Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1#include <linux/export.h>
2#include <net/ip.h>
3#include <net/tso.h>
4
5/* Calculate expected number of TX descriptors */
6int tso_count_descs(struct sk_buff *skb)
7{
8 /* The Marvell Way */
9 return skb_shinfo(skb)->gso_segs * 2 + skb_shinfo(skb)->nr_frags;
10}
11EXPORT_SYMBOL(tso_count_descs);
12
13void tso_build_hdr(struct sk_buff *skb, char *hdr, struct tso_t *tso,
14 int size, bool is_last)
15{
16 struct iphdr *iph;
17 struct tcphdr *tcph;
18 int hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
19 int mac_hdr_len = skb_network_offset(skb);
20
21 memcpy(hdr, skb->data, hdr_len);
22 iph = (struct iphdr *)(hdr + mac_hdr_len);
23 iph->id = htons(tso->ip_id);
24 iph->tot_len = htons(size + hdr_len - mac_hdr_len);
25 tcph = (struct tcphdr *)(hdr + skb_transport_offset(skb));
26 tcph->seq = htonl(tso->tcp_seq);
27 tso->ip_id++;
28
29 if (!is_last) {
30 /* Clear all special flags for not last packet */
31 tcph->psh = 0;
32 tcph->fin = 0;
33 tcph->rst = 0;
34 }
35}
36EXPORT_SYMBOL(tso_build_hdr);
37
38void tso_build_data(struct sk_buff *skb, struct tso_t *tso, int size)
39{
40 tso->tcp_seq += size;
41 tso->size -= size;
42 tso->data += size;
43
44 if ((tso->size == 0) &&
45 (tso->next_frag_idx < skb_shinfo(skb)->nr_frags)) {
46 skb_frag_t *frag = &skb_shinfo(skb)->frags[tso->next_frag_idx];
47
48 /* Move to next segment */
49 tso->size = frag->size;
50 tso->data = page_address(frag->page.p) + frag->page_offset;
51 tso->next_frag_idx++;
52 }
53}
54EXPORT_SYMBOL(tso_build_data);
55
56void tso_start(struct sk_buff *skb, struct tso_t *tso)
57{
58 int hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
59
60 tso->ip_id = ntohs(ip_hdr(skb)->id);
61 tso->tcp_seq = ntohl(tcp_hdr(skb)->seq);
62 tso->next_frag_idx = 0;
63
64 /* Build first data */
65 tso->size = skb_headlen(skb) - hdr_len;
66 tso->data = skb->data + hdr_len;
67 if ((tso->size == 0) &&
68 (tso->next_frag_idx < skb_shinfo(skb)->nr_frags)) {
69 skb_frag_t *frag = &skb_shinfo(skb)->frags[tso->next_frag_idx];
70
71 /* Move to next segment */
72 tso->size = frag->size;
73 tso->data = page_address(frag->page.p) + frag->page_offset;
74 tso->next_frag_idx++;
75 }
76}
77EXPORT_SYMBOL(tso_start);