issub.c

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#include <unistd.h>
#include "stralloc.h"
#include "getln.h"
#include "readwrite.h"
#include "buffer.h"
#include "open.h"
#include "byte.h"
#include "case.h"
#include "error.h"
#include "uint_t.h"
#include "fmt.h"
#include "subscribe.h"
#include "errtxt.h"
#include "idx.h"
#include "logmsg.h"
 
#define WHO "issub"

 
static stralloc addr = {0};
static stralloc lcaddr = {0};
static stralloc line = {0};
static stralloc fn = {0};
static buffer bi;
static char inbuf[512];
 
static void die_nomem() { logmsg(WHO,111,FATAL,ERR_NOMEM); }

 
 
const char *issub(const char *dbname,const char *userhost,const char *tab)
{
 
  int fd;
  unsigned int j;
  uint32 h, lch;
  char ch, lcch;
  int match;
 
    if (!stralloc_copys(&addr,"T")) die_nomem();
    if (!stralloc_cats(&addr,userhost)) die_nomem();
 
    j = byte_rchr(addr.s,addr.len,'@');
    if (j == addr.len) return (char *) 0;
    case_lowerb(addr.s + j + 1,addr.len - j - 1);
    if (!stralloc_copy(&lcaddr,&addr)) die_nomem();
    case_lowerb(lcaddr.s + 1,j - 1);             /* totally lc version of addr */
 
    h = 5381;
    lch = h;                                     /* make hash for both for backwards comp */
    for (j = 0; j < addr.len; ++j) {             /* (lcaddr.len == addr.len) */
      h = (h + (h << 5)) ^ (uint32) (unsigned char) addr.s[j];
      lch = (lch + (lch << 5)) ^ (uint32) (unsigned char) lcaddr.s[j];
    }
    ch = 64 + (h % 53);
    lcch = 64 + (lch % 53);
 
    if (!stralloc_0(&addr)) die_nomem();
    if (!stralloc_0(&lcaddr)) die_nomem();
    if (!stralloc_copys(&fn,dbname)) die_nomem();
    if (!stralloc_cats(&fn,"/subscribers/")) die_nomem();
    if (!stralloc_catb(&fn,&lcch,1)) die_nomem();
    if (!stralloc_0(&fn)) die_nomem();
 
    fd = open_read(fn.s);
    if (fd == -1) {
      if (errno != ENOENT)
        logmsg(WHO,111,FATAL,B(ERR_OPEN,fn.s));
    } else {
      buffer_init(&bi,buffer_unixread,fd,inbuf,sizeof(inbuf));
 
      for (;;) {
        if (getln(&bi,&line,&match,'\0') == -1)
          logmsg(WHO,111,FATAL,B(ERR_READ,fn.s));
        if (!match) break;
        if (line.len == lcaddr.len)
          if (!case_diffb(line.s,line.len,lcaddr.s))
            { close(fd); return line.s + 1; }
      }
 
      close(fd);
    }
    /* here if file not found or (file found && addr not there) */
 
    if (ch == lcch) return (char *) 0;
 
    /* try case sensitive hash for backwards compatibility */
    fn.s[fn.len - 2] = ch;
    fd = open_read(fn.s);
    if (fd == -1) {
      if (errno != ENOENT)
        logmsg(WHO,111,FATAL,B(ERR_OPEN,fn.s));
      return (char *) 0;
    }
    buffer_init(&bi,buffer_unixread,fd,inbuf,sizeof(inbuf));
 
    for (;;) {
      if (getln(&bi,&line,&match,'\0') == -1)
        logmsg(WHO,111,FATAL,B(ERR_READ,fn.s));
      if (!match) break;
      if (line.len == addr.len)
        if (!case_diffb(line.s,line.len,addr.s))
          { close(fd); return line.s + 1; }
    }
 
    close(fd);
 
    return (char *) 0;
}