1 files changed, 279 insertions, 10 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index f1813bc..c8666b7 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -264,6 +264,7 @@
 #include <linux/cache.h>
 #include <linux/err.h>
 #include <linux/crypto.h>
+#include <linux/time.h>
 
 #include <net/icmp.h>
 #include <net/tcp.h>
@@ -2042,7 +2043,7 @@ int tcp_disconnect(struct sock *sk, int flags)
 	__skb_queue_purge(&sk->sk_async_wait_queue);
 #endif
 
-	inet->dport = 0;
+	inet->inet_dport = 0;
 
 	if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
 		inet_reset_saddr(sk);
@@ -2059,6 +2060,7 @@ int tcp_disconnect(struct sock *sk, int flags)
 	tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
 	tp->snd_cwnd_cnt = 0;
 	tp->bytes_acked = 0;
+	tp->window_clamp = 0;
 	tcp_set_ca_state(sk, TCP_CA_Open);
 	tcp_clear_retrans(tp);
 	inet_csk_delack_init(sk);
@@ -2066,7 +2068,7 @@ int tcp_disconnect(struct sock *sk, int flags)
 	memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
 	__sk_dst_reset(sk);
 
-	WARN_ON(inet->num && !icsk->icsk_bind_hash);
+	WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
 
 	sk->sk_error_report(sk);
 	return err;
@@ -2083,8 +2085,9 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
 	int val;
 	int err = 0;
 
-	/* This is a string value all the others are int's */
-	if (optname == TCP_CONGESTION) {
+	/* These are data/string values, all the others are ints */
+	switch (optname) {
+	case TCP_CONGESTION: {
 		char name[TCP_CA_NAME_MAX];
 
 		if (optlen < 1)
@@ -2101,6 +2104,93 @@ 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;
+		}
+		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);
+				kref_init(&cvp->kref);
+				tp->cookie_values = cvp;
+			} 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 */
+			}
+		}
+		release_sock(sk);
+		return err;
+	}
+	default:
+		/* fallthru */
+		break;
+	};
 
 	if (optlen < sizeof(int))
 		return -EINVAL;
@@ -2425,6 +2515,47 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
 		if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
 			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;
+
+			/* Cookie(s) saved, return as nonce */
+			if (sizeof(ctd.tcpct_value) < cvp->cookie_pair_size) {
+				/* impossible? */
+				return -EINVAL;
+			}
+			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;
+	}
 	default:
 		return -ENOPROTOOPT;
 	}
@@ -2847,6 +2978,135 @@ 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)
 {
 	if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
@@ -2881,6 +3141,7 @@ void __init tcp_init(void)
 	struct sk_buff *skb = NULL;
 	unsigned long nr_pages, limit;
 	int order, i, max_share;
+	unsigned long jiffy = jiffies;
 
 	BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
 
@@ -2903,11 +3164,10 @@ void __init tcp_init(void)
 					(totalram_pages >= 128 * 1024) ?
 					13 : 15,
 					0,
-					&tcp_hashinfo.ehash_size,
 					NULL,
+					&tcp_hashinfo.ehash_mask,
 					thash_entries ? 0 : 512 * 1024);
-	tcp_hashinfo.ehash_size = 1 << tcp_hashinfo.ehash_size;
-	for (i = 0; i < tcp_hashinfo.ehash_size; i++) {
+	for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) {
 		INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
 		INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].twchain, i);
 	}
@@ -2916,7 +3176,7 @@ void __init tcp_init(void)
 	tcp_hashinfo.bhash =
 		alloc_large_system_hash("TCP bind",
 					sizeof(struct inet_bind_hashbucket),
-					tcp_hashinfo.ehash_size,
+					tcp_hashinfo.ehash_mask + 1,
 					(totalram_pages >= 128 * 1024) ?
 					13 : 15,
 					0,
@@ -2971,10 +3231,19 @@ void __init tcp_init(void)
 	sysctl_tcp_rmem[2] = max(87380, max_share);
 
 	printk(KERN_INFO "TCP: Hash tables configured "
-	       "(established %d bind %d)\n",
-	       tcp_hashinfo.ehash_size, tcp_hashinfo.bhash_size);
+	       "(established %u bind %u)\n",
+	       tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size);
 
 	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;
 }
 
 EXPORT_SYMBOL(tcp_close);