]> git.ipfire.org Git - thirdparty/kernel/stable.git/commitdiff
ipv6: sr: Use HMAC-SHA1 and HMAC-SHA256 library functions
authorEric Biggers <ebiggers@kernel.org>
Sun, 24 Aug 2025 01:36:43 +0000 (21:36 -0400)
committerJakub Kicinski <kuba@kernel.org>
Wed, 27 Aug 2025 01:11:29 +0000 (18:11 -0700)
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 <ebiggers@kernel.org>
Link: https://patch.msgid.link/20250824013644.71928-2-ebiggers@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
include/net/seg6_hmac.h
net/ipv6/Kconfig
net/ipv6/seg6.c
net/ipv6/seg6_hmac.c

index 24f733b3e3fe9c4afa14a017124026b36815630d..3fe4123dbbf0aa5db8e090de53ace01fe2ef5acc 100644 (file)
@@ -19,7 +19,6 @@
 #include <linux/seg6_hmac.h>
 #include <linux/rhashtable-types.h>
 
-#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
index 1c9c686d9522f7864130f9ba8f2197fff252f5f7..b8f9a8c0302ee816fd0affb36eac05db047914a6 100644 (file)
@@ -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.
index 180da19c148c1d4a24ca9b117b4ad60037cc066c..a5c4c629b788cc66bc23bbf99fd06f3f6db9704d 100644 (file)
@@ -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);
index fd58426f222beb95938e8a887025c8a315f45186..61f6019df55b67fadfc9dec057f9d3491a7df70b 100644 (file)
@@ -16,7 +16,6 @@
 #include <linux/in6.h>
 #include <linux/icmpv6.h>
 #include <linux/mroute6.h>
-#include <linux/slab.h>
 #include <linux/rhashtable.h>
 
 #include <linux/netfilter.h>
@@ -34,7 +33,8 @@
 #include <net/addrconf.h>
 #include <net/xfrm.h>
 
-#include <crypto/hash.h>
+#include <crypto/sha1.h>
+#include <crypto/sha2.h>
 #include <crypto/utils.h>
 #include <net/seg6.h>
 #include <net/genetlink.h>
@@ -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);