From: Eric Biggers Date: Sun, 24 Aug 2025 01:36:43 +0000 (-0400) Subject: ipv6: sr: Use HMAC-SHA1 and HMAC-SHA256 library functions X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=095928e7d80186c524013a5b5d54889fa2ec1eaa;p=thirdparty%2Fkernel%2Fstable.git ipv6: sr: Use HMAC-SHA1 and HMAC-SHA256 library functions Use the HMAC-SHA1 and HMAC-SHA256 library functions instead of crypto_shash. This is simpler and faster. Pre-allocating per-CPU hash transformation objects and descriptors is no longer needed, and a microbenchmark on x86_64 shows seg6_hmac_compute() (with HMAC-SHA256) dropping from ~2494 cycles to ~1978 cycles, a 20% improvement. Signed-off-by: Eric Biggers Link: https://patch.msgid.link/20250824013644.71928-2-ebiggers@kernel.org Signed-off-by: Jakub Kicinski --- diff --git a/include/net/seg6_hmac.h b/include/net/seg6_hmac.h index 24f733b3e3fe9..3fe4123dbbf0a 100644 --- a/include/net/seg6_hmac.h +++ b/include/net/seg6_hmac.h @@ -19,7 +19,6 @@ #include #include -#define SEG6_HMAC_MAX_DIGESTSIZE 160 #define SEG6_HMAC_RING_SIZE 256 struct seg6_hmac_info { @@ -32,13 +31,6 @@ struct seg6_hmac_info { 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); @@ -50,13 +42,9 @@ 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); #ifdef CONFIG_IPV6_SEG6_HMAC -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); #else -static inline int seg6_hmac_init(void) { return 0; } -static inline void seg6_hmac_exit(void) {} static inline int seg6_hmac_net_init(struct net *net) { return 0; } static inline void seg6_hmac_net_exit(struct net *net) {} #endif diff --git a/net/ipv6/Kconfig b/net/ipv6/Kconfig index 1c9c686d9522f..b8f9a8c0302ee 100644 --- a/net/ipv6/Kconfig +++ b/net/ipv6/Kconfig @@ -304,10 +304,9 @@ config IPV6_SEG6_LWTUNNEL config IPV6_SEG6_HMAC bool "IPv6: Segment Routing HMAC support" depends on IPV6 - select CRYPTO - select CRYPTO_HMAC - select CRYPTO_SHA1 - select CRYPTO_SHA256 + select CRYPTO_LIB_SHA1 + select CRYPTO_LIB_SHA256 + select CRYPTO_LIB_UTILS help Support for HMAC signature generation and verification of SR-enabled packets. diff --git a/net/ipv6/seg6.c b/net/ipv6/seg6.c index 180da19c148c1..a5c4c629b788c 100644 --- a/net/ipv6/seg6.c +++ b/net/ipv6/seg6.c @@ -522,16 +522,10 @@ int __init seg6_init(void) if (err) goto out_unregister_iptun; - err = seg6_hmac_init(); - if (err) - goto out_unregister_seg6; - pr_info("Segment Routing with IPv6\n"); out: return err; -out_unregister_seg6: - seg6_local_exit(); out_unregister_iptun: seg6_iptunnel_exit(); out_unregister_genl: @@ -543,7 +537,6 @@ out_unregister_pernet: void seg6_exit(void) { - seg6_hmac_exit(); seg6_local_exit(); seg6_iptunnel_exit(); genl_unregister_family(&seg6_genl_family); diff --git a/net/ipv6/seg6_hmac.c b/net/ipv6/seg6_hmac.c index fd58426f222be..61f6019df55b6 100644 --- a/net/ipv6/seg6_hmac.c +++ b/net/ipv6/seg6_hmac.c @@ -16,7 +16,6 @@ #include #include #include -#include #include #include @@ -34,7 +33,8 @@ #include #include -#include +#include +#include #include #include #include @@ -78,17 +78,6 @@ static const struct rhashtable_params rht_params = { .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; @@ -108,75 +97,13 @@ static struct sr6_tlv_hmac *seg6_get_tlv_hmac(struct ipv6_sr_hdr *srh) return tlv; } -static struct seg6_hmac_algo *__hmac_get_algo(u8 alg_id) -{ - struct seg6_hmac_algo *algo; - int i, alg_count; - - alg_count = ARRAY_SIZE(hmac_algos); - 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; + int plen, i, ret = 0; 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) + flags(1) + keyid(4) + seglist(16n) */ plen = 16 + 1 + 1 + 4 + (hdr->first_segment + 1) * 16; @@ -219,22 +146,26 @@ int seg6_hmac_compute(struct seg6_hmac_info *hinfo, struct ipv6_sr_hdr *hdr, off += 16; } - dgsize = __do_hmac(hinfo, ring, plen, tmp_out, - SEG6_HMAC_MAX_DIGESTSIZE); + switch (hinfo->alg_id) { + case SEG6_HMAC_ALGO_SHA1: + hmac_sha1_usingrawkey(hinfo->secret, hinfo->slen, ring, plen, + output); + static_assert(SEG6_HMAC_FIELD_LEN > SHA1_DIGEST_SIZE); + memset(&output[SHA1_DIGEST_SIZE], 0, + SEG6_HMAC_FIELD_LEN - SHA1_DIGEST_SIZE); + break; + case SEG6_HMAC_ALGO_SHA256: + hmac_sha256_usingrawkey(hinfo->secret, hinfo->slen, ring, plen, + output); + static_assert(SEG6_HMAC_FIELD_LEN == SHA256_DIGEST_SIZE); + break; + default: + ret = -ENOENT; + break; + } local_unlock_nested_bh(&hmac_storage.bh_lock); 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; + return ret; } EXPORT_SYMBOL(seg6_hmac_compute); @@ -305,8 +236,13 @@ 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; - if (!__hmac_get_algo(hinfo->alg_id)) + switch (hinfo->alg_id) { + case SEG6_HMAC_ALGO_SHA1: + case SEG6_HMAC_ALGO_SHA256: + break; + default: return -EINVAL; + } err = rhashtable_lookup_insert_fast(&sdata->hmac_infos, &hinfo->node, rht_params); @@ -363,65 +299,6 @@ out: } EXPORT_SYMBOL(seg6_push_hmac); -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; - int ret = -ENOMEM; - - alg_count = ARRAY_SIZE(hmac_algos); - - 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) - goto error_out; - - for_each_possible_cpu(cpu) { - tfm = crypto_alloc_shash(algo->name, 0, 0); - if (IS_ERR(tfm)) { - ret = PTR_ERR(tfm); - goto error_out; - } - p_tfm = per_cpu_ptr(algo->tfms, cpu); - *p_tfm = tfm; - } - - p_tfm = raw_cpu_ptr(algo->tfms); - tfm = *p_tfm; - - shsize = sizeof(*shash) + crypto_shash_descsize(tfm); - - algo->shashs = alloc_percpu(struct shash_desc *); - if (!algo->shashs) - goto error_out; - - for_each_possible_cpu(cpu) { - shash = kzalloc_node(shsize, GFP_KERNEL, - cpu_to_node(cpu)); - if (!shash) - goto error_out; - *per_cpu_ptr(algo->shashs, cpu) = shash; - } - } - - return 0; - -error_out: - seg6_hmac_exit(); - return ret; -} - -int __init seg6_hmac_init(void) -{ - return seg6_hmac_init_algo(); -} - int __net_init seg6_hmac_net_init(struct net *net) { struct seg6_pernet_data *sdata = seg6_pernet(net); @@ -429,36 +306,6 @@ int __net_init seg6_hmac_net_init(struct net *net) return rhashtable_init(&sdata->hmac_infos, &rht_params); } -void seg6_hmac_exit(void) -{ - struct seg6_hmac_algo *algo = NULL; - struct crypto_shash *tfm; - struct shash_desc *shash; - int i, alg_count, cpu; - - alg_count = ARRAY_SIZE(hmac_algos); - for (i = 0; i < alg_count; i++) { - algo = &hmac_algos[i]; - - if (algo->shashs) { - for_each_possible_cpu(cpu) { - shash = *per_cpu_ptr(algo->shashs, cpu); - kfree(shash); - } - free_percpu(algo->shashs); - } - - if (algo->tfms) { - for_each_possible_cpu(cpu) { - tfm = *per_cpu_ptr(algo->tfms, cpu); - crypto_free_shash(tfm); - } - free_percpu(algo->tfms); - } - } -} -EXPORT_SYMBOL(seg6_hmac_exit); - void __net_exit seg6_hmac_net_exit(struct net *net) { struct seg6_pernet_data *sdata = seg6_pernet(net);