[ZSvirt] bug: GetFreeIp returns fewer addresses across multiple IP ranges

[tllovesxs]

Component

network / L3 network

Problem description

L3BasicNetwork.handle(APIGetFreeIpMsg) subtracts the cumulative result size (freeIpInventorys.size()) from the remaining limit after each IP range. The remaining limit must be reduced only by the number returned from the current range.

With several IP ranges and a requested limit, the remaining limit can become negative and later ranges return only one address, so the API returns fewer addresses than requested even when enough free addresses exist.

Relevant code:
https://github.com/ZSvirt/zsvirt/blob/main/network/src/main/java/org/zstack/network/l3/L3BasicNetwork.java#L876

Steps to reproduce

1. Create an L3 network with at least six non-overlapping IP ranges, each with at least 20 free IPs.
2. Call GetFreeIpOfL3Network with limit=100.
3. Observe that the response contains fewer than 100 free IPs.

Expected behavior

The API should return up to the requested limit across all matching IP ranges.

Proposed fix

Subtract tempFreeIpInventorys.size() from the remaining limit and stop early when the remaining limit is zero. Add a regression test covering multiple ranges.

[zsphere-opensource]

Thanks for the detailed report and for linking PR #34. We’ll evaluate the proposed fix through our internal review and validation process, and update this issue once the evaluation is complete.