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authorDmitry Safonov <dima@arista.com>2023-10-23 21:21:59 +0200
committerDavid S. Miller <davem@davemloft.net>2023-10-27 11:35:44 +0200
commitf7dca36fc54afa2eb76bff8d0589a2ef18caea91 (patch)
tree318f2f477d23c115b66a9a1ea136f562ed588430 /net/ipv4/tcp_ipv4.c
parentnet/tcp: Add TCP-AO sign to outgoing packets (diff)
downloadlinux-f7dca36fc54afa2eb76bff8d0589a2ef18caea91.tar.xz
linux-f7dca36fc54afa2eb76bff8d0589a2ef18caea91.zip
net/tcp: Add tcp_parse_auth_options()
Introduce a helper that: (1) shares the common code with TCP-MD5 header options parsing (2) looks for hash signature only once for both TCP-MD5 and TCP-AO (3) fails with -EEXIST if any TCP sign option is present twice, see RFC5925 (2.2): ">> A single TCP segment MUST NOT have more than one TCP-AO in its options sequence. When multiple TCP-AOs appear, TCP MUST discard the segment." Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_ipv4.c')
-rw-r--r--net/ipv4/tcp_ipv4.c15
1 files changed, 10 insertions, 5 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index b002f6497d19..83e069d0f778 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -670,7 +670,9 @@ EXPORT_SYMBOL(tcp_v4_send_check);
* Exception: precedence violation. We do not implement it in any case.
*/
-#ifdef CONFIG_TCP_MD5SIG
+#ifdef CONFIG_TCP_AO
+#define OPTION_BYTES MAX_TCP_OPTION_SPACE
+#elif defined(CONFIG_TCP_MD5SIG)
#define OPTION_BYTES TCPOLEN_MD5SIG_ALIGNED
#else
#define OPTION_BYTES sizeof(__be32)
@@ -685,8 +687,8 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
} rep;
struct ip_reply_arg arg;
#ifdef CONFIG_TCP_MD5SIG
+ const __u8 *md5_hash_location = NULL;
struct tcp_md5sig_key *key = NULL;
- const __u8 *hash_location = NULL;
unsigned char newhash[16];
int genhash;
struct sock *sk1 = NULL;
@@ -727,8 +729,11 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
#ifdef CONFIG_TCP_MD5SIG
+ /* Invalid TCP option size or twice included auth */
+ if (tcp_parse_auth_options(tcp_hdr(skb), &md5_hash_location, NULL))
+ return;
+
rcu_read_lock();
- hash_location = tcp_parse_md5sig_option(th);
if (sk && sk_fullsock(sk)) {
const union tcp_md5_addr *addr;
int l3index;
@@ -739,7 +744,7 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0;
addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr;
key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET);
- } else if (hash_location) {
+ } else if (md5_hash_location) {
const union tcp_md5_addr *addr;
int sdif = tcp_v4_sdif(skb);
int dif = inet_iif(skb);
@@ -771,7 +776,7 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, skb);
- if (genhash || memcmp(hash_location, newhash, 16) != 0)
+ if (genhash || memcmp(md5_hash_location, newhash, 16) != 0)
goto out;
}