static int harvest_records(struct rfc1035_res *res,
struct rfc1035_mxlist **list,
struct rfc1035_reply *mxreply,
int mxpreference,
char *mxname,
int q_type, int *found,
int flags, int port)
{
struct rfc1035_reply *areply=0;
int index;
#if RFC1035_IPV6
struct in6_addr in;
#else
struct in_addr in;
#endif
index= -1;
if (!mxreply || (
((index=rfc1035_replysearch_all( res, mxreply, mxname,
q_type,
RFC1035_CLASS_IN,
0)) < 0 ||
mxreply->allrrs[index]->rrtype != q_type)
&& (flags & HARVEST_AUTOQUERY))
)
{
index=rfc1035_resolve_cname(res,
RFC1035_RESOLVE_RECURSIVE, mxname,
q_type,
RFC1035_CLASS_IN, &areply, RFC1035_X_RANDOMIZE);
if (index < 0)
{
if (!areply)
{
if (index == RFC1035_ERR_CNAME_RECURSIVE)
return (RFC1035_MX_BADDNS);
return (RFC1035_MX_INTERNAL);
}
if (areply->rcode == RFC1035_RCODE_NXDOMAIN ||
areply->rcode == RFC1035_RCODE_NOERROR)
{
rfc1035_replyfree(areply);
return (RFC1035_MX_OK);
}
rfc1035_replyfree(areply);
return (RFC1035_MX_SOFTERR);
}
mxreply=areply;
}
for ( ; index >= 0 ;
index=rfc1035_replysearch_all( res, mxreply, mxname,
q_type,
RFC1035_CLASS_IN,
index+1))
{
if (mxreply->allrrs[index]->rrtype != q_type)
continue;
#if RFC1035_IPV6
if (q_type == RFC1035_TYPE_A)
{
struct rfc1035_mxlist *q;
/* Map it to an IPv4 address */
rfc1035_ipv4to6(&in,
&mxreply->allrrs[index]->rr.inaddr);
/* See if it's already here */
for (q= *list; q; q=q->next)
{
struct sockaddr_in6 sin6;
if (q->protocol != PF_INET6)
continue;
memcpy(&sin6, &q->address, sizeof(sin6));
if (memcmp(&sin6.sin6_addr, &in, sizeof(in))
== 0 && q->priority == mxpreference)
break;
}
if ((flags & HARVEST_NODUPE) && q) continue;
}
else
in=mxreply->allrrs[index]->rr.in6addr;
#else
in.s_addr=mxreply->allrrs[index]->rr.inaddr.s_addr;
#endif
*found=1;
if (addrecord(list, mxname, mxpreference, &in, port))
{
if (areply)
rfc1035_replyfree(areply);
return (RFC1035_MX_INTERNAL);
}
}
if (areply)
rfc1035_replyfree(areply);
return (RFC1035_MX_OK);
}
static int domxlistcreate(struct rfc1035_res *res,
const char *q_name, int opts,
struct rfc1035_mxlist **list, int port)
{
char namebuf[RFC1035_MAXNAMESIZE+1];
struct rfc1035_reply *replyp;
int index;
RFC1035_ADDR in;
int seen_softerr=0;
int seen_good=0;
*list=0;
if (rfc1035_aton(q_name, &in) == 0)
return (RFC1035_MX_HARDERR); /* Don't gimme an IP address */
namebuf[0]=0;
strncat(namebuf, q_name, RFC1035_MAXNAMESIZE);
if (namebuf[0] == '[')
{
char *q=strchr(namebuf, ']');
if (!q || q[1]) return (RFC1035_MX_HARDERR); /* Bad addr */
*q=0;
if (rfc1035_aton(namebuf+1, &in))
return (RFC1035_MX_HARDERR);
if (addrecord(list, q_name, -1, &in, port))
return (RFC1035_MX_INTERNAL);
return (RFC1035_MX_OK);
}
index=rfc1035_resolve_cname(res,
RFC1035_RESOLVE_RECURSIVE, namebuf,
RFC1035_TYPE_MX,
RFC1035_CLASS_IN, &replyp, RFC1035_X_RANDOMIZE);
if (index < 0)
{
if (!replyp)
{
if (index == RFC1035_ERR_CNAME_RECURSIVE)
return (RFC1035_MX_BADDNS);
return (RFC1035_MX_INTERNAL);
}
if (replyp->rcode == RFC1035_RCODE_NXDOMAIN ||
replyp->rcode == RFC1035_RCODE_NOERROR)
{
rfc1035_replyfree(replyp);
strcpy(namebuf, q_name);
if (opts & RFC1035_MX_AFALLBACK)
return (add_arecords(res, list, 0, -1,
namebuf, port));
return RFC1035_MX_HARDERR;
}
rfc1035_replyfree(replyp);
return (RFC1035_MX_SOFTERR);
}
for ( ; index >= 0;
index=rfc1035_replysearch_all( res, replyp, namebuf,
RFC1035_TYPE_MX,
RFC1035_CLASS_IN,
index+1))
{
char mxname[RFC1035_MAXNAMESIZE+1];
if (replyp->allrrs[index]->rrtype != RFC1035_TYPE_MX)
continue;
if (rfc1035_replyhostname(replyp,
replyp->allrrs[index]->rr.mx.mx_label, mxname) == 0)
continue;
switch (add_arecords(res, list, replyp,
replyp->allrrs[index]->rr.mx.preference, mxname,
port)) {
case RFC1035_MX_SOFTERR:
seen_softerr=1;
continue;
case RFC1035_MX_INTERNAL:
rfc1035_replyfree(replyp);
return (RFC1035_MX_INTERNAL);
case RFC1035_MX_BADDNS:
rfc1035_replyfree(replyp);
return (RFC1035_MX_BADDNS);
default:
seen_good=1;
continue;
}
}
rfc1035_replyfree(replyp);
if (seen_good && (opts & RFC1035_MX_IGNORESOFTERR))
seen_softerr=0;
/* At least some A records were probably fetched */
if (seen_softerr)
return (RFC1035_MX_SOFTERR);
if (*list) return (RFC1035_MX_OK);
return (RFC1035_MX_HARDERR);
}
static char *sts_getid(const char *domain)
{
struct rfc1035_res res;
struct rfc1035_reply *replyp;
int n;
char lookup_domain[RFC1035_MAXNAMESIZE];
char txtbuf[256];
char *id_str=NULL;
/* Domain cannot be too long */
if (strlen(domain) >= RFC1035_MAXNAMESIZE-10)
return 0;
strcat(strcpy(lookup_domain, "_mta-sts."), domain);
rfc1035_init_resolv(&res);
(void)rfc1035_resolve_cname(&res,
lookup_domain,
RFC1035_TYPE_TXT,
RFC1035_CLASS_IN, &replyp, 0);
if (!replyp)
{
rfc1035_destroy_resolv(&res);
return 0;
}
for (n=0; (n=rfc1035_replysearch_an(&res,
replyp,
lookup_domain, RFC1035_TYPE_TXT,
RFC1035_CLASS_IN, n)) >= 0; ++n)
{
char *p;
rfc1035_rr_gettxt(replyp->allrrs[n], 0, txtbuf);
p=strtok(txtbuf, "; ");
if (!p || strcmp(p, "v=STSv1"))
continue;
if (id_str)
{
/* RFC 8461 prohibits two or more. */
free(id_str);
id_str=NULL;
break;
}
id_str=sts_getid1();
if (!id_str)
break;
}
rfc1035_replyfree(replyp);
rfc1035_destroy_resolv(&res);
return id_str;
}
