diff options
Diffstat (limited to 'net/mptcp/sched.c')
| -rw-r--r-- | net/mptcp/sched.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/net/mptcp/sched.c b/net/mptcp/sched.c new file mode 100644 index 000000000000..4ab0693c069c --- /dev/null +++ b/net/mptcp/sched.c @@ -0,0 +1,173 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Multipath TCP + * + * Copyright (c) 2022, SUSE. + */ + +#define pr_fmt(fmt) "MPTCP: " fmt + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/list.h> +#include <linux/rculist.h> +#include <linux/spinlock.h> +#include "protocol.h" + +static DEFINE_SPINLOCK(mptcp_sched_list_lock); +static LIST_HEAD(mptcp_sched_list); + +static int mptcp_sched_default_get_subflow(struct mptcp_sock *msk, + struct mptcp_sched_data *data) +{ + struct sock *ssk; + + ssk = data->reinject ? mptcp_subflow_get_retrans(msk) : + mptcp_subflow_get_send(msk); + if (!ssk) + return -EINVAL; + + mptcp_subflow_set_scheduled(mptcp_subflow_ctx(ssk), true); + return 0; +} + +static struct mptcp_sched_ops mptcp_sched_default = { + .get_subflow = mptcp_sched_default_get_subflow, + .name = "default", + .owner = THIS_MODULE, +}; + +/* Must be called with rcu read lock held */ +struct mptcp_sched_ops *mptcp_sched_find(const char *name) +{ + struct mptcp_sched_ops *sched, *ret = NULL; + + list_for_each_entry_rcu(sched, &mptcp_sched_list, list) { + if (!strcmp(sched->name, name)) { + ret = sched; + break; + } + } + + return ret; +} + +int mptcp_register_scheduler(struct mptcp_sched_ops *sched) +{ + if (!sched->get_subflow) + return -EINVAL; + + spin_lock(&mptcp_sched_list_lock); + if (mptcp_sched_find(sched->name)) { + spin_unlock(&mptcp_sched_list_lock); + return -EEXIST; + } + list_add_tail_rcu(&sched->list, &mptcp_sched_list); + spin_unlock(&mptcp_sched_list_lock); + + pr_debug("%s registered", sched->name); + return 0; +} + +void mptcp_unregister_scheduler(struct mptcp_sched_ops *sched) +{ + if (sched == &mptcp_sched_default) + return; + + spin_lock(&mptcp_sched_list_lock); + list_del_rcu(&sched->list); + spin_unlock(&mptcp_sched_list_lock); +} + +void mptcp_sched_init(void) +{ + mptcp_register_scheduler(&mptcp_sched_default); +} + +int mptcp_init_sched(struct mptcp_sock *msk, + struct mptcp_sched_ops *sched) +{ + if (!sched) + sched = &mptcp_sched_default; + + if (!bpf_try_module_get(sched, sched->owner)) + return -EBUSY; + + msk->sched = sched; + if (msk->sched->init) + msk->sched->init(msk); + + pr_debug("sched=%s", msk->sched->name); + + return 0; +} + +void mptcp_release_sched(struct mptcp_sock *msk) +{ + struct mptcp_sched_ops *sched = msk->sched; + + if (!sched) + return; + + msk->sched = NULL; + if (sched->release) + sched->release(msk); + + bpf_module_put(sched, sched->owner); +} + +void mptcp_subflow_set_scheduled(struct mptcp_subflow_context *subflow, + bool scheduled) +{ + WRITE_ONCE(subflow->scheduled, scheduled); +} + +int mptcp_sched_get_send(struct mptcp_sock *msk) +{ + struct mptcp_subflow_context *subflow; + struct mptcp_sched_data data; + + msk_owned_by_me(msk); + + /* the following check is moved out of mptcp_subflow_get_send */ + if (__mptcp_check_fallback(msk)) { + if (msk->first && + __tcp_can_send(msk->first) && + sk_stream_memory_free(msk->first)) { + mptcp_subflow_set_scheduled(mptcp_subflow_ctx(msk->first), true); + return 0; + } + return -EINVAL; + } + + mptcp_for_each_subflow(msk, subflow) { + if (READ_ONCE(subflow->scheduled)) + return 0; + } + + data.reinject = false; + if (msk->sched == &mptcp_sched_default || !msk->sched) + return mptcp_sched_default_get_subflow(msk, &data); + return msk->sched->get_subflow(msk, &data); +} + +int mptcp_sched_get_retrans(struct mptcp_sock *msk) +{ + struct mptcp_subflow_context *subflow; + struct mptcp_sched_data data; + + msk_owned_by_me(msk); + + /* the following check is moved out of mptcp_subflow_get_retrans */ + if (__mptcp_check_fallback(msk)) + return -EINVAL; + + mptcp_for_each_subflow(msk, subflow) { + if (READ_ONCE(subflow->scheduled)) + return 0; + } + + data.reinject = true; + if (msk->sched == &mptcp_sched_default || !msk->sched) + return mptcp_sched_default_get_subflow(msk, &data); + return msk->sched->get_subflow(msk, &data); +} |