| 1 | /* |
| 2 | * internal.h |
| 3 | * - declarations of private objects with external linkage (adns__*) |
| 4 | * - definitons of internal macros |
| 5 | * - comments regarding library data structures |
| 6 | */ |
| 7 | /* |
| 8 | * This file is part of adns, which is |
| 9 | * Copyright (C) 1997-2000,2003,2006 Ian Jackson |
| 10 | * Copyright (C) 1999-2000,2003,2006 Tony Finch |
| 11 | * Copyright (C) 1991 Massachusetts Institute of Technology |
| 12 | * (See the file INSTALL for full details.) |
| 13 | * |
| 14 | * This program is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU General Public License as published by |
| 16 | * the Free Software Foundation; either version 2, or (at your option) |
| 17 | * any later version. |
| 18 | * |
| 19 | * This program is distributed in the hope that it will be useful, |
| 20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 22 | * GNU General Public License for more details. |
| 23 | * |
| 24 | * You should have received a copy of the GNU General Public License |
| 25 | * along with this program; if not, write to the Free Software Foundation, |
| 26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 27 | */ |
| 28 | |
| 29 | #ifndef ADNS_INTERNAL_H_INCLUDED |
| 30 | #define ADNS_INTERNAL_H_INCLUDED |
| 31 | |
| 32 | #include "config.h" |
| 33 | typedef unsigned char byte; |
| 34 | |
| 35 | #include <stdarg.h> |
| 36 | #include <assert.h> |
| 37 | #include <unistd.h> |
| 38 | #include <signal.h> |
| 39 | #include <errno.h> |
| 40 | #include <string.h> |
| 41 | #include <stdlib.h> |
| 42 | |
| 43 | #include <sys/time.h> |
| 44 | |
| 45 | #include "adns.h" |
| 46 | #include "dlist.h" |
| 47 | |
| 48 | #ifdef ADNS_REGRESS_TEST |
| 49 | # include "hredirect.h" |
| 50 | #endif |
| 51 | |
| 52 | /* Configuration and constants */ |
| 53 | |
| 54 | #define MAXSERVERS 5 |
| 55 | #define MAXSORTLIST 15 |
| 56 | #define UDPMAXRETRIES 15 |
| 57 | #define UDPRETRYMS 2000 |
| 58 | #define TCPWAITMS 30000 |
| 59 | #define TCPCONNMS 14000 |
| 60 | #define TCPIDLEMS 30000 |
| 61 | #define MAXTTLBELIEVE (7*86400) /* any TTL > 7 days is capped */ |
| 62 | |
| 63 | #define DNS_PORT 53 |
| 64 | #define DNS_MAXUDP 512 |
| 65 | #define DNS_MAXLABEL 63 |
| 66 | #define DNS_MAXDOMAIN 255 |
| 67 | #define DNS_HDRSIZE 12 |
| 68 | #define DNS_IDOFFSET 0 |
| 69 | #define DNS_CLASS_IN 1 |
| 70 | |
| 71 | #define DNS_INADDR_ARPA "in-addr", "arpa" |
| 72 | #define DNS_IP6_ARPA "ip6", "arpa" |
| 73 | |
| 74 | #define MAX_POLLFDS ADNS_POLLFDS_RECOMMENDED |
| 75 | |
| 76 | /* Some preprocessor hackery */ |
| 77 | |
| 78 | #define GLUE(x, y) GLUE_(x, y) |
| 79 | #define GLUE_(x, y) x##y |
| 80 | |
| 81 | /* C99 macro `...' must match at least one argument, so the naive definition |
| 82 | * `#define CAR(car, ...) car' won't work. But it's easy to arrange for the |
| 83 | * tail to be nonempty if we're just going to discard it anyway. */ |
| 84 | #define CAR(...) CAR_(__VA_ARGS__, _) |
| 85 | #define CAR_(car, ...) car |
| 86 | |
| 87 | /* Extracting the tail of an argument list is rather more difficult. The |
| 88 | * following trick is based on one by Laurent Deniau to count the number of |
| 89 | * arguments to a macro, simplified in two ways: (a) it only handles up to |
| 90 | * eight arguments, and (b) it only needs to distinguish the one-argument |
| 91 | * case from many arguments. */ |
| 92 | #define CDR(...) CDR_(__VA_ARGS__, m, m, m, m, m, m, m, 1, _)(__VA_ARGS__) |
| 93 | #define CDR_(_1, _2, _3, _4, _5, _6, _7, _8, n, ...) CDR_##n |
| 94 | #define CDR_1(_) |
| 95 | #define CDR_m(_, ...) __VA_ARGS__ |
| 96 | |
| 97 | typedef enum { |
| 98 | cc_user, |
| 99 | cc_entex, |
| 100 | cc_freq |
| 101 | } consistency_checks; |
| 102 | |
| 103 | typedef enum { |
| 104 | rcode_noerror, |
| 105 | rcode_formaterror, |
| 106 | rcode_servfail, |
| 107 | rcode_nxdomain, |
| 108 | rcode_notimp, |
| 109 | rcode_refused |
| 110 | } dns_rcode; |
| 111 | |
| 112 | /* Shared data structures */ |
| 113 | |
| 114 | typedef struct { |
| 115 | int used, avail; |
| 116 | byte *buf; |
| 117 | } vbuf; |
| 118 | |
| 119 | typedef struct { |
| 120 | adns_state ads; |
| 121 | adns_query qu; |
| 122 | int serv; |
| 123 | const byte *dgram; |
| 124 | int dglen, nsstart, nscount, arcount; |
| 125 | struct timeval now; |
| 126 | } parseinfo; |
| 127 | |
| 128 | union gen_addr { |
| 129 | struct in_addr v4; |
| 130 | struct in6_addr v6; |
| 131 | }; |
| 132 | |
| 133 | struct af_addr { int af; union gen_addr addr; }; |
| 134 | |
| 135 | #define NREVDOMAINS 2 /* keep in sync with addrfam! */ |
| 136 | struct revparse_state { |
| 137 | unsigned map; /* which domains are still live */ |
| 138 | byte ipv[NREVDOMAINS][32]; /* address components so far */ |
| 139 | }; |
| 140 | |
| 141 | union checklabel_state { |
| 142 | struct revparse_state ptr; |
| 143 | }; |
| 144 | |
| 145 | typedef struct { |
| 146 | void *ext; |
| 147 | void (*callback)(adns_query parent, adns_query child); |
| 148 | |
| 149 | union { |
| 150 | struct { |
| 151 | adns_rrtype rev_rrtype; |
| 152 | struct af_addr addr; |
| 153 | } ptr; |
| 154 | } tinfo; /* type-specific state for the query itself: zero-init if you |
| 155 | * don't know better. */ |
| 156 | |
| 157 | union { |
| 158 | adns_rr_hostaddr *hostaddr; |
| 159 | } pinfo; /* state for use by parent's callback function */ |
| 160 | } qcontext; |
| 161 | |
| 162 | typedef struct typeinfo { |
| 163 | adns_rrtype typekey; |
| 164 | const char *rrtname; |
| 165 | const char *fmtname; |
| 166 | int fixed_rrsz; |
| 167 | |
| 168 | void (*makefinal)(adns_query qu, void *data); |
| 169 | /* Change memory management of *data. |
| 170 | * Previously, used alloc_interim, now use alloc_final. |
| 171 | */ |
| 172 | |
| 173 | adns_status (*convstring)(vbuf *vb, const void *data); |
| 174 | /* Converts the RR data to a string representation in vbuf. |
| 175 | * vbuf will be appended to (it must have been initialised), |
| 176 | * and will not be null-terminated by convstring. |
| 177 | */ |
| 178 | |
| 179 | adns_status (*parse)(const parseinfo *pai, int cbyte, |
| 180 | int max, void *store_r); |
| 181 | /* Parse one RR, in dgram of length dglen, starting at cbyte and |
| 182 | * extending until at most max. |
| 183 | * |
| 184 | * The RR should be stored at *store_r, of length qu->typei->getrrsz(). |
| 185 | * |
| 186 | * If there is an overrun which might indicate truncation, it should set |
| 187 | * *rdstart to -1; otherwise it may set it to anything else positive. |
| 188 | * |
| 189 | * nsstart is the offset of the authority section. |
| 190 | */ |
| 191 | |
| 192 | int (*diff_needswap)(adns_state ads,const void *datap_a,const void *datap_b); |
| 193 | /* Returns !0 if RR a should be strictly after RR b in the sort order, |
| 194 | * 0 otherwise. Must not fail. |
| 195 | */ |
| 196 | |
| 197 | adns_status (*checklabel)(adns_state ads, adns_queryflags flags, |
| 198 | union checklabel_state *cls, qcontext *ctx, |
| 199 | int labnum, const char *label, int lablen); |
| 200 | /* Check a label from the query domain string. The label is not |
| 201 | * necessarily null-terminated. The hook can refuse the query's submission |
| 202 | * by returning a nonzero status. State can be stored in *cls between |
| 203 | * calls, and useful information can be stashed in ctx->tinfo, to be stored |
| 204 | * with the query (e.g., it will be available to the parse hook). This |
| 205 | * hook can detect a first call because labnum is zero, and a final call |
| 206 | * because lablen is zero. |
| 207 | */ |
| 208 | |
| 209 | void (*postsort)(adns_state ads, void *array, int nrrs,int rrsz, |
| 210 | const struct typeinfo *typei); |
| 211 | /* Called immediately after the RRs have been sorted, and may rearrange |
| 212 | * them. (This is really for the benefit of SRV's bizarre weighting |
| 213 | * stuff.) May be 0 to mean nothing needs to be done. |
| 214 | */ |
| 215 | |
| 216 | int (*getrrsz)(const struct typeinfo *typei, adns_rrtype type); |
| 217 | /* Return the output resource-record element size; if this is null, then |
| 218 | * the rrsz member can be used. |
| 219 | */ |
| 220 | } typeinfo; |
| 221 | |
| 222 | adns_status adns__ckl_hostname(adns_state ads, adns_queryflags flags, |
| 223 | union checklabel_state *cls, |
| 224 | qcontext *ctx, int labnum, |
| 225 | const char *label, int lablen); |
| 226 | /* implemented in query.c, used by types.c as default |
| 227 | * and as part of implementation for some fancier types |
| 228 | * doesn't require any state */ |
| 229 | |
| 230 | typedef struct allocnode { |
| 231 | struct allocnode *next, *back; |
| 232 | size_t sz; |
| 233 | } allocnode; |
| 234 | |
| 235 | union maxalign { |
| 236 | byte d[1]; |
| 237 | struct in_addr ia; |
| 238 | long l; |
| 239 | void *p; |
| 240 | void (*fp)(void); |
| 241 | union maxalign *up; |
| 242 | } data; |
| 243 | |
| 244 | struct adns__query { |
| 245 | adns_state ads; |
| 246 | enum { query_tosend, query_tcpw, query_childw, query_done } state; |
| 247 | adns_query back, next, parent; |
| 248 | struct { adns_query head, tail; } children; |
| 249 | struct { adns_query back, next; } siblings; |
| 250 | struct { allocnode *head, *tail; } allocations; |
| 251 | int interim_allocd, preserved_allocd; |
| 252 | void *final_allocspace; |
| 253 | |
| 254 | const typeinfo *typei; |
| 255 | byte *query_dgram; |
| 256 | int query_dglen; |
| 257 | |
| 258 | vbuf vb; |
| 259 | /* General-purpose messing-about buffer. |
| 260 | * Wherever a `big' interface is crossed, this may be corrupted/changed |
| 261 | * unless otherwise specified. |
| 262 | */ |
| 263 | |
| 264 | adns_answer *answer; |
| 265 | /* This is allocated when a query is submitted, to avoid being unable |
| 266 | * to relate errors to queries if we run out of memory. During |
| 267 | * query processing status, rrs is 0. cname is set if |
| 268 | * we found a cname (this corresponds to cname_dgram in the query |
| 269 | * structure). type is set from the word go. nrrs and rrs |
| 270 | * are set together, when we find how many rrs there are. |
| 271 | * owner is set during querying unless we're doing searchlist, |
| 272 | * in which case it is set only when we find an answer. |
| 273 | */ |
| 274 | |
| 275 | byte *cname_dgram; |
| 276 | int cname_dglen, cname_begin; |
| 277 | /* If non-0, has been allocated using . */ |
| 278 | |
| 279 | vbuf search_vb; |
| 280 | int search_origlen, search_pos, search_doneabs; |
| 281 | /* Used by the searching algorithm. The query domain in textual form |
| 282 | * is copied into the vbuf, and _origlen set to its length. Then |
| 283 | * we walk the searchlist, if we want to. _pos says where we are |
| 284 | * (next entry to try), and _doneabs says whether we've done the |
| 285 | * absolute query yet (0=not yet, 1=done, -1=must do straight away, |
| 286 | * but not done yet). If flags doesn't have adns_qf_search then |
| 287 | * the vbuf is initialised but empty and everything else is zero. |
| 288 | */ |
| 289 | |
| 290 | int id, flags, retries; |
| 291 | int udpnextserver; |
| 292 | unsigned long udpsent; /* bitmap indexed by server */ |
| 293 | struct timeval timeout; |
| 294 | time_t expires; /* Earliest expiry time of any record we used. */ |
| 295 | |
| 296 | qcontext ctx; |
| 297 | |
| 298 | /* Possible states: |
| 299 | * |
| 300 | * state Queue child id nextudpserver udpsent tcpfailed |
| 301 | * |
| 302 | * tosend NONE null >=0 0 zero zero |
| 303 | * tosend udpw null >=0 any nonzero zero |
| 304 | * tosend NONE null >=0 any nonzero zero |
| 305 | * |
| 306 | * tcpw tcpw null >=0 irrelevant any any |
| 307 | * |
| 308 | * child childw set >=0 irrelevant irrelevant irrelevant |
| 309 | * child NONE null >=0 irrelevant irrelevant irrelevant |
| 310 | * done output null -1 irrelevant irrelevant irrelevant |
| 311 | * |
| 312 | * Queries are only not on a queue when they are actually being processed. |
| 313 | * Queries in state tcpw/tcpw have been sent (or are in the to-send buffer) |
| 314 | * iff the tcp connection is in state server_ok. |
| 315 | * |
| 316 | * +------------------------+ |
| 317 | * START -----> | tosend/NONE | |
| 318 | * +------------------------+ |
| 319 | * / |\ \ |
| 320 | * too big for UDP / UDP timeout \ \ send via UDP |
| 321 | * send via TCP / more retries \ \ |
| 322 | * when conn'd / desired \ \ |
| 323 | * | | | |
| 324 | * v | v |
| 325 | * +-----------+ +-------------+ |
| 326 | * | tcpw/tcpw | ________ | tosend/udpw | |
| 327 | * +-----------+ \ +-------------+ |
| 328 | * | | | UDP timeout | | |
| 329 | * | | | no more | | |
| 330 | * | | | retries | | |
| 331 | * \ | TCP died | desired | | |
| 332 | * \ \ no more | | | |
| 333 | * \ \ servers | TCP / | |
| 334 | * \ \ to try | timeout / | |
| 335 | * got \ \ v |_ | got |
| 336 | * reply \ _| +------------------+ / reply |
| 337 | * \ | done/output FAIL | / |
| 338 | * \ +------------------+ / |
| 339 | * \ / |
| 340 | * _| |_ |
| 341 | * (..... got reply ....) |
| 342 | * / \ |
| 343 | * need child query/ies / \ no child query |
| 344 | * / \ |
| 345 | * |_ _| |
| 346 | * +---------------+ +----------------+ |
| 347 | * | childw/childw | ----------------> | done/output OK | |
| 348 | * +---------------+ children done +----------------+ |
| 349 | */ |
| 350 | }; |
| 351 | |
| 352 | struct query_queue { adns_query head, tail; }; |
| 353 | |
| 354 | #define MAXUDP 2 |
| 355 | |
| 356 | struct adns__state { |
| 357 | adns_initflags iflags; |
| 358 | adns_logcallbackfn *logfn; |
| 359 | void *logfndata; |
| 360 | int configerrno; |
| 361 | struct query_queue udpw, tcpw, childw, output; |
| 362 | adns_query forallnext; |
| 363 | int nextid, tcpsocket; |
| 364 | struct udpsocket { int af; int fd; } udpsocket[MAXUDP]; |
| 365 | int nudp; |
| 366 | vbuf tcpsend, tcprecv; |
| 367 | int nservers, nsortlist, nsearchlist, searchndots, tcpserver, tcprecv_skip; |
| 368 | enum adns__tcpstate { |
| 369 | server_disconnected, server_connecting, |
| 370 | server_ok, server_broken |
| 371 | } tcpstate; |
| 372 | struct timeval tcptimeout; |
| 373 | /* This will have tv_sec==0 if it is not valid. It will always be |
| 374 | * valid if tcpstate _connecting. When _ok, it will be nonzero if |
| 375 | * we are idle (ie, tcpw queue is empty), in which case it is the |
| 376 | * absolute time when we will close the connection. |
| 377 | */ |
| 378 | struct sigaction stdsigpipe; |
| 379 | sigset_t stdsigmask; |
| 380 | struct pollfd pollfds_buf[MAX_POLLFDS]; |
| 381 | adns_rr_addr servers[MAXSERVERS]; |
| 382 | struct sortlist { |
| 383 | int af; |
| 384 | union gen_addr base, mask; |
| 385 | } sortlist[MAXSORTLIST]; |
| 386 | char **searchlist; |
| 387 | unsigned short rand48xsubi[3]; |
| 388 | }; |
| 389 | |
| 390 | /* From addrfam.c: */ |
| 391 | |
| 392 | extern int adns__af_supported_p(int af); |
| 393 | /* Return nonzero if the address family af known to the library and supported |
| 394 | * by the other addrfam operations. Note that the other operations will |
| 395 | * abort on an unrecognized address family rather than returning an error |
| 396 | * code. |
| 397 | */ |
| 398 | |
| 399 | extern int adns__genaddr_equal_p(int af, const union gen_addr *a, |
| 400 | int bf, const void *b); |
| 401 | /* b should point to a `struct in_addr' or equivalent for the address family |
| 402 | * bf. Returns nonzero if the two addresses are equal. |
| 403 | */ |
| 404 | |
| 405 | extern int adns__sockaddr_equal_p(const struct sockaddr *sa, |
| 406 | const struct sockaddr *sb); |
| 407 | /* Return nonzero if the two socket addresses are equal (in all significant |
| 408 | * respects). |
| 409 | */ |
| 410 | |
| 411 | extern int adns__addr_width(int af); |
| 412 | /* Return the width of addresses of family af, in bits. */ |
| 413 | |
| 414 | extern void adns__prefix_mask(int af, int len, union gen_addr *mask_r); |
| 415 | /* Store in mask_r an address mask for address family af, whose first len |
| 416 | * bits are set and the remainder are clear. This is what you want for |
| 417 | * converting a prefix length into a netmask. |
| 418 | */ |
| 419 | |
| 420 | extern int adns__guess_prefix_length(int af, const union gen_addr *addr); |
| 421 | /* Given a network base address, guess the appropriate prefix length based on |
| 422 | * the appropriate rules for the address family (e.g., for IPv4, this uses |
| 423 | * the old address classes). |
| 424 | */ |
| 425 | |
| 426 | extern int adns__addr_match_p(int addraf, const union gen_addr *addr, |
| 427 | int netaf, const union gen_addr *base, |
| 428 | const union gen_addr *mask); |
| 429 | /* Given an address af (with family addraf) and a network (with family netaf, |
| 430 | * base address base, and netmask mask), return nonzero if the address lies |
| 431 | * within the network. |
| 432 | */ |
| 433 | |
| 434 | extern void adns__sockaddr_extract(const struct sockaddr *sa, |
| 435 | union gen_addr *a_r, int *port_r); |
| 436 | /* Extract fields from the socket address, filling in *a_r and *port_r with |
| 437 | * the address and (integer, host byte-order) port number, respectively. |
| 438 | * Either (or, pointlessly, both) of a_r and port_r may be null to mean |
| 439 | * `don't care'. |
| 440 | */ |
| 441 | |
| 442 | extern void adns__sockaddr_inject(const union gen_addr *a, int port, |
| 443 | struct sockaddr *sa); |
| 444 | /* Inject fields into the socket adress sa. If a is not null, copy the |
| 445 | * address in; if port is not -1, then copy the port (converting from host |
| 446 | * byte-order). Assumes that sa->sa_family is already set correctly. |
| 447 | */ |
| 448 | |
| 449 | char *adns__sockaddr_ntoa(const struct sockaddr *sa, char *buf); |
| 450 | /* Convert sa to a string, and write it to buf, which must be at least |
| 451 | * ADNS_ADDR2TEXT_BUFLEN bytes long (unchecked). Return buf; can't fail. |
| 452 | */ |
| 453 | |
| 454 | extern int adns__make_reverse_domain(const struct sockaddr *sa, |
| 455 | const char *zone, |
| 456 | char **buf_io, size_t bufsz, |
| 457 | char **buf_free_r); |
| 458 | /* Construct a reverse domain string, given a socket address and a parent |
| 459 | * zone. If zone is null, then use the standard reverse-lookup zone for the |
| 460 | * address family. If the length of the resulting string is no larger than |
| 461 | * bufsz, then the result is stored starting at *buf_io; otherwise a new |
| 462 | * buffer is allocated is used, and a pointer to it is stored in both *buf_io |
| 463 | * and *buf_free_r (the latter of which should be null on entry). If |
| 464 | * something goes wrong, then an errno value is returned: ENOSYS if the |
| 465 | * address family of sa isn't recognized, or ENOMEM if the attempt to |
| 466 | * allocate an output buffer failed. |
| 467 | */ |
| 468 | |
| 469 | extern int adns__revparse_label(struct revparse_state *rps, int labnum, |
| 470 | const char *label, int lablen); |
| 471 | /* Parse a label in a reverse-domain name, given its index labnum (starting |
| 472 | * from zero), a pointer to its contents (which need not be null-terminated), |
| 473 | * and its length. The state in *rps is initialized implicitly when labnum |
| 474 | * is zero. |
| 475 | * |
| 476 | * Returns zero if the parse was successful, nonzero if the domain name is |
| 477 | * definitely invalid and the parse must be abandoned. |
| 478 | */ |
| 479 | |
| 480 | extern int adns__revparse_done(struct revparse_state *rps, int nlabels, |
| 481 | adns_rrtype *rrtype_r, struct af_addr *addr_r); |
| 482 | /* Finishes parsing a reverse-domain name, given the total number of labels |
| 483 | * in the name. On success, fills in the address in *addr_r, and the forward |
| 484 | * query type in *rrtype_r (because that turns out to be useful). Returns |
| 485 | * nonzero if the parse must be abandoned. |
| 486 | */ |
| 487 | |
| 488 | /* From setup.c: */ |
| 489 | |
| 490 | int adns__setnonblock(adns_state ads, int fd); /* => errno value */ |
| 491 | |
| 492 | /* From general.c: */ |
| 493 | |
| 494 | void adns__vlprintf(adns_state ads, const char *fmt, va_list al); |
| 495 | void adns__lprintf(adns_state ads, const char *fmt, |
| 496 | ...) PRINTFFORMAT(2,3); |
| 497 | |
| 498 | void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent, |
| 499 | int serv, adns_query qu, const char *fmt, va_list al); |
| 500 | |
| 501 | void adns__debug(adns_state ads, int serv, adns_query qu, |
| 502 | const char *fmt, ...) PRINTFFORMAT(4,5); |
| 503 | void adns__warn(adns_state ads, int serv, adns_query qu, |
| 504 | const char *fmt, ...) PRINTFFORMAT(4,5); |
| 505 | void adns__diag(adns_state ads, int serv, adns_query qu, |
| 506 | const char *fmt, ...) PRINTFFORMAT(4,5); |
| 507 | |
| 508 | int adns__vbuf_ensure(vbuf *vb, int want); |
| 509 | int adns__vbuf_appendstr(vbuf *vb, const char *data); /* doesn't include nul */ |
| 510 | int adns__vbuf_append(vbuf *vb, const byte *data, int len); |
| 511 | /* 1=>success, 0=>realloc failed */ |
| 512 | void adns__vbuf_appendq(vbuf *vb, const byte *data, int len); |
| 513 | void adns__vbuf_init(vbuf *vb); |
| 514 | void adns__vbuf_free(vbuf *vb); |
| 515 | |
| 516 | const char *adns__diag_domain(adns_state ads, int serv, adns_query qu, |
| 517 | vbuf *vb, |
| 518 | const byte *dgram, int dglen, int cbyte); |
| 519 | /* Unpicks a domain in a datagram and returns a string suitable for |
| 520 | * printing it as. Never fails - if an error occurs, it will |
| 521 | * return some kind of string describing the error. |
| 522 | * |
| 523 | * serv may be -1 and qu may be 0. vb must have been initialised, |
| 524 | * and will be left in an arbitrary consistent state. |
| 525 | * |
| 526 | * Returns either vb->buf, or a pointer to a string literal. Do not modify |
| 527 | * vb before using the return value. |
| 528 | */ |
| 529 | |
| 530 | int adns__getrrsz_default(const typeinfo *typei, adns_rrtype type); |
| 531 | /* Default function for the `getrrsz' type hook; returns the `fixed_rrsz' |
| 532 | * value from the typeinfo entry. |
| 533 | */ |
| 534 | |
| 535 | void adns__isort(void *array, int nobjs, int sz, void *tempbuf, |
| 536 | int (*needswap)(void *context, const void *a, const void *b), |
| 537 | void *context); |
| 538 | /* Does an insertion sort of array which must contain nobjs objects |
| 539 | * each sz bytes long. tempbuf must point to a buffer at least |
| 540 | * sz bytes long. needswap should return !0 if a>b (strictly, ie |
| 541 | * wrong order) 0 if a<=b (ie, order is fine). |
| 542 | */ |
| 543 | |
| 544 | void adns__sigpipe_protect(adns_state); |
| 545 | void adns__sigpipe_unprotect(adns_state); |
| 546 | /* If SIGPIPE protection is not disabled, will block all signals except |
| 547 | * SIGPIPE, and set SIGPIPE's disposition to SIG_IGN. (And then restore.) |
| 548 | * Each call to _protect must be followed by a call to _unprotect before |
| 549 | * any significant amount of code gets to run, since the old signal mask |
| 550 | * is stored in the adns structure. |
| 551 | */ |
| 552 | |
| 553 | /* From transmit.c: */ |
| 554 | |
| 555 | adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r, |
| 556 | const char *owner, int ol, |
| 557 | const typeinfo *typei, adns_rrtype type, |
| 558 | adns_queryflags flags); |
| 559 | /* Assembles a query packet in vb. A new id is allocated and returned. |
| 560 | */ |
| 561 | |
| 562 | adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r, |
| 563 | const byte *qd_dgram, int qd_dglen, |
| 564 | int qd_begin, |
| 565 | adns_rrtype type, adns_queryflags flags); |
| 566 | /* Same as adns__mkquery, but takes the owner domain from an existing datagram. |
| 567 | * That domain must be correct and untruncated. |
| 568 | */ |
| 569 | |
| 570 | void adns__querysend_tcp(adns_query qu, struct timeval now); |
| 571 | /* Query must be in state tcpw/tcpw; it will be sent if possible and |
| 572 | * no further processing can be done on it for now. The connection |
| 573 | * might be broken, but no reconnect will be attempted. |
| 574 | */ |
| 575 | |
| 576 | struct udpsocket *adns__udpsocket_by_af(adns_state ads, int af); |
| 577 | /* Find the UDP socket structure in ads which has the given address family. |
| 578 | * Return null if there isn't one. |
| 579 | * |
| 580 | * This is used during initialization, so ads is only partially filled in. |
| 581 | * The requirements are that nudp is set, and that udpsocket[i].af are |
| 582 | * defined for 0<=i<nudp. |
| 583 | */ |
| 584 | |
| 585 | void adns__query_send(adns_query qu, struct timeval now); |
| 586 | /* Query must be in state tosend/NONE; it will be moved to a new state, |
| 587 | * and no further processing can be done on it for now. |
| 588 | * (Resulting state is one of udp/timew, tcpwait/timew (if server not |
| 589 | * connected), tcpsent/timew, child/childw or done/output.) |
| 590 | * __query_send may decide to use either UDP or TCP depending whether |
| 591 | * _qf_usevc is set (or has become set) and whether the query is too |
| 592 | * large. |
| 593 | */ |
| 594 | |
| 595 | /* From query.c: */ |
| 596 | |
| 597 | adns_status adns__internal_submit(adns_state ads, adns_query *query_r, |
| 598 | const typeinfo *typei, adns_rrtype type, |
| 599 | vbuf *qumsg_vb, int id, |
| 600 | adns_queryflags flags, struct timeval now, |
| 601 | qcontext *ctx); |
| 602 | /* Submits a query (for internal use, called during external submits). |
| 603 | * |
| 604 | * The new query is returned in *query_r, or we return adns_s_nomemory. |
| 605 | * |
| 606 | * The query datagram should already have been assembled in qumsg_vb; |
| 607 | * the memory for it is _taken over_ by this routine whether it |
| 608 | * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb). |
| 609 | * |
| 610 | * *ctx is copied byte-for-byte into the query. Before doing this, its tinfo |
| 611 | * field may be modified by type hooks. |
| 612 | * |
| 613 | * When the child query is done, ctx->callback will be called. The |
| 614 | * child will already have been taken off both the global list of |
| 615 | * queries in ads and the list of children in the parent. The child |
| 616 | * will be freed when the callback returns. The parent will have been |
| 617 | * taken off the global childw queue. |
| 618 | * |
| 619 | * The callback should either call adns__query_done, if it is |
| 620 | * complete, or adns__query_fail, if an error has occurred, in which |
| 621 | * case the other children (if any) will be cancelled. If the parent |
| 622 | * has more unfinished children (or has just submitted more) then the |
| 623 | * callback may choose to wait for them - it must then put the parent |
| 624 | * back on the childw queue. |
| 625 | */ |
| 626 | |
| 627 | void adns__search_next(adns_state ads, adns_query qu, struct timeval now); |
| 628 | /* Walks down the searchlist for a query with adns_qf_search. |
| 629 | * The query should have just had a negative response, or not had |
| 630 | * any queries sent yet, and should not be on any queue. |
| 631 | * The query_dgram if any will be freed and forgotten and a new |
| 632 | * one constructed from the search_* members of the query. |
| 633 | * |
| 634 | * Cannot fail (in case of error, calls adns__query_fail). |
| 635 | */ |
| 636 | |
| 637 | void *adns__alloc_interim(adns_query qu, size_t sz); |
| 638 | void *adns__alloc_preserved(adns_query qu, size_t sz); |
| 639 | /* Allocates some memory, and records which query it came from |
| 640 | * and how much there was. |
| 641 | * |
| 642 | * If an error occurs in the query, all the memory from _interim is |
| 643 | * simply freed. If the query succeeds, one large buffer will be made |
| 644 | * which is big enough for all these allocations, and then |
| 645 | * adns__alloc_final will get memory from this buffer. |
| 646 | * |
| 647 | * _alloc_interim can fail (and return 0). |
| 648 | * The caller must ensure that the query is failed. |
| 649 | * |
| 650 | * The memory from _preserved is is kept and transferred into the |
| 651 | * larger buffer - unless we run out of memory, in which case it too |
| 652 | * is freed. When you use _preserved you have to add code to the |
| 653 | * x_nomem error exit case in adns__makefinal_query to clear out the |
| 654 | * pointers you made to those allocations, because that's when they're |
| 655 | * thrown away; you should also make a note in the declaration of |
| 656 | * those pointer variables, to note that they are _preserved rather |
| 657 | * than _interim. If they're in the answer, note it here: |
| 658 | * answer->cname and answer->owner are _preserved. |
| 659 | */ |
| 660 | |
| 661 | void adns__transfer_interim(adns_query from, adns_query to, void *block); |
| 662 | /* Transfers an interim allocation from one query to another, so that |
| 663 | * the `to' query will have room for the data when we get to makefinal |
| 664 | * and so that the free will happen when the `to' query is freed |
| 665 | * rather than the `from' query. |
| 666 | * |
| 667 | * It is legal to call adns__transfer_interim with a null pointer; this |
| 668 | * has no effect. |
| 669 | * |
| 670 | * _transfer_interim also ensures that the expiry time of the `to' query |
| 671 | * is no later than that of the `from' query, so that child queries' |
| 672 | * TTLs get inherited by their parents. |
| 673 | */ |
| 674 | |
| 675 | void adns__free_interim(adns_query qu, void *p); |
| 676 | /* Forget about a block allocated by adns__alloc_interim. |
| 677 | */ |
| 678 | |
| 679 | void *adns__alloc_mine(adns_query qu, size_t sz); |
| 680 | /* Like _interim, but does not record the length for later |
| 681 | * copying into the answer. This just ensures that the memory |
| 682 | * will be freed when we're done with the query. |
| 683 | */ |
| 684 | |
| 685 | void *adns__alloc_final(adns_query qu, size_t sz); |
| 686 | /* Cannot fail, and cannot return 0. |
| 687 | */ |
| 688 | |
| 689 | void adns__makefinal_block(adns_query qu, void **blpp, size_t sz); |
| 690 | void adns__makefinal_str(adns_query qu, char **strp); |
| 691 | |
| 692 | void adns__reset_preserved(adns_query qu); |
| 693 | /* Resets all of the memory management stuff etc. to take account of |
| 694 | * only the _preserved stuff from _alloc_preserved. Used when we find |
| 695 | * an error somewhere and want to just report the error (with perhaps |
| 696 | * CNAME, owner, etc. info), and also when we're halfway through RRs |
| 697 | * in a datagram and discover that we need to retry the query. |
| 698 | */ |
| 699 | |
| 700 | void adns__query_done(adns_query qu); |
| 701 | void adns__query_fail(adns_query qu, adns_status stat); |
| 702 | |
| 703 | /* From reply.c: */ |
| 704 | |
| 705 | void adns__procdgram(adns_state ads, const byte *dgram, int len, |
| 706 | int serv, int viatcp, struct timeval now); |
| 707 | /* This function is allowed to cause new datagrams to be constructed |
| 708 | * and sent, or even new queries to be started. However, |
| 709 | * query-sending functions are not allowed to call any general event |
| 710 | * loop functions in case they accidentally call this. |
| 711 | * |
| 712 | * Ie, receiving functions may call sending functions. |
| 713 | * Sending functions may NOT call receiving functions. |
| 714 | */ |
| 715 | |
| 716 | /* From types.c: */ |
| 717 | |
| 718 | const typeinfo *adns__findtype(adns_rrtype type); |
| 719 | |
| 720 | /* From parse.c: */ |
| 721 | |
| 722 | typedef struct { |
| 723 | adns_state ads; |
| 724 | adns_query qu; |
| 725 | int serv; |
| 726 | const byte *dgram; |
| 727 | int dglen, max, cbyte, namelen; |
| 728 | int *dmend_r; |
| 729 | } findlabel_state; |
| 730 | |
| 731 | void adns__findlabel_start(findlabel_state *fls, adns_state ads, |
| 732 | int serv, adns_query qu, |
| 733 | const byte *dgram, int dglen, int max, |
| 734 | int dmbegin, int *dmend_rlater); |
| 735 | /* Finds labels in a domain in a datagram. |
| 736 | * |
| 737 | * Call this routine first. |
| 738 | * dmend_rlater may be null. ads (and of course fls) may not be. |
| 739 | * serv may be -1, qu may be null - they are for error reporting. |
| 740 | */ |
| 741 | |
| 742 | adns_status adns__findlabel_next(findlabel_state *fls, |
| 743 | int *lablen_r, int *labstart_r); |
| 744 | /* Then, call this one repeatedly. |
| 745 | * |
| 746 | * It will return adns_s_ok if all is well, and tell you the length |
| 747 | * and start of successive labels. labstart_r may be null, but |
| 748 | * lablen_r must not be. |
| 749 | * |
| 750 | * After the last label, it will return with *lablen_r zero. |
| 751 | * Do not then call it again; instead, just throw away the findlabel_state. |
| 752 | * |
| 753 | * *dmend_rlater will have been set to point to the next part of |
| 754 | * the datagram after the label (or after the uncompressed part, |
| 755 | * if compression was used). *namelen_rlater will have been set |
| 756 | * to the length of the domain name (total length of labels plus |
| 757 | * 1 for each intervening dot). |
| 758 | * |
| 759 | * If the datagram appears to be truncated, *lablen_r will be -1. |
| 760 | * *dmend_rlater, *labstart_r and *namelen_r may contain garbage. |
| 761 | * Do not call _next again. |
| 762 | * |
| 763 | * There may also be errors, in which case *dmend_rlater, |
| 764 | * *namelen_rlater, *lablen_r and *labstart_r may contain garbage. |
| 765 | * Do not then call findlabel_next again. |
| 766 | */ |
| 767 | |
| 768 | typedef enum { |
| 769 | pdf_quoteok= 0x001 |
| 770 | } parsedomain_flags; |
| 771 | |
| 772 | adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu, |
| 773 | vbuf *vb, parsedomain_flags flags, |
| 774 | const byte *dgram, int dglen, int *cbyte_io, |
| 775 | int max); |
| 776 | /* vb must already have been initialised; it will be reset if necessary. |
| 777 | * If there is truncation, vb->used will be set to 0; otherwise |
| 778 | * (if there is no error) vb will be null-terminated. |
| 779 | * If there is an error vb and *cbyte_io may be left indeterminate. |
| 780 | * |
| 781 | * serv may be -1 and qu may be 0 - they are used for error reporting only. |
| 782 | */ |
| 783 | |
| 784 | adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads, |
| 785 | adns_query qu, vbuf *vb, |
| 786 | parsedomain_flags flags, |
| 787 | const byte *dgram); |
| 788 | /* Like adns__parse_domain, but you pass it a pre-initialised findlabel_state, |
| 789 | * for continuing an existing domain or some such of some kind. Also, unlike |
| 790 | * _parse_domain, the domain data will be appended to vb, rather than replacing |
| 791 | * the existing contents. |
| 792 | */ |
| 793 | |
| 794 | adns_status adns__findrr(adns_query qu, int serv, |
| 795 | const byte *dgram, int dglen, int *cbyte_io, |
| 796 | int *type_r, int *class_r, unsigned long *ttl_r, |
| 797 | int *rdlen_r, int *rdstart_r, |
| 798 | int *ownermatchedquery_r); |
| 799 | /* Finds the extent and some of the contents of an RR in a datagram |
| 800 | * and does some checks. The datagram is *dgram, length dglen, and |
| 801 | * the RR starts at *cbyte_io (which is updated afterwards to point |
| 802 | * to the end of the RR). |
| 803 | * |
| 804 | * The type, class, TTL and RRdata length and start are returned iff |
| 805 | * the corresponding pointer variables are not null. type_r, class_r |
| 806 | * and ttl_r may not be null. The TTL will be capped. |
| 807 | * |
| 808 | * If ownermatchedquery_r != 0 then the owner domain of this |
| 809 | * RR will be compared with that in the query (or, if the query |
| 810 | * has gone to a CNAME lookup, with the canonical name). |
| 811 | * In this case, *ownermatchedquery_r will be set to 0 or 1. |
| 812 | * The query datagram (or CNAME datagram) MUST be valid and not truncated. |
| 813 | * |
| 814 | * If there is truncation then *type_r will be set to -1 and |
| 815 | * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be |
| 816 | * undefined. |
| 817 | * |
| 818 | * qu must obviously be non-null. |
| 819 | * |
| 820 | * If an error is returned then *type_r will be undefined too. |
| 821 | */ |
| 822 | |
| 823 | adns_status adns__findrr_anychk(adns_query qu, int serv, |
| 824 | const byte *dgram, int dglen, int *cbyte_io, |
| 825 | int *type_r, int *class_r, |
| 826 | unsigned long *ttl_r, |
| 827 | int *rdlen_r, int *rdstart_r, |
| 828 | const byte *eo_dgram, int eo_dglen, |
| 829 | int eo_cbyte, int *eo_matched_r); |
| 830 | /* Like adns__findrr_checked, except that the datagram and |
| 831 | * owner to compare with can be specified explicitly. |
| 832 | * |
| 833 | * If the caller thinks they know what the owner of the RR ought to |
| 834 | * be they can pass in details in eo_*: this is another (or perhaps |
| 835 | * the same datagram), and a pointer to where the putative owner |
| 836 | * starts in that datagram. In this case *eo_matched_r will be set |
| 837 | * to 1 if the datagram matched or 0 if it did not. Either |
| 838 | * both eo_dgram and eo_matched_r must both be non-null, or they |
| 839 | * must both be null (in which case eo_dglen and eo_cbyte will be ignored). |
| 840 | * The eo datagram and contained owner domain MUST be valid and |
| 841 | * untruncated. |
| 842 | */ |
| 843 | |
| 844 | void adns__update_expires(adns_query qu, unsigned long ttl, |
| 845 | struct timeval now); |
| 846 | /* Updates the `expires' field in the query, so that it doesn't exceed |
| 847 | * now + ttl. |
| 848 | */ |
| 849 | |
| 850 | int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len); |
| 851 | |
| 852 | /* From event.c: */ |
| 853 | |
| 854 | void adns__tcp_broken(adns_state ads, const char *what, const char *why); |
| 855 | /* what and why may be both 0, or both non-0. */ |
| 856 | |
| 857 | void adns__tcp_tryconnect(adns_state ads, struct timeval now); |
| 858 | |
| 859 | void adns__autosys(adns_state ads, struct timeval now); |
| 860 | /* Make all the system calls we want to if the application wants us to. |
| 861 | * Must not be called from within adns internal processing functions, |
| 862 | * lest we end up in recursive descent ! |
| 863 | */ |
| 864 | |
| 865 | void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io, |
| 866 | struct timeval *tv_buf); |
| 867 | |
| 868 | int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]); |
| 869 | void adns__fdevents(adns_state ads, |
| 870 | const struct pollfd *pollfds, int npollfds, |
| 871 | int maxfd, const fd_set *readfds, |
| 872 | const fd_set *writefds, const fd_set *exceptfds, |
| 873 | struct timeval now, int *r_r); |
| 874 | int adns__internal_check(adns_state ads, |
| 875 | adns_query *query_io, |
| 876 | adns_answer **answer, |
| 877 | void **context_r); |
| 878 | |
| 879 | void adns__timeouts(adns_state ads, int act, |
| 880 | struct timeval **tv_io, struct timeval *tvbuf, |
| 881 | struct timeval now); |
| 882 | /* If act is !0, then this will also deal with the TCP connection |
| 883 | * if previous events broke it or require it to be connected. |
| 884 | */ |
| 885 | |
| 886 | /* From check.c: */ |
| 887 | |
| 888 | void adns__consistency(adns_state ads, adns_query qu, consistency_checks cc); |
| 889 | |
| 890 | /* Useful static inline functions: */ |
| 891 | |
| 892 | static inline int ctype_whitespace(int c) { |
| 893 | return c==' ' || c=='\n' || c=='\t'; |
| 894 | } |
| 895 | static inline int ctype_digit(int c) { return c>='0' && c<='9'; } |
| 896 | static inline int ctype_alpha(int c) { |
| 897 | return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'); |
| 898 | } |
| 899 | static inline int ctype_822special(int c) { |
| 900 | return strchr("()<>@,;:\\\".[]",c) != 0; |
| 901 | } |
| 902 | static inline int ctype_domainunquoted(int c) { |
| 903 | return ctype_alpha(c) || ctype_digit(c) || (strchr("-_/+",c) != 0); |
| 904 | } |
| 905 | |
| 906 | static inline int errno_resources(int e) { return e==ENOMEM || e==ENOBUFS; } |
| 907 | |
| 908 | /* Useful macros */ |
| 909 | |
| 910 | #define MEM_ROUND(sz) \ |
| 911 | (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \ |
| 912 | * sizeof(union maxalign) ) |
| 913 | |
| 914 | #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ff) |
| 915 | #define GET_B(cb,tv) ((tv)= GETIL_B((cb))) |
| 916 | #define GET_W(cb,tv) ((tv)=0,(tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv)) |
| 917 | #define GET_L(cb,tv) ( (tv)=0, \ |
| 918 | (tv)|=(GETIL_B((cb))<<24), \ |
| 919 | (tv)|=(GETIL_B((cb))<<16), \ |
| 920 | (tv)|=(GETIL_B((cb))<<8), \ |
| 921 | (tv)|=GETIL_B(cb), \ |
| 922 | (tv) ) |
| 923 | |
| 924 | #endif |