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authorD. Wythe <alibuda@linux.alibaba.com>2025-11-07 11:56:31 +0800
committerMartin KaFai Lau <martin.lau@kernel.org>2025-11-10 11:19:41 -0800
commit15f295f55656658e65bdbc9b901d6b2e49d68d72 (patch)
tree9ed5919603e8caf148a619f10388736cc776f561 /include
parent07c428ece3222832bdbfcc4ffa8b8d3991c5eb39 (diff)
net/smc: bpf: Introduce generic hook for handshake flow
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. User can write their own implememtion via bpf_struct_ops now to choose whether to use SMC or not before TCP 3rd handshake to be comleted. Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Reviewed-by: Dust Li <dust.li@linux.alibaba.com> Link: https://patch.msgid.link/20251107035632.115950-3-alibuda@linux.alibaba.com
Diffstat (limited to 'include')
-rw-r--r--include/net/netns/smc.h3
-rw-r--r--include/net/smc.h53
2 files changed, 56 insertions, 0 deletions
diff --git a/include/net/netns/smc.h b/include/net/netns/smc.h
index 6ceb12baec24..ed24c9f638ee 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_HS_CTRL_BPF)
+ struct smc_hs_ctrl __rcu *hs_ctrl;
+#endif /* CONFIG_SMC_HS_CTRL_BPF */
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 08bee529ed8d..bfdc4c41f019 100644
--- a/include/net/smc.h
+++ b/include/net/smc.h
@@ -17,6 +17,8 @@
#include <linux/wait.h>
#include <linux/dibs.h>
+struct tcp_sock;
+struct inet_request_sock;
struct sock;
#define SMC_MAX_PNETID_LEN 16 /* Max. length of PNET id */
@@ -50,4 +52,55 @@ struct smcd_dev {
u8 going_away : 1;
};
+#define SMC_HS_CTRL_NAME_MAX 16
+
+enum {
+ /* ops can be inherit from init_net */
+ SMC_HS_CTRL_FLAG_INHERITABLE = 0x1,
+
+ SMC_HS_CTRL_ALL_FLAGS = SMC_HS_CTRL_FLAG_INHERITABLE,
+};
+
+struct smc_hs_ctrl {
+ /* private */
+
+ struct list_head list;
+ struct module *owner;
+
+ /* public */
+
+ /* unique name */
+ char name[SMC_HS_CTRL_NAME_MAX];
+ int flags;
+
+ /* Invoked before computing SMC option for SYN packets.
+ * We can control whether to set SMC options by returning various value.
+ * Return 0 to disable SMC, or return any other value to enable it.
+ */
+ int (*syn_option)(struct tcp_sock *tp);
+
+ /* Invoked before Set up SMC options for SYN-ACK packets
+ * We can control whether to respond SMC options by returning various
+ * value. Return 0 to disable SMC, or return any other value to enable
+ * it.
+ */
+ int (*synack_option)(const struct tcp_sock *tp,
+ struct inet_request_sock *ireq);
+};
+
+#if IS_ENABLED(CONFIG_SMC_HS_CTRL_BPF)
+#define smc_call_hsbpf(init_val, tp, func, ...) ({ \
+ typeof(init_val) __ret = (init_val); \
+ struct smc_hs_ctrl *ctrl; \
+ rcu_read_lock(); \
+ ctrl = rcu_dereference(sock_net((struct sock *)(tp))->smc.hs_ctrl); \
+ if (ctrl && ctrl->func) \
+ __ret = ctrl->func(tp, ##__VA_ARGS__); \
+ rcu_read_unlock(); \
+ __ret; \
+})
+#else
+#define smc_call_hsbpf(init_val, tp, ...) ({ (void)(tp); (init_val); })
+#endif /* CONFIG_SMC_HS_CTRL_BPF */
+
#endif /* _SMC_H */