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)
24 #define ntohs(v) htons(v)
36 #define DHCP_MAGIC 0x63825363
40 uint8_t htype; // 1 = Ethernet
41 uint8_t hlen; // 6 bytes for MAC
42 uint8_t hops; // Hop counting
53 uint32_t dhcp_magic; // 0x63 0x82 0x53 0x63
57 typedef struct sInterface
67 int main(int argc, char *argv[]);
68 int Start_Interface(tInterface *Iface);
69 void Send_DHCPDISCOVER(tInterface *Iface);
70 void Send_DHCPREQUEST(tInterface *Iface, void *OfferBuffer, int TypeOffset);
71 void Handle_Packet(tInterface *Iface);
72 void SetAddress(tInterface *Iface, void *Addr, void *Mask, void *Router);
75 int main(int argc, char *argv[])
80 fprintf(stderr, "Usage: %s <interface>\n", argv[0]);
84 iface.State = STATE_PREINIT;
85 iface.Adapter = argv[1];
87 if( Start_Interface(&iface) < 0 ) {
92 Send_DHCPDISCOVER(&iface);
101 FD_SET(iface.SocketFD, &fds); if(maxfd < iface.SocketFD) maxfd = iface.SocketFD;
102 if( select(maxfd+1, &fds, NULL, NULL, NULL) < 0 )
104 // TODO: Check error result
108 _SysDebug("select returned");
110 if( FD_ISSET(iface.SocketFD, &fds) )
112 // TODO: Catch response
113 Handle_Packet( &iface );
121 int Start_Interface(tInterface *Iface)
124 char path[] = "/Devices/ip/XXXXX/udpc";
125 char addr[4] = {0,0,0,0};
127 // TODO: Check that the adapter is not in use
129 // Initialise an interface, with a dummy IP address (zero)
130 fd = open("/Devices/ip", 0);
132 fprintf(stderr, "ERROR: Unable to open '/Devices/ip'\n");
135 Iface->Num = ioctl(fd, 4, (void*)Iface->Adapter); // Create interface
136 if( Iface->Num == -1 ) {
137 fprintf(stderr, "ERROR: Unable to create new interface\n");
142 // Open new interface
143 snprintf(path, sizeof(path), "/Devices/ip/%i", Iface->Num);
144 Iface->IfaceFD = fd = open(path, 0);
146 fprintf(stderr, "ERROR: Unable to open '%s'\n", path);
149 tmp = 4; ioctl(fd, 4, &tmp); // Set to IPv4
150 ioctl(fd, 6, addr); // Set address to 0.0.0.0
151 tmp = 0; ioctl(fd, 7, &tmp); // Set subnet mask to 0
154 snprintf(path, sizeof(path), "/Devices/ip/%i/udp", Iface->Num);
155 Iface->SocketFD = fd = open(path, O_RDWR);
157 fprintf(stderr, "ERROR: Unable to open '%s'\n", path);
160 tmp = 68; ioctl(fd, 4, &tmp); // Local port
161 tmp = 67; ioctl(fd, 5, &tmp); // Remote port
162 tmp = 0; ioctl(fd, 7, &tmp); // Remote addr mask - we don't care where the reply comes from
163 addr[0] = addr[1] = addr[2] = addr[3] = 255; // 255.255.255.255
164 ioctl(fd, 8, addr); // Remote address
169 void Send_DHCPDISCOVER(tInterface *Iface)
171 uint32_t transaction_id;
172 struct sDHCP_Message *msg;
173 char data[8 + sizeof(struct sDHCP_Message) + 3 + 1];
174 msg = (void*)data + 8;
176 transaction_id = rand();
178 msg->op = htonb(1); // BOOTREQUEST
179 msg->htype = htonb(1); // 10mb Ethernet
180 msg->hlen = htonb(6); // 6 byte MAC
181 msg->hops = htonb(0); // Hop count so far
182 msg->xid = htonl(transaction_id); // Transaction ID
183 msg->secs = htons(0); // secs - No time has elapsed
184 msg->flags = htons(0); // flags - TODO: Check if broadcast bit need be set
185 msg->ciaddr = htonl(0); // ciaddr - Zero, as we don't have one yet
186 msg->yiaddr = htonl(0); // yiaddr - Zero?
187 msg->siaddr = htonl(0); // siaddr - Zero? maybe -1
188 msg->giaddr = htonl(0); // giaddr - Zero?
189 // Request MAC address from network adapter
191 int fd = open(Iface->Adapter, 0);
192 // TODO: Check if open() failed
193 ioctl(fd, 4, msg->chaddr);
194 // TODO: Check if ioctl() failed
197 memset(msg->sname, 0, sizeof(msg->sname)); // Nuke the rest
198 memset(msg->file, 0, sizeof(msg->file)); // Nuke the rest
199 msg->dhcp_magic = htonl(DHCP_MAGIC);
202 msg->options[i++] = 53; // DHCP Message Type
203 msg->options[i++] = 1;
204 msg->options[i++] = 1; // - DHCPDISCOVER
205 msg->options[i++] = 255; // End of list
208 data[0] = 67; data[1] = 0; // Port
209 data[2] = 4; data[3] = 0; // AddrType
210 data[4] = 255; data[5] = 255; data[6] = 255; data[7] = 255;
212 write(Iface->SocketFD, data, sizeof(data));
213 Iface->State = STATE_DISCOVER_SENT;
216 void Send_DHCPREQUEST(tInterface *Iface, void *OfferPacket, int TypeOffset)
218 struct sDHCP_Message *msg;
219 msg = (void*) ((char*)OfferPacket) + 8;
221 // Reuses old data :)
223 msg->options[TypeOffset+2] = 3; // DHCPREQUEST
224 msg->options[TypeOffset+3] = 255;
226 write(Iface->SocketFD, OfferPacket, 8 + sizeof(*msg) + TypeOffset + 4);
227 Iface->State = STATE_REQUEST_SENT;
230 void Handle_Packet(tInterface *Iface)
233 struct sDHCP_Message *msg = (void*)(data + 8);
236 int dhcp_msg_type = 0, dhcp_msg_type_ofs;
238 void *subnet_mask = NULL;
240 _SysDebug("Doing read on %i", Iface->SocketFD);
241 len = read(Iface->SocketFD, data, sizeof(data));
242 _SysDebug("len = %i", len);
244 _SysDebug("*msg = {");
245 _SysDebug(" .op = %i", msg->op);
246 _SysDebug(" .htype = %i", msg->htype);
247 _SysDebug(" .ciaddr = 0x%x", ntohl(msg->ciaddr));
248 _SysDebug(" .yiaddr = 0x%x", ntohl(msg->yiaddr));
252 _SysDebug("Not a response message");
256 if( htonl(msg->dhcp_magic) != DHCP_MAGIC ) {
257 _SysDebug("DHCP magic doesn't match (got 0x%x, expected 0x%x)",
258 htonl(msg->dhcp_magic), DHCP_MAGIC);
263 while( i < len - sizeof(*msg) - 8 && msg->options[i] != 255 )
265 if( msg->options[i] == 0 ) {
269 _SysDebug("Option %i, %i bytes long", msg->options[i], msg->options[i+1]);
270 switch(msg->options[i])
273 subnet_mask = &msg->options[i+2];
276 router = &msg->options[i+2];
279 dhcp_msg_type_ofs = i;
280 dhcp_msg_type = msg->options[i+2];
283 i += msg->options[i+1]+2;
286 _SysDebug("dhcp_msg_type = %i", dhcp_msg_type);
288 switch( dhcp_msg_type )
290 case 1: // DHCPDISCOVER - wut?
293 // Send out request for this address
294 if( Iface->State != STATE_DISCOVER_SENT ) return ;
295 Send_DHCPREQUEST(Iface, data, dhcp_msg_type_ofs);
297 case 3: // DHCPREQUEST - wut?
299 case 4: // DHCPDECLINE - ?
302 // TODO: Apply address
303 SetAddress(Iface, &msg->yiaddr, subnet_mask, router);
309 void SetAddress(tInterface *Iface, void *Addr, void *Mask, void *Router)
313 // Translate the mask
316 uint8_t *mask = Mask;
318 _SysDebug("Mask %i.%i.%i.%i", mask[0], mask[1], mask[2], mask[3]);
319 for( i = 0; i < 4 && mask[i] == 0xFF; i ++ ) ;
329 case 0x00: mask_bits += 0; break;
330 case 0x80: mask_bits += 1; break;
331 case 0xC0: mask_bits += 2; break;
332 case 0xE0: mask_bits += 3; break;
333 case 0xF0: mask_bits += 4; break;
334 case 0xF8: mask_bits += 5; break;
335 case 0xFC: mask_bits += 6; break;
336 case 0xFE: mask_bits += 7; break;
345 uint8_t *addr = Addr;
346 _SysDebug("Addr %i.%i.%i.%i/%i", addr[0], addr[1], addr[2], addr[3], mask_bits);
348 printf("Assigned %i.%i.%i.%i/%i to IF#%i (%s)\n",
349 addr[0], addr[1], addr[2], addr[3], mask_bits,
350 Iface->Num, Iface->Adapter
354 ioctl(Iface->IfaceFD, 6, Addr);
355 ioctl(Iface->IfaceFD, 7, &mask_bits);
359 uint8_t *addr = Router;
360 _SysDebug("Router %i.%i.%i.%i", addr[0], addr[1], addr[2], addr[3]);
364 fd = open("/Devices/ip/routes/4:00000000:0:0", OPENFLAG_CREATE);
366 fprintf(stderr, "ERROR: Unable to open default route\n");
369 char ifname[snprintf(NULL,0,"%i",Iface->Num)+1];
370 sprintf(ifname, "%i", Iface->Num);
371 ioctl(fd, ioctl(fd, 3, "set_nexthop"), Router);
372 ioctl(fd, ioctl(fd, 3, "set_interface"), ifname);