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android_kernel_xiaomi_sm8350/net/dccp/ipv6.c
Arnaldo Carvalho de Melo 6d6ee43e0b [TWSK]: Introduce struct timewait_sock_ops 
So that we can share several timewait sockets related functions and
make the timewait mini sockets infrastructure closer to the request
mini sockets one.

Next changesets will take advantage of this, moving more code out of
TCP and DCCP v4 and v6 to common infrastructure.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-03 13:10:54 -08:00

1443 lines
36 KiB
C
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/*
* DCCP over IPv6
* Linux INET6 implementation
*
* Based on net/dccp6/ipv6.c
*
* Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/xfrm.h>
#include <net/addrconf.h>
#include <net/inet_common.h>
#include <net/inet_hashtables.h>
#include <net/inet6_connection_sock.h>
#include <net/inet6_hashtables.h>
#include <net/ip6_route.h>
#include <net/ipv6.h>
#include <net/protocol.h>
#include <net/transp_v6.h>
#include <net/xfrm.h>
#include "dccp.h"
#include "ipv6.h"
static void dccp_v6_ctl_send_reset(struct sk_buff *skb);
static void dccp_v6_reqsk_send_ack(struct sk_buff *skb,
struct request_sock *req);
static void dccp_v6_send_check(struct sock *sk, int len, struct sk_buff *skb);
static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
static struct inet_connection_sock_af_ops dccp_ipv6_mapped;
static struct inet_connection_sock_af_ops dccp_ipv6_af_ops;
static int dccp_v6_get_port(struct sock *sk, unsigned short snum)
{
return inet_csk_get_port(&dccp_hashinfo, sk, snum,
inet6_csk_bind_conflict);
}
static void dccp_v6_hash(struct sock *sk)
{
if (sk->sk_state != DCCP_CLOSED) {
if (inet_csk(sk)->icsk_af_ops == &dccp_ipv6_mapped) {
dccp_prot.hash(sk);
return;
}
local_bh_disable();
__inet6_hash(&dccp_hashinfo, sk);
local_bh_enable();
}
}
static inline u16 dccp_v6_check(struct dccp_hdr *dh, int len,
struct in6_addr *saddr,
struct in6_addr *daddr,
unsigned long base)
{
return csum_ipv6_magic(saddr, daddr, len, IPPROTO_DCCP, base);
}
static __u32 dccp_v6_init_sequence(struct sock *sk, struct sk_buff *skb)
{
const struct dccp_hdr *dh = dccp_hdr(skb);
if (skb->protocol == htons(ETH_P_IPV6))
return secure_tcpv6_sequence_number(skb->nh.ipv6h->daddr.s6_addr32,
skb->nh.ipv6h->saddr.s6_addr32,
dh->dccph_dport,
dh->dccph_sport);
else
return secure_dccp_sequence_number(skb->nh.iph->daddr,
skb->nh.iph->saddr,
dh->dccph_dport,
dh->dccph_sport);
}
static int __dccp_v6_check_established(struct sock *sk, const __u16 lport,
struct inet_timewait_sock **twp)
{
struct inet_sock *inet = inet_sk(sk);
const struct ipv6_pinfo *np = inet6_sk(sk);
const struct in6_addr *daddr = &np->rcv_saddr;
const struct in6_addr *saddr = &np->daddr;
const int dif = sk->sk_bound_dev_if;
const u32 ports = INET_COMBINED_PORTS(inet->dport, lport);
const unsigned int hash = inet6_ehashfn(daddr, inet->num,
saddr, inet->dport);
struct inet_ehash_bucket *head = inet_ehash_bucket(&dccp_hashinfo, hash);
struct sock *sk2;
const struct hlist_node *node;
struct inet_timewait_sock *tw;
prefetch(head->chain.first);
write_lock(&head->lock);
/* Check TIME-WAIT sockets first. */
sk_for_each(sk2, node, &(head + dccp_hashinfo.ehash_size)->chain) {
const struct inet6_timewait_sock *tw6 = inet6_twsk(sk2);
tw = inet_twsk(sk2);
if(*((__u32 *)&(tw->tw_dport)) == ports &&
sk2->sk_family == PF_INET6 &&
ipv6_addr_equal(&tw6->tw_v6_daddr, saddr) &&
ipv6_addr_equal(&tw6->tw_v6_rcv_saddr, daddr) &&
sk2->sk_bound_dev_if == sk->sk_bound_dev_if)
goto not_unique;
}
tw = NULL;
/* And established part... */
sk_for_each(sk2, node, &head->chain) {
if (INET6_MATCH(sk2, hash, saddr, daddr, ports, dif))
goto not_unique;
}
BUG_TRAP(sk_unhashed(sk));
__sk_add_node(sk, &head->chain);
sk->sk_hash = hash;
sock_prot_inc_use(sk->sk_prot);
write_unlock(&head->lock);
if (twp) {
*twp = tw;
NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
} else if (tw) {
/* Silly. Should hash-dance instead... */
inet_twsk_deschedule(tw, &dccp_death_row);
NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
inet_twsk_put(tw);
}
return 0;
not_unique:
write_unlock(&head->lock);
return -EADDRNOTAVAIL;
}
static inline u32 dccp_v6_port_offset(const struct sock *sk)
{
const struct inet_sock *inet = inet_sk(sk);
const struct ipv6_pinfo *np = inet6_sk(sk);
return secure_tcpv6_port_ephemeral(np->rcv_saddr.s6_addr32,
np->daddr.s6_addr32,
inet->dport);
}
static int dccp_v6_hash_connect(struct sock *sk)
{
const unsigned short snum = inet_sk(sk)->num;
struct inet_bind_hashbucket *head;
struct inet_bind_bucket *tb;
int ret;
if (snum == 0) {
int low = sysctl_local_port_range[0];
int high = sysctl_local_port_range[1];
int range = high - low;
int i;
int port;
static u32 hint;
u32 offset = hint + dccp_v6_port_offset(sk);
struct hlist_node *node;
struct inet_timewait_sock *tw = NULL;
local_bh_disable();
for (i = 1; i <= range; i++) {
port = low + (i + offset) % range;
head = &dccp_hashinfo.bhash[inet_bhashfn(port,
dccp_hashinfo.bhash_size)];
spin_lock(&head->lock);
/* Does not bother with rcv_saddr checks,
* because the established check is already
* unique enough.
*/
inet_bind_bucket_for_each(tb, node, &head->chain) {
if (tb->port == port) {
BUG_TRAP(!hlist_empty(&tb->owners));
if (tb->fastreuse >= 0)
goto next_port;
if (!__dccp_v6_check_established(sk,
port,
&tw))
goto ok;
goto next_port;
}
}
tb = inet_bind_bucket_create(dccp_hashinfo.bind_bucket_cachep,
head, port);
if (!tb) {
spin_unlock(&head->lock);
break;
}
tb->fastreuse = -1;
goto ok;
next_port:
spin_unlock(&head->lock);
}
local_bh_enable();
return -EADDRNOTAVAIL;
ok:
hint += i;
/* Head lock still held and bh's disabled */
inet_bind_hash(sk, tb, port);
if (sk_unhashed(sk)) {
inet_sk(sk)->sport = htons(port);
__inet6_hash(&dccp_hashinfo, sk);
}
spin_unlock(&head->lock);
if (tw) {
inet_twsk_deschedule(tw, &dccp_death_row);
inet_twsk_put(tw);
}
ret = 0;
goto out;
}
head = &dccp_hashinfo.bhash[inet_bhashfn(snum,
dccp_hashinfo.bhash_size)];
tb = inet_csk(sk)->icsk_bind_hash;
spin_lock_bh(&head->lock);
if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) {
__inet6_hash(&dccp_hashinfo, sk);
spin_unlock_bh(&head->lock);
return 0;
} else {
spin_unlock(&head->lock);
/* No definite answer... Walk to established hash table */
ret = __dccp_v6_check_established(sk, snum, NULL);
out:
local_bh_enable();
return ret;
}
}
static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
int addr_len)
{
struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
struct inet_sock *inet = inet_sk(sk);
struct ipv6_pinfo *np = inet6_sk(sk);
struct dccp_sock *dp = dccp_sk(sk);
struct in6_addr *saddr = NULL, *final_p = NULL, final;
struct flowi fl;
struct dst_entry *dst;
int addr_type;
int err;
dp->dccps_role = DCCP_ROLE_CLIENT;
if (addr_len < SIN6_LEN_RFC2133)
return -EINVAL;
if (usin->sin6_family != AF_INET6)
return -EAFNOSUPPORT;
memset(&fl, 0, sizeof(fl));
if (np->sndflow) {
fl.fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
IP6_ECN_flow_init(fl.fl6_flowlabel);
if (fl.fl6_flowlabel & IPV6_FLOWLABEL_MASK) {
struct ip6_flowlabel *flowlabel;
flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
if (flowlabel == NULL)
return -EINVAL;
ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
fl6_sock_release(flowlabel);
}
}
/*
* connect() to INADDR_ANY means loopback (BSD'ism).
*/
if (ipv6_addr_any(&usin->sin6_addr))
usin->sin6_addr.s6_addr[15] = 0x1;
addr_type = ipv6_addr_type(&usin->sin6_addr);
if(addr_type & IPV6_ADDR_MULTICAST)
return -ENETUNREACH;
if (addr_type & IPV6_ADDR_LINKLOCAL) {
if (addr_len >= sizeof(struct sockaddr_in6) &&
usin->sin6_scope_id) {
/* If interface is set while binding, indices
* must coincide.
*/
if (sk->sk_bound_dev_if &&
sk->sk_bound_dev_if != usin->sin6_scope_id)
return -EINVAL;
sk->sk_bound_dev_if = usin->sin6_scope_id;
}
/* Connect to link-local address requires an interface */
if (!sk->sk_bound_dev_if)
return -EINVAL;
}
ipv6_addr_copy(&np->daddr, &usin->sin6_addr);
np->flow_label = fl.fl6_flowlabel;
/*
* DCCP over IPv4
*/
if (addr_type == IPV6_ADDR_MAPPED) {
u32 exthdrlen = dp->dccps_ext_header_len;
struct sockaddr_in sin;
SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
if (__ipv6_only_sock(sk))
return -ENETUNREACH;
sin.sin_family = AF_INET;
sin.sin_port = usin->sin6_port;
sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
inet_csk(sk)->icsk_af_ops = &dccp_ipv6_mapped;
sk->sk_backlog_rcv = dccp_v4_do_rcv;
err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
if (err) {
dp->dccps_ext_header_len = exthdrlen;
inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops;
sk->sk_backlog_rcv = dccp_v6_do_rcv;
goto failure;
} else {
ipv6_addr_set(&np->saddr, 0, 0, htonl(0x0000FFFF),
inet->saddr);
ipv6_addr_set(&np->rcv_saddr, 0, 0, htonl(0x0000FFFF),
inet->rcv_saddr);
}
return err;
}
if (!ipv6_addr_any(&np->rcv_saddr))
saddr = &np->rcv_saddr;
fl.proto = IPPROTO_DCCP;
ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
ipv6_addr_copy(&fl.fl6_src, saddr ? saddr : &np->saddr);
fl.oif = sk->sk_bound_dev_if;
fl.fl_ip_dport = usin->sin6_port;
fl.fl_ip_sport = inet->sport;
if (np->opt && np->opt->srcrt) {
struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
ipv6_addr_copy(&final, &fl.fl6_dst);
ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
final_p = &final;
}
err = ip6_dst_lookup(sk, &dst, &fl);
if (err)
goto failure;
if (final_p)
ipv6_addr_copy(&fl.fl6_dst, final_p);
if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0)
goto failure;
if (saddr == NULL) {
saddr = &fl.fl6_src;
ipv6_addr_copy(&np->rcv_saddr, saddr);
}
/* set the source address */
ipv6_addr_copy(&np->saddr, saddr);
inet->rcv_saddr = LOOPBACK4_IPV6;
ip6_dst_store(sk, dst, NULL);
dp->dccps_ext_header_len = 0;
if (np->opt)
dp->dccps_ext_header_len = np->opt->opt_flen + np->opt->opt_nflen;
inet->dport = usin->sin6_port;
dccp_set_state(sk, DCCP_REQUESTING);
err = dccp_v6_hash_connect(sk);
if (err)
goto late_failure;
/* FIXME */
#if 0
dp->dccps_gar = secure_dccp_v6_sequence_number(np->saddr.s6_addr32,
np->daddr.s6_addr32,
inet->sport,
inet->dport);
#endif
err = dccp_connect(sk);
if (err)
goto late_failure;
return 0;
late_failure:
dccp_set_state(sk, DCCP_CLOSED);
__sk_dst_reset(sk);
failure:
inet->dport = 0;
sk->sk_route_caps = 0;
return err;
}
static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
int type, int code, int offset, __u32 info)
{
struct ipv6hdr *hdr = (struct ipv6hdr *)skb->data;
const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data + offset);
struct ipv6_pinfo *np;
struct sock *sk;
int err;
__u64 seq;
sk = inet6_lookup(&dccp_hashinfo, &hdr->daddr, dh->dccph_dport,
&hdr->saddr, dh->dccph_sport, skb->dev->ifindex);
if (sk == NULL) {
ICMP6_INC_STATS_BH(__in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
return;
}
if (sk->sk_state == DCCP_TIME_WAIT) {
inet_twsk_put((struct inet_timewait_sock *)sk);
return;
}
bh_lock_sock(sk);
if (sock_owned_by_user(sk))
NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS);
if (sk->sk_state == DCCP_CLOSED)
goto out;
np = inet6_sk(sk);
if (type == ICMPV6_PKT_TOOBIG) {
struct dccp_sock *dp = dccp_sk(sk);
struct dst_entry *dst = NULL;
if (sock_owned_by_user(sk))
goto out;
if ((1 << sk->sk_state) & (DCCPF_LISTEN | DCCPF_CLOSED))
goto out;
/* icmp should have updated the destination cache entry */
dst = __sk_dst_check(sk, np->dst_cookie);
if (dst == NULL) {
struct inet_sock *inet = inet_sk(sk);
struct flowi fl;
/* BUGGG_FUTURE: Again, it is not clear how
to handle rthdr case. Ignore this complexity
for now.
*/
memset(&fl, 0, sizeof(fl));
fl.proto = IPPROTO_DCCP;
ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
ipv6_addr_copy(&fl.fl6_src, &np->saddr);
fl.oif = sk->sk_bound_dev_if;
fl.fl_ip_dport = inet->dport;
fl.fl_ip_sport = inet->sport;
if ((err = ip6_dst_lookup(sk, &dst, &fl))) {
sk->sk_err_soft = -err;
goto out;
}
if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) {
sk->sk_err_soft = -err;
goto out;
}
} else
dst_hold(dst);
if (dp->dccps_pmtu_cookie > dst_mtu(dst)) {
dccp_sync_mss(sk, dst_mtu(dst));
} /* else let the usual retransmit timer handle it */
dst_release(dst);
goto out;
}
icmpv6_err_convert(type, code, &err);
seq = DCCP_SKB_CB(skb)->dccpd_seq;
/* Might be for an request_sock */
switch (sk->sk_state) {
struct request_sock *req, **prev;
case DCCP_LISTEN:
if (sock_owned_by_user(sk))
goto out;
req = inet6_csk_search_req(sk, &prev, dh->dccph_dport,
&hdr->daddr, &hdr->saddr,
inet6_iif(skb));
if (!req)
goto out;
/* ICMPs are not backlogged, hence we cannot get
* an established socket here.
*/
BUG_TRAP(req->sk == NULL);
if (seq != dccp_rsk(req)->dreq_iss) {
NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
goto out;
}
inet_csk_reqsk_queue_drop(sk, req, prev);
goto out;
case DCCP_REQUESTING:
case DCCP_RESPOND: /* Cannot happen.
It can, it SYNs are crossed. --ANK */
if (!sock_owned_by_user(sk)) {
DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
sk->sk_err = err;
/*
* Wake people up to see the error
* (see connect in sock.c)
*/
sk->sk_error_report(sk);
dccp_done(sk);
} else
sk->sk_err_soft = err;
goto out;
}
if (!sock_owned_by_user(sk) && np->recverr) {
sk->sk_err = err;
sk->sk_error_report(sk);
} else
sk->sk_err_soft = err;
out:
bh_unlock_sock(sk);
sock_put(sk);
}
static int dccp_v6_send_response(struct sock *sk, struct request_sock *req,
struct dst_entry *dst)
{
struct inet6_request_sock *ireq6 = inet6_rsk(req);
struct ipv6_pinfo *np = inet6_sk(sk);
struct sk_buff *skb;
struct ipv6_txoptions *opt = NULL;
struct in6_addr *final_p = NULL, final;
struct flowi fl;
int err = -1;
memset(&fl, 0, sizeof(fl));
fl.proto = IPPROTO_DCCP;
ipv6_addr_copy(&fl.fl6_dst, &ireq6->rmt_addr);
ipv6_addr_copy(&fl.fl6_src, &ireq6->loc_addr);
fl.fl6_flowlabel = 0;
fl.oif = ireq6->iif;
fl.fl_ip_dport = inet_rsk(req)->rmt_port;
fl.fl_ip_sport = inet_sk(sk)->sport;
if (dst == NULL) {
opt = np->opt;
if (opt == NULL &&
np->rxopt.bits.osrcrt == 2 &&
ireq6->pktopts) {
struct sk_buff *pktopts = ireq6->pktopts;
struct inet6_skb_parm *rxopt = IP6CB(pktopts);
if (rxopt->srcrt)
opt = ipv6_invert_rthdr(sk,
(struct ipv6_rt_hdr *)(pktopts->nh.raw +
rxopt->srcrt));
}
if (opt && opt->srcrt) {
struct rt0_hdr *rt0 = (struct rt0_hdr *)opt->srcrt;
ipv6_addr_copy(&final, &fl.fl6_dst);
ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
final_p = &final;
}
err = ip6_dst_lookup(sk, &dst, &fl);
if (err)
goto done;
if (final_p)
ipv6_addr_copy(&fl.fl6_dst, final_p);
if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0)
goto done;
}
skb = dccp_make_response(sk, dst, req);
if (skb != NULL) {
struct dccp_hdr *dh = dccp_hdr(skb);
dh->dccph_checksum = dccp_v6_check(dh, skb->len,
&ireq6->loc_addr,
&ireq6->rmt_addr,
csum_partial((char *)dh,
skb->len,
skb->csum));
ipv6_addr_copy(&fl.fl6_dst, &ireq6->rmt_addr);
err = ip6_xmit(sk, skb, &fl, opt, 0);
if (err == NET_XMIT_CN)
err = 0;
}
done:
if (opt && opt != np->opt)
sock_kfree_s(sk, opt, opt->tot_len);
return err;
}
static void dccp_v6_reqsk_destructor(struct request_sock *req)
{
if (inet6_rsk(req)->pktopts != NULL)
kfree_skb(inet6_rsk(req)->pktopts);
}
static struct request_sock_ops dccp6_request_sock_ops = {
.family = AF_INET6,
.obj_size = sizeof(struct dccp6_request_sock),
.rtx_syn_ack = dccp_v6_send_response,
.send_ack = dccp_v6_reqsk_send_ack,
.destructor = dccp_v6_reqsk_destructor,
.send_reset = dccp_v6_ctl_send_reset,
};
static struct timewait_sock_ops dccp6_timewait_sock_ops = {
.twsk_obj_size = sizeof(struct dccp6_timewait_sock),
};
static void dccp_v6_send_check(struct sock *sk, int len, struct sk_buff *skb)
{
struct ipv6_pinfo *np = inet6_sk(sk);
struct dccp_hdr *dh = dccp_hdr(skb);
dh->dccph_checksum = csum_ipv6_magic(&np->saddr, &np->daddr,
len, IPPROTO_DCCP,
csum_partial((char *)dh,
dh->dccph_doff << 2,
skb->csum));
}
static void dccp_v6_ctl_send_reset(struct sk_buff *rxskb)
{
struct dccp_hdr *rxdh = dccp_hdr(rxskb), *dh;
const int dccp_hdr_reset_len = sizeof(struct dccp_hdr) +
sizeof(struct dccp_hdr_ext) +
sizeof(struct dccp_hdr_reset);
struct sk_buff *skb;
struct flowi fl;
u64 seqno;
if (rxdh->dccph_type == DCCP_PKT_RESET)
return;
if (!ipv6_unicast_destination(rxskb))
return;
/*
* We need to grab some memory, and put together an RST,
* and then put it into the queue to be sent.
*/
skb = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) +
dccp_hdr_reset_len, GFP_ATOMIC);
if (skb == NULL)
return;
skb_reserve(skb, MAX_HEADER + sizeof(struct ipv6hdr) +
dccp_hdr_reset_len);
skb->h.raw = skb_push(skb, dccp_hdr_reset_len);
dh = dccp_hdr(skb);
memset(dh, 0, dccp_hdr_reset_len);
/* Swap the send and the receive. */
dh->dccph_type = DCCP_PKT_RESET;
dh->dccph_sport = rxdh->dccph_dport;
dh->dccph_dport = rxdh->dccph_sport;
dh->dccph_doff = dccp_hdr_reset_len / 4;
dh->dccph_x = 1;
dccp_hdr_reset(skb)->dccph_reset_code =
DCCP_SKB_CB(rxskb)->dccpd_reset_code;
/* See "8.3.1. Abnormal Termination" in draft-ietf-dccp-spec-11 */
seqno = 0;
if (DCCP_SKB_CB(rxskb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
dccp_set_seqno(&seqno, DCCP_SKB_CB(rxskb)->dccpd_ack_seq + 1);
dccp_hdr_set_seq(dh, seqno);
dccp_hdr_set_ack(dccp_hdr_ack_bits(skb),
DCCP_SKB_CB(rxskb)->dccpd_seq);
memset(&fl, 0, sizeof(fl));
ipv6_addr_copy(&fl.fl6_dst, &rxskb->nh.ipv6h->saddr);
ipv6_addr_copy(&fl.fl6_src, &rxskb->nh.ipv6h->daddr);
dh->dccph_checksum = csum_ipv6_magic(&fl.fl6_src, &fl.fl6_dst,
sizeof(*dh), IPPROTO_DCCP,
skb->csum);
fl.proto = IPPROTO_DCCP;
fl.oif = inet6_iif(rxskb);
fl.fl_ip_dport = dh->dccph_dport;
fl.fl_ip_sport = dh->dccph_sport;
/* sk = NULL, but it is safe for now. RST socket required. */
if (!ip6_dst_lookup(NULL, &skb->dst, &fl)) {
if (xfrm_lookup(&skb->dst, &fl, NULL, 0) >= 0) {
ip6_xmit(NULL, skb, &fl, NULL, 0);
DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
return;
}
}
kfree_skb(skb);
}
static void dccp_v6_ctl_send_ack(struct sk_buff *rxskb)
{
struct flowi fl;
struct dccp_hdr *rxdh = dccp_hdr(rxskb), *dh;
const int dccp_hdr_ack_len = sizeof(struct dccp_hdr) +
sizeof(struct dccp_hdr_ext) +
sizeof(struct dccp_hdr_ack_bits);
struct sk_buff *skb;
skb = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) +
dccp_hdr_ack_len, GFP_ATOMIC);
if (skb == NULL)
return;
skb_reserve(skb, MAX_HEADER + sizeof(struct ipv6hdr) +
dccp_hdr_ack_len);
skb->h.raw = skb_push(skb, dccp_hdr_ack_len);
dh = dccp_hdr(skb);
memset(dh, 0, dccp_hdr_ack_len);
/* Build DCCP header and checksum it. */
dh->dccph_type = DCCP_PKT_ACK;
dh->dccph_sport = rxdh->dccph_dport;
dh->dccph_dport = rxdh->dccph_sport;
dh->dccph_doff = dccp_hdr_ack_len / 4;
dh->dccph_x = 1;
dccp_hdr_set_seq(dh, DCCP_SKB_CB(rxskb)->dccpd_ack_seq);
dccp_hdr_set_ack(dccp_hdr_ack_bits(skb),
DCCP_SKB_CB(rxskb)->dccpd_seq);
memset(&fl, 0, sizeof(fl));
ipv6_addr_copy(&fl.fl6_dst, &rxskb->nh.ipv6h->saddr);
ipv6_addr_copy(&fl.fl6_src, &rxskb->nh.ipv6h->daddr);
/* FIXME: calculate checksum, IPv4 also should... */
fl.proto = IPPROTO_DCCP;
fl.oif = inet6_iif(rxskb);
fl.fl_ip_dport = dh->dccph_dport;
fl.fl_ip_sport = dh->dccph_sport;
if (!ip6_dst_lookup(NULL, &skb->dst, &fl)) {
if (xfrm_lookup(&skb->dst, &fl, NULL, 0) >= 0) {
ip6_xmit(NULL, skb, &fl, NULL, 0);
DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
return;
}
}
kfree_skb(skb);
}
static void dccp_v6_reqsk_send_ack(struct sk_buff *skb,
struct request_sock *req)
{
dccp_v6_ctl_send_ack(skb);
}
static struct sock *dccp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
{
const struct dccp_hdr *dh = dccp_hdr(skb);
const struct ipv6hdr *iph = skb->nh.ipv6h;
struct sock *nsk;
struct request_sock **prev;
/* Find possible connection requests. */
struct request_sock *req = inet6_csk_search_req(sk, &prev,
dh->dccph_sport,
&iph->saddr,
&iph->daddr,
inet6_iif(skb));
if (req != NULL)
return dccp_check_req(sk, skb, req, prev);
nsk = __inet6_lookup_established(&dccp_hashinfo,
&iph->saddr, dh->dccph_sport,
&iph->daddr, ntohs(dh->dccph_dport),
inet6_iif(skb));
if (nsk != NULL) {
if (nsk->sk_state != DCCP_TIME_WAIT) {
bh_lock_sock(nsk);
return nsk;
}
inet_twsk_put((struct inet_timewait_sock *)nsk);
return NULL;
}
return sk;
}
static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
{
struct inet_request_sock *ireq;
struct dccp_sock dp;
struct request_sock *req;
struct dccp_request_sock *dreq;
struct inet6_request_sock *ireq6;
struct ipv6_pinfo *np = inet6_sk(sk);
const __u32 service = dccp_hdr_request(skb)->dccph_req_service;
struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
__u8 reset_code = DCCP_RESET_CODE_TOO_BUSY;
if (skb->protocol == htons(ETH_P_IP))
return dccp_v4_conn_request(sk, skb);
if (!ipv6_unicast_destination(skb))
goto drop;
if (dccp_bad_service_code(sk, service)) {
reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
goto drop;
}
/*
* There are no SYN attacks on IPv6, yet...
*/
if (inet_csk_reqsk_queue_is_full(sk))
goto drop;
if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
goto drop;
req = inet6_reqsk_alloc(sk->sk_prot->rsk_prot);
if (req == NULL)
goto drop;
/* FIXME: process options */
dccp_openreq_init(req, &dp, skb);
ireq6 = inet6_rsk(req);
ireq = inet_rsk(req);
ipv6_addr_copy(&ireq6->rmt_addr, &skb->nh.ipv6h->saddr);
ipv6_addr_copy(&ireq6->loc_addr, &skb->nh.ipv6h->daddr);
req->rcv_wnd = 100; /* Fake, option parsing will get the
right value */
ireq6->pktopts = NULL;
if (ipv6_opt_accepted(sk, skb) ||
np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
atomic_inc(&skb->users);
ireq6->pktopts = skb;
}
ireq6->iif = sk->sk_bound_dev_if;
/* So that link locals have meaning */
if (!sk->sk_bound_dev_if &&
ipv6_addr_type(&ireq6->rmt_addr) & IPV6_ADDR_LINKLOCAL)
ireq6->iif = inet6_iif(skb);
/*
* Step 3: Process LISTEN state
*
* Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
*
* In fact we defer setting S.GSR, S.SWL, S.SWH to
* dccp_create_openreq_child.
*/
dreq = dccp_rsk(req);
dreq->dreq_isr = dcb->dccpd_seq;
dreq->dreq_iss = dccp_v6_init_sequence(sk, skb);
dreq->dreq_service = service;
if (dccp_v6_send_response(sk, req, NULL))
goto drop_and_free;
inet6_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
return 0;
drop_and_free:
reqsk_free(req);
drop:
DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
dcb->dccpd_reset_code = reset_code;
return -1;
}
static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
struct sk_buff *skb,
struct request_sock *req,
struct dst_entry *dst)
{
struct inet6_request_sock *ireq6 = inet6_rsk(req);
struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
struct inet_sock *newinet;
struct dccp_sock *newdp;
struct dccp6_sock *newdp6;
struct sock *newsk;
struct ipv6_txoptions *opt;
if (skb->protocol == htons(ETH_P_IP)) {
/*
* v6 mapped
*/
newsk = dccp_v4_request_recv_sock(sk, skb, req, dst);
if (newsk == NULL)
return NULL;
newdp6 = (struct dccp6_sock *)newsk;
newdp = dccp_sk(newsk);
newinet = inet_sk(newsk);
newinet->pinet6 = &newdp6->inet6;
newnp = inet6_sk(newsk);
memcpy(newnp, np, sizeof(struct ipv6_pinfo));
ipv6_addr_set(&newnp->daddr, 0, 0, htonl(0x0000FFFF),
newinet->daddr);
ipv6_addr_set(&newnp->saddr, 0, 0, htonl(0x0000FFFF),
newinet->saddr);
ipv6_addr_copy(&newnp->rcv_saddr, &newnp->saddr);
inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped;
newsk->sk_backlog_rcv = dccp_v4_do_rcv;
newnp->pktoptions = NULL;
newnp->opt = NULL;
newnp->mcast_oif = inet6_iif(skb);
newnp->mcast_hops = skb->nh.ipv6h->hop_limit;
/*
* No need to charge this sock to the relevant IPv6 refcnt debug socks count
* here, dccp_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.
*/
dccp_sync_mss(newsk, newdp->dccps_pmtu_cookie);
return newsk;
}
opt = np->opt;
if (sk_acceptq_is_full(sk))
goto out_overflow;
if (np->rxopt.bits.osrcrt == 2 &&
opt == NULL && ireq6->pktopts) {
struct inet6_skb_parm *rxopt = IP6CB(ireq6->pktopts);
if (rxopt->srcrt)
opt = ipv6_invert_rthdr(sk,
(struct ipv6_rt_hdr *)(ireq6->pktopts->nh.raw +
rxopt->srcrt));
}
if (dst == NULL) {
struct in6_addr *final_p = NULL, final;
struct flowi fl;
memset(&fl, 0, sizeof(fl));
fl.proto = IPPROTO_DCCP;
ipv6_addr_copy(&fl.fl6_dst, &ireq6->rmt_addr);
if (opt && opt->srcrt) {
struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
ipv6_addr_copy(&final, &fl.fl6_dst);
ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
final_p = &final;
}
ipv6_addr_copy(&fl.fl6_src, &ireq6->loc_addr);
fl.oif = sk->sk_bound_dev_if;
fl.fl_ip_dport = inet_rsk(req)->rmt_port;
fl.fl_ip_sport = inet_sk(sk)->sport;
if (ip6_dst_lookup(sk, &dst, &fl))
goto out;
if (final_p)
ipv6_addr_copy(&fl.fl6_dst, final_p);
if ((xfrm_lookup(&dst, &fl, sk, 0)) < 0)
goto out;
}
newsk = dccp_create_openreq_child(sk, req, skb);
if (newsk == NULL)
goto out;
/*
* No need to charge this sock to the relevant IPv6 refcnt debug socks
* count here, dccp_create_openreq_child now does this for us, see the
* comment in that function for the gory details. -acme
*/
ip6_dst_store(newsk, dst, NULL);
newsk->sk_route_caps = dst->dev->features &
~(NETIF_F_IP_CSUM | NETIF_F_TSO);
newdp6 = (struct dccp6_sock *)newsk;
newinet = inet_sk(newsk);
newinet->pinet6 = &newdp6->inet6;
newdp = dccp_sk(newsk);
newnp = inet6_sk(newsk);
memcpy(newnp, np, sizeof(struct ipv6_pinfo));
ipv6_addr_copy(&newnp->daddr, &ireq6->rmt_addr);
ipv6_addr_copy(&newnp->saddr, &ireq6->loc_addr);
ipv6_addr_copy(&newnp->rcv_saddr, &ireq6->loc_addr);
newsk->sk_bound_dev_if = ireq6->iif;
/* Now IPv6 options...
First: no IPv4 options.
*/
newinet->opt = NULL;
/* Clone RX bits */
newnp->rxopt.all = np->rxopt.all;
/* Clone pktoptions received with SYN */
newnp->pktoptions = NULL;
if (ireq6->pktopts != NULL) {
newnp->pktoptions = skb_clone(ireq6->pktopts, GFP_ATOMIC);
kfree_skb(ireq6->pktopts);
ireq6->pktopts = NULL;
if (newnp->pktoptions)
skb_set_owner_r(newnp->pktoptions, newsk);
}
newnp->opt = NULL;
newnp->mcast_oif = inet6_iif(skb);
newnp->mcast_hops = skb->nh.ipv6h->hop_limit;
/* 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.
*/
if (opt) {
newnp->opt = ipv6_dup_options(newsk, opt);
if (opt != np->opt)
sock_kfree_s(sk, opt, opt->tot_len);
}
newdp->dccps_ext_header_len = 0;
if (newnp->opt)
newdp->dccps_ext_header_len = newnp->opt->opt_nflen +
newnp->opt->opt_flen;
dccp_sync_mss(newsk, dst_mtu(dst));
newinet->daddr = newinet->saddr = newinet->rcv_saddr = LOOPBACK4_IPV6;
__inet6_hash(&dccp_hashinfo, newsk);
inet_inherit_port(&dccp_hashinfo, sk, newsk);
return newsk;
out_overflow:
NET_INC_STATS_BH(LINUX_MIB_LISTENOVERFLOWS);
out:
NET_INC_STATS_BH(LINUX_MIB_LISTENDROPS);
if (opt && opt != np->opt)
sock_kfree_s(sk, opt, opt->tot_len);
dst_release(dst);
return NULL;
}
/* The socket must have it's spinlock held when we get
* here.
*
* 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.
*/
static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
{
struct ipv6_pinfo *np = inet6_sk(sk);
struct sk_buff *opt_skb = NULL;
/* Imagine: socket is IPv6. IPv4 packet arrives,
goes to IPv4 receive handler and backlogged.
From backlog it always goes here. Kerboom...
Fortunately, dccp_rcv_established and rcv_established
handle them correctly, but it is not case with
dccp_v6_hnd_req and dccp_v6_ctl_send_reset(). --ANK
*/
if (skb->protocol == htons(ETH_P_IP))
return dccp_v4_do_rcv(sk, skb);
if (sk_filter(sk, skb, 0))
goto discard;
/*
* 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, GFP_ATOMIC);
if (sk->sk_state == DCCP_OPEN) { /* Fast path */
if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len))
goto reset;
return 0;
}
if (sk->sk_state == DCCP_LISTEN) {
struct sock *nsk = dccp_v6_hnd_req(sk, skb);
if (!nsk)
goto discard;
/*
* Queue it on the new socket if the new socket is active,
* otherwise we just shortcircuit this and continue with
* the new socket..
*/
if(nsk != sk) {
if (dccp_child_process(sk, nsk, skb))
goto reset;
if (opt_skb)
__kfree_skb(opt_skb);
return 0;
}
}
if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len))
goto reset;
return 0;
reset:
dccp_v6_ctl_send_reset(skb);
discard:
if (opt_skb)
__kfree_skb(opt_skb);
kfree_skb(skb);
return 0;
}
static int dccp_v6_rcv(struct sk_buff **pskb, unsigned int *nhoffp)
{
const struct dccp_hdr *dh;
struct sk_buff *skb = *pskb;
struct sock *sk;
int rc;
/* Step 1: Check header basics: */
if (dccp_invalid_packet(skb))
goto discard_it;
dh = dccp_hdr(skb);
DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(skb);
DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
if (dccp_packet_without_ack(skb))
DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
else
DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
/* Step 2:
* Look up flow ID in table and get corresponding socket */
sk = __inet6_lookup(&dccp_hashinfo, &skb->nh.ipv6h->saddr,
dh->dccph_sport,
&skb->nh.ipv6h->daddr, ntohs(dh->dccph_dport),
inet6_iif(skb));
/*
* Step 2:
* If no socket ...
* Generate Reset(No Connection) unless P.type == Reset
* Drop packet and return
*/
if (sk == NULL)
goto no_dccp_socket;
/*
* Step 2:
* ... or S.state == TIMEWAIT,
* Generate Reset(No Connection) unless P.type == Reset
* Drop packet and return
*/
if (sk->sk_state == DCCP_TIME_WAIT)
goto do_time_wait;
if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
goto discard_and_relse;
if (sk_filter(sk, skb, 0))
goto discard_and_relse;
skb->dev = NULL;
bh_lock_sock(sk);
rc = 0;
if (!sock_owned_by_user(sk))
rc = dccp_v6_do_rcv(sk, skb);
else
sk_add_backlog(sk, skb);
bh_unlock_sock(sk);
sock_put(sk);
return rc ? -1 : 0;
no_dccp_socket:
if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
goto discard_it;
/*
* Step 2:
* Generate Reset(No Connection) unless P.type == Reset
* Drop packet and return
*/
if (dh->dccph_type != DCCP_PKT_RESET) {
DCCP_SKB_CB(skb)->dccpd_reset_code =
DCCP_RESET_CODE_NO_CONNECTION;
dccp_v6_ctl_send_reset(skb);
}
discard_it:
/*
* Discard frame
*/
kfree_skb(skb);
return 0;
discard_and_relse:
sock_put(sk);
goto discard_it;
do_time_wait:
inet_twsk_put((struct inet_timewait_sock *)sk);
goto no_dccp_socket;
}
static struct inet_connection_sock_af_ops dccp_ipv6_af_ops = {
.queue_xmit = inet6_csk_xmit,
.send_check = dccp_v6_send_check,
.rebuild_header = inet6_sk_rebuild_header,
.conn_request = dccp_v6_conn_request,
.syn_recv_sock = dccp_v6_request_recv_sock,
.net_header_len = sizeof(struct ipv6hdr),
.setsockopt = ipv6_setsockopt,
.getsockopt = ipv6_getsockopt,
.addr2sockaddr = inet6_csk_addr2sockaddr,
.sockaddr_len = sizeof(struct sockaddr_in6)
};
/*
* DCCP over IPv4 via INET6 API
*/
static struct inet_connection_sock_af_ops dccp_ipv6_mapped = {
.queue_xmit = ip_queue_xmit,
.send_check = dccp_v4_send_check,
.rebuild_header = inet_sk_rebuild_header,
.conn_request = dccp_v6_conn_request,
.syn_recv_sock = dccp_v6_request_recv_sock,
.net_header_len = sizeof(struct iphdr),
.setsockopt = ipv6_setsockopt,
.getsockopt = ipv6_getsockopt,
.addr2sockaddr = inet6_csk_addr2sockaddr,
.sockaddr_len = sizeof(struct sockaddr_in6)
};
/* NOTE: A lot of things set to zero explicitly by call to
* sk_alloc() so need not be done here.
*/
static int dccp_v6_init_sock(struct sock *sk)
{
int err = dccp_v4_init_sock(sk);
if (err == 0)
inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops;
return err;
}
static int dccp_v6_destroy_sock(struct sock *sk)
{
dccp_v4_destroy_sock(sk);
return inet6_destroy_sock(sk);
}
static struct proto dccp_v6_prot = {
.name = "DCCPv6",
.owner = THIS_MODULE,
.close = dccp_close,
.connect = dccp_v6_connect,
.disconnect = dccp_disconnect,
.ioctl = dccp_ioctl,
.init = dccp_v6_init_sock,
.setsockopt = dccp_setsockopt,
.getsockopt = dccp_getsockopt,
.sendmsg = dccp_sendmsg,
.recvmsg = dccp_recvmsg,
.backlog_rcv = dccp_v6_do_rcv,
.hash = dccp_v6_hash,
.unhash = dccp_unhash,
.accept = inet_csk_accept,
.get_port = dccp_v6_get_port,
.shutdown = dccp_shutdown,
.destroy = dccp_v6_destroy_sock,
.orphan_count = &dccp_orphan_count,
.max_header = MAX_DCCP_HEADER,
.obj_size = sizeof(struct dccp6_sock),
.rsk_prot = &dccp6_request_sock_ops,
.twsk_prot = &dccp6_timewait_sock_ops,
};
static struct inet6_protocol dccp_v6_protocol = {
.handler = dccp_v6_rcv,
.err_handler = dccp_v6_err,
.flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
};
static struct proto_ops inet6_dccp_ops = {
.family = PF_INET6,
.owner = THIS_MODULE,
.release = inet6_release,
.bind = inet6_bind,
.connect = inet_stream_connect,
.socketpair = sock_no_socketpair,
.accept = inet_accept,
.getname = inet6_getname,
.poll = dccp_poll,
.ioctl = inet6_ioctl,
.listen = inet_dccp_listen,
.shutdown = inet_shutdown,
.setsockopt = sock_common_setsockopt,
.getsockopt = sock_common_getsockopt,
.sendmsg = inet_sendmsg,
.recvmsg = sock_common_recvmsg,
.mmap = sock_no_mmap,
.sendpage = sock_no_sendpage,
};
static struct inet_protosw dccp_v6_protosw = {
.type = SOCK_DCCP,
.protocol = IPPROTO_DCCP,
.prot = &dccp_v6_prot,
.ops = &inet6_dccp_ops,
.capability = -1,
};
static int __init dccp_v6_init(void)
{
int err = proto_register(&dccp_v6_prot, 1);
if (err != 0)
goto out;
err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
if (err != 0)
goto out_unregister_proto;
inet6_register_protosw(&dccp_v6_protosw);
out:
return err;
out_unregister_proto:
proto_unregister(&dccp_v6_prot);
goto out;
}
static void __exit dccp_v6_exit(void)
{
inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
inet6_unregister_protosw(&dccp_v6_protosw);
proto_unregister(&dccp_v6_prot);
}
module_init(dccp_v6_init);
module_exit(dccp_v6_exit);
/*
* __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
* values directly, Also cover the case where the protocol is not specified,
* i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP
*/
MODULE_ALIAS("net-pf-" __stringify(PF_INET6) "-proto-33-type-6");
MODULE_ALIAS("net-pf-" __stringify(PF_INET6) "-proto-0-type-6");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
MODULE_DESCRIPTION("DCCPv6 - Datagram Congestion Controlled Protocol");
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