diff options
| -rw-r--r-- | include/linux/seg6_iptunnel.h | 6 | ||||
| -rw-r--r-- | include/net/seg6.h | 6 | ||||
| -rw-r--r-- | include/uapi/linux/lwtunnel.h | 1 | ||||
| -rw-r--r-- | include/uapi/linux/seg6_iptunnel.h | 44 | ||||
| -rw-r--r-- | net/core/lwtunnel.c | 2 | ||||
| -rw-r--r-- | net/ipv6/Kconfig | 12 | ||||
| -rw-r--r-- | net/ipv6/Makefile | 2 | ||||
| -rw-r--r-- | net/ipv6/seg6.c | 44 | ||||
| -rw-r--r-- | net/ipv6/seg6_iptunnel.c | 410 |
9 files changed, 526 insertions, 1 deletions
diff --git a/include/linux/seg6_iptunnel.h b/include/linux/seg6_iptunnel.h new file mode 100644 index 000000000000..5377cf6a5a02 --- /dev/null +++ b/include/linux/seg6_iptunnel.h @@ -0,0 +1,6 @@ +#ifndef _LINUX_SEG6_IPTUNNEL_H +#define _LINUX_SEG6_IPTUNNEL_H + +#include <uapi/linux/seg6_iptunnel.h> + +#endif diff --git a/include/net/seg6.h b/include/net/seg6.h index 7c7b8ed39661..ff5da0ce83e9 100644 --- a/include/net/seg6.h +++ b/include/net/seg6.h @@ -16,6 +16,8 @@ #include <linux/net.h> #include <linux/ipv6.h> +#include <net/lwtunnel.h> +#include <linux/seg6.h> static inline void update_csum_diff4(struct sk_buff *skb, __be32 from, __be32 to) @@ -48,5 +50,9 @@ static inline struct seg6_pernet_data *seg6_pernet(struct net *net) extern int seg6_init(void); extern void seg6_exit(void); +extern int seg6_iptunnel_init(void); +extern void seg6_iptunnel_exit(void); + +extern bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len); #endif diff --git a/include/uapi/linux/lwtunnel.h b/include/uapi/linux/lwtunnel.h index a478fe80e203..453cc6215bfd 100644 --- a/include/uapi/linux/lwtunnel.h +++ b/include/uapi/linux/lwtunnel.h @@ -9,6 +9,7 @@ enum lwtunnel_encap_types { LWTUNNEL_ENCAP_IP, LWTUNNEL_ENCAP_ILA, LWTUNNEL_ENCAP_IP6, + LWTUNNEL_ENCAP_SEG6, __LWTUNNEL_ENCAP_MAX, }; diff --git a/include/uapi/linux/seg6_iptunnel.h b/include/uapi/linux/seg6_iptunnel.h new file mode 100644 index 000000000000..0f7dbd280a9c --- /dev/null +++ b/include/uapi/linux/seg6_iptunnel.h @@ -0,0 +1,44 @@ +/* + * SR-IPv6 implementation + * + * Author: + * David Lebrun <david.lebrun@uclouvain.be> + * + * + * 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_SEG6_IPTUNNEL_H +#define _UAPI_LINUX_SEG6_IPTUNNEL_H + +enum { + SEG6_IPTUNNEL_UNSPEC, + SEG6_IPTUNNEL_SRH, + __SEG6_IPTUNNEL_MAX, +}; +#define SEG6_IPTUNNEL_MAX (__SEG6_IPTUNNEL_MAX - 1) + +struct seg6_iptunnel_encap { + int mode; + struct ipv6_sr_hdr srh[0]; +}; + +#define SEG6_IPTUN_ENCAP_SIZE(x) ((sizeof(*x)) + (((x)->srh->hdrlen + 1) << 3)) + +enum { + SEG6_IPTUN_MODE_INLINE, + SEG6_IPTUN_MODE_ENCAP, +}; + +static inline size_t seg6_lwt_headroom(struct seg6_iptunnel_encap *tuninfo) +{ + int encap = (tuninfo->mode == SEG6_IPTUN_MODE_ENCAP); + + return ((tuninfo->srh->hdrlen + 1) << 3) + + (encap * sizeof(struct ipv6hdr)); +} + +#endif diff --git a/net/core/lwtunnel.c b/net/core/lwtunnel.c index 88fd64250b02..03976e939818 100644 --- a/net/core/lwtunnel.c +++ b/net/core/lwtunnel.c @@ -39,6 +39,8 @@ static const char *lwtunnel_encap_str(enum lwtunnel_encap_types encap_type) return "MPLS"; case LWTUNNEL_ENCAP_ILA: return "ILA"; + case LWTUNNEL_ENCAP_SEG6: + return "SEG6"; case LWTUNNEL_ENCAP_IP6: case LWTUNNEL_ENCAP_IP: case LWTUNNEL_ENCAP_NONE: diff --git a/net/ipv6/Kconfig b/net/ipv6/Kconfig index 2343e4f2e0bf..1123a001d729 100644 --- a/net/ipv6/Kconfig +++ b/net/ipv6/Kconfig @@ -289,4 +289,16 @@ config IPV6_PIMSM_V2 Support for IPv6 PIM multicast routing protocol PIM-SMv2. If unsure, say N. +config IPV6_SEG6_INLINE + bool "IPv6: direct Segment Routing Header insertion " + depends on IPV6 + ---help--- + Support for direct insertion of the Segment Routing Header, + also known as inline mode. Be aware that direct insertion of + extension headers (as opposed to encapsulation) may break + multiple mechanisms such as PMTUD or IPSec AH. Use this feature + only if you know exactly what you are doing. + + If unsure, say N. + endif # IPV6 diff --git a/net/ipv6/Makefile b/net/ipv6/Makefile index c92010d62afc..59ee92fb3689 100644 --- a/net/ipv6/Makefile +++ b/net/ipv6/Makefile @@ -9,7 +9,7 @@ ipv6-objs := af_inet6.o anycast.o ip6_output.o ip6_input.o addrconf.o \ route.o ip6_fib.o ipv6_sockglue.o ndisc.o udp.o udplite.o \ raw.o icmp.o mcast.o reassembly.o tcp_ipv6.o ping.o \ exthdrs.o datagram.o ip6_flowlabel.o inet6_connection_sock.o \ - udp_offload.o seg6.o + udp_offload.o seg6.o seg6_iptunnel.o ipv6-offload := ip6_offload.o tcpv6_offload.o exthdrs_offload.o diff --git a/net/ipv6/seg6.c b/net/ipv6/seg6.c index e246b0ba12ac..9c78053e67e0 100644 --- a/net/ipv6/seg6.c +++ b/net/ipv6/seg6.c @@ -26,6 +26,43 @@ #include <linux/seg6.h> #include <linux/seg6_genl.h> +bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len) +{ + int trailing; + unsigned int tlv_offset; + + if (srh->type != IPV6_SRCRT_TYPE_4) + return false; + + if (((srh->hdrlen + 1) << 3) != len) + return false; + + if (srh->segments_left != srh->first_segment) + return false; + + tlv_offset = sizeof(*srh) + ((srh->first_segment + 1) << 4); + + trailing = len - tlv_offset; + if (trailing < 0) + return false; + + while (trailing) { + struct sr6_tlv *tlv; + unsigned int tlv_len; + + tlv = (struct sr6_tlv *)((unsigned char *)srh + tlv_offset); + tlv_len = sizeof(*tlv) + tlv->len; + + trailing -= tlv_len; + if (trailing < 0) + return false; + + tlv_offset += tlv_len; + } + + return true; +} + static struct genl_family seg6_genl_family; static const struct nla_policy seg6_genl_policy[SEG6_ATTR_MAX + 1] = { @@ -198,10 +235,16 @@ int __init seg6_init(void) if (err) goto out_unregister_genl; + err = seg6_iptunnel_init(); + if (err) + goto out_unregister_pernet; + pr_info("Segment Routing with IPv6\n"); out: return err; +out_unregister_pernet: + unregister_pernet_subsys(&ip6_segments_ops); out_unregister_genl: genl_unregister_family(&seg6_genl_family); goto out; @@ -209,6 +252,7 @@ out_unregister_genl: void seg6_exit(void) { + seg6_iptunnel_exit(); unregister_pernet_subsys(&ip6_segments_ops); genl_unregister_family(&seg6_genl_family); } diff --git a/net/ipv6/seg6_iptunnel.c b/net/ipv6/seg6_iptunnel.c new file mode 100644 index 000000000000..39762b2fa7a2 --- /dev/null +++ b/net/ipv6/seg6_iptunnel.c @@ -0,0 +1,410 @@ +/* + * SR-IPv6 implementation + * + * Author: + * David Lebrun <david.lebrun@uclouvain.be> + * + * + * 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 <net/ip.h> +#include <net/lwtunnel.h> +#include <net/netevent.h> +#include <net/netns/generic.h> +#include <net/ip6_fib.h> +#include <net/route.h> +#include <net/seg6.h> +#include <linux/seg6.h> +#include <linux/seg6_iptunnel.h> +#include <net/addrconf.h> +#include <net/ip6_route.h> +#ifdef CONFIG_DST_CACHE +#include <net/dst_cache.h> +#endif + +struct seg6_lwt { +#ifdef CONFIG_DST_CACHE + struct dst_cache cache; +#endif + struct seg6_iptunnel_encap tuninfo[0]; +}; + +static inline struct seg6_lwt *seg6_lwt_lwtunnel(struct lwtunnel_state *lwt) +{ + return (struct seg6_lwt *)lwt->data; +} + +static inline struct seg6_iptunnel_encap * +seg6_encap_lwtunnel(struct lwtunnel_state *lwt) +{ + return seg6_lwt_lwtunnel(lwt)->tuninfo; +} + +static const struct nla_policy seg6_iptunnel_policy[SEG6_IPTUNNEL_MAX + 1] = { + [SEG6_IPTUNNEL_SRH] = { .type = NLA_BINARY }, +}; + +int nla_put_srh(struct sk_buff *skb, int attrtype, + struct seg6_iptunnel_encap *tuninfo) +{ + struct seg6_iptunnel_encap *data; + struct nlattr *nla; + int len; + + len = SEG6_IPTUN_ENCAP_SIZE(tuninfo); + + nla = nla_reserve(skb, attrtype, len); + if (!nla) + return -EMSGSIZE; + + data = nla_data(nla); + memcpy(data, tuninfo, len); + + return 0; +} + +static void set_tun_src(struct net *net, struct net_device *dev, + struct in6_addr *daddr, struct in6_addr *saddr) +{ + struct seg6_pernet_data *sdata = seg6_pernet(net); + struct in6_addr *tun_src; + + rcu_read_lock(); + + tun_src = rcu_dereference(sdata->tun_src); + + if (!ipv6_addr_any(tun_src)) { + memcpy(saddr, tun_src, sizeof(struct in6_addr)); + } else { + ipv6_dev_get_saddr(net, dev, daddr, IPV6_PREFER_SRC_PUBLIC, + saddr); + } + + rcu_read_unlock(); +} + +/* encapsulate an IPv6 packet within an outer IPv6 header with a given SRH */ +static int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh) +{ + struct net *net = dev_net(skb_dst(skb)->dev); + struct ipv6hdr *hdr, *inner_hdr; + struct ipv6_sr_hdr *isrh; + int hdrlen, tot_len, err; + + hdrlen = (osrh->hdrlen + 1) << 3; + tot_len = hdrlen + sizeof(*hdr); + + err = pskb_expand_head(skb, tot_len, 0, GFP_ATOMIC); + if (unlikely(err)) + return err; + + inner_hdr = ipv6_hdr(skb); + + skb_push(skb, tot_len); + skb_reset_network_header(skb); + skb_mac_header_rebuild(skb); + hdr = ipv6_hdr(skb); + + /* inherit tc, flowlabel and hlim + * hlim will be decremented in ip6_forward() afterwards and + * decapsulation will overwrite inner hlim with outer hlim + */ + ip6_flow_hdr(hdr, ip6_tclass(ip6_flowinfo(inner_hdr)), + ip6_flowlabel(inner_hdr)); + hdr->hop_limit = inner_hdr->hop_limit; + hdr->nexthdr = NEXTHDR_ROUTING; + + isrh = (void *)hdr + sizeof(*hdr); + memcpy(isrh, osrh, hdrlen); + + isrh->nexthdr = NEXTHDR_IPV6; + + hdr->daddr = isrh->segments[isrh->first_segment]; + set_tun_src(net, skb->dev, &hdr->daddr, &hdr->saddr); + + skb_postpush_rcsum(skb, hdr, tot_len); + + return 0; +} + +/* insert an SRH within an IPv6 packet, just after the IPv6 header */ +#ifdef CONFIG_IPV6_SEG6_INLINE +static int seg6_do_srh_inline(struct sk_buff *skb, struct ipv6_sr_hdr *osrh) +{ + struct ipv6hdr *hdr, *oldhdr; + struct ipv6_sr_hdr *isrh; + int hdrlen, err; + + hdrlen = (osrh->hdrlen + 1) << 3; + + err = pskb_expand_head(skb, hdrlen, 0, GFP_ATOMIC); + if (unlikely(err)) + return err; + + oldhdr = ipv6_hdr(skb); + + skb_pull(skb, sizeof(struct ipv6hdr)); + skb_postpull_rcsum(skb, skb_network_header(skb), + sizeof(struct ipv6hdr)); + + skb_push(skb, sizeof(struct ipv6hdr) + hdrlen); + skb_reset_network_header(skb); + skb_mac_header_rebuild(skb); + + hdr = ipv6_hdr(skb); + + memmove(hdr, oldhdr, sizeof(*hdr)); + + isrh = (void *)hdr + sizeof(*hdr); + memcpy(isrh, osrh, hdrlen); + + isrh->nexthdr = hdr->nexthdr; + hdr->nexthdr = NEXTHDR_ROUTING; + + isrh->segments[0] = hdr->daddr; + hdr->daddr = isrh->segments[isrh->first_segment]; + + skb_postpush_rcsum(skb, hdr, sizeof(struct ipv6hdr) + hdrlen); + + return 0; +} +#endif + +static int seg6_do_srh(struct sk_buff *skb) +{ + struct dst_entry *dst = skb_dst(skb); + struct seg6_iptunnel_encap *tinfo; + int err = 0; + + tinfo = seg6_encap_lwtunnel(dst->lwtstate); + + if (likely(!skb->encapsulation)) { + skb_reset_inner_headers(skb); + skb->encapsulation = 1; + } + + switch (tinfo->mode) { +#ifdef CONFIG_IPV6_SEG6_INLINE + case SEG6_IPTUN_MODE_INLINE: + err = seg6_do_srh_inline(skb, tinfo->srh); + skb_reset_inner_headers(skb); + break; +#endif + case SEG6_IPTUN_MODE_ENCAP: + err = seg6_do_srh_encap(skb, tinfo->srh); + break; + } + + if (err) + return err; + + ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); + skb_set_transport_header(skb, sizeof(struct ipv6hdr)); + + skb_set_inner_protocol(skb, skb->protocol); + + return 0; +} + +int seg6_input(struct sk_buff *skb) +{ + int err; + + err = seg6_do_srh(skb); + if (unlikely(err)) { + kfree_skb(skb); + return err; + } + + skb_dst_drop(skb); + ip6_route_input(skb); + + return dst_input(skb); +} + +int seg6_output(struct net *net, struct sock *sk, struct sk_buff *skb) +{ + struct dst_entry *orig_dst = skb_dst(skb); + struct dst_entry *dst = NULL; + struct seg6_lwt *slwt; + int err = -EINVAL; + + err = seg6_do_srh(skb); + if (unlikely(err)) + goto drop; + + slwt = seg6_lwt_lwtunnel(orig_dst->lwtstate); + +#ifdef CONFIG_DST_CACHE + dst = dst_cache_get(&slwt->cache); +#endif + + if (unlikely(!dst)) { + struct ipv6hdr *hdr = ipv6_hdr(skb); + struct flowi6 fl6; + + fl6.daddr = hdr->daddr; + fl6.saddr = hdr->saddr; + fl6.flowlabel = ip6_flowinfo(hdr); + fl6.flowi6_mark = skb->mark; + fl6.flowi6_proto = hdr->nexthdr; + + dst = ip6_route_output(net, NULL, &fl6); + if (dst->error) { + err = dst->error; + dst_release(dst); + goto drop; + } + +#ifdef CONFIG_DST_CACHE + dst_cache_set_ip6(&slwt->cache, dst, &fl6.saddr); +#endif + } + + skb_dst_drop(skb); + skb_dst_set(skb, dst); + + return dst_output(net, sk, skb); +drop: + kfree_skb(skb); + return err; +} + +static int seg6_build_state(struct net_device *dev, struct nlattr *nla, + unsigned int family, const void *cfg, + struct lwtunnel_state **ts) +{ + struct nlattr *tb[SEG6_IPTUNNEL_MAX + 1]; + struct seg6_iptunnel_encap *tuninfo; + struct lwtunnel_state *newts; + int tuninfo_len, min_size; + struct seg6_lwt *slwt; + int err; + + err = nla_parse_nested(tb, SEG6_IPTUNNEL_MAX, nla, + seg6_iptunnel_policy); + + if (err < 0) + return err; + + if (!tb[SEG6_IPTUNNEL_SRH]) + return -EINVAL; + + tuninfo = nla_data(tb[SEG6_IPTUNNEL_SRH]); + tuninfo_len = nla_len(tb[SEG6_IPTUNNEL_SRH]); + + /* tuninfo must contain at least the iptunnel encap structure, + * the SRH and one segment + */ + min_size = sizeof(*tuninfo) + sizeof(struct ipv6_sr_hdr) + + sizeof(struct in6_addr); + if (tuninfo_len < min_size) + return -EINVAL; + + switch (tuninfo->mode) { +#ifdef CONFIG_IPV6_SEG6_INLINE + case SEG6_IPTUN_MODE_INLINE: + break; +#endif + case SEG6_IPTUN_MODE_ENCAP: + break; + default: + return -EINVAL; + } + + /* verify that SRH is consistent */ + if (!seg6_validate_srh(tuninfo->srh, tuninfo_len - sizeof(*tuninfo))) + return -EINVAL; + + newts = lwtunnel_state_alloc(tuninfo_len + sizeof(*slwt)); + if (!newts) + return -ENOMEM; + + slwt = seg6_lwt_lwtunnel(newts); + +#ifdef CONFIG_DST_CACHE + err = dst_cache_init(&slwt->cache, GFP_KERNEL); + if (err) { + kfree(newts); + return err; + } +#endif + + memcpy(&slwt->tuninfo, tuninfo, tuninfo_len); + + newts->type = LWTUNNEL_ENCAP_SEG6; + newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT | + LWTUNNEL_STATE_INPUT_REDIRECT; + newts->headroom = seg6_lwt_headroom(tuninfo); + + *ts = newts; + + return 0; +} + +#ifdef CONFIG_DST_CACHE +static void seg6_destroy_state(struct lwtunnel_state *lwt) +{ + dst_cache_destroy(&seg6_lwt_lwtunnel(lwt)->cache); +} +#endif + +static int seg6_fill_encap_info(struct sk_buff *skb, + struct lwtunnel_state *lwtstate) +{ + struct seg6_iptunnel_encap *tuninfo = seg6_encap_lwtunnel(lwtstate); + + if (nla_put_srh(skb, SEG6_IPTUNNEL_SRH, tuninfo)) + return -EMSGSIZE; + + return 0; +} + +static int seg6_encap_nlsize(struct lwtunnel_state *lwtstate) +{ + struct seg6_iptunnel_encap *tuninfo = seg6_encap_lwtunnel(lwtstate); + + return nla_total_size(SEG6_IPTUN_ENCAP_SIZE(tuninfo)); +} + +static int seg6_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b) +{ + struct seg6_iptunnel_encap *a_hdr = seg6_encap_lwtunnel(a); + struct seg6_iptunnel_encap *b_hdr = seg6_encap_lwtunnel(b); + int len = SEG6_IPTUN_ENCAP_SIZE(a_hdr); + + if (len != SEG6_IPTUN_ENCAP_SIZE(b_hdr)) + return 1; + + return memcmp(a_hdr, b_hdr, len); +} + +static const struct lwtunnel_encap_ops seg6_iptun_ops = { + .build_state = seg6_build_state, +#ifdef CONFIG_DST_CACHE + .destroy_state = seg6_destroy_state, +#endif + .output = seg6_output, + .input = seg6_input, + .fill_encap = seg6_fill_encap_info, + .get_encap_size = seg6_encap_nlsize, + .cmp_encap = seg6_encap_cmp, +}; + +int __init seg6_iptunnel_init(void) +{ + return lwtunnel_encap_add_ops(&seg6_iptun_ops, LWTUNNEL_ENCAP_SEG6); +} + +void seg6_iptunnel_exit(void) +{ + lwtunnel_encap_del_ops(&seg6_iptun_ops, LWTUNNEL_ENCAP_SEG6); +} |