1 files changed, 97 insertions, 0 deletions
diff --git a/latency.c b/latency.c
new file mode 100644
index 0000000..6181e84
--- /dev/null
+++ b/latency.c
@@ -0,0 +1,97 @@
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/uio.h>
+#include <errno.h>
+#include <netdb.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include "proxy.h"
+
+static int parse_host(const char *host, const char *port, struct addrinfo **addr)
+{
+	struct addrinfo hints = {
+		.ai_family   = AF_UNSPEC,
+		.ai_socktype = SOCK_STREAM,
+		.ai_flags    = AI_PASSIVE,
+	};
+
+	int err;
+	if ((err = getaddrinfo(host, port, &hints, addr))) {
+		fprintf(stderr, "getaddrinfo failed: %s\n", gai_strerror(err));
+		return -1;
+	}
+
+	return 0;
+}
+
+static int listen_source(struct addrinfo *source)
+{
+	int fd = -1;
+	for (struct addrinfo *a = source; a; a = a->ai_next) {
+		if ((fd = socket(a->ai_family, a->ai_socktype, a->ai_protocol)) == -1)
+			continue;
+		if (!bind(fd, a->ai_addr, a->ai_addrlen) && !listen(fd, 1))
+			break;
+		close(fd);
+		fd = -1;
+	}
+	return fd;
+}
+
+static int connect_target(struct addrinfo *target)
+{
+	int fd = -1;
+	for (struct addrinfo *a = target; a; a = a->ai_next) {
+		if ((fd = socket(a->ai_family, a->ai_socktype, a->ai_protocol)) == -1)
+			continue;
+		if (connect(fd, a->ai_addr, a->ai_addrlen) != -1)
+			break;
+		close(fd);
+		fd = -1;
+	}
+	return fd;
+}
+
+int main(int argc, char **argv)
+{
+	struct addrinfo *source;
+	struct addrinfo *target;
+
+	if (argc != 3) {
+		fprintf(stderr, "usage: %s targethost targetport\n", argv[0]);
+		return -1;
+	}
+
+	if (parse_host(NULL, "1234", &source))
+		return -1;
+	if (parse_host(argv[1], argv[2], &target))
+		return -1;
+
+	int listenfd = listen_source(source);
+	if (listenfd < 0) {
+		perror("listen_source");
+		return -1;
+	}
+
+	for (;;) {
+		int sourcefd = accept(listenfd, NULL, NULL);
+		if (sourcefd == -1) break;
+
+		int targetfd = connect_target(target);
+		if (targetfd == -1) {
+			perror("connect_target");
+			close(sourcefd);
+			break;
+		}
+
+		proxy(sourcefd, targetfd, 500);
+
+		close(targetfd);
+		close(sourcefd);
+	}
+
+	close(listenfd);
+	return 0;
+}
+