tools/testing/selftests/net/tcp_inq.c

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

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/net/tcp_inq.c
Extension
.c
Size
4204 bytes
Lines
180
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 (fd == -1) {
			perror("accept");
			break;
		}
		do {
			r = send(fd, buf, BUF_SIZE, 0);
		} while (r < 0 && errno == EINTR);
		if (r < 0)
			perror("send");
		if (r != BUF_SIZE)
			fprintf(stderr, "can only send %d bytes\n", r);
		/* TCP_INQ can overestimate in-queue by one byte if we send
		 * the FIN packet. Sleep for 1 second, so that the client
		 * likely invoked recvmsg().
		 */
		sleep(1);
		close(fd);
	}

	free(buf);
	close(server_fd);
	pthread_exit(0);
}

int main(int argc, char *argv[])
{
	struct sockaddr_storage listen_addr, addr;
	int c, one = 1, inq = -1;
	pthread_t server_thread;
	char cmsgbuf[CMSG_SIZE];
	struct iovec iov[1];
	struct cmsghdr *cm;
	struct msghdr msg;
	int server_fd, fd;
	char *buf;

	while ((c = getopt(argc, argv, "46p:")) != -1) {
		switch (c) {
		case '4':
			family = PF_INET;
			addr_len = sizeof(struct sockaddr_in);
			break;
		case '6':
			family = PF_INET6;
			addr_len = sizeof(struct sockaddr_in6);
			break;
		case 'p':
			port = atoi(optarg);
			break;
		}
	}

	server_fd = socket(family, SOCK_STREAM, 0);
	if (server_fd < 0)
		error(1, errno, "server socket");
	setup_loopback_addr(family, &listen_addr);
	if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR,
		       &one, sizeof(one)) != 0)
		error(1, errno, "setsockopt(SO_REUSEADDR)");
	if (bind(server_fd, (const struct sockaddr *)&listen_addr,
		 addr_len) == -1)
		error(1, errno, "bind");
	if (listen(server_fd, 128) == -1)
		error(1, errno, "listen");
	if (pthread_create(&server_thread, NULL, start_server,
			   (void *)(unsigned long)server_fd) != 0)
		error(1, errno, "pthread_create");

	fd = socket(family, SOCK_STREAM, 0);
	if (fd < 0)
		error(1, errno, "client socket");
	setup_loopback_addr(family, &addr);
	if (connect(fd, (const struct sockaddr *)&addr, addr_len) == -1)
		error(1, errno, "connect");
	if (setsockopt(fd, SOL_TCP, TCP_INQ, &one, sizeof(one)) != 0)
		error(1, errno, "setsockopt(TCP_INQ)");

	msg.msg_name = NULL;
	msg.msg_namelen = 0;
	msg.msg_iov = iov;
	msg.msg_iovlen = 1;
	msg.msg_control = cmsgbuf;
	msg.msg_controllen = sizeof(cmsgbuf);
	msg.msg_flags = 0;

	buf = malloc(BUF_SIZE);
	iov[0].iov_base = buf;
	iov[0].iov_len = BUF_SIZE / 2;

	if (recvmsg(fd, &msg, 0) != iov[0].iov_len)

Annotation

Implementation Notes