Adding upstream version 2.3~rc1.upstream/2.3_rc1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 184 insertions, 15 deletions

diff --git a/staslib/udev.py b/staslib/udev.py
index 12ef61b..80555dd 100644
--- a/staslib/udev.py
+++ b/staslib/udev.py
@@ -153,6 +153,169 @@ class Udev:
 
         return False
 
+    @staticmethod
+    def _cid_matches_tcp_tid_legacy(tid, cid):  # pylint: disable=too-many-return-statements,too-many-branches
+        '''On kernels older than 6.1, the src_addr parameter is not available
+        from the sysfs. Therefore, we need to infer a match based on other
+        parameters. And there are a few cases where we're simply not sure
+        whether an existing connection (cid) matches the candidate
+        connection (tid).
+        '''
+        cid_host_iface = cid['host-iface']
+        cid_host_traddr = iputil.get_ipaddress_obj(cid['host-traddr'], ipv4_mapped_convert=True)
+
+        if not cid_host_iface:  # cid.host_iface is undefined
+            if not cid_host_traddr:  # cid.host_traddr is undefined
+                # When the existing cid.src_addr, cid.host_traddr, and cid.host_iface
+                # are all undefined (which can only happen on kernels prior to 6.1),
+                # we can't know for sure on which interface an existing connection
+                # was made. In this case, we can only declare a match if both
+                # tid.host_iface and tid.host_traddr are undefined as well.
+                logging.debug(
+                    'Udev._cid_matches_tcp_tid_legacy() - cid=%s, tid=%s - Not enough info. Assume "match" but this could be wrong.',
+                    cid,
+                    tid,
+                )
+                return True
+
+            # cid.host_traddr is defined. If tid.host_traddr is also
+            # defined, then it must match the existing cid.host_traddr.
+            if tid.host_traddr:
+                tid_host_traddr = iputil.get_ipaddress_obj(tid.host_traddr, ipv4_mapped_convert=True)
+                if tid_host_traddr != cid_host_traddr:
+                    return False
+
+            # If tid.host_iface is defined, then the interface where
+            # the connection is located must match. If tid.host_iface
+            # is not defined, then we don't really care on which
+            # interface the connection was made and we can skip this test.
+            if tid.host_iface:
+                # With the existing cid.host_traddr, we can find the
+                # interface of the exisiting connection.
+                connection_iface = iputil.get_interface(str(cid_host_traddr))
+                if tid.host_iface != connection_iface:
+                    return False
+
+            return True
+
+        # cid.host_iface is defined
+        if not cid_host_traddr:  # cid.host_traddr is undefined
+            if tid.host_iface and tid.host_iface != cid_host_iface:
+                return False
+
+            if tid.host_traddr:
+                # It's impossible to tell the existing connection source
+                # address. So, we can't tell if it matches tid.host_traddr.
+                # However, if the existing host_iface has only one source
+                # address assigned to it, we can assume that the source
+                # address used for the existing connection is that address.
+                if_addrs = iputil.net_if_addrs().get(cid_host_iface, {4: [], 6: []})
+                tid_host_traddr = iputil.get_ipaddress_obj(tid.host_traddr, ipv4_mapped_convert=True)
+                source_addrs = if_addrs[tid_host_traddr.version]
+                if len(source_addrs) != 1:
+                    return False
+
+                src_addr0 = iputil.get_ipaddress_obj(source_addrs[0], ipv4_mapped_convert=True)
+                if src_addr0 != tid_host_traddr:
+                    return False
+
+            return True
+
+        # cid.host_traddr is defined
+        if tid.host_iface and tid.host_iface != cid_host_iface:
+            return False
+
+        if tid.host_traddr:
+            tid_host_traddr = iputil.get_ipaddress_obj(tid.host_traddr, ipv4_mapped_convert=True)
+            if tid_host_traddr != cid_host_traddr:
+                return False
+
+        return True
+
+    @staticmethod
+    def _cid_matches_tid(tid, cid):  #  pylint: disable=too-many-return-statements,too-many-branches
+        '''Check if existing controller's cid matches candidate controller's tid.
+        @param cid: The Connection ID of an existing controller (from the sysfs).
+        @param tid: The Transport ID of a candidate controller.
+
+        We're trying to find if an existing connection (specified by cid) can
+        be re-used for the candidate controller (specified by tid).
+
+        We do not have a match if the candidate's tid.transport, tid.traddr,
+        tid.trsvcid, and tid.subsysnqn are not identical to those of the cid.
+        These 4 parameters are mandatory for a match.
+
+        The tid.host_traddr and tid.host_iface depend on the transport type.
+        These parameters may not apply or have a different syntax/meaning
+        depending on the transport type.
+
+        For TCP only:
+            With regards to the candidate's tid.host_traddr and tid.host_iface,
+            if those are defined but do not match the existing cid.host_traddr
+            and cid.host_iface, we may still be able to find a match by taking
+            the existing cid.src_addr into consideration since that parameter
+            identifies the actual source address of the connection and therefore
+            can be used to infer the interface of the connection. However, the
+            cid.src_addr can only be read from the sysfs starting with kernel
+            6.1.
+        '''
+        # 'transport', 'traddr', 'trsvcid', and 'subsysnqn' must exactly match.
+        if cid['transport'] != tid.transport or cid['trsvcid'] != tid.trsvcid or cid['subsysnqn'] != tid.subsysnqn:
+            return False
+
+        if tid.transport in ('tcp', 'rdma'):
+            # Need to convert to ipaddress objects to properly
+            # handle all variations of IPv6 addresses.
+            tid_traddr = iputil.get_ipaddress_obj(tid.traddr, ipv4_mapped_convert=True)
+            cid_traddr = iputil.get_ipaddress_obj(cid['traddr'], ipv4_mapped_convert=True)
+        else:
+            cid_traddr = cid['traddr']
+            tid_traddr = tid.traddr
+
+        if cid_traddr != tid_traddr:
+            return False
+
+        # We need to know the type of transport to compare 'host-traddr' and
+        # 'host-iface'. These parameters don't apply to all transport types
+        # and may have a different meaning/syntax.
+        if tid.transport == 'tcp':
+            if tid.host_traddr or tid.host_iface:
+                src_addr = iputil.get_ipaddress_obj(cid['src-addr'], ipv4_mapped_convert=True)
+                if not src_addr:
+                    # For legacy kernels (i.e. older than 6.1), the existing cid.src_addr
+                    # is always undefined. We need to use advanced logic to determine
+                    # whether cid and tid match.
+                    return Udev._cid_matches_tcp_tid_legacy(tid, cid)
+
+                # The existing controller's cid.src_addr is always defined for kernel
+                # 6.1 and later. We can use the existing controller's cid.src_addr to
+                # find the interface on which the connection was made and therefore
+                # match it to the candidate's tid.host_iface. And the cid.src_addr
+                # can also be used to match the candidate's tid.host_traddr.
+                if tid.host_traddr:
+                    tid_host_traddr = iputil.get_ipaddress_obj(tid.host_traddr, ipv4_mapped_convert=True)
+                    if tid_host_traddr != src_addr:
+                        return False
+
+                # host-iface is an optional tcp-only parameter.
+                if tid.host_iface and tid.host_iface != iputil.get_interface(str(src_addr)):
+                    return False
+
+        elif tid.transport == 'fc':
+            # host-traddr is mandatory for FC.
+            if tid.host_traddr != cid['host-traddr']:
+                return False
+
+        elif tid.transport == 'rdma':
+            # host-traddr is optional for RDMA and is expressed as an IP address.
+            if tid.host_traddr:
+                tid_host_traddr = iputil.get_ipaddress_obj(tid.host_traddr, ipv4_mapped_convert=True)
+                cid_host_traddr = iputil.get_ipaddress_obj(cid['host-traddr'], ipv4_mapped_convert=True)
+                if tid_host_traddr != cid_host_traddr:
+                    return False
+
+        return True
+
     def find_nvme_dc_device(self, tid):
         '''@brief  Find the nvme device associated with the specified
                 Discovery Controller.
@@ -164,7 +327,8 @@ class Udev:
             if not self.is_dc_device(device):
                 continue
 
-            if self.get_tid(device) != tid:
+            cid = self.get_cid(device)
+            if not self._cid_matches_tid(tid, cid):
                 continue
 
             return device
@@ -182,7 +346,8 @@ class Udev:
             if not self.is_ioc_device(device):
                 continue
 
-            if self.get_tid(device) != tid:
+            cid = self.get_cid(device)
+            if not self._cid_matches_tid(tid, cid):
                 continue
 
             return device
@@ -300,28 +465,32 @@ class Udev:
         return attr_str[start:end]
 
     @staticmethod
-    def _get_host_iface(device):
-        host_iface = Udev._get_property(device, 'NVME_HOST_IFACE')
-        if not host_iface:
-            # We'll try to find the interface from the source address on
-            # the connection. Only available if kernel exposes the source
-            # address (src_addr) in the "address" attribute.
-            src_addr = Udev.get_key_from_attr(device, 'address', 'src_addr=')
-            host_iface = iputil.get_interface(src_addr)
-        return host_iface
-
-    @staticmethod
     def get_tid(device):
         '''@brief return the Transport ID associated with a udev device'''
+        cid = Udev.get_cid(device)
+        if cid['transport'] == 'tcp':
+            src_addr = cid['src-addr']
+            if not cid['host-iface'] and src_addr:
+                # We'll try to find the interface from the source address on
+                # the connection. Only available if kernel exposes the source
+                # address (src_addr) in the "address" attribute.
+                cid['host-iface'] = iputil.get_interface(src_addr)
+
+        return trid.TID(cid)
+
+    @staticmethod
+    def get_cid(device):
+        '''@brief return the Connection ID associated with a udev device'''
         cid = {
             'transport': Udev._get_property(device, 'NVME_TRTYPE'),
             'traddr': Udev._get_property(device, 'NVME_TRADDR'),
             'trsvcid': Udev._get_property(device, 'NVME_TRSVCID'),
             'host-traddr': Udev._get_property(device, 'NVME_HOST_TRADDR'),
-            'host-iface': Udev._get_host_iface(device),
+            'host-iface': Udev._get_property(device, 'NVME_HOST_IFACE'),
             'subsysnqn': Udev._get_attribute(device, 'subsysnqn'),
+            'src-addr': Udev.get_key_from_attr(device, 'address', 'src_addr='),
         }
-        return trid.TID(cid)
+        return cid
 
 
 UDEV = Udev()  # Singleton