9 // --- Translation functions ---
10 static inline uint32_t htonl(uint32_t v)
12 return (((v >> 24) & 0xFF) << 0)
13 | (((v >> 16) & 0xFF) << 8)
14 | (((v >> 8) & 0xFF) << 16)
15 | (((v >> 0) & 0xFF) << 24);
17 static inline uint16_t htons(uint16_t v)
19 return (((v >> 8) & 0xFF) << 0)
20 | (((v >> 0) & 0xFF) << 8);
23 #define ntohl(v) htonl(v)
35 #define DHCP_MAGIC 0x63825363
39 uint8_t htype; // 1 = Ethernet
40 uint8_t hlen; // 6 bytes for MAC
41 uint8_t hops; // Hop counting
52 uint32_t dhcp_magic; // 0x63 0x82 0x53 0x63
56 typedef struct sInterface
66 int main(int argc, char *argv[]);
67 int Start_Interface(tInterface *Iface);
68 void Send_DHCPDISCOVER(tInterface *Iface);
69 void Send_DHCPREQUEST(tInterface *Iface, void *OfferBuffer, int TypeOffset);
70 void Handle_Packet(tInterface *Iface);
71 void SetAddress(tInterface *Iface, void *Addr, void *Mask, void *Router);
74 int main(int argc, char *argv[])
79 fprintf(stderr, "Usage: %s <interface>\n", argv[0]);
83 iface.State = STATE_PREINIT;
84 iface.Adapter = argv[1];
86 if( Start_Interface(&iface) < 0 ) {
91 Send_DHCPDISCOVER(&iface);
100 FD_SET(iface.SocketFD, &fds); if(maxfd < iface.SocketFD) maxfd = iface.SocketFD;
101 if( select(maxfd+1, &fds, NULL, NULL, NULL) < 0 )
103 // TODO: Check error result
107 _SysDebug("select returned");
109 if( FD_ISSET(iface.SocketFD, &fds) )
111 // TODO: Catch response
112 Handle_Packet( &iface );
120 int Start_Interface(tInterface *Iface)
123 char path[] = "/Devices/ip/XXXXX/udpc";
124 char addr[4] = {0,0,0,0};
126 // TODO: Check that the adapter is not in use
128 // Initialise an interface, with a dummy IP address (zero)
129 fd = open("/Devices/ip", 0);
131 fprintf(stderr, "ERROR: Unable to open '/Devices/ip'\n");
134 Iface->Num = ioctl(fd, 4, (void*)Iface->Adapter); // Create interface
135 if( Iface->Num == -1 ) {
136 fprintf(stderr, "ERROR: Unable to create new interface\n");
141 // Open new interface
142 snprintf(path, sizeof(path), "/Devices/ip/%i", Iface->Num);
143 Iface->IfaceFD = fd = open(path, 0);
145 fprintf(stderr, "ERROR: Unable to open '%s'\n", path);
148 tmp = 4; ioctl(fd, 4, &tmp); // Set to IPv4
149 ioctl(fd, 6, addr); // Set address to 0.0.0.0
150 tmp = 0; ioctl(fd, 7, &tmp); // Set subnet mask to 0
153 snprintf(path, sizeof(path), "/Devices/ip/%i/udp", Iface->Num);
154 Iface->SocketFD = fd = open(path, O_RDWR);
156 fprintf(stderr, "ERROR: Unable to open '%s'\n", path);
159 tmp = 68; ioctl(fd, 4, &tmp); // Local port
160 tmp = 67; ioctl(fd, 5, &tmp); // Remote port
161 tmp = 0; ioctl(fd, 7, &tmp); // Remote addr mask - we don't care where the reply comes from
162 addr[0] = addr[1] = addr[2] = addr[3] = 255; // 255.255.255.255
163 ioctl(fd, 8, addr); // Remote address
168 void Send_DHCPDISCOVER(tInterface *Iface)
170 uint32_t transaction_id;
171 struct sDHCP_Message *msg;
172 char data[8 + sizeof(struct sDHCP_Message) + 3 + 1];
173 msg = (void*)data + 8;
175 transaction_id = rand();
177 msg->op = htonb(1); // BOOTREQUEST
178 msg->htype = htonb(1); // 10mb Ethernet
179 msg->hlen = htonb(6); // 6 byte MAC
180 msg->hops = htonb(0); // Hop count so far
181 msg->xid = htonl(transaction_id); // Transaction ID
182 msg->secs = htons(0); // secs - No time has elapsed
183 msg->flags = htons(0); // flags - TODO: Check if broadcast bit need be set
184 msg->ciaddr = htonl(0); // ciaddr - Zero, as we don't have one yet
185 msg->yiaddr = htonl(0); // yiaddr - Zero?
186 msg->siaddr = htonl(0); // siaddr - Zero? maybe -1
187 msg->giaddr = htonl(0); // giaddr - Zero?
188 // Request MAC address from network adapter
190 int fd = open(Iface->Adapter, 0);
191 // TODO: Check if open() failed
192 ioctl(fd, 4, msg->chaddr);
193 // TODO: Check if ioctl() failed
196 memset(msg->sname, 0, sizeof(msg->sname)); // Nuke the rest
197 memset(msg->file, 0, sizeof(msg->file)); // Nuke the rest
198 msg->dhcp_magic = htonl(DHCP_MAGIC);
201 msg->options[i++] = 53; // DHCP Message Type
202 msg->options[i++] = 1;
203 msg->options[i++] = 1; // - DHCPDISCOVER
204 msg->options[i++] = 255; // End of list
207 data[0] = 67; data[1] = 0; // Port
208 data[2] = 4; data[3] = 0; // AddrType
209 data[4] = 255; data[5] = 255; data[6] = 255; data[7] = 255;
211 write(Iface->SocketFD, data, sizeof(data));
212 Iface->State = STATE_DISCOVER_SENT;
215 void Send_DHCPREQUEST(tInterface *Iface, void *OfferPacket, int TypeOffset)
217 struct sDHCP_Message *msg;
218 msg = (void*) ((char*)OfferPacket) + 8;
220 // Reuses old data :)
222 msg->options[TypeOffset+2] = 3; // DHCPREQUEST
223 msg->options[TypeOffset+3] = 255;
225 write(Iface->SocketFD, OfferPacket, 8 + sizeof(*msg) + TypeOffset + 4);
226 Iface->State = STATE_REQUEST_SENT;
229 void Handle_Packet(tInterface *Iface)
232 struct sDHCP_Message *msg = (void*)(data + 8);
235 int dhcp_msg_type = 0, dhcp_msg_type_ofs;
237 void *subnet_mask = NULL;
239 _SysDebug("Doing read on %i", Iface->SocketFD);
240 len = read(Iface->SocketFD, data, sizeof(data));
241 _SysDebug("len = %i", len);
243 _SysDebug("*msg = {");
244 _SysDebug(" .op = %i", msg->op);
245 _SysDebug(" .htype = %i", msg->htype);
246 _SysDebug(" .ciaddr = 0x%x", ntohl(msg->ciaddr));
247 _SysDebug(" .yiaddr = 0x%x", ntohl(msg->yiaddr));
251 _SysDebug("Not a response message");
255 if( htonl(msg->dhcp_magic) != DHCP_MAGIC ) {
256 _SysDebug("DHCP magic doesn't match (got 0x%x, expected 0x%x)",
257 htonl(msg->dhcp_magic), DHCP_MAGIC);
262 while( i < len - sizeof(*msg) - 8 && msg->options[i] != 255 )
264 if( msg->options[i] == 0 ) {
268 _SysDebug("Option %i, %i bytes long", msg->options[i], msg->options[i+1]);
269 switch(msg->options[i])
272 subnet_mask = &msg->options[i+2];
275 router = &msg->options[i+2];
278 dhcp_msg_type_ofs = i;
279 dhcp_msg_type = msg->options[i+2];
282 i += msg->options[i+1]+2;
285 _SysDebug("dhcp_msg_type = %i", dhcp_msg_type);
287 switch( dhcp_msg_type )
289 case 1: // DHCPDISCOVER - wut?
292 // Send out request for this address
293 if( Iface->State != STATE_DISCOVER_SENT ) return ;
294 Send_DHCPREQUEST(Iface, data, dhcp_msg_type_ofs);
296 case 3: // DHCPREQUEST - wut?
298 case 4: // DHCPDECLINE - ?
301 // TODO: Apply address
302 SetAddress(Iface, &msg->yiaddr, subnet_mask, router);
308 void SetAddress(tInterface *Iface, void *Addr, void *Mask, void *Router)
312 // Translate the mask
315 uint8_t *mask = Mask;
317 _SysDebug("Mask %i.%i.%i.%i", mask[0], mask[1], mask[2], mask[3]);
318 for( i = 0; i < 4 && mask[i] == 0xFF; i ++ ) ;
328 case 0x00: mask_bits += 0; break;
329 case 0x80: mask_bits += 1; break;
330 case 0xC0: mask_bits += 2; break;
331 case 0xE0: mask_bits += 3; break;
332 case 0xF0: mask_bits += 4; break;
333 case 0xF8: mask_bits += 5; break;
334 case 0xFC: mask_bits += 6; break;
335 case 0xFE: mask_bits += 7; break;
344 uint8_t *addr = Addr;
345 _SysDebug("Addr %i.%i.%i.%i/%i", addr[0], addr[1], addr[2], addr[3], mask_bits);
347 printf("Assigned %i.%i.%i.%i/%i to IF#%i (%s)\n",
348 addr[0], addr[1], addr[2], addr[3], mask_bits,
349 Iface->Num, Iface->Adapter
353 ioctl(Iface->IfaceFD, 6, Addr);
354 ioctl(Iface->IfaceFD, 7, &mask_bits);
358 uint8_t *addr = Router;
359 _SysDebug("Router %i.%i.%i.%i", addr[0], addr[1], addr[2], addr[3]);
360 // ioctl(Iface->IfaceFD, 8, addr);
361 // TODO: Default route