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>
---
v2: style fix
v3: change dest->tun_type checks to else if statement
---
include/uapi/linux/ip_vs.h | 1 +
net/netfilter/ipvs/ip_vs_ctl.c | 1 +
net/netfilter/ipvs/ip_vs_xmit.c | 66 +++++++++++++++++++++++++++++++++++++++--
3 files changed, 65 insertions(+), 3 deletions(-)
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_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 84384d8..998353b 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -525,6 +525,7 @@ static void ip_vs_rs_hash(struct netns_ipvs *ipvs, struct ip_vs_dest *dest)
port = dest->tun_port;
break;
case IP_VS_CONN_F_TUNNEL_TYPE_IPIP:
+ case IP_VS_CONN_F_TUNNEL_TYPE_GRE:
port = 0;
break;
default:
diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c
index 71fc6d6..9c464d2 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 */
@@ -388,6 +389,12 @@ static inline bool decrement_ttl(struct netns_ipvs *ipvs,
IP_VS_TUNNEL_ENCAP_FLAG_REMCSUM) &&
skb->ip_summed == CHECKSUM_PARTIAL)
mtu -= GUE_PLEN_REMCSUM + GUE_LEN_PRIV;
+ } else 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__);
@@ -548,6 +555,12 @@ static inline bool decrement_ttl(struct netns_ipvs *ipvs,
IP_VS_TUNNEL_ENCAP_FLAG_REMCSUM) &&
skb->ip_summed == CHECKSUM_PARTIAL)
mtu -= GUE_PLEN_REMCSUM + GUE_LEN_PRIV;
+ } else 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__,
@@ -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)
+{
+ __be16 proto = *next_protocol == IPPROTO_IPIP ?
+ htons(ETH_P_IP) : htons(ETH_P_IPV6);
+ __be16 tflags = 0;
+ size_t hdrlen;
+
+ 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
*
@@ -1151,6 +1182,15 @@ static inline int __tun_gso_type_mask(int encaps_af, int orig_af)
gue_hdrlen = sizeof(struct guehdr) + gue_optlen;
max_headroom += sizeof(struct udphdr) + gue_hdrlen;
+ } else 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 */
@@ -1172,6 +1212,11 @@ static inline int __tun_gso_type_mask(int encaps_af, int orig_af)
skb->ip_summed == CHECKSUM_PARTIAL) {
gso_type |= SKB_GSO_TUNNEL_REMCSUM;
}
+ } else 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))
@@ -1192,8 +1237,8 @@ static inline int __tun_gso_type_mask(int encaps_af, int orig_af)
check = true;
udp_set_csum(!check, skb, saddr, cp->daddr.ip, skb->len);
- }
-
+ } else 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);
@@ -1287,6 +1332,15 @@ static inline int __tun_gso_type_mask(int encaps_af, int orig_af)
gue_hdrlen = sizeof(struct guehdr) + gue_optlen;
max_headroom += sizeof(struct udphdr) + gue_hdrlen;
+ } else 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,
@@ -1306,6 +1360,11 @@ static inline int __tun_gso_type_mask(int encaps_af, int orig_af)
skb->ip_summed == CHECKSUM_PARTIAL) {
gso_type |= SKB_GSO_TUNNEL_REMCSUM;
}
+ } else 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))
@@ -1326,7 +1385,8 @@ static inline int __tun_gso_type_mask(int encaps_af, int orig_af)
check = true;
udp6_set_csum(!check, skb, &saddr, &cp->daddr.in6, skb->len);
- }
+ } else 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);
--
1.9.1
