diff options
Diffstat (limited to 'net/ipv4/icmp.c')
-rw-r--r-- | net/ipv4/icmp.c | 125 |
1 files changed, 76 insertions, 49 deletions
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index 0777ea949223..fc310db2708b 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -209,19 +209,17 @@ static struct sock *icmp_sk(struct net *net) return *this_cpu_ptr(net->ipv4.icmp_sk); } +/* Called with BH disabled */ static inline struct sock *icmp_xmit_lock(struct net *net) { struct sock *sk; - local_bh_disable(); - sk = icmp_sk(net); if (unlikely(!spin_trylock(&sk->sk_lock.slock))) { /* This can happen if the output path signals a * dst_link_failure() for an outgoing ICMP packet. */ - local_bh_enable(); return NULL; } return sk; @@ -229,7 +227,7 @@ static inline struct sock *icmp_xmit_lock(struct net *net) static inline void icmp_xmit_unlock(struct sock *sk) { - spin_unlock_bh(&sk->sk_lock.slock); + spin_unlock(&sk->sk_lock.slock); } int sysctl_icmp_msgs_per_sec __read_mostly = 1000; @@ -282,6 +280,33 @@ bool icmp_global_allow(void) } EXPORT_SYMBOL(icmp_global_allow); +static bool icmpv4_mask_allow(struct net *net, int type, int code) +{ + if (type > NR_ICMP_TYPES) + return true; + + /* Don't limit PMTU discovery. */ + if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) + return true; + + /* Limit if icmp type is enabled in ratemask. */ + if (!((1 << type) & net->ipv4.sysctl_icmp_ratemask)) + return true; + + return false; +} + +static bool icmpv4_global_allow(struct net *net, int type, int code) +{ + if (icmpv4_mask_allow(net, type, code)) + return true; + + if (icmp_global_allow()) + return true; + + return false; +} + /* * Send an ICMP frame. */ @@ -290,34 +315,22 @@ static bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt, struct flowi4 *fl4, int type, int code) { struct dst_entry *dst = &rt->dst; + struct inet_peer *peer; bool rc = true; + int vif; - if (type > NR_ICMP_TYPES) - goto out; - - /* Don't limit PMTU discovery. */ - if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) + if (icmpv4_mask_allow(net, type, code)) goto out; /* No rate limit on loopback */ if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) goto out; - /* Limit if icmp type is enabled in ratemask. */ - if (!((1 << type) & net->ipv4.sysctl_icmp_ratemask)) - goto out; - - rc = false; - if (icmp_global_allow()) { - int vif = l3mdev_master_ifindex(dst->dev); - struct inet_peer *peer; - - peer = inet_getpeer_v4(net->ipv4.peers, fl4->daddr, vif, 1); - rc = inet_peer_xrlim_allow(peer, - net->ipv4.sysctl_icmp_ratelimit); - if (peer) - inet_putpeer(peer); - } + vif = l3mdev_master_ifindex(dst->dev); + peer = inet_getpeer_v4(net->ipv4.peers, fl4->daddr, vif, 1); + rc = inet_peer_xrlim_allow(peer, net->ipv4.sysctl_icmp_ratelimit); + if (peer) + inet_putpeer(peer); out: return rc; } @@ -396,13 +409,22 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) struct inet_sock *inet; __be32 daddr, saddr; u32 mark = IP4_REPLY_MARK(net, skb->mark); + int type = icmp_param->data.icmph.type; + int code = icmp_param->data.icmph.code; if (ip_options_echo(&icmp_param->replyopts.opt.opt, skb)) return; + /* Needed by both icmp_global_allow and icmp_xmit_lock */ + local_bh_disable(); + + /* global icmp_msgs_per_sec */ + if (!icmpv4_global_allow(net, type, code)) + goto out_bh_enable; + sk = icmp_xmit_lock(net); if (!sk) - return; + goto out_bh_enable; inet = inet_sk(sk); icmp_param->data.icmph.checksum = 0; @@ -433,12 +455,13 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) rt = ip_route_output_key(net, &fl4); if (IS_ERR(rt)) goto out_unlock; - if (icmpv4_xrlim_allow(net, rt, &fl4, icmp_param->data.icmph.type, - icmp_param->data.icmph.code)) + if (icmpv4_xrlim_allow(net, rt, &fl4, type, code)) icmp_push_reply(icmp_param, &fl4, &ipc, &rt); ip_rt_put(rt); out_unlock: icmp_xmit_unlock(sk); +out_bh_enable: + local_bh_enable(); } #ifdef CONFIG_IP_ROUTE_MULTIPATH @@ -571,7 +594,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) { struct iphdr *iph; int room; - struct icmp_bxm *icmp_param; + struct icmp_bxm icmp_param; struct rtable *rt = skb_rtable(skb_in); struct ipcm_cookie ipc; struct flowi4 fl4; @@ -648,13 +671,16 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) } } - icmp_param = kmalloc(sizeof(*icmp_param), GFP_ATOMIC); - if (!icmp_param) - return; + /* Needed by both icmp_global_allow and icmp_xmit_lock */ + local_bh_disable(); + + /* Check global sysctl_icmp_msgs_per_sec ratelimit */ + if (!icmpv4_global_allow(net, type, code)) + goto out_bh_enable; sk = icmp_xmit_lock(net); if (!sk) - goto out_free; + goto out_bh_enable; /* * Construct source address and options. @@ -681,7 +707,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) iph->tos; mark = IP4_REPLY_MARK(net, skb_in->mark); - if (ip_options_echo(&icmp_param->replyopts.opt.opt, skb_in)) + if (ip_options_echo(&icmp_param.replyopts.opt.opt, skb_in)) goto out_unlock; @@ -689,25 +715,26 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) * Prepare data for ICMP header. */ - icmp_param->data.icmph.type = type; - icmp_param->data.icmph.code = code; - icmp_param->data.icmph.un.gateway = info; - icmp_param->data.icmph.checksum = 0; - icmp_param->skb = skb_in; - icmp_param->offset = skb_network_offset(skb_in); + icmp_param.data.icmph.type = type; + icmp_param.data.icmph.code = code; + icmp_param.data.icmph.un.gateway = info; + icmp_param.data.icmph.checksum = 0; + icmp_param.skb = skb_in; + icmp_param.offset = skb_network_offset(skb_in); inet_sk(sk)->tos = tos; sk->sk_mark = mark; ipc.addr = iph->saddr; - ipc.opt = &icmp_param->replyopts.opt; + ipc.opt = &icmp_param.replyopts.opt; ipc.tx_flags = 0; ipc.ttl = 0; ipc.tos = -1; rt = icmp_route_lookup(net, &fl4, skb_in, iph, saddr, tos, mark, - type, code, icmp_param); + type, code, &icmp_param); if (IS_ERR(rt)) goto out_unlock; + /* peer icmp_ratelimit */ if (!icmpv4_xrlim_allow(net, rt, &fl4, type, code)) goto ende; @@ -716,21 +743,21 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) room = dst_mtu(&rt->dst); if (room > 576) room = 576; - room -= sizeof(struct iphdr) + icmp_param->replyopts.opt.opt.optlen; + room -= sizeof(struct iphdr) + icmp_param.replyopts.opt.opt.optlen; room -= sizeof(struct icmphdr); - icmp_param->data_len = skb_in->len - icmp_param->offset; - if (icmp_param->data_len > room) - icmp_param->data_len = room; - icmp_param->head_len = sizeof(struct icmphdr); + icmp_param.data_len = skb_in->len - icmp_param.offset; + if (icmp_param.data_len > room) + icmp_param.data_len = room; + icmp_param.head_len = sizeof(struct icmphdr); - icmp_push_reply(icmp_param, &fl4, &ipc, &rt); + icmp_push_reply(&icmp_param, &fl4, &ipc, &rt); ende: ip_rt_put(rt); out_unlock: icmp_xmit_unlock(sk); -out_free: - kfree(icmp_param); +out_bh_enable: + local_bh_enable(); out:; } EXPORT_SYMBOL(icmp_send); |