RxPrefixTableLookupName function (prefix.h)

Article
02/22/2024

RxPrefixTableLookupName looks up a name in a prefix table used to catalog SRV_CALL, NET_ROOT, and V_NET_ROOT names and converts the underlying pointer to a structure that contains the name.

Syntax

PVOID RxPrefixTableLookupName(
  [in]  IN PRX_PREFIX_TABLE  ThisTable,
  [in]  IN PUNICODE_STRING   CanonicalName,
  [out] OUT PUNICODE_STRING  RemainingName,
        IN PRX_CONNECTION_ID ConnectionId
);

Parameters

[in] ThisTable

A pointer to the RX_PREFIX_TABLE structure in which to look.

[in] CanonicalName

A pointer to the Unicode string name to look up.

[out] RemainingName

A pointer to the Unicode string name of the portion of the name that was unmatched.

ConnectionId

An optional parameter that represents a pointer to the RX_CONNECTION_ID to be used.

Return value

RxPrefixTableLookupName returns a pointer to the node that was found if a match is found. If no match is found, RxPrefixTableLookupName returns a NULL pointer.

Remarks

This routine is used internally by RDBSS in response to a call from MUP to claim a name or form the create path for a NET_ROOT or V_NET_ROOT structure. The RxPrefixTableLookupName routine can also be used by network mini-redirectors as long as the appropriate lock is acquired before accessing the table, and the lock is released when work is completed. The normal use by a driver would be as follows:

Acquire a shared lock by calling RxpAcquirePrefixTableLockShared.
Look up a name by calling RxPrefixTableLookupName.
Release the shared lock by calling RxpReleasePrefixTableLock.

Note that if a match is found, the reference count on the found node will be incremented.

On checked builds, RxPrefixTableLookupName causes the system to ASSERT if the length of the CanonicalName string is not greater than zero.

Requirements

Requirement	Value
Target Platform	Desktop
Header	prefix.h (include Prefix.h)
IRQL	<= APC_LEVEL