sys/src/cmd/ndb/dnarea.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <bio.h>
   4 #include <ndb.h>
   5 #include <ip.h>
   6 #include "dns.h"
   7
   8 Area *owned, *delegated;
   9
  10 /*
  11  *  true if a name is in our area
  12  */
  13 Area*
  14 inmyarea(char *name)
  15 {
  16         int len;
  17         Area *s, *d;
  18
  19         len = strlen(name);
  20         for(s = owned; s; s = s->next){
  21                 if(s->len > len)
  22                         continue;
  23                 if(cistrcmp(s->soarr->owner->name, name + len - s->len) == 0)
  24                         if(len == s->len || name[len - s->len - 1] == '.')
  25                                 break;
  26         }
  27         if(s == nil)
  28                 return nil;
  29
  30         /* name is in area `s' */
  31         for(d = delegated; d; d = d->next){
  32                 if(d->len > len)
  33                         continue;
  34                 if(cistrcmp(d->soarr->owner->name, name + len - d->len) == 0)
  35                         if(len == d->len || name[len - d->len - 1] == '.')
  36                                 return nil; /* name is in a delegated subarea */
  37         }
  38
  39         return s;       /* name is in area `s' and not in a delegated subarea */
  40 }
  41
  42 /*
  43  *  our area is the part of the domain tree that
  44  *  we serve
  45  */
  46 void
  47 addarea(DN *dp, RR *rp, Ndbtuple *t)
  48 {
  49         Area *s;
  50         Area **l;
  51
  52         lock(&dnlock);
  53         if(t->val[0])
  54                 l = &delegated;
  55         else
  56                 l = &owned;
  57
  58         for (s = *l; s != nil; s = s->next)
  59                 if (strcmp(dp->name, s->soarr->owner->name) == 0) {
  60                         unlock(&dnlock);
  61                         return;         /* we've already got one */
  62                 }
  63
  64         /*
  65          *  The area contains a copy of the soa rr that created it.
  66          *  The owner of the the soa rr should stick around as long
  67          *  as the area does.
  68          */
  69         s = emalloc(sizeof(*s));
  70         s->len = strlen(dp->name);
  71         rrcopy(rp, &s->soarr);
  72         s->soarr->owner = dp;
  73         s->soarr->db = 1;
  74         s->soarr->ttl = Hour;
  75         s->neednotify = 1;
  76         s->needrefresh = 0;
  77
  78         if (debug)
  79                 dnslog("new area %s %s", dp->name,
  80                         l == &delegated? "delegated": "owned");
  81
  82         s->next = *l;
  83         *l = s;
  84         unlock(&dnlock);
  85 }
  86
  87 void
  88 freearea(Area **l)
  89 {
  90         Area *s;
  91
  92         while(s = *l){
  93                 *l = s->next;
  94                 lock(&dnlock);
  95                 rrfree(s->soarr);
  96                 memset(s, 0, sizeof *s);        /* cause trouble */
  97                 unlock(&dnlock);
  98                 free(s);
  99         }
 100 }
 101
 102 /*
 103  * refresh all areas that need it
 104  *  this entails running a command 'zonerefreshprogram'.  This could
 105  *  copy over databases from elsewhere or just do a zone transfer.
 106  */
 107 void
 108 refresh_areas(Area *s)
 109 {
 110         int pid;
 111         Waitmsg *w;
 112
 113         for(; s != nil; s = s->next){
 114                 if(!s->needrefresh)
 115                         continue;
 116
 117                 if(zonerefreshprogram == nil){
 118                         s->needrefresh = 0;
 119                         continue;
 120                 }
 121
 122                 pid = fork();
 123                 if (pid == -1) {
 124                         sleep(1000);    /* don't fork again immediately */
 125                         continue;
 126                 }
 127                 if (pid == 0){
 128                         execl(zonerefreshprogram, "zonerefresh",
 129                                 s->soarr->owner->name, nil);
 130                         exits("exec zonerefresh failed");
 131                 }
 132                 while ((w = wait()) != nil && w->pid != pid)
 133                         free(w);
 134                 if (w && w->pid == pid)
 135                         if(w->msg == nil || *w->msg == '\0')
 136                                 s->needrefresh = 0;
 137                 free(w);
 138         }
 139 }