1 files changed, 305 insertions, 0 deletions
diff --git a/libevent/sample/le-proxy.c b/libevent/sample/le-proxy.c
new file mode 100644
index 0000000..13e0e2a
--- /dev/null
+++ b/libevent/sample/le-proxy.c
@@ -0,0 +1,305 @@
+/*
+  This example code shows how to write an (optionally encrypting) SSL proxy
+  with Libevent's bufferevent layer.
+
+  XXX It's a little ugly and should probably be cleaned up.
+ */
+
+// Get rid of OSX 10.7 and greater deprecation warnings.
+#if defined(__APPLE__) && defined(__clang__)
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
+#endif
+
+#include <stdio.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#ifdef _WIN32
+#include <winsock2.h>
+#include <ws2tcpip.h>
+#else
+#include <sys/socket.h>
+#include <netinet/in.h>
+#endif
+
+#include <event2/bufferevent_ssl.h>
+#include <event2/bufferevent.h>
+#include <event2/buffer.h>
+#include <event2/listener.h>
+#include <event2/util.h>
+
+#include "util-internal.h"
+#include <openssl/ssl.h>
+#include <openssl/err.h>
+#include <openssl/rand.h>
+#include "openssl-compat.h"
+
+static struct event_base *base;
+static struct sockaddr_storage listen_on_addr;
+static struct sockaddr_storage connect_to_addr;
+static int connect_to_addrlen;
+static int use_wrapper = 1;
+
+static SSL_CTX *ssl_ctx = NULL;
+
+#define MAX_OUTPUT (512*1024)
+
+static void drained_writecb(struct bufferevent *bev, void *ctx);
+static void eventcb(struct bufferevent *bev, short what, void *ctx);
+
+static void
+readcb(struct bufferevent *bev, void *ctx)
+{
+	struct bufferevent *partner = ctx;
+	struct evbuffer *src, *dst;
+	size_t len;
+	src = bufferevent_get_input(bev);
+	len = evbuffer_get_length(src);
+	if (!partner) {
+		evbuffer_drain(src, len);
+		return;
+	}
+	dst = bufferevent_get_output(partner);
+	evbuffer_add_buffer(dst, src);
+
+	if (evbuffer_get_length(dst) >= MAX_OUTPUT) {
+		/* We're giving the other side data faster than it can
+		 * pass it on.  Stop reading here until we have drained the
+		 * other side to MAX_OUTPUT/2 bytes. */
+		bufferevent_setcb(partner, readcb, drained_writecb,
+		    eventcb, bev);
+		bufferevent_setwatermark(partner, EV_WRITE, MAX_OUTPUT/2,
+		    MAX_OUTPUT);
+		bufferevent_disable(bev, EV_READ);
+	}
+}
+
+static void
+drained_writecb(struct bufferevent *bev, void *ctx)
+{
+	struct bufferevent *partner = ctx;
+
+	/* We were choking the other side until we drained our outbuf a bit.
+	 * Now it seems drained. */
+	bufferevent_setcb(bev, readcb, NULL, eventcb, partner);
+	bufferevent_setwatermark(bev, EV_WRITE, 0, 0);
+	if (partner)
+		bufferevent_enable(partner, EV_READ);
+}
+
+static void
+close_on_finished_writecb(struct bufferevent *bev, void *ctx)
+{
+	struct evbuffer *b = bufferevent_get_output(bev);
+
+	if (evbuffer_get_length(b) == 0) {
+		bufferevent_free(bev);
+	}
+}
+
+static void
+eventcb(struct bufferevent *bev, short what, void *ctx)
+{
+	struct bufferevent *partner = ctx;
+
+	if (what & (BEV_EVENT_EOF|BEV_EVENT_ERROR)) {
+		if (what & BEV_EVENT_ERROR) {
+			unsigned long err;
+			while ((err = (bufferevent_get_openssl_error(bev)))) {
+				const char *msg = (const char*)
+				    ERR_reason_error_string(err);
+				const char *lib = (const char*)
+				    ERR_lib_error_string(err);
+				const char *func = (const char*)
+				    ERR_func_error_string(err);
+				fprintf(stderr,
+				    "%s in %s %s\n", msg, lib, func);
+			}
+			if (errno)
+				perror("connection error");
+		}
+
+		if (partner) {
+			/* Flush all pending data */
+			readcb(bev, ctx);
+
+			if (evbuffer_get_length(
+				    bufferevent_get_output(partner))) {
+				/* We still have to flush data from the other
+				 * side, but when that's done, close the other
+				 * side. */
+				bufferevent_setcb(partner,
+				    NULL, close_on_finished_writecb,
+				    eventcb, NULL);
+				bufferevent_disable(partner, EV_READ);
+			} else {
+				/* We have nothing left to say to the other
+				 * side; close it. */
+				bufferevent_free(partner);
+			}
+		}
+		bufferevent_free(bev);
+	}
+}
+
+static void
+syntax(void)
+{
+	fputs("Syntax:\n", stderr);
+	fputs("   le-proxy [-s] [-W] <listen-on-addr> <connect-to-addr>\n", stderr);
+	fputs("Example:\n", stderr);
+	fputs("   le-proxy 127.0.0.1:8888 1.2.3.4:80\n", stderr);
+
+	exit(1);
+}
+
+static void
+accept_cb(struct evconnlistener *listener, evutil_socket_t fd,
+    struct sockaddr *a, int slen, void *p)
+{
+	struct bufferevent *b_out, *b_in;
+	/* Create two linked bufferevent objects: one to connect, one for the
+	 * new connection */
+	b_in = bufferevent_socket_new(base, fd,
+	    BEV_OPT_CLOSE_ON_FREE|BEV_OPT_DEFER_CALLBACKS);
+
+	if (!ssl_ctx || use_wrapper)
+		b_out = bufferevent_socket_new(base, -1,
+		    BEV_OPT_CLOSE_ON_FREE|BEV_OPT_DEFER_CALLBACKS);
+	else {
+		SSL *ssl = SSL_new(ssl_ctx);
+		b_out = bufferevent_openssl_socket_new(base, -1, ssl,
+		    BUFFEREVENT_SSL_CONNECTING,
+		    BEV_OPT_CLOSE_ON_FREE|BEV_OPT_DEFER_CALLBACKS);
+	}
+
+	assert(b_in && b_out);
+
+	if (bufferevent_socket_connect(b_out,
+		(struct sockaddr*)&connect_to_addr, connect_to_addrlen)<0) {
+		perror("bufferevent_socket_connect");
+		bufferevent_free(b_out);
+		bufferevent_free(b_in);
+		return;
+	}
+
+	if (ssl_ctx && use_wrapper) {
+		struct bufferevent *b_ssl;
+		SSL *ssl = SSL_new(ssl_ctx);
+		b_ssl = bufferevent_openssl_filter_new(base,
+		    b_out, ssl, BUFFEREVENT_SSL_CONNECTING,
+		    BEV_OPT_CLOSE_ON_FREE|BEV_OPT_DEFER_CALLBACKS);
+		if (!b_ssl) {
+			perror("Bufferevent_openssl_new");
+			bufferevent_free(b_out);
+			bufferevent_free(b_in);
+			return;
+		}
+		b_out = b_ssl;
+	}
+
+	bufferevent_setcb(b_in, readcb, NULL, eventcb, b_out);
+	bufferevent_setcb(b_out, readcb, NULL, eventcb, b_in);
+
+	bufferevent_enable(b_in, EV_READ|EV_WRITE);
+	bufferevent_enable(b_out, EV_READ|EV_WRITE);
+}
+
+int
+main(int argc, char **argv)
+{
+	int i;
+	int socklen;
+
+	int use_ssl = 0;
+	struct evconnlistener *listener;
+
+#ifdef _WIN32
+	WORD wVersionRequested;
+	WSADATA wsaData;
+	wVersionRequested = MAKEWORD(2, 2);
+	(void) WSAStartup(wVersionRequested, &wsaData);
+#endif
+
+	if (argc < 3)
+		syntax();
+
+	for (i=1; i < argc; ++i) {
+		if (!strcmp(argv[i], "-s")) {
+			use_ssl = 1;
+		} else if (!strcmp(argv[i], "-W")) {
+			use_wrapper = 0;
+		} else if (argv[i][0] == '-') {
+			syntax();
+		} else
+			break;
+	}
+
+	if (i+2 != argc)
+		syntax();
+
+	memset(&listen_on_addr, 0, sizeof(listen_on_addr));
+	socklen = sizeof(listen_on_addr);
+	if (evutil_parse_sockaddr_port(argv[i],
+		(struct sockaddr*)&listen_on_addr, &socklen)<0) {
+		int p = atoi(argv[i]);
+		struct sockaddr_in *sin = (struct sockaddr_in*)&listen_on_addr;
+		if (p < 1 || p > 65535)
+			syntax();
+		sin->sin_port = htons(p);
+		sin->sin_addr.s_addr = htonl(0x7f000001);
+		sin->sin_family = AF_INET;
+		socklen = sizeof(struct sockaddr_in);
+	}
+
+	memset(&connect_to_addr, 0, sizeof(connect_to_addr));
+	connect_to_addrlen = sizeof(connect_to_addr);
+	if (evutil_parse_sockaddr_port(argv[i+1],
+		(struct sockaddr*)&connect_to_addr, &connect_to_addrlen)<0)
+		syntax();
+
+	base = event_base_new();
+	if (!base) {
+		perror("event_base_new()");
+		return 1;
+	}
+
+	if (use_ssl) {
+		int r;
+#if (OPENSSL_VERSION_NUMBER < 0x10100000L) || \
+	(defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER < 0x20700000L)
+		SSL_library_init();
+		ERR_load_crypto_strings();
+		SSL_load_error_strings();
+		OpenSSL_add_all_algorithms();
+#endif
+		r = RAND_poll();
+		if (r == 0) {
+			fprintf(stderr, "RAND_poll() failed.\n");
+			return 1;
+		}
+		ssl_ctx = SSL_CTX_new(TLS_method());
+	}
+
+	listener = evconnlistener_new_bind(base, accept_cb, NULL,
+	    LEV_OPT_CLOSE_ON_FREE|LEV_OPT_CLOSE_ON_EXEC|LEV_OPT_REUSEABLE,
+	    -1, (struct sockaddr*)&listen_on_addr, socklen);
+
+	if (! listener) {
+		fprintf(stderr, "Couldn't open listener.\n");
+		event_base_free(base);
+		return 1;
+	}
+	event_base_dispatch(base);
+
+	evconnlistener_free(listener);
+	event_base_free(base);
+
+#ifdef _WIN32
+	WSACleanup();
+#endif
+
+	return 0;
+}