@@ -295,6 +295,8 @@ struct smc_sock { /* smc sock container */
atomic_t queued_smc_hs; /* queued smc handshakes */
struct inet_connection_sock_af_ops af_ops;
const struct inet_connection_sock_af_ops *ori_af_ops;
+ /* protocol negotiator ops */
+ const struct smc_sock_negotiator_ops *negotiator_ops;
/* original af ops */
int sockopt_defer_accept;
/* sockopt TCP_DEFER_ACCEPT
@@ -315,4 +317,45 @@ struct smc_sock { /* smc sock container */
*/
};
+#ifdef CONFIG_SMC_BPF
+
+#define SMC_NEGOTIATOR_NAME_MAX (16)
+#define SMC_SOCK_CLOSED_TIMING (0)
+
+/* BPF struct ops for smc protocol negotiator */
+struct smc_sock_negotiator_ops {
+
+ struct list_head list;
+
+ /* ops name */
+ char name[16];
+ /* key for name */
+ u32 key;
+
+ /* init with sk */
+ void (*init)(struct sock *sk);
+
+ /* release with sk */
+ void (*release)(struct sock *sk);
+
+ /* advice for negotiate */
+ int (*negotiate)(struct sock *sk);
+
+ /* info gathering timing */
+ void (*collect_info)(struct sock *sk, int timing);
+
+ /* module owner */
+ struct module *owner;
+};
+
+int smc_sock_register_negotiator_ops(struct smc_sock_negotiator_ops *ops);
+int smc_sock_update_negotiator_ops(struct smc_sock_negotiator_ops *ops,
+ struct smc_sock_negotiator_ops *old_ops);
+void smc_sock_unregister_negotiator_ops(struct smc_sock_negotiator_ops *ops);
+int smc_sock_assign_negotiator_ops(struct smc_sock *smc, const char *name);
+void smc_sock_cleanup_negotiator_ops(struct smc_sock *smc, int in_release);
+void smc_sock_clone_negotiator_ops(struct sock *parent, struct sock *child);
+
+#endif
+
#endif /* _SMC_H */
@@ -52,6 +52,7 @@ obj-$(CONFIG_TIPC) += tipc/
obj-$(CONFIG_NETLABEL) += netlabel/
obj-$(CONFIG_IUCV) += iucv/
obj-$(CONFIG_SMC) += smc/
+obj-$(CONFIG_SMC_BPF) += smc/bpf_smc.o
obj-$(CONFIG_RFKILL) += rfkill/
obj-$(CONFIG_NET_9P) += 9p/
obj-$(CONFIG_CAIF) += caif/
@@ -19,3 +19,16 @@ config SMC_DIAG
smcss.
if unsure, say Y.
+
+if SMC
+config SMC_BPF
+ bool "SMC: support eBPF" if SMC
+ depends on BPF_SYSCALL
+ default n
+ help
+ Supports eBPF to allows user mode participation in SMC's protocol process
+ via ebpf programs. Alternatively, obtain information about the SMC socks
+ through the ebpf program.
+
+ If unsure, say N.
+endif
@@ -68,6 +68,49 @@
static void smc_tcp_listen_work(struct work_struct *);
static void smc_connect_work(struct work_struct *);
+static int smc_sock_should_select_smc(const struct smc_sock *smc)
+{
+#ifdef CONFIG_SMC_BPF
+ const struct smc_sock_negotiator_ops *ops;
+ int ret;
+
+ rcu_read_lock();
+ ops = READ_ONCE(smc->negotiator_ops);
+
+ /* No negotiator_ops supply or no negotiate func set,
+ * always pass it.
+ */
+ if (!ops || !ops->negotiate) {
+ rcu_read_unlock();
+ return SK_PASS;
+ }
+
+ ret = ops->negotiate((struct sock *)&smc->sk);
+ rcu_read_unlock();
+ return ret;
+#else
+ return SK_PASS;
+#endif
+}
+
+#ifdef CONFIG_SMC_BPF
+static void smc_sock_perform_collecting_info(const struct smc_sock *smc, int timing)
+{
+ const struct smc_sock_negotiator_ops *ops;
+
+ rcu_read_lock();
+ ops = READ_ONCE(smc->negotiator_ops);
+
+ if (!ops || !ops->collect_info) {
+ rcu_read_unlock();
+ return;
+ }
+
+ ops->collect_info((struct sock *)&smc->sk, timing);
+ rcu_read_unlock();
+}
+#endif
+
int smc_nl_dump_hs_limitation(struct sk_buff *skb, struct netlink_callback *cb)
{
struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
@@ -166,6 +209,9 @@ static bool smc_hs_congested(const struct sock *sk)
if (workqueue_congested(WORK_CPU_UNBOUND, smc_hs_wq))
return true;
+ if (!smc_sock_should_select_smc(smc))
+ return true;
+
return false;
}
@@ -320,6 +366,11 @@ static int smc_release(struct socket *sock)
sock_hold(sk); /* sock_put below */
smc = smc_sk(sk);
+#ifdef CONFIG_SMC_BPF
+ /* trigger info gathering if needed.*/
+ smc_sock_perform_collecting_info(smc, SMC_SOCK_CLOSED_TIMING);
+#endif
+
old_state = sk->sk_state;
/* cleanup for a dangling non-blocking connect */
@@ -360,6 +411,10 @@ static void smc_destruct(struct sock *sk)
return;
if (!sock_flag(sk, SOCK_DEAD))
return;
+#ifdef CONFIG_SMC_BPF
+ /* cleanup negotiator_ops if set */
+ smc_sock_cleanup_negotiator_ops(smc_sk(sk), /* in release */ 1);
+#endif
}
static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
@@ -1627,7 +1682,14 @@ static int smc_connect(struct socket *sock, struct sockaddr *addr,
}
smc_copy_sock_settings_to_clc(smc);
- tcp_sk(smc->clcsock->sk)->syn_smc = 1;
+ /* accept out connection as SMC connection */
+ if (smc_sock_should_select_smc(smc) == SK_PASS) {
+ tcp_sk(smc->clcsock->sk)->syn_smc = 1;
+ } else {
+ tcp_sk(smc->clcsock->sk)->syn_smc = 0;
+ smc_switch_to_fallback(smc, /* active fallback */ 0);
+ }
+
if (smc->connect_nonblock) {
rc = -EALREADY;
goto out;
@@ -1679,6 +1741,10 @@ static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
}
*new_smc = smc_sk(new_sk);
+#ifdef CONFIG_SMC_BPF
+ smc_sock_clone_negotiator_ops(lsk, new_sk);
+#endif
+
mutex_lock(&lsmc->clcsock_release_lock);
if (lsmc->clcsock)
rc = kernel_accept(lsmc->clcsock, &new_clcsock, SOCK_NONBLOCK);
new file mode 100644
@@ -0,0 +1,200 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Support eBPF for Shared Memory Communications over RDMA (SMC-R) and RoCE
+ *
+ * Copyright IBM Corp. 2016, 2018
+ *
+ * Author(s): D. Wythe <alibuda@linux.alibaba.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/bpf.h>
+#include <linux/smc.h>
+#include <net/sock.h>
+#include "smc.h"
+
+static DEFINE_SPINLOCK(smc_sock_negotiator_list_lock);
+static LIST_HEAD(smc_sock_negotiator_list);
+
+/* required smc_sock_negotiator_list_lock locked */
+static struct smc_sock_negotiator_ops *smc_negotiator_ops_get_by_key(u32 key)
+{
+ struct smc_sock_negotiator_ops *ops;
+
+ list_for_each_entry_rcu(ops, &smc_sock_negotiator_list, list) {
+ if (ops->key == key)
+ return ops;
+ }
+
+ return NULL;
+}
+
+/* required smc_sock_negotiator_list_lock locked */
+struct smc_sock_negotiator_ops *smc_negotiator_ops_get_by_name(const char *name)
+{
+ struct smc_sock_negotiator_ops *ops;
+
+ list_for_each_entry_rcu(ops, &smc_sock_negotiator_list, list) {
+ if (strcmp(ops->name, name) == 0)
+ return ops;
+ }
+
+ return NULL;
+}
+
+static int smc_sock_validate_negotiator_ops(struct smc_sock_negotiator_ops *ops)
+{
+ /* not required yet */
+ return 0;
+}
+
+/* register ops */
+int smc_sock_register_negotiator_ops(struct smc_sock_negotiator_ops *ops)
+{
+ int ret;
+
+ ret = smc_sock_validate_negotiator_ops(ops);
+ if (ret)
+ return ret;
+
+ /* calt key by name hash */
+ ops->key = jhash(ops->name, sizeof(ops->name), strlen(ops->name));
+
+ spin_lock(&smc_sock_negotiator_list_lock);
+ if (smc_negotiator_ops_get_by_key(ops->key)) {
+ pr_notice("smc: %s negotiator already registered\n", ops->name);
+ ret = -EEXIST;
+ } else {
+ list_add_tail_rcu(&ops->list, &smc_sock_negotiator_list);
+ }
+ spin_unlock(&smc_sock_negotiator_list_lock);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(smc_sock_register_negotiator_ops);
+
+/* unregister ops */
+void smc_sock_unregister_negotiator_ops(struct smc_sock_negotiator_ops *ops)
+{
+ spin_lock(&smc_sock_negotiator_list_lock);
+ list_del_rcu(&ops->list);
+ spin_unlock(&smc_sock_negotiator_list_lock);
+
+ /* Wait for outstanding readers to complete before the
+ * ops gets removed entirely.
+ */
+ synchronize_rcu();
+}
+EXPORT_SYMBOL_GPL(smc_sock_unregister_negotiator_ops);
+
+int smc_sock_update_negotiator_ops(struct smc_sock_negotiator_ops *ops,
+ struct smc_sock_negotiator_ops *old_ops)
+{
+ struct smc_sock_negotiator_ops *existing;
+ int ret;
+
+ ret = smc_sock_validate_negotiator_ops(ops);
+ if (ret)
+ return ret;
+
+ ops->key = jhash(ops->name, sizeof(ops->name), strlen(ops->name));
+ if (unlikely(!ops->key))
+ return -EINVAL;
+
+ spin_lock(&smc_sock_negotiator_list_lock);
+ existing = smc_negotiator_ops_get_by_key(old_ops->key);
+ if (!existing || strcmp(existing->name, ops->name)) {
+ ret = -EINVAL;
+ } else if (existing != old_ops) {
+ pr_notice("invalid old negotiator to replace\n");
+ ret = -EINVAL;
+ } else {
+ list_add_tail_rcu(&ops->list, &smc_sock_negotiator_list);
+ list_del_rcu(&existing->list);
+ }
+
+ spin_unlock(&smc_sock_negotiator_list_lock);
+ if (ret)
+ return ret;
+
+ synchronize_rcu();
+ return 0;
+}
+EXPORT_SYMBOL_GPL(smc_sock_update_negotiator_ops);
+
+/* assign ops to sock */
+int smc_sock_assign_negotiator_ops(struct smc_sock *smc, const char *name)
+{
+ struct smc_sock_negotiator_ops *ops;
+ int ret = -EINVAL;
+
+ /* already set */
+ if (READ_ONCE(smc->negotiator_ops))
+ smc_sock_cleanup_negotiator_ops(smc, /* in release */ 0);
+
+ /* Just for clear negotiator_ops */
+ if (!name || !strlen(name))
+ return 0;
+
+ rcu_read_lock();
+ ops = smc_negotiator_ops_get_by_name(name);
+ if (likely(ops)) {
+ if (unlikely(!bpf_try_module_get(ops, ops->owner))) {
+ ret = -EACCES;
+ } else {
+ WRITE_ONCE(smc->negotiator_ops, ops);
+ /* make sure ops can be seen */
+ smp_wmb();
+ if (ops->init)
+ ops->init(&smc->sk);
+ ret = 0;
+ }
+ }
+ rcu_read_unlock();
+ return ret;
+}
+EXPORT_SYMBOL_GPL(smc_sock_assign_negotiator_ops);
+
+/* reset ops to sock */
+void smc_sock_cleanup_negotiator_ops(struct smc_sock *smc, int in_release)
+{
+ const struct smc_sock_negotiator_ops *ops;
+
+ ops = READ_ONCE(smc->negotiator_ops);
+
+ /* not all smc sock has negotiator_ops */
+ if (!ops)
+ return;
+
+ might_sleep();
+
+ /* Just ensure data integrity */
+ WRITE_ONCE(smc->negotiator_ops, NULL);
+ /* make sure NULL can be seen */
+ smp_wmb();
+ /* If the cleanup was not caused by the release of the sock,
+ * it means that we may need to wait for the readers of ops
+ * to complete.
+ */
+ if (unlikely(!in_release))
+ synchronize_rcu();
+ if (ops->release)
+ ops->release(&smc->sk);
+ bpf_module_put(ops, ops->owner);
+}
+EXPORT_SYMBOL_GPL(smc_sock_cleanup_negotiator_ops);
+
+void smc_sock_clone_negotiator_ops(struct sock *parent, struct sock *child)
+{
+ const struct smc_sock_negotiator_ops *ops;
+
+ rcu_read_lock();
+ ops = READ_ONCE(smc_sk(parent)->negotiator_ops);
+ if (ops && bpf_try_module_get(ops, ops->owner)) {
+ smc_sk(child)->negotiator_ops = ops;
+ if (ops->init)
+ ops->init(child);
+ }
+ rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(smc_sock_clone_negotiator_ops);
+