Re: [PATCH bpf-next v5 2/5] net/smc: Introduce generic hook smc_ops

[Dust Li <dust.li@linux.alibaba.com>]

On 2025-01-07 12:17:12, D. Wythe wrote:
>The introduction of IPPROTO_SMC enables eBPF programs to determine
>whether to use SMC based on the context of socket creation, such as
>network namespaces, PID and comm name, etc.
>
>As a subsequent enhancement, to introduce a new generic hook that
>allows decisions on whether to use SMC or not at runtime, including
>but not limited to local/remote IP address or ports.
>
>Moreover, in the future, we can achieve more complex extensions to the
>protocol stack by extending this ops.
>
>Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
>---
> include/net/netns/smc.h |  3 ++
> include/net/smc.h       | 51 ++++++++++++++++++++++
> net/ipv4/tcp_output.c   | 15 +++++--
> net/smc/Kconfig         | 12 ++++++
> net/smc/Makefile        |  1 +
> net/smc/smc_ops.c       | 51 ++++++++++++++++++++++
> net/smc/smc_ops.h       | 25 +++++++++++
> net/smc/smc_sysctl.c    | 95 +++++++++++++++++++++++++++++++++++++++++
> 8 files changed, 249 insertions(+), 4 deletions(-)
> create mode 100644 net/smc/smc_ops.c
> create mode 100644 net/smc/smc_ops.h
>
>diff --git a/include/net/netns/smc.h b/include/net/netns/smc.h
>index fc752a50f91b..59d069f56b2d 100644
>--- a/include/net/netns/smc.h
>+++ b/include/net/netns/smc.h
>@@ -17,6 +17,9 @@ struct netns_smc {
> #ifdef CONFIG_SYSCTL
> 	struct ctl_table_header		*smc_hdr;
> #endif
>+#if IS_ENABLED(CONFIG_SMC_OPS)
>+	struct smc_ops __rcu *ops;
>+#endif /* CONFIG_SMC_OPS */
> 	unsigned int			sysctl_autocorking_size;
> 	unsigned int			sysctl_smcr_buf_type;
> 	int				sysctl_smcr_testlink_time;
>diff --git a/include/net/smc.h b/include/net/smc.h
>index db84e4e35080..326a217001d4 100644
>--- a/include/net/smc.h
>+++ b/include/net/smc.h
>@@ -18,6 +18,8 @@
> #include "linux/ism.h"
> 
> struct sock;
>+struct tcp_sock;
>+struct inet_request_sock;
> 
> #define SMC_MAX_PNETID_LEN	16	/* Max. length of PNET id */
> 
>@@ -97,4 +99,53 @@ struct smcd_dev {
> 	u8 going_away : 1;
> };
> 
>+#define  SMC_OPS_NAME_MAX 16
>+
>+enum {
>+	/* ops can be inherit from init_net */
>+	SMC_OPS_FLAG_INHERITABLE = 0x1,
>+
>+	SMC_OPS_ALL_FLAGS = SMC_OPS_FLAG_INHERITABLE,
>+};
>+
>+struct smc_ops {

One more thing.
Can we call it smc_bpf_ops ? I think smc_ops is a bit ambiguous.
Same for smc_ops.h/c source file.

Best regards,
Dust