ipvs: add sysctl to ignore tunneled packets

This is a way to avoid nasty routing loops when multiple ipvs instances can
forward to eachother.

Signed-off-by: Alex Gartrell <agartrell@fb.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
This commit is contained in:
Alex Gartrell 2015-09-14 23:23:05 -07:00 committed by Simon Horman
parent 5e26b1b3ab
commit 4e478098ac
4 changed files with 37 additions and 1 deletions

View File

@ -157,6 +157,16 @@ expire_quiescent_template - BOOLEAN
persistence template if it is to be used to schedule a new
connection and the destination server is quiescent.
ignore_tunneled - BOOLEAN
0 - disabled (default)
not 0 - enabled
If set, ipvs will set the ipvs_property on all packets which are of
unrecognized protocols. This prevents us from routing tunneled
protocols like ipip, which is useful to prevent rescheduling
packets that have been tunneled to the ipvs host (i.e. to prevent
ipvs routing loops when ipvs is also acting as a real server).
nat_icmp_send - BOOLEAN
0 - disabled (default)
not 0 - enabled

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@ -998,6 +998,7 @@ struct netns_ipvs {
int sysctl_backup_only;
int sysctl_conn_reuse_mode;
int sysctl_schedule_icmp;
int sysctl_ignore_tunneled;
/* ip_vs_lblc */
int sysctl_lblc_expiration;
@ -1121,6 +1122,11 @@ static inline int sysctl_schedule_icmp(struct netns_ipvs *ipvs)
return ipvs->sysctl_schedule_icmp;
}
static inline int sysctl_ignore_tunneled(struct netns_ipvs *ipvs)
{
return ipvs->sysctl_ignore_tunneled;
}
#else
static inline int sysctl_sync_threshold(struct netns_ipvs *ipvs)
@ -1198,6 +1204,11 @@ static inline int sysctl_schedule_icmp(struct netns_ipvs *ipvs)
return 0;
}
static inline int sysctl_ignore_tunneled(struct netns_ipvs *ipvs)
{
return 0;
}
#endif
/* IPVS core functions

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@ -1760,8 +1760,16 @@ ip_vs_in(unsigned int hooknum, struct sk_buff *skb, int af)
/* Protocol supported? */
pd = ip_vs_proto_data_get(net, iph.protocol);
if (unlikely(!pd))
if (unlikely(!pd)) {
/* The only way we'll see this packet again is if it's
* encapsulated, so mark it with ipvs_property=1 so we
* skip it if we're ignoring tunneled packets
*/
if (sysctl_ignore_tunneled(ipvs))
skb->ipvs_property = 1;
return NF_ACCEPT;
}
pp = pd->pp;
/*
* Check if the packet belongs to an existing connection entry

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@ -1850,6 +1850,12 @@ static struct ctl_table vs_vars[] = {
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "ignore_tunneled",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
#ifdef CONFIG_IP_VS_DEBUG
{
.procname = "debug_level",
@ -3902,6 +3908,7 @@ static int __net_init ip_vs_control_net_init_sysctl(struct net *net)
ipvs->sysctl_conn_reuse_mode = 1;
tbl[idx++].data = &ipvs->sysctl_conn_reuse_mode;
tbl[idx++].data = &ipvs->sysctl_schedule_icmp;
tbl[idx++].data = &ipvs->sysctl_ignore_tunneled;
ipvs->sysctl_hdr = register_net_sysctl(net, "net/ipv4/vs", tbl);
if (ipvs->sysctl_hdr == NULL) {