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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 18:02:34 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 18:02:34 +0000 |
commit | fadeddfbb2aa38a980dd959b5ec1ffba7afd43cb (patch) | |
tree | a7bde6111c84ea64619656a38fba50909fa0bf60 /libevent/sample/le-proxy.c | |
parent | Initial commit. (diff) | |
download | lldpd-fadeddfbb2aa38a980dd959b5ec1ffba7afd43cb.tar.xz lldpd-fadeddfbb2aa38a980dd959b5ec1ffba7afd43cb.zip |
Adding upstream version 1.0.18.upstream/1.0.18upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'libevent/sample/le-proxy.c')
-rw-r--r-- | libevent/sample/le-proxy.c | 305 |
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; +} |