Function

NM-1.0 ▶ NM ▶ utils_hwaddr_matches

  • Generalized hardware address comparison function. Tests if hwaddr1 and hwaddr2 "equal" (or more precisely, "equivalent"), with several advantages over a simple memcmp():

    1. If hwaddr1_len or hwaddr2_len is -1, then the corresponding address is assumed to be ASCII rather than binary, and will be converted to binary before being compared.

    2. If hwaddr1 or hwaddr2 is null, it is treated instead as though it was a zero-filled buffer hwaddr1_len or hwaddr2_len bytes long.

    3. If hwaddr1 and hwaddr2 are InfiniBand hardware addresses (that is, if they are INFINIBAND_ALEN bytes long in binary form) then only the last 8 bytes are compared, since those are the only bytes that actually identify the hardware. (The other 12 bytes will change depending on the configuration of the InfiniBand fabric that the device is connected to.)

    If a passed-in ASCII hardware address cannot be parsed, or would parse to an address larger than NM_UTILS_HWADDR_LEN_MAX, then it will silently fail to match. (This means that externally-provided address strings do not need to be sanity-checked before comparing them against known good addresses; they are guaranteed to not match if they are invalid.)

    Parameters

    • hwaddr1: any

      pointer to a binary or ASCII hardware address, or null

    • hwaddr1_len: number

      size of hwaddr1, or -1 if hwaddr1 is ASCII

    • hwaddr2: any

      pointer to a binary or ASCII hardware address, or null

    • hwaddr2_len: number

      size of hwaddr2, or -1 if hwaddr2 is ASCII

    Returns boolean

    true if hwaddr1 and hwaddr2 are equivalent, false if they are different (or either of them is invalid).