// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */
#include <linux/skmsg.h>
#include <linux/skbuff.h>
#include <linux/scatterlist.h>
#include <net/sock.h>
#include <net/tcp.h>
#include <net/tls.h>
#include <trace/events/sock.h>
static bool sk_msg_try_coalesce_ok(struct sk_msg *msg, int elem_first_coalesce)
{
if (msg->sg.end > msg->sg.start &&
elem_first_coalesce < msg->sg.end)
return true;
if (msg->sg.end < msg->sg.start &&
(elem_first_coalesce > msg->sg.start ||
elem_first_coalesce < msg->sg.end))
return true;
return false;
}
int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len,
int elem_first_coalesce)
{
struct page_frag *pfrag = sk_page_frag(sk);
u32 osize = msg->sg.size;
int ret = 0;
len -= msg->sg.size;
while (len > 0) {
struct scatterlist *sge;
u32 orig_offset;
int use, i;
if (!sk_page_frag_refill(sk, pfrag)) {
ret = -ENOMEM;
goto msg_trim;
}
orig_offset = pfrag->offset;
use = min_t(int, len, pfrag->size - orig_offset);
if (!sk_wmem_schedule(sk, use)) {
ret = -ENOMEM;
goto msg_trim;
}
i = msg->sg.end;
sk_msg_iter_var_prev(i);
sge = &msg->sg.data[i];
if (sk_msg_try_coalesce_ok(msg, elem_first_coalesce) &&
sg_page(sge) == pfrag->page &&
sge->offset + sge->length == orig_offset) {
sge->length += use;
} else {
if (sk_msg_full(msg)) {
ret = -ENOSPC;
break;
}
sge = &msg->sg.data[msg->sg.end];
sg_unmark_end(sge);
sg_set_page(sge, pfrag->page, use, orig_offset);
get_page(pfrag->page);
sk_msg_iter_next(msg, end);
}
sk_mem_charge(sk, use);
msg->sg.size += use;
pfrag->offset += use;
len -= use;
}
return ret;
msg_trim:
sk_msg_trim(sk, msg, osize);
return ret;
}
EXPORT_SYMBOL_GPL(sk_msg_alloc);
int sk_msg_clone(struct sock *sk, struct sk_msg *dst, struct sk_msg *src,
u32 off, u32 len)
{
int i = src->sg.start;
struct scatterlist *sge = sk_msg_elem(src, i);
struct scatterlist *sgd = NULL;
u32 sge_len, sge_off;
while (off) {
if (sge->length > off)
break;
off -= sge->length;
sk_msg_iter_var_next(i);
if (i == src->sg.end && off)
return -ENOSPC;
sge = sk_msg_elem(src, i);
}
while (len) {
sge_len = sge->length - off;
if (sge_len > len)
sge_len = len;
if (dst->sg.end)
sgd = sk_msg_elem(dst, dst->sg.end - 1);
if (sgd &&
(sg_page(sge) == sg_page(sgd)) &&
(sg_virt(sge) + off == sg_virt(sgd) + sgd->length)) {
sgd->length += sge_len;
dst->sg.size += sge_len;
} else if (!sk_msg_full(dst)) {
sge_off = sge->offset + off;
sk_msg_page_add(dst, sg_page(sge), sge_len, sge_off);
} else {
return -ENOSPC;
}
off = 0;
len -= sge_len;
sk_mem_charge(sk, sge_len);
sk_msg_iter_var_next(i);
if (i == src->sg.end && len)
return -ENOSPC;
sge = sk_msg_elem(src, i);
}
return 0;
}
EXPORT_SYMBOL_GPL(sk_msg_clone);
void sk_msg_return_zero(struct sock *sk, struct sk_msg *msg, int bytes)
{
int i = msg->sg.start;
do {
struct scatterlist *sge = sk_msg_elem(msg, i);
if (bytes < sge->length) {
sge->length -= bytes;
sge->offset += bytes;
sk_mem_uncharge(sk, bytes);
break;
}
sk_mem_uncharge(sk, sge->length);
bytes -= sge->length;
sge->length = 0;
sge->offset = 0;
sk_msg_iter_var_next(i);
} while (bytes && i != msg->sg.end);
msg->sg.start = i;
}
EXPORT_SYMBOL_GPL(sk_msg_return_zero);
void sk_msg_return(struct sock *sk, struct sk_msg *msg, int bytes)
{
int i = msg->sg.start;
do {
struct scatterlist *sge = &msg->sg.data[i];
int uncharge = (bytes < sge->length) ? bytes : sge->length;
sk_mem_uncharge(sk, uncharge);
bytes -= uncharge;
sk_msg_iter_var_next(i);
} while (i != msg->sg.end);
}
EXPORT_SYMBOL_GPL(sk_msg_return);
static int sk_msg_free_elem(struct sock *sk, struct sk_msg *msg, u32 i,
bool charge)
{
struct scatterlist *sge = sk_msg_elem(msg, i);
u32 len = sge->length;
/* When the skb owns the memory we free it from consume_skb path. */
if (!msg->skb) {
if (charge)
sk_mem_uncharge(sk, len);
put_page(sg_page(sge));
}
memset(sge, 0, sizeof(*sge));
return len;
}
static int __sk_msg_free(struct sock *sk, struct sk_msg *msg, u32 i,
bool charge)
{
struct scatterlist *sge = sk_msg_elem(msg, i);
int freed = 0;
while (msg->sg.size) {
msg->sg.size -= sge->length;
freed += sk_msg_free_elem(sk, msg, i, charge);
sk_msg_iter_var_next(i);
sk_msg_check_to_free(msg, i, msg->sg.size);
sge = sk_msg_elem(msg, i);
}
consume_skb(msg->skb);
sk_msg_init(msg);
return freed;
}
int sk_msg_free_nocharge(struct sock *sk, struct sk_msg *msg)
{
return __sk_msg_free(sk, msg, msg->sg.start, false);
}
EXPORT_SYMBOL_GPL(sk_msg_free_nocharge);
int sk_msg_free(struct sock *sk, struct sk_msg *msg)
{
return __sk_msg_free(sk, msg, msg->sg.start, true);
}
EXPORT_SYMBOL_GPL(sk_msg_free);
static void __sk_msg_free_partial(struct sock *sk, struct sk_msg *msg,
u32 bytes, bool charge)
{
struct scatterlist *sge;
u32 i = msg->sg.start;
while (bytes) {
sge = sk_msg_elem(msg, i);
if (!sge->length)
break;
if (bytes < sge->length) {
if (charge)
sk_mem_uncharge(sk, bytes);
sge->length -= bytes;
sge->offset += bytes;
msg->sg.size -= bytes;
break;
}
msg->sg.size -= sge->length;
bytes -= sge->length;
sk_msg_free_elem(sk, msg, i, charge);
sk_msg_iter_var_next(i);
sk_msg_check_to_free(msg, i, bytes);
}
msg->sg.start = i;
}
void sk_msg_free_partial(struct sock *sk, struct sk_msg *msg, u32 bytes)
{
__sk_msg_free_partial(sk, msg, bytes, true);
}
EXPORT_SYMBOL_GPL(sk_msg_free_partial);
void sk_msg_free_partial_nocharge(struct sock *sk, struct sk_msg *msg,
u32 bytes)
{
__sk_msg_free_partial(sk, msg, bytes, false);
}
void sk_msg_trim(struct sock *sk, struct sk_msg *msg, int len)
{
int trim = msg->sg.size - len;
u32 i = msg->sg.end;
if (trim <= 0) {
WARN_ON(trim < 0);
return;
}
sk_msg_iter_var_prev(i);
msg->sg.size = len;
while (msg->sg.data[i].length &&
trim >= msg->sg.data[i].length) {
trim -= msg->sg.data[i].length;
sk_msg_free_elem(sk, msg, i, true);
sk_msg_iter_var_prev(i);
if (!trim)
goto out;
}
msg->sg.data[i].length -= trim;
sk_mem_uncharge(sk, trim);
/* Adjust copybreak if it falls into the trimmed part of last buf */
if (msg->sg.curr == i && msg->sg.copybreak > msg->sg.data[i].length)
msg->sg.copybreak = msg->sg.data[i].length;
out:
sk_msg_iter_var_next(i);
msg->sg.end = i;
/* If we trim data a full sg elem before curr pointer update
* copybreak and current so that any future copy operations
* start at new copy location.
* However trimmed data that has not yet been used in a copy op
* does not require an update.
*/
if (!msg->sg.size) {
msg->sg.curr = msg->sg.start;
msg->sg.copybreak = 0;
} else if (sk_msg_iter_dist(msg->sg.start, msg->sg.curr) >=
sk_msg_iter_dist(msg->sg.start, msg->sg.end)) {
sk_msg_iter_var_prev(i);
msg->sg.curr = i;
msg->sg.copybreak = msg->sg.data[i].length;
}
}
EXPORT_SYMBOL_GPL(sk_msg_trim);
int sk_msg_zerocopy_from_iter(struct sock *sk, struct iov_iter *from,
struct sk_msg *msg, u32 bytes)
{
int i, maxpages, ret = 0, num_elems = sk_msg_elem_used(msg);
const int to_max_pages = MAX_MSG_FRAGS;
struct page *pages[MAX_MSG_FRAGS];
ssize_t orig, copied, use, offset;
orig = msg->sg.size;
while (bytes > 0) {
i = 0;
maxpages = to_max_pages - num_elems;
if (maxpages == 0) {
ret = -EFAULT;
goto out;
}
copied = iov_iter_get_pages2(from, pages, bytes, maxpages,
&offset);
if (copied <= 0) {
ret = -EFAULT;
goto out;
}
bytes -= copied;
msg->sg.size += copied;
while (copied) {
use = min_t(int, copied, PAGE_SIZE - offset);
sg_set_page(&msg->sg.data[msg->sg.end],
pages[i], use, offset);
sg_unmark_end(&msg->sg.data[msg->sg.end]);
sk_mem_charge(sk, use);
offset = 0;
copied -= use;
sk_msg_iter_next(msg, end);
num_elems++;
i++;
}
/* When zerocopy is mixed with sk_msg_*copy* operations we
* may have a copybreak set in this case clear and prefer
* zerocopy remainder when possible.
*/
msg->sg.copybreak = 0;
msg->sg.curr = msg->sg.end;
}
out:
/* Revert iov_iter updates, msg will need to use 'trim' later if it
* also needs to be cleared.
*/
if (ret)
iov_iter_revert(from, msg->sg.size - orig);
return ret;
}
EXPORT_SYMBOL_GPL(sk_msg_zerocopy_from_iter);
int sk_msg_memcopy_from_iter(struct sock *sk, struct iov_iter *from,
struct sk_msg *msg, u32 bytes)
{
int ret = -ENOSPC, i = msg->sg.curr;
struct scatterlist *sge;
u32 copy, buf_size;
void *to;
do {
sge = sk_msg_elem(msg, i);
/* This is possible if a trim operation shrunk the buffer */
if (msg->sg.copybreak >= sge->length) {
msg->sg.copybreak = 0;
sk_msg_iter_var_next(i);
if (i == msg->sg.end)
break;
sge = sk_msg_elem(msg, i);
}
buf_size = sge->length - msg->sg.copybreak;
copy = (buf_size > bytes) ? bytes : buf_size;
to = sg_virt(sge) + msg->sg.copybreak;
msg->sg.copybreak += copy;
if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY)
ret = copy_from_iter_nocache(to, copy, from);
else
ret = copy_from_iter(to, copy, from);
if (ret != copy) {
ret = -EFAULT;
goto out;
}
bytes -= copy;
if (!bytes)
break;
msg->sg.copybreak = 0;
sk_msg_iter_var_next(i);
} while (i != msg->sg.end);
out:
msg->sg.curr = i;
return ret;
}
EXPORT_SYMBOL_GPL(sk_msg_memcopy_from_iter);
/* Receive sk_msg from psock->ingress_msg to @msg. */
int sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg,
int len, int flags)
{
struct iov_iter *iter = &msg->msg_iter;
int peek = flags & MSG_PEEK;
struct sk_msg *msg_rx;
int i, copied = 0;
msg_rx = sk_psock_peek_msg(psock);
while (copied != len) {
struct scatterlist *sge;
if (unlikely(!msg_rx))
break;
i = msg_rx->sg.start;
do {
struct page *page;
int copy;
sge = sk_msg_elem(msg_rx, i);
copy = sge->length;
page = sg_page(sge);
if (copied + copy > len)
copy = len - copied;
if (copy)
copy = copy_page_to_iter(page, sge->offset, copy, iter);
if (!copy) {
copied = copied ? copied : -EFAULT;
goto out;
}
copied += copy;
if (likely(!peek)) {
sge->offset += copy;
sge->length -= copy;
if (!msg_rx->skb)
sk_mem_uncharge(sk, copy);
msg_rx->sg.size -= copy;
if (!sge->length) {
sk_msg_iter_var_next(i);
if (!msg_rx->skb)
put_page(page);
}
} else {
/* Lets not optimize peek case if copy_page_to_iter
* didn't copy the entire length lets just break.
*/
if (copy != sge->length)
goto out;
sk_msg_iter_var_next(i);
}
if (copied == len)
break;
} while ((i != msg_rx->sg.end) && !sg_is_last(sge));
if (unlikely(peek)) {
msg_rx = sk_psock_next_msg(psock, msg_rx);
if (!msg_rx)
break;
continue;
}
msg_rx->sg.start = i;
if (!sge->length && (i == msg_rx->sg.end || sg_is_last(sge))) {
msg_rx = sk_psock_dequeue_msg(psock);
kfree_sk_msg(msg_rx);
}
msg_rx = sk_psock_peek_msg(psock);
}
out:
return copied;
}
EXPORT_SYMBOL_GPL(sk_msg_recvmsg);
bool sk_msg_is_readable(struct sock *sk)
{
struct sk_psock *psock;
bool empty = true;
rcu_read_lock();
psock = sk_psock(sk);
if (likely(psock))
empty = list_empty(&psock->ingress_msg);
rcu_read_unlock();
return !empty;
}
EXPORT_SYMBOL_GPL(sk_msg_is_readable);
static struct sk_msg *alloc_sk_msg(gfp_t gfp)
{
struct sk_msg *msg;
msg = kzalloc(sizeof(*msg), gfp | __GFP_NOWARN);
if (unlikely(!msg))
return NULL;
sg_init_marker(msg->sg.data, NR_MSG_FRAG_IDS);
return msg;
}
static struct sk_msg *sk_psock_create_ingress_msg(struct sock *sk,
struct sk_buff *skb)
{
if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf)
return NULL;
if (!sk_rmem_schedule(sk, skb, skb->truesize))
return NULL;
return alloc_sk_msg(GFP_KERNEL);
}
static int sk_psock_skb_ingress_enqueue(struct sk_buff *skb,
u32 off, u32 len,
struct sk_psock *psock,
struct sock *sk,
struct sk_msg *msg)
{
int num_sge, copied;
num_sge = skb_to_sgvec(skb, msg->sg.data, off, len);
if (num_sge < 0) {
/* skb linearize may fail with ENOMEM, but lets simply try again
* later if this happens. Under memory pressure we don't want to
* drop the skb. We need to linearize the skb so that the mapping
* in skb_to_sgvec can not error.
*/
if (skb_linearize(skb))
return -EAGAIN;
num_sge = skb_to_sgvec(skb, msg->sg.data, off, len);
if (unlikely(num_sge < 0))
return num_sge;
}
copied = len;
msg->sg.start = 0;
msg->sg.size = copied;
msg->sg.end = num_sge;
msg->skb = skb;
sk_psock_queue_msg(psock, msg);
sk_psock_data_ready(sk, psock);
return copied;
}
static int sk_psock_skb_ingress_self(struct sk_psock *psock, struct sk_buff *skb,
u32 off, u32 len);
static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb,
u32 off, u32 len)
{
struct sock *sk = psock->sk;
struct sk_msg *msg;
int err;
/* If we are receiving on the same sock skb->sk is already assigned,
* skip memory accounting and owner transition seeing it already set
* correctly.
*/
if (unlikely(skb->sk == sk))
return sk_psock_skb_ingress_self(psock, skb, off, len);
msg = sk_psock_create_ingress_msg(sk, skb);
if (!msg)
return -EAGAIN;
/* This will transition ownership of the data from the socket where
* the BPF program was run initiating the redirect to the socket
* we will eventually receive this data on. The data will be released
* from skb_consume found in __tcp_bpf_recvmsg() after its been copied
* into user buffers.
*/
skb_set_owner_r(skb, sk);
err = sk_psock_skb_ingress_enqueue(skb, off, len, psock, sk, msg);
if (err < 0)
kfree(msg);
return err;
}
/* Puts an skb on the ingress queue of the socket already assigned to the
* skb. In this case we do not need to check memory limits or skb_set_owner_r
* because the skb is already accounted for here.
*/
static int sk_psock_skb_ingress_self(struct sk_psock *psock, struct sk_buff *skb,
u32 off, u32 len)
{
struct sk_msg *msg = alloc_sk_msg(GFP_ATOMIC);
struct sock *sk = psock->sk;
int err;
if (unlikely(!msg))
return -EAGAIN;
skb_set_owner_r(skb, sk);
err = sk_psock_skb_ingress_enqueue(skb, off, len, psock, sk, msg);
if (err < 0)
kfree(msg);
return err;
}
static int sk_psock_handle_skb(struct sk_psock *psock, struct sk_buff *skb,
u32 off, u32 len, bool ingress)
{
int err = 0;
if (!ingress) {
if (!sock_writeable(psock->sk))
return -EAGAIN;
return skb_send_sock(psock->sk, skb, off, len);
}
skb_get(skb);
err = sk_psock_skb_ingress(psock, skb, off, len);
if (err < 0)
kfree_skb(skb);
return err;
}
static void sk_psock_skb_state(struct sk_psock *psock,
struct sk_psock_work_state *state,
int len, int off)
{
spin_lock_bh(&psock->ingress_lock);
if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) {
state->len = len;
state->off = off;
}
spin_unlock_bh(&psock->ingress_lock);
}
static void sk_psock_backlog(struct work_struct *work)
{
struct delayed_work *dwork = to_delayed_work(work);
struct sk_psock *psock = container_of(dwork, struct sk_psock, work);
struct sk_psock_work_state *state = &psock->work_state;
struct sk_buff *skb = NULL;
u32 len = 0, off = 0;
bool ingress;
int ret;
mutex_lock(&psock->work_mutex);
if (unlikely(state->len)) {
len = state->len;
off = state->off;
}
while ((skb = skb_peek(&psock->ingress_skb))) {
len = skb->len;
off = 0;
if (skb_bpf_strparser(skb)) {
struct strp_msg *stm = strp_msg(skb);
off = stm->offset;
len = stm->full_len;
}
ingress = skb_bpf_ingress(skb);
skb_bpf_redirect_clear(skb);
do {
ret = -EIO;
if (!sock_flag(psock->sk, SOCK_DEAD))
ret = sk_psock_handle_skb(psock, skb, off,
len, ingress);
if (ret <= 0) {
if (ret == -EAGAIN) {
sk_psock_skb_state(psock, state, len, off);
/* Delay slightly to prioritize any
* other work that might be here.
*/
if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED))
schedule_delayed_work(&psock->work, 1);
goto end;
}
/* Hard errors break pipe and stop xmit. */
sk_psock_report_error(psock, ret ? -ret : EPIPE);
sk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED);
goto end;
}
off += ret;
len -= ret;
} while (len);
skb = skb_dequeue(&psock->ingress_skb);
kfree_skb(skb);
}
end:
mutex_unlock(&psock->work_mutex);
}
struct sk_psock *sk_psock_init(struct sock *sk, int node)
{
struct sk_psock *psock;
struct proto *prot;
write_lock_bh(&sk->sk_callback_lock);
if (sk_is_inet(sk) && inet_csk_has_ulp(sk)) {
psock = ERR_PTR(-EINVAL);
goto out;
}
if (sk->sk_user_data) {
psock = ERR_PTR(-EBUSY);
goto out;
}
psock = kzalloc_node(sizeof(*psock), GFP_ATOMIC | __GFP_NOWARN, node);
if (!psock) {
psock = ERR_PTR(-ENOMEM);
goto out;
}
prot = READ_ONCE(sk->sk_prot);
psock->sk = sk;
psock->eval = __SK_NONE;
psock->sk_proto = prot;
psock->saved_unhash = prot->unhash;
psock->saved_destroy = prot->destroy;
psock->saved_close = prot->close;
psock->saved_write_space = sk->sk_write_space;
INIT_LIST_HEAD(&psock->link);
spin_lock_init(&psock->link_lock);
INIT_DELAYED_WORK(&psock->work, sk_psock_backlog);
mutex_init(&psock->work_mutex);
INIT_LIST_HEAD(&psock->ingress_msg);
spin_lock_init(&psock->ingress_lock);
skb_queue_head_init(&psock->ingress_skb);
sk_psock_set_state(psock, SK_PSOCK_TX_ENABLED);
refcount_set(&psock->refcnt, 1);
__rcu_assign_sk_user_data_with_flags(sk, psock,
SK_USER_DATA_NOCOPY |
SK_USER_DATA_PSOCK);
sock_hold(sk);
out:
write_unlock_bh(&sk->sk_callback_lock);
return psock;
}
EXPORT_SYMBOL_GPL(sk_psock_init);
struct sk_psock_link *sk_psock_link_pop(struct sk_psock *psock)
{
struct sk_psock_link *link;
spin_lock_bh(&psock->link_lock);
link = list_first_entry_or_null(&psock->link, struct sk_psock_link,
list);
if (link)
list_del(&link->list);
spin_unlock_bh(&psock->link_lock);
return link;
}
static void __sk_psock_purge_ingress_msg(struct sk_psock *psock)
{
struct sk_msg *msg, *tmp;
list_for_each_entry_safe(msg, tmp, &psock->ingress_msg, list) {
list_del(&msg->list);
sk_msg_free(psock->sk, msg);
kfree(msg);
}
}
static void __sk_psock_zap_ingress(struct sk_psock *psock)
{
struct sk_buff *skb;
while ((skb = skb_dequeue(&psock->ingress_skb)) != NULL) {
skb_bpf_redirect_clear(skb);
sock_drop(psock->sk, skb);
}
__sk_psock_purge_ingress_msg(psock);
}
static void sk_psock_link_destroy(struct sk_psock *psock)
{
struct sk_psock_link *link, *tmp;
list_for_each_entry_safe(link, tmp, &psock->link, list) {
list_del(&link->list);
sk_psock_free_link(link);
}
}
void sk_psock_stop(struct sk_psock *psock)
{
spin_lock_bh(&psock->ingress_lock);
sk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED);
sk_psock_cork_free(psock);
spin_unlock_bh(&psock->ingress_lock);
}
static void sk_psock_done_strp(struct sk_psock *psock);
static void sk_psock_destroy(struct work_struct *work)
{
struct sk_psock *psock = container_of(to_rcu_work(work),
struct sk_psock, rwork);
/* No sk_callback_lock since already detached. */
sk_psock_done_strp(psock);
cancel_delayed_work_sync(&psock->work);
__sk_psock_zap_ingress(psock);
mutex_destroy(&psock->work_mutex);
psock_progs_drop(&psock->progs);
sk_psock_link_destroy(psock);
sk_psock_cork_free(psock);
if (psock->sk_redir)
sock_put(psock->sk_redir);
if (psock->sk_pair)
sock_put(psock->sk_pair);
sock_put(psock->sk);
kfree(psock);
}
void sk_psock_drop(struct sock *sk, struct sk_psock *psock)
{
write_lock_bh(&sk->sk_callback_lock);
sk_psock_restore_proto(sk, psock);
rcu_assign_sk_user_data(sk, NULL);
if (psock->progs.stream_parser)
sk_psock_stop_strp(sk, psock);
else if (psock->progs.stream_verdict || psock->progs.skb_verdict)
sk_psock_stop_verdict(sk, psock);
write_unlock_bh(&sk->sk_callback_lock);
sk_psock_stop(psock);
INIT_RCU_WORK(&psock->rwork, sk_psock_destroy);
queue_rcu_work(system_wq, &psock->rwork);
}
EXPORT_SYMBOL_GPL(sk_psock_drop);
static int sk_psock_map_verd(int verdict, bool redir)
{
switch (verdict) {
case SK_PASS:
return redir ? __SK_REDIRECT : __SK_PASS;
case SK_DROP:
default:
break;
}
return __SK_DROP;
}
int sk_psock_msg_verdict(struct sock *sk, struct sk_psock *psock,
struct sk_msg *msg)
{
struct bpf_prog *prog;
int ret;
rcu_read_lock();
prog = READ_ONCE(psock->progs.msg_parser);
if (unlikely(!prog)) {
ret = __SK_PASS;
goto out;
}
sk_msg_compute_data_pointers(msg);
msg->sk = sk;
ret = bpf_prog_run_pin_on_cpu(prog, msg);
ret = sk_psock_map_verd(ret, msg->sk_redir);
psock->apply_bytes = msg->apply_bytes;
if (ret == __SK_REDIRECT) {
if (psock->sk_redir) {
sock_put(psock->sk_redir);
psock->sk_redir = NULL;
}
if (!msg->sk_redir) {
ret = __SK_DROP;
goto out;
}
psock->redir_ingress = sk_msg_to_ingress(msg);
psock->sk_redir = msg->sk_redir;
sock_hold(psock->sk_redir);
}
out:
rcu_read_unlock();
return ret;
}
EXPORT_SYMBOL_GPL(sk_psock_msg_verdict);
static int sk_psock_skb_redirect(struct sk_psock *from, struct sk_buff *skb)
{
struct sk_psock *psock_other;
struct sock *sk_other;
sk_other = skb_bpf_redirect_fetch(skb);
/* This error is a buggy BPF program, it returned a redirect
* return code, but then didn't set a redirect interface.
*/
if (unlikely(!sk_other)) {
skb_bpf_redirect_clear(skb);
sock_drop(from->sk, skb);
return -EIO;
}
psock_other = sk_psock(sk_other);
/* This error indicates the socket is being torn down or had another
* error that caused the pipe to break. We can't send a packet on
* a socket that is in this state so we drop the skb.
*/
if (!psock_other || sock_flag(sk_other, SOCK_DEAD)) {
skb_bpf_redirect_clear(skb);
sock_drop(from->sk, skb);
return -EIO;
}
spin_lock_bh(&psock_other->ingress_lock);
if (!sk_psock_test_state(psock_other, SK_PSOCK_TX_ENABLED)) {
spin_unlock_bh(&psock_other->ingress_lock);
skb_bpf_redirect_clear(skb);
sock_drop(from->sk, skb);
return -EIO;
}
skb_queue_tail(&psock_other->ingress_skb, skb);
schedule_delayed_work(&psock_other->work, 0);
spin_unlock_bh(&psock_other->ingress_lock);
return 0;
}
static void sk_psock_tls_verdict_apply(struct sk_buff *skb,
struct sk_psock *from, int verdict)
{
switch (verdict) {
case __SK_REDIRECT:
sk_psock_skb_redirect(from, skb);
break;
case __SK_PASS:
case __SK_DROP:
default:
break;
}
}
int sk_psock_tls_strp_read(struct sk_psock *psock, struct sk_buff *skb)
{
struct bpf_prog *prog;
int ret = __SK_PASS;
rcu_read_lock();
prog = READ_ONCE(psock->progs.stream_verdict);
if (likely(prog)) {
skb->sk = psock->sk;
skb_dst_drop(skb);
skb_bpf_redirect_clear(skb);
ret = bpf_prog_run_pin_on_cpu(prog, skb);
ret = sk_psock_map_verd(ret, skb_bpf_redirect_fetch(skb));
skb->sk = NULL;
}
sk_psock_tls_verdict_apply(skb, psock, ret);
rcu_read_unlock();
return ret;
}
EXPORT_SYMBOL_GPL(sk_psock_tls_strp_read);
static int sk_psock_verdict_apply(struct sk_psock *psock, struct sk_buff *skb,
int verdict)
{
struct sock *sk_other;
int err = 0;
u32 len, off;
switch (verdict) {
case __SK_PASS:
err = -EIO;
sk_other = psock->sk;
if (sock_flag(sk_other, SOCK_DEAD) ||
!sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED))
goto out_free;
skb_bpf_set_ingress(skb);
/* If the queue is empty then we can submit directly
* into the msg queue. If its not empty we have to
* queue work otherwise we may get OOO data. Otherwise,
* if sk_psock_skb_ingress errors will be handled by
* retrying later from workqueue.
*/
if (skb_queue_empty(&psock->ingress_skb)) {
len = skb->len;
off = 0;
if (skb_bpf_strparser(skb)) {
struct strp_msg *stm = strp_msg(skb);
off = stm->offset;
len = stm->full_len;
}
err = sk_psock_skb_ingress_self(psock, skb, off, len);
}
if (err < 0) {
spin_lock_bh(&psock->ingress_lock);
if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) {
skb_queue_tail(&psock->ingress_skb, skb);
schedule_delayed_work(&psock->work, 0);
err = 0;
}
spin_unlock_bh(&psock->ingress_lock);
if (err < 0)
goto out_free;
}
break;
case __SK_REDIRECT:
tcp_eat_skb(psock->sk, skb);
err = sk_psock_skb_redirect(psock, skb);
break;
case __SK_DROP:
default:
out_free:
skb_bpf_redirect_clear(skb);
tcp_eat_skb(psock->sk, skb);
sock_drop(psock->sk, skb);
}
return err;
}
static void sk_psock_write_space(struct sock *sk)
{
struct sk_psock *psock;
void (*write_space)(struct sock *sk) = NULL;
rcu_read_lock();
psock = sk_psock(sk);
if (likely(psock)) {
if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED))
schedule_delayed_work(&psock->work, 0);
write_space = psock->saved_write_space;
}
rcu_read_unlock();
if (write_space)
write_space(sk);
}
#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
static void sk_psock_strp_read(struct strparser *strp, struct sk_buff *skb)
{
struct sk_psock *psock;
struct bpf_prog *prog;
int ret = __SK_DROP;
struct sock *sk;
rcu_read_lock();
sk = strp->sk;
psock = sk_psock(sk);
if (unlikely(!psock)) {
sock_drop(sk, skb);
goto out;
}
prog = READ_ONCE(psock->progs.stream_verdict);
if (likely(prog)) {
skb->sk = sk;
skb_dst_drop(skb);
skb_bpf_redirect_clear(skb);
ret = bpf_prog_run_pin_on_cpu(prog, skb);
skb_bpf_set_strparser(skb);
ret = sk_psock_map_verd(ret, skb_bpf_redirect_fetch(skb));
skb->sk = NULL;
}
sk_psock_verdict_apply(psock, skb, ret);
out:
rcu_read_unlock();
}
static int sk_psock_strp_read_done(struct strparser *strp, int err)
{
return err;
}
static int sk_psock_strp_parse(struct strparser *strp, struct sk_buff *skb)
{
struct sk_psock *psock = container_of(strp, struct sk_psock, strp);
struct bpf_prog *prog;
int ret = skb->len;
rcu_read_lock();
prog = READ_ONCE(psock->progs.stream_parser);
if (likely(prog)) {
skb->sk = psock->sk;
ret = bpf_prog_run_pin_on_cpu(prog, skb);
skb->sk = NULL;
}
rcu_read_unlock();
return ret;
}
/* Called with socket lock held. */
static void sk_psock_strp_data_ready(struct sock *sk)
{
struct sk_psock *psock;
trace_sk_data_ready(sk);
rcu_read_lock();
psock = sk_psock(sk);
if (likely(psock)) {
if (tls_sw_has_ctx_rx(sk)) {
psock->saved_data_ready(sk);
} else {
write_lock_bh(&sk->sk_callback_lock);
strp_data_ready(&psock->strp);
write_unlock_bh(&sk->sk_callback_lock);
}
}
rcu_read_unlock();
}
int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock)
{
int ret;
static const struct strp_callbacks cb = {
.rcv_msg = sk_psock_strp_read,
.read_sock_done = sk_psock_strp_read_done,
.parse_msg = sk_psock_strp_parse,
};
ret = strp_init(&psock->strp, sk, &cb);
if (!ret)
sk_psock_set_state(psock, SK_PSOCK_RX_STRP_ENABLED);
return ret;
}
void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock)
{
if (psock->saved_data_ready)
return;
psock->saved_data_ready = sk->sk_data_ready;
sk->sk_data_ready = sk_psock_strp_data_ready;
sk->sk_write_space = sk_psock_write_space;
}
void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock)
{
psock_set_prog(&psock->progs.stream_parser, NULL);
if (!psock->saved_data_ready)
return;
sk->sk_data_ready = psock->saved_data_ready;
psock->saved_data_ready = NULL;
strp_stop(&psock->strp);
}
static void sk_psock_done_strp(struct sk_psock *psock)
{
/* Parser has been stopped */
if (sk_psock_test_state(psock, SK_PSOCK_RX_STRP_ENABLED))
strp_done(&psock->strp);
}
#else
static void sk_psock_done_strp(struct sk_psock *psock)
{
}
#endif /* CONFIG_BPF_STREAM_PARSER */
static int sk_psock_verdict_recv(struct sock *sk, struct sk_buff *skb)
{
struct sk_psock *psock;
struct bpf_prog *prog;
int ret = __SK_DROP;
int len = skb->len;
rcu_read_lock();
psock = sk_psock(sk);
if (unlikely(!psock)) {
len = 0;
tcp_eat_skb(sk, skb);
sock_drop(sk, skb);
goto out;
}
prog = READ_ONCE(psock->progs.stream_verdict);
if (!prog)
prog = READ_ONCE(psock->progs.skb_verdict);
if (likely(prog)) {
skb_dst_drop(skb);
skb_bpf_redirect_clear(skb);
ret = bpf_prog_run_pin_on_cpu(prog, skb);
ret = sk_psock_map_verd(ret, skb_bpf_redirect_fetch(skb));
}
ret = sk_psock_verdict_apply(psock, skb, ret);
if (ret < 0)
len = ret;
out:
rcu_read_unlock();
return len;
}
static void sk_psock_verdict_data_ready(struct sock *sk)
{
struct socket *sock = sk->sk_socket;
const struct proto_ops *ops;
int copied;
trace_sk_data_ready(sk);
if (unlikely(!sock))
return;
ops = READ_ONCE(sock->ops);
if (!ops || !ops->read_skb)
return;
copied = ops->read_skb(sk, sk_psock_verdict_recv);
if (copied >= 0) {
struct sk_psock *psock;
rcu_read_lock();
psock = sk_psock(sk);
if (psock)
sk_psock_data_ready(sk, psock);
rcu_read_unlock();
}
}
void sk_psock_start_verdict(struct sock *sk, struct sk_psock *psock)
{
if (psock->saved_data_ready)
return;
psock->saved_data_ready = sk->sk_data_ready;
sk->sk_data_ready = sk_psock_verdict_data_ready;
sk->sk_write_space = sk_psock_write_space;
}
void sk_psock_stop_verdict(struct sock *sk, struct sk_psock *psock)
{
psock_set_prog(&psock->progs.stream_verdict, NULL);
psock_set_prog(&psock->progs.skb_verdict, NULL);
if (!psock->saved_data_ready)
return;
sk->sk_data_ready = psock->saved_data_ready;
psock->saved_data_ready = NULL;
}
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