tools/testing/selftests/net/psock_fanout.c

Source file repositories/reference/linux-study-clean/tools/testing/selftests/net/psock_fanout.c

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/net/psock_fanout.c
Extension
.c
Size
16085 bytes
Lines
612
Domain
Support Tooling And Documentation
Bucket
tools
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

if (err) {
			perror("SIOCSIFFLAGS");
			exit(1);
		}
	}
	close(fd);
}

/* Open a socket in a given fanout mode.
 * @return -1 if mode is bad, a valid socket otherwise */
static int sock_fanout_open(uint16_t typeflags, uint16_t group_id)
{
	struct sockaddr_ll addr = {0};
	struct fanout_args args;
	int fd, val, err;

	fd = socket(PF_PACKET, SOCK_RAW, 0);
	if (fd < 0) {
		perror("socket packet");
		exit(1);
	}

	pair_udp_setfilter(fd);

	addr.sll_family = AF_PACKET;
	addr.sll_protocol = htons(ETH_P_IP);
	addr.sll_ifindex = if_nametoindex("lo");
	if (addr.sll_ifindex == 0) {
		perror("if_nametoindex");
		exit(1);
	}
	if (bind(fd, (void *) &addr, sizeof(addr))) {
		perror("bind packet");
		exit(1);
	}

	if (cfg_max_num_members) {
		args.id = group_id;
		args.type_flags = typeflags;
		args.max_num_members = cfg_max_num_members;
		err = setsockopt(fd, SOL_PACKET, PACKET_FANOUT, &args,
				 sizeof(args));
	} else {
		val = (((int) typeflags) << 16) | group_id;
		err = setsockopt(fd, SOL_PACKET, PACKET_FANOUT, &val,
				 sizeof(val));
	}
	if (err) {
		if (close(fd)) {
			perror("close packet");
			exit(1);
		}
		return -1;
	}

	return fd;
}

static void sock_fanout_set_cbpf(int fd)
{
	struct sock_filter bpf_filter[] = {
		BPF_STMT(BPF_LD | BPF_B | BPF_ABS, 80),	      /* ldb [80] */
		BPF_STMT(BPF_RET | BPF_A, 0),		      /* ret A */
	};
	struct sock_fprog bpf_prog;

	bpf_prog.filter = bpf_filter;
	bpf_prog.len = ARRAY_SIZE(bpf_filter);

	if (setsockopt(fd, SOL_PACKET, PACKET_FANOUT_DATA, &bpf_prog,
		       sizeof(bpf_prog))) {
		perror("fanout data cbpf");
		exit(1);
	}
}

static void sock_fanout_getopts(int fd, uint16_t *typeflags, uint16_t *group_id)
{
	int sockopt;
	socklen_t sockopt_len = sizeof(sockopt);

	if (getsockopt(fd, SOL_PACKET, PACKET_FANOUT,
		       &sockopt, &sockopt_len)) {
		perror("failed to getsockopt");
		exit(1);
	}
	*typeflags = sockopt >> 16;
	*group_id = sockopt & 0xfffff;
}

Annotation

Implementation Notes