lldp: Tolerate multiple management address TLVs#130
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Unlike the other basic TLV types (System Name, Port Description, etc.), the Management Address TLV may appear more than once in a single LLDPDU, e.g. one per address family (IPv4, IPv6). Switches commonly do this. Commit 44006eb ("lldp: Reject frames with duplicate TLVs") treated a second Management Address TLV as a fatal frame error and aborted processing the entire frame with `goto out`. This caused all subsequent TLVs (including 802.1Qaz ETS/PFC/APP TLVs and the End TLV) to be skipped, resulting in the ETS state machine never receiving the peer's configuration. This broke PFC/ETS learning from switches that send multiple Management Address TLVs, such as Nvidia Cumulus Linux switches (MSN4600, MSN4700). Fix by removing the checks for if an additional TLV type 8 is received. Instead leaving the idempotent check that the RCVD_LLDP_TLV_TYPE8 bit is set and then freeing the tlv and continuing on with the processing of TLVs. Due to mgmtadd being write-only, it has been removed as there is no need for it in rxProcessFrame. Signed-off-by: Michal Schmidt <mschmidt@redhat.com> Signed-off-by: Thomas Walsh <thwalsh@redhat.com>
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Unlike the other basic TLV types (System Name, Port Description, etc.), the Management Address TLV may appear more than once in a single LLDPDU, e.g. one per address family (IPv4, IPv6). Switches commonly do this.
Commit 44006eb ("lldp: Reject frames with duplicate TLVs") treated a second Management Address TLV as a fatal frame error and aborted processing the entire frame with
goto out. This caused all subsequent TLVs (including 802.1Qaz ETS/PFC/APP TLVs and the End TLV) to be skipped, resulting in the ETS state machine never receiving the peer's configuration.This broke PFC/ETS learning from switches that send multiple Management Address TLVs, such as Nvidia Cumulus Linux switches (MSN4600, MSN4700).
Fix by removing the checks for if an additional TLV type 8 is received. Instead leaving the idempotent check that the RCVD_LLDP_TLV_TYPE8 bit is set and then freeing the tlv and continuing on with the processing of TLVs.
Due to mgmtadd being write-only, it has been removed as there is no need for it in rxProcessFrame.