xsk_build_skb() has gone wild with its size and one of the things we can do about it is to pull out a branch that takes care of metadata handling and make it a separate function. While at it, let us add metadata SW support for devices supporting IFF_TX_SKB_NO_LINEAR flag, that happen to have separate logic for building skb in xsk's generic xmit path. Acked-by: Stanislav Fomichev Reviewed-by: Jason Xing Signed-off-by: Maciej Fijalkowski --- net/xdp/xsk.c | 92 +++++++++++++++++++++++++++++---------------------- 1 file changed, 53 insertions(+), 39 deletions(-) diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index f7e0d254a723..7b0c68a70888 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -657,6 +657,45 @@ static void xsk_drop_skb(struct sk_buff *skb) xsk_consume_skb(skb); } +static int xsk_skb_metadata(struct sk_buff *skb, void *buffer, + struct xdp_desc *desc, struct xsk_buff_pool *pool, + u32 hr) +{ + struct xsk_tx_metadata *meta = NULL; + + if (unlikely(pool->tx_metadata_len == 0)) + return -EINVAL; + + meta = buffer - pool->tx_metadata_len; + if (unlikely(!xsk_buff_valid_tx_metadata(meta))) + return -EINVAL; + + if (meta->flags & XDP_TXMD_FLAGS_CHECKSUM) { + if (unlikely(meta->request.csum_start + + meta->request.csum_offset + + sizeof(__sum16) > desc->len)) + return -EINVAL; + + skb->csum_start = hr + meta->request.csum_start; + skb->csum_offset = meta->request.csum_offset; + skb->ip_summed = CHECKSUM_PARTIAL; + + if (unlikely(pool->tx_sw_csum)) { + int err; + + err = skb_checksum_help(skb); + if (err) + return err; + } + } + + if (meta->flags & XDP_TXMD_FLAGS_LAUNCH_TIME) + skb->skb_mstamp_ns = meta->request.launch_time; + xsk_tx_metadata_to_compl(meta, &skb_shinfo(skb)->xsk_meta); + + return 0; +} + static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs, struct xdp_desc *desc) { @@ -669,6 +708,9 @@ static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs, int err, i; u64 addr; + addr = desc->addr; + buffer = xsk_buff_raw_get_data(pool, addr); + if (!skb) { hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(xs->dev->needed_headroom)); @@ -679,6 +721,11 @@ static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs, skb_reserve(skb, hr); xsk_skb_init_misc(skb, xs, desc->addr); + if (desc->options & XDP_TX_METADATA) { + err = xsk_skb_metadata(skb, buffer, desc, pool, hr); + if (unlikely(err)) + return ERR_PTR(err); + } } else { xsk_addr = kmem_cache_zalloc(xsk_tx_generic_cache, GFP_KERNEL); if (!xsk_addr) @@ -692,11 +739,9 @@ static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs, list_add_tail(&xsk_addr->addr_node, &XSKCB(skb)->addrs_list); } - addr = desc->addr; len = desc->len; ts = pool->unaligned ? len : pool->chunk_size; - buffer = xsk_buff_raw_get_data(pool, addr); offset = offset_in_page(buffer); addr = buffer - pool->addrs; @@ -727,7 +772,6 @@ static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs, static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, struct xdp_desc *desc) { - struct xsk_tx_metadata *meta = NULL; struct net_device *dev = xs->dev; struct sk_buff *skb = xs->skb; int err; @@ -761,6 +805,12 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, goto free_err; xsk_skb_init_misc(skb, xs, desc->addr); + if (desc->options & XDP_TX_METADATA) { + err = xsk_skb_metadata(skb, buffer, desc, + xs->pool, hr); + if (unlikely(err)) + goto free_err; + } } else { int nr_frags = skb_shinfo(skb)->nr_frags; struct xsk_addr_node *xsk_addr; @@ -795,42 +845,6 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, xsk_addr->addr = desc->addr; list_add_tail(&xsk_addr->addr_node, &XSKCB(skb)->addrs_list); } - - if (!skb_shinfo(skb)->nr_frags && desc->options & XDP_TX_METADATA) { - if (unlikely(xs->pool->tx_metadata_len == 0)) { - err = -EINVAL; - goto free_err; - } - - meta = buffer - xs->pool->tx_metadata_len; - if (unlikely(!xsk_buff_valid_tx_metadata(meta))) { - err = -EINVAL; - goto free_err; - } - - if (meta->flags & XDP_TXMD_FLAGS_CHECKSUM) { - if (unlikely(meta->request.csum_start + - meta->request.csum_offset + - sizeof(__sum16) > len)) { - err = -EINVAL; - goto free_err; - } - - skb->csum_start = hr + meta->request.csum_start; - skb->csum_offset = meta->request.csum_offset; - skb->ip_summed = CHECKSUM_PARTIAL; - - if (unlikely(xs->pool->tx_sw_csum)) { - err = skb_checksum_help(skb); - if (err) - goto free_err; - } - } - - if (meta->flags & XDP_TXMD_FLAGS_LAUNCH_TIME) - skb->skb_mstamp_ns = meta->request.launch_time; - xsk_tx_metadata_to_compl(meta, &skb_shinfo(skb)->xsk_meta); - } } xsk_inc_num_desc(skb); -- 2.43.0