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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/tcp_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/tcp_offload.c')
-rw-r--r--net/ipv4/tcp_offload.c478
1 files changed, 478 insertions, 0 deletions
diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
new file mode 100644
index 000000000..3b1fdcd3c
--- /dev/null
+++ b/net/ipv4/tcp_offload.c
@@ -0,0 +1,478 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * IPV4 GSO/GRO offload support
+ * Linux INET implementation
+ *
+ * TCPv4 GSO/GRO support
+ */
+
+#include <linux/indirect_call_wrapper.h>
+#include <linux/skbuff.h>
+#include <net/gro.h>
+#include <net/gso.h>
+#include <net/tcp.h>
+#include <net/protocol.h>
+
+static void tcp_gso_tstamp(struct sk_buff *skb, struct sk_buff *gso_skb,
+ unsigned int seq, unsigned int mss)
+{
+ u32 flags = skb_shinfo(gso_skb)->tx_flags & SKBTX_ANY_TSTAMP;
+ u32 ts_seq = skb_shinfo(gso_skb)->tskey;
+
+ while (skb) {
+ if (before(ts_seq, seq + mss)) {
+ skb_shinfo(skb)->tx_flags |= flags;
+ skb_shinfo(skb)->tskey = ts_seq;
+ return;
+ }
+
+ skb = skb->next;
+ seq += mss;
+ }
+}
+
+static void __tcpv4_gso_segment_csum(struct sk_buff *seg,
+ __be32 *oldip, __be32 newip,
+ __be16 *oldport, __be16 newport)
+{
+ struct tcphdr *th;
+ struct iphdr *iph;
+
+ if (*oldip == newip && *oldport == newport)
+ return;
+
+ th = tcp_hdr(seg);
+ iph = ip_hdr(seg);
+
+ inet_proto_csum_replace4(&th->check, seg, *oldip, newip, true);
+ inet_proto_csum_replace2(&th->check, seg, *oldport, newport, false);
+ *oldport = newport;
+
+ csum_replace4(&iph->check, *oldip, newip);
+ *oldip = newip;
+}
+
+static struct sk_buff *__tcpv4_gso_segment_list_csum(struct sk_buff *segs)
+{
+ const struct tcphdr *th;
+ const struct iphdr *iph;
+ struct sk_buff *seg;
+ struct tcphdr *th2;
+ struct iphdr *iph2;
+
+ seg = segs;
+ th = tcp_hdr(seg);
+ iph = ip_hdr(seg);
+ th2 = tcp_hdr(seg->next);
+ iph2 = ip_hdr(seg->next);
+
+ if (!(*(const u32 *)&th->source ^ *(const u32 *)&th2->source) &&
+ iph->daddr == iph2->daddr && iph->saddr == iph2->saddr)
+ return segs;
+
+ while ((seg = seg->next)) {
+ th2 = tcp_hdr(seg);
+ iph2 = ip_hdr(seg);
+
+ __tcpv4_gso_segment_csum(seg,
+ &iph2->saddr, iph->saddr,
+ &th2->source, th->source);
+ __tcpv4_gso_segment_csum(seg,
+ &iph2->daddr, iph->daddr,
+ &th2->dest, th->dest);
+ }
+
+ return segs;
+}
+
+static struct sk_buff *__tcp4_gso_segment_list(struct sk_buff *skb,
+ netdev_features_t features)
+{
+ skb = skb_segment_list(skb, features, skb_mac_header_len(skb));
+ if (IS_ERR(skb))
+ return skb;
+
+ return __tcpv4_gso_segment_list_csum(skb);
+}
+
+static struct sk_buff *tcp4_gso_segment(struct sk_buff *skb,
+ netdev_features_t features)
+{
+ if (!(skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4))
+ return ERR_PTR(-EINVAL);
+
+ if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
+ return ERR_PTR(-EINVAL);
+
+ if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST) {
+ struct tcphdr *th = tcp_hdr(skb);
+
+ if ((skb_pagelen(skb) - th->doff * 4 == skb_shinfo(skb)->gso_size) &&
+ !(skb_shinfo(skb)->gso_type & SKB_GSO_DODGY))
+ return __tcp4_gso_segment_list(skb, features);
+
+ skb->ip_summed = CHECKSUM_NONE;
+ }
+
+ if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
+ const struct iphdr *iph = ip_hdr(skb);
+ struct tcphdr *th = tcp_hdr(skb);
+
+ /* Set up checksum pseudo header, usually expect stack to
+ * have done this already.
+ */
+
+ th->check = 0;
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ __tcp_v4_send_check(skb, iph->saddr, iph->daddr);
+ }
+
+ return tcp_gso_segment(skb, features);
+}
+
+struct sk_buff *tcp_gso_segment(struct sk_buff *skb,
+ netdev_features_t features)
+{
+ struct sk_buff *segs = ERR_PTR(-EINVAL);
+ unsigned int sum_truesize = 0;
+ struct tcphdr *th;
+ unsigned int thlen;
+ unsigned int seq;
+ unsigned int oldlen;
+ unsigned int mss;
+ struct sk_buff *gso_skb = skb;
+ __sum16 newcheck;
+ bool ooo_okay, copy_destructor;
+ bool ecn_cwr_mask;
+ __wsum delta;
+
+ th = tcp_hdr(skb);
+ thlen = th->doff * 4;
+ if (thlen < sizeof(*th))
+ goto out;
+
+ if (unlikely(skb_checksum_start(skb) != skb_transport_header(skb)))
+ goto out;
+
+ if (!pskb_may_pull(skb, thlen))
+ goto out;
+
+ oldlen = ~skb->len;
+ __skb_pull(skb, thlen);
+
+ mss = skb_shinfo(skb)->gso_size;
+ if (unlikely(skb->len <= mss))
+ goto out;
+
+ if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
+ /* Packet is from an untrusted source, reset gso_segs. */
+
+ skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
+
+ segs = NULL;
+ goto out;
+ }
+
+ copy_destructor = gso_skb->destructor == tcp_wfree;
+ ooo_okay = gso_skb->ooo_okay;
+ /* All segments but the first should have ooo_okay cleared */
+ skb->ooo_okay = 0;
+
+ segs = skb_segment(skb, features);
+ if (IS_ERR(segs))
+ goto out;
+
+ /* Only first segment might have ooo_okay set */
+ segs->ooo_okay = ooo_okay;
+
+ /* GSO partial and frag_list segmentation only requires splitting
+ * the frame into an MSS multiple and possibly a remainder, both
+ * cases return a GSO skb. So update the mss now.
+ */
+ if (skb_is_gso(segs))
+ mss *= skb_shinfo(segs)->gso_segs;
+
+ delta = (__force __wsum)htonl(oldlen + thlen + mss);
+
+ skb = segs;
+ th = tcp_hdr(skb);
+ seq = ntohl(th->seq);
+
+ if (unlikely(skb_shinfo(gso_skb)->tx_flags & SKBTX_ANY_TSTAMP))
+ tcp_gso_tstamp(segs, gso_skb, seq, mss);
+
+ newcheck = ~csum_fold(csum_add(csum_unfold(th->check), delta));
+
+ ecn_cwr_mask = !!(skb_shinfo(gso_skb)->gso_type & SKB_GSO_TCP_ACCECN);
+
+ while (skb->next) {
+ th->fin = th->psh = 0;
+ th->check = newcheck;
+
+ if (skb->ip_summed == CHECKSUM_PARTIAL)
+ gso_reset_checksum(skb, ~th->check);
+ else
+ th->check = gso_make_checksum(skb, ~th->check);
+
+ seq += mss;
+ if (copy_destructor) {
+ skb->destructor = gso_skb->destructor;
+ skb->sk = gso_skb->sk;
+ sum_truesize += skb->truesize;
+ }
+ skb = skb->next;
+ th = tcp_hdr(skb);
+
+ th->seq = htonl(seq);
+
+ th->cwr &= ecn_cwr_mask;
+ }
+
+ /* Following permits TCP Small Queues to work well with GSO :
+ * The callback to TCP stack will be called at the time last frag
+ * is freed at TX completion, and not right now when gso_skb
+ * is freed by GSO engine
+ */
+ if (copy_destructor) {
+ int delta;
+
+ swap(gso_skb->sk, skb->sk);
+ swap(gso_skb->destructor, skb->destructor);
+ sum_truesize += skb->truesize;
+ delta = sum_truesize - gso_skb->truesize;
+ /* In some pathological cases, delta can be negative.
+ * We need to either use refcount_add() or refcount_sub_and_test()
+ */
+ if (likely(delta >= 0))
+ refcount_add(delta, &skb->sk->sk_wmem_alloc);
+ else
+ WARN_ON_ONCE(refcount_sub_and_test(-delta, &skb->sk->sk_wmem_alloc));
+ }
+
+ delta = (__force __wsum)htonl(oldlen +
+ (skb_tail_pointer(skb) -
+ skb_transport_header(skb)) +
+ skb->data_len);
+ th->check = ~csum_fold(csum_add(csum_unfold(th->check), delta));
+ if (skb->ip_summed == CHECKSUM_PARTIAL)
+ gso_reset_checksum(skb, ~th->check);
+ else
+ th->check = gso_make_checksum(skb, ~th->check);
+out:
+ return segs;
+}
+
+struct sk_buff *tcp_gro_lookup(struct list_head *head, struct tcphdr *th)
+{
+ struct tcphdr *th2;
+ struct sk_buff *p;
+
+ list_for_each_entry(p, head, list) {
+ if (!NAPI_GRO_CB(p)->same_flow)
+ continue;
+
+ th2 = tcp_hdr(p);
+ if (*(u32 *)&th->source ^ *(u32 *)&th2->source) {
+ NAPI_GRO_CB(p)->same_flow = 0;
+ continue;
+ }
+
+ return p;
+ }
+
+ return NULL;
+}
+
+struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb,
+ struct tcphdr *th)
+{
+ unsigned int thlen = th->doff * 4;
+ struct sk_buff *pp = NULL;
+ struct sk_buff *p;
+ struct tcphdr *th2;
+ unsigned int len;
+ __be32 flags;
+ unsigned int mss = 1;
+ int flush = 1;
+ int i;
+
+ len = skb_gro_len(skb);
+ flags = tcp_flag_word(th);
+
+ p = tcp_gro_lookup(head, th);
+ if (!p)
+ goto out_check_final;
+
+ th2 = tcp_hdr(p);
+ flush = (__force int)((flags ^ tcp_flag_word(th2)) &
+ ~(TCP_FLAG_FIN | TCP_FLAG_PSH));
+ flush |= (__force int)(th->ack_seq ^ th2->ack_seq);
+ for (i = sizeof(*th); i < thlen; i += 4)
+ flush |= *(u32 *)((u8 *)th + i) ^
+ *(u32 *)((u8 *)th2 + i);
+
+ flush |= gro_receive_network_flush(th, th2, p);
+
+ mss = skb_shinfo(p)->gso_size;
+
+ /* If skb is a GRO packet, make sure its gso_size matches prior packet mss.
+ * If it is a single frame, do not aggregate it if its length
+ * is bigger than our mss.
+ */
+ if (unlikely(skb_is_gso(skb)))
+ flush |= (mss != skb_shinfo(skb)->gso_size);
+ else
+ flush |= (len - 1) >= mss;
+
+ flush |= (ntohl(th2->seq) + skb_gro_len(p)) ^ ntohl(th->seq);
+ flush |= skb_cmp_decrypted(p, skb);
+
+ if (unlikely(NAPI_GRO_CB(p)->is_flist)) {
+ flush |= (__force int)(flags ^ tcp_flag_word(th2));
+ flush |= skb->ip_summed != p->ip_summed;
+ flush |= skb->csum_level != p->csum_level;
+ flush |= NAPI_GRO_CB(p)->count >= 64;
+ skb_set_network_header(skb, skb_gro_receive_network_offset(skb));
+
+ if (flush || skb_gro_receive_list(p, skb))
+ mss = 1;
+
+ goto out_check_final;
+ }
+
+ if (flush || skb_gro_receive(p, skb)) {
+ mss = 1;
+ goto out_check_final;
+ }
+
+ tcp_flag_word(th2) |= flags & (TCP_FLAG_FIN | TCP_FLAG_PSH);
+
+out_check_final:
+ /* Force a flush if last segment is smaller than mss. */
+ if (unlikely(skb_is_gso(skb)))
+ flush = len != NAPI_GRO_CB(skb)->count * skb_shinfo(skb)->gso_size;
+ else
+ flush = len < mss;
+
+ flush |= (__force int)(flags & (TCP_FLAG_URG | TCP_FLAG_PSH |
+ TCP_FLAG_RST | TCP_FLAG_SYN |
+ TCP_FLAG_FIN));
+
+ if (p && (!NAPI_GRO_CB(skb)->same_flow || flush))
+ pp = p;
+
+ NAPI_GRO_CB(skb)->flush |= (flush != 0);
+
+ return pp;
+}
+
+void tcp_gro_complete(struct sk_buff *skb)
+{
+ struct tcphdr *th = tcp_hdr(skb);
+ struct skb_shared_info *shinfo;
+
+ if (skb->encapsulation)
+ skb->inner_transport_header = skb->transport_header;
+
+ skb->csum_start = (unsigned char *)th - skb->head;
+ skb->csum_offset = offsetof(struct tcphdr, check);
+ skb->ip_summed = CHECKSUM_PARTIAL;
+
+ shinfo = skb_shinfo(skb);
+ shinfo->gso_segs = NAPI_GRO_CB(skb)->count;
+
+ if (th->cwr)
+ shinfo->gso_type |= SKB_GSO_TCP_ACCECN;
+}
+EXPORT_SYMBOL(tcp_gro_complete);
+
+static void tcp4_check_fraglist_gro(struct list_head *head, struct sk_buff *skb,
+ struct tcphdr *th)
+{
+ const struct iphdr *iph;
+ struct sk_buff *p;
+ struct sock *sk;
+ struct net *net;
+ int iif, sdif;
+
+ if (likely(!(skb->dev->features & NETIF_F_GRO_FRAGLIST)))
+ return;
+
+ p = tcp_gro_lookup(head, th);
+ if (p) {
+ NAPI_GRO_CB(skb)->is_flist = NAPI_GRO_CB(p)->is_flist;
+ return;
+ }
+
+ inet_get_iif_sdif(skb, &iif, &sdif);
+ iph = skb_gro_network_header(skb);
+ net = dev_net_rcu(skb->dev);
+ sk = __inet_lookup_established(net, iph->saddr, th->source,
+ iph->daddr, ntohs(th->dest),
+ iif, sdif);
+ NAPI_GRO_CB(skb)->is_flist = !sk;
+ if (sk)
+ sock_gen_put(sk);
+}
+
+INDIRECT_CALLABLE_SCOPE
+struct sk_buff *tcp4_gro_receive(struct list_head *head, struct sk_buff *skb)
+{
+ struct tcphdr *th;
+
+ /* Don't bother verifying checksum if we're going to flush anyway. */
+ if (!NAPI_GRO_CB(skb)->flush &&
+ skb_gro_checksum_validate(skb, IPPROTO_TCP,
+ inet_gro_compute_pseudo))
+ goto flush;
+
+ th = tcp_gro_pull_header(skb);
+ if (!th)
+ goto flush;
+
+ tcp4_check_fraglist_gro(head, skb, th);
+
+ return tcp_gro_receive(head, skb, th);
+
+flush:
+ NAPI_GRO_CB(skb)->flush = 1;
+ return NULL;
+}
+
+INDIRECT_CALLABLE_SCOPE int tcp4_gro_complete(struct sk_buff *skb, int thoff)
+{
+ const u16 offset = NAPI_GRO_CB(skb)->network_offsets[skb->encapsulation];
+ const struct iphdr *iph = (struct iphdr *)(skb->data + offset);
+ struct tcphdr *th = tcp_hdr(skb);
+
+ if (unlikely(NAPI_GRO_CB(skb)->is_flist)) {
+ skb_shinfo(skb)->gso_type |= SKB_GSO_FRAGLIST | SKB_GSO_TCPV4;
+ skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
+
+ __skb_incr_checksum_unnecessary(skb);
+
+ return 0;
+ }
+
+ th->check = ~tcp_v4_check(skb->len - thoff, iph->saddr,
+ iph->daddr, 0);
+
+ BUILD_BUG_ON(SKB_GSO_TCP_FIXEDID << 1 != SKB_GSO_TCP_FIXEDID_INNER);
+ skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV4 |
+ (NAPI_GRO_CB(skb)->ip_fixedid * SKB_GSO_TCP_FIXEDID);
+
+ tcp_gro_complete(skb);
+ return 0;
+}
+
+int __init tcpv4_offload_init(void)
+{
+ net_hotdata.tcpv4_offload = (struct net_offload) {
+ .callbacks = {
+ .gso_segment = tcp4_gso_segment,
+ .gro_receive = tcp4_gro_receive,
+ .gro_complete = tcp4_gro_complete,
+ },
+ };
+ return inet_add_offload(&net_hotdata.tcpv4_offload, IPPROTO_TCP);
+}