Commit 13832ae2 authored by Davide Caratti's avatar Davide Caratti Committed by David S. Miller
Browse files

mptcp: fix ADD_ADDR HMAC in case port is specified 



Currently, Linux computes the HMAC contained in ADD_ADDR sub-option using
the Address Id and the IP Address, and hardcodes a destination port equal
to zero. This is not ok for ADD_ADDR with port: ensure to account for the
endpoint port when computing the HMAC, in compliance with RFC8684 §3.4.1.

Fixes: 22fb85ff ("mptcp: add port support for ADD_ADDR suboption writing")
Reviewed-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Acked-by: default avatarGeliang Tang <geliangtang@gmail.com>
Signed-off-by: default avatarDavide Caratti <dcaratti@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7233da86

net/mptcp/options.c

+14 −10
Original line number Diff line number Diff line
@@ -567,15 +567,15 @@ static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb, 
}



static u64 add_addr_generate_hmac(u64 key1, u64 key2, u8 addr_id,

				  struct in_addr *addr)

				  struct in_addr *addr, u16 port)

{

	u8 hmac[SHA256_DIGEST_SIZE];

	u8 msg[7];



	msg[0] = addr_id;

	memcpy(&msg[1], &addr->s_addr, 4);

	msg[5] = 0;

	msg[6] = 0;

	msg[5] = port >> 8;

	msg[6] = port & 0xFF;



	mptcp_crypto_hmac_sha(key1, key2, msg, 7, hmac);
@@ -584,15 +584,15 @@ static u64 add_addr_generate_hmac(u64 key1, u64 key2, u8 addr_id, 


#if IS_ENABLED(CONFIG_MPTCP_IPV6)

static u64 add_addr6_generate_hmac(u64 key1, u64 key2, u8 addr_id,

				   struct in6_addr *addr)

				   struct in6_addr *addr, u16 port)

{

	u8 hmac[SHA256_DIGEST_SIZE];

	u8 msg[19];



	msg[0] = addr_id;

	memcpy(&msg[1], &addr->s6_addr, 16);

	msg[17] = 0;

	msg[18] = 0;

	msg[17] = port >> 8;

	msg[18] = port & 0xFF;



	mptcp_crypto_hmac_sha(key1, key2, msg, 19, hmac);
@@ -646,7 +646,8 @@ static bool mptcp_established_options_add_addr(struct sock *sk, struct sk_buff * 
			opts->ahmac = add_addr_generate_hmac(msk->local_key,

							     msk->remote_key,

							     opts->addr_id,

							     &opts->addr);

							     &opts->addr,

							     opts->port);

		}

	}

#if IS_ENABLED(CONFIG_MPTCP_IPV6)
@@ -657,7 +658,8 @@ static bool mptcp_established_options_add_addr(struct sock *sk, struct sk_buff * 
			opts->ahmac = add_addr6_generate_hmac(msk->local_key,

							      msk->remote_key,

							      opts->addr_id,

							      &opts->addr6);

							      &opts->addr6,

							      opts->port);

		}

	}

#endif
@@ -962,12 +964,14 @@ static bool add_addr_hmac_valid(struct mptcp_sock *msk, 
	if (mp_opt->family == MPTCP_ADDR_IPVERSION_4)

		hmac = add_addr_generate_hmac(msk->remote_key,

					      msk->local_key,

					      mp_opt->addr_id, &mp_opt->addr);

					      mp_opt->addr_id, &mp_opt->addr,

					      mp_opt->port);

#if IS_ENABLED(CONFIG_MPTCP_IPV6)

	else

		hmac = add_addr6_generate_hmac(msk->remote_key,

					       msk->local_key,

					       mp_opt->addr_id, &mp_opt->addr6);

					       mp_opt->addr_id, &mp_opt->addr6,

					       mp_opt->port);

#endif



	pr_debug("msk=%p, ahmac=%llu, mp_opt->ahmac=%llu\n",