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                      ((1 << sk2->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))) &&
  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 struct dst_entry *inet6_csk_route_req(struct sock *sk,
  58                                       const struct request_sock *req)
  59 {
  60         struct inet6_request_sock *treq = inet6_rsk(req);
  61         struct ipv6_pinfo *np = inet6_sk(sk);
  62         struct in6_addr *final_p, final;
  63         struct dst_entry *dst;
  64         struct flowi fl;
  65
  66         memset(&fl, 0, sizeof(fl));
  67         fl.proto = IPPROTO_TCP;
  68         ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
  69         final_p = fl6_update_dst(&fl, np->opt, &final);
  70         ipv6_addr_copy(&fl.fl6_src, &treq->loc_addr);
  71         fl.oif = sk->sk_bound_dev_if;
  72         fl.mark = sk->sk_mark;
  73         fl.fl_ip_dport = inet_rsk(req)->rmt_port;
  74         fl.fl_ip_sport = inet_rsk(req)->loc_port;
  75         security_req_classify_flow(req, &fl);
  76
  77         if (ip6_dst_lookup(sk, &dst, &fl))
  78                 return NULL;
  79
  80         if (final_p)
  81                 ipv6_addr_copy(&fl.fl6_dst, final_p);
  82
  83         if ((xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0)
  84                 return NULL;
  85
  86         return dst;
  87 }
  88
  89 /*
  90  * request_sock (formerly open request) hash tables.
  91  */
  92 static u32 inet6_synq_hash(const struct in6_addr *raddr, const __be16 rport,
  93                            const u32 rnd, const u16 synq_hsize)
  94 {
  95         u32 c;
  96
  97         c = jhash_3words((__force u32)raddr->s6_addr32[0],
  98                          (__force u32)raddr->s6_addr32[1],
  99                          (__force u32)raddr->s6_addr32[2],
 100                          rnd);
 101
 102         c = jhash_2words((__force u32)raddr->s6_addr32[3],
 103                          (__force u32)rport,
 104                          c);
 105
 106         return c & (synq_hsize - 1);
 107 }
 108
 109 struct request_sock *inet6_csk_search_req(const struct sock *sk,
 110                                           struct request_sock ***prevp,
 111                                           const __be16 rport,
 112                                           const struct in6_addr *raddr,
 113                                           const struct in6_addr *laddr,
 114                                           const int iif)
 115 {
 116         const struct inet_connection_sock *icsk = inet_csk(sk);
 117         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 118         struct request_sock *req, **prev;
 119
 120         for (prev = &lopt->syn_table[inet6_synq_hash(raddr, rport,
 121                                                      lopt->hash_rnd,
 122                                                      lopt->nr_table_entries)];
 123              (req = *prev) != NULL;
 124              prev = &req->dl_next) {
 125                 const struct inet6_request_sock *treq = inet6_rsk(req);
 126
 127                 if (inet_rsk(req)->rmt_port == rport &&
 128                     req->rsk_ops->family == AF_INET6 &&
 129                     ipv6_addr_equal(&treq->rmt_addr, raddr) &&
 130                     ipv6_addr_equal(&treq->loc_addr, laddr) &&
 131                     (!treq->iif || treq->iif == iif)) {
 132                         WARN_ON(req->sk != NULL);
 133                         *prevp = prev;
 134                         return req;
 135                 }
 136         }
 137
 138         return NULL;
 139 }
 140
 141 EXPORT_SYMBOL_GPL(inet6_csk_search_req);
 142
 143 void inet6_csk_reqsk_queue_hash_add(struct sock *sk,
 144                                     struct request_sock *req,
 145                                     const unsigned long timeout)
 146 {
 147         struct inet_connection_sock *icsk = inet_csk(sk);
 148         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 149         const u32 h = inet6_synq_hash(&inet6_rsk(req)->rmt_addr,
 150                                       inet_rsk(req)->rmt_port,
 151                                       lopt->hash_rnd, lopt->nr_table_entries);
 152
 153         reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
 154         inet_csk_reqsk_queue_added(sk, timeout);
 155 }
 156
 157 EXPORT_SYMBOL_GPL(inet6_csk_reqsk_queue_hash_add);
 158
 159 void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr)
 160 {
 161         struct ipv6_pinfo *np = inet6_sk(sk);
 162         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr;
 163
 164         sin6->sin6_family = AF_INET6;
 165         ipv6_addr_copy(&sin6->sin6_addr, &np->daddr);
 166         sin6->sin6_port = inet_sk(sk)->inet_dport;
 167         /* We do not store received flowlabel for TCP */
 168         sin6->sin6_flowinfo = 0;
 169         sin6->sin6_scope_id = 0;
 170         if (sk->sk_bound_dev_if &&
 171             ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 172                 sin6->sin6_scope_id = sk->sk_bound_dev_if;
 173 }
 174
 175 EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr);
 176
 177 static inline
 178 void __inet6_csk_dst_store(struct sock *sk, struct dst_entry *dst,
 179                            struct in6_addr *daddr, struct in6_addr *saddr)
 180 {
 181         __ip6_dst_store(sk, dst, daddr, saddr);
 182
 183 #ifdef CONFIG_XFRM
 184         {
 185                 struct rt6_info *rt = (struct rt6_info  *)dst;
 186                 rt->rt6i_flow_cache_genid = atomic_read(&flow_cache_genid);
 187         }
 188 #endif
 189 }
 190
 191 static inline
 192 struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie)
 193 {
 194         struct dst_entry *dst;
 195
 196         dst = __sk_dst_check(sk, cookie);
 197
 198 #ifdef CONFIG_XFRM
 199         if (dst) {
 200                 struct rt6_info *rt = (struct rt6_info *)dst;
 201                 if (rt->rt6i_flow_cache_genid != atomic_read(&flow_cache_genid)) {
 202                         __sk_dst_reset(sk);
 203                         dst = NULL;
 204                 }
 205         }
 206 #endif
 207
 208         return dst;
 209 }
 210
 211 int inet6_csk_xmit(struct sk_buff *skb)
 212 {
 213         struct sock *sk = skb->sk;
 214         struct inet_sock *inet = inet_sk(sk);
 215         struct ipv6_pinfo *np = inet6_sk(sk);
 216         struct flowi fl;
 217         struct dst_entry *dst;
 218         struct in6_addr *final_p, final;
 219
 220         memset(&fl, 0, sizeof(fl));
 221         fl.proto = sk->sk_protocol;
 222         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 223         ipv6_addr_copy(&fl.fl6_src, &np->saddr);
 224         fl.fl6_flowlabel = np->flow_label;
 225         IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
 226         fl.oif = sk->sk_bound_dev_if;
 227         fl.mark = sk->sk_mark;
 228         fl.fl_ip_sport = inet->inet_sport;
 229         fl.fl_ip_dport = inet->inet_dport;
 230         security_sk_classify_flow(sk, &fl);
 231
 232         final_p = fl6_update_dst(&fl, np->opt, &final);
 233
 234         dst = __inet6_csk_dst_check(sk, np->dst_cookie);
 235
 236         if (dst == NULL) {
 237                 int err = ip6_dst_lookup(sk, &dst, &fl);
 238
 239                 if (err) {
 240                         sk->sk_err_soft = -err;
 241                         kfree_skb(skb);
 242                         return err;
 243                 }
 244
 245                 if (final_p)
 246                         ipv6_addr_copy(&fl.fl6_dst, final_p);
 247
 248                 if ((err = xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0) {
 249                         sk->sk_route_caps = 0;
 250                         kfree_skb(skb);
 251                         return err;
 252                 }
 253
 254                 __inet6_csk_dst_store(sk, dst, NULL, NULL);
 255         }
 256
 257         skb_dst_set(skb, dst_clone(dst));
 258
 259         /* Restore final destination back after routing done */
 260         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 261
 262         return ip6_xmit(sk, skb, &fl, np->opt);
 263 }
 264
 265 EXPORT_SYMBOL_GPL(inet6_csk_xmit);