cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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offload.c (2652B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * sctp_offload - GRO/GSO Offloading for SCTP
      4 *
      5 * Copyright (C) 2015, Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
      6 */
      7
      8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
      9
     10#include <linux/kernel.h>
     11#include <linux/kprobes.h>
     12#include <linux/socket.h>
     13#include <linux/sctp.h>
     14#include <linux/proc_fs.h>
     15#include <linux/vmalloc.h>
     16#include <linux/module.h>
     17#include <linux/kfifo.h>
     18#include <linux/time.h>
     19#include <net/net_namespace.h>
     20
     21#include <linux/skbuff.h>
     22#include <net/sctp/sctp.h>
     23#include <net/sctp/checksum.h>
     24#include <net/protocol.h>
     25
     26static __le32 sctp_gso_make_checksum(struct sk_buff *skb)
     27{
     28	skb->ip_summed = CHECKSUM_NONE;
     29	skb->csum_not_inet = 0;
     30	/* csum and csum_start in GSO CB may be needed to do the UDP
     31	 * checksum when it's a UDP tunneling packet.
     32	 */
     33	SKB_GSO_CB(skb)->csum = (__force __wsum)~0;
     34	SKB_GSO_CB(skb)->csum_start = skb_headroom(skb) + skb->len;
     35	return sctp_compute_cksum(skb, skb_transport_offset(skb));
     36}
     37
     38static struct sk_buff *sctp_gso_segment(struct sk_buff *skb,
     39					netdev_features_t features)
     40{
     41	struct sk_buff *segs = ERR_PTR(-EINVAL);
     42	struct sctphdr *sh;
     43
     44	if (!skb_is_gso_sctp(skb))
     45		goto out;
     46
     47	sh = sctp_hdr(skb);
     48	if (!pskb_may_pull(skb, sizeof(*sh)))
     49		goto out;
     50
     51	__skb_pull(skb, sizeof(*sh));
     52
     53	if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
     54		/* Packet is from an untrusted source, reset gso_segs. */
     55		struct skb_shared_info *pinfo = skb_shinfo(skb);
     56		struct sk_buff *frag_iter;
     57
     58		pinfo->gso_segs = 0;
     59		if (skb->len != skb->data_len) {
     60			/* Means we have chunks in here too */
     61			pinfo->gso_segs++;
     62		}
     63
     64		skb_walk_frags(skb, frag_iter)
     65			pinfo->gso_segs++;
     66
     67		segs = NULL;
     68		goto out;
     69	}
     70
     71	segs = skb_segment(skb, (features | NETIF_F_HW_CSUM) & ~NETIF_F_SG);
     72	if (IS_ERR(segs))
     73		goto out;
     74
     75	/* All that is left is update SCTP CRC if necessary */
     76	if (!(features & NETIF_F_SCTP_CRC)) {
     77		for (skb = segs; skb; skb = skb->next) {
     78			if (skb->ip_summed == CHECKSUM_PARTIAL) {
     79				sh = sctp_hdr(skb);
     80				sh->checksum = sctp_gso_make_checksum(skb);
     81			}
     82		}
     83	}
     84
     85out:
     86	return segs;
     87}
     88
     89static const struct net_offload sctp_offload = {
     90	.callbacks = {
     91		.gso_segment = sctp_gso_segment,
     92	},
     93};
     94
     95static const struct net_offload sctp6_offload = {
     96	.callbacks = {
     97		.gso_segment = sctp_gso_segment,
     98	},
     99};
    100
    101int __init sctp_offload_init(void)
    102{
    103	int ret;
    104
    105	ret = inet_add_offload(&sctp_offload, IPPROTO_SCTP);
    106	if (ret)
    107		goto out;
    108
    109	ret = inet6_add_offload(&sctp6_offload, IPPROTO_SCTP);
    110	if (ret)
    111		goto ipv4;
    112
    113	crc32c_csum_stub = &sctp_csum_ops;
    114	return ret;
    115
    116ipv4:
    117	inet_del_offload(&sctp_offload, IPPROTO_SCTP);
    118out:
    119	return ret;
    120}