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2272 lines
58 KiB
2272 lines
58 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* |
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* TCP over IPv6 |
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* Linux INET6 implementation |
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* |
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* Authors: |
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* Pedro Roque <[email protected]> |
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* |
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* Based on: |
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* linux/net/ipv4/tcp.c |
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* linux/net/ipv4/tcp_input.c |
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* linux/net/ipv4/tcp_output.c |
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* |
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* Fixes: |
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* Hideaki YOSHIFUJI : sin6_scope_id support |
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* YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which |
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* Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind |
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* a single port at the same time. |
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* YOSHIFUJI Hideaki @USAGI: convert /proc/net/tcp6 to seq_file. |
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*/ |
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|
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#include <linux/bottom_half.h> |
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#include <linux/module.h> |
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#include <linux/errno.h> |
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#include <linux/types.h> |
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#include <linux/socket.h> |
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#include <linux/sockios.h> |
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#include <linux/net.h> |
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#include <linux/jiffies.h> |
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#include <linux/in.h> |
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#include <linux/in6.h> |
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#include <linux/netdevice.h> |
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#include <linux/init.h> |
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#include <linux/jhash.h> |
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#include <linux/ipsec.h> |
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#include <linux/times.h> |
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#include <linux/slab.h> |
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#include <linux/uaccess.h> |
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#include <linux/ipv6.h> |
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#include <linux/icmpv6.h> |
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#include <linux/random.h> |
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#include <linux/indirect_call_wrapper.h> |
|
|
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#include <net/tcp.h> |
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#include <net/ndisc.h> |
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#include <net/inet6_hashtables.h> |
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#include <net/inet6_connection_sock.h> |
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#include <net/ipv6.h> |
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#include <net/transp_v6.h> |
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#include <net/addrconf.h> |
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#include <net/ip6_route.h> |
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#include <net/ip6_checksum.h> |
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#include <net/inet_ecn.h> |
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#include <net/protocol.h> |
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#include <net/xfrm.h> |
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#include <net/snmp.h> |
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#include <net/dsfield.h> |
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#include <net/timewait_sock.h> |
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#include <net/inet_common.h> |
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#include <net/secure_seq.h> |
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#include <net/busy_poll.h> |
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|
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#include <linux/proc_fs.h> |
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#include <linux/seq_file.h> |
|
|
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#include <crypto/hash.h> |
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#include <linux/scatterlist.h> |
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|
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#include <trace/events/tcp.h> |
|
|
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static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb); |
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static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, |
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struct request_sock *req); |
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|
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INDIRECT_CALLABLE_SCOPE int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb); |
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|
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static const struct inet_connection_sock_af_ops ipv6_mapped; |
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const struct inet_connection_sock_af_ops ipv6_specific; |
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#ifdef CONFIG_TCP_MD5SIG |
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static const struct tcp_sock_af_ops tcp_sock_ipv6_specific; |
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static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific; |
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#else |
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static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk, |
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const struct in6_addr *addr, |
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int l3index) |
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{ |
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return NULL; |
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} |
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#endif |
|
|
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/* Helper returning the inet6 address from a given tcp socket. |
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* It can be used in TCP stack instead of inet6_sk(sk). |
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* This avoids a dereference and allow compiler optimizations. |
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* It is a specialized version of inet6_sk_generic(). |
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*/ |
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static struct ipv6_pinfo *tcp_inet6_sk(const struct sock *sk) |
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{ |
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unsigned int offset = sizeof(struct tcp6_sock) - sizeof(struct ipv6_pinfo); |
|
|
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return (struct ipv6_pinfo *)(((u8 *)sk) + offset); |
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} |
|
|
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static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb) |
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{ |
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struct dst_entry *dst = skb_dst(skb); |
|
|
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if (dst && dst_hold_safe(dst)) { |
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const struct rt6_info *rt = (const struct rt6_info *)dst; |
|
|
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rcu_assign_pointer(sk->sk_rx_dst, dst); |
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sk->sk_rx_dst_ifindex = skb->skb_iif; |
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sk->sk_rx_dst_cookie = rt6_get_cookie(rt); |
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} |
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} |
|
|
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static u32 tcp_v6_init_seq(const struct sk_buff *skb) |
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{ |
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return secure_tcpv6_seq(ipv6_hdr(skb)->daddr.s6_addr32, |
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ipv6_hdr(skb)->saddr.s6_addr32, |
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tcp_hdr(skb)->dest, |
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tcp_hdr(skb)->source); |
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} |
|
|
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static u32 tcp_v6_init_ts_off(const struct net *net, const struct sk_buff *skb) |
|
{ |
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return secure_tcpv6_ts_off(net, ipv6_hdr(skb)->daddr.s6_addr32, |
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ipv6_hdr(skb)->saddr.s6_addr32); |
|
} |
|
|
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static int tcp_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr, |
|
int addr_len) |
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{ |
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/* This check is replicated from tcp_v6_connect() and intended to |
|
* prevent BPF program called below from accessing bytes that are out |
|
* of the bound specified by user in addr_len. |
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*/ |
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if (addr_len < SIN6_LEN_RFC2133) |
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return -EINVAL; |
|
|
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sock_owned_by_me(sk); |
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|
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return BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr); |
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} |
|
|
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static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, |
|
int addr_len) |
|
{ |
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struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; |
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struct inet_connection_sock *icsk = inet_csk(sk); |
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struct in6_addr *saddr = NULL, *final_p, final; |
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struct inet_timewait_death_row *tcp_death_row; |
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struct ipv6_pinfo *np = tcp_inet6_sk(sk); |
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struct inet_sock *inet = inet_sk(sk); |
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struct tcp_sock *tp = tcp_sk(sk); |
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struct net *net = sock_net(sk); |
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struct ipv6_txoptions *opt; |
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struct dst_entry *dst; |
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struct flowi6 fl6; |
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int addr_type; |
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int err; |
|
|
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if (addr_len < SIN6_LEN_RFC2133) |
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return -EINVAL; |
|
|
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if (usin->sin6_family != AF_INET6) |
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return -EAFNOSUPPORT; |
|
|
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memset(&fl6, 0, sizeof(fl6)); |
|
|
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if (np->sndflow) { |
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fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK; |
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IP6_ECN_flow_init(fl6.flowlabel); |
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if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { |
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struct ip6_flowlabel *flowlabel; |
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flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); |
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if (IS_ERR(flowlabel)) |
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return -EINVAL; |
|
fl6_sock_release(flowlabel); |
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} |
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} |
|
|
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/* |
|
* connect() to INADDR_ANY means loopback (BSD'ism). |
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*/ |
|
|
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if (ipv6_addr_any(&usin->sin6_addr)) { |
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if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr)) |
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ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK), |
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&usin->sin6_addr); |
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else |
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usin->sin6_addr = in6addr_loopback; |
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} |
|
|
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addr_type = ipv6_addr_type(&usin->sin6_addr); |
|
|
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if (addr_type & IPV6_ADDR_MULTICAST) |
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return -ENETUNREACH; |
|
|
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if (addr_type&IPV6_ADDR_LINKLOCAL) { |
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if (addr_len >= sizeof(struct sockaddr_in6) && |
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usin->sin6_scope_id) { |
|
/* If interface is set while binding, indices |
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* must coincide. |
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*/ |
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if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id)) |
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return -EINVAL; |
|
|
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sk->sk_bound_dev_if = usin->sin6_scope_id; |
|
} |
|
|
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/* Connect to link-local address requires an interface */ |
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if (!sk->sk_bound_dev_if) |
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return -EINVAL; |
|
} |
|
|
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if (tp->rx_opt.ts_recent_stamp && |
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!ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) { |
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tp->rx_opt.ts_recent = 0; |
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tp->rx_opt.ts_recent_stamp = 0; |
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WRITE_ONCE(tp->write_seq, 0); |
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} |
|
|
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sk->sk_v6_daddr = usin->sin6_addr; |
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np->flow_label = fl6.flowlabel; |
|
|
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/* |
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* TCP over IPv4 |
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*/ |
|
|
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if (addr_type & IPV6_ADDR_MAPPED) { |
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u32 exthdrlen = icsk->icsk_ext_hdr_len; |
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struct sockaddr_in sin; |
|
|
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if (ipv6_only_sock(sk)) |
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return -ENETUNREACH; |
|
|
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sin.sin_family = AF_INET; |
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sin.sin_port = usin->sin6_port; |
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sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3]; |
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|
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/* Paired with READ_ONCE() in tcp_(get|set)sockopt() */ |
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WRITE_ONCE(icsk->icsk_af_ops, &ipv6_mapped); |
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if (sk_is_mptcp(sk)) |
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mptcpv6_handle_mapped(sk, true); |
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sk->sk_backlog_rcv = tcp_v4_do_rcv; |
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#ifdef CONFIG_TCP_MD5SIG |
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tp->af_specific = &tcp_sock_ipv6_mapped_specific; |
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#endif |
|
|
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err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin)); |
|
|
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if (err) { |
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icsk->icsk_ext_hdr_len = exthdrlen; |
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/* Paired with READ_ONCE() in tcp_(get|set)sockopt() */ |
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WRITE_ONCE(icsk->icsk_af_ops, &ipv6_specific); |
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if (sk_is_mptcp(sk)) |
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mptcpv6_handle_mapped(sk, false); |
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sk->sk_backlog_rcv = tcp_v6_do_rcv; |
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#ifdef CONFIG_TCP_MD5SIG |
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tp->af_specific = &tcp_sock_ipv6_specific; |
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#endif |
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goto failure; |
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} |
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np->saddr = sk->sk_v6_rcv_saddr; |
|
|
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return err; |
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} |
|
|
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if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) |
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saddr = &sk->sk_v6_rcv_saddr; |
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|
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fl6.flowi6_proto = IPPROTO_TCP; |
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fl6.daddr = sk->sk_v6_daddr; |
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fl6.saddr = saddr ? *saddr : np->saddr; |
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fl6.flowi6_oif = sk->sk_bound_dev_if; |
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fl6.flowi6_mark = sk->sk_mark; |
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fl6.fl6_dport = usin->sin6_port; |
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fl6.fl6_sport = inet->inet_sport; |
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fl6.flowi6_uid = sk->sk_uid; |
|
|
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opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk)); |
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final_p = fl6_update_dst(&fl6, opt, &final); |
|
|
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security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6)); |
|
|
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dst = ip6_dst_lookup_flow(net, sk, &fl6, final_p); |
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if (IS_ERR(dst)) { |
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err = PTR_ERR(dst); |
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goto failure; |
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} |
|
|
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tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row; |
|
|
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if (!saddr) { |
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saddr = &fl6.saddr; |
|
|
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err = inet_bhash2_update_saddr(sk, saddr, AF_INET6); |
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if (err) |
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goto failure; |
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} |
|
|
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/* set the source address */ |
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np->saddr = *saddr; |
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inet->inet_rcv_saddr = LOOPBACK4_IPV6; |
|
|
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sk->sk_gso_type = SKB_GSO_TCPV6; |
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ip6_dst_store(sk, dst, NULL, NULL); |
|
|
|
icsk->icsk_ext_hdr_len = 0; |
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if (opt) |
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icsk->icsk_ext_hdr_len = opt->opt_flen + |
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opt->opt_nflen; |
|
|
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tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr); |
|
|
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inet->inet_dport = usin->sin6_port; |
|
|
|
tcp_set_state(sk, TCP_SYN_SENT); |
|
err = inet6_hash_connect(tcp_death_row, sk); |
|
if (err) |
|
goto late_failure; |
|
|
|
sk_set_txhash(sk); |
|
|
|
if (likely(!tp->repair)) { |
|
if (!tp->write_seq) |
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WRITE_ONCE(tp->write_seq, |
|
secure_tcpv6_seq(np->saddr.s6_addr32, |
|
sk->sk_v6_daddr.s6_addr32, |
|
inet->inet_sport, |
|
inet->inet_dport)); |
|
tp->tsoffset = secure_tcpv6_ts_off(net, np->saddr.s6_addr32, |
|
sk->sk_v6_daddr.s6_addr32); |
|
} |
|
|
|
if (tcp_fastopen_defer_connect(sk, &err)) |
|
return err; |
|
if (err) |
|
goto late_failure; |
|
|
|
err = tcp_connect(sk); |
|
if (err) |
|
goto late_failure; |
|
|
|
return 0; |
|
|
|
late_failure: |
|
tcp_set_state(sk, TCP_CLOSE); |
|
inet_bhash2_reset_saddr(sk); |
|
failure: |
|
inet->inet_dport = 0; |
|
sk->sk_route_caps = 0; |
|
return err; |
|
} |
|
|
|
static void tcp_v6_mtu_reduced(struct sock *sk) |
|
{ |
|
struct dst_entry *dst; |
|
u32 mtu; |
|
|
|
if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) |
|
return; |
|
|
|
mtu = READ_ONCE(tcp_sk(sk)->mtu_info); |
|
|
|
/* Drop requests trying to increase our current mss. |
|
* Check done in __ip6_rt_update_pmtu() is too late. |
|
*/ |
|
if (tcp_mtu_to_mss(sk, mtu) >= tcp_sk(sk)->mss_cache) |
|
return; |
|
|
|
dst = inet6_csk_update_pmtu(sk, mtu); |
|
if (!dst) |
|
return; |
|
|
|
if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) { |
|
tcp_sync_mss(sk, dst_mtu(dst)); |
|
tcp_simple_retransmit(sk); |
|
} |
|
} |
|
|
|
static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, |
|
u8 type, u8 code, int offset, __be32 info) |
|
{ |
|
const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data; |
|
const struct tcphdr *th = (struct tcphdr *)(skb->data+offset); |
|
struct net *net = dev_net(skb->dev); |
|
struct request_sock *fastopen; |
|
struct ipv6_pinfo *np; |
|
struct tcp_sock *tp; |
|
__u32 seq, snd_una; |
|
struct sock *sk; |
|
bool fatal; |
|
int err; |
|
|
|
sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo, |
|
&hdr->daddr, th->dest, |
|
&hdr->saddr, ntohs(th->source), |
|
skb->dev->ifindex, inet6_sdif(skb)); |
|
|
|
if (!sk) { |
|
__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), |
|
ICMP6_MIB_INERRORS); |
|
return -ENOENT; |
|
} |
|
|
|
if (sk->sk_state == TCP_TIME_WAIT) { |
|
inet_twsk_put(inet_twsk(sk)); |
|
return 0; |
|
} |
|
seq = ntohl(th->seq); |
|
fatal = icmpv6_err_convert(type, code, &err); |
|
if (sk->sk_state == TCP_NEW_SYN_RECV) { |
|
tcp_req_err(sk, seq, fatal); |
|
return 0; |
|
} |
|
|
|
bh_lock_sock(sk); |
|
if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG) |
|
__NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS); |
|
|
|
if (sk->sk_state == TCP_CLOSE) |
|
goto out; |
|
|
|
if (static_branch_unlikely(&ip6_min_hopcount)) { |
|
/* min_hopcount can be changed concurrently from do_ipv6_setsockopt() */ |
|
if (ipv6_hdr(skb)->hop_limit < READ_ONCE(tcp_inet6_sk(sk)->min_hopcount)) { |
|
__NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP); |
|
goto out; |
|
} |
|
} |
|
|
|
tp = tcp_sk(sk); |
|
/* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */ |
|
fastopen = rcu_dereference(tp->fastopen_rsk); |
|
snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una; |
|
if (sk->sk_state != TCP_LISTEN && |
|
!between(seq, snd_una, tp->snd_nxt)) { |
|
__NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS); |
|
goto out; |
|
} |
|
|
|
np = tcp_inet6_sk(sk); |
|
|
|
if (type == NDISC_REDIRECT) { |
|
if (!sock_owned_by_user(sk)) { |
|
struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie); |
|
|
|
if (dst) |
|
dst->ops->redirect(dst, sk, skb); |
|
} |
|
goto out; |
|
} |
|
|
|
if (type == ICMPV6_PKT_TOOBIG) { |
|
u32 mtu = ntohl(info); |
|
|
|
/* We are not interested in TCP_LISTEN and open_requests |
|
* (SYN-ACKs send out by Linux are always <576bytes so |
|
* they should go through unfragmented). |
|
*/ |
|
if (sk->sk_state == TCP_LISTEN) |
|
goto out; |
|
|
|
if (!ip6_sk_accept_pmtu(sk)) |
|
goto out; |
|
|
|
if (mtu < IPV6_MIN_MTU) |
|
goto out; |
|
|
|
WRITE_ONCE(tp->mtu_info, mtu); |
|
|
|
if (!sock_owned_by_user(sk)) |
|
tcp_v6_mtu_reduced(sk); |
|
else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED, |
|
&sk->sk_tsq_flags)) |
|
sock_hold(sk); |
|
goto out; |
|
} |
|
|
|
|
|
/* Might be for an request_sock */ |
|
switch (sk->sk_state) { |
|
case TCP_SYN_SENT: |
|
case TCP_SYN_RECV: |
|
/* Only in fast or simultaneous open. If a fast open socket is |
|
* already accepted it is treated as a connected one below. |
|
*/ |
|
if (fastopen && !fastopen->sk) |
|
break; |
|
|
|
ipv6_icmp_error(sk, skb, err, th->dest, ntohl(info), (u8 *)th); |
|
|
|
if (!sock_owned_by_user(sk)) { |
|
sk->sk_err = err; |
|
sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */ |
|
|
|
tcp_done(sk); |
|
} else |
|
sk->sk_err_soft = err; |
|
goto out; |
|
case TCP_LISTEN: |
|
break; |
|
default: |
|
/* check if this ICMP message allows revert of backoff. |
|
* (see RFC 6069) |
|
*/ |
|
if (!fastopen && type == ICMPV6_DEST_UNREACH && |
|
code == ICMPV6_NOROUTE) |
|
tcp_ld_RTO_revert(sk, seq); |
|
} |
|
|
|
if (!sock_owned_by_user(sk) && np->recverr) { |
|
sk->sk_err = err; |
|
sk_error_report(sk); |
|
} else |
|
sk->sk_err_soft = err; |
|
|
|
out: |
|
bh_unlock_sock(sk); |
|
sock_put(sk); |
|
return 0; |
|
} |
|
|
|
|
|
static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst, |
|
struct flowi *fl, |
|
struct request_sock *req, |
|
struct tcp_fastopen_cookie *foc, |
|
enum tcp_synack_type synack_type, |
|
struct sk_buff *syn_skb) |
|
{ |
|
struct inet_request_sock *ireq = inet_rsk(req); |
|
struct ipv6_pinfo *np = tcp_inet6_sk(sk); |
|
struct ipv6_txoptions *opt; |
|
struct flowi6 *fl6 = &fl->u.ip6; |
|
struct sk_buff *skb; |
|
int err = -ENOMEM; |
|
u8 tclass; |
|
|
|
/* First, grab a route. */ |
|
if (!dst && (dst = inet6_csk_route_req(sk, fl6, req, |
|
IPPROTO_TCP)) == NULL) |
|
goto done; |
|
|
|
skb = tcp_make_synack(sk, dst, req, foc, synack_type, syn_skb); |
|
|
|
if (skb) { |
|
__tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr, |
|
&ireq->ir_v6_rmt_addr); |
|
|
|
fl6->daddr = ireq->ir_v6_rmt_addr; |
|
if (np->repflow && ireq->pktopts) |
|
fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts)); |
|
|
|
tclass = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos) ? |
|
(tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) | |
|
(np->tclass & INET_ECN_MASK) : |
|
np->tclass; |
|
|
|
if (!INET_ECN_is_capable(tclass) && |
|
tcp_bpf_ca_needs_ecn((struct sock *)req)) |
|
tclass |= INET_ECN_ECT_0; |
|
|
|
rcu_read_lock(); |
|
opt = ireq->ipv6_opt; |
|
if (!opt) |
|
opt = rcu_dereference(np->opt); |
|
err = ip6_xmit(sk, skb, fl6, skb->mark ? : sk->sk_mark, opt, |
|
tclass, sk->sk_priority); |
|
rcu_read_unlock(); |
|
err = net_xmit_eval(err); |
|
} |
|
|
|
done: |
|
return err; |
|
} |
|
|
|
|
|
static void tcp_v6_reqsk_destructor(struct request_sock *req) |
|
{ |
|
kfree(inet_rsk(req)->ipv6_opt); |
|
consume_skb(inet_rsk(req)->pktopts); |
|
} |
|
|
|
#ifdef CONFIG_TCP_MD5SIG |
|
static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk, |
|
const struct in6_addr *addr, |
|
int l3index) |
|
{ |
|
return tcp_md5_do_lookup(sk, l3index, |
|
(union tcp_md5_addr *)addr, AF_INET6); |
|
} |
|
|
|
static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk, |
|
const struct sock *addr_sk) |
|
{ |
|
int l3index; |
|
|
|
l3index = l3mdev_master_ifindex_by_index(sock_net(sk), |
|
addr_sk->sk_bound_dev_if); |
|
return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr, |
|
l3index); |
|
} |
|
|
|
static int tcp_v6_parse_md5_keys(struct sock *sk, int optname, |
|
sockptr_t optval, int optlen) |
|
{ |
|
struct tcp_md5sig cmd; |
|
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr; |
|
int l3index = 0; |
|
u8 prefixlen; |
|
u8 flags; |
|
|
|
if (optlen < sizeof(cmd)) |
|
return -EINVAL; |
|
|
|
if (copy_from_sockptr(&cmd, optval, sizeof(cmd))) |
|
return -EFAULT; |
|
|
|
if (sin6->sin6_family != AF_INET6) |
|
return -EINVAL; |
|
|
|
flags = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX; |
|
|
|
if (optname == TCP_MD5SIG_EXT && |
|
cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) { |
|
prefixlen = cmd.tcpm_prefixlen; |
|
if (prefixlen > 128 || (ipv6_addr_v4mapped(&sin6->sin6_addr) && |
|
prefixlen > 32)) |
|
return -EINVAL; |
|
} else { |
|
prefixlen = ipv6_addr_v4mapped(&sin6->sin6_addr) ? 32 : 128; |
|
} |
|
|
|
if (optname == TCP_MD5SIG_EXT && cmd.tcpm_ifindex && |
|
cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX) { |
|
struct net_device *dev; |
|
|
|
rcu_read_lock(); |
|
dev = dev_get_by_index_rcu(sock_net(sk), cmd.tcpm_ifindex); |
|
if (dev && netif_is_l3_master(dev)) |
|
l3index = dev->ifindex; |
|
rcu_read_unlock(); |
|
|
|
/* ok to reference set/not set outside of rcu; |
|
* right now device MUST be an L3 master |
|
*/ |
|
if (!dev || !l3index) |
|
return -EINVAL; |
|
} |
|
|
|
if (!cmd.tcpm_keylen) { |
|
if (ipv6_addr_v4mapped(&sin6->sin6_addr)) |
|
return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3], |
|
AF_INET, prefixlen, |
|
l3index, flags); |
|
return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr, |
|
AF_INET6, prefixlen, l3index, flags); |
|
} |
|
|
|
if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) |
|
return -EINVAL; |
|
|
|
if (ipv6_addr_v4mapped(&sin6->sin6_addr)) |
|
return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3], |
|
AF_INET, prefixlen, l3index, flags, |
|
cmd.tcpm_key, cmd.tcpm_keylen, |
|
GFP_KERNEL); |
|
|
|
return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr, |
|
AF_INET6, prefixlen, l3index, flags, |
|
cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL); |
|
} |
|
|
|
static int tcp_v6_md5_hash_headers(struct tcp_md5sig_pool *hp, |
|
const struct in6_addr *daddr, |
|
const struct in6_addr *saddr, |
|
const struct tcphdr *th, int nbytes) |
|
{ |
|
struct tcp6_pseudohdr *bp; |
|
struct scatterlist sg; |
|
struct tcphdr *_th; |
|
|
|
bp = hp->scratch; |
|
/* 1. TCP pseudo-header (RFC2460) */ |
|
bp->saddr = *saddr; |
|
bp->daddr = *daddr; |
|
bp->protocol = cpu_to_be32(IPPROTO_TCP); |
|
bp->len = cpu_to_be32(nbytes); |
|
|
|
_th = (struct tcphdr *)(bp + 1); |
|
memcpy(_th, th, sizeof(*th)); |
|
_th->check = 0; |
|
|
|
sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th)); |
|
ahash_request_set_crypt(hp->md5_req, &sg, NULL, |
|
sizeof(*bp) + sizeof(*th)); |
|
return crypto_ahash_update(hp->md5_req); |
|
} |
|
|
|
static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key, |
|
const struct in6_addr *daddr, struct in6_addr *saddr, |
|
const struct tcphdr *th) |
|
{ |
|
struct tcp_md5sig_pool *hp; |
|
struct ahash_request *req; |
|
|
|
hp = tcp_get_md5sig_pool(); |
|
if (!hp) |
|
goto clear_hash_noput; |
|
req = hp->md5_req; |
|
|
|
if (crypto_ahash_init(req)) |
|
goto clear_hash; |
|
if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2)) |
|
goto clear_hash; |
|
if (tcp_md5_hash_key(hp, key)) |
|
goto clear_hash; |
|
ahash_request_set_crypt(req, NULL, md5_hash, 0); |
|
if (crypto_ahash_final(req)) |
|
goto clear_hash; |
|
|
|
tcp_put_md5sig_pool(); |
|
return 0; |
|
|
|
clear_hash: |
|
tcp_put_md5sig_pool(); |
|
clear_hash_noput: |
|
memset(md5_hash, 0, 16); |
|
return 1; |
|
} |
|
|
|
static int tcp_v6_md5_hash_skb(char *md5_hash, |
|
const struct tcp_md5sig_key *key, |
|
const struct sock *sk, |
|
const struct sk_buff *skb) |
|
{ |
|
const struct in6_addr *saddr, *daddr; |
|
struct tcp_md5sig_pool *hp; |
|
struct ahash_request *req; |
|
const struct tcphdr *th = tcp_hdr(skb); |
|
|
|
if (sk) { /* valid for establish/request sockets */ |
|
saddr = &sk->sk_v6_rcv_saddr; |
|
daddr = &sk->sk_v6_daddr; |
|
} else { |
|
const struct ipv6hdr *ip6h = ipv6_hdr(skb); |
|
saddr = &ip6h->saddr; |
|
daddr = &ip6h->daddr; |
|
} |
|
|
|
hp = tcp_get_md5sig_pool(); |
|
if (!hp) |
|
goto clear_hash_noput; |
|
req = hp->md5_req; |
|
|
|
if (crypto_ahash_init(req)) |
|
goto clear_hash; |
|
|
|
if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, skb->len)) |
|
goto clear_hash; |
|
if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2)) |
|
goto clear_hash; |
|
if (tcp_md5_hash_key(hp, key)) |
|
goto clear_hash; |
|
ahash_request_set_crypt(req, NULL, md5_hash, 0); |
|
if (crypto_ahash_final(req)) |
|
goto clear_hash; |
|
|
|
tcp_put_md5sig_pool(); |
|
return 0; |
|
|
|
clear_hash: |
|
tcp_put_md5sig_pool(); |
|
clear_hash_noput: |
|
memset(md5_hash, 0, 16); |
|
return 1; |
|
} |
|
|
|
#endif |
|
|
|
static void tcp_v6_init_req(struct request_sock *req, |
|
const struct sock *sk_listener, |
|
struct sk_buff *skb) |
|
{ |
|
bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags); |
|
struct inet_request_sock *ireq = inet_rsk(req); |
|
const struct ipv6_pinfo *np = tcp_inet6_sk(sk_listener); |
|
|
|
ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr; |
|
ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr; |
|
|
|
/* So that link locals have meaning */ |
|
if ((!sk_listener->sk_bound_dev_if || l3_slave) && |
|
ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL) |
|
ireq->ir_iif = tcp_v6_iif(skb); |
|
|
|
if (!TCP_SKB_CB(skb)->tcp_tw_isn && |
|
(ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) || |
|
np->rxopt.bits.rxinfo || |
|
np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim || |
|
np->rxopt.bits.rxohlim || np->repflow)) { |
|
refcount_inc(&skb->users); |
|
ireq->pktopts = skb; |
|
} |
|
} |
|
|
|
static struct dst_entry *tcp_v6_route_req(const struct sock *sk, |
|
struct sk_buff *skb, |
|
struct flowi *fl, |
|
struct request_sock *req) |
|
{ |
|
tcp_v6_init_req(req, sk, skb); |
|
|
|
if (security_inet_conn_request(sk, skb, req)) |
|
return NULL; |
|
|
|
return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP); |
|
} |
|
|
|
struct request_sock_ops tcp6_request_sock_ops __read_mostly = { |
|
.family = AF_INET6, |
|
.obj_size = sizeof(struct tcp6_request_sock), |
|
.rtx_syn_ack = tcp_rtx_synack, |
|
.send_ack = tcp_v6_reqsk_send_ack, |
|
.destructor = tcp_v6_reqsk_destructor, |
|
.send_reset = tcp_v6_send_reset, |
|
.syn_ack_timeout = tcp_syn_ack_timeout, |
|
}; |
|
|
|
const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = { |
|
.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - |
|
sizeof(struct ipv6hdr), |
|
#ifdef CONFIG_TCP_MD5SIG |
|
.req_md5_lookup = tcp_v6_md5_lookup, |
|
.calc_md5_hash = tcp_v6_md5_hash_skb, |
|
#endif |
|
#ifdef CONFIG_SYN_COOKIES |
|
.cookie_init_seq = cookie_v6_init_sequence, |
|
#endif |
|
.route_req = tcp_v6_route_req, |
|
.init_seq = tcp_v6_init_seq, |
|
.init_ts_off = tcp_v6_init_ts_off, |
|
.send_synack = tcp_v6_send_synack, |
|
}; |
|
|
|
static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq, |
|
u32 ack, u32 win, u32 tsval, u32 tsecr, |
|
int oif, struct tcp_md5sig_key *key, int rst, |
|
u8 tclass, __be32 label, u32 priority, u32 txhash) |
|
{ |
|
const struct tcphdr *th = tcp_hdr(skb); |
|
struct tcphdr *t1; |
|
struct sk_buff *buff; |
|
struct flowi6 fl6; |
|
struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev); |
|
struct sock *ctl_sk = net->ipv6.tcp_sk; |
|
unsigned int tot_len = sizeof(struct tcphdr); |
|
__be32 mrst = 0, *topt; |
|
struct dst_entry *dst; |
|
__u32 mark = 0; |
|
|
|
if (tsecr) |
|
tot_len += TCPOLEN_TSTAMP_ALIGNED; |
|
#ifdef CONFIG_TCP_MD5SIG |
|
if (key) |
|
tot_len += TCPOLEN_MD5SIG_ALIGNED; |
|
#endif |
|
|
|
#ifdef CONFIG_MPTCP |
|
if (rst && !key) { |
|
mrst = mptcp_reset_option(skb); |
|
|
|
if (mrst) |
|
tot_len += sizeof(__be32); |
|
} |
|
#endif |
|
|
|
buff = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC); |
|
if (!buff) |
|
return; |
|
|
|
skb_reserve(buff, MAX_TCP_HEADER); |
|
|
|
t1 = skb_push(buff, tot_len); |
|
skb_reset_transport_header(buff); |
|
|
|
/* Swap the send and the receive. */ |
|
memset(t1, 0, sizeof(*t1)); |
|
t1->dest = th->source; |
|
t1->source = th->dest; |
|
t1->doff = tot_len / 4; |
|
t1->seq = htonl(seq); |
|
t1->ack_seq = htonl(ack); |
|
t1->ack = !rst || !th->ack; |
|
t1->rst = rst; |
|
t1->window = htons(win); |
|
|
|
topt = (__be32 *)(t1 + 1); |
|
|
|
if (tsecr) { |
|
*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | |
|
(TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP); |
|
*topt++ = htonl(tsval); |
|
*topt++ = htonl(tsecr); |
|
} |
|
|
|
if (mrst) |
|
*topt++ = mrst; |
|
|
|
#ifdef CONFIG_TCP_MD5SIG |
|
if (key) { |
|
*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | |
|
(TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG); |
|
tcp_v6_md5_hash_hdr((__u8 *)topt, key, |
|
&ipv6_hdr(skb)->saddr, |
|
&ipv6_hdr(skb)->daddr, t1); |
|
} |
|
#endif |
|
|
|
memset(&fl6, 0, sizeof(fl6)); |
|
fl6.daddr = ipv6_hdr(skb)->saddr; |
|
fl6.saddr = ipv6_hdr(skb)->daddr; |
|
fl6.flowlabel = label; |
|
|
|
buff->ip_summed = CHECKSUM_PARTIAL; |
|
|
|
__tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr); |
|
|
|
fl6.flowi6_proto = IPPROTO_TCP; |
|
if (rt6_need_strict(&fl6.daddr) && !oif) |
|
fl6.flowi6_oif = tcp_v6_iif(skb); |
|
else { |
|
if (!oif && netif_index_is_l3_master(net, skb->skb_iif)) |
|
oif = skb->skb_iif; |
|
|
|
fl6.flowi6_oif = oif; |
|
} |
|
|
|
if (sk) { |
|
if (sk->sk_state == TCP_TIME_WAIT) |
|
mark = inet_twsk(sk)->tw_mark; |
|
else |
|
mark = sk->sk_mark; |
|
skb_set_delivery_time(buff, tcp_transmit_time(sk), true); |
|
} |
|
if (txhash) { |
|
/* autoflowlabel/skb_get_hash_flowi6 rely on buff->hash */ |
|
skb_set_hash(buff, txhash, PKT_HASH_TYPE_L4); |
|
} |
|
fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark) ?: mark; |
|
fl6.fl6_dport = t1->dest; |
|
fl6.fl6_sport = t1->source; |
|
fl6.flowi6_uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL); |
|
security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6)); |
|
|
|
/* Pass a socket to ip6_dst_lookup either it is for RST |
|
* Underlying function will use this to retrieve the network |
|
* namespace |
|
*/ |
|
if (sk && sk->sk_state != TCP_TIME_WAIT) |
|
dst = ip6_dst_lookup_flow(net, sk, &fl6, NULL); /*sk's xfrm_policy can be referred*/ |
|
else |
|
dst = ip6_dst_lookup_flow(net, ctl_sk, &fl6, NULL); |
|
if (!IS_ERR(dst)) { |
|
skb_dst_set(buff, dst); |
|
ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL, |
|
tclass & ~INET_ECN_MASK, priority); |
|
TCP_INC_STATS(net, TCP_MIB_OUTSEGS); |
|
if (rst) |
|
TCP_INC_STATS(net, TCP_MIB_OUTRSTS); |
|
return; |
|
} |
|
|
|
kfree_skb(buff); |
|
} |
|
|
|
static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) |
|
{ |
|
const struct tcphdr *th = tcp_hdr(skb); |
|
struct ipv6hdr *ipv6h = ipv6_hdr(skb); |
|
u32 seq = 0, ack_seq = 0; |
|
struct tcp_md5sig_key *key = NULL; |
|
#ifdef CONFIG_TCP_MD5SIG |
|
const __u8 *hash_location = NULL; |
|
unsigned char newhash[16]; |
|
int genhash; |
|
struct sock *sk1 = NULL; |
|
#endif |
|
__be32 label = 0; |
|
u32 priority = 0; |
|
struct net *net; |
|
u32 txhash = 0; |
|
int oif = 0; |
|
|
|
if (th->rst) |
|
return; |
|
|
|
/* If sk not NULL, it means we did a successful lookup and incoming |
|
* route had to be correct. prequeue might have dropped our dst. |
|
*/ |
|
if (!sk && !ipv6_unicast_destination(skb)) |
|
return; |
|
|
|
net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev); |
|
#ifdef CONFIG_TCP_MD5SIG |
|
rcu_read_lock(); |
|
hash_location = tcp_parse_md5sig_option(th); |
|
if (sk && sk_fullsock(sk)) { |
|
int l3index; |
|
|
|
/* sdif set, means packet ingressed via a device |
|
* in an L3 domain and inet_iif is set to it. |
|
*/ |
|
l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0; |
|
key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr, l3index); |
|
} else if (hash_location) { |
|
int dif = tcp_v6_iif_l3_slave(skb); |
|
int sdif = tcp_v6_sdif(skb); |
|
int l3index; |
|
|
|
/* |
|
* active side is lost. Try to find listening socket through |
|
* source port, and then find md5 key through listening socket. |
|
* we are not loose security here: |
|
* Incoming packet is checked with md5 hash with finding key, |
|
* no RST generated if md5 hash doesn't match. |
|
*/ |
|
sk1 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo, |
|
NULL, 0, &ipv6h->saddr, th->source, |
|
&ipv6h->daddr, ntohs(th->source), |
|
dif, sdif); |
|
if (!sk1) |
|
goto out; |
|
|
|
/* sdif set, means packet ingressed via a device |
|
* in an L3 domain and dif is set to it. |
|
*/ |
|
l3index = tcp_v6_sdif(skb) ? dif : 0; |
|
|
|
key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr, l3index); |
|
if (!key) |
|
goto out; |
|
|
|
genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb); |
|
if (genhash || memcmp(hash_location, newhash, 16) != 0) |
|
goto out; |
|
} |
|
#endif |
|
|
|
if (th->ack) |
|
seq = ntohl(th->ack_seq); |
|
else |
|
ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len - |
|
(th->doff << 2); |
|
|
|
if (sk) { |
|
oif = sk->sk_bound_dev_if; |
|
if (sk_fullsock(sk)) { |
|
const struct ipv6_pinfo *np = tcp_inet6_sk(sk); |
|
|
|
trace_tcp_send_reset(sk, skb); |
|
if (np->repflow) |
|
label = ip6_flowlabel(ipv6h); |
|
priority = sk->sk_priority; |
|
txhash = sk->sk_hash; |
|
} |
|
if (sk->sk_state == TCP_TIME_WAIT) { |
|
label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel); |
|
priority = inet_twsk(sk)->tw_priority; |
|
txhash = inet_twsk(sk)->tw_txhash; |
|
} |
|
} else { |
|
if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET) |
|
label = ip6_flowlabel(ipv6h); |
|
} |
|
|
|
tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, |
|
ipv6_get_dsfield(ipv6h), label, priority, txhash); |
|
|
|
#ifdef CONFIG_TCP_MD5SIG |
|
out: |
|
rcu_read_unlock(); |
|
#endif |
|
} |
|
|
|
static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq, |
|
u32 ack, u32 win, u32 tsval, u32 tsecr, int oif, |
|
struct tcp_md5sig_key *key, u8 tclass, |
|
__be32 label, u32 priority, u32 txhash) |
|
{ |
|
tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0, |
|
tclass, label, priority, txhash); |
|
} |
|
|
|
static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb) |
|
{ |
|
struct inet_timewait_sock *tw = inet_twsk(sk); |
|
struct tcp_timewait_sock *tcptw = tcp_twsk(sk); |
|
|
|
tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, |
|
tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, |
|
tcp_time_stamp_raw() + tcptw->tw_ts_offset, |
|
tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw), |
|
tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority, |
|
tw->tw_txhash); |
|
|
|
inet_twsk_put(tw); |
|
} |
|
|
|
static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, |
|
struct request_sock *req) |
|
{ |
|
int l3index; |
|
|
|
l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0; |
|
|
|
/* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV |
|
* sk->sk_state == TCP_SYN_RECV -> for Fast Open. |
|
*/ |
|
/* RFC 7323 2.3 |
|
* The window field (SEG.WND) of every outgoing segment, with the |
|
* exception of <SYN> segments, MUST be right-shifted by |
|
* Rcv.Wind.Shift bits: |
|
*/ |
|
tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ? |
|
tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt, |
|
tcp_rsk(req)->rcv_nxt, |
|
req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale, |
|
tcp_time_stamp_raw() + tcp_rsk(req)->ts_off, |
|
req->ts_recent, sk->sk_bound_dev_if, |
|
tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr, l3index), |
|
ipv6_get_dsfield(ipv6_hdr(skb)), 0, sk->sk_priority, |
|
tcp_rsk(req)->txhash); |
|
} |
|
|
|
|
|
static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb) |
|
{ |
|
#ifdef CONFIG_SYN_COOKIES |
|
const struct tcphdr *th = tcp_hdr(skb); |
|
|
|
if (!th->syn) |
|
sk = cookie_v6_check(sk, skb); |
|
#endif |
|
return sk; |
|
} |
|
|
|
u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph, |
|
struct tcphdr *th, u32 *cookie) |
|
{ |
|
u16 mss = 0; |
|
#ifdef CONFIG_SYN_COOKIES |
|
mss = tcp_get_syncookie_mss(&tcp6_request_sock_ops, |
|
&tcp_request_sock_ipv6_ops, sk, th); |
|
if (mss) { |
|
*cookie = __cookie_v6_init_sequence(iph, th, &mss); |
|
tcp_synq_overflow(sk); |
|
} |
|
#endif |
|
return mss; |
|
} |
|
|
|
static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb) |
|
{ |
|
if (skb->protocol == htons(ETH_P_IP)) |
|
return tcp_v4_conn_request(sk, skb); |
|
|
|
if (!ipv6_unicast_destination(skb)) |
|
goto drop; |
|
|
|
if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) { |
|
__IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS); |
|
return 0; |
|
} |
|
|
|
return tcp_conn_request(&tcp6_request_sock_ops, |
|
&tcp_request_sock_ipv6_ops, sk, skb); |
|
|
|
drop: |
|
tcp_listendrop(sk); |
|
return 0; /* don't send reset */ |
|
} |
|
|
|
static void tcp_v6_restore_cb(struct sk_buff *skb) |
|
{ |
|
/* We need to move header back to the beginning if xfrm6_policy_check() |
|
* and tcp_v6_fill_cb() are going to be called again. |
|
* ip6_datagram_recv_specific_ctl() also expects IP6CB to be there. |
|
*/ |
|
memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6, |
|
sizeof(struct inet6_skb_parm)); |
|
} |
|
|
|
static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, |
|
struct request_sock *req, |
|
struct dst_entry *dst, |
|
struct request_sock *req_unhash, |
|
bool *own_req) |
|
{ |
|
struct inet_request_sock *ireq; |
|
struct ipv6_pinfo *newnp; |
|
const struct ipv6_pinfo *np = tcp_inet6_sk(sk); |
|
struct ipv6_txoptions *opt; |
|
struct inet_sock *newinet; |
|
bool found_dup_sk = false; |
|
struct tcp_sock *newtp; |
|
struct sock *newsk; |
|
#ifdef CONFIG_TCP_MD5SIG |
|
struct tcp_md5sig_key *key; |
|
int l3index; |
|
#endif |
|
struct flowi6 fl6; |
|
|
|
if (skb->protocol == htons(ETH_P_IP)) { |
|
/* |
|
* v6 mapped |
|
*/ |
|
|
|
newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst, |
|
req_unhash, own_req); |
|
|
|
if (!newsk) |
|
return NULL; |
|
|
|
inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk); |
|
|
|
newnp = tcp_inet6_sk(newsk); |
|
newtp = tcp_sk(newsk); |
|
|
|
memcpy(newnp, np, sizeof(struct ipv6_pinfo)); |
|
|
|
newnp->saddr = newsk->sk_v6_rcv_saddr; |
|
|
|
inet_csk(newsk)->icsk_af_ops = &ipv6_mapped; |
|
if (sk_is_mptcp(newsk)) |
|
mptcpv6_handle_mapped(newsk, true); |
|
newsk->sk_backlog_rcv = tcp_v4_do_rcv; |
|
#ifdef CONFIG_TCP_MD5SIG |
|
newtp->af_specific = &tcp_sock_ipv6_mapped_specific; |
|
#endif |
|
|
|
newnp->ipv6_mc_list = NULL; |
|
newnp->ipv6_ac_list = NULL; |
|
newnp->ipv6_fl_list = NULL; |
|
newnp->pktoptions = NULL; |
|
newnp->opt = NULL; |
|
newnp->mcast_oif = inet_iif(skb); |
|
newnp->mcast_hops = ip_hdr(skb)->ttl; |
|
newnp->rcv_flowinfo = 0; |
|
if (np->repflow) |
|
newnp->flow_label = 0; |
|
|
|
/* |
|
* No need to charge this sock to the relevant IPv6 refcnt debug socks count |
|
* here, tcp_create_openreq_child now does this for us, see the comment in |
|
* that function for the gory details. -acme |
|
*/ |
|
|
|
/* It is tricky place. Until this moment IPv4 tcp |
|
worked with IPv6 icsk.icsk_af_ops. |
|
Sync it now. |
|
*/ |
|
tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie); |
|
|
|
return newsk; |
|
} |
|
|
|
ireq = inet_rsk(req); |
|
|
|
if (sk_acceptq_is_full(sk)) |
|
goto out_overflow; |
|
|
|
if (!dst) { |
|
dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP); |
|
if (!dst) |
|
goto out; |
|
} |
|
|
|
newsk = tcp_create_openreq_child(sk, req, skb); |
|
if (!newsk) |
|
goto out_nonewsk; |
|
|
|
/* |
|
* No need to charge this sock to the relevant IPv6 refcnt debug socks |
|
* count here, tcp_create_openreq_child now does this for us, see the |
|
* comment in that function for the gory details. -acme |
|
*/ |
|
|
|
newsk->sk_gso_type = SKB_GSO_TCPV6; |
|
ip6_dst_store(newsk, dst, NULL, NULL); |
|
inet6_sk_rx_dst_set(newsk, skb); |
|
|
|
inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk); |
|
|
|
newtp = tcp_sk(newsk); |
|
newinet = inet_sk(newsk); |
|
newnp = tcp_inet6_sk(newsk); |
|
|
|
memcpy(newnp, np, sizeof(struct ipv6_pinfo)); |
|
|
|
newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr; |
|
newnp->saddr = ireq->ir_v6_loc_addr; |
|
newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr; |
|
newsk->sk_bound_dev_if = ireq->ir_iif; |
|
|
|
/* Now IPv6 options... |
|
|
|
First: no IPv4 options. |
|
*/ |
|
newinet->inet_opt = NULL; |
|
newnp->ipv6_mc_list = NULL; |
|
newnp->ipv6_ac_list = NULL; |
|
newnp->ipv6_fl_list = NULL; |
|
|
|
/* Clone RX bits */ |
|
newnp->rxopt.all = np->rxopt.all; |
|
|
|
newnp->pktoptions = NULL; |
|
newnp->opt = NULL; |
|
newnp->mcast_oif = tcp_v6_iif(skb); |
|
newnp->mcast_hops = ipv6_hdr(skb)->hop_limit; |
|
newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb)); |
|
if (np->repflow) |
|
newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb)); |
|
|
|
/* Set ToS of the new socket based upon the value of incoming SYN. |
|
* ECT bits are set later in tcp_init_transfer(). |
|
*/ |
|
if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos)) |
|
newnp->tclass = tcp_rsk(req)->syn_tos & ~INET_ECN_MASK; |
|
|
|
/* Clone native IPv6 options from listening socket (if any) |
|
|
|
Yes, keeping reference count would be much more clever, |
|
but we make one more one thing there: reattach optmem |
|
to newsk. |
|
*/ |
|
opt = ireq->ipv6_opt; |
|
if (!opt) |
|
opt = rcu_dereference(np->opt); |
|
if (opt) { |
|
opt = ipv6_dup_options(newsk, opt); |
|
RCU_INIT_POINTER(newnp->opt, opt); |
|
} |
|
inet_csk(newsk)->icsk_ext_hdr_len = 0; |
|
if (opt) |
|
inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen + |
|
opt->opt_flen; |
|
|
|
tcp_ca_openreq_child(newsk, dst); |
|
|
|
tcp_sync_mss(newsk, dst_mtu(dst)); |
|
newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst)); |
|
|
|
tcp_initialize_rcv_mss(newsk); |
|
|
|
newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6; |
|
newinet->inet_rcv_saddr = LOOPBACK4_IPV6; |
|
|
|
#ifdef CONFIG_TCP_MD5SIG |
|
l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif); |
|
|
|
/* Copy over the MD5 key from the original socket */ |
|
key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index); |
|
if (key) { |
|
/* We're using one, so create a matching key |
|
* on the newsk structure. If we fail to get |
|
* memory, then we end up not copying the key |
|
* across. Shucks. |
|
*/ |
|
tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr, |
|
AF_INET6, 128, l3index, key->flags, key->key, key->keylen, |
|
sk_gfp_mask(sk, GFP_ATOMIC)); |
|
} |
|
#endif |
|
|
|
if (__inet_inherit_port(sk, newsk) < 0) { |
|
inet_csk_prepare_forced_close(newsk); |
|
tcp_done(newsk); |
|
goto out; |
|
} |
|
*own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash), |
|
&found_dup_sk); |
|
if (*own_req) { |
|
tcp_move_syn(newtp, req); |
|
|
|
/* Clone pktoptions received with SYN, if we own the req */ |
|
if (ireq->pktopts) { |
|
newnp->pktoptions = skb_clone(ireq->pktopts, |
|
sk_gfp_mask(sk, GFP_ATOMIC)); |
|
consume_skb(ireq->pktopts); |
|
ireq->pktopts = NULL; |
|
if (newnp->pktoptions) { |
|
tcp_v6_restore_cb(newnp->pktoptions); |
|
skb_set_owner_r(newnp->pktoptions, newsk); |
|
} |
|
} |
|
} else { |
|
if (!req_unhash && found_dup_sk) { |
|
/* This code path should only be executed in the |
|
* syncookie case only |
|
*/ |
|
bh_unlock_sock(newsk); |
|
sock_put(newsk); |
|
newsk = NULL; |
|
} |
|
} |
|
|
|
return newsk; |
|
|
|
out_overflow: |
|
__NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); |
|
out_nonewsk: |
|
dst_release(dst); |
|
out: |
|
tcp_listendrop(sk); |
|
return NULL; |
|
} |
|
|
|
INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *, |
|
u32)); |
|
/* The socket must have it's spinlock held when we get |
|
* here, unless it is a TCP_LISTEN socket. |
|
* |
|
* We have a potential double-lock case here, so even when |
|
* doing backlog processing we use the BH locking scheme. |
|
* This is because we cannot sleep with the original spinlock |
|
* held. |
|
*/ |
|
INDIRECT_CALLABLE_SCOPE |
|
int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb) |
|
{ |
|
struct ipv6_pinfo *np = tcp_inet6_sk(sk); |
|
struct sk_buff *opt_skb = NULL; |
|
enum skb_drop_reason reason; |
|
struct tcp_sock *tp; |
|
|
|
/* Imagine: socket is IPv6. IPv4 packet arrives, |
|
goes to IPv4 receive handler and backlogged. |
|
From backlog it always goes here. Kerboom... |
|
Fortunately, tcp_rcv_established and rcv_established |
|
handle them correctly, but it is not case with |
|
tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK |
|
*/ |
|
|
|
if (skb->protocol == htons(ETH_P_IP)) |
|
return tcp_v4_do_rcv(sk, skb); |
|
|
|
/* |
|
* socket locking is here for SMP purposes as backlog rcv |
|
* is currently called with bh processing disabled. |
|
*/ |
|
|
|
/* Do Stevens' IPV6_PKTOPTIONS. |
|
|
|
Yes, guys, it is the only place in our code, where we |
|
may make it not affecting IPv4. |
|
The rest of code is protocol independent, |
|
and I do not like idea to uglify IPv4. |
|
|
|
Actually, all the idea behind IPV6_PKTOPTIONS |
|
looks not very well thought. For now we latch |
|
options, received in the last packet, enqueued |
|
by tcp. Feel free to propose better solution. |
|
--ANK (980728) |
|
*/ |
|
if (np->rxopt.all) |
|
opt_skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC)); |
|
|
|
reason = SKB_DROP_REASON_NOT_SPECIFIED; |
|
if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */ |
|
struct dst_entry *dst; |
|
|
|
dst = rcu_dereference_protected(sk->sk_rx_dst, |
|
lockdep_sock_is_held(sk)); |
|
|
|
sock_rps_save_rxhash(sk, skb); |
|
sk_mark_napi_id(sk, skb); |
|
if (dst) { |
|
if (sk->sk_rx_dst_ifindex != skb->skb_iif || |
|
INDIRECT_CALL_1(dst->ops->check, ip6_dst_check, |
|
dst, sk->sk_rx_dst_cookie) == NULL) { |
|
RCU_INIT_POINTER(sk->sk_rx_dst, NULL); |
|
dst_release(dst); |
|
} |
|
} |
|
|
|
tcp_rcv_established(sk, skb); |
|
if (opt_skb) |
|
goto ipv6_pktoptions; |
|
return 0; |
|
} |
|
|
|
if (tcp_checksum_complete(skb)) |
|
goto csum_err; |
|
|
|
if (sk->sk_state == TCP_LISTEN) { |
|
struct sock *nsk = tcp_v6_cookie_check(sk, skb); |
|
|
|
if (!nsk) |
|
goto discard; |
|
|
|
if (nsk != sk) { |
|
if (tcp_child_process(sk, nsk, skb)) |
|
goto reset; |
|
if (opt_skb) |
|
__kfree_skb(opt_skb); |
|
return 0; |
|
} |
|
} else |
|
sock_rps_save_rxhash(sk, skb); |
|
|
|
if (tcp_rcv_state_process(sk, skb)) |
|
goto reset; |
|
if (opt_skb) |
|
goto ipv6_pktoptions; |
|
return 0; |
|
|
|
reset: |
|
tcp_v6_send_reset(sk, skb); |
|
discard: |
|
if (opt_skb) |
|
__kfree_skb(opt_skb); |
|
kfree_skb_reason(skb, reason); |
|
return 0; |
|
csum_err: |
|
reason = SKB_DROP_REASON_TCP_CSUM; |
|
trace_tcp_bad_csum(skb); |
|
TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS); |
|
TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS); |
|
goto discard; |
|
|
|
|
|
ipv6_pktoptions: |
|
/* Do you ask, what is it? |
|
|
|
1. skb was enqueued by tcp. |
|
2. skb is added to tail of read queue, rather than out of order. |
|
3. socket is not in passive state. |
|
4. Finally, it really contains options, which user wants to receive. |
|
*/ |
|
tp = tcp_sk(sk); |
|
if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt && |
|
!((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) { |
|
if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo) |
|
np->mcast_oif = tcp_v6_iif(opt_skb); |
|
if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) |
|
np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit; |
|
if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass) |
|
np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb)); |
|
if (np->repflow) |
|
np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb)); |
|
if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) { |
|
skb_set_owner_r(opt_skb, sk); |
|
tcp_v6_restore_cb(opt_skb); |
|
opt_skb = xchg(&np->pktoptions, opt_skb); |
|
} else { |
|
__kfree_skb(opt_skb); |
|
opt_skb = xchg(&np->pktoptions, NULL); |
|
} |
|
} |
|
|
|
consume_skb(opt_skb); |
|
return 0; |
|
} |
|
|
|
static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr, |
|
const struct tcphdr *th) |
|
{ |
|
/* This is tricky: we move IP6CB at its correct location into |
|
* TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because |
|
* _decode_session6() uses IP6CB(). |
|
* barrier() makes sure compiler won't play aliasing games. |
|
*/ |
|
memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb), |
|
sizeof(struct inet6_skb_parm)); |
|
barrier(); |
|
|
|
TCP_SKB_CB(skb)->seq = ntohl(th->seq); |
|
TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin + |
|
skb->len - th->doff*4); |
|
TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq); |
|
TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th); |
|
TCP_SKB_CB(skb)->tcp_tw_isn = 0; |
|
TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr); |
|
TCP_SKB_CB(skb)->sacked = 0; |
|
TCP_SKB_CB(skb)->has_rxtstamp = |
|
skb->tstamp || skb_hwtstamps(skb)->hwtstamp; |
|
} |
|
|
|
INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb) |
|
{ |
|
enum skb_drop_reason drop_reason; |
|
int sdif = inet6_sdif(skb); |
|
int dif = inet6_iif(skb); |
|
const struct tcphdr *th; |
|
const struct ipv6hdr *hdr; |
|
bool refcounted; |
|
struct sock *sk; |
|
int ret; |
|
struct net *net = dev_net(skb->dev); |
|
|
|
drop_reason = SKB_DROP_REASON_NOT_SPECIFIED; |
|
if (skb->pkt_type != PACKET_HOST) |
|
goto discard_it; |
|
|
|
/* |
|
* Count it even if it's bad. |
|
*/ |
|
__TCP_INC_STATS(net, TCP_MIB_INSEGS); |
|
|
|
if (!pskb_may_pull(skb, sizeof(struct tcphdr))) |
|
goto discard_it; |
|
|
|
th = (const struct tcphdr *)skb->data; |
|
|
|
if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) { |
|
drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL; |
|
goto bad_packet; |
|
} |
|
if (!pskb_may_pull(skb, th->doff*4)) |
|
goto discard_it; |
|
|
|
if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo)) |
|
goto csum_error; |
|
|
|
th = (const struct tcphdr *)skb->data; |
|
hdr = ipv6_hdr(skb); |
|
|
|
lookup: |
|
sk = __inet6_lookup_skb(net->ipv4.tcp_death_row.hashinfo, skb, __tcp_hdrlen(th), |
|
th->source, th->dest, inet6_iif(skb), sdif, |
|
&refcounted); |
|
if (!sk) |
|
goto no_tcp_socket; |
|
|
|
process: |
|
if (sk->sk_state == TCP_TIME_WAIT) |
|
goto do_time_wait; |
|
|
|
if (sk->sk_state == TCP_NEW_SYN_RECV) { |
|
struct request_sock *req = inet_reqsk(sk); |
|
bool req_stolen = false; |
|
struct sock *nsk; |
|
|
|
sk = req->rsk_listener; |
|
drop_reason = tcp_inbound_md5_hash(sk, skb, |
|
&hdr->saddr, &hdr->daddr, |
|
AF_INET6, dif, sdif); |
|
if (drop_reason) { |
|
sk_drops_add(sk, skb); |
|
reqsk_put(req); |
|
goto discard_it; |
|
} |
|
if (tcp_checksum_complete(skb)) { |
|
reqsk_put(req); |
|
goto csum_error; |
|
} |
|
if (unlikely(sk->sk_state != TCP_LISTEN)) { |
|
nsk = reuseport_migrate_sock(sk, req_to_sk(req), skb); |
|
if (!nsk) { |
|
inet_csk_reqsk_queue_drop_and_put(sk, req); |
|
goto lookup; |
|
} |
|
sk = nsk; |
|
/* reuseport_migrate_sock() has already held one sk_refcnt |
|
* before returning. |
|
*/ |
|
} else { |
|
sock_hold(sk); |
|
} |
|
refcounted = true; |
|
nsk = NULL; |
|
if (!tcp_filter(sk, skb)) { |
|
th = (const struct tcphdr *)skb->data; |
|
hdr = ipv6_hdr(skb); |
|
tcp_v6_fill_cb(skb, hdr, th); |
|
nsk = tcp_check_req(sk, skb, req, false, &req_stolen); |
|
} else { |
|
drop_reason = SKB_DROP_REASON_SOCKET_FILTER; |
|
} |
|
if (!nsk) { |
|
reqsk_put(req); |
|
if (req_stolen) { |
|
/* Another cpu got exclusive access to req |
|
* and created a full blown socket. |
|
* Try to feed this packet to this socket |
|
* instead of discarding it. |
|
*/ |
|
tcp_v6_restore_cb(skb); |
|
sock_put(sk); |
|
goto lookup; |
|
} |
|
goto discard_and_relse; |
|
} |
|
if (nsk == sk) { |
|
reqsk_put(req); |
|
tcp_v6_restore_cb(skb); |
|
} else if (tcp_child_process(sk, nsk, skb)) { |
|
tcp_v6_send_reset(nsk, skb); |
|
goto discard_and_relse; |
|
} else { |
|
sock_put(sk); |
|
return 0; |
|
} |
|
} |
|
|
|
if (static_branch_unlikely(&ip6_min_hopcount)) { |
|
/* min_hopcount can be changed concurrently from do_ipv6_setsockopt() */ |
|
if (hdr->hop_limit < READ_ONCE(tcp_inet6_sk(sk)->min_hopcount)) { |
|
__NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP); |
|
goto discard_and_relse; |
|
} |
|
} |
|
|
|
if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) { |
|
drop_reason = SKB_DROP_REASON_XFRM_POLICY; |
|
goto discard_and_relse; |
|
} |
|
|
|
drop_reason = tcp_inbound_md5_hash(sk, skb, &hdr->saddr, &hdr->daddr, |
|
AF_INET6, dif, sdif); |
|
if (drop_reason) |
|
goto discard_and_relse; |
|
|
|
if (tcp_filter(sk, skb)) { |
|
drop_reason = SKB_DROP_REASON_SOCKET_FILTER; |
|
goto discard_and_relse; |
|
} |
|
th = (const struct tcphdr *)skb->data; |
|
hdr = ipv6_hdr(skb); |
|
tcp_v6_fill_cb(skb, hdr, th); |
|
|
|
skb->dev = NULL; |
|
|
|
if (sk->sk_state == TCP_LISTEN) { |
|
ret = tcp_v6_do_rcv(sk, skb); |
|
goto put_and_return; |
|
} |
|
|
|
sk_incoming_cpu_update(sk); |
|
|
|
bh_lock_sock_nested(sk); |
|
tcp_segs_in(tcp_sk(sk), skb); |
|
ret = 0; |
|
if (!sock_owned_by_user(sk)) { |
|
ret = tcp_v6_do_rcv(sk, skb); |
|
} else { |
|
if (tcp_add_backlog(sk, skb, &drop_reason)) |
|
goto discard_and_relse; |
|
} |
|
bh_unlock_sock(sk); |
|
put_and_return: |
|
if (refcounted) |
|
sock_put(sk); |
|
return ret ? -1 : 0; |
|
|
|
no_tcp_socket: |
|
drop_reason = SKB_DROP_REASON_NO_SOCKET; |
|
if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) |
|
goto discard_it; |
|
|
|
tcp_v6_fill_cb(skb, hdr, th); |
|
|
|
if (tcp_checksum_complete(skb)) { |
|
csum_error: |
|
drop_reason = SKB_DROP_REASON_TCP_CSUM; |
|
trace_tcp_bad_csum(skb); |
|
__TCP_INC_STATS(net, TCP_MIB_CSUMERRORS); |
|
bad_packet: |
|
__TCP_INC_STATS(net, TCP_MIB_INERRS); |
|
} else { |
|
tcp_v6_send_reset(NULL, skb); |
|
} |
|
|
|
discard_it: |
|
SKB_DR_OR(drop_reason, NOT_SPECIFIED); |
|
kfree_skb_reason(skb, drop_reason); |
|
return 0; |
|
|
|
discard_and_relse: |
|
sk_drops_add(sk, skb); |
|
if (refcounted) |
|
sock_put(sk); |
|
goto discard_it; |
|
|
|
do_time_wait: |
|
if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
|
drop_reason = SKB_DROP_REASON_XFRM_POLICY; |
|
inet_twsk_put(inet_twsk(sk)); |
|
goto discard_it; |
|
} |
|
|
|
tcp_v6_fill_cb(skb, hdr, th); |
|
|
|
if (tcp_checksum_complete(skb)) { |
|
inet_twsk_put(inet_twsk(sk)); |
|
goto csum_error; |
|
} |
|
|
|
switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) { |
|
case TCP_TW_SYN: |
|
{ |
|
struct sock *sk2; |
|
|
|
sk2 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo, |
|
skb, __tcp_hdrlen(th), |
|
&ipv6_hdr(skb)->saddr, th->source, |
|
&ipv6_hdr(skb)->daddr, |
|
ntohs(th->dest), |
|
tcp_v6_iif_l3_slave(skb), |
|
sdif); |
|
if (sk2) { |
|
struct inet_timewait_sock *tw = inet_twsk(sk); |
|
inet_twsk_deschedule_put(tw); |
|
sk = sk2; |
|
tcp_v6_restore_cb(skb); |
|
refcounted = false; |
|
goto process; |
|
} |
|
} |
|
/* to ACK */ |
|
fallthrough; |
|
case TCP_TW_ACK: |
|
tcp_v6_timewait_ack(sk, skb); |
|
break; |
|
case TCP_TW_RST: |
|
tcp_v6_send_reset(sk, skb); |
|
inet_twsk_deschedule_put(inet_twsk(sk)); |
|
goto discard_it; |
|
case TCP_TW_SUCCESS: |
|
; |
|
} |
|
goto discard_it; |
|
} |
|
|
|
void tcp_v6_early_demux(struct sk_buff *skb) |
|
{ |
|
struct net *net = dev_net(skb->dev); |
|
const struct ipv6hdr *hdr; |
|
const struct tcphdr *th; |
|
struct sock *sk; |
|
|
|
if (skb->pkt_type != PACKET_HOST) |
|
return; |
|
|
|
if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr))) |
|
return; |
|
|
|
hdr = ipv6_hdr(skb); |
|
th = tcp_hdr(skb); |
|
|
|
if (th->doff < sizeof(struct tcphdr) / 4) |
|
return; |
|
|
|
/* Note : We use inet6_iif() here, not tcp_v6_iif() */ |
|
sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo, |
|
&hdr->saddr, th->source, |
|
&hdr->daddr, ntohs(th->dest), |
|
inet6_iif(skb), inet6_sdif(skb)); |
|
if (sk) { |
|
skb->sk = sk; |
|
skb->destructor = sock_edemux; |
|
if (sk_fullsock(sk)) { |
|
struct dst_entry *dst = rcu_dereference(sk->sk_rx_dst); |
|
|
|
if (dst) |
|
dst = dst_check(dst, sk->sk_rx_dst_cookie); |
|
if (dst && |
|
sk->sk_rx_dst_ifindex == skb->skb_iif) |
|
skb_dst_set_noref(skb, dst); |
|
} |
|
} |
|
} |
|
|
|
static struct timewait_sock_ops tcp6_timewait_sock_ops = { |
|
.twsk_obj_size = sizeof(struct tcp6_timewait_sock), |
|
.twsk_unique = tcp_twsk_unique, |
|
.twsk_destructor = tcp_twsk_destructor, |
|
}; |
|
|
|
INDIRECT_CALLABLE_SCOPE void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb) |
|
{ |
|
__tcp_v6_send_check(skb, &sk->sk_v6_rcv_saddr, &sk->sk_v6_daddr); |
|
} |
|
|
|
const struct inet_connection_sock_af_ops ipv6_specific = { |
|
.queue_xmit = inet6_csk_xmit, |
|
.send_check = tcp_v6_send_check, |
|
.rebuild_header = inet6_sk_rebuild_header, |
|
.sk_rx_dst_set = inet6_sk_rx_dst_set, |
|
.conn_request = tcp_v6_conn_request, |
|
.syn_recv_sock = tcp_v6_syn_recv_sock, |
|
.net_header_len = sizeof(struct ipv6hdr), |
|
.net_frag_header_len = sizeof(struct frag_hdr), |
|
.setsockopt = ipv6_setsockopt, |
|
.getsockopt = ipv6_getsockopt, |
|
.addr2sockaddr = inet6_csk_addr2sockaddr, |
|
.sockaddr_len = sizeof(struct sockaddr_in6), |
|
.mtu_reduced = tcp_v6_mtu_reduced, |
|
}; |
|
|
|
#ifdef CONFIG_TCP_MD5SIG |
|
static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = { |
|
.md5_lookup = tcp_v6_md5_lookup, |
|
.calc_md5_hash = tcp_v6_md5_hash_skb, |
|
.md5_parse = tcp_v6_parse_md5_keys, |
|
}; |
|
#endif |
|
|
|
/* |
|
* TCP over IPv4 via INET6 API |
|
*/ |
|
static const struct inet_connection_sock_af_ops ipv6_mapped = { |
|
.queue_xmit = ip_queue_xmit, |
|
.send_check = tcp_v4_send_check, |
|
.rebuild_header = inet_sk_rebuild_header, |
|
.sk_rx_dst_set = inet_sk_rx_dst_set, |
|
.conn_request = tcp_v6_conn_request, |
|
.syn_recv_sock = tcp_v6_syn_recv_sock, |
|
.net_header_len = sizeof(struct iphdr), |
|
.setsockopt = ipv6_setsockopt, |
|
.getsockopt = ipv6_getsockopt, |
|
.addr2sockaddr = inet6_csk_addr2sockaddr, |
|
.sockaddr_len = sizeof(struct sockaddr_in6), |
|
.mtu_reduced = tcp_v4_mtu_reduced, |
|
}; |
|
|
|
#ifdef CONFIG_TCP_MD5SIG |
|
static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = { |
|
.md5_lookup = tcp_v4_md5_lookup, |
|
.calc_md5_hash = tcp_v4_md5_hash_skb, |
|
.md5_parse = tcp_v6_parse_md5_keys, |
|
}; |
|
#endif |
|
|
|
/* NOTE: A lot of things set to zero explicitly by call to |
|
* sk_alloc() so need not be done here. |
|
*/ |
|
static int tcp_v6_init_sock(struct sock *sk) |
|
{ |
|
struct inet_connection_sock *icsk = inet_csk(sk); |
|
|
|
tcp_init_sock(sk); |
|
|
|
icsk->icsk_af_ops = &ipv6_specific; |
|
|
|
#ifdef CONFIG_TCP_MD5SIG |
|
tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific; |
|
#endif |
|
|
|
return 0; |
|
} |
|
|
|
static void tcp_v6_destroy_sock(struct sock *sk) |
|
{ |
|
tcp_v4_destroy_sock(sk); |
|
inet6_destroy_sock(sk); |
|
} |
|
|
|
#ifdef CONFIG_PROC_FS |
|
/* Proc filesystem TCPv6 sock list dumping. */ |
|
static void get_openreq6(struct seq_file *seq, |
|
const struct request_sock *req, int i) |
|
{ |
|
long ttd = req->rsk_timer.expires - jiffies; |
|
const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr; |
|
const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr; |
|
|
|
if (ttd < 0) |
|
ttd = 0; |
|
|
|
seq_printf(seq, |
|
"%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " |
|
"%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n", |
|
i, |
|
src->s6_addr32[0], src->s6_addr32[1], |
|
src->s6_addr32[2], src->s6_addr32[3], |
|
inet_rsk(req)->ir_num, |
|
dest->s6_addr32[0], dest->s6_addr32[1], |
|
dest->s6_addr32[2], dest->s6_addr32[3], |
|
ntohs(inet_rsk(req)->ir_rmt_port), |
|
TCP_SYN_RECV, |
|
0, 0, /* could print option size, but that is af dependent. */ |
|
1, /* timers active (only the expire timer) */ |
|
jiffies_to_clock_t(ttd), |
|
req->num_timeout, |
|
from_kuid_munged(seq_user_ns(seq), |
|
sock_i_uid(req->rsk_listener)), |
|
0, /* non standard timer */ |
|
0, /* open_requests have no inode */ |
|
0, req); |
|
} |
|
|
|
static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i) |
|
{ |
|
const struct in6_addr *dest, *src; |
|
__u16 destp, srcp; |
|
int timer_active; |
|
unsigned long timer_expires; |
|
const struct inet_sock *inet = inet_sk(sp); |
|
const struct tcp_sock *tp = tcp_sk(sp); |
|
const struct inet_connection_sock *icsk = inet_csk(sp); |
|
const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq; |
|
int rx_queue; |
|
int state; |
|
|
|
dest = &sp->sk_v6_daddr; |
|
src = &sp->sk_v6_rcv_saddr; |
|
destp = ntohs(inet->inet_dport); |
|
srcp = ntohs(inet->inet_sport); |
|
|
|
if (icsk->icsk_pending == ICSK_TIME_RETRANS || |
|
icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT || |
|
icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) { |
|
timer_active = 1; |
|
timer_expires = icsk->icsk_timeout; |
|
} else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { |
|
timer_active = 4; |
|
timer_expires = icsk->icsk_timeout; |
|
} else if (timer_pending(&sp->sk_timer)) { |
|
timer_active = 2; |
|
timer_expires = sp->sk_timer.expires; |
|
} else { |
|
timer_active = 0; |
|
timer_expires = jiffies; |
|
} |
|
|
|
state = inet_sk_state_load(sp); |
|
if (state == TCP_LISTEN) |
|
rx_queue = READ_ONCE(sp->sk_ack_backlog); |
|
else |
|
/* Because we don't lock the socket, |
|
* we might find a transient negative value. |
|
*/ |
|
rx_queue = max_t(int, READ_ONCE(tp->rcv_nxt) - |
|
READ_ONCE(tp->copied_seq), 0); |
|
|
|
seq_printf(seq, |
|
"%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " |
|
"%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n", |
|
i, |
|
src->s6_addr32[0], src->s6_addr32[1], |
|
src->s6_addr32[2], src->s6_addr32[3], srcp, |
|
dest->s6_addr32[0], dest->s6_addr32[1], |
|
dest->s6_addr32[2], dest->s6_addr32[3], destp, |
|
state, |
|
READ_ONCE(tp->write_seq) - tp->snd_una, |
|
rx_queue, |
|
timer_active, |
|
jiffies_delta_to_clock_t(timer_expires - jiffies), |
|
icsk->icsk_retransmits, |
|
from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)), |
|
icsk->icsk_probes_out, |
|
sock_i_ino(sp), |
|
refcount_read(&sp->sk_refcnt), sp, |
|
jiffies_to_clock_t(icsk->icsk_rto), |
|
jiffies_to_clock_t(icsk->icsk_ack.ato), |
|
(icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sp), |
|
tcp_snd_cwnd(tp), |
|
state == TCP_LISTEN ? |
|
fastopenq->max_qlen : |
|
(tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh) |
|
); |
|
} |
|
|
|
static void get_timewait6_sock(struct seq_file *seq, |
|
struct inet_timewait_sock *tw, int i) |
|
{ |
|
long delta = tw->tw_timer.expires - jiffies; |
|
const struct in6_addr *dest, *src; |
|
__u16 destp, srcp; |
|
|
|
dest = &tw->tw_v6_daddr; |
|
src = &tw->tw_v6_rcv_saddr; |
|
destp = ntohs(tw->tw_dport); |
|
srcp = ntohs(tw->tw_sport); |
|
|
|
seq_printf(seq, |
|
"%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " |
|
"%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n", |
|
i, |
|
src->s6_addr32[0], src->s6_addr32[1], |
|
src->s6_addr32[2], src->s6_addr32[3], srcp, |
|
dest->s6_addr32[0], dest->s6_addr32[1], |
|
dest->s6_addr32[2], dest->s6_addr32[3], destp, |
|
tw->tw_substate, 0, 0, |
|
3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0, |
|
refcount_read(&tw->tw_refcnt), tw); |
|
} |
|
|
|
static int tcp6_seq_show(struct seq_file *seq, void *v) |
|
{ |
|
struct tcp_iter_state *st; |
|
struct sock *sk = v; |
|
|
|
if (v == SEQ_START_TOKEN) { |
|
seq_puts(seq, |
|
" sl " |
|
"local_address " |
|
"remote_address " |
|
"st tx_queue rx_queue tr tm->when retrnsmt" |
|
" uid timeout inode\n"); |
|
goto out; |
|
} |
|
st = seq->private; |
|
|
|
if (sk->sk_state == TCP_TIME_WAIT) |
|
get_timewait6_sock(seq, v, st->num); |
|
else if (sk->sk_state == TCP_NEW_SYN_RECV) |
|
get_openreq6(seq, v, st->num); |
|
else |
|
get_tcp6_sock(seq, v, st->num); |
|
out: |
|
return 0; |
|
} |
|
|
|
static const struct seq_operations tcp6_seq_ops = { |
|
.show = tcp6_seq_show, |
|
.start = tcp_seq_start, |
|
.next = tcp_seq_next, |
|
.stop = tcp_seq_stop, |
|
}; |
|
|
|
static struct tcp_seq_afinfo tcp6_seq_afinfo = { |
|
.family = AF_INET6, |
|
}; |
|
|
|
int __net_init tcp6_proc_init(struct net *net) |
|
{ |
|
if (!proc_create_net_data("tcp6", 0444, net->proc_net, &tcp6_seq_ops, |
|
sizeof(struct tcp_iter_state), &tcp6_seq_afinfo)) |
|
return -ENOMEM; |
|
return 0; |
|
} |
|
|
|
void tcp6_proc_exit(struct net *net) |
|
{ |
|
remove_proc_entry("tcp6", net->proc_net); |
|
} |
|
#endif |
|
|
|
struct proto tcpv6_prot = { |
|
.name = "TCPv6", |
|
.owner = THIS_MODULE, |
|
.close = tcp_close, |
|
.pre_connect = tcp_v6_pre_connect, |
|
.connect = tcp_v6_connect, |
|
.disconnect = tcp_disconnect, |
|
.accept = inet_csk_accept, |
|
.ioctl = tcp_ioctl, |
|
.init = tcp_v6_init_sock, |
|
.destroy = tcp_v6_destroy_sock, |
|
.shutdown = tcp_shutdown, |
|
.setsockopt = tcp_setsockopt, |
|
.getsockopt = tcp_getsockopt, |
|
.bpf_bypass_getsockopt = tcp_bpf_bypass_getsockopt, |
|
.keepalive = tcp_set_keepalive, |
|
.recvmsg = tcp_recvmsg, |
|
.sendmsg = tcp_sendmsg, |
|
.sendpage = tcp_sendpage, |
|
.backlog_rcv = tcp_v6_do_rcv, |
|
.release_cb = tcp_release_cb, |
|
.hash = inet6_hash, |
|
.unhash = inet_unhash, |
|
.get_port = inet_csk_get_port, |
|
.put_port = inet_put_port, |
|
#ifdef CONFIG_BPF_SYSCALL |
|
.psock_update_sk_prot = tcp_bpf_update_proto, |
|
#endif |
|
.enter_memory_pressure = tcp_enter_memory_pressure, |
|
.leave_memory_pressure = tcp_leave_memory_pressure, |
|
.stream_memory_free = tcp_stream_memory_free, |
|
.sockets_allocated = &tcp_sockets_allocated, |
|
|
|
.memory_allocated = &tcp_memory_allocated, |
|
.per_cpu_fw_alloc = &tcp_memory_per_cpu_fw_alloc, |
|
|
|
.memory_pressure = &tcp_memory_pressure, |
|
.orphan_count = &tcp_orphan_count, |
|
.sysctl_mem = sysctl_tcp_mem, |
|
.sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem), |
|
.sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem), |
|
.max_header = MAX_TCP_HEADER, |
|
.obj_size = sizeof(struct tcp6_sock), |
|
.slab_flags = SLAB_TYPESAFE_BY_RCU, |
|
.twsk_prot = &tcp6_timewait_sock_ops, |
|
.rsk_prot = &tcp6_request_sock_ops, |
|
.h.hashinfo = NULL, |
|
.no_autobind = true, |
|
.diag_destroy = tcp_abort, |
|
}; |
|
EXPORT_SYMBOL_GPL(tcpv6_prot); |
|
|
|
static const struct inet6_protocol tcpv6_protocol = { |
|
.handler = tcp_v6_rcv, |
|
.err_handler = tcp_v6_err, |
|
.flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, |
|
}; |
|
|
|
static struct inet_protosw tcpv6_protosw = { |
|
.type = SOCK_STREAM, |
|
.protocol = IPPROTO_TCP, |
|
.prot = &tcpv6_prot, |
|
.ops = &inet6_stream_ops, |
|
.flags = INET_PROTOSW_PERMANENT | |
|
INET_PROTOSW_ICSK, |
|
}; |
|
|
|
static int __net_init tcpv6_net_init(struct net *net) |
|
{ |
|
return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6, |
|
SOCK_RAW, IPPROTO_TCP, net); |
|
} |
|
|
|
static void __net_exit tcpv6_net_exit(struct net *net) |
|
{ |
|
inet_ctl_sock_destroy(net->ipv6.tcp_sk); |
|
} |
|
|
|
static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list) |
|
{ |
|
tcp_twsk_purge(net_exit_list, AF_INET6); |
|
} |
|
|
|
static struct pernet_operations tcpv6_net_ops = { |
|
.init = tcpv6_net_init, |
|
.exit = tcpv6_net_exit, |
|
.exit_batch = tcpv6_net_exit_batch, |
|
}; |
|
|
|
int __init tcpv6_init(void) |
|
{ |
|
int ret; |
|
|
|
ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP); |
|
if (ret) |
|
goto out; |
|
|
|
/* register inet6 protocol */ |
|
ret = inet6_register_protosw(&tcpv6_protosw); |
|
if (ret) |
|
goto out_tcpv6_protocol; |
|
|
|
ret = register_pernet_subsys(&tcpv6_net_ops); |
|
if (ret) |
|
goto out_tcpv6_protosw; |
|
|
|
ret = mptcpv6_init(); |
|
if (ret) |
|
goto out_tcpv6_pernet_subsys; |
|
|
|
out: |
|
return ret; |
|
|
|
out_tcpv6_pernet_subsys: |
|
unregister_pernet_subsys(&tcpv6_net_ops); |
|
out_tcpv6_protosw: |
|
inet6_unregister_protosw(&tcpv6_protosw); |
|
out_tcpv6_protocol: |
|
inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP); |
|
goto out; |
|
} |
|
|
|
void tcpv6_exit(void) |
|
{ |
|
unregister_pernet_subsys(&tcpv6_net_ops); |
|
inet6_unregister_protosw(&tcpv6_protosw); |
|
inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP); |
|
}
|
|
|