CasperSecurity
/* 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
#define NR_MSG_FRAG_IDS (MAX_MSG_FRAGS + 1)
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;
unsigned long copy;
/* The extra two elements:
* 1) used for chaining the front and sections when the list becomes
* partitioned (e.g. end < start). The crypto APIs require the
* chaining;
* 2) to chain tailer SG entries after the message.
*/
struct scatterlist data[MAX_MSG_FRAGS + 2];
};
static_assert(BITS_PER_LONG >= NR_MSG_FRAG_IDS);
/* UAPI in filter.c depends on struct sk_msg_sg being first element. */
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 *stream_parser;
struct bpf_prog *stream_verdict;
struct bpf_prog *skb_verdict;
};
enum sk_psock_state_bits {
SK_PSOCK_TX_ENABLED,
SK_PSOCK_RX_STRP_ENABLED,
};
struct sk_psock_link {
struct list_head list;
struct bpf_map *map;
void *link_raw;
};
struct sk_psock_work_state {
u32 len;
u32 off;
};
struct sk_psock {
struct sock *sk;
struct sock *sk_redir;
u32 apply_bytes;
u32 cork_bytes;
u32 eval;
bool redir_ingress; /* undefined if sk_redir is null */
struct sk_msg *cork;
struct sk_psock_progs progs;
#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
struct strparser strp;
#endif
struct sk_buff_head ingress_skb;
struct list_head ingress_msg;
spinlock_t ingress_lock;
unsigned long state;
struct list_head link;
spinlock_t link_lock;
refcount_t refcnt;
void (*saved_unhash)(struct sock *sk);
void (*saved_destroy)(struct sock *sk);
void (*saved_close)(struct sock *sk, long timeout);
void (*saved_write_space)(struct sock *sk);
void (*saved_data_ready)(struct sock *sk);
int (*psock_update_sk_prot)(struct sock *sk, struct sk_psock *psock,
bool restore);
struct proto *sk_proto;
struct mutex work_mutex;
struct sk_psock_work_state work_state;
struct delayed_work work;
struct rcu_work rwork;
};
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);
int sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg,
int len, int flags);
bool sk_msg_is_readable(struct sock *sk);
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;
}
}
static inline u32 sk_msg_iter_dist(u32 start, u32 end)
{
return end >= start ? end - start : end + (NR_MSG_FRAG_IDS - start);
}
#define sk_msg_iter_var_prev(var) \
do { \
if (var == 0) \
var = NR_MSG_FRAG_IDS - 1; \
else \
var--; \
} while (0)
#define sk_msg_iter_var_next(var) \
do { \
var++; \
if (var == NR_MSG_FRAG_IDS) \
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 != NR_MSG_FRAG_IDS);
memset(msg, 0, sizeof(*msg));
sg_init_marker(msg->sg.data, NR_MSG_FRAG_IDS);
}
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.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 sk_msg_iter_dist(msg->sg.start, msg->sg.end) == MAX_MSG_FRAGS;
}
static inline u32 sk_msg_elem_used(const struct sk_msg *msg)
{
return sk_msg_iter_dist(msg->sg.start, msg->sg.end);
}
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 (test_bit(msg->sg.start, &msg->sg.copy)) {
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);
__set_bit(msg->sg.end, &msg->sg.copy);
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 {
if (copy_state)
__set_bit(i, &msg->sg.copy);
else
__clear_bit(i, &msg->sg.copy);
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_with_flags(sk,
SK_USER_DATA_PSOCK);
}
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 void sock_drop(struct sock *sk, struct sk_buff *skb)
{
sk_drops_add(sk, skb);
kfree_skb(skb);
}
static inline bool sk_psock_queue_msg(struct sk_psock *psock,
struct sk_msg *msg)
{
bool ret;
spin_lock_bh(&psock->ingress_lock);
if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) {
list_add_tail(&msg->list, &psock->ingress_msg);
ret = true;
} else {
sk_msg_free(psock->sk, msg);
kfree(msg);
ret = false;
}
spin_unlock_bh(&psock->ingress_lock);
return ret;
}
static inline struct sk_msg *sk_psock_dequeue_msg(struct sk_psock *psock)
{
struct sk_msg *msg;
spin_lock_bh(&psock->ingress_lock);
msg = list_first_entry_or_null(&psock->ingress_msg, struct sk_msg, list);
if (msg)
list_del(&msg->list);
spin_unlock_bh(&psock->ingress_lock);
return msg;
}
static inline struct sk_msg *sk_psock_peek_msg(struct sk_psock *psock)
{
struct sk_msg *msg;
spin_lock_bh(&psock->ingress_lock);
msg = list_first_entry_or_null(&psock->ingress_msg, struct sk_msg, list);
spin_unlock_bh(&psock->ingress_lock);
return msg;
}
static inline struct sk_msg *sk_psock_next_msg(struct sk_psock *psock,
struct sk_msg *msg)
{
struct sk_msg *ret;
spin_lock_bh(&psock->ingress_lock);
if (list_is_last(&msg->list, &psock->ingress_msg))
ret = NULL;
else
ret = list_next_entry(msg, list);
spin_unlock_bh(&psock->ingress_lock);
return ret;
}
static inline bool sk_psock_queue_empty(const struct sk_psock *psock)
{
return psock ? list_empty(&psock->ingress_msg) : true;
}
static inline void kfree_sk_msg(struct sk_msg *msg)
{
if (msg->skb)
consume_skb(msg->skb);
kfree(msg);
}
static inline void sk_psock_report_error(struct sk_psock *psock, int err)
{
struct sock *sk = psock->sk;
sk->sk_err = err;
sk_error_report(sk);
}
struct sk_psock *sk_psock_init(struct sock *sk, int node);
void sk_psock_stop(struct sk_psock *psock);
#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
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);
#else
static inline int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock)
{
return -EOPNOTSUPP;
}
static inline void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock)
{
}
static inline void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock)
{
}
#endif
void sk_psock_start_verdict(struct sock *sk, struct sk_psock *psock);
void sk_psock_stop_verdict(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);
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_restore_proto(struct sock *sk,
struct sk_psock *psock)
{
if (psock->psock_update_sk_prot)
psock->psock_update_sk_prot(sk, psock, true);
}
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_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 sk_psock_data_ready(struct sock *sk, struct sk_psock *psock)
{
read_lock_bh(&sk->sk_callback_lock);
if (psock->saved_data_ready)
psock->saved_data_ready(sk);
else
sk->sk_data_ready(sk);
read_unlock_bh(&sk->sk_callback_lock);
}
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 int psock_replace_prog(struct bpf_prog **pprog,
struct bpf_prog *prog,
struct bpf_prog *old)
{
if (cmpxchg(pprog, old, prog) != old)
return -ENOENT;
if (old)
bpf_prog_put(old);
return 0;
}
static inline void psock_progs_drop(struct sk_psock_progs *progs)
{
psock_set_prog(&progs->msg_parser, NULL);
psock_set_prog(&progs->stream_parser, NULL);
psock_set_prog(&progs->stream_verdict, NULL);
psock_set_prog(&progs->skb_verdict, NULL);
}
int sk_psock_tls_strp_read(struct sk_psock *psock, struct sk_buff *skb);
static inline bool sk_psock_strp_enabled(struct sk_psock *psock)
{
if (!psock)
return false;
return !!psock->saved_data_ready;
}
#if IS_ENABLED(CONFIG_NET_SOCK_MSG)
#define BPF_F_STRPARSER (1UL << 1)
/* We only have two bits so far. */
#define BPF_F_PTR_MASK ~(BPF_F_INGRESS | BPF_F_STRPARSER)
static inline bool skb_bpf_strparser(const struct sk_buff *skb)
{
unsigned long sk_redir = skb->_sk_redir;
return sk_redir & BPF_F_STRPARSER;
}
static inline void skb_bpf_set_strparser(struct sk_buff *skb)
{
skb->_sk_redir |= BPF_F_STRPARSER;
}
static inline bool skb_bpf_ingress(const struct sk_buff *skb)
{
unsigned long sk_redir = skb->_sk_redir;
return sk_redir & BPF_F_INGRESS;
}
static inline void skb_bpf_set_ingress(struct sk_buff *skb)
{
skb->_sk_redir |= BPF_F_INGRESS;
}
static inline void skb_bpf_set_redir(struct sk_buff *skb, struct sock *sk_redir,
bool ingress)
{
skb->_sk_redir = (unsigned long)sk_redir;
if (ingress)
skb->_sk_redir |= BPF_F_INGRESS;
}
static inline struct sock *skb_bpf_redirect_fetch(const struct sk_buff *skb)
{
unsigned long sk_redir = skb->_sk_redir;
return (struct sock *)(sk_redir & BPF_F_PTR_MASK);
}
static inline void skb_bpf_redirect_clear(struct sk_buff *skb)
{
skb->_sk_redir = 0;
}
#endif /* CONFIG_NET_SOCK_MSG */
#endif /* _LINUX_SKMSG_H */