1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * sctp_offload - GRO/GSO Offloading for SCTP
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (C) 2015, Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
6*4882a593Smuzhiyun */
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun #include <linux/kernel.h>
11*4882a593Smuzhiyun #include <linux/kprobes.h>
12*4882a593Smuzhiyun #include <linux/socket.h>
13*4882a593Smuzhiyun #include <linux/sctp.h>
14*4882a593Smuzhiyun #include <linux/proc_fs.h>
15*4882a593Smuzhiyun #include <linux/vmalloc.h>
16*4882a593Smuzhiyun #include <linux/module.h>
17*4882a593Smuzhiyun #include <linux/kfifo.h>
18*4882a593Smuzhiyun #include <linux/time.h>
19*4882a593Smuzhiyun #include <net/net_namespace.h>
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun #include <linux/skbuff.h>
22*4882a593Smuzhiyun #include <net/sctp/sctp.h>
23*4882a593Smuzhiyun #include <net/sctp/checksum.h>
24*4882a593Smuzhiyun #include <net/protocol.h>
25*4882a593Smuzhiyun
sctp_gso_make_checksum(struct sk_buff * skb)26*4882a593Smuzhiyun static __le32 sctp_gso_make_checksum(struct sk_buff *skb)
27*4882a593Smuzhiyun {
28*4882a593Smuzhiyun skb->ip_summed = CHECKSUM_NONE;
29*4882a593Smuzhiyun skb->csum_not_inet = 0;
30*4882a593Smuzhiyun gso_reset_checksum(skb, ~0);
31*4882a593Smuzhiyun return sctp_compute_cksum(skb, skb_transport_offset(skb));
32*4882a593Smuzhiyun }
33*4882a593Smuzhiyun
sctp_gso_segment(struct sk_buff * skb,netdev_features_t features)34*4882a593Smuzhiyun static struct sk_buff *sctp_gso_segment(struct sk_buff *skb,
35*4882a593Smuzhiyun netdev_features_t features)
36*4882a593Smuzhiyun {
37*4882a593Smuzhiyun struct sk_buff *segs = ERR_PTR(-EINVAL);
38*4882a593Smuzhiyun struct sctphdr *sh;
39*4882a593Smuzhiyun
40*4882a593Smuzhiyun if (!skb_is_gso_sctp(skb))
41*4882a593Smuzhiyun goto out;
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun sh = sctp_hdr(skb);
44*4882a593Smuzhiyun if (!pskb_may_pull(skb, sizeof(*sh)))
45*4882a593Smuzhiyun goto out;
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun __skb_pull(skb, sizeof(*sh));
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
50*4882a593Smuzhiyun /* Packet is from an untrusted source, reset gso_segs. */
51*4882a593Smuzhiyun struct skb_shared_info *pinfo = skb_shinfo(skb);
52*4882a593Smuzhiyun struct sk_buff *frag_iter;
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun pinfo->gso_segs = 0;
55*4882a593Smuzhiyun if (skb->len != skb->data_len) {
56*4882a593Smuzhiyun /* Means we have chunks in here too */
57*4882a593Smuzhiyun pinfo->gso_segs++;
58*4882a593Smuzhiyun }
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun skb_walk_frags(skb, frag_iter)
61*4882a593Smuzhiyun pinfo->gso_segs++;
62*4882a593Smuzhiyun
63*4882a593Smuzhiyun segs = NULL;
64*4882a593Smuzhiyun goto out;
65*4882a593Smuzhiyun }
66*4882a593Smuzhiyun
67*4882a593Smuzhiyun segs = skb_segment(skb, features | NETIF_F_HW_CSUM | NETIF_F_SG);
68*4882a593Smuzhiyun if (IS_ERR(segs))
69*4882a593Smuzhiyun goto out;
70*4882a593Smuzhiyun
71*4882a593Smuzhiyun /* All that is left is update SCTP CRC if necessary */
72*4882a593Smuzhiyun if (!(features & NETIF_F_SCTP_CRC)) {
73*4882a593Smuzhiyun for (skb = segs; skb; skb = skb->next) {
74*4882a593Smuzhiyun if (skb->ip_summed == CHECKSUM_PARTIAL) {
75*4882a593Smuzhiyun sh = sctp_hdr(skb);
76*4882a593Smuzhiyun sh->checksum = sctp_gso_make_checksum(skb);
77*4882a593Smuzhiyun }
78*4882a593Smuzhiyun }
79*4882a593Smuzhiyun }
80*4882a593Smuzhiyun
81*4882a593Smuzhiyun out:
82*4882a593Smuzhiyun return segs;
83*4882a593Smuzhiyun }
84*4882a593Smuzhiyun
85*4882a593Smuzhiyun static const struct net_offload sctp_offload = {
86*4882a593Smuzhiyun .callbacks = {
87*4882a593Smuzhiyun .gso_segment = sctp_gso_segment,
88*4882a593Smuzhiyun },
89*4882a593Smuzhiyun };
90*4882a593Smuzhiyun
91*4882a593Smuzhiyun static const struct net_offload sctp6_offload = {
92*4882a593Smuzhiyun .callbacks = {
93*4882a593Smuzhiyun .gso_segment = sctp_gso_segment,
94*4882a593Smuzhiyun },
95*4882a593Smuzhiyun };
96*4882a593Smuzhiyun
sctp_offload_init(void)97*4882a593Smuzhiyun int __init sctp_offload_init(void)
98*4882a593Smuzhiyun {
99*4882a593Smuzhiyun int ret;
100*4882a593Smuzhiyun
101*4882a593Smuzhiyun ret = inet_add_offload(&sctp_offload, IPPROTO_SCTP);
102*4882a593Smuzhiyun if (ret)
103*4882a593Smuzhiyun goto out;
104*4882a593Smuzhiyun
105*4882a593Smuzhiyun ret = inet6_add_offload(&sctp6_offload, IPPROTO_SCTP);
106*4882a593Smuzhiyun if (ret)
107*4882a593Smuzhiyun goto ipv4;
108*4882a593Smuzhiyun
109*4882a593Smuzhiyun crc32c_csum_stub = &sctp_csum_ops;
110*4882a593Smuzhiyun return ret;
111*4882a593Smuzhiyun
112*4882a593Smuzhiyun ipv4:
113*4882a593Smuzhiyun inet_del_offload(&sctp_offload, IPPROTO_SCTP);
114*4882a593Smuzhiyun out:
115*4882a593Smuzhiyun return ret;
116*4882a593Smuzhiyun }
117