@@ -335,6 +335,14 @@ tcp_keepalive_intvl - INTEGER
after probes started. Default value: 75sec i.e. connection
will be aborted after ~11 minutes of retries.
+tcp_l3mdev_accept - BOOLEAN
+ Enables child sockets to inherit the L3 master device index.
+ Enabling this option allows a "global" listen socket to work
+ across L3 master domains (e.g., VRFs) with connected sockets
+ derived from the listen socket to be bound to the L3 domain in
+ which the packets originated. Only valid when the kernel was
+ compiled with CONFIG_NET_L3_MASTER_DEV.
+
tcp_low_latency - BOOLEAN
If set, the TCP stack makes decisions that prefer lower
latency as opposed to higher throughput. By default, this
@@ -28,6 +28,7 @@
#include <net/request_sock.h>
#include <net/netns/hash.h>
#include <net/tcp_states.h>
+#include <net/l3mdev.h>
/** struct ip_options - IP Options
*
@@ -113,6 +114,19 @@ static inline u32 inet_request_mark(const struct sock *sk, struct sk_buff *skb)
return sk->sk_mark;
}
+static inline int inet_request_bound_dev_if(const struct sock *sk,
+ struct sk_buff *skb)
+{
+#ifdef CONFIG_NET_L3_MASTER_DEV
+ struct net *net = sock_net(sk);
+
+ if (!sk->sk_bound_dev_if && net->ipv4.sysctl_tcp_l3mdev_accept)
+ return l3mdev_master_ifindex_by_index(net, skb->skb_iif);
+#endif
+
+ return sk->sk_bound_dev_if;
+}
+
struct inet_cork {
unsigned int flags;
__be32 addr;
@@ -86,6 +86,9 @@ struct netns_ipv4 {
int sysctl_fwmark_reflect;
int sysctl_tcp_fwmark_accept;
+#ifdef CONFIG_NET_L3_MASTER_DEV
+ int sysctl_tcp_l3mdev_accept;
+#endif
int sysctl_tcp_mtu_probing;
int sysctl_tcp_base_mss;
int sysctl_tcp_probe_threshold;
@@ -351,7 +351,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
treq->snt_synack.v64 = 0;
treq->tfo_listener = false;
- ireq->ir_iif = sk->sk_bound_dev_if;
+ ireq->ir_iif = inet_request_bound_dev_if(sk, skb);
/* We throwed the options of the initial SYN away, so we hope
* the ACK carries the same options again (see RFC1122 4.2.3.8)
@@ -371,7 +371,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
* hasn't changed since we received the original syn, but I see
* no easy way to do this.
*/
- flowi4_init_output(&fl4, sk->sk_bound_dev_if, ireq->ir_mark,
+ flowi4_init_output(&fl4, ireq->ir_iif, ireq->ir_mark,
RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, IPPROTO_TCP,
inet_sk_flowi_flags(sk),
opt->srr ? opt->faddr : ireq->ir_rmt_addr,
@@ -915,6 +915,17 @@ static struct ctl_table ipv4_net_table[] = {
.mode = 0644,
.proc_handler = proc_dointvec,
},
+#ifdef CONFIG_NET_L3_MASTER_DEV
+ {
+ .procname = "tcp_l3mdev_accept",
+ .data = &init_net.ipv4.sysctl_tcp_l3mdev_accept,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &one,
+ },
+#endif
{
.procname = "tcp_mtu_probing",
.data = &init_net.ipv4.sysctl_tcp_mtu_probing,
@@ -6204,7 +6204,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
tcp_openreq_init(req, &tmp_opt, skb, sk);
/* Note: tcp_v6_init_req() might override ir_iif for link locals */
- inet_rsk(req)->ir_iif = sk->sk_bound_dev_if;
+ inet_rsk(req)->ir_iif = inet_request_bound_dev_if(sk, skb);
af_ops->init_req(req, sk, skb);
@@ -1276,6 +1276,7 @@ struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
ireq = inet_rsk(req);
sk_daddr_set(newsk, ireq->ir_rmt_addr);
sk_rcv_saddr_set(newsk, ireq->ir_loc_addr);
+ newsk->sk_bound_dev_if = ireq->ir_iif;
newinet->inet_saddr = ireq->ir_loc_addr;
inet_opt = ireq->opt;
rcu_assign_pointer(newinet->inet_opt, inet_opt);
@@ -193,7 +193,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
ireq->pktopts = skb;
}
- ireq->ir_iif = sk->sk_bound_dev_if;
+ ireq->ir_iif = inet_request_bound_dev_if(sk, skb);
/* So that link locals have meaning */
if (!sk->sk_bound_dev_if &&
ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
@@ -224,7 +224,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
fl6.daddr = ireq->ir_v6_rmt_addr;
final_p = fl6_update_dst(&fl6, rcu_dereference(np->opt), &final);
fl6.saddr = ireq->ir_v6_loc_addr;
- fl6.flowi6_oif = sk->sk_bound_dev_if;
+ fl6.flowi6_oif = ireq->ir_iif;
fl6.flowi6_mark = ireq->ir_mark;
fl6.fl6_dport = ireq->ir_rmt_port;
fl6.fl6_sport = inet_sk(sk)->inet_sport;
Allow accepted sockets to derive their sk_bound_dev_if setting from the l3mdev domain in which the packets originated. A sysctl setting is added to control the behavior which is similar to sk_mark and sysctl_tcp_fwmark_accept. This effectively allow a process to have a "VRF-global" listen socket, with child sockets bound to the VRF device in which the packet originated. A similar behavior can be achieved using sk_mark, but a solution using marks is incomplete as it does not handle duplicate addresses in different L3 domains/VRFs. Allowing sockets to inherit the sk_bound_dev_if from l3mdev domain provides a complete solution. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> --- v3 - wrap the sysctl and its use with CONFIG_NET_L3_MASTER_DEV check v2 - added sysctl option. wrapped l3mdev lookup in helper function similar to marks Documentation/networking/ip-sysctl.txt | 8 ++++++++ include/net/inet_sock.h | 14 ++++++++++++++ include/net/netns/ipv4.h | 3 +++ net/ipv4/syncookies.c | 4 ++-- net/ipv4/sysctl_net_ipv4.c | 11 +++++++++++ net/ipv4/tcp_input.c | 2 +- net/ipv4/tcp_ipv4.c | 1 + net/ipv6/syncookies.c | 4 ++-- 8 files changed, 42 insertions(+), 5 deletions(-)