int hslen; /* Length of data in hsbuf */
} client;
+struct mxentry
+{
+ char *name;
+ int pref;
+};
+
extern char krb_realm[REALM_SZ];
/* max length of query argument allowed */
int access_container(struct query *q, char *argv[], client *cl);
int access_update_user(struct query *q, char *argv[], client *cl);
int check_mail_string(char *mailstring);
+struct mxentry *getmxrecords(const char *);
/* prototypes from qfollow.pc */
int followup_fix_modby(struct query *q, struct save_queue *sq,
#include <ctype.h>
#include <stdlib.h>
#include <netdb.h>
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <arpa/nameser.h>
EXEC SQL INCLUDE sqlca;
EXEC SQL END DECLARE SECTION;
char *p, *host, *hostdomain;
struct hostent *hp;
+ struct mxentry *mxrecords = NULL;
int index;
p = strchr(mailstring, '@');
}
else
{
- /* couldn't resolve hostname, return MR_PERM. */
- free(host);
- return MR_BAD_MAIL_STRING;
+ /* Possibly a host with no A record but MX records. Check. */
+ mxrecords = getmxrecords(host);
+ if (!mxrecords)
+ return MR_BAD_MAIL_STRING;
+ else
+ return MR_SUCCESS;
}
if (!strcasecmp(host, "MIT.EDU"))
return MR_SUCCESS;
}
+
+/*
+ * This ought to be in the bind library. It's adapted from sendmail.
+ */
+
+/*
+ * These are defined in RFC833. Some bind interface headers don't declare them.
+ * Ghod help us if they're ever actually incompatible with what's in
+ * the arpa/nameser.h header.
+ */
+#ifndef PACKETSZ
+#define PACKETSZ 512 /* maximum packet size */
+#endif
+#ifndef HFIXEDSZ
+#define HFIXEDSZ 12 /* #/bytes of fixed data in header */
+#endif
+#ifndef INT32SZ
+#define INT32SZ 4 /* for systems without 32-bit ints */
+#endif
+#ifndef INT16SZ
+#define INT16SZ 2 /* for systems without 16-bit ints */
+#endif
+
+/* minimum possible size of MX record in packet */
+#define MIN_MX_SIZE 8 /* corresp to "a.com 0" w/ terminating space */
+
+struct mxentry *getmxrecords(const char *name)
+{
+ char answer[PACKETSZ], *eom, *cp, *bp;
+ int n, ancount, qdcount, buflen, type, pref, ind;
+ static struct mxentry pmx[(PACKETSZ - HFIXEDSZ) / MIN_MX_SIZE];
+ static char MXHostBuf[PACKETSZ - HFIXEDSZ];
+ HEADER *hp;
+
+ pmx->name = (char *)NULL;
+ pmx->pref = -1;
+ n = res_search(name, C_IN,T_MX, (unsigned char *)&answer, sizeof(answer));
+ if (n == -1)
+ return((struct mxentry *)NULL);
+ if ((size_t)n > sizeof(answer))
+ n = sizeof(answer);
+
+ hp = (HEADER *)&answer;
+ cp = answer + HFIXEDSZ;
+ eom = answer + n;
+ h_errno = 0;
+ for (qdcount = ntohs(hp->qdcount); qdcount--; cp += n + QFIXEDSZ)
+ if ((n = dn_skipname((unsigned char *)cp, (unsigned char *)eom)) < 0)
+ return((struct mxentry *)NULL);
+ buflen = sizeof(MXHostBuf) - 1;
+ bp = MXHostBuf;
+ ind = 0;
+ ancount = ntohs(hp->ancount);
+ while (--ancount >= 0 && cp < eom)
+ {
+ if ((n = dn_expand((unsigned char *)answer, (unsigned char *)eom,
+ (unsigned char *)cp, bp, buflen)) < 0)
+ break;
+ cp += n;
+ GETSHORT(type, cp);
+ cp += INT16SZ + INT32SZ;
+ GETSHORT(n, cp);
+ if (type != T_MX)
+ {
+ cp += n;
+ continue;
+ }
+ GETSHORT(pref, cp);
+ if ((n = dn_expand((unsigned char *)answer, (unsigned char *)eom,
+ (unsigned char *)cp, bp, buflen)) < 0)
+ break;
+ cp += n;
+
+ pmx[ind].name = bp;
+ pmx[ind].pref = pref;
+ ++ind;
+
+ n = strlen((const char *)bp);
+ bp += n;
+ *bp++ = '\0';
+
+ buflen -= n + 1;
+ }
+
+ pmx[ind].name = (char *)NULL;
+ pmx[ind].pref = -1;
+ return(pmx);
+}