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synced 2024-08-26 02:39:48 +00:00
ipvs: Add generic ensure_mtu_is_adequate to handle mixed pools
The out_rt functions check to see if the mtu is large enough for the packet and, if not, send icmp messages (TOOBIG or DEST_UNREACH) to the source and bail out. We needed the ability to send ICMP from the out_rt_v6 function and DEST_UNREACH from the out_rt function, so we just pulled it out into a common function. Signed-off-by: Alex Gartrell <agartrell@fb.com> Acked-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au>
This commit is contained in:
parent
919aa0b2bb
commit
c63e4de2be
1 changed files with 51 additions and 26 deletions
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@ -213,17 +213,57 @@ static inline void maybe_update_pmtu(int skb_af, struct sk_buff *skb, int mtu)
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ort->dst.ops->update_pmtu(&ort->dst, sk, NULL, mtu);
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}
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static inline bool ensure_mtu_is_adequate(int skb_af, int rt_mode,
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struct ip_vs_iphdr *ipvsh,
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struct sk_buff *skb, int mtu)
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{
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#ifdef CONFIG_IP_VS_IPV6
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if (skb_af == AF_INET6) {
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struct net *net = dev_net(skb_dst(skb)->dev);
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if (unlikely(__mtu_check_toobig_v6(skb, mtu))) {
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if (!skb->dev)
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skb->dev = net->loopback_dev;
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/* only send ICMP too big on first fragment */
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if (!ipvsh->fragoffs)
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icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
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IP_VS_DBG(1, "frag needed for %pI6c\n",
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&ipv6_hdr(skb)->saddr);
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return false;
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}
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} else
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#endif
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{
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struct netns_ipvs *ipvs = net_ipvs(skb_net(skb));
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/* If we're going to tunnel the packet and pmtu discovery
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* is disabled, we'll just fragment it anyway
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*/
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if ((rt_mode & IP_VS_RT_MODE_TUNNEL) && !sysctl_pmtu_disc(ipvs))
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return true;
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if (unlikely(ip_hdr(skb)->frag_off & htons(IP_DF) &&
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skb->len > mtu && !skb_is_gso(skb))) {
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icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
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htonl(mtu));
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IP_VS_DBG(1, "frag needed for %pI4\n",
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&ip_hdr(skb)->saddr);
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return false;
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}
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}
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return true;
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}
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/* Get route to destination or remote server */
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static int
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__ip_vs_get_out_rt(int skb_af, struct sk_buff *skb, struct ip_vs_dest *dest,
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__be32 daddr, int rt_mode, __be32 *ret_saddr)
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__be32 daddr, int rt_mode, __be32 *ret_saddr,
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struct ip_vs_iphdr *ipvsh)
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{
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struct net *net = dev_net(skb_dst(skb)->dev);
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struct netns_ipvs *ipvs = net_ipvs(net);
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struct ip_vs_dest_dst *dest_dst;
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struct rtable *rt; /* Route to the other host */
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struct iphdr *iph;
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__be16 df;
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int mtu;
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int local, noref = 1;
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@ -279,7 +319,6 @@ __ip_vs_get_out_rt(int skb_af, struct sk_buff *skb, struct ip_vs_dest *dest,
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" daddr=%pI4\n", &dest->addr.ip);
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goto err_put;
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}
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iph = ip_hdr(skb);
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if (unlikely(local)) {
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/* skb to local stack, preserve old route */
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@ -290,7 +329,6 @@ __ip_vs_get_out_rt(int skb_af, struct sk_buff *skb, struct ip_vs_dest *dest,
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if (likely(!(rt_mode & IP_VS_RT_MODE_TUNNEL))) {
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mtu = dst_mtu(&rt->dst);
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df = iph->frag_off & htons(IP_DF);
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} else {
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mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);
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if (mtu < 68) {
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@ -298,16 +336,10 @@ __ip_vs_get_out_rt(int skb_af, struct sk_buff *skb, struct ip_vs_dest *dest,
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goto err_put;
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}
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maybe_update_pmtu(skb_af, skb, mtu);
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/* MTU check allowed? */
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df = sysctl_pmtu_disc(ipvs) ? iph->frag_off & htons(IP_DF) : 0;
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}
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/* MTU checking */
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if (unlikely(df && skb->len > mtu && !skb_is_gso(skb))) {
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icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
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IP_VS_DBG(1, "frag needed for %pI4\n", &iph->saddr);
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if (!ensure_mtu_is_adequate(skb_af, rt_mode, ipvsh, skb, mtu))
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goto err_put;
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}
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skb_dst_drop(skb);
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if (noref) {
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@ -450,15 +482,8 @@ __ip_vs_get_out_rt_v6(int skb_af, struct sk_buff *skb, struct ip_vs_dest *dest,
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maybe_update_pmtu(skb_af, skb, mtu);
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}
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if (unlikely(__mtu_check_toobig_v6(skb, mtu))) {
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if (!skb->dev)
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skb->dev = net->loopback_dev;
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/* only send ICMP too big on first fragment */
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if (!ipvsh->fragoffs)
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icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
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IP_VS_DBG(1, "frag needed for %pI6c\n", &ipv6_hdr(skb)->saddr);
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if (!ensure_mtu_is_adequate(skb_af, rt_mode, ipvsh, skb, mtu))
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goto err_put;
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}
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skb_dst_drop(skb);
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if (noref) {
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@ -565,7 +590,7 @@ ip_vs_bypass_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
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rcu_read_lock();
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if (__ip_vs_get_out_rt(cp->af, skb, NULL, iph->daddr,
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IP_VS_RT_MODE_NON_LOCAL, NULL) < 0)
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IP_VS_RT_MODE_NON_LOCAL, NULL, ipvsh) < 0)
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goto tx_error;
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ip_send_check(iph);
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@ -644,7 +669,7 @@ ip_vs_nat_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
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local = __ip_vs_get_out_rt(cp->af, skb, cp->dest, cp->daddr.ip,
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IP_VS_RT_MODE_LOCAL |
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IP_VS_RT_MODE_NON_LOCAL |
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IP_VS_RT_MODE_RDR, NULL);
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IP_VS_RT_MODE_RDR, NULL, ipvsh);
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if (local < 0)
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goto tx_error;
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rt = skb_rtable(skb);
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@ -841,7 +866,7 @@ ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
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IP_VS_RT_MODE_LOCAL |
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IP_VS_RT_MODE_NON_LOCAL |
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IP_VS_RT_MODE_CONNECT |
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IP_VS_RT_MODE_TUNNEL, &saddr);
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IP_VS_RT_MODE_TUNNEL, &saddr, ipvsh);
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if (local < 0)
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goto tx_error;
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if (local) {
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@ -1032,7 +1057,7 @@ ip_vs_dr_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
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local = __ip_vs_get_out_rt(cp->af, skb, cp->dest, cp->daddr.ip,
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IP_VS_RT_MODE_LOCAL |
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IP_VS_RT_MODE_NON_LOCAL |
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IP_VS_RT_MODE_KNOWN_NH, NULL);
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IP_VS_RT_MODE_KNOWN_NH, NULL, ipvsh);
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if (local < 0)
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goto tx_error;
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if (local) {
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@ -1137,7 +1162,7 @@ ip_vs_icmp_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
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IP_VS_RT_MODE_RDR : IP_VS_RT_MODE_NON_LOCAL;
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rcu_read_lock();
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local = __ip_vs_get_out_rt(cp->af, skb, cp->dest, cp->daddr.ip, rt_mode,
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NULL);
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NULL, iph);
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if (local < 0)
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goto tx_error;
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rt = skb_rtable(skb);
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