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