_done && txp->want_handshake_done
&& tx_helper_get_space_left(&h) >= MIN_FRAME_SIZE_HANDSHAKE_DONE) {
WPACKET *wpkt = tx_helper_begin(&h);
if (wpkt == NULL)
goto fatal_err;
if (ossl_quic_wire_encode_frame_handshake_done(wpkt)) {
tpkt->had_handshake_done_frame = 1;
have_ack_eliciting = 1;
if (!tx_helper_commit(&h))
goto fatal_err;
tx_helper_unrestrict(&h); /* no longer need PING */
} else {
tx_helper_rollback(&h);
}
}
/* MAX_DATA (Regenerate) */
if (a.allow_conn_fc
&& (txp->want_max_data
|| ossl_quic_rxfc_has_cwm_changed(txp->args.conn_rxfc, 0))
&& tx_helper_get_space_left(&h) >= MIN_FRAME_SIZE_MAX_DATA) {
WPACKET *wpkt = tx_helper_begin(&h);
uint64_t cwm = ossl_quic_rxfc_get_cwm(txp->args.conn_rxfc);
if (wpkt == NULL)
goto fatal_err;
if (ossl_quic_wire_encode_frame_max_data(wpkt, cwm)) {
tpkt->had_max_data_frame = 1;
have_ack_eliciting = 1;
if (!tx_helper_commit(&h))
goto fatal_err;
tx_helper_unrestrict(&h); /* no longer need PING */
} else {
tx_helper_rollback(&h);
}
}
/* MAX_STREAMS_BIDI (Regenerate) */
/*
* TODO(STREAMS): Once we support multiple streams, add stream count FC
* and plug this in.
*/
if (a.allow_conn_fc
&& txp->want_max_streams_bidi
&& tx_helper_get_space_left(&h) >= MIN_FRAME_SIZE_MAX_STREAMS_BIDI) {
WPACKET *wpkt = tx_helper_begin(&h);
uint64_t max_streams = 1; /* TODO */
if (wpkt == NULL)
goto fatal_err;
if (ossl_quic_wire_encode_frame_max_streams(wpkt, /*is_uni=*/0,
max_streams)) {
tpkt->had_max_streams_bidi_frame = 1;
have_ack_eliciting = 1;
if (!tx_helper_commit(&h))
goto fatal_err;
tx_helper_unrestrict(&h); /* no longer need PING */
} else {
tx_helper_rollback(&h);
}
}
/* MAX_STREAMS_UNI (Regenerate) */
if (a.allow_conn_fc
&& txp->want_max_streams_uni
&& tx_helper_get_space_left(&h) >= MIN_FRAME_SIZE_MAX_STREAMS_UNI) {
WPACKET *wpkt = tx_helper_begin(&h);
uint64_t max_streams = 0; /* TODO */
if (wpkt == NULL)
goto fatal_err;
if (ossl_quic_wire_encode_frame_max_streams(wpkt, /*is_uni=*/1,
max_streams)) {
tpkt->had_max_streams_uni_frame = 1;
have_ack_eliciting = 1;
if (!tx_helper_commit(&h))
goto fatal_err;
tx_helper_unrestrict(&h); /* no longer need PING */
} else {
tx_helper_rollback(&h);
}
}
/* GCR Frames */
for (cfq_item = ossl_quic_cfq_get_priority_head(txp->args.cfq, pn_space);
cfq_item != NULL;
cfq_item = ossl_quic_cfq_item_get_priority_next(cfq_item, pn_space)) {
uint64_t frame_type = ossl_quic_cfq_item_get_frame_type(cfq_item);
const unsigned char *encoded = ossl_quic_cfq_item_get_encoded(cfq_item);
size_t encoded_len = ossl_quic_cfq_item_get_encoded_len(cfq_item);
switch (frame_type) {
case OSSL_QUIC_FRAME_TYPE_NEW_CONN_ID:
if (!a.allow_new_conn_id)
continue;
break;
case OSSL_QUIC_FRAME_TYPE_RETIRE_CONN_ID:
if (!a.allow_retire_conn_id)
continue;
break;
case OSSL_QUIC_FRAME_TYPE_NEW_TOKEN:
if (!a.allow_new_token)
continue;
/*
* NEW_TOKEN frames are handled via GCR, but some
* Regenerate-strategy frames should come before them (namely
* ACK, CONNECTION_CLOSE, PATH_CHALLENGE and PATH_RESPONSE). If
* we find a NEW_TOKEN frame, do these now. If there are no
* NEW_TOKEN frames in the GCR queue we will handle these below.
*/
if (!done_pre_token)
if (txp_generate_pre_token(txp, &h, tpkt, pn_space, &a))
done_pre_token = 1;
break;
default:
if (!a.allow_cfq_other)
continue;
break;
}
/*
* If the frame is too big, don't try to schedule any more GCR frames in
* this packet rather than sending subsequent ones out of order.
*/
if (encoded_len > tx_helper_get_space_left(&h))
break;
if (!tx_helper_append_iovec(&h, encoded, encoded_len))
goto fatal_err;
ossl_quic_txpim_pkt_add_cfq_item(tpkt, cfq_item);
if (ossl_quic_frame_type_is_ack_eliciting(frame_type)) {
have_ack_eliciting = 1;
tx_helper_unrestrict(&h); /* no longer need PING */
}
}
/*
* If we didn't generate ACK, CONNECTION_CLOSE, PATH_CHALLENGE or
* PATH_RESPONSE (as desired) before, do so now.
*/
if (!done_pre_token)
if (txp_generate_pre_token(txp, &h, tpkt, pn_space, &a))
done_pre_token = 1;
/* CRYPTO Frames */
if (a.allow_crypto)
if (!txp_generate_crypto_frames(txp, &h, pn_space, tpkt,
&have_ack_eliciting))
goto fatal_err;
/* Stream-specific frames */
if (a.allow_stream_rel)
if (!txp_generate_stream_related(txp, &h, pn_space, tpkt, min_ppl,
&have_ack_eliciting,
&tmp_head))
goto fatal_err;
/* PING */
tx_helper_unrestrict(&h);
if (require_ack_eliciting && !have_ack_eliciting && a.allow_ping) {
WPACKET *wpkt;
wpkt = tx_helper_begin(&h);
if (wpkt == NULL)
goto fatal_err;
if (!ossl_quic_wire_encode_frame_ping(wpkt)
|| !tx_helper_commit(&h))
/*
* We treat a request to be ACK-eliciting as a requirement, so this
* is an error.
*/
goto fatal_err;
have_ack_eliciting = 1;
}
/* PADDING */
if (h.bytes_appended < min_ppl) {
WPACKET *wpkt = tx_helper_begin(&h);
if (wpkt == NULL)
goto fatal_err;
if (!ossl_quic_wire_encode_padding(wpkt, min_ppl - h.bytes_appended)
|| !tx_helper_commit(&h))
goto fatal_err;
}
/*
* Dispatch
* ========
*/
/* ACKM Data */
tpkt->ackm_pkt.num_bytes = h.bytes_appended + pkt_overhead;
tpkt->ackm_pkt.pkt_num = txp->next_pn[pn_space];
/* largest_acked is set in txp_generate_pre_token */
tpkt->ackm_pkt.pkt_space = pn_space;
tpkt->ackm_pkt.is_inflight = 1;
tpkt->ackm_pkt.is_ack_eliciting = have_ack_eliciting;
tpkt->ackm_pkt.is_pto_probe = 0;
tpkt->ackm_pkt.is_mtu_probe = 0;
tpkt->ackm_pkt.time = ossl_time_now();
/* Packet Information for QTX */
pkt.hdr = phdr;
pkt.iovec = txp->iovec;
pkt.num_iovec = h.num_iovec;
pkt.local = NULL;
pkt.peer = BIO_ADDR_family(&txp->args.peer) == AF_UNSPEC
? NULL : &txp->args.peer;
pkt.pn = txp->next_pn[pn_space];
pkt.flags = OSSL_QTX_PKT_FLAG_COALESCE; /* always try to coalesce */
/* Do TX key update if needed. */
if (enc_level == QUIC_ENC_LEVEL_1RTT) {
uint64_t cur_pkt_count, max_pkt_count;
cur_pkt_count = ossl_qtx_get_cur_epoch_pkt_count(txp->args.qtx, enc_level);
max_pkt_count = ossl_qtx_get_max_epoch_pkt_count(txp->args.qtx, enc_level);
if (cur_pkt_count >= max_pkt_count / 2)
if (!ossl_qtx_trigger_key_update(txp->args.qtx))
goto fatal_err;
}
if (!ossl_assert(h.bytes_appended > 0))
goto fatal_err;
/* Generate TXPIM chunks representing STOP_SENDING and RESET_STREAM frames. */
for (stream = tmp_head; stream != NULL; stream = stream->txp_next)
if (stream->txp_sent_stop_sending || stream->txp_sent_reset_stream) {
/* Log STOP_SENDING chunk to TXPIM. */
QUIC_TXPIM_CHUNK chunk;
chunk.stream_id = stream->id;
chunk.start = UINT64_MAX;
chunk.end = 0;
chunk.has_fin = 0;
chunk.has_stop_sending = stream->txp_sent_stop_sending;
chunk.has_reset_stream = stream->txp_sent_reset_stream;
if (!ossl_quic_txpim_pkt_append_chunk(tpkt, &chunk))
return 0; /* alloc error */
}
/* Dispatch to FIFD. */
if (!ossl_quic_fifd_pkt_commit(&txp->fifd, tpkt))
goto fatal_err;
/* Send the packet. */
if (!ossl_qtx_write_pkt(txp->args.qtx, &pkt))
goto fatal_err;
++txp->next_pn[pn_space];
/*
* Record FC and stream abort frames as sent; deactivate streams which no
* longer have anything to do.
*/
for (stream = tmp_head; stream != NULL; stream = stream->txp_next) {
if (stream->txp_sent_fc) {
stream->want_max_stream_data = 0;
ossl_quic_rxfc_has_cwm_changed(&stream->rxfc, 1);
}
if (stream->txp_sent_stop_sending)
stream->want_stop_sending = 0;
if (stream->txp_sent_reset_stream)
stream->want_reset_stream = 0;
if (stream->txp_txfc_new_credit_consumed > 0) {
if (!ossl_assert(ossl_quic_txfc_consume_credit(&stream->txfc,
stream->txp_txfc_new_credit_consumed)))
/*
* Should not be possible, but we should continue with our
* bookkeeping as we have already committed the packet to the
* FIFD. Just change the value we return.
*/
rc = TXP_ERR_INTERNAL;
stream->txp_txfc_new_credit_consumed = 0;
}
/*
* If we no longer need to generate any flow control (MAX_STREAM_DATA),
* STOP_SENDING or RESET_STREAM frames, nor any STREAM frames (because
* the stream is drained of data or TXFC-blocked), we can mark the
* stream as inactive.
*/
ossl_quic_stream_map_update_state(txp->args.qsm, stream);
if (!stream->want_max_stream_data
&& !stream->want_stop_sending
&& !stream->want_reset_stream
&& (stream->txp_drained || stream->txp_blocked))
assert(!stream->active);
}
/* We have now sent the packet, so update state accordingly. */
if (have_ack_eliciting)
txp->force_ack_eliciting &= ~(1UL << pn_space);
if (tpkt->had_handshake_done_frame)
txp->want_handshake_done = 0;
if (tpkt->had_max_data_frame) {
txp->want_max_data = 0;
ossl_quic_rxfc_has_cwm_changed(txp->args.conn_rxfc, 1);
}
if (tpkt->had_max_streams_bidi_frame)
txp->want_max_streams_bidi = 0;
if (tpkt->had_max_streams_uni_frame)
txp->want_max_streams_uni = 0;
if (tpkt->had_ack_frame)
txp->want_ack &= ~(1UL << pn_space);
/* Done. */
tx_helper_cleanup(&h);
return rc;
fatal_err:
/*
* Handler for fatal errors, i.e. errors causing us to abort the entire
* packet rather than just one frame. Examples of such errors include
* allocation errors.
*/
if (have_helper)
tx_helper_cleanup(&h);
if (tpkt != NULL)
ossl_quic_txpim_pkt_release(txp->args.txpim, tpkt);
return TXP_ERR_INTERNAL;
}
/* Ensure the iovec array is at least num elements long. */
static int txp_ensure_iovec(OSSL_QUIC_TX_PACKETISER *txp, size_t num)
{
OSSL_QTX_IOVEC *iovec;
if (txp->alloc_iovec >= num)
return 1;
num = txp->alloc_iovec != 0 ? txp->alloc_iovec * 2 : 8;
iovec = OPENSSL_realloc(txp->iovec, sizeof(OSSL_QTX_IOVEC) * num);
if (iovec == NULL)
return 0;
txp->iovec = iovec;
txp->alloc_iovec = num;
return 1;
}
int ossl_quic_tx_packetiser_schedule_conn_close(OSSL_QUIC_TX_PACKETISER *txp,
const OSSL_QUIC_FRAME_CONN_CLOSE *f)
{
char *reason = NULL;
size_t reason_len = f->reason_len;
size_t max_reason_len = txp_get_mdpl(txp) / 2;
if (txp->want_conn_close)
return 0;
/*
* Arbitrarily limit the length of the reason length string to half of the
* MDPL.
*/
if (reason_len > max_reason_len)
reason_len = max_reason_len;
if (reason_len > 0) {
reason = OPENSSL_memdup(f->reason, reason_len);
if (reason == NULL)
return 0;
}
txp->conn_close_frame = *f;
txp->conn_close_frame.reason = reason;
txp->conn_close_frame.reason_len = reason_len;
txp->want_conn_close = 1;
return 1;
}
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