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rtnl: when querying local addresses and gateways, take address family into account
[elogind.git] / src / nss-myhostname / nss-myhostname.c
diff --git a/src/nss-myhostname/nss-myhostname.c b/src/nss-myhostname/nss-myhostname.c
index 06bd842fc61bfd70b7b9dc225af8f2ae604b5aec..aa92cc96e4a1d46f772f85c3ee4012be20b15b1c 100644 (file)
--- a/src/nss-myhostname/nss-myhostname.c
+++ b/src/nss-myhostname/nss-myhostname.c
@@ -35,11 +35,6 @@
 #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
@@ -82,6 +77,18 @@ enum nss_status _nss_myhostname_gethostbyname4_r(
 
                 canonical = "localhost";
                 local_address_ipv4 = htonl(INADDR_LOOPBACK);
+
+        } else if (streq(name, "gateway")) {
+
+                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 +104,7 @@ 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 +177,11 @@ 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;
 }
 
@@ -184,9 +196,8 @@ static enum nss_status fill_in_hostent(
                 int32_t *ttlp,
                 char **canonp) {
 
-        size_t l_canonical, l_additional, idx, ms;
+        size_t l_canonical, l_additional, idx, ms, alen;
         char *r_addr, *r_name, *r_aliases, *r_alias = NULL, *r_addr_list;
-        size_t alen;
         struct local_address *a;
         unsigned n, c;
 
@@ -196,7 +207,7 @@ 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)
@@ -208,7 +219,7 @@ static enum nss_status fill_in_hostent(
                 (additional ? ALIGN(l_additional+1) : 0) +
                 sizeof(char*) +
                 (additional ? sizeof(char*) : 0) +
-                (c > 0 ? c : 1) * ALIGN(alen)+
+                (c > 0 ? c : 1) * ALIGN(alen) +
                 (c > 0 ? c+1 : 2) * sizeof(char*);
 
         if (buflen < ms) {
@@ -266,24 +277,18 @@ static enum nss_status fill_in_hostent(
         /* Fourth, add address pointer array */
         r_addr_list = buffer + idx;
         if (c > 0) {
-                unsigned i = 0;
+                unsigned i;
 
-                for (a = addresses, n = 0; n < n_addresses; a++, n++) {
-                        if (af != a->family)
-                                continue;
+                for (i = 0; i < c; i++)
+                        ((char**) r_addr_list)[i] = r_addr + i*ALIGN(alen);
 
-                        ((char**) r_addr_list)[i] = (r_addr + i*ALIGN(alen));
-                        i++;
-                }
-
-                assert(i == c);
-                ((char**) r_addr_list)[c] = NULL;
-                idx += (c+1)*sizeof(char*);
+                ((char**) r_addr_list)[i] = NULL;
+                idx += (c+1) * sizeof(char*);
 
         } else {
                 ((char**) r_addr_list)[0] = r_addr;
                 ((char**) r_addr_list)[1] = NULL;
-                idx += 2*sizeof(char*);
+                idx += 2 * sizeof(char*);
         }
 
         /* Verify the size matches */
@@ -301,6 +306,11 @@ 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;
 }
 
@@ -316,7 +326,7 @@ 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);
@@ -337,6 +347,18 @@ enum nss_status _nss_myhostname_gethostbyname3_r(
         if (is_localhost(name)) {
                 canonical = "localhost";
                 local_address_ipv4 = htonl(INADDR_LOOPBACK);
+
+        } else if (streq(name, "gateway")) {
+
+                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) {
@@ -351,7 +373,7 @@ 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;
 
@@ -394,7 +416,13 @@ 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;
@@ -411,29 +439,52 @@ 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";
                         goto found;
                 }
 
-        } else {
-                *errnop = EAFNOSUPPORT;
-                *h_errnop = NO_DATA;
-                return NSS_STATUS_UNAVAIL;
         }
 
-        n_addresses = local_addresses(&addresses);
-        if (n_addresses < 0)
-                n_addresses = 0;
+        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;
 
-        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) {
 
-                if (memcmp(addr, &a->address, PROTO_ADDRESS_SIZE(af)) == 0)
-                        goto found;
+                                hn = gethostname_malloc();
+                                if (!hn) {
+                                        *errnop = ENOMEM;
+                                        *h_errnop = NO_RECOVERY;
+                                        return NSS_STATUS_TRYAGAIN;
+                                }
+
+                                canonical = hn;
+                                goto found;
+                        }
+                }
+        }
+
+        free(addresses);
+        addresses = NULL;
+
+        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, FAMILY_ADDRESS_SIZE(af)) == 0) {
+
+                                canonical = "gateway";
+                                goto found;
+                        }
+                }
         }
 
         *errnop = ENOENT;
@@ -442,16 +493,6 @@ enum nss_status _nss_myhostname_gethostbyaddr2_r(
         return NSS_STATUS_NOTFOUND;
 
 found:
-        if (!canonical) {
-                hn = gethostname_malloc();
-                if (!hn) {
-                        *errnop = ENOMEM;
-                        *h_errnop = NO_RECOVERY;
-                        return NSS_STATUS_TRYAGAIN;
-                }
-
-                canonical = hn;
-        }
 
         return fill_in_hostent(
                         canonical, additional,
Unnamed repository; edit this file 'description' to name the repository.