diff options
Diffstat (limited to '')
| -rw-r--r-- | lib/ngtcp2_pkt.c | 2527 |
1 files changed, 2527 insertions, 0 deletions
diff --git a/lib/ngtcp2_pkt.c b/lib/ngtcp2_pkt.c new file mode 100644 index 0000000..f76e07b --- /dev/null +++ b/lib/ngtcp2_pkt.c @@ -0,0 +1,2527 @@ +/* + * ngtcp2 + * + * Copyright (c) 2017 ngtcp2 contributors + * + * Permission is hereby granted, free of charge, to any person obtaining + * a copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sublicense, and/or sell copies of the Software, and to + * permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE + * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION + * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION + * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + */ +#include "ngtcp2_pkt.h" + +#include <assert.h> +#include <string.h> + +#include "ngtcp2_conv.h" +#include "ngtcp2_str.h" +#include "ngtcp2_macro.h" +#include "ngtcp2_cid.h" +#include "ngtcp2_mem.h" +#include "ngtcp2_vec.h" +#include "ngtcp2_unreachable.h" +#include "ngtcp2_str.h" + +int ngtcp2_pkt_chain_new(ngtcp2_pkt_chain **ppc, const ngtcp2_path *path, + const ngtcp2_pkt_info *pi, const uint8_t *pkt, + size_t pktlen, size_t dgramlen, ngtcp2_tstamp ts, + const ngtcp2_mem *mem) { + *ppc = ngtcp2_mem_malloc(mem, sizeof(ngtcp2_pkt_chain) + pktlen); + if (*ppc == NULL) { + return NGTCP2_ERR_NOMEM; + } + + ngtcp2_path_storage_init2(&(*ppc)->path, path); + (*ppc)->pi = *pi; + (*ppc)->next = NULL; + (*ppc)->pkt = (uint8_t *)(*ppc) + sizeof(ngtcp2_pkt_chain); + (*ppc)->pktlen = pktlen; + (*ppc)->dgramlen = dgramlen; + (*ppc)->ts = ts; + + memcpy((*ppc)->pkt, pkt, pktlen); + + return 0; +} + +void ngtcp2_pkt_chain_del(ngtcp2_pkt_chain *pc, const ngtcp2_mem *mem) { + ngtcp2_mem_free(mem, pc); +} + +int ngtcp2_pkt_decode_version_cid(ngtcp2_version_cid *dest, const uint8_t *data, + size_t datalen, size_t short_dcidlen) { + size_t len; + uint32_t version; + size_t dcidlen, scidlen; + int supported_version; + + assert(datalen); + + if (data[0] & NGTCP2_HEADER_FORM_BIT) { + /* 1 byte (Header Form, Fixed Bit, Long Packet Type, Type-Specific bits) + * 4 bytes Version + * 1 byte DCID Length + * 1 byte SCID Length + */ + len = 1 + 4 + 1 + 1; + if (datalen < len) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + + dcidlen = data[5]; + len += dcidlen; + if (datalen < len) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + scidlen = data[5 + 1 + dcidlen]; + len += scidlen; + if (datalen < len) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + + ngtcp2_get_uint32(&version, &data[1]); + + supported_version = ngtcp2_is_supported_version(version); + + if (supported_version && + (dcidlen > NGTCP2_MAX_CIDLEN || scidlen > NGTCP2_MAX_CIDLEN)) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + + if (version && !supported_version && + datalen < NGTCP2_MAX_UDP_PAYLOAD_SIZE) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + + dest->version = version; + dest->dcid = &data[6]; + dest->dcidlen = dcidlen; + dest->scid = &data[6 + dcidlen + 1]; + dest->scidlen = scidlen; + + if (!version) { + /* VN */ + return 0; + } + + if (!supported_version) { + return NGTCP2_ERR_VERSION_NEGOTIATION; + } + return 0; + } + + assert(short_dcidlen <= NGTCP2_MAX_CIDLEN); + + len = 1 + short_dcidlen; + if (datalen < len) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + + dest->version = 0; + dest->dcid = &data[1]; + dest->dcidlen = short_dcidlen; + dest->scid = NULL; + dest->scidlen = 0; + + return 0; +} + +void ngtcp2_pkt_hd_init(ngtcp2_pkt_hd *hd, uint8_t flags, uint8_t type, + const ngtcp2_cid *dcid, const ngtcp2_cid *scid, + int64_t pkt_num, size_t pkt_numlen, uint32_t version, + size_t len) { + hd->flags = flags; + hd->type = type; + if (dcid) { + hd->dcid = *dcid; + } else { + ngtcp2_cid_zero(&hd->dcid); + } + if (scid) { + hd->scid = *scid; + } else { + ngtcp2_cid_zero(&hd->scid); + } + hd->pkt_num = pkt_num; + hd->token.base = NULL; + hd->token.len = 0; + hd->pkt_numlen = pkt_numlen; + hd->version = version; + hd->len = len; +} + +static int has_mask(uint8_t b, uint8_t mask) { return (b & mask) == mask; } + +ngtcp2_ssize ngtcp2_pkt_decode_hd_long(ngtcp2_pkt_hd *dest, const uint8_t *pkt, + size_t pktlen) { + uint8_t type; + uint32_t version; + size_t dcil, scil; + const uint8_t *p; + size_t len = 0; + size_t n; + size_t ntokenlen = 0; + const uint8_t *token = NULL; + size_t tokenlen = 0; + uint64_t vi; + uint8_t flags = NGTCP2_PKT_FLAG_LONG_FORM; + + if (pktlen < 5) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + + if (!(pkt[0] & NGTCP2_HEADER_FORM_BIT)) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + + ngtcp2_get_uint32(&version, &pkt[1]); + + if (version == 0) { + type = NGTCP2_PKT_VERSION_NEGOTIATION; + /* Version Negotiation is not a long header packet. */ + flags = NGTCP2_PKT_FLAG_NONE; + /* This must be Version Negotiation packet which lacks packet + number and payload length fields. */ + len = 5 + 2; + } else { + if (!(pkt[0] & NGTCP2_FIXED_BIT_MASK)) { + flags |= NGTCP2_PKT_FLAG_FIXED_BIT_CLEAR; + } + + type = ngtcp2_pkt_get_type_long(version, pkt[0]); + switch (type) { + case 0: + return NGTCP2_ERR_INVALID_ARGUMENT; + case NGTCP2_PKT_INITIAL: + len = 1 /* Token Length */ + NGTCP2_MIN_LONG_HEADERLEN - + 1; /* Cut packet number field */ + break; + case NGTCP2_PKT_RETRY: + /* Retry packet does not have packet number and length fields */ + len = 5 + 2; + break; + case NGTCP2_PKT_HANDSHAKE: + case NGTCP2_PKT_0RTT: + len = NGTCP2_MIN_LONG_HEADERLEN - 1; /* Cut packet number field */ + break; + default: + /* Unreachable */ + ngtcp2_unreachable(); + } + } + + if (pktlen < len) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + + p = &pkt[5]; + dcil = *p; + if (dcil > NGTCP2_MAX_CIDLEN) { + /* QUIC v1 implementation never expect to receive CID length more + than NGTCP2_MAX_CIDLEN. */ + return NGTCP2_ERR_INVALID_ARGUMENT; + } + len += dcil; + + if (pktlen < len) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + + p += 1 + dcil; + scil = *p; + if (scil > NGTCP2_MAX_CIDLEN) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + len += scil; + + if (pktlen < len) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + + p += 1 + scil; + + if (type == NGTCP2_PKT_INITIAL) { + /* Token Length */ + ntokenlen = ngtcp2_get_uvarintlen(p); + len += ntokenlen - 1; + + if (pktlen < len) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + + p = ngtcp2_get_uvarint(&vi, p); + if (pktlen - len < vi) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + tokenlen = (size_t)vi; + len += tokenlen; + + if (tokenlen) { + token = p; + } + + p += tokenlen; + } + + switch (type) { + case NGTCP2_PKT_RETRY: + break; + default: + if (!(flags & NGTCP2_PKT_FLAG_LONG_FORM)) { + assert(type == NGTCP2_PKT_VERSION_NEGOTIATION); + /* Version Negotiation is not a long header packet. */ + break; + } + + /* Length */ + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (pktlen < len) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + } + + dest->flags = flags; + dest->type = type; + dest->version = version; + dest->pkt_num = 0; + dest->pkt_numlen = 0; + + p = &pkt[6]; + ngtcp2_cid_init(&dest->dcid, p, dcil); + p += dcil + 1; + ngtcp2_cid_init(&dest->scid, p, scil); + p += scil; + + dest->token.base = (uint8_t *)token; + dest->token.len = tokenlen; + p += ntokenlen + tokenlen; + + switch (type) { + case NGTCP2_PKT_RETRY: + dest->len = 0; + break; + default: + if (!(flags & NGTCP2_PKT_FLAG_LONG_FORM)) { + assert(type == NGTCP2_PKT_VERSION_NEGOTIATION); + /* Version Negotiation is not a long header packet. */ + dest->len = 0; + break; + } + + p = ngtcp2_get_uvarint(&vi, p); + if (vi > SIZE_MAX) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + dest->len = (size_t)vi; + } + + assert((size_t)(p - pkt) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_decode_hd_short(ngtcp2_pkt_hd *dest, const uint8_t *pkt, + size_t pktlen, size_t dcidlen) { + size_t len = 1 + dcidlen; + const uint8_t *p = pkt; + uint8_t flags = NGTCP2_PKT_FLAG_NONE; + + assert(dcidlen <= NGTCP2_MAX_CIDLEN); + + if (pktlen < len) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + + if (pkt[0] & NGTCP2_HEADER_FORM_BIT) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + + if (!(pkt[0] & NGTCP2_FIXED_BIT_MASK)) { + flags |= NGTCP2_PKT_FLAG_FIXED_BIT_CLEAR; + } + + p = &pkt[1]; + + dest->type = NGTCP2_PKT_1RTT; + + ngtcp2_cid_init(&dest->dcid, p, dcidlen); + p += dcidlen; + + /* Set 0 to SCID so that we don't accidentally reference it and gets + garbage. */ + ngtcp2_cid_zero(&dest->scid); + + dest->flags = flags; + dest->version = 0; + dest->len = 0; + dest->pkt_num = 0; + dest->pkt_numlen = 0; + dest->token.base = NULL; + dest->token.len = 0; + + assert((size_t)(p - pkt) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_encode_hd_long(uint8_t *out, size_t outlen, + const ngtcp2_pkt_hd *hd) { + uint8_t *p; + size_t len = NGTCP2_MIN_LONG_HEADERLEN + hd->dcid.datalen + hd->scid.datalen - + 2; /* NGTCP2_MIN_LONG_HEADERLEN includes 1 byte for + len and 1 byte for packet number. */ + + if (hd->type != NGTCP2_PKT_RETRY) { + len += NGTCP2_PKT_LENGTHLEN /* Length */ + hd->pkt_numlen; + } + + if (hd->type == NGTCP2_PKT_INITIAL) { + len += ngtcp2_put_uvarintlen(hd->token.len) + hd->token.len; + } + + if (outlen < len) { + return NGTCP2_ERR_NOBUF; + } + + p = out; + + *p = (uint8_t)(NGTCP2_HEADER_FORM_BIT | + (ngtcp2_pkt_versioned_type(hd->version, hd->type) << 4) | + (uint8_t)(hd->pkt_numlen - 1)); + if (!(hd->flags & NGTCP2_PKT_FLAG_FIXED_BIT_CLEAR)) { + *p |= NGTCP2_FIXED_BIT_MASK; + } + + ++p; + + p = ngtcp2_put_uint32be(p, hd->version); + *p++ = (uint8_t)hd->dcid.datalen; + if (hd->dcid.datalen) { + p = ngtcp2_cpymem(p, hd->dcid.data, hd->dcid.datalen); + } + *p++ = (uint8_t)hd->scid.datalen; + if (hd->scid.datalen) { + p = ngtcp2_cpymem(p, hd->scid.data, hd->scid.datalen); + } + + if (hd->type == NGTCP2_PKT_INITIAL) { + p = ngtcp2_put_uvarint(p, hd->token.len); + if (hd->token.len) { + p = ngtcp2_cpymem(p, hd->token.base, hd->token.len); + } + } + + if (hd->type != NGTCP2_PKT_RETRY) { + p = ngtcp2_put_uvarint30(p, (uint32_t)hd->len); + p = ngtcp2_put_pkt_num(p, hd->pkt_num, hd->pkt_numlen); + } + + assert((size_t)(p - out) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_encode_hd_short(uint8_t *out, size_t outlen, + const ngtcp2_pkt_hd *hd) { + uint8_t *p; + size_t len = 1 + hd->dcid.datalen + hd->pkt_numlen; + + if (outlen < len) { + return NGTCP2_ERR_NOBUF; + } + + p = out; + + *p = (uint8_t)(hd->pkt_numlen - 1); + if (!(hd->flags & NGTCP2_PKT_FLAG_FIXED_BIT_CLEAR)) { + *p |= NGTCP2_FIXED_BIT_MASK; + } + if (hd->flags & NGTCP2_PKT_FLAG_KEY_PHASE) { + *p |= NGTCP2_SHORT_KEY_PHASE_BIT; + } + + ++p; + + if (hd->dcid.datalen) { + p = ngtcp2_cpymem(p, hd->dcid.data, hd->dcid.datalen); + } + + p = ngtcp2_put_pkt_num(p, hd->pkt_num, hd->pkt_numlen); + + assert((size_t)(p - out) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_decode_frame(ngtcp2_frame *dest, const uint8_t *payload, + size_t payloadlen) { + uint8_t type; + + if (payloadlen == 0) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + type = payload[0]; + + switch (type) { + case NGTCP2_FRAME_PADDING: + return ngtcp2_pkt_decode_padding_frame(&dest->padding, payload, payloadlen); + case NGTCP2_FRAME_RESET_STREAM: + return ngtcp2_pkt_decode_reset_stream_frame(&dest->reset_stream, payload, + payloadlen); + case NGTCP2_FRAME_CONNECTION_CLOSE: + case NGTCP2_FRAME_CONNECTION_CLOSE_APP: + return ngtcp2_pkt_decode_connection_close_frame(&dest->connection_close, + payload, payloadlen); + case NGTCP2_FRAME_MAX_DATA: + return ngtcp2_pkt_decode_max_data_frame(&dest->max_data, payload, + payloadlen); + case NGTCP2_FRAME_MAX_STREAM_DATA: + return ngtcp2_pkt_decode_max_stream_data_frame(&dest->max_stream_data, + payload, payloadlen); + case NGTCP2_FRAME_MAX_STREAMS_BIDI: + case NGTCP2_FRAME_MAX_STREAMS_UNI: + return ngtcp2_pkt_decode_max_streams_frame(&dest->max_streams, payload, + payloadlen); + case NGTCP2_FRAME_PING: + return ngtcp2_pkt_decode_ping_frame(&dest->ping, payload, payloadlen); + case NGTCP2_FRAME_DATA_BLOCKED: + return ngtcp2_pkt_decode_data_blocked_frame(&dest->data_blocked, payload, + payloadlen); + case NGTCP2_FRAME_STREAM_DATA_BLOCKED: + return ngtcp2_pkt_decode_stream_data_blocked_frame( + &dest->stream_data_blocked, payload, payloadlen); + case NGTCP2_FRAME_STREAMS_BLOCKED_BIDI: + case NGTCP2_FRAME_STREAMS_BLOCKED_UNI: + return ngtcp2_pkt_decode_streams_blocked_frame(&dest->streams_blocked, + payload, payloadlen); + case NGTCP2_FRAME_NEW_CONNECTION_ID: + return ngtcp2_pkt_decode_new_connection_id_frame(&dest->new_connection_id, + payload, payloadlen); + case NGTCP2_FRAME_STOP_SENDING: + return ngtcp2_pkt_decode_stop_sending_frame(&dest->stop_sending, payload, + payloadlen); + case NGTCP2_FRAME_ACK: + case NGTCP2_FRAME_ACK_ECN: + return ngtcp2_pkt_decode_ack_frame(&dest->ack, payload, payloadlen); + case NGTCP2_FRAME_PATH_CHALLENGE: + return ngtcp2_pkt_decode_path_challenge_frame(&dest->path_challenge, + payload, payloadlen); + case NGTCP2_FRAME_PATH_RESPONSE: + return ngtcp2_pkt_decode_path_response_frame(&dest->path_response, payload, + payloadlen); + case NGTCP2_FRAME_CRYPTO: + return ngtcp2_pkt_decode_crypto_frame(&dest->crypto, payload, payloadlen); + case NGTCP2_FRAME_NEW_TOKEN: + return ngtcp2_pkt_decode_new_token_frame(&dest->new_token, payload, + payloadlen); + case NGTCP2_FRAME_RETIRE_CONNECTION_ID: + return ngtcp2_pkt_decode_retire_connection_id_frame( + &dest->retire_connection_id, payload, payloadlen); + case NGTCP2_FRAME_HANDSHAKE_DONE: + return ngtcp2_pkt_decode_handshake_done_frame(&dest->handshake_done, + payload, payloadlen); + case NGTCP2_FRAME_DATAGRAM: + case NGTCP2_FRAME_DATAGRAM_LEN: + return ngtcp2_pkt_decode_datagram_frame(&dest->datagram, payload, + payloadlen); + default: + if (has_mask(type, NGTCP2_FRAME_STREAM)) { + return ngtcp2_pkt_decode_stream_frame(&dest->stream, payload, payloadlen); + } + return NGTCP2_ERR_FRAME_ENCODING; + } +} + +ngtcp2_ssize ngtcp2_pkt_decode_stream_frame(ngtcp2_stream *dest, + const uint8_t *payload, + size_t payloadlen) { + uint8_t type; + size_t len = 1 + 1; + const uint8_t *p; + size_t datalen; + size_t ndatalen = 0; + size_t n; + uint64_t vi; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + type = payload[0]; + + p = payload + 1; + + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p += n; + + if (type & NGTCP2_STREAM_OFF_BIT) { + ++len; + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p += n; + } + + if (type & NGTCP2_STREAM_LEN_BIT) { + ++len; + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + ndatalen = ngtcp2_get_uvarintlen(p); + len += ndatalen - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + /* p = */ ngtcp2_get_uvarint(&vi, p); + if (payloadlen - len < vi) { + return NGTCP2_ERR_FRAME_ENCODING; + } + datalen = (size_t)vi; + len += datalen; + } else { + len = payloadlen; + } + + p = payload + 1; + + dest->type = NGTCP2_FRAME_STREAM; + dest->flags = (uint8_t)(type & ~NGTCP2_FRAME_STREAM); + dest->fin = (type & NGTCP2_STREAM_FIN_BIT) != 0; + p = ngtcp2_get_varint(&dest->stream_id, p); + + if (type & NGTCP2_STREAM_OFF_BIT) { + p = ngtcp2_get_uvarint(&dest->offset, p); + } else { + dest->offset = 0; + } + + if (type & NGTCP2_STREAM_LEN_BIT) { + p += ndatalen; + } else { + datalen = payloadlen - (size_t)(p - payload); + } + + if (datalen) { + dest->data[0].len = datalen; + dest->data[0].base = (uint8_t *)p; + dest->datacnt = 1; + p += datalen; + } else { + dest->datacnt = 0; + } + + assert((size_t)(p - payload) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_decode_ack_frame(ngtcp2_ack *dest, + const uint8_t *payload, + size_t payloadlen) { + size_t rangecnt, max_rangecnt; + size_t nrangecnt; + size_t len = 1 + 1 + 1 + 1 + 1; + const uint8_t *p; + size_t i, j; + ngtcp2_ack_range *range; + size_t n; + uint8_t type; + uint64_t vi; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + type = payload[0]; + + p = payload + 1; + + /* Largest Acknowledged */ + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p += n; + + /* ACK Delay */ + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p += n; + + /* ACK Range Count */ + nrangecnt = ngtcp2_get_uvarintlen(p); + len += nrangecnt - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = ngtcp2_get_uvarint(&vi, p); + if (vi > SIZE_MAX / (1 + 1) || payloadlen - len < vi * (1 + 1)) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + rangecnt = (size_t)vi; + len += rangecnt * (1 + 1); + + /* First ACK Range */ + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p += n; + + for (i = 0; i < rangecnt; ++i) { + /* Gap, and Additional ACK Range */ + for (j = 0; j < 2; ++j) { + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p += n; + } + } + + if (type == NGTCP2_FRAME_ACK_ECN) { + len += 3; + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + for (i = 0; i < 3; ++i) { + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p += n; + } + } + + /* TODO We might not decode all ranges. It could be very large. */ + max_rangecnt = ngtcp2_min(NGTCP2_MAX_ACK_RANGES, rangecnt); + + p = payload + 1; + + dest->type = type; + p = ngtcp2_get_varint(&dest->largest_ack, p); + p = ngtcp2_get_uvarint(&dest->ack_delay, p); + /* This value will be assigned in the upper layer. */ + dest->ack_delay_unscaled = 0; + dest->rangecnt = max_rangecnt; + p += nrangecnt; + p = ngtcp2_get_uvarint(&dest->first_ack_range, p); + + for (i = 0; i < max_rangecnt; ++i) { + range = &dest->ranges[i]; + p = ngtcp2_get_uvarint(&range->gap, p); + p = ngtcp2_get_uvarint(&range->len, p); + } + for (i = max_rangecnt; i < rangecnt; ++i) { + p += ngtcp2_get_uvarintlen(p); + p += ngtcp2_get_uvarintlen(p); + } + + if (type == NGTCP2_FRAME_ACK_ECN) { + p = ngtcp2_get_uvarint(&dest->ecn.ect0, p); + p = ngtcp2_get_uvarint(&dest->ecn.ect1, p); + p = ngtcp2_get_uvarint(&dest->ecn.ce, p); + } + + assert((size_t)(p - payload) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_decode_padding_frame(ngtcp2_padding *dest, + const uint8_t *payload, + size_t payloadlen) { + const uint8_t *p, *ep; + + assert(payloadlen > 0); + + p = payload + 1; + ep = payload + payloadlen; + + for (; p != ep && *p == NGTCP2_FRAME_PADDING; ++p) + ; + + dest->type = NGTCP2_FRAME_PADDING; + dest->len = (size_t)(p - payload); + + return (ngtcp2_ssize)dest->len; +} + +ngtcp2_ssize ngtcp2_pkt_decode_reset_stream_frame(ngtcp2_reset_stream *dest, + const uint8_t *payload, + size_t payloadlen) { + size_t len = 1 + 1 + 1 + 1; + const uint8_t *p; + size_t n; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = payload + 1; + + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + p += n; + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + p += n; + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = payload + 1; + + dest->type = NGTCP2_FRAME_RESET_STREAM; + p = ngtcp2_get_varint(&dest->stream_id, p); + p = ngtcp2_get_uvarint(&dest->app_error_code, p); + p = ngtcp2_get_uvarint(&dest->final_size, p); + + assert((size_t)(p - payload) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_decode_connection_close_frame( + ngtcp2_connection_close *dest, const uint8_t *payload, size_t payloadlen) { + size_t len = 1 + 1 + 1; + const uint8_t *p; + size_t reasonlen; + size_t nreasonlen; + size_t n; + uint8_t type; + uint64_t vi; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + type = payload[0]; + + p = payload + 1; + + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p += n; + + if (type == NGTCP2_FRAME_CONNECTION_CLOSE) { + ++len; + + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p += n; + } + + nreasonlen = ngtcp2_get_uvarintlen(p); + len += nreasonlen - 1; + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = ngtcp2_get_uvarint(&vi, p); + if (payloadlen - len < vi) { + return NGTCP2_ERR_FRAME_ENCODING; + } + reasonlen = (size_t)vi; + len += reasonlen; + + p = payload + 1; + + dest->type = type; + p = ngtcp2_get_uvarint(&dest->error_code, p); + if (type == NGTCP2_FRAME_CONNECTION_CLOSE) { + p = ngtcp2_get_uvarint(&dest->frame_type, p); + } else { + dest->frame_type = 0; + } + dest->reasonlen = reasonlen; + p += nreasonlen; + if (reasonlen == 0) { + dest->reason = NULL; + } else { + dest->reason = (uint8_t *)p; + p += reasonlen; + } + + assert((size_t)(p - payload) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_decode_max_data_frame(ngtcp2_max_data *dest, + const uint8_t *payload, + size_t payloadlen) { + size_t len = 1 + 1; + const uint8_t *p; + size_t n; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = payload + 1; + + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + dest->type = NGTCP2_FRAME_MAX_DATA; + p = ngtcp2_get_uvarint(&dest->max_data, p); + + assert((size_t)(p - payload) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_decode_max_stream_data_frame( + ngtcp2_max_stream_data *dest, const uint8_t *payload, size_t payloadlen) { + size_t len = 1 + 1 + 1; + const uint8_t *p; + size_t n; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = payload + 1; + + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p += n; + + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = payload + 1; + + dest->type = NGTCP2_FRAME_MAX_STREAM_DATA; + p = ngtcp2_get_varint(&dest->stream_id, p); + p = ngtcp2_get_uvarint(&dest->max_stream_data, p); + + assert((size_t)(p - payload) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_decode_max_streams_frame(ngtcp2_max_streams *dest, + const uint8_t *payload, + size_t payloadlen) { + size_t len = 1 + 1; + const uint8_t *p; + size_t n; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = payload + 1; + + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + dest->type = payload[0]; + p = ngtcp2_get_uvarint(&dest->max_streams, p); + + assert((size_t)(p - payload) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_decode_ping_frame(ngtcp2_ping *dest, + const uint8_t *payload, + size_t payloadlen) { + (void)payload; + (void)payloadlen; + + dest->type = NGTCP2_FRAME_PING; + return 1; +} + +ngtcp2_ssize ngtcp2_pkt_decode_data_blocked_frame(ngtcp2_data_blocked *dest, + const uint8_t *payload, + size_t payloadlen) { + size_t len = 1 + 1; + const uint8_t *p; + size_t n; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = payload + 1; + + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + dest->type = NGTCP2_FRAME_DATA_BLOCKED; + p = ngtcp2_get_uvarint(&dest->offset, p); + + assert((size_t)(p - payload) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize +ngtcp2_pkt_decode_stream_data_blocked_frame(ngtcp2_stream_data_blocked *dest, + const uint8_t *payload, + size_t payloadlen) { + size_t len = 1 + 1 + 1; + const uint8_t *p; + size_t n; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = payload + 1; + + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p += n; + + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = payload + 1; + + dest->type = NGTCP2_FRAME_STREAM_DATA_BLOCKED; + p = ngtcp2_get_varint(&dest->stream_id, p); + p = ngtcp2_get_uvarint(&dest->offset, p); + + assert((size_t)(p - payload) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_decode_streams_blocked_frame( + ngtcp2_streams_blocked *dest, const uint8_t *payload, size_t payloadlen) { + size_t len = 1 + 1; + const uint8_t *p; + size_t n; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = payload + 1; + + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + dest->type = payload[0]; + p = ngtcp2_get_uvarint(&dest->max_streams, p); + + assert((size_t)(p - payload) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_decode_new_connection_id_frame( + ngtcp2_new_connection_id *dest, const uint8_t *payload, size_t payloadlen) { + size_t len = 1 + 1 + 1 + 1 + 16; + const uint8_t *p; + size_t n; + size_t cil; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = payload + 1; + + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p += n; + + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p += n; + + cil = *p; + if (cil < NGTCP2_MIN_CIDLEN || cil > NGTCP2_MAX_CIDLEN) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + len += cil; + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = payload + 1; + + dest->type = NGTCP2_FRAME_NEW_CONNECTION_ID; + p = ngtcp2_get_uvarint(&dest->seq, p); + p = ngtcp2_get_uvarint(&dest->retire_prior_to, p); + ++p; + ngtcp2_cid_init(&dest->cid, p, cil); + p += cil; + p = ngtcp2_get_bytes(dest->stateless_reset_token, p, + NGTCP2_STATELESS_RESET_TOKENLEN); + + assert((size_t)(p - payload) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_decode_stop_sending_frame(ngtcp2_stop_sending *dest, + const uint8_t *payload, + size_t payloadlen) { + size_t len = 1 + 1 + 1; + const uint8_t *p; + size_t n; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = payload + 1; + + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + p += n; + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = payload + 1; + + dest->type = NGTCP2_FRAME_STOP_SENDING; + p = ngtcp2_get_varint(&dest->stream_id, p); + p = ngtcp2_get_uvarint(&dest->app_error_code, p); + + assert((size_t)(p - payload) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_decode_path_challenge_frame(ngtcp2_path_challenge *dest, + const uint8_t *payload, + size_t payloadlen) { + size_t len = 1 + 8; + const uint8_t *p; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = payload + 1; + + dest->type = NGTCP2_FRAME_PATH_CHALLENGE; + ngtcp2_cpymem(dest->data, p, sizeof(dest->data)); + p += sizeof(dest->data); + + assert((size_t)(p - payload) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_decode_path_response_frame(ngtcp2_path_response *dest, + const uint8_t *payload, + size_t payloadlen) { + size_t len = 1 + 8; + const uint8_t *p; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = payload + 1; + + dest->type = NGTCP2_FRAME_PATH_RESPONSE; + ngtcp2_cpymem(dest->data, p, sizeof(dest->data)); + p += sizeof(dest->data); + + assert((size_t)(p - payload) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_decode_crypto_frame(ngtcp2_crypto *dest, + const uint8_t *payload, + size_t payloadlen) { + size_t len = 1 + 1 + 1; + const uint8_t *p; + size_t datalen; + size_t ndatalen; + size_t n; + uint64_t vi; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = payload + 1; + + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p += n; + + ndatalen = ngtcp2_get_uvarintlen(p); + len += ndatalen - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = ngtcp2_get_uvarint(&vi, p); + if (payloadlen - len < vi) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + datalen = (size_t)vi; + len += datalen; + + p = payload + 1; + + dest->type = NGTCP2_FRAME_CRYPTO; + p = ngtcp2_get_uvarint(&dest->offset, p); + dest->data[0].len = datalen; + p += ndatalen; + if (dest->data[0].len) { + dest->data[0].base = (uint8_t *)p; + p += dest->data[0].len; + dest->datacnt = 1; + } else { + dest->data[0].base = NULL; + dest->datacnt = 0; + } + + assert((size_t)(p - payload) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_decode_new_token_frame(ngtcp2_new_token *dest, + const uint8_t *payload, + size_t payloadlen) { + size_t len = 1 + 1; + const uint8_t *p; + size_t n; + size_t datalen; + uint64_t vi; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = payload + 1; + + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = ngtcp2_get_uvarint(&vi, p); + if (payloadlen - len < vi) { + return NGTCP2_ERR_FRAME_ENCODING; + } + datalen = (size_t)vi; + len += datalen; + + dest->type = NGTCP2_FRAME_NEW_TOKEN; + dest->token.len = datalen; + dest->token.base = (uint8_t *)p; + p += dest->token.len; + + assert((size_t)(p - payload) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize +ngtcp2_pkt_decode_retire_connection_id_frame(ngtcp2_retire_connection_id *dest, + const uint8_t *payload, + size_t payloadlen) { + size_t len = 1 + 1; + const uint8_t *p; + size_t n; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = payload + 1; + + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + dest->type = NGTCP2_FRAME_RETIRE_CONNECTION_ID; + p = ngtcp2_get_uvarint(&dest->seq, p); + + assert((size_t)(p - payload) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_decode_handshake_done_frame(ngtcp2_handshake_done *dest, + const uint8_t *payload, + size_t payloadlen) { + (void)payload; + (void)payloadlen; + + dest->type = NGTCP2_FRAME_HANDSHAKE_DONE; + return 1; +} + +ngtcp2_ssize ngtcp2_pkt_decode_datagram_frame(ngtcp2_datagram *dest, + const uint8_t *payload, + size_t payloadlen) { + size_t len = 1; + const uint8_t *p; + uint8_t type; + size_t datalen; + size_t n; + uint64_t vi; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + type = payload[0]; + + p = payload + 1; + + switch (type) { + case NGTCP2_FRAME_DATAGRAM: + datalen = payloadlen - 1; + len = payloadlen; + break; + case NGTCP2_FRAME_DATAGRAM_LEN: + ++len; + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + n = ngtcp2_get_uvarintlen(p); + len += n - 1; + + if (payloadlen < len) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + p = ngtcp2_get_uvarint(&vi, p); + if (payloadlen - len < vi) { + return NGTCP2_ERR_FRAME_ENCODING; + } + + datalen = (size_t)vi; + len += datalen; + break; + default: + ngtcp2_unreachable(); + } + + dest->type = type; + + if (datalen == 0) { + dest->datacnt = 0; + dest->data = NULL; + } else { + dest->datacnt = 1; + dest->data = dest->rdata; + dest->rdata[0].len = datalen; + + dest->rdata[0].base = (uint8_t *)p; + p += datalen; + } + + assert((size_t)(p - payload) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_encode_frame(uint8_t *out, size_t outlen, + ngtcp2_frame *fr) { + switch (fr->type) { + case NGTCP2_FRAME_STREAM: + return ngtcp2_pkt_encode_stream_frame(out, outlen, &fr->stream); + case NGTCP2_FRAME_ACK: + case NGTCP2_FRAME_ACK_ECN: + return ngtcp2_pkt_encode_ack_frame(out, outlen, &fr->ack); + case NGTCP2_FRAME_PADDING: + return ngtcp2_pkt_encode_padding_frame(out, outlen, &fr->padding); + case NGTCP2_FRAME_RESET_STREAM: + return ngtcp2_pkt_encode_reset_stream_frame(out, outlen, &fr->reset_stream); + case NGTCP2_FRAME_CONNECTION_CLOSE: + case NGTCP2_FRAME_CONNECTION_CLOSE_APP: + return ngtcp2_pkt_encode_connection_close_frame(out, outlen, + &fr->connection_close); + case NGTCP2_FRAME_MAX_DATA: + return ngtcp2_pkt_encode_max_data_frame(out, outlen, &fr->max_data); + case NGTCP2_FRAME_MAX_STREAM_DATA: + return ngtcp2_pkt_encode_max_stream_data_frame(out, outlen, + &fr->max_stream_data); + case NGTCP2_FRAME_MAX_STREAMS_BIDI: + case NGTCP2_FRAME_MAX_STREAMS_UNI: + return ngtcp2_pkt_encode_max_streams_frame(out, outlen, &fr->max_streams); + case NGTCP2_FRAME_PING: + return ngtcp2_pkt_encode_ping_frame(out, outlen, &fr->ping); + case NGTCP2_FRAME_DATA_BLOCKED: + return ngtcp2_pkt_encode_data_blocked_frame(out, outlen, &fr->data_blocked); + case NGTCP2_FRAME_STREAM_DATA_BLOCKED: + return ngtcp2_pkt_encode_stream_data_blocked_frame( + out, outlen, &fr->stream_data_blocked); + case NGTCP2_FRAME_STREAMS_BLOCKED_BIDI: + case NGTCP2_FRAME_STREAMS_BLOCKED_UNI: + return ngtcp2_pkt_encode_streams_blocked_frame(out, outlen, + &fr->streams_blocked); + case NGTCP2_FRAME_NEW_CONNECTION_ID: + return ngtcp2_pkt_encode_new_connection_id_frame(out, outlen, + &fr->new_connection_id); + case NGTCP2_FRAME_STOP_SENDING: + return ngtcp2_pkt_encode_stop_sending_frame(out, outlen, &fr->stop_sending); + case NGTCP2_FRAME_PATH_CHALLENGE: + return ngtcp2_pkt_encode_path_challenge_frame(out, outlen, + &fr->path_challenge); + case NGTCP2_FRAME_PATH_RESPONSE: + return ngtcp2_pkt_encode_path_response_frame(out, outlen, + &fr->path_response); + case NGTCP2_FRAME_CRYPTO: + return ngtcp2_pkt_encode_crypto_frame(out, outlen, &fr->crypto); + case NGTCP2_FRAME_NEW_TOKEN: + return ngtcp2_pkt_encode_new_token_frame(out, outlen, &fr->new_token); + case NGTCP2_FRAME_RETIRE_CONNECTION_ID: + return ngtcp2_pkt_encode_retire_connection_id_frame( + out, outlen, &fr->retire_connection_id); + case NGTCP2_FRAME_HANDSHAKE_DONE: + return ngtcp2_pkt_encode_handshake_done_frame(out, outlen, + &fr->handshake_done); + case NGTCP2_FRAME_DATAGRAM: + case NGTCP2_FRAME_DATAGRAM_LEN: + return ngtcp2_pkt_encode_datagram_frame(out, outlen, &fr->datagram); + default: + return NGTCP2_ERR_INVALID_ARGUMENT; + } +} + +ngtcp2_ssize ngtcp2_pkt_encode_stream_frame(uint8_t *out, size_t outlen, + ngtcp2_stream *fr) { + size_t len = 1; + uint8_t flags = NGTCP2_STREAM_LEN_BIT; + uint8_t *p; + size_t i; + size_t datalen = 0; + + if (fr->fin) { + flags |= NGTCP2_STREAM_FIN_BIT; + } + + if (fr->offset) { + flags |= NGTCP2_STREAM_OFF_BIT; + len += ngtcp2_put_uvarintlen(fr->offset); + } + + len += ngtcp2_put_uvarintlen((uint64_t)fr->stream_id); + + for (i = 0; i < fr->datacnt; ++i) { + datalen += fr->data[i].len; + } + + len += ngtcp2_put_uvarintlen(datalen); + len += datalen; + + if (outlen < len) { + return NGTCP2_ERR_NOBUF; + } + + p = out; + + *p++ = flags | NGTCP2_FRAME_STREAM; + + fr->flags = flags; + + p = ngtcp2_put_uvarint(p, (uint64_t)fr->stream_id); + + if (fr->offset) { + p = ngtcp2_put_uvarint(p, fr->offset); + } + + p = ngtcp2_put_uvarint(p, datalen); + + for (i = 0; i < fr->datacnt; ++i) { + assert(fr->data[i].len); + assert(fr->data[i].base); + p = ngtcp2_cpymem(p, fr->data[i].base, fr->data[i].len); + } + + assert((size_t)(p - out) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_encode_ack_frame(uint8_t *out, size_t outlen, + ngtcp2_ack *fr) { + size_t len = 1 + ngtcp2_put_uvarintlen((uint64_t)fr->largest_ack) + + ngtcp2_put_uvarintlen(fr->ack_delay) + + ngtcp2_put_uvarintlen(fr->rangecnt) + + ngtcp2_put_uvarintlen(fr->first_ack_range); + uint8_t *p; + size_t i; + const ngtcp2_ack_range *range; + + for (i = 0; i < fr->rangecnt; ++i) { + range = &fr->ranges[i]; + len += ngtcp2_put_uvarintlen(range->gap); + len += ngtcp2_put_uvarintlen(range->len); + } + + if (fr->type == NGTCP2_FRAME_ACK_ECN) { + len += ngtcp2_put_uvarintlen(fr->ecn.ect0) + + ngtcp2_put_uvarintlen(fr->ecn.ect1) + + ngtcp2_put_uvarintlen(fr->ecn.ce); + } + + if (outlen < len) { + return NGTCP2_ERR_NOBUF; + } + + p = out; + + *p++ = fr->type; + p = ngtcp2_put_uvarint(p, (uint64_t)fr->largest_ack); + p = ngtcp2_put_uvarint(p, fr->ack_delay); + p = ngtcp2_put_uvarint(p, fr->rangecnt); + p = ngtcp2_put_uvarint(p, fr->first_ack_range); + + for (i = 0; i < fr->rangecnt; ++i) { + range = &fr->ranges[i]; + p = ngtcp2_put_uvarint(p, range->gap); + p = ngtcp2_put_uvarint(p, range->len); + } + + if (fr->type == NGTCP2_FRAME_ACK_ECN) { + p = ngtcp2_put_uvarint(p, fr->ecn.ect0); + p = ngtcp2_put_uvarint(p, fr->ecn.ect1); + p = ngtcp2_put_uvarint(p, fr->ecn.ce); + } + + assert((size_t)(p - out) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_encode_padding_frame(uint8_t *out, size_t outlen, + const ngtcp2_padding *fr) { + if (outlen < fr->len) { + return NGTCP2_ERR_NOBUF; + } + + memset(out, 0, fr->len); + + return (ngtcp2_ssize)fr->len; +} + +ngtcp2_ssize +ngtcp2_pkt_encode_reset_stream_frame(uint8_t *out, size_t outlen, + const ngtcp2_reset_stream *fr) { + size_t len = 1 + ngtcp2_put_uvarintlen((uint64_t)fr->stream_id) + + ngtcp2_put_uvarintlen(fr->app_error_code) + + ngtcp2_put_uvarintlen(fr->final_size); + uint8_t *p; + + if (outlen < len) { + return NGTCP2_ERR_NOBUF; + } + + p = out; + + *p++ = NGTCP2_FRAME_RESET_STREAM; + p = ngtcp2_put_uvarint(p, (uint64_t)fr->stream_id); + p = ngtcp2_put_uvarint(p, fr->app_error_code); + p = ngtcp2_put_uvarint(p, fr->final_size); + + assert((size_t)(p - out) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize +ngtcp2_pkt_encode_connection_close_frame(uint8_t *out, size_t outlen, + const ngtcp2_connection_close *fr) { + size_t len = 1 + ngtcp2_put_uvarintlen(fr->error_code) + + (fr->type == NGTCP2_FRAME_CONNECTION_CLOSE + ? ngtcp2_put_uvarintlen(fr->frame_type) + : 0) + + ngtcp2_put_uvarintlen(fr->reasonlen) + fr->reasonlen; + uint8_t *p; + + if (outlen < len) { + return NGTCP2_ERR_NOBUF; + } + + p = out; + + *p++ = fr->type; + p = ngtcp2_put_uvarint(p, fr->error_code); + if (fr->type == NGTCP2_FRAME_CONNECTION_CLOSE) { + p = ngtcp2_put_uvarint(p, fr->frame_type); + } + p = ngtcp2_put_uvarint(p, fr->reasonlen); + if (fr->reasonlen) { + p = ngtcp2_cpymem(p, fr->reason, fr->reasonlen); + } + + assert((size_t)(p - out) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_encode_max_data_frame(uint8_t *out, size_t outlen, + const ngtcp2_max_data *fr) { + size_t len = 1 + ngtcp2_put_uvarintlen(fr->max_data); + uint8_t *p; + + if (outlen < len) { + return NGTCP2_ERR_NOBUF; + } + + p = out; + + *p++ = NGTCP2_FRAME_MAX_DATA; + p = ngtcp2_put_uvarint(p, fr->max_data); + + assert((size_t)(p - out) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize +ngtcp2_pkt_encode_max_stream_data_frame(uint8_t *out, size_t outlen, + const ngtcp2_max_stream_data *fr) { + size_t len = 1 + ngtcp2_put_uvarintlen((uint64_t)fr->stream_id) + + ngtcp2_put_uvarintlen(fr->max_stream_data); + uint8_t *p; + + if (outlen < len) { + return NGTCP2_ERR_NOBUF; + } + + p = out; + + *p++ = NGTCP2_FRAME_MAX_STREAM_DATA; + p = ngtcp2_put_uvarint(p, (uint64_t)fr->stream_id); + p = ngtcp2_put_uvarint(p, fr->max_stream_data); + + assert((size_t)(p - out) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_encode_max_streams_frame(uint8_t *out, size_t outlen, + const ngtcp2_max_streams *fr) { + size_t len = 1 + ngtcp2_put_uvarintlen(fr->max_streams); + uint8_t *p; + + if (outlen < len) { + return NGTCP2_ERR_NOBUF; + } + + p = out; + + *p++ = fr->type; + p = ngtcp2_put_uvarint(p, fr->max_streams); + + assert((size_t)(p - out) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_encode_ping_frame(uint8_t *out, size_t outlen, + const ngtcp2_ping *fr) { + (void)fr; + + if (outlen < 1) { + return NGTCP2_ERR_NOBUF; + } + + *out++ = NGTCP2_FRAME_PING; + + return 1; +} + +ngtcp2_ssize +ngtcp2_pkt_encode_data_blocked_frame(uint8_t *out, size_t outlen, + const ngtcp2_data_blocked *fr) { + size_t len = 1 + ngtcp2_put_uvarintlen(fr->offset); + uint8_t *p; + + if (outlen < len) { + return NGTCP2_ERR_NOBUF; + } + + p = out; + + *p++ = NGTCP2_FRAME_DATA_BLOCKED; + p = ngtcp2_put_uvarint(p, fr->offset); + + assert((size_t)(p - out) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_encode_stream_data_blocked_frame( + uint8_t *out, size_t outlen, const ngtcp2_stream_data_blocked *fr) { + size_t len = 1 + ngtcp2_put_uvarintlen((uint64_t)fr->stream_id) + + ngtcp2_put_uvarintlen(fr->offset); + uint8_t *p; + + if (outlen < len) { + return NGTCP2_ERR_NOBUF; + } + + p = out; + + *p++ = NGTCP2_FRAME_STREAM_DATA_BLOCKED; + p = ngtcp2_put_uvarint(p, (uint64_t)fr->stream_id); + p = ngtcp2_put_uvarint(p, fr->offset); + + assert((size_t)(p - out) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize +ngtcp2_pkt_encode_streams_blocked_frame(uint8_t *out, size_t outlen, + const ngtcp2_streams_blocked *fr) { + size_t len = 1 + ngtcp2_put_uvarintlen(fr->max_streams); + uint8_t *p; + + if (outlen < len) { + return NGTCP2_ERR_NOBUF; + } + + p = out; + + *p++ = fr->type; + p = ngtcp2_put_uvarint(p, fr->max_streams); + + assert((size_t)(p - out) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize +ngtcp2_pkt_encode_new_connection_id_frame(uint8_t *out, size_t outlen, + const ngtcp2_new_connection_id *fr) { + size_t len = 1 + ngtcp2_put_uvarintlen(fr->seq) + + ngtcp2_put_uvarintlen(fr->retire_prior_to) + 1 + + fr->cid.datalen + NGTCP2_STATELESS_RESET_TOKENLEN; + uint8_t *p; + + if (outlen < len) { + return NGTCP2_ERR_NOBUF; + } + + p = out; + + *p++ = NGTCP2_FRAME_NEW_CONNECTION_ID; + p = ngtcp2_put_uvarint(p, fr->seq); + p = ngtcp2_put_uvarint(p, fr->retire_prior_to); + *p++ = (uint8_t)fr->cid.datalen; + p = ngtcp2_cpymem(p, fr->cid.data, fr->cid.datalen); + p = ngtcp2_cpymem(p, fr->stateless_reset_token, + NGTCP2_STATELESS_RESET_TOKENLEN); + + assert((size_t)(p - out) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize +ngtcp2_pkt_encode_stop_sending_frame(uint8_t *out, size_t outlen, + const ngtcp2_stop_sending *fr) { + size_t len = 1 + ngtcp2_put_uvarintlen((uint64_t)fr->stream_id) + + ngtcp2_put_uvarintlen(fr->app_error_code); + uint8_t *p; + + if (outlen < len) { + return NGTCP2_ERR_NOBUF; + } + + p = out; + + *p++ = NGTCP2_FRAME_STOP_SENDING; + p = ngtcp2_put_uvarint(p, (uint64_t)fr->stream_id); + p = ngtcp2_put_uvarint(p, fr->app_error_code); + + assert((size_t)(p - out) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize +ngtcp2_pkt_encode_path_challenge_frame(uint8_t *out, size_t outlen, + const ngtcp2_path_challenge *fr) { + size_t len = 1 + 8; + uint8_t *p; + + if (outlen < len) { + return NGTCP2_ERR_NOBUF; + } + + p = out; + + *p++ = NGTCP2_FRAME_PATH_CHALLENGE; + p = ngtcp2_cpymem(p, fr->data, sizeof(fr->data)); + + assert((size_t)(p - out) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize +ngtcp2_pkt_encode_path_response_frame(uint8_t *out, size_t outlen, + const ngtcp2_path_response *fr) { + size_t len = 1 + 8; + uint8_t *p; + + if (outlen < len) { + return NGTCP2_ERR_NOBUF; + } + + p = out; + + *p++ = NGTCP2_FRAME_PATH_RESPONSE; + p = ngtcp2_cpymem(p, fr->data, sizeof(fr->data)); + + assert((size_t)(p - out) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_encode_crypto_frame(uint8_t *out, size_t outlen, + const ngtcp2_crypto *fr) { + size_t len = 1; + uint8_t *p; + size_t i; + size_t datalen = 0; + + len += ngtcp2_put_uvarintlen(fr->offset); + + for (i = 0; i < fr->datacnt; ++i) { + datalen += fr->data[i].len; + } + + len += ngtcp2_put_uvarintlen(datalen); + len += datalen; + + if (outlen < len) { + return NGTCP2_ERR_NOBUF; + } + + p = out; + + *p++ = NGTCP2_FRAME_CRYPTO; + + p = ngtcp2_put_uvarint(p, fr->offset); + p = ngtcp2_put_uvarint(p, datalen); + + for (i = 0; i < fr->datacnt; ++i) { + assert(fr->data[i].base); + p = ngtcp2_cpymem(p, fr->data[i].base, fr->data[i].len); + } + + assert((size_t)(p - out) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_encode_new_token_frame(uint8_t *out, size_t outlen, + const ngtcp2_new_token *fr) { + size_t len = 1 + ngtcp2_put_uvarintlen(fr->token.len) + fr->token.len; + uint8_t *p; + + assert(fr->token.len); + + if (outlen < len) { + return NGTCP2_ERR_NOBUF; + } + + p = out; + + *p++ = NGTCP2_FRAME_NEW_TOKEN; + + p = ngtcp2_put_uvarint(p, fr->token.len); + p = ngtcp2_cpymem(p, fr->token.base, fr->token.len); + + assert((size_t)(p - out) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_encode_retire_connection_id_frame( + uint8_t *out, size_t outlen, const ngtcp2_retire_connection_id *fr) { + size_t len = 1 + ngtcp2_put_uvarintlen(fr->seq); + uint8_t *p; + + if (outlen < len) { + return NGTCP2_ERR_NOBUF; + } + + p = out; + + *p++ = NGTCP2_FRAME_RETIRE_CONNECTION_ID; + + p = ngtcp2_put_uvarint(p, fr->seq); + + assert((size_t)(p - out) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize +ngtcp2_pkt_encode_handshake_done_frame(uint8_t *out, size_t outlen, + const ngtcp2_handshake_done *fr) { + (void)fr; + + if (outlen < 1) { + return NGTCP2_ERR_NOBUF; + } + + *out++ = NGTCP2_FRAME_HANDSHAKE_DONE; + + return 1; +} + +ngtcp2_ssize ngtcp2_pkt_encode_datagram_frame(uint8_t *out, size_t outlen, + const ngtcp2_datagram *fr) { + uint64_t datalen = ngtcp2_vec_len(fr->data, fr->datacnt); + uint64_t len = + 1 + + (fr->type == NGTCP2_FRAME_DATAGRAM ? 0 : ngtcp2_put_uvarintlen(datalen)) + + datalen; + uint8_t *p; + size_t i; + + assert(fr->type == NGTCP2_FRAME_DATAGRAM || + fr->type == NGTCP2_FRAME_DATAGRAM_LEN); + + if (outlen < len) { + return NGTCP2_ERR_NOBUF; + } + + p = out; + + *p++ = fr->type; + if (fr->type == NGTCP2_FRAME_DATAGRAM_LEN) { + p = ngtcp2_put_uvarint(p, datalen); + } + + for (i = 0; i < fr->datacnt; ++i) { + assert(fr->data[i].len); + assert(fr->data[i].base); + p = ngtcp2_cpymem(p, fr->data[i].base, fr->data[i].len); + } + + assert((size_t)(p - out) == len); + + return (ngtcp2_ssize)len; +} + +ngtcp2_ssize ngtcp2_pkt_write_version_negotiation( + uint8_t *dest, size_t destlen, uint8_t unused_random, const uint8_t *dcid, + size_t dcidlen, const uint8_t *scid, size_t scidlen, const uint32_t *sv, + size_t nsv) { + size_t len = 1 + 4 + 1 + dcidlen + 1 + scidlen + nsv * 4; + uint8_t *p; + size_t i; + + assert(dcidlen < 256); + assert(scidlen < 256); + + if (destlen < len) { + return NGTCP2_ERR_NOBUF; + } + + p = dest; + + *p++ = 0x80 | unused_random; + p = ngtcp2_put_uint32be(p, 0); + *p++ = (uint8_t)dcidlen; + if (dcidlen) { + p = ngtcp2_cpymem(p, dcid, dcidlen); + } + *p++ = (uint8_t)scidlen; + if (scidlen) { + p = ngtcp2_cpymem(p, scid, scidlen); + } + + for (i = 0; i < nsv; ++i) { + p = ngtcp2_put_uint32be(p, sv[i]); + } + + assert((size_t)(p - dest) == len); + + return (ngtcp2_ssize)len; +} + +size_t ngtcp2_pkt_decode_version_negotiation(uint32_t *dest, + const uint8_t *payload, + size_t payloadlen) { + const uint8_t *end = payload + payloadlen; + + assert((payloadlen % sizeof(uint32_t)) == 0); + + for (; payload != end;) { + payload = ngtcp2_get_uint32(dest++, payload); + } + + return payloadlen / sizeof(uint32_t); +} + +int ngtcp2_pkt_decode_stateless_reset(ngtcp2_pkt_stateless_reset *sr, + const uint8_t *payload, + size_t payloadlen) { + const uint8_t *p = payload; + + if (payloadlen < + NGTCP2_MIN_STATELESS_RESET_RANDLEN + NGTCP2_STATELESS_RESET_TOKENLEN) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + + sr->rand = p; + sr->randlen = payloadlen - NGTCP2_STATELESS_RESET_TOKENLEN; + p += sr->randlen; + memcpy(sr->stateless_reset_token, p, NGTCP2_STATELESS_RESET_TOKENLEN); + + return 0; +} + +int ngtcp2_pkt_decode_retry(ngtcp2_pkt_retry *dest, const uint8_t *payload, + size_t payloadlen) { + size_t len = /* token */ 1 + NGTCP2_RETRY_TAGLEN; + + if (payloadlen < len) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + + dest->token.base = (uint8_t *)payload; + dest->token.len = (size_t)(payloadlen - NGTCP2_RETRY_TAGLEN); + ngtcp2_cpymem(dest->tag, payload + dest->token.len, NGTCP2_RETRY_TAGLEN); + + return 0; +} + +int64_t ngtcp2_pkt_adjust_pkt_num(int64_t max_pkt_num, int64_t pkt_num, + size_t n) { + int64_t expected = max_pkt_num + 1; + int64_t win = (int64_t)1 << n; + int64_t hwin = win / 2; + int64_t mask = win - 1; + int64_t cand = (expected & ~mask) | pkt_num; + + if (cand <= expected - hwin) { + assert(cand <= (int64_t)NGTCP2_MAX_VARINT - win); + return cand + win; + } + if (cand > expected + hwin && cand >= win) { + return cand - win; + } + return cand; +} + +int ngtcp2_pkt_validate_ack(ngtcp2_ack *fr) { + int64_t largest_ack = fr->largest_ack; + size_t i; + + if (largest_ack < (int64_t)fr->first_ack_range) { + return NGTCP2_ERR_ACK_FRAME; + } + + largest_ack -= (int64_t)fr->first_ack_range; + + for (i = 0; i < fr->rangecnt; ++i) { + if (largest_ack < (int64_t)fr->ranges[i].gap + 2) { + return NGTCP2_ERR_ACK_FRAME; + } + + largest_ack -= (int64_t)fr->ranges[i].gap + 2; + + if (largest_ack < (int64_t)fr->ranges[i].len) { + return NGTCP2_ERR_ACK_FRAME; + } + + largest_ack -= (int64_t)fr->ranges[i].len; + } + + return 0; +} + +ngtcp2_ssize +ngtcp2_pkt_write_stateless_reset(uint8_t *dest, size_t destlen, + const uint8_t *stateless_reset_token, + const uint8_t *rand, size_t randlen) { + uint8_t *p; + + if (destlen < + NGTCP2_MIN_STATELESS_RESET_RANDLEN + NGTCP2_STATELESS_RESET_TOKENLEN) { + return NGTCP2_ERR_NOBUF; + } + + if (randlen < NGTCP2_MIN_STATELESS_RESET_RANDLEN) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + + p = dest; + + randlen = ngtcp2_min(destlen - NGTCP2_STATELESS_RESET_TOKENLEN, randlen); + + p = ngtcp2_cpymem(p, rand, randlen); + p = ngtcp2_cpymem(p, stateless_reset_token, NGTCP2_STATELESS_RESET_TOKENLEN); + *dest = (uint8_t)((*dest & 0x7fu) | 0x40u); + + return p - dest; +} + +ngtcp2_ssize ngtcp2_pkt_write_retry( + uint8_t *dest, size_t destlen, uint32_t version, const ngtcp2_cid *dcid, + const ngtcp2_cid *scid, const ngtcp2_cid *odcid, const uint8_t *token, + size_t tokenlen, ngtcp2_encrypt encrypt, const ngtcp2_crypto_aead *aead, + const ngtcp2_crypto_aead_ctx *aead_ctx) { + ngtcp2_pkt_hd hd; + uint8_t pseudo_retry[1500]; + ngtcp2_ssize pseudo_retrylen; + uint8_t tag[NGTCP2_RETRY_TAGLEN]; + int rv; + uint8_t *p; + size_t offset; + const uint8_t *nonce; + size_t noncelen; + + assert(tokenlen > 0); + assert(!ngtcp2_cid_eq(scid, odcid)); + + /* Retry packet is sent at most once per one connection attempt. In + the first connection attempt, client has to send random DCID + which is at least NGTCP2_MIN_INITIAL_DCIDLEN bytes long. */ + if (odcid->datalen < NGTCP2_MIN_INITIAL_DCIDLEN) { + return NGTCP2_ERR_INVALID_ARGUMENT; + } + + ngtcp2_pkt_hd_init(&hd, NGTCP2_PKT_FLAG_LONG_FORM, NGTCP2_PKT_RETRY, dcid, + scid, /* pkt_num = */ 0, /* pkt_numlen = */ 1, version, + /* len = */ 0); + + pseudo_retrylen = + ngtcp2_pkt_encode_pseudo_retry(pseudo_retry, sizeof(pseudo_retry), &hd, + /* unused = */ 0, odcid, token, tokenlen); + if (pseudo_retrylen < 0) { + return pseudo_retrylen; + } + + switch (version) { + case NGTCP2_PROTO_VER_V1: + nonce = (const uint8_t *)NGTCP2_RETRY_NONCE_V1; + noncelen = sizeof(NGTCP2_RETRY_NONCE_V1) - 1; + break; + case NGTCP2_PROTO_VER_V2_DRAFT: + nonce = (const uint8_t *)NGTCP2_RETRY_NONCE_V2_DRAFT; + noncelen = sizeof(NGTCP2_RETRY_NONCE_V2_DRAFT) - 1; + break; + default: + nonce = (const uint8_t *)NGTCP2_RETRY_NONCE_DRAFT; + noncelen = sizeof(NGTCP2_RETRY_NONCE_DRAFT) - 1; + } + + /* OpenSSL does not like NULL plaintext. */ + rv = encrypt(tag, aead, aead_ctx, (const uint8_t *)"", 0, nonce, noncelen, + pseudo_retry, (size_t)pseudo_retrylen); + if (rv != 0) { + return rv; + } + + offset = 1 + odcid->datalen; + if (destlen < (size_t)pseudo_retrylen + sizeof(tag) - offset) { + return NGTCP2_ERR_NOBUF; + } + + p = ngtcp2_cpymem(dest, pseudo_retry + offset, + (size_t)pseudo_retrylen - offset); + p = ngtcp2_cpymem(p, tag, sizeof(tag)); + + return p - dest; +} + +ngtcp2_ssize ngtcp2_pkt_encode_pseudo_retry( + uint8_t *dest, size_t destlen, const ngtcp2_pkt_hd *hd, uint8_t unused, + const ngtcp2_cid *odcid, const uint8_t *token, size_t tokenlen) { + uint8_t *p = dest; + ngtcp2_ssize nwrite; + + if (destlen < 1 + odcid->datalen) { + return NGTCP2_ERR_NOBUF; + } + + *p++ = (uint8_t)odcid->datalen; + p = ngtcp2_cpymem(p, odcid->data, odcid->datalen); + destlen -= (size_t)(p - dest); + + nwrite = ngtcp2_pkt_encode_hd_long(p, destlen, hd); + if (nwrite < 0) { + return nwrite; + } + + if (destlen < (size_t)nwrite + tokenlen) { + return NGTCP2_ERR_NOBUF; + } + + *p &= 0xf0; + *p |= unused; + + p += nwrite; + + p = ngtcp2_cpymem(p, token, tokenlen); + + return p - dest; +} + +int ngtcp2_pkt_verify_retry_tag(uint32_t version, const ngtcp2_pkt_retry *retry, + const uint8_t *pkt, size_t pktlen, + ngtcp2_encrypt encrypt, + const ngtcp2_crypto_aead *aead, + const ngtcp2_crypto_aead_ctx *aead_ctx) { + uint8_t pseudo_retry[1500]; + size_t pseudo_retrylen; + uint8_t *p = pseudo_retry; + int rv; + uint8_t tag[NGTCP2_RETRY_TAGLEN]; + const uint8_t *nonce; + size_t noncelen; + + assert(pktlen >= sizeof(retry->tag)); + + if (sizeof(pseudo_retry) < + 1 + retry->odcid.datalen + pktlen - sizeof(retry->tag)) { + return NGTCP2_ERR_PROTO; + } + + *p++ = (uint8_t)retry->odcid.datalen; + p = ngtcp2_cpymem(p, retry->odcid.data, retry->odcid.datalen); + p = ngtcp2_cpymem(p, pkt, pktlen - sizeof(retry->tag)); + + pseudo_retrylen = (size_t)(p - pseudo_retry); + + switch (version) { + case NGTCP2_PROTO_VER_V1: + nonce = (const uint8_t *)NGTCP2_RETRY_NONCE_V1; + noncelen = sizeof(NGTCP2_RETRY_NONCE_V1) - 1; + break; + case NGTCP2_PROTO_VER_V2_DRAFT: + nonce = (const uint8_t *)NGTCP2_RETRY_NONCE_V2_DRAFT; + noncelen = sizeof(NGTCP2_RETRY_NONCE_V2_DRAFT) - 1; + break; + default: + nonce = (const uint8_t *)NGTCP2_RETRY_NONCE_DRAFT; + noncelen = sizeof(NGTCP2_RETRY_NONCE_DRAFT) - 1; + } + + /* OpenSSL does not like NULL plaintext. */ + rv = encrypt(tag, aead, aead_ctx, (const uint8_t *)"", 0, nonce, noncelen, + pseudo_retry, pseudo_retrylen); + if (rv != 0) { + return rv; + } + + if (0 != memcmp(retry->tag, tag, sizeof(retry->tag))) { + return NGTCP2_ERR_PROTO; + } + + return 0; +} + +size_t ngtcp2_pkt_stream_max_datalen(int64_t stream_id, uint64_t offset, + uint64_t len, size_t left) { + size_t n = 1 /* type */ + ngtcp2_put_uvarintlen((uint64_t)stream_id) + + (offset ? ngtcp2_put_uvarintlen(offset) : 0); + + if (left <= n) { + return (size_t)-1; + } + + left -= n; + + if (left > 8 + 1073741823 && len > 1073741823) { +#if SIZE_MAX > UINT32_MAX + len = ngtcp2_min(len, 4611686018427387903lu); +#endif /* SIZE_MAX > UINT32_MAX */ + return (size_t)ngtcp2_min(len, (uint64_t)(left - 8)); + } + + if (left > 4 + 16383 && len > 16383) { + len = ngtcp2_min(len, 1073741823); + return (size_t)ngtcp2_min(len, (uint64_t)(left - 4)); + } + + if (left > 2 + 63 && len > 63) { + len = ngtcp2_min(len, 16383); + return (size_t)ngtcp2_min(len, (uint64_t)(left - 2)); + } + + len = ngtcp2_min(len, 63); + return (size_t)ngtcp2_min(len, (uint64_t)(left - 1)); +} + +size_t ngtcp2_pkt_crypto_max_datalen(uint64_t offset, size_t len, size_t left) { + size_t n = 1 /* type */ + ngtcp2_put_uvarintlen(offset); + + /* CRYPTO frame must contain nonzero length data. Return -1 if + there is no space to write crypto data. */ + if (left <= n + 1) { + return (size_t)-1; + } + + left -= n; + + if (left > 8 + 1073741823 && len > 1073741823) { +#if SIZE_MAX > UINT32_MAX + len = ngtcp2_min(len, 4611686018427387903lu); +#endif /* SIZE_MAX > UINT32_MAX */ + return ngtcp2_min(len, left - 8); + } + + if (left > 4 + 16383 && len > 16383) { + len = ngtcp2_min(len, 1073741823); + return ngtcp2_min(len, left - 4); + } + + if (left > 2 + 63 && len > 63) { + len = ngtcp2_min(len, 16383); + return ngtcp2_min(len, left - 2); + } + + len = ngtcp2_min(len, 63); + return ngtcp2_min(len, left - 1); +} + +size_t ngtcp2_pkt_datagram_framelen(size_t len) { + return 1 /* type */ + ngtcp2_put_uvarintlen(len) + len; +} + +int ngtcp2_is_supported_version(uint32_t version) { + switch (version) { + case NGTCP2_PROTO_VER_V1: + case NGTCP2_PROTO_VER_V2_DRAFT: + return 1; + default: + return NGTCP2_PROTO_VER_DRAFT_MIN <= version && + version <= NGTCP2_PROTO_VER_DRAFT_MAX; + } +} + +int ngtcp2_is_reserved_version(uint32_t version) { + return (version & NGTCP2_RESERVED_VERSION_MASK) == + NGTCP2_RESERVED_VERSION_MASK; +} + +uint8_t ngtcp2_pkt_get_type_long(uint32_t version, uint8_t c) { + uint8_t pkt_type = (uint8_t)((c & NGTCP2_LONG_TYPE_MASK) >> 4); + + switch (version) { + case NGTCP2_PROTO_VER_V2_DRAFT: + switch (pkt_type) { + case NGTCP2_PKT_TYPE_INITIAL_V2_DRAFT: + return NGTCP2_PKT_INITIAL; + case NGTCP2_PKT_TYPE_0RTT_V2_DRAFT: + return NGTCP2_PKT_0RTT; + case NGTCP2_PKT_TYPE_HANDSHAKE_V2_DRAFT: + return NGTCP2_PKT_HANDSHAKE; + case NGTCP2_PKT_TYPE_RETRY_V2_DRAFT: + return NGTCP2_PKT_RETRY; + default: + return 0; + } + default: + if (!ngtcp2_is_supported_version(version)) { + return 0; + } + + /* QUIC v1 and draft versions share the same numeric packet + types. */ + switch (pkt_type) { + case NGTCP2_PKT_TYPE_INITIAL_V1: + return NGTCP2_PKT_INITIAL; + case NGTCP2_PKT_TYPE_0RTT_V1: + return NGTCP2_PKT_0RTT; + case NGTCP2_PKT_TYPE_HANDSHAKE_V1: + return NGTCP2_PKT_HANDSHAKE; + case NGTCP2_PKT_TYPE_RETRY_V1: + return NGTCP2_PKT_RETRY; + default: + return 0; + } + } +} + +uint8_t ngtcp2_pkt_versioned_type(uint32_t version, uint32_t pkt_type) { + switch (version) { + case NGTCP2_PROTO_VER_V2_DRAFT: + switch (pkt_type) { + case NGTCP2_PKT_INITIAL: + return NGTCP2_PKT_TYPE_INITIAL_V2_DRAFT; + case NGTCP2_PKT_0RTT: + return NGTCP2_PKT_TYPE_0RTT_V2_DRAFT; + case NGTCP2_PKT_HANDSHAKE: + return NGTCP2_PKT_TYPE_HANDSHAKE_V2_DRAFT; + case NGTCP2_PKT_RETRY: + return NGTCP2_PKT_TYPE_RETRY_V2_DRAFT; + default: + ngtcp2_unreachable(); + } + default: + /* Assume that unsupported versions share the numeric long packet + types with QUIC v1 in order to send a packet to elicit Version + Negotiation packet. */ + + /* QUIC v1 and draft versions share the same numeric packet + types. */ + switch (pkt_type) { + case NGTCP2_PKT_INITIAL: + return NGTCP2_PKT_TYPE_INITIAL_V1; + case NGTCP2_PKT_0RTT: + return NGTCP2_PKT_TYPE_0RTT_V1; + case NGTCP2_PKT_HANDSHAKE: + return NGTCP2_PKT_TYPE_HANDSHAKE_V1; + case NGTCP2_PKT_RETRY: + return NGTCP2_PKT_TYPE_RETRY_V1; + default: + ngtcp2_unreachable(); + } + } +} + +int ngtcp2_pkt_verify_reserved_bits(uint8_t c) { + if (c & NGTCP2_HEADER_FORM_BIT) { + return (c & NGTCP2_LONG_RESERVED_BIT_MASK) == 0 ? 0 : NGTCP2_ERR_PROTO; + } + return (c & NGTCP2_SHORT_RESERVED_BIT_MASK) == 0 ? 0 : NGTCP2_ERR_PROTO; +} |