diff options
Diffstat (limited to 'include/linux/skmsg.h')
| -rw-r--r-- | include/linux/skmsg.h | 434 |
1 files changed, 434 insertions, 0 deletions
diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h new file mode 100644 index 000000000000..2a11e9d91dfa --- /dev/null +++ b/include/linux/skmsg.h @@ -0,0 +1,434 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */ + +#ifndef _LINUX_SKMSG_H +#define _LINUX_SKMSG_H + +#include <linux/bpf.h> +#include <linux/filter.h> +#include <linux/scatterlist.h> +#include <linux/skbuff.h> + +#include <net/sock.h> +#include <net/tcp.h> +#include <net/strparser.h> + +#define MAX_MSG_FRAGS MAX_SKB_FRAGS + +enum __sk_action { + __SK_DROP = 0, + __SK_PASS, + __SK_REDIRECT, + __SK_NONE, +}; + +struct sk_msg_sg { + u32 start; + u32 curr; + u32 end; + u32 size; + u32 copybreak; + bool copy[MAX_MSG_FRAGS]; + /* The extra element is used for chaining the front and sections when + * the list becomes partitioned (e.g. end < start). The crypto APIs + * require the chaining. + */ + struct scatterlist data[MAX_MSG_FRAGS + 1]; +}; + +struct sk_msg { + struct sk_msg_sg sg; + void *data; + void *data_end; + u32 apply_bytes; + u32 cork_bytes; + u32 flags; + struct sk_buff *skb; + struct sock *sk_redir; + struct sock *sk; + struct list_head list; +}; + +struct sk_psock_progs { + struct bpf_prog *msg_parser; + struct bpf_prog *skb_parser; + struct bpf_prog *skb_verdict; +}; + +enum sk_psock_state_bits { + SK_PSOCK_TX_ENABLED, +}; + +struct sk_psock_link { + struct list_head list; + struct bpf_map *map; + void *link_raw; +}; + +struct sk_psock_parser { + struct strparser strp; + bool enabled; + void (*saved_data_ready)(struct sock *sk); +}; + +struct sk_psock_work_state { + struct sk_buff *skb; + u32 len; + u32 off; +}; + +struct sk_psock { + struct sock *sk; + struct sock *sk_redir; + u32 apply_bytes; + u32 cork_bytes; + u32 eval; + struct sk_msg *cork; + struct sk_psock_progs progs; + struct sk_psock_parser parser; + struct sk_buff_head ingress_skb; + struct list_head ingress_msg; + unsigned long state; + struct list_head link; + spinlock_t link_lock; + refcount_t refcnt; + void (*saved_unhash)(struct sock *sk); + void (*saved_close)(struct sock *sk, long timeout); + void (*saved_write_space)(struct sock *sk); + struct proto *sk_proto; + struct sk_psock_work_state work_state; + struct work_struct work; + union { + struct rcu_head rcu; + struct work_struct gc; + }; +}; + +int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len, + int elem_first_coalesce); +int sk_msg_clone(struct sock *sk, struct sk_msg *dst, struct sk_msg *src, + u32 off, u32 len); +void sk_msg_trim(struct sock *sk, struct sk_msg *msg, int len); +int sk_msg_free(struct sock *sk, struct sk_msg *msg); +int sk_msg_free_nocharge(struct sock *sk, struct sk_msg *msg); +void sk_msg_free_partial(struct sock *sk, struct sk_msg *msg, u32 bytes); +void sk_msg_free_partial_nocharge(struct sock *sk, struct sk_msg *msg, + u32 bytes); + +void sk_msg_return(struct sock *sk, struct sk_msg *msg, int bytes); +void sk_msg_return_zero(struct sock *sk, struct sk_msg *msg, int bytes); + +int sk_msg_zerocopy_from_iter(struct sock *sk, struct iov_iter *from, + struct sk_msg *msg, u32 bytes); +int sk_msg_memcopy_from_iter(struct sock *sk, struct iov_iter *from, + struct sk_msg *msg, u32 bytes); + +static inline void sk_msg_check_to_free(struct sk_msg *msg, u32 i, u32 bytes) +{ + WARN_ON(i == msg->sg.end && bytes); +} + +static inline void sk_msg_apply_bytes(struct sk_psock *psock, u32 bytes) +{ + if (psock->apply_bytes) { + if (psock->apply_bytes < bytes) + psock->apply_bytes = 0; + else + psock->apply_bytes -= bytes; + } +} + +#define sk_msg_iter_var_prev(var) \ + do { \ + if (var == 0) \ + var = MAX_MSG_FRAGS - 1; \ + else \ + var--; \ + } while (0) + +#define sk_msg_iter_var_next(var) \ + do { \ + var++; \ + if (var == MAX_MSG_FRAGS) \ + var = 0; \ + } while (0) + +#define sk_msg_iter_prev(msg, which) \ + sk_msg_iter_var_prev(msg->sg.which) + +#define sk_msg_iter_next(msg, which) \ + sk_msg_iter_var_next(msg->sg.which) + +static inline void sk_msg_clear_meta(struct sk_msg *msg) +{ + memset(&msg->sg, 0, offsetofend(struct sk_msg_sg, copy)); +} + +static inline void sk_msg_init(struct sk_msg *msg) +{ + BUILD_BUG_ON(ARRAY_SIZE(msg->sg.data) - 1 != MAX_MSG_FRAGS); + memset(msg, 0, sizeof(*msg)); + sg_init_marker(msg->sg.data, MAX_MSG_FRAGS); +} + +static inline void sk_msg_xfer(struct sk_msg *dst, struct sk_msg *src, + int which, u32 size) +{ + dst->sg.data[which] = src->sg.data[which]; + dst->sg.data[which].length = size; + dst->sg.size += size; + src->sg.data[which].length -= size; + src->sg.data[which].offset += size; +} + +static inline void sk_msg_xfer_full(struct sk_msg *dst, struct sk_msg *src) +{ + memcpy(dst, src, sizeof(*src)); + sk_msg_init(src); +} + +static inline bool sk_msg_full(const struct sk_msg *msg) +{ + return (msg->sg.end == msg->sg.start) && msg->sg.size; +} + +static inline u32 sk_msg_elem_used(const struct sk_msg *msg) +{ + if (sk_msg_full(msg)) + return MAX_MSG_FRAGS; + + return msg->sg.end >= msg->sg.start ? + msg->sg.end - msg->sg.start : + msg->sg.end + (MAX_MSG_FRAGS - msg->sg.start); +} + +static inline struct scatterlist *sk_msg_elem(struct sk_msg *msg, int which) +{ + return &msg->sg.data[which]; +} + +static inline struct scatterlist sk_msg_elem_cpy(struct sk_msg *msg, int which) +{ + return msg->sg.data[which]; +} + +static inline struct page *sk_msg_page(struct sk_msg *msg, int which) +{ + return sg_page(sk_msg_elem(msg, which)); +} + +static inline bool sk_msg_to_ingress(const struct sk_msg *msg) +{ + return msg->flags & BPF_F_INGRESS; +} + +static inline void sk_msg_compute_data_pointers(struct sk_msg *msg) +{ + struct scatterlist *sge = sk_msg_elem(msg, msg->sg.start); + + if (msg->sg.copy[msg->sg.start]) { + msg->data = NULL; + msg->data_end = NULL; + } else { + msg->data = sg_virt(sge); + msg->data_end = msg->data + sge->length; + } +} + +static inline void sk_msg_page_add(struct sk_msg *msg, struct page *page, + u32 len, u32 offset) +{ + struct scatterlist *sge; + + get_page(page); + sge = sk_msg_elem(msg, msg->sg.end); + sg_set_page(sge, page, len, offset); + sg_unmark_end(sge); + + msg->sg.copy[msg->sg.end] = true; + msg->sg.size += len; + sk_msg_iter_next(msg, end); +} + +static inline void sk_msg_sg_copy(struct sk_msg *msg, u32 i, bool copy_state) +{ + do { + msg->sg.copy[i] = copy_state; + sk_msg_iter_var_next(i); + if (i == msg->sg.end) + break; + } while (1); +} + +static inline void sk_msg_sg_copy_set(struct sk_msg *msg, u32 start) +{ + sk_msg_sg_copy(msg, start, true); +} + +static inline void sk_msg_sg_copy_clear(struct sk_msg *msg, u32 start) +{ + sk_msg_sg_copy(msg, start, false); +} + +static inline struct sk_psock *sk_psock(const struct sock *sk) +{ + return rcu_dereference_sk_user_data(sk); +} + +static inline void sk_psock_queue_msg(struct sk_psock *psock, + struct sk_msg *msg) +{ + list_add_tail(&msg->list, &psock->ingress_msg); +} + +static inline bool sk_psock_queue_empty(const struct sk_psock *psock) +{ + return psock ? list_empty(&psock->ingress_msg) : true; +} + +static inline void sk_psock_report_error(struct sk_psock *psock, int err) +{ + struct sock *sk = psock->sk; + + sk->sk_err = err; + sk->sk_error_report(sk); +} + +struct sk_psock *sk_psock_init(struct sock *sk, int node); + +int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock); +void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock); +void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock); + +int sk_psock_msg_verdict(struct sock *sk, struct sk_psock *psock, + struct sk_msg *msg); + +static inline struct sk_psock_link *sk_psock_init_link(void) +{ + return kzalloc(sizeof(struct sk_psock_link), + GFP_ATOMIC | __GFP_NOWARN); +} + +static inline void sk_psock_free_link(struct sk_psock_link *link) +{ + kfree(link); +} + +struct sk_psock_link *sk_psock_link_pop(struct sk_psock *psock); +#if defined(CONFIG_BPF_STREAM_PARSER) +void sk_psock_unlink(struct sock *sk, struct sk_psock_link *link); +#else +static inline void sk_psock_unlink(struct sock *sk, + struct sk_psock_link *link) +{ +} +#endif + +void __sk_psock_purge_ingress_msg(struct sk_psock *psock); + +static inline void sk_psock_cork_free(struct sk_psock *psock) +{ + if (psock->cork) { + sk_msg_free(psock->sk, psock->cork); + kfree(psock->cork); + psock->cork = NULL; + } +} + +static inline void sk_psock_update_proto(struct sock *sk, + struct sk_psock *psock, + struct proto *ops) +{ + psock->saved_unhash = sk->sk_prot->unhash; + psock->saved_close = sk->sk_prot->close; + psock->saved_write_space = sk->sk_write_space; + + psock->sk_proto = sk->sk_prot; + sk->sk_prot = ops; +} + +static inline void sk_psock_restore_proto(struct sock *sk, + struct sk_psock *psock) +{ + if (psock->sk_proto) { + sk->sk_prot = psock->sk_proto; + psock->sk_proto = NULL; + } +} + +static inline void sk_psock_set_state(struct sk_psock *psock, + enum sk_psock_state_bits bit) +{ + set_bit(bit, &psock->state); +} + +static inline void sk_psock_clear_state(struct sk_psock *psock, + enum sk_psock_state_bits bit) +{ + clear_bit(bit, &psock->state); +} + +static inline bool sk_psock_test_state(const struct sk_psock *psock, + enum sk_psock_state_bits bit) +{ + return test_bit(bit, &psock->state); +} + +static inline struct sk_psock *sk_psock_get_checked(struct sock *sk) +{ + struct sk_psock *psock; + + rcu_read_lock(); + psock = sk_psock(sk); + if (psock) { + if (sk->sk_prot->recvmsg != tcp_bpf_recvmsg) { + psock = ERR_PTR(-EBUSY); + goto out; + } + + if (!refcount_inc_not_zero(&psock->refcnt)) + psock = ERR_PTR(-EBUSY); + } +out: + rcu_read_unlock(); + return psock; +} + +static inline struct sk_psock *sk_psock_get(struct sock *sk) +{ + struct sk_psock *psock; + + rcu_read_lock(); + psock = sk_psock(sk); + if (psock && !refcount_inc_not_zero(&psock->refcnt)) + psock = NULL; + rcu_read_unlock(); + return psock; +} + +void sk_psock_stop(struct sock *sk, struct sk_psock *psock); +void sk_psock_destroy(struct rcu_head *rcu); +void sk_psock_drop(struct sock *sk, struct sk_psock *psock); + +static inline void sk_psock_put(struct sock *sk, struct sk_psock *psock) +{ + if (refcount_dec_and_test(&psock->refcnt)) + sk_psock_drop(sk, psock); +} + +static inline void psock_set_prog(struct bpf_prog **pprog, + struct bpf_prog *prog) +{ + prog = xchg(pprog, prog); + if (prog) + bpf_prog_put(prog); +} + +static inline void psock_progs_drop(struct sk_psock_progs *progs) +{ + psock_set_prog(&progs->msg_parser, NULL); + psock_set_prog(&progs->skb_parser, NULL); + psock_set_prog(&progs->skb_verdict, NULL); +} + +#endif /* _LINUX_SKMSG_H */ |