This is xnu-11215.1.10. See this file in:
/*
* Copyright (c) 2015-2024 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/* TCP-cache to store and retrieve TCP-related information */
#include <net/flowhash.h>
#include <net/route.h>
#include <net/necp.h>
#include <netinet/in_pcb.h>
#include <netinet/mptcp.h>
#include <netinet/mptcp_var.h>
#include <netinet/tcp_cache.h>
#include <netinet/tcp_seq.h>
#include <netinet/tcp_var.h>
#include <kern/locks.h>
#include <sys/queue.h>
#include <dev/random/randomdev.h>
#include <net/sockaddr_utils.h>
typedef union {
struct in_addr addr;
struct in6_addr addr6;
} in_4_6_addr;
struct tcp_heuristic_key {
union {
uint8_t thk_net_signature[IFNET_SIGNATURELEN];
in_4_6_addr thk_ip;
};
sa_family_t thk_family;
};
struct tcp_heuristic {
SLIST_ENTRY(tcp_heuristic) list;
uint32_t th_last_access;
struct tcp_heuristic_key th_key;
#define th_val_start th_tfo_data_loss
uint8_t th_tfo_data_loss; /* The number of times a SYN+data has been lost */
uint8_t th_tfo_req_loss; /* The number of times a SYN+cookie-req has been lost */
uint8_t th_tfo_data_rst; /* The number of times a SYN+data has received a RST */
uint8_t th_tfo_req_rst; /* The number of times a SYN+cookie-req has received a RST */
uint8_t th_mptcp_loss; /* The number of times a SYN+MP_CAPABLE has been lost */
uint8_t th_mptcp_success; /* The number of times MPTCP-negotiation has been successful */
uint8_t th_ecn_loss; /* The number of times a SYN+ecn has been lost */
uint8_t th_ecn_aggressive; /* The number of times we did an aggressive fallback */
uint8_t th_ecn_droprst; /* The number of times ECN connections received a RST after first data pkt */
uint8_t th_ecn_droprxmt; /* The number of times ECN connection is dropped after multiple retransmits */
uint8_t th_ecn_synrst; /* number of times RST was received in response to an ECN enabled SYN */
uint32_t th_tfo_enabled_time; /* The moment when we reenabled TFO after backing off */
uint32_t th_tfo_backoff_until; /* Time until when we should not try out TFO */
uint32_t th_tfo_backoff; /* Current backoff timer */
uint32_t th_mptcp_backoff; /* Time until when we should not try out MPTCP */
uint32_t th_ecn_backoff; /* Time until when we should not try out ECN */
uint8_t th_tfo_in_backoff:1, /* Are we avoiding TFO due to the backoff timer? */
th_mptcp_in_backoff:1, /* Are we avoiding MPTCP due to the backoff timer? */
th_mptcp_heuristic_disabled:1; /* Are heuristics disabled? */
// N.B.: we may sometimes erase ALL values from th_val_start to the end of the structure.
};
struct tcp_heuristics_head {
SLIST_HEAD(tcp_heur_bucket, tcp_heuristic) tcp_heuristics;
/* Per-hashbucket lock to avoid lock-contention */
lck_mtx_t thh_mtx;
};
struct tcp_cache_key {
sa_family_t tck_family;
struct tcp_heuristic_key tck_src;
in_4_6_addr tck_dst;
};
#define MPTCP_VERSION_SUPPORTED 1
#define MPTCP_VERSION_UNSUPPORTED -1
#define MPTCP_VERSION_SUPPORTED_UNKNOWN 0
struct tcp_cache {
SLIST_ENTRY(tcp_cache) list;
uint32_t tc_last_access;
struct tcp_cache_key tc_key;
uint8_t tc_tfo_cookie[TFO_COOKIE_LEN_MAX];
uint8_t tc_tfo_cookie_len;
uint8_t tc_mptcp_version_confirmed:1;
uint8_t tc_mptcp_version; /* version to use right now */
uint32_t tc_mptcp_next_version_try; /* Time, until we try preferred version again */
};
struct tcp_cache_head {
SLIST_HEAD(tcp_cache_bucket, tcp_cache) tcp_caches;
/* Per-hashbucket lock to avoid lock-contention */
lck_mtx_t tch_mtx;
};
struct tcp_cache_key_src {
struct ifnet *ifp;
in_4_6_addr laddr;
in_4_6_addr faddr;
int af;
};
static uint32_t tcp_cache_hash_seed;
static size_t tcp_cache_size;
static size_t tcp_heuristics_size;
/*
* The maximum depth of the hash-bucket. This way we limit the tcp_cache to
* TCP_CACHE_BUCKET_SIZE * tcp_cache_size and have "natural" garbage collection
*/
#define TCP_CACHE_BUCKET_SIZE 5
static struct tcp_cache_head *__counted_by(tcp_cache_size) tcp_cache;
static LCK_ATTR_DECLARE(tcp_cache_mtx_attr, 0, 0);
static LCK_GRP_DECLARE(tcp_cache_mtx_grp, "tcpcache");
static struct tcp_heuristics_head *__counted_by(tcp_heuristics_size) tcp_heuristics;
static LCK_ATTR_DECLARE(tcp_heuristic_mtx_attr, 0, 0);
static LCK_GRP_DECLARE(tcp_heuristic_mtx_grp, "tcpheuristic");
static uint32_t tcp_backoff_maximum = 65536;
SYSCTL_UINT(_net_inet_tcp, OID_AUTO, backoff_maximum, CTLFLAG_RW | CTLFLAG_LOCKED,
&tcp_backoff_maximum, 0, "Maximum time for which we won't try TFO");
static uint32_t tcp_ecn_timeout = 60;
SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ecn_timeout, CTLFLAG_RW | CTLFLAG_LOCKED,
&tcp_ecn_timeout, 60, "Initial minutes to wait before re-trying ECN");
static int disable_tcp_heuristics = 0;
SYSCTL_INT(_net_inet_tcp, OID_AUTO, disable_tcp_heuristics, CTLFLAG_RW | CTLFLAG_LOCKED,
&disable_tcp_heuristics, 0, "Set to 1, to disable all TCP heuristics (TFO, ECN, MPTCP)");
static uint32_t mptcp_version_timeout = 24 * 60;
SYSCTL_UINT(_net_inet_tcp, OID_AUTO, mptcp_version_timeout, CTLFLAG_RW | CTLFLAG_LOCKED,
&mptcp_version_timeout, 24 * 60, "Initial minutes to wait before re-trying MPTCP's preferred version");
static uint32_t
tcp_min_to_hz(uint32_t minutes)
{
if (minutes > 65536) {
return (uint32_t)65536 * 60 * TCP_RETRANSHZ;
}
return minutes * 60 * TCP_RETRANSHZ;
}
/*
* This number is coupled with tcp_ecn_timeout, because we want to prevent
* integer overflow. Need to find an unexpensive way to prevent integer overflow
* while still allowing a dynamic sysctl.
*/
#define TCP_CACHE_OVERFLOW_PROTECT 9
/* Number of SYN-losses we accept */
#define TFO_MAX_COOKIE_LOSS 2
#define ECN_MAX_SYN_LOSS 2
#define MPTCP_MAX_SYN_LOSS 2
#define MPTCP_SUCCESS_TRIGGER 10
#define MPTCP_VERSION_MAX_FAIL 2
#define ECN_MAX_DROPRST 1
#define ECN_MAX_DROPRXMT 4
#define ECN_MAX_SYNRST 4
/* Flags for setting/unsetting loss-heuristics, limited to 4 bytes */
#define TCPCACHE_F_TFO_REQ 0x01
#define TCPCACHE_F_TFO_DATA 0x02
#define TCPCACHE_F_ECN 0x04
#define TCPCACHE_F_MPTCP 0x08
#define TCPCACHE_F_ECN_DROPRST 0x10
#define TCPCACHE_F_ECN_DROPRXMT 0x20
#define TCPCACHE_F_TFO_REQ_RST 0x40
#define TCPCACHE_F_TFO_DATA_RST 0x80
#define TCPCACHE_F_ECN_SYNRST 0x100
/* Always retry ECN after backing off to this level for some heuristics */
#define ECN_RETRY_LIMIT 9
#define TCP_CACHE_INC_IFNET_STAT(_ifp_, _af_, _stat_) { \
if ((_ifp_) != NULL) { \
if ((_af_) == AF_INET6) { \
(_ifp_)->if_ipv6_stat->_stat_++;\
} else { \
(_ifp_)->if_ipv4_stat->_stat_++;\
}\
}\
}
/*
* Round up to next higher power-of 2. See "Bit Twiddling Hacks".
*
* Might be worth moving this to a library so that others
* (e.g., scale_to_powerof2()) can use this as well instead of a while-loop.
*/
static uint32_t
tcp_cache_roundup2(uint32_t a)
{
a--;
a |= a >> 1;
a |= a >> 2;
a |= a >> 4;
a |= a >> 8;
a |= a >> 16;
a++;
return a;
}
static void
tcp_cache_hash_src(struct tcp_cache_key_src *tcks, struct tcp_heuristic_key *key)
{
struct ifnet *ifp = tcks->ifp;
uint8_t len = sizeof(key->thk_net_signature);
uint16_t flags;
if (tcks->af == AF_INET6) {
int ret;
key->thk_family = AF_INET6;
ret = ifnet_get_netsignature(ifp, AF_INET6, &len, &flags,
key->thk_net_signature);
/*
* ifnet_get_netsignature only returns EINVAL if ifn is NULL
* (we made sure that in the other cases it does not). So,
* in this case we should take the connection's address.
*/
if (ret == ENOENT || ret == EINVAL) {
memcpy(&key->thk_ip.addr6, &tcks->laddr.addr6, sizeof(struct in6_addr));
}
} else {
int ret;
key->thk_family = AF_INET;
ret = ifnet_get_netsignature(ifp, AF_INET, &len, &flags,
key->thk_net_signature);
/*
* ifnet_get_netsignature only returns EINVAL if ifn is NULL
* (we made sure that in the other cases it does not). So,
* in this case we should take the connection's address.
*/
if (ret == ENOENT || ret == EINVAL) {
memcpy(&key->thk_ip.addr, &tcks->laddr.addr, sizeof(struct in_addr));
}
}
}
static uint16_t
tcp_cache_hash(struct tcp_cache_key_src *tcks, struct tcp_cache_key *key)
{
uint32_t hash;
bzero(key, sizeof(struct tcp_cache_key));
tcp_cache_hash_src(tcks, &key->tck_src);
if (tcks->af == AF_INET6) {
key->tck_family = AF_INET6;
memcpy(&key->tck_dst.addr6, &tcks->faddr.addr6,
sizeof(struct in6_addr));
} else {
key->tck_family = AF_INET;
memcpy(&key->tck_dst.addr, &tcks->faddr.addr,
sizeof(struct in_addr));
}
hash = net_flowhash(key, sizeof(struct tcp_cache_key),
tcp_cache_hash_seed);
return (uint16_t)(hash & (tcp_cache_size - 1));
}
static void
tcp_cache_unlock(struct tcp_cache_head *head)
{
lck_mtx_unlock(&head->tch_mtx);
}
/*
* Make sure that everything that happens after tcp_getcache_with_lock()
* is short enough to justify that you hold the per-bucket lock!!!
*
* Otherwise, better build another lookup-function that does not hold the
* lock and you copy out the bits and bytes.
*
* That's why we provide the head as a "return"-pointer so that the caller
* can give it back to use for tcp_cache_unlock().
*/
static struct tcp_cache *
tcp_getcache_with_lock(struct tcp_cache_key_src *tcks,
int create, struct tcp_cache_head **headarg)
{
struct tcp_cache *__single tpcache = NULL;
struct tcp_cache_head *__single head;
struct tcp_cache_key key;
uint16_t hash;
int i = 0;
hash = tcp_cache_hash(tcks, &key);
head = &tcp_cache[hash];
lck_mtx_lock(&head->tch_mtx);
/*** First step: Look for the tcp_cache in our bucket ***/
SLIST_FOREACH(tpcache, &head->tcp_caches, list) {
if (memcmp(&tpcache->tc_key, &key, sizeof(key)) == 0) {
break;
}
i++;
}
/*** Second step: If it's not there, create/recycle it ***/
if ((tpcache == NULL) && create) {
if (i >= TCP_CACHE_BUCKET_SIZE) {
struct tcp_cache *oldest_cache = NULL;
uint32_t max_age = 0;
/* Look for the oldest tcp_cache in the bucket */
SLIST_FOREACH(tpcache, &head->tcp_caches, list) {
uint32_t age = tcp_now - tpcache->tc_last_access;
if (age >= max_age) {
max_age = age;
oldest_cache = tpcache;
}
}
VERIFY(oldest_cache != NULL);
tpcache = oldest_cache;
/* We recycle, thus let's indicate that there is no cookie */
tpcache->tc_tfo_cookie_len = 0;
} else {
/* Create a new cache and add it to the list */
tpcache = kalloc_type(struct tcp_cache, Z_NOPAGEWAIT | Z_ZERO);
if (tpcache == NULL) {
os_log_error(OS_LOG_DEFAULT, "%s could not allocate cache", __func__);
goto out_null;
}
tpcache->tc_mptcp_version = (uint8_t)mptcp_preferred_version;
tpcache->tc_mptcp_next_version_try = tcp_now;
SLIST_INSERT_HEAD(&head->tcp_caches, tpcache, list);
}
memcpy(&tpcache->tc_key, &key, sizeof(key));
}
if (tpcache == NULL) {
goto out_null;
}
/* Update timestamp for garbage collection purposes */
tpcache->tc_last_access = tcp_now;
*headarg = head;
return tpcache;
out_null:
tcp_cache_unlock(head);
return NULL;
}
static void
tcp_cache_key_src_create(struct tcpcb *tp, struct tcp_cache_key_src *tcks)
{
struct inpcb *inp = tp->t_inpcb;
memset(tcks, 0, sizeof(*tcks));
tcks->ifp = inp->inp_last_outifp;
if (inp->inp_vflag & INP_IPV6) {
memcpy(&tcks->laddr.addr6, &inp->in6p_laddr, sizeof(struct in6_addr));
memcpy(&tcks->faddr.addr6, &inp->in6p_faddr, sizeof(struct in6_addr));
tcks->af = AF_INET6;
} else {
memcpy(&tcks->laddr.addr, &inp->inp_laddr, sizeof(struct in_addr));
memcpy(&tcks->faddr.addr, &inp->inp_faddr, sizeof(struct in_addr));
tcks->af = AF_INET;
}
return;
}
static void
mptcp_version_cache_key_src_init(struct sockaddr *dst, struct tcp_cache_key_src *tcks)
{
memset(tcks, 0, sizeof(*tcks));
if (dst->sa_family == AF_INET) {
memcpy(&tcks->faddr.addr, &SIN(dst)->sin_addr, sizeof(struct in_addr));
tcks->af = AF_INET;
} else {
memcpy(&tcks->faddr.addr6, &SIN6(dst)->sin6_addr, sizeof(struct in6_addr));
tcks->af = AF_INET6;
}
return;
}
static void
tcp_cache_set_cookie_common(struct tcp_cache_key_src *tcks, u_char *__counted_by(len) cookie, uint8_t len)
{
struct tcp_cache_head *__single head;
struct tcp_cache *__single tpcache;
/* Call lookup/create function */
tpcache = tcp_getcache_with_lock(tcks, 1, &head);
if (tpcache == NULL) {
return;
}
tpcache->tc_tfo_cookie_len = len > TFO_COOKIE_LEN_MAX ?
TFO_COOKIE_LEN_MAX : len;
memcpy(tpcache->tc_tfo_cookie, cookie, tpcache->tc_tfo_cookie_len);
tcp_cache_unlock(head);
}
void
tcp_cache_set_cookie(struct tcpcb *tp, u_char *__counted_by(len) cookie, uint8_t len)
{
struct tcp_cache_key_src tcks;
tcp_cache_key_src_create(tp, &tcks);
tcp_cache_set_cookie_common(&tcks, cookie, len);
}
static int
tcp_cache_get_cookie_common(struct tcp_cache_key_src *tcks,
u_char *__counted_by(maxlen) cookie, uint8_t maxlen, uint8_t *len)
{
#pragma unused(maxlen)
struct tcp_cache_head *__single head;
struct tcp_cache *__single tpcache;
/* Call lookup/create function */
tpcache = tcp_getcache_with_lock(tcks, 1, &head);
if (tpcache == NULL) {
return 0;
}
if (tpcache->tc_tfo_cookie_len == 0) {
tcp_cache_unlock(head);
return 0;
}
/*
* Not enough space - this should never happen as it has been checked
* in tcp_tfo_check. So, fail here!
*/
VERIFY(tpcache->tc_tfo_cookie_len <= *len);
memcpy(cookie, tpcache->tc_tfo_cookie, tpcache->tc_tfo_cookie_len);
*len = tpcache->tc_tfo_cookie_len;
tcp_cache_unlock(head);
return 1;
}
/*
* Get the cookie related to 'tp', and copy it into 'cookie', provided that len
* is big enough (len designates the available memory.
* Upon return, 'len' is set to the cookie's length.
*
* Returns 0 if we should request a cookie.
* Returns 1 if the cookie has been found and written.
*/
int
tcp_cache_get_cookie(struct tcpcb *tp, u_char *__counted_by(maxlen) cookie,
uint8_t maxlen, uint8_t *len)
{
struct tcp_cache_key_src tcks;
tcp_cache_key_src_create(tp, &tcks);
return tcp_cache_get_cookie_common(&tcks, cookie, maxlen, len);
}
static unsigned int
tcp_cache_get_cookie_len_common(struct tcp_cache_key_src *tcks)
{
struct tcp_cache_head *__single head;
struct tcp_cache *__single tpcache;
unsigned int cookie_len;
/* Call lookup/create function */
tpcache = tcp_getcache_with_lock(tcks, 1, &head);
if (tpcache == NULL) {
return 0;
}
cookie_len = tpcache->tc_tfo_cookie_len;
tcp_cache_unlock(head);
return cookie_len;
}
unsigned int
tcp_cache_get_cookie_len(struct tcpcb *tp)
{
struct tcp_cache_key_src tcks;
tcp_cache_key_src_create(tp, &tcks);
return tcp_cache_get_cookie_len_common(&tcks);
}
/*
* @return:
* 0 MPTCP_VERSION_0
* 1 MPTCP_VERSION_1
*/
uint8_t
tcp_cache_get_mptcp_version(struct sockaddr *dst)
{
struct tcp_cache_key_src tcks;
mptcp_version_cache_key_src_init(dst, &tcks);
uint8_t version = (uint8_t) mptcp_preferred_version;
struct tcp_cache_head *__single head;
struct tcp_cache *__single tpcache;
/* Call lookup/create function */
tpcache = tcp_getcache_with_lock(&tcks, 1, &head);
if (tpcache == NULL) {
return version;
}
version = tpcache->tc_mptcp_version;
/* Let's see if we should try the preferred version again */
if (!tpcache->tc_mptcp_version_confirmed &&
version != mptcp_preferred_version &&
TSTMP_GEQ(tcp_now, tpcache->tc_mptcp_next_version_try)) {
version = (uint8_t) mptcp_preferred_version;
}
tcp_cache_unlock(head);
return version;
}
void
tcp_cache_update_mptcp_version(struct tcpcb *tp, boolean_t succeeded)
{
uint8_t version = tptomptp(tp)->mpt_version;
struct inpcb *inp = tp->t_inpcb;
struct tcp_cache_key_src tcks;
struct tcp_cache_head *__single head;
struct tcp_cache *__single tpcache;
if (inp->inp_vflag & INP_IPV6) {
struct sockaddr_in6 dst = {
.sin6_len = sizeof(struct sockaddr_in6),
.sin6_family = AF_INET6,
.sin6_addr = inp->in6p_faddr,
};
mptcp_version_cache_key_src_init(SA(&dst), &tcks);
} else {
struct sockaddr_in dst = {
.sin_len = sizeof(struct sockaddr_in),
.sin_family = AF_INET,
.sin_addr = inp->inp_faddr,
};
mptcp_version_cache_key_src_init(SA(&dst), &tcks);
}
/* Call lookup/create function */
tpcache = tcp_getcache_with_lock(&tcks, 1, &head);
if (tpcache == NULL) {
return;
}
/* We are still in probing phase */
if (tpcache->tc_mptcp_version_confirmed) {
goto exit;
}
if (succeeded) {
if (version == (uint8_t)mptcp_preferred_version) {
/* Preferred version succeeded - make it sticky */
tpcache->tc_mptcp_version_confirmed = true;
tpcache->tc_mptcp_version = version;
} else {
/* If we are past the next version try, set it
* so that we try preferred again in 24h
*/
if (TSTMP_GEQ(tcp_now, tpcache->tc_mptcp_next_version_try)) {
tpcache->tc_mptcp_next_version_try = tcp_now + tcp_min_to_hz(mptcp_version_timeout);
}
}
} else {
if (version == (uint8_t)mptcp_preferred_version) {
/* Preferred version failed - try the other version */
tpcache->tc_mptcp_version = version == MPTCP_VERSION_0 ? MPTCP_VERSION_1 : MPTCP_VERSION_0;
}
/* Preferred version failed - make sure we give the preferred another
* shot in 24h.
*/
if (TSTMP_GEQ(tcp_now, tpcache->tc_mptcp_next_version_try)) {
tpcache->tc_mptcp_next_version_try = tcp_now + tcp_min_to_hz(mptcp_version_timeout);
}
}
exit:
tcp_cache_unlock(head);
}
static uint16_t
tcp_heuristics_hash(struct tcp_cache_key_src *tcks, struct tcp_heuristic_key *key)
{
uint32_t hash;
bzero(key, sizeof(struct tcp_heuristic_key));
tcp_cache_hash_src(tcks, key);
hash = net_flowhash(key, sizeof(struct tcp_heuristic_key),
tcp_cache_hash_seed);
return (uint16_t)(hash & (tcp_cache_size - 1));
}
static void
tcp_heuristic_unlock(struct tcp_heuristics_head *head)
{
lck_mtx_unlock(&head->thh_mtx);
}
/*
* Make sure that everything that happens after tcp_getheuristic_with_lock()
* is short enough to justify that you hold the per-bucket lock!!!
*
* Otherwise, better build another lookup-function that does not hold the
* lock and you copy out the bits and bytes.
*
* That's why we provide the head as a "return"-pointer so that the caller
* can give it back to use for tcp_heur_unlock().
*
*
* ToDo - way too much code-duplication. We should create an interface to handle
* bucketized hashtables with recycling of the oldest element.
*/
static struct tcp_heuristic *
tcp_getheuristic_with_lock(struct tcp_cache_key_src *tcks,
int create, struct tcp_heuristics_head **headarg)
{
struct tcp_heuristic *__single tpheur = NULL;
struct tcp_heuristics_head *__single head;
struct tcp_heuristic_key key;
uint16_t hash;
int i = 0;
hash = tcp_heuristics_hash(tcks, &key);
head = &tcp_heuristics[hash];
lck_mtx_lock(&head->thh_mtx);
/*** First step: Look for the tcp_heur in our bucket ***/
SLIST_FOREACH(tpheur, &head->tcp_heuristics, list) {
if (memcmp(&tpheur->th_key, &key, sizeof(key)) == 0) {
break;
}
i++;
}
/*** Second step: If it's not there, create/recycle it ***/
if ((tpheur == NULL) && create) {
if (i >= TCP_CACHE_BUCKET_SIZE) {
struct tcp_heuristic *__single oldest_heur = NULL;
uint32_t max_age = 0;
/* Look for the oldest tcp_heur in the bucket */
SLIST_FOREACH(tpheur, &head->tcp_heuristics, list) {
uint32_t age = tcp_now - tpheur->th_last_access;
if (age >= max_age) {
max_age = age;
oldest_heur = tpheur;
}
}
VERIFY(oldest_heur != NULL);
tpheur = oldest_heur;
/* We recycle - set everything to 0 */
uint8_t *ptr = (uint8_t *)(struct tcp_heuristic *__indexable)tpheur;
const size_t preamble = offsetof(struct tcp_heuristic, th_val_start);
const size_t size = sizeof(struct tcp_heuristic) - preamble;
bzero(ptr + preamble, size);
} else {
/* Create a new heuristic and add it to the list */
tpheur = kalloc_type(struct tcp_heuristic, Z_NOPAGEWAIT | Z_ZERO);
if (tpheur == NULL) {
os_log_error(OS_LOG_DEFAULT, "%s could not allocate heuristic", __func__);
goto out_null;
}
SLIST_INSERT_HEAD(&head->tcp_heuristics, tpheur, list);
}
/*
* Set to tcp_now, to make sure it won't be > than tcp_now in the
* near future.
*/
tpheur->th_ecn_backoff = tcp_now;
tpheur->th_tfo_backoff_until = tcp_now;
tpheur->th_mptcp_backoff = tcp_now;
tpheur->th_tfo_backoff = tcp_min_to_hz(tcp_ecn_timeout);
memcpy(&tpheur->th_key, &key, sizeof(key));
}
if (tpheur == NULL) {
goto out_null;
}
/* Update timestamp for garbage collection purposes */
tpheur->th_last_access = tcp_now;
*headarg = head;
return tpheur;
out_null:
tcp_heuristic_unlock(head);
return NULL;
}
static void
tcp_heuristic_reset_counters(struct tcp_cache_key_src *tcks, uint8_t flags)
{
struct tcp_heuristics_head *__single head;
struct tcp_heuristic *__single tpheur;
/*
* Always create heuristics here because MPTCP needs to write success
* into it. Thus, we always end up creating them.
*/
tpheur = tcp_getheuristic_with_lock(tcks, 1, &head);
if (tpheur == NULL) {
return;
}
if (flags & TCPCACHE_F_TFO_DATA) {
if (tpheur->th_tfo_data_loss >= TFO_MAX_COOKIE_LOSS) {
os_log(OS_LOG_DEFAULT, "%s: Resetting TFO-data loss to 0 from %u on heur %lx\n",
__func__, tpheur->th_tfo_data_loss, (unsigned long)VM_KERNEL_ADDRPERM(tpheur));
}
tpheur->th_tfo_data_loss = 0;
}
if (flags & TCPCACHE_F_TFO_REQ) {
if (tpheur->th_tfo_req_loss >= TFO_MAX_COOKIE_LOSS) {
os_log(OS_LOG_DEFAULT, "%s: Resetting TFO-req loss to 0 from %u on heur %lx\n",
__func__, tpheur->th_tfo_req_loss, (unsigned long)VM_KERNEL_ADDRPERM(tpheur));
}
tpheur->th_tfo_req_loss = 0;
}
if (flags & TCPCACHE_F_TFO_DATA_RST) {
if (tpheur->th_tfo_data_rst >= TFO_MAX_COOKIE_LOSS) {
os_log(OS_LOG_DEFAULT, "%s: Resetting TFO-data RST to 0 from %u on heur %lx\n",
__func__, tpheur->th_tfo_data_rst, (unsigned long)VM_KERNEL_ADDRPERM(tpheur));
}
tpheur->th_tfo_data_rst = 0;
}
if (flags & TCPCACHE_F_TFO_REQ_RST) {
if (tpheur->th_tfo_req_rst >= TFO_MAX_COOKIE_LOSS) {
os_log(OS_LOG_DEFAULT, "%s: Resetting TFO-req RST to 0 from %u on heur %lx\n",
__func__, tpheur->th_tfo_req_rst, (unsigned long)VM_KERNEL_ADDRPERM(tpheur));
}
tpheur->th_tfo_req_rst = 0;
}
if (flags & TCPCACHE_F_ECN) {
if (tpheur->th_ecn_loss >= ECN_MAX_SYN_LOSS || tpheur->th_ecn_synrst >= ECN_MAX_SYNRST) {
os_log(OS_LOG_DEFAULT, "%s: Resetting ECN-loss to 0 from %u and synrst from %u on heur %lx\n",
__func__, tpheur->th_ecn_loss, tpheur->th_ecn_synrst, (unsigned long)VM_KERNEL_ADDRPERM(tpheur));
}
tpheur->th_ecn_loss = 0;
tpheur->th_ecn_synrst = 0;
}
if (flags & TCPCACHE_F_MPTCP) {
tpheur->th_mptcp_loss = 0;
if (tpheur->th_mptcp_success < MPTCP_SUCCESS_TRIGGER) {
tpheur->th_mptcp_success++;
if (tpheur->th_mptcp_success == MPTCP_SUCCESS_TRIGGER) {
os_log(mptcp_log_handle, "%s disabling heuristics for 12 hours", __func__);
tpheur->th_mptcp_heuristic_disabled = 1;
/* Disable heuristics for 12 hours */
tpheur->th_mptcp_backoff = tcp_now + tcp_min_to_hz(tcp_ecn_timeout * 12);
}
}
}
tcp_heuristic_unlock(head);
}
void
tcp_heuristic_tfo_success(struct tcpcb *tp)
{
struct tcp_cache_key_src tcks;
uint8_t flag = 0;
tcp_cache_key_src_create(tp, &tcks);
if (tp->t_tfo_stats & TFO_S_SYN_DATA_SENT) {
flag = (TCPCACHE_F_TFO_DATA | TCPCACHE_F_TFO_REQ |
TCPCACHE_F_TFO_DATA_RST | TCPCACHE_F_TFO_REQ_RST);
}
if (tp->t_tfo_stats & TFO_S_COOKIE_REQ) {
flag = (TCPCACHE_F_TFO_REQ | TCPCACHE_F_TFO_REQ_RST);
}
tcp_heuristic_reset_counters(&tcks, flag);
}
void
tcp_heuristic_mptcp_success(struct tcpcb *tp)
{
struct tcp_cache_key_src tcks;
tcp_cache_key_src_create(tp, &tcks);
tcp_heuristic_reset_counters(&tcks, TCPCACHE_F_MPTCP);
}
void
tcp_heuristic_ecn_success(struct tcpcb *tp)
{
struct tcp_cache_key_src tcks;
tcp_cache_key_src_create(tp, &tcks);
tcp_heuristic_reset_counters(&tcks, TCPCACHE_F_ECN);
}
static void
__tcp_heuristic_tfo_middlebox_common(struct tcp_heuristic *tpheur)
{
if (tpheur->th_tfo_in_backoff) {
return;
}
tpheur->th_tfo_in_backoff = 1;
if (tpheur->th_tfo_enabled_time) {
uint32_t old_backoff = tpheur->th_tfo_backoff;
tpheur->th_tfo_backoff -= (tcp_now - tpheur->th_tfo_enabled_time);
if (tpheur->th_tfo_backoff > old_backoff) {
tpheur->th_tfo_backoff = tcp_min_to_hz(tcp_ecn_timeout);
}
}
tpheur->th_tfo_backoff_until = tcp_now + tpheur->th_tfo_backoff;
/* Then, increase the backoff time */
tpheur->th_tfo_backoff *= 2;
if (tpheur->th_tfo_backoff > tcp_min_to_hz(tcp_backoff_maximum)) {
tpheur->th_tfo_backoff = tcp_min_to_hz(tcp_ecn_timeout);
}
os_log(OS_LOG_DEFAULT, "%s disable TFO until %u now %u on %lx\n", __func__,
tpheur->th_tfo_backoff_until, tcp_now, (unsigned long)VM_KERNEL_ADDRPERM(tpheur));
}
static void
tcp_heuristic_tfo_middlebox_common(struct tcp_cache_key_src *tcks)
{
struct tcp_heuristics_head *__single head;
struct tcp_heuristic *__single tpheur;
tpheur = tcp_getheuristic_with_lock(tcks, 1, &head);
if (tpheur == NULL) {
return;
}
__tcp_heuristic_tfo_middlebox_common(tpheur);
tcp_heuristic_unlock(head);
}
static void
tcp_heuristic_inc_counters(struct tcp_cache_key_src *tcks,
uint32_t flags)
{
struct tcp_heuristics_head *__single head;
struct tcp_heuristic *__single tpheur;
tpheur = tcp_getheuristic_with_lock(tcks, 1, &head);
if (tpheur == NULL) {
return;
}
/* Limit to prevent integer-overflow during exponential backoff */
if ((flags & TCPCACHE_F_TFO_DATA) && tpheur->th_tfo_data_loss < TCP_CACHE_OVERFLOW_PROTECT) {
tpheur->th_tfo_data_loss++;
if (tpheur->th_tfo_data_loss >= TFO_MAX_COOKIE_LOSS) {
__tcp_heuristic_tfo_middlebox_common(tpheur);
}
}
if ((flags & TCPCACHE_F_TFO_REQ) && tpheur->th_tfo_req_loss < TCP_CACHE_OVERFLOW_PROTECT) {
tpheur->th_tfo_req_loss++;
if (tpheur->th_tfo_req_loss >= TFO_MAX_COOKIE_LOSS) {
__tcp_heuristic_tfo_middlebox_common(tpheur);
}
}
if ((flags & TCPCACHE_F_TFO_DATA_RST) && tpheur->th_tfo_data_rst < TCP_CACHE_OVERFLOW_PROTECT) {
tpheur->th_tfo_data_rst++;
if (tpheur->th_tfo_data_rst >= TFO_MAX_COOKIE_LOSS) {
__tcp_heuristic_tfo_middlebox_common(tpheur);
}
}
if ((flags & TCPCACHE_F_TFO_REQ_RST) && tpheur->th_tfo_req_rst < TCP_CACHE_OVERFLOW_PROTECT) {
tpheur->th_tfo_req_rst++;
if (tpheur->th_tfo_req_rst >= TFO_MAX_COOKIE_LOSS) {
__tcp_heuristic_tfo_middlebox_common(tpheur);
}
}
if ((flags & TCPCACHE_F_ECN) &&
tpheur->th_ecn_loss < TCP_CACHE_OVERFLOW_PROTECT &&
TSTMP_LEQ(tpheur->th_ecn_backoff, tcp_now)) {
tpheur->th_ecn_loss++;
if (tpheur->th_ecn_loss >= ECN_MAX_SYN_LOSS) {
tcpstat.tcps_ecn_fallback_synloss++;
TCP_CACHE_INC_IFNET_STAT(tcks->ifp, tcks->af, ecn_fallback_synloss);
tpheur->th_ecn_backoff = tcp_now +
(tcp_min_to_hz(tcp_ecn_timeout) <<
(tpheur->th_ecn_loss - ECN_MAX_SYN_LOSS));
os_log(OS_LOG_DEFAULT, "%s disable ECN until %u now %u on %lx for SYN-loss\n",
__func__, tpheur->th_ecn_backoff, tcp_now,
(unsigned long)VM_KERNEL_ADDRPERM(tpheur));
}
}
if ((flags & TCPCACHE_F_MPTCP) &&
tpheur->th_mptcp_loss < TCP_CACHE_OVERFLOW_PROTECT &&
tpheur->th_mptcp_heuristic_disabled == 0) {
tpheur->th_mptcp_loss++;
if (tpheur->th_mptcp_loss >= MPTCP_MAX_SYN_LOSS) {
/*
* Yes, we take tcp_ecn_timeout, to avoid adding yet
* another sysctl that is just used for testing.
*/
tpheur->th_mptcp_backoff = tcp_now +
(tcp_min_to_hz(tcp_ecn_timeout) <<
(tpheur->th_mptcp_loss - MPTCP_MAX_SYN_LOSS));
tpheur->th_mptcp_in_backoff = 1;
os_log(OS_LOG_DEFAULT, "%s disable MPTCP until %u now %u on %lx\n",
__func__, tpheur->th_mptcp_backoff, tcp_now,
(unsigned long)VM_KERNEL_ADDRPERM(tpheur));
}
}
if ((flags & TCPCACHE_F_ECN_DROPRST) &&
tpheur->th_ecn_droprst < TCP_CACHE_OVERFLOW_PROTECT &&
TSTMP_LEQ(tpheur->th_ecn_backoff, tcp_now)) {
tpheur->th_ecn_droprst++;
if (tpheur->th_ecn_droprst >= ECN_MAX_DROPRST) {
tcpstat.tcps_ecn_fallback_droprst++;
TCP_CACHE_INC_IFNET_STAT(tcks->ifp, tcks->af,
ecn_fallback_droprst);
tpheur->th_ecn_backoff = tcp_now +
(tcp_min_to_hz(tcp_ecn_timeout) <<
(tpheur->th_ecn_droprst - ECN_MAX_DROPRST));
os_log(OS_LOG_DEFAULT, "%s disable ECN until %u now %u on %lx for drop-RST\n",
__func__, tpheur->th_ecn_backoff, tcp_now,
(unsigned long)VM_KERNEL_ADDRPERM(tpheur));
}
}
if ((flags & TCPCACHE_F_ECN_DROPRXMT) &&
tpheur->th_ecn_droprxmt < TCP_CACHE_OVERFLOW_PROTECT &&
TSTMP_LEQ(tpheur->th_ecn_backoff, tcp_now)) {
tpheur->th_ecn_droprxmt++;
if (tpheur->th_ecn_droprxmt >= ECN_MAX_DROPRXMT) {
tcpstat.tcps_ecn_fallback_droprxmt++;
TCP_CACHE_INC_IFNET_STAT(tcks->ifp, tcks->af,
ecn_fallback_droprxmt);
tpheur->th_ecn_backoff = tcp_now +
(tcp_min_to_hz(tcp_ecn_timeout) <<
(tpheur->th_ecn_droprxmt - ECN_MAX_DROPRXMT));
os_log(OS_LOG_DEFAULT, "%s disable ECN until %u now %u on %lx for drop-Rxmit\n",
__func__, tpheur->th_ecn_backoff, tcp_now,
(unsigned long)VM_KERNEL_ADDRPERM(tpheur));
}
}
if ((flags & TCPCACHE_F_ECN_SYNRST) &&
tpheur->th_ecn_synrst < TCP_CACHE_OVERFLOW_PROTECT) {
tpheur->th_ecn_synrst++;
if (tpheur->th_ecn_synrst >= ECN_MAX_SYNRST) {
tcpstat.tcps_ecn_fallback_synrst++;
TCP_CACHE_INC_IFNET_STAT(tcks->ifp, tcks->af,
ecn_fallback_synrst);
tpheur->th_ecn_backoff = tcp_now +
(tcp_min_to_hz(tcp_ecn_timeout) <<
(tpheur->th_ecn_synrst - ECN_MAX_SYNRST));
os_log(OS_LOG_DEFAULT, "%s disable ECN until %u now %u on %lx for SYN-RST\n",
__func__, tpheur->th_ecn_backoff, tcp_now,
(unsigned long)VM_KERNEL_ADDRPERM(tpheur));
}
}
tcp_heuristic_unlock(head);
}
void
tcp_heuristic_tfo_loss(struct tcpcb *tp)
{
struct tcp_cache_key_src tcks;
uint32_t flag = 0;
if (symptoms_is_wifi_lossy() &&
IFNET_IS_WIFI(tp->t_inpcb->inp_last_outifp)) {
return;
}
tcp_cache_key_src_create(tp, &tcks);
if (tp->t_tfo_stats & TFO_S_SYN_DATA_SENT) {
flag = (TCPCACHE_F_TFO_DATA | TCPCACHE_F_TFO_REQ);
}
if (tp->t_tfo_stats & TFO_S_COOKIE_REQ) {
flag = TCPCACHE_F_TFO_REQ;
}
tcp_heuristic_inc_counters(&tcks, flag);
}
void
tcp_heuristic_tfo_rst(struct tcpcb *tp)
{
struct tcp_cache_key_src tcks;
uint32_t flag = 0;
tcp_cache_key_src_create(tp, &tcks);
if (tp->t_tfo_stats & TFO_S_SYN_DATA_SENT) {
flag = (TCPCACHE_F_TFO_DATA_RST | TCPCACHE_F_TFO_REQ_RST);
}
if (tp->t_tfo_stats & TFO_S_COOKIE_REQ) {
flag = TCPCACHE_F_TFO_REQ_RST;
}
tcp_heuristic_inc_counters(&tcks, flag);
}
void
tcp_heuristic_mptcp_loss(struct tcpcb *tp)
{
struct tcp_cache_key_src tcks;
if (symptoms_is_wifi_lossy() &&
IFNET_IS_WIFI(tp->t_inpcb->inp_last_outifp)) {
return;
}
tcp_cache_key_src_create(tp, &tcks);
tcp_heuristic_inc_counters(&tcks, TCPCACHE_F_MPTCP);
}
void
tcp_heuristic_ecn_loss(struct tcpcb *tp)
{
struct tcp_cache_key_src tcks;
if (symptoms_is_wifi_lossy() &&
IFNET_IS_WIFI(tp->t_inpcb->inp_last_outifp)) {
return;
}
tcp_cache_key_src_create(tp, &tcks);
tcp_heuristic_inc_counters(&tcks, TCPCACHE_F_ECN);
}
void
tcp_heuristic_ecn_droprst(struct tcpcb *tp)
{
struct tcp_cache_key_src tcks;
tcp_cache_key_src_create(tp, &tcks);
tcp_heuristic_inc_counters(&tcks, TCPCACHE_F_ECN_DROPRST);
}
void
tcp_heuristic_ecn_droprxmt(struct tcpcb *tp)
{
struct tcp_cache_key_src tcks;
tcp_cache_key_src_create(tp, &tcks);
tcp_heuristic_inc_counters(&tcks, TCPCACHE_F_ECN_DROPRXMT);
}
void
tcp_heuristic_ecn_synrst(struct tcpcb *tp)
{
struct tcp_cache_key_src tcks;
tcp_cache_key_src_create(tp, &tcks);
tcp_heuristic_inc_counters(&tcks, TCPCACHE_F_ECN_SYNRST);
}
void
tcp_heuristic_tfo_middlebox(struct tcpcb *tp)
{
struct tcp_cache_key_src tcks;
tp->t_tfo_flags |= TFO_F_HEURISTIC_DONE;
tcp_cache_key_src_create(tp, &tcks);
tcp_heuristic_tfo_middlebox_common(&tcks);
}
static void
tcp_heuristic_ecn_aggressive_common(struct tcp_cache_key_src *tcks)
{
struct tcp_heuristics_head *__single head;
struct tcp_heuristic *__single tpheur;
tpheur = tcp_getheuristic_with_lock(tcks, 1, &head);
if (tpheur == NULL) {
return;
}
if (TSTMP_GT(tpheur->th_ecn_backoff, tcp_now)) {
/* We are already in aggressive mode */
tcp_heuristic_unlock(head);
return;
}
/* Must be done before, otherwise we will start off with expo-backoff */
tpheur->th_ecn_backoff = tcp_now +
(tcp_min_to_hz(tcp_ecn_timeout) << (tpheur->th_ecn_aggressive));
/*
* Ugly way to prevent integer overflow... limit to prevent in
* overflow during exp. backoff.
*/
if (tpheur->th_ecn_aggressive < TCP_CACHE_OVERFLOW_PROTECT) {
tpheur->th_ecn_aggressive++;
}
tcp_heuristic_unlock(head);
os_log(OS_LOG_DEFAULT, "%s disable ECN until %u now %u on %lx\n", __func__,
tpheur->th_ecn_backoff, tcp_now, (unsigned long)VM_KERNEL_ADDRPERM(tpheur));
}
void
tcp_heuristic_ecn_aggressive(struct tcpcb *tp)
{
struct tcp_cache_key_src tcks;
tcp_cache_key_src_create(tp, &tcks);
tcp_heuristic_ecn_aggressive_common(&tcks);
}
static boolean_t
tcp_heuristic_do_tfo_common(struct tcp_cache_key_src *tcks)
{
struct tcp_heuristics_head *__single head;
struct tcp_heuristic *__single tpheur;
if (disable_tcp_heuristics) {
return TRUE;
}
/* Get the tcp-heuristic. */
tpheur = tcp_getheuristic_with_lock(tcks, 0, &head);
if (tpheur == NULL) {
return TRUE;
}
if (tpheur->th_tfo_in_backoff == 0) {
goto tfo_ok;
}
if (TSTMP_GT(tcp_now, tpheur->th_tfo_backoff_until)) {
tpheur->th_tfo_in_backoff = 0;
tpheur->th_tfo_enabled_time = tcp_now;
goto tfo_ok;
}
tcp_heuristic_unlock(head);
return FALSE;
tfo_ok:
tcp_heuristic_unlock(head);
return TRUE;
}
boolean_t
tcp_heuristic_do_tfo(struct tcpcb *tp)
{
struct tcp_cache_key_src tcks;
tcp_cache_key_src_create(tp, &tcks);
if (tcp_heuristic_do_tfo_common(&tcks)) {
return TRUE;
}
return FALSE;
}
/*
* @return:
* 0 Enable MPTCP (we are still discovering middleboxes)
* -1 Enable MPTCP (heuristics have been temporarily disabled)
* 1 Disable MPTCP
*/
int
tcp_heuristic_do_mptcp(struct tcpcb *tp)
{
struct tcp_cache_key_src tcks;
struct tcp_heuristics_head *__single head = NULL;
struct tcp_heuristic *__single tpheur;
int ret = 0;
if (disable_tcp_heuristics ||
(tptomptp(tp)->mpt_mpte->mpte_flags & MPTE_FORCE_ENABLE)) {
return 0;
}
tcp_cache_key_src_create(tp, &tcks);
/* Get the tcp-heuristic. */
tpheur = tcp_getheuristic_with_lock(&tcks, 0, &head);
if (tpheur == NULL) {
return 0;
}
if (tpheur->th_mptcp_in_backoff == 0 ||
tpheur->th_mptcp_heuristic_disabled == 1) {
goto mptcp_ok;
}
if (TSTMP_GT(tpheur->th_mptcp_backoff, tcp_now)) {
goto fallback;
}
tpheur->th_mptcp_in_backoff = 0;
mptcp_ok:
if (tpheur->th_mptcp_heuristic_disabled) {
ret = -1;
if (TSTMP_GT(tcp_now, tpheur->th_mptcp_backoff)) {
tpheur->th_mptcp_heuristic_disabled = 0;
tpheur->th_mptcp_success = 0;
}
}
tcp_heuristic_unlock(head);
return ret;
fallback:
if (head) {
tcp_heuristic_unlock(head);
}
if (tptomptp(tp)->mpt_mpte->mpte_flags & MPTE_FIRSTPARTY) {
tcpstat.tcps_mptcp_fp_heuristic_fallback++;
} else {
tcpstat.tcps_mptcp_heuristic_fallback++;
}
return 1;
}
static boolean_t
tcp_heuristic_do_ecn_common(struct tcp_cache_key_src *tcks)
{
struct tcp_heuristics_head *__single head;
struct tcp_heuristic *__single tpheur;
boolean_t ret = TRUE;
if (disable_tcp_heuristics) {
return TRUE;
}
/* Get the tcp-heuristic. */
tpheur = tcp_getheuristic_with_lock(tcks, 0, &head);
if (tpheur == NULL) {
return ret;
}
if (TSTMP_GT(tpheur->th_ecn_backoff, tcp_now)) {
ret = FALSE;
} else {
/* Reset the following counters to start re-evaluating */
if (tpheur->th_ecn_droprst >= ECN_RETRY_LIMIT) {
tpheur->th_ecn_droprst = 0;
}
if (tpheur->th_ecn_droprxmt >= ECN_RETRY_LIMIT) {
tpheur->th_ecn_droprxmt = 0;
}
if (tpheur->th_ecn_synrst >= ECN_RETRY_LIMIT) {
tpheur->th_ecn_synrst = 0;
}
/* Make sure it follows along */
tpheur->th_ecn_backoff = tcp_now;
}
tcp_heuristic_unlock(head);
return ret;
}
boolean_t
tcp_heuristic_do_ecn(struct tcpcb *tp)
{
struct tcp_cache_key_src tcks;
tcp_cache_key_src_create(tp, &tcks);
return tcp_heuristic_do_ecn_common(&tcks);
}
boolean_t
tcp_heuristic_do_ecn_with_address(struct ifnet *ifp,
union sockaddr_in_4_6 *local_address)
{
struct tcp_cache_key_src tcks;
memset(&tcks, 0, sizeof(tcks));
tcks.ifp = ifp;
calculate_tcp_clock();
if (local_address->sa.sa_family == AF_INET6) {
memcpy(&tcks.laddr.addr6, &local_address->sin6.sin6_addr, sizeof(struct in6_addr));
tcks.af = AF_INET6;
} else if (local_address->sa.sa_family == AF_INET) {
memcpy(&tcks.laddr.addr, &local_address->sin.sin_addr, sizeof(struct in_addr));
tcks.af = AF_INET;
}
return tcp_heuristic_do_ecn_common(&tcks);
}
void
tcp_heuristics_ecn_update(struct necp_tcp_ecn_cache *necp_buffer,
struct ifnet *ifp, union sockaddr_in_4_6 *local_address)
{
struct tcp_cache_key_src tcks;
memset(&tcks, 0, sizeof(tcks));
tcks.ifp = ifp;
calculate_tcp_clock();
if (local_address->sa.sa_family == AF_INET6) {
memcpy(&tcks.laddr.addr6, &local_address->sin6.sin6_addr, sizeof(struct in6_addr));
tcks.af = AF_INET6;
} else if (local_address->sa.sa_family == AF_INET) {
memcpy(&tcks.laddr.addr, &local_address->sin.sin_addr, sizeof(struct in_addr));
tcks.af = AF_INET;
}
if (necp_buffer->necp_tcp_ecn_heuristics_success) {
tcp_heuristic_reset_counters(&tcks, TCPCACHE_F_ECN);
} else if (necp_buffer->necp_tcp_ecn_heuristics_loss) {
tcp_heuristic_inc_counters(&tcks, TCPCACHE_F_ECN);
} else if (necp_buffer->necp_tcp_ecn_heuristics_drop_rst) {
tcp_heuristic_inc_counters(&tcks, TCPCACHE_F_ECN_DROPRST);
} else if (necp_buffer->necp_tcp_ecn_heuristics_drop_rxmt) {
tcp_heuristic_inc_counters(&tcks, TCPCACHE_F_ECN_DROPRXMT);
} else if (necp_buffer->necp_tcp_ecn_heuristics_syn_rst) {
tcp_heuristic_inc_counters(&tcks, TCPCACHE_F_ECN_SYNRST);
} else if (necp_buffer->necp_tcp_ecn_heuristics_aggressive) {
tcp_heuristic_ecn_aggressive_common(&tcks);
}
return;
}
boolean_t
tcp_heuristic_do_tfo_with_address(struct ifnet *ifp,
union sockaddr_in_4_6 *local_address, union sockaddr_in_4_6 *remote_address,
uint8_t *__counted_by(maxlen) cookie, uint8_t maxlen, uint8_t *cookie_len)
{
struct tcp_cache_key_src tcks;
memset(&tcks, 0, sizeof(tcks));
tcks.ifp = ifp;
calculate_tcp_clock();
if (remote_address->sa.sa_family == AF_INET6) {
memcpy(&tcks.laddr.addr6, &local_address->sin6.sin6_addr, sizeof(struct in6_addr));
memcpy(&tcks.faddr.addr6, &remote_address->sin6.sin6_addr, sizeof(struct in6_addr));
tcks.af = AF_INET6;
} else if (remote_address->sa.sa_family == AF_INET) {
memcpy(&tcks.laddr.addr, &local_address->sin.sin_addr, sizeof(struct in_addr));
memcpy(&tcks.faddr.addr, &remote_address->sin.sin_addr, sizeof(struct in_addr));
tcks.af = AF_INET;
}
if (tcp_heuristic_do_tfo_common(&tcks)) {
if (!tcp_cache_get_cookie_common(&tcks, cookie, maxlen, cookie_len)) {
*cookie_len = 0;
}
return TRUE;
}
return FALSE;
}
void
tcp_heuristics_tfo_update(struct necp_tcp_tfo_cache *necp_buffer,
struct ifnet *ifp, union sockaddr_in_4_6 *local_address,
union sockaddr_in_4_6 *remote_address)
{
struct tcp_cache_key_src tcks;
memset(&tcks, 0, sizeof(tcks));
tcks.ifp = ifp;
calculate_tcp_clock();
if (remote_address->sa.sa_family == AF_INET6) {
memcpy(&tcks.laddr.addr6, &local_address->sin6.sin6_addr, sizeof(struct in6_addr));
memcpy(&tcks.faddr.addr6, &remote_address->sin6.sin6_addr, sizeof(struct in6_addr));
tcks.af = AF_INET6;
} else if (remote_address->sa.sa_family == AF_INET) {
memcpy(&tcks.laddr.addr, &local_address->sin.sin_addr, sizeof(struct in_addr));
memcpy(&tcks.faddr.addr, &remote_address->sin.sin_addr, sizeof(struct in_addr));
tcks.af = AF_INET;
}
if (necp_buffer->necp_tcp_tfo_heuristics_success) {
tcp_heuristic_reset_counters(&tcks, TCPCACHE_F_TFO_REQ | TCPCACHE_F_TFO_DATA |
TCPCACHE_F_TFO_REQ_RST | TCPCACHE_F_TFO_DATA_RST);
}
if (necp_buffer->necp_tcp_tfo_heuristics_success_req) {
tcp_heuristic_reset_counters(&tcks, TCPCACHE_F_TFO_REQ | TCPCACHE_F_TFO_REQ_RST);
}
if (necp_buffer->necp_tcp_tfo_heuristics_loss) {
tcp_heuristic_inc_counters(&tcks, TCPCACHE_F_TFO_REQ | TCPCACHE_F_TFO_DATA);
}
if (necp_buffer->necp_tcp_tfo_heuristics_loss_req) {
tcp_heuristic_inc_counters(&tcks, TCPCACHE_F_TFO_REQ);
}
if (necp_buffer->necp_tcp_tfo_heuristics_rst_data) {
tcp_heuristic_inc_counters(&tcks, TCPCACHE_F_TFO_REQ_RST | TCPCACHE_F_TFO_DATA_RST);
}
if (necp_buffer->necp_tcp_tfo_heuristics_rst_req) {
tcp_heuristic_inc_counters(&tcks, TCPCACHE_F_TFO_REQ_RST);
}
if (necp_buffer->necp_tcp_tfo_heuristics_middlebox) {
tcp_heuristic_tfo_middlebox_common(&tcks);
}
if (necp_buffer->necp_tcp_tfo_cookie_len != 0) {
tcp_cache_set_cookie_common(&tcks,
necp_buffer->necp_tcp_tfo_cookie, necp_buffer->necp_tcp_tfo_cookie_len);
}
return;
}
#if (DEVELOPMENT || DEBUG)
/*
* This test sysctl forces the hash table to be full which will force us to
* erase portions of it.
*/
static int
sysctl_fill_hashtable SYSCTL_HANDLER_ARGS
{
#pragma unused(arg1, arg2)
int error = 0, val;
val = 0;
error = sysctl_handle_int(oidp, &val, 0, req);
if (error || !req->newptr) {
return error;
}
if (val == 1) {
struct necp_tcp_tfo_cache necp_buffer = {};
union sockaddr_in_4_6 local_address = {}, remote_address = {};
necp_buffer.necp_tcp_tfo_heuristics_success = 1;
necp_buffer.necp_tcp_tfo_heuristics_loss = 1;
necp_buffer.necp_tcp_tfo_heuristics_middlebox = 1;
for (unsigned i = 0; i < 1024; i++) {
local_address.sin.sin_family = AF_INET;
local_address.sin.sin_len = sizeof(struct sockaddr_in);
local_address.sin.sin_port = random() % UINT16_MAX;
local_address.sin.sin_addr.s_addr = random();
remote_address.sin.sin_family = AF_INET;
remote_address.sin.sin_len = sizeof(struct sockaddr_in);
remote_address.sin.sin_port = random() % UINT16_MAX;
remote_address.sin.sin_addr.s_addr = random();
tcp_heuristics_tfo_update(&necp_buffer, lo_ifp,
&local_address,
&remote_address);
}
}
return error;
}
static int fill_hash_table = 0;
SYSCTL_PROC(_net_inet_tcp, OID_AUTO, test_cache, CTLTYPE_INT | CTLFLAG_RW |
CTLFLAG_LOCKED, &fill_hash_table, 0, &sysctl_fill_hashtable, "I",
"Tests the hash table erasing procedures");
#endif /* DEVELOPMENT || DEBUG */
static void
sysctl_cleartfocache(void)
{
int i;
for (i = 0; i < tcp_cache_size; i++) {
struct tcp_cache_head *__single head = &tcp_cache[i];
struct tcp_cache *__single tpcache, *__single tmp;
struct tcp_heuristics_head *__single hhead = &tcp_heuristics[i];
struct tcp_heuristic *__single tpheur, *__single htmp;
lck_mtx_lock(&head->tch_mtx);
SLIST_FOREACH_SAFE(tpcache, &head->tcp_caches, list, tmp) {
SLIST_REMOVE(&head->tcp_caches, tpcache, tcp_cache, list);
kfree_type(struct tcp_cache, tpcache);
}
lck_mtx_unlock(&head->tch_mtx);
lck_mtx_lock(&hhead->thh_mtx);
SLIST_FOREACH_SAFE(tpheur, &hhead->tcp_heuristics, list, htmp) {
SLIST_REMOVE(&hhead->tcp_heuristics, tpheur, tcp_heuristic, list);
kfree_type(struct tcp_heuristic, tpheur);
}
lck_mtx_unlock(&hhead->thh_mtx);
}
}
/* This sysctl is useful for testing purposes only */
static int tcpcleartfo = 0;
static int sysctl_cleartfo SYSCTL_HANDLER_ARGS
{
#pragma unused(arg1, arg2)
int error = 0, val, oldval = tcpcleartfo;
val = oldval;
error = sysctl_handle_int(oidp, &val, 0, req);
if (error || !req->newptr) {
if (error) {
os_log_error(OS_LOG_DEFAULT, "%s could not parse int: %d", __func__, error);
}
return error;
}
/*
* The actual value does not matter. If the value is set, it triggers
* the clearing of the TFO cache. If a future implementation does not
* use the route entry to hold the TFO cache, replace the route sysctl.
*/
if (val != oldval) {
sysctl_cleartfocache();
}
tcpcleartfo = val;
return error;
}
SYSCTL_PROC(_net_inet_tcp, OID_AUTO, clear_tfocache, CTLTYPE_INT | CTLFLAG_RW |
CTLFLAG_LOCKED, &tcpcleartfo, 0, &sysctl_cleartfo, "I",
"Toggle to clear the TFO destination based heuristic cache");
void
tcp_cache_init(void)
{
uint64_t sane_size_meg = sane_size / 1024 / 1024;
size_t cache_size;
/*
* On machines with <100MB of memory this will result in a (full) cache-size
* of 32 entries, thus 32 * 5 * 64bytes = 10KB. (about 0.01 %)
* On machines with > 4GB of memory, we have a cache-size of 1024 entries,
* thus about 327KB.
*
* Side-note: we convert to uint32_t. If sane_size is more than
* 16000 TB, we loose precision. But, who cares? :)
*/
cache_size = tcp_cache_roundup2((uint32_t)(sane_size_meg >> 2));
if (cache_size < 32) {
cache_size = 32;
} else if (cache_size > 1024) {
cache_size = 1024;
}
tcp_cache = zalloc_permanent(sizeof(struct tcp_cache_head) * cache_size,
ZALIGN(struct tcp_cache_head));
tcp_cache_size = cache_size;
tcp_heuristics = zalloc_permanent(sizeof(struct tcp_heuristics_head) * cache_size,
ZALIGN(struct tcp_heuristics_head));
tcp_heuristics_size = cache_size;
for (int i = 0; i < tcp_cache_size; i++) {
lck_mtx_init(&tcp_cache[i].tch_mtx, &tcp_cache_mtx_grp,
&tcp_cache_mtx_attr);
SLIST_INIT(&tcp_cache[i].tcp_caches);
lck_mtx_init(&tcp_heuristics[i].thh_mtx, &tcp_heuristic_mtx_grp,
&tcp_heuristic_mtx_attr);
SLIST_INIT(&tcp_heuristics[i].tcp_heuristics);
}
tcp_cache_hash_seed = RandomULong();
}