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, bool relax)
  32 {
  33         const struct sock *sk2;
  34         const struct hlist_node *node;
  35         int reuse = sk->sk_reuse;
  36         int reuseport = sk->sk_reuseport;
  37         kuid_t uid = sock_i_uid((struct sock *)sk);
  38
  39         /* We must walk the whole port owner list in this case. -DaveM */
  40         /*
  41          * See comment in inet_csk_bind_conflict about sock lookup
  42          * vs net namespaces issues.
  43          */
  44         sk_for_each_bound(sk2, node, &tb->owners) {
  45                 if (sk != sk2 &&
  46                     (!sk->sk_bound_dev_if ||
  47                      !sk2->sk_bound_dev_if ||
  48                      sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
  49                         if ((!reuse || !sk2->sk_reuse ||
  50                              sk2->sk_state == TCP_LISTEN) &&
  51                             (!reuseport || !sk2->sk_reuseport ||
  52                              (sk2->sk_state != TCP_TIME_WAIT &&
  53                               !uid_eq(uid,
  54                                       sock_i_uid((struct sock *)sk2))))) {
  55                                 if (ipv6_rcv_saddr_equal(sk, sk2))
  56                                         break;
  57                         }
  58                 }
  59         }
  60
  61         return node != NULL;
  62 }
  63
  64 EXPORT_SYMBOL_GPL(inet6_csk_bind_conflict);
  65
  66 struct dst_entry *inet6_csk_route_req(struct sock *sk,
  67                                       struct flowi6 *fl6,
  68                                       const struct request_sock *req)
  69 {
  70         struct inet6_request_sock *treq = inet6_rsk(req);
  71         struct ipv6_pinfo *np = inet6_sk(sk);
  72         struct in6_addr *final_p, final;
  73         struct dst_entry *dst;
  74
  75         memset(fl6, 0, sizeof(*fl6));
  76         fl6->flowi6_proto = IPPROTO_TCP;
  77         fl6->daddr = treq->rmt_addr;
  78         final_p = fl6_update_dst(fl6, np->opt, &final);
  79         fl6->saddr = treq->loc_addr;
  80         fl6->flowi6_oif = treq->iif;
  81         fl6->flowi6_mark = sk->sk_mark;
  82         fl6->fl6_dport = inet_rsk(req)->rmt_port;
  83         fl6->fl6_sport = inet_rsk(req)->loc_port;
  84         security_req_classify_flow(req, flowi6_to_flowi(fl6));
  85
  86         dst = ip6_dst_lookup_flow(sk, fl6, final_p, false);
  87         if (IS_ERR(dst))
  88                 return NULL;
  89
  90         return dst;
  91 }
  92
  93 /*
  94  * request_sock (formerly open request) hash tables.
  95  */
  96 static u32 inet6_synq_hash(const struct in6_addr *raddr, const __be16 rport,
  97                            const u32 rnd, const u32 synq_hsize)
  98 {
  99         u32 c;
 100
 101         c = jhash_3words((__force u32)raddr->s6_addr32[0],
 102                          (__force u32)raddr->s6_addr32[1],
 103                          (__force u32)raddr->s6_addr32[2],
 104                          rnd);
 105
 106         c = jhash_2words((__force u32)raddr->s6_addr32[3],
 107                          (__force u32)rport,
 108                          c);
 109
 110         return c & (synq_hsize - 1);
 111 }
 112
 113 struct request_sock *inet6_csk_search_req(const struct sock *sk,
 114                                           struct request_sock ***prevp,
 115                                           const __be16 rport,
 116                                           const struct in6_addr *raddr,
 117                                           const struct in6_addr *laddr,
 118                                           const int iif)
 119 {
 120         const struct inet_connection_sock *icsk = inet_csk(sk);
 121         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 122         struct request_sock *req, **prev;
 123
 124         for (prev = &lopt->syn_table[inet6_synq_hash(raddr, rport,
 125                                                      lopt->hash_rnd,
 126                                                      lopt->nr_table_entries)];
 127              (req = *prev) != NULL;
 128              prev = &req->dl_next) {
 129                 const struct inet6_request_sock *treq = inet6_rsk(req);
 130
 131                 if (inet_rsk(req)->rmt_port == rport &&
 132                     req->rsk_ops->family == AF_INET6 &&
 133                     ipv6_addr_equal(&treq->rmt_addr, raddr) &&
 134                     ipv6_addr_equal(&treq->loc_addr, laddr) &&
 135                     (!treq->iif || treq->iif == iif)) {
 136                         WARN_ON(req->sk != NULL);
 137                         *prevp = prev;
 138                         return req;
 139                 }
 140         }
 141
 142         return NULL;
 143 }
 144
 145 EXPORT_SYMBOL_GPL(inet6_csk_search_req);
 146
 147 void inet6_csk_reqsk_queue_hash_add(struct sock *sk,
 148                                     struct request_sock *req,
 149                                     const unsigned long timeout)
 150 {
 151         struct inet_connection_sock *icsk = inet_csk(sk);
 152         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 153         const u32 h = inet6_synq_hash(&inet6_rsk(req)->rmt_addr,
 154                                       inet_rsk(req)->rmt_port,
 155                                       lopt->hash_rnd, lopt->nr_table_entries);
 156
 157         reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
 158         inet_csk_reqsk_queue_added(sk, timeout);
 159 }
 160
 161 EXPORT_SYMBOL_GPL(inet6_csk_reqsk_queue_hash_add);
 162
 163 void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr)
 164 {
 165         struct ipv6_pinfo *np = inet6_sk(sk);
 166         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr;
 167
 168         sin6->sin6_family = AF_INET6;
 169         sin6->sin6_addr = np->daddr;
 170         sin6->sin6_port = inet_sk(sk)->inet_dport;
 171         /* We do not store received flowlabel for TCP */
 172         sin6->sin6_flowinfo = 0;
 173         sin6->sin6_scope_id = 0;
 174         if (sk->sk_bound_dev_if &&
 175             ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 176                 sin6->sin6_scope_id = sk->sk_bound_dev_if;
 177 }
 178
 179 EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr);
 180
 181 static inline
 182 void __inet6_csk_dst_store(struct sock *sk, struct dst_entry *dst,
 183                            const struct in6_addr *daddr,
 184                            const struct in6_addr *saddr)
 185 {
 186         __ip6_dst_store(sk, dst, daddr, saddr);
 187 }
 188
 189 static inline
 190 struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie)
 191 {
 192         return __sk_dst_check(sk, cookie);
 193 }
 194
 195 static struct dst_entry *inet6_csk_route_socket(struct sock *sk,
 196                                                 struct flowi6 *fl6)
 197 {
 198         struct inet_sock *inet = inet_sk(sk);
 199         struct ipv6_pinfo *np = inet6_sk(sk);
 200         struct in6_addr *final_p, final;
 201         struct dst_entry *dst;
 202
 203         memset(fl6, 0, sizeof(*fl6));
 204         fl6->flowi6_proto = sk->sk_protocol;
 205         fl6->daddr = np->daddr;
 206         fl6->saddr = np->saddr;
 207         fl6->flowlabel = np->flow_label;
 208         IP6_ECN_flow_xmit(sk, fl6->flowlabel);
 209         fl6->flowi6_oif = sk->sk_bound_dev_if;
 210         fl6->flowi6_mark = sk->sk_mark;
 211         fl6->fl6_sport = inet->inet_sport;
 212         fl6->fl6_dport = inet->inet_dport;
 213         security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
 214
 215         final_p = fl6_update_dst(fl6, np->opt, &final);
 216
 217         dst = __inet6_csk_dst_check(sk, np->dst_cookie);
 218         if (!dst) {
 219                 dst = ip6_dst_lookup_flow(sk, fl6, final_p, false);
 220
 221                 if (!IS_ERR(dst))
 222                         __inet6_csk_dst_store(sk, dst, NULL, NULL);
 223         }
 224         return dst;
 225 }
 226
 227 int inet6_csk_xmit(struct sk_buff *skb, struct flowi *fl_unused)
 228 {
 229         struct sock *sk = skb->sk;
 230         struct ipv6_pinfo *np = inet6_sk(sk);
 231         struct flowi6 fl6;
 232         struct dst_entry *dst;
 233         int res;
 234
 235         dst = inet6_csk_route_socket(sk, &fl6);
 236         if (IS_ERR(dst)) {
 237                 sk->sk_err_soft = -PTR_ERR(dst);
 238                 sk->sk_route_caps = 0;
 239                 kfree_skb(skb);
 240                 return PTR_ERR(dst);
 241         }
 242
 243         rcu_read_lock();
 244         skb_dst_set_noref(skb, dst);
 245
 246         /* Restore final destination back after routing done */
 247         fl6.daddr = np->daddr;
 248
 249         res = ip6_xmit(sk, skb, &fl6, np->opt, np->tclass);
 250         rcu_read_unlock();
 251         return res;
 252 }
 253 EXPORT_SYMBOL_GPL(inet6_csk_xmit);
 254
 255 struct dst_entry *inet6_csk_update_pmtu(struct sock *sk, u32 mtu)
 256 {
 257         struct flowi6 fl6;
 258         struct dst_entry *dst = inet6_csk_route_socket(sk, &fl6);
 259
 260         if (IS_ERR(dst))
 261                 return NULL;
 262         dst->ops->update_pmtu(dst, sk, NULL, mtu);
 263
 264         dst = inet6_csk_route_socket(sk, &fl6);
 265         return IS_ERR(dst) ? NULL : dst;
 266 }
 267 EXPORT_SYMBOL_GPL(inet6_csk_update_pmtu);