1 files changed, 333 insertions, 0 deletions
diff --git a/src/VBox/NetworkServices/NAT/fwtcp.c b/src/VBox/NetworkServices/NAT/fwtcp.c
new file mode 100644
index 00000000..e1271943
--- /dev/null
+++ b/src/VBox/NetworkServices/NAT/fwtcp.c
@@ -0,0 +1,333 @@
+/* $Id: fwtcp.c $ */
+/** @file
+ * NAT Network - TCP port-forwarding.
+ */
+
+/*
+ * Copyright (C) 2013-2022 Oracle and/or its affiliates.
+ *
+ * This file is part of VirtualBox base platform packages, as
+ * available from https://www.virtualbox.org.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, in version 3 of the
+ * License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <https://www.gnu.org/licenses>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+#define LOG_GROUP LOG_GROUP_NAT_SERVICE
+
+#include "winutils.h"
+#include "proxy.h"
+#include "proxy_pollmgr.h"
+#include "portfwd.h"
+#include "pxtcp.h"
+
+#ifndef RT_OS_WINDOWS
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <stdio.h>
+#include <poll.h>
+
+#include <err.h>                /* BSD'ism */
+#else
+#include <stdio.h>
+#include "winpoll.h"
+#endif
+
+#include "lwip/opt.h"
+
+#include "lwip/sys.h"
+#include "lwip/tcpip.h"
+
+
+/**
+ */
+struct fwtcp {
+    /**
+     * Our poll manager handler.
+     */
+    struct pollmgr_handler pmhdl;
+
+    /**
+     * Forwarding specification.
+     */
+    struct fwspec fwspec;
+
+    /**
+     * Listening socket.
+     */
+    SOCKET sock;
+
+    /**
+     * Mailbox for new inbound connections.
+     *
+     * XXX: since we have single producer and single consumer we can
+     * use lockless ringbuf like for pxtcp.
+     */
+    sys_mbox_t connmbox;
+
+    struct tcpip_msg msg_connect;
+    struct tcpip_msg msg_delete;
+
+    /**
+     * Linked list entry.
+     */
+    struct fwtcp *next;
+};
+
+
+static struct fwtcp *fwtcp_create(struct fwspec *);
+
+/* poll manager callback for fwtcp listening socket */
+static int fwtcp_pmgr_listen(struct pollmgr_handler *, SOCKET, int);
+
+/* lwip thread callbacks called via proxy_lwip_post() */
+static void fwtcp_pcb_connect(void *);
+static void fwtcp_pcb_delete(void *);
+
+
+/**
+ * Linked list of active fwtcp forwarders.
+ */
+struct fwtcp *fwtcp_list = NULL;
+
+
+void
+fwtcp_init(void)
+{
+    return;
+}
+
+
+void
+fwtcp_add(struct fwspec *fwspec)
+{
+    struct fwtcp *fwtcp;
+
+    fwtcp = fwtcp_create(fwspec);
+    if (fwtcp == NULL) {
+        DPRINTF0(("%s: failed to add rule for TCP ...\n", __func__));
+        return;
+    }
+
+    DPRINTF0(("%s\n", __func__));
+    /* fwtcp_create has put fwtcp on the linked list */
+}
+
+
+void
+fwtcp_del(struct fwspec *fwspec)
+{
+    struct fwtcp *fwtcp;
+    struct fwtcp **pprev;
+
+    for (pprev = &fwtcp_list; (fwtcp = *pprev) != NULL; pprev = &fwtcp->next) {
+        if (fwspec_equal(&fwtcp->fwspec, fwspec)) {
+            *pprev = fwtcp->next;
+            fwtcp->next = NULL;
+            break;
+        }
+    }
+
+    if (fwtcp == NULL) {
+        DPRINTF0(("%s: not found\n", __func__));
+        return;
+    }
+
+    DPRINTF0(("%s\n", __func__));
+
+    pollmgr_del_slot(fwtcp->pmhdl.slot);
+    fwtcp->pmhdl.slot = -1;
+
+    closesocket(fwtcp->sock);
+    fwtcp->sock = INVALID_SOCKET;
+
+    /* let pending msg_connect be processed before we delete fwtcp */
+    proxy_lwip_post(&fwtcp->msg_delete);
+}
+
+
+struct fwtcp *
+fwtcp_create(struct fwspec *fwspec)
+{
+    struct fwtcp *fwtcp;
+    SOCKET lsock;
+    int status;
+    err_t error;
+
+    lsock = proxy_bound_socket(fwspec->sdom, fwspec->stype, &fwspec->src.sa);
+    if (lsock == INVALID_SOCKET) {
+        return NULL;
+    }
+
+    fwtcp = (struct fwtcp *)malloc(sizeof(*fwtcp));
+    if (fwtcp == NULL) {
+        closesocket(lsock);
+        return NULL;
+    }
+
+    fwtcp->pmhdl.callback = fwtcp_pmgr_listen;
+    fwtcp->pmhdl.data = (void *)fwtcp;
+    fwtcp->pmhdl.slot = -1;
+
+    fwtcp->sock = lsock;
+    fwtcp->fwspec = *fwspec;    /* struct copy */
+
+    error = sys_mbox_new(&fwtcp->connmbox, 16);
+    if (error != ERR_OK) {
+        closesocket(lsock);
+        free(fwtcp);
+        return (NULL);
+    }
+
+#define CALLBACK_MSG(MSG, FUNC)                         \
+    do {                                                \
+        fwtcp->MSG.type = TCPIP_MSG_CALLBACK_STATIC;    \
+        fwtcp->MSG.sem = NULL;                          \
+        fwtcp->MSG.msg.cb.function = FUNC;              \
+        fwtcp->MSG.msg.cb.ctx = (void *)fwtcp;          \
+    } while (0)
+
+    CALLBACK_MSG(msg_connect, fwtcp_pcb_connect);
+    CALLBACK_MSG(msg_delete,  fwtcp_pcb_delete);
+
+#undef CALLBACK_MSG
+
+    status = pollmgr_add(&fwtcp->pmhdl, fwtcp->sock, POLLIN);
+    if (status < 0) {
+        sys_mbox_free(&fwtcp->connmbox);
+        closesocket(lsock);
+        free(fwtcp);
+        return NULL;
+    }
+
+    fwtcp->next = fwtcp_list;
+    fwtcp_list = fwtcp;
+
+    return fwtcp;
+}
+
+
+int
+fwtcp_pmgr_listen(struct pollmgr_handler *handler, SOCKET fd, int revents)
+{
+    struct fwtcp *fwtcp;
+    struct sockaddr_storage ss;
+    socklen_t sslen;
+    struct pxtcp *pxtcp;
+    SOCKET newsock;
+    int status;
+    err_t error;
+
+    fwtcp = (struct fwtcp *)handler->data;
+    pxtcp = NULL;
+
+    LWIP_ASSERT1(fwtcp != NULL);
+    LWIP_ASSERT1(fd == fwtcp->sock);
+    LWIP_ASSERT1(revents == POLLIN);
+    LWIP_UNUSED_ARG(fd);
+    LWIP_UNUSED_ARG(revents);
+
+    LWIP_ASSERT1(sys_mbox_valid(&fwtcp->connmbox));
+
+    sslen = sizeof(ss);
+    newsock = accept(fwtcp->sock, (struct sockaddr *)&ss, &sslen);
+    if (newsock == INVALID_SOCKET) {
+        return POLLIN;
+    }
+
+#ifdef RT_OS_LINUX
+    status = proxy_fixup_accepted_socket(newsock);
+    if (status < 0) {
+        proxy_reset_socket(newsock);
+        return POLLIN;
+    }
+#endif
+
+    if (ss.ss_family == PF_INET) {
+        struct sockaddr_in *peer4 = (struct sockaddr_in *)&ss;
+        RT_NOREF(peer4);
+        DPRINTF(("<--- TCP %RTnaipv4:%d\n",
+                 peer4->sin_addr.s_addr, ntohs(peer4->sin_port)));
+    }
+    else { /* PF_INET6 */
+        struct sockaddr_in6 *peer6 = (struct sockaddr_in6 *)&ss;
+        RT_NOREF(peer6);
+        DPRINTF(("<--- TCP %RTnaipv6:%d\n",
+                 &peer6->sin6_addr, ntohs(peer6->sin6_port)));
+    }
+
+    pxtcp = pxtcp_create_forwarded(newsock);
+    if (pxtcp == NULL) {
+        proxy_reset_socket(newsock);
+        return POLLIN;
+    }
+
+    status = pxtcp_pmgr_add(pxtcp);
+    if (status < 0) {
+        pxtcp_cancel_forwarded(pxtcp);
+        return POLLIN;
+    }
+
+    error = sys_mbox_trypost(&fwtcp->connmbox, (void *)pxtcp);
+    if (error != ERR_OK) {
+        pxtcp_pmgr_del(pxtcp);
+        pxtcp_cancel_forwarded(pxtcp);
+        return POLLIN;
+    }
+
+    proxy_lwip_post(&fwtcp->msg_connect);
+    return POLLIN;
+}
+
+
+void
+fwtcp_pcb_connect(void *arg)
+{
+    struct fwtcp *fwtcp = (struct fwtcp *)arg;
+    struct pxtcp *pxtcp;
+    u32_t timo;
+
+    if (!sys_mbox_valid(&fwtcp->connmbox)) {
+        return;
+    }
+
+    pxtcp = NULL;
+    timo = sys_mbox_tryfetch(&fwtcp->connmbox, (void **)&pxtcp);
+    if (timo == SYS_MBOX_EMPTY) {
+        return;
+    }
+
+    LWIP_ASSERT1(pxtcp != NULL);
+
+    /* hand off to pxtcp */
+    pxtcp_pcb_connect(pxtcp, &fwtcp->fwspec);
+}
+
+
+static void
+fwtcp_pcb_delete(void *arg)
+{
+    struct fwtcp *fwtcp = (struct fwtcp *)arg;
+    void *data;
+    u32_t timo;
+
+    timo = sys_mbox_tryfetch(&fwtcp->connmbox, &data);
+    LWIP_ASSERT1(timo == SYS_MBOX_EMPTY);
+    LWIP_UNUSED_ARG(timo);      /* only in assert */
+
+    sys_mbox_free(&fwtcp->connmbox);
+    free(fwtcp);
+}