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author | Martin KaFai Lau <martin.lau@kernel.org> | 2023-08-16 20:22:17 +0300 |
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committer | Martin KaFai Lau <martin.lau@kernel.org> | 2023-08-16 21:42:35 +0300 |
commit | de40537364c34fd665a0f00d156d24c6c0e89a66 (patch) | |
tree | 04764d5159b1301502abda24221d7d418eb4386f /net/mptcp | |
parent | 053bbf9bff58864be880d7e9a5af586793dbb7de (diff) | |
parent | ddba122428a75261fc4d3547f4e7e4aa6b67caef (diff) | |
download | linux-de40537364c34fd665a0f00d156d24c6c0e89a66.tar.xz |
Merge branch 'bpf: Force to MPTCP'
Geliang Tang says:
====================
As is described in the "How to use MPTCP?" section in MPTCP wiki [1]:
"Your app should create sockets with IPPROTO_MPTCP as the proto:
( socket(AF_INET, SOCK_STREAM, IPPROTO_MPTCP); ). Legacy apps can be
forced to create and use MPTCP sockets instead of TCP ones via the
mptcpize command bundled with the mptcpd daemon."
But the mptcpize (LD_PRELOAD technique) command has some limitations
[2]:
- it doesn't work if the application is not using libc (e.g. GoLang
apps)
- in some envs, it might not be easy to set env vars / change the way
apps are launched, e.g. on Android
- mptcpize needs to be launched with all apps that want MPTCP: we could
have more control from BPF to enable MPTCP only for some apps or all the
ones of a netns or a cgroup, etc.
- it is not in BPF, we cannot talk about it at netdev conf.
So this patchset attempts to use BPF to implement functions similer to
mptcpize.
The main idea is to add a hook in sys_socket() to change the protocol id
from IPPROTO_TCP (or 0) to IPPROTO_MPTCP.
[1]
https://github.com/multipath-tcp/mptcp_net-next/wiki
[2]
https://github.com/multipath-tcp/mptcp_net-next/issues/79
v14:
- Use getsockopt(MPTCP_INFO) to verify mptcp protocol intead of using
nstat command.
v13:
- drop "Use random netns name for mptcp" patch.
v12:
- update diag_* log of update_socket_protocol.
- add 'ip netns show' after 'ip netns del' to check if there is
a test did not clean up its netns.
- return libbpf_get_error() instead of -EIO for the error from
open_and_load().
- Use getsockopt(SOL_PROTOCOL) to verify mptcp protocol intead of
using 'ss -tOni'.
v11:
- add comments about outputs of 'ss' and 'nstat'.
- use "err = verify_mptcpify()" instead of using =+.
v10:
- drop "#ifdef CONFIG_BPF_JIT".
- include vmlinux.h and bpf_tracing_net.h to avoid defining some
macros.
- drop unneeded checks for mptcp.
v9:
- update comment for 'update_socket_protocol'.
v8:
- drop the additional checks on the 'protocol' value after the
'update_socket_protocol()' call.
v7:
- add __weak and __diag_* for update_socket_protocol.
v6:
- add update_socket_protocol.
v5:
- add bpf_mptcpify helper.
v4:
- use lsm_cgroup/socket_create
v3:
- patch 8: char cmd[128]; -> char cmd[256];
v2:
- Fix build selftests errors reported by CI
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/79
====================
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Diffstat (limited to 'net/mptcp')
-rw-r--r-- | net/mptcp/bpf.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c index 5a0a84ad94af..8a16672b94e2 100644 --- a/net/mptcp/bpf.c +++ b/net/mptcp/bpf.c @@ -19,3 +19,18 @@ struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) return NULL; } + +BTF_SET8_START(bpf_mptcp_fmodret_ids) +BTF_ID_FLAGS(func, update_socket_protocol) +BTF_SET8_END(bpf_mptcp_fmodret_ids) + +static const struct btf_kfunc_id_set bpf_mptcp_fmodret_set = { + .owner = THIS_MODULE, + .set = &bpf_mptcp_fmodret_ids, +}; + +static int __init bpf_mptcp_kfunc_init(void) +{ + return register_btf_fmodret_id_set(&bpf_mptcp_fmodret_set); +} +late_initcall(bpf_mptcp_kfunc_init); |