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_UDPPORT 53
  26 #define DNS_MAXUDP 512
  27 #define DNS_MAXDOMAIN 255
  28 #define DNS_HDRSIZE 12
  29 #define DNS_CLASS_IN 1
  30
  31 /* Shared data structures */
  32
  33 typedef union {
  34   adns_status status;
  35   char *cp;
  36   adns_rrtype type;
  37   int i;
  38   struct in_addr ia;
  39   unsigned long ul;
  40 } rr_align;
  41
  42 typedef struct {
  43   int used, avail;
  44   byte *buf;
  45 } vbuf;
  46
  47 typedef union {
  48   void *ext;
  49   int dmaddr_index;
  50 } qcontext;
  51
  52 struct adns__query {
  53   /* FIXME: make sure this is all init'd properly */
  54   enum { query_udp, query_tcpwait, query_tcpsent, query_child, query_done } state;
  55   adns_query back, next, parent;
  56   struct { adns_query head, tail; } children;
  57   struct { adns_query back, next; } siblings;
  58   adns_rrtype type;
  59   vbuf ans;
  60   int id, flags, udpretries;
  61   int udpnextserver;
  62   unsigned long udpsent, tcpfailed; /* bitmap indexed by server */
  63   struct timeval timeout;
  64   byte *querymsg;
  65   int querylen;
  66   qcontext context;
  67   char owner[1];
  68   /* After the owner name and nul comes the query message, pointed to by querymsg */
  69
  70   /* Possible states:
  71    *
  72    *  state   Queue   child  id   answer    nextudpserver  sentudp     failedtcp
  73    *
  74    *  udp     NONE    null   >=0  null      0              zero        zero
  75    *  udp     timew   null   >=0  null      any            nonzero     zero
  76    *  udp     NONE    null   >=0  null      any            nonzero     zero
  77    *
  78    *  tcpwait timew   null   >=0  null      irrelevant     zero        any
  79    *  tcpsent timew   null   >=0  null      irrelevant     zero        any
  80    *
  81    *  child   childw  set    >=0  partial   irrelevant     irrelevant  irrelevant
  82    *  done    output  null   -1   set/null  irrelevant     irrelevant  irrelevant
  83    *
  84    *                          +------------------------+
  85    *             START -----> |      udp/NONE          |
  86    *                          +------------------------+
  87    *                         /                       |\  \
  88    *        too big for UDP /             UDP timeout  \  \ send via UDP
  89    *        do this ASAP!  /              more retries  \  \   do this ASAP!
  90    *                     |_                  desired     \  _|
  91    *              +---------------+                     +-----------+
  92    *              | tcpwait/timew | ____                | udp/timew |
  93    *              +---------------+     \               +-----------+
  94    *                    |  ^             |                 | |
  95    *     TCP conn'd;    |  | TCP died    |                 | |
  96    *     send via TCP   |  | more        |     UDP timeout | |
  97    *     do this ASAP!  |  | servers     |      no more    | |
  98    *                    v  | to try      |      retries    | |
  99    *              +---------------+      |      desired    | |
 100    *              | tcpsent/timew | ____ |                 | |
 101    *              +---------------+     \|                 | |
 102    *                  \   \ TCP died     | TCP             | |
 103    *                   \   \ no more     | timeout         / |
 104    *                    \   \ servers    |                /  |
 105    *                     \   \ to try    |               /   |
 106    *                  got \   \          v             |_    / got
 107    *                 reply \   _| +------------------+      / reply
 108    *                        \     | done/output FAIL |     /
 109    *                         \    +------------------+    /
 110    *                          \                          /
 111    *                           _|                      |_
 112    *                             (..... got reply ....)
 113    *                              /                   \
 114    *        need child query/ies /                     \ no child query
 115    *                            /                       \
 116    *                          |_                         _|
 117    *                +--------------+                   +----------------+
 118    *                | child/childw | ----------------> | done/output OK |
 119    *                +--------------+  children done    +----------------+
 120    */
 121 };
 122
 123 struct adns__state {
 124   adns_initflags iflags;
 125   FILE *diagfile;
 126   struct { adns_query head, tail; } timew, childw, output;
 127   int nextid, udpsocket, tcpsocket;
 128   vbuf rqbuf, tcpsend, tcprecv;
 129   int nservers, tcpserver;
 130   enum adns__tcpstate { server_disconnected, server_connecting, server_ok } tcpstate;
 131   struct timeval tcptimeout;
 132   struct server {
 133     struct in_addr addr;
 134   } servers[MAXSERVERS];
 135 };
 136
 137 /* From setup.c: */
 138
 139 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
 140                  int serv, const char *fmt, va_list al);
 141 void adns__debug(adns_state ads, int serv, const char *fmt, ...) PRINTFFORMAT(3,4);
 142 void adns__warn(adns_state ads, int serv, const char *fmt, ...) PRINTFFORMAT(3,4);
 143 void adns__diag(adns_state ads, int serv, const char *fmt, ...) PRINTFFORMAT(3,4);
 144
 145 int adns__vbuf_ensure(vbuf *vb, int want);
 146 int adns__vbuf_append(vbuf *vb, const byte *data, int len);
 147 /* 1=>success, 0=>realloc failed */
 148 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
 149 void adns__vbuf_init(vbuf *vb);
 150
 151 int adns__setnonblock(adns_state ads, int fd); /* => errno value */
 152
 153 /* From submit.c: */
 154
 155 void adns__query_nomem(adns_state ads, adns_query qu);
 156 void adns__query_fail(adns_state ads, adns_query qu, adns_status stat);
 157
 158 /* From query.c: */
 159
 160 void adns__query_udp(adns_state ads, adns_query qu, struct timeval now);
 161 void adns__query_tcp(adns_state ads, adns_query qu, struct timeval now);
 162 adns_status adns__mkquery(adns_state ads, const char *owner, int ol, int id,
 163                           adns_rrtype type, adns_queryflags flags);
 164
 165 /* From reply.c: */
 166
 167 void adns__procdgram(adns_state ads, const byte *dgram, int len, int serv);
 168
 169 /* From event.c: */
 170
 171 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
 172 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
 173 void adns__autosys(adns_state ads, struct timeval now);
 174
 175 /* Useful static inline functions: */
 176
 177 static inline void timevaladd(struct timeval *tv_io, long ms) {
 178   struct timeval tmp;
 179   assert(ms>=0);
 180   tmp= *tv_io;
 181   tmp.tv_usec += (ms%1000)*1000000;
 182   tmp.tv_sec += ms/1000;
 183   if (tmp.tv_usec >= 1000000) { tmp.tv_sec++; tmp.tv_usec -= 1000; }
 184   *tv_io= tmp;
 185 }
 186
 187 static inline int ctype_whitespace(int c) { return c==' ' || c=='\n' || c=='\t'; }
 188 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
 189
 190 /* Useful macros */
 191
 192 #define LIST_INIT(list) ((list).head= (list).tail= 0)
 193
 194 #define LIST_UNLINK_PART(list,node,part) \
 195   do { \
 196     if ((node)->back) (node)->back->part next= (node)->part next; \
 197       else                        (list).head= (node)->part next; \
 198     if ((node)->next) (node)->next->part back= (node)->part back; \
 199       else                        (list).tail= (node)->part back; \
 200   } while(0)
 201
 202 #define LIST_LINK_TAIL_PART(list,node,part) \
 203   do { \
 204     (node)->part back= 0; \
 205     (node)->part next= (list).tail; \
 206     if ((list).tail) (list).tail->part back= (node); else (list).part head= (node); \
 207     (list).tail= (node); \
 208   } while(0)
 209
 210 #define LIST_UNLINK(list,node) LIST_UNLINK_PART(list,node,)
 211 #define LIST_LINK_TAIL(list,node) LIST_LINK_TAIL_PART(list,node,)
 212
 213 #endif