[PATCH bpf-next 1/2] net: xdp: introduce __xdp_build_skb_from_frame utility routine
From: Lorenzo Bianconi <lorenzo@kernel.org>
Date: 2020-12-16 19:33:05
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), networking [general], the rest, xdp (express data path) · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Jesper Dangaard Brouer, John Fastabend
Introduce __xdp_build_skb_from_frame utility routine to build the skb from xdp_frame. Rely on __xdp_build_skb_from_frame in cpumap code. Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> --- include/net/xdp.h | 3 +++ kernel/bpf/cpumap.c | 45 +-------------------------------------------- net/core/xdp.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 48 insertions(+), 44 deletions(-)
diff --git a/include/net/xdp.h b/include/net/xdp.h
index 600acb307db6..da62fa20fa8a 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h@@ -145,6 +145,9 @@ void xdp_warn(const char *msg, const char *func, const int line); #define XDP_WARN(msg) xdp_warn(msg, __func__, __LINE__) struct xdp_frame *xdp_convert_zc_to_xdp_frame(struct xdp_buff *xdp); +struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf, + struct sk_buff *skb, + struct net_device *dev); static inline void xdp_convert_frame_to_buff(struct xdp_frame *frame, struct xdp_buff *xdp)
diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index 747313698178..49113880b82a 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c@@ -141,49 +141,6 @@ static void cpu_map_kthread_stop(struct work_struct *work) kthread_stop(rcpu->kthread); } -static struct sk_buff *cpu_map_build_skb(struct xdp_frame *xdpf, - struct sk_buff *skb) -{ - unsigned int hard_start_headroom; - unsigned int frame_size; - void *pkt_data_start; - - /* Part of headroom was reserved to xdpf */ - hard_start_headroom = sizeof(struct xdp_frame) + xdpf->headroom; - - /* Memory size backing xdp_frame data already have reserved - * room for build_skb to place skb_shared_info in tailroom. - */ - frame_size = xdpf->frame_sz; - - pkt_data_start = xdpf->data - hard_start_headroom; - skb = build_skb_around(skb, pkt_data_start, frame_size); - if (unlikely(!skb)) - return NULL; - - skb_reserve(skb, hard_start_headroom); - __skb_put(skb, xdpf->len); - if (xdpf->metasize) - skb_metadata_set(skb, xdpf->metasize); - - /* Essential SKB info: protocol and skb->dev */ - skb->protocol = eth_type_trans(skb, xdpf->dev_rx); - - /* Optional SKB info, currently missing: - * - HW checksum info (skb->ip_summed) - * - HW RX hash (skb_set_hash) - * - RX ring dev queue index (skb_record_rx_queue) - */ - - /* Until page_pool get SKB return path, release DMA here */ - xdp_release_frame(xdpf); - - /* Allow SKB to reuse area used by xdp_frame */ - xdp_scrub_frame(xdpf); - - return skb; -} - static void __cpu_map_ring_cleanup(struct ptr_ring *ring) { /* The tear-down procedure should have made sure that queue is
@@ -350,7 +307,7 @@ static int cpu_map_kthread_run(void *data) struct sk_buff *skb = skbs[i]; int ret; - skb = cpu_map_build_skb(xdpf, skb); + skb = __xdp_build_skb_from_frame(xdpf, skb, xdpf->dev_rx); if (!skb) { xdp_return_frame(xdpf); continue;
diff --git a/net/core/xdp.c b/net/core/xdp.c
index 3a8c9ab4ecbe..aeb09ed0704c 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c@@ -513,3 +513,47 @@ void xdp_warn(const char *msg, const char *func, const int line) WARN(1, "XDP_WARN: %s(line:%d): %s\n", func, line, msg); }; EXPORT_SYMBOL_GPL(xdp_warn); + +struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf, + struct sk_buff *skb, + struct net_device *dev) +{ + unsigned int headroom, frame_size; + void *hard_start; + + /* Part of headroom was reserved to xdpf */ + headroom = sizeof(*xdpf) + xdpf->headroom; + + /* Memory size backing xdp_frame data already have reserved + * room for build_skb to place skb_shared_info in tailroom. + */ + frame_size = xdpf->frame_sz; + + hard_start = xdpf->data - headroom; + skb = build_skb_around(skb, hard_start, frame_size); + if (unlikely(!skb)) + return NULL; + + skb_reserve(skb, headroom); + __skb_put(skb, xdpf->len); + if (xdpf->metasize) + skb_metadata_set(skb, xdpf->metasize); + + /* Essential SKB info: protocol and skb->dev */ + skb->protocol = eth_type_trans(skb, dev); + + /* Optional SKB info, currently missing: + * - HW checksum info (skb->ip_summed) + * - HW RX hash (skb_set_hash) + * - RX ring dev queue index (skb_record_rx_queue) + */ + + /* Until page_pool get SKB return path, release DMA here */ + xdp_release_frame(xdpf); + + /* Allow SKB to reuse area used by xdp_frame */ + xdp_scrub_frame(xdpf); + + return skb; +} +EXPORT_SYMBOL_GPL(__xdp_build_skb_from_frame);
--
2.29.2