2023-01-18 21:42:20

by Dmitry Safonov

[permalink] [raw]
Subject: [PATCH v4 2/4] crypto/net/tcp: Use crypto_pool for TCP-MD5

Use crypto_pool API that was designed with tcp_md5sig_pool in mind.
The conversion to use crypto_pool will allow:
- to reuse ahash_request(s) for different users
- to allocate only one per-CPU scratch buffer rather than a new one for
each user
- to have a common API for net/ users that need ahash on RX/TX fast path

Signed-off-by: Dmitry Safonov <[email protected]>
---
include/net/tcp.h | 24 +++------
net/ipv4/Kconfig | 1 +
net/ipv4/tcp.c | 104 ++++++++++-----------------------------
net/ipv4/tcp_ipv4.c | 100 +++++++++++++++++++++----------------
net/ipv4/tcp_minisocks.c | 21 +++++---
net/ipv6/tcp_ipv6.c | 61 +++++++++++------------
6 files changed, 135 insertions(+), 176 deletions(-)

diff --git a/include/net/tcp.h b/include/net/tcp.h
index db9f828e9d1e..048057cb4c2e 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1664,12 +1664,6 @@ union tcp_md5sum_block {
#endif
};

-/* - pool: digest algorithm, hash description and scratch buffer */
-struct tcp_md5sig_pool {
- struct ahash_request *md5_req;
- void *scratch;
-};
-
/* - functions */
int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key,
const struct sock *sk, const struct sk_buff *skb);
@@ -1725,17 +1719,15 @@ tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
#define tcp_twsk_md5_key(twsk) NULL
#endif

-bool tcp_alloc_md5sig_pool(void);
-
-struct tcp_md5sig_pool *tcp_get_md5sig_pool(void);
-static inline void tcp_put_md5sig_pool(void)
-{
- local_bh_enable();
-}
+struct crypto_pool_ahash;
+int tcp_md5_alloc_crypto_pool(void);
+void tcp_md5_release_crypto_pool(void);
+void tcp_md5_add_crypto_pool(void);
+extern int tcp_md5_crypto_pool_id;

-int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *, const struct sk_buff *,
- unsigned int header_len);
-int tcp_md5_hash_key(struct tcp_md5sig_pool *hp,
+int tcp_md5_hash_skb_data(struct crypto_pool_ahash *hp,
+ const struct sk_buff *skb, unsigned int header_len);
+int tcp_md5_hash_key(struct crypto_pool_ahash *hp,
const struct tcp_md5sig_key *key);

/* From tcp_fastopen.c */
diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 2dfb12230f08..7e851ec0fc0e 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -744,6 +744,7 @@ config DEFAULT_TCP_CONG
config TCP_MD5SIG
bool "TCP: MD5 Signature Option support (RFC2385)"
select CRYPTO
+ select CRYPTO_POOL
select CRYPTO_MD5
help
RFC2385 specifies a method of giving MD5 protection to TCP sessions.
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index c567d5e8053e..e226771f5985 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -244,6 +244,7 @@
#define pr_fmt(fmt) "TCP: " fmt

#include <crypto/hash.h>
+#include <crypto/pool.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
@@ -4411,98 +4412,42 @@ int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
EXPORT_SYMBOL(tcp_getsockopt);

#ifdef CONFIG_TCP_MD5SIG
-static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool);
-static DEFINE_MUTEX(tcp_md5sig_mutex);
-static bool tcp_md5sig_pool_populated = false;
+int tcp_md5_crypto_pool_id = -1;
+EXPORT_SYMBOL(tcp_md5_crypto_pool_id);

-static void __tcp_alloc_md5sig_pool(void)
+int tcp_md5_alloc_crypto_pool(void)
{
- struct crypto_ahash *hash;
- int cpu;
-
- hash = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC);
- if (IS_ERR(hash))
- return;
-
- for_each_possible_cpu(cpu) {
- void *scratch = per_cpu(tcp_md5sig_pool, cpu).scratch;
- struct ahash_request *req;
-
- if (!scratch) {
- scratch = kmalloc_node(sizeof(union tcp_md5sum_block) +
- sizeof(struct tcphdr),
- GFP_KERNEL,
- cpu_to_node(cpu));
- if (!scratch)
- return;
- per_cpu(tcp_md5sig_pool, cpu).scratch = scratch;
- }
- if (per_cpu(tcp_md5sig_pool, cpu).md5_req)
- continue;
-
- req = ahash_request_alloc(hash, GFP_KERNEL);
- if (!req)
- return;
-
- ahash_request_set_callback(req, 0, NULL, NULL);
+ size_t scratch_size;
+ int ret;

- per_cpu(tcp_md5sig_pool, cpu).md5_req = req;
+ scratch_size = sizeof(union tcp_md5sum_block) + sizeof(struct tcphdr);
+ ret = crypto_pool_alloc_ahash("md5", scratch_size);
+ if (ret >= 0) {
+ tcp_md5_crypto_pool_id = ret;
+ return 0;
}
- /* before setting tcp_md5sig_pool_populated, we must commit all writes
- * to memory. See smp_rmb() in tcp_get_md5sig_pool()
- */
- smp_wmb();
- /* Paired with READ_ONCE() from tcp_alloc_md5sig_pool()
- * and tcp_get_md5sig_pool().
- */
- WRITE_ONCE(tcp_md5sig_pool_populated, true);
+ return ret;
}
+EXPORT_SYMBOL(tcp_md5_alloc_crypto_pool);

-bool tcp_alloc_md5sig_pool(void)
+void tcp_md5_release_crypto_pool(void)
{
- /* Paired with WRITE_ONCE() from __tcp_alloc_md5sig_pool() */
- if (unlikely(!READ_ONCE(tcp_md5sig_pool_populated))) {
- mutex_lock(&tcp_md5sig_mutex);
-
- if (!tcp_md5sig_pool_populated)
- __tcp_alloc_md5sig_pool();
-
- mutex_unlock(&tcp_md5sig_mutex);
- }
- /* Paired with WRITE_ONCE() from __tcp_alloc_md5sig_pool() */
- return READ_ONCE(tcp_md5sig_pool_populated);
+ crypto_pool_release(tcp_md5_crypto_pool_id);
}
-EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
+EXPORT_SYMBOL(tcp_md5_release_crypto_pool);

-
-/**
- * tcp_get_md5sig_pool - get md5sig_pool for this user
- *
- * We use percpu structure, so if we succeed, we exit with preemption
- * and BH disabled, to make sure another thread or softirq handling
- * wont try to get same context.
- */
-struct tcp_md5sig_pool *tcp_get_md5sig_pool(void)
+void tcp_md5_add_crypto_pool(void)
{
- local_bh_disable();
-
- /* Paired with WRITE_ONCE() from __tcp_alloc_md5sig_pool() */
- if (READ_ONCE(tcp_md5sig_pool_populated)) {
- /* coupled with smp_wmb() in __tcp_alloc_md5sig_pool() */
- smp_rmb();
- return this_cpu_ptr(&tcp_md5sig_pool);
- }
- local_bh_enable();
- return NULL;
+ crypto_pool_get(tcp_md5_crypto_pool_id);
}
-EXPORT_SYMBOL(tcp_get_md5sig_pool);
+EXPORT_SYMBOL(tcp_md5_add_crypto_pool);

-int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
+int tcp_md5_hash_skb_data(struct crypto_pool_ahash *hp,
const struct sk_buff *skb, unsigned int header_len)
{
struct scatterlist sg;
const struct tcphdr *tp = tcp_hdr(skb);
- struct ahash_request *req = hp->md5_req;
+ struct ahash_request *req = hp->req;
unsigned int i;
const unsigned int head_data_len = skb_headlen(skb) > header_len ?
skb_headlen(skb) - header_len : 0;
@@ -4536,16 +4481,17 @@ int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
}
EXPORT_SYMBOL(tcp_md5_hash_skb_data);

-int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key)
+int tcp_md5_hash_key(struct crypto_pool_ahash *hp,
+ const struct tcp_md5sig_key *key)
{
u8 keylen = READ_ONCE(key->keylen); /* paired with WRITE_ONCE() in tcp_md5_do_add */
struct scatterlist sg;

sg_init_one(&sg, key->key, keylen);
- ahash_request_set_crypt(hp->md5_req, &sg, NULL, keylen);
+ ahash_request_set_crypt(hp->req, &sg, NULL, keylen);

/* We use data_race() because tcp_md5_do_add() might change key->key under us */
- return data_race(crypto_ahash_update(hp->md5_req));
+ return data_race(crypto_ahash_update(hp->req));
}
EXPORT_SYMBOL(tcp_md5_hash_key);

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 8320d0ecb13a..53938e080c5f 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -79,6 +79,7 @@
#include <linux/btf_ids.h>

#include <crypto/hash.h>
+#include <crypto/pool.h>
#include <linux/scatterlist.h>

#include <trace/events/tcp.h>
@@ -1212,10 +1213,6 @@ static int __tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
key = sock_kmalloc(sk, sizeof(*key), gfp | __GFP_ZERO);
if (!key)
return -ENOMEM;
- if (!tcp_alloc_md5sig_pool()) {
- sock_kfree_s(sk, key, sizeof(*key));
- return -ENOMEM;
- }

memcpy(key->key, newkey, newkeylen);
key->keylen = newkeylen;
@@ -1237,8 +1234,13 @@ int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
struct tcp_sock *tp = tcp_sk(sk);

if (!rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk))) {
- if (tcp_md5sig_info_add(sk, GFP_KERNEL))
+ if (tcp_md5_alloc_crypto_pool())
+ return -ENOMEM;
+
+ if (tcp_md5sig_info_add(sk, GFP_KERNEL)) {
+ tcp_md5_release_crypto_pool();
return -ENOMEM;
+ }

if (!static_branch_inc(&tcp_md5_needed.key)) {
struct tcp_md5sig_info *md5sig;
@@ -1246,6 +1248,7 @@ int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
md5sig = rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk));
rcu_assign_pointer(tp->md5sig_info, NULL);
kfree_rcu(md5sig, rcu);
+ tcp_md5_release_crypto_pool();
return -EUSERS;
}
}
@@ -1262,8 +1265,12 @@ int tcp_md5_key_copy(struct sock *sk, const union tcp_md5_addr *addr,
struct tcp_sock *tp = tcp_sk(sk);

if (!rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk))) {
- if (tcp_md5sig_info_add(sk, sk_gfp_mask(sk, GFP_ATOMIC)))
+ tcp_md5_add_crypto_pool();
+
+ if (tcp_md5sig_info_add(sk, sk_gfp_mask(sk, GFP_ATOMIC))) {
+ tcp_md5_release_crypto_pool();
return -ENOMEM;
+ }

if (!static_key_fast_inc_not_disabled(&tcp_md5_needed.key.key)) {
struct tcp_md5sig_info *md5sig;
@@ -1272,6 +1279,7 @@ int tcp_md5_key_copy(struct sock *sk, const union tcp_md5_addr *addr,
net_warn_ratelimited("Too many TCP-MD5 keys in the system\n");
rcu_assign_pointer(tp->md5sig_info, NULL);
kfree_rcu(md5sig, rcu);
+ tcp_md5_release_crypto_pool();
return -EUSERS;
}
}
@@ -1371,7 +1379,7 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, int optname,
cmd.tcpm_key, cmd.tcpm_keylen);
}

-static int tcp_v4_md5_hash_headers(struct tcp_md5sig_pool *hp,
+static int tcp_v4_md5_hash_headers(struct crypto_pool_ahash *hp,
__be32 daddr, __be32 saddr,
const struct tcphdr *th, int nbytes)
{
@@ -1379,7 +1387,7 @@ static int tcp_v4_md5_hash_headers(struct tcp_md5sig_pool *hp,
struct scatterlist sg;
struct tcphdr *_th;

- bp = hp->scratch;
+ bp = hp->base.scratch;
bp->saddr = saddr;
bp->daddr = daddr;
bp->pad = 0;
@@ -1391,38 +1399,35 @@ static int tcp_v4_md5_hash_headers(struct tcp_md5sig_pool *hp,
_th->check = 0;

sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
- ahash_request_set_crypt(hp->md5_req, &sg, NULL,
+ ahash_request_set_crypt(hp->req, &sg, NULL,
sizeof(*bp) + sizeof(*th));
- return crypto_ahash_update(hp->md5_req);
+ return crypto_ahash_update(hp->req);
}

static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
__be32 daddr, __be32 saddr, const struct tcphdr *th)
{
- struct tcp_md5sig_pool *hp;
- struct ahash_request *req;
+ struct crypto_pool_ahash hp;

- hp = tcp_get_md5sig_pool();
- if (!hp)
- goto clear_hash_noput;
- req = hp->md5_req;
+ if (crypto_pool_start(tcp_md5_crypto_pool_id, &hp.base))
+ goto clear_hash_nostart;

- if (crypto_ahash_init(req))
+ if (crypto_ahash_init(hp.req))
goto clear_hash;
- if (tcp_v4_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2))
+ if (tcp_v4_md5_hash_headers(&hp, daddr, saddr, th, th->doff << 2))
goto clear_hash;
- if (tcp_md5_hash_key(hp, key))
+ if (tcp_md5_hash_key(&hp, key))
goto clear_hash;
- ahash_request_set_crypt(req, NULL, md5_hash, 0);
- if (crypto_ahash_final(req))
+ ahash_request_set_crypt(hp.req, NULL, md5_hash, 0);
+ if (crypto_ahash_final(hp.req))
goto clear_hash;

- tcp_put_md5sig_pool();
+ crypto_pool_end();
return 0;

clear_hash:
- tcp_put_md5sig_pool();
-clear_hash_noput:
+ crypto_pool_end();
+clear_hash_nostart:
memset(md5_hash, 0, 16);
return 1;
}
@@ -1431,8 +1436,7 @@ int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key,
const struct sock *sk,
const struct sk_buff *skb)
{
- struct tcp_md5sig_pool *hp;
- struct ahash_request *req;
+ struct crypto_pool_ahash hp;
const struct tcphdr *th = tcp_hdr(skb);
__be32 saddr, daddr;

@@ -1445,30 +1449,28 @@ int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key,
daddr = iph->daddr;
}

- hp = tcp_get_md5sig_pool();
- if (!hp)
- goto clear_hash_noput;
- req = hp->md5_req;
+ if (crypto_pool_start(tcp_md5_crypto_pool_id, &hp.base))
+ goto clear_hash_nostart;

- if (crypto_ahash_init(req))
+ if (crypto_ahash_init(hp.req))
goto clear_hash;

- if (tcp_v4_md5_hash_headers(hp, daddr, saddr, th, skb->len))
+ if (tcp_v4_md5_hash_headers(&hp, daddr, saddr, th, skb->len))
goto clear_hash;
- if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
+ if (tcp_md5_hash_skb_data(&hp, skb, th->doff << 2))
goto clear_hash;
- if (tcp_md5_hash_key(hp, key))
+ if (tcp_md5_hash_key(&hp, key))
goto clear_hash;
- ahash_request_set_crypt(req, NULL, md5_hash, 0);
- if (crypto_ahash_final(req))
+ ahash_request_set_crypt(hp.req, NULL, md5_hash, 0);
+ if (crypto_ahash_final(hp.req))
goto clear_hash;

- tcp_put_md5sig_pool();
+ crypto_pool_end();
return 0;

clear_hash:
- tcp_put_md5sig_pool();
-clear_hash_noput:
+ crypto_pool_end();
+clear_hash_nostart:
memset(md5_hash, 0, 16);
return 1;
}
@@ -2285,6 +2287,18 @@ static int tcp_v4_init_sock(struct sock *sk)
return 0;
}

+#ifdef CONFIG_TCP_MD5SIG
+static void tcp_md5sig_info_free_rcu(struct rcu_head *head)
+{
+ struct tcp_md5sig_info *md5sig;
+
+ md5sig = container_of(head, struct tcp_md5sig_info, rcu);
+ kfree(md5sig);
+ static_branch_slow_dec_deferred(&tcp_md5_needed);
+ tcp_md5_release_crypto_pool();
+}
+#endif
+
void tcp_v4_destroy_sock(struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
@@ -2309,10 +2323,12 @@ void tcp_v4_destroy_sock(struct sock *sk)
#ifdef CONFIG_TCP_MD5SIG
/* Clean up the MD5 key list, if any */
if (tp->md5sig_info) {
+ struct tcp_md5sig_info *md5sig;
+
+ md5sig = rcu_dereference_protected(tp->md5sig_info, 1);
tcp_clear_md5_list(sk);
- kfree_rcu(rcu_dereference_protected(tp->md5sig_info, 1), rcu);
- tp->md5sig_info = NULL;
- static_branch_slow_dec_deferred(&tcp_md5_needed);
+ call_rcu(&md5sig->rcu, tcp_md5sig_info_free_rcu);
+ rcu_assign_pointer(tp->md5sig_info, NULL);
}
#endif

diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index e002f2e1d4f2..6fbf2d4a4a97 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -261,10 +261,9 @@ static void tcp_time_wait_init(struct sock *sk, struct tcp_timewait_sock *tcptw)
tcptw->tw_md5_key = kmemdup(key, sizeof(*key), GFP_ATOMIC);
if (!tcptw->tw_md5_key)
return;
- if (!tcp_alloc_md5sig_pool())
- goto out_free;
if (!static_key_fast_inc_not_disabled(&tcp_md5_needed.key.key))
goto out_free;
+ tcp_md5_add_crypto_pool();
}
return;
out_free:
@@ -349,16 +348,26 @@ void tcp_time_wait(struct sock *sk, int state, int timeo)
}
EXPORT_SYMBOL(tcp_time_wait);

+#ifdef CONFIG_TCP_MD5SIG
+static void tcp_md5_twsk_free_rcu(struct rcu_head *head)
+{
+ struct tcp_md5sig_key *key;
+
+ key = container_of(head, struct tcp_md5sig_key, rcu);
+ kfree(key);
+ static_branch_slow_dec_deferred(&tcp_md5_needed);
+ tcp_md5_release_crypto_pool();
+}
+#endif
+
void tcp_twsk_destructor(struct sock *sk)
{
#ifdef CONFIG_TCP_MD5SIG
if (static_branch_unlikely(&tcp_md5_needed.key)) {
struct tcp_timewait_sock *twsk = tcp_twsk(sk);

- if (twsk->tw_md5_key) {
- kfree_rcu(twsk->tw_md5_key, rcu);
- static_branch_slow_dec_deferred(&tcp_md5_needed);
- }
+ if (twsk->tw_md5_key)
+ call_rcu(&twsk->tw_md5_key->rcu, tcp_md5_twsk_free_rcu);
}
#endif
}
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 11b736a76bd7..eb02224c7725 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -64,6 +64,7 @@
#include <linux/seq_file.h>

#include <crypto/hash.h>
+#include <crypto/pool.h>
#include <linux/scatterlist.h>

#include <trace/events/tcp.h>
@@ -672,7 +673,7 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
cmd.tcpm_key, cmd.tcpm_keylen);
}

-static int tcp_v6_md5_hash_headers(struct tcp_md5sig_pool *hp,
+static int tcp_v6_md5_hash_headers(struct crypto_pool_ahash *hp,
const struct in6_addr *daddr,
const struct in6_addr *saddr,
const struct tcphdr *th, int nbytes)
@@ -681,7 +682,7 @@ static int tcp_v6_md5_hash_headers(struct tcp_md5sig_pool *hp,
struct scatterlist sg;
struct tcphdr *_th;

- bp = hp->scratch;
+ bp = hp->base.scratch;
/* 1. TCP pseudo-header (RFC2460) */
bp->saddr = *saddr;
bp->daddr = *daddr;
@@ -693,39 +694,36 @@ static int tcp_v6_md5_hash_headers(struct tcp_md5sig_pool *hp,
_th->check = 0;

sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
- ahash_request_set_crypt(hp->md5_req, &sg, NULL,
+ ahash_request_set_crypt(hp->req, &sg, NULL,
sizeof(*bp) + sizeof(*th));
- return crypto_ahash_update(hp->md5_req);
+ return crypto_ahash_update(hp->req);
}

static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
const struct in6_addr *daddr, struct in6_addr *saddr,
const struct tcphdr *th)
{
- struct tcp_md5sig_pool *hp;
- struct ahash_request *req;
+ struct crypto_pool_ahash hp;

- hp = tcp_get_md5sig_pool();
- if (!hp)
- goto clear_hash_noput;
- req = hp->md5_req;
+ if (crypto_pool_start(tcp_md5_crypto_pool_id, &hp.base))
+ goto clear_hash_nostart;

- if (crypto_ahash_init(req))
+ if (crypto_ahash_init(hp.req))
goto clear_hash;
- if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2))
+ if (tcp_v6_md5_hash_headers(&hp, daddr, saddr, th, th->doff << 2))
goto clear_hash;
- if (tcp_md5_hash_key(hp, key))
+ if (tcp_md5_hash_key(&hp, key))
goto clear_hash;
- ahash_request_set_crypt(req, NULL, md5_hash, 0);
- if (crypto_ahash_final(req))
+ ahash_request_set_crypt(hp.req, NULL, md5_hash, 0);
+ if (crypto_ahash_final(hp.req))
goto clear_hash;

- tcp_put_md5sig_pool();
+ crypto_pool_end();
return 0;

clear_hash:
- tcp_put_md5sig_pool();
-clear_hash_noput:
+ crypto_pool_end();
+clear_hash_nostart:
memset(md5_hash, 0, 16);
return 1;
}
@@ -736,8 +734,7 @@ static int tcp_v6_md5_hash_skb(char *md5_hash,
const struct sk_buff *skb)
{
const struct in6_addr *saddr, *daddr;
- struct tcp_md5sig_pool *hp;
- struct ahash_request *req;
+ struct crypto_pool_ahash hp;
const struct tcphdr *th = tcp_hdr(skb);

if (sk) { /* valid for establish/request sockets */
@@ -749,30 +746,28 @@ static int tcp_v6_md5_hash_skb(char *md5_hash,
daddr = &ip6h->daddr;
}

- hp = tcp_get_md5sig_pool();
- if (!hp)
- goto clear_hash_noput;
- req = hp->md5_req;
+ if (crypto_pool_start(tcp_md5_crypto_pool_id, &hp.base))
+ goto clear_hash_nostart;

- if (crypto_ahash_init(req))
+ if (crypto_ahash_init(hp.req))
goto clear_hash;

- if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, skb->len))
+ if (tcp_v6_md5_hash_headers(&hp, daddr, saddr, th, skb->len))
goto clear_hash;
- if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
+ if (tcp_md5_hash_skb_data(&hp, skb, th->doff << 2))
goto clear_hash;
- if (tcp_md5_hash_key(hp, key))
+ if (tcp_md5_hash_key(&hp, key))
goto clear_hash;
- ahash_request_set_crypt(req, NULL, md5_hash, 0);
- if (crypto_ahash_final(req))
+ ahash_request_set_crypt(hp.req, NULL, md5_hash, 0);
+ if (crypto_ahash_final(hp.req))
goto clear_hash;

- tcp_put_md5sig_pool();
+ crypto_pool_end();
return 0;

clear_hash:
- tcp_put_md5sig_pool();
-clear_hash_noput:
+ crypto_pool_end();
+clear_hash_nostart:
memset(md5_hash, 0, 16);
return 1;
}
--
2.39.0


2023-01-19 10:10:18

by Herbert Xu

[permalink] [raw]
Subject: Re: [PATCH v4 2/4] crypto/net/tcp: Use crypto_pool for TCP-MD5

On Wed, Jan 18, 2023 at 09:41:09PM +0000, Dmitry Safonov wrote:
> Use crypto_pool API that was designed with tcp_md5sig_pool in mind.
> The conversion to use crypto_pool will allow:
> - to reuse ahash_request(s) for different users
> - to allocate only one per-CPU scratch buffer rather than a new one for
> each user
> - to have a common API for net/ users that need ahash on RX/TX fast path
>
> Signed-off-by: Dmitry Safonov <[email protected]>
> ---
> include/net/tcp.h | 24 +++------
> net/ipv4/Kconfig | 1 +
> net/ipv4/tcp.c | 104 ++++++++++-----------------------------
> net/ipv4/tcp_ipv4.c | 100 +++++++++++++++++++++----------------
> net/ipv4/tcp_minisocks.c | 21 +++++---
> net/ipv6/tcp_ipv6.c | 61 +++++++++++------------
> 6 files changed, 135 insertions(+), 176 deletions(-)

I think the best option for the legacy tcp md5 code is to move
md5 over to lib/crypto like sha1 and invoke it that way.

Going through the generic Crypto API when you use a single algorithm
in synchronous mode is pointless.

Thanks,
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt