MagicStack / MagicStack/uvloop
getaddrinfo() returns wrong scope ID for IPv6 link-local addresses when type=SocketKind.SOCK_STREAM
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Description
* **uvloop version**: 0.17.0
* **Python version**: 3.11.3
* **Platform**: Linux
* **Can you reproduce the bug with `PYTHONASYNCIODEBUG` in env?**: yes
* **Does uvloop behave differently from vanilla asyncio? How?**: Vanilla asyncio returns the correct scope ID, uvloop returns 0
When passing `type=SocketKind.SOCK_STREAM` to `getaddrinfo()` in uvloop, the scope ID for link-local addresses is left as 0. This works correctly (returns nonzero scope ID) in `socket.getaddrinfo()` and vanilla asyncio's corresponding function.
Repro script (requires `psutil` installed):
```python
from asyncio import get_running_loop, run
from socket import SocketKind
import psutil
import uvloop
async def main():
for ifname, addresses in psutil.net_if_addrs().items():
for addr in addresses:
if addr.address.startswith("fe80::") and "%" in addr.address:
gai_res = await get_running_loop().getaddrinfo(addr.address, 0, type=SocketKind.SOCK_STREAM)
scope_id = gai_res[-1][-1][-1]
print("Scope id for", gai_res[-1], "is", scope_id)
return
print("Could not find a suitable link-local address")
# Comment out this line, and it works fine
uvloop.install()
run(main())
```
Contributor guide
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Research direction
Start by running the provided reproduction script on Linux with a link-local IPv6 address, comparing uvloop with vanilla asyncio and socket.getaddrinfo(). The issue is done when uvloop returns the correct nonzero scope ID for SOCK_STREAM, matching the other implementations.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- networking
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100