/*
* hostname-like (A, MX, WKS) owners can have "*" as their first label
* but must otherwise be as a host name.
*/
int
res_ownok(const char *dn) {
if (asterchar(dn[0])) {
if (periodchar(dn[1]))
return (res_hnok(dn+2));
if (dn[1] == '\0')
return (1);
}
return (res_hnok(dn));
}
/*
* SOA RNAMEs and RP RNAMEs can have any printable character in their first
* label, but the rest of the name has to look like a host name.
*/
int
res_mailok(
const char *dn
)
{
int ch, escaped = 0;
/* "." is a valid missing representation */
if (*dn == '\0')
return (1);
/* otherwise <label>.<hostname> */
while ((ch = *dn++) != '\0') {
if (!domainchar(ch))
return (0);
if (!escaped && periodchar(ch))
break;
if (escaped)
escaped = 0;
else if (bslashchar(ch))
escaped = 1;
}
if (periodchar(ch))
return (res_hnok(dn));
return (0);
}
int
valid_domainpart(const char *s)
{
struct in_addr ina;
struct in6_addr ina6;
char *c, domain[SMTPD_MAXDOMAINPARTSIZE];
const char *p;
if (*s == '[') {
if (strncasecmp("[IPv6:", s, 6) == 0)
p = s + 6;
else
p = s + 1;
if (strlcpy(domain, p, sizeof domain) >= sizeof domain)
return 0;
c = strchr(domain, (int)']');
if (!c || c[1] != '\0')
return 0;
*c = '\0';
if (inet_pton(AF_INET6, domain, &ina6) == 1)
return 1;
if (inet_pton(AF_INET, domain, &ina) == 1)
return 1;
return 0;
}
return res_hnok(s);
}
static int
hostent_add_alias(struct hostent_ext *h, const char *name, int isdname)
{
char buf[MAXDNAME];
size_t i, n;
for (i = 0; i < MAXALIASES; i++)
if (h->aliases[i] == NULL)
break;
if (i == MAXALIASES)
return (0);
if (isdname) {
_asr_strdname(name, buf, sizeof buf);
buf[strlen(buf)-1] = '\0';
if (!res_hnok(buf))
return (-1);
name = buf;
}
n = strlen(name) + 1;
if (h->pos + n >= h->end)
return (0);
h->aliases[i] = h->pos;
memmove(h->pos, name, n);
h->pos += n;
return (0);
}
static int
hostent_set_cname(struct hostent_ext *h, const char *name, int isdname)
{
char buf[MAXDNAME];
size_t n;
if (h->h.h_name)
return (-1);
if (isdname) {
_asr_strdname(name, buf, sizeof buf);
buf[strlen(buf) - 1] = '\0';
if (!res_hnok(buf))
return (-1);
name = buf;
}
n = strlen(name) + 1;
if (h->pos + n >= h->end)
return (-1);
h->h.h_name = h->pos;
memmove(h->pos, name, n);
h->pos += n;
return (0);
}
static int
addrinfo_from_pkt(struct asr_query *as, char *pkt, size_t pktlen)
{
struct asr_unpack p;
struct asr_dns_header h;
struct asr_dns_query q;
struct asr_dns_rr rr;
int i;
union {
struct sockaddr sa;
struct sockaddr_in sain;
struct sockaddr_in6 sain6;
} u;
char buf[MAXDNAME], *c;
_asr_unpack_init(&p, pkt, pktlen);
_asr_unpack_header(&p, &h);
for (; h.qdcount; h.qdcount--)
_asr_unpack_query(&p, &q);
for (i = 0; i < h.ancount; i++) {
_asr_unpack_rr(&p, &rr);
if (rr.rr_type != q.q_type ||
rr.rr_class != q.q_class)
continue;
memset(&u, 0, sizeof u);
if (rr.rr_type == T_A) {
#ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN
u.sain.sin_len = sizeof u.sain;
#endif
u.sain.sin_family = AF_INET;
u.sain.sin_addr = rr.rr.in_a.addr;
u.sain.sin_port = 0;
} else if (rr.rr_type == T_AAAA) {
#ifdef HAVE_STRUCT_SOCKADDR_IN6_SIN6_LEN
u.sain6.sin6_len = sizeof u.sain6;
#endif
u.sain6.sin6_family = AF_INET6;
u.sain6.sin6_addr = rr.rr.in_aaaa.addr6;
u.sain6.sin6_port = 0;
} else
continue;
if (as->as.ai.hints.ai_flags & AI_CANONNAME) {
_asr_strdname(rr.rr_dname, buf, sizeof buf);
buf[strlen(buf) - 1] = '\0';
c = res_hnok(buf) ? buf : NULL;
} else if (as->as.ai.hints.ai_flags & AI_FQDN)
c = as->as.ai.fqdn;
else
c = NULL;
if (addrinfo_add(as, &u.sa, c))
return (-1); /* errno set */
}
return (0);
}
