[TCP]: MD5 Signature Option (RFC2385) support.
Based on implementation by Rick Payne.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index c05e8ed..dadef86 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -258,6 +258,7 @@
#include <linux/bootmem.h>
#include <linux/cache.h>
#include <linux/err.h>
+#include <linux/crypto.h>
#include <net/icmp.h>
#include <net/tcp.h>
@@ -1942,6 +1943,13 @@
}
break;
+#ifdef CONFIG_TCP_MD5SIG
+ case TCP_MD5SIG:
+ /* Read the IP->Key mappings from userspace */
+ err = tp->af_specific->md5_parse(sk, optval, optlen);
+ break;
+#endif
+
default:
err = -ENOPROTOOPT;
break;
@@ -2231,6 +2239,135 @@
}
EXPORT_SYMBOL(tcp_tso_segment);
+#ifdef CONFIG_TCP_MD5SIG
+static unsigned long tcp_md5sig_users;
+static struct tcp_md5sig_pool **tcp_md5sig_pool;
+static DEFINE_SPINLOCK(tcp_md5sig_pool_lock);
+
+static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool **pool)
+{
+ int cpu;
+ for_each_possible_cpu(cpu) {
+ struct tcp_md5sig_pool *p = *per_cpu_ptr(pool, cpu);
+ if (p) {
+ if (p->md5_desc.tfm)
+ crypto_free_hash(p->md5_desc.tfm);
+ kfree(p);
+ p = NULL;
+ }
+ }
+ free_percpu(pool);
+}
+
+void tcp_free_md5sig_pool(void)
+{
+ struct tcp_md5sig_pool **pool = NULL;
+
+ spin_lock(&tcp_md5sig_pool_lock);
+ if (--tcp_md5sig_users == 0) {
+ pool = tcp_md5sig_pool;
+ tcp_md5sig_pool = NULL;
+ }
+ spin_unlock(&tcp_md5sig_pool_lock);
+ if (pool)
+ __tcp_free_md5sig_pool(pool);
+}
+
+EXPORT_SYMBOL(tcp_free_md5sig_pool);
+
+struct tcp_md5sig_pool **__tcp_alloc_md5sig_pool(void)
+{
+ int cpu;
+ struct tcp_md5sig_pool **pool;
+
+ pool = alloc_percpu(struct tcp_md5sig_pool *);
+ if (!pool)
+ return NULL;
+
+ for_each_possible_cpu(cpu) {
+ struct tcp_md5sig_pool *p;
+ struct crypto_hash *hash;
+
+ p = kzalloc(sizeof(*p), GFP_KERNEL);
+ if (!p)
+ goto out_free;
+ *per_cpu_ptr(pool, cpu) = p;
+
+ hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
+ if (!hash || IS_ERR(hash))
+ goto out_free;
+
+ p->md5_desc.tfm = hash;
+ }
+ return pool;
+out_free:
+ __tcp_free_md5sig_pool(pool);
+ return NULL;
+}
+
+struct tcp_md5sig_pool **tcp_alloc_md5sig_pool(void)
+{
+ struct tcp_md5sig_pool **pool;
+ int alloc = 0;
+
+retry:
+ spin_lock(&tcp_md5sig_pool_lock);
+ pool = tcp_md5sig_pool;
+ if (tcp_md5sig_users++ == 0) {
+ alloc = 1;
+ spin_unlock(&tcp_md5sig_pool_lock);
+ } else if (!pool) {
+ tcp_md5sig_users--;
+ spin_unlock(&tcp_md5sig_pool_lock);
+ cpu_relax();
+ goto retry;
+ } else
+ spin_unlock(&tcp_md5sig_pool_lock);
+
+ if (alloc) {
+ /* we cannot hold spinlock here because this may sleep. */
+ struct tcp_md5sig_pool **p = __tcp_alloc_md5sig_pool();
+ spin_lock(&tcp_md5sig_pool_lock);
+ if (!p) {
+ tcp_md5sig_users--;
+ spin_unlock(&tcp_md5sig_pool_lock);
+ return NULL;
+ }
+ pool = tcp_md5sig_pool;
+ if (pool) {
+ /* oops, it has already been assigned. */
+ spin_unlock(&tcp_md5sig_pool_lock);
+ __tcp_free_md5sig_pool(p);
+ } else {
+ tcp_md5sig_pool = pool = p;
+ spin_unlock(&tcp_md5sig_pool_lock);
+ }
+ }
+ return pool;
+}
+
+EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
+
+struct tcp_md5sig_pool *__tcp_get_md5sig_pool(int cpu)
+{
+ struct tcp_md5sig_pool **p;
+ spin_lock(&tcp_md5sig_pool_lock);
+ p = tcp_md5sig_pool;
+ if (p)
+ tcp_md5sig_users++;
+ spin_unlock(&tcp_md5sig_pool_lock);
+ return (p ? *per_cpu_ptr(p, cpu) : NULL);
+}
+
+EXPORT_SYMBOL(__tcp_get_md5sig_pool);
+
+void __tcp_put_md5sig_pool(void) {
+ __tcp_free_md5sig_pool(tcp_md5sig_pool);
+}
+
+EXPORT_SYMBOL(__tcp_put_md5sig_pool);
+#endif
+
extern void __skb_cb_too_small_for_tcp(int, int);
extern struct tcp_congestion_ops tcp_reno;