diff options
Diffstat (limited to 'net/nsh')
| -rw-r--r-- | net/nsh/Kconfig | 9 | ||||
| -rw-r--r-- | net/nsh/Makefile | 1 | ||||
| -rw-r--r-- | net/nsh/nsh.c | 155 |
3 files changed, 165 insertions, 0 deletions
diff --git a/net/nsh/Kconfig b/net/nsh/Kconfig new file mode 100644 index 000000000..bafc3dd60 --- /dev/null +++ b/net/nsh/Kconfig @@ -0,0 +1,9 @@ +menuconfig NET_NSH + tristate "Network Service Header (NSH) protocol" + default n + ---help--- + Network Service Header is an implementation of Service Function + Chaining (RFC 7665). The current implementation in Linux supports + only MD type 1 and only with the openvswitch module. + + If unsure, say N. diff --git a/net/nsh/Makefile b/net/nsh/Makefile new file mode 100644 index 000000000..c93c78738 --- /dev/null +++ b/net/nsh/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_NET_NSH) += nsh.o diff --git a/net/nsh/nsh.c b/net/nsh/nsh.c new file mode 100644 index 000000000..1a30e165e --- /dev/null +++ b/net/nsh/nsh.c @@ -0,0 +1,155 @@ +/* + * Network Service Header + * + * Copyright (c) 2017 Red Hat, Inc. -- Jiri Benc <jbenc@redhat.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/module.h> +#include <linux/netdevice.h> +#include <linux/skbuff.h> +#include <net/nsh.h> +#include <net/tun_proto.h> + +int nsh_push(struct sk_buff *skb, const struct nshhdr *pushed_nh) +{ + struct nshhdr *nh; + size_t length = nsh_hdr_len(pushed_nh); + u8 next_proto; + + if (skb->mac_len) { + next_proto = TUN_P_ETHERNET; + } else { + next_proto = tun_p_from_eth_p(skb->protocol); + if (!next_proto) + return -EAFNOSUPPORT; + } + + /* Add the NSH header */ + if (skb_cow_head(skb, length) < 0) + return -ENOMEM; + + skb_push(skb, length); + nh = (struct nshhdr *)(skb->data); + memcpy(nh, pushed_nh, length); + nh->np = next_proto; + skb_postpush_rcsum(skb, nh, length); + + skb->protocol = htons(ETH_P_NSH); + skb_reset_mac_header(skb); + skb_reset_network_header(skb); + skb_reset_mac_len(skb); + + return 0; +} +EXPORT_SYMBOL_GPL(nsh_push); + +int nsh_pop(struct sk_buff *skb) +{ + struct nshhdr *nh; + size_t length; + __be16 inner_proto; + + if (!pskb_may_pull(skb, NSH_BASE_HDR_LEN)) + return -ENOMEM; + nh = (struct nshhdr *)(skb->data); + length = nsh_hdr_len(nh); + if (length < NSH_BASE_HDR_LEN) + return -EINVAL; + inner_proto = tun_p_to_eth_p(nh->np); + if (!pskb_may_pull(skb, length)) + return -ENOMEM; + + if (!inner_proto) + return -EAFNOSUPPORT; + + skb_pull_rcsum(skb, length); + skb_reset_mac_header(skb); + skb_reset_network_header(skb); + skb_reset_mac_len(skb); + skb->protocol = inner_proto; + + return 0; +} +EXPORT_SYMBOL_GPL(nsh_pop); + +static struct sk_buff *nsh_gso_segment(struct sk_buff *skb, + netdev_features_t features) +{ + struct sk_buff *segs = ERR_PTR(-EINVAL); + unsigned int nsh_len, mac_len; + __be16 proto; + int nhoff; + + skb_reset_network_header(skb); + + nhoff = skb->network_header - skb->mac_header; + mac_len = skb->mac_len; + + if (unlikely(!pskb_may_pull(skb, NSH_BASE_HDR_LEN))) + goto out; + nsh_len = nsh_hdr_len(nsh_hdr(skb)); + if (nsh_len < NSH_BASE_HDR_LEN) + goto out; + if (unlikely(!pskb_may_pull(skb, nsh_len))) + goto out; + + proto = tun_p_to_eth_p(nsh_hdr(skb)->np); + if (!proto) + goto out; + + __skb_pull(skb, nsh_len); + + skb_reset_mac_header(skb); + skb->mac_len = proto == htons(ETH_P_TEB) ? ETH_HLEN : 0; + skb->protocol = proto; + + features &= NETIF_F_SG; + segs = skb_mac_gso_segment(skb, features); + if (IS_ERR_OR_NULL(segs)) { + skb_gso_error_unwind(skb, htons(ETH_P_NSH), nsh_len, + skb->network_header - nhoff, + mac_len); + goto out; + } + + for (skb = segs; skb; skb = skb->next) { + skb->protocol = htons(ETH_P_NSH); + __skb_push(skb, nsh_len); + skb_set_mac_header(skb, -nhoff); + skb->network_header = skb->mac_header + mac_len; + skb->mac_len = mac_len; + } + +out: + return segs; +} + +static struct packet_offload nsh_packet_offload __read_mostly = { + .type = htons(ETH_P_NSH), + .priority = 15, + .callbacks = { + .gso_segment = nsh_gso_segment, + }, +}; + +static int __init nsh_init_module(void) +{ + dev_add_offload(&nsh_packet_offload); + return 0; +} + +static void __exit nsh_cleanup_module(void) +{ + dev_remove_offload(&nsh_packet_offload); +} + +module_init(nsh_init_module); +module_exit(nsh_cleanup_module); + +MODULE_AUTHOR("Jiri Benc <jbenc@redhat.com>"); +MODULE_DESCRIPTION("NSH protocol"); +MODULE_LICENSE("GPL v2"); |