diff options
Diffstat (limited to 'net/ipv4/icmp.c')
-rw-r--r-- | net/ipv4/icmp.c | 240 |
1 files changed, 113 insertions, 127 deletions
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index 4aa1b7f01ea..a91dc161108 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -233,48 +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; -} -EXPORT_SYMBOL(xrlim_allow); - -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->dst; - int rc = 1; + bool rc = true; if (type > NR_ICMP_TYPES) goto out; @@ -288,8 +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; } @@ -386,12 +353,15 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) daddr = icmp_param->replyopts.faddr; } { - 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)) + struct flowi4 fl4 = { + .daddr = daddr, + .saddr = rt->rt_spec_dst, + .flowi4_tos = RT_TOS(ip_hdr(skb)->tos), + .flowi4_proto = IPPROTO_ICMP, + }; + security_skb_classify_flow(skb, flowi4_to_flowi(&fl4)); + rt = ip_route_output_key(net, &fl4); + if (IS_ERR(rt)) goto out_unlock; } if (icmpv4_xrlim_allow(net, rt, icmp_param->data.icmph.type, @@ -402,6 +372,97 @@ 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 flowi4 fl4 = { + .daddr = (param->replyopts.srr ? + param->replyopts.faddr : iph->saddr), + .saddr = saddr, + .flowi4_tos = RT_TOS(tos), + .flowi4_proto = IPPROTO_ICMP, + .fl4_icmp_type = type, + .fl4_icmp_code = code, + }; + struct rtable *rt, *rt2; + int err; + + security_skb_classify_flow(skb_in, flowi4_to_flowi(&fl4)); + rt = __ip_route_output_key(net, &fl4); + if (IS_ERR(rt)) + return rt; + + /* No need to clone since we're just using its address. */ + rt2 = rt; + + if (!fl4.saddr) + fl4.saddr = rt->rt_src; + + rt = (struct rtable *) xfrm_lookup(net, &rt->dst, + flowi4_to_flowi(&fl4), NULL, 0); + if (!IS_ERR(rt)) { + if (rt != rt2) + return rt; + } else if (PTR_ERR(rt) == -EPERM) { + rt = NULL; + } else + return rt; + + err = xfrm_decode_session_reverse(skb_in, flowi4_to_flowi(&fl4), AF_INET); + if (err) + goto relookup_failed; + + if (inet_addr_type(net, fl4.saddr) == RTN_LOCAL) { + rt2 = __ip_route_output_key(net, &fl4); + if (IS_ERR(rt2)) + err = PTR_ERR(rt2); + } else { + struct flowi4 fl4_2 = {}; + unsigned long orefdst; + + fl4_2.daddr = fl4.saddr; + rt2 = ip_route_output_key(net, &fl4_2); + if (IS_ERR(rt2)) { + err = PTR_ERR(rt2); + goto relookup_failed; + } + /* Ugh! */ + orefdst = skb_in->_skb_refdst; /* save old refdst */ + err = ip_route_input(skb_in, fl4.daddr, fl4.saddr, + 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; + + rt2 = (struct rtable *) xfrm_lookup(net, &rt2->dst, + flowi4_to_flowi(&fl4), NULL, + XFRM_LOOKUP_ICMP); + if (!IS_ERR(rt2)) { + dst_release(&rt->dst); + rt = rt2; + } else if (PTR_ERR(rt2) == -EPERM) { + if (rt) + dst_release(&rt->dst); + return rt2; + } else { + err = PTR_ERR(rt2); + goto relookup_failed; + } + return rt; + +relookup_failed: + if (rt) + return rt; + return ERR_PTR(err); +} /* * Send an ICMP message in response to a situation @@ -507,7 +568,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) rcu_read_lock(); if (rt_is_input_route(rt) && net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr) - dev = dev_get_by_index_rcu(net, rt->fl.iif); + dev = dev_get_by_index_rcu(net, rt->rt_iif); if (dev) saddr = inet_select_addr(dev, 0, RT_SCOPE_LINK); @@ -539,86 +600,11 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) ipc.opt = &icmp_param.replyopts; ipc.tx_flags = 0; - { - struct flowi fl = { - .fl4_dst = icmp_param.replyopts.srr ? - icmp_param.replyopts.faddr : iph->saddr, - .fl4_src = saddr, - .fl4_tos = RT_TOS(tos), - .proto = IPPROTO_ICMP, - .fl_icmp_type = type, - .fl_icmp_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; - - if (!fl.nl_u.ip4_u.saddr) - fl.nl_u.ip4_u.saddr = rt->rt_src; - - 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->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: - 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; |