![Linus Torvalds](/assets/img/avatar_default.png)
Pull networking updates from David Miller: "Highlights: 1) Support more Realtek wireless chips, from Jes Sorenson. 2) New BPF types for per-cpu hash and arrap maps, from Alexei Starovoitov. 3) Make several TCP sysctls per-namespace, from Nikolay Borisov. 4) Allow the use of SO_REUSEPORT in order to do per-thread processing of incoming TCP/UDP connections. The muxing can be done using a BPF program which hashes the incoming packet. From Craig Gallek. 5) Add a multiplexer for TCP streams, to provide a messaged based interface. BPF programs can be used to determine the message boundaries. From Tom Herbert. 6) Add 802.1AE MACSEC support, from Sabrina Dubroca. 7) Avoid factorial complexity when taking down an inetdev interface with lots of configured addresses. We were doing things like traversing the entire address less for each address removed, and flushing the entire netfilter conntrack table for every address as well. 8) Add and use SKB bulk free infrastructure, from Jesper Brouer. 9) Allow offloading u32 classifiers to hardware, and implement for ixgbe, from John Fastabend. 10) Allow configuring IRQ coalescing parameters on a per-queue basis, from Kan Liang. 11) Extend ethtool so that larger link mode masks can be supported. From David Decotigny. 12) Introduce devlink, which can be used to configure port link types (ethernet vs Infiniband, etc.), port splitting, and switch device level attributes as a whole. From Jiri Pirko. 13) Hardware offload support for flower classifiers, from Amir Vadai. 14) Add "Local Checksum Offload". Basically, for a tunneled packet the checksum of the outer header is 'constant' (because with the checksum field filled into the inner protocol header, the payload of the outer frame checksums to 'zero'), and we can take advantage of that in various ways. From Edward Cree" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1548 commits) bonding: fix bond_get_stats() net: bcmgenet: fix dma api length mismatch net/mlx4_core: Fix backward compatibility on VFs phy: mdio-thunder: Fix some Kconfig typos lan78xx: add ndo_get_stats64 lan78xx: handle statistics counter rollover RDS: TCP: Remove unused constant RDS: TCP: Add sysctl tunables for sndbuf/rcvbuf on rds-tcp socket net: smc911x: convert pxa dma to dmaengine team: remove duplicate set of flag IFF_MULTICAST bonding: remove duplicate set of flag IFF_MULTICAST net: fix a comment typo ethernet: micrel: fix some error codes ip_tunnels, bpf: define IP_TUNNEL_OPTS_MAX and use it bpf, dst: add and use dst_tclassid helper bpf: make skb->tc_classid also readable net: mvneta: bm: clarify dependencies cls_bpf: reset class and reuse major in da ldmvsw: Checkpatch sunvnet.c and sunvnet_common.c ldmvsw: Add ldmvsw.c driver code ...
326 lines
9.1 KiB
C
326 lines
9.1 KiB
C
#include <linux/crypto.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/list.h>
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#include <linux/tcp.h>
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#include <linux/rcupdate.h>
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#include <linux/rculist.h>
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#include <net/inetpeer.h>
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#include <net/tcp.h>
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int sysctl_tcp_fastopen __read_mostly = TFO_CLIENT_ENABLE;
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struct tcp_fastopen_context __rcu *tcp_fastopen_ctx;
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static DEFINE_SPINLOCK(tcp_fastopen_ctx_lock);
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void tcp_fastopen_init_key_once(bool publish)
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{
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static u8 key[TCP_FASTOPEN_KEY_LENGTH];
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/* tcp_fastopen_reset_cipher publishes the new context
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* atomically, so we allow this race happening here.
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*
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* All call sites of tcp_fastopen_cookie_gen also check
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* for a valid cookie, so this is an acceptable risk.
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*/
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if (net_get_random_once(key, sizeof(key)) && publish)
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tcp_fastopen_reset_cipher(key, sizeof(key));
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}
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static void tcp_fastopen_ctx_free(struct rcu_head *head)
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{
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struct tcp_fastopen_context *ctx =
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container_of(head, struct tcp_fastopen_context, rcu);
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crypto_free_cipher(ctx->tfm);
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kfree(ctx);
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}
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int tcp_fastopen_reset_cipher(void *key, unsigned int len)
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{
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int err;
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struct tcp_fastopen_context *ctx, *octx;
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ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
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if (!ctx)
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return -ENOMEM;
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ctx->tfm = crypto_alloc_cipher("aes", 0, 0);
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if (IS_ERR(ctx->tfm)) {
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err = PTR_ERR(ctx->tfm);
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error: kfree(ctx);
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pr_err("TCP: TFO aes cipher alloc error: %d\n", err);
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return err;
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}
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err = crypto_cipher_setkey(ctx->tfm, key, len);
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if (err) {
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pr_err("TCP: TFO cipher key error: %d\n", err);
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crypto_free_cipher(ctx->tfm);
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goto error;
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}
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memcpy(ctx->key, key, len);
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spin_lock(&tcp_fastopen_ctx_lock);
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octx = rcu_dereference_protected(tcp_fastopen_ctx,
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lockdep_is_held(&tcp_fastopen_ctx_lock));
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rcu_assign_pointer(tcp_fastopen_ctx, ctx);
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spin_unlock(&tcp_fastopen_ctx_lock);
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if (octx)
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call_rcu(&octx->rcu, tcp_fastopen_ctx_free);
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return err;
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}
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static bool __tcp_fastopen_cookie_gen(const void *path,
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struct tcp_fastopen_cookie *foc)
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{
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struct tcp_fastopen_context *ctx;
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bool ok = false;
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rcu_read_lock();
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ctx = rcu_dereference(tcp_fastopen_ctx);
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if (ctx) {
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crypto_cipher_encrypt_one(ctx->tfm, foc->val, path);
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foc->len = TCP_FASTOPEN_COOKIE_SIZE;
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ok = true;
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}
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rcu_read_unlock();
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return ok;
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}
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/* Generate the fastopen cookie by doing aes128 encryption on both
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* the source and destination addresses. Pad 0s for IPv4 or IPv4-mapped-IPv6
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* addresses. For the longer IPv6 addresses use CBC-MAC.
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*
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* XXX (TFO) - refactor when TCP_FASTOPEN_COOKIE_SIZE != AES_BLOCK_SIZE.
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*/
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static bool tcp_fastopen_cookie_gen(struct request_sock *req,
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struct sk_buff *syn,
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struct tcp_fastopen_cookie *foc)
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{
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if (req->rsk_ops->family == AF_INET) {
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const struct iphdr *iph = ip_hdr(syn);
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__be32 path[4] = { iph->saddr, iph->daddr, 0, 0 };
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return __tcp_fastopen_cookie_gen(path, foc);
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}
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#if IS_ENABLED(CONFIG_IPV6)
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if (req->rsk_ops->family == AF_INET6) {
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const struct ipv6hdr *ip6h = ipv6_hdr(syn);
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struct tcp_fastopen_cookie tmp;
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if (__tcp_fastopen_cookie_gen(&ip6h->saddr, &tmp)) {
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struct in6_addr *buf = (struct in6_addr *) tmp.val;
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int i;
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for (i = 0; i < 4; i++)
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buf->s6_addr32[i] ^= ip6h->daddr.s6_addr32[i];
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return __tcp_fastopen_cookie_gen(buf, foc);
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}
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}
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#endif
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return false;
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}
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/* If an incoming SYN or SYNACK frame contains a payload and/or FIN,
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* queue this additional data / FIN.
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*/
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void tcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb)
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{
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struct tcp_sock *tp = tcp_sk(sk);
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if (TCP_SKB_CB(skb)->end_seq == tp->rcv_nxt)
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return;
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skb = skb_clone(skb, GFP_ATOMIC);
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if (!skb)
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return;
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skb_dst_drop(skb);
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/* segs_in has been initialized to 1 in tcp_create_openreq_child().
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* Hence, reset segs_in to 0 before calling tcp_segs_in()
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* to avoid double counting. Also, tcp_segs_in() expects
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* skb->len to include the tcp_hdrlen. Hence, it should
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* be called before __skb_pull().
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*/
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tp->segs_in = 0;
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tcp_segs_in(tp, skb);
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__skb_pull(skb, tcp_hdrlen(skb));
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skb_set_owner_r(skb, sk);
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TCP_SKB_CB(skb)->seq++;
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TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_SYN;
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tp->rcv_nxt = TCP_SKB_CB(skb)->end_seq;
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__skb_queue_tail(&sk->sk_receive_queue, skb);
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tp->syn_data_acked = 1;
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/* u64_stats_update_begin(&tp->syncp) not needed here,
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* as we certainly are not changing upper 32bit value (0)
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*/
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tp->bytes_received = skb->len;
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if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
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tcp_fin(sk);
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}
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static struct sock *tcp_fastopen_create_child(struct sock *sk,
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struct sk_buff *skb,
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struct dst_entry *dst,
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struct request_sock *req)
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{
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struct tcp_sock *tp;
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struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue;
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struct sock *child;
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bool own_req;
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req->num_retrans = 0;
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req->num_timeout = 0;
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req->sk = NULL;
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child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL,
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NULL, &own_req);
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if (!child)
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return NULL;
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spin_lock(&queue->fastopenq.lock);
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queue->fastopenq.qlen++;
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spin_unlock(&queue->fastopenq.lock);
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/* Initialize the child socket. Have to fix some values to take
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* into account the child is a Fast Open socket and is created
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* only out of the bits carried in the SYN packet.
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*/
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tp = tcp_sk(child);
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tp->fastopen_rsk = req;
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tcp_rsk(req)->tfo_listener = true;
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/* RFC1323: The window in SYN & SYN/ACK segments is never
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* scaled. So correct it appropriately.
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*/
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tp->snd_wnd = ntohs(tcp_hdr(skb)->window);
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/* Activate the retrans timer so that SYNACK can be retransmitted.
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* The request socket is not added to the ehash
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* because it's been added to the accept queue directly.
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*/
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inet_csk_reset_xmit_timer(child, ICSK_TIME_RETRANS,
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TCP_TIMEOUT_INIT, TCP_RTO_MAX);
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atomic_set(&req->rsk_refcnt, 2);
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/* Now finish processing the fastopen child socket. */
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inet_csk(child)->icsk_af_ops->rebuild_header(child);
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tcp_init_congestion_control(child);
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tcp_mtup_init(child);
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tcp_init_metrics(child);
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tcp_init_buffer_space(child);
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tp->rcv_nxt = TCP_SKB_CB(skb)->seq + 1;
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tcp_fastopen_add_skb(child, skb);
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tcp_rsk(req)->rcv_nxt = tp->rcv_nxt;
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/* tcp_conn_request() is sending the SYNACK,
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* and queues the child into listener accept queue.
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*/
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return child;
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}
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static bool tcp_fastopen_queue_check(struct sock *sk)
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{
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struct fastopen_queue *fastopenq;
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/* Make sure the listener has enabled fastopen, and we don't
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* exceed the max # of pending TFO requests allowed before trying
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* to validating the cookie in order to avoid burning CPU cycles
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* unnecessarily.
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*
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* XXX (TFO) - The implication of checking the max_qlen before
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* processing a cookie request is that clients can't differentiate
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* between qlen overflow causing Fast Open to be disabled
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* temporarily vs a server not supporting Fast Open at all.
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*/
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fastopenq = &inet_csk(sk)->icsk_accept_queue.fastopenq;
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if (fastopenq->max_qlen == 0)
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return false;
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if (fastopenq->qlen >= fastopenq->max_qlen) {
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struct request_sock *req1;
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spin_lock(&fastopenq->lock);
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req1 = fastopenq->rskq_rst_head;
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if (!req1 || time_after(req1->rsk_timer.expires, jiffies)) {
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spin_unlock(&fastopenq->lock);
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NET_INC_STATS_BH(sock_net(sk),
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LINUX_MIB_TCPFASTOPENLISTENOVERFLOW);
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return false;
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}
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fastopenq->rskq_rst_head = req1->dl_next;
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fastopenq->qlen--;
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spin_unlock(&fastopenq->lock);
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reqsk_put(req1);
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}
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return true;
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}
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/* Returns true if we should perform Fast Open on the SYN. The cookie (foc)
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* may be updated and return the client in the SYN-ACK later. E.g., Fast Open
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* cookie request (foc->len == 0).
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*/
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struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb,
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struct request_sock *req,
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struct tcp_fastopen_cookie *foc,
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struct dst_entry *dst)
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{
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struct tcp_fastopen_cookie valid_foc = { .len = -1 };
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bool syn_data = TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq + 1;
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struct sock *child;
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if (foc->len == 0) /* Client requests a cookie */
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NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPFASTOPENCOOKIEREQD);
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if (!((sysctl_tcp_fastopen & TFO_SERVER_ENABLE) &&
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(syn_data || foc->len >= 0) &&
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tcp_fastopen_queue_check(sk))) {
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foc->len = -1;
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return NULL;
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}
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if (syn_data && (sysctl_tcp_fastopen & TFO_SERVER_COOKIE_NOT_REQD))
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goto fastopen;
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if (foc->len >= 0 && /* Client presents or requests a cookie */
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tcp_fastopen_cookie_gen(req, skb, &valid_foc) &&
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foc->len == TCP_FASTOPEN_COOKIE_SIZE &&
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foc->len == valid_foc.len &&
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!memcmp(foc->val, valid_foc.val, foc->len)) {
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/* Cookie is valid. Create a (full) child socket to accept
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* the data in SYN before returning a SYN-ACK to ack the
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* data. If we fail to create the socket, fall back and
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* ack the ISN only but includes the same cookie.
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*
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* Note: Data-less SYN with valid cookie is allowed to send
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* data in SYN_RECV state.
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*/
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fastopen:
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child = tcp_fastopen_create_child(sk, skb, dst, req);
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if (child) {
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foc->len = -1;
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NET_INC_STATS_BH(sock_net(sk),
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LINUX_MIB_TCPFASTOPENPASSIVE);
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return child;
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}
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NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPFASTOPENPASSIVEFAIL);
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} else if (foc->len > 0) /* Client presents an invalid cookie */
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NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPFASTOPENPASSIVEFAIL);
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valid_foc.exp = foc->exp;
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*foc = valid_foc;
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return NULL;
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}
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