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Diffstat (limited to '')
| -rw-r--r-- | lib/ngtcp2_pv.h | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/lib/ngtcp2_pv.h b/lib/ngtcp2_pv.h new file mode 100644 index 0000000..293cbca --- /dev/null +++ b/lib/ngtcp2_pv.h @@ -0,0 +1,198 @@ +/* + * ngtcp2 + * + * Copyright (c) 2019 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. + */ +#ifndef NGTCP2_PV_H +#define NGTCP2_PV_H + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif /* HAVE_CONFIG_H */ + +#include <ngtcp2/ngtcp2.h> + +#include "ngtcp2_cid.h" +#include "ngtcp2_ringbuf.h" + +/* NGTCP2_PV_MAX_ENTRIES is the maximum number of entries that + ngtcp2_pv can contain. It must be power of 2. */ +#define NGTCP2_PV_MAX_ENTRIES 8 +/* NGTCP2_PV_NUM_PROBE_PKT is the number of probe packets containing + PATH_CHALLENGE sent at a time. */ +#define NGTCP2_PV_NUM_PROBE_PKT 2 + +typedef struct ngtcp2_log ngtcp2_log; + +typedef struct ngtcp2_frame_chain ngtcp2_frame_chain; + +/* NGTCP2_PV_ENTRY_FLAG_NONE indicates that no flag is set. */ +#define NGTCP2_PV_ENTRY_FLAG_NONE 0x00u +/* NGTCP2_PV_ENTRY_FLAG_UNDERSIZED indicates that UDP datagram which + contains PATH_CHALLENGE is undersized (< 1200 bytes) */ +#define NGTCP2_PV_ENTRY_FLAG_UNDERSIZED 0x01u + +typedef struct ngtcp2_pv_entry { + /* expiry is the timestamp when this PATH_CHALLENGE expires. */ + ngtcp2_tstamp expiry; + /* flags is zero or more of NGTCP2_PV_ENTRY_FLAG_*. */ + uint8_t flags; + /* data is a byte string included in PATH_CHALLENGE. */ + uint8_t data[8]; +} ngtcp2_pv_entry; + +void ngtcp2_pv_entry_init(ngtcp2_pv_entry *pvent, const uint8_t *data, + ngtcp2_tstamp expiry, uint8_t flags); + +/* NGTCP2_PV_FLAG_NONE indicates no flag is set. */ +#define NGTCP2_PV_FLAG_NONE 0x00u +/* NGTCP2_PV_FLAG_DONT_CARE indicates that the outcome of path + validation should be ignored entirely. */ +#define NGTCP2_PV_FLAG_DONT_CARE 0x01u +/* NGTCP2_PV_FLAG_CANCEL_TIMER indicates that the expiry timer is + cancelled. */ +#define NGTCP2_PV_FLAG_CANCEL_TIMER 0x02u +/* NGTCP2_PV_FLAG_FALLBACK_ON_FAILURE indicates that fallback DCID is + available in ngtcp2_pv. If path validation fails, fallback to the + fallback DCID. If path validation succeeds, fallback DCID is + retired if it does not equal to the current DCID. */ +#define NGTCP2_PV_FLAG_FALLBACK_ON_FAILURE 0x04u +/* NGTCP2_PV_FLAG_MTU_PROBE indicates that a validation must probe + least MTU that QUIC requires, which is 1200 bytes. If it fails, a + path is not viable. */ +#define NGTCP2_PV_FLAG_MTU_PROBE 0x08u +/* NGTCP2_PV_FLAG_PREFERRED_ADDR indicates that client is migrating to + server's preferred address. This flag is only used by client. */ +#define NGTCP2_PV_FLAG_PREFERRED_ADDR 0x10u + +typedef struct ngtcp2_pv ngtcp2_pv; + +ngtcp2_static_ringbuf_def(pv_ents, NGTCP2_PV_MAX_ENTRIES, + sizeof(ngtcp2_pv_entry)); +/* + * ngtcp2_pv is the context of a single path validation. + */ +struct ngtcp2_pv { + const ngtcp2_mem *mem; + ngtcp2_log *log; + /* dcid is DCID and path this path validation uses. */ + ngtcp2_dcid dcid; + /* fallback_dcid is the usually validated DCID and used as a + fallback if this path validation fails. */ + ngtcp2_dcid fallback_dcid; + /* ents is the ring buffer of ngtcp2_pv_entry */ + ngtcp2_static_ringbuf_pv_ents ents; + /* timeout is the duration within which this path validation should + succeed. */ + ngtcp2_duration timeout; + /* fallback_pto is PTO of fallback connection. */ + ngtcp2_duration fallback_pto; + /* started_ts is the timestamp this path validation starts. */ + ngtcp2_tstamp started_ts; + /* round is the number of times that probe_pkt_left is reset. */ + size_t round; + /* probe_pkt_left is the number of probe packets containing + PATH_CHALLENGE which can be send without waiting for an + expiration of a previous flight. */ + size_t probe_pkt_left; + /* flags is bitwise-OR of zero or more of NGTCP2_PV_FLAG_*. */ + uint8_t flags; +}; + +/* + * ngtcp2_pv_new creates new ngtcp2_pv object and assigns its pointer + * to |*ppv|. This function makes a copy of |dcid|. |timeout| is a + * duration within which this path validation must succeed. + * + * This function returns 0 if it succeeds, or one of the following + * negative error codes: + * + * NGTCP2_ERR_NOMEM + * Out of memory + */ +int ngtcp2_pv_new(ngtcp2_pv **ppv, const ngtcp2_dcid *dcid, + ngtcp2_duration timeout, uint8_t flags, ngtcp2_log *log, + const ngtcp2_mem *mem); + +/* + * ngtcp2_pv_del deallocates |pv|. This function frees memory |pv| + * points too. + */ +void ngtcp2_pv_del(ngtcp2_pv *pv); + +/* + * ngtcp2_pv_add_entry adds new entry with |data|. |expiry| is the + * expiry time of the entry. + */ +void ngtcp2_pv_add_entry(ngtcp2_pv *pv, const uint8_t *data, + ngtcp2_tstamp expiry, uint8_t flags, ngtcp2_tstamp ts); + +/* + * ngtcp2_pv_full returns nonzero if |pv| is full of ngtcp2_pv_entry. + */ +int ngtcp2_pv_full(ngtcp2_pv *pv); + +/* + * ngtcp2_pv_validate validates that the received |data| matches the + * one of the existing entry. The flag of ngtcp2_pv_entry that + * matches |data| is assigned to |*pflags| if this function succeeds. + * + * This function returns 0 if it succeeds, or one of the following + * negative error codes: + * + * NGTCP2_ERR_PATH_VALIDATION_FAILED + * path validation has failed and must be abandoned + * NGTCP2_ERR_INVALID_STATE + * |pv| includes no entry + * NGTCP2_ERR_INVALID_ARGUMENT + * |pv| does not have an entry which has |data| and |path| + */ +int ngtcp2_pv_validate(ngtcp2_pv *pv, uint8_t *pflags, const uint8_t *data); + +/* + * ngtcp2_pv_handle_entry_expiry checks expiry of existing entries. + */ +void ngtcp2_pv_handle_entry_expiry(ngtcp2_pv *pv, ngtcp2_tstamp ts); + +/* + * ngtcp2_pv_should_send_probe returns nonzero if new entry can be + * added by ngtcp2_pv_add_entry. + */ +int ngtcp2_pv_should_send_probe(ngtcp2_pv *pv); + +/* + * ngtcp2_pv_validation_timed_out returns nonzero if the path + * validation fails because of timeout. + */ +int ngtcp2_pv_validation_timed_out(ngtcp2_pv *pv, ngtcp2_tstamp ts); + +/* + * ngtcp2_pv_next_expiry returns the earliest expiry. + */ +ngtcp2_tstamp ngtcp2_pv_next_expiry(ngtcp2_pv *pv); + +/* + * ngtcp2_pv_cancel_expired_timer cancels the expired timer. + */ +void ngtcp2_pv_cancel_expired_timer(ngtcp2_pv *pv, ngtcp2_tstamp ts); + +#endif /* NGTCP2_PV_H */ |