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

   1 #include "stralloc.h"
   2 #include "getln.h"
   3 #include "readwrite.h"
   4 #include "substdio.h"
   5 #include "strerr.h"
   6 #include "open.h"
   7 #include "byte.h"
   8 #include "case.h"
   9 #include "lock.h"
  10 #include "error.h"
  11 #include "uint32.h"
  12 #include "subscribe.h"
  13
  14 static stralloc addr = {0};
  15 static stralloc line = {0};
  16 static stralloc fnnew = {0};
  17 static stralloc fn = {0};
  18
  19 static int fd;
  20 static substdio ss;
  21 static char ssbuf[256];
  22 static int fdnew;
  23 static substdio ssnew;
  24 static char ssnewbuf[256];
  25
  26 static int doit(userhost,flagadd)
  27 char *userhost;
  28 int flagadd;
  29 {
  30   int j;
  31   uint32 h;
  32   char ch;
  33   int match;
  34   int flagwasthere;
  35
  36   if (userhost[str_chr(userhost,'\n')]) return -8;
  37   if (!stralloc_copys(&addr,"T")) return -2;
  38   if (!stralloc_cats(&addr,userhost)) return -2;
  39   if (addr.len > 401) return -7;
  40
  41   j = byte_rchr(addr.s,addr.len,'@');
  42   if (j == addr.len) return -6;
  43   case_lowerb(addr.s + j + 1,addr.len - j - 1);
  44
  45   h = 5381;
  46   for (j = 0;j < addr.len;++j)
  47     h = (h + (h << 5)) ^ (uint32) (unsigned char) addr.s[j];
  48   ch = 64 + (h % 53);
  49
  50   if (!stralloc_0(&addr)) return -2;
  51
  52   if (!stralloc_copys(&fn,"subscribers/")) return -2;
  53   if (!stralloc_catb(&fn,&ch,1)) return -2;
  54   if (!stralloc_copy(&fnnew,&fn)) return -2;
  55   if (!stralloc_cats(&fnnew,"n")) return -2;
  56   if (!stralloc_0(&fnnew)) return -2;
  57   if (!stralloc_0(&fn)) return -2;
  58
  59   fdnew = open_trunc(fnnew.s);
  60   if (fdnew == -1) return -4;
  61   substdio_fdbuf(&ssnew,write,fdnew,ssnewbuf,sizeof(ssnewbuf));
  62
  63   flagwasthere = 0;
  64
  65   fd = open_read(fn.s);
  66   if (fd == -1) {
  67     if (errno != error_noent) { close(fdnew); return -3; }
  68   }
  69   else {
  70     substdio_fdbuf(&ss,read,fd,ssbuf,sizeof(ssbuf));
  71
  72     for (;;) {
  73       if (getln(&ss,&line,&match,'\0') == -1) { close(fd); close(fdnew); return -3; }
  74       if (!match) break;
  75       if (line.len == addr.len)
  76         if (!byte_diff(line.s,line.len,addr.s)) {
  77           flagwasthere = 1;
  78           if (!flagadd)
  79             continue;
  80         }
  81       if (substdio_bput(&ssnew,line.s,line.len) == -1) { close(fd); close(fdnew); return -4; }
  82     }
  83
  84     close(fd);
  85   }
  86
  87   if (flagadd && !flagwasthere)
  88     if (substdio_bput(&ssnew,addr.s,addr.len) == -1) { close(fdnew); return -4; }
  89
  90   if (substdio_flush(&ssnew) == -1) { close(fdnew); return -4; }
  91   if (fsync(fdnew) == -1) { close(fdnew); return -4; }
  92   close(fdnew);
  93
  94   if (rename(fnnew.s,fn.s) == -1) return -5;
  95   return flagadd ^ flagwasthere;
  96 }
  97
  98 struct strerr subscribe_err;
  99
 100 int subscribe(userhost,flagadd)
 101 char *userhost;
 102 int flagadd;
 103 {
 104   int fdlock;
 105   int r;
 106
 107   fdlock = open_append("lock");
 108   if (fdlock == -1)
 109     STRERR_SYS(-1,subscribe_err,"unable to open lock: ")
 110   if (lock_ex(fdlock) == -1) {
 111     close(fdlock);
 112     STRERR_SYS(-1,subscribe_err,"unable to obtain lock: ")
 113   }
 114
 115   r = doit(userhost,flagadd);
 116   close(fdlock);
 117
 118   if (r == -2) STRERR(-1,subscribe_err,"out of memory")
 119   if (r == -3) STRERR_SYS3(-1,subscribe_err,"unable to read ",fn.s,": ")
 120   if (r == -4) STRERR_SYS3(-1,subscribe_err,"unable to write ",fnnew.s,": ")
 121   if (r == -5) STRERR_SYS3(-1,subscribe_err,"unable to move temporary file to ",fn.s,": ")
 122   if (r == -6) STRERR(-2,subscribe_err,"address does not contain @")
 123   if (r == -7) STRERR(-2,subscribe_err,"address is too long")
 124   if (r == -8) STRERR(-2,subscribe_err,"address contains newline")
 125
 126   return r;
 127 }