tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * sctp_offload - GRO/GSO Offloading for SCTP
3 *
4 * Copyright (C) 2015, Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 */
16
17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
19#include <linux/kernel.h>
20#include <linux/kprobes.h>
21#include <linux/socket.h>
22#include <linux/sctp.h>
23#include <linux/proc_fs.h>
24#include <linux/vmalloc.h>
25#include <linux/module.h>
26#include <linux/kfifo.h>
27#include <linux/time.h>
28#include <net/net_namespace.h>
29
30#include <linux/skbuff.h>
31#include <net/sctp/sctp.h>
32#include <net/sctp/checksum.h>
33#include <net/protocol.h>
34
35static __le32 sctp_gso_make_checksum(struct sk_buff *skb)
36{
37 skb->ip_summed = CHECKSUM_NONE;
38 skb->csum_not_inet = 0;
39 return sctp_compute_cksum(skb, skb_transport_offset(skb));
40}
41
42static struct sk_buff *sctp_gso_segment(struct sk_buff *skb,
43 netdev_features_t features)
44{
45 struct sk_buff *segs = ERR_PTR(-EINVAL);
46 struct sctphdr *sh;
47
48 sh = sctp_hdr(skb);
49 if (!pskb_may_pull(skb, sizeof(*sh)))
50 goto out;
51
52 __skb_pull(skb, sizeof(*sh));
53
54 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
55 /* Packet is from an untrusted source, reset gso_segs. */
56 struct skb_shared_info *pinfo = skb_shinfo(skb);
57 struct sk_buff *frag_iter;
58
59 pinfo->gso_segs = 0;
60 if (skb->len != skb->data_len) {
61 /* Means we have chunks in here too */
62 pinfo->gso_segs++;
63 }
64
65 skb_walk_frags(skb, frag_iter)
66 pinfo->gso_segs++;
67
68 segs = NULL;
69 goto out;
70 }
71
72 segs = skb_segment(skb, features | NETIF_F_HW_CSUM | NETIF_F_SG);
73 if (IS_ERR(segs))
74 goto out;
75
76 /* All that is left is update SCTP CRC if necessary */
77 if (!(features & NETIF_F_SCTP_CRC)) {
78 for (skb = segs; skb; skb = skb->next) {
79 if (skb->ip_summed == CHECKSUM_PARTIAL) {
80 sh = sctp_hdr(skb);
81 sh->checksum = sctp_gso_make_checksum(skb);
82 }
83 }
84 }
85
86out:
87 return segs;
88}
89
90static const struct net_offload sctp_offload = {
91 .callbacks = {
92 .gso_segment = sctp_gso_segment,
93 },
94};
95
96static const struct net_offload sctp6_offload = {
97 .callbacks = {
98 .gso_segment = sctp_gso_segment,
99 },
100};
101
102static const struct skb_checksum_ops crc32c_csum_ops = {
103 .update = sctp_csum_update,
104 .combine = sctp_csum_combine,
105};
106
107int __init sctp_offload_init(void)
108{
109 int ret;
110
111 ret = inet_add_offload(&sctp_offload, IPPROTO_SCTP);
112 if (ret)
113 goto out;
114
115 ret = inet6_add_offload(&sctp6_offload, IPPROTO_SCTP);
116 if (ret)
117 goto ipv4;
118
119 crc32c_csum_stub = &crc32c_csum_ops;
120 return ret;
121
122ipv4:
123 inet_del_offload(&sctp_offload, IPPROTO_SCTP);
124out:
125 return ret;
126}