chiark / gitweb /
Use space after a silencing (void)
[elogind.git] / src / nss-myhostname / nss-myhostname.c
index 23646e6e8a6c68924f27a35da9856c639af688da..fed76c62e72f1ce2e915c556e4ff60991d9782bd 100644 (file)
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
-#include <limits.h>
 #include <nss.h>
-#include <sys/types.h>
 #include <netdb.h>
 #include <errno.h>
 #include <string.h>
-#include <unistd.h>
 #include <net/if.h>
 #include <stdlib.h>
-#include <arpa/inet.h>
 
 #include "local-addresses.h"
 #include "macro.h"
 #include "nss-util.h"
 #include "util.h"
 
-/* Ensure that glibc's assert is used. We cannot use assert from macro.h, as
- * libnss_myhostname will be linked into arbitrary programs which will, in turn
- * attempt to write to the journal via log_dispatch() */
-#include <assert.h>
-
 /* We use 127.0.0.2 as IPv4 address. This has the advantage over
  * 127.0.0.1 that it can be translated back to the local hostname. For
  * IPv6 we use ::1 which unfortunately will not translate back to the
- * hostname but instead something like "localhost6" or so. */
+ * hostname but instead something like "localhost" or so. */
 
 #define LOCALADDRESS_IPV4 (htonl(0x7F000002))
 #define LOCALADDRESS_IPV6 &in6addr_loopback
 NSS_GETHOSTBYNAME_PROTOTYPES(myhostname);
 NSS_GETHOSTBYADDR_PROTOTYPES(myhostname);
 
+static bool is_gateway(const char *hostname) {
+        assert(hostname);
+
+        return streq(hostname, "gateway") ||
+               streq(hostname, "gateway.");
+}
+
 enum nss_status _nss_myhostname_gethostbyname4_r(
                 const char *name,
                 struct gaih_addrtuple **pat,
@@ -82,6 +80,18 @@ enum nss_status _nss_myhostname_gethostbyname4_r(
 
                 canonical = "localhost";
                 local_address_ipv4 = htonl(INADDR_LOOPBACK);
+
+        } else if (is_gateway(name)) {
+
+                n_addresses = local_gateways(NULL, 0, AF_UNSPEC, &addresses);
+                if (n_addresses <= 0) {
+                        *errnop = ENOENT;
+                        *h_errnop = HOST_NOT_FOUND;
+                        return NSS_STATUS_NOTFOUND;
+                }
+
+                canonical = "gateway";
+
         } else {
                 hn = gethostname_malloc();
                 if (!hn) {
@@ -97,7 +107,7 @@ enum nss_status _nss_myhostname_gethostbyname4_r(
                         return NSS_STATUS_NOTFOUND;
                 }
 
-                n_addresses = local_addresses(&addresses);
+                n_addresses = local_addresses(NULL, 0, AF_UNSPEC, &addresses);
                 if (n_addresses < 0)
                         n_addresses = 0;
 
@@ -170,6 +180,11 @@ enum nss_status _nss_myhostname_gethostbyname4_r(
         if (ttlp)
                 *ttlp = 0;
 
+        /* Explicitly reset all error variables */
+        *errnop = 0;
+        *h_errnop = NETDB_SUCCESS;
+        h_errno = 0;
+
         return NSS_STATUS_SUCCESS;
 }
 
@@ -195,7 +210,7 @@ static enum nss_status fill_in_hostent(
         assert(errnop);
         assert(h_errnop);
 
-        alen = PROTO_ADDRESS_SIZE(af);
+        alen = FAMILY_ADDRESS_SIZE(af);
 
         for (a = addresses, n = 0, c = 0; n < n_addresses; a++, n++)
                 if (af == a->family)
@@ -294,6 +309,11 @@ static enum nss_status fill_in_hostent(
         if (canonp)
                 *canonp = r_name;
 
+        /* Explicitly reset all error variables */
+        *errnop = 0;
+        *h_errnop = NETDB_SUCCESS;
+        h_errno = 0;
+
         return NSS_STATUS_SUCCESS;
 }
 
@@ -309,7 +329,7 @@ enum nss_status _nss_myhostname_gethostbyname3_r(
         _cleanup_free_ struct local_address *addresses = NULL;
         const char *canonical, *additional = NULL;
         _cleanup_free_ char *hn = NULL;
-        uint32_t local_address_ipv4;
+        uint32_t local_address_ipv4 = 0;
         int n_addresses = 0;
 
         assert(name);
@@ -330,6 +350,18 @@ enum nss_status _nss_myhostname_gethostbyname3_r(
         if (is_localhost(name)) {
                 canonical = "localhost";
                 local_address_ipv4 = htonl(INADDR_LOOPBACK);
+
+        } else if (is_gateway(name)) {
+
+                n_addresses = local_gateways(NULL, 0, af, &addresses);
+                if (n_addresses <= 0) {
+                        *errnop = ENOENT;
+                        *h_errnop = HOST_NOT_FOUND;
+                        return NSS_STATUS_NOTFOUND;
+                }
+
+                canonical = "gateway";
+
         } else {
                 hn = gethostname_malloc();
                 if (!hn) {
@@ -344,7 +376,7 @@ enum nss_status _nss_myhostname_gethostbyname3_r(
                         return NSS_STATUS_NOTFOUND;
                 }
 
-                n_addresses = local_addresses(&addresses);
+                n_addresses = local_addresses(NULL, 0, af, &addresses);
                 if (n_addresses < 0)
                         n_addresses = 0;
 
@@ -379,6 +411,7 @@ enum nss_status _nss_myhostname_gethostbyaddr2_r(
         _cleanup_free_ char *hn = NULL;
         int n_addresses = 0;
         struct local_address *a;
+        bool additional_from_hostname = false;
         unsigned n;
 
         assert(addr);
@@ -387,14 +420,19 @@ enum nss_status _nss_myhostname_gethostbyaddr2_r(
         assert(errnop);
         assert(h_errnop);
 
-        if (len != PROTO_ADDRESS_SIZE(af)) {
+        if (!IN_SET(af, AF_INET, AF_INET6)) {
+                *errnop = EAFNOSUPPORT;
+                *h_errnop = NO_DATA;
+                return NSS_STATUS_UNAVAIL;
+        }
+
+        if (len != FAMILY_ADDRESS_SIZE(af)) {
                 *errnop = EINVAL;
                 *h_errnop = NO_RECOVERY;
                 return NSS_STATUS_UNAVAIL;
         }
 
         if (af == AF_INET) {
-
                 if ((*(uint32_t*) addr) == LOCALADDRESS_IPV4)
                         goto found;
 
@@ -404,29 +442,41 @@ enum nss_status _nss_myhostname_gethostbyaddr2_r(
                         goto found;
                 }
 
-        } else if (af == AF_INET6) {
+        } else {
+                assert(af == AF_INET6);
 
                 if (memcmp(addr, LOCALADDRESS_IPV6, 16) == 0) {
-                        additional = "localhost";
+                        canonical = "localhost";
+                        additional_from_hostname = true;
                         goto found;
                 }
+        }
 
-        } else {
-                *errnop = EAFNOSUPPORT;
-                *h_errnop = NO_DATA;
-                return NSS_STATUS_UNAVAIL;
+        n_addresses = local_addresses(NULL, 0, AF_UNSPEC, &addresses);
+        if (n_addresses > 0) {
+                for (a = addresses, n = 0; (int) n < n_addresses; n++, a++) {
+                        if (af != a->family)
+                                continue;
+
+                        if (memcmp(addr, &a->address, FAMILY_ADDRESS_SIZE(af)) == 0)
+                                goto found;
+                }
         }
 
-        n_addresses = local_addresses(&addresses);
-        if (n_addresses < 0)
-                n_addresses = 0;
+        free(addresses);
+        addresses = NULL;
 
-        for (a = addresses, n = 0; (int) n < n_addresses; n++, a++) {
-                if (af != a->family)
-                        continue;
+        n_addresses = local_gateways(NULL, 0, AF_UNSPEC, &addresses);
+        if (n_addresses > 0) {
+                for (a = addresses, n = 0; (int) n < n_addresses; n++, a++) {
+                        if (af != a->family)
+                                continue;
 
-                if (memcmp(addr, &a->address, PROTO_ADDRESS_SIZE(af)) == 0)
-                        goto found;
+                        if (memcmp(addr, &a->address, FAMILY_ADDRESS_SIZE(af)) == 0) {
+                                canonical = "gateway";
+                                goto found;
+                        }
+                }
         }
 
         *errnop = ENOENT;
@@ -435,7 +485,7 @@ enum nss_status _nss_myhostname_gethostbyaddr2_r(
         return NSS_STATUS_NOTFOUND;
 
 found:
-        if (!canonical) {
+        if (!canonical || (!additional && additional_from_hostname)) {
                 hn = gethostname_malloc();
                 if (!hn) {
                         *errnop = ENOMEM;
@@ -443,7 +493,11 @@ found:
                         return NSS_STATUS_TRYAGAIN;
                 }
 
-                canonical = hn;
+                if (!canonical)
+                        canonical = hn;
+
+                if (!additional && additional_from_hostname)
+                        additional = hn;
         }
 
         return fill_in_hostent(
@@ -456,7 +510,6 @@ found:
                         errnop, h_errnop,
                         ttlp,
                         NULL);
-
 }
 
 NSS_GETHOSTBYNAME_FALLBACKS(myhostname);