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 | #include <net/gso.h> |
26 | |
27 | static __le32 sctp_gso_make_checksum(struct sk_buff *skb) |
28 | { |
29 | skb->ip_summed = CHECKSUM_NONE; |
30 | skb->csum_not_inet = 0; |
31 | /* csum and csum_start in GSO CB may be needed to do the UDP |
32 | * checksum when it's a UDP tunneling packet. |
33 | */ |
34 | SKB_GSO_CB(skb)->csum = (__force __wsum)~0; |
35 | SKB_GSO_CB(skb)->csum_start = skb_headroom(skb) + skb->len; |
36 | return sctp_compute_cksum(skb, offset: skb_transport_offset(skb)); |
37 | } |
38 | |
39 | static struct sk_buff *sctp_gso_segment(struct sk_buff *skb, |
40 | netdev_features_t features) |
41 | { |
42 | struct sk_buff *segs = ERR_PTR(error: -EINVAL); |
43 | struct sctphdr *sh; |
44 | |
45 | if (!skb_is_gso_sctp(skb)) |
46 | goto out; |
47 | |
48 | sh = sctp_hdr(skb); |
49 | if (!pskb_may_pull(skb, len: sizeof(*sh))) |
50 | goto out; |
51 | |
52 | __skb_pull(skb, len: sizeof(*sh)); |
53 | |
54 | if (skb_gso_ok(skb, features: 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: (features | NETIF_F_HW_CSUM) & ~NETIF_F_SG); |
73 | if (IS_ERR(ptr: 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 | |
86 | out: |
87 | return segs; |
88 | } |
89 | |
90 | static const struct net_offload sctp_offload = { |
91 | .callbacks = { |
92 | .gso_segment = sctp_gso_segment, |
93 | }, |
94 | }; |
95 | |
96 | static const struct net_offload sctp6_offload = { |
97 | .callbacks = { |
98 | .gso_segment = sctp_gso_segment, |
99 | }, |
100 | }; |
101 | |
102 | int __init sctp_offload_init(void) |
103 | { |
104 | int ret; |
105 | |
106 | ret = inet_add_offload(prot: &sctp_offload, IPPROTO_SCTP); |
107 | if (ret) |
108 | goto out; |
109 | |
110 | ret = inet6_add_offload(prot: &sctp6_offload, IPPROTO_SCTP); |
111 | if (ret) |
112 | goto ipv4; |
113 | |
114 | crc32c_csum_stub = &sctp_csum_ops; |
115 | return ret; |
116 | |
117 | ipv4: |
118 | inet_del_offload(prot: &sctp_offload, IPPROTO_SCTP); |
119 | out: |
120 | return ret; |
121 | } |
122 | |