1c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin/* 2c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin * IPv6 Syncookies implementation for the Linux kernel 3c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin * 4c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin * Authors: 5c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin * Glenn Griffin <ggriffin.kernel@gmail.com> 6c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin * 7c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin * Based on IPv4 implementation by Andi Kleen 8c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin * linux/net/ipv4/syncookies.c 9c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin * 10c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin * This program is free software; you can redistribute it and/or 11c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin * modify it under the terms of the GNU General Public License 12c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin * as published by the Free Software Foundation; either version 13c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin * 2 of the License, or (at your option) any later version. 14c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin * 15c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin */ 16c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 17c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin#include <linux/tcp.h> 18c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin#include <linux/random.h> 19c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin#include <linux/cryptohash.h> 20c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin#include <linux/kernel.h> 21c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin#include <net/ipv6.h> 22c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin#include <net/tcp.h> 23c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 24c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin#define COOKIEBITS 24 /* Upper bits store count */ 25c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin#define COOKIEMASK (((__u32)1 << COOKIEBITS) - 1) 26c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 27253ff51635ad6690276ef065d59523c4bd1cd584Florian Westphalstatic u32 syncookie6_secret[2][16-4+SHA_DIGEST_WORDS] __read_mostly; 28b23a002fc6f0c19846ee0382f019429af54a27e9Hannes Frederic Sowa 29086293542b991fb88a2e41ae7b4f82ac65a20e1aFlorian Westphal/* RFC 2460, Section 8.3: 30086293542b991fb88a2e41ae7b4f82ac65a20e1aFlorian Westphal * [ipv6 tcp] MSS must be computed as the maximum packet size minus 60 [..] 31086293542b991fb88a2e41ae7b4f82ac65a20e1aFlorian Westphal * 32086293542b991fb88a2e41ae7b4f82ac65a20e1aFlorian Westphal * Due to IPV6_MIN_MTU=1280 the lowest possible MSS is 1220, which allows 33086293542b991fb88a2e41ae7b4f82ac65a20e1aFlorian Westphal * using higher values than ipv4 tcp syncookies. 34086293542b991fb88a2e41ae7b4f82ac65a20e1aFlorian Westphal * The other values are chosen based on ethernet (1500 and 9k MTU), plus 35086293542b991fb88a2e41ae7b4f82ac65a20e1aFlorian Westphal * one that accounts for common encap (PPPoe) overhead. Table must be sorted. 36086293542b991fb88a2e41ae7b4f82ac65a20e1aFlorian Westphal */ 37c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffinstatic __u16 const msstab[] = { 38086293542b991fb88a2e41ae7b4f82ac65a20e1aFlorian Westphal 1280 - 60, /* IPV6_MIN_MTU - 60 */ 395918e2fb9035b35164002c3a268feaf70b7c04d5Florian Westphal 1480 - 60, 405918e2fb9035b35164002c3a268feaf70b7c04d5Florian Westphal 1500 - 60, 415918e2fb9035b35164002c3a268feaf70b7c04d5Florian Westphal 9000 - 60, 42c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin}; 43c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 44c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffinstatic inline struct sock *get_cookie_sock(struct sock *sk, struct sk_buff *skb, 45c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin struct request_sock *req, 46c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin struct dst_entry *dst) 47c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin{ 48c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin struct inet_connection_sock *icsk = inet_csk(sk); 49c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin struct sock *child; 50c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 51c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin child = icsk->icsk_af_ops->syn_recv_sock(sk, skb, req, dst); 52c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin if (child) 53c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin inet_csk_reqsk_queue_add(sk, req, child); 54c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin else 55c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin reqsk_free(req); 56c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 57c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin return child; 58c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin} 59c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 60245b2e70eabd797932adb263a65da0bab3711753Tejun Heostatic DEFINE_PER_CPU(__u32 [16 + 5 + SHA_WORKSPACE_WORDS], 61245b2e70eabd797932adb263a65da0bab3711753Tejun Heo ipv6_cookie_scratch); 62c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 63b71d1d426d263b0b6cb5760322efebbfc89d4463Eric Dumazetstatic u32 cookie_hash(const struct in6_addr *saddr, const struct in6_addr *daddr, 64c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin __be16 sport, __be16 dport, u32 count, int c) 65c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin{ 66b23a002fc6f0c19846ee0382f019429af54a27e9Hannes Frederic Sowa __u32 *tmp; 67b23a002fc6f0c19846ee0382f019429af54a27e9Hannes Frederic Sowa 68b23a002fc6f0c19846ee0382f019429af54a27e9Hannes Frederic Sowa net_get_random_once(syncookie6_secret, sizeof(syncookie6_secret)); 69b23a002fc6f0c19846ee0382f019429af54a27e9Hannes Frederic Sowa 70903ceff7ca7b4d80c083a80ee5163b74e9fa359fChristoph Lameter tmp = this_cpu_ptr(ipv6_cookie_scratch); 71c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 72c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin /* 73c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin * we have 320 bits of information to hash, copy in the remaining 74b23a002fc6f0c19846ee0382f019429af54a27e9Hannes Frederic Sowa * 192 bits required for sha_transform, from the syncookie6_secret 75c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin * and overwrite the digest with the secret 76c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin */ 77b23a002fc6f0c19846ee0382f019429af54a27e9Hannes Frederic Sowa memcpy(tmp + 10, syncookie6_secret[c], 44); 78c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin memcpy(tmp, saddr, 16); 79c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin memcpy(tmp + 4, daddr, 16); 80c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin tmp[8] = ((__force u32)sport << 16) + (__force u32)dport; 81c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin tmp[9] = count; 82c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin sha_transform(tmp + 16, (__u8 *)tmp, tmp + 16 + 5); 83c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 84c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin return tmp[17]; 85c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin} 86c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 87b71d1d426d263b0b6cb5760322efebbfc89d4463Eric Dumazetstatic __u32 secure_tcp_syn_cookie(const struct in6_addr *saddr, 88b71d1d426d263b0b6cb5760322efebbfc89d4463Eric Dumazet const struct in6_addr *daddr, 89c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin __be16 sport, __be16 dport, __u32 sseq, 908c27bd75f04fb9cb70c69c3cfe24f4e6d8e15906Florian Westphal __u32 data) 91c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin{ 928c27bd75f04fb9cb70c69c3cfe24f4e6d8e15906Florian Westphal u32 count = tcp_cookie_time(); 93c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin return (cookie_hash(saddr, daddr, sport, dport, 0, 0) + 94c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin sseq + (count << COOKIEBITS) + 95c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin ((cookie_hash(saddr, daddr, sport, dport, count, 1) + data) 96c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin & COOKIEMASK)); 97c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin} 98c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 99b71d1d426d263b0b6cb5760322efebbfc89d4463Eric Dumazetstatic __u32 check_tcp_syn_cookie(__u32 cookie, const struct in6_addr *saddr, 100b71d1d426d263b0b6cb5760322efebbfc89d4463Eric Dumazet const struct in6_addr *daddr, __be16 sport, 1018c27bd75f04fb9cb70c69c3cfe24f4e6d8e15906Florian Westphal __be16 dport, __u32 sseq) 102c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin{ 1038c27bd75f04fb9cb70c69c3cfe24f4e6d8e15906Florian Westphal __u32 diff, count = tcp_cookie_time(); 104c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 105c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin cookie -= cookie_hash(saddr, daddr, sport, dport, 0, 0) + sseq; 106c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 107c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin diff = (count - (cookie >> COOKIEBITS)) & ((__u32) -1 >> COOKIEBITS); 1088c27bd75f04fb9cb70c69c3cfe24f4e6d8e15906Florian Westphal if (diff >= MAX_SYNCOOKIE_AGE) 109c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin return (__u32)-1; 110c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 111c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin return (cookie - 112c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin cookie_hash(saddr, daddr, sport, dport, count - diff, 1)) 113c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin & COOKIEMASK; 114c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin} 115c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 11681eb6a1487718a89621a0e0be7fafd0cd7c429a4Patrick McHardyu32 __cookie_v6_init_sequence(const struct ipv6hdr *iph, 11781eb6a1487718a89621a0e0be7fafd0cd7c429a4Patrick McHardy const struct tcphdr *th, __u16 *mssp) 118c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin{ 119c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin int mssind; 120c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin const __u16 mss = *mssp; 121c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 1225918e2fb9035b35164002c3a268feaf70b7c04d5Florian Westphal for (mssind = ARRAY_SIZE(msstab) - 1; mssind ; mssind--) 1235918e2fb9035b35164002c3a268feaf70b7c04d5Florian Westphal if (mss >= msstab[mssind]) 1245918e2fb9035b35164002c3a268feaf70b7c04d5Florian Westphal break; 1255918e2fb9035b35164002c3a268feaf70b7c04d5Florian Westphal 1265918e2fb9035b35164002c3a268feaf70b7c04d5Florian Westphal *mssp = msstab[mssind]; 127c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 128c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin return secure_tcp_syn_cookie(&iph->saddr, &iph->daddr, th->source, 1298c27bd75f04fb9cb70c69c3cfe24f4e6d8e15906Florian Westphal th->dest, ntohl(th->seq), mssind); 130c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin} 13181eb6a1487718a89621a0e0be7fafd0cd7c429a4Patrick McHardyEXPORT_SYMBOL_GPL(__cookie_v6_init_sequence); 132c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 13381eb6a1487718a89621a0e0be7fafd0cd7c429a4Patrick McHardy__u32 cookie_v6_init_sequence(struct sock *sk, const struct sk_buff *skb, __u16 *mssp) 134c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin{ 135b71d1d426d263b0b6cb5760322efebbfc89d4463Eric Dumazet const struct ipv6hdr *iph = ipv6_hdr(skb); 136c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin const struct tcphdr *th = tcp_hdr(skb); 13781eb6a1487718a89621a0e0be7fafd0cd7c429a4Patrick McHardy 13881eb6a1487718a89621a0e0be7fafd0cd7c429a4Patrick McHardy tcp_synq_overflow(sk); 13981eb6a1487718a89621a0e0be7fafd0cd7c429a4Patrick McHardy NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESSENT); 14081eb6a1487718a89621a0e0be7fafd0cd7c429a4Patrick McHardy 14181eb6a1487718a89621a0e0be7fafd0cd7c429a4Patrick McHardy return __cookie_v6_init_sequence(iph, th, mssp); 14281eb6a1487718a89621a0e0be7fafd0cd7c429a4Patrick McHardy} 14381eb6a1487718a89621a0e0be7fafd0cd7c429a4Patrick McHardy 14481eb6a1487718a89621a0e0be7fafd0cd7c429a4Patrick McHardyint __cookie_v6_check(const struct ipv6hdr *iph, const struct tcphdr *th, 14581eb6a1487718a89621a0e0be7fafd0cd7c429a4Patrick McHardy __u32 cookie) 14681eb6a1487718a89621a0e0be7fafd0cd7c429a4Patrick McHardy{ 147c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin __u32 seq = ntohl(th->seq) - 1; 148c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin __u32 mssind = check_tcp_syn_cookie(cookie, &iph->saddr, &iph->daddr, 1498c27bd75f04fb9cb70c69c3cfe24f4e6d8e15906Florian Westphal th->source, th->dest, seq); 150c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 1515918e2fb9035b35164002c3a268feaf70b7c04d5Florian Westphal return mssind < ARRAY_SIZE(msstab) ? msstab[mssind] : 0; 152c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin} 15381eb6a1487718a89621a0e0be7fafd0cd7c429a4Patrick McHardyEXPORT_SYMBOL_GPL(__cookie_v6_check); 154c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 155c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffinstruct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) 156c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin{ 1574957faade11b3a278c3b3cade3411ddc20afa791William Allen Simpson struct tcp_options_received tcp_opt; 158c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin struct inet_request_sock *ireq; 159c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin struct tcp_request_sock *treq; 160c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin struct ipv6_pinfo *np = inet6_sk(sk); 161c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin struct tcp_sock *tp = tcp_sk(sk); 162c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin const struct tcphdr *th = tcp_hdr(skb); 163c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin __u32 cookie = ntohl(th->ack_seq) - 1; 164c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin struct sock *ret = sk; 165c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin struct request_sock *req; 166c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin int mss; 167c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin struct dst_entry *dst; 168c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin __u8 rcv_wscale; 169f0e3d0689da401f7d1981c2777a714ba295ea5ffMike Waychison bool ecn_ok = false; 170c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 171af9b4738574b46025de7ccbe75c7b24fd8914379Florian Westphal if (!sysctl_tcp_syncookies || !th->ack || th->rst) 172c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin goto out; 173c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 174a0f82f64e26929776c58a5c93c2ecb38e3d82815Florian Westphal if (tcp_synq_no_recent_overflow(sk) || 17581eb6a1487718a89621a0e0be7fafd0cd7c429a4Patrick McHardy (mss = __cookie_v6_check(ipv6_hdr(skb), th, cookie)) == 0) { 176de0744af1fe2d0a3d428f6af0f2fe1f6179b1a9cPavel Emelyanov NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESFAILED); 177c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin goto out; 178c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin } 179c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 180de0744af1fe2d0a3d428f6af0f2fe1f6179b1a9cPavel Emelyanov NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESRECV); 181c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 182bb5b7c11263dbbe78253cd05945a6bf8f55add8eDavid S. Miller /* check for timestamp cookie support */ 183bb5b7c11263dbbe78253cd05945a6bf8f55add8eDavid S. Miller memset(&tcp_opt, 0, sizeof(tcp_opt)); 1841a2c6181c4a1922021b4d7df373bba612c3e5f04Christoph Paasch tcp_parse_options(skb, &tcp_opt, 0, NULL); 185bb5b7c11263dbbe78253cd05945a6bf8f55add8eDavid S. Miller 1865d134f1c1f36166e8a738de92c4d2f4c262ff91bHannes Frederic Sowa if (!cookie_check_timestamp(&tcp_opt, sock_net(sk), &ecn_ok)) 1878c76368174ed2359739f1b7b8a9c042b1ef839c4Florian Westphal goto out; 188bb5b7c11263dbbe78253cd05945a6bf8f55add8eDavid S. Miller 189c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin ret = NULL; 190476eab8251641ea2ae4666ca8a1436ebc2b8e9c3Octavian Purdila req = inet_reqsk_alloc(&tcp6_request_sock_ops); 191c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin if (!req) 192c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin goto out; 193c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 194c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin ireq = inet_rsk(req); 195c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin treq = tcp_rsk(req); 1968336886f786fdacbc19b719c1f7ea91eb70706d4Jerry Chu treq->listener = NULL; 197c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 1981730554f253deb65fe5112c54b2f898d5318a328Florian Westphal if (security_inet_conn_request(sk, skb, req)) 1991730554f253deb65fe5112c54b2f898d5318a328Florian Westphal goto out_free; 200c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 201c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin req->mss = mss; 202634fb979e8f3a70f04c1f2f519d0cd1142eb5c1aEric Dumazet ireq->ir_rmt_port = th->source; 203b44084c2c822f99dd3f2334b288b7e463d222662Eric Dumazet ireq->ir_num = ntohs(th->dest); 204634fb979e8f3a70f04c1f2f519d0cd1142eb5c1aEric Dumazet ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr; 205634fb979e8f3a70f04c1f2f519d0cd1142eb5c1aEric Dumazet ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr; 206a224772db8420ecb7ce91a9ba5d535ee3a50d982Eric Dumazet if (ipv6_opt_accepted(sk, skb, &TCP_SKB_CB(skb)->header.h6) || 207c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo || 208c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) { 209c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin atomic_inc(&skb->users); 210634fb979e8f3a70f04c1f2f519d0cd1142eb5c1aEric Dumazet ireq->pktopts = skb; 211c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin } 212c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 213634fb979e8f3a70f04c1f2f519d0cd1142eb5c1aEric Dumazet ireq->ir_iif = sk->sk_bound_dev_if; 214c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin /* So that link locals have meaning */ 215c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin if (!sk->sk_bound_dev_if && 216634fb979e8f3a70f04c1f2f519d0cd1142eb5c1aEric Dumazet ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL) 217870c3151382c980590d4d609babf3b0243e7db93Eric Dumazet ireq->ir_iif = tcp_v6_iif(skb); 218c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 21984f39b08d7868ce10eeaf640627cb89777f0ae93Lorenzo Colitti ireq->ir_mark = inet_request_mark(sk, skb); 22084f39b08d7868ce10eeaf640627cb89777f0ae93Lorenzo Colitti 221c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin req->expires = 0UL; 222e6c022a4fa2d2d9ca9d0a7ac3b05ad988f39fc30Eric Dumazet req->num_retrans = 0; 223172d69e63c7f1e8300d0e1c1bbd8eb0f630faa15Florian Westphal ireq->ecn_ok = ecn_ok; 224bb5b7c11263dbbe78253cd05945a6bf8f55add8eDavid S. Miller ireq->snd_wscale = tcp_opt.snd_wscale; 225bb5b7c11263dbbe78253cd05945a6bf8f55add8eDavid S. Miller ireq->sack_ok = tcp_opt.sack_ok; 226bb5b7c11263dbbe78253cd05945a6bf8f55add8eDavid S. Miller ireq->wscale_ok = tcp_opt.wscale_ok; 227bb5b7c11263dbbe78253cd05945a6bf8f55add8eDavid S. Miller ireq->tstamp_ok = tcp_opt.saw_tstamp; 228bb5b7c11263dbbe78253cd05945a6bf8f55add8eDavid S. Miller req->ts_recent = tcp_opt.saw_tstamp ? tcp_opt.rcv_tsval : 0; 2299ad7c049f0f79c418e293b1b68cf10d68f54fcdbJerry Chu treq->snt_synack = tcp_opt.saw_tstamp ? tcp_opt.rcv_tsecr : 0; 230c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin treq->rcv_isn = ntohl(th->seq) - 1; 231c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin treq->snt_isn = cookie; 232c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 233c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin /* 234c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin * We need to lookup the dst_entry to get the correct window size. 235c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin * This is taken from tcp_v6_syn_recv_sock. Somebody please enlighten 236c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin * me if there is a preferred way. 237c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin */ 238c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin { 23920c59de2e6b6bc74bbf714dcd4e720afe8d516cfArnaud Ebalard struct in6_addr *final_p, final; 2404c9483b2fb5d2548c3cc1fe03cdd4484ceeb5d1cDavid S. Miller struct flowi6 fl6; 2414c9483b2fb5d2548c3cc1fe03cdd4484ceeb5d1cDavid S. Miller memset(&fl6, 0, sizeof(fl6)); 2424c9483b2fb5d2548c3cc1fe03cdd4484ceeb5d1cDavid S. Miller fl6.flowi6_proto = IPPROTO_TCP; 243634fb979e8f3a70f04c1f2f519d0cd1142eb5c1aEric Dumazet fl6.daddr = ireq->ir_v6_rmt_addr; 2444c9483b2fb5d2548c3cc1fe03cdd4484ceeb5d1cDavid S. Miller final_p = fl6_update_dst(&fl6, np->opt, &final); 245634fb979e8f3a70f04c1f2f519d0cd1142eb5c1aEric Dumazet fl6.saddr = ireq->ir_v6_loc_addr; 2464c9483b2fb5d2548c3cc1fe03cdd4484ceeb5d1cDavid S. Miller fl6.flowi6_oif = sk->sk_bound_dev_if; 24784f39b08d7868ce10eeaf640627cb89777f0ae93Lorenzo Colitti fl6.flowi6_mark = ireq->ir_mark; 248634fb979e8f3a70f04c1f2f519d0cd1142eb5c1aEric Dumazet fl6.fl6_dport = ireq->ir_rmt_port; 2491958b856c1a59c0f1e892b92debb8c9fe4f364dcDavid S. Miller fl6.fl6_sport = inet_sk(sk)->inet_sport; 250ba3d8d3f9f65807763b2e0e1ea7645d74a962248Lorenzo Colitti fl6.flowi6_uid = sock_i_uid(sk); 2514c9483b2fb5d2548c3cc1fe03cdd4484ceeb5d1cDavid S. Miller security_req_classify_flow(req, flowi6_to_flowi(&fl6)); 2524c9483b2fb5d2548c3cc1fe03cdd4484ceeb5d1cDavid S. Miller 2530e0d44ab4275549998567cd4700b43f7496eb62bSteffen Klassert dst = ip6_dst_lookup_flow(sk, &fl6, final_p); 25468d0c6d34d586a893292d4fb633a3bf8c547b222David S. Miller if (IS_ERR(dst)) 2551730554f253deb65fe5112c54b2f898d5318a328Florian Westphal goto out_free; 256c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin } 257c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 2584dfc2817025965a2fc78a18c50f540736a6b5c24Florian Westphal req->window_clamp = tp->window_clamp ? :dst_metric(dst, RTAX_WINDOW); 259c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin tcp_select_initial_window(tcp_full_space(sk), req->mss, 260c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin &req->rcv_wnd, &req->window_clamp, 26131d12926e37291970dd4f6e9940df3897766a81dlaurent chavey ireq->wscale_ok, &rcv_wscale, 26231d12926e37291970dd4f6e9940df3897766a81dlaurent chavey dst_metric(dst, RTAX_INITRWND)); 263c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 264c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin ireq->rcv_wscale = rcv_wscale; 265c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 266c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin ret = get_cookie_sock(sk, skb, req, dst); 2671730554f253deb65fe5112c54b2f898d5318a328Florian Westphalout: 2681730554f253deb65fe5112c54b2f898d5318a328Florian Westphal return ret; 2691730554f253deb65fe5112c54b2f898d5318a328Florian Westphalout_free: 2701730554f253deb65fe5112c54b2f898d5318a328Florian Westphal reqsk_free(req); 2711730554f253deb65fe5112c54b2f898d5318a328Florian Westphal return NULL; 272c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin} 273c6aefafb7ec620911d46174eed514f9df639e5a4Glenn Griffin 274