Add A record parsing.
[adns] / src / internal.h
CommitLineData
37e28fde 1/**/
2
3#ifndef ADNS_INTERNAL_H_INCLUDED
4#define ADNS_INTERNAL_H_INCLUDED
5
4353a5c4 6#define PRINTFFORMAT(a,b) __attribute__((format(printf,a,b)))
7typedef unsigned char byte;
8
9#include <stdarg.h>
10#include <assert.h>
11#include <unistd.h>
12
37e28fde 13#include <sys/time.h>
14
15#include "adns.h"
16
17/* Configuration and constants */
18
19#define MAXSERVERS 5
b9de380c 20#define UDPMAXRETRIES /*15*/5
37e28fde 21#define UDPRETRYMS 2000
22#define TCPMS 30000
23#define LOCALRESOURCEMS 20
b9de380c 24
98a3f706 25#define DNS_PORT 53
b9de380c 26#define DNS_MAXUDP 512
27#define DNS_MAXDOMAIN 255
28#define DNS_HDRSIZE 12
29#define DNS_CLASS_IN 1
37e28fde 30
98a3f706 31typedef enum {
32 rcode_noerror,
33 rcode_formaterror,
34 rcode_servfail,
35 rcode_nxdomain,
36 rcode_notimp,
37 rcode_refused
38} dns_rcode;
39
37e28fde 40/* Shared data structures */
41
4353a5c4 42typedef union {
37e28fde 43 adns_status status;
44 char *cp;
45 adns_rrtype type;
4353a5c4 46 int i;
37e28fde 47 struct in_addr ia;
48 unsigned long ul;
4353a5c4 49} rr_align;
50
51typedef struct {
52 int used, avail;
53 byte *buf;
54} vbuf;
55
56typedef union {
57 void *ext;
58 int dmaddr_index;
59} qcontext;
37e28fde 60
0ba0614a 61typedef struct {
0ba0614a 62 adns_rrtype type;
98a3f706 63 int rrsz;
8e5b0abb 64
65 adns_status (*parse)(adns_state ads, adns_query qu, int serv,
31144a72 66 const byte *dgram, int dglen, int cbyte, int max,
67 void *store_r);
68 /* Parse one RR, in dgram of length dglen, starting at cbyte and
69 * extending until at most max.
70 *
71 * The RR should be stored at *store_r, of length qu->typei->rrsz.
72 *
73 * If there is an overrun which might indicate truncation, it should set
74 * *rdstart to -1; otherwise it may set it to anything else positive.
8e5b0abb 75 */
76
77 void (*makefinal)(adns_state ads, adns_query qu, void *data);
78 /* Change memory management of *data.
79 * Previously, used alloc_interim, now use alloc_final.
31144a72 80 */
0ba0614a 81} typeinfo;
82
8e5b0abb 83typedef struct allocnode {
84 struct allocnode *next;
85} allocnode;
86
87union maxalign {
88 byte d[1];
89 struct in_addr ia;
90 long l;
91 void *p;
92 void (*fp)(void);
93 union maxalign *up;
94} data;
95
37e28fde 96struct adns__query {
ddfda861 97 enum { query_udp, query_tcpwait, query_tcpsent, query_child, query_done } state;
4353a5c4 98 adns_query back, next, parent;
37e28fde 99 struct { adns_query head, tail; } children;
100 struct { adns_query back, next; } siblings;
8e5b0abb 101 struct allocnode *allocations;
102 int interim_alloced, final_used;
0ba0614a 103
104 const typeinfo *typei;
8e5b0abb 105 char *query_dgram;
106 int query_dglen;
31144a72 107
8e5b0abb 108 vbuf vb;
109 /* General-purpose messing-about buffer.
110 * Wherever a `big' interface is crossed, this may be corrupted/changed
111 * unless otherwise specified.
112 */
113
114 adns_answer *answer;
115 /* This is allocated when a query is submitted, to avoid being unable
116 * to relate errors to queries if we run out of memory. During
117 * query processing status, rrs is 0. cname is set if
118 * we found a cname (this corresponds to cname_dgram in the query
119 * structure). type is set from the word go. nrrs and rrs
120 * are set together, when we find how many rrs there are.
121 */
31144a72 122
31144a72 123 byte *cname_dgram;
124 int cname_dglen, cname_begin;
125
ddfda861 126 int id, flags, udpretries;
4353a5c4 127 int udpnextserver;
128 unsigned long udpsent, tcpfailed; /* bitmap indexed by server */
37e28fde 129 struct timeval timeout;
4353a5c4 130 qcontext context;
ddfda861 131
37e28fde 132 /* Possible states:
ddfda861 133 *
8e5b0abb 134 * state Queue child id nextudpserver sentudp failedtcp
135 *
136 * udp NONE null >=0 0 zero zero
137 * udp timew null >=0 any nonzero zero
138 * udp NONE null >=0 any nonzero zero
139 *
140 * tcpwait timew null >=0 irrelevant zero any
141 * tcpsent timew null >=0 irrelevant zero any
142 *
143 * child childw set >=0 irrelevant irrelevant irrelevant
144 * done output null -1 irrelevant irrelevant irrelevant
ddfda861 145 *
146 * +------------------------+
147 * START -----> | udp/NONE |
148 * +------------------------+
149 * / |\ \
150 * too big for UDP / UDP timeout \ \ send via UDP
151 * do this ASAP! / more retries \ \ do this ASAP!
152 * |_ desired \ _|
153 * +---------------+ +-----------+
154 * | tcpwait/timew | ____ | udp/timew |
155 * +---------------+ \ +-----------+
156 * | ^ | | |
157 * TCP conn'd; | | TCP died | | |
158 * send via TCP | | more | UDP timeout | |
159 * do this ASAP! | | servers | no more | |
160 * v | to try | retries | |
161 * +---------------+ | desired | |
162 * | tcpsent/timew | ____ | | |
163 * +---------------+ \| | |
164 * \ \ TCP died | TCP | |
165 * \ \ no more | timeout / |
166 * \ \ servers | / |
167 * \ \ to try | / |
168 * got \ \ v |_ / got
169 * reply \ _| +------------------+ / reply
170 * \ | done/output FAIL | /
171 * \ +------------------+ /
172 * \ /
173 * _| |_
174 * (..... got reply ....)
175 * / \
176 * need child query/ies / \ no child query
177 * / \
178 * |_ _|
179 * +--------------+ +----------------+
180 * | child/childw | ----------------> | done/output OK |
181 * +--------------+ children done +----------------+
37e28fde 182 */
183};
184
37e28fde 185struct adns__state {
37e28fde 186 adns_initflags iflags;
187 FILE *diagfile;
ddfda861 188 struct { adns_query head, tail; } timew, childw, output;
4353a5c4 189 int nextid, udpsocket, tcpsocket;
8e5b0abb 190 vbuf tcpsend, tcprecv;
37e28fde 191 int nservers, tcpserver;
8402e34c 192 enum adns__tcpstate { server_disconnected, server_connecting, server_ok } tcpstate;
37e28fde 193 struct timeval tcptimeout;
194 struct server {
195 struct in_addr addr;
196 } servers[MAXSERVERS];
197};
198
199/* From setup.c: */
200
4353a5c4 201void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
37e28fde 202 int serv, const char *fmt, va_list al);
31144a72 203
204void adns__debug(adns_state ads, int serv, adns_query qu,
205 const char *fmt, ...) PRINTFFORMAT(3,4);
206void adns__warn(adns_state ads, int serv, adns_query qu,
207 const char *fmt, ...) PRINTFFORMAT(3,4);
208void adns__diag(adns_state ads, int serv, adns_query qu,
209 const char *fmt, ...) PRINTFFORMAT(3,4);
37e28fde 210
4353a5c4 211int adns__vbuf_ensure(vbuf *vb, int want);
31144a72 212int adns__vbuf_appendstr(vbuf *vb, const char *data);
4353a5c4 213int adns__vbuf_append(vbuf *vb, const byte *data, int len);
ddfda861 214/* 1=>success, 0=>realloc failed */
4353a5c4 215void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
216void adns__vbuf_init(vbuf *vb);
8e5b0abb 217void adns__vbuf_free(vbuf *vb);
4353a5c4 218
219int adns__setnonblock(adns_state ads, int fd); /* => errno value */
ddfda861 220
37e28fde 221/* From submit.c: */
222
8e5b0abb 223int adns__internal_submit(adns_state ads, adns_query *query_r,
224 adns_rrtype type, char *query_dgram, int query_len,
225 adns_queryflags flags, struct timeval now,
226 adns_status failstat, const qcontext *ctx);
227/* Submits a query (for internal use, called during external submits).
228 *
229 * The new query is returned in *query_r, or we return adns_s_nomemory.
230 *
231 * The query datagram should already have been assembled; memory for it
232 * is taken over by this routine whether it succeeds or fails.
233 *
234 * If failstat is nonzero then if we are successful in creating the query
235 * it is immediately failed with code failstat (but _submit still succeds).
236 *
237 * ctx is copied byte-for-byte into the query.
238 */
239
240void *adns__alloc_interim(adns_query qu, size_t sz);
241/* Allocates some memory, and records which query it came from
242 * and how much there was.
243 *
244 * If an error occurs in the query, all its memory is simply freed.
245 *
246 * If the query succeeds, one large buffer will be made which is
247 * big enough for all these allocations, and then adns__alloc_final
248 * will get memory from this buffer.
249 *
250 * _alloc_interim can fail, in which case it will fail the query too,
251 * so nothing more need be done with it.
252 */
253
254void *adns__alloc_final(adns_query qu, size_t sz);
255/* Cannot fail.
256 */
37e28fde 257
258/* From query.c: */
259
ddfda861 260void adns__query_udp(adns_state ads, adns_query qu, struct timeval now);
261void adns__query_tcp(adns_state ads, adns_query qu, struct timeval now);
4bec51a4 262adns_status adns__mkquery(adns_state ads, const char *owner, int ol, int id,
98a3f706 263 const typeinfo *typei, adns_queryflags flags);
4353a5c4 264
8e5b0abb 265void adns__query_ok(adns_state ads, adns_query qu);
266void adns__query_fail(adns_state ads, adns_query qu, adns_status stat);
267
4353a5c4 268/* From reply.c: */
269
98a3f706 270void adns__procdgram(adns_state ads, const byte *dgram, int len,
271 int serv, struct timeval now);
272
273/* From types.c: */
274
275const typeinfo *adns__findtype(adns_rrtype type);
276
277/* From parse.c: */
278
f1e474dd 279typedef struct {
280 adns_state ads, int serv;
281 const byte *dgram;
282 int dglen, max, cbyte, namelen;
283 int *dmend_rlater, *namelen_rlater;
284} findlabel_state;
285
286void adns__findlabel_start(findlabel_state *fls,
287 adns_state ads, int serv,
288 const byte *dgram, int dglen, int max,
289 int dmbegin, int *dmend_rlater);
290/* Finds labels in a domain in a datagram.
291 *
292 * Call this routine first.
293 * endpoint_rlater may be null.
294 */
295
296adns_status adns__findlabel_next(findlabel_state *fls,
297 int *lablen_r, int *labstart_r);
298/* Then, call this one repeatedly.
299 *
300 * It will return adns_s_ok if all is well, and tell you the length
301 * and start of successive labels. labstart_r may be null, but
302 * lablen_r must not be.
303 *
304 * After the last label, it will return with *lablen_r zero.
305 * Do not then call it again; instead, just throw away the findlabel_state.
306 *
307 * *dmend_rlater will have been set to point to the next part of
308 * the datagram after the label (or after the uncompressed part,
309 * if compression was used). *namelen_rlater will have been set
310 * to the length of the domain name (total length of labels plus
311 * 1 for each intervening dot).
312 *
313 * If the datagram appears to be truncated, *lablen_r will be -1.
314 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
315 * Do not call _next again.
316 *
317 * There may also be errors, in which case *dmend_rlater,
318 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
319 * Do not then call findlabel_next again.
320 */
321
322adns_status adns__parse_domain(adns_state ads, int serv, vbuf *vb,
323 const byte *dgram, int dglen,
324 int *cbyte_io, int max);
325/* vb must already have been initialised; it will be reset if necessary.
326 * If there is truncation, vb->used will be set to 0; otherwise
327 * (if there is no error) vb will be null-terminated.
328 * If there is an error vb and *cbyte_io may be left indeterminate.
329 */
330
331adns_status adns__findrr(adns_state ads, int serv,
332 const byte *dgram, int dglen, int *cbyte_io,
333 int *type_r, int *class_r, int *rdlen_r, int *rdstart_r,
334 const byte *eo_dgram, int eo_dglen, int eo_cbyte,
335 int *eo_matched_r);
336 /* Finds the extent and some of the contents of an RR in a datagram
337 * and does some checks. The datagram is *dgram, length dglen, and
338 * the RR starts at *cbyte_io (which is updated afterwards to point
339 * to the end of the RR).
340 *
341 * The type, class and RRdata length and start are returned iff
342 * the corresponding pointer variables are not null. type_r and
343 * class_r may not be null.
344 *
345 * If the caller thinks they know what the owner of the RR ought to
346 * be they can pass in details in eo_*: this is another (or perhaps
347 * the same datagram), and a pointer to where the putative owner
348 * starts in that datagram. In this case *eo_matched_r will be set
349 * to 1 if the datagram matched or 0 if it did not. Either
350 * both eo_dgram and eo_matched_r must both be non-null, or they
351 * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
352 * The eo datagram and contained owner domain MUST be valid and
353 * untruncated.
354 *
355 * If there is truncation then *type_r will be set to -1 and
356 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
357 * undefined.
358 *
359 * If an error is returned then *type_r will be undefined too.
360 */
98a3f706 361
f1e474dd 362int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len);
8402e34c 363
364/* From event.c: */
4353a5c4 365
8402e34c 366void adns__tcp_broken(adns_state ads, const char *what, const char *why);
4353a5c4 367void adns__tcp_tryconnect(adns_state ads, struct timeval now);
368void adns__autosys(adns_state ads, struct timeval now);
37e28fde 369
370/* Useful static inline functions: */
371
372static inline void timevaladd(struct timeval *tv_io, long ms) {
373 struct timeval tmp;
374 assert(ms>=0);
375 tmp= *tv_io;
94436798 376 tmp.tv_usec += (ms%1000)*1000000;
37e28fde 377 tmp.tv_sec += ms/1000;
94436798 378 if (tmp.tv_usec >= 1000000) { tmp.tv_sec++; tmp.tv_usec -= 1000; }
37e28fde 379 *tv_io= tmp;
ddfda861 380}
37e28fde 381
382static inline int ctype_whitespace(int c) { return c==' ' || c=='\n' || c=='\t'; }
383static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
98a3f706 384static inline int ctype_alpha(int c) {
385 return (c >= 'a' && c <= 'z') || (c >= 'A' || c <= 'Z');
386}
37e28fde 387
388/* Useful macros */
389
8e5b0abb 390#define MEM_ROUND(sz) \
391 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
392 * sizeof(union maxalign) )
393
4353a5c4 394#define LIST_INIT(list) ((list).head= (list).tail= 0)
395
37e28fde 396#define LIST_UNLINK_PART(list,node,part) \
397 do { \
398 if ((node)->back) (node)->back->part next= (node)->part next; \
399 else (list).head= (node)->part next; \
400 if ((node)->next) (node)->next->part back= (node)->part back; \
401 else (list).tail= (node)->part back; \
402 } while(0)
403
404#define LIST_LINK_TAIL_PART(list,node,part) \
405 do { \
406 (node)->part back= 0; \
407 (node)->part next= (list).tail; \
408 if ((list).tail) (list).tail->part back= (node); else (list).part head= (node); \
409 (list).tail= (node); \
410 } while(0)
411
412#define LIST_UNLINK(list,node) LIST_UNLINK_PART(list,node,)
4353a5c4 413#define LIST_LINK_TAIL(list,node) LIST_LINK_TAIL_PART(list,node,)
37e28fde 414
98a3f706 415#define GETIL_B(cb) (dgram[(cb)++])
416#define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
417#define GET_W(cb,tv) ((tv)=0, (tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
418
37e28fde 419#endif