]> nv-tegra.nvidia Code Review - linux-3.10.git/blobdiff - net/ipv4/icmp.c
ipv4: Make icmp route lookup code a bit clearer.
[linux-3.10.git] / net / ipv4 / icmp.c
index bdb6c71e72a631e179fce4462c2cc407f5d1ee03..2a86c8951dcd135c987b9495d441e30dfa58ee57 100644 (file)
@@ -181,6 +181,7 @@ const struct icmp_err icmp_err_convert[] = {
                .fatal = 1,
        },
 };
+EXPORT_SYMBOL(icmp_err_convert);
 
 /*
  *     ICMP control array. This specifies what to do with each ICMP.
@@ -232,47 +233,11 @@ static inline void icmp_xmit_unlock(struct sock *sk)
  *     Send an ICMP frame.
  */
 
-/*
- *     Check transmit rate limitation for given message.
- *     The rate information is held in the destination cache now.
- *     This function is generic and could be used for other purposes
- *     too. It uses a Token bucket filter as suggested by Alexey Kuznetsov.
- *
- *     Note that the same dst_entry fields are modified by functions in
- *     route.c too, but these work for packet destinations while xrlim_allow
- *     works for icmp destinations. This means the rate limiting information
- *     for one "ip object" is shared - and these ICMPs are twice limited:
- *     by source and by destination.
- *
- *     RFC 1812: 4.3.2.8 SHOULD be able to limit error message rate
- *                       SHOULD allow setting of rate limits
- *
- *     Shared between ICMPv4 and ICMPv6.
- */
-#define XRLIM_BURST_FACTOR 6
-int xrlim_allow(struct dst_entry *dst, int timeout)
-{
-       unsigned long now, token = dst->rate_tokens;
-       int rc = 0;
-
-       now = jiffies;
-       token += now - dst->rate_last;
-       dst->rate_last = now;
-       if (token > XRLIM_BURST_FACTOR * timeout)
-               token = XRLIM_BURST_FACTOR * timeout;
-       if (token >= timeout) {
-               token -= timeout;
-               rc = 1;
-       }
-       dst->rate_tokens = token;
-       return rc;
-}
-
-static inline int icmpv4_xrlim_allow(struct net *net, struct rtable *rt,
+static inline bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt,
                int type, int code)
 {
-       struct dst_entry *dst = &rt->u.dst;
-       int rc = 1;
+       struct dst_entry *dst = &rt->dst;
+       bool rc = true;
 
        if (type > NR_ICMP_TYPES)
                goto out;
@@ -286,8 +251,12 @@ static inline int icmpv4_xrlim_allow(struct net *net, struct rtable *rt,
                goto out;
 
        /* Limit if icmp type is enabled in ratemask. */
-       if ((1 << type) & net->ipv4.sysctl_icmp_ratemask)
-               rc = xrlim_allow(dst, net->ipv4.sysctl_icmp_ratelimit);
+       if ((1 << type) & net->ipv4.sysctl_icmp_ratemask) {
+               if (!rt->peer)
+                       rt_bind_peer(rt, 1);
+               rc = inet_peer_xrlim_allow(rt->peer,
+                                          net->ipv4.sysctl_icmp_ratelimit);
+       }
 out:
        return rc;
 }
@@ -327,7 +296,7 @@ static void icmp_push_reply(struct icmp_bxm *icmp_param,
        struct sock *sk;
        struct sk_buff *skb;
 
-       sk = icmp_sk(dev_net((*rt)->u.dst.dev));
+       sk = icmp_sk(dev_net((*rt)->dst.dev));
        if (ip_append_data(sk, icmp_glue_bits, icmp_param,
                           icmp_param->data_len+icmp_param->head_len,
                           icmp_param->head_len,
@@ -359,7 +328,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
 {
        struct ipcm_cookie ipc;
        struct rtable *rt = skb_rtable(skb);
-       struct net *net = dev_net(rt->u.dst.dev);
+       struct net *net = dev_net(rt->dst.dev);
        struct sock *sk;
        struct inet_sock *inet;
        __be32 daddr;
@@ -377,17 +346,16 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
        inet->tos = ip_hdr(skb)->tos;
        daddr = ipc.addr = rt->rt_src;
        ipc.opt = NULL;
-       ipc.shtx.flags = 0;
+       ipc.tx_flags = 0;
        if (icmp_param->replyopts.optlen) {
                ipc.opt = &icmp_param->replyopts;
                if (ipc.opt->srr)
                        daddr = icmp_param->replyopts.faddr;
        }
        {
-               struct flowi fl = { .nl_u = { .ip4_u =
-                                             { .daddr = daddr,
-                                               .saddr = rt->rt_spec_dst,
-                                               .tos = RT_TOS(ip_hdr(skb)->tos) } },
+               struct flowi fl = { .fl4_dst= daddr,
+                                   .fl4_src = rt->rt_spec_dst,
+                                   .fl4_tos = RT_TOS(ip_hdr(skb)->tos),
                                    .proto = IPPROTO_ICMP };
                security_skb_classify_flow(skb, &fl);
                if (ip_route_output_key(net, &rt, &fl))
@@ -401,6 +369,98 @@ out_unlock:
        icmp_xmit_unlock(sk);
 }
 
+static struct rtable *icmp_route_lookup(struct net *net, struct sk_buff *skb_in,
+                                       struct iphdr *iph,
+                                       __be32 saddr, u8 tos,
+                                       int type, int code,
+                                       struct icmp_bxm *param)
+{
+       struct flowi fl = {
+               .fl4_dst = (param->replyopts.srr ?
+                           param->replyopts.faddr : iph->saddr),
+               .fl4_src = saddr,
+               .fl4_tos = RT_TOS(tos),
+               .proto = IPPROTO_ICMP,
+               .fl_icmp_type = type,
+               .fl_icmp_code = code,
+       };
+       struct rtable *rt, *rt2;
+       int err;
+
+       security_skb_classify_flow(skb_in, &fl);
+       err = __ip_route_output_key(net, &rt, &fl);
+       if (err)
+               return ERR_PTR(err);
+
+       /* No need to clone since we're just using its address. */
+       rt2 = rt;
+
+       if (!fl.fl4_src)
+               fl.fl4_src = rt->rt_src;
+
+       err = xfrm_lookup(net, (struct dst_entry **)&rt, &fl, NULL, 0);
+       switch (err) {
+       case 0:
+               if (rt != rt2)
+                       return rt;
+               break;
+       case -EPERM:
+               rt = NULL;
+               break;
+       default:
+               return ERR_PTR(err);
+       }
+
+       err = xfrm_decode_session_reverse(skb_in, &fl, AF_INET);
+       if (err)
+               goto relookup_failed;
+
+       if (inet_addr_type(net, fl.fl4_src) == RTN_LOCAL) {
+               err = __ip_route_output_key(net, &rt2, &fl);
+       } else {
+               struct flowi fl2 = {};
+               unsigned long orefdst;
+
+               fl2.fl4_dst = fl.fl4_src;
+               err = ip_route_output_key(net, &rt2, &fl2);
+               if (err)
+                       goto relookup_failed;
+               /* Ugh! */
+               orefdst = skb_in->_skb_refdst; /* save old refdst */
+               err = ip_route_input(skb_in, fl.fl4_dst, fl.fl4_src,
+                                    RT_TOS(tos), rt2->dst.dev);
+
+               dst_release(&rt2->dst);
+               rt2 = skb_rtable(skb_in);
+               skb_in->_skb_refdst = orefdst; /* restore old refdst */
+       }
+
+       if (err)
+               goto relookup_failed;
+
+       err = xfrm_lookup(net, (struct dst_entry **)&rt2, &fl, NULL,
+                         XFRM_LOOKUP_ICMP);
+       switch (err) {
+       case 0:
+               dst_release(&rt->dst);
+               rt = rt2;
+               break;
+       case -EPERM:
+               return ERR_PTR(err);
+       default:
+               if (!rt)
+                       return ERR_PTR(err);
+               break;
+       }
+
+
+       return rt;
+
+relookup_failed:
+       if (rt)
+               return rt;
+       return ERR_PTR(err);
+}
 
 /*
  *     Send an ICMP message in response to a situation
@@ -427,7 +487,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
 
        if (!rt)
                goto out;
-       net = dev_net(rt->u.dst.dev);
+       net = dev_net(rt->dst.dev);
 
        /*
         *      Find the original header. It is expected to be valid, of course.
@@ -504,8 +564,8 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
                struct net_device *dev = NULL;
 
                rcu_read_lock();
-               if (rt->fl.iif &&
-                       net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr)
+               if (rt_is_input_route(rt) &&
+                   net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr)
                        dev = dev_get_by_index_rcu(net, rt->fl.iif);
 
                if (dev)
@@ -536,100 +596,19 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
        inet_sk(sk)->tos = tos;
        ipc.addr = iph->saddr;
        ipc.opt = &icmp_param.replyopts;
-       ipc.shtx.flags = 0;
+       ipc.tx_flags = 0;
 
-       {
-               struct flowi fl = {
-                       .nl_u = {
-                               .ip4_u = {
-                                       .daddr = icmp_param.replyopts.srr ?
-                                               icmp_param.replyopts.faddr :
-                                               iph->saddr,
-                                       .saddr = saddr,
-                                       .tos = RT_TOS(tos)
-                               }
-                       },
-                       .proto = IPPROTO_ICMP,
-                       .uli_u = {
-                               .icmpt = {
-                                       .type = type,
-                                       .code = code
-                               }
-                       }
-               };
-               int err;
-               struct rtable *rt2;
-
-               security_skb_classify_flow(skb_in, &fl);
-               if (__ip_route_output_key(net, &rt, &fl))
-                       goto out_unlock;
-
-               /* No need to clone since we're just using its address. */
-               rt2 = rt;
-
-               err = xfrm_lookup(net, (struct dst_entry **)&rt, &fl, NULL, 0);
-               switch (err) {
-               case 0:
-                       if (rt != rt2)
-                               goto route_done;
-                       break;
-               case -EPERM:
-                       rt = NULL;
-                       break;
-               default:
-                       goto out_unlock;
-               }
-
-               if (xfrm_decode_session_reverse(skb_in, &fl, AF_INET))
-                       goto relookup_failed;
-
-               if (inet_addr_type(net, fl.fl4_src) == RTN_LOCAL)
-                       err = __ip_route_output_key(net, &rt2, &fl);
-               else {
-                       struct flowi fl2 = {};
-                       unsigned long orefdst;
-
-                       fl2.fl4_dst = fl.fl4_src;
-                       if (ip_route_output_key(net, &rt2, &fl2))
-                               goto relookup_failed;
-
-                       /* Ugh! */
-                       orefdst = skb_in->_skb_refdst; /* save old refdst */
-                       err = ip_route_input(skb_in, fl.fl4_dst, fl.fl4_src,
-                                            RT_TOS(tos), rt2->u.dst.dev);
-
-                       dst_release(&rt2->u.dst);
-                       rt2 = skb_rtable(skb_in);
-                       skb_in->_skb_refdst = orefdst; /* restore old refdst */
-               }
-
-               if (err)
-                       goto relookup_failed;
-
-               err = xfrm_lookup(net, (struct dst_entry **)&rt2, &fl, NULL,
-                                 XFRM_LOOKUP_ICMP);
-               switch (err) {
-               case 0:
-                       dst_release(&rt->u.dst);
-                       rt = rt2;
-                       break;
-               case -EPERM:
-                       goto ende;
-               default:
-relookup_failed:
-                       if (!rt)
-                               goto out_unlock;
-                       break;
-               }
-       }
+       rt = icmp_route_lookup(net, skb_in, iph, saddr, tos,
+                              type, code, &icmp_param);
+       if (IS_ERR(rt))
+               goto out_unlock;
 
-route_done:
        if (!icmpv4_xrlim_allow(net, rt, type, code))
                goto ende;
 
        /* RFC says return as much as we can without exceeding 576 bytes. */
 
-       room = dst_mtu(&rt->u.dst);
+       room = dst_mtu(&rt->dst);
        if (room > 576)
                room = 576;
        room -= sizeof(struct iphdr) + icmp_param.replyopts.optlen;
@@ -647,6 +626,7 @@ out_unlock:
        icmp_xmit_unlock(sk);
 out:;
 }
+EXPORT_SYMBOL(icmp_send);
 
 
 /*
@@ -972,7 +952,7 @@ int icmp_rcv(struct sk_buff *skb)
 {
        struct icmphdr *icmph;
        struct rtable *rt = skb_rtable(skb);
-       struct net *net = dev_net(rt->u.dst.dev);
+       struct net *net = dev_net(rt->dst.dev);
 
        if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
                struct sec_path *sp = skb_sec_path(skb);
@@ -1214,7 +1194,3 @@ int __init icmp_init(void)
 {
        return register_pernet_subsys(&icmp_sk_ops);
 }
-
-EXPORT_SYMBOL(icmp_err_convert);
-EXPORT_SYMBOL(icmp_send);
-EXPORT_SYMBOL(xrlim_allow);