From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/net/ipv4/ip_forward.c | 159 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 159 insertions(+) create mode 100644 kernel/net/ipv4/ip_forward.c (limited to 'kernel/net/ipv4/ip_forward.c') diff --git a/kernel/net/ipv4/ip_forward.c b/kernel/net/ipv4/ip_forward.c new file mode 100644 index 000000000..367448494 --- /dev/null +++ b/kernel/net/ipv4/ip_forward.c @@ -0,0 +1,159 @@ +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * The IP forwarding functionality. + * + * Authors: see ip.c + * + * Fixes: + * Many : Split from ip.c , see ip_input.c for + * history. + * Dave Gregorich : NULL ip_rt_put fix for multicast + * routing. + * Jos Vos : Add call_out_firewall before sending, + * use output device for accounting. + * Jos Vos : Call forward firewall after routing + * (always use output device). + * Mike McLagan : Routing by source + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static bool ip_may_fragment(const struct sk_buff *skb) +{ + return unlikely((ip_hdr(skb)->frag_off & htons(IP_DF)) == 0) || + skb->ignore_df; +} + +static bool ip_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu) +{ + if (skb->len <= mtu) + return false; + + if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu) + return false; + + return true; +} + + +static int ip_forward_finish(struct sock *sk, struct sk_buff *skb) +{ + struct ip_options *opt = &(IPCB(skb)->opt); + + IP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTFORWDATAGRAMS); + IP_ADD_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTOCTETS, skb->len); + + if (unlikely(opt->optlen)) + ip_forward_options(skb); + + skb_sender_cpu_clear(skb); + return dst_output_sk(sk, skb); +} + +int ip_forward(struct sk_buff *skb) +{ + u32 mtu; + struct iphdr *iph; /* Our header */ + struct rtable *rt; /* Route we use */ + struct ip_options *opt = &(IPCB(skb)->opt); + + /* that should never happen */ + if (skb->pkt_type != PACKET_HOST) + goto drop; + + if (unlikely(skb->sk)) + goto drop; + + if (skb_warn_if_lro(skb)) + goto drop; + + if (!xfrm4_policy_check(NULL, XFRM_POLICY_FWD, skb)) + goto drop; + + if (IPCB(skb)->opt.router_alert && ip_call_ra_chain(skb)) + return NET_RX_SUCCESS; + + skb_forward_csum(skb); + + /* + * According to the RFC, we must first decrease the TTL field. If + * that reaches zero, we must reply an ICMP control message telling + * that the packet's lifetime expired. + */ + if (ip_hdr(skb)->ttl <= 1) + goto too_many_hops; + + if (!xfrm4_route_forward(skb)) + goto drop; + + rt = skb_rtable(skb); + + if (opt->is_strictroute && rt->rt_uses_gateway) + goto sr_failed; + + IPCB(skb)->flags |= IPSKB_FORWARDED; + mtu = ip_dst_mtu_maybe_forward(&rt->dst, true); + if (!ip_may_fragment(skb) && ip_exceeds_mtu(skb, mtu)) { + IP_INC_STATS(dev_net(rt->dst.dev), IPSTATS_MIB_FRAGFAILS); + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, + htonl(mtu)); + goto drop; + } + + /* We are about to mangle packet. Copy it! */ + if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+rt->dst.header_len)) + goto drop; + iph = ip_hdr(skb); + + /* Decrease ttl after skb cow done */ + ip_decrease_ttl(iph); + + /* + * We now generate an ICMP HOST REDIRECT giving the route + * we calculated. + */ + if (IPCB(skb)->flags & IPSKB_DOREDIRECT && !opt->srr && + !skb_sec_path(skb)) + ip_rt_send_redirect(skb); + + skb->priority = rt_tos2priority(iph->tos); + + return NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD, NULL, skb, + skb->dev, rt->dst.dev, ip_forward_finish); + +sr_failed: + /* + * Strict routing permits no gatewaying + */ + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_SR_FAILED, 0); + goto drop; + +too_many_hops: + /* Tell the sender its packet died... */ + IP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_INHDRERRORS); + icmp_send(skb, ICMP_TIME_EXCEEDED, ICMP_EXC_TTL, 0); +drop: + kfree_skb(skb); + return NET_RX_DROP; +} -- cgit 1.2.3-korg