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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /net/ipv4/gre_offload.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'net/ipv4/gre_offload.c')
-rw-r--r--net/ipv4/gre_offload.c287
1 files changed, 287 insertions, 0 deletions
diff --git a/net/ipv4/gre_offload.c b/net/ipv4/gre_offload.c
new file mode 100644
index 000000000..5028c72d4
--- /dev/null
+++ b/net/ipv4/gre_offload.c
@@ -0,0 +1,287 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * IPV4 GSO/GRO offload support
+ * Linux INET implementation
+ *
+ * GRE GSO support
+ */
+
+#include <linux/skbuff.h>
+#include <linux/init.h>
+#include <net/protocol.h>
+#include <net/gre.h>
+#include <net/gro.h>
+#include <net/gso.h>
+
+static struct sk_buff *gre_gso_segment(struct sk_buff *skb,
+ netdev_features_t features)
+{
+ int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb);
+ bool need_csum, offload_csum, gso_partial, need_ipsec;
+ struct sk_buff *segs = ERR_PTR(-EINVAL);
+ u16 mac_offset = skb->mac_header;
+ __be16 protocol = skb->protocol;
+ u16 mac_len = skb->mac_len;
+ int gre_offset, outer_hlen;
+
+ if (!skb->encapsulation)
+ goto out;
+
+ if (unlikely(tnl_hlen < sizeof(struct gre_base_hdr)))
+ goto out;
+
+ if (unlikely(!pskb_may_pull(skb, tnl_hlen)))
+ goto out;
+
+ /* setup inner skb. */
+ skb->encapsulation = 0;
+ SKB_GSO_CB(skb)->encap_level = 0;
+ __skb_pull(skb, tnl_hlen);
+ skb_reset_mac_header(skb);
+ skb_set_network_header(skb, skb_inner_network_offset(skb));
+ skb->mac_len = skb_inner_network_offset(skb);
+ skb->protocol = skb->inner_protocol;
+
+ need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_GRE_CSUM);
+ skb->encap_hdr_csum = need_csum;
+
+ features &= skb->dev->hw_enc_features;
+ if (need_csum)
+ features &= ~NETIF_F_SCTP_CRC;
+
+ need_ipsec = skb_dst(skb) && dst_xfrm(skb_dst(skb));
+ /* Try to offload checksum if possible */
+ offload_csum = !!(need_csum && !need_ipsec &&
+ (skb->dev->features & NETIF_F_HW_CSUM));
+
+ /* segment inner packet. */
+ segs = skb_mac_gso_segment(skb, features);
+ if (IS_ERR_OR_NULL(segs)) {
+ skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset,
+ mac_len);
+ goto out;
+ }
+
+ gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
+
+ outer_hlen = skb_tnl_header_len(skb);
+ gre_offset = outer_hlen - tnl_hlen;
+ skb = segs;
+ do {
+ struct gre_base_hdr *greh;
+ __sum16 *pcsum;
+
+ /* Set up inner headers if we are offloading inner checksum */
+ if (skb->ip_summed == CHECKSUM_PARTIAL) {
+ skb_reset_inner_headers(skb);
+ skb->encapsulation = 1;
+ }
+
+ skb->mac_len = mac_len;
+ skb->protocol = protocol;
+
+ __skb_push(skb, outer_hlen);
+ skb_reset_mac_header(skb);
+ skb_set_network_header(skb, mac_len);
+ skb_set_transport_header(skb, gre_offset);
+
+ if (!need_csum)
+ continue;
+
+ greh = (struct gre_base_hdr *)skb_transport_header(skb);
+ pcsum = (__sum16 *)(greh + 1);
+
+ if (gso_partial && skb_is_gso(skb)) {
+ unsigned int partial_adj;
+
+ /* Adjust checksum to account for the fact that
+ * the partial checksum is based on actual size
+ * whereas headers should be based on MSS size.
+ */
+ partial_adj = skb->len + skb_headroom(skb) -
+ SKB_GSO_CB(skb)->data_offset -
+ skb_shinfo(skb)->gso_size;
+ *pcsum = ~csum_fold((__force __wsum)htonl(partial_adj));
+ } else {
+ *pcsum = 0;
+ }
+
+ *(pcsum + 1) = 0;
+ if (skb->encapsulation || !offload_csum) {
+ *pcsum = gso_make_checksum(skb, 0);
+ } else {
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ skb->csum_start = skb_transport_header(skb) - skb->head;
+ skb->csum_offset = sizeof(*greh);
+ }
+ } while ((skb = skb->next));
+out:
+ return segs;
+}
+
+static struct sk_buff *gre_gro_receive(struct list_head *head,
+ struct sk_buff *skb)
+{
+ struct sk_buff *pp = NULL;
+ struct sk_buff *p;
+ const struct gre_base_hdr *greh;
+ unsigned int hlen, grehlen;
+ unsigned int off;
+ int flush = 1;
+ struct packet_offload *ptype;
+ __be16 type;
+
+ if (NAPI_GRO_CB(skb)->encap_mark)
+ goto out;
+
+ NAPI_GRO_CB(skb)->encap_mark = 1;
+
+ off = skb_gro_offset(skb);
+ hlen = off + sizeof(*greh);
+ greh = skb_gro_header(skb, hlen, off);
+ if (unlikely(!greh))
+ goto out;
+
+ /* Only support version 0 and K (key), C (csum) flags. Note that
+ * although the support for the S (seq#) flag can be added easily
+ * for GRO, this is problematic for GSO hence can not be enabled
+ * here because a GRO pkt may end up in the forwarding path, thus
+ * requiring GSO support to break it up correctly.
+ */
+ if ((greh->flags & ~(GRE_KEY|GRE_CSUM)) != 0)
+ goto out;
+
+ /* We can only support GRE_CSUM if we can track the location of
+ * the GRE header. In the case of FOU/GUE we cannot because the
+ * outer UDP header displaces the GRE header leaving us in a state
+ * of limbo.
+ */
+ if ((greh->flags & GRE_CSUM) && NAPI_GRO_CB(skb)->is_fou)
+ goto out;
+
+ type = greh->protocol;
+
+ ptype = gro_find_receive_by_type(type);
+ if (!ptype)
+ goto out;
+
+ grehlen = GRE_HEADER_SECTION;
+
+ if (greh->flags & GRE_KEY)
+ grehlen += GRE_HEADER_SECTION;
+
+ if (greh->flags & GRE_CSUM)
+ grehlen += GRE_HEADER_SECTION;
+
+ hlen = off + grehlen;
+ if (!skb_gro_may_pull(skb, hlen)) {
+ greh = skb_gro_header_slow(skb, hlen, off);
+ if (unlikely(!greh))
+ goto out;
+ }
+
+ /* Don't bother verifying checksum if we're going to flush anyway. */
+ if ((greh->flags & GRE_CSUM) && !NAPI_GRO_CB(skb)->flush) {
+ if (skb_gro_checksum_simple_validate(skb))
+ goto out;
+
+ skb_gro_checksum_try_convert(skb, IPPROTO_GRE,
+ null_compute_pseudo);
+ }
+
+ list_for_each_entry(p, head, list) {
+ const struct gre_base_hdr *greh2;
+
+ if (!NAPI_GRO_CB(p)->same_flow)
+ continue;
+
+ /* The following checks are needed to ensure only pkts
+ * from the same tunnel are considered for aggregation.
+ * The criteria for "the same tunnel" includes:
+ * 1) same version (we only support version 0 here)
+ * 2) same protocol (we only support ETH_P_IP for now)
+ * 3) same set of flags
+ * 4) same key if the key field is present.
+ */
+ greh2 = (struct gre_base_hdr *)(p->data + off);
+
+ if (greh2->flags != greh->flags ||
+ greh2->protocol != greh->protocol) {
+ NAPI_GRO_CB(p)->same_flow = 0;
+ continue;
+ }
+ if (greh->flags & GRE_KEY) {
+ /* compare keys */
+ if (*(__be32 *)(greh2+1) != *(__be32 *)(greh+1)) {
+ NAPI_GRO_CB(p)->same_flow = 0;
+ continue;
+ }
+ }
+ }
+
+ skb_gro_pull(skb, grehlen);
+
+ /* Adjusted NAPI_GRO_CB(skb)->csum after skb_gro_pull()*/
+ skb_gro_postpull_rcsum(skb, greh, grehlen);
+
+ pp = call_gro_receive(ptype->callbacks.gro_receive, head, skb);
+ flush = 0;
+
+out:
+ skb_gro_flush_final(skb, pp, flush);
+
+ return pp;
+}
+
+static int gre_gro_complete(struct sk_buff *skb, int nhoff)
+{
+ struct gre_base_hdr *greh = (struct gre_base_hdr *)(skb->data + nhoff);
+ struct packet_offload *ptype;
+ unsigned int grehlen = sizeof(*greh);
+ int err = -ENOENT;
+ __be16 type;
+
+ skb->encapsulation = 1;
+ skb_shinfo(skb)->gso_type = SKB_GSO_GRE;
+
+ type = greh->protocol;
+ if (greh->flags & GRE_KEY)
+ grehlen += GRE_HEADER_SECTION;
+
+ if (greh->flags & GRE_CSUM)
+ grehlen += GRE_HEADER_SECTION;
+
+ ptype = gro_find_complete_by_type(type);
+ if (ptype)
+ err = ptype->callbacks.gro_complete(skb, nhoff + grehlen);
+
+ skb_set_inner_mac_header(skb, nhoff + grehlen);
+
+ return err;
+}
+
+static const struct net_offload gre_offload = {
+ .callbacks = {
+ .gso_segment = gre_gso_segment,
+ .gro_receive = gre_gro_receive,
+ .gro_complete = gre_gro_complete,
+ },
+};
+
+static int __init gre_offload_init(void)
+{
+ int err;
+
+ err = inet_add_offload(&gre_offload, IPPROTO_GRE);
+#if IS_ENABLED(CONFIG_IPV6)
+ if (err)
+ return err;
+
+ err = inet6_add_offload(&gre_offload, IPPROTO_GRE);
+ if (err)
+ inet_del_offload(&gre_offload, IPPROTO_GRE);
+#endif
+
+ return err;
+}
+device_initcall(gre_offload_init);