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#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "ibuf.h"
#include "striter.h"
#include "dns.h"
static str data = {0};
static int init(str *rules)
{
char host[256];
const char *x;
int i;
int j;
int k;
striter s;
if (!str_copys(rules,"")) return -1;
x = getenv("DNSREWRITEFILE");
if (!x) x = "/etc/dnsrewrite";
i = ibuf_openreadclose(x,&data);
if (i == -1) return -1;
if (i) {
if (!str_catc(&data,'\n')) return -1;
striter_loop(&s, &data, '\n') {
if (!str_catb(rules, s.startptr, s.len)) return -1;
while (rules->len) {
if (rules->s[rules->len - 1] != ' '
&& rules->s[rules->len - 1] != '\t'
&& rules->s[rules->len - 1] != '\r')
break;
--rules->len;
}
if (!str_catc(rules,0)) return -1;
}
return 0;
}
x = getenv("LOCALDOMAIN");
if (x) {
if (!str_copys(&data,x)) return -1;
if (!str_catc(&data,' ')) return -1;
if (!str_copys(rules,"?:")) return -1;
striter_loop(&s, &data, ' ') {
if (!str_cats(rules, "+.")) return -1;
if (!str_catb(rules, s.startptr, s.len)) return -1;
}
if (!str_catc(rules,0)) return -1;
if (!str_cats(rules,"*.:")) return -1;
if (!str_catc(rules,0)) return -1;
return 0;
}
i = dns_read_resolvconf(&data);
if (i == -1) return -1;
if (i) {
if (!str_catc(&data,'\n')) return -1;
striter_loop(&s, &data, '\n') {
if (memcmp("search ", s.startptr, 7) == 0
|| memcmp("search\t", s.startptr, 7) == 0
|| memcmp("domain ", s.startptr, 7) == 0
|| memcmp("domain\t", s.startptr, 7) == 0) {
if (!str_copys(rules,"?:")) return -1;
i = 7;
j = s.len;
while (i < j) {
x = memchr(s.startptr + i,' ',j - i);
k = x ? x - (s.startptr + i) : j - i;
x = memchr(s.startptr + i,'\t',k);
k = x ? x - (s.startptr + i) : k;
if (!k) { ++i; continue; }
if (!str_cats(rules,"+.")) return -1;
if (!str_catb(rules, s.startptr + i, k)) return -1;
i += k;
}
if (!str_catc(rules,0)) return -1;
if (!str_cats(rules,"*.:")) return -1;
if (!str_catc(rules,0)) return -1;
return 0;
}
}
}
host[0] = 0;
if (gethostname(host,sizeof host) == -1) return -1;
host[(sizeof host) - 1] = 0;
x = strchr(host,'.');
if (x) {
if (!str_copys(rules,"?:")) return -1;
if (!str_cats(rules,host + i)) return -1;
if (!str_catc(rules,0)) return -1;
}
if (!str_cats(rules,"*.:")) return -1;
if (!str_catc(rules,0)) return -1;
return 0;
}
static int ok = 0;
static unsigned int uses;
static struct timeval deadline;
static str rules = {0}; /* defined if ok */
/** Load the domain name qualification rules.
The rules are loaded from the file named by \c $DNSREWRITEFILE
(defaults to "/etc/dnsrewrite").
For compatibility, if the rewriting rules file is not present, the
qualification procedure looks for a local domain name in three
places:
-# The value of the \c $LOCALDOMAIN environment variable, if it is set.
-# The first \c domain or \c search line in \c /etc/resolv.conf (if any).
-# Everything after the first period in the system's hostname.
It translate these into instructions that add the local domain name
to any name without dots or brackets.
See http://cr.yp.to/djbdns/qualify.html for complete details.
*/
int dns_resolvconfrewrite(str *out)
{
struct timeval now;
gettimeofday(&now,0);
if (TV_LESS(&deadline,&now)) ok = 0;
if (!uses) ok = 0;
if (!ok) {
if (init(&rules) == -1) return -1;
deadline = now;
deadline.tv_sec += 600;
uses = 10000;
ok = 1;
}
--uses;
if (!str_copy(out,&rules)) return -1;
return 0;
}
#ifdef SELFTEST_MAIN
MAIN
{
str rcfile = {0};
makefile(&rcfile, "search \tdomain1.com\ndomain domain2.com");
debugfn(setenv("DNSRESOLVCONF", rcfile.s, 1));
debugstrfn(dns_resolvconfrewrite(&rules), &rules);
unlink(rcfile.s);
uses = 0; data.len = 0;
debugfn(setenv("LOCALDOMAIN", "local.domain", 1));
debugstrfn(dns_resolvconfrewrite(&rules), &rules);
uses = 0; data.len = 0;
makefile(&rcfile, "-.local:me.local\n=me:127.0.0.1\n*.a:.af.mil\n?:.heaven.af.mil\n*.:\n");
debugfn(setenv("DNSREWRITEFILE", rcfile.s, 1));
debugstrfn(dns_resolvconfrewrite(&rules), &rules);
unlink(rcfile.s);
}
#endif
#ifdef SELFTEST_EXP
result=0
result=0 len=20 size=32 s=?:+.domain1.com^@*.:^@
result=0
result=0 len=21 size=32 s=?:+.local.domain^@*.:^@
result=0
result=0 len=65 size=80 s=-.local:me.local^@=me:127.0.0.1^@*.a:.af.mil^@?:.heaven.af.mil^@*.:^@^@
#endif
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