commit 7e832e09d1e991fcf4deb7ad3351e3499377916a
parent 18abedd9d12115dea8ee019ab61d270b0911608a
Author: Brian Swetland <swetland@frotz.net>
Date: Sat, 21 May 2022 21:02:39 -0700
net: add net_init(), compute ip6 addresses, etc from chosen mac
Diffstat:
3 files changed, 89 insertions(+), 28 deletions(-)
diff --git a/example/ex05-ethernet.c b/example/ex05-ethernet.c
@@ -77,6 +77,8 @@ void start(void) {
// enable interrupts
//irq_enable();
+ uint8_t mac[6] = { 0x42,0x42,0x10,0x20,0x30,0x40 };
+ net_init(mac);
eth_init();
while (1) {
diff --git a/net/inc/net/ipv6.h b/net/inc/net/ipv6.h
@@ -110,6 +110,8 @@ static inline void eth_addr_copy(uint8_t *_dst, uint8_t *_src) {
dst[2] = src[2];
}
+void net_init(const uint8_t *mac);
+
// push rx packets into the network stack
void net_rx_eth(void *data, unsigned len);
diff --git a/net/ipv6.c b/net/ipv6.c
@@ -21,9 +21,47 @@ void hexdump(void *data, int len) {
}
}
-#define NETBUF_MAX 1536 // 1.5KB
+// create IP6 Link Local Address from Ethernet MAC
+void ip6lla_from_ethmac(ip6_addr_t* ip, const uint8_t *mac){
+ ip->w[0] = 0;
+ ip->w[1] = 0;
+ ip->b[0] = 0xFE;
+ ip->b[1] = 0x80;
+ ip->b[8] = mac[0] ^ 2;
+ ip->b[9] = mac[1];
+ ip->b[10] = mac[2];
+ ip->b[11] = 0xFF;
+ ip->b[12] = 0xFE;
+ ip->b[13] = mac[3];
+ ip->b[14] = mac[4];
+ ip->b[15] = mac[5];
+}
+
+// create IP6 Solicit Neighbor Multicast Address from Ethernet MAC
+void ip6ns_from_ethmac(ip6_addr_t *ip, const uint8_t *mac) {
+ ip->w[0] = 0;
+ ip->w[1] = 0;
+ ip->w[2] = 0;
+ ip->b[0] = 0xFF;
+ ip->b[1] = 0x02;
+ ip->b[11] = 0x01;
+ ip->b[12] = 0xFF;
+ ip->b[13] = mac[3];
+ ip->b[14] = mac[4];
+ ip->b[15] = mac[5];
+}
-#define TRACE_DISCARD 1
+// create Ethernet Multicast MAC from IP6 Multicast Address
+void ethmac_from_ip6mc(uint8_t *mac, const ip6_addr_t* ip) {
+ mac[0] = 0x33;
+ mac[1] = 0x33;
+ mac[2] = ip->b[12];
+ mac[3] = ip->b[13];
+ mac[4] = ip->b[14];
+ mac[5] = ip->b[15];
+}
+
+#define NETBUF_MAX 1536 // 1.5KB
typedef struct netbuf {
struct netbuf* next;
@@ -33,29 +71,48 @@ typedef struct netbuf {
uint8_t data[NETBUF_MAX];
} netbuf_t;
+// Interface Ethernet MAC
+static uint8_t ifc_mac[ETH_ADDR_LEN] = { 0x72, 0x72, 0xaa, 0xbb, 0xcc, 0xdd };
+
+// Interface IP6 Link Local IP6 Address
+static ip6_addr_t ifc_ll_ip6 = { .b = {
+ 0xFE, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x70, 0x72, 0xaa, 0xff, 0xfe, 0xbb, 0xcc, 0xdd, } };
+
+// Multicast Neighbor Solicitation IP6 Address
+static ip6_addr_t mcast_ns_ip6 = { .b = {
+ 0xFF, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x01, 0xff, 0xbb, 0xcc, 0xdd } };
+
+// Multicast Link Local All IP6 Address
+static const ip6_addr_t mcast_ll_ip6 = { .b = {
+ 0xFF, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, } };
+
// fast mac matching via word comparison
typedef union {
uint32_t w[2];
uint8_t b[8];
} match_t;
-match_t m_dev_mac = { .b = { 0, 0, 0x72, 0x72, 0xaa, 0xbb, 0xcc, 0xdd } };
-match_t m_mcast_all = { .b = { 0, 0, 0x33, 0x33, 0x00, 0x00, 0x00, 0x01 } };
-match_t m_mcast_ns = { .b = { 0, 0, 0x33, 0x33, 0xff, 0xbb, 0xcc, 0xdd } };
-
-uint8_t device_mac[ETH_ADDR_LEN] = { 0x72, 0x72, 0xaa, 0xbb, 0xcc, 0xdd };
+// Fast Match for Interface, Link Local Multicast,
+// and Neighbor Solicitation Multicast MACs
+static match_t m_ifc_mac = { .b = { 0, 0, 0x72, 0x72, 0xaa, 0xbb, 0xcc, 0xdd } };
+static match_t m_ns_mac = { .b = { 0, 0, 0x33, 0x33, 0xff, 0xbb, 0xcc, 0xdd } };
+static const match_t m_ll_mac = { .b = { 0, 0, 0x33, 0x33, 0x00, 0x00, 0x00, 0x01 } };
-ip6_addr_t device_ip6 = { .b = {
- 0xFE, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x70, 0x72, 0xaa, 0xff, 0xfe, 0xbb, 0xcc, 0xdd, } };
+void net_init(const uint8_t *mac) {
+ // store our interface ether mac
+ memcpy(ifc_mac, mac, ETH_ADDR_LEN);
+ memcpy(m_ifc_mac.b + 2, mac, ETH_ADDR_LEN);
-ip6_addr_t mcast_all_ip6 = { .b = {
- 0xFF, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, } };
+ // generate an ip6 link layer address from it
+ ip6lla_from_ethmac(&ifc_ll_ip6, mac);
-ip6_addr_t mcast_ns_ip6 = { .b = {
- 0xFF, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x00, 0x00, 0x01, 0xff, 0xbb, 0xcc, 0xdd } };
+ // generate ip6 NDP addresses from our ether mac
+ ip6ns_from_ethmac(&mcast_ns_ip6, mac);
+ ethmac_from_ip6mc(m_ns_mac.b + 2, &mcast_ns_ip6);
+}
// returns 16bit checksum of provided byte data buffer
static uint32_t checksum(const void* _data, unsigned len, uint32_t sum) {
@@ -115,7 +172,7 @@ void net_rx_icmp6(void *data, unsigned dlen, int mcast) {
if ((dlen < sizeof(ndp_hdr_t)) || (ndp->code != 0)) {
return;
}
- if (memcmp(&ndp->target, &device_ip6, sizeof(ip6_addr_t))) {
+ if (memcmp(&ndp->target, &ifc_ll_ip6, sizeof(ip6_addr_t))) {
return; // not for us
}
@@ -130,8 +187,8 @@ void net_rx_icmp6(void *data, unsigned dlen, int mcast) {
.opt[0] = NDP_N_TGT_LL_ADDR,
.opt[1] = 1,
};
- memcpy(&reply.hdr.target, &device_ip6, sizeof(ip6_addr_t));
- memcpy(&reply.opt[2], device_mac, ETH_ADDR_LEN);
+ memcpy(&reply.hdr.target, &ifc_ll_ip6, sizeof(ip6_addr_t));
+ memcpy(&reply.opt[2], ifc_mac, ETH_ADDR_LEN);
net_tx_ip6_reply(data, &reply, sizeof(reply), IP_HDR_ICMP, offsetof(ndp_hdr_t, checksum));
return;
@@ -156,13 +213,13 @@ void net_rx_ip6(void *data, unsigned len, int mcast) {
ip6_hdr_t *ip6 = data;
if (mcast) {
- if (memcmp(&ip6->dst, &mcast_all_ip6, sizeof(ip6_addr_t)) &&
+ if (memcmp(&ip6->dst, &mcast_ll_ip6, sizeof(ip6_addr_t)) &&
memcmp(&ip6->dst, &mcast_ns_ip6, sizeof(ip6_addr_t))) {
xprintf("IP6: MA ?\n");
return;
}
} else {
- if (memcmp(&ip6->dst, &device_ip6, sizeof(ip6_addr_t))) {
+ if (memcmp(&ip6->dst, &ifc_ll_ip6, sizeof(ip6_addr_t))) {
xprintf("IP6: UA ?\n");
return;
}
@@ -197,11 +254,11 @@ void net_rx_eth(void *data, unsigned len) {
// accept packets which match our ethernet MAC or multicast address
uint32_t *w = data;
- if ((w[0] == m_dev_mac.w[0]) && (w[1] == m_dev_mac.w[1])) {
+ if ((w[0] == m_ifc_mac.w[0]) && (w[1] == m_ifc_mac.w[1])) {
net_rx_ip6(data + sizeof(eth_hdr_t), len - sizeof(eth_hdr_t), 0);
- } else if ((w[0] == m_mcast_ns.w[0]) && (w[1] == m_mcast_ns.w[1])) {
+ } else if ((w[0] == m_ns_mac.w[0]) && (w[1] == m_ns_mac.w[1])) {
net_rx_ip6(data + sizeof(eth_hdr_t), len - sizeof(eth_hdr_t), 1);
- } else if ((w[0] == m_mcast_all.w[0]) && (w[1] == m_mcast_all.w[1])) {
+ } else if ((w[0] == m_ll_mac.w[0]) && (w[1] == m_ll_mac.w[1])) {
net_rx_ip6(data + sizeof(eth_hdr_t), len - sizeof(eth_hdr_t), 1);
} else {
xprintf("ETH ? %02x %02x %02x %02x %02x %02x\n",
@@ -231,14 +288,14 @@ void net_tx_udp_reply(void *replyto, void *data, unsigned len, unsigned port) {
}
eth_addr_copy(tx->eth.dst, rx->eth.src);
- eth_addr_copy(tx->eth.src, device_mac);
+ eth_addr_copy(tx->eth.src, ifc_mac);
tx->eth.type = htons(ETH_TYPE_IP6);
tx->ip6.bits = 0x00000060; // ver=0, tc=0, flow=0
tx->ip6.length = htons(UDP_HDR_LEN + len);
tx->ip6.next_header = IP_HDR_UDP;
tx->ip6.hop_limit = 255;
- ip6_addr_copy(&tx->ip6.src, &device_ip6);
+ ip6_addr_copy(&tx->ip6.src, &ifc_ll_ip6);
ip6_addr_copy(&tx->ip6.dst, &rx->ip6.src);
tx->udp.src_port = htons(port);
@@ -273,14 +330,14 @@ void net_tx_ip6_reply(void *replyto, void *data, unsigned len,
}
eth_addr_copy(tx->eth.dst, rx->eth.src);
- eth_addr_copy(tx->eth.src, device_mac);
+ eth_addr_copy(tx->eth.src, ifc_mac);
tx->eth.type = htons(ETH_TYPE_IP6);
tx->ip6.bits = 0x00000060; // ver=0, tc=0, flow=0
tx->ip6.length = htons(len);
tx->ip6.next_header = type;
tx->ip6.hop_limit = 255;
- ip6_addr_copy(&tx->ip6.src, &device_ip6);
+ ip6_addr_copy(&tx->ip6.src, &ifc_ll_ip6);
ip6_addr_copy(&tx->ip6.dst, &rx->ip6.src);
memcpy(tx->data, data, len);
