Commit dd1ecaaa authored by Tomek Mrugalski's avatar Tomek Mrugalski 🛰

[3546] Initial version of Pkt::getMAC() method implemented.

parent 80f05781
......@@ -86,5 +86,22 @@ Pkt::setHWAddrMember(const uint8_t htype, const uint8_t,
hw_addr.reset(new HWAddr(mac_addr, htype));
}
HWAddrPtr
Pkt::getMAC(MACSource from) {
HWAddrPtr mac;
if (from == MAC_SOURCE_RAW || from == MAC_SOURCE_ANY) {
mac = getRemoteHWAddr();
if (mac) {
return (mac);
}
}
/// @todo: add other MAC acquisition methods here
// Ok, none of the methods were suitable. Return NULL.
return (HWAddrPtr());
}
};
};
......@@ -34,6 +34,49 @@ namespace dhcp {
/// This class is purely virtual. Please instantiate Pkt4, Pkt6 or any
/// other derived classes.
class Pkt {
public:
/// @brief specified where did we get this MAC address from?
///
/// The list covers all possible MAC sources. The uncommented ones
/// are currently supported. When you implement a new method, please
/// uncomment appropriate line here.
enum MACSource {
/// Not really a type, only used in getMAC() calls
MAC_SOURCE_ANY,
/// obtained first hand from raw socket (100% reliable)
MAC_SOURCE_RAW,
/// extracted from DUID-LL or DUID-LLT (not reliable as the client
/// can send fake DUID)
// MAC_SOURCE_DUID,
/// extracted from IPv6 link-local address. Client can use different
/// IID other than EUI-64, e.g. Windows supports RFC4941 and uses
/// random values instead of EUI-64.
// MAC_SOURCE_IPV6_LINK_LOCAL,
/// RFC6939 (a relay agent can insert client link layer address option)
/// Note that a skilled attacker can fake that by sending his request
/// relayed, so the legitimate relay will think it's a second relay.
// MAC_SOURCE_CLIENT_ADDR_RELAY_OPTION,
/// A relay can insert remote-id. In some deployments it contains a MAC
/// address.
// MAC_SOURCE_REMOTE_ID,
/// A relay can insert a subscriber-id option. In some deployments it
/// contains a MAC address.
// MAC_SOURCE_SUBSCRIBER_ID,
/// A CMTS (acting as DHCP relay agent) that supports DOCSIS standard
/// can insert DOCSIS options that contain client's MAC address.
/// Client in this context would be a cable modem.
// MAC_SOURCE_DOCSIS_OPTIONS
};
protected:
Pkt(uint32_t transid, const isc::asiolink::IOAddress& local_addr,
const isc::asiolink::IOAddress& remote_addr, uint16_t local_port,
......@@ -381,13 +424,22 @@ public:
void setRemoteHWAddr(const uint8_t htype, const uint8_t hlen,
const std::vector<uint8_t>& mac_addr);
/// @brief Returns the remote HW address.
/// @brief Returns the remote HW address obtained from raw sockets.
///
/// @return remote HW address.
HWAddrPtr getRemoteHWAddr() const {
return (remote_hwaddr_);
}
/// @brief Returns MAC address.
///
/// The difference between this method and getRemoteHWAddr() is that
/// getRemoteHWAddr() returns only what was obtained from raw sockets.
/// This method is more generic and can attempt to obtain MAC from
/// varied sources: raw sockets, client-id, link-local IPv6 address,
/// and various relay options.
HWAddrPtr getMAC(MACSource from);
/// @brief virtual desctructor
///
/// There is nothing to clean up here, but since there are virtual methods,
......
......@@ -851,4 +851,30 @@ TEST_F(Pkt4Test, clientClasses) {
EXPECT_TRUE(pkt.inClass("foo"));
}
// Tests whether MAC can be obtained and that MAC sources are not
// confused.
TEST_F(Pkt4Test, getMAC) {
Pkt4 pkt(DHCPOFFER, 1234);
// DHCPv6 packet by default doens't have MAC address specified.
EXPECT_FALSE(pkt.getMAC(Pkt::MAC_SOURCE_ANY));
EXPECT_FALSE(pkt.getMAC(Pkt::MAC_SOURCE_RAW));
// Let's invent a MAC
const uint8_t hw[] = { 2, 4, 6, 8, 10, 12 }; // MAC
const uint8_t hw_type = 123; // hardware type
HWAddrPtr dummy_hwaddr(new HWAddr(hw, sizeof(hw), hw_type));
// Now let's pretend that we obtained it from raw sockets
pkt.setRemoteHWAddr(dummy_hwaddr);
// Now we should be able to get something
ASSERT_TRUE(pkt.getMAC(Pkt::MAC_SOURCE_ANY));
ASSERT_TRUE(pkt.getMAC(Pkt::MAC_SOURCE_RAW));
// Check that the returned MAC is indeed the expected one
ASSERT_TRUE(*dummy_hwaddr == *pkt.getMAC(Pkt::MAC_SOURCE_ANY));
ASSERT_TRUE(*dummy_hwaddr == *pkt.getMAC(Pkt::MAC_SOURCE_RAW));
}
} // end of anonymous namespace
......@@ -22,6 +22,7 @@
#include <dhcp/option_int.h>
#include <dhcp/option_int_array.h>
#include <dhcp/pkt6.h>
#include <dhcp/hwaddr.h>
#include <dhcp/docsis3_option_defs.h>
#include <util/range_utilities.h>
......@@ -810,4 +811,30 @@ TEST_F(Pkt6Test, clientClasses) {
EXPECT_TRUE(pkt.inClass("foo"));
}
// Tests whether MAC can be obtained and that MAC sources are not
// confused.
TEST_F(Pkt6Test, getMAC) {
Pkt6 pkt(DHCPV6_ADVERTISE, 1234);
// DHCPv6 packet by default doens't have MAC address specified.
EXPECT_FALSE(pkt.getMAC(Pkt::MAC_SOURCE_ANY));
EXPECT_FALSE(pkt.getMAC(Pkt::MAC_SOURCE_RAW));
// Let's invent a MAC
const uint8_t hw[] = { 2, 4, 6, 8, 10, 12 }; // MAC
const uint8_t hw_type = 123; // hardware type
HWAddrPtr dummy_hwaddr(new HWAddr(hw, sizeof(hw), hw_type));
// Now let's pretend that we obtained it from raw sockets
pkt.setRemoteHWAddr(dummy_hwaddr);
// Now we should be able to get something
ASSERT_TRUE(pkt.getMAC(Pkt::MAC_SOURCE_ANY));
ASSERT_TRUE(pkt.getMAC(Pkt::MAC_SOURCE_RAW));
// Check that the returned MAC is indeed the expected one
ASSERT_TRUE(*dummy_hwaddr == *pkt.getMAC(Pkt::MAC_SOURCE_ANY));
ASSERT_TRUE(*dummy_hwaddr == *pkt.getMAC(Pkt::MAC_SOURCE_RAW));
}
}
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