From: Roopa Prabhu <ro...@cumulusnetworks.com> Support ip mpls tunnels using the new lwt infrastructure.
Signed-off-by: Roopa Prabhu <ro...@cumulusnetworks.com> --- include/linux/mpls_iptunnel.h | 6 ++ include/net/mpls_iptunnel.h | 29 +++++ include/uapi/linux/mpls_iptunnel.h | 26 +++++ net/mpls/Kconfig | 5 + net/mpls/Makefile | 1 + net/mpls/af_mpls.c | 9 +- net/mpls/internal.h | 3 + net/mpls/mpls_iptunnel.c | 205 ++++++++++++++++++++++++++++++++++++ 8 files changed, 281 insertions(+), 3 deletions(-) create mode 100644 include/linux/mpls_iptunnel.h create mode 100644 include/net/mpls_iptunnel.h create mode 100644 include/uapi/linux/mpls_iptunnel.h create mode 100644 net/mpls/mpls_iptunnel.c diff --git a/include/linux/mpls_iptunnel.h b/include/linux/mpls_iptunnel.h new file mode 100644 index 0000000..ef29eb2 --- /dev/null +++ b/include/linux/mpls_iptunnel.h @@ -0,0 +1,6 @@ +#ifndef _LINUX_MPLS_IPTUNNEL_H +#define _LINUX_MPLS_IPTUNNEL_H + +#include <uapi/linux/mpls_iptunnel.h> + +#endif /* _LINUX_MPLS_IPTUNNEL_H */ diff --git a/include/net/mpls_iptunnel.h b/include/net/mpls_iptunnel.h new file mode 100644 index 0000000..4234efc --- /dev/null +++ b/include/net/mpls_iptunnel.h @@ -0,0 +1,29 @@ +/* + * Copyright (c) 2015 Cumulus Networks, Inc. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ + +#ifndef _NET_MPLS_IPTUNNEL_H +#define _NET_MPLS_IPTUNNEL_H 1 + +#define MAX_NEW_LABELS 2 + +struct mpls_iptunnel_encap { + u32 label[MAX_NEW_LABELS]; + u8 labels; +}; + +static inline struct mpls_iptunnel_encap *mpls_lwt_hdr(struct lwtunnel_state *lwtstate) +{ + return (struct mpls_iptunnel_encap *)lwtstate->tunnel.data; +} + +#endif diff --git a/include/uapi/linux/mpls_iptunnel.h b/include/uapi/linux/mpls_iptunnel.h new file mode 100644 index 0000000..228e36a --- /dev/null +++ b/include/uapi/linux/mpls_iptunnel.h @@ -0,0 +1,26 @@ +/* + * mpls tunnel api + * + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#ifndef _UAPI_LINUX_MPLS_IPTUNNEL_H +#define _UAPI_LINUX_MPLS_IPTUNNEL_H + +/* MPLS tunnel attributes + * [RTA_ENCAP] = { + * [MPLS_IPTUNNEL_DST] + * } + */ +enum { + MPLS_IPTUNNEL_UNSPEC, + MPLS_IPTUNNEL_DST, + __MPLS_IPTUNNEL_MAX, +}; +#define MPLS_IPTUNNEL_MAX (__MPLS_IPTUNNEL_MAX - 1) + +#endif /* _UAPI_LINUX_MPLS_IPTUNNEL_H */ diff --git a/net/mpls/Kconfig b/net/mpls/Kconfig index 17bde79..3e87a6b 100644 --- a/net/mpls/Kconfig +++ b/net/mpls/Kconfig @@ -27,4 +27,9 @@ config MPLS_ROUTING help Add support for forwarding of mpls packets. +config MPLS_IPTUNNEL + tristate "MPLS: IP over MPLS tunnel support" + help + Light weight tunnel handling for mpls tunnel packets + endif # MPLS diff --git a/net/mpls/Makefile b/net/mpls/Makefile index 65bbe68..9ca9236 100644 --- a/net/mpls/Makefile +++ b/net/mpls/Makefile @@ -3,5 +3,6 @@ # obj-$(CONFIG_NET_MPLS_GSO) += mpls_gso.o obj-$(CONFIG_MPLS_ROUTING) += mpls_router.o +obj-$(CONFIG_MPLS_IPTUNNEL) += mpls_iptunnel.o mpls_router-y := af_mpls.o diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c index 1f93a59..c6f17ab 100644 --- a/net/mpls/af_mpls.c +++ b/net/mpls/af_mpls.c @@ -58,10 +58,11 @@ static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev) return rcu_dereference_rtnl(dev->mpls_ptr); } -static bool mpls_output_possible(const struct net_device *dev) +bool mpls_output_possible(const struct net_device *dev) { return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev); } +EXPORT_SYMBOL(mpls_output_possible); static unsigned int mpls_rt_header_size(const struct mpls_route *rt) { @@ -69,13 +70,14 @@ static unsigned int mpls_rt_header_size(const struct mpls_route *rt) return rt->rt_labels * sizeof(struct mpls_shim_hdr); } -static unsigned int mpls_dev_mtu(const struct net_device *dev) +unsigned int mpls_dev_mtu(const struct net_device *dev) { /* The amount of data the layer 2 frame can hold */ return dev->mtu; } +EXPORT_SYMBOL(mpls_dev_mtu); -static bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu) +bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu) { if (skb->len <= mtu) return false; @@ -85,6 +87,7 @@ static bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu) return true; } +EXPORT_SYMBOL(mpls_pkt_too_big); static bool mpls_egress(struct mpls_route *rt, struct sk_buff *skb, struct mpls_entry_decoded dec) diff --git a/net/mpls/internal.h b/net/mpls/internal.h index 8cabeb5..8e3af1e 100644 --- a/net/mpls/internal.h +++ b/net/mpls/internal.h @@ -52,5 +52,8 @@ static inline struct mpls_entry_decoded mpls_entry_decode(struct mpls_shim_hdr * int nla_put_labels(struct sk_buff *skb, int attrtype, u8 labels, const u32 label[]); int nla_get_labels(const struct nlattr *nla, u32 max_labels, u32 *labels, u32 label[]); +bool mpls_output_possible(const struct net_device *dev); +unsigned int mpls_dev_mtu(const struct net_device *dev); +bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu); #endif /* MPLS_INTERNAL_H */ diff --git a/net/mpls/mpls_iptunnel.c b/net/mpls/mpls_iptunnel.c new file mode 100644 index 0000000..79a9969 --- /dev/null +++ b/net/mpls/mpls_iptunnel.c @@ -0,0 +1,205 @@ +/* + * mpls tunnels An implementation mpls tunnels using the light weight tunnel + * infrastructure + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + */ +#include <linux/types.h> +#include <linux/skbuff.h> +#include <linux/net.h> +#include <linux/module.h> +#include <linux/mpls.h> +#include <linux/vmalloc.h> +#include <net/ip.h> +#include <net/dst.h> +#include <net/lwtunnel.h> +#include <net/netevent.h> +#include <net/netns/generic.h> +#include <net/mpls_iptunnel.h> +#include <linux/mpls_iptunnel.h> +#include "internal.h" + +static const struct nla_policy mpls_iptunnel_policy[MPLS_IPTUNNEL_MAX+1] = { + [MPLS_IPTUNNEL_DST] = { .type = NLA_U32 }, +}; + +static unsigned int mpls_encap_size(struct mpls_iptunnel_encap *en) +{ + /* The size of the layer 2.5 labels to be added for this route */ + return en->labels * sizeof(struct mpls_shim_hdr); +} + +int mpls_output(struct sock *sk, struct sk_buff *skb) +{ + struct mpls_iptunnel_encap *tun_encap_info; + struct mpls_shim_hdr *hdr; + struct mpls_entry_decoded dec; + struct net_device *out_dev; + unsigned int hh_len; + unsigned int new_header_size; + unsigned int mtu; + struct lwtunnel_state *lwtstate; + struct rtable *rt = skb_rtable(skb); + int err; + bool bos; + int i; + + if (skb->pkt_type != PACKET_HOST) + goto drop; + + if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) + goto drop; + + if (!rt) + goto drop; + + /* Find the output device */ + out_dev = rcu_dereference(skb_dst(skb)->dev); + if (!mpls_output_possible(out_dev)) + goto drop; + + if (skb_warn_if_lro(skb)) + goto drop; + skb_forward_csum(skb); + + lwtstate = rt->rt_lwtstate; + if (!lwtstate) + goto drop; + + tun_encap_info = mpls_lwt_hdr(lwtstate); + + /* Verify the destination can hold the packet */ + new_header_size = mpls_encap_size(tun_encap_info); + mtu = mpls_dev_mtu(out_dev); + if (mpls_pkt_too_big(skb, mtu - new_header_size)) + goto drop; + + hh_len = LL_RESERVED_SPACE(out_dev); + if (!out_dev->header_ops) + hh_len = 0; + + /* Ensure there is enough space for the headers in the skb */ + if (skb_cow(skb, hh_len + new_header_size)) + goto drop; + + skb->dev = out_dev; + skb->protocol = htons(ETH_P_MPLS_UC); + + skb_push(skb, new_header_size); + skb_reset_network_header(skb); + + /* Push the new labels */ + hdr = mpls_hdr(skb); + bos = true; + for (i = tun_encap_info->labels - 1; i >= 0; i--) { + hdr[i] = mpls_entry_encode(tun_encap_info->label[i], + dec.ttl, 0, bos); + bos = false; + } + + err = neigh_xmit(NEIGH_ARP_TABLE, out_dev, &rt->rt_gateway, + skb); + if (err) + net_dbg_ratelimited("%s: packet transmission failed: " + "%d\n", __func__, err); + + return 0; + +drop: + kfree_skb(skb); + return -EINVAL; +} + +static int mpls_build_state(struct net_device *dev, struct nlattr *nla, + struct lwtunnel_state **ts) +{ + struct mpls_iptunnel_encap *tun_encap_info; + struct nlattr *tb[MPLS_IPTUNNEL_MAX+1]; + struct lwtunnel_state *newts; + int tun_encap_info_len; + int ret; + + ret = nla_parse_nested(tb, MPLS_IPTUNNEL_MAX, nla, + mpls_iptunnel_policy); + if (ret < 0) + return ret; + + if (!tb[MPLS_IPTUNNEL_DST]) + return -EINVAL; + + tun_encap_info_len = sizeof(*tun_encap_info); + + newts = lwtunnel_state_alloc(tun_encap_info_len); + if (!newts) + return -ENOMEM; + + newts->tunnel.len = tun_encap_info_len; + tun_encap_info = mpls_lwt_hdr(newts); + ret = nla_get_labels(tb[MPLS_IPTUNNEL_DST], MAX_NEW_LABELS, + &tun_encap_info->labels, tun_encap_info->label); + if (ret) + goto errout; + newts->type = LWTUNNEL_ENCAP_MPLS; + newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT; + + *ts = newts; + + return 0; + +errout: + kfree(newts); + *ts = NULL; + + return ret; +} + +static int mpls_fill_encap_info(struct sk_buff *skb, + struct lwtunnel_state *lwtstate) +{ + struct mpls_iptunnel_encap *tun_encap_info; + + tun_encap_info = mpls_lwt_hdr(lwtstate); + if (nla_put_labels(skb, MPLS_IPTUNNEL_DST, tun_encap_info->labels, + tun_encap_info->label)) + goto nla_put_failure; + + return 0; + +nla_put_failure: + return -EMSGSIZE; +} + +static int mpls_encap_nlsize(struct lwtunnel_state *lwtstate) +{ + struct mpls_iptunnel_encap *tun_encap_info = mpls_lwt_hdr(lwtstate); + + return nla_total_size(tun_encap_info->labels * 4); +} + +static const struct lwtunnel_encap_ops mpls_iptun_ops = { + .build_state = mpls_build_state, + .output = mpls_output, + .fill_encap = mpls_fill_encap_info, + .get_encap_size = mpls_encap_nlsize, +}; + +static int __init mpls_iptunnel_init(void) +{ + lwtunnel_encap_add_ops(&mpls_iptun_ops, LWTUNNEL_ENCAP_MPLS); + + return 0; +} +module_init(mpls_iptunnel_init); + +static void __exit mpls_iptunnel_exit(void) +{ + lwtunnel_encap_del_ops(&mpls_iptun_ops, LWTUNNEL_ENCAP_MPLS); +} +module_exit(mpls_iptunnel_exit); + +MODULE_DESCRIPTION("MultiProtocol Label Switching IP Tunnels"); +MODULE_LICENSE("GPL v2"); -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html