blob: fe98400f7d6047fc38c40e02f317afa8e51b4c2d
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * Mini DNS server implementation for busybox |
4 | * |
5 | * Copyright (C) 2005 Roberto A. Foglietta (me@roberto.foglietta.name) |
6 | * Copyright (C) 2005 Odd Arild Olsen (oao at fibula dot no) |
7 | * Copyright (C) 2003 Paul Sheer |
8 | * |
9 | * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
10 | * |
11 | * Odd Arild Olsen started out with the sheerdns [1] of Paul Sheer and rewrote |
12 | * it into a shape which I believe is both easier to understand and maintain. |
13 | * I also reused the input buffer for output and removed services he did not |
14 | * need. [1] http://threading.2038bug.com/sheerdns/ |
15 | * |
16 | * Some bugfix and minor changes was applied by Roberto A. Foglietta who made |
17 | * the first porting of oao' scdns to busybox also. |
18 | */ |
19 | |
20 | //usage:#define dnsd_trivial_usage |
21 | //usage: "[-dvs] [-c CONFFILE] [-t TTL_SEC] [-p PORT] [-i ADDR]" |
22 | //usage:#define dnsd_full_usage "\n\n" |
23 | //usage: "Small static DNS server daemon\n" |
24 | //usage: "\n -c FILE Config file" |
25 | //usage: "\n -t SEC TTL" |
26 | //usage: "\n -p PORT Listen on PORT" |
27 | //usage: "\n -i ADDR Listen on ADDR" |
28 | //usage: "\n -d Daemonize" |
29 | //usage: "\n -v Verbose" |
30 | //usage: "\n -s Send successful replies only. Use this if you want" |
31 | //usage: "\n to use /etc/resolv.conf with two nameserver lines:" |
32 | //usage: "\n nameserver DNSD_SERVER" |
33 | //usage: "\n nameserver NORMAL_DNS_SERVER" |
34 | |
35 | #include "libbb.h" |
36 | #include <syslog.h> |
37 | |
38 | //#define DEBUG 1 |
39 | #define DEBUG 0 |
40 | |
41 | enum { |
42 | /* can tweak this */ |
43 | DEFAULT_TTL = 120, |
44 | |
45 | /* cannot get bigger packets than 512 per RFC1035. */ |
46 | MAX_PACK_LEN = 512, |
47 | IP_STRING_LEN = sizeof(".xxx.xxx.xxx.xxx"), |
48 | MAX_NAME_LEN = IP_STRING_LEN - 1 + sizeof(".in-addr.arpa"), |
49 | REQ_A = 1, |
50 | REQ_PTR = 12, |
51 | }; |
52 | |
53 | /* the message from client and first part of response msg */ |
54 | struct dns_head { |
55 | uint16_t id; |
56 | uint16_t flags; |
57 | uint16_t nquer; |
58 | uint16_t nansw; |
59 | uint16_t nauth; |
60 | uint16_t nadd; |
61 | }; |
62 | /* Structure used to access type and class fields. |
63 | * They are totally unaligned, but gcc 4.3.4 thinks that pointer of type uint16_t* |
64 | * is 16-bit aligned and replaces 16-bit memcpy (in move_from_unaligned16 macro) |
65 | * with aligned halfword access on arm920t! |
66 | * Oh well. Slapping PACKED everywhere seems to help: */ |
67 | struct type_and_class { |
68 | uint16_t type PACKED; |
69 | uint16_t class PACKED; |
70 | } PACKED; |
71 | /* element of known name, ip address and reversed ip address */ |
72 | struct dns_entry { |
73 | struct dns_entry *next; |
74 | uint32_t ip; |
75 | char rip[IP_STRING_LEN]; /* length decimal reversed IP */ |
76 | char name[1]; |
77 | }; |
78 | |
79 | #define OPT_verbose (option_mask32 & 1) |
80 | #define OPT_silent (option_mask32 & 2) |
81 | |
82 | |
83 | /* |
84 | * Insert length of substrings instead of dots |
85 | */ |
86 | static void undot(char *rip) |
87 | { |
88 | int i = 0; |
89 | int s = 0; |
90 | |
91 | while (rip[i]) |
92 | i++; |
93 | for (--i; i >= 0; i--) { |
94 | if (rip[i] == '.') { |
95 | rip[i] = s; |
96 | s = 0; |
97 | } else { |
98 | s++; |
99 | } |
100 | } |
101 | } |
102 | |
103 | /* |
104 | * Read hostname/IP records from file |
105 | */ |
106 | static struct dns_entry *parse_conf_file(const char *fileconf) |
107 | { |
108 | char *token[2]; |
109 | parser_t *parser; |
110 | struct dns_entry *m, *conf_data; |
111 | struct dns_entry **nextp; |
112 | |
113 | conf_data = NULL; |
114 | nextp = &conf_data; |
115 | |
116 | parser = config_open(fileconf); |
117 | while (config_read(parser, token, 2, 2, "# \t", PARSE_NORMAL)) { |
118 | struct in_addr ip; |
119 | uint32_t v32; |
120 | |
121 | if (inet_aton(token[1], &ip) == 0) { |
122 | bb_error_msg("error at line %u, skipping", parser->lineno); |
123 | continue; |
124 | } |
125 | |
126 | if (OPT_verbose) |
127 | bb_error_msg("name:%s, ip:%s", token[0], token[1]); |
128 | |
129 | /* sizeof(*m) includes 1 byte for m->name[0] */ |
130 | m = xzalloc(sizeof(*m) + strlen(token[0]) + 1); |
131 | /*m->next = NULL;*/ |
132 | *nextp = m; |
133 | nextp = &m->next; |
134 | |
135 | m->name[0] = '.'; |
136 | strcpy(m->name + 1, token[0]); |
137 | undot(m->name); |
138 | m->ip = ip.s_addr; /* in network order */ |
139 | v32 = ntohl(m->ip); |
140 | /* inverted order */ |
141 | sprintf(m->rip, ".%u.%u.%u.%u", |
142 | (uint8_t)(v32), |
143 | (uint8_t)(v32 >> 8), |
144 | (uint8_t)(v32 >> 16), |
145 | (v32 >> 24) |
146 | ); |
147 | undot(m->rip); |
148 | } |
149 | config_close(parser); |
150 | return conf_data; |
151 | } |
152 | |
153 | /* |
154 | * Look query up in dns records and return answer if found. |
155 | */ |
156 | static char *table_lookup(struct dns_entry *d, |
157 | uint16_t type, |
158 | char* query_string) |
159 | { |
160 | while (d) { |
161 | unsigned len = d->name[0]; |
162 | /* d->name[len] is the last (non NUL) char */ |
163 | #if DEBUG |
164 | char *p, *q; |
165 | q = query_string + 1; |
166 | p = d->name + 1; |
167 | fprintf(stderr, "%d/%d p:%s q:%s %d\n", |
168 | (int)strlen(p), len, |
169 | p, q, (int)strlen(q) |
170 | ); |
171 | #endif |
172 | if (type == htons(REQ_A)) { |
173 | /* search by host name */ |
174 | if (len != 1 || d->name[1] != '*') { |
175 | /* we are lax, hope no name component is ever >64 so that length |
176 | * (which will be represented as 'A','B'...) matches a lowercase letter. |
177 | * Actually, I think false matches are hard to construct. |
178 | * Example. |
179 | * [31] len is represented as '1', [65] as 'A', [65+32] as 'a'. |
180 | * [65] <65 same chars>[31]<31 same chars>NUL |
181 | * [65+32]<65 same chars>1 <31 same chars>NUL |
182 | * This example seems to be the minimal case when false match occurs. |
183 | */ |
184 | if (strcasecmp(d->name, query_string) != 0) |
185 | goto next; |
186 | } |
187 | return (char *)&d->ip; |
188 | #if DEBUG |
189 | fprintf(stderr, "Found IP:%x\n", (int)d->ip); |
190 | #endif |
191 | return 0; |
192 | } |
193 | /* search by IP-address */ |
194 | if ((len != 1 || d->name[1] != '*') |
195 | /* we assume (do not check) that query_string |
196 | * ends in ".in-addr.arpa" */ |
197 | && strncmp(d->rip, query_string, strlen(d->rip)) == 0 |
198 | ) { |
199 | #if DEBUG |
200 | fprintf(stderr, "Found name:%s\n", d->name); |
201 | #endif |
202 | return d->name; |
203 | } |
204 | next: |
205 | d = d->next; |
206 | } |
207 | |
208 | return NULL; |
209 | } |
210 | |
211 | /* |
212 | * Decode message and generate answer |
213 | */ |
214 | /* RFC 1035 |
215 | ... |
216 | Whenever an octet represents a numeric quantity, the left most bit |
217 | in the diagram is the high order or most significant bit. |
218 | That is, the bit labeled 0 is the most significant bit. |
219 | ... |
220 | |
221 | 4.1.1. Header section format |
222 | 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 |
223 | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
224 | | ID | |
225 | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
226 | |QR| OPCODE |AA|TC|RD|RA| 0 0 0| RCODE | |
227 | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
228 | | QDCOUNT | |
229 | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
230 | | ANCOUNT | |
231 | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
232 | | NSCOUNT | |
233 | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
234 | | ARCOUNT | |
235 | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
236 | ID 16 bit random identifier assigned by querying peer. |
237 | Used to match query/response. |
238 | QR message is a query (0), or a response (1). |
239 | OPCODE 0 standard query (QUERY) |
240 | 1 inverse query (IQUERY) |
241 | 2 server status request (STATUS) |
242 | AA Authoritative Answer - this bit is valid in responses. |
243 | Responding name server is an authority for the domain name |
244 | in question section. Answer section may have multiple owner names |
245 | because of aliases. The AA bit corresponds to the name which matches |
246 | the query name, or the first owner name in the answer section. |
247 | TC TrunCation - this message was truncated. |
248 | RD Recursion Desired - this bit may be set in a query and |
249 | is copied into the response. If RD is set, it directs |
250 | the name server to pursue the query recursively. |
251 | Recursive query support is optional. |
252 | RA Recursion Available - this be is set or cleared in a |
253 | response, and denotes whether recursive query support is |
254 | available in the name server. |
255 | RCODE Response code. |
256 | 0 No error condition |
257 | 1 Format error |
258 | 2 Server failure - server was unable to process the query |
259 | due to a problem with the name server. |
260 | 3 Name Error - meaningful only for responses from |
261 | an authoritative name server. The referenced domain name |
262 | does not exist. |
263 | 4 Not Implemented. |
264 | 5 Refused. |
265 | QDCOUNT number of entries in the question section. |
266 | ANCOUNT number of records in the answer section. |
267 | NSCOUNT number of records in the authority records section. |
268 | ARCOUNT number of records in the additional records section. |
269 | |
270 | 4.1.2. Question section format |
271 | |
272 | The section contains QDCOUNT (usually 1) entries, each of this format: |
273 | 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 |
274 | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
275 | / QNAME / |
276 | / / |
277 | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
278 | | QTYPE | |
279 | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
280 | | QCLASS | |
281 | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
282 | QNAME a domain name represented as a sequence of labels, where |
283 | each label consists of a length octet followed by that |
284 | number of octets. The domain name terminates with the |
285 | zero length octet for the null label of the root. Note |
286 | that this field may be an odd number of octets; no |
287 | padding is used. |
288 | QTYPE a two octet type of the query. |
289 | 1 a host address [REQ_A const] |
290 | 2 an authoritative name server |
291 | 3 a mail destination (Obsolete - use MX) |
292 | 4 a mail forwarder (Obsolete - use MX) |
293 | 5 the canonical name for an alias |
294 | 6 marks the start of a zone of authority |
295 | 7 a mailbox domain name (EXPERIMENTAL) |
296 | 8 a mail group member (EXPERIMENTAL) |
297 | 9 a mail rename domain name (EXPERIMENTAL) |
298 | 10 a null RR (EXPERIMENTAL) |
299 | 11 a well known service description |
300 | 12 a domain name pointer [REQ_PTR const] |
301 | 13 host information |
302 | 14 mailbox or mail list information |
303 | 15 mail exchange |
304 | 16 text strings |
305 | 0x1c IPv6? |
306 | 252 a request for a transfer of an entire zone |
307 | 253 a request for mailbox-related records (MB, MG or MR) |
308 | 254 a request for mail agent RRs (Obsolete - see MX) |
309 | 255 a request for all records |
310 | QCLASS a two octet code that specifies the class of the query. |
311 | 1 the Internet |
312 | (others are historic only) |
313 | 255 any class |
314 | |
315 | 4.1.3. Resource Record format |
316 | |
317 | The answer, authority, and additional sections all share the same format: |
318 | a variable number of resource records, where the number of records |
319 | is specified in the corresponding count field in the header. |
320 | Each resource record has this format: |
321 | 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 |
322 | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
323 | / / |
324 | / NAME / |
325 | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
326 | | TYPE | |
327 | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
328 | | CLASS | |
329 | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
330 | | TTL | |
331 | | | |
332 | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
333 | | RDLENGTH | |
334 | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| |
335 | / RDATA / |
336 | / / |
337 | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
338 | NAME a domain name to which this resource record pertains. |
339 | TYPE two octets containing one of the RR type codes. This |
340 | field specifies the meaning of the data in the RDATA field. |
341 | CLASS two octets which specify the class of the data in the RDATA field. |
342 | TTL a 32 bit unsigned integer that specifies the time interval |
343 | (in seconds) that the record may be cached. |
344 | RDLENGTH a 16 bit integer, length in octets of the RDATA field. |
345 | RDATA a variable length string of octets that describes the resource. |
346 | The format of this information varies according to the TYPE |
347 | and CLASS of the resource record. |
348 | If the TYPE is A and the CLASS is IN, it's a 4 octet IP address. |
349 | |
350 | 4.1.4. Message compression |
351 | |
352 | In order to reduce the size of messages, domain names coan be compressed. |
353 | An entire domain name or a list of labels at the end of a domain name |
354 | is replaced with a pointer to a prior occurance of the same name. |
355 | |
356 | The pointer takes the form of a two octet sequence: |
357 | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
358 | | 1 1| OFFSET | |
359 | +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
360 | The first two bits are ones. This allows a pointer to be distinguished |
361 | from a label, since the label must begin with two zero bits because |
362 | labels are restricted to 63 octets or less. The OFFSET field specifies |
363 | an offset from the start of the message (i.e., the first octet |
364 | of the ID field in the domain header). |
365 | A zero offset specifies the first byte of the ID field, etc. |
366 | Domain name in a message can be represented as either: |
367 | - a sequence of labels ending in a zero octet |
368 | - a pointer |
369 | - a sequence of labels ending with a pointer |
370 | */ |
371 | static int process_packet(struct dns_entry *conf_data, |
372 | uint32_t conf_ttl, |
373 | uint8_t *buf) |
374 | { |
375 | struct dns_head *head; |
376 | struct type_and_class *unaligned_type_class; |
377 | const char *err_msg; |
378 | char *query_string; |
379 | char *answstr; |
380 | uint8_t *answb; |
381 | uint16_t outr_rlen; |
382 | uint16_t outr_flags; |
383 | uint16_t type; |
384 | uint16_t class; |
385 | int query_len; |
386 | |
387 | head = (struct dns_head *)buf; |
388 | if (head->nquer == 0) { |
389 | bb_error_msg("packet has 0 queries, ignored"); |
390 | return 0; /* don't reply */ |
391 | } |
392 | if (head->flags & htons(0x8000)) { /* QR bit */ |
393 | bb_error_msg("response packet, ignored"); |
394 | return 0; /* don't reply */ |
395 | } |
396 | /* QR = 1 "response", RCODE = 4 "Not Implemented" */ |
397 | outr_flags = htons(0x8000 | 4); |
398 | err_msg = NULL; |
399 | |
400 | /* start of query string */ |
401 | query_string = (void *)(head + 1); |
402 | /* caller guarantees strlen is <= MAX_PACK_LEN */ |
403 | query_len = strlen(query_string) + 1; |
404 | /* may be unaligned! */ |
405 | unaligned_type_class = (void *)(query_string + query_len); |
406 | query_len += sizeof(*unaligned_type_class); |
407 | /* where to append answer block */ |
408 | answb = (void *)(unaligned_type_class + 1); |
409 | |
410 | /* OPCODE != 0 "standard query"? */ |
411 | if ((head->flags & htons(0x7800)) != 0) { |
412 | err_msg = "opcode != 0"; |
413 | goto empty_packet; |
414 | } |
415 | move_from_unaligned16(class, &unaligned_type_class->class); |
416 | if (class != htons(1)) { /* not class INET? */ |
417 | err_msg = "class != 1"; |
418 | goto empty_packet; |
419 | } |
420 | move_from_unaligned16(type, &unaligned_type_class->type); |
421 | if (type != htons(REQ_A) && type != htons(REQ_PTR)) { |
422 | /* we can't handle this query type */ |
423 | //TODO: happens all the time with REQ_AAAA (0x1c) requests - implement those? |
424 | err_msg = "type is !REQ_A and !REQ_PTR"; |
425 | goto empty_packet; |
426 | } |
427 | |
428 | /* look up the name */ |
429 | answstr = table_lookup(conf_data, type, query_string); |
430 | #if DEBUG |
431 | /* Shows lengths instead of dots, unusable for !DEBUG */ |
432 | bb_error_msg("'%s'->'%s'", query_string, answstr); |
433 | #endif |
434 | outr_rlen = 4; |
435 | if (answstr && type == htons(REQ_PTR)) { |
436 | /* returning a host name */ |
437 | outr_rlen = strlen(answstr) + 1; |
438 | } |
439 | if (!answstr |
440 | || (unsigned)(answb - buf) + query_len + 4 + 2 + outr_rlen > MAX_PACK_LEN |
441 | ) { |
442 | /* QR = 1 "response" |
443 | * AA = 1 "Authoritative Answer" |
444 | * RCODE = 3 "Name Error" */ |
445 | err_msg = "name is not found"; |
446 | outr_flags = htons(0x8000 | 0x0400 | 3); |
447 | goto empty_packet; |
448 | } |
449 | |
450 | /* Append answer Resource Record */ |
451 | memcpy(answb, query_string, query_len); /* name, type, class */ |
452 | answb += query_len; |
453 | move_to_unaligned32((uint32_t *)answb, htonl(conf_ttl)); |
454 | answb += 4; |
455 | move_to_unaligned16((uint16_t *)answb, htons(outr_rlen)); |
456 | answb += 2; |
457 | memcpy(answb, answstr, outr_rlen); |
458 | answb += outr_rlen; |
459 | |
460 | /* QR = 1 "response", |
461 | * AA = 1 "Authoritative Answer", |
462 | * TODO: need to set RA bit 0x80? One user says nslookup complains |
463 | * "Got recursion not available from SERVER, trying next server" |
464 | * "** server can't find HOSTNAME" |
465 | * RCODE = 0 "success" |
466 | */ |
467 | if (OPT_verbose) |
468 | bb_error_msg("returning positive reply"); |
469 | outr_flags = htons(0x8000 | 0x0400 | 0); |
470 | /* we have one answer */ |
471 | head->nansw = htons(1); |
472 | |
473 | empty_packet: |
474 | if ((outr_flags & htons(0xf)) != 0) { /* not a positive response */ |
475 | if (OPT_verbose) { |
476 | bb_error_msg("%s, %s", |
477 | err_msg, |
478 | OPT_silent ? "dropping query" : "sending error reply" |
479 | ); |
480 | } |
481 | if (OPT_silent) |
482 | return 0; |
483 | } |
484 | head->flags |= outr_flags; |
485 | head->nauth = head->nadd = 0; |
486 | head->nquer = htons(1); // why??? |
487 | |
488 | return answb - buf; |
489 | } |
490 | |
491 | int dnsd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
492 | int dnsd_main(int argc UNUSED_PARAM, char **argv) |
493 | { |
494 | const char *listen_interface = "0.0.0.0"; |
495 | const char *fileconf = "/etc/dnsd.conf"; |
496 | struct dns_entry *conf_data; |
497 | uint32_t conf_ttl = DEFAULT_TTL; |
498 | char *sttl, *sport; |
499 | len_and_sockaddr *lsa, *from, *to; |
500 | unsigned lsa_size; |
501 | int udps, opts; |
502 | uint16_t port = 53; |
503 | /* Ensure buf is 32bit aligned (we need 16bit, but 32bit can't hurt) */ |
504 | uint8_t buf[MAX_PACK_LEN + 1] ALIGN4; |
505 | |
506 | opts = getopt32(argv, "vsi:c:t:p:d", &listen_interface, &fileconf, &sttl, &sport); |
507 | //if (opts & (1 << 0)) // -v |
508 | //if (opts & (1 << 1)) // -s |
509 | //if (opts & (1 << 2)) // -i |
510 | //if (opts & (1 << 3)) // -c |
511 | if (opts & (1 << 4)) // -t |
512 | conf_ttl = xatou_range(sttl, 1, 0xffffffff); |
513 | if (opts & (1 << 5)) // -p |
514 | port = xatou_range(sport, 1, 0xffff); |
515 | if (opts & (1 << 6)) { // -d |
516 | bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS, argv); |
517 | openlog(applet_name, LOG_PID, LOG_DAEMON); |
518 | logmode = LOGMODE_SYSLOG; |
519 | } |
520 | |
521 | conf_data = parse_conf_file(fileconf); |
522 | |
523 | lsa = xdotted2sockaddr(listen_interface, port); |
524 | udps = xsocket(lsa->u.sa.sa_family, SOCK_DGRAM, 0); |
525 | xbind(udps, &lsa->u.sa, lsa->len); |
526 | socket_want_pktinfo(udps); /* needed for recv_from_to to work */ |
527 | lsa_size = LSA_LEN_SIZE + lsa->len; |
528 | from = xzalloc(lsa_size); |
529 | to = xzalloc(lsa_size); |
530 | |
531 | { |
532 | char *p = xmalloc_sockaddr2dotted(&lsa->u.sa); |
533 | bb_error_msg("accepting UDP packets on %s", p); |
534 | free(p); |
535 | } |
536 | |
537 | while (1) { |
538 | int r; |
539 | /* Try to get *DEST* address (to which of our addresses |
540 | * this query was directed), and reply from the same address. |
541 | * Or else we can exhibit usual UDP ugliness: |
542 | * [ip1.multihomed.ip2] <= query to ip1 <= peer |
543 | * [ip1.multihomed.ip2] => reply from ip2 => peer (confused) */ |
544 | memcpy(to, lsa, lsa_size); |
545 | r = recv_from_to(udps, buf, MAX_PACK_LEN + 1, 0, &from->u.sa, &to->u.sa, lsa->len); |
546 | if (r < 12 || r > MAX_PACK_LEN) { |
547 | bb_error_msg("packet size %d, ignored", r); |
548 | continue; |
549 | } |
550 | if (OPT_verbose) |
551 | bb_error_msg("got UDP packet"); |
552 | buf[r] = '\0'; /* paranoia */ |
553 | r = process_packet(conf_data, conf_ttl, buf); |
554 | if (r <= 0) |
555 | continue; |
556 | send_to_from(udps, buf, r, 0, &from->u.sa, &to->u.sa, lsa->len); |
557 | } |
558 | return 0; |
559 | } |
560 |