Commit | Line | Data |
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2fe58dfd SE |
1 | /* User-kernel network link */ |
2 | ||
ff05a229 | 3 | /* See RFCs 791, 792, 1123 and 1812 */ |
2fe58dfd | 4 | |
ff05a229 SE |
5 | /* The netlink device is actually a router. Tunnels are unnumbered |
6 | point-to-point lines (RFC1812 section 2.2.7); the router has a | |
7 | single address (the 'router-id'). */ | |
8 | ||
9 | /* This is where we currently have the anti-spoofing paranoia - before | |
10 | sending a packet to the kernel we check that the tunnel it came | |
11 | over could reasonably have produced it. */ | |
12 | ||
13 | ||
14 | /* Points to note from RFC1812 (which may require changes in this | |
15 | file): | |
16 | ||
17 | 3.3.4 Maximum Transmission Unit - MTU | |
18 | ||
19 | The MTU of each logical interface MUST be configurable within the | |
20 | range of legal MTUs for the interface. | |
21 | ||
22 | Many Link Layer protocols define a maximum frame size that may be | |
23 | sent. In such cases, a router MUST NOT allow an MTU to be set which | |
24 | would allow sending of frames larger than those allowed by the Link | |
25 | Layer protocol. However, a router SHOULD be willing to receive a | |
26 | packet as large as the maximum frame size even if that is larger than | |
27 | the MTU. | |
28 | ||
29 | 4.2.1 A router SHOULD count datagrams discarded. | |
30 | ||
31 | 4.2.2.1 Source route options - we probably should implement processing | |
32 | of source routes, even though mostly the security policy will prevent | |
33 | their use. | |
34 | ||
35 | 5.3.13.4 Source Route Options | |
36 | ||
37 | A router MUST implement support for source route options in forwarded | |
38 | packets. A router MAY implement a configuration option that, when | |
39 | enabled, causes all source-routed packets to be discarded. However, | |
40 | such an option MUST NOT be enabled by default. | |
41 | ||
42 | 5.3.13.5 Record Route Option | |
43 | ||
44 | Routers MUST support the Record Route option in forwarded packets. | |
45 | ||
46 | A router MAY provide a configuration option that, if enabled, will | |
47 | cause the router to ignore (i.e., pass through unchanged) Record | |
48 | Route options in forwarded packets. If provided, such an option MUST | |
49 | default to enabling the record-route. This option should not affect | |
50 | the processing of Record Route options in datagrams received by the | |
51 | router itself (in particular, Record Route options in ICMP echo | |
52 | requests will still be processed according to Section [4.3.3.6]). | |
53 | ||
54 | 5.3.13.6 Timestamp Option | |
55 | ||
56 | Routers MUST support the timestamp option in forwarded packets. A | |
57 | timestamp value MUST follow the rules given [INTRO:2]. | |
58 | ||
59 | If the flags field = 3 (timestamp and prespecified address), the | |
60 | router MUST add its timestamp if the next prespecified address | |
61 | matches any of the router's IP addresses. It is not necessary that | |
62 | the prespecified address be either the address of the interface on | |
63 | which the packet arrived or the address of the interface over which | |
64 | it will be sent. | |
65 | ||
66 | ||
67 | 4.2.2.7 Fragmentation: RFC 791 Section 3.2 | |
68 | ||
69 | Fragmentation, as described in [INTERNET:1], MUST be supported by a | |
70 | router. | |
71 | ||
72 | 4.2.2.8 Reassembly: RFC 791 Section 3.2 | |
73 | ||
74 | As specified in the corresponding section of [INTRO:2], a router MUST | |
75 | support reassembly of datagrams that it delivers to itself. | |
76 | ||
77 | 4.2.2.9 Time to Live: RFC 791 Section 3.2 | |
78 | ||
79 | Note in particular that a router MUST NOT check the TTL of a packet | |
80 | except when forwarding it. | |
81 | ||
82 | A router MUST NOT discard a datagram just because it was received | |
83 | with TTL equal to zero or one; if it is to the router and otherwise | |
84 | valid, the router MUST attempt to receive it. | |
85 | ||
86 | On messages the router originates, the IP layer MUST provide a means | |
87 | for the transport layer to set the TTL field of every datagram that | |
88 | is sent. When a fixed TTL value is used, it MUST be configurable. | |
89 | ||
90 | ||
91 | 8.1 The Simple Network Management Protocol - SNMP | |
92 | 8.1.1 SNMP Protocol Elements | |
93 | ||
94 | Routers MUST be manageable by SNMP [MGT:3]. The SNMP MUST operate | |
95 | using UDP/IP as its transport and network protocols. | |
96 | ||
97 | ||
98 | */ | |
2fe58dfd | 99 | |
3b83c932 | 100 | #include <string.h> |
59230b9b IJ |
101 | #include <assert.h> |
102 | #include <limits.h> | |
8689b3a9 | 103 | #include "secnet.h" |
2fe58dfd | 104 | #include "util.h" |
7138d0c5 | 105 | #include "ipaddr.h" |
9d3a4132 | 106 | #include "netlink.h" |
042a8da9 | 107 | #include "process.h" |
2fe58dfd | 108 | |
a0b107b8 IJ |
109 | #ifdef NETLINK_DEBUG |
110 | #define MDEBUG(...) Message(M_DEBUG, __VA_ARGS__) | |
111 | #else /* !NETLINK_DEBUG */ | |
112 | #define MDEBUG(...) ((void)0) | |
113 | #endif /* !NETLINK_DEBUG */ | |
114 | ||
ff05a229 SE |
115 | #define ICMP_TYPE_ECHO_REPLY 0 |
116 | ||
117 | #define ICMP_TYPE_UNREACHABLE 3 | |
118 | #define ICMP_CODE_NET_UNREACHABLE 0 | |
119 | #define ICMP_CODE_PROTOCOL_UNREACHABLE 2 | |
120 | #define ICMP_CODE_FRAGMENTATION_REQUIRED 4 | |
121 | #define ICMP_CODE_NET_PROHIBITED 13 | |
122 | ||
123 | #define ICMP_TYPE_ECHO_REQUEST 8 | |
124 | ||
125 | #define ICMP_TYPE_TIME_EXCEEDED 11 | |
126 | #define ICMP_CODE_TTL_EXCEEDED 0 | |
127 | ||
4efd681a | 128 | /* Generic IP checksum routine */ |
211cd627 | 129 | static inline uint16_t ip_csum(const uint8_t *iph,int32_t count) |
2fe58dfd | 130 | { |
4efd681a SE |
131 | register uint32_t sum=0; |
132 | ||
133 | while (count>1) { | |
134 | sum+=ntohs(*(uint16_t *)iph); | |
135 | iph+=2; | |
136 | count-=2; | |
137 | } | |
138 | if(count>0) | |
139 | sum+=*(uint8_t *)iph; | |
140 | while (sum>>16) | |
141 | sum=(sum&0xffff)+(sum>>16); | |
142 | return htons(~sum); | |
2fe58dfd SE |
143 | } |
144 | ||
4efd681a SE |
145 | #ifdef i386 |
146 | /* | |
147 | * This is a version of ip_compute_csum() optimized for IP headers, | |
148 | * which always checksum on 4 octet boundaries. | |
149 | * | |
150 | * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by | |
151 | * Arnt Gulbrandsen. | |
152 | */ | |
211cd627 | 153 | static inline uint16_t ip_fast_csum(const uint8_t *iph, int32_t ihl) { |
4efd681a SE |
154 | uint32_t sum; |
155 | ||
20d324b6 SE |
156 | __asm__ __volatile__( |
157 | "movl (%1), %0 ;\n" | |
158 | "subl $4, %2 ;\n" | |
159 | "jbe 2f ;\n" | |
160 | "addl 4(%1), %0 ;\n" | |
161 | "adcl 8(%1), %0 ;\n" | |
162 | "adcl 12(%1), %0 ;\n" | |
163 | "1: adcl 16(%1), %0 ;\n" | |
164 | "lea 4(%1), %1 ;\n" | |
165 | "decl %2 ;\n" | |
166 | "jne 1b ;\n" | |
167 | "adcl $0, %0 ;\n" | |
168 | "movl %0, %2 ;\n" | |
169 | "shrl $16, %0 ;\n" | |
170 | "addw %w2, %w0 ;\n" | |
171 | "adcl $0, %0 ;\n" | |
172 | "notl %0 ;\n" | |
173 | "2: ;\n" | |
4efd681a SE |
174 | /* Since the input registers which are loaded with iph and ipl |
175 | are modified, we must also specify them as outputs, or gcc | |
176 | will assume they contain their original values. */ | |
177 | : "=r" (sum), "=r" (iph), "=r" (ihl) | |
20d324b6 SE |
178 | : "1" (iph), "2" (ihl) |
179 | : "memory"); | |
4efd681a SE |
180 | return sum; |
181 | } | |
182 | #else | |
fe21ce55 | 183 | static inline uint16_t ip_fast_csum(const uint8_t *iph, int32_t ihl) |
2fe58dfd | 184 | { |
1caa23ff | 185 | assert(ihl < INT_MAX/4); |
4efd681a SE |
186 | return ip_csum(iph,ihl*4); |
187 | } | |
188 | #endif | |
189 | ||
190 | struct iphdr { | |
191 | #if defined (WORDS_BIGENDIAN) | |
192 | uint8_t version:4, | |
193 | ihl:4; | |
194 | #else | |
195 | uint8_t ihl:4, | |
196 | version:4; | |
197 | #endif | |
198 | uint8_t tos; | |
199 | uint16_t tot_len; | |
200 | uint16_t id; | |
a6768d7c | 201 | uint16_t frag; |
eff13010 IJ |
202 | #define IPHDR_FRAG_OFF ((uint16_t)0x1fff) |
203 | #define IPHDR_FRAG_MORE ((uint16_t)0x2000) | |
204 | #define IPHDR_FRAG_DONT ((uint16_t)0x4000) | |
205 | /* reserved 0x8000 */ | |
4efd681a SE |
206 | uint8_t ttl; |
207 | uint8_t protocol; | |
208 | uint16_t check; | |
209 | uint32_t saddr; | |
210 | uint32_t daddr; | |
211 | /* The options start here. */ | |
212 | }; | |
213 | ||
214 | struct icmphdr { | |
215 | struct iphdr iph; | |
216 | uint8_t type; | |
217 | uint8_t code; | |
218 | uint16_t check; | |
cfd79482 | 219 | union icmpinfofield { |
4efd681a SE |
220 | uint32_t unused; |
221 | struct { | |
222 | uint8_t pointer; | |
223 | uint8_t unused1; | |
224 | uint16_t unused2; | |
225 | } pprob; | |
226 | uint32_t gwaddr; | |
227 | struct { | |
228 | uint16_t id; | |
229 | uint16_t seq; | |
230 | } echo; | |
f3d69e41 IJ |
231 | struct { |
232 | uint16_t unused; | |
233 | uint16_t mtu; | |
234 | } fragneeded; | |
4efd681a SE |
235 | } d; |
236 | }; | |
cfd79482 IJ |
237 | |
238 | static const union icmpinfofield icmp_noinfo; | |
4efd681a | 239 | |
826b47e9 IJ |
240 | static void netlink_client_deliver(struct netlink *st, |
241 | struct netlink_client *client, | |
242 | uint32_t source, uint32_t dest, | |
243 | struct buffer_if *buf); | |
244 | static void netlink_host_deliver(struct netlink *st, | |
245 | struct netlink_client *sender, | |
246 | uint32_t source, uint32_t dest, | |
247 | struct buffer_if *buf); | |
248 | ||
dbe11c20 IJ |
249 | static const char *sender_name(struct netlink_client *sender /* or NULL */) |
250 | { | |
251 | return sender?sender->name:"(local)"; | |
252 | } | |
253 | ||
70dc107b SE |
254 | static void netlink_packet_deliver(struct netlink *st, |
255 | struct netlink_client *client, | |
256 | struct buffer_if *buf); | |
4efd681a | 257 | |
ff05a229 SE |
258 | /* XXX RFC1812 4.3.2.5: |
259 | All other ICMP error messages (Destination Unreachable, | |
260 | Redirect, Time Exceeded, and Parameter Problem) SHOULD have their | |
261 | precedence value set to 6 (INTERNETWORK CONTROL) or 7 (NETWORK | |
262 | CONTROL). The IP Precedence value for these error messages MAY be | |
263 | settable. | |
264 | */ | |
4efd681a | 265 | static struct icmphdr *netlink_icmp_tmpl(struct netlink *st, |
826b47e9 IJ |
266 | uint32_t source, uint32_t dest, |
267 | uint16_t len) | |
4efd681a SE |
268 | { |
269 | struct icmphdr *h; | |
270 | ||
271 | BUF_ALLOC(&st->icmp,"netlink_icmp_tmpl"); | |
3abd18e8 | 272 | buffer_init(&st->icmp,calculate_max_start_pad()); |
4efd681a SE |
273 | h=buf_append(&st->icmp,sizeof(*h)); |
274 | ||
275 | h->iph.version=4; | |
276 | h->iph.ihl=5; | |
277 | h->iph.tos=0; | |
278 | h->iph.tot_len=htons(len+(h->iph.ihl*4)+8); | |
279 | h->iph.id=0; | |
a6768d7c | 280 | h->iph.frag=0; |
ff05a229 | 281 | h->iph.ttl=255; /* XXX should be configurable */ |
4efd681a | 282 | h->iph.protocol=1; |
826b47e9 | 283 | h->iph.saddr=htonl(source); |
4efd681a SE |
284 | h->iph.daddr=htonl(dest); |
285 | h->iph.check=0; | |
286 | h->iph.check=ip_fast_csum((uint8_t *)&h->iph,h->iph.ihl); | |
287 | h->check=0; | |
288 | h->d.unused=0; | |
289 | ||
290 | return h; | |
291 | } | |
292 | ||
293 | /* Fill in the ICMP checksum field correctly */ | |
294 | static void netlink_icmp_csum(struct icmphdr *h) | |
295 | { | |
1caa23ff | 296 | int32_t len; |
4efd681a SE |
297 | |
298 | len=ntohs(h->iph.tot_len)-(4*h->iph.ihl); | |
299 | h->check=0; | |
300 | h->check=ip_csum(&h->type,len); | |
301 | } | |
302 | ||
303 | /* RFC1122: | |
304 | * An ICMP error message MUST NOT be sent as the result of | |
305 | * receiving: | |
306 | * | |
307 | * * an ICMP error message, or | |
308 | * | |
309 | * * a datagram destined to an IP broadcast or IP multicast | |
310 | * address, or | |
311 | * | |
312 | * * a datagram sent as a link-layer broadcast, or | |
313 | * | |
314 | * * a non-initial fragment, or | |
315 | * | |
316 | * * a datagram whose source address does not define a single | |
317 | * host -- e.g., a zero address, a loopback address, a | |
318 | * broadcast address, a multicast address, or a Class E | |
319 | * address. | |
320 | */ | |
321 | static bool_t netlink_icmp_may_reply(struct buffer_if *buf) | |
322 | { | |
323 | struct iphdr *iph; | |
8dea8d37 | 324 | struct icmphdr *icmph; |
4efd681a SE |
325 | uint32_t source; |
326 | ||
975820aa | 327 | if (buf->size < (int)sizeof(struct icmphdr)) return False; |
4efd681a | 328 | iph=(struct iphdr *)buf->start; |
8dea8d37 SE |
329 | icmph=(struct icmphdr *)buf->start; |
330 | if (iph->protocol==1) { | |
331 | switch(icmph->type) { | |
686b7f1d IJ |
332 | /* Based on http://www.iana.org/assignments/icmp-parameters/icmp-parameters.xhtml#icmp-parameters-types |
333 | * as retrieved Thu, 20 Mar 2014 00:16:44 +0000. | |
334 | * Deprecated, reserved, unassigned and experimental | |
335 | * options are treated as not safe to reply to. | |
336 | */ | |
337 | case 0: /* Echo Reply */ | |
338 | case 8: /* Echo */ | |
339 | case 13: /* Timestamp */ | |
340 | case 14: /* Timestamp Reply */ | |
341 | return True; | |
342 | default: | |
8dea8d37 SE |
343 | return False; |
344 | } | |
345 | } | |
4efd681a | 346 | /* How do we spot broadcast destination addresses? */ |
a6768d7c | 347 | if (ntohs(iph->frag)&IPHDR_FRAG_OFF) return False; |
4efd681a SE |
348 | source=ntohl(iph->saddr); |
349 | if (source==0) return False; | |
350 | if ((source&0xff000000)==0x7f000000) return False; | |
351 | /* How do we spot broadcast source addresses? */ | |
352 | if ((source&0xf0000000)==0xe0000000) return False; /* Multicast */ | |
353 | if ((source&0xf0000000)==0xf0000000) return False; /* Class E */ | |
354 | return True; | |
355 | } | |
356 | ||
357 | /* How much of the original IP packet do we include in its ICMP | |
358 | response? The header plus up to 64 bits. */ | |
ff05a229 SE |
359 | |
360 | /* XXX TODO RFC1812: | |
361 | 4.3.2.3 Original Message Header | |
362 | ||
363 | Historically, every ICMP error message has included the Internet | |
364 | header and at least the first 8 data bytes of the datagram that | |
365 | triggered the error. This is no longer adequate, due to the use of | |
366 | IP-in-IP tunneling and other technologies. Therefore, the ICMP | |
367 | datagram SHOULD contain as much of the original datagram as possible | |
368 | without the length of the ICMP datagram exceeding 576 bytes. The | |
369 | returned IP header (and user data) MUST be identical to that which | |
370 | was received, except that the router is not required to undo any | |
371 | modifications to the IP header that are normally performed in | |
372 | forwarding that were performed before the error was detected (e.g., | |
373 | decrementing the TTL, or updating options). Note that the | |
374 | requirements of Section [4.3.3.5] supersede this requirement in some | |
375 | cases (i.e., for a Parameter Problem message, if the problem is in a | |
376 | modified field, the router must undo the modification). See Section | |
377 | [4.3.3.5]). | |
378 | */ | |
4efd681a SE |
379 | static uint16_t netlink_icmp_reply_len(struct buffer_if *buf) |
380 | { | |
975820aa | 381 | if (buf->size < (int)sizeof(struct iphdr)) return 0; |
4efd681a SE |
382 | struct iphdr *iph=(struct iphdr *)buf->start; |
383 | uint16_t hlen,plen; | |
384 | ||
385 | hlen=iph->ihl*4; | |
386 | /* We include the first 8 bytes of the packet data, provided they exist */ | |
387 | hlen+=8; | |
388 | plen=ntohs(iph->tot_len); | |
4ea3eeb8 | 389 | return MIN(hlen,plen); |
4efd681a SE |
390 | } |
391 | ||
70dc107b SE |
392 | /* client indicates where the packet we're constructing a response to |
393 | comes from. NULL indicates the host. */ | |
ab62c3ed IJ |
394 | static void netlink_icmp_simple(struct netlink *st, |
395 | struct netlink_client *origsender, | |
396 | struct buffer_if *buf, | |
cfd79482 IJ |
397 | uint8_t type, uint8_t code, |
398 | union icmpinfofield info) | |
4efd681a | 399 | { |
4efd681a SE |
400 | struct icmphdr *h; |
401 | uint16_t len; | |
402 | ||
403 | if (netlink_icmp_may_reply(buf)) { | |
975820aa | 404 | struct iphdr *iph=(struct iphdr *)buf->start; |
826b47e9 IJ |
405 | |
406 | uint32_t icmpdest = ntohl(iph->saddr); | |
407 | uint32_t icmpsource; | |
408 | const char *icmpsourcedebugprefix; | |
409 | if (!st->ptp) { | |
410 | icmpsource=st->secnet_address; | |
411 | icmpsourcedebugprefix=""; | |
412 | } else if (origsender) { | |
413 | /* was from peer, send reply as if from host */ | |
414 | icmpsource=st->local_address; | |
415 | icmpsourcedebugprefix="L!"; | |
416 | } else { | |
417 | /* was from host, send reply as if from peer */ | |
418 | icmpsource=st->secnet_address; /* actually, peer address */ | |
419 | icmpsourcedebugprefix="P!"; | |
420 | } | |
421 | MDEBUG("%s: generating ICMP re %s[%s]->[%s]:" | |
422 | " from %s%s type=%u code=%u\n", | |
423 | st->name, sender_name(origsender), | |
424 | ipaddr_to_string(ntohl(iph->saddr)), | |
425 | ipaddr_to_string(ntohl(iph->daddr)), | |
426 | icmpsourcedebugprefix, | |
427 | ipaddr_to_string(icmpsource), | |
428 | type, code); | |
429 | ||
4efd681a | 430 | len=netlink_icmp_reply_len(buf); |
826b47e9 | 431 | h=netlink_icmp_tmpl(st,icmpsource,icmpdest,len); |
cfd79482 | 432 | h->type=type; h->code=code; h->d=info; |
4f28e77e | 433 | BUF_ADD_BYTES(append,&st->icmp,buf->start,len); |
4efd681a | 434 | netlink_icmp_csum(h); |
826b47e9 IJ |
435 | |
436 | if (!st->ptp) { | |
437 | netlink_packet_deliver(st,NULL,&st->icmp); | |
438 | } else if (origsender) { | |
439 | netlink_client_deliver(st,origsender,icmpsource,icmpdest,&st->icmp); | |
440 | } else { | |
441 | netlink_host_deliver(st,NULL,icmpsource,icmpdest,&st->icmp); | |
442 | } | |
4efd681a SE |
443 | BUF_ASSERT_FREE(&st->icmp); |
444 | } | |
445 | } | |
446 | ||
447 | /* | |
448 | * RFC1122: 3.1.2.2 MUST silently discard any IP frame that fails the | |
449 | * checksum. | |
ff05a229 | 450 | * RFC1812: 4.2.2.5 MUST discard messages containing invalid checksums. |
4efd681a SE |
451 | * |
452 | * Is the datagram acceptable? | |
453 | * | |
454 | * 1. Length at least the size of an ip header | |
455 | * 2. Version of 4 | |
456 | * 3. Checksums correctly. | |
457 | * 4. Doesn't have a bogus length | |
458 | */ | |
d714da29 IJ |
459 | static bool_t netlink_check(struct netlink *st, struct buffer_if *buf, |
460 | char *errmsgbuf, int errmsgbuflen) | |
4efd681a | 461 | { |
d714da29 IJ |
462 | #define BAD(...) do{ \ |
463 | snprintf(errmsgbuf,errmsgbuflen,__VA_ARGS__); \ | |
464 | return False; \ | |
465 | }while(0) | |
466 | ||
975820aa | 467 | if (buf->size < (int)sizeof(struct iphdr)) BAD("len %"PRIu32"",buf->size); |
4efd681a | 468 | struct iphdr *iph=(struct iphdr *)buf->start; |
1caa23ff | 469 | int32_t len; |
4efd681a | 470 | |
d714da29 IJ |
471 | if (iph->ihl < 5) BAD("ihl %u",iph->ihl); |
472 | if (iph->version != 4) BAD("version %u",iph->version); | |
473 | if (buf->size < iph->ihl*4) BAD("size %"PRId32"<%u*4",buf->size,iph->ihl); | |
474 | if (ip_fast_csum((uint8_t *)iph, iph->ihl)!=0) BAD("csum"); | |
4efd681a SE |
475 | len=ntohs(iph->tot_len); |
476 | /* There should be no padding */ | |
d714da29 IJ |
477 | if (buf->size!=len) BAD("len %"PRId32"!=%"PRId32,buf->size,len); |
478 | if (len<(iph->ihl<<2)) BAD("len %"PRId32"<(%u<<2)",len,iph->ihl); | |
4efd681a SE |
479 | /* XXX check that there's no source route specified */ |
480 | return True; | |
d714da29 IJ |
481 | |
482 | #undef BAD | |
4efd681a SE |
483 | } |
484 | ||
f3d69e41 IJ |
485 | static const char *fragment_filter_header(uint8_t *base, long *hlp) |
486 | { | |
487 | const int fixedhl = sizeof(struct iphdr); | |
488 | long hl = *hlp; | |
489 | const uint8_t *ipend = base + hl; | |
490 | uint8_t *op = base + fixedhl; | |
491 | const uint8_t *ip = op; | |
492 | ||
493 | while (ip < ipend) { | |
494 | uint8_t opt = ip[0]; | |
495 | int remain = ipend - ip; | |
496 | if (opt == 0x00) /* End of Options List */ break; | |
497 | if (opt == 0x01) /* No Operation */ continue; | |
498 | if (remain < 2) return "IPv4 options truncated at length"; | |
499 | int optlen = ip[1]; | |
500 | if (remain < optlen) return "IPv4 options truncated in option"; | |
501 | if (opt & 0x80) /* copy */ { | |
502 | memmove(op, ip, optlen); | |
503 | op += optlen; | |
504 | } | |
505 | ip += optlen; | |
506 | } | |
507 | while ((hl = (op - base)) & 0x3) | |
508 | *op++ = 0x00 /* End of Option List */; | |
509 | ((struct iphdr*)base)->ihl = hl >> 2; | |
510 | *hlp = hl; | |
511 | ||
512 | return 0; | |
513 | } | |
514 | ||
515 | /* Fragment or send ICMP Fragmentation Needed */ | |
516 | static void netlink_maybe_fragment(struct netlink *st, | |
ab62c3ed | 517 | struct netlink_client *sender, |
f3d69e41 IJ |
518 | netlink_deliver_fn *deliver, |
519 | void *deliver_dst, | |
520 | const char *delivery_name, | |
521 | int32_t mtu, | |
522 | uint32_t source, uint32_t dest, | |
523 | struct buffer_if *buf) | |
524 | { | |
525 | struct iphdr *iph=(struct iphdr*)buf->start; | |
526 | long hl = iph->ihl*4; | |
527 | const char *ssource = ipaddr_to_string(source); | |
528 | ||
529 | if (buf->size <= mtu) { | |
530 | deliver(deliver_dst, buf); | |
531 | return; | |
532 | } | |
533 | ||
534 | MDEBUG("%s: fragmenting %s->%s org.size=%"PRId32"\n", | |
535 | st->name, ssource, delivery_name, buf->size); | |
536 | ||
537 | #define BADFRAG(m, ...) \ | |
538 | Message(M_WARNING, \ | |
539 | "%s: fragmenting packet from source %s" \ | |
540 | " for transmission via %s: " m "\n", \ | |
541 | st->name, ssource, delivery_name, \ | |
542 | ## __VA_ARGS__); | |
543 | ||
544 | unsigned orig_frag = ntohs(iph->frag); | |
545 | ||
546 | if (orig_frag&IPHDR_FRAG_DONT) { | |
547 | union icmpinfofield info = | |
548 | { .fragneeded = { .unused = 0, .mtu = htons(mtu) } }; | |
ab62c3ed | 549 | netlink_icmp_simple(st,sender,buf, |
f3d69e41 IJ |
550 | ICMP_TYPE_UNREACHABLE, |
551 | ICMP_CODE_FRAGMENTATION_REQUIRED, | |
552 | info); | |
553 | BUF_FREE(buf); | |
554 | return; | |
555 | } | |
556 | if (mtu < hl + 8) { | |
557 | BADFRAG("mtu %"PRId32" too small", mtu); | |
558 | BUF_FREE(buf); | |
559 | return; | |
560 | } | |
561 | ||
562 | /* we (ab)use the icmp buffer to stash the original packet */ | |
563 | struct buffer_if *orig = &st->icmp; | |
564 | BUF_ALLOC(orig,"netlink_client_deliver fragment orig"); | |
565 | buffer_copy(orig,buf); | |
566 | BUF_FREE(buf); | |
567 | ||
568 | const uint8_t *startindata = orig->start + hl; | |
569 | const uint8_t *indata = startindata; | |
570 | const uint8_t *endindata = orig->start + orig->size; | |
571 | _Bool filtered = 0; | |
572 | ||
573 | for (;;) { | |
574 | /* compute our fragment offset */ | |
575 | long dataoffset = indata - startindata | |
576 | + (orig_frag & IPHDR_FRAG_OFF)*8; | |
577 | assert(!(dataoffset & 7)); | |
578 | if (dataoffset > IPHDR_FRAG_OFF*8) { | |
579 | BADFRAG("ultimate fragment offset out of range"); | |
580 | break; | |
581 | } | |
582 | ||
583 | BUF_ALLOC(buf,"netlink_client_deliver fragment frag"); | |
584 | buffer_init(buf,calculate_max_start_pad()); | |
585 | ||
586 | /* copy header (possibly filtered); will adjust in a bit */ | |
587 | struct iphdr *fragh = buf_append(buf, hl); | |
588 | memcpy(fragh, orig->start, hl); | |
589 | ||
590 | /* decide how much payload to copy and copy it */ | |
591 | long avail = mtu - hl; | |
592 | long remain = endindata - indata; | |
593 | long use = avail < remain ? (avail & ~(long)7) : remain; | |
4f28e77e | 594 | BUF_ADD_BYTES(append, buf, indata, use); |
f3d69e41 IJ |
595 | indata += use; |
596 | ||
597 | _Bool last_frag = indata >= endindata; | |
598 | ||
599 | /* adjust the header */ | |
600 | fragh->tot_len = htons(buf->size); | |
601 | fragh->frag = | |
602 | htons((orig_frag & ~IPHDR_FRAG_OFF) | | |
603 | (last_frag ? 0 : IPHDR_FRAG_MORE) | | |
604 | (dataoffset >> 3)); | |
605 | fragh->check = 0; | |
606 | fragh->check = ip_fast_csum((const void*)fragh, fragh->ihl); | |
607 | ||
608 | /* actually send it */ | |
609 | deliver(deliver_dst, buf); | |
610 | if (last_frag) | |
611 | break; | |
612 | ||
613 | /* after copying the header for the first frag, | |
614 | * we filter the header for the remaining frags */ | |
615 | if (!filtered++) { | |
616 | const char *bad = fragment_filter_header(orig->start, &hl); | |
617 | if (bad) { BADFRAG("%s", bad); break; } | |
618 | } | |
619 | } | |
620 | ||
621 | BUF_FREE(orig); | |
622 | ||
623 | #undef BADFRAG | |
624 | } | |
625 | ||
7b6abafa | 626 | /* Deliver a packet _to_ client; used after we have decided |
55bc97e6 IJ |
627 | * what to do with it (and just to check that the client has |
628 | * actually registered a delivery function with us). */ | |
7b6abafa IJ |
629 | static void netlink_client_deliver(struct netlink *st, |
630 | struct netlink_client *client, | |
631 | uint32_t source, uint32_t dest, | |
632 | struct buffer_if *buf) | |
633 | { | |
55bc97e6 IJ |
634 | if (!client->deliver) { |
635 | string_t s,d; | |
636 | s=ipaddr_to_string(source); | |
637 | d=ipaddr_to_string(dest); | |
638 | Message(M_ERR,"%s: dropping %s->%s, client not registered\n", | |
639 | st->name,s,d); | |
55bc97e6 IJ |
640 | BUF_FREE(buf); |
641 | return; | |
642 | } | |
ab62c3ed | 643 | netlink_maybe_fragment(st,NULL, client->deliver,client->dst,client->name, |
f3d69e41 | 644 | client->mtu, source,dest,buf); |
7b6abafa IJ |
645 | client->outcount++; |
646 | } | |
647 | ||
f928f069 IJ |
648 | /* Deliver a packet to the host; used after we have decided that that |
649 | * is what to do with it. */ | |
650 | static void netlink_host_deliver(struct netlink *st, | |
ab62c3ed | 651 | struct netlink_client *sender, |
f928f069 IJ |
652 | uint32_t source, uint32_t dest, |
653 | struct buffer_if *buf) | |
654 | { | |
ab62c3ed | 655 | netlink_maybe_fragment(st,sender, st->deliver_to_host,st->dst,"(host)", |
f3d69e41 | 656 | st->mtu, source,dest,buf); |
f928f069 IJ |
657 | st->outcount++; |
658 | } | |
659 | ||
f2b711bd | 660 | /* Deliver a packet. "sender"==NULL for packets from the host and packets |
d3fe100d | 661 | generated internally in secnet. */ |
70dc107b | 662 | static void netlink_packet_deliver(struct netlink *st, |
f2b711bd | 663 | struct netlink_client *sender, |
70dc107b | 664 | struct buffer_if *buf) |
4efd681a | 665 | { |
975820aa IJ |
666 | if (buf->size < (int)sizeof(struct iphdr)) { |
667 | Message(M_ERR,"%s: trying to deliver a too-short packet" | |
dbe11c20 | 668 | " from %s!\n",st->name, sender_name(sender)); |
975820aa IJ |
669 | BUF_FREE(buf); |
670 | return; | |
671 | } | |
672 | ||
4efd681a SE |
673 | struct iphdr *iph=(struct iphdr *)buf->start; |
674 | uint32_t dest=ntohl(iph->daddr); | |
70dc107b SE |
675 | uint32_t source=ntohl(iph->saddr); |
676 | uint32_t best_quality; | |
469fd1d9 SE |
677 | bool_t allow_route=False; |
678 | bool_t found_allowed=False; | |
70dc107b SE |
679 | int best_match; |
680 | int i; | |
2fe58dfd | 681 | |
4efd681a | 682 | BUF_ASSERT_USED(buf); |
2fe58dfd | 683 | |
4efd681a | 684 | if (dest==st->secnet_address) { |
4f5e39ec | 685 | Message(M_ERR,"%s: trying to deliver a packet to myself!\n",st->name); |
4efd681a | 686 | BUF_FREE(buf); |
2fe58dfd SE |
687 | return; |
688 | } | |
4efd681a | 689 | |
f2b711bd | 690 | /* Packets from the host (sender==NULL) may always be routed. Packets |
469fd1d9 | 691 | from clients with the allow_route option will also be routed. */ |
f2b711bd | 692 | if (!sender || (sender && (sender->options & OPT_ALLOWROUTE))) |
469fd1d9 SE |
693 | allow_route=True; |
694 | ||
695 | /* If !allow_route, we check the routing table anyway, and if | |
696 | there's a suitable route with OPT_ALLOWROUTE set we use it. If | |
697 | there's a suitable route, but none with OPT_ALLOWROUTE set then | |
698 | we generate ICMP 'communication with destination network | |
699 | administratively prohibited'. */ | |
700 | ||
701 | best_quality=0; | |
702 | best_match=-1; | |
d3fe100d SE |
703 | for (i=0; i<st->n_clients; i++) { |
704 | if (st->routes[i]->up && | |
705 | ipset_contains_addr(st->routes[i]->networks,dest)) { | |
469fd1d9 SE |
706 | /* It's an available route to the correct destination. But is |
707 | it better than the one we already have? */ | |
708 | ||
709 | /* If we have already found an allowed route then we don't | |
710 | bother looking at routes we're not allowed to use. If | |
711 | we don't yet have an allowed route we'll consider any. */ | |
712 | if (!allow_route && found_allowed) { | |
d3fe100d | 713 | if (!(st->routes[i]->options&OPT_ALLOWROUTE)) continue; |
70dc107b | 714 | } |
469fd1d9 | 715 | |
d3fe100d | 716 | if (st->routes[i]->link_quality>best_quality |
469fd1d9 | 717 | || best_quality==0) { |
d3fe100d | 718 | best_quality=st->routes[i]->link_quality; |
469fd1d9 | 719 | best_match=i; |
d3fe100d | 720 | if (st->routes[i]->options&OPT_ALLOWROUTE) |
469fd1d9 SE |
721 | found_allowed=True; |
722 | /* If quality isn't perfect we may wish to | |
723 | consider kicking the tunnel with a 0-length | |
724 | packet to prompt it to perform a key setup. | |
725 | Then it'll eventually decide it's up or | |
726 | down. */ | |
727 | /* If quality is perfect and we're allowed to use the | |
728 | route we don't need to search any more. */ | |
729 | if (best_quality>=MAXIMUM_LINK_QUALITY && | |
730 | (allow_route || found_allowed)) break; | |
4efd681a | 731 | } |
70dc107b | 732 | } |
469fd1d9 SE |
733 | } |
734 | if (best_match==-1) { | |
735 | /* The packet's not going down a tunnel. It might (ought to) | |
736 | be for the host. */ | |
794f2398 | 737 | if (ipset_contains_addr(st->networks,dest)) { |
ab62c3ed | 738 | netlink_host_deliver(st,sender,source,dest,buf); |
70dc107b SE |
739 | BUF_ASSERT_FREE(buf); |
740 | } else { | |
469fd1d9 SE |
741 | string_t s,d; |
742 | s=ipaddr_to_string(source); | |
743 | d=ipaddr_to_string(dest); | |
ff05a229 | 744 | Message(M_DEBUG,"%s: don't know where to deliver packet " |
469fd1d9 | 745 | "(s=%s, d=%s)\n", st->name, s, d); |
ab62c3ed | 746 | netlink_icmp_simple(st,sender,buf,ICMP_TYPE_UNREACHABLE, |
cfd79482 | 747 | ICMP_CODE_NET_UNREACHABLE, icmp_noinfo); |
70dc107b | 748 | BUF_FREE(buf); |
2fe58dfd | 749 | } |
469fd1d9 SE |
750 | } else { |
751 | if (!allow_route && | |
d3fe100d | 752 | !(st->routes[best_match]->options&OPT_ALLOWROUTE)) { |
469fd1d9 SE |
753 | string_t s,d; |
754 | s=ipaddr_to_string(source); | |
755 | d=ipaddr_to_string(dest); | |
756 | /* We have a usable route but aren't allowed to use it. | |
757 | Generate ICMP destination unreachable: communication | |
758 | with destination network administratively prohibited */ | |
759 | Message(M_NOTICE,"%s: denied forwarding for packet (s=%s, d=%s)\n", | |
760 | st->name,s,d); | |
469fd1d9 | 761 | |
ab62c3ed | 762 | netlink_icmp_simple(st,sender,buf,ICMP_TYPE_UNREACHABLE, |
cfd79482 | 763 | ICMP_CODE_NET_PROHIBITED, icmp_noinfo); |
469fd1d9 | 764 | BUF_FREE(buf); |
469fd1d9 | 765 | } else { |
ea7ec970 | 766 | if (best_quality>0) { |
7b6abafa IJ |
767 | netlink_client_deliver(st,st->routes[best_match], |
768 | source,dest,buf); | |
ea7ec970 SE |
769 | BUF_ASSERT_FREE(buf); |
770 | } else { | |
771 | /* Generate ICMP destination unreachable */ | |
ab62c3ed | 772 | netlink_icmp_simple(st,sender,buf, |
cfd79482 IJ |
773 | ICMP_TYPE_UNREACHABLE, |
774 | ICMP_CODE_NET_UNREACHABLE, | |
775 | icmp_noinfo); | |
ea7ec970 SE |
776 | BUF_FREE(buf); |
777 | } | |
469fd1d9 | 778 | } |
2fe58dfd | 779 | } |
70dc107b | 780 | BUF_ASSERT_FREE(buf); |
4efd681a SE |
781 | } |
782 | ||
70dc107b | 783 | static void netlink_packet_forward(struct netlink *st, |
f2b711bd | 784 | struct netlink_client *sender, |
70dc107b | 785 | struct buffer_if *buf) |
4efd681a | 786 | { |
975820aa | 787 | if (buf->size < (int)sizeof(struct iphdr)) return; |
4efd681a SE |
788 | struct iphdr *iph=(struct iphdr *)buf->start; |
789 | ||
790 | BUF_ASSERT_USED(buf); | |
791 | ||
792 | /* Packet has already been checked */ | |
793 | if (iph->ttl<=1) { | |
794 | /* Generate ICMP time exceeded */ | |
ab62c3ed | 795 | netlink_icmp_simple(st,sender,buf,ICMP_TYPE_TIME_EXCEEDED, |
cfd79482 | 796 | ICMP_CODE_TTL_EXCEEDED,icmp_noinfo); |
4efd681a SE |
797 | BUF_FREE(buf); |
798 | return; | |
799 | } | |
800 | iph->ttl--; | |
801 | iph->check=0; | |
802 | iph->check=ip_fast_csum((uint8_t *)iph,iph->ihl); | |
803 | ||
f2b711bd | 804 | netlink_packet_deliver(st,sender,buf); |
4efd681a SE |
805 | BUF_ASSERT_FREE(buf); |
806 | } | |
807 | ||
9d3a4132 | 808 | /* Deal with packets addressed explicitly to us */ |
70dc107b | 809 | static void netlink_packet_local(struct netlink *st, |
f2b711bd | 810 | struct netlink_client *sender, |
70dc107b | 811 | struct buffer_if *buf) |
4efd681a SE |
812 | { |
813 | struct icmphdr *h; | |
814 | ||
469fd1d9 SE |
815 | st->localcount++; |
816 | ||
975820aa IJ |
817 | if (buf->size < (int)sizeof(struct icmphdr)) { |
818 | Message(M_WARNING,"%s: short packet addressed to secnet; " | |
819 | "ignoring it\n",st->name); | |
820 | BUF_FREE(buf); | |
821 | return; | |
822 | } | |
4efd681a SE |
823 | h=(struct icmphdr *)buf->start; |
824 | ||
6e3fd952 IJ |
825 | unsigned fraginfo = ntohs(h->iph.frag); |
826 | if ((fraginfo&(IPHDR_FRAG_OFF|IPHDR_FRAG_MORE))!=0) { | |
827 | if (!(fraginfo & IPHDR_FRAG_OFF)) | |
828 | /* report only for first fragment */ | |
829 | Message(M_WARNING,"%s: fragmented packet addressed to secnet; " | |
830 | "ignoring it\n",st->name); | |
4efd681a SE |
831 | BUF_FREE(buf); |
832 | return; | |
833 | } | |
834 | ||
835 | if (h->iph.protocol==1) { | |
836 | /* It's ICMP */ | |
ff05a229 | 837 | if (h->type==ICMP_TYPE_ECHO_REQUEST && h->code==0) { |
4efd681a SE |
838 | /* ICMP echo-request. Special case: we re-use the buffer |
839 | to construct the reply. */ | |
ff05a229 | 840 | h->type=ICMP_TYPE_ECHO_REPLY; |
4efd681a SE |
841 | h->iph.daddr=h->iph.saddr; |
842 | h->iph.saddr=htonl(st->secnet_address); | |
ff05a229 | 843 | h->iph.ttl=255; |
4efd681a SE |
844 | h->iph.check=0; |
845 | h->iph.check=ip_fast_csum((uint8_t *)h,h->iph.ihl); | |
846 | netlink_icmp_csum(h); | |
70dc107b | 847 | netlink_packet_deliver(st,NULL,buf); |
4efd681a SE |
848 | return; |
849 | } | |
850 | Message(M_WARNING,"%s: unknown incoming ICMP\n",st->name); | |
851 | } else { | |
852 | /* Send ICMP protocol unreachable */ | |
ab62c3ed | 853 | netlink_icmp_simple(st,sender,buf,ICMP_TYPE_UNREACHABLE, |
cfd79482 | 854 | ICMP_CODE_PROTOCOL_UNREACHABLE,icmp_noinfo); |
4efd681a SE |
855 | BUF_FREE(buf); |
856 | return; | |
857 | } | |
858 | ||
859 | BUF_FREE(buf); | |
860 | } | |
861 | ||
9d3a4132 SE |
862 | /* If cid==NULL packet is from host, otherwise cid specifies which tunnel |
863 | it came from. */ | |
f2b711bd | 864 | static void netlink_incoming(struct netlink *st, struct netlink_client *sender, |
469fd1d9 | 865 | struct buffer_if *buf) |
4efd681a | 866 | { |
4efd681a SE |
867 | uint32_t source,dest; |
868 | struct iphdr *iph; | |
d714da29 | 869 | char errmsgbuf[50]; |
f2b711bd | 870 | const char *sourcedesc=sender?sender->name:"host"; |
4efd681a SE |
871 | |
872 | BUF_ASSERT_USED(buf); | |
a28d65a5 | 873 | |
d714da29 IJ |
874 | if (!netlink_check(st,buf,errmsgbuf,sizeof(errmsgbuf))) { |
875 | Message(M_WARNING,"%s: bad IP packet from %s: %s\n", | |
a28d65a5 | 876 | st->name,sourcedesc, |
d714da29 | 877 | errmsgbuf); |
4efd681a SE |
878 | BUF_FREE(buf); |
879 | return; | |
880 | } | |
e8b1adac | 881 | assert(buf->size >= (int)sizeof(struct iphdr)); |
4efd681a SE |
882 | iph=(struct iphdr *)buf->start; |
883 | ||
884 | source=ntohl(iph->saddr); | |
885 | dest=ntohl(iph->daddr); | |
886 | ||
d3fe100d SE |
887 | /* Check source. If we don't like the source, there's no point |
888 | generating ICMP because we won't know how to get it to the | |
889 | source of the packet. */ | |
f2b711bd | 890 | if (sender) { |
c6f79b17 SE |
891 | /* Check that the packet source is appropriate for the tunnel |
892 | it came down */ | |
f2b711bd | 893 | if (!ipset_contains_addr(sender->networks,source)) { |
9d3a4132 SE |
894 | string_t s,d; |
895 | s=ipaddr_to_string(source); | |
896 | d=ipaddr_to_string(dest); | |
897 | Message(M_WARNING,"%s: packet from tunnel %s with bad " | |
f2b711bd | 898 | "source address (s=%s,d=%s)\n",st->name,sender->name,s,d); |
9d3a4132 SE |
899 | BUF_FREE(buf); |
900 | return; | |
901 | } | |
902 | } else { | |
c6f79b17 SE |
903 | /* Check that the packet originates in our configured local |
904 | network, and hasn't been forwarded from elsewhere or | |
905 | generated with the wrong source address */ | |
794f2398 | 906 | if (!ipset_contains_addr(st->networks,source)) { |
9d3a4132 SE |
907 | string_t s,d; |
908 | s=ipaddr_to_string(source); | |
909 | d=ipaddr_to_string(dest); | |
910 | Message(M_WARNING,"%s: outgoing packet with bad source address " | |
911 | "(s=%s,d=%s)\n",st->name,s,d); | |
9d3a4132 SE |
912 | BUF_FREE(buf); |
913 | return; | |
914 | } | |
4efd681a | 915 | } |
c6f79b17 | 916 | |
794f2398 SE |
917 | /* If this is a point-to-point device we don't examine the |
918 | destination address at all; we blindly send it down our | |
919 | one-and-only registered tunnel, or to the host, depending on | |
d3fe100d SE |
920 | where it came from. It's up to external software to check |
921 | address validity and generate ICMP, etc. */ | |
c6f79b17 | 922 | if (st->ptp) { |
f2b711bd | 923 | if (sender) { |
ab62c3ed | 924 | netlink_host_deliver(st,sender,source,dest,buf); |
c6f79b17 | 925 | } else { |
7b6abafa | 926 | netlink_client_deliver(st,st->clients,source,dest,buf); |
c6f79b17 SE |
927 | } |
928 | BUF_ASSERT_FREE(buf); | |
929 | return; | |
930 | } | |
931 | ||
d3fe100d SE |
932 | /* st->secnet_address needs checking before matching destination |
933 | addresses */ | |
2fe58dfd | 934 | if (dest==st->secnet_address) { |
f2b711bd | 935 | netlink_packet_local(st,sender,buf); |
4efd681a | 936 | BUF_ASSERT_FREE(buf); |
2fe58dfd SE |
937 | return; |
938 | } | |
f2b711bd | 939 | netlink_packet_forward(st,sender,buf); |
4efd681a SE |
940 | BUF_ASSERT_FREE(buf); |
941 | } | |
942 | ||
469fd1d9 SE |
943 | static void netlink_inst_incoming(void *sst, struct buffer_if *buf) |
944 | { | |
945 | struct netlink_client *c=sst; | |
946 | struct netlink *st=c->nst; | |
947 | ||
948 | netlink_incoming(st,c,buf); | |
949 | } | |
950 | ||
951 | static void netlink_dev_incoming(void *sst, struct buffer_if *buf) | |
952 | { | |
953 | struct netlink *st=sst; | |
954 | ||
955 | netlink_incoming(st,NULL,buf); | |
956 | } | |
957 | ||
d3fe100d | 958 | static void netlink_set_quality(void *sst, uint32_t quality) |
4efd681a | 959 | { |
d3fe100d SE |
960 | struct netlink_client *c=sst; |
961 | struct netlink *st=c->nst; | |
4efd681a | 962 | |
d3fe100d SE |
963 | c->link_quality=quality; |
964 | c->up=(c->link_quality==LINK_QUALITY_DOWN)?False:True; | |
965 | if (c->options&OPT_SOFTROUTE) { | |
966 | st->set_routes(st->dst,c); | |
4efd681a | 967 | } |
4efd681a SE |
968 | } |
969 | ||
d3fe100d SE |
970 | static void netlink_output_subnets(struct netlink *st, uint32_t loglevel, |
971 | struct subnet_list *snets) | |
4efd681a | 972 | { |
1caa23ff | 973 | int32_t i; |
d3fe100d | 974 | string_t net; |
4efd681a | 975 | |
d3fe100d SE |
976 | for (i=0; i<snets->entries; i++) { |
977 | net=subnet_to_string(snets->list[i]); | |
978 | Message(loglevel,"%s ",net); | |
9d3a4132 | 979 | } |
4efd681a SE |
980 | } |
981 | ||
042a8da9 | 982 | static void netlink_dump_routes(struct netlink *st, bool_t requested) |
9d3a4132 SE |
983 | { |
984 | int i; | |
985 | string_t net; | |
042a8da9 | 986 | uint32_t c=M_INFO; |
9d3a4132 | 987 | |
042a8da9 | 988 | if (requested) c=M_WARNING; |
469fd1d9 SE |
989 | if (st->ptp) { |
990 | net=ipaddr_to_string(st->secnet_address); | |
34d3bf4c | 991 | Message(c,"%s: point-to-point (remote end is %s); routes: ", |
469fd1d9 | 992 | st->name, net); |
d3fe100d | 993 | netlink_output_subnets(st,c,st->clients->subnets); |
469fd1d9 SE |
994 | Message(c,"\n"); |
995 | } else { | |
996 | Message(c,"%s: routing table:\n",st->name); | |
d3fe100d SE |
997 | for (i=0; i<st->n_clients; i++) { |
998 | netlink_output_subnets(st,c,st->routes[i]->subnets); | |
ff05a229 | 999 | Message(c,"-> tunnel %s (%s,mtu %d,%s routes,%s," |
ea7ec970 | 1000 | "quality %d,use %d,pri %lu)\n", |
d3fe100d | 1001 | st->routes[i]->name, |
ff05a229 SE |
1002 | st->routes[i]->up?"up":"down", |
1003 | st->routes[i]->mtu, | |
d3fe100d SE |
1004 | st->routes[i]->options&OPT_SOFTROUTE?"soft":"hard", |
1005 | st->routes[i]->options&OPT_ALLOWROUTE?"free":"restricted", | |
d3fe100d | 1006 | st->routes[i]->link_quality, |
ea7ec970 SE |
1007 | st->routes[i]->outcount, |
1008 | (unsigned long)st->routes[i]->priority); | |
469fd1d9 SE |
1009 | } |
1010 | net=ipaddr_to_string(st->secnet_address); | |
1011 | Message(c,"%s/32 -> netlink \"%s\" (use %d)\n", | |
1012 | net,st->name,st->localcount); | |
794f2398 SE |
1013 | for (i=0; i<st->subnets->entries; i++) { |
1014 | net=subnet_to_string(st->subnets->list[i]); | |
1015 | Message(c,"%s ",net); | |
469fd1d9 | 1016 | } |
794f2398 SE |
1017 | if (i>0) |
1018 | Message(c,"-> host (use %d)\n",st->outcount); | |
9d3a4132 SE |
1019 | } |
1020 | } | |
1021 | ||
d3fe100d SE |
1022 | /* ap is a pointer to a member of the routes array */ |
1023 | static int netlink_compare_client_priority(const void *ap, const void *bp) | |
70dc107b | 1024 | { |
d3fe100d SE |
1025 | const struct netlink_client *const*a=ap; |
1026 | const struct netlink_client *const*b=bp; | |
70dc107b | 1027 | |
d3fe100d SE |
1028 | if ((*a)->priority==(*b)->priority) return 0; |
1029 | if ((*a)->priority<(*b)->priority) return 1; | |
70dc107b SE |
1030 | return -1; |
1031 | } | |
1032 | ||
1033 | static void netlink_phase_hook(void *sst, uint32_t new_phase) | |
1034 | { | |
1035 | struct netlink *st=sst; | |
1036 | struct netlink_client *c; | |
1caa23ff | 1037 | int32_t i; |
70dc107b SE |
1038 | |
1039 | /* All the networks serviced by the various tunnels should now | |
1040 | * have been registered. We build a routing table by sorting the | |
d3fe100d | 1041 | * clients by priority. */ |
bb9d0561 IJ |
1042 | st->routes=safe_malloc_ary(sizeof(*st->routes),st->n_clients, |
1043 | "netlink_phase_hook"); | |
70dc107b SE |
1044 | /* Fill the table */ |
1045 | i=0; | |
59230b9b IJ |
1046 | for (c=st->clients; c; c=c->next) { |
1047 | assert(i<INT_MAX); | |
d3fe100d | 1048 | st->routes[i++]=c; |
59230b9b | 1049 | } |
d3fe100d SE |
1050 | /* Sort the table in descending order of priority */ |
1051 | qsort(st->routes,st->n_clients,sizeof(*st->routes), | |
1052 | netlink_compare_client_priority); | |
9d3a4132 | 1053 | |
042a8da9 SE |
1054 | netlink_dump_routes(st,False); |
1055 | } | |
1056 | ||
1057 | static void netlink_signal_handler(void *sst, int signum) | |
1058 | { | |
1059 | struct netlink *st=sst; | |
1060 | Message(M_INFO,"%s: route dump requested by SIGUSR1\n",st->name); | |
1061 | netlink_dump_routes(st,True); | |
70dc107b SE |
1062 | } |
1063 | ||
1caa23ff | 1064 | static void netlink_inst_set_mtu(void *sst, int32_t new_mtu) |
d3fe100d SE |
1065 | { |
1066 | struct netlink_client *c=sst; | |
1067 | ||
1068 | c->mtu=new_mtu; | |
1069 | } | |
1070 | ||
469fd1d9 | 1071 | static void netlink_inst_reg(void *sst, netlink_deliver_fn *deliver, |
1c085348 | 1072 | void *dst, uint32_t *localmtu_r) |
469fd1d9 SE |
1073 | { |
1074 | struct netlink_client *c=sst; | |
1c085348 | 1075 | struct netlink *st=c->nst; |
469fd1d9 | 1076 | |
469fd1d9 SE |
1077 | c->deliver=deliver; |
1078 | c->dst=dst; | |
1c085348 IJ |
1079 | |
1080 | if (localmtu_r) | |
1081 | *localmtu_r=st->mtu; | |
469fd1d9 SE |
1082 | } |
1083 | ||
1084 | static struct flagstr netlink_option_table[]={ | |
1085 | { "soft", OPT_SOFTROUTE }, | |
1086 | { "allow-route", OPT_ALLOWROUTE }, | |
1087 | { NULL, 0} | |
1088 | }; | |
1089 | /* This is the routine that gets called when the closure that's | |
1090 | returned by an invocation of a netlink device closure (eg. tun, | |
1091 | userv-ipif) is invoked. It's used to create routes and pass in | |
1092 | information about them; the closure it returns is used by site | |
1093 | code. */ | |
1094 | static closure_t *netlink_inst_create(struct netlink *st, | |
1095 | struct cloc loc, dict_t *dict) | |
1096 | { | |
1097 | struct netlink_client *c; | |
1098 | string_t name; | |
794f2398 | 1099 | struct ipset *networks; |
1caa23ff IJ |
1100 | uint32_t options,priority; |
1101 | int32_t mtu; | |
794f2398 | 1102 | list_t *l; |
469fd1d9 SE |
1103 | |
1104 | name=dict_read_string(dict, "name", True, st->name, loc); | |
1105 | ||
794f2398 SE |
1106 | l=dict_lookup(dict,"routes"); |
1107 | if (!l) | |
1108 | cfgfatal(loc,st->name,"required parameter \"routes\" not found\n"); | |
1109 | networks=string_list_to_ipset(l,loc,st->name,"routes"); | |
469fd1d9 SE |
1110 | options=string_list_to_word(dict_lookup(dict,"options"), |
1111 | netlink_option_table,st->name); | |
1112 | ||
d3fe100d SE |
1113 | priority=dict_read_number(dict,"priority",False,st->name,loc,0); |
1114 | mtu=dict_read_number(dict,"mtu",False,st->name,loc,0); | |
1115 | ||
1116 | if ((options&OPT_SOFTROUTE) && !st->set_routes) { | |
469fd1d9 SE |
1117 | cfgfatal(loc,st->name,"this netlink device does not support " |
1118 | "soft routes.\n"); | |
1119 | return NULL; | |
1120 | } | |
1121 | ||
1122 | if (options&OPT_SOFTROUTE) { | |
1123 | /* XXX for now we assume that soft routes require root privilege; | |
1124 | this may not always be true. The device driver can tell us. */ | |
1125 | require_root_privileges=True; | |
1126 | require_root_privileges_explanation="netlink: soft routes"; | |
1127 | if (st->ptp) { | |
1128 | cfgfatal(loc,st->name,"point-to-point netlinks do not support " | |
1129 | "soft routes.\n"); | |
1130 | return NULL; | |
1131 | } | |
1132 | } | |
1133 | ||
794f2398 SE |
1134 | /* Check that nets are a subset of st->remote_networks; |
1135 | refuse to register if they are not. */ | |
1136 | if (!ipset_is_subset(st->remote_networks,networks)) { | |
1137 | cfgfatal(loc,st->name,"routes are not allowed\n"); | |
469fd1d9 SE |
1138 | return NULL; |
1139 | } | |
1140 | ||
1141 | c=safe_malloc(sizeof(*c),"netlink_inst_create"); | |
1142 | c->cl.description=name; | |
1143 | c->cl.type=CL_NETLINK; | |
1144 | c->cl.apply=NULL; | |
1145 | c->cl.interface=&c->ops; | |
1146 | c->ops.st=c; | |
1147 | c->ops.reg=netlink_inst_reg; | |
1148 | c->ops.deliver=netlink_inst_incoming; | |
1149 | c->ops.set_quality=netlink_set_quality; | |
d3fe100d | 1150 | c->ops.set_mtu=netlink_inst_set_mtu; |
469fd1d9 SE |
1151 | c->nst=st; |
1152 | ||
1153 | c->networks=networks; | |
794f2398 | 1154 | c->subnets=ipset_to_subnet_list(networks); |
d3fe100d | 1155 | c->priority=priority; |
469fd1d9 SE |
1156 | c->deliver=NULL; |
1157 | c->dst=NULL; | |
1158 | c->name=name; | |
f208b9a9 | 1159 | c->link_quality=LINK_QUALITY_UNUSED; |
d3fe100d SE |
1160 | c->mtu=mtu?mtu:st->mtu; |
1161 | c->options=options; | |
1162 | c->outcount=0; | |
1163 | c->up=False; | |
1164 | c->kup=False; | |
469fd1d9 SE |
1165 | c->next=st->clients; |
1166 | st->clients=c; | |
59230b9b | 1167 | assert(st->n_clients < INT_MAX); |
d3fe100d | 1168 | st->n_clients++; |
469fd1d9 SE |
1169 | |
1170 | return &c->cl; | |
1171 | } | |
1172 | ||
1173 | static list_t *netlink_inst_apply(closure_t *self, struct cloc loc, | |
1174 | dict_t *context, list_t *args) | |
1175 | { | |
1176 | struct netlink *st=self->interface; | |
1177 | ||
1178 | dict_t *dict; | |
1179 | item_t *item; | |
1180 | closure_t *cl; | |
1181 | ||
469fd1d9 SE |
1182 | item=list_elem(args,0); |
1183 | if (!item || item->type!=t_dict) { | |
1184 | cfgfatal(loc,st->name,"must have a dictionary argument\n"); | |
1185 | } | |
1186 | dict=item->data.dict; | |
1187 | ||
1188 | cl=netlink_inst_create(st,loc,dict); | |
1189 | ||
1190 | return new_closure(cl); | |
1191 | } | |
1192 | ||
9d3a4132 SE |
1193 | netlink_deliver_fn *netlink_init(struct netlink *st, |
1194 | void *dst, struct cloc loc, | |
fe5e9cc4 | 1195 | dict_t *dict, cstring_t description, |
d3fe100d | 1196 | netlink_route_fn *set_routes, |
9d3a4132 | 1197 | netlink_deliver_fn *to_host) |
4efd681a | 1198 | { |
c6f79b17 | 1199 | item_t *sa, *ptpa; |
794f2398 | 1200 | list_t *l; |
c6f79b17 | 1201 | |
4efd681a SE |
1202 | st->dst=dst; |
1203 | st->cl.description=description; | |
469fd1d9 SE |
1204 | st->cl.type=CL_PURE; |
1205 | st->cl.apply=netlink_inst_apply; | |
1206 | st->cl.interface=st; | |
4efd681a | 1207 | st->clients=NULL; |
d3fe100d SE |
1208 | st->routes=NULL; |
1209 | st->n_clients=0; | |
1210 | st->set_routes=set_routes; | |
4efd681a SE |
1211 | st->deliver_to_host=to_host; |
1212 | ||
794f2398 | 1213 | st->name=dict_read_string(dict,"name",False,description,loc); |
4efd681a | 1214 | if (!st->name) st->name=description; |
794f2398 SE |
1215 | l=dict_lookup(dict,"networks"); |
1216 | if (l) | |
1217 | st->networks=string_list_to_ipset(l,loc,st->name,"networks"); | |
1218 | else { | |
4f5e39ec SE |
1219 | struct ipset *empty; |
1220 | empty=ipset_new(); | |
1221 | st->networks=ipset_complement(empty); | |
1222 | ipset_free(empty); | |
794f2398 SE |
1223 | } |
1224 | l=dict_lookup(dict,"remote-networks"); | |
1225 | if (l) { | |
1226 | st->remote_networks=string_list_to_ipset(l,loc,st->name, | |
1227 | "remote-networks"); | |
1228 | } else { | |
1229 | struct ipset *empty; | |
1230 | empty=ipset_new(); | |
1231 | st->remote_networks=ipset_complement(empty); | |
1232 | ipset_free(empty); | |
1233 | } | |
091433c6 IJ |
1234 | st->local_address=string_item_to_ipaddr( |
1235 | dict_find_item(dict,"local-address", True, "netlink", loc),"netlink"); | |
794f2398 | 1236 | |
c6f79b17 | 1237 | sa=dict_find_item(dict,"secnet-address",False,"netlink",loc); |
469fd1d9 | 1238 | ptpa=dict_find_item(dict,"ptp-address",False,"netlink",loc); |
c6f79b17 SE |
1239 | if (sa && ptpa) { |
1240 | cfgfatal(loc,st->name,"you may not specify secnet-address and " | |
1241 | "ptp-address in the same netlink device\n"); | |
1242 | } | |
1243 | if (!(sa || ptpa)) { | |
1244 | cfgfatal(loc,st->name,"you must specify secnet-address or " | |
1245 | "ptp-address for this netlink device\n"); | |
1246 | } | |
1247 | if (sa) { | |
794f2398 | 1248 | st->secnet_address=string_item_to_ipaddr(sa,"netlink"); |
c6f79b17 SE |
1249 | st->ptp=False; |
1250 | } else { | |
794f2398 | 1251 | st->secnet_address=string_item_to_ipaddr(ptpa,"netlink"); |
c6f79b17 SE |
1252 | st->ptp=True; |
1253 | } | |
d3fe100d SE |
1254 | /* To be strictly correct we could subtract secnet_address from |
1255 | networks here. It shouldn't make any practical difference, | |
794f2398 SE |
1256 | though, and will make the route dump look complicated... */ |
1257 | st->subnets=ipset_to_subnet_list(st->networks); | |
4efd681a | 1258 | st->mtu=dict_read_number(dict, "mtu", False, "netlink", loc, DEFAULT_MTU); |
f3d69e41 | 1259 | buffer_new(&st->icmp,MAX(ICMP_BUFSIZE,st->mtu)); |
469fd1d9 SE |
1260 | st->outcount=0; |
1261 | st->localcount=0; | |
70dc107b SE |
1262 | |
1263 | add_hook(PHASE_SETUP,netlink_phase_hook,st); | |
042a8da9 | 1264 | request_signal_notification(SIGUSR1, netlink_signal_handler, st); |
4efd681a | 1265 | |
469fd1d9 SE |
1266 | /* If we're point-to-point then we return a CL_NETLINK directly, |
1267 | rather than a CL_NETLINK_OLD or pure closure (depending on | |
1268 | compatibility). This CL_NETLINK is for our one and only | |
1269 | client. Our cl.apply function is NULL. */ | |
1270 | if (st->ptp) { | |
1271 | closure_t *cl; | |
1272 | cl=netlink_inst_create(st,loc,dict); | |
1273 | st->cl=*cl; | |
1274 | } | |
1275 | return netlink_dev_incoming; | |
2fe58dfd SE |
1276 | } |
1277 | ||
9d3a4132 | 1278 | /* No connection to the kernel at all... */ |
2fe58dfd | 1279 | |
9d3a4132 | 1280 | struct null { |
4efd681a | 1281 | struct netlink nl; |
4efd681a | 1282 | }; |
2fe58dfd | 1283 | |
d3fe100d | 1284 | static bool_t null_set_route(void *sst, struct netlink_client *routes) |
4efd681a | 1285 | { |
9d3a4132 | 1286 | struct null *st=sst; |
d3fe100d SE |
1287 | |
1288 | if (routes->up!=routes->kup) { | |
1289 | Message(M_INFO,"%s: setting routes for tunnel %s to state %s\n", | |
1290 | st->nl.name,routes->name, | |
1291 | routes->up?"up":"down"); | |
1292 | routes->kup=routes->up; | |
9d3a4132 | 1293 | return True; |
2fe58dfd | 1294 | } |
9d3a4132 | 1295 | return False; |
2fe58dfd | 1296 | } |
9d3a4132 | 1297 | |
469fd1d9 | 1298 | static void null_deliver(void *sst, struct buffer_if *buf) |
2fe58dfd SE |
1299 | { |
1300 | return; | |
1301 | } | |
1302 | ||
1303 | static list_t *null_apply(closure_t *self, struct cloc loc, dict_t *context, | |
1304 | list_t *args) | |
1305 | { | |
1306 | struct null *st; | |
4efd681a SE |
1307 | item_t *item; |
1308 | dict_t *dict; | |
2fe58dfd | 1309 | |
4efd681a | 1310 | st=safe_malloc(sizeof(*st),"null_apply"); |
2fe58dfd | 1311 | |
4efd681a SE |
1312 | item=list_elem(args,0); |
1313 | if (!item || item->type!=t_dict) | |
1314 | cfgfatal(loc,"null-netlink","parameter must be a dictionary\n"); | |
1315 | ||
1316 | dict=item->data.dict; | |
1317 | ||
9d3a4132 SE |
1318 | netlink_init(&st->nl,st,loc,dict,"null-netlink",null_set_route, |
1319 | null_deliver); | |
4efd681a SE |
1320 | |
1321 | return new_closure(&st->nl.cl); | |
2fe58dfd SE |
1322 | } |
1323 | ||
2fe58dfd SE |
1324 | void netlink_module(dict_t *dict) |
1325 | { | |
4efd681a | 1326 | add_closure(dict,"null-netlink",null_apply); |
2fe58dfd | 1327 | } |