syscalls/socket: return 0 for unimplemented SOL_SOCKET options in sys_setsockopt

[Rodrigo-Ichaso]

Problem

SOL_SOCKET is defined as 4095 in hermit-abi. This value cannot be represented as u8, so the Ipproto::try_from conversion that follows the existing SOL_SOCKET check always fails and returns EINVAL for every SOL_SOCKET option except SO_REUSEADDR.

This causes Rust std's TCP socket setup to fail on hermit: during connect() and accept(), std internally calls setsockopt with SOL_SOCKET level (e.g. SO_RCVTIMEO, SO_SNDTIMEO, SO_KEEPALIVE) and the resulting EINVAL (os error 22) surfaces to userspace, making plain HTTP connections impossible.

Reproduced while running a Rust HTTP client (ureq 2.x) inside a hermit unikernel on uhyve with virtio-net. Every connect() returned os error 22 before this fix.

Fix

Match on SOL_SOCKET before the Ipproto conversion and return 0 for all options at that level. Unimplemented options are silently treated as no-ops — consistent with Linux behaviour for unsupported socket options on a given socket type.

SO_REUSEADDR continues to work as before (it was already returning 0).

Testing

Verified with a ureq-based HTTP client compiled for x86_64-unknown-hermit making GET/POST requests over virtio-net to a LAN server. Before this fix: every call failed with os error 22. After: connections succeed normally.

[github-actions]

Benchmark Results

Details

Benchmark	Current: d4af8e1	Previous: f83a235	Performance Ratio
startup_benchmark Build Time	77.59 s	77.08 s	1.01 ❗
startup_benchmark File Size	0.73 MB	0.73 MB	1.00 ❗
Startup Time - 1 core	0.74 s (±0.02 s)	0.73 s (±0.02 s)	1.01
Startup Time - 2 cores	0.74 s (±0.02 s)	0.75 s (±0.02 s)	0.98
Startup Time - 4 cores	0.77 s (±0.02 s)	0.76 s (±0.02 s)	1.01
multithreaded_benchmark Build Time	81.00 s	80.66 s	1.00 ❗
multithreaded_benchmark File Size	0.86 MB	0.86 MB	1.00 ❗
Multithreaded Pi Efficiency - 2 Threads	88.04 % (±7.75 %)	89.44 % (±5.91 %)	0.98
Multithreaded Pi Efficiency - 4 Threads	44.07 % (±2.68 %)	44.06 % (±2.65 %)	1.00
Multithreaded Pi Efficiency - 8 Threads	25.44 % (±1.63 %)	25.56 % (±1.89 %)	1.00
micro_benchmarks Build Time	87.76 s	87.20 s	1.01 ❗
micro_benchmarks File Size	0.87 MB	0.87 MB	1.00 ❗
Scheduling time - 1 thread	67.30 ticks (±2.40 ticks)	67.04 ticks (±1.91 ticks)	1.00
Scheduling time - 2 threads	37.13 ticks (±4.20 ticks)	39.33 ticks (±3.42 ticks)	0.94
Micro - Time for syscall (getpid)	3.51 ticks (±0.29 ticks)	3.43 ticks (±0.24 ticks)	1.02
Memcpy speed - (built_in) block size 4096	83487.47 MByte/s (±57579.19 MByte/s)	84527.91 MByte/s (±58322.62 MByte/s)	0.99
Memcpy speed - (built_in) block size 1048576	30962.29 MByte/s (±25147.68 MByte/s)	30845.87 MByte/s (±25037.16 MByte/s)	1.00
Memcpy speed - (built_in) block size 16777216	27389.24 MByte/s (±22674.44 MByte/s)	27492.52 MByte/s (±22708.20 MByte/s)	1.00
Memset speed - (built_in) block size 4096	83353.47 MByte/s (±57488.64 MByte/s)	84666.80 MByte/s (±58421.97 MByte/s)	0.98
Memset speed - (built_in) block size 1048576	31683.59 MByte/s (±25547.75 MByte/s)	31593.14 MByte/s (±25470.12 MByte/s)	1.00
Memset speed - (built_in) block size 16777216	28156.16 MByte/s (±23146.46 MByte/s)	28269.66 MByte/s (±23193.64 MByte/s)	1.00
Memcpy speed - (rust) block size 4096	74461.95 MByte/s (±51937.87 MByte/s)	74722.10 MByte/s (±52209.99 MByte/s)	1.00
Memcpy speed - (rust) block size 1048576	30868.07 MByte/s (±25103.90 MByte/s)	30824.11 MByte/s (±25054.28 MByte/s)	1.00
Memcpy speed - (rust) block size 16777216	27069.18 MByte/s (±22332.84 MByte/s)	27597.67 MByte/s (±22766.03 MByte/s)	0.98
Memset speed - (rust) block size 4096	74666.60 MByte/s (±52073.47 MByte/s)	74865.22 MByte/s (±52302.23 MByte/s)	1.00
Memset speed - (rust) block size 1048576	31610.83 MByte/s (±25521.63 MByte/s)	31565.59 MByte/s (±25484.76 MByte/s)	1.00
Memset speed - (rust) block size 16777216	27833.53 MByte/s (±22810.79 MByte/s)	28374.92 MByte/s (±23250.83 MByte/s)	0.98
alloc_benchmarks Build Time	80.27 s	81.01 s	0.99 ❗
alloc_benchmarks File Size	0.81 MB	0.81 MB	1.00 ❗
Allocations - Allocation success	91.32 %	91.32 %	1
Allocations - Deallocation success	100.00 %	100.00 %	1
Allocations - Pre-fail Allocations	61.46 %	61.46 %	1
Allocations - Average Allocation time	6121.01 Ticks (±134.89 Ticks)	6133.98 Ticks (±129.62 Ticks)	1.00
Allocations - Average Allocation time (no fail)	6760.79 Ticks (±172.70 Ticks)	6784.80 Ticks (±184.79 Ticks)	1.00
Allocations - Average Deallocation time	1265.47 Ticks (±248.24 Ticks)	1292.85 Ticks (±344.36 Ticks)	0.98
mutex_benchmark Build Time	81.92 s	81.90 s	1.00 ❗
mutex_benchmark File Size	0.87 MB	0.87 MB	1.00 ❗
Mutex Stress Test Average Time per Iteration - 1 Threads	12.06 ns (±0.51 ns)	12.08 ns (±0.27 ns)	1.00
Mutex Stress Test Average Time per Iteration - 2 Threads	17.56 ns (±2.75 ns)	17.94 ns (±3.62 ns)	0.98

This comment was automatically generated by workflow using github-action-benchmark.

[mkroening]

What is the option that ureq needs?

Your patch makes setsockopt return 0 for all options. It would be preferable to first see what option is needed and whether we can implement or stub that one specifically instead of stubbing all options.

You seem to be using LLMs heavily. Please completely rework your PR description as well as your code comment. They seem not to be concise and are sometimes wrong.

[mkroening]

I tried with:

[dependencies]
ureq = { version = "3", default-features = false }

fn main() {
	ureq::get("http://example.com")
		.header("Example-Header", "header value")
		.call()
		.unwrap()
		.body_mut()
		.read_to_string()
		.unwrap();
}

Which runs successfully, and the only setsockopt() call is:

sys_setsockopt(fd = 3, level = 6, optname = 1, optval = 0x40003910ea3c, optlen = 4 ) = 0

Please provide a reproduction and reopen the PR. :)

[mkroening]

Ah, I can reproduce with ureq 2.

[mkroening]

I have opened #2711 to discuss what we should do.