KEYCTL\_RESTRICT\_KEYRING(3) Linux Key Management Calls KEYCTL\_RESTRICT\_KEYRING(3) # [NAME](#NAME) keyctl\_restrict\_keyring - restrict keys that may be linked to a keyring # [SYNOPSIS](#SYNOPSIS) ``` #include long keyctl_restrict_keyring(key_serial_t keyring, const char *type, const char *restriction); ``` # [DESCRIPTION](#DESCRIPTION) **keyctl\_restrict\_keyring**() limits the linkage of keys to the given *keyring* using a provided key *type* and *restriction* scheme. The available options vary depending on the key type, and typically contain a restriction name possibly followed by key ids or other data relevant to the restriction. If the type and restriction are both **NULL,** the keyring will reject all links. # [RETURN VALUE](#RETURN_VALUE) On success **keyctl\_restrict\_keyring**() returns **0**. On error, the value **-1** will be returned and *errno* will have been set to an appropriate error. # [ERRORS](#ERRORS) [**EDEADLK**](#EDEADLK) A restriction cycle was avoided. Two keyrings cannot restrict each other. [**EEXIST**](#EEXIST) The keyring is already restricted. [**EINVAL**](#EINVAL) The restriction string is invalid or too large. [**ENOKEY**](#ENOKEY) The key type in the restriction is invalid or not available. [**ENOTDIR**](#ENOTDIR) The provided key id references an item that is not a keyring. [**ENOENT**](#ENOENT) The key type exists but does not support restrictions. # [LINKING](#LINKING) This is a library function that can be found in *libkeyutils*. When linking, **-lkeyutils** should be specified to the linker. # [SEE ALSO](#SEE_ALSO) [**keyctl**(1)](/man/os/keyutils/keyctl.1), [**keyctl**(2)](/man/os/keyutils/keyctl.2), [**keyctl**(3)](/man/os/keyutils/keyctl.3), [**keyutils**(7)](/man/os/keyutils/keyutils.7) 28 Feb 2017 Linux --- Document: keyctl_restrict_keyring(3) from keyutils 1.6.3-r40 (Chainguard OS) Source: https://kernel.googlesource.com/pub/scm/linux/kernel/git/dhowells/keyutils.git