confile_legacy: fix lxc_clear_nic error

`lxc_clear_nic` can not clear the nic, because it will not found
the right `netdev`.

testcase from get_item.c

```
313         if (!c->set_config_item(c, "lxc.network.hwaddr", "00:16:3e:xx:xx:xx")) {
314                 fprintf(stderr, "%d: failed to set network.hwaddr\n", __LINE__);
315                 goto out;
316         }
317         if (!c->set_config_item(c, "lxc.network.ipv4", "10.2.3.4")) {
318                 fprintf(stderr, "%d: failed to set ipv4\n", __LINE__);
319                 goto out;
320         }
321
322         ret = c->get_config_item(c, "lxc.network.0.ipv4", v2, 255);
323         if (ret <= 0) {
324                 fprintf(stderr, "%d: lxc.network.0.ipv4 returned %d\n", __LINE__, ret);
325                 goto out;
326         }
327         if (!c->clear_config_item(c, "lxc.network.0.ipv4")) {
328                 fprintf(stderr, "%d: failed clearing all ipv4 entries\n", __LINE__);
329                 goto out;
330         }
331         ret = c->get_config_item(c, "lxc.network.0.ipv4", v2, 255);
332         if (ret != 0) {
333                 fprintf(stderr, "%d: after clearing ipv4 entries get_item(lxc.network.0.ipv4 returned %d\n", __LINE__, ret);
334                 goto out;
335         }
```

line `327` will failed to clear nic, and line `333` give the error.

Signed-off-by: 0x0916 <w@laoqinren.net>

diff --git a/src/lxc/confile_legacy.c b/src/lxc/confile_legacy.c
index bb5c63c52740f59a616249b396271969cd560770..ba8bfe6cedfb85efebe9616990c712c6c4697090 100644 (file)
--- a/src/lxc/confile_legacy.c
+++ b/src/lxc/confile_legacy.c
@@ -945,34 +945,33 @@ int get_config_network_legacy_item(const char *key, char *retv, int inlen,
 static int lxc_clear_nic(struct lxc_conf *c, const char *key)
 {
        char *p1;
-       int ret, idx, i;
-       struct lxc_list *it;
-       struct lxc_netdev *netdev;
-
-       p1 = strchr(key, '.');
-       if (!p1 || *(p1+1) == '\0')
-               p1 = NULL;
+       int idx;
+       struct lxc_list *it = NULL;
+       struct lxc_netdev *netdev = NULL;
 
-       ret = sscanf(key, "%d", &idx);
-       if (ret != 1) return -1;
-       if (idx < 0)
+       if (lxc_list_empty(&c->network)) {
+               ERROR("network is not created for %s", key);
                return -1;
-
-       i = 0;
-       lxc_list_for_each(it, &c->network) {
-               if (i == idx)
-                       break;
-               i++;
        }
-       if (i < idx)  // we don't have that many nics defined
-               return -1;
 
-       if (!it || !it->elem)
+       if ((idx = get_network_netdev_idx(key)) == EINVAL)
+               netdev = lxc_list_last_elem(&c->network);
+       else {
+               lxc_list_for_each(it, &c->network) {
+                       netdev = it->elem;
+                       if (idx == netdev->idx)
+                               break;
+                       netdev = NULL;
+               }
+       }
+       if (!netdev)
                return -1;
 
-       netdev = it->elem;
+       p1 = strchr(key, '.');
+       if (!p1 || *(p1+1) == '\0')
+               p1 = NULL;
 
-       if (!p1) {
+       if (!p1 && it) {
                lxc_remove_nic(it);
        } else if (strcmp(p1, ".ipv4") == 0) {
                struct lxc_list *it2,*next;
@@ -989,7 +988,7 @@ static int lxc_clear_nic(struct lxc_conf *c, const char *key)
                        free(it2);
                }
        }
-               else return -1;
+       else return -1;
 
        return 0;
 }