/*% Stub function. Always returns failure. */
struct hostent *
lwres_gethostent(void) {
if (he != NULL)
lwres_freehostent(he);
return (NULL);
}
/* Return values:
* 0 : host found listed in dnsbl
* 1 : host not found listed in dnsbl
*/
int
check_dnsbl(int a, int b, int c, int d, char *dnsbl)
{
char *name;
int l, herr;
struct hostent *he;
/* An IPv4 address is max 15 chars long (xxx.xxx.xxx.xxx) */
l = 18 + strlen(dnsbl);
name = (char *)malloc(l);
if (name == NULL) {
syslog(LOG_INFO, "check_dnsbl(): malloc() error: aborting");
return(0);
}
memset(name, '\0', l);
if (*dnsbl == '.') {
sprintf(name, "%d.%d.%d.%d%s", d, c, b, a, dnsbl);
} else {
sprintf(name, "%d.%d.%d.%d.%s", d, c, b, a, dnsbl);
}
he = lwres_getipnodebyname(name, AF_INET, 0, &herr);
free(name);
if (he == NULL) {
return(1);
}
lwres_freehostent(he);
return(0);
}
/*% Looks for either an IPv4 or IPv6 address. */
struct hostent *
lwres_gethostbyname2(const char *name, int af) {
if (he != NULL)
lwres_freehostent(he);
he = lwres_getipnodebyname(name, af, 0, &lwres_h_errno);
return (he);
}
/*% Reverse lookup of addresses. */
struct hostent *
lwres_gethostbyaddr(const char *addr, int len, int type) {
if (he != NULL)
lwres_freehostent(he);
he = lwres_getipnodebyaddr(addr, len, type, &lwres_h_errno);
return (he);
}
/*% Always looks for an IPv4 address. */
struct hostent *
lwres_gethostbyname(const char *name) {
if (he != NULL)
lwres_freehostent(he);
he = lwres_getipnodebyname(name, AF_INET, 0, &lwres_h_errno);
return (he);
}
/*% Thread-safe function for forward lookups. */
struct hostent *
lwres_gethostbyname_r(const char *name, struct hostent *resbuf,
char *buf, int buflen, int *error)
{
struct hostent *he;
int res;
he = lwres_getipnodebyname(name, AF_INET, 0, error);
if (he == NULL)
return (NULL);
res = copytobuf(he, resbuf, buf, buflen);
lwres_freehostent(he);
if (res != 0) {
errno = ERANGE;
return (NULL);
}
return (resbuf);
}
/*% Thread-safe reverse lookup. */
struct hostent *
lwres_gethostbyaddr_r(const char *addr, int len, int type,
struct hostent *resbuf, char *buf, int buflen,
int *error)
{
struct hostent *he;
int res;
he = lwres_getipnodebyaddr(addr, len, type, error);
if (he == NULL)
return (NULL);
res = copytobuf(he, resbuf, buf, buflen);
lwres_freehostent(he);
if (res != 0) {
errno = ERANGE;
return (NULL);
}
return (resbuf);
}
/*% performs a reverse lookup of address src which is len bytes long. af denotes the protocol family, typically #PF_INET or PF_INET6. */
struct hostent *
lwres_getipnodebyaddr(const void *src, size_t len, int af, int *error_num) {
struct hostent *he1, *he2;
lwres_context_t *lwrctx = NULL;
lwres_gnbaresponse_t *by = NULL;
lwres_result_t n;
union {
const void *konst;
struct in6_addr *in6;
} u;
/*
* Sanity checks.
*/
if (src == NULL) {
*error_num = NO_RECOVERY;
return (NULL);
}
switch (af) {
case AF_INET:
if (len != (unsigned int)INADDRSZ) {
*error_num = NO_RECOVERY;
return (NULL);
}
break;
case AF_INET6:
if (len != (unsigned int)IN6ADDRSZ) {
*error_num = NO_RECOVERY;
return (NULL);
}
break;
default:
*error_num = NO_RECOVERY;
return (NULL);
}
/*
* The de-"const"-ing game is done because at least one
* vendor's system (RedHat 6.0) defines the IN6_IS_ADDR_*
* macros in such a way that they discard the const with
* internal casting, and gcc ends up complaining. Rather
* than replacing their own (possibly optimized) definitions
* with our own, cleanly discarding the const is the easiest
* thing to do.
*/
u.konst = src;
/*
* Look up IPv4 and IPv4 mapped/compatible addresses.
*/
if ((af == AF_INET6 && IN6_IS_ADDR_V4COMPAT(u.in6)) ||
(af == AF_INET6 && IN6_IS_ADDR_V4MAPPED(u.in6)) ||
(af == AF_INET)) {
const unsigned char *cp = src;
if (af == AF_INET6)
cp += 12;
n = lwres_context_create(&lwrctx, NULL, NULL, NULL, 0);
if (n == LWRES_R_SUCCESS)
(void) lwres_conf_parse(lwrctx, lwres_resolv_conf);
if (n == LWRES_R_SUCCESS)
n = lwres_getnamebyaddr(lwrctx, LWRES_ADDRTYPE_V4,
INADDRSZ, cp, &by);
if (n != LWRES_R_SUCCESS) {
lwres_conf_clear(lwrctx);
lwres_context_destroy(&lwrctx);
if (n == LWRES_R_NOTFOUND)
*error_num = HOST_NOT_FOUND;
else
*error_num = NO_RECOVERY;
return (NULL);
}
he1 = hostfromaddr(by, AF_INET, cp);
lwres_gnbaresponse_free(lwrctx, &by);
lwres_conf_clear(lwrctx);
lwres_context_destroy(&lwrctx);
if (af != AF_INET6)
return (he1);
/*
* Convert from AF_INET to AF_INET6.
*/
he2 = copyandmerge(he1, NULL, af, error_num);
lwres_freehostent(he1);
if (he2 == NULL)
return (NULL);
/*
* Restore original address.
*/
memcpy(he2->h_addr, src, len);
return (he2);
}
/*
* Lookup IPv6 address.
*/
if (memcmp(src, &in6addr_any, IN6ADDRSZ) == 0) {
*error_num = HOST_NOT_FOUND;
return (NULL);
}
n = lwres_context_create(&lwrctx, NULL, NULL, NULL, 0);
if (n == LWRES_R_SUCCESS)
(void) lwres_conf_parse(lwrctx, lwres_resolv_conf);
if (n == LWRES_R_SUCCESS)
n = lwres_getnamebyaddr(lwrctx, LWRES_ADDRTYPE_V6, IN6ADDRSZ,
src, &by);
if (n != 0) {
lwres_conf_clear(lwrctx);
lwres_context_destroy(&lwrctx);
if (n == LWRES_R_NOTFOUND)
*error_num = HOST_NOT_FOUND;
else
*error_num = NO_RECOVERY;
return (NULL);
}
he1 = hostfromaddr(by, AF_INET6, src);
lwres_gnbaresponse_free(lwrctx, &by);
if (he1 == NULL)
*error_num = NO_RECOVERY;
lwres_conf_clear(lwrctx);
lwres_context_destroy(&lwrctx);
return (he1);
}
struct hostent *
lwres_getipnodebyname(const char *name, int af, int flags, int *error_num) {
int have_v4 = 1, have_v6 = 1;
struct in_addr in4;
struct in6_addr in6;
struct hostent he, *he1 = NULL, *he2 = NULL, *he3 = NULL;
int v4 = 0, v6 = 0;
int tmp_err = 0;
lwres_context_t *lwrctx = NULL;
lwres_gabnresponse_t *by = NULL;
int n;
/*
* If we care about active interfaces then check.
*/
if ((flags & AI_ADDRCONFIG) != 0)
if (scan_interfaces(&have_v4, &have_v6) == -1) {
*error_num = NO_RECOVERY;
return (NULL);
}
/* Check for literal address. */
if ((v4 = lwres_net_pton(AF_INET, name, &in4)) != 1)
v6 = lwres_net_pton(AF_INET6, name, &in6);
/*
* Impossible combination?
*/
if ((af == AF_INET6 && (flags & AI_V4MAPPED) == 0 && v4 == 1) ||
(af == AF_INET && v6 == 1) ||
(have_v4 == 0 && v4 == 1) ||
(have_v6 == 0 && v6 == 1) ||
(have_v4 == 0 && af == AF_INET) ||
(have_v6 == 0 && af == AF_INET6 &&
(((flags & AI_V4MAPPED) != 0 && have_v4) ||
(flags & AI_V4MAPPED) == 0))) {
*error_num = HOST_NOT_FOUND;
return (NULL);
}
/*
* Literal address?
*/
if (v4 == 1 || v6 == 1) {
char *addr_list[2];
char *aliases[1];
char mappedname[sizeof("::ffff:123.123.123.123")];
union {
const char *const_name;
char *deconst_name;
} u;
u.const_name = name;
if (v4 == 1 && af == AF_INET6) {
strcpy(mappedname, "::ffff:");
lwres_net_ntop(AF_INET, (char *)&in4,
mappedname + sizeof("::ffff:") - 1,
sizeof(mappedname) - sizeof("::ffff:")
+ 1);
he.h_name = mappedname;
} else
he.h_name = u.deconst_name;
he.h_addr_list = addr_list;
he.h_addr_list[0] = (v4 == 1) ? (char *)&in4 : (char *)&in6;
he.h_addr_list[1] = NULL;
he.h_aliases = aliases;
he.h_aliases[0] = NULL;
he.h_length = (v4 == 1) ? INADDRSZ : IN6ADDRSZ;
he.h_addrtype = (v4 == 1) ? AF_INET : AF_INET6;
return (copyandmerge(&he, NULL, af, error_num));
}
n = lwres_context_create(&lwrctx, NULL, NULL, NULL, 0);
if (n != 0) {
*error_num = NO_RECOVERY;
goto cleanup;
}
(void) lwres_conf_parse(lwrctx, lwres_resolv_conf);
tmp_err = NO_RECOVERY;
if (have_v6 && af == AF_INET6) {
n = lwres_getaddrsbyname(lwrctx, name, LWRES_ADDRTYPE_V6, &by);
if (n == 0) {
he1 = hostfromname(by, AF_INET6);
lwres_gabnresponse_free(lwrctx, &by);
if (he1 == NULL) {
*error_num = NO_RECOVERY;
goto cleanup;
}
} else {
if (n == LWRES_R_NOTFOUND)
tmp_err = HOST_NOT_FOUND;
else {
*error_num = NO_RECOVERY;
goto cleanup;
}
}
}
if (have_v4 &&
((af == AF_INET) ||
(af == AF_INET6 && (flags & AI_V4MAPPED) != 0 &&
(he1 == NULL || (flags & AI_ALL) != 0)))) {
n = lwres_getaddrsbyname(lwrctx, name, LWRES_ADDRTYPE_V4, &by);
if (n == 0) {
he2 = hostfromname(by, AF_INET);
lwres_gabnresponse_free(lwrctx, &by);
if (he2 == NULL) {
*error_num = NO_RECOVERY;
goto cleanup;
}
} else if (he1 == NULL) {
if (n == LWRES_R_NOTFOUND)
*error_num = HOST_NOT_FOUND;
else
*error_num = NO_RECOVERY;
goto cleanup;
}
} else
*error_num = tmp_err;
he3 = copyandmerge(he1, he2, af, error_num);
cleanup:
if (he1 != NULL)
lwres_freehostent(he1);
if (he2 != NULL)
lwres_freehostent(he2);
if (lwrctx != NULL) {
lwres_conf_clear(lwrctx);
lwres_context_destroy(&lwrctx);
}
return (he3);
}
