Re: [libvirt] [PATCHv2] network: truncate bridges' dummy tap device names to IFNAMSIZ (15) chars

(Change from V1 - define a static char[] containing the desired prefix, and use its size to figure out how much to truncate, rather than having a bunch of magic numbers. This also makes it simpler and less error-prone to change the suffix if we decide to.)

The solution is to shorten the part of the original name used to generate the tap device name. However, simply truncating it is insufficient, because the last few characters of an interface name are often a number used to indicate one of a list of several similar devices (for example, "verylongname123", "verylongname124", etc) and simple truncation would lead to duplicate names (eg "verlongnam-nic" and "verylongnam-nic"). So instead we take the first 8 characters of $bridgename ("verylong" in the example), add on the final 3 bytes ("123"), then add "-nic" (so "verylong123-nic"). Not pretty, but it is much more likely to generate a unique name, and is reproducible (unlike, say, a random number). --- src/network/bridge_driver.c | 16 +++++++++++++++- 1 files changed, 15 insertions(+), 1 deletions(-)