summaryrefslogtreecommitdiff
path: root/network
diff options
context:
space:
mode:
Diffstat (limited to 'network')
-rw-r--r--network/arp.c83
-rw-r--r--network/arp.h3
-rw-r--r--network/bytes.c10
-rw-r--r--network/bytes.h5
-rw-r--r--network/ethernet.c101
-rw-r--r--network/ethernet.h5
6 files changed, 207 insertions, 0 deletions
diff --git a/network/arp.c b/network/arp.c
new file mode 100644
index 0000000..eb8aca3
--- /dev/null
+++ b/network/arp.c
@@ -0,0 +1,83 @@
+#include <assert.h>
+#include <drivers/rtl8139.h>
+#include <network/arp.h>
+#include <network/bytes.h>
+#include <network/ethernet.h>
+#include <stdio.h>
+#include <string.h>
+
+struct ARP_DATA {
+ uint16_t htype; // Hardware type
+ uint16_t ptype; // Protocol type
+ uint8_t hlen; // Hardware address length (Ethernet = 6)
+ uint8_t plen; // Protocol address length (IPv4 = 4)
+ uint16_t opcode; // ARP Operation Code
+ uint8_t srchw[6]; // Source hardware address - hlen bytes (see above)
+ uint8_t srcpr[4]; // Source protocol address - plen bytes (see above).
+ // If IPv4 can just be a "u32" type.
+ uint8_t dsthw[6]; // Destination hardware address - hlen bytes (see above)
+ uint8_t dstpr[4]; // Destination protocol address - plen bytes (see
+ // above). If IPv4 can just be a "u32" type.
+};
+
+// FIXME: This is hardcoded, don't do this.
+uint8_t ip_address[4] = {10, 0, 2, 15};
+
+void print_mac(const char *str, uint8_t *mac) {
+ kprintf("%s: ", str);
+ for (int i = 0; i < 6; i++) {
+ kprintf("%x", mac[i]);
+ if (5 != i)
+ kprintf(":");
+ }
+ kprintf("\n");
+}
+
+void print_ip(const char *str, uint8_t *ip) {
+ kprintf("%s: ", str);
+ for (int i = 0; i < 4; i++) {
+ kprintf("%d", ip[i]);
+ if (3 != i)
+ kprintf(".");
+ }
+ kprintf("\n");
+}
+
+void handle_arp(uint8_t *payload) {
+ struct ARP_DATA *data = (struct ARP_DATA *)payload;
+
+ // Assert that communication is over ethernet
+ assert(1 == ntohs(data->htype));
+ // Assert it is a request
+ assert(0x0001 == ntohs(data->opcode));
+ // Assert that request uses IP
+ assert(0x0800 == ntohs(data->ptype));
+
+ assert(6 == data->hlen);
+ assert(4 == data->plen);
+ print_mac("srchw: ", data->srchw);
+ print_ip("srcpr: ", data->srcpr);
+
+ print_mac("dsthw: ", data->dsthw);
+ print_ip("dstpr: ", data->dstpr);
+
+ uint8_t mac[6];
+ get_mac_address(mac);
+ print_mac("THIS DEVICE MAC: ", mac);
+ assert(0 == memcmp(data->dstpr, ip_address, sizeof(uint8_t[4])));
+
+ // Now we have to construct a ARP response
+ struct ARP_DATA response;
+ response.htype = htons(1);
+ response.ptype = htons(0x0800);
+ response.opcode = htons(0x00002);
+ response.hlen = 6;
+ response.plen = 4;
+ get_mac_address(response.srchw);
+ memcpy(response.srcpr, ip_address, sizeof(uint8_t[4]));
+
+ memcpy(response.dsthw, data->srchw, sizeof(uint8_t[6]));
+ memcpy(response.dstpr, data->srcpr, sizeof(uint8_t[4]));
+
+ send_ethernet_packet(data->srchw, 0x0806, (uint8_t*)&response, sizeof(response));
+}
diff --git a/network/arp.h b/network/arp.h
new file mode 100644
index 0000000..1e8df1b
--- /dev/null
+++ b/network/arp.h
@@ -0,0 +1,3 @@
+#include <stdint.h>
+
+void handle_arp(uint8_t *payload);
diff --git a/network/bytes.c b/network/bytes.c
new file mode 100644
index 0000000..94afa73
--- /dev/null
+++ b/network/bytes.c
@@ -0,0 +1,10 @@
+#include <network/bytes.h>
+
+uint16_t ntohs(uint16_t net) { return (net >> 8) | (net << 8); }
+
+uint16_t htons(uint16_t net) { return (net >> 8) | (net << 8); }
+
+uint32_t htonl(uint32_t net) {
+ return (((net & 0x000000FF) << 24) | ((net & 0x0000FF00) << 8) |
+ ((net & 0x00FF0000) >> 8) | ((net & 0xFF000000) >> 24));
+}
diff --git a/network/bytes.h b/network/bytes.h
new file mode 100644
index 0000000..c291589
--- /dev/null
+++ b/network/bytes.h
@@ -0,0 +1,5 @@
+#include <stdint.h>
+
+uint16_t ntohs(uint16_t net);
+uint16_t htons(uint16_t net);
+uint32_t htonl(uint32_t net);
diff --git a/network/ethernet.c b/network/ethernet.c
new file mode 100644
index 0000000..ae8e814
--- /dev/null
+++ b/network/ethernet.c
@@ -0,0 +1,101 @@
+#include <assert.h>
+#include <drivers/rtl8139.h>
+#include <kmalloc.h>
+#include <network/arp.h>
+#include <network/bytes.h>
+#include <network/ethernet.h>
+#include <stdio.h>
+
+struct ETHERNET_HEADER {
+ uint8_t mac_dst[6];
+ uint8_t mac_src[6];
+ uint16_t type;
+};
+
+uint32_t crc32(const char *buf, size_t len) {
+ static uint32_t table[256];
+ static int have_table = 0;
+ uint32_t rem;
+ uint8_t octet;
+ int i, j;
+ const char *p, *q;
+
+ if (have_table == 0) {
+ for (i = 0; i < 256; i++) {
+ rem = i;
+ for (j = 0; j < 8; j++) {
+ if (rem & 1) {
+ rem >>= 1;
+ rem ^= 0xedb88320;
+ } else
+ rem >>= 1;
+ }
+ table[i] = rem;
+ }
+ have_table = 1;
+ }
+
+ uint32_t crc = 0xFFFFFFFF;
+ q = buf + len;
+ for (p = buf; p < q; p++) {
+ octet = *p;
+ crc = (crc >> 8) ^ table[(crc & 0xff) ^ octet];
+ }
+ return ~crc;
+}
+
+void handle_ethernet(uint8_t *packet, uint64_t packet_length) {
+ struct ETHERNET_HEADER *eth_header = (struct ETHERNET_HEADER *)packet;
+ packet += sizeof(struct ETHERNET_HEADER);
+ uint8_t *payload = packet;
+ packet += packet_length - sizeof(struct ETHERNET_HEADER);
+ uint32_t crc = *((uint32_t *)packet - 1);
+ kprintf("PACKET crc: %x\n", crc);
+ kprintf("OUR OWN CALCULATED crc: %x\n",
+ crc32((const char *)eth_header, (packet_length - 4)));
+
+ kprintf("mac dst: ");
+ for (int i = 0; i < 6; i++)
+ kprintf("%x", eth_header->mac_dst[i]);
+ kprintf("\n");
+ kprintf("mac src: ");
+ for (int i = 0; i < 6; i++)
+ kprintf("%x", eth_header->mac_src[i]);
+ kprintf("\n");
+
+ uint16_t type = ntohs(eth_header->type);
+ kprintf("Etheretype: %x\n", type);
+ switch (type) {
+ case 0x0806:
+ handle_arp(payload);
+ break;
+ case 0x0800:
+ kprintf("IPV4 message\n");
+ break;
+ default:
+ kprintf("Can't handle ethernet type\n");
+ break;
+ }
+}
+
+void send_ethernet_packet(uint8_t mac_dst[6], uint16_t type, uint8_t *payload,
+ uint64_t payload_length) {
+ // FIXME: Janky allocation, do this better
+ uint64_t buffer_size =
+ sizeof(struct ETHERNET_HEADER) + payload_length + sizeof(uint32_t);
+ uint8_t *buffer = kmalloc(buffer_size);
+ uint8_t *buffer_start = buffer;
+ struct ETHERNET_HEADER *eth_header = (struct ETHERNET_HEADER *)buffer;
+ buffer += sizeof(struct ETHERNET_HEADER);
+ memcpy(buffer, payload, payload_length);
+ buffer += payload_length;
+
+ memcpy(eth_header->mac_dst, mac_dst, sizeof(uint8_t[6]));
+ get_mac_address(eth_header->mac_src);
+ eth_header->type = htons(type);
+ *(uint32_t *)(buffer) =
+ htonl(crc32((const char *)buffer_start, buffer_size - 4));
+
+ assert(rtl8139_send_data(buffer_start, buffer_size));
+ kprintf("sent data\n");
+}
diff --git a/network/ethernet.h b/network/ethernet.h
new file mode 100644
index 0000000..88a4dc6
--- /dev/null
+++ b/network/ethernet.h
@@ -0,0 +1,5 @@
+#include <stdint.h>
+
+void handle_ethernet(uint8_t *packet, uint64_t packet_length);
+void send_ethernet_packet(uint8_t mac_dst[6], uint16_t type, uint8_t *payload,
+ uint64_t payload_length);
generated by cgit v1.2.3 (git 2.39.1) at 2025-11-04 10:52:04 +0000