From 6dd9a14e92e54895e143f10fef4d0b9abe109aa9 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Wed, 16 Dec 2015 13:20:44 -0800 Subject: [PATCH] net: Allow accepted sockets to be bound to l3mdev domain 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 Signed-off-by: David S. Miller --- 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(-) diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 5de632ed0ec0..ceb44a095a27 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -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 diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h index 625bdf95d673..012b1f91f3ec 100644 --- a/include/net/inet_sock.h +++ b/include/net/inet_sock.h @@ -28,6 +28,7 @@ #include #include #include +#include /** 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; diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h index c68926b4899c..d75be32650ba 100644 --- a/include/net/netns/ipv4.h +++ b/include/net/netns/ipv4.h @@ -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; diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index 4cbe9f0a4281..643a86c49020 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -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, diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index a0bd7a55193e..41ff1f87dfd7 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -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, diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 2d656eef7f8e..7b1fddc47019 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -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); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 205e6745393f..46e92fbd26a8 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -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); diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c index eaf7ac496d50..2906ef20795e 100644 --- a/net/ipv6/syncookies.c +++ b/net/ipv6/syncookies.c @@ -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; -- 2.20.1