static int ip_tunnel_bind_dev(struct net_device *dev) { struct net_device *tdev = NULL; struct ip_tunnel *tunnel = netdev_priv(dev); const struct iphdr *iph; int hlen = LL_MAX_HEADER; int mtu = ETH_DATA_LEN; int t_hlen = tunnel->hlen + sizeof(struct iphdr); iph = &tunnel->parms.iph; /* Guess output device to choose reasonable mtu and needed_headroom */ if (iph->daddr) { struct flowi4 fl4; struct rtable *rt; rt = ip_route_output_tunnel(dev_net(dev), &fl4, tunnel->parms.iph.protocol, iph->daddr, iph->saddr, tunnel->parms.o_key, RT_TOS(iph->tos), tunnel->parms.link); if (!IS_ERR(rt)) { tdev = rt->dst.dev; ip_rt_put(rt); } if (dev->type != ARPHRD_ETHER) dev->flags |= IFF_POINTOPOINT; } if (!tdev && tunnel->parms.link) tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link); if (tdev) { hlen = tdev->hard_header_len + tdev->needed_headroom; mtu = tdev->mtu; } dev->iflink = tunnel->parms.link; dev->needed_headroom = t_hlen + hlen; mtu -= (dev->hard_header_len + t_hlen); if (mtu < 68) mtu = 68; return mtu; }
void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, const struct iphdr *tnl_params, const u8 protocol) { struct ip_tunnel *tunnel = netdev_priv(dev); const struct iphdr *inner_iph; struct flowi4 fl4; u8 tos, ttl; __be16 df; struct rtable *rt; /* Route to the other host */ unsigned int max_headroom; /* The extra header space needed */ __be32 dst; int err; inner_iph = (const struct iphdr *)skb_inner_network_header(skb); dst = tnl_params->daddr; if (dst == 0) { /* NBMA tunnel */ if (skb_dst(skb) == NULL) { dev->stats.tx_fifo_errors++; goto tx_error; } if (skb->protocol == htons(ETH_P_IP)) { rt = skb_rtable(skb); dst = rt_nexthop(rt, inner_iph->daddr); } #if IS_ENABLED(CONFIG_IPV6) else if (skb->protocol == htons(ETH_P_IPV6)) { const struct in6_addr *addr6; struct neighbour *neigh; bool do_tx_error_icmp; int addr_type; neigh = dst_neigh_lookup(skb_dst(skb), &ipv6_hdr(skb)->daddr); if (neigh == NULL) goto tx_error; addr6 = (const struct in6_addr *)&neigh->primary_key; addr_type = ipv6_addr_type(addr6); if (addr_type == IPV6_ADDR_ANY) { addr6 = &ipv6_hdr(skb)->daddr; addr_type = ipv6_addr_type(addr6); } if ((addr_type & IPV6_ADDR_COMPATv4) == 0) do_tx_error_icmp = true; else { do_tx_error_icmp = false; dst = addr6->s6_addr32[3]; } neigh_release(neigh); if (do_tx_error_icmp) goto tx_error_icmp; } #endif else goto tx_error; } tos = tnl_params->tos; if (tos & 0x1) { tos &= ~0x1; if (skb->protocol == htons(ETH_P_IP)) tos = inner_iph->tos; else if (skb->protocol == htons(ETH_P_IPV6)) tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph); } rt = ip_route_output_tunnel(tunnel->net, &fl4, protocol, dst, tnl_params->saddr, tunnel->parms.o_key, RT_TOS(tos), tunnel->parms.link); if (IS_ERR(rt)) { dev->stats.tx_carrier_errors++; goto tx_error; } if (rt->dst.dev == dev) { ip_rt_put(rt); dev->stats.collisions++; goto tx_error; } if (tnl_update_pmtu(dev, skb, rt, tnl_params->frag_off)) { ip_rt_put(rt); goto tx_error; } if (tunnel->net != dev_net(dev)) skb_scrub_packet(skb); if (tunnel->err_count > 0) { if (time_before(jiffies, tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { tunnel->err_count--; dst_link_failure(skb); } else tunnel->err_count = 0; } tos = ip_tunnel_ecn_encap(tos, inner_iph, skb); ttl = tnl_params->ttl; if (ttl == 0) { if (skb->protocol == htons(ETH_P_IP)) ttl = inner_iph->ttl; #if IS_ENABLED(CONFIG_IPV6) else if (skb->protocol == htons(ETH_P_IPV6)) ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit; #endif else ttl = ip4_dst_hoplimit(&rt->dst); } df = tnl_params->frag_off; if (skb->protocol == htons(ETH_P_IP)) df |= (inner_iph->frag_off&htons(IP_DF)); max_headroom = LL_RESERVED_SPACE(rt->dst.dev) + sizeof(struct iphdr) + rt->dst.header_len; if (max_headroom > dev->needed_headroom) dev->needed_headroom = max_headroom; if (skb_cow_head(skb, dev->needed_headroom)) { dev->stats.tx_dropped++; dev_kfree_skb(skb); return; } err = iptunnel_xmit(dev_net(dev), rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl, df); iptunnel_xmit_stats(err, &dev->stats, dev->tstats); return; #if IS_ENABLED(CONFIG_IPV6) tx_error_icmp: dst_link_failure(skb); #endif tx_error: dev->stats.tx_errors++; dev_kfree_skb(skb); }
void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, const struct iphdr *tnl_params) { struct ip_tunnel *tunnel = netdev_priv(dev); const struct iphdr *inner_iph; struct iphdr *iph; struct flowi4 fl4; u8 tos, ttl; __be16 df; struct rtable *rt; /* Route to the other host */ struct net_device *tdev; /* Device to other host */ unsigned int max_headroom; /* The extra header space needed */ __be32 dst; int mtu; inner_iph = (const struct iphdr *)skb_inner_network_header(skb); memset(IPCB(skb), 0, sizeof(*IPCB(skb))); dst = tnl_params->daddr; if (dst == 0) { /* NBMA tunnel */ if (skb_dst(skb) == NULL) { dev->stats.tx_fifo_errors++; goto tx_error; } if (skb->protocol == htons(ETH_P_IP)) { rt = skb_rtable(skb); dst = rt_nexthop(rt, inner_iph->daddr); } #if IS_ENABLED(CONFIG_IPV6) else if (skb->protocol == htons(ETH_P_IPV6)) { const struct in6_addr *addr6; struct neighbour *neigh; bool do_tx_error_icmp; int addr_type; neigh = dst_neigh_lookup(skb_dst(skb), &ipv6_hdr(skb)->daddr); if (neigh == NULL) goto tx_error; addr6 = (const struct in6_addr *)&neigh->primary_key; addr_type = ipv6_addr_type(addr6); if (addr_type == IPV6_ADDR_ANY) { addr6 = &ipv6_hdr(skb)->daddr; addr_type = ipv6_addr_type(addr6); } if ((addr_type & IPV6_ADDR_COMPATv4) == 0) do_tx_error_icmp = true; else { do_tx_error_icmp = false; dst = addr6->s6_addr32[3]; } neigh_release(neigh); if (do_tx_error_icmp) goto tx_error_icmp; } #endif else goto tx_error; } tos = tnl_params->tos; if (tos & 0x1) { tos &= ~0x1; if (skb->protocol == htons(ETH_P_IP)) tos = inner_iph->tos; else if (skb->protocol == htons(ETH_P_IPV6)) tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph); } rt = ip_route_output_tunnel(dev_net(dev), &fl4, tunnel->parms.iph.protocol, dst, tnl_params->saddr, tunnel->parms.o_key, RT_TOS(tos), tunnel->parms.link); if (IS_ERR(rt)) { dev->stats.tx_carrier_errors++; goto tx_error; } tdev = rt->dst.dev; if (tdev == dev) { ip_rt_put(rt); dev->stats.collisions++; goto tx_error; } df = tnl_params->frag_off; if (df) mtu = dst_mtu(&rt->dst) - dev->hard_header_len - sizeof(struct iphdr); else mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu; if (skb_dst(skb)) skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu); if (skb->protocol == htons(ETH_P_IP)) { df |= (inner_iph->frag_off&htons(IP_DF)); if (!skb_is_gso(skb) && (inner_iph->frag_off&htons(IP_DF)) && mtu < ntohs(inner_iph->tot_len)) { icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); ip_rt_put(rt); goto tx_error; } } #if IS_ENABLED(CONFIG_IPV6) else if (skb->protocol == htons(ETH_P_IPV6)) { struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb); if (rt6 && mtu < dst_mtu(skb_dst(skb)) && mtu >= IPV6_MIN_MTU) { if ((tunnel->parms.iph.daddr && !ipv4_is_multicast(tunnel->parms.iph.daddr)) || rt6->rt6i_dst.plen == 128) { rt6->rt6i_flags |= RTF_MODIFIED; dst_metric_set(skb_dst(skb), RTAX_MTU, mtu); } } if (!skb_is_gso(skb) && mtu >= IPV6_MIN_MTU && mtu < skb->len) { icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); ip_rt_put(rt); goto tx_error; } } #endif if (tunnel->err_count > 0) { if (time_before(jiffies, tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { tunnel->err_count--; dst_link_failure(skb); } else tunnel->err_count = 0; } ttl = tnl_params->ttl; if (ttl == 0) { if (skb->protocol == htons(ETH_P_IP)) ttl = inner_iph->ttl; #if IS_ENABLED(CONFIG_IPV6) else if (skb->protocol == htons(ETH_P_IPV6)) ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit; #endif else ttl = ip4_dst_hoplimit(&rt->dst); } max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(struct iphdr) + rt->dst.header_len; if (max_headroom > dev->needed_headroom) { dev->needed_headroom = max_headroom; if (skb_cow_head(skb, dev->needed_headroom)) { dev->stats.tx_dropped++; dev_kfree_skb(skb); return; } } skb_dst_drop(skb); skb_dst_set(skb, &rt->dst); /* Push down and install the IP header. */ skb_push(skb, sizeof(struct iphdr)); skb_reset_network_header(skb); iph = ip_hdr(skb); inner_iph = (const struct iphdr *)skb_inner_network_header(skb); iph->version = 4; iph->ihl = sizeof(struct iphdr) >> 2; iph->frag_off = df; iph->protocol = tnl_params->protocol; iph->tos = ip_tunnel_ecn_encap(tos, inner_iph, skb); iph->daddr = fl4.daddr; iph->saddr = fl4.saddr; iph->ttl = ttl; tunnel_ip_select_ident(skb, inner_iph, &rt->dst); iptunnel_xmit(skb, dev); return; #if IS_ENABLED(CONFIG_IPV6) tx_error_icmp: dst_link_failure(skb); #endif tx_error: dev->stats.tx_errors++; dev_kfree_skb(skb); }