samples/bpf/tcp_clamp_kern.c

Source file repositories/reference/linux-study-clean/samples/bpf/tcp_clamp_kern.c

File Facts

System
Linux kernel
Corpus path
samples/bpf/tcp_clamp_kern.c
Extension
.c
Size
2758 bytes
Lines
98
Domain
Support Tooling And Documentation
Bucket
samples
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

switch (op) {
		case BPF_SOCK_OPS_TIMEOUT_INIT:
			rv = to_init;
			break;
		case BPF_SOCK_OPS_TCP_CONNECT_CB:
			/* Set sndbuf and rcvbuf of active connections */
			rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF,
					    &bufsize, sizeof(bufsize));
			rv += bpf_setsockopt(skops, SOL_SOCKET,
					     SO_RCVBUF, &bufsize,
					     sizeof(bufsize));
			break;
		case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
			rv = bpf_setsockopt(skops, SOL_TCP,
					    TCP_BPF_SNDCWND_CLAMP,
					    &clamp, sizeof(clamp));
			break;
		case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
			/* Set sndbuf and rcvbuf of passive connections */
			rv = bpf_setsockopt(skops, SOL_TCP,
					    TCP_BPF_SNDCWND_CLAMP,
					    &clamp, sizeof(clamp));
			rv += bpf_setsockopt(skops, SOL_SOCKET,
					     SO_SNDBUF, &bufsize,
					     sizeof(bufsize));
			rv += bpf_setsockopt(skops, SOL_SOCKET,
					     SO_RCVBUF, &bufsize,
					     sizeof(bufsize));
			break;
		default:
			rv = -1;
		}
	} else {
		rv = -1;
	}
#ifdef DEBUG
	bpf_printk("Returning %d\n", rv);
#endif
	skops->reply = rv;
	return 1;
}
char _license[] SEC("license") = "GPL";

Annotation

Implementation Notes