relay.c

#include "def.h"
#include "helper.h"
#include "server.h"
#include "crypto.h"
#include "log.h"

struct settings settings;
static void  relay_streamcb(struct bufferevent *bev, void *ctx);

void evs_setcb_for_local(struct bufferevent *bev, void *context)
{
    bufferevent_setcb(bev, fast_streamcb, NULL, eventcb, context);
}

void fast_streamcb(struct bufferevent *bev, void *ctx)
{
    struct e_context_s *context = ctx;
    struct bufferevent *partner = context->partner;
    struct evbuffer *src = bufferevent_get_input(bev);
    size_t buf_size = evbuffer_get_length(src);
    u8 buf[buf_size];
    u8 enc_buf[SOCKS_MAX_BUFFER_SIZE];
    int buflen;

    if (!partner || !buf_size) {
	evbuffer_drain(src, buf_size);
	return;
    }

    evbuffer_copyout(src, buf, buf_size);
    evbuffer_drain(src, buf_size);

    if (context->st == e_connected && context->partner) {
	// enc
	buflen = openssl_encrypt(context->evp_cipher_ctx, enc_buf, buf, buf_size);
	if (bufferevent_write(partner, enc_buf, buflen) != 0) {
	    log_e("failed to write");
	    context->st = e_destroy;
	} else {
	    context->reversed = true;

	    // Keep doing proxy until there is no data
	    bufferevent_setcb(partner, relay_streamcb, NULL, eventcb, context);
	    bufferevent_enable(partner, EV_READ|EV_WRITE);
	}
    }
}

static void relay_streamcb(struct bufferevent *bev, void *ctx)
{
    struct e_context_s *context = ctx;
    struct bufferevent *partner = context->bev;
    struct evbuffer *src = bufferevent_get_input(bev);
    int buflen;
    size_t buf_size = evbuffer_get_length(src);
    u8 buf[buf_size];
    u8 dec_buf[SOCKS_MAX_BUFFER_SIZE];

    if (!partner || !buf_size) {
	evbuffer_drain(src, buf_size);
	return;
    }

    if (context->st == e_connected && buf_size && context->partner) {
	// dec
	evbuffer_copyout(src, buf, buf_size);
	evbuffer_drain(src, buf_size);

	buflen = openssl_decrypt(context->evp_decipher_ctx, dec_buf, buf, buf_size);
	if (bufferevent_write(partner, dec_buf, buflen) != 0) {
	    log_e("failed to write");
	    context->st = e_destroy;
	} else {
	    // Keep doing proxy until there is no data
	    bufferevent_setcb(bev, relay_streamcb, NULL, eventcb, context);
	    bufferevent_enable(bev, EV_READ|EV_WRITE);
	}
    }
}