1*c411ed85SJiri Benc /* 2*c411ed85SJiri Benc * Network Service Header 3*c411ed85SJiri Benc * 4*c411ed85SJiri Benc * Copyright (c) 2017 Red Hat, Inc. -- Jiri Benc <jbenc@redhat.com> 5*c411ed85SJiri Benc * 6*c411ed85SJiri Benc * This program is free software; you can redistribute it and/or modify 7*c411ed85SJiri Benc * it under the terms of the GNU General Public License version 2 as 8*c411ed85SJiri Benc * published by the Free Software Foundation. 9*c411ed85SJiri Benc */ 10*c411ed85SJiri Benc 11*c411ed85SJiri Benc #include <linux/module.h> 12*c411ed85SJiri Benc #include <linux/netdevice.h> 13*c411ed85SJiri Benc #include <linux/skbuff.h> 14*c411ed85SJiri Benc #include <net/nsh.h> 15*c411ed85SJiri Benc #include <net/tun_proto.h> 16*c411ed85SJiri Benc 17*c411ed85SJiri Benc static struct sk_buff *nsh_gso_segment(struct sk_buff *skb, 18*c411ed85SJiri Benc netdev_features_t features) 19*c411ed85SJiri Benc { 20*c411ed85SJiri Benc struct sk_buff *segs = ERR_PTR(-EINVAL); 21*c411ed85SJiri Benc unsigned int nsh_len, mac_len; 22*c411ed85SJiri Benc __be16 proto; 23*c411ed85SJiri Benc int nhoff; 24*c411ed85SJiri Benc 25*c411ed85SJiri Benc skb_reset_network_header(skb); 26*c411ed85SJiri Benc 27*c411ed85SJiri Benc nhoff = skb->network_header - skb->mac_header; 28*c411ed85SJiri Benc mac_len = skb->mac_len; 29*c411ed85SJiri Benc 30*c411ed85SJiri Benc if (unlikely(!pskb_may_pull(skb, NSH_BASE_HDR_LEN))) 31*c411ed85SJiri Benc goto out; 32*c411ed85SJiri Benc nsh_len = nsh_hdr_len(nsh_hdr(skb)); 33*c411ed85SJiri Benc if (unlikely(!pskb_may_pull(skb, nsh_len))) 34*c411ed85SJiri Benc goto out; 35*c411ed85SJiri Benc 36*c411ed85SJiri Benc proto = tun_p_to_eth_p(nsh_hdr(skb)->np); 37*c411ed85SJiri Benc if (!proto) 38*c411ed85SJiri Benc goto out; 39*c411ed85SJiri Benc 40*c411ed85SJiri Benc __skb_pull(skb, nsh_len); 41*c411ed85SJiri Benc 42*c411ed85SJiri Benc skb_reset_mac_header(skb); 43*c411ed85SJiri Benc skb_reset_mac_len(skb); 44*c411ed85SJiri Benc skb->protocol = proto; 45*c411ed85SJiri Benc 46*c411ed85SJiri Benc features &= NETIF_F_SG; 47*c411ed85SJiri Benc segs = skb_mac_gso_segment(skb, features); 48*c411ed85SJiri Benc if (IS_ERR_OR_NULL(segs)) { 49*c411ed85SJiri Benc skb_gso_error_unwind(skb, htons(ETH_P_NSH), nsh_len, 50*c411ed85SJiri Benc skb->network_header - nhoff, 51*c411ed85SJiri Benc mac_len); 52*c411ed85SJiri Benc goto out; 53*c411ed85SJiri Benc } 54*c411ed85SJiri Benc 55*c411ed85SJiri Benc for (skb = segs; skb; skb = skb->next) { 56*c411ed85SJiri Benc skb->protocol = htons(ETH_P_NSH); 57*c411ed85SJiri Benc __skb_push(skb, nsh_len); 58*c411ed85SJiri Benc skb_set_mac_header(skb, -nhoff); 59*c411ed85SJiri Benc skb->network_header = skb->mac_header + mac_len; 60*c411ed85SJiri Benc skb->mac_len = mac_len; 61*c411ed85SJiri Benc } 62*c411ed85SJiri Benc 63*c411ed85SJiri Benc out: 64*c411ed85SJiri Benc return segs; 65*c411ed85SJiri Benc } 66*c411ed85SJiri Benc 67*c411ed85SJiri Benc static struct packet_offload nsh_packet_offload __read_mostly = { 68*c411ed85SJiri Benc .type = htons(ETH_P_NSH), 69*c411ed85SJiri Benc .priority = 15, 70*c411ed85SJiri Benc .callbacks = { 71*c411ed85SJiri Benc .gso_segment = nsh_gso_segment, 72*c411ed85SJiri Benc }, 73*c411ed85SJiri Benc }; 74*c411ed85SJiri Benc 75*c411ed85SJiri Benc static int __init nsh_init_module(void) 76*c411ed85SJiri Benc { 77*c411ed85SJiri Benc dev_add_offload(&nsh_packet_offload); 78*c411ed85SJiri Benc return 0; 79*c411ed85SJiri Benc } 80*c411ed85SJiri Benc 81*c411ed85SJiri Benc static void __exit nsh_cleanup_module(void) 82*c411ed85SJiri Benc { 83*c411ed85SJiri Benc dev_remove_offload(&nsh_packet_offload); 84*c411ed85SJiri Benc } 85*c411ed85SJiri Benc 86*c411ed85SJiri Benc module_init(nsh_init_module); 87*c411ed85SJiri Benc module_exit(nsh_cleanup_module); 88*c411ed85SJiri Benc 89*c411ed85SJiri Benc MODULE_AUTHOR("Jiri Benc <jbenc@redhat.com>"); 90*c411ed85SJiri Benc MODULE_DESCRIPTION("NSH protocol"); 91*c411ed85SJiri Benc MODULE_LICENSE("GPL v2"); 92