ength before invoking the function that performs the allocation to avoid creating an invalid skb. If the packet has to be forwarded to userspace the 2-byte prefix can be pushed to the head safely, without misalignment. As a side effect, this approach also avoids the expensive linearization that pskb_pull triggers on cloned skbs with page fragments. In testing, this resulted in TCP throughput improvements of up to 74%. Fixes: 11851cbd60ea ("ovpn: implement TCP transport") Signed-off-by: Ralf Lici Signed-off-by: Antonio Quartulli Reviewed-by: Sabrina Dubroca Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/ovpn/tcp.c | 53 ++++++++++++++++++++++++++++-------------- 1 file changed, 36 insertions(+), 17 deletions(-) diff --git a/drivers/net/ovpn/tcp.c b/drivers/net/ovpn/tcp.c index ec2bbc28c1966..5499c1572f3e2 100644 --- a/drivers/net/ovpn/tcp.c +++ b/drivers/net/ovpn/tcp.c @@ -70,37 +70,56 @@ static void ovpn_tcp_to_userspace(struct ovpn_peer *peer, struct sock *sk, peer->tcp.sk_cb.sk_data_ready(sk); } -static void ovpn_tcp_rcv(struct strparser *strp, struct sk_buff *skb) +static struct sk_buff *ovpn_tcp_skb_packet(const struct ovpn_peer *peer, + struct sk_buff *orig_skb, + const int pkt_len, const int pkt_off) { - struct ovpn_peer *peer = container_of(strp, struct ovpn_peer, tcp.strp); - struct strp_msg *msg = strp_msg(skb); - size_t pkt_len = msg->full_len - 2; - size_t off = msg->offset + 2; - u8 opcode; + struct sk_buff *ovpn_skb; + int err; - /* ensure skb->data points to the beginning of the openvpn packet */ - if (!pskb_pull(skb, off)) { - net_warn_ratelimited("%s: packet too small for peer %u\n", - netdev_name(peer->ovpn->dev), peer->id); + /* create a new skb with only the content of the current packet */ + ovpn_skb = netdev_alloc_skb(peer->ovpn->dev, pkt_len); + if (unlikely(!ovpn_skb)) goto err; - } - /* strparser does not trim the skb for us, therefore we do it now */ - if (pskb_trim(skb, pkt_len) != 0) { - net_warn_ratelimited("%s: trimming skb failed for peer %u\n", + skb_copy_header(ovpn_skb, orig_skb); + err = skb_copy_bits(orig_skb, pkt_off, skb_put(ovpn_skb, pkt_len), + pkt_len); + if (unlikely(err)) { + net_warn_ratelimited("%s: skb_copy_bits failed for peer %u\n", netdev_name(peer->ovpn->dev), peer->id); + kfree_skb(ovpn_skb); goto err; } - /* we need the first 4 bytes of data to be accessible + consume_skb(orig_skb); + return ovpn_skb; +err: + kfree_skb(orig_skb); + return NULL; +} + +static void ovpn_tcp_rcv(struct strparser *strp, struct sk_buff *skb) +{ + struct ovpn_peer *peer = container_of(strp, struct ovpn_peer, tcp.strp); + struct strp_msg *msg = strp_msg(skb); + int pkt_len = msg->full_len - 2; + u8 opcode; + + /* we need at least 4 bytes of data in the packet * to extract the opcode and the key ID later on */ - if (!pskb_may_pull(skb, OVPN_OPCODE_SIZE)) { + if (unlikely(pkt_len < OVPN_OPCODE_SIZE)) { net_warn_ratelimited("%s: packet too small to fetch opcode for peer %u\n", netdev_name(peer->ovpn->dev), peer->id); goto err; } + /* extract the packet into a new skb */ + skb = ovpn_tcp_skb_packet(peer, skb, pkt_len, msg->offset + 2); + if (unlikely(!skb)) + goto err; + /* DATA_V2 packets are handled in kernel, the rest goes to user space */ opcode = ovpn_opcode_from_skb(skb, 0); if (unlikely(opcode != OVPN_DATA_V2)) { @@ -113,7 +132,7 @@ static void ovpn_tcp_rcv(struct strparser *strp, struct sk_buff *skb) /* The packet size header must be there when sending the packet * to userspace, therefore we put it back */ - skb_push(skb, 2); + *(__be16 *)__skb_push(skb, sizeof(u16)) = htons(pkt_len); ovpn_tcp_to_userspace(peer, strp->sk, skb); return; } -- 2.51.0[PATCH 6.19 463/844] ovpn: tcp - fix packet extraction from streamSasha Levin undefinedlinux-kernel@vger.kernel.org, stable@vger.kernel.org undefined undefined undefined undefined undefined undefinedŠ†¨?