net/ipv6/inet6_connection_sock.c

   1 /*
   2  * INET        An implementation of the TCP/IP protocol suite for the LINUX
   3  *             operating system.  INET is implemented using the  BSD Socket
   4  *             interface as the means of communication with the user level.
   5  *
   6  *             Support for INET6 connection oriented protocols.
   7  *
   8  * Authors:    See the TCPv6 sources
   9  *
  10  *             This program is free software; you can redistribute it and/or
  11  *             modify it under the terms of the GNU General Public License
  12  *             as published by the Free Software Foundation; either version
  13  *             2 of the License, or(at your option) any later version.
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/in6.h>
  18 #include <linux/ipv6.h>
  19 #include <linux/jhash.h>
  20 #include <linux/slab.h>
  21
  22 #include <net/addrconf.h>
  23 #include <net/inet_connection_sock.h>
  24 #include <net/inet_ecn.h>
  25 #include <net/inet_hashtables.h>
  26 #include <net/ip6_route.h>
  27 #include <net/sock.h>
  28 #include <net/inet6_connection_sock.h>
  29
  30 int inet6_csk_bind_conflict(const struct sock *sk,
  31                             const struct inet_bind_bucket *tb)
  32 {
  33         const struct sock *sk2;
  34         const struct hlist_node *node;
  35
  36         /* We must walk the whole port owner list in this case. -DaveM */
  37         /*
  38          * See comment in inet_csk_bind_conflict about sock lookup
  39          * vs net namespaces issues.
  40          */
  41         sk_for_each_bound(sk2, node, &tb->owners) {
  42                 if (sk != sk2 &&
  43                     (!sk->sk_bound_dev_if ||
  44                      !sk2->sk_bound_dev_if ||
  45                      sk->sk_bound_dev_if == sk2->sk_bound_dev_if) &&
  46                     (!sk->sk_reuse || !sk2->sk_reuse ||
  47                      sk2->sk_state == TCP_LISTEN) &&
  48                      ipv6_rcv_saddr_equal(sk, sk2))
  49                         break;
  50         }
  51
  52         return node != NULL;
  53 }
  54
  55 EXPORT_SYMBOL_GPL(inet6_csk_bind_conflict);
  56
  57 /*
  58  * request_sock (formerly open request) hash tables.
  59  */
  60 static u32 inet6_synq_hash(const struct in6_addr *raddr, const __be16 rport,
  61                            const u32 rnd, const u16 synq_hsize)
  62 {
  63         u32 a = (__force u32)raddr->s6_addr32[0];
  64         u32 b = (__force u32)raddr->s6_addr32[1];
  65         u32 c = (__force u32)raddr->s6_addr32[2];
  66
  67         a += JHASH_GOLDEN_RATIO;
  68         b += JHASH_GOLDEN_RATIO;
  69         c += rnd;
  70         __jhash_mix(a, b, c);
  71
  72         a += (__force u32)raddr->s6_addr32[3];
  73         b += (__force u32)rport;
  74         __jhash_mix(a, b, c);
  75
  76         return c & (synq_hsize - 1);
  77 }
  78
  79 struct request_sock *inet6_csk_search_req(const struct sock *sk,
  80                                           struct request_sock ***prevp,
  81                                           const __be16 rport,
  82                                           const struct in6_addr *raddr,
  83                                           const struct in6_addr *laddr,
  84                                           const int iif)
  85 {
  86         const struct inet_connection_sock *icsk = inet_csk(sk);
  87         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
  88         struct request_sock *req, **prev;
  89
  90         for (prev = &lopt->syn_table[inet6_synq_hash(raddr, rport,
  91                                                      lopt->hash_rnd,
  92                                                      lopt->nr_table_entries)];
  93              (req = *prev) != NULL;
  94              prev = &req->dl_next) {
  95                 const struct inet6_request_sock *treq = inet6_rsk(req);
  96
  97                 if (inet_rsk(req)->rmt_port == rport &&
  98                     req->rsk_ops->family == AF_INET6 &&
  99                     ipv6_addr_equal(&treq->rmt_addr, raddr) &&
 100                     ipv6_addr_equal(&treq->loc_addr, laddr) &&
 101                     (!treq->iif || treq->iif == iif)) {
 102                         WARN_ON(req->sk != NULL);
 103                         *prevp = prev;
 104                         return req;
 105                 }
 106         }
 107
 108         return NULL;
 109 }
 110
 111 EXPORT_SYMBOL_GPL(inet6_csk_search_req);
 112
 113 void inet6_csk_reqsk_queue_hash_add(struct sock *sk,
 114                                     struct request_sock *req,
 115                                     const unsigned long timeout)
 116 {
 117         struct inet_connection_sock *icsk = inet_csk(sk);
 118         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 119         const u32 h = inet6_synq_hash(&inet6_rsk(req)->rmt_addr,
 120                                       inet_rsk(req)->rmt_port,
 121                                       lopt->hash_rnd, lopt->nr_table_entries);
 122
 123         reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
 124         inet_csk_reqsk_queue_added(sk, timeout);
 125 }
 126
 127 EXPORT_SYMBOL_GPL(inet6_csk_reqsk_queue_hash_add);
 128
 129 void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr)
 130 {
 131         struct ipv6_pinfo *np = inet6_sk(sk);
 132         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr;
 133
 134         sin6->sin6_family = AF_INET6;
 135         ipv6_addr_copy(&sin6->sin6_addr, &np->daddr);
 136         sin6->sin6_port = inet_sk(sk)->inet_dport;
 137         /* We do not store received flowlabel for TCP */
 138         sin6->sin6_flowinfo = 0;
 139         sin6->sin6_scope_id = 0;
 140         if (sk->sk_bound_dev_if &&
 141             ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 142                 sin6->sin6_scope_id = sk->sk_bound_dev_if;
 143 }
 144
 145 EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr);
 146
 147 static inline
 148 void __inet6_csk_dst_store(struct sock *sk, struct dst_entry *dst,
 149                            struct in6_addr *daddr, struct in6_addr *saddr)
 150 {
 151         __ip6_dst_store(sk, dst, daddr, saddr);
 152
 153 #ifdef CONFIG_XFRM
 154         {
 155                 struct rt6_info *rt = (struct rt6_info  *)dst;
 156                 rt->rt6i_flow_cache_genid = atomic_read(&flow_cache_genid);
 157         }
 158 #endif
 159 }
 160
 161 static inline
 162 struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie)
 163 {
 164         struct dst_entry *dst;
 165
 166         dst = __sk_dst_check(sk, cookie);
 167
 168 #ifdef CONFIG_XFRM
 169         if (dst) {
 170                 struct rt6_info *rt = (struct rt6_info *)dst;
 171                 if (rt->rt6i_flow_cache_genid != atomic_read(&flow_cache_genid)) {
 172                         __sk_dst_reset(sk);
 173                         dst = NULL;
 174                 }
 175         }
 176 #endif
 177
 178         return dst;
 179 }
 180
 181 int inet6_csk_xmit(struct sk_buff *skb, int ipfragok)
 182 {
 183         struct sock *sk = skb->sk;
 184         struct inet_sock *inet = inet_sk(sk);
 185         struct ipv6_pinfo *np = inet6_sk(sk);
 186         struct flowi fl;
 187         struct dst_entry *dst;
 188         struct in6_addr *final_p = NULL, final;
 189
 190         memset(&fl, 0, sizeof(fl));
 191         fl.proto = sk->sk_protocol;
 192         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 193         ipv6_addr_copy(&fl.fl6_src, &np->saddr);
 194         fl.fl6_flowlabel = np->flow_label;
 195         IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
 196         fl.oif = sk->sk_bound_dev_if;
 197         fl.mark = sk->sk_mark;
 198         fl.fl_ip_sport = inet->inet_sport;
 199         fl.fl_ip_dport = inet->inet_dport;
 200         security_sk_classify_flow(sk, &fl);
 201
 202         if (np->opt && np->opt->srcrt) {
 203                 struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
 204                 ipv6_addr_copy(&final, &fl.fl6_dst);
 205                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 206                 final_p = &final;
 207         }
 208
 209         dst = __inet6_csk_dst_check(sk, np->dst_cookie);
 210
 211         if (dst == NULL) {
 212                 int err = ip6_dst_lookup(sk, &dst, &fl);
 213
 214                 if (err) {
 215                         sk->sk_err_soft = -err;
 216                         kfree_skb(skb);
 217                         return err;
 218                 }
 219
 220                 if (final_p)
 221                         ipv6_addr_copy(&fl.fl6_dst, final_p);
 222
 223                 if ((err = xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0) {
 224                         sk->sk_route_caps = 0;
 225                         kfree_skb(skb);
 226                         return err;
 227                 }
 228
 229                 __inet6_csk_dst_store(sk, dst, NULL, NULL);
 230         }
 231
 232         skb_dst_set(skb, dst_clone(dst));
 233
 234         /* Restore final destination back after routing done */
 235         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 236
 237         return ip6_xmit(sk, skb, &fl, np->opt, 0);
 238 }
 239
 240 EXPORT_SYMBOL_GPL(inet6_csk_xmit);