From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/net/ipv4/tcp_fastopen.c | 313 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 313 insertions(+) create mode 100644 kernel/net/ipv4/tcp_fastopen.c (limited to 'kernel/net/ipv4/tcp_fastopen.c') diff --git a/kernel/net/ipv4/tcp_fastopen.c b/kernel/net/ipv4/tcp_fastopen.c new file mode 100644 index 000000000..f9c0fb84e --- /dev/null +++ b/kernel/net/ipv4/tcp_fastopen.c @@ -0,0 +1,313 @@ +#include +#include +#include +#include +#include +#include +#include +#include +#include + +int sysctl_tcp_fastopen __read_mostly = TFO_CLIENT_ENABLE; + +struct tcp_fastopen_context __rcu *tcp_fastopen_ctx; + +static DEFINE_SPINLOCK(tcp_fastopen_ctx_lock); + +void tcp_fastopen_init_key_once(bool publish) +{ + static u8 key[TCP_FASTOPEN_KEY_LENGTH]; + + /* tcp_fastopen_reset_cipher publishes the new context + * atomically, so we allow this race happening here. + * + * All call sites of tcp_fastopen_cookie_gen also check + * for a valid cookie, so this is an acceptable risk. + */ + if (net_get_random_once(key, sizeof(key)) && publish) + tcp_fastopen_reset_cipher(key, sizeof(key)); +} + +static void tcp_fastopen_ctx_free(struct rcu_head *head) +{ + struct tcp_fastopen_context *ctx = + container_of(head, struct tcp_fastopen_context, rcu); + crypto_free_cipher(ctx->tfm); + kfree(ctx); +} + +int tcp_fastopen_reset_cipher(void *key, unsigned int len) +{ + int err; + struct tcp_fastopen_context *ctx, *octx; + + ctx = kmalloc(sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + ctx->tfm = crypto_alloc_cipher("aes", 0, 0); + + if (IS_ERR(ctx->tfm)) { + err = PTR_ERR(ctx->tfm); +error: kfree(ctx); + pr_err("TCP: TFO aes cipher alloc error: %d\n", err); + return err; + } + err = crypto_cipher_setkey(ctx->tfm, key, len); + if (err) { + pr_err("TCP: TFO cipher key error: %d\n", err); + crypto_free_cipher(ctx->tfm); + goto error; + } + memcpy(ctx->key, key, len); + + spin_lock(&tcp_fastopen_ctx_lock); + + octx = rcu_dereference_protected(tcp_fastopen_ctx, + lockdep_is_held(&tcp_fastopen_ctx_lock)); + rcu_assign_pointer(tcp_fastopen_ctx, ctx); + spin_unlock(&tcp_fastopen_ctx_lock); + + if (octx) + call_rcu(&octx->rcu, tcp_fastopen_ctx_free); + return err; +} + +static bool __tcp_fastopen_cookie_gen(const void *path, + struct tcp_fastopen_cookie *foc) +{ + struct tcp_fastopen_context *ctx; + bool ok = false; + + rcu_read_lock(); + ctx = rcu_dereference(tcp_fastopen_ctx); + if (ctx) { + crypto_cipher_encrypt_one(ctx->tfm, foc->val, path); + foc->len = TCP_FASTOPEN_COOKIE_SIZE; + ok = true; + } + rcu_read_unlock(); + return ok; +} + +/* Generate the fastopen cookie by doing aes128 encryption on both + * the source and destination addresses. Pad 0s for IPv4 or IPv4-mapped-IPv6 + * addresses. For the longer IPv6 addresses use CBC-MAC. + * + * XXX (TFO) - refactor when TCP_FASTOPEN_COOKIE_SIZE != AES_BLOCK_SIZE. + */ +static bool tcp_fastopen_cookie_gen(struct request_sock *req, + struct sk_buff *syn, + struct tcp_fastopen_cookie *foc) +{ + if (req->rsk_ops->family == AF_INET) { + const struct iphdr *iph = ip_hdr(syn); + + __be32 path[4] = { iph->saddr, iph->daddr, 0, 0 }; + return __tcp_fastopen_cookie_gen(path, foc); + } + +#if IS_ENABLED(CONFIG_IPV6) + if (req->rsk_ops->family == AF_INET6) { + const struct ipv6hdr *ip6h = ipv6_hdr(syn); + struct tcp_fastopen_cookie tmp; + + if (__tcp_fastopen_cookie_gen(&ip6h->saddr, &tmp)) { + struct in6_addr *buf = (struct in6_addr *) tmp.val; + int i; + + for (i = 0; i < 4; i++) + buf->s6_addr32[i] ^= ip6h->daddr.s6_addr32[i]; + return __tcp_fastopen_cookie_gen(buf, foc); + } + } +#endif + return false; +} + +static bool tcp_fastopen_create_child(struct sock *sk, + struct sk_buff *skb, + struct dst_entry *dst, + struct request_sock *req) +{ + struct tcp_sock *tp; + struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue; + struct sock *child; + u32 end_seq; + + req->num_retrans = 0; + req->num_timeout = 0; + req->sk = NULL; + + child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL); + if (!child) + return false; + + spin_lock(&queue->fastopenq->lock); + queue->fastopenq->qlen++; + spin_unlock(&queue->fastopenq->lock); + + /* Initialize the child socket. Have to fix some values to take + * into account the child is a Fast Open socket and is created + * only out of the bits carried in the SYN packet. + */ + tp = tcp_sk(child); + + tp->fastopen_rsk = req; + tcp_rsk(req)->tfo_listener = true; + + /* RFC1323: The window in SYN & SYN/ACK segments is never + * scaled. So correct it appropriately. + */ + tp->snd_wnd = ntohs(tcp_hdr(skb)->window); + + /* Activate the retrans timer so that SYNACK can be retransmitted. + * The request socket is not added to the SYN table of the parent + * because it's been added to the accept queue directly. + */ + inet_csk_reset_xmit_timer(child, ICSK_TIME_RETRANS, + TCP_TIMEOUT_INIT, TCP_RTO_MAX); + + atomic_set(&req->rsk_refcnt, 1); + /* Add the child socket directly into the accept queue */ + inet_csk_reqsk_queue_add(sk, req, child); + + /* Now finish processing the fastopen child socket. */ + inet_csk(child)->icsk_af_ops->rebuild_header(child); + tcp_init_congestion_control(child); + tcp_mtup_init(child); + tcp_init_metrics(child); + tcp_init_buffer_space(child); + + /* Queue the data carried in the SYN packet. We need to first + * bump skb's refcnt because the caller will attempt to free it. + * Note that IPv6 might also have used skb_get() trick + * in tcp_v6_conn_request() to keep this SYN around (treq->pktopts) + * So we need to eventually get a clone of the packet, + * before inserting it in sk_receive_queue. + * + * XXX (TFO) - we honor a zero-payload TFO request for now, + * (any reason not to?) but no need to queue the skb since + * there is no data. How about SYN+FIN? + */ + end_seq = TCP_SKB_CB(skb)->end_seq; + if (end_seq != TCP_SKB_CB(skb)->seq + 1) { + struct sk_buff *skb2; + + if (unlikely(skb_shared(skb))) + skb2 = skb_clone(skb, GFP_ATOMIC); + else + skb2 = skb_get(skb); + + if (likely(skb2)) { + skb_dst_drop(skb2); + __skb_pull(skb2, tcp_hdrlen(skb)); + skb_set_owner_r(skb2, child); + __skb_queue_tail(&child->sk_receive_queue, skb2); + tp->syn_data_acked = 1; + + /* u64_stats_update_begin(&tp->syncp) not needed here, + * as we certainly are not changing upper 32bit value (0) + */ + tp->bytes_received = end_seq - TCP_SKB_CB(skb)->seq - 1; + } else { + end_seq = TCP_SKB_CB(skb)->seq + 1; + } + } + tcp_rsk(req)->rcv_nxt = tp->rcv_nxt = end_seq; + sk->sk_data_ready(sk); + bh_unlock_sock(child); + sock_put(child); + WARN_ON(!req->sk); + return true; +} + +static bool tcp_fastopen_queue_check(struct sock *sk) +{ + struct fastopen_queue *fastopenq; + + /* Make sure the listener has enabled fastopen, and we don't + * exceed the max # of pending TFO requests allowed before trying + * to validating the cookie in order to avoid burning CPU cycles + * unnecessarily. + * + * XXX (TFO) - The implication of checking the max_qlen before + * processing a cookie request is that clients can't differentiate + * between qlen overflow causing Fast Open to be disabled + * temporarily vs a server not supporting Fast Open at all. + */ + fastopenq = inet_csk(sk)->icsk_accept_queue.fastopenq; + if (!fastopenq || fastopenq->max_qlen == 0) + return false; + + if (fastopenq->qlen >= fastopenq->max_qlen) { + struct request_sock *req1; + spin_lock(&fastopenq->lock); + req1 = fastopenq->rskq_rst_head; + if (!req1 || time_after(req1->rsk_timer.expires, jiffies)) { + spin_unlock(&fastopenq->lock); + NET_INC_STATS_BH(sock_net(sk), + LINUX_MIB_TCPFASTOPENLISTENOVERFLOW); + return false; + } + fastopenq->rskq_rst_head = req1->dl_next; + fastopenq->qlen--; + spin_unlock(&fastopenq->lock); + reqsk_put(req1); + } + return true; +} + +/* Returns true if we should perform Fast Open on the SYN. The cookie (foc) + * may be updated and return the client in the SYN-ACK later. E.g., Fast Open + * cookie request (foc->len == 0). + */ +bool tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, + struct request_sock *req, + struct tcp_fastopen_cookie *foc, + struct dst_entry *dst) +{ + struct tcp_fastopen_cookie valid_foc = { .len = -1 }; + bool syn_data = TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq + 1; + + if (foc->len == 0) /* Client requests a cookie */ + NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPFASTOPENCOOKIEREQD); + + if (!((sysctl_tcp_fastopen & TFO_SERVER_ENABLE) && + (syn_data || foc->len >= 0) && + tcp_fastopen_queue_check(sk))) { + foc->len = -1; + return false; + } + + if (syn_data && (sysctl_tcp_fastopen & TFO_SERVER_COOKIE_NOT_REQD)) + goto fastopen; + + if (foc->len >= 0 && /* Client presents or requests a cookie */ + tcp_fastopen_cookie_gen(req, skb, &valid_foc) && + foc->len == TCP_FASTOPEN_COOKIE_SIZE && + foc->len == valid_foc.len && + !memcmp(foc->val, valid_foc.val, foc->len)) { + /* Cookie is valid. Create a (full) child socket to accept + * the data in SYN before returning a SYN-ACK to ack the + * data. If we fail to create the socket, fall back and + * ack the ISN only but includes the same cookie. + * + * Note: Data-less SYN with valid cookie is allowed to send + * data in SYN_RECV state. + */ +fastopen: + if (tcp_fastopen_create_child(sk, skb, dst, req)) { + foc->len = -1; + NET_INC_STATS_BH(sock_net(sk), + LINUX_MIB_TCPFASTOPENPASSIVE); + return true; + } + NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPFASTOPENPASSIVEFAIL); + } else if (foc->len > 0) /* Client presents an invalid cookie */ + NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPFASTOPENPASSIVEFAIL); + + valid_foc.exp = foc->exp; + *foc = valid_foc; + return false; +} +EXPORT_SYMBOL(tcp_try_fastopen); -- cgit 1.2.3-korg