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Hash :
49d6b4b0
Author :
Date :
2024-07-08T10:10:42
samples: use evutil_socket_t instead and handle 64 bit Windows (#1682) * Use evutil_socket_t instead in http server sample and handle 64 bit Windows * Update http-server.c * consistently using EV_SOCK_FMT for Windows compatibility * code review: fix missing symbol strsignal * Add evutil_strsignal() helper instead of strsignal() macro --------- Co-authored-by: Hernan Martinez <hernan.c.martinez@gmail.com> Co-authored-by: Azat Khuzhin <azat@libevent.org>
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/**
* This is an analog of nc/ncat/telnet that uses libevent's bufferevents
*
* TODO:
* - optional SSL
*/
#include <event2/event.h>
#include <event2/listener.h>
#include <event2/buffer.h>
#include <event2/bufferevent.h>
#include <event2/event-config.h>
#include "../util-internal.h"
#include <event2/bufferevent_ssl.h>
#include <openssl/ssl.h>
#include <openssl/rsa.h>
#include <openssl/bn.h>
#include <openssl/x509.h>
#include <openssl/err.h>
#include "openssl-compat.h"
#ifdef _WIN32
#include <winsock2.h>
#include <ws2tcpip.h>
#include <windows.h>
#include <getopt.h>
#include <io.h>
#include <fcntl.h>
#else /* _WIN32 */
#include <sys/stat.h>
#include <sys/socket.h>
#include <netinet/tcp.h>
#include <fcntl.h>
#include <unistd.h>
#endif /* !_WIN32 */
#include <string.h>
#include <signal.h>
#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#ifdef __GNUC__
#define CHECK_FMT(a,b) __attribute__((format(printf, a, b)))
#else
#define CHECK_FMT(a,b)
#endif
#ifndef STDIN_FILENO
#define STDIN_FILENO 0
#endif
static int verbose;
struct addr
{
int port;
char *address;
};
struct options
{
struct addr src;
struct addr dst;
int max_read;
struct {
int read; /* seconds */
int write; /* seconds */
} timeout;
int tcp_keepalive_timeout; /* seconds */
struct {
int listen:1;
int keep:1;
int ssl:1;
} extra;
};
struct ssl_context
{
SSL_CTX *ctx;
EVP_PKEY *pkey;
X509 *cert;
};
struct context
{
struct options *opts;
struct ssl_context ssl;
struct bufferevent *in;
struct bufferevent *out;
FILE *fout;
};
static void info(const char *fmt, ...) CHECK_FMT(1,2);
static void error(const char *fmt, ...) CHECK_FMT(1,2);
static void info(const char *fmt, ...)
{
va_list ap;
if (!verbose)
return;
va_start(ap, fmt);
vfprintf(stdout, fmt, ap);
va_end(ap);
}
static void error(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
}
static void be_free(struct bufferevent **bevp)
{
evutil_socket_t fd;
struct bufferevent *bev = *bevp;
if (!bev)
return;
fd = bufferevent_getfd(bev);
info("Freeing bufferevent with fd=%d\n", fd);
bufferevent_free(bev);
*bevp = NULL;
}
static struct bufferevent *
be_new(struct context *ctx, struct event_base *base, evutil_socket_t fd)
{
SSL *ssl = NULL;
struct bufferevent *bev = NULL;
int flags = BEV_OPT_CLOSE_ON_FREE;
enum bufferevent_ssl_state state = BUFFEREVENT_SSL_CONNECTING;
if (fd != -1)
state = BUFFEREVENT_SSL_ACCEPTING;
if (ctx->opts->extra.ssl) {
ssl = SSL_new(ctx->ssl.ctx);
if (!ssl)
goto err;
if (SSL_use_certificate(ssl, ctx->ssl.cert) != 1)
goto err;
if (SSL_use_PrivateKey(ssl, ctx->ssl.pkey) != 1)
goto err;
bev = bufferevent_openssl_socket_new(base, fd, ssl, state, flags);
} else {
bev = bufferevent_socket_new(base, fd, flags);
}
if (ctx->opts->max_read != -1) {
if (bufferevent_set_max_single_read(bev, ctx->opts->max_read))
goto err;
}
return bev;
err:
if (ssl)
SSL_free(ssl);
return NULL;
}
static int be_set_timeout(struct bufferevent *bev, const struct options *o)
{
struct timeval tv_read = { o->timeout.read, 0 };
struct timeval tv_write = { o->timeout.write, 0 };
info("Set timeout to (read=%i, write=%i)\n", o->timeout.read, o->timeout.write);
return bufferevent_set_timeouts(bev, &tv_read, &tv_write);
}
#if (OPENSSL_VERSION_NUMBER < 0x10100000L) || \
(defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER < 0x20700000L)
static inline void ssl_init(void)
{
SSL_library_init();
ERR_load_crypto_strings();
SSL_load_error_strings();
OpenSSL_add_all_algorithms();
}
#else /* OPENSSL_VERSION_NUMBER */
static inline void ssl_init(void) {}
#endif /* OPENSSL_VERSION_NUMBER */
static void ssl_ctx_free(struct ssl_context *ssl)
{
SSL_CTX_free(ssl->ctx);
EVP_PKEY_free(ssl->pkey);
X509_free(ssl->cert);
}
static int ssl_load_key(struct ssl_context *ssl)
{
int err = 1;
#if OPENSSL_VERSION_NUMBER >= 0x30000000
ssl->pkey = EVP_RSA_gen(4096);
err = ssl->pkey == NULL;
#else
BIGNUM *bn;
RSA *key;
ssl->pkey = EVP_PKEY_new();
bn = BN_new();
if (BN_set_word(bn, RSA_F4) != 1)
goto err;
/** Will be freed with ctx.pkey */
key = RSA_new();
if (RSA_generate_key_ex(key, 2048, bn, NULL) != 1)
goto err;
if (EVP_PKEY_assign_RSA(ssl->pkey, key) != 1)
goto err;
err = 0;
err:
BN_free(bn);
#endif
return err;
}
static int ssl_load_cert(struct ssl_context *ssl)
{
X509_NAME *name;
ssl->cert = X509_new();
ASN1_INTEGER_set(X509_get_serialNumber(ssl->cert), 1);
X509_gmtime_adj(X509_getm_notBefore(ssl->cert), 0);
/** 1 year lifetime */
X509_gmtime_adj(X509_getm_notAfter(ssl->cert),
(long)time(NULL) + 365 * 86400);
X509_set_pubkey(ssl->cert, ssl->pkey);
name = X509_get_subject_name(ssl->cert);
X509_NAME_add_entry_by_txt(
name, "C", MBSTRING_ASC, (unsigned char *)"--", -1, -1, 0);
X509_NAME_add_entry_by_txt(
name, "O", MBSTRING_ASC, (unsigned char *)"<NULL>", -1, -1, 0);
X509_NAME_add_entry_by_txt(
name, "CN", MBSTRING_ASC, (unsigned char *)"*", -1, -1, 0);
X509_set_issuer_name(ssl->cert, name);
X509_sign(ssl->cert, ssl->pkey, EVP_sha1());
return 0;
}
static int ssl_ctx_init(struct ssl_context *ssl)
{
const SSL_METHOD *method;
ssl_init();
method = TLS_method();
if (!method)
goto err;
ssl->ctx = SSL_CTX_new(method);
if (ssl_load_key(ssl))
goto err;
if (ssl_load_cert(ssl))
goto err;
return 0;
err:
ssl_ctx_free(ssl);
return 1;
}
static void print_usage(FILE *out, const char *name)
{
fprintf(out, "Syntax: %s [ OPTS ] [hostname] [port]\n", name);
fprintf(out,
"\n"
"ncat like utility\n"
"\n"
" -p Specify source port to use\n"
" -s Specify source address to use (*does* affect -l, unlike ncat)\n"
" -l Bind and listen for incoming connections\n"
" -k Accept multiple connections in listen mode\n"
" -K TCP_KEEPALIVE timeout\n"
" -S Connect or listen with SSL\n"
" -t read timeout\n"
" -T write timeout\n"
" -b read buffer size\n"
"\n"
" -v Increase verbosity\n"
" -h Print usage\n"
);
}
static struct options parse_opts(int argc, char **argv)
{
struct options o;
int opt;
memset(&o, 0, sizeof(o));
o.src.port = o.dst.port = 10024;
o.max_read = -1;
while ((opt = getopt(argc, argv, "p:s:b:t:T:K:" "lkSvh")) != -1) {
switch (opt) {
case 'p': o.src.port = atoi(optarg); break;
case 's': o.src.address = strdup("127.1"); break;
case 'b': o.max_read = atoi(optarg); break;
case 't': o.timeout.read = atoi(optarg); break;
case 'T': o.timeout.write = atoi(optarg); break;
case 'K': o.tcp_keepalive_timeout = atoi(optarg); break;
case 'l': o.extra.listen |= 1; break;
case 'k': o.extra.keep |= 1; break;
case 'S': o.extra.ssl |= 1; break;
/**
* TODO: implement other bits:
* - filters
* - pair
* - watermarks
* - ratelimits
*/
case 'v': ++verbose; break;
case 'h':
print_usage(stdout, argv[0]);
exit(EXIT_SUCCESS);
default:
fprintf(stderr, "Unknown option -%c\n", opt); break;
exit(EXIT_FAILURE);
}
}
if ((argc-optind) > 0) {
o.dst.address = strdup(argv[optind]);
++optind;
}
if ((argc-optind) > 0) {
o.dst.port = atoi(argv[optind]);
++optind;
}
if ((argc-optind) > 0) {
print_usage(stderr, argv[0]);
exit(1);
}
if (!o.src.address)
o.src.address = strdup("127.1");
if (!o.dst.address)
o.dst.address = strdup("127.1");
return o;
}
static void do_term(evutil_socket_t sig, short events, void *arg)
{
struct event_base *base = arg;
event_base_loopexit(base, NULL);
fprintf(stderr, "%s signal received. Terminating\n",
evutil_strsignal(EV_SOCK_ARG(sig)));
}
static ev_socklen_t
make_address(struct sockaddr_storage *ss, const char *address, ev_uint16_t port)
{
struct evutil_addrinfo *ai = NULL;
struct evutil_addrinfo hints;
char strport[NI_MAXSERV];
int ai_result;
ev_socklen_t ret = 0;
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = EVUTIL_AI_PASSIVE|EVUTIL_AI_ADDRCONFIG;
evutil_snprintf(strport, sizeof(strport), "%d", port);
if ((ai_result = evutil_getaddrinfo(address, strport, &hints, &ai)) != 0) {
return 0;
}
if (!ai)
return 0;
if (ai->ai_addrlen > sizeof(*ss)) {
evutil_freeaddrinfo(ai);
return 0;
}
memcpy(ss, ai->ai_addr, ai->ai_addrlen);
/** Hm.. I do not like this cast. */
ret = (ev_socklen_t)ai->ai_addrlen;
evutil_freeaddrinfo(ai);
return ret;
}
static void be_ssl_errors(struct bufferevent *bev)
{
int err;
while ((err = bufferevent_get_openssl_error(bev))) {
const char *msg = ERR_reason_error_string(err);
const char *lib = ERR_lib_error_string(err);
#if OPENSSL_VERSION_NUMBER >= 0x30000000
error("ssl/err=%d/%s in %s\n", err, msg, lib);
#else
const char *func = ERR_func_error_string(err);
error("ssl/err=%d/%s in %s %s\n", err, msg, lib, func);
#endif
}
}
static int event_cb_(struct bufferevent *bev, short what, int ssl, int stop)
{
struct event_base *base = bufferevent_get_base(bev);
evutil_socket_t fd = bufferevent_getfd(bev);
if (what & BEV_EVENT_CONNECTED) {
info("Connected\n");
return 0;
}
if (ssl && what & BEV_EVENT_ERROR) {
be_ssl_errors(bev);
}
if (stop)
event_base_loopexit(base, NULL);
error("Got 0x%x event on fd=%d. Terminating connection\n", what, fd);
be_free(&bev);
return 1;
}
static void read_cb(struct bufferevent *bev, void *arg)
{
struct context *ctx = arg;
struct evbuffer *in = bufferevent_get_input(bev);
evbuffer_write(in, fileno(ctx->fout));
}
static void write_cb(struct bufferevent *bev, void *arg)
{
struct context *ctx = arg;
bufferevent_write_buffer(bev, bufferevent_get_input(ctx->in));
}
static void server_event_cb(struct bufferevent *bev, short what, void *arg)
{
struct context *ctx = arg;
EVUTIL_ASSERT(bev == ctx->out);
if (!event_cb_(bev, what, ctx->opts->extra.ssl, !ctx->opts->extra.keep))
return;
ctx->out = NULL;
}
static void
accept_cb(struct evconnlistener *listener, evutil_socket_t fd,
struct sockaddr *sa, int socklen, void *arg)
{
char buffer[128];
struct context *ctx = arg;
struct bufferevent *bev = NULL;
struct event_base *base = evconnlistener_get_base(listener);
if (!ctx->opts->extra.keep)
evconnlistener_disable(listener);
info("Accepting %s (fd=%d)\n",
evutil_format_sockaddr_port_(sa, buffer, sizeof(buffer)-1), fd);
if (evutil_set_tcp_keepalive(fd, 1, ctx->opts->tcp_keepalive_timeout))
goto err;
bev = be_new(ctx, base, fd);
if (!bev) {
error("Cannot make bufferevent for fd=%d\n", fd);
goto err;
}
bufferevent_setcb(bev, read_cb, write_cb, server_event_cb, ctx);
if (bufferevent_enable(bev, EV_READ|EV_WRITE)) {
error("Cannot monitor EV_READ|EV_WRITE for server\n");
goto err;
}
if (be_set_timeout(bev, ctx->opts)) {
info("Cannot set timeout for server\n");
goto err;
}
/** TODO: support multiple bevs */
EVUTIL_ASSERT(!ctx->out);
ctx->out = bev;
if (bufferevent_enable(ctx->in, EV_READ)) {
error("Cannot monitor EV_READ on input\n");
goto err;
}
return;
err:
be_free(&bev);
}
static void client_event_cb(struct bufferevent *bev, short what, void *arg)
{
struct context *ctx = arg;
if (!event_cb_(bev, what, ctx->opts->extra.ssl, 1))
return;
ctx->out = NULL;
}
static void in_event_cb(struct bufferevent *bev, short what, void *arg)
{
struct context *ctx = arg;
if (!event_cb_(bev, what, ctx->opts->extra.ssl, 1))
return;
ctx->in = NULL;
be_free(&ctx->out);
}
static void trigger_bev_write_cb(struct bufferevent *bev, void *arg)
{
struct context *ctx = arg;
if (!ctx->out)
return;
bufferevent_trigger(ctx->out, EV_WRITE, 0);
}
int main(int argc, char **argv)
{
struct event_base *base = NULL;
struct event *term = NULL;
struct evconnlistener *listener = NULL;
struct bufferevent *bev = NULL;
struct sockaddr_storage ss;
struct sockaddr *sa = (struct sockaddr *)&ss;
ev_socklen_t ss_len;
char buffer[128];
struct context ctx;
struct options o = parse_opts(argc, argv);
int err = EXIT_SUCCESS;
memset(&ctx, 0, sizeof(ctx));
ctx.opts = &o;
if (verbose || getenv("EVENT_DEBUG_LOGGING_ALL"))
event_enable_debug_logging(EVENT_DBG_ALL);
base = event_base_new();
if (!base)
goto err;
term = evsignal_new(base, SIGINT, do_term, base);
if (!term)
goto err;
if (event_add(term, NULL))
goto err;
#ifdef _WIN32
{
WORD wVersionRequested;
WSADATA wsaData;
wVersionRequested = MAKEWORD(2, 2);
WSAStartup(wVersionRequested, &wsaData);
}
#else
if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
goto err;
#endif
if (o.extra.ssl && ssl_ctx_init(&ctx.ssl))
goto err;
if (o.extra.listen) {
int flags = 0;
flags |= LEV_OPT_CLOSE_ON_FREE;
flags |= LEV_OPT_CLOSE_ON_EXEC;
flags |= LEV_OPT_REUSEABLE;
ss_len = make_address(&ss, o.src.address, o.src.port);
if (!ss_len) {
error("Cannot make address from %s:%d\n",
o.src.address, o.src.port);
goto err;
}
info("Listening on %s\n",
evutil_format_sockaddr_port_(sa, buffer, sizeof(buffer)-1));
listener = evconnlistener_new_bind(base, accept_cb, &ctx, flags, -1, sa, ss_len);
if (!listener) {
error("Cannot listen\n");
goto err;
}
if (o.tcp_keepalive_timeout) {
evutil_socket_t fd = evconnlistener_get_fd(listener);
if (evutil_set_tcp_keepalive(fd, 1, o.tcp_keepalive_timeout)) {
goto err;
}
}
} else {
ss_len = make_address(&ss, o.dst.address, o.dst.port);
if (!ss_len) {
error("Cannot make address from %s:%d\n",
o.src.address, o.src.port);
goto err;
}
info("Connecting to %s\n",
evutil_format_sockaddr_port_(sa, buffer, sizeof(buffer)-1));
bev = be_new(&ctx, base, -1);
if (!bev) {
error("Cannot make bufferevent\n");
goto err;
}
bufferevent_setcb(bev, read_cb, write_cb, client_event_cb, &ctx);
if (bufferevent_enable(bev, EV_READ|EV_WRITE)) {
error("Cannot monitor EV_READ|EV_WRITE for client\n");
goto err;
}
if (be_set_timeout(bev, &o)) {
info("Cannot set timeout for client\n");
goto err;
}
if (bufferevent_socket_connect(bev, sa, ss_len)) {
info("Connection failed\n");
goto err;
}
{
evutil_socket_t fd = bufferevent_getfd(bev);
if (evutil_set_tcp_keepalive(fd, 1, o.tcp_keepalive_timeout))
goto err;
}
}
ctx.out = bev;
ctx.fout = stdout;
ctx.in = bufferevent_socket_new(base, STDIN_FILENO, 0);
if (o.max_read != -1) {
if (bufferevent_set_max_single_read(ctx.in, o.max_read))
goto err;
}
if (!ctx.in) {
error("Cannot create input bufferevent\n");
goto err;
}
bufferevent_setcb(ctx.in, trigger_bev_write_cb, NULL, in_event_cb, &ctx);
if (ctx.out && bufferevent_enable(ctx.in, EV_READ)) {
error("Cannot monitor EV_READ on input\n");
goto err;
}
bufferevent_disable(ctx.in, EV_WRITE);
if (!event_base_dispatch(base))
goto out;
err:
if (!err)
err = EXIT_FAILURE;
out:
if (term)
event_free(term);
be_free(&ctx.in);
be_free(&ctx.out);
if (listener)
evconnlistener_free(listener);
if (base)
event_base_free(base);
free(o.src.address);
free(o.dst.address);
ssl_ctx_free(&ctx.ssl);
#ifdef _WIN32
WSACleanup();
#endif
return err;
}