Re: [PATCH v5] ipvs: allow tunneling with gue encapsulation

Simon Horman
2019-03-25T16:37:29Z

On Mon, Mar 25, 2019 at 08:56:08PM +0800, Jacky Hu wrote:
> On Mon, Mar 25, 2019 at 11:46:40AM +0100, Simon Horman wrote:
> > On Tue, Mar 19, 2019 at 01:26:55PM +0800, Jacky Hu wrote:
> > > ipip packets are blocked in some public cloud environments, this patch
> > > allows gue encapsulation with the tunneling method, which would make
> > > tunneling working in those environments.
> > >
> > > Signed-off-by: Jacky Hu <hengqing.hu@gmail.com>
> > > ---
> > > include/net/ip_vs.h | 5 ++
> > > include/uapi/linux/ip_vs.h | 11 +++
> > > net/netfilter/ipvs/ip_vs_ctl.c | 43 ++++++++++-
> > > net/netfilter/ipvs/ip_vs_xmit.c | 124 ++++++++++++++++++++++++++++++--
> > > 4 files changed, 178 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
> > > index a0d2e0bb9a94..cdc7b621930d 100644
> > > --- a/include/net/ip_vs.h
> > > +++ b/include/net/ip_vs.h
> > > @@ -603,6 +603,9 @@ struct ip_vs_dest_user_kern {
> > >
> > > /* Address family of addr */
> > > u16 af;
> > > +
> > > + u16 tun_type; /* tunnel type */
> > > + __be16 tun_port; /* tunnel port */
> > > };
> > >
> > >
> > > @@ -663,6 +666,8 @@ struct ip_vs_dest {
> > > atomic_t conn_flags; /* flags to copy to conn */
> > > atomic_t weight; /* server weight */
> > > atomic_t last_weight; /* server latest weight */
> > > + __u16 tun_type; /* tunnel type */
> > > + __be16 tun_port; /* tunnel port */
> > >
> > > refcount_t refcnt; /* reference counter */
> > > struct ip_vs_stats stats; /* statistics */
> > > diff --git a/include/uapi/linux/ip_vs.h b/include/uapi/linux/ip_vs.h
> > > index 1c916b2f89dc..e34f436fc79d 100644
> > > --- a/include/uapi/linux/ip_vs.h
> > > +++ b/include/uapi/linux/ip_vs.h
> > > @@ -124,6 +124,13 @@
> > >
> > > #define IP_VS_PEDATA_MAXLEN 255
> > >
> > > +/* Tunnel types */
> > > +enum {
> > > + IP_VS_CONN_F_TUNNEL_TYPE_IPIP = 0, /* IPIP */
> > > + IP_VS_CONN_F_TUNNEL_TYPE_GUE, /* GUE */
> > > + IP_VS_CONN_F_TUNNEL_TYPE_MAX,
> > > +};
> > > +
> > > /*
> > > * The struct ip_vs_service_user and struct ip_vs_dest_user are
> > > * used to set IPVS rules through setsockopt.
> > > @@ -392,6 +399,10 @@ enum {
> > >
> > > IPVS_DEST_ATTR_STATS64, /* nested attribute for dest stats */
> > >
> > > + IPVS_DEST_ATTR_TUN_TYPE, /* tunnel type */
> > > +
> > > + IPVS_DEST_ATTR_TUN_PORT, /* tunnel port */
> > > +
> > > __IPVS_DEST_ATTR_MAX,
> > > };
> > >
> > > diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
> > > index 432141f04af3..ddee6266b78b 100644
> > > --- a/net/netfilter/ipvs/ip_vs_ctl.c
> > > +++ b/net/netfilter/ipvs/ip_vs_ctl.c
> > > @@ -830,6 +830,10 @@ __ip_vs_update_dest(struct ip_vs_service *svc, struct ip_vs_dest *dest,
> > > conn_flags = udest->conn_flags & IP_VS_CONN_F_DEST_MASK;
> > > conn_flags |= IP_VS_CONN_F_INACTIVE;
> > >
> > > + /* set the tunnel info */
> > > + dest->tun_type = udest->tun_type;
> > > + dest->tun_port = udest->tun_port;
> > > +
> > > /* set the IP_VS_CONN_F_NOOUTPUT flag if not masquerading/NAT */
> > > if ((conn_flags & IP_VS_CONN_F_FWD_MASK) != IP_VS_CONN_F_MASQ) {
> > > conn_flags |= IP_VS_CONN_F_NOOUTPUT;
> > > @@ -980,6 +984,17 @@ ip_vs_add_dest(struct ip_vs_service *svc, struct ip_vs_dest_user_kern *udest)
> > > return -ERANGE;
> > > }
> > >
> > > + switch (udest->tun_type) {
> > > + case IP_VS_CONN_F_TUNNEL_TYPE_GUE:
> >
> > Given that tun_type check acts on an integer, as opposed to an enum,
> > I don't see that using a switch statement gives us much here,
> > and throughout the patch, other than extra verbosity.
> >
> > Did you consider simply using an if statement?
> >
> I was thinking about maybe IP_VS_CONN_F_TUNNEL_TYPE_FOU would be introduced
> later.
> But yes, I can simply using an if statement if you think that's more
> appropriate.

Thanks, I think that would be best.

We can always change the code to use a switch statement later if
more cases need to be handled.

> > > + if (udest->tun_port == 0) {
> > > + pr_err("%s(): tunnel port is zero\n", __func__);
> > > + return -EINVAL;
> > > + }
> > > + break;
> > > + default:
> > > + break;
> > > + }
> > > +
> > > ip_vs_addr_copy(udest->af, &daddr, &udest->addr);
> > >
> > > /* We use function that requires RCU lock */
> > > @@ -1044,6 +1059,17 @@ ip_vs_edit_dest(struct ip_vs_service *svc, struct ip_vs_dest_user_kern *udest)
> > > return -ERANGE;
> > > }
> > >
> > > + switch (udest->tun_type) {
> > > + case IP_VS_CONN_F_TUNNEL_TYPE_GUE:
> > > + if (udest->tun_port == 0) {
> > > + pr_err("%s(): tunnel port is zero\n", __func__);
> > > + return -EINVAL;
> > > + }
> > > + break;
> > > + default:
> > > + break;
> > > + }
> > > +
> > > ip_vs_addr_copy(udest->af, &daddr, &udest->addr);
> > >
> > > /* We use function that requires RCU lock */
> > > @@ -2310,6 +2336,7 @@ static void ip_vs_copy_udest_compat(struct ip_vs_dest_user_kern *udest,
> > > udest->u_threshold = udest_compat->u_threshold;
> > > udest->l_threshold = udest_compat->l_threshold;
> > > udest->af = AF_INET;
> > > + udest->tun_type = IP_VS_CONN_F_TUNNEL_TYPE_IPIP;
> > > }
> > >
> > > static int
> > > @@ -2869,6 +2896,8 @@ static const struct nla_policy ip_vs_dest_policy[IPVS_DEST_ATTR_MAX + 1] = {
> > > [IPVS_DEST_ATTR_PERSIST_CONNS] = { .type = NLA_U32 },
> > > [IPVS_DEST_ATTR_STATS] = { .type = NLA_NESTED },
> > > [IPVS_DEST_ATTR_ADDR_FAMILY] = { .type = NLA_U16 },
> > > + [IPVS_DEST_ATTR_TUN_TYPE] = { .type = NLA_U8 },
> > > + [IPVS_DEST_ATTR_TUN_PORT] = { .type = NLA_U16 },
> > > };
> > >
> > > static int ip_vs_genl_fill_stats(struct sk_buff *skb, int container_type,
> > > @@ -3172,6 +3201,10 @@ static int ip_vs_genl_fill_dest(struct sk_buff *skb, struct ip_vs_dest *dest)
> > > IP_VS_CONN_F_FWD_MASK)) ||
> > > nla_put_u32(skb, IPVS_DEST_ATTR_WEIGHT,
> > > atomic_read(&dest->weight)) ||
> > > + nla_put_u8(skb, IPVS_DEST_ATTR_TUN_TYPE,
> > > + dest->tun_type) ||
> > > + nla_put_be16(skb, IPVS_DEST_ATTR_TUN_PORT,
> > > + dest->tun_port) ||
> > > nla_put_u32(skb, IPVS_DEST_ATTR_U_THRESH, dest->u_threshold) ||
> > > nla_put_u32(skb, IPVS_DEST_ATTR_L_THRESH, dest->l_threshold) ||
> > > nla_put_u32(skb, IPVS_DEST_ATTR_ACTIVE_CONNS,
> > > @@ -3294,12 +3327,14 @@ static int ip_vs_genl_parse_dest(struct ip_vs_dest_user_kern *udest,
> > > /* If a full entry was requested, check for the additional fields */
> > > if (full_entry) {
> > > struct nlattr *nla_fwd, *nla_weight, *nla_u_thresh,
> > > - *nla_l_thresh;
> > > + *nla_l_thresh, *nla_tun_type, *nla_tun_port;
> > >
> > > nla_fwd = attrs[IPVS_DEST_ATTR_FWD_METHOD];
> > > nla_weight = attrs[IPVS_DEST_ATTR_WEIGHT];
> > > nla_u_thresh = attrs[IPVS_DEST_ATTR_U_THRESH];
> > > nla_l_thresh = attrs[IPVS_DEST_ATTR_L_THRESH];
> > > + nla_tun_type = attrs[IPVS_DEST_ATTR_TUN_TYPE];
> > > + nla_tun_port = attrs[IPVS_DEST_ATTR_TUN_PORT];
> > >
> > > if (!(nla_fwd && nla_weight && nla_u_thresh && nla_l_thresh))
> > > return -EINVAL;
> > > @@ -3309,6 +3344,12 @@ static int ip_vs_genl_parse_dest(struct ip_vs_dest_user_kern *udest,
> > > udest->weight = nla_get_u32(nla_weight);
> > > udest->u_threshold = nla_get_u32(nla_u_thresh);
> > > udest->l_threshold = nla_get_u32(nla_l_thresh);
> > > +
> > > + if (nla_tun_type)
> > > + udest->tun_type = nla_get_u8(nla_tun_type);
> > > +
> > > + if (nla_tun_port)
> > > + udest->tun_port = nla_get_be16(nla_tun_port);
> > > }
> > >
> > > return 0;
> > > diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c
> > > index 473cce2a5231..730e108b9f36 100644
> > > --- a/net/netfilter/ipvs/ip_vs_xmit.c
> > > +++ b/net/netfilter/ipvs/ip_vs_xmit.c
> > > @@ -32,6 +32,7 @@
> > > #include <linux/slab.h>
> > > #include <linux/tcp.h> /* for tcphdr */
> > > #include <net/ip.h>
> > > +#include <net/gue.h>
> > > #include <net/tcp.h> /* for csum_tcpudp_magic */
> > > #include <net/udp.h>
> > > #include <net/icmp.h> /* for icmp_send */
> > > @@ -382,6 +383,15 @@ __ip_vs_get_out_rt(struct netns_ipvs *ipvs, int skb_af, struct sk_buff *skb,
> > > mtu = dst_mtu(&rt->dst);
> > > } else {
> > > mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);
> > > + if (!dest)
> > > + goto err_put;
> > > + switch (dest->tun_type) {
> > > + case IP_VS_CONN_F_TUNNEL_TYPE_GUE:
> > > + mtu -= sizeof(struct udphdr) + sizeof(struct guehdr);
> > > + break;
> > > + default:
> > > + break;
> > > + }
> > > if (mtu < 68) {
> > > IP_VS_DBG_RL("%s(): mtu less than 68\n", __func__);
> > > goto err_put;
> > > @@ -533,6 +543,15 @@ __ip_vs_get_out_rt_v6(struct netns_ipvs *ipvs, int skb_af, struct sk_buff *skb,
> > > mtu = dst_mtu(&rt->dst);
> > > else {
> > > mtu = dst_mtu(&rt->dst) - sizeof(struct ipv6hdr);
> > > + if (!dest)
> > > + goto err_put;
> > > + switch (dest->tun_type) {
> > > + case IP_VS_CONN_F_TUNNEL_TYPE_GUE:
> > > + mtu -= sizeof(struct udphdr) + sizeof(struct guehdr);
> > > + break;
> > > + default:
> > > + break;
> > > + }
> > > if (mtu < IPV6_MIN_MTU) {
> > > IP_VS_DBG_RL("%s(): mtu less than %d\n", __func__,
> > > IPV6_MIN_MTU);
> > > @@ -989,6 +1008,41 @@ static inline int __tun_gso_type_mask(int encaps_af, int orig_af)
> > > }
> > > }
> > >
> > > +static int
> > > +ipvs_gue_encap(struct net *net, struct sk_buff *skb,
> > > + struct ip_vs_conn *cp, __u8 *next_protocol)
> > > +{
> > > + __be16 dport;
> > > + __be16 sport = udp_flow_src_port(net, skb, 0, 0, false);
> > > + struct udphdr *udph; /* Our new UDP header */
> > > + struct guehdr *gueh; /* Our new GUE header */
> > > +
> > > + skb_push(skb, sizeof(struct guehdr));
> > > +
> > > + gueh = (struct guehdr *)skb->data;
> > > +
> > > + gueh->control = 0;
> > > + gueh->version = 0;
> > > + gueh->hlen = 0;
> > > + gueh->flags = 0;
> > > + gueh->proto_ctype = *next_protocol;
> > > +
> > > + skb_push(skb, sizeof(struct udphdr));
> > > + skb_reset_transport_header(skb);
> > > +
> > > + udph = udp_hdr(skb);
> > > +
> > > + dport = cp->dest->tun_port;
> > > + udph->dest = dport;
> > > + udph->source = sport;
> > > + udph->len = htons(skb->len);
> > > + udph->check = 0;
> > > +
> > > + *next_protocol = IPPROTO_UDP;
> > > +
> > > + return 0;
> > > +}
> > > +
> > > /*
> > > * IP Tunneling transmitter
> > > *
> > > @@ -1025,6 +1079,7 @@ ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
> > > struct iphdr *iph; /* Our new IP header */
> > > unsigned int max_headroom; /* The extra header space needed */
> > > int ret, local;
> > > + int tun_type, gso_type;
> > >
> > > EnterFunction(10);
> > >
> > > @@ -1046,6 +1101,16 @@ ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
> > > */
> > > max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(struct iphdr);
> > >
> > > + tun_type = cp->dest->tun_type;
> > > +
> > > + switch (tun_type) {
> > > + case IP_VS_CONN_F_TUNNEL_TYPE_GUE:
> > > + max_headroom += sizeof(struct udphdr) + sizeof(struct guehdr);
> > > + break;
> > > + default:
> > > + break;
> > > + }
> > > +
> > > /* 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,
> > > @@ -1054,11 +1119,30 @@ ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
> > > if (IS_ERR(skb))
> > > goto tx_error;
> > >
> > > - if (iptunnel_handle_offloads(skb, __tun_gso_type_mask(AF_INET, cp->af)))
> > > + switch (tun_type) {
> > > + case IP_VS_CONN_F_TUNNEL_TYPE_GUE:
> > > + gso_type = SKB_GSO_UDP_TUNNEL;
> > > + break;
> > > + default:
> > > + gso_type = __tun_gso_type_mask(AF_INET, cp->af);
> > > + break;
> > > + }
> > > +
> > > + if (iptunnel_handle_offloads(skb, gso_type))
> > > goto tx_error;
> > >
> > > skb->transport_header = skb->network_header;
> > >
> > > + skb_set_inner_ipproto(skb, next_protocol);
> > > +
> > > + switch (tun_type) {
> > > + case IP_VS_CONN_F_TUNNEL_TYPE_GUE:
> > > + ipvs_gue_encap(net, skb, cp, &next_protocol);
> > > + break;
> > > + default:
> > > + break;
> > > + }
> > > +
> > > skb_push(skb, sizeof(struct iphdr));
> > > skb_reset_network_header(skb);
> > > memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
> > > @@ -1102,6 +1186,8 @@ int
> > > ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
> > > struct ip_vs_protocol *pp, struct ip_vs_iphdr *ipvsh)
> > > {
> > > + struct netns_ipvs *ipvs = cp->ipvs;
> > > + struct net *net = ipvs->net;
> > > struct rt6_info *rt; /* Route to the other host */
> > > struct in6_addr saddr; /* Source for tunnel */
> > > struct net_device *tdev; /* Device to other host */
> > > @@ -1112,10 +1198,11 @@ ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
> > > struct ipv6hdr *iph; /* Our new IP header */
> > > unsigned int max_headroom; /* The extra header space needed */
> > > int ret, local;
> > > + int tun_type, gso_type;
> > >
> > > EnterFunction(10);
> > >
> > > - local = __ip_vs_get_out_rt_v6(cp->ipvs, cp->af, skb, cp->dest,
> > > + local = __ip_vs_get_out_rt_v6(ipvs, cp->af, skb, cp->dest,
> > > &cp->daddr.in6,
> > > &saddr, ipvsh, 1,
> > > IP_VS_RT_MODE_LOCAL |
> > > @@ -1134,17 +1221,46 @@ ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
> > > */
> > > max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(struct ipv6hdr);
> > >
> > > + tun_type = cp->dest->tun_type;
> > > +
> > > + switch (tun_type) {
> > > + case IP_VS_CONN_F_TUNNEL_TYPE_GUE:
> > > + max_headroom += sizeof(struct udphdr) + sizeof(struct guehdr);
> > > + break;
> > > + default:
> > > + break;
> > > + }
> > > +
> > > skb = ip_vs_prepare_tunneled_skb(skb, cp->af, max_headroom,
> > > &next_protocol, &payload_len,
> > > &dsfield, &ttl, NULL);
> > > if (IS_ERR(skb))
> > > goto tx_error;
> > >
> > > - if (iptunnel_handle_offloads(skb, __tun_gso_type_mask(AF_INET6, cp->af)))
> > > + switch (tun_type) {
> > > + case IP_VS_CONN_F_TUNNEL_TYPE_GUE:
> > > + gso_type = SKB_GSO_UDP_TUNNEL;
> > > + break;
> > > + default:
> > > + gso_type = __tun_gso_type_mask(AF_INET6, cp->af);
> > > + break;
> > > + }
> > > +
> > > + if (iptunnel_handle_offloads(skb, gso_type))
> > > goto tx_error;
> > >
> > > skb->transport_header = skb->network_header;
> > >
> > > + skb_set_inner_ipproto(skb, next_protocol);
> > > +
> > > + switch (tun_type) {
> > > + case IP_VS_CONN_F_TUNNEL_TYPE_GUE:
> > > + ipvs_gue_encap(net, skb, cp, &next_protocol);
> > > + break;
> > > + default:
> > > + break;
> > > + }
> > > +
> > > skb_push(skb, sizeof(struct ipv6hdr));
> > > skb_reset_network_header(skb);
> > > memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
> > > @@ -1167,7 +1283,7 @@ ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
> > >
> > > ret = ip_vs_tunnel_xmit_prepare(skb, cp);
> > > if (ret == NF_ACCEPT)
> > > - ip6_local_out(cp->ipvs->net, skb->sk, skb);
> > > + ip6_local_out(net, skb->sk, skb);
> > > else if (ret == NF_DROP)
> > > kfree_skb(skb);
> > >
> > > --
> > > 2.21.0
> > >
>