lkml.org 
[lkml]   [2021]   [Mar]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.11 007/306] mptcp: fix length of ADD_ADDR with port sub-option
    Date
    From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    From: Davide Caratti <dcaratti@redhat.com>

    commit 27ab92d9996e4e003a726d22c56d780a1655d6b4 upstream.

    in current Linux, MPTCP peers advertising endpoints with port numbers use
    a sub-option length that wrongly accounts for the trailing TCP NOP. Also,
    receivers will only process incoming ADD_ADDR with port having such wrong
    sub-option length. Fix this, making ADD_ADDR compliant to RFC8684 §3.4.1.

    this can be verified running tcpdump on the kselftests artifacts:

    unpatched kernel:
    [root@bottarga mptcp]# tcpdump -tnnr unpatched.pcap | grep add-addr
    reading from file unpatched.pcap, link-type LINUX_SLL (Linux cooked v1), snapshot length 65535
    IP 10.0.1.1.10000 > 10.0.1.2.53078: Flags [.], ack 101, win 509, options [nop,nop,TS val 214459678 ecr 521312851,mptcp add-addr v1 id 1 a00:201:2774:2d88:7436:85c3:17fd:101], length 0
    IP 10.0.1.2.53078 > 10.0.1.1.10000: Flags [.], ack 101, win 502, options [nop,nop,TS val 521312852 ecr 214459678,mptcp add-addr[bad opt]]

    patched kernel:
    [root@bottarga mptcp]# tcpdump -tnnr patched.pcap | grep add-addr
    reading from file patched.pcap, link-type LINUX_SLL (Linux cooked v1), snapshot length 65535
    IP 10.0.1.1.10000 > 10.0.1.2.38178: Flags [.], ack 101, win 509, options [nop,nop,TS val 3728873902 ecr 2732713192,mptcp add-addr v1 id 1 10.0.2.1:10100 hmac 0xbccdfcbe59292a1f,nop,nop], length 0
    IP 10.0.1.2.38178 > 10.0.1.1.10000: Flags [.], ack 101, win 502, options [nop,nop,TS val 2732713195 ecr 3728873902,mptcp add-addr v1-echo id 1 10.0.2.1:10100,nop,nop], length 0

    Fixes: 22fb85ffaefb ("mptcp: add port support for ADD_ADDR suboption writing")
    CC: stable@vger.kernel.org # 5.11+
    Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
    Acked-and-tested-by: Geliang Tang <geliangtang@gmail.com>
    Signed-off-by: Davide Caratti <dcaratti@redhat.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    net/mptcp/protocol.h | 14 ++++++++------
    1 file changed, 8 insertions(+), 6 deletions(-)

    --- a/net/mptcp/protocol.h
    +++ b/net/mptcp/protocol.h
    @@ -50,14 +50,15 @@
    #define TCPOLEN_MPTCP_DSS_MAP64 14
    #define TCPOLEN_MPTCP_DSS_CHECKSUM 2
    #define TCPOLEN_MPTCP_ADD_ADDR 16
    -#define TCPOLEN_MPTCP_ADD_ADDR_PORT 20
    +#define TCPOLEN_MPTCP_ADD_ADDR_PORT 18
    #define TCPOLEN_MPTCP_ADD_ADDR_BASE 8
    -#define TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT 12
    +#define TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT 10
    #define TCPOLEN_MPTCP_ADD_ADDR6 28
    -#define TCPOLEN_MPTCP_ADD_ADDR6_PORT 32
    +#define TCPOLEN_MPTCP_ADD_ADDR6_PORT 30
    #define TCPOLEN_MPTCP_ADD_ADDR6_BASE 20
    -#define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT 24
    -#define TCPOLEN_MPTCP_PORT_LEN 4
    +#define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT 22
    +#define TCPOLEN_MPTCP_PORT_LEN 2
    +#define TCPOLEN_MPTCP_PORT_ALIGN 2
    #define TCPOLEN_MPTCP_RM_ADDR_BASE 4
    #define TCPOLEN_MPTCP_FASTCLOSE 12

    @@ -587,8 +588,9 @@ static inline unsigned int mptcp_add_add
    len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
    if (!echo)
    len += MPTCPOPT_THMAC_LEN;
    + /* account for 2 trailing 'nop' options */
    if (port)
    - len += TCPOLEN_MPTCP_PORT_LEN;
    + len += TCPOLEN_MPTCP_PORT_LEN + TCPOLEN_MPTCP_PORT_ALIGN;

    return len;
    }

    \
     
     \ /
      Last update: 2021-03-15 15:02    [W:9.285 / U:0.108 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site