windows real servers can handle gre tunnels, this patch allows
gre encapsulation with the tunneling method, thereby letting ipvs
be load balancer for windows-based services
Signed-off-by: Vadim Fedorenko <vfedorenko@xxxxxxxxxxxxxx>
---
include/uapi/linux/ip_vs.h | 1 +
net/netfilter/ipvs/ip_vs_xmit.c | 76 +++++++++++++++++++++++++++++++++++++++++
2 files changed, 77 insertions(+)
diff --git a/include/uapi/linux/ip_vs.h b/include/uapi/linux/ip_vs.h
index e4f1806..4102ddc 100644
--- a/include/uapi/linux/ip_vs.h
+++ b/include/uapi/linux/ip_vs.h
@@ -128,6 +128,7 @@
enum {
IP_VS_CONN_F_TUNNEL_TYPE_IPIP = 0, /* IPIP */
IP_VS_CONN_F_TUNNEL_TYPE_GUE, /* GUE */
+ IP_VS_CONN_F_TUNNEL_TYPE_GRE, /* GRE */
IP_VS_CONN_F_TUNNEL_TYPE_MAX,
};
diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c
index 71fc6d6..fad3f33 100644
--- a/net/netfilter/ipvs/ip_vs_xmit.c
+++ b/net/netfilter/ipvs/ip_vs_xmit.c
@@ -29,6 +29,7 @@
#include <linux/tcp.h> /* for tcphdr */
#include <net/ip.h>
#include <net/gue.h>
+#include <net/gre.h>
#include <net/tcp.h> /* for csum_tcpudp_magic */
#include <net/udp.h>
#include <net/icmp.h> /* for icmp_send */
@@ -389,6 +390,12 @@ static inline bool decrement_ttl(struct netns_ipvs *ipvs,
skb->ip_summed == CHECKSUM_PARTIAL)
mtu -= GUE_PLEN_REMCSUM + GUE_LEN_PRIV;
}
+ if (dest->tun_type == IP_VS_CONN_F_TUNNEL_TYPE_GRE) {
+ __be16 tflags = 0;
+ if (dest->tun_flags & IP_VS_TUNNEL_ENCAP_FLAG_CSUM)
+ tflags |= TUNNEL_CSUM;
+ mtu -= gre_calc_hlen(tflags);
+ }
if (mtu < 68) {
IP_VS_DBG_RL("%s(): mtu less than 68\n", __func__);
goto err_put;
@@ -549,6 +556,12 @@ static inline bool decrement_ttl(struct netns_ipvs *ipvs,
skb->ip_summed == CHECKSUM_PARTIAL)
mtu -= GUE_PLEN_REMCSUM + GUE_LEN_PRIV;
}
+ if (dest->tun_type == IP_VS_CONN_F_TUNNEL_TYPE_GRE) {
+ __be16 tflags = 0;
+ if (dest->tun_flags & IP_VS_TUNNEL_ENCAP_FLAG_CSUM)
+ tflags |= TUNNEL_CSUM;
+ mtu -= gre_calc_hlen(tflags);
+ }
if (mtu < IPV6_MIN_MTU) {
IP_VS_DBG_RL("%s(): mtu less than %d\n", __func__,
IPV6_MIN_MTU);
@@ -1079,6 +1092,24 @@ static inline int __tun_gso_type_mask(int encaps_af, int
orig_af)
return 0;
}
+static void
+ipvs_gre_encap(struct net *net, struct sk_buff *skb,
+ struct ip_vs_conn *cp, __u8 *next_protocol)
+{
+ size_t hdrlen;
+ __be16 tflags = 0;
+ __be16 proto = *next_protocol == IPPROTO_IPIP ? htons(ETH_P_IP) :
htons(ETH_P_IPV6);
+
+ if (cp->dest->tun_flags & IP_VS_TUNNEL_ENCAP_FLAG_CSUM)
+ tflags |= TUNNEL_CSUM;
+
+ hdrlen = gre_calc_hlen(tflags);
+
+ gre_build_header(skb, hdrlen, tflags, proto, 0, 0);
+
+ *next_protocol = IPPROTO_GRE;
+}
+
/*
* IP Tunneling transmitter
*
@@ -1153,6 +1184,18 @@ static inline int __tun_gso_type_mask(int encaps_af, int
orig_af)
max_headroom += sizeof(struct udphdr) + gue_hdrlen;
}
+ if (tun_type == IP_VS_CONN_F_TUNNEL_TYPE_GRE) {
+ size_t gre_hdrlen;
+ __be16 tflags = 0;
+
+ if (tun_flags & IP_VS_TUNNEL_ENCAP_FLAG_CSUM)
+ tflags |= TUNNEL_CSUM;
+
+ gre_hdrlen = gre_calc_hlen(tflags);
+
+ max_headroom += gre_hdrlen;
+ }
+
/* We only care about the df field if sysctl_pmtu_disc(ipvs) is set */
dfp = sysctl_pmtu_disc(ipvs) ? &df : NULL;
skb = ip_vs_prepare_tunneled_skb(skb, cp->af, max_headroom,
@@ -1174,6 +1217,13 @@ static inline int __tun_gso_type_mask(int encaps_af, int
orig_af)
}
}
+ if (tun_type == IP_VS_CONN_F_TUNNEL_TYPE_GRE) {
+ if (tun_flags & IP_VS_TUNNEL_ENCAP_FLAG_CSUM)
+ gso_type |= SKB_GSO_GRE_CSUM;
+ else
+ gso_type |= SKB_GSO_GRE;
+ }
+
if (iptunnel_handle_offloads(skb, gso_type))
goto tx_error;
@@ -1194,6 +1244,9 @@ static inline int __tun_gso_type_mask(int encaps_af, int
orig_af)
udp_set_csum(!check, skb, saddr, cp->daddr.ip, skb->len);
}
+ if (tun_type == IP_VS_CONN_F_TUNNEL_TYPE_GRE) {
+ ipvs_gre_encap(net, skb, cp, &next_protocol);
+ }
skb_push(skb, sizeof(struct iphdr));
skb_reset_network_header(skb);
@@ -1289,6 +1342,18 @@ static inline int __tun_gso_type_mask(int encaps_af, int
orig_af)
max_headroom += sizeof(struct udphdr) + gue_hdrlen;
}
+ if (tun_type == IP_VS_CONN_F_TUNNEL_TYPE_GRE) {
+ size_t gre_hdrlen;
+ __be16 tflags = 0;
+
+ if (tun_flags & IP_VS_TUNNEL_ENCAP_FLAG_CSUM)
+ tflags |= TUNNEL_CSUM;
+
+ gre_hdrlen = gre_calc_hlen(tflags);
+
+ max_headroom += gre_hdrlen;
+ }
+
skb = ip_vs_prepare_tunneled_skb(skb, cp->af, max_headroom,
&next_protocol, &payload_len,
&dsfield, &ttl, NULL);
@@ -1308,6 +1373,13 @@ static inline int __tun_gso_type_mask(int encaps_af, int
orig_af)
}
}
+ if (tun_type == IP_VS_CONN_F_TUNNEL_TYPE_GRE) {
+ if (tun_flags & IP_VS_TUNNEL_ENCAP_FLAG_CSUM)
+ gso_type |= SKB_GSO_GRE_CSUM;
+ else
+ gso_type |= SKB_GSO_GRE;
+ }
+
if (iptunnel_handle_offloads(skb, gso_type))
goto tx_error;
@@ -1328,6 +1400,10 @@ static inline int __tun_gso_type_mask(int encaps_af, int
orig_af)
udp6_set_csum(!check, skb, &saddr, &cp->daddr.in6, skb->len);
}
+ if (tun_type == IP_VS_CONN_F_TUNNEL_TYPE_GRE) {
+ ipvs_gre_encap(net, skb, cp, &next_protocol);
+ }
+
skb_push(skb, sizeof(struct ipv6hdr));
skb_reset_network_header(skb);
memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
--
1.9.1
