From faa91b839b09b15d6f9655fc866fa433bb65454c Mon Sep 17 00:00:00 2001 From: Tirthendu Sarkar Date: Wed, 19 Jul 2023 15:24:01 +0200 Subject: [PATCH] xsk: move xdp_buff's data length check to xsk_rcv_check If the data in xdp_buff exceeds the xsk frame length, the packet needs to be dropped. This check is currently being done in __xsk_rcv(). Move the described logic to xsk_rcv_check() so that such a xdp_buff will only be dropped if the application does not support multi-buffer (absence of XDP_USE_SG bind flag). This is applicable for all cases: copy mode, zero copy mode as well as skb mode. Signed-off-by: Tirthendu Sarkar Link: https://lore.kernel.org/r/20230719132421.584801-5-maciej.fijalkowski@intel.com Signed-off-by: Alexei Starovoitov --- net/xdp/xsk.c | 27 +++++++++++++-------------- 1 file changed, 13 insertions(+), 14 deletions(-) diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 029a092582da4..a968ac506f4a1 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -177,18 +177,11 @@ static void xsk_copy_xdp(struct xdp_buff *to, struct xdp_buff *from, u32 len) memcpy(to_buf, from_buf, len + metalen); } -static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) +static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) { struct xdp_buff_xsk *xskb; struct xdp_buff *xsk_xdp; int err; - u32 len; - - len = xdp->data_end - xdp->data; - if (len > xsk_pool_get_rx_frame_size(xs->pool)) { - xs->rx_dropped++; - return -ENOSPC; - } xsk_xdp = xsk_buff_alloc(xs->pool); if (!xsk_xdp) { @@ -224,7 +217,7 @@ static bool xsk_is_bound(struct xdp_sock *xs) return false; } -static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp) +static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) { if (!xsk_is_bound(xs)) return -ENXIO; @@ -232,6 +225,11 @@ static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp) if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index) return -EINVAL; + if (len > xsk_pool_get_rx_frame_size(xs->pool)) { + xs->rx_dropped++; + return -ENOSPC; + } + sk_mark_napi_id_once_xdp(&xs->sk, xdp); return 0; } @@ -245,12 +243,13 @@ static void xsk_flush(struct xdp_sock *xs) int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) { + u32 len = xdp_get_buff_len(xdp); int err; spin_lock_bh(&xs->rx_lock); - err = xsk_rcv_check(xs, xdp); + err = xsk_rcv_check(xs, xdp, len); if (!err) { - err = __xsk_rcv(xs, xdp); + err = __xsk_rcv(xs, xdp, len); xsk_flush(xs); } spin_unlock_bh(&xs->rx_lock); @@ -259,10 +258,10 @@ int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) { + u32 len = xdp_get_buff_len(xdp); int err; - u32 len; - err = xsk_rcv_check(xs, xdp); + err = xsk_rcv_check(xs, xdp, len); if (err) return err; @@ -271,7 +270,7 @@ static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) return xsk_rcv_zc(xs, xdp, len); } - err = __xsk_rcv(xs, xdp); + err = __xsk_rcv(xs, xdp, len); if (!err) xdp_return_buff(xdp); return err;