sys/src/libndb/csipinfo.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <bio.h>
   4 #include <ndb.h>
   5 #include <ndbhf.h>
   6
   7 /*
   8  *  look up the ip attributes 'list' for an entry that has the
   9  *  given 'attr=val' and a 'ip=' tuples.
  10  *
  11  *  return nil if not found.
  12  */
  13 Ndbtuple*
  14 csipinfo(char *netroot, char *attr, char *val, char **list, int n)
  15 {
  16         Ndbtuple *t, *first, *last;
  17         int i;
  18         char line[1024];
  19         int fd;
  20         char *p, *e;
  21
  22         if(netroot)
  23                 snprint(line, sizeof(line), "%s/cs", netroot);
  24         else
  25                 strcpy(line, "/net/cs");
  26         fd = open(line, ORDWR);
  27         if(fd < 0)
  28                 return 0;
  29         seek(fd, 0, 0);
  30         e = line + sizeof(line);
  31         p = seprint(line, e, "!ipinfo %s=%s", attr, val);
  32         for(i = 0; i < n; i++){
  33                 if(*list == nil)
  34                         break;
  35                 p = seprint(p, e, " %s", *list++);
  36         }
  37
  38         if(write(fd, line, strlen(line)) < 0){
  39                 close(fd);
  40                 return 0;
  41         }
  42         seek(fd, 0, 0);
  43
  44         first = last = 0;
  45         for(;;){
  46                 n = read(fd, line, sizeof(line)-2);
  47                 if(n <= 0)
  48                         break;
  49                 line[n] = '\n';
  50                 line[n+1] = 0;
  51
  52                 t = _ndbparseline(line);
  53                 if(t == 0)
  54                         continue;
  55                 if(first)
  56                         last->entry = t;
  57                 else
  58                         first = t;
  59                 last = t;
  60
  61                 while(last->entry)
  62                         last = last->entry;
  63         }
  64         close(fd);
  65
  66         ndbsetmalloctag(first, getcallerpc(&netroot));
  67         return first;
  68 }