| Message ID | 20210521182104.18273-2-kuniyu@amazon.co.jp (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF |
| Headers | show |
| Series | Socket migration for SO_REUSEPORT. | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Clearly marked for bpf-next |
| netdev/subject_prefix | success | Link |
| netdev/cc_maintainers | warning | 11 maintainers not CCed: dsahern@kernel.org yhs@fb.com kpsingh@kernel.org yoshfuji@linux-ipv6.org idosch@OSS.NVIDIA.COM linux-doc@vger.kernel.org john.fastabend@gmail.com corbet@lwn.net songliubraving@fb.com fw@strlen.de weiwan@google.com |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 5514 this patch: 5514 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 53 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 5579 this patch: 5579 |
| netdev/header_inline | success | Link |
On 5/21/21 8:20 PM, Kuniyuki Iwashima wrote: > This commit adds a new sysctl option: net.ipv4.tcp_migrate_req. If this > option is enabled or eBPF program is attached, we will be able to migrate > child sockets from a listener to another in the same reuseport group after > close() or shutdown() syscalls. > > Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp> > Reviewed-by: Benjamin Herrenschmidt <benh@amazon.com> > Acked-by: Martin KaFai Lau <kafai@fb.com> > --- > Documentation/networking/ip-sysctl.rst | 25 +++++++++++++++++++++++++ > include/net/netns/ipv4.h | 1 + > net/ipv4/sysctl_net_ipv4.c | 9 +++++++++ > 3 files changed, 35 insertions(+) Reviewed-by: Eric Dumazet <edumazet@google.com>
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Thu, 10 Jun 2021 19:24:14 +0200 > On 5/21/21 8:20 PM, Kuniyuki Iwashima wrote: > > This commit adds a new sysctl option: net.ipv4.tcp_migrate_req. If this > > option is enabled or eBPF program is attached, we will be able to migrate > > child sockets from a listener to another in the same reuseport group after > > close() or shutdown() syscalls. > > > > Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp> > > Reviewed-by: Benjamin Herrenschmidt <benh@amazon.com> > > Acked-by: Martin KaFai Lau <kafai@fb.com> > > --- > > Documentation/networking/ip-sysctl.rst | 25 +++++++++++++++++++++++++ > > include/net/netns/ipv4.h | 1 + > > net/ipv4/sysctl_net_ipv4.c | 9 +++++++++ > > 3 files changed, 35 insertions(+) > > Reviewed-by: Eric Dumazet <edumazet@google.com> Thank you!
diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst index a5c250044500..b0436d3a4f11 100644 --- a/Documentation/networking/ip-sysctl.rst +++ b/Documentation/networking/ip-sysctl.rst @@ -761,6 +761,31 @@ tcp_syncookies - INTEGER network connections you can set this knob to 2 to enable unconditionally generation of syncookies. +tcp_migrate_req - BOOLEAN + The incoming connection is tied to a specific listening socket when + the initial SYN packet is received during the three-way handshake. + When a listener is closed, in-flight request sockets during the + handshake and established sockets in the accept queue are aborted. + + If the listener has SO_REUSEPORT enabled, other listeners on the + same port should have been able to accept such connections. This + option makes it possible to migrate such child sockets to another + listener after close() or shutdown(). + + The BPF_SK_REUSEPORT_SELECT_OR_MIGRATE type of eBPF program should + usually be used to define the policy to pick an alive listener. + Otherwise, the kernel will randomly pick an alive listener only if + this option is enabled. + + Note that migration between listeners with different settings may + crash applications. Let's say migration happens from listener A to + B, and only B has TCP_SAVE_SYN enabled. B cannot read SYN data from + the requests migrated from A. To avoid such a situation, cancel + migration by returning SK_DROP in the type of eBPF program, or + disable this option. + + Default: 0 + tcp_fastopen - INTEGER Enable TCP Fast Open (RFC7413) to send and accept data in the opening SYN packet. diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h index 746c80cd4257..b8620519eace 100644 --- a/include/net/netns/ipv4.h +++ b/include/net/netns/ipv4.h @@ -126,6 +126,7 @@ struct netns_ipv4 { u8 sysctl_tcp_syn_retries; u8 sysctl_tcp_synack_retries; u8 sysctl_tcp_syncookies; + u8 sysctl_tcp_migrate_req; int sysctl_tcp_reordering; u8 sysctl_tcp_retries1; u8 sysctl_tcp_retries2; diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index 4fa77f182dcb..6f1e64d49232 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -960,6 +960,15 @@ static struct ctl_table ipv4_net_table[] = { .proc_handler = proc_dou8vec_minmax, }, #endif + { + .procname = "tcp_migrate_req", + .data = &init_net.ipv4.sysctl_tcp_migrate_req, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE + }, { .procname = "tcp_reordering", .data = &init_net.ipv4.sysctl_tcp_reordering,