add wire module

.gitignore

 *.o
+*.a
 _vimrc_local.vim
 dummy_nic/dummy_nic
-nicsim_common/libnicsim_common.a
 corundum/obj_dir
 corundum/corundum_verilator
+net_wire/net_wire
+net_tap/net_tap

net_wire/Makefile

+CPPFLAGS += -I../proto -I../netsim_common/include
+CFLAGS += -Wall -Wextra -Wno-unused-parameter -O3
+
+net_wire: net_wire.o ../netsim_common/libnetsim_common.a
+
+all: net_wire
+
+clean:
+	rm -f *.o net_wire

net_wire/net_wire.c

+/*
+ * Copyright 2020 Max Planck Institute for Software Systems
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <fcntl.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#include <linux/if.h>
+#include <linux/if_tun.h>
+
+#include <netsim.h>
+
+static void move_pkt(struct netsim_interface *from, struct netsim_interface *to)
+{
+    volatile union cosim_eth_proto_d2n *msg_from = netsim_d2n_poll(from);
+    volatile union cosim_eth_proto_n2d *msg_to;
+    volatile struct cosim_eth_proto_d2n_send *tx;
+    volatile struct cosim_eth_proto_n2d_recv *rx;
+    uint8_t type;
+
+    if (msg_from == NULL)
+        return;
+
+    type = msg_from->dummy.own_type & COSIM_ETH_PROTO_D2N_MSG_MASK;
+    if (type == COSIM_ETH_PROTO_D2N_MSG_SEND) {
+        tx = &msg_from->send;
+
+        msg_to = netsim_n2d_alloc(to);
+        if (msg_to != NULL) {
+            rx = &msg_to->recv;
+            rx->len = tx->len;
+            rx->port = 0;
+            memcpy((void *) rx->data, (void *) tx->data, tx->len);
+
+            // WMB();
+            rx->own_type = COSIM_ETH_PROTO_N2D_MSG_RECV |
+                COSIM_ETH_PROTO_N2D_OWN_DEV;
+        } else {
+            fprintf(stderr, "move_pkt: dropping packet\n");
+        }
+    } else {
+        fprintf(stderr, "move_pkt: unsupported type=%u\n", type);
+        abort();
+    }
+
+    netsim_d2n_done(from, msg_from);
+}
+
+int main(int argc, char *argv[])
+{
+    struct netsim_interface nsif_a, nsif_b;
+    int sync;
+
+    if (argc != 3) {
+        fprintf(stderr, "Usage: net_tap SOCKET-A SOCKET-B\n");
+        return EXIT_FAILURE;
+    }
+
+    sync = 0;
+    if (netsim_init(&nsif_a, argv[1], &sync) != 0) {
+        return -1;
+    }
+    if (netsim_init(&nsif_b, argv[2], &sync) != 0) {
+        return -1;
+    }
+
+    printf("start polling\n");
+    while (1) {
+        move_pkt(&nsif_a, &nsif_b);
+        move_pkt(&nsif_b, &nsif_a);
+    }
+    return 0;
+}