mdw@git.distorted.org.uk Git - adns/blob - src/internal.h

   1 /**/
   2
   3 #ifndef ADNS_INTERNAL_H_INCLUDED
   4 #define ADNS_INTERNAL_H_INCLUDED
   5
   6 #define PRINTFFORMAT(a,b) __attribute__((format(printf,a,b)))
   7 typedef unsigned char byte;
   8
   9 #include <stdarg.h>
  10 #include <assert.h>
  11 #include <unistd.h>
  12
  13 #include <sys/time.h>
  14
  15 #include "adns.h"
  16
  17 /* Configuration and constants */
  18
  19 #define MAXSERVERS 5
  20 #define UDPMAXRETRIES /*15*/5
  21 #define UDPRETRYMS 2000
  22 #define TCPMS 30000
  23 #define LOCALRESOURCEMS 20
  24
  25 #define DNS_PORT 53
  26 #define DNS_MAXUDP 512
  27 #define DNS_MAXDOMAIN 255
  28 #define DNS_HDRSIZE 12
  29 #define DNS_CLASS_IN 1
  30
  31 typedef enum {
  32   rcode_noerror,
  33   rcode_formaterror,
  34   rcode_servfail,
  35   rcode_nxdomain,
  36   rcode_notimp,
  37   rcode_refused
  38 } dns_rcode;
  39
  40 /* Shared data structures */
  41
  42 typedef union {
  43   adns_status status;
  44   char *cp;
  45   adns_rrtype type;
  46   int i;
  47   struct in_addr ia;
  48   unsigned long ul;
  49 } rr_align;
  50
  51 typedef struct {
  52   int used, avail;
  53   byte *buf;
  54 } vbuf;
  55
  56 typedef union {
  57   void *ext;
  58   int dmaddr_index;
  59 } qcontext;
  60
  61 typedef struct {
  62   adns_rrtype type;
  63   int rrsz;
  64   adns_status (*parse)(adns_state ads, adns_query qu, int serv, vbuf *vb,
  65                        const byte *dgram, int dglen, int cbyte, int max,
  66                        void *store_r);
  67   /* Parse one RR, in dgram of length dglen, starting at cbyte and
  68    * extending until at most max.
  69    *
  70    * The RR should be stored at *store_r, of length qu->typei->rrsz.
  71    *
  72    * If there is an overrun which might indicate truncation, it should set
  73    * *rdstart to -1; otherwise it may set it to anything else positive.
  74    *
  75    * This function may use vb (which has been initialised) however it likes.
  76    */
  77 } typeinfo;
  78
  79 struct adns__query {
  80   /* FIXME: make sure this is all init'd properly */
  81   enum { query_udp, query_tcpwait, query_tcpsent, query_child, query_done } state;
  82   adns_query back, next, parent;
  83   struct { adns_query head, tail; } children;
  84   struct { adns_query back, next; } siblings;
  85
  86   const typeinfo *typei;
  87
  88 #error make sure all this is init'd properly
  89 #error make sure all this is freed properly
  90   byte *querymsg;
  91   int querylen;
  92
  93   vbuf ansbuf; /* Used for answer RRs */
  94   char *cname_str;
  95   byte *cname_dgram;
  96   int cname_dglen, cname_begin;
  97
  98   int id, flags, udpretries;
  99   int udpnextserver;
 100   unsigned long udpsent, tcpfailed; /* bitmap indexed by server */
 101   struct timeval timeout;
 102   qcontext context;
 103   char owner[1];
 104   /* After the owner name and nul comes the query message, pointed to by querymsg */
 105
 106   /* Possible states:
 107    *
 108    *  state   Queue   child  id   ansbuf    nextudpserver  sentudp     failedtcp
 109    *
 110    *  udp     NONE    null   >=0  null      0              zero        zero
 111    *  udp     timew   null   >=0  null      any            nonzero     zero
 112    *  udp     NONE    null   >=0  null      any            nonzero     zero
 113    *
 114    *  tcpwait timew   null   >=0  null      irrelevant     zero        any
 115    *  tcpsent timew   null   >=0  null      irrelevant     zero        any
 116    *
 117    *  child   childw  set    >=0  partial   irrelevant     irrelevant  irrelevant
 118    *  done    output  null   -1   set/null  irrelevant     irrelevant  irrelevant
 119    *
 120    *                          +------------------------+
 121    *             START -----> |      udp/NONE          |
 122    *                          +------------------------+
 123    *                         /                       |\  \
 124    *        too big for UDP /             UDP timeout  \  \ send via UDP
 125    *        do this ASAP!  /              more retries  \  \   do this ASAP!
 126    *                     |_                  desired     \  _|
 127    *              +---------------+                     +-----------+
 128    *              | tcpwait/timew | ____                | udp/timew |
 129    *              +---------------+     \               +-----------+
 130    *                    |  ^             |                 | |
 131    *     TCP conn'd;    |  | TCP died    |                 | |
 132    *     send via TCP   |  | more        |     UDP timeout | |
 133    *     do this ASAP!  |  | servers     |      no more    | |
 134    *                    v  | to try      |      retries    | |
 135    *              +---------------+      |      desired    | |
 136    *              | tcpsent/timew | ____ |                 | |
 137    *              +---------------+     \|                 | |
 138    *                  \   \ TCP died     | TCP             | |
 139    *                   \   \ no more     | timeout         / |
 140    *                    \   \ servers    |                /  |
 141    *                     \   \ to try    |               /   |
 142    *                  got \   \          v             |_    / got
 143    *                 reply \   _| +------------------+      / reply
 144    *                        \     | done/output FAIL |     /
 145    *                         \    +------------------+    /
 146    *                          \                          /
 147    *                           _|                      |_
 148    *                             (..... got reply ....)
 149    *                              /                   \
 150    *        need child query/ies /                     \ no child query
 151    *                            /                       \
 152    *                          |_                         _|
 153    *                +--------------+                   +----------------+
 154    *                | child/childw | ----------------> | done/output OK |
 155    *                +--------------+  children done    +----------------+
 156    */
 157 };
 158
 159 struct adns__state {
 160   adns_initflags iflags;
 161   FILE *diagfile;
 162   struct { adns_query head, tail; } timew, childw, output;
 163   int nextid, udpsocket, tcpsocket;
 164   vbuf rqbuf, tcpsend, tcprecv;
 165   int nservers, tcpserver;
 166   enum adns__tcpstate { server_disconnected, server_connecting, server_ok } tcpstate;
 167   struct timeval tcptimeout;
 168   struct server {
 169     struct in_addr addr;
 170   } servers[MAXSERVERS];
 171 };
 172
 173 /* From setup.c: */
 174
 175 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
 176                  int serv, const char *fmt, va_list al);
 177
 178 void adns__debug(adns_state ads, int serv, adns_query qu,
 179                  const char *fmt, ...) PRINTFFORMAT(3,4);
 180 void adns__warn(adns_state ads, int serv, adns_query qu,
 181                 const char *fmt, ...) PRINTFFORMAT(3,4);
 182 void adns__diag(adns_state ads, int serv, adns_query qu,
 183                 const char *fmt, ...) PRINTFFORMAT(3,4);
 184
 185 int adns__vbuf_ensure(vbuf *vb, int want);
 186 int adns__vbuf_appendstr(vbuf *vb, const char *data);
 187 int adns__vbuf_append(vbuf *vb, const byte *data, int len);
 188 /* 1=>success, 0=>realloc failed */
 189 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
 190 void adns__vbuf_init(vbuf *vb);
 191
 192 int adns__setnonblock(adns_state ads, int fd); /* => errno value */
 193
 194 /* From submit.c: */
 195
 196 void adns__query_nomem(adns_state ads, adns_query qu);
 197 void adns__query_finish(adns_state ads, adns_query qu, adns_status stat);
 198 void adns__query_fail(adns_state ads, adns_query qu, adns_status stat);
 199
 200 /* From query.c: */
 201
 202 void adns__query_udp(adns_state ads, adns_query qu, struct timeval now);
 203 void adns__query_tcp(adns_state ads, adns_query qu, struct timeval now);
 204 adns_status adns__mkquery(adns_state ads, const char *owner, int ol, int id,
 205                           const typeinfo *typei, adns_queryflags flags);
 206
 207 /* From reply.c: */
 208
 209 void adns__procdgram(adns_state ads, const byte *dgram, int len,
 210                      int serv, struct timeval now);
 211
 212 /* From types.c: */
 213
 214 const typeinfo *adns__findtype(adns_rrtype type);
 215
 216 /* From parse.c: */
 217
 218 typedef struct {
 219   adns_state ads, int serv;
 220   const byte *dgram;
 221   int dglen, max, cbyte, namelen;
 222   int *dmend_rlater, *namelen_rlater;
 223 } findlabel_state;
 224
 225 void adns__findlabel_start(findlabel_state *fls,
 226                            adns_state ads, int serv,
 227                            const byte *dgram, int dglen, int max,
 228                            int dmbegin, int *dmend_rlater);
 229 /* Finds labels in a domain in a datagram.
 230  *
 231  * Call this routine first.
 232  * endpoint_rlater may be null.
 233  */
 234
 235 adns_status adns__findlabel_next(findlabel_state *fls,
 236                                  int *lablen_r, int *labstart_r);
 237 /* Then, call this one repeatedly.
 238  *
 239  * It will return adns_s_ok if all is well, and tell you the length
 240  * and start of successive labels.  labstart_r may be null, but
 241  * lablen_r must not be.
 242  *
 243  * After the last label, it will return with *lablen_r zero.
 244  * Do not then call it again; instead, just throw away the findlabel_state.
 245  *
 246  * *dmend_rlater will have been set to point to the next part of
 247  * the datagram after the label (or after the uncompressed part,
 248  * if compression was used).  *namelen_rlater will have been set
 249  * to the length of the domain name (total length of labels plus
 250  * 1 for each intervening dot).
 251  *
 252  * If the datagram appears to be truncated, *lablen_r will be -1.
 253  * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
 254  * Do not call _next again.
 255  *
 256  * There may also be errors, in which case *dmend_rlater,
 257  * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
 258  * Do not then call findlabel_next again.
 259  */
 260
 261 adns_status adns__parse_domain(adns_state ads, int serv, vbuf *vb,
 262                                const byte *dgram, int dglen,
 263                                int *cbyte_io, int max);
 264 /* vb must already have been initialised; it will be reset if necessary.
 265  * If there is truncation, vb->used will be set to 0; otherwise
 266  * (if there is no error) vb will be null-terminated.
 267  * If there is an error vb and *cbyte_io may be left indeterminate.
 268  */
 269
 270 adns_status adns__findrr(adns_state ads, int serv,
 271                          const byte *dgram, int dglen, int *cbyte_io,
 272                          int *type_r, int *class_r, int *rdlen_r, int *rdstart_r,
 273                          const byte *eo_dgram, int eo_dglen, int eo_cbyte,
 274                          int *eo_matched_r);
 275   /* Finds the extent and some of the contents of an RR in a datagram
 276    * and does some checks.  The datagram is *dgram, length dglen, and
 277    * the RR starts at *cbyte_io (which is updated afterwards to point
 278    * to the end of the RR).
 279    *
 280    * The type, class and RRdata length and start are returned iff
 281    * the corresponding pointer variables are not null.  type_r and
 282    * class_r may not be null.
 283    *
 284    * If the caller thinks they know what the owner of the RR ought to
 285    * be they can pass in details in eo_*: this is another (or perhaps
 286    * the same datagram), and a pointer to where the putative owner
 287    * starts in that datagram.  In this case *eo_matched_r will be set
 288    * to 1 if the datagram matched or 0 if it did not.  Either
 289    * both eo_dgram and eo_matched_r must both be non-null, or they
 290    * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
 291    * The eo datagram and contained owner domain MUST be valid and
 292    * untruncated.
 293    *
 294    * If there is truncation then *type_r will be set to -1 and
 295    * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
 296    * undefined.
 297    *
 298    * If an error is returned then *type_r will be undefined too.
 299    */
 300
 301 int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len);
 302
 303 /* From event.c: */
 304
 305 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
 306 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
 307 void adns__autosys(adns_state ads, struct timeval now);
 308
 309 /* Useful static inline functions: */
 310
 311 static inline void timevaladd(struct timeval *tv_io, long ms) {
 312   struct timeval tmp;
 313   assert(ms>=0);
 314   tmp= *tv_io;
 315   tmp.tv_usec += (ms%1000)*1000000;
 316   tmp.tv_sec += ms/1000;
 317   if (tmp.tv_usec >= 1000000) { tmp.tv_sec++; tmp.tv_usec -= 1000; }
 318   *tv_io= tmp;
 319 }
 320
 321 static inline int ctype_whitespace(int c) { return c==' ' || c=='\n' || c=='\t'; }
 322 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
 323 static inline int ctype_alpha(int c) {
 324   return (c >= 'a' && c <= 'z') || (c >= 'A' || c <= 'Z');
 325 }
 326
 327 /* Useful macros */
 328
 329 #define LIST_INIT(list) ((list).head= (list).tail= 0)
 330
 331 #define LIST_UNLINK_PART(list,node,part) \
 332   do { \
 333     if ((node)->back) (node)->back->part next= (node)->part next; \
 334       else                        (list).head= (node)->part next; \
 335     if ((node)->next) (node)->next->part back= (node)->part back; \
 336       else                        (list).tail= (node)->part back; \
 337   } while(0)
 338
 339 #define LIST_LINK_TAIL_PART(list,node,part) \
 340   do { \
 341     (node)->part back= 0; \
 342     (node)->part next= (list).tail; \
 343     if ((list).tail) (list).tail->part back= (node); else (list).part head= (node); \
 344     (list).tail= (node); \
 345   } while(0)
 346
 347 #define LIST_UNLINK(list,node) LIST_UNLINK_PART(list,node,)
 348 #define LIST_LINK_TAIL(list,node) LIST_LINK_TAIL_PART(list,node,)
 349
 350 #define GETIL_B(cb) (dgram[(cb)++])
 351 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
 352 #define GET_W(cb,tv) ((tv)=0, (tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
 353
 354 #endif