From faee676944dab731c9b2b91cf86c769d291a2237 Mon Sep 17 00:00:00 2001 From: Alexander Aring Date: Fri, 27 Mar 2020 18:00:21 -0400 Subject: net: add net available in build_state The build_state callback of lwtunnel doesn't contain the net namespace structure yet. This patch will add it so we can check on specific address configuration at creation time of rpl source routes. Signed-off-by: Alexander Aring Signed-off-by: David S. Miller --- net/core/lwtunnel.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/core/lwtunnel.c') diff --git a/net/core/lwtunnel.c b/net/core/lwtunnel.c index 2f9c0de533c7..4cd03955fa32 100644 --- a/net/core/lwtunnel.c +++ b/net/core/lwtunnel.c @@ -98,7 +98,7 @@ int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *ops, } EXPORT_SYMBOL_GPL(lwtunnel_encap_del_ops); -int lwtunnel_build_state(u16 encap_type, +int lwtunnel_build_state(struct net *net, u16 encap_type, struct nlattr *encap, unsigned int family, const void *cfg, struct lwtunnel_state **lws, struct netlink_ext_ack *extack) @@ -122,7 +122,7 @@ int lwtunnel_build_state(u16 encap_type, rcu_read_unlock(); if (found) { - ret = ops->build_state(encap, family, cfg, lws, extack); + ret = ops->build_state(net, encap, family, cfg, lws, extack); if (ret) module_put(ops->owner); } else { -- cgit v1.2.3 From a7a29f9c361f8542604ef959ae6627f423b7a412 Mon Sep 17 00:00:00 2001 From: Alexander Aring Date: Fri, 27 Mar 2020 18:00:22 -0400 Subject: net: ipv6: add rpl sr tunnel This patch adds functionality to configure routes for RPL source routing functionality. There is no IPIP functionality yet implemented which can be added later when the cases when to use IPv6 encapuslation comes more clear. Signed-off-by: Alexander Aring Signed-off-by: David S. Miller --- include/net/rpl.h | 12 ++ include/uapi/linux/lwtunnel.h | 1 + include/uapi/linux/rpl_iptunnel.h | 21 +++ net/core/lwtunnel.c | 2 + net/ipv6/Kconfig | 10 + net/ipv6/Makefile | 1 + net/ipv6/af_inet6.c | 7 + net/ipv6/rpl_iptunnel.c | 380 ++++++++++++++++++++++++++++++++++++++ 8 files changed, 434 insertions(+) create mode 100644 include/uapi/linux/rpl_iptunnel.h create mode 100644 net/ipv6/rpl_iptunnel.c (limited to 'net/core/lwtunnel.c') diff --git a/include/net/rpl.h b/include/net/rpl.h index d694d49a61db..dceff60e8baf 100644 --- a/include/net/rpl.h +++ b/include/net/rpl.h @@ -11,6 +11,18 @@ #include +#if IS_ENABLED(CONFIG_IPV6_RPL_LWTUNNEL) +extern int rpl_init(void); +extern void rpl_exit(void); +#else +static inline int rpl_init(void) +{ + return 0; +} + +static inline void rpl_exit(void) {} +#endif + /* Worst decompression memory usage ipv6 address (16) + pad 7 */ #define IPV6_RPL_SRH_WORST_SWAP_SIZE (sizeof(struct in6_addr) + 7) diff --git a/include/uapi/linux/lwtunnel.h b/include/uapi/linux/lwtunnel.h index f6035f737193..568a4303ccce 100644 --- a/include/uapi/linux/lwtunnel.h +++ b/include/uapi/linux/lwtunnel.h @@ -13,6 +13,7 @@ enum lwtunnel_encap_types { LWTUNNEL_ENCAP_SEG6, LWTUNNEL_ENCAP_BPF, LWTUNNEL_ENCAP_SEG6_LOCAL, + LWTUNNEL_ENCAP_RPL, __LWTUNNEL_ENCAP_MAX, }; diff --git a/include/uapi/linux/rpl_iptunnel.h b/include/uapi/linux/rpl_iptunnel.h new file mode 100644 index 000000000000..f4eed1f92baa --- /dev/null +++ b/include/uapi/linux/rpl_iptunnel.h @@ -0,0 +1,21 @@ +/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ +/* + * IPv6 RPL-SR implementation + * + * Author: + * (C) 2020 Alexander Aring + */ + +#ifndef _UAPI_LINUX_RPL_IPTUNNEL_H +#define _UAPI_LINUX_RPL_IPTUNNEL_H + +enum { + RPL_IPTUNNEL_UNSPEC, + RPL_IPTUNNEL_SRH, + __RPL_IPTUNNEL_MAX, +}; +#define RPL_IPTUNNEL_MAX (__RPL_IPTUNNEL_MAX - 1) + +#define RPL_IPTUNNEL_SRH_SIZE(srh) (((srh)->hdrlen + 1) << 3) + +#endif diff --git a/net/core/lwtunnel.c b/net/core/lwtunnel.c index 4cd03955fa32..8ec7d13d2860 100644 --- a/net/core/lwtunnel.c +++ b/net/core/lwtunnel.c @@ -41,6 +41,8 @@ static const char *lwtunnel_encap_str(enum lwtunnel_encap_types encap_type) return "BPF"; case LWTUNNEL_ENCAP_SEG6_LOCAL: return "SEG6LOCAL"; + case LWTUNNEL_ENCAP_RPL: + return "RPL"; case LWTUNNEL_ENCAP_IP6: case LWTUNNEL_ENCAP_IP: case LWTUNNEL_ENCAP_NONE: diff --git a/net/ipv6/Kconfig b/net/ipv6/Kconfig index ae1344e4cec5..2ccaee98fddb 100644 --- a/net/ipv6/Kconfig +++ b/net/ipv6/Kconfig @@ -303,4 +303,14 @@ config IPV6_SEG6_BPF depends on IPV6_SEG6_LWTUNNEL depends on IPV6 = y +config IPV6_RPL_LWTUNNEL + bool "IPv6: RPL Source Routing Header support" + depends on IPV6 + select LWTUNNEL + ---help--- + Support for RFC6554 RPL Source Routing Header using the lightweight + tunnels mechanism. + + If unsure, say N. + endif # IPV6 diff --git a/net/ipv6/Makefile b/net/ipv6/Makefile index 9d3e9bd2334f..cf7b47bdb9b3 100644 --- a/net/ipv6/Makefile +++ b/net/ipv6/Makefile @@ -26,6 +26,7 @@ ipv6-$(CONFIG_SYN_COOKIES) += syncookies.o ipv6-$(CONFIG_NETLABEL) += calipso.o ipv6-$(CONFIG_IPV6_SEG6_LWTUNNEL) += seg6_iptunnel.o seg6_local.o ipv6-$(CONFIG_IPV6_SEG6_HMAC) += seg6_hmac.o +ipv6-$(CONFIG_IPV6_RPL_LWTUNNEL) += rpl_iptunnel.o ipv6-objs += $(ipv6-y) diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index d727c3b41495..345baa0a754f 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -59,6 +59,7 @@ #endif #include #include +#include #include #include @@ -1114,6 +1115,10 @@ static int __init inet6_init(void) if (err) goto seg6_fail; + err = rpl_init(); + if (err) + goto rpl_fail; + err = igmp6_late_init(); if (err) goto igmp6_late_err; @@ -1136,6 +1141,8 @@ sysctl_fail: igmp6_late_cleanup(); #endif igmp6_late_err: + rpl_exit(); +rpl_fail: seg6_exit(); seg6_fail: calipso_exit(); diff --git a/net/ipv6/rpl_iptunnel.c b/net/ipv6/rpl_iptunnel.c new file mode 100644 index 000000000000..203037afe001 --- /dev/null +++ b/net/ipv6/rpl_iptunnel.c @@ -0,0 +1,380 @@ +// SPDX-License-Identifier: GPL-2.0-only +/** + * Authors: + * (C) 2020 Alexander Aring + */ + +#include + +#include +#include +#include +#include +#include + +struct rpl_iptunnel_encap { + struct ipv6_rpl_sr_hdr srh[0]; +}; + +struct rpl_lwt { + struct dst_cache cache; + struct rpl_iptunnel_encap tuninfo; +}; + +static inline struct rpl_lwt *rpl_lwt_lwtunnel(struct lwtunnel_state *lwt) +{ + return (struct rpl_lwt *)lwt->data; +} + +static inline struct rpl_iptunnel_encap * +rpl_encap_lwtunnel(struct lwtunnel_state *lwt) +{ + return &rpl_lwt_lwtunnel(lwt)->tuninfo; +} + +static const struct nla_policy rpl_iptunnel_policy[RPL_IPTUNNEL_MAX + 1] = { + [RPL_IPTUNNEL_SRH] = { .type = NLA_BINARY }, +}; + +static bool rpl_validate_srh(struct net *net, struct ipv6_rpl_sr_hdr *srh, + size_t seglen) +{ + int err; + + if ((srh->hdrlen << 3) != seglen) + return false; + + /* check at least one segment and seglen fit with segments_left */ + if (!srh->segments_left || + (srh->segments_left * sizeof(struct in6_addr)) != seglen) + return false; + + if (srh->cmpri || srh->cmpre) + return false; + + err = ipv6_chk_rpl_srh_loop(net, srh->rpl_segaddr, + srh->segments_left); + if (err) + return false; + + if (ipv6_addr_type(&srh->rpl_segaddr[srh->segments_left - 1]) & + IPV6_ADDR_MULTICAST) + return false; + + return true; +} + +static int rpl_build_state(struct net *net, struct nlattr *nla, + unsigned int family, const void *cfg, + struct lwtunnel_state **ts, + struct netlink_ext_ack *extack) +{ + struct nlattr *tb[RPL_IPTUNNEL_MAX + 1]; + struct lwtunnel_state *newts; + struct ipv6_rpl_sr_hdr *srh; + struct rpl_lwt *rlwt; + int err, srh_len; + + if (family != AF_INET6) + return -EINVAL; + + err = nla_parse_nested(tb, RPL_IPTUNNEL_MAX, nla, + rpl_iptunnel_policy, extack); + if (err < 0) + return err; + + if (!tb[RPL_IPTUNNEL_SRH]) + return -EINVAL; + + srh = nla_data(tb[RPL_IPTUNNEL_SRH]); + srh_len = nla_len(tb[RPL_IPTUNNEL_SRH]); + + if (srh_len < sizeof(*srh)) + return -EINVAL; + + /* verify that SRH is consistent */ + if (!rpl_validate_srh(net, srh, srh_len - sizeof(*srh))) + return -EINVAL; + + newts = lwtunnel_state_alloc(srh_len + sizeof(*rlwt)); + if (!newts) + return -ENOMEM; + + rlwt = rpl_lwt_lwtunnel(newts); + + err = dst_cache_init(&rlwt->cache, GFP_ATOMIC); + if (err) { + kfree(newts); + return err; + } + + memcpy(&rlwt->tuninfo.srh, srh, srh_len); + + newts->type = LWTUNNEL_ENCAP_RPL; + newts->flags |= LWTUNNEL_STATE_INPUT_REDIRECT; + newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT; + + *ts = newts; + + return 0; +} + +static void rpl_destroy_state(struct lwtunnel_state *lwt) +{ + dst_cache_destroy(&rpl_lwt_lwtunnel(lwt)->cache); +} + +static int rpl_do_srh_inline(struct sk_buff *skb, const struct rpl_lwt *rlwt, + const struct ipv6_rpl_sr_hdr *srh) +{ + struct ipv6_rpl_sr_hdr *isrh, *csrh; + const struct ipv6hdr *oldhdr; + struct ipv6hdr *hdr; + unsigned char *buf; + size_t hdrlen; + int err; + + oldhdr = ipv6_hdr(skb); + + buf = kzalloc(ipv6_rpl_srh_alloc_size(srh->segments_left - 1) * 2, + GFP_ATOMIC); + if (!buf) + return -ENOMEM; + + isrh = (struct ipv6_rpl_sr_hdr *)buf; + csrh = (struct ipv6_rpl_sr_hdr *)(buf + ((srh->hdrlen + 1) << 3)); + + memcpy(isrh, srh, sizeof(*isrh)); + memcpy(isrh->rpl_segaddr, &srh->rpl_segaddr[1], + (srh->segments_left - 1) * 16); + isrh->rpl_segaddr[srh->segments_left - 1] = oldhdr->daddr; + + ipv6_rpl_srh_compress(csrh, isrh, &srh->rpl_segaddr[0], + isrh->segments_left - 1); + + hdrlen = ((csrh->hdrlen + 1) << 3); + + err = skb_cow_head(skb, hdrlen + skb->mac_len); + if (unlikely(err)) + return err; + + 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, csrh, hdrlen); + + isrh->nexthdr = hdr->nexthdr; + hdr->nexthdr = NEXTHDR_ROUTING; + hdr->daddr = srh->rpl_segaddr[0]; + + ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); + skb_set_transport_header(skb, sizeof(struct ipv6hdr)); + + skb_postpush_rcsum(skb, hdr, sizeof(struct ipv6hdr) + hdrlen); + + kfree(buf); + + return 0; +} + +static int rpl_do_srh(struct sk_buff *skb, const struct rpl_lwt *rlwt) +{ + struct dst_entry *dst = skb_dst(skb); + struct rpl_iptunnel_encap *tinfo; + int err = 0; + + if (skb->protocol != htons(ETH_P_IPV6)) + return -EINVAL; + + tinfo = rpl_encap_lwtunnel(dst->lwtstate); + + err = rpl_do_srh_inline(skb, rlwt, tinfo->srh); + if (err) + return err; + + return 0; +} + +static int rpl_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 rpl_lwt *rlwt; + int err = -EINVAL; + + rlwt = rpl_lwt_lwtunnel(orig_dst->lwtstate); + + err = rpl_do_srh(skb, rlwt); + if (unlikely(err)) + goto drop; + + preempt_disable(); + dst = dst_cache_get(&rlwt->cache); + preempt_enable(); + + if (unlikely(!dst)) { + struct ipv6hdr *hdr = ipv6_hdr(skb); + struct flowi6 fl6; + + memset(&fl6, 0, sizeof(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; + } + + preempt_disable(); + dst_cache_set_ip6(&rlwt->cache, dst, &fl6.saddr); + preempt_enable(); + } + + skb_dst_drop(skb); + skb_dst_set(skb, dst); + + err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev)); + if (unlikely(err)) + goto drop; + + return dst_output(net, sk, skb); + +drop: + kfree_skb(skb); + return err; +} + +static int rpl_input(struct sk_buff *skb) +{ + struct dst_entry *orig_dst = skb_dst(skb); + struct dst_entry *dst = NULL; + struct rpl_lwt *rlwt; + int err; + + rlwt = rpl_lwt_lwtunnel(orig_dst->lwtstate); + + err = rpl_do_srh(skb, rlwt); + if (unlikely(err)) { + kfree_skb(skb); + return err; + } + + preempt_disable(); + dst = dst_cache_get(&rlwt->cache); + preempt_enable(); + + skb_dst_drop(skb); + + if (!dst) { + ip6_route_input(skb); + dst = skb_dst(skb); + if (!dst->error) { + preempt_disable(); + dst_cache_set_ip6(&rlwt->cache, dst, + &ipv6_hdr(skb)->saddr); + preempt_enable(); + } + } else { + skb_dst_set(skb, dst); + } + + err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev)); + if (unlikely(err)) + return err; + + return dst_input(skb); +} + +static int nla_put_rpl_srh(struct sk_buff *skb, int attrtype, + struct rpl_iptunnel_encap *tuninfo) +{ + struct rpl_iptunnel_encap *data; + struct nlattr *nla; + int len; + + len = RPL_IPTUNNEL_SRH_SIZE(tuninfo->srh); + + nla = nla_reserve(skb, attrtype, len); + if (!nla) + return -EMSGSIZE; + + data = nla_data(nla); + memcpy(data, tuninfo->srh, len); + + return 0; +} + +static int rpl_fill_encap_info(struct sk_buff *skb, + struct lwtunnel_state *lwtstate) +{ + struct rpl_iptunnel_encap *tuninfo = rpl_encap_lwtunnel(lwtstate); + + if (nla_put_rpl_srh(skb, RPL_IPTUNNEL_SRH, tuninfo)) + return -EMSGSIZE; + + return 0; +} + +static int rpl_encap_nlsize(struct lwtunnel_state *lwtstate) +{ + struct rpl_iptunnel_encap *tuninfo = rpl_encap_lwtunnel(lwtstate); + + return nla_total_size(RPL_IPTUNNEL_SRH_SIZE(tuninfo->srh)); +} + +static int rpl_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b) +{ + struct rpl_iptunnel_encap *a_hdr = rpl_encap_lwtunnel(a); + struct rpl_iptunnel_encap *b_hdr = rpl_encap_lwtunnel(b); + int len = RPL_IPTUNNEL_SRH_SIZE(a_hdr->srh); + + if (len != RPL_IPTUNNEL_SRH_SIZE(b_hdr->srh)) + return 1; + + return memcmp(a_hdr, b_hdr, len); +} + +static const struct lwtunnel_encap_ops rpl_ops = { + .build_state = rpl_build_state, + .destroy_state = rpl_destroy_state, + .output = rpl_output, + .input = rpl_input, + .fill_encap = rpl_fill_encap_info, + .get_encap_size = rpl_encap_nlsize, + .cmp_encap = rpl_encap_cmp, + .owner = THIS_MODULE, +}; + +int __init rpl_init(void) +{ + int err; + + err = lwtunnel_encap_add_ops(&rpl_ops, LWTUNNEL_ENCAP_RPL); + if (err) + goto out; + + pr_info("RPL Segment Routing with IPv6\n"); + + return 0; + +out: + return err; +} + +void rpl_exit(void) +{ + lwtunnel_encap_del_ops(&rpl_ops, LWTUNNEL_ENCAP_RPL); +} -- cgit v1.2.3