1: /* upf.c
2:
3: Ultrix PacketFilter interface code. */
4:
5: /*
6: * Copyright (c) 2004,2007,2009 by Internet Systems Consortium, Inc. ("ISC")
7: * Copyright (c) 1996-2003 by Internet Software Consortium
8: *
9: * Permission to use, copy, modify, and distribute this software for any
10: * purpose with or without fee is hereby granted, provided that the above
11: * copyright notice and this permission notice appear in all copies.
12: *
13: * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
14: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
15: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
16: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
17: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
18: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
19: * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20: *
21: * Internet Systems Consortium, Inc.
22: * 950 Charter Street
23: * Redwood City, CA 94063
24: * <info@isc.org>
25: * https://www.isc.org/
26: *
27: * This software has been written for Internet Systems Consortium
28: * by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc.
29: * To learn more about Internet Systems Consortium, see
30: * ``https://www.isc.org/''. To learn more about Vixie Enterprises,
31: * see ``http://www.vix.com''. To learn more about Nominum, Inc., see
32: * ``http://www.nominum.com''.
33: */
34:
35: #include "dhcpd.h"
36: #if defined (USE_UPF_SEND) || defined (USE_UPF_RECEIVE)
37: #include <sys/ioctl.h>
38: #include <sys/uio.h>
39:
40: #include <net/pfilt.h>
41: #include <netinet/in_systm.h>
42: #include "includes/netinet/ip.h"
43: #include "includes/netinet/udp.h"
44: #include "includes/netinet/if_ether.h"
45:
46: /* Reinitializes the specified interface after an address change. This
47: is not required for packet-filter APIs. */
48:
49: #ifdef USE_UPF_SEND
50: void if_reinitialize_send (info)
51: struct interface_info *info;
52: {
53: }
54: #endif
55:
56: #ifdef USE_UPF_RECEIVE
57: void if_reinitialize_receive (info)
58: struct interface_info *info;
59: {
60: }
61: #endif
62:
63: /* Called by get_interface_list for each interface that's discovered.
64: Opens a packet filter for each interface and adds it to the select
65: mask. */
66:
67: int if_register_upf (info)
68: struct interface_info *info;
69: {
70: int sock;
71: char filename[50];
72: int b;
73: struct endevp param;
74:
75: /* Open a UPF device */
76: for (b = 0; 1; b++) {
77: /* %Audit% Cannot exceed 36 bytes. %2004.06.17,Safe% */
78: sprintf(filename, "/dev/pf/pfilt%d", b);
79:
80: sock = open (filename, O_RDWR, 0);
81: if (sock < 0) {
82: if (errno == EBUSY) {
83: continue;
84: } else {
85: log_fatal ("Can't find free upf: %m");
86: }
87: } else {
88: break;
89: }
90: }
91:
92: /* Set the UPF device to point at this interface. */
93: if (ioctl (sock, EIOCSETIF, info -> ifp) < 0)
94: log_fatal ("Can't attach interface %s to upf device %s: %m",
95: info -> name, filename);
96:
97: /* Get the hardware address. */
98: if (ioctl (sock, EIOCDEVP, ¶m) < 0)
99: log_fatal ("Can't get interface %s hardware address: %m",
100: info -> name);
101:
102: /* We only know how to do ethernet. */
103: if (param.end_dev_type != ENDT_10MB)
104: log_fatal ("Invalid device type on network interface %s: %d",
105: info -> name, param.end_dev_type);
106:
107: if (param.end_addr_len != 6)
108: log_fatal ("Invalid hardware address length on %s: %d",
109: info -> name, param.end_addr_len);
110:
111: info -> hw_address.hlen = 7;
112: info -> hw_address.hbuf [0] = ARPHRD_ETHER;
113: memcpy (&info -> hw_address.hbuf [1], param.end_addr, 6);
114:
115: return sock;
116: }
117: #endif /* USE_UPF_SEND || USE_UPF_RECEIVE */
118:
119: #ifdef USE_UPF_SEND
120: void if_register_send (info)
121: struct interface_info *info;
122: {
123: /* If we're using the upf API for sending and receiving,
124: we don't need to register this interface twice. */
125: #ifndef USE_UPF_RECEIVE
126: info -> wfdesc = if_register_upf (info, interface);
127: #else
128: info -> wfdesc = info -> rfdesc;
129: #endif
130: if (!quiet_interface_discovery)
131: log_info ("Sending on UPF/%s/%s%s%s",
132: info -> name,
133: print_hw_addr (info -> hw_address.hbuf [0],
134: info -> hw_address.hlen - 1,
135: &info -> hw_address.hbuf [1]),
136: (info -> shared_network ? "/" : ""),
137: (info -> shared_network ?
138: info -> shared_network -> name : ""));
139: }
140:
141: void if_deregister_send (info)
142: struct interface_info *info;
143: {
144: #ifndef USE_UPF_RECEIVE
145: close (info -> wfdesc);
146: #endif
147: info -> wfdesc = -1;
148: if (!quiet_interface_discovery)
149: log_info ("Disabling output on UPF/%s/%s%s%s",
150: info -> name,
151: print_hw_addr (info -> hw_address.hbuf [0],
152: info -> hw_address.hlen - 1,
153: &info -> hw_address.hbuf [1]),
154: (info -> shared_network ? "/" : ""),
155: (info -> shared_network ?
156: info -> shared_network -> name : ""));
157: }
158: #endif /* USE_UPF_SEND */
159:
160: #ifdef USE_UPF_RECEIVE
161: /* Packet filter program...
162: XXX Changes to the filter program may require changes to the constant
163: offsets used in if_register_send to patch the UPF program! XXX */
164:
165:
166: void if_register_receive (info)
167: struct interface_info *info;
168: {
169: int flag = 1;
170: u_int32_t addr;
171: struct enfilter pf;
172: u_int32_t bits;
173:
174: /* Open a UPF device and hang it on this interface... */
175: info -> rfdesc = if_register_upf (info);
176:
177: /* Allow the copyall flag to be set... */
178: if (ioctl(info -> rfdesc, EIOCALLOWCOPYALL, &flag) < 0)
179: log_fatal ("Can't set ALLOWCOPYALL: %m");
180:
181: /* Clear all the packet filter mode bits first... */
182: flag = (ENHOLDSIG | ENBATCH | ENTSTAMP | ENPROMISC |
183: ENNONEXCL | ENCOPYALL);
184: if (ioctl (info -> rfdesc, EIOCMBIC, &flag) < 0)
185: log_fatal ("Can't clear pfilt bits: %m");
186:
187: /* Set the ENBATCH and ENCOPYALL bits... */
188: bits = ENBATCH | ENCOPYALL;
189: if (ioctl (info -> rfdesc, EIOCMBIS, &bits) < 0)
190: log_fatal ("Can't set ENBATCH|ENCOPYALL: %m");
191:
192: /* Set up the UPF filter program. */
193: /* XXX Unlike the BPF filter program, this one won't work if the
194: XXX IP packet is fragmented or if there are options on the IP
195: XXX header. */
196: pf.enf_Priority = 0;
197: pf.enf_FilterLen = 0;
198:
199: pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHWORD + 6;
200: pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHLIT + ENF_CAND;
201: pf.enf_Filter [pf.enf_FilterLen++] = htons (ETHERTYPE_IP);
202: pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHLIT;
203: pf.enf_Filter [pf.enf_FilterLen++] = htons (IPPROTO_UDP);
204: pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHWORD + 11;
205: pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHLIT + ENF_AND;
206: pf.enf_Filter [pf.enf_FilterLen++] = htons (0xFF);
207: pf.enf_Filter [pf.enf_FilterLen++] = ENF_CAND;
208: pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHWORD + 18;
209: pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHLIT + ENF_CAND;
210: pf.enf_Filter [pf.enf_FilterLen++] = local_port;
211:
212: if (ioctl (info -> rfdesc, EIOCSETF, &pf) < 0)
213: log_fatal ("Can't install packet filter program: %m");
214: if (!quiet_interface_discovery)
215: log_info ("Listening on UPF/%s/%s%s%s",
216: info -> name,
217: print_hw_addr (info -> hw_address.hbuf [0],
218: info -> hw_address.hlen - 1,
219: &info -> hw_address.hbuf [1]),
220: (info -> shared_network ? "/" : ""),
221: (info -> shared_network ?
222: info -> shared_network -> name : ""));
223: }
224:
225: void if_deregister_receive (info)
226: struct interface_info *info;
227: {
228: close (info -> rfdesc);
229: info -> rfdesc = -1;
230: if (!quiet_interface_discovery)
231: log_info ("Disabling input on UPF/%s/%s%s%s",
232: info -> name,
233: print_hw_addr (info -> hw_address.hbuf [0],
234: info -> hw_address.hlen - 1,
235: &info -> hw_address.hbuf [1]),
236: (info -> shared_network ? "/" : ""),
237: (info -> shared_network ?
238: info -> shared_network -> name : ""));
239: }
240: #endif /* USE_UPF_RECEIVE */
241:
242: #ifdef USE_UPF_SEND
243: ssize_t send_packet (interface, packet, raw, len, from, to, hto)
244: struct interface_info *interface;
245: struct packet *packet;
246: struct dhcp_packet *raw;
247: size_t len;
248: struct in_addr from;
249: struct sockaddr_in *to;
250: struct hardware *hto;
251: {
252: unsigned hbufp = 0, ibufp = 0;
253: double hw [4];
254: double ip [32];
255: struct iovec iov [3];
256: int result;
257: int fudge;
258:
259: if (!strcmp (interface -> name, "fallback"))
260: return send_fallback (interface, packet, raw,
261: len, from, to, hto);
262:
263: /* Assemble the headers... */
264: assemble_hw_header (interface, (unsigned char *)hw, &hbufp, hto);
265: assemble_udp_ip_header (interface,
266: (unsigned char *)ip, &ibufp, from.s_addr,
267: to -> sin_addr.s_addr, to -> sin_port,
268: (unsigned char *)raw, len);
269:
270: /* Fire it off */
271: iov [0].iov_base = ((char *)hw);
272: iov [0].iov_len = hbufp;
273: iov [1].iov_base = ((char *)ip);
274: iov [1].iov_len = ibufp;
275: iov [2].iov_base = (char *)raw;
276: iov [2].iov_len = len;
277:
278: result = writev(interface -> wfdesc, iov, 3);
279: if (result < 0)
280: log_error ("send_packet: %m");
281: return result;
282: }
283: #endif /* USE_UPF_SEND */
284:
285: #ifdef USE_UPF_RECEIVE
286: ssize_t receive_packet (interface, buf, len, from, hfrom)
287: struct interface_info *interface;
288: unsigned char *buf;
289: size_t len;
290: struct sockaddr_in *from;
291: struct hardware *hfrom;
292: {
293: int nread;
294: int length = 0;
295: int offset = 0;
296: unsigned char ibuf [1500 + sizeof (struct enstamp)];
297: int bufix = 0;
298: unsigned paylen;
299:
300: length = read (interface -> rfdesc, ibuf, sizeof ibuf);
301: if (length <= 0)
302: return length;
303:
304: bufix = sizeof (struct enstamp);
305: /* Decode the physical header... */
306: offset = decode_hw_header (interface, ibuf, bufix, hfrom);
307:
308: /* If a physical layer checksum failed (dunno of any
309: physical layer that supports this, but WTH), skip this
310: packet. */
311: if (offset < 0) {
312: return 0;
313: }
314:
315: bufix += offset;
316: length -= offset;
317:
318: /* Decode the IP and UDP headers... */
319: offset = decode_udp_ip_header (interface, ibuf, bufix,
320: from, length, &paylen);
321:
322: /* If the IP or UDP checksum was bad, skip the packet... */
323: if (offset < 0)
324: return 0;
325:
326: bufix += offset;
327: length -= offset;
328:
329: if (length < paylen)
330: log_fatal("Internal inconsistency at %s:%d.", MDL);
331:
332: /* Copy out the data in the packet... */
333: memcpy (buf, &ibuf[bufix], paylen);
334: return paylen;
335: }
336:
337: int can_unicast_without_arp (ip)
338: struct interface_info *ip;
339: {
340: return 1;
341: }
342:
343: int can_receive_unicast_unconfigured (ip)
344: struct interface_info *ip;
345: {
346: return 1;
347: }
348:
349: int supports_multiple_interfaces (ip)
350: struct interface_info *ip;
351: {
352: return 1;
353: }
354:
355: void maybe_setup_fallback ()
356: {
357: isc_result_t status;
358: struct interface_info *fbi = (struct interface_info *)0;
359: if (setup_fallback (&fbi, MDL)) {
360: if_register_fallback (fbi);
361: status = omapi_register_io_object ((omapi_object_t *)fbi,
362: if_readsocket, 0,
363: fallback_discard, 0, 0);
364: if (status != ISC_R_SUCCESS)
365: log_fatal ("Can't register I/O handle for %s: %s",
366: fbi -> name, isc_result_totext (status));
367: interface_dereference (&fbi, MDL);
368: }
369: }
370: #endif
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