diff options
| -rw-r--r-- | include/linux/ipv6.h | 3 | ||||
| -rw-r--r-- | include/linux/seg6_hmac.h | 6 | ||||
| -rw-r--r-- | include/net/seg6.h | 4 | ||||
| -rw-r--r-- | include/net/seg6_hmac.h | 62 | ||||
| -rw-r--r-- | include/uapi/linux/ipv6.h | 1 | ||||
| -rw-r--r-- | include/uapi/linux/seg6_hmac.h | 21 | ||||
| -rw-r--r-- | net/ipv6/Kconfig | 12 | ||||
| -rw-r--r-- | net/ipv6/Makefile | 1 | ||||
| -rw-r--r-- | net/ipv6/addrconf.c | 18 | ||||
| -rw-r--r-- | net/ipv6/seg6_hmac.c | 484 |
10 files changed, 612 insertions, 0 deletions
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index 68d3f71f0abf..93756585521f 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -65,6 +65,9 @@ struct ipv6_devconf { __s32 use_oif_addrs_only; __s32 keep_addr_on_down; __s32 seg6_enabled; +#ifdef CONFIG_IPV6_SEG6_HMAC + __s32 seg6_require_hmac; +#endif struct ctl_table_header *sysctl_header; }; diff --git a/include/linux/seg6_hmac.h b/include/linux/seg6_hmac.h new file mode 100644 index 000000000000..da437ebdc6cd --- /dev/null +++ b/include/linux/seg6_hmac.h @@ -0,0 +1,6 @@ +#ifndef _LINUX_SEG6_HMAC_H +#define _LINUX_SEG6_HMAC_H + +#include <uapi/linux/seg6_hmac.h> + +#endif diff --git a/include/net/seg6.h b/include/net/seg6.h index ff5da0ce83e9..4e0357517d79 100644 --- a/include/net/seg6.h +++ b/include/net/seg6.h @@ -18,6 +18,7 @@ #include <linux/ipv6.h> #include <net/lwtunnel.h> #include <linux/seg6.h> +#include <linux/rhashtable.h> static inline void update_csum_diff4(struct sk_buff *skb, __be32 from, __be32 to) @@ -41,6 +42,9 @@ static inline void update_csum_diff16(struct sk_buff *skb, __be32 *from, struct seg6_pernet_data { struct mutex lock; struct in6_addr __rcu *tun_src; +#ifdef CONFIG_IPV6_SEG6_HMAC + struct rhashtable hmac_infos; +#endif }; static inline struct seg6_pernet_data *seg6_pernet(struct net *net) diff --git a/include/net/seg6_hmac.h b/include/net/seg6_hmac.h new file mode 100644 index 000000000000..69c3a106056b --- /dev/null +++ b/include/net/seg6_hmac.h @@ -0,0 +1,62 @@ +/* + * 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 _NET_SEG6_HMAC_H +#define _NET_SEG6_HMAC_H + +#include <net/flow.h> +#include <net/ip6_fib.h> +#include <net/sock.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <linux/route.h> +#include <net/seg6.h> +#include <linux/seg6_hmac.h> +#include <linux/rhashtable.h> + +#define SEG6_HMAC_MAX_DIGESTSIZE 160 +#define SEG6_HMAC_RING_SIZE 256 + +struct seg6_hmac_info { + struct rhash_head node; + struct rcu_head rcu; + + u32 hmackeyid; + char secret[SEG6_HMAC_SECRET_LEN]; + u8 slen; + u8 alg_id; +}; + +struct seg6_hmac_algo { + u8 alg_id; + char name[64]; + struct crypto_shash * __percpu *tfms; + struct shash_desc * __percpu *shashs; +}; + +extern int seg6_hmac_compute(struct seg6_hmac_info *hinfo, + struct ipv6_sr_hdr *hdr, struct in6_addr *saddr, + u8 *output); +extern struct seg6_hmac_info *seg6_hmac_info_lookup(struct net *net, u32 key); +extern int seg6_hmac_info_add(struct net *net, u32 key, + struct seg6_hmac_info *hinfo); +extern int seg6_hmac_info_del(struct net *net, u32 key); +extern int seg6_push_hmac(struct net *net, struct in6_addr *saddr, + struct ipv6_sr_hdr *srh); +extern bool seg6_hmac_validate_skb(struct sk_buff *skb); +extern int seg6_hmac_init(void); +extern void seg6_hmac_exit(void); +extern int seg6_hmac_net_init(struct net *net); +extern void seg6_hmac_net_exit(struct net *net); + +#endif diff --git a/include/uapi/linux/ipv6.h b/include/uapi/linux/ipv6.h index 7ff1d654e333..53561be1ac21 100644 --- a/include/uapi/linux/ipv6.h +++ b/include/uapi/linux/ipv6.h @@ -180,6 +180,7 @@ enum { DEVCONF_KEEP_ADDR_ON_DOWN, DEVCONF_RTR_SOLICIT_MAX_INTERVAL, DEVCONF_SEG6_ENABLED, + DEVCONF_SEG6_REQUIRE_HMAC, DEVCONF_MAX }; diff --git a/include/uapi/linux/seg6_hmac.h b/include/uapi/linux/seg6_hmac.h new file mode 100644 index 000000000000..b652dfd51bc5 --- /dev/null +++ b/include/uapi/linux/seg6_hmac.h @@ -0,0 +1,21 @@ +#ifndef _UAPI_LINUX_SEG6_HMAC_H +#define _UAPI_LINUX_SEG6_HMAC_H + +#include <linux/seg6.h> + +#define SEG6_HMAC_SECRET_LEN 64 +#define SEG6_HMAC_FIELD_LEN 32 + +struct sr6_tlv_hmac { + struct sr6_tlv tlvhdr; + __u16 reserved; + __be32 hmackeyid; + __u8 hmac[SEG6_HMAC_FIELD_LEN]; +}; + +enum { + SEG6_HMAC_ALGO_SHA1 = 1, + SEG6_HMAC_ALGO_SHA256 = 2, +}; + +#endif diff --git a/net/ipv6/Kconfig b/net/ipv6/Kconfig index 1123a001d729..0f00811a785f 100644 --- a/net/ipv6/Kconfig +++ b/net/ipv6/Kconfig @@ -301,4 +301,16 @@ config IPV6_SEG6_INLINE If unsure, say N. +config IPV6_SEG6_HMAC + bool "IPv6: Segment Routing HMAC support" + depends on IPV6 + select CRYPTO_HMAC + select CRYPTO_SHA1 + select CRYPTO_SHA256 + ---help--- + Support for HMAC signature generation and verification + of SR-enabled packets. + + If unsure, say N. + endif # IPV6 diff --git a/net/ipv6/Makefile b/net/ipv6/Makefile index 59ee92fb3689..129cad2ba960 100644 --- a/net/ipv6/Makefile +++ b/net/ipv6/Makefile @@ -44,6 +44,7 @@ obj-$(CONFIG_IPV6_SIT) += sit.o obj-$(CONFIG_IPV6_TUNNEL) += ip6_tunnel.o obj-$(CONFIG_IPV6_GRE) += ip6_gre.o obj-$(CONFIG_IPV6_FOU) += fou6.o +obj-$(CONFIG_IPV6_SEG6_HMAC) += seg6_hmac.o obj-y += addrconf_core.o exthdrs_core.o ip6_checksum.o ip6_icmp.o obj-$(CONFIG_INET) += output_core.o protocol.o $(ipv6-offload) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 2ac6cb460af0..86219c0a0104 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -239,6 +239,9 @@ static struct ipv6_devconf ipv6_devconf __read_mostly = { .ignore_routes_with_linkdown = 0, .keep_addr_on_down = 0, .seg6_enabled = 0, +#ifdef CONFIG_IPV6_SEG6_HMAC + .seg6_require_hmac = 0, +#endif }; static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = { @@ -286,6 +289,9 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = { .ignore_routes_with_linkdown = 0, .keep_addr_on_down = 0, .seg6_enabled = 0, +#ifdef CONFIG_IPV6_SEG6_HMAC + .seg6_require_hmac = 0, +#endif }; /* Check if a valid qdisc is available */ @@ -4947,6 +4953,9 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf, array[DEVCONF_DROP_UNSOLICITED_NA] = cnf->drop_unsolicited_na; array[DEVCONF_KEEP_ADDR_ON_DOWN] = cnf->keep_addr_on_down; array[DEVCONF_SEG6_ENABLED] = cnf->seg6_enabled; +#ifdef CONFIG_IPV6_SEG6_HMAC + array[DEVCONF_SEG6_REQUIRE_HMAC] = cnf->seg6_require_hmac; +#endif } static inline size_t inet6_ifla6_size(void) @@ -6045,6 +6054,15 @@ static const struct ctl_table addrconf_sysctl[] = { .mode = 0644, .proc_handler = proc_dointvec, }, +#ifdef CONFIG_IPV6_SEG6_HMAC + { + .procname = "seg6_require_hmac", + .data = &ipv6_devconf.seg6_require_hmac, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, +#endif { /* sentinel */ } diff --git a/net/ipv6/seg6_hmac.c b/net/ipv6/seg6_hmac.c new file mode 100644 index 000000000000..ef1c8a46e7ac --- /dev/null +++ b/net/ipv6/seg6_hmac.c @@ -0,0 +1,484 @@ +/* + * SR-IPv6 implementation -- HMAC functions + * + * 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/errno.h> +#include <linux/types.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/net.h> +#include <linux/netdevice.h> +#include <linux/in6.h> +#include <linux/icmpv6.h> +#include <linux/mroute6.h> +#include <linux/slab.h> + +#include <linux/netfilter.h> +#include <linux/netfilter_ipv6.h> + +#include <net/sock.h> +#include <net/snmp.h> + +#include <net/ipv6.h> +#include <net/protocol.h> +#include <net/transp_v6.h> +#include <net/rawv6.h> +#include <net/ndisc.h> +#include <net/ip6_route.h> +#include <net/addrconf.h> +#include <net/xfrm.h> + +#include <linux/cryptohash.h> +#include <crypto/hash.h> +#include <crypto/sha.h> +#include <net/seg6.h> +#include <net/genetlink.h> +#include <net/seg6_hmac.h> +#include <linux/random.h> + +static char * __percpu *hmac_ring; + +static int seg6_hmac_cmpfn(struct rhashtable_compare_arg *arg, const void *obj) +{ + const struct seg6_hmac_info *hinfo = obj; + + return (hinfo->hmackeyid != *(__u32 *)arg->key); +} + +static inline void seg6_hinfo_release(struct seg6_hmac_info *hinfo) +{ + kfree_rcu(hinfo, rcu); +} + +static void seg6_free_hi(void *ptr, void *arg) +{ + struct seg6_hmac_info *hinfo = (struct seg6_hmac_info *)ptr; + + if (hinfo) + seg6_hinfo_release(hinfo); +} + +static const struct rhashtable_params rht_params = { + .head_offset = offsetof(struct seg6_hmac_info, node), + .key_offset = offsetof(struct seg6_hmac_info, hmackeyid), + .key_len = sizeof(u32), + .automatic_shrinking = true, + .obj_cmpfn = seg6_hmac_cmpfn, +}; + +static struct seg6_hmac_algo hmac_algos[] = { + { + .alg_id = SEG6_HMAC_ALGO_SHA1, + .name = "hmac(sha1)", + }, + { + .alg_id = SEG6_HMAC_ALGO_SHA256, + .name = "hmac(sha256)", + }, +}; + +static struct sr6_tlv_hmac *seg6_get_tlv_hmac(struct ipv6_sr_hdr *srh) +{ + struct sr6_tlv_hmac *tlv; + + if (srh->hdrlen < (srh->first_segment + 1) * 2 + 5) + return NULL; + + if (!sr_has_hmac(srh)) + return NULL; + + tlv = (struct sr6_tlv_hmac *) + ((char *)srh + ((srh->hdrlen + 1) << 3) - 40); + + if (tlv->tlvhdr.type != SR6_TLV_HMAC || tlv->tlvhdr.len != 38) + return NULL; + + return tlv; +} + +static struct seg6_hmac_algo *__hmac_get_algo(u8 alg_id) +{ + struct seg6_hmac_algo *algo; + int i, alg_count; + + alg_count = sizeof(hmac_algos) / sizeof(struct seg6_hmac_algo); + for (i = 0; i < alg_count; i++) { + algo = &hmac_algos[i]; + if (algo->alg_id == alg_id) + return algo; + } + + return NULL; +} + +static int __do_hmac(struct seg6_hmac_info *hinfo, const char *text, u8 psize, + u8 *output, int outlen) +{ + struct seg6_hmac_algo *algo; + struct crypto_shash *tfm; + struct shash_desc *shash; + int ret, dgsize; + + algo = __hmac_get_algo(hinfo->alg_id); + if (!algo) + return -ENOENT; + + tfm = *this_cpu_ptr(algo->tfms); + + dgsize = crypto_shash_digestsize(tfm); + if (dgsize > outlen) { + pr_debug("sr-ipv6: __do_hmac: digest size too big (%d / %d)\n", + dgsize, outlen); + return -ENOMEM; + } + + ret = crypto_shash_setkey(tfm, hinfo->secret, hinfo->slen); + if (ret < 0) { + pr_debug("sr-ipv6: crypto_shash_setkey failed: err %d\n", ret); + goto failed; + } + + shash = *this_cpu_ptr(algo->shashs); + shash->tfm = tfm; + + ret = crypto_shash_digest(shash, text, psize, output); + if (ret < 0) { + pr_debug("sr-ipv6: crypto_shash_digest failed: err %d\n", ret); + goto failed; + } + + return dgsize; + +failed: + return ret; +} + +int seg6_hmac_compute(struct seg6_hmac_info *hinfo, struct ipv6_sr_hdr *hdr, + struct in6_addr *saddr, u8 *output) +{ + __be32 hmackeyid = cpu_to_be32(hinfo->hmackeyid); + u8 tmp_out[SEG6_HMAC_MAX_DIGESTSIZE]; + int plen, i, dgsize, wrsize; + char *ring, *off; + + /* a 160-byte buffer for digest output allows to store highest known + * hash function (RadioGatun) with up to 1216 bits + */ + + /* saddr(16) + first_seg(1) + cleanup(1) + keyid(4) + seglist(16n) */ + plen = 16 + 1 + 1 + 4 + (hdr->first_segment + 1) * 16; + + /* this limit allows for 14 segments */ + if (plen >= SEG6_HMAC_RING_SIZE) + return -EMSGSIZE; + + /* Let's build the HMAC text on the ring buffer. The text is composed + * as follows, in order: + * + * 1. Source IPv6 address (128 bits) + * 2. first_segment value (8 bits) + * 3. cleanup flag (8 bits: highest bit is cleanup value, others are 0) + * 4. HMAC Key ID (32 bits) + * 5. All segments in the segments list (n * 128 bits) + */ + + local_bh_disable(); + ring = *this_cpu_ptr(hmac_ring); + off = ring; + + /* source address */ + memcpy(off, saddr, 16); + off += 16; + + /* first_segment value */ + *off++ = hdr->first_segment; + + /* cleanup flag */ + *off++ = !!(sr_has_cleanup(hdr)) << 7; + + /* HMAC Key ID */ + memcpy(off, &hmackeyid, 4); + off += 4; + + /* all segments in the list */ + for (i = 0; i < hdr->first_segment + 1; i++) { + memcpy(off, hdr->segments + i, 16); + off += 16; + } + + dgsize = __do_hmac(hinfo, ring, plen, tmp_out, + SEG6_HMAC_MAX_DIGESTSIZE); + local_bh_enable(); + + if (dgsize < 0) + return dgsize; + + wrsize = SEG6_HMAC_FIELD_LEN; + if (wrsize > dgsize) + wrsize = dgsize; + + memset(output, 0, SEG6_HMAC_FIELD_LEN); + memcpy(output, tmp_out, wrsize); + + return 0; +} +EXPORT_SYMBOL(seg6_hmac_compute); + +/* checks if an incoming SR-enabled packet's HMAC status matches + * the incoming policy. + * + * called with rcu_read_lock() + */ +bool seg6_hmac_validate_skb(struct sk_buff *skb) +{ + u8 hmac_output[SEG6_HMAC_FIELD_LEN]; + struct net *net = dev_net(skb->dev); + struct seg6_hmac_info *hinfo; + struct sr6_tlv_hmac *tlv; + struct ipv6_sr_hdr *srh; + struct inet6_dev *idev; + + idev = __in6_dev_get(skb->dev); + + srh = (struct ipv6_sr_hdr *)skb_transport_header(skb); + + tlv = seg6_get_tlv_hmac(srh); + + /* mandatory check but no tlv */ + if (idev->cnf.seg6_require_hmac > 0 && !tlv) + return false; + + /* no check */ + if (idev->cnf.seg6_require_hmac < 0) + return true; + + /* check only if present */ + if (idev->cnf.seg6_require_hmac == 0 && !tlv) + return true; + + /* now, seg6_require_hmac >= 0 && tlv */ + + hinfo = seg6_hmac_info_lookup(net, be32_to_cpu(tlv->hmackeyid)); + if (!hinfo) + return false; + + if (seg6_hmac_compute(hinfo, srh, &ipv6_hdr(skb)->saddr, hmac_output)) + return false; + + if (memcmp(hmac_output, tlv->hmac, SEG6_HMAC_FIELD_LEN) != 0) + return false; + + return true; +} +EXPORT_SYMBOL(seg6_hmac_validate_skb); + +/* called with rcu_read_lock() */ +struct seg6_hmac_info *seg6_hmac_info_lookup(struct net *net, u32 key) +{ + struct seg6_pernet_data *sdata = seg6_pernet(net); + struct seg6_hmac_info *hinfo; + + hinfo = rhashtable_lookup_fast(&sdata->hmac_infos, &key, rht_params); + + return hinfo; +} +EXPORT_SYMBOL(seg6_hmac_info_lookup); + +int seg6_hmac_info_add(struct net *net, u32 key, struct seg6_hmac_info *hinfo) +{ + struct seg6_pernet_data *sdata = seg6_pernet(net); + int err; + + err = rhashtable_lookup_insert_fast(&sdata->hmac_infos, &hinfo->node, + rht_params); + + return err; +} +EXPORT_SYMBOL(seg6_hmac_info_add); + +int seg6_hmac_info_del(struct net *net, u32 key) +{ + struct seg6_pernet_data *sdata = seg6_pernet(net); + struct seg6_hmac_info *hinfo; + int err = -ENOENT; + + hinfo = rhashtable_lookup_fast(&sdata->hmac_infos, &key, rht_params); + if (!hinfo) + goto out; + + err = rhashtable_remove_fast(&sdata->hmac_infos, &hinfo->node, + rht_params); + if (err) + goto out; + + seg6_hinfo_release(hinfo); + +out: + return err; +} +EXPORT_SYMBOL(seg6_hmac_info_del); + +int seg6_push_hmac(struct net *net, struct in6_addr *saddr, + struct ipv6_sr_hdr *srh) +{ + struct seg6_hmac_info *hinfo; + struct sr6_tlv_hmac *tlv; + int err = -ENOENT; + + tlv = seg6_get_tlv_hmac(srh); + if (!tlv) + return -EINVAL; + + rcu_read_lock(); + + hinfo = seg6_hmac_info_lookup(net, be32_to_cpu(tlv->hmackeyid)); + if (!hinfo) + goto out; + + memset(tlv->hmac, 0, SEG6_HMAC_FIELD_LEN); + err = seg6_hmac_compute(hinfo, srh, saddr, tlv->hmac); + +out: + rcu_read_unlock(); + return err; +} +EXPORT_SYMBOL(seg6_push_hmac); + +static int seg6_hmac_init_ring(void) +{ + int i; + + hmac_ring = alloc_percpu(char *); + + if (!hmac_ring) + return -ENOMEM; + + for_each_possible_cpu(i) { + char *ring = kzalloc(SEG6_HMAC_RING_SIZE, GFP_KERNEL); + + if (!ring) + return -ENOMEM; + + *per_cpu_ptr(hmac_ring, i) = ring; + } + + return 0; +} + +static int seg6_hmac_init_algo(void) +{ + struct seg6_hmac_algo *algo; + struct crypto_shash *tfm; + struct shash_desc *shash; + int i, alg_count, cpu; + + alg_count = sizeof(hmac_algos) / sizeof(struct seg6_hmac_algo); + + for (i = 0; i < alg_count; i++) { + struct crypto_shash **p_tfm; + int shsize; + + algo = &hmac_algos[i]; + algo->tfms = alloc_percpu(struct crypto_shash *); + if (!algo->tfms) + return -ENOMEM; + + for_each_possible_cpu(cpu) { + tfm = crypto_alloc_shash(algo->name, 0, GFP_KERNEL); + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + p_tfm = per_cpu_ptr(algo->tfms, cpu); + *p_tfm = tfm; + } + + p_tfm = this_cpu_ptr(algo->tfms); + tfm = *p_tfm; + + shsize = sizeof(*shash) + crypto_shash_descsize(tfm); + + algo->shashs = alloc_percpu(struct shash_desc *); + if (!algo->shashs) + return -ENOMEM; + + for_each_possible_cpu(cpu) { + shash = kzalloc(shsize, GFP_KERNEL); + if (!shash) + return -ENOMEM; + *per_cpu_ptr(algo->shashs, cpu) = shash; + } + } + + return 0; +} + +int __init seg6_hmac_init(void) +{ + int ret; + + ret = seg6_hmac_init_ring(); + if (ret < 0) + goto out; + + ret = seg6_hmac_init_algo(); + +out: + return ret; +} +EXPORT_SYMBOL(seg6_hmac_init); + +int __net_init seg6_hmac_net_init(struct net *net) +{ + struct seg6_pernet_data *sdata = seg6_pernet(net); + + rhashtable_init(&sdata->hmac_infos, &rht_params); + + return 0; +} +EXPORT_SYMBOL(seg6_hmac_net_init); + +void seg6_hmac_exit(void) +{ + struct seg6_hmac_algo *algo = NULL; + int i, alg_count, cpu; + + for_each_possible_cpu(i) { + char *ring = *per_cpu_ptr(hmac_ring, i); + + kfree(ring); + } + free_percpu(hmac_ring); + + alg_count = sizeof(hmac_algos) / sizeof(struct seg6_hmac_algo); + for (i = 0; i < alg_count; i++) { + algo = &hmac_algos[i]; + for_each_possible_cpu(cpu) { + struct crypto_shash *tfm; + struct shash_desc *shash; + + shash = *per_cpu_ptr(algo->shashs, cpu); + kfree(shash); + tfm = *per_cpu_ptr(algo->tfms, cpu); + crypto_free_shash(tfm); + } + free_percpu(algo->tfms); + free_percpu(algo->shashs); + } +} +EXPORT_SYMBOL(seg6_hmac_exit); + +void __net_exit seg6_hmac_net_exit(struct net *net) +{ + struct seg6_pernet_data *sdata = seg6_pernet(net); + + rhashtable_free_and_destroy(&sdata->hmac_infos, seg6_free_hi, NULL); +} +EXPORT_SYMBOL(seg6_hmac_net_exit); |