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-rw-r--r--net/arp.c126
-rw-r--r--net/arp.h28
-rw-r--r--net/eth.c1
-rw-r--r--net/eth.h16
-rw-r--r--net/inet.h20
-rw-r--r--net/netdev.c16
-rw-r--r--net/netdev.h15
7 files changed, 222 insertions, 0 deletions
diff --git a/net/arp.c b/net/arp.c
new file mode 100644
index 0000000..501186f
--- /dev/null
+++ b/net/arp.c
@@ -0,0 +1,126 @@
+// https://github.com/saminiir/level-ip/blob/e9ceb08f01a5499b85f03e2d615309c655b97e8f/src/arp.c#L53
+// https://github.com/chobits/tapip
+// https://tools.ietf.org/html/rfc826
+
+#include "inet.h"
+#include "eth.h"
+#include "arp.h"
+#include "netdev.h"
+#include "log.h"
+
+#include "lib/string/string.h"
+
+/*
+ */
+/*
+static struct arp_cache_entry arp_cache[ARP_CACHE_LEN];
+
+static int insert_arp_translation_table(struct arp_hdr *hdr, struct arp_ipv4 *data)
+{
+ struct arp_cache_entry *entry;
+ for (int i = 0; i<ARP_CACHE_LEN; i++) {
+ entry = &arp_cache[i];
+
+ if (entry->state == ARP_FREE) {
+ entry->state = ARP_RESOLVED;
+
+ entry->hwtype = hdr->hwtype;
+ entry->sip = data->sip;
+ memcpy(entry->smac, data->smac, sizeof(entry->smac));
+
+ return 0;
+ }
+ }
+
+ return -1;
+}
+
+static int update_arp_translation_table(struct arp_hdr *hdr, struct arp_ipv4 *data)
+{
+ struct arp_cache_entry *entry;
+
+ for (int i = 0; i<ARP_CACHE_LEN; i++) {
+ entry = &arp_cache[i];
+
+ if (entry->state == ARP_FREE) continue;
+
+ if (entry->hwtype == hdr->hwtype && entry->sip == data->sip) {
+ memcpy(entry->smac, data->smac, 6);
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+void arp_init()
+{
+ memset(arp_cache, 0, ARP_CACHE_LEN * sizeof(struct arp_cache_entry));
+}
+*/
+
+void arp_reply(struct netdev *netdev, struct eth_hdr *hdr, struct arp_hdr *arphdr)
+{
+ struct arp_ipv4 *arpdata;
+ int len;
+
+ arpdata = (struct arp_ipv4 *) arphdr->data;
+
+ memcpy(arpdata->dmac, arpdata->smac, 6);
+ arpdata->dip = arpdata->sip;
+ memcpy(arpdata->smac, netdev->hwaddr, 6);
+ arpdata->sip = netdev->ip;
+
+ arphdr->opcode = ARP_REPLY;
+
+ arphdr->opcode = htons(arphdr->opcode);
+ arphdr->hwtype = htons(arphdr->hwtype);
+ arphdr->protype = htons(arphdr->protype);
+
+ len = sizeof(struct arp_hdr) + sizeof(struct arp_ipv4);
+ netdev_transmit(netdev, hdr, ETH_P_ARP, len, arpdata->dmac);
+}
+
+void arp_incoming(struct netdev *netdev, struct eth_hdr *hdr)
+{
+ struct arp_hdr *arphdr;
+ struct arp_ipv4 *arpdata;
+ int merge = 0;
+
+ arphdr = (struct arp_hdr *) hdr->payload;
+
+ arphdr->hwtype = ntohs(arphdr->hwtype);
+ arphdr->protype = ntohs(arphdr->protype);
+ arphdr->opcode = ntohs(arphdr->opcode);
+
+ if (arphdr->hwtype != ARP_ETHERNET) {
+ klog("Unsupported HW type\n");
+ return;
+ }
+
+ if (arphdr->protype != ARP_IPV4) {
+ klog("Unsupported protocol\n");
+ return;
+ }
+
+ arpdata = (struct arp_ipv4 *) arphdr->data;
+
+// merge = update_arp_translation_table(arphdr, arpdata);
+
+ if (netdev->ip != arpdata->dip) {
+ klog("ARP was not for us\n");
+ }
+
+// if (!merge && insert_arp_translation_table(arphdr, arpdata) != 0) {
+ // klog("ERR: No free space in ARP translation table\n");
+ // }
+
+ switch (arphdr->opcode) {
+ case ARP_REQUEST:
+ arp_reply(netdev, hdr, arphdr);
+ break;
+ default:
+ klog("Opcode not supported\n");
+ break;
+ }
+}
diff --git a/net/arp.h b/net/arp.h
new file mode 100644
index 0000000..a690ac0
--- /dev/null
+++ b/net/arp.h
@@ -0,0 +1,28 @@
+// http://www.saminiir.com/lets-code-tcp-ip-stack-1-ethernet-arp/
+//
+
+#include <stdint.h>
+
+#include "netdev.h"
+
+struct arp_hdr
+{
+ uint16_t hwtype; // link layer type (1 - ethernet)
+ uint16_t protype; // protocol (0x800 - ipv4)
+ unsigned char hwsize; // hardware field size (6 bytes mac)
+ unsigned char prosize; // protocol field size (4 byte ip)
+ uint16_t opcode; // arp message type (1- arp request, 2- arp reply, 3- rarp request, 4- rarp reply)
+ unsigned char data[]; // payload
+} __attribute__((packed));
+
+// arp ipv4 payload
+struct arp_ipv4
+{
+ unsigned char smac[6]; // sender mac
+ uint32_t sip; // sender ip
+ unsigned char dmac[6]; // receiver mac
+ uint32_t dip; // receiver ip
+} __attribute__((packed));
+
+void arp_incoming(struct netdev *netdev, struct eth_hdr *hdr);
+void arp_reply(struct netdev *netdev, struct eth_hdr *hdr, struct arp_hdr *arphdr);
diff --git a/net/eth.c b/net/eth.c
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/net/eth.c
@@ -0,0 +1 @@
+
diff --git a/net/eth.h b/net/eth.h
new file mode 100644
index 0000000..f90e615
--- /dev/null
+++ b/net/eth.h
@@ -0,0 +1,16 @@
+//http://www.saminiir.com/lets-code-tcp-ip-stack-1-ethernet-arp/
+//https://tools.ietf.org/html/rfc7414
+#ifndef FOOLOS_ETH_H
+#define FOOLOS_ETH_H
+
+#include <stdint.h>
+
+struct eth_hdr
+{
+ unsigned char dmac[6]; // destination mac
+ unsigned char smac[6]; // source mac
+ uint16_t ethertype; // length or type
+ unsigned char payload[]; // payload
+} __attribute__((packed));
+
+#endif
diff --git a/net/inet.h b/net/inet.h
new file mode 100644
index 0000000..a2e8dd8
--- /dev/null
+++ b/net/inet.h
@@ -0,0 +1,20 @@
+/*
+ * @file
+ * https://en.wikipedia.org/wiki/OSI_model
+ */
+#include <stdint.h>
+
+#define ARP_ETHERNET 1
+#define ARP_IPV4 0x800
+#define ARP_REPLY 2
+#define ARP_REQUEST 1
+#define ETH_P_ARP 0x0806
+
+static uint16_t ntohs(uint16_t val)
+{
+ return val<<8|val>>8;
+}
+static uint16_t htons(uint16_t val)
+{
+ return val<<8|val>>8;
+}
diff --git a/net/netdev.c b/net/netdev.c
new file mode 100644
index 0000000..3acd7a4
--- /dev/null
+++ b/net/netdev.c
@@ -0,0 +1,16 @@
+#include <stdint.h>
+#include "inet.h"
+#include "eth.h"
+#include "netdev.h"
+#include "lib/string/string.h"
+
+void netdev_transmit(struct netdev *dev, struct eth_hdr *hdr, uint16_t ethertype, int len, unsigned char *dst)
+{
+ hdr->ethertype = htons(ethertype);
+ memcpy(hdr->smac, dev->hwaddr, 6);
+ memcpy(hdr->dmac, dst, 6);
+
+ len += sizeof(struct eth_hdr);
+
+ dev->transmit(hdr,len);
+}
diff --git a/net/netdev.h b/net/netdev.h
new file mode 100644
index 0000000..c6c02dd
--- /dev/null
+++ b/net/netdev.h
@@ -0,0 +1,15 @@
+#ifndef FOOLOS_NETDEV_H
+#define FOOLOS_NETDEV_H
+
+#include "eth.h"
+
+struct netdev
+{
+ unsigned char hwaddr[6]; // device hardware address
+ uint32_t ip; // device ip
+ int (*transmit)(const void *data, uint16_t p_len);
+};
+
+void netdev_transmit(struct netdev *dev, struct eth_hdr *hdr, uint16_t ethertype, int len, unsigned char *dst);
+
+#endif
generated by cgit v1.2.3 (git 2.25.1) at 2025-11-08 23:13:33 +0000