Merge tag 'nfs-for-5.2-2' of git://git.linux-nfs.org/projects/anna/linux-nfs
[sfrench/cifs-2.6.git] / net / sctp / offload.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * sctp_offload - GRO/GSO Offloading for SCTP
4  *
5  * Copyright (C) 2015, Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
6  */
7
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10 #include <linux/kernel.h>
11 #include <linux/kprobes.h>
12 #include <linux/socket.h>
13 #include <linux/sctp.h>
14 #include <linux/proc_fs.h>
15 #include <linux/vmalloc.h>
16 #include <linux/module.h>
17 #include <linux/kfifo.h>
18 #include <linux/time.h>
19 #include <net/net_namespace.h>
20
21 #include <linux/skbuff.h>
22 #include <net/sctp/sctp.h>
23 #include <net/sctp/checksum.h>
24 #include <net/protocol.h>
25
26 static __le32 sctp_gso_make_checksum(struct sk_buff *skb)
27 {
28         skb->ip_summed = CHECKSUM_NONE;
29         skb->csum_not_inet = 0;
30         gso_reset_checksum(skb, ~0);
31         return sctp_compute_cksum(skb, skb_transport_offset(skb));
32 }
33
34 static struct sk_buff *sctp_gso_segment(struct sk_buff *skb,
35                                         netdev_features_t features)
36 {
37         struct sk_buff *segs = ERR_PTR(-EINVAL);
38         struct sctphdr *sh;
39
40         if (!skb_is_gso_sctp(skb))
41                 goto out;
42
43         sh = sctp_hdr(skb);
44         if (!pskb_may_pull(skb, sizeof(*sh)))
45                 goto out;
46
47         __skb_pull(skb, sizeof(*sh));
48
49         if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
50                 /* Packet is from an untrusted source, reset gso_segs. */
51                 struct skb_shared_info *pinfo = skb_shinfo(skb);
52                 struct sk_buff *frag_iter;
53
54                 pinfo->gso_segs = 0;
55                 if (skb->len != skb->data_len) {
56                         /* Means we have chunks in here too */
57                         pinfo->gso_segs++;
58                 }
59
60                 skb_walk_frags(skb, frag_iter)
61                         pinfo->gso_segs++;
62
63                 segs = NULL;
64                 goto out;
65         }
66
67         segs = skb_segment(skb, features | NETIF_F_HW_CSUM | NETIF_F_SG);
68         if (IS_ERR(segs))
69                 goto out;
70
71         /* All that is left is update SCTP CRC if necessary */
72         if (!(features & NETIF_F_SCTP_CRC)) {
73                 for (skb = segs; skb; skb = skb->next) {
74                         if (skb->ip_summed == CHECKSUM_PARTIAL) {
75                                 sh = sctp_hdr(skb);
76                                 sh->checksum = sctp_gso_make_checksum(skb);
77                         }
78                 }
79         }
80
81 out:
82         return segs;
83 }
84
85 static const struct net_offload sctp_offload = {
86         .callbacks = {
87                 .gso_segment = sctp_gso_segment,
88         },
89 };
90
91 static const struct net_offload sctp6_offload = {
92         .callbacks = {
93                 .gso_segment = sctp_gso_segment,
94         },
95 };
96
97 static const struct skb_checksum_ops crc32c_csum_ops = {
98         .update  = sctp_csum_update,
99         .combine = sctp_csum_combine,
100 };
101
102 int __init sctp_offload_init(void)
103 {
104         int ret;
105
106         ret = inet_add_offload(&sctp_offload, IPPROTO_SCTP);
107         if (ret)
108                 goto out;
109
110         ret = inet6_add_offload(&sctp6_offload, IPPROTO_SCTP);
111         if (ret)
112                 goto ipv4;
113
114         crc32c_csum_stub = &crc32c_csum_ops;
115         return ret;
116
117 ipv4:
118         inet_del_offload(&sctp_offload, IPPROTO_SCTP);
119 out:
120         return ret;
121 }