mdw@git.distorted.org.uk Git - ezmlm/blob - issub.c

   1 #include "stralloc.h"
   2 #include "getln.h"
   3 #include "readwrite.h"
   4 #include "substdio.h"
   5 #include "open.h"
   6 #include "byte.h"
   7 #include "case.h"
   8 #include "lock.h"
   9 #include "error.h"
  10 #include "issub.h"
  11 #include "uint32.h"
  12
  13 static stralloc addr = {0};
  14 static stralloc line = {0};
  15 static stralloc fn = {0};
  16 static int fd;
  17 static substdio ss;
  18 static char ssbuf[256];
  19
  20 static int doit(userhost)
  21 char *userhost;
  22 {
  23   int j;
  24   uint32 h;
  25   char ch;
  26   int match;
  27
  28   if (!stralloc_copys(&addr,"T")) return -2;
  29   if (!stralloc_cats(&addr,userhost)) return -2;
  30
  31   j = byte_rchr(addr.s,addr.len,'@');
  32   if (j == addr.len) return 0;
  33   case_lowerb(addr.s + j + 1,addr.len - j - 1);
  34
  35   h = 5381;
  36   for (j = 0;j < addr.len;++j)
  37     h = (h + (h << 5)) ^ (uint32) (unsigned char) addr.s[j];
  38   ch = 64 + (h % 53);
  39
  40   if (!stralloc_0(&addr)) return -2;
  41
  42   if (!stralloc_copys(&fn,"subscribers/")) return -2;
  43   if (!stralloc_catb(&fn,&ch,1)) return -2;
  44   if (!stralloc_0(&fn)) return -2;
  45
  46   fd = open_read(fn.s);
  47   if (fd == -1) {
  48     if (errno != error_noent) return -3;
  49     return 0;
  50   }
  51   substdio_fdbuf(&ss,read,fd,ssbuf,sizeof(ssbuf));
  52
  53   for (;;) {
  54     if (getln(&ss,&line,&match,'\0') == -1) { close(fd); return -3; }
  55     if (!match) break;
  56     if (line.len == addr.len)
  57       if (!byte_diff(line.s,line.len,addr.s)) { close(fd); return 1; }
  58   }
  59
  60   close(fd);
  61   return 0;
  62 }
  63
  64 struct strerr issub_err;
  65
  66 int issub(userhost)
  67 char *userhost;
  68 {
  69   int fdlock;
  70   int r;
  71
  72   fdlock = open_append("lock");
  73   if (fdlock == -1)
  74     STRERR_SYS(-1,issub_err,"unable to open lock: ")
  75   if (lock_ex(fdlock) == -1) {
  76     close(fdlock);
  77     STRERR_SYS(-1,issub_err,"unable to obtain lock: ")
  78   }
  79
  80   r = doit(userhost);
  81   close(fdlock);
  82
  83   if (r == -2) STRERR(-1,issub_err,"out of memory")
  84   if (r == -3) STRERR_SYS3(-1,issub_err,"unable to read ",fn.s,": ")
  85
  86   return r;
  87 }