mtcp.c

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/*
 *  OpenVPN -- An application to securely tunnel IP networks
 *             over a single TCP/UDP port, with support for SSL/TLS-based
 *             session authentication and key exchange,
 *             packet encryption, packet authentication, and
 *             packet compression.
 *
 *  Copyright (C) 2002-2026 OpenVPN Inc <sales@openvpn.net>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2
 *  as published by the Free Software Foundation.
 *
 *  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/>.
 */
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include "syshead.h"
 
#include "multi.h"
#include "forward.h"
#include "mtcp.h"
#include "multi_io.h"
 
#include "memdbg.h"
 
#ifdef HAVE_SYS_INOTIFY_H
#include <sys/inotify.h>
#endif
 
struct multi_instance *
multi_create_instance_tcp(struct multi_context *m, struct link_socket *sock)
{
    struct gc_arena gc = gc_new();
    struct multi_instance *mi = NULL;
 
    mi = multi_create_instance(m, NULL, sock);
    if (mi)
    {
        mi->real.proto = sock->info.proto;
        multi_assign_peer_id(m, mi);
    }
 
#ifndef ENABLE_SMALL
    if (mi)
    {
        dmsg(D_MULTI_DEBUG, "MULTI TCP: instance added: %s", mroute_addr_print(&mi->real, &gc));
    }
    else
    {
        dmsg(D_MULTI_DEBUG, "MULTI TCP: new client instance failed");
    }
#endif
 
    gc_free(&gc);
    ASSERT(!(mi && mi->halt));
    return mi;
}
 
bool
multi_tcp_instance_specific_init(const struct multi_context *m, struct multi_instance *mi)
{
    /* buffer for queued TCP socket output packets */
    mi->tcp_link_out_deferred = mbuf_init(m->top.options.n_bcast_buf);
 
    ASSERT(mi->context.c2.link_sockets);
    ASSERT(mi->context.c2.link_sockets[0]);
    ASSERT(mi->context.c2.link_sockets[0]->info.lsa);
    ASSERT(mi->context.c2.link_sockets[0]->mode == LS_MODE_TCP_ACCEPT_FROM);
    ASSERT(mi->context.c2.link_sockets[0]->info.lsa->actual.dest.addr.sa.sa_family == AF_INET
           || mi->context.c2.link_sockets[0]->info.lsa->actual.dest.addr.sa.sa_family == AF_INET6);
    mi->real.proto = mi->context.c2.link_sockets[0]->info.proto;
    if (!mroute_extract_openvpn_sockaddr(
            &mi->real, &mi->context.c2.link_sockets[0]->info.lsa->actual.dest, true))
    {
        msg(D_MULTI_ERRORS, "MULTI TCP: TCP client address is undefined");
        return false;
    }
    return true;
}
 
void
multi_tcp_instance_specific_free(struct multi_instance *mi)
{
    mbuf_free(mi->tcp_link_out_deferred);
}
 
void
multi_tcp_delete_event(struct multi_io *multi_io, event_t event)
{
    if (multi_io && multi_io->es)
    {
        event_del(multi_io->es, event);
    }
}
 
void
multi_tcp_dereference_instance(struct multi_io *multi_io, struct multi_instance *mi)
{
    const struct link_socket *sock = mi->context.c2.link_sockets[0];
    if (sock && mi->socket_set_called)
    {
        event_del(multi_io->es, socket_event_handle(sock));
        mi->socket_set_called = false;
    }
    multi_io->n_esr = 0;
}
 
void
multi_tcp_set_global_rw_flags(struct multi_context *m, struct multi_instance *mi)
{
    if (mi && !proto_is_dgram(mi->context.c2.link_sockets[0]->info.proto))
    {
        mi->socket_set_called = true;
        socket_set(mi->context.c2.link_sockets[0], m->multi_io->es,
                   mbuf_defined(mi->tcp_link_out_deferred) ? EVENT_WRITE : EVENT_READ, &mi->ev_arg,
                   &mi->tcp_rwflags);
    }
}