Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
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 return sctp_compute_cksum(skb, skb_transport_offset(skb));
39}
40
41static struct sk_buff *sctp_gso_segment(struct sk_buff *skb,
42 netdev_features_t features)
43{
44 struct sk_buff *segs = ERR_PTR(-EINVAL);
45 struct sctphdr *sh;
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);
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 return ret;
114
115ipv4:
116 inet_del_offload(&sctp_offload, IPPROTO_SCTP);
117out:
118 return ret;
119}