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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tso.c (2666B)

      1// SPDX-License-Identifier: GPL-2.0
      2#include <linux/export.h>
      3#include <linux/if_vlan.h>
      4#include <net/ip.h>
      5#include <net/tso.h>
      6#include <asm/unaligned.h>
      7
      8/* Calculate expected number of TX descriptors */
      9int tso_count_descs(const struct sk_buff *skb)
     10{
     11	/* The Marvell Way */
     12	return skb_shinfo(skb)->gso_segs * 2 + skb_shinfo(skb)->nr_frags;
     13}
     14EXPORT_SYMBOL(tso_count_descs);
     15
     16void tso_build_hdr(const struct sk_buff *skb, char *hdr, struct tso_t *tso,
     17		   int size, bool is_last)
     18{
     19	int hdr_len = skb_transport_offset(skb) + tso->tlen;
     20	int mac_hdr_len = skb_network_offset(skb);
     21
     22	memcpy(hdr, skb->data, hdr_len);
     23	if (!tso->ipv6) {
     24		struct iphdr *iph = (void *)(hdr + mac_hdr_len);
     25
     26		iph->id = htons(tso->ip_id);
     27		iph->tot_len = htons(size + hdr_len - mac_hdr_len);
     28		tso->ip_id++;
     29	} else {
     30		struct ipv6hdr *iph = (void *)(hdr + mac_hdr_len);
     31
     32		iph->payload_len = htons(size + tso->tlen);
     33	}
     34	hdr += skb_transport_offset(skb);
     35	if (tso->tlen != sizeof(struct udphdr)) {
     36		struct tcphdr *tcph = (struct tcphdr *)hdr;
     37
     38		put_unaligned_be32(tso->tcp_seq, &tcph->seq);
     39
     40		if (!is_last) {
     41			/* Clear all special flags for not last packet */
     42			tcph->psh = 0;
     43			tcph->fin = 0;
     44			tcph->rst = 0;
     45		}
     46	} else {
     47		struct udphdr *uh = (struct udphdr *)hdr;
     48
     49		uh->len = htons(sizeof(*uh) + size);
     50	}
     51}
     52EXPORT_SYMBOL(tso_build_hdr);
     53
     54void tso_build_data(const struct sk_buff *skb, struct tso_t *tso, int size)
     55{
     56	tso->tcp_seq += size; /* not worth avoiding this operation for UDP */
     57	tso->size -= size;
     58	tso->data += size;
     59
     60	if ((tso->size == 0) &&
     61	    (tso->next_frag_idx < skb_shinfo(skb)->nr_frags)) {
     62		skb_frag_t *frag = &skb_shinfo(skb)->frags[tso->next_frag_idx];
     63
     64		/* Move to next segment */
     65		tso->size = skb_frag_size(frag);
     66		tso->data = skb_frag_address(frag);
     67		tso->next_frag_idx++;
     68	}
     69}
     70EXPORT_SYMBOL(tso_build_data);
     71
     72int tso_start(struct sk_buff *skb, struct tso_t *tso)
     73{
     74	int tlen = skb_is_gso_tcp(skb) ? tcp_hdrlen(skb) : sizeof(struct udphdr);
     75	int hdr_len = skb_transport_offset(skb) + tlen;
     76
     77	tso->tlen = tlen;
     78	tso->ip_id = ntohs(ip_hdr(skb)->id);
     79	tso->tcp_seq = (tlen != sizeof(struct udphdr)) ? ntohl(tcp_hdr(skb)->seq) : 0;
     80	tso->next_frag_idx = 0;
     81	tso->ipv6 = vlan_get_protocol(skb) == htons(ETH_P_IPV6);
     82
     83	/* Build first data */
     84	tso->size = skb_headlen(skb) - hdr_len;
     85	tso->data = skb->data + hdr_len;
     86	if ((tso->size == 0) &&
     87	    (tso->next_frag_idx < skb_shinfo(skb)->nr_frags)) {
     88		skb_frag_t *frag = &skb_shinfo(skb)->frags[tso->next_frag_idx];
     89
     90		/* Move to next segment */
     91		tso->size = skb_frag_size(frag);
     92		tso->data = skb_frag_address(frag);
     93		tso->next_frag_idx++;
     94	}
     95	return hdr_len;
     96}
     97EXPORT_SYMBOL(tso_start);