examples: Add common linux component tapif_io

That can be used with linux target on lwip to pass packets from lwip to linux host networking stack, e.g. routing the trafic to internet.
2025-08-10 04:43:33 +00:00 · 2023-01-31 08:29:00 +01:00
parent 332e4902b4
commit 854e16feb3
12 changed files with 593 additions and 0 deletions
--- a/examples/common_components/protocol_examples_tapif_io/lwip/tapif.c
+++ b/examples/common_components/protocol_examples_tapif_io/lwip/tapif.c
@@ -0,0 +1,100 @@
+/*
+ * SPDX-FileCopyrightText: 2001-2003 Swedish Institute of Computer Science
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * SPDX-FileContributor: 2022-2023 Espressif Systems (Shanghai) CO LTD
+ */
+#include <string.h>
+#include "lwip/opt.h"
+#include "lwip/pbuf.h"
+#include "lwip/snmp.h"
+#include "lwip/ethip6.h"
+#include "netif/etharp.h"
+
+#include "esp_netif.h"
+#include "esp_netif_net_stack.h"
+
+#define IFNAME0 't'
+#define IFNAME1 'p'
+
+static err_t
+low_level_output(struct netif *netif, struct pbuf *p)
+{
+    esp_netif_t *esp_netif = esp_netif_get_handle_from_netif_impl(netif);
+    char buf[1518]; /* max packet size including VLAN excluding CRC */
+
+    if (p->tot_len > sizeof(buf)) {
+        MIB2_STATS_NETIF_INC(netif, ifoutdiscards);
+        LWIP_DEBUGF(NETIF_DEBUG, ("tapif: packet too large"));
+        return ERR_IF;
+    }
+
+    /* initiate transfer(); */
+    pbuf_copy_partial(p, buf, p->tot_len, 0);
+
+    int ret = esp_netif_transmit(esp_netif, buf, p->tot_len);
+    /* Check error */
+    if (likely(ret == ESP_OK)) {
+        return ERR_OK;
+    }
+    if (ret == ESP_ERR_NO_MEM) {
+        return ERR_MEM;
+    }
+    return ERR_IF;
+}
+
+static void
+low_level_init(struct netif *netif)
+{
+
+    /* Obtain MAC address from network interface. */
+    netif->hwaddr[0] = 0x02;
+    netif->hwaddr[1] = 0x12;
+    netif->hwaddr[2] = 0x34;
+    netif->hwaddr[3] = 0x56;
+    netif->hwaddr[4] = 0x78;
+    netif->hwaddr[5] = 0xab;
+    netif->hwaddr_len = 6;
+
+    /* device capabilities */
+    netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_IGMP;
+}
+
+err_t lwip_tapif_init(struct netif *netif)
+{
+    LWIP_ASSERT("Tried to initialize tapif with NULL netif", netif != NULL);
+    netif->name[0] = IFNAME0;
+    netif->name[1] = IFNAME1;
+#if LWIP_IPV4
+    netif->output = etharp_output;
+#endif /* LWIP_IPV4 */
+#if LWIP_IPV6
+    netif->output_ip6 = ethip6_output;
+#endif /* LWIP_IPV6 */
+    netif->linkoutput = low_level_output;
+    netif->mtu = 1500;
+
+    low_level_init(netif);
+    netif_set_link_up(netif);
+    return ERR_OK;
+}
+
+void lwip_tapif_input(void *h, void *buffer, size_t len, void *l2_buff)
+{
+    struct netif *netif = h;
+    struct pbuf *p;
+    LWIP_ASSERT("running tapif input with NULL netif", netif != NULL);
+
+    p = pbuf_alloc(PBUF_RAW, len, PBUF_RAM);
+    if (p == NULL) {
+        return;
+    }
+    memcpy(p->payload, buffer, len);
+
+    /* full packet send to tcpip_thread to process */
+    if (unlikely(netif->input(p, netif) != ERR_OK)) {
+        LWIP_DEBUGF(NETIF_DEBUG, ("tapif_input: IP input error\n"));
+        pbuf_free(p);
+    }
+}