the DNS record type that is being sought
The output from the program is written to stdout. It is supposed to be in
-exactly the same format as a traditional namserver response (see RFC 1035) so
+exactly the same format as a traditional nameserver response (see RFC 1035) so
that Exim can process it as normal. At present, no compression is used.
Error messages are written to stderr.
Any DNS record line in a zone file can be prefixed with "DELAY=" and
a number of milliseconds (followed by one space).
-Any DNS record line in a zone file can be prefixed with "DNSSEC ";
+Any DNS record line can be prefixed with "DNSSEC ";
if all the records found by a lookup are marked
as such then the response will have the "AD" bit set.
-Any DNS record line in a zone file can be prefixed with "AA "
+Any DNS record line can be prefixed with "NXDOMAIN ";
+The record will be ignored (but the prefix set still applied);
+This lets us return a DNSSEC NXDOMAIN (=> HOST_NOT_FOUND).
+
+Any DNS record line can be prefixed with "AA "
if all the records found by a lookup are marked
as such then the response will have the "AA" bit set.
+Any DNS record line in a zone file can be prefixed with "TTL=" and
+a number of seconds (followed by one space).
+
*/
#include <ctype.h>
#include <errno.h>
#include <signal.h>
#include <arpa/nameser.h>
+#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/time.h>
#include <dirent.h>
+#include <unistd.h>
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
#define FALSE 0
#define TRUE 1
#define Ustrlen(s) (int)strlen(CCS(s))
#define Ustrncmp(s,t,n) strncmp(CCS(s),CCS(t),n)
#define Ustrncpy(s,t,n) strncpy(CS(s),CCS(t),n)
+#define Ustrtok(s,t) (uschar*)strtok(CS(s),CCS(t))
typedef struct zoneitem {
uschar *zone;
int value;
} tlist;
+#define DEFAULT_TTL 3600U
+
/* On some (older?) operating systems, the standard ns_t_xxx definitions are
not available, and only the older T_xxx ones exist in nameser.h. If ns_t_a is
not defined, assume we are in this state. A really old system might not even
rrdomain[0] = 0; /* No previous domain */
(void)fseek(f, 0, SEEK_SET); /* Start again at the beginning */
-if (dnssec) *dnssec = TRUE; /* cancelled by first nonsecure rec found */
-if (aa) *aa = TRUE; /* cancelled by first non-aa rec found */
-
/* Scan for RRs */
while (fgets(CS buffer, sizeof(buffer), f) != NULL)
int qtlen = qtypelen;
BOOL rr_sec = FALSE;
BOOL rr_aa = FALSE;
+ BOOL rr_ignore = FALSE;
int delay = 0;
+ uint ttl = DEFAULT_TTL;
p = buffer;
while (isspace(*p)) p++;
rr_sec = TRUE;
p += 7;
}
- else if (Ustrncmp(p, US"AA ", 3) == 0) /* tagged as authoritive */
+ if (Ustrncmp(p, US"NXDOMAIN ", 9) == 0) /* ignore record content */
+ {
+ rr_ignore = TRUE;
+ p += 9;
+ }
+ else if (Ustrncmp(p, US"AA ", 3) == 0) /* tagged as authoritative */
{
rr_aa = TRUE;
p += 3;
for (p += 6; *p >= '0' && *p <= '9'; p++) delay = delay*10 + *p - '0';
if (isspace(*p)) p++;
}
+ else if (Ustrncmp(p, US"TTL=", 4) == 0) /* TTL for record */
+ {
+ ttl = 0;
+ for (p += 4; *p >= '0' && *p <= '9'; p++) ttl = ttl*10 + *p - '0';
+ if (isspace(*p)) p++;
+ }
else
break;
}
/* The domain matches */
- if (yield == HOST_NOT_FOUND) yield = NO_DATA;
+ if (yield == HOST_NOT_FOUND)
+ {
+ yield = NO_DATA;
+ if (dnssec) *dnssec = TRUE; /* cancelled by first nonsecure rec found */
+ if (aa) *aa = TRUE; /* cancelled by first non-aa rec found */
+ }
/* Compare RR types; a CNAME record is always returned */
if (aa && !rr_aa)
*aa = FALSE; /* cancel AA return */
+ if (rr_ignore) continue;
+
yield = 0;
*countptr = *countptr + 1;
*pk++ = 0;
*pk++ = 1; /* class = IN */
- pk += 4; /* TTL field; don't care */
+ *pk++ = (ttl >>24) & 255;
+ *pk++ = (ttl >>16) & 255;
+ *pk++ = (ttl >> 8) & 255;
+ *pk++ = ttl & 255;
rdlptr = pk; /* remember rdlength field */
pk += 2;
switch (tvalue)
{
case ns_t_soa:
- p = strtok(p, " ");
- ep = p + strlen(p);
+ p = Ustrtok(p, " ");
+ ep = p + Ustrlen(p);
if (ep[-1] != '.') sprintf(CS ep, "%s.", zone);
pk = packname(p, pk); /* primary ns */
- p = strtok(NULL, " ");
+ p = Ustrtok(NULL, " ");
pk = packname(p , pk); /* responsible mailbox */
- *(p += strlen(p)) = ' ';
+ *(p += Ustrlen(p)) = ' ';
while (isspace(*p)) p++;
pk = longfield(&p, pk); /* serial */
pk = longfield(&p, pk); /* refresh */
break;
case ns_t_a:
- for (i = 0; i < 4; i++)
- {
- value = 0;
- while (isdigit(*p)) value = value*10 + *p++ - '0';
- *pk++ = value;
- p++;
- }
+ inet_pton(AF_INET, CCS p, pk); /* FIXME: error checking */
+ pk += 4;
break;
- /* The only occurrence of a double colon is for ::1 */
case ns_t_aaaa:
- if (Ustrcmp(p, "::1") == 0)
- {
- memset(pk, 0, 15);
- pk += 15;
- *pk++ = 1;
- }
- else for (i = 0; i < 8; i++)
- {
- value = 0;
- while (isxdigit(*p))
- {
- value = value * 16 + toupper(*p) - (isdigit(*p)? '0' : '7');
- p++;
- }
- *pk++ = (value >> 8) & 255;
- *pk++ = value & 255;
- p++;
- }
+ inet_pton(AF_INET6, CCS p, pk); /* FIXME: error checking */
+ pk += 16;
break;
case ns_t_mx:
(void)sprintf(CS buffer, "%s/dnszones/%s", argv[1], zonefile);
-/* Initialize the start of the response packet. We don't have to fake up
-everything, because we know that Exim will look only at the answer and
-additional section parts. */
+/* Initialize the start of the response packet. */
memset(packet, 0, 12);
pk += 12;
/* Open the zone file. */
-f = fopen(CS buffer, "r");
-if (f == NULL)
+if (!(f = fopen(CS buffer, "r")))
{
fprintf(stderr, "fakens: failed to open %s: %s\n", buffer, strerror(errno));
return NO_RECOVERY;
}
+header->qr = 1; /* query */
+header->opcode = QUERY; /* standard query */
+header->tc = 0; /* no trucation */
+
/* Find the records we want, and add them to the result. */
count = 0;
header->ancount = htons(count);
/* If the AA bit should be set (as indicated by the AA prefix in the zone file),
-we are expected to return some records in the authortive section. Bind9: If
-there is data in the answer section, the authoritive section contains the NS
-records, otherwise it contains the SOA record. Currently we mimic this
-behaviour for the first case (there is some answer record).
+we are expected to return some records in the authoritative section. Bind9: If
+there is data in the answer section, the authoritative section contains the NS
+records, otherwise it contains the SOA record. Mimic that.
*/
-if (aa)
- find_records(f, zone, zone[0] == '.' ? zone+1 : zone, US"NS", 2, &pk, &count, NULL, NULL);
+if (strcmp(qtype, "SOA") != 0 && strcmp(qtype, "NS") != 0)
+ if (count)
+ find_records(f, zone, zone[0] == '.' ? zone+1 : zone, US"NS", 2, &pk, &count, NULL, NULL);
+ else
+ find_records(f, zone, zone[0] == '.' ? zone+1 : zone, US"SOA", 3, &pk, &count, NULL, NULL);
header->nscount = htons(count - ntohs(header->ancount));
/* There is no need to return any additional records because Exim no longer
git://git.exim.org / users / heiko / exim.git / blobdiff