From 85c675d0d09a45a135bddd15d7b385f8758c32fb Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 18 May 2024 19:35:05 +0200 Subject: Adding upstream version 6.7.7. Signed-off-by: Daniel Baumann --- net/ipv4/tcp_sigpool.c | 357 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 357 insertions(+) create mode 100644 net/ipv4/tcp_sigpool.c (limited to 'net/ipv4/tcp_sigpool.c') diff --git a/net/ipv4/tcp_sigpool.c b/net/ipv4/tcp_sigpool.c new file mode 100644 index 000000000..8512cb09e --- /dev/null +++ b/net/ipv4/tcp_sigpool.c @@ -0,0 +1,357 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +#include +#include +#include +#include +#include +#include +#include +#include + +static size_t __scratch_size; +static DEFINE_PER_CPU(void __rcu *, sigpool_scratch); + +struct sigpool_entry { + struct crypto_ahash *hash; + const char *alg; + struct kref kref; + uint16_t needs_key:1, + reserved:15; +}; + +#define CPOOL_SIZE (PAGE_SIZE / sizeof(struct sigpool_entry)) +static struct sigpool_entry cpool[CPOOL_SIZE]; +static unsigned int cpool_populated; +static DEFINE_MUTEX(cpool_mutex); + +/* Slow-path */ +struct scratches_to_free { + struct rcu_head rcu; + unsigned int cnt; + void *scratches[]; +}; + +static void free_old_scratches(struct rcu_head *head) +{ + struct scratches_to_free *stf; + + stf = container_of(head, struct scratches_to_free, rcu); + while (stf->cnt--) + kfree(stf->scratches[stf->cnt]); + kfree(stf); +} + +/** + * sigpool_reserve_scratch - re-allocates scratch buffer, slow-path + * @size: request size for the scratch/temp buffer + */ +static int sigpool_reserve_scratch(size_t size) +{ + struct scratches_to_free *stf; + size_t stf_sz = struct_size(stf, scratches, num_possible_cpus()); + int cpu, err = 0; + + lockdep_assert_held(&cpool_mutex); + if (__scratch_size >= size) + return 0; + + stf = kmalloc(stf_sz, GFP_KERNEL); + if (!stf) + return -ENOMEM; + stf->cnt = 0; + + size = max(size, __scratch_size); + cpus_read_lock(); + for_each_possible_cpu(cpu) { + void *scratch, *old_scratch; + + scratch = kmalloc_node(size, GFP_KERNEL, cpu_to_node(cpu)); + if (!scratch) { + err = -ENOMEM; + break; + } + + old_scratch = rcu_replace_pointer(per_cpu(sigpool_scratch, cpu), + scratch, lockdep_is_held(&cpool_mutex)); + if (!cpu_online(cpu) || !old_scratch) { + kfree(old_scratch); + continue; + } + stf->scratches[stf->cnt++] = old_scratch; + } + cpus_read_unlock(); + if (!err) + __scratch_size = size; + + call_rcu(&stf->rcu, free_old_scratches); + return err; +} + +static void sigpool_scratch_free(void) +{ + int cpu; + + for_each_possible_cpu(cpu) + kfree(rcu_replace_pointer(per_cpu(sigpool_scratch, cpu), + NULL, lockdep_is_held(&cpool_mutex))); + __scratch_size = 0; +} + +static int __cpool_try_clone(struct crypto_ahash *hash) +{ + struct crypto_ahash *tmp; + + tmp = crypto_clone_ahash(hash); + if (IS_ERR(tmp)) + return PTR_ERR(tmp); + + crypto_free_ahash(tmp); + return 0; +} + +static int __cpool_alloc_ahash(struct sigpool_entry *e, const char *alg) +{ + struct crypto_ahash *cpu0_hash; + int ret; + + e->alg = kstrdup(alg, GFP_KERNEL); + if (!e->alg) + return -ENOMEM; + + cpu0_hash = crypto_alloc_ahash(alg, 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(cpu0_hash)) { + ret = PTR_ERR(cpu0_hash); + goto out_free_alg; + } + + e->needs_key = crypto_ahash_get_flags(cpu0_hash) & CRYPTO_TFM_NEED_KEY; + + ret = __cpool_try_clone(cpu0_hash); + if (ret) + goto out_free_cpu0_hash; + e->hash = cpu0_hash; + kref_init(&e->kref); + return 0; + +out_free_cpu0_hash: + crypto_free_ahash(cpu0_hash); +out_free_alg: + kfree(e->alg); + e->alg = NULL; + return ret; +} + +/** + * tcp_sigpool_alloc_ahash - allocates pool for ahash requests + * @alg: name of async hash algorithm + * @scratch_size: reserve a tcp_sigpool::scratch buffer of this size + */ +int tcp_sigpool_alloc_ahash(const char *alg, size_t scratch_size) +{ + int i, ret; + + /* slow-path */ + mutex_lock(&cpool_mutex); + ret = sigpool_reserve_scratch(scratch_size); + if (ret) + goto out; + for (i = 0; i < cpool_populated; i++) { + if (!cpool[i].alg) + continue; + if (strcmp(cpool[i].alg, alg)) + continue; + + /* pairs with tcp_sigpool_release() */ + if (!kref_get_unless_zero(&cpool[i].kref)) + kref_init(&cpool[i].kref); + ret = i; + goto out; + } + + for (i = 0; i < cpool_populated; i++) { + if (!cpool[i].alg) + break; + } + if (i >= CPOOL_SIZE) { + ret = -ENOSPC; + goto out; + } + + ret = __cpool_alloc_ahash(&cpool[i], alg); + if (!ret) { + ret = i; + if (i == cpool_populated) + cpool_populated++; + } +out: + mutex_unlock(&cpool_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(tcp_sigpool_alloc_ahash); + +static void __cpool_free_entry(struct sigpool_entry *e) +{ + crypto_free_ahash(e->hash); + kfree(e->alg); + memset(e, 0, sizeof(*e)); +} + +static void cpool_cleanup_work_cb(struct work_struct *work) +{ + bool free_scratch = true; + unsigned int i; + + mutex_lock(&cpool_mutex); + for (i = 0; i < cpool_populated; i++) { + if (kref_read(&cpool[i].kref) > 0) { + free_scratch = false; + continue; + } + if (!cpool[i].alg) + continue; + __cpool_free_entry(&cpool[i]); + } + if (free_scratch) + sigpool_scratch_free(); + mutex_unlock(&cpool_mutex); +} + +static DECLARE_WORK(cpool_cleanup_work, cpool_cleanup_work_cb); +static void cpool_schedule_cleanup(struct kref *kref) +{ + schedule_work(&cpool_cleanup_work); +} + +/** + * tcp_sigpool_release - decreases number of users for a pool. If it was + * the last user of the pool, releases any memory that was consumed. + * @id: tcp_sigpool that was previously allocated by tcp_sigpool_alloc_ahash() + */ +void tcp_sigpool_release(unsigned int id) +{ + if (WARN_ON_ONCE(id >= cpool_populated || !cpool[id].alg)) + return; + + /* slow-path */ + kref_put(&cpool[id].kref, cpool_schedule_cleanup); +} +EXPORT_SYMBOL_GPL(tcp_sigpool_release); + +/** + * tcp_sigpool_get - increases number of users (refcounter) for a pool + * @id: tcp_sigpool that was previously allocated by tcp_sigpool_alloc_ahash() + */ +void tcp_sigpool_get(unsigned int id) +{ + if (WARN_ON_ONCE(id >= cpool_populated || !cpool[id].alg)) + return; + kref_get(&cpool[id].kref); +} +EXPORT_SYMBOL_GPL(tcp_sigpool_get); + +int tcp_sigpool_start(unsigned int id, struct tcp_sigpool *c) __cond_acquires(RCU_BH) +{ + struct crypto_ahash *hash; + + rcu_read_lock_bh(); + if (WARN_ON_ONCE(id >= cpool_populated || !cpool[id].alg)) { + rcu_read_unlock_bh(); + return -EINVAL; + } + + hash = crypto_clone_ahash(cpool[id].hash); + if (IS_ERR(hash)) { + rcu_read_unlock_bh(); + return PTR_ERR(hash); + } + + c->req = ahash_request_alloc(hash, GFP_ATOMIC); + if (!c->req) { + crypto_free_ahash(hash); + rcu_read_unlock_bh(); + return -ENOMEM; + } + ahash_request_set_callback(c->req, 0, NULL, NULL); + + /* Pairs with tcp_sigpool_reserve_scratch(), scratch area is + * valid (allocated) until tcp_sigpool_end(). + */ + c->scratch = rcu_dereference_bh(*this_cpu_ptr(&sigpool_scratch)); + return 0; +} +EXPORT_SYMBOL_GPL(tcp_sigpool_start); + +void tcp_sigpool_end(struct tcp_sigpool *c) __releases(RCU_BH) +{ + struct crypto_ahash *hash = crypto_ahash_reqtfm(c->req); + + rcu_read_unlock_bh(); + ahash_request_free(c->req); + crypto_free_ahash(hash); +} +EXPORT_SYMBOL_GPL(tcp_sigpool_end); + +/** + * tcp_sigpool_algo - return algorithm of tcp_sigpool + * @id: tcp_sigpool that was previously allocated by tcp_sigpool_alloc_ahash() + * @buf: buffer to return name of algorithm + * @buf_len: size of @buf + */ +size_t tcp_sigpool_algo(unsigned int id, char *buf, size_t buf_len) +{ + if (WARN_ON_ONCE(id >= cpool_populated || !cpool[id].alg)) + return -EINVAL; + + return strscpy(buf, cpool[id].alg, buf_len); +} +EXPORT_SYMBOL_GPL(tcp_sigpool_algo); + +/** + * tcp_sigpool_hash_skb_data - hash data in skb with initialized tcp_sigpool + * @hp: tcp_sigpool pointer + * @skb: buffer to add sign for + * @header_len: TCP header length for this segment + */ +int tcp_sigpool_hash_skb_data(struct tcp_sigpool *hp, + const struct sk_buff *skb, + unsigned int header_len) +{ + const unsigned int head_data_len = skb_headlen(skb) > header_len ? + skb_headlen(skb) - header_len : 0; + const struct skb_shared_info *shi = skb_shinfo(skb); + const struct tcphdr *tp = tcp_hdr(skb); + struct ahash_request *req = hp->req; + struct sk_buff *frag_iter; + struct scatterlist sg; + unsigned int i; + + sg_init_table(&sg, 1); + + sg_set_buf(&sg, ((u8 *)tp) + header_len, head_data_len); + ahash_request_set_crypt(req, &sg, NULL, head_data_len); + if (crypto_ahash_update(req)) + return 1; + + for (i = 0; i < shi->nr_frags; ++i) { + const skb_frag_t *f = &shi->frags[i]; + unsigned int offset = skb_frag_off(f); + struct page *page; + + page = skb_frag_page(f) + (offset >> PAGE_SHIFT); + sg_set_page(&sg, page, skb_frag_size(f), offset_in_page(offset)); + ahash_request_set_crypt(req, &sg, NULL, skb_frag_size(f)); + if (crypto_ahash_update(req)) + return 1; + } + + skb_walk_frags(skb, frag_iter) + if (tcp_sigpool_hash_skb_data(hp, frag_iter, 0)) + return 1; + + return 0; +} +EXPORT_SYMBOL(tcp_sigpool_hash_skb_data); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Per-CPU pool of crypto requests"); -- cgit v1.2.3