Jiri Benc | c411ed8 | 2017-08-28 21:43:24 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Network Service Header |
| 3 | * |
| 4 | * Copyright (c) 2017 Red Hat, Inc. -- Jiri Benc <jbenc@redhat.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 version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/netdevice.h> |
| 13 | #include <linux/skbuff.h> |
| 14 | #include <net/nsh.h> |
| 15 | #include <net/tun_proto.h> |
| 16 | |
| 17 | static struct sk_buff *nsh_gso_segment(struct sk_buff *skb, |
| 18 | netdev_features_t features) |
| 19 | { |
| 20 | struct sk_buff *segs = ERR_PTR(-EINVAL); |
| 21 | unsigned int nsh_len, mac_len; |
| 22 | __be16 proto; |
| 23 | int nhoff; |
| 24 | |
| 25 | skb_reset_network_header(skb); |
| 26 | |
| 27 | nhoff = skb->network_header - skb->mac_header; |
| 28 | mac_len = skb->mac_len; |
| 29 | |
| 30 | if (unlikely(!pskb_may_pull(skb, NSH_BASE_HDR_LEN))) |
| 31 | goto out; |
| 32 | nsh_len = nsh_hdr_len(nsh_hdr(skb)); |
| 33 | if (unlikely(!pskb_may_pull(skb, nsh_len))) |
| 34 | goto out; |
| 35 | |
| 36 | proto = tun_p_to_eth_p(nsh_hdr(skb)->np); |
| 37 | if (!proto) |
| 38 | goto out; |
| 39 | |
| 40 | __skb_pull(skb, nsh_len); |
| 41 | |
| 42 | skb_reset_mac_header(skb); |
| 43 | skb_reset_mac_len(skb); |
| 44 | skb->protocol = proto; |
| 45 | |
| 46 | features &= NETIF_F_SG; |
| 47 | segs = skb_mac_gso_segment(skb, features); |
| 48 | if (IS_ERR_OR_NULL(segs)) { |
| 49 | skb_gso_error_unwind(skb, htons(ETH_P_NSH), nsh_len, |
| 50 | skb->network_header - nhoff, |
| 51 | mac_len); |
| 52 | goto out; |
| 53 | } |
| 54 | |
| 55 | for (skb = segs; skb; skb = skb->next) { |
| 56 | skb->protocol = htons(ETH_P_NSH); |
| 57 | __skb_push(skb, nsh_len); |
| 58 | skb_set_mac_header(skb, -nhoff); |
| 59 | skb->network_header = skb->mac_header + mac_len; |
| 60 | skb->mac_len = mac_len; |
| 61 | } |
| 62 | |
| 63 | out: |
| 64 | return segs; |
| 65 | } |
| 66 | |
| 67 | static struct packet_offload nsh_packet_offload __read_mostly = { |
| 68 | .type = htons(ETH_P_NSH), |
| 69 | .priority = 15, |
| 70 | .callbacks = { |
| 71 | .gso_segment = nsh_gso_segment, |
| 72 | }, |
| 73 | }; |
| 74 | |
| 75 | static int __init nsh_init_module(void) |
| 76 | { |
| 77 | dev_add_offload(&nsh_packet_offload); |
| 78 | return 0; |
| 79 | } |
| 80 | |
| 81 | static void __exit nsh_cleanup_module(void) |
| 82 | { |
| 83 | dev_remove_offload(&nsh_packet_offload); |
| 84 | } |
| 85 | |
| 86 | module_init(nsh_init_module); |
| 87 | module_exit(nsh_cleanup_module); |
| 88 | |
| 89 | MODULE_AUTHOR("Jiri Benc <jbenc@redhat.com>"); |
| 90 | MODULE_DESCRIPTION("NSH protocol"); |
| 91 | MODULE_LICENSE("GPL v2"); |