From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- net/ipv4/gre_offload.c | 287 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 287 insertions(+) create mode 100644 net/ipv4/gre_offload.c (limited to 'net/ipv4/gre_offload.c') diff --git a/net/ipv4/gre_offload.c b/net/ipv4/gre_offload.c new file mode 100644 index 000000000..311e70bfc --- /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 +#include +#include +#include +#include +#include + +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_header_hard(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); -- cgit v1.2.3