diff options
Diffstat (limited to 'net/ipv4/tcp.c')
| -rw-r--r-- | net/ipv4/tcp.c | 363 |
1 files changed, 335 insertions, 28 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 64d0af67582..c8666b70cde 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> @@ -326,6 +327,43 @@ void tcp_enter_memory_pressure(struct sock *sk) EXPORT_SYMBOL(tcp_enter_memory_pressure); +/* Convert seconds to retransmits based on initial and max timeout */ +static u8 secs_to_retrans(int seconds, int timeout, int rto_max) +{ + u8 res = 0; + + if (seconds > 0) { + int period = timeout; + + res = 1; + while (seconds > period && res < 255) { + res++; + timeout <<= 1; + if (timeout > rto_max) + timeout = rto_max; + period += timeout; + } + } + return res; +} + +/* Convert retransmits to seconds based on initial and max timeout */ +static int retrans_to_secs(u8 retrans, int timeout, int rto_max) +{ + int period = 0; + + if (retrans > 0) { + period = timeout; + while (--retrans) { + timeout <<= 1; + if (timeout > rto_max) + timeout = rto_max; + period += timeout; + } + } + return period; +} + /* * Wait for a TCP event. * @@ -1146,7 +1184,9 @@ void tcp_cleanup_rbuf(struct sock *sk, int copied) #if TCP_DEBUG struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); - WARN_ON(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq)); + WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq), + KERN_INFO "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n", + tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt); #endif if (inet_csk_ack_scheduled(sk)) { @@ -1393,11 +1433,13 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, /* Now that we have two receive queues this * shouldn't happen. */ - if (before(*seq, TCP_SKB_CB(skb)->seq)) { - printk(KERN_INFO "recvmsg bug: copied %X " - "seq %X\n", *seq, TCP_SKB_CB(skb)->seq); + if (WARN(before(*seq, TCP_SKB_CB(skb)->seq), + KERN_INFO "recvmsg bug: copied %X " + "seq %X rcvnxt %X fl %X\n", *seq, + TCP_SKB_CB(skb)->seq, tp->rcv_nxt, + flags)) break; - } + offset = *seq - TCP_SKB_CB(skb)->seq; if (tcp_hdr(skb)->syn) offset--; @@ -1405,7 +1447,10 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, goto found_ok_skb; if (tcp_hdr(skb)->fin) goto found_fin_ok; - WARN_ON(!(flags & MSG_PEEK)); + WARN(!(flags & MSG_PEEK), KERN_INFO "recvmsg bug 2: " + "copied %X seq %X rcvnxt %X fl %X\n", + *seq, TCP_SKB_CB(skb)->seq, + tp->rcv_nxt, flags); } /* Well, if we have backlog, try to process it now yet. */ @@ -1998,7 +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); @@ -2015,6 +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); @@ -2022,7 +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; @@ -2039,8 +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) @@ -2057,6 +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; @@ -2163,16 +2297,10 @@ static int do_tcp_setsockopt(struct sock *sk, int level, break; case TCP_DEFER_ACCEPT: - icsk->icsk_accept_queue.rskq_defer_accept = 0; - if (val > 0) { - /* Translate value in seconds to number of - * retransmits */ - while (icsk->icsk_accept_queue.rskq_defer_accept < 32 && - val > ((TCP_TIMEOUT_INIT / HZ) << - icsk->icsk_accept_queue.rskq_defer_accept)) - icsk->icsk_accept_queue.rskq_defer_accept++; - icsk->icsk_accept_queue.rskq_defer_accept++; - } + /* Translate value in seconds to number of retransmits */ + icsk->icsk_accept_queue.rskq_defer_accept = + secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ, + TCP_RTO_MAX / HZ); break; case TCP_WINDOW_CLAMP: @@ -2353,8 +2481,8 @@ static int do_tcp_getsockopt(struct sock *sk, int level, val = (val ? : sysctl_tcp_fin_timeout) / HZ; break; case TCP_DEFER_ACCEPT: - val = !icsk->icsk_accept_queue.rskq_defer_accept ? 0 : - ((TCP_TIMEOUT_INIT / HZ) << (icsk->icsk_accept_queue.rskq_defer_accept - 1)); + val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept, + TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ); break; case TCP_WINDOW_CLAMP: val = tp->window_clamp; @@ -2387,6 +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; } @@ -2809,6 +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) @@ -2843,6 +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)); @@ -2865,11 +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); } @@ -2878,7 +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, @@ -2933,10 +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); |