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authorChristoph Paasch <christoph.paasch@uclouvain.be>2013-03-17 08:23:34 +0000
committerDavid S. Miller <davem@davemloft.net>2013-03-17 14:35:13 -0400
commit1a2c6181c4a1922021b4d7df373bba612c3e5f04 (patch)
tree1346c9b1db83495a98fbcf95f8e521c67fc55cb9 /net/ipv4/tcp.c
parent94d8f2b133c9ff97105adc1233d1a35e16e1e7a6 (diff)
downloadlinux-stericsson-1a2c6181c4a1922021b4d7df373bba612c3e5f04.tar.gz
tcp: Remove TCPCT
TCPCT uses option-number 253, reserved for experimental use and should not be used in production environments. Further, TCPCT does not fully implement RFC 6013. As a nice side-effect, removing TCPCT increases TCP's performance for very short flows: Doing an apache-benchmark with -c 100 -n 100000, sending HTTP-requests for files of 1KB size. before this patch: average (among 7 runs) of 20845.5 Requests/Second after: average (among 7 runs) of 21403.6 Requests/Second Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp.c')
-rw-r--r--net/ipv4/tcp.c267
1 files changed, 0 insertions, 267 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 8d14573ade77..17a6810af5c8 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -409,15 +409,6 @@ void tcp_init_sock(struct sock *sk)
icsk->icsk_sync_mss = tcp_sync_mss;
- /* TCP Cookie Transactions */
- if (sysctl_tcp_cookie_size > 0) {
- /* Default, cookies without s_data_payload. */
- tp->cookie_values =
- kzalloc(sizeof(*tp->cookie_values),
- sk->sk_allocation);
- if (tp->cookie_values != NULL)
- kref_init(&tp->cookie_values->kref);
- }
/* Presumed zeroed, in order of appearance:
* cookie_in_always, cookie_out_never,
* s_data_constant, s_data_in, s_data_out
@@ -2397,92 +2388,6 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
release_sock(sk);
return err;
}
- case TCP_COOKIE_TRANSACTIONS: {
- struct tcp_cookie_transactions ctd;
- struct tcp_cookie_values *cvp = NULL;
-
- if (sizeof(ctd) > optlen)
- return -EINVAL;
- if (copy_from_user(&ctd, optval, sizeof(ctd)))
- return -EFAULT;
-
- if (ctd.tcpct_used > sizeof(ctd.tcpct_value) ||
- ctd.tcpct_s_data_desired > TCP_MSS_DESIRED)
- return -EINVAL;
-
- if (ctd.tcpct_cookie_desired == 0) {
- /* default to global value */
- } else if ((0x1 & ctd.tcpct_cookie_desired) ||
- ctd.tcpct_cookie_desired > TCP_COOKIE_MAX ||
- ctd.tcpct_cookie_desired < TCP_COOKIE_MIN) {
- return -EINVAL;
- }
-
- if (TCP_COOKIE_OUT_NEVER & ctd.tcpct_flags) {
- /* Supercedes all other values */
- lock_sock(sk);
- if (tp->cookie_values != NULL) {
- kref_put(&tp->cookie_values->kref,
- tcp_cookie_values_release);
- tp->cookie_values = NULL;
- }
- tp->rx_opt.cookie_in_always = 0; /* false */
- tp->rx_opt.cookie_out_never = 1; /* true */
- release_sock(sk);
- return err;
- }
-
- /* Allocate ancillary memory before locking.
- */
- if (ctd.tcpct_used > 0 ||
- (tp->cookie_values == NULL &&
- (sysctl_tcp_cookie_size > 0 ||
- ctd.tcpct_cookie_desired > 0 ||
- ctd.tcpct_s_data_desired > 0))) {
- cvp = kzalloc(sizeof(*cvp) + ctd.tcpct_used,
- GFP_KERNEL);
- if (cvp == NULL)
- return -ENOMEM;
-
- kref_init(&cvp->kref);
- }
- lock_sock(sk);
- tp->rx_opt.cookie_in_always =
- (TCP_COOKIE_IN_ALWAYS & ctd.tcpct_flags);
- tp->rx_opt.cookie_out_never = 0; /* false */
-
- if (tp->cookie_values != NULL) {
- if (cvp != NULL) {
- /* Changed values are recorded by a changed
- * pointer, ensuring the cookie will differ,
- * without separately hashing each value later.
- */
- kref_put(&tp->cookie_values->kref,
- tcp_cookie_values_release);
- } else {
- cvp = tp->cookie_values;
- }
- }
-
- if (cvp != NULL) {
- cvp->cookie_desired = ctd.tcpct_cookie_desired;
-
- if (ctd.tcpct_used > 0) {
- memcpy(cvp->s_data_payload, ctd.tcpct_value,
- ctd.tcpct_used);
- cvp->s_data_desired = ctd.tcpct_used;
- cvp->s_data_constant = 1; /* true */
- } else {
- /* No constant payload data. */
- cvp->s_data_desired = ctd.tcpct_s_data_desired;
- cvp->s_data_constant = 0; /* false */
- }
-
- tp->cookie_values = cvp;
- }
- release_sock(sk);
- return err;
- }
default:
/* fallthru */
break;
@@ -2902,41 +2807,6 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
return -EFAULT;
return 0;
- case TCP_COOKIE_TRANSACTIONS: {
- struct tcp_cookie_transactions ctd;
- struct tcp_cookie_values *cvp = tp->cookie_values;
-
- if (get_user(len, optlen))
- return -EFAULT;
- if (len < sizeof(ctd))
- return -EINVAL;
-
- memset(&ctd, 0, sizeof(ctd));
- ctd.tcpct_flags = (tp->rx_opt.cookie_in_always ?
- TCP_COOKIE_IN_ALWAYS : 0)
- | (tp->rx_opt.cookie_out_never ?
- TCP_COOKIE_OUT_NEVER : 0);
-
- if (cvp != NULL) {
- ctd.tcpct_flags |= (cvp->s_data_in ?
- TCP_S_DATA_IN : 0)
- | (cvp->s_data_out ?
- TCP_S_DATA_OUT : 0);
-
- ctd.tcpct_cookie_desired = cvp->cookie_desired;
- ctd.tcpct_s_data_desired = cvp->s_data_desired;
-
- memcpy(&ctd.tcpct_value[0], &cvp->cookie_pair[0],
- cvp->cookie_pair_size);
- ctd.tcpct_used = cvp->cookie_pair_size;
- }
-
- if (put_user(sizeof(ctd), optlen))
- return -EFAULT;
- if (copy_to_user(optval, &ctd, sizeof(ctd)))
- return -EFAULT;
- return 0;
- }
case TCP_THIN_LINEAR_TIMEOUTS:
val = tp->thin_lto;
break;
@@ -3409,134 +3279,6 @@ EXPORT_SYMBOL(tcp_md5_hash_key);
#endif
-/* Each Responder maintains up to two secret values concurrently for
- * efficient secret rollover. Each secret value has 4 states:
- *
- * Generating. (tcp_secret_generating != tcp_secret_primary)
- * Generates new Responder-Cookies, but not yet used for primary
- * verification. This is a short-term state, typically lasting only
- * one round trip time (RTT).
- *
- * Primary. (tcp_secret_generating == tcp_secret_primary)
- * Used both for generation and primary verification.
- *
- * Retiring. (tcp_secret_retiring != tcp_secret_secondary)
- * Used for verification, until the first failure that can be
- * verified by the newer Generating secret. At that time, this
- * cookie's state is changed to Secondary, and the Generating
- * cookie's state is changed to Primary. This is a short-term state,
- * typically lasting only one round trip time (RTT).
- *
- * Secondary. (tcp_secret_retiring == tcp_secret_secondary)
- * Used for secondary verification, after primary verification
- * failures. This state lasts no more than twice the Maximum Segment
- * Lifetime (2MSL). Then, the secret is discarded.
- */
-struct tcp_cookie_secret {
- /* The secret is divided into two parts. The digest part is the
- * equivalent of previously hashing a secret and saving the state,
- * and serves as an initialization vector (IV). The message part
- * serves as the trailing secret.
- */
- u32 secrets[COOKIE_WORKSPACE_WORDS];
- unsigned long expires;
-};
-
-#define TCP_SECRET_1MSL (HZ * TCP_PAWS_MSL)
-#define TCP_SECRET_2MSL (HZ * TCP_PAWS_MSL * 2)
-#define TCP_SECRET_LIFE (HZ * 600)
-
-static struct tcp_cookie_secret tcp_secret_one;
-static struct tcp_cookie_secret tcp_secret_two;
-
-/* Essentially a circular list, without dynamic allocation. */
-static struct tcp_cookie_secret *tcp_secret_generating;
-static struct tcp_cookie_secret *tcp_secret_primary;
-static struct tcp_cookie_secret *tcp_secret_retiring;
-static struct tcp_cookie_secret *tcp_secret_secondary;
-
-static DEFINE_SPINLOCK(tcp_secret_locker);
-
-/* Select a pseudo-random word in the cookie workspace.
- */
-static inline u32 tcp_cookie_work(const u32 *ws, const int n)
-{
- return ws[COOKIE_DIGEST_WORDS + ((COOKIE_MESSAGE_WORDS-1) & ws[n])];
-}
-
-/* Fill bakery[COOKIE_WORKSPACE_WORDS] with generator, updating as needed.
- * Called in softirq context.
- * Returns: 0 for success.
- */
-int tcp_cookie_generator(u32 *bakery)
-{
- unsigned long jiffy = jiffies;
-
- if (unlikely(time_after_eq(jiffy, tcp_secret_generating->expires))) {
- spin_lock_bh(&tcp_secret_locker);
- if (!time_after_eq(jiffy, tcp_secret_generating->expires)) {
- /* refreshed by another */
- memcpy(bakery,
- &tcp_secret_generating->secrets[0],
- COOKIE_WORKSPACE_WORDS);
- } else {
- /* still needs refreshing */
- get_random_bytes(bakery, COOKIE_WORKSPACE_WORDS);
-
- /* The first time, paranoia assumes that the
- * randomization function isn't as strong. But,
- * this secret initialization is delayed until
- * the last possible moment (packet arrival).
- * Although that time is observable, it is
- * unpredictably variable. Mash in the most
- * volatile clock bits available, and expire the
- * secret extra quickly.
- */
- if (unlikely(tcp_secret_primary->expires ==
- tcp_secret_secondary->expires)) {
- struct timespec tv;
-
- getnstimeofday(&tv);
- bakery[COOKIE_DIGEST_WORDS+0] ^=
- (u32)tv.tv_nsec;
-
- tcp_secret_secondary->expires = jiffy
- + TCP_SECRET_1MSL
- + (0x0f & tcp_cookie_work(bakery, 0));
- } else {
- tcp_secret_secondary->expires = jiffy
- + TCP_SECRET_LIFE
- + (0xff & tcp_cookie_work(bakery, 1));
- tcp_secret_primary->expires = jiffy
- + TCP_SECRET_2MSL
- + (0x1f & tcp_cookie_work(bakery, 2));
- }
- memcpy(&tcp_secret_secondary->secrets[0],
- bakery, COOKIE_WORKSPACE_WORDS);
-
- rcu_assign_pointer(tcp_secret_generating,
- tcp_secret_secondary);
- rcu_assign_pointer(tcp_secret_retiring,
- tcp_secret_primary);
- /*
- * Neither call_rcu() nor synchronize_rcu() needed.
- * Retiring data is not freed. It is replaced after
- * further (locked) pointer updates, and a quiet time
- * (minimum 1MSL, maximum LIFE - 2MSL).
- */
- }
- spin_unlock_bh(&tcp_secret_locker);
- } else {
- rcu_read_lock_bh();
- memcpy(bakery,
- &rcu_dereference(tcp_secret_generating)->secrets[0],
- COOKIE_WORKSPACE_WORDS);
- rcu_read_unlock_bh();
- }
- return 0;
-}
-EXPORT_SYMBOL(tcp_cookie_generator);
-
void tcp_done(struct sock *sk)
{
struct request_sock *req = tcp_sk(sk)->fastopen_rsk;
@@ -3591,7 +3333,6 @@ void __init tcp_init(void)
unsigned long limit;
int max_rshare, max_wshare, cnt;
unsigned int i;
- unsigned long jiffy = jiffies;
BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
@@ -3667,13 +3408,5 @@ void __init tcp_init(void)
tcp_register_congestion_control(&tcp_reno);
- memset(&tcp_secret_one.secrets[0], 0, sizeof(tcp_secret_one.secrets));
- memset(&tcp_secret_two.secrets[0], 0, sizeof(tcp_secret_two.secrets));
- tcp_secret_one.expires = jiffy; /* past due */
- tcp_secret_two.expires = jiffy; /* past due */
- tcp_secret_generating = &tcp_secret_one;
- tcp_secret_primary = &tcp_secret_one;
- tcp_secret_retiring = &tcp_secret_two;
- tcp_secret_secondary = &tcp_secret_two;
tcp_tasklet_init();
}