+/*
+ */
+#include <unistd.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <net.h>
+
+// --- Translation functions ---
+static inline uint32_t htonl(uint32_t v)
+{
+ return (((v >> 24) & 0xFF) << 0)
+ | (((v >> 16) & 0xFF) << 8)
+ | (((v >> 8) & 0xFF) << 16)
+ | (((v >> 0) & 0xFF) << 24);
+}
+static inline uint16_t htons(uint16_t v)
+{
+ return (((v >> 8) & 0xFF) << 0)
+ | (((v >> 0) & 0xFF) << 8);
+}
+#define htonb(v) v
+#define ntohl(v) htonl(v)
+
+// === CONSTANTS ===
+enum eStates
+{
+ STATE_PREINIT,
+ STATE_DISCOVER_SENT,
+ STATE_REQUEST_SENT,
+ STATE_COMPLETE
+};
+
+// === STRUCTURES ===
+#define DHCP_MAGIC 0x63825363
+struct sDHCP_Message
+{
+ uint8_t op;
+ uint8_t htype; // 1 = Ethernet
+ uint8_t hlen; // 6 bytes for MAC
+ uint8_t hops; // Hop counting
+ uint32_t xid;
+ uint16_t secs;
+ uint16_t flags;
+ uint32_t ciaddr;
+ uint32_t yiaddr;
+ uint32_t siaddr;
+ uint32_t giaddr;
+ uint8_t chaddr[16];
+ uint8_t sname[64];
+ uint8_t file[128];
+ uint32_t dhcp_magic; // 0x63 0x82 0x53 0x63
+ uint8_t options[];
+};
+
+typedef struct sInterface
+{
+ const char *Adapter;
+ int State;
+ int Num;
+ int SocketFD;
+ int IfaceFD;
+} tInterface;
+
+// === PROTOTYPES ===
+int main(int argc, char *argv[]);
+int Start_Interface(tInterface *Iface);
+void Send_DHCPDISCOVER(tInterface *Iface);
+void Send_DHCPREQUEST(tInterface *Iface, void *OfferBuffer, int TypeOffset);
+void Handle_Packet(tInterface *Iface);
+void SetAddress(tInterface *Iface, void *Addr, void *Mask, void *Router);
+
+// === CODE ===
+int main(int argc, char *argv[])
+{
+ tInterface iface;
+
+ if( argc != 2 ) {
+ fprintf(stderr, "Usage: %s <interface>\n", argv[0]);
+ return -1;
+ }
+
+ iface.State = STATE_PREINIT;
+ iface.Adapter = argv[1];
+
+ if( Start_Interface(&iface) < 0 ) {
+ return -1;
+ }
+
+ // Send request
+ Send_DHCPDISCOVER(&iface);
+
+ for( ;; )
+ {
+ int maxfd;
+ fd_set fds;
+
+ maxfd = 0;
+ FD_ZERO(&fds);
+ FD_SET(iface.SocketFD, &fds); if(maxfd < iface.SocketFD) maxfd = iface.SocketFD;
+ if( select(maxfd+1, &fds, NULL, NULL, NULL) < 0 )
+ {
+ // TODO: Check error result
+ return -1;
+ }
+
+ _SysDebug("select returned");
+
+ if( FD_ISSET(iface.SocketFD, &fds) )
+ {
+ // TODO: Catch response
+ Handle_Packet( &iface );
+
+ }
+ }
+ return 0;
+}
+
+// RETURN: Client FD
+int Start_Interface(tInterface *Iface)
+{
+ int fd, tmp;
+ char path[] = "/Devices/ip/XXXXX/udpc";
+ char addr[4] = {0,0,0,0};
+
+ // TODO: Check that the adapter is not in use
+
+ // Initialise an interface, with a dummy IP address (zero)
+ fd = open("/Devices/ip", 0);
+ if( fd == -1 ) {
+ fprintf(stderr, "ERROR: Unable to open '/Devices/ip'\n");
+ return -1;
+ }
+ Iface->Num = ioctl(fd, 4, (void*)Iface->Adapter); // Create interface
+ if( Iface->Num == -1 ) {
+ fprintf(stderr, "ERROR: Unable to create new interface\n");
+ return -1;
+ }
+ close(fd);
+
+ // Open new interface
+ snprintf(path, sizeof(path), "/Devices/ip/%i", Iface->Num);
+ Iface->IfaceFD = fd = open(path, 0);
+ if( fd == -1 ) {
+ fprintf(stderr, "ERROR: Unable to open '%s'\n", path);
+ return -1;
+ }
+ tmp = 4; ioctl(fd, 4, &tmp); // Set to IPv4
+ ioctl(fd, 6, addr); // Set address to 0.0.0.0
+ tmp = 0; ioctl(fd, 7, &tmp); // Set subnet mask to 0
+
+ // Open UDP Client
+ snprintf(path, sizeof(path), "/Devices/ip/%i/udp", Iface->Num);
+ Iface->SocketFD = fd = open(path, O_RDWR);
+ if( fd == -1 ) {
+ fprintf(stderr, "ERROR: Unable to open '%s'\n", path);
+ return -1;
+ }
+ tmp = 68; ioctl(fd, 4, &tmp); // Local port
+ tmp = 67; ioctl(fd, 5, &tmp); // Remote port
+ tmp = 0; ioctl(fd, 7, &tmp); // Remote addr mask - we don't care where the reply comes from
+ addr[0] = addr[1] = addr[2] = addr[3] = 255; // 255.255.255.255
+ ioctl(fd, 8, addr); // Remote address
+
+ return fd;
+}
+
+void Send_DHCPDISCOVER(tInterface *Iface)
+{
+ uint32_t transaction_id;
+ struct sDHCP_Message *msg;
+ char data[8 + sizeof(struct sDHCP_Message) + 3 + 1];
+ msg = (void*)data + 8;
+
+ transaction_id = rand();
+
+ msg->op = htonb(1); // BOOTREQUEST
+ msg->htype = htonb(1); // 10mb Ethernet
+ msg->hlen = htonb(6); // 6 byte MAC
+ msg->hops = htonb(0); // Hop count so far
+ msg->xid = htonl(transaction_id); // Transaction ID
+ msg->secs = htons(0); // secs - No time has elapsed
+ msg->flags = htons(0); // flags - TODO: Check if broadcast bit need be set
+ msg->ciaddr = htonl(0); // ciaddr - Zero, as we don't have one yet
+ msg->yiaddr = htonl(0); // yiaddr - Zero?
+ msg->siaddr = htonl(0); // siaddr - Zero? maybe -1
+ msg->giaddr = htonl(0); // giaddr - Zero?
+ // Request MAC address from network adapter
+ {
+ int fd = open(Iface->Adapter, 0);
+ // TODO: Check if open() failed
+ ioctl(fd, 4, msg->chaddr);
+ // TODO: Check if ioctl() failed
+ close(fd);
+ }
+ memset(msg->sname, 0, sizeof(msg->sname)); // Nuke the rest
+ memset(msg->file, 0, sizeof(msg->file)); // Nuke the rest
+ msg->dhcp_magic = htonl(DHCP_MAGIC);
+
+ int i = 0;
+ msg->options[i++] = 53; // DHCP Message Type
+ msg->options[i++] = 1;
+ msg->options[i++] = 1; // - DHCPDISCOVER
+ msg->options[i++] = 255; // End of list
+
+
+ data[0] = 67; data[1] = 0; // Port
+ data[2] = 4; data[3] = 0; // AddrType
+ data[4] = 255; data[5] = 255; data[6] = 255; data[7] = 255;
+
+ write(Iface->SocketFD, data, sizeof(data));
+ Iface->State = STATE_DISCOVER_SENT;
+}
+
+void Send_DHCPREQUEST(tInterface *Iface, void *OfferPacket, int TypeOffset)
+{
+ struct sDHCP_Message *msg;
+ msg = (void*) ((char*)OfferPacket) + 8;
+
+ // Reuses old data :)
+ msg->op = 1;
+ msg->options[TypeOffset+2] = 3; // DHCPREQUEST
+ msg->options[TypeOffset+3] = 255;
+
+ write(Iface->SocketFD, OfferPacket, 8 + sizeof(*msg) + TypeOffset + 4);
+ Iface->State = STATE_REQUEST_SENT;
+}
+
+void Handle_Packet(tInterface *Iface)
+{
+ char data[8+576];
+ struct sDHCP_Message *msg = (void*)(data + 8);
+ int len, i;
+
+ int dhcp_msg_type = 0, dhcp_msg_type_ofs;
+ void *router = NULL;
+ void *subnet_mask = NULL;
+
+ _SysDebug("Doing read on %i", Iface->SocketFD);
+ len = read(Iface->SocketFD, data, sizeof(data));
+ _SysDebug("len = %i", len);
+
+ _SysDebug("*msg = {");
+ _SysDebug(" .op = %i", msg->op);
+ _SysDebug(" .htype = %i", msg->htype);
+ _SysDebug(" .ciaddr = 0x%x", ntohl(msg->ciaddr));
+ _SysDebug(" .yiaddr = 0x%x", ntohl(msg->yiaddr));
+ _SysDebug("}");
+ if( msg->op != 2 ) {
+ // Not a response
+ _SysDebug("Not a response message");
+ return ;
+ }
+
+ if( htonl(msg->dhcp_magic) != DHCP_MAGIC ) {
+ _SysDebug("DHCP magic doesn't match (got 0x%x, expected 0x%x)",
+ htonl(msg->dhcp_magic), DHCP_MAGIC);
+ return ;
+ }
+
+ i = 0;
+ while( i < len - sizeof(*msg) - 8 && msg->options[i] != 255 )
+ {
+ if( msg->options[i] == 0 ) {
+ i ++;
+ continue ;
+ }
+ _SysDebug("Option %i, %i bytes long", msg->options[i], msg->options[i+1]);
+ switch(msg->options[i])
+ {
+ case 1:
+ subnet_mask = &msg->options[i+2];
+ break;
+ case 3:
+ router = &msg->options[i+2];
+ break;
+ case 53:
+ dhcp_msg_type_ofs = i;
+ dhcp_msg_type = msg->options[i+2];
+ break;
+ }
+ i += msg->options[i+1]+2;
+ }
+
+ _SysDebug("dhcp_msg_type = %i", dhcp_msg_type);
+
+ switch( dhcp_msg_type )
+ {
+ case 1: // DHCPDISCOVER - wut?
+ break;
+ case 2: // DHCPOFFER
+ // Send out request for this address
+ if( Iface->State != STATE_DISCOVER_SENT ) return ;
+ Send_DHCPREQUEST(Iface, data, dhcp_msg_type_ofs);
+ break;
+ case 3: // DHCPREQUEST - wut?
+ break;
+ case 4: // DHCPDECLINE - ?
+ break;
+ case 5: // DHCPACK
+ // TODO: Apply address
+ SetAddress(Iface, &msg->yiaddr, subnet_mask, router);
+ exit( 0 );
+ break;
+ }
+}
+
+void SetAddress(tInterface *Iface, void *Addr, void *Mask, void *Router)
+{
+ int mask_bits = 0;
+
+ // Translate the mask
+ if( Mask )
+ {
+ uint8_t *mask = Mask;
+ int i;
+ _SysDebug("Mask %i.%i.%i.%i", mask[0], mask[1], mask[2], mask[3]);
+ for( i = 0; i < 4 && mask[i] == 0xFF; i ++ ) ;
+ mask_bits = i*8;
+ if( i == 4 )
+ {
+ // Wut? /32?
+ }
+ else
+ {
+ switch(mask[i])
+ {
+ case 0x00: mask_bits += 0; break;
+ case 0x80: mask_bits += 1; break;
+ case 0xC0: mask_bits += 2; break;
+ case 0xE0: mask_bits += 3; break;
+ case 0xF0: mask_bits += 4; break;
+ case 0xF8: mask_bits += 5; break;
+ case 0xFC: mask_bits += 6; break;
+ case 0xFE: mask_bits += 7; break;
+ default:
+ // Bad mask!
+ break;
+ }
+ }
+ }
+
+ {
+ uint8_t *addr = Addr;
+ _SysDebug("Addr %i.%i.%i.%i/%i", addr[0], addr[1], addr[2], addr[3], mask_bits);
+
+ printf("Assigned %i.%i.%i.%i/%i to IF#%i (%s)\n",
+ addr[0], addr[1], addr[2], addr[3], mask_bits,
+ Iface->Num, Iface->Adapter
+ );
+ }
+
+ ioctl(Iface->IfaceFD, 6, Addr);
+ ioctl(Iface->IfaceFD, 7, &mask_bits);
+
+ if( Router );
+ {
+ uint8_t *addr = Router;
+ _SysDebug("Router %i.%i.%i.%i", addr[0], addr[1], addr[2], addr[3]);
+// ioctl(Iface->IfaceFD, 8, addr);
+ // TODO: Default route
+ }
+}
+