forked from Minki/linux
9635720b7c
If backlog handler is running during a tear down operation we may enqueue
data on the ingress msg queue while tear down is trying to free it.
sk_psock_backlog()
sk_psock_handle_skb()
skb_psock_skb_ingress()
sk_psock_skb_ingress_enqueue()
sk_psock_queue_msg(psock,msg)
spin_lock(ingress_lock)
sk_psock_zap_ingress()
_sk_psock_purge_ingerss_msg()
_sk_psock_purge_ingress_msg()
-- free ingress_msg list --
spin_unlock(ingress_lock)
spin_lock(ingress_lock)
list_add_tail(msg,ingress_msg) <- entry on list with no one
left to free it.
spin_unlock(ingress_lock)
To fix we only enqueue from backlog if the ENABLED bit is set. The tear
down logic clears the bit with ingress_lock set so we wont enqueue the
msg in the last step.
Fixes: 799aa7f98d
("skmsg: Avoid lock_sock() in sk_psock_backlog()")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210727160500.1713554-4-john.fastabend@gmail.com
1184 lines
27 KiB
C
1184 lines
27 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */
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#include <linux/skmsg.h>
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#include <linux/skbuff.h>
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#include <linux/scatterlist.h>
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#include <net/sock.h>
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#include <net/tcp.h>
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#include <net/tls.h>
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static bool sk_msg_try_coalesce_ok(struct sk_msg *msg, int elem_first_coalesce)
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{
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if (msg->sg.end > msg->sg.start &&
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elem_first_coalesce < msg->sg.end)
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return true;
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if (msg->sg.end < msg->sg.start &&
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(elem_first_coalesce > msg->sg.start ||
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elem_first_coalesce < msg->sg.end))
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return true;
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return false;
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}
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int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len,
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int elem_first_coalesce)
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{
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struct page_frag *pfrag = sk_page_frag(sk);
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int ret = 0;
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len -= msg->sg.size;
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while (len > 0) {
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struct scatterlist *sge;
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u32 orig_offset;
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int use, i;
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if (!sk_page_frag_refill(sk, pfrag))
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return -ENOMEM;
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orig_offset = pfrag->offset;
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use = min_t(int, len, pfrag->size - orig_offset);
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if (!sk_wmem_schedule(sk, use))
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return -ENOMEM;
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i = msg->sg.end;
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sk_msg_iter_var_prev(i);
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sge = &msg->sg.data[i];
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if (sk_msg_try_coalesce_ok(msg, elem_first_coalesce) &&
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sg_page(sge) == pfrag->page &&
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sge->offset + sge->length == orig_offset) {
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sge->length += use;
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} else {
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if (sk_msg_full(msg)) {
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ret = -ENOSPC;
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break;
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}
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sge = &msg->sg.data[msg->sg.end];
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sg_unmark_end(sge);
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sg_set_page(sge, pfrag->page, use, orig_offset);
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get_page(pfrag->page);
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sk_msg_iter_next(msg, end);
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}
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sk_mem_charge(sk, use);
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msg->sg.size += use;
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pfrag->offset += use;
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len -= use;
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}
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return ret;
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}
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EXPORT_SYMBOL_GPL(sk_msg_alloc);
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int sk_msg_clone(struct sock *sk, struct sk_msg *dst, struct sk_msg *src,
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u32 off, u32 len)
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{
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int i = src->sg.start;
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struct scatterlist *sge = sk_msg_elem(src, i);
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struct scatterlist *sgd = NULL;
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u32 sge_len, sge_off;
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while (off) {
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if (sge->length > off)
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break;
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off -= sge->length;
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sk_msg_iter_var_next(i);
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if (i == src->sg.end && off)
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return -ENOSPC;
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sge = sk_msg_elem(src, i);
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}
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while (len) {
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sge_len = sge->length - off;
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if (sge_len > len)
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sge_len = len;
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if (dst->sg.end)
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sgd = sk_msg_elem(dst, dst->sg.end - 1);
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if (sgd &&
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(sg_page(sge) == sg_page(sgd)) &&
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(sg_virt(sge) + off == sg_virt(sgd) + sgd->length)) {
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sgd->length += sge_len;
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dst->sg.size += sge_len;
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} else if (!sk_msg_full(dst)) {
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sge_off = sge->offset + off;
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sk_msg_page_add(dst, sg_page(sge), sge_len, sge_off);
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} else {
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return -ENOSPC;
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}
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off = 0;
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len -= sge_len;
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sk_mem_charge(sk, sge_len);
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sk_msg_iter_var_next(i);
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if (i == src->sg.end && len)
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return -ENOSPC;
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sge = sk_msg_elem(src, i);
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}
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return 0;
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}
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EXPORT_SYMBOL_GPL(sk_msg_clone);
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void sk_msg_return_zero(struct sock *sk, struct sk_msg *msg, int bytes)
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{
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int i = msg->sg.start;
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do {
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struct scatterlist *sge = sk_msg_elem(msg, i);
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if (bytes < sge->length) {
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sge->length -= bytes;
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sge->offset += bytes;
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sk_mem_uncharge(sk, bytes);
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break;
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}
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sk_mem_uncharge(sk, sge->length);
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bytes -= sge->length;
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sge->length = 0;
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sge->offset = 0;
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sk_msg_iter_var_next(i);
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} while (bytes && i != msg->sg.end);
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msg->sg.start = i;
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}
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EXPORT_SYMBOL_GPL(sk_msg_return_zero);
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void sk_msg_return(struct sock *sk, struct sk_msg *msg, int bytes)
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{
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int i = msg->sg.start;
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do {
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struct scatterlist *sge = &msg->sg.data[i];
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int uncharge = (bytes < sge->length) ? bytes : sge->length;
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sk_mem_uncharge(sk, uncharge);
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bytes -= uncharge;
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sk_msg_iter_var_next(i);
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} while (i != msg->sg.end);
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}
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EXPORT_SYMBOL_GPL(sk_msg_return);
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static int sk_msg_free_elem(struct sock *sk, struct sk_msg *msg, u32 i,
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bool charge)
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{
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struct scatterlist *sge = sk_msg_elem(msg, i);
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u32 len = sge->length;
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/* When the skb owns the memory we free it from consume_skb path. */
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if (!msg->skb) {
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if (charge)
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sk_mem_uncharge(sk, len);
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put_page(sg_page(sge));
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}
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memset(sge, 0, sizeof(*sge));
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return len;
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}
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static int __sk_msg_free(struct sock *sk, struct sk_msg *msg, u32 i,
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bool charge)
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{
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struct scatterlist *sge = sk_msg_elem(msg, i);
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int freed = 0;
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while (msg->sg.size) {
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msg->sg.size -= sge->length;
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freed += sk_msg_free_elem(sk, msg, i, charge);
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sk_msg_iter_var_next(i);
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sk_msg_check_to_free(msg, i, msg->sg.size);
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sge = sk_msg_elem(msg, i);
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}
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consume_skb(msg->skb);
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sk_msg_init(msg);
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return freed;
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}
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int sk_msg_free_nocharge(struct sock *sk, struct sk_msg *msg)
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{
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return __sk_msg_free(sk, msg, msg->sg.start, false);
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}
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EXPORT_SYMBOL_GPL(sk_msg_free_nocharge);
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int sk_msg_free(struct sock *sk, struct sk_msg *msg)
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{
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return __sk_msg_free(sk, msg, msg->sg.start, true);
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}
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EXPORT_SYMBOL_GPL(sk_msg_free);
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static void __sk_msg_free_partial(struct sock *sk, struct sk_msg *msg,
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u32 bytes, bool charge)
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{
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struct scatterlist *sge;
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u32 i = msg->sg.start;
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while (bytes) {
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sge = sk_msg_elem(msg, i);
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if (!sge->length)
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break;
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if (bytes < sge->length) {
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if (charge)
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sk_mem_uncharge(sk, bytes);
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sge->length -= bytes;
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sge->offset += bytes;
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msg->sg.size -= bytes;
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break;
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}
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msg->sg.size -= sge->length;
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bytes -= sge->length;
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sk_msg_free_elem(sk, msg, i, charge);
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sk_msg_iter_var_next(i);
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sk_msg_check_to_free(msg, i, bytes);
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}
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msg->sg.start = i;
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}
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void sk_msg_free_partial(struct sock *sk, struct sk_msg *msg, u32 bytes)
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{
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__sk_msg_free_partial(sk, msg, bytes, true);
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}
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EXPORT_SYMBOL_GPL(sk_msg_free_partial);
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void sk_msg_free_partial_nocharge(struct sock *sk, struct sk_msg *msg,
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u32 bytes)
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{
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__sk_msg_free_partial(sk, msg, bytes, false);
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}
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void sk_msg_trim(struct sock *sk, struct sk_msg *msg, int len)
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{
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int trim = msg->sg.size - len;
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u32 i = msg->sg.end;
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if (trim <= 0) {
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WARN_ON(trim < 0);
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return;
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}
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sk_msg_iter_var_prev(i);
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msg->sg.size = len;
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while (msg->sg.data[i].length &&
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trim >= msg->sg.data[i].length) {
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trim -= msg->sg.data[i].length;
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sk_msg_free_elem(sk, msg, i, true);
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sk_msg_iter_var_prev(i);
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if (!trim)
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goto out;
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}
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msg->sg.data[i].length -= trim;
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sk_mem_uncharge(sk, trim);
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/* Adjust copybreak if it falls into the trimmed part of last buf */
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if (msg->sg.curr == i && msg->sg.copybreak > msg->sg.data[i].length)
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msg->sg.copybreak = msg->sg.data[i].length;
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out:
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sk_msg_iter_var_next(i);
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msg->sg.end = i;
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/* If we trim data a full sg elem before curr pointer update
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* copybreak and current so that any future copy operations
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* start at new copy location.
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* However trimed data that has not yet been used in a copy op
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* does not require an update.
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*/
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if (!msg->sg.size) {
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msg->sg.curr = msg->sg.start;
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msg->sg.copybreak = 0;
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} else if (sk_msg_iter_dist(msg->sg.start, msg->sg.curr) >=
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sk_msg_iter_dist(msg->sg.start, msg->sg.end)) {
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sk_msg_iter_var_prev(i);
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msg->sg.curr = i;
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msg->sg.copybreak = msg->sg.data[i].length;
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}
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}
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EXPORT_SYMBOL_GPL(sk_msg_trim);
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int sk_msg_zerocopy_from_iter(struct sock *sk, struct iov_iter *from,
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struct sk_msg *msg, u32 bytes)
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{
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int i, maxpages, ret = 0, num_elems = sk_msg_elem_used(msg);
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const int to_max_pages = MAX_MSG_FRAGS;
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struct page *pages[MAX_MSG_FRAGS];
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ssize_t orig, copied, use, offset;
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orig = msg->sg.size;
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while (bytes > 0) {
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i = 0;
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maxpages = to_max_pages - num_elems;
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if (maxpages == 0) {
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ret = -EFAULT;
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goto out;
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}
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copied = iov_iter_get_pages(from, pages, bytes, maxpages,
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&offset);
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if (copied <= 0) {
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ret = -EFAULT;
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goto out;
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}
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iov_iter_advance(from, copied);
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bytes -= copied;
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msg->sg.size += copied;
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while (copied) {
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use = min_t(int, copied, PAGE_SIZE - offset);
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sg_set_page(&msg->sg.data[msg->sg.end],
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pages[i], use, offset);
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sg_unmark_end(&msg->sg.data[msg->sg.end]);
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sk_mem_charge(sk, use);
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offset = 0;
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copied -= use;
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sk_msg_iter_next(msg, end);
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num_elems++;
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i++;
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}
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/* When zerocopy is mixed with sk_msg_*copy* operations we
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* may have a copybreak set in this case clear and prefer
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* zerocopy remainder when possible.
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*/
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msg->sg.copybreak = 0;
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msg->sg.curr = msg->sg.end;
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}
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out:
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/* Revert iov_iter updates, msg will need to use 'trim' later if it
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* also needs to be cleared.
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*/
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if (ret)
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iov_iter_revert(from, msg->sg.size - orig);
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return ret;
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}
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EXPORT_SYMBOL_GPL(sk_msg_zerocopy_from_iter);
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int sk_msg_memcopy_from_iter(struct sock *sk, struct iov_iter *from,
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struct sk_msg *msg, u32 bytes)
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{
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int ret = -ENOSPC, i = msg->sg.curr;
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struct scatterlist *sge;
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u32 copy, buf_size;
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void *to;
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do {
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sge = sk_msg_elem(msg, i);
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/* This is possible if a trim operation shrunk the buffer */
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if (msg->sg.copybreak >= sge->length) {
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msg->sg.copybreak = 0;
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sk_msg_iter_var_next(i);
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if (i == msg->sg.end)
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break;
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sge = sk_msg_elem(msg, i);
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}
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buf_size = sge->length - msg->sg.copybreak;
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copy = (buf_size > bytes) ? bytes : buf_size;
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to = sg_virt(sge) + msg->sg.copybreak;
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msg->sg.copybreak += copy;
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if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY)
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ret = copy_from_iter_nocache(to, copy, from);
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else
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ret = copy_from_iter(to, copy, from);
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if (ret != copy) {
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ret = -EFAULT;
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goto out;
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}
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bytes -= copy;
|
|
if (!bytes)
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break;
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msg->sg.copybreak = 0;
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sk_msg_iter_var_next(i);
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} while (i != msg->sg.end);
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out:
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msg->sg.curr = i;
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return ret;
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}
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EXPORT_SYMBOL_GPL(sk_msg_memcopy_from_iter);
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|
|
/* Receive sk_msg from psock->ingress_msg to @msg. */
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int sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg,
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int len, int flags)
|
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{
|
|
struct iov_iter *iter = &msg->msg_iter;
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int peek = flags & MSG_PEEK;
|
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struct sk_msg *msg_rx;
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int i, copied = 0;
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|
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msg_rx = sk_psock_peek_msg(psock);
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while (copied != len) {
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struct scatterlist *sge;
|
|
|
|
if (unlikely(!msg_rx))
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break;
|
|
|
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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;
|
|
copy = copy_page_to_iter(page, sge->offset, copy, iter);
|
|
if (!copy)
|
|
return copied ? copied : -EFAULT;
|
|
|
|
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)
|
|
return copied;
|
|
sk_msg_iter_var_next(i);
|
|
}
|
|
|
|
if (copied == len)
|
|
break;
|
|
} while (i != msg_rx->sg.end);
|
|
|
|
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 && msg_rx->sg.start == msg_rx->sg.end) {
|
|
msg_rx = sk_psock_dequeue_msg(psock);
|
|
kfree_sk_msg(msg_rx);
|
|
}
|
|
msg_rx = sk_psock_peek_msg(psock);
|
|
}
|
|
|
|
return copied;
|
|
}
|
|
EXPORT_SYMBOL_GPL(sk_msg_recvmsg);
|
|
|
|
static struct sk_msg *sk_psock_create_ingress_msg(struct sock *sk,
|
|
struct sk_buff *skb)
|
|
{
|
|
struct sk_msg *msg;
|
|
|
|
if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf)
|
|
return NULL;
|
|
|
|
if (!sk_rmem_schedule(sk, skb, skb->truesize))
|
|
return NULL;
|
|
|
|
msg = kzalloc(sizeof(*msg), __GFP_NOWARN | GFP_KERNEL);
|
|
if (unlikely(!msg))
|
|
return NULL;
|
|
|
|
sk_msg_init(msg);
|
|
return msg;
|
|
}
|
|
|
|
static int sk_psock_skb_ingress_enqueue(struct sk_buff *skb,
|
|
struct sk_psock *psock,
|
|
struct sock *sk,
|
|
struct sk_msg *msg)
|
|
{
|
|
int num_sge, copied;
|
|
|
|
/* 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, 0, skb->len);
|
|
if (unlikely(num_sge < 0))
|
|
return num_sge;
|
|
|
|
copied = skb->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);
|
|
|
|
static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb)
|
|
{
|
|
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);
|
|
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, 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)
|
|
{
|
|
struct sk_msg *msg = kzalloc(sizeof(*msg), __GFP_NOWARN | GFP_ATOMIC);
|
|
struct sock *sk = psock->sk;
|
|
int err;
|
|
|
|
if (unlikely(!msg))
|
|
return -EAGAIN;
|
|
sk_msg_init(msg);
|
|
skb_set_owner_r(skb, sk);
|
|
err = sk_psock_skb_ingress_enqueue(skb, 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)
|
|
{
|
|
if (!ingress) {
|
|
if (!sock_writeable(psock->sk))
|
|
return -EAGAIN;
|
|
return skb_send_sock(psock->sk, skb, off, len);
|
|
}
|
|
return sk_psock_skb_ingress(psock, skb);
|
|
}
|
|
|
|
static void sk_psock_skb_state(struct sk_psock *psock,
|
|
struct sk_psock_work_state *state,
|
|
struct sk_buff *skb,
|
|
int len, int off)
|
|
{
|
|
spin_lock_bh(&psock->ingress_lock);
|
|
if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) {
|
|
state->skb = skb;
|
|
state->len = len;
|
|
state->off = off;
|
|
} else {
|
|
sock_drop(psock->sk, skb);
|
|
}
|
|
spin_unlock_bh(&psock->ingress_lock);
|
|
}
|
|
|
|
static void sk_psock_backlog(struct work_struct *work)
|
|
{
|
|
struct sk_psock *psock = container_of(work, struct sk_psock, work);
|
|
struct sk_psock_work_state *state = &psock->work_state;
|
|
struct sk_buff *skb = NULL;
|
|
bool ingress;
|
|
u32 len, off;
|
|
int ret;
|
|
|
|
mutex_lock(&psock->work_mutex);
|
|
if (unlikely(state->skb)) {
|
|
spin_lock_bh(&psock->ingress_lock);
|
|
skb = state->skb;
|
|
len = state->len;
|
|
off = state->off;
|
|
state->skb = NULL;
|
|
spin_unlock_bh(&psock->ingress_lock);
|
|
}
|
|
if (skb)
|
|
goto start;
|
|
|
|
while ((skb = skb_dequeue(&psock->ingress_skb))) {
|
|
len = skb->len;
|
|
off = 0;
|
|
start:
|
|
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, skb,
|
|
len, off);
|
|
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);
|
|
sock_drop(psock->sk, skb);
|
|
goto end;
|
|
}
|
|
off += ret;
|
|
len -= ret;
|
|
} while (len);
|
|
|
|
if (!ingress)
|
|
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->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_close = prot->close;
|
|
psock->saved_write_space = sk->sk_write_space;
|
|
|
|
INIT_LIST_HEAD(&psock->link);
|
|
spin_lock_init(&psock->link_lock);
|
|
|
|
INIT_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_nocopy(sk, 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);
|
|
}
|
|
kfree_skb(psock->work_state.skb);
|
|
/* We null the skb here to ensure that calls to sk_psock_backlog
|
|
* do not pick up the free'd skb.
|
|
*/
|
|
psock->work_state.skb = NULL;
|
|
__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, bool wait)
|
|
{
|
|
spin_lock_bh(&psock->ingress_lock);
|
|
sk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED);
|
|
sk_psock_cork_free(psock);
|
|
__sk_psock_zap_ingress(psock);
|
|
spin_unlock_bh(&psock->ingress_lock);
|
|
|
|
if (wait)
|
|
cancel_work_sync(&psock->work);
|
|
}
|
|
|
|
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_work_sync(&psock->work);
|
|
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);
|
|
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, false);
|
|
|
|
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 = msg->sk_redir;
|
|
if (!psock->sk_redir) {
|
|
ret = __SK_DROP;
|
|
goto out;
|
|
}
|
|
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)) {
|
|
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_work(&psock_other->work);
|
|
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;
|
|
|
|
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)) {
|
|
err = sk_psock_skb_ingress_self(psock, skb);
|
|
}
|
|
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_work(&psock->work);
|
|
err = 0;
|
|
}
|
|
spin_unlock_bh(&psock->ingress_lock);
|
|
if (err < 0) {
|
|
skb_bpf_redirect_clear(skb);
|
|
goto out_free;
|
|
}
|
|
}
|
|
break;
|
|
case __SK_REDIRECT:
|
|
err = sk_psock_skb_redirect(psock, skb);
|
|
break;
|
|
case __SK_DROP:
|
|
default:
|
|
out_free:
|
|
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_work(&psock->work);
|
|
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);
|
|
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;
|
|
|
|
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)
|
|
{
|
|
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,
|
|
};
|
|
|
|
return strp_init(&psock->strp, sk, &cb);
|
|
}
|
|
|
|
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)
|
|
{
|
|
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 (psock->progs.stream_parser)
|
|
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(read_descriptor_t *desc, struct sk_buff *skb,
|
|
unsigned int offset, size_t orig_len)
|
|
{
|
|
struct sock *sk = (struct sock *)desc->arg.data;
|
|
struct sk_psock *psock;
|
|
struct bpf_prog *prog;
|
|
int ret = __SK_DROP;
|
|
int len = skb->len;
|
|
|
|
/* clone here so sk_eat_skb() in tcp_read_sock does not drop our data */
|
|
skb = skb_clone(skb, GFP_ATOMIC);
|
|
if (!skb) {
|
|
desc->error = -ENOMEM;
|
|
return 0;
|
|
}
|
|
|
|
rcu_read_lock();
|
|
psock = sk_psock(sk);
|
|
if (unlikely(!psock)) {
|
|
len = 0;
|
|
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->sk = 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;
|
|
}
|
|
if (sk_psock_verdict_apply(psock, skb, ret) < 0)
|
|
len = 0;
|
|
out:
|
|
rcu_read_unlock();
|
|
return len;
|
|
}
|
|
|
|
static void sk_psock_verdict_data_ready(struct sock *sk)
|
|
{
|
|
struct socket *sock = sk->sk_socket;
|
|
read_descriptor_t desc;
|
|
|
|
if (unlikely(!sock || !sock->ops || !sock->ops->read_sock))
|
|
return;
|
|
|
|
desc.arg.data = sk;
|
|
desc.error = 0;
|
|
desc.count = 1;
|
|
|
|
sock->ops->read_sock(sk, &desc, sk_psock_verdict_recv);
|
|
}
|
|
|
|
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)
|
|
{
|
|
if (!psock->saved_data_ready)
|
|
return;
|
|
|
|
sk->sk_data_ready = psock->saved_data_ready;
|
|
psock->saved_data_ready = NULL;
|
|
}
|