/* * NAT transmitter (only for outside-to-inside nat forwarding) * Not used for related ICMP */ int ip_vs_nat_xmit(struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp) { struct rtable *rt; /* Route to the other host */ int mtu; struct iphdr *iph = ip_hdr(skb); int local; EnterFunction(10); /* check if it is a connection of no-client-port */ if (unlikely(cp->flags & IP_VS_CONN_F_NO_CPORT)) { __be16 _pt, *p; p = skb_header_pointer(skb, iph->ihl*4, sizeof(_pt), &_pt); if (p == NULL) goto tx_error; ip_vs_conn_fill_cport(cp, *p); IP_VS_DBG(10, "filled cport=%d\n", ntohs(*p)); } if (!(rt = __ip_vs_get_out_rt(skb, cp->dest, cp->daddr.ip, RT_TOS(iph->tos), IP_VS_RT_MODE_LOCAL | IP_VS_RT_MODE_NON_LOCAL | IP_VS_RT_MODE_RDR))) goto tx_error_icmp; local = rt->rt_flags & RTCF_LOCAL; /* * Avoid duplicate tuple in reply direction for NAT traffic * to local address when connection is sync-ed */ #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) if (cp->flags & IP_VS_CONN_F_SYNC && local) { enum ip_conntrack_info ctinfo; struct nf_conn *ct = ct = nf_ct_get(skb, &ctinfo); if (ct && !nf_ct_is_untracked(ct)) { IP_VS_DBG_RL_PKT(10, AF_INET, pp, skb, 0, "ip_vs_nat_xmit(): " "stopping DNAT to local address"); goto tx_error_put; } } #endif /* From world but DNAT to loopback address? */ if (local && ipv4_is_loopback(rt->rt_dst) && rt_is_input_route(skb_rtable(skb))) { IP_VS_DBG_RL_PKT(1, AF_INET, pp, skb, 0, "ip_vs_nat_xmit(): " "stopping DNAT to loopback address"); goto tx_error_put; } /* MTU checking */ mtu = dst_mtu(&rt->dst); if ((skb->len > mtu) && (iph->frag_off & htons(IP_DF)) && !skb_is_gso(skb)) { icmp_send(skb, ICMP_DEST_UNREACH,ICMP_FRAG_NEEDED, htonl(mtu)); IP_VS_DBG_RL_PKT(0, AF_INET, pp, skb, 0, "ip_vs_nat_xmit(): frag needed for"); goto tx_error_put; } /* copy-on-write the packet before mangling it */ if (!skb_make_writable(skb, sizeof(struct iphdr))) goto tx_error_put; if (skb_cow(skb, rt->dst.dev->hard_header_len)) goto tx_error_put; /* mangle the packet */ if (pp->dnat_handler && !pp->dnat_handler(skb, pp, cp)) goto tx_error_put; ip_hdr(skb)->daddr = cp->daddr.ip; ip_send_check(ip_hdr(skb)); if (!local) { /* drop old route */ skb_dst_drop(skb); skb_dst_set(skb, &rt->dst); } else { ip_rt_put(rt); /* * Some IPv4 replies get local address from routes, * not from iph, so while we DNAT after routing * we need this second input/output route. */ if (!__ip_vs_reroute_locally(skb)) goto tx_error; } IP_VS_DBG_PKT(10, AF_INET, pp, skb, 0, "After DNAT"); /* FIXME: when application helper enlarges the packet and the length is larger than the MTU of outgoing device, there will be still MTU problem. */ /* Another hack: avoid icmp_send in ip_fragment */ skb->local_df = 1; IP_VS_XMIT_NAT(NFPROTO_IPV4, skb, cp, local); LeaveFunction(10); return NF_STOLEN; tx_error_icmp: dst_link_failure(skb); tx_error: kfree_skb(skb); LeaveFunction(10); return NF_STOLEN; tx_error_put: ip_rt_put(rt); goto tx_error; }
int ip_vs_nat_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp) { struct rt6_info *rt; /* Route to the other host */ int mtu; int local; EnterFunction(10); /* check if it is a connection of no-client-port */ if (unlikely(cp->flags & IP_VS_CONN_F_NO_CPORT)) { __be16 _pt, *p; p = skb_header_pointer(skb, sizeof(struct ipv6hdr), sizeof(_pt), &_pt); if (p == NULL) goto tx_error; ip_vs_conn_fill_cport(cp, *p); IP_VS_DBG(10, "filled cport=%d\n", ntohs(*p)); } if (!(rt = __ip_vs_get_out_rt_v6(skb, cp->dest, &cp->daddr.in6, NULL, 0, 1|2|4))) goto tx_error_icmp; local = __ip_vs_is_local_route6(rt); /* * Avoid duplicate tuple in reply direction for NAT traffic * to local address when connection is sync-ed */ #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) if (cp->flags & IP_VS_CONN_F_SYNC && local) { enum ip_conntrack_info ctinfo; struct nf_conn *ct = ct = nf_ct_get(skb, &ctinfo); if (ct && !nf_ct_is_untracked(ct)) { IP_VS_DBG_RL_PKT(10, AF_INET6, pp, skb, 0, "ip_vs_nat_xmit_v6(): " "stopping DNAT to local address"); goto tx_error_put; } } #endif /* From world but DNAT to loopback address? */ if (local && skb->dev && !(skb->dev->flags & IFF_LOOPBACK) && ipv6_addr_type(&rt->rt6i_dst.addr) & IPV6_ADDR_LOOPBACK) { IP_VS_DBG_RL_PKT(1, AF_INET6, pp, skb, 0, "ip_vs_nat_xmit_v6(): " "stopping DNAT to loopback address"); goto tx_error_put; } /* MTU checking */ mtu = dst_mtu(&rt->dst); if (skb->len > mtu && !skb_is_gso(skb)) { if (!skb->dev) { struct net *net = dev_net(skb_dst(skb)->dev); skb->dev = net->loopback_dev; } icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); IP_VS_DBG_RL_PKT(0, AF_INET6, pp, skb, 0, "ip_vs_nat_xmit_v6(): frag needed for"); goto tx_error_put; } /* copy-on-write the packet before mangling it */ if (!skb_make_writable(skb, sizeof(struct ipv6hdr))) goto tx_error_put; if (skb_cow(skb, rt->dst.dev->hard_header_len)) goto tx_error_put; /* mangle the packet */ if (pp->dnat_handler && !pp->dnat_handler(skb, pp, cp)) goto tx_error; ipv6_addr_copy(&ipv6_hdr(skb)->daddr, &cp->daddr.in6); if (!local || !skb->dev) { /* drop the old route when skb is not shared */ skb_dst_drop(skb); skb_dst_set(skb, &rt->dst); } else { /* destined to loopback, do we need to change route? */ dst_release(&rt->dst); } IP_VS_DBG_PKT(10, AF_INET6, pp, skb, 0, "After DNAT"); /* FIXME: when application helper enlarges the packet and the length is larger than the MTU of outgoing device, there will be still MTU problem. */ /* Another hack: avoid icmp_send in ip_fragment */ skb->local_df = 1; IP_VS_XMIT_NAT(NFPROTO_IPV6, skb, cp, local); LeaveFunction(10); return NF_STOLEN; tx_error_icmp: dst_link_failure(skb); tx_error: LeaveFunction(10); kfree_skb(skb); return NF_STOLEN; tx_error_put: dst_release(&rt->dst); goto tx_error; }
int ip_vs_nat_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp, struct ip_vs_iphdr *ipvsh) { struct rt6_info *rt; /* Route to the other host */ int local, rc; EnterFunction(10); rcu_read_lock(); /* check if it is a connection of no-client-port */ if (unlikely(cp->flags & IP_VS_CONN_F_NO_CPORT && !ipvsh->fragoffs)) { __be16 _pt, *p; p = skb_header_pointer(skb, ipvsh->len, sizeof(_pt), &_pt); if (p == NULL) goto tx_error; ip_vs_conn_fill_cport(cp, *p); IP_VS_DBG(10, "filled cport=%d\n", ntohs(*p)); } local = __ip_vs_get_out_rt_v6(skb, cp->dest, &cp->daddr.in6, NULL, ipvsh, 0, IP_VS_RT_MODE_LOCAL | IP_VS_RT_MODE_NON_LOCAL | IP_VS_RT_MODE_RDR); if (local < 0) goto tx_error; rt = (struct rt6_info *) skb_dst(skb); /* * Avoid duplicate tuple in reply direction for NAT traffic * to local address when connection is sync-ed */ #if IS_ENABLED(CONFIG_NF_CONNTRACK) if (cp->flags & IP_VS_CONN_F_SYNC && local) { enum ip_conntrack_info ctinfo; struct nf_conn *ct = nf_ct_get(skb, &ctinfo); if (ct && !nf_ct_is_untracked(ct)) { IP_VS_DBG_RL_PKT(10, AF_INET6, pp, skb, 0, "ip_vs_nat_xmit_v6(): " "stopping DNAT to local address"); goto tx_error; } } #endif /* From world but DNAT to loopback address? */ if (local && skb->dev && !(skb->dev->flags & IFF_LOOPBACK) && ipv6_addr_type(&rt->rt6i_dst.addr) & IPV6_ADDR_LOOPBACK) { IP_VS_DBG_RL_PKT(1, AF_INET6, pp, skb, 0, "ip_vs_nat_xmit_v6(): " "stopping DNAT to loopback address"); goto tx_error; } /* copy-on-write the packet before mangling it */ if (!skb_make_writable(skb, sizeof(struct ipv6hdr))) goto tx_error; if (skb_cow(skb, rt->dst.dev->hard_header_len)) goto tx_error; /* mangle the packet */ if (pp->dnat_handler && !pp->dnat_handler(skb, pp, cp, ipvsh)) goto tx_error; ipv6_hdr(skb)->daddr = cp->daddr.in6; IP_VS_DBG_PKT(10, AF_INET6, pp, skb, 0, "After DNAT"); /* FIXME: when application helper enlarges the packet and the length is larger than the MTU of outgoing device, there will be still MTU problem. */ /* Another hack: avoid icmp_send in ip_fragment */ skb->local_df = 1; rc = ip_vs_nat_send_or_cont(NFPROTO_IPV6, skb, cp, local); rcu_read_unlock(); LeaveFunction(10); return rc; tx_error: LeaveFunction(10); kfree_skb(skb); rcu_read_unlock(); return NF_STOLEN; }