From 3edede08ff37c6a9370510508d5eeb54890baf47 Mon Sep 17 00:00:00 2001 From: Justin Iurman Date: Tue, 20 Jul 2021 21:42:59 +0200 Subject: ipv6: ioam: Support for IOAM injection with lwtunnels Add support for the IOAM inline insertion (only for the host-to-host use case) which is per-route configured with lightweight tunnels. The target is iproute2 and the patch is ready. It will be posted as soon as this patchset is merged. Here is an overview: $ ip -6 ro ad fc00::1/128 encap ioam6 trace type 0x800000 ns 1 size 12 dev eth0 This example configures an IOAM Pre-allocated Trace option attached to the fc00::1/128 prefix. The IOAM namespace (ns) is 1, the size of the pre-allocated trace data block is 12 octets (size) and only the first IOAM data (bit 0: hop_limit + node id) is included in the trace (type) represented as a bitfield. The reason why the in-transit (IPv6-in-IPv6 encapsulation) use case is not implemented is explained on the patchset cover. Signed-off-by: Justin Iurman Signed-off-by: David S. Miller --- include/linux/ioam6_iptunnel.h | 13 ++ include/net/ioam6.h | 3 + include/uapi/linux/ioam6.h | 1 + include/uapi/linux/ioam6_iptunnel.h | 20 +++ include/uapi/linux/lwtunnel.h | 1 + net/core/lwtunnel.c | 2 + net/ipv6/Kconfig | 11 ++ net/ipv6/Makefile | 1 + net/ipv6/ioam6.c | 44 ++++-- net/ipv6/ioam6_iptunnel.c | 274 ++++++++++++++++++++++++++++++++++++ 10 files changed, 358 insertions(+), 12 deletions(-) create mode 100644 include/linux/ioam6_iptunnel.h create mode 100644 include/uapi/linux/ioam6_iptunnel.h create mode 100644 net/ipv6/ioam6_iptunnel.c diff --git a/include/linux/ioam6_iptunnel.h b/include/linux/ioam6_iptunnel.h new file mode 100644 index 000000000000..07d9dfedd29d --- /dev/null +++ b/include/linux/ioam6_iptunnel.h @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * IPv6 IOAM Lightweight Tunnel API + * + * Author: + * Justin Iurman + */ +#ifndef _LINUX_IOAM6_IPTUNNEL_H +#define _LINUX_IOAM6_IPTUNNEL_H + +#include + +#endif /* _LINUX_IOAM6_IPTUNNEL_H */ diff --git a/include/net/ioam6.h b/include/net/ioam6.h index 772b91ee2e87..3c2993bc48c8 100644 --- a/include/net/ioam6.h +++ b/include/net/ioam6.h @@ -61,4 +61,7 @@ void ioam6_fill_trace_data(struct sk_buff *skb, int ioam6_init(void); void ioam6_exit(void); +int ioam6_iptunnel_init(void); +void ioam6_iptunnel_exit(void); + #endif /* _NET_IOAM6_H */ diff --git a/include/uapi/linux/ioam6.h b/include/uapi/linux/ioam6.h index 23ba6e85582f..ac4de376f0ce 100644 --- a/include/uapi/linux/ioam6.h +++ b/include/uapi/linux/ioam6.h @@ -126,6 +126,7 @@ struct ioam6_trace_hdr { #error "Please fix " #endif +#define IOAM6_TRACE_DATA_SIZE_MAX 244 __u8 data[0]; } __attribute__((packed)); diff --git a/include/uapi/linux/ioam6_iptunnel.h b/include/uapi/linux/ioam6_iptunnel.h new file mode 100644 index 000000000000..bae14636a8c8 --- /dev/null +++ b/include/uapi/linux/ioam6_iptunnel.h @@ -0,0 +1,20 @@ +/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ +/* + * IPv6 IOAM Lightweight Tunnel API + * + * Author: + * Justin Iurman + */ + +#ifndef _UAPI_LINUX_IOAM6_IPTUNNEL_H +#define _UAPI_LINUX_IOAM6_IPTUNNEL_H + +enum { + IOAM6_IPTUNNEL_UNSPEC, + IOAM6_IPTUNNEL_TRACE, /* struct ioam6_trace_hdr */ + __IOAM6_IPTUNNEL_MAX, +}; + +#define IOAM6_IPTUNNEL_MAX (__IOAM6_IPTUNNEL_MAX - 1) + +#endif /* _UAPI_LINUX_IOAM6_IPTUNNEL_H */ diff --git a/include/uapi/linux/lwtunnel.h b/include/uapi/linux/lwtunnel.h index 568a4303ccce..2e206919125c 100644 --- a/include/uapi/linux/lwtunnel.h +++ b/include/uapi/linux/lwtunnel.h @@ -14,6 +14,7 @@ enum lwtunnel_encap_types { LWTUNNEL_ENCAP_BPF, LWTUNNEL_ENCAP_SEG6_LOCAL, LWTUNNEL_ENCAP_RPL, + LWTUNNEL_ENCAP_IOAM6, __LWTUNNEL_ENCAP_MAX, }; diff --git a/net/core/lwtunnel.c b/net/core/lwtunnel.c index 8ec7d13d2860..d0ae987d2de9 100644 --- a/net/core/lwtunnel.c +++ b/net/core/lwtunnel.c @@ -43,6 +43,8 @@ static const char *lwtunnel_encap_str(enum lwtunnel_encap_types encap_type) return "SEG6LOCAL"; case LWTUNNEL_ENCAP_RPL: return "RPL"; + case LWTUNNEL_ENCAP_IOAM6: + return "IOAM6"; case LWTUNNEL_ENCAP_IP6: case LWTUNNEL_ENCAP_IP: case LWTUNNEL_ENCAP_NONE: diff --git a/net/ipv6/Kconfig b/net/ipv6/Kconfig index 747f56e0c636..e504204bca92 100644 --- a/net/ipv6/Kconfig +++ b/net/ipv6/Kconfig @@ -328,4 +328,15 @@ config IPV6_RPL_LWTUNNEL If unsure, say N. +config IPV6_IOAM6_LWTUNNEL + bool "IPv6: IOAM Pre-allocated Trace insertion support" + depends on IPV6 + select LWTUNNEL + help + Support for the inline insertion of IOAM Pre-allocated + Trace Header (only on locally generated packets), using + the lightweight tunnels mechanism. + + If unsure, say N. + endif # IPV6 diff --git a/net/ipv6/Makefile b/net/ipv6/Makefile index b7ef10d417d6..1bc7e143217b 100644 --- a/net/ipv6/Makefile +++ b/net/ipv6/Makefile @@ -27,6 +27,7 @@ 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-$(CONFIG_IPV6_IOAM6_LWTUNNEL) += ioam6_iptunnel.o ipv6-objs += $(ipv6-y) diff --git a/net/ipv6/ioam6.c b/net/ipv6/ioam6.c index ba59671f32b8..5e8961004832 100644 --- a/net/ipv6/ioam6.c +++ b/net/ipv6/ioam6.c @@ -648,7 +648,7 @@ static void __ioam6_fill_trace_data(struct sk_buff *skb, if (skb->dev) byte--; - raw32 = dev_net(skb->dev)->ipv6.sysctl.ioam6_id; + raw32 = dev_net(skb_dst(skb)->dev)->ipv6.sysctl.ioam6_id; *(__be32 *)data = cpu_to_be32((byte << 24) | raw32); data += sizeof(__be32); @@ -675,24 +675,31 @@ static void __ioam6_fill_trace_data(struct sk_buff *skb, /* timestamp seconds */ if (trace->type.bit2) { - if (!skb->tstamp) - __net_timestamp(skb); - - skb_get_new_timestamp(skb, &ts); + if (!skb->dev) { + *(__be32 *)data = cpu_to_be32(IOAM6_U32_UNAVAILABLE); + } else { + if (!skb->tstamp) + __net_timestamp(skb); - *(__be32 *)data = cpu_to_be32((u32)ts.tv_sec); + skb_get_new_timestamp(skb, &ts); + *(__be32 *)data = cpu_to_be32((u32)ts.tv_sec); + } data += sizeof(__be32); } /* timestamp subseconds */ if (trace->type.bit3) { - if (!skb->tstamp) - __net_timestamp(skb); + if (!skb->dev) { + *(__be32 *)data = cpu_to_be32(IOAM6_U32_UNAVAILABLE); + } else { + if (!skb->tstamp) + __net_timestamp(skb); - if (!trace->type.bit2) - skb_get_new_timestamp(skb, &ts); + if (!trace->type.bit2) + skb_get_new_timestamp(skb, &ts); - *(__be32 *)data = cpu_to_be32((u32)ts.tv_usec); + *(__be32 *)data = cpu_to_be32((u32)ts.tv_usec); + } data += sizeof(__be32); } @@ -726,7 +733,7 @@ static void __ioam6_fill_trace_data(struct sk_buff *skb, if (skb->dev) byte--; - raw64 = dev_net(skb->dev)->ipv6.sysctl.ioam6_id_wide; + raw64 = dev_net(skb_dst(skb)->dev)->ipv6.sysctl.ioam6_id_wide; *(__be64 *)data = cpu_to_be64(((u64)byte << 56) | raw64); data += sizeof(__be64); @@ -874,10 +881,20 @@ int __init ioam6_init(void) if (err) goto out_unregister_pernet_subsys; +#ifdef CONFIG_IPV6_IOAM6_LWTUNNEL + err = ioam6_iptunnel_init(); + if (err) + goto out_unregister_genl; +#endif + pr_info("In-situ OAM (IOAM) with IPv6\n"); out: return err; +#ifdef CONFIG_IPV6_IOAM6_LWTUNNEL +out_unregister_genl: + genl_unregister_family(&ioam6_genl_family); +#endif out_unregister_pernet_subsys: unregister_pernet_subsys(&ioam6_net_ops); goto out; @@ -885,6 +902,9 @@ out_unregister_pernet_subsys: void ioam6_exit(void) { +#ifdef CONFIG_IPV6_IOAM6_LWTUNNEL + ioam6_iptunnel_exit(); +#endif genl_unregister_family(&ioam6_genl_family); unregister_pernet_subsys(&ioam6_net_ops); } diff --git a/net/ipv6/ioam6_iptunnel.c b/net/ipv6/ioam6_iptunnel.c new file mode 100644 index 000000000000..f9ee04541c17 --- /dev/null +++ b/net/ipv6/ioam6_iptunnel.c @@ -0,0 +1,274 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * IPv6 IOAM Lightweight Tunnel implementation + * + * Author: + * Justin Iurman + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define IOAM6_MASK_SHORT_FIELDS 0xff100000 +#define IOAM6_MASK_WIDE_FIELDS 0xe00000 + +struct ioam6_lwt_encap { + struct ipv6_hopopt_hdr eh; + u8 pad[2]; /* 2-octet padding for 4n-alignment */ + struct ioam6_hdr ioamh; + struct ioam6_trace_hdr traceh; +} __packed; + +struct ioam6_lwt { + struct ioam6_lwt_encap tuninfo; +}; + +static struct ioam6_lwt *ioam6_lwt_state(struct lwtunnel_state *lwt) +{ + return (struct ioam6_lwt *)lwt->data; +} + +static struct ioam6_lwt_encap *ioam6_lwt_info(struct lwtunnel_state *lwt) +{ + return &ioam6_lwt_state(lwt)->tuninfo; +} + +static struct ioam6_trace_hdr *ioam6_trace(struct lwtunnel_state *lwt) +{ + return &(ioam6_lwt_state(lwt)->tuninfo.traceh); +} + +static const struct nla_policy ioam6_iptunnel_policy[IOAM6_IPTUNNEL_MAX + 1] = { + [IOAM6_IPTUNNEL_TRACE] = NLA_POLICY_EXACT_LEN(sizeof(struct ioam6_trace_hdr)), +}; + +static int nla_put_ioam6_trace(struct sk_buff *skb, int attrtype, + struct ioam6_trace_hdr *trace) +{ + struct ioam6_trace_hdr *data; + struct nlattr *nla; + int len; + + len = sizeof(*trace); + + nla = nla_reserve(skb, attrtype, len); + if (!nla) + return -EMSGSIZE; + + data = nla_data(nla); + memcpy(data, trace, len); + + return 0; +} + +static bool ioam6_validate_trace_hdr(struct ioam6_trace_hdr *trace) +{ + u32 fields; + + if (!trace->type_be32 || !trace->remlen || + trace->remlen > IOAM6_TRACE_DATA_SIZE_MAX / 4) + return false; + + trace->nodelen = 0; + fields = be32_to_cpu(trace->type_be32); + + trace->nodelen += hweight32(fields & IOAM6_MASK_SHORT_FIELDS) + * (sizeof(__be32) / 4); + trace->nodelen += hweight32(fields & IOAM6_MASK_WIDE_FIELDS) + * (sizeof(__be64) / 4); + + return true; +} + +static int ioam6_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[IOAM6_IPTUNNEL_MAX + 1]; + struct ioam6_lwt_encap *tuninfo; + struct ioam6_trace_hdr *trace; + struct lwtunnel_state *s; + int len_aligned; + int len, err; + + if (family != AF_INET6) + return -EINVAL; + + err = nla_parse_nested(tb, IOAM6_IPTUNNEL_MAX, nla, + ioam6_iptunnel_policy, extack); + if (err < 0) + return err; + + if (!tb[IOAM6_IPTUNNEL_TRACE]) { + NL_SET_ERR_MSG(extack, "missing trace"); + return -EINVAL; + } + + trace = nla_data(tb[IOAM6_IPTUNNEL_TRACE]); + if (!ioam6_validate_trace_hdr(trace)) { + NL_SET_ERR_MSG_ATTR(extack, tb[IOAM6_IPTUNNEL_TRACE], + "invalid trace validation"); + return -EINVAL; + } + + len = sizeof(*tuninfo) + trace->remlen * 4; + len_aligned = ALIGN(len, 8); + + s = lwtunnel_state_alloc(len_aligned); + if (!s) + return -ENOMEM; + + tuninfo = ioam6_lwt_info(s); + tuninfo->eh.hdrlen = (len_aligned >> 3) - 1; + tuninfo->pad[0] = IPV6_TLV_PADN; + tuninfo->ioamh.type = IOAM6_TYPE_PREALLOC; + tuninfo->ioamh.opt_type = IPV6_TLV_IOAM; + tuninfo->ioamh.opt_len = sizeof(tuninfo->ioamh) - 2 + sizeof(*trace) + + trace->remlen * 4; + + memcpy(&tuninfo->traceh, trace, sizeof(*trace)); + + len = len_aligned - len; + if (len == 1) { + tuninfo->traceh.data[trace->remlen * 4] = IPV6_TLV_PAD1; + } else if (len > 0) { + tuninfo->traceh.data[trace->remlen * 4] = IPV6_TLV_PADN; + tuninfo->traceh.data[trace->remlen * 4 + 1] = len - 2; + } + + s->type = LWTUNNEL_ENCAP_IOAM6; + s->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT; + + *ts = s; + + return 0; +} + +static int ioam6_do_inline(struct sk_buff *skb, struct ioam6_lwt_encap *tuninfo) +{ + struct ioam6_trace_hdr *trace; + struct ipv6hdr *oldhdr, *hdr; + struct ioam6_namespace *ns; + int hdrlen, err; + + hdrlen = (tuninfo->eh.hdrlen + 1) << 3; + + err = skb_cow_head(skb, hdrlen + skb->mac_len); + if (unlikely(err)) + return err; + + oldhdr = ipv6_hdr(skb); + skb_pull(skb, sizeof(*oldhdr)); + skb_postpull_rcsum(skb, skb_network_header(skb), sizeof(*oldhdr)); + + skb_push(skb, sizeof(*oldhdr) + hdrlen); + skb_reset_network_header(skb); + skb_mac_header_rebuild(skb); + + hdr = ipv6_hdr(skb); + memmove(hdr, oldhdr, sizeof(*oldhdr)); + tuninfo->eh.nexthdr = hdr->nexthdr; + + skb_set_transport_header(skb, sizeof(*hdr)); + skb_postpush_rcsum(skb, hdr, sizeof(*hdr) + hdrlen); + + memcpy(skb_transport_header(skb), (u8 *)tuninfo, hdrlen); + + hdr->nexthdr = NEXTHDR_HOP; + hdr->payload_len = cpu_to_be16(skb->len - sizeof(*hdr)); + + trace = (struct ioam6_trace_hdr *)(skb_transport_header(skb) + + sizeof(struct ipv6_hopopt_hdr) + 2 + + sizeof(struct ioam6_hdr)); + + ns = ioam6_namespace(dev_net(skb_dst(skb)->dev), trace->namespace_id); + if (ns) + ioam6_fill_trace_data(skb, ns, trace); + + return 0; +} + +static int ioam6_output(struct net *net, struct sock *sk, struct sk_buff *skb) +{ + struct lwtunnel_state *lwt = skb_dst(skb)->lwtstate; + int err = -EINVAL; + + if (skb->protocol != htons(ETH_P_IPV6)) + goto drop; + + /* Only for packets we send and + * that do not contain a Hop-by-Hop yet + */ + if (skb->dev || ipv6_hdr(skb)->nexthdr == NEXTHDR_HOP) + goto out; + + err = ioam6_do_inline(skb, ioam6_lwt_info(lwt)); + if (unlikely(err)) + goto drop; + + err = skb_cow_head(skb, LL_RESERVED_SPACE(skb_dst(skb)->dev)); + if (unlikely(err)) + goto drop; + +out: + return lwt->orig_output(net, sk, skb); + +drop: + kfree_skb(skb); + return err; +} + +static int ioam6_fill_encap_info(struct sk_buff *skb, + struct lwtunnel_state *lwtstate) +{ + struct ioam6_trace_hdr *trace = ioam6_trace(lwtstate); + + if (nla_put_ioam6_trace(skb, IOAM6_IPTUNNEL_TRACE, trace)) + return -EMSGSIZE; + + return 0; +} + +static int ioam6_encap_nlsize(struct lwtunnel_state *lwtstate) +{ + struct ioam6_trace_hdr *trace = ioam6_trace(lwtstate); + + return nla_total_size(sizeof(*trace)); +} + +static int ioam6_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b) +{ + struct ioam6_trace_hdr *a_hdr = ioam6_trace(a); + struct ioam6_trace_hdr *b_hdr = ioam6_trace(b); + + return (a_hdr->namespace_id != b_hdr->namespace_id); +} + +static const struct lwtunnel_encap_ops ioam6_iptun_ops = { + .build_state = ioam6_build_state, + .output = ioam6_output, + .fill_encap = ioam6_fill_encap_info, + .get_encap_size = ioam6_encap_nlsize, + .cmp_encap = ioam6_encap_cmp, + .owner = THIS_MODULE, +}; + +int __init ioam6_iptunnel_init(void) +{ + return lwtunnel_encap_add_ops(&ioam6_iptun_ops, LWTUNNEL_ENCAP_IOAM6); +} + +void ioam6_iptunnel_exit(void) +{ + lwtunnel_encap_del_ops(&ioam6_iptun_ops, LWTUNNEL_ENCAP_IOAM6); +} -- cgit