* isys/nl.c (netlink_init_interfaces_list): Fix RTM_GETLINK message

        reassembly.  Also, make sure we read the entire interface name rather
        than just the first four characters.  Use BUFSZ macro throughout code.
        Fixes numerous problems, including the missing HWADDR line (#234764)
        * isys/nl.h: Define BUFSZ.
        * isys/isys.c: Looks like I fixed some whitespace.

3 files changed, 38 insertions, 30 deletions

diff --git a/isys/isys.c b/isys/isys.c
index 9b6549d3f..07dcba192 100644
--- a/isys/isys.c
+++ b/isys/isys.c
@@ -1104,7 +1104,7 @@ static PyObject * doGetMacAddress(PyObject * s, PyObject * args) {
     char *ret;
 
     if (!PyArg_ParseTuple(args, "s", &dev))
-	return NULL;
+        return NULL;
 
     ret = netlink_interfaces_mac2str(dev);
 
diff --git a/isys/nl.c b/isys/nl.c
index 9fc8bb71d..c96893287 100644
--- a/isys/nl.c
+++ b/isys/nl.c
@@ -127,7 +127,7 @@ int netlink_create_socket(void) {
  */
 int netlink_send_dump_request(int sock, int type, int family) {
     int ret;
-    char buf[4096];
+    char buf[BUFSZ];
     struct sockaddr_nl snl;
     struct nlmsghdr *nlh;
     struct rtgenmsg *g;
@@ -164,7 +164,7 @@ int netlink_send_dump_request(int sock, int type, int family) {
  */
 int netlink_get_interface_ip(int index, int family, void *addr) {
     int sock, ret, len, alen;
-    char buf[4096];
+    char buf[BUFSZ];
     struct nlmsghdr *nlh;
     struct ifaddrmsg *ifa;
     struct rtattr *rta;
@@ -257,8 +257,7 @@ int netlink_get_interface_ip(int index, int family, void *addr) {
  * @return 0 on succes, -1 on error.
  */
 int netlink_init_interfaces_list(void) {
-    int sock, ret, len, alen, r;
-    char chunk[4096];
+    int sock, len, alen, r, bufsz, havemsg, namelen;
     char *buf = NULL;
     struct nlmsghdr *nlh;
     struct ifinfomsg *ifi;
@@ -285,46 +284,43 @@ int netlink_init_interfaces_list(void) {
     }
 
     /* read back messages */
-    if ((buf = calloc(4096, sizeof(char))) == NULL) {
-        perror("malloc on buf in netlink_init_interfaces_list");
+    if ((buf = calloc(BUFSZ, sizeof(char))) == NULL) {
+        perror("calloc on 1st buf in netlink_init_interfaces_list");
         close(sock);
         return -1;
     }
 
-    ret = recvfrom(sock, chunk, sizeof(chunk), MSG_DONTWAIT, NULL, 0);
-    if (ret < 0) {
-        perror("recvfrom in netlink_init_interfaces_list");
-        close(sock);
-        return -1;
-    } else {
-        buf = strncat(buf, chunk, strlen(chunk));
-    }
+    havemsg = 0;
+    while (!havemsg) {
+        bufsz = recvfrom(sock, buf, BUFSZ, 0, NULL, 0);
 
-    /* read remaining part of message */
-    while (ret != -1) {
-        ret = recvfrom(sock, chunk, sizeof(chunk), MSG_DONTWAIT, NULL, 0);
+        if (bufsz < 0) {
+            perror("recvfrom in netlink_init_interfaces_list");
+            close(sock);
+            return -1;
+        } else if (bufsz > BUFSZ) {
+            free(buf);
+            buf = NULL;
 
-        if (ret > 0) {
-            buf = realloc(buf, strlen(buf) + ret + 1);
-            if (buf == NULL) {
-                perror("realloc on buf in netlink_init_interfaces_list");
+            if ((buf = calloc(bufsz, sizeof(char))) == NULL) {
+                perror("calloc on 2nd buf in netlink_init_interfaces_list");
                 close(sock);
                 return -1;
             }
-
-            buf = strncat(buf, chunk, strlen(chunk));
+        } else  {
+            havemsg = 1;
         }
     }
 
     nlh = (struct nlmsghdr *) buf;
-    while (NLMSG_OK(nlh, ret)) {
+    while (NLMSG_OK(nlh, bufsz)) {
         switch (nlh->nlmsg_type) {
             case NLMSG_DONE:
                 break;
             case RTM_NEWLINK:
                 break;
             default:
-                nlh = NLMSG_NEXT(nlh, ret);
+                nlh = NLMSG_NEXT(nlh, bufsz);
                 continue;
         }
 
@@ -338,13 +334,21 @@ int netlink_init_interfaces_list(void) {
 
         /* we only do things with ethernet mac addrs, so ... */
         if (ifi->ifi_type != ARPHRD_ETHER) {
-            nlh = NLMSG_NEXT(nlh, ret);
+            nlh = NLMSG_NEXT(nlh, bufsz);
             continue;
         }
 
+        namelen = 0;
+
         while (RTA_OK(rta, len)) {
-            if (rta->rta_type <= len)
+            if (rta->rta_type <= len) {
+                if (rta->rta_type == IFLA_IFNAME) {
+                   namelen = rta->rta_len;
+                }
+
                 tb[rta->rta_type] = rta;
+            }
+
             rta = RTA_NEXT(rta, len);
         }
 
@@ -365,7 +369,7 @@ int netlink_init_interfaces_list(void) {
 
             /* copy the interface name (eth0, eth1, ...) */
             intfinfo->name = strndup((char *) RTA_DATA(tb[IFLA_IFNAME]),
-                                             sizeof(RTA_DATA(tb[IFLA_IFNAME])));
+                                     namelen);
 
             /* copy the MAC addr */
             memcpy(&intfinfo->mac, RTA_DATA(tb[IFLA_ADDRESS]), alen);
@@ -390,7 +394,7 @@ int netlink_init_interfaces_list(void) {
         }
 
         /* next netlink msg */
-        nlh = NLMSG_NEXT(nlh, ret);
+        nlh = NLMSG_NEXT(nlh, bufsz);
     }
 
     close(sock);
@@ -491,6 +495,7 @@ void netlink_interfaces_list_free(void) {
     g_slist_foreach(interfaces, &_netlink_interfaces_elem_free, NULL);
     g_slist_free(interfaces);
     interfaces = NULL;
+    return;
 }
 
 /**
@@ -501,6 +506,7 @@ void netlink_interfaces_list_free(void) {
  */
 void _netlink_interfaces_elem_free(gpointer data, gpointer user_data) {
     free(data);
+    data = NULL;
     return;
 }
 
diff --git a/isys/nl.h b/isys/nl.h
index 72c8bd11a..55861179c 100644
--- a/isys/nl.h
+++ b/isys/nl.h
@@ -16,6 +16,8 @@
 #include <netinet/in.h>
 #include <glib.h>
 
+#define BUFSZ 4096
+
 /* Information per interface */
 typedef struct _interface_info_t {
    int i;                            /* interface index        */