/src/samba/third_party/ngtcp2/lib/ngtcp2_pmtud.c

Source
/*
 * ngtcp2
 *
 * Copyright (c) 2022 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_pmtud.h"

#include <assert.h>

#include "ngtcp2_mem.h"
#include "ngtcp2_macro.h"

/* NGTCP2_PMTUD_PROBE_NUM_MAX is the maximum number of packets sent
   for each probe. */
#define NGTCP2_PMTUD_PROBE_NUM_MAX 3

static uint16_t pmtud_default_probes[] = {
  1454 - 48, /* The well known MTU used by a domestic optic fiber
                service in Japan. */
  1390 - 48, /* Typical Tunneled MTU */
  1280 - 48, /* IPv6 minimum MTU */
  1492 - 48, /* PPPoE */
};

int ngtcp2_pmtud_new(ngtcp2_pmtud **ppmtud, size_t max_udp_payload_size,
                     size_t hard_max_udp_payload_size, int64_t tx_pkt_num,
                     const uint16_t *probes, size_t probeslen,
                     const ngtcp2_mem *mem) {
  ngtcp2_pmtud *pmtud = ngtcp2_mem_malloc(mem, sizeof(ngtcp2_pmtud));

  if (pmtud == NULL) {
    return NGTCP2_ERR_NOMEM;
  }

  pmtud->mem = mem;
  pmtud->mtu_idx = 0;
  pmtud->num_pkts_sent = 0;
  pmtud->expiry = UINT64_MAX;
  pmtud->tx_pkt_num = tx_pkt_num;
  pmtud->max_udp_payload_size = max_udp_payload_size;
  pmtud->hard_max_udp_payload_size = hard_max_udp_payload_size;
  pmtud->min_fail_udp_payload_size = SIZE_MAX;

  if (probeslen) {
    pmtud->probes = probes;
    pmtud->probeslen = probeslen;
  } else {
    pmtud->probes = pmtud_default_probes;
    pmtud->probeslen = ngtcp2_arraylen(pmtud_default_probes);
  }

  for (; pmtud->mtu_idx < pmtud->probeslen; ++pmtud->mtu_idx) {
    if (pmtud->probes[pmtud->mtu_idx] > pmtud->hard_max_udp_payload_size) {
      continue;
    }
    if (pmtud->probes[pmtud->mtu_idx] > pmtud->max_udp_payload_size) {
      break;
    }
  }

  *ppmtud = pmtud;

  return 0;
}

void ngtcp2_pmtud_del(ngtcp2_pmtud *pmtud) {
  if (!pmtud) {
    return;
  }

  ngtcp2_mem_free(pmtud->mem, pmtud);
}

size_t ngtcp2_pmtud_probelen(ngtcp2_pmtud *pmtud) {
  assert(pmtud->mtu_idx < pmtud->probeslen);

  return pmtud->probes[pmtud->mtu_idx];
}

void ngtcp2_pmtud_probe_sent(ngtcp2_pmtud *pmtud, ngtcp2_duration pto,
                             ngtcp2_tstamp ts) {
  ngtcp2_tstamp timeout;

  if (++pmtud->num_pkts_sent < NGTCP2_PMTUD_PROBE_NUM_MAX) {
    timeout = pto;
  } else {
    timeout = 3 * pto;
  }

  pmtud->expiry = ts + timeout;
}

int ngtcp2_pmtud_require_probe(ngtcp2_pmtud *pmtud) {
  return pmtud->expiry == UINT64_MAX;
}

static void pmtud_next_probe(ngtcp2_pmtud *pmtud) {
  assert(pmtud->mtu_idx < pmtud->probeslen);

  ++pmtud->mtu_idx;
  pmtud->num_pkts_sent = 0;
  pmtud->expiry = UINT64_MAX;

  for (; pmtud->mtu_idx < pmtud->probeslen; ++pmtud->mtu_idx) {
    if (pmtud->probes[pmtud->mtu_idx] <= pmtud->max_udp_payload_size ||
        pmtud->probes[pmtud->mtu_idx] > pmtud->hard_max_udp_payload_size) {
      continue;
    }

    if (pmtud->probes[pmtud->mtu_idx] < pmtud->min_fail_udp_payload_size) {
      break;
    }
  }
}

void ngtcp2_pmtud_probe_success(ngtcp2_pmtud *pmtud, size_t payloadlen) {
  pmtud->max_udp_payload_size =
    ngtcp2_max_size(pmtud->max_udp_payload_size, payloadlen);

  assert(pmtud->mtu_idx < pmtud->probeslen);

  if (pmtud->probes[pmtud->mtu_idx] > pmtud->max_udp_payload_size) {
    return;
  }

  pmtud_next_probe(pmtud);
}

void ngtcp2_pmtud_handle_expiry(ngtcp2_pmtud *pmtud, ngtcp2_tstamp ts) {
  if (ts < pmtud->expiry) {
    return;
  }

  pmtud->expiry = UINT64_MAX;

  if (pmtud->num_pkts_sent < NGTCP2_PMTUD_PROBE_NUM_MAX) {
    return;
  }

  pmtud->min_fail_udp_payload_size = ngtcp2_min_size(
    pmtud->min_fail_udp_payload_size, pmtud->probes[pmtud->mtu_idx]);

  pmtud_next_probe(pmtud);
}

int ngtcp2_pmtud_finished(ngtcp2_pmtud *pmtud) {
  return pmtud->mtu_idx >= pmtud->probeslen;
}

Line	Count	Source
1		/*
2		* ngtcp2
3		*
4		* Copyright (c) 2022 ngtcp2 contributors
5		*
6		* Permission is hereby granted, free of charge, to any person obtaining
7		* a copy of this software and associated documentation files (the
8		* "Software"), to deal in the Software without restriction, including
9		* without limitation the rights to use, copy, modify, merge, publish,
10		* distribute, sublicense, and/or sell copies of the Software, and to
11		* permit persons to whom the Software is furnished to do so, subject to
12		* the following conditions:
13		*
14		* The above copyright notice and this permission notice shall be
15		* included in all copies or substantial portions of the Software.
16		*
17		* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18		* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19		* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
20		* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
21		* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
22		* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
23		* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24		*/
25		#include "ngtcp2_pmtud.h"
26
27		#include <assert.h>
28
29		#include "ngtcp2_mem.h"
30		#include "ngtcp2_macro.h"
31
32		/* NGTCP2_PMTUD_PROBE_NUM_MAX is the maximum number of packets sent
33		for each probe. */
34	0	#define NGTCP2_PMTUD_PROBE_NUM_MAX 3
35
36		static uint16_t pmtud_default_probes[] = {
37		1454 - 48, /* The well known MTU used by a domestic optic fiber
38		service in Japan. */
39		1390 - 48, /* Typical Tunneled MTU */
40		1280 - 48, /* IPv6 minimum MTU */
41		1492 - 48, /* PPPoE */
42		};
43
44		int ngtcp2_pmtud_new(ngtcp2_pmtud **ppmtud, size_t max_udp_payload_size,
45		size_t hard_max_udp_payload_size, int64_t tx_pkt_num,
46		const uint16_t *probes, size_t probeslen,
47	0	const ngtcp2_mem *mem) {
48	0	ngtcp2_pmtud *pmtud = ngtcp2_mem_malloc(mem, sizeof(ngtcp2_pmtud));
49
50	0	if (pmtud == NULL) {
51	0	return NGTCP2_ERR_NOMEM;
52	0	}
53
54	0	pmtud->mem = mem;
55	0	pmtud->mtu_idx = 0;
56	0	pmtud->num_pkts_sent = 0;
57	0	pmtud->expiry = UINT64_MAX;
58	0	pmtud->tx_pkt_num = tx_pkt_num;
59	0	pmtud->max_udp_payload_size = max_udp_payload_size;
60	0	pmtud->hard_max_udp_payload_size = hard_max_udp_payload_size;
61	0	pmtud->min_fail_udp_payload_size = SIZE_MAX;
62
63	0	if (probeslen) {
64	0	pmtud->probes = probes;
65	0	pmtud->probeslen = probeslen;
66	0	} else {
67	0	pmtud->probes = pmtud_default_probes;
68	0	pmtud->probeslen = ngtcp2_arraylen(pmtud_default_probes);
69	0	}
70
71	0	for (; pmtud->mtu_idx < pmtud->probeslen; ++pmtud->mtu_idx) {
72	0	if (pmtud->probes[pmtud->mtu_idx] > pmtud->hard_max_udp_payload_size) {
73	0	continue;
74	0	}
75	0	if (pmtud->probes[pmtud->mtu_idx] > pmtud->max_udp_payload_size) {
76	0	break;
77	0	}
78	0	}
79
80	0	*ppmtud = pmtud;
81
82	0	return 0;
83	0	}
84
85	0	void ngtcp2_pmtud_del(ngtcp2_pmtud *pmtud) {
86	0	if (!pmtud) {
87	0	return;
88	0	}
89
90	0	ngtcp2_mem_free(pmtud->mem, pmtud);
91	0	}
92
93	0	size_t ngtcp2_pmtud_probelen(ngtcp2_pmtud *pmtud) {
94	0	assert(pmtud->mtu_idx < pmtud->probeslen);
95
96	0	return pmtud->probes[pmtud->mtu_idx];
97	0	}
98
99		void ngtcp2_pmtud_probe_sent(ngtcp2_pmtud *pmtud, ngtcp2_duration pto,
100	0	ngtcp2_tstamp ts) {
101	0	ngtcp2_tstamp timeout;
102
103	0	if (++pmtud->num_pkts_sent < NGTCP2_PMTUD_PROBE_NUM_MAX) {
104	0	timeout = pto;
105	0	} else {
106	0	timeout = 3 * pto;
107	0	}
108
109	0	pmtud->expiry = ts + timeout;
110	0	}
111
112	0	int ngtcp2_pmtud_require_probe(ngtcp2_pmtud *pmtud) {
113	0	return pmtud->expiry == UINT64_MAX;
114	0	}
115
116	0	static void pmtud_next_probe(ngtcp2_pmtud *pmtud) {
117	0	assert(pmtud->mtu_idx < pmtud->probeslen);
118
119	0	++pmtud->mtu_idx;
120	0	pmtud->num_pkts_sent = 0;
121	0	pmtud->expiry = UINT64_MAX;
122
123	0	for (; pmtud->mtu_idx < pmtud->probeslen; ++pmtud->mtu_idx) {
124	0	if (pmtud->probes[pmtud->mtu_idx] <= pmtud->max_udp_payload_size \|\|
125	0	pmtud->probes[pmtud->mtu_idx] > pmtud->hard_max_udp_payload_size) {
126	0	continue;
127	0	}
128
129	0	if (pmtud->probes[pmtud->mtu_idx] < pmtud->min_fail_udp_payload_size) {
130	0	break;
131	0	}
132	0	}
133	0	}
134
135	0	void ngtcp2_pmtud_probe_success(ngtcp2_pmtud *pmtud, size_t payloadlen) {
136	0	pmtud->max_udp_payload_size =
137	0	ngtcp2_max_size(pmtud->max_udp_payload_size, payloadlen);
138
139	0	assert(pmtud->mtu_idx < pmtud->probeslen);
140
141	0	if (pmtud->probes[pmtud->mtu_idx] > pmtud->max_udp_payload_size) {
142	0	return;
143	0	}
144
145	0	pmtud_next_probe(pmtud);
146	0	}
147
148	0	void ngtcp2_pmtud_handle_expiry(ngtcp2_pmtud *pmtud, ngtcp2_tstamp ts) {
149	0	if (ts < pmtud->expiry) {
150	0	return;
151	0	}
152
153	0	pmtud->expiry = UINT64_MAX;
154
155	0	if (pmtud->num_pkts_sent < NGTCP2_PMTUD_PROBE_NUM_MAX) {
156	0	return;
157	0	}
158
159	0	pmtud->min_fail_udp_payload_size = ngtcp2_min_size(
160	0	pmtud->min_fail_udp_payload_size, pmtud->probes[pmtud->mtu_idx]);
161
162	0	pmtud_next_probe(pmtud);
163	0	}
164
165	0	int ngtcp2_pmtud_finished(ngtcp2_pmtud *pmtud) {
166	0	return pmtud->mtu_idx >= pmtud->probeslen;
167	0	}

Coverage Report

Created: 2026-09-03 07:24