confile: make lxc_get_config() and lxc_get_config_net() always return non-NULL

Introduce the concept of an unsupported config item.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/lxc/commands.c b/src/lxc/commands.c
index 37e2282e80da944311b35558d53bc06472024f7b..08f4dea86ba4f183ac353fc42b42a1dc232625e4 100644 (file)
--- a/src/lxc/commands.c
+++ b/src/lxc/commands.c
@@ -1005,9 +1005,6 @@ static int lxc_cmd_get_config_item_callback(int fd, struct lxc_cmd_req *req,
 
        memset(&rsp, 0, sizeof(rsp));
        item = lxc_get_config(req->data);
-       if (!item)
-               goto err1;
-
        cilen = item->get(req->data, NULL, 0, handler->conf, NULL);
        if (cilen <= 0)
                goto err1;

diff --git a/src/lxc/confile.c b/src/lxc/confile.c
index ed470f9b8772c8ca784f75ba87b47eebb6b54a6b..baa691245b4e45623ddd50624c92e4af91509b95 100644 (file)
--- a/src/lxc/confile.c
+++ b/src/lxc/confile.c
@@ -82,6 +82,7 @@ lxc_config_define(console_logfile);
 lxc_config_define(console_path);
 lxc_config_define(console_rotate);
 lxc_config_define(console_size);
+lxc_config_define(unsupported_key);
 lxc_config_define(environment);
 lxc_config_define(ephemeral);
 lxc_config_define(execute_cmd);
@@ -158,6 +159,24 @@ lxc_config_define(uts_name);
 lxc_config_define(sysctl);
 lxc_config_define(proc);
 
+static int set_config_unsupported_key(const char *key, const char *value,
+                                     struct lxc_conf *lxc_conf, void *data)
+{
+       return syserror_set(-EINVAL, "Unsupported config key \"%s\"", key);
+}
+
+static int get_config_unsupported_key(const char *key, char *retv, int inlen,
+                                     struct lxc_conf *c, void *data)
+{
+       return syserror_set(-EINVAL, "Unsupported config key \"%s\"", key);
+}
+
+static int clr_config_unsupported_key(const char *key,
+                                     struct lxc_conf *lxc_conf, void *data)
+{
+       return syserror_set(-EINVAL, "Unsupported config key \"%s\"", key);
+}
+
 /*
  * Important Note:
  * If a new config option is added to this table, be aware that
@@ -257,6 +276,14 @@ static struct lxc_config_t config_jump_table[] = {
        { "lxc.proc",                       false, set_config_proc,                       get_config_proc,                       clr_config_proc,                       },
 };
 
+static struct lxc_config_t unsupported_config_key = {
+       NULL,
+       false,
+       set_config_unsupported_key,
+       get_config_unsupported_key,
+       clr_config_unsupported_key,
+};
+
 struct lxc_config_net_t {
        LXC_CONFIG_MEMBERS;
 };
@@ -289,6 +316,14 @@ static struct lxc_config_net_t config_jump_table_net[] = {
        { "veth.vlan.tagged.id",    true,  set_config_net_veth_vlan_tagged_id,    get_config_net_veth_vlan_tagged_id,    clr_config_net_veth_vlan_tagged_id,    },
 };
 
+static struct lxc_config_net_t unsupported_config_net_key = {
+       NULL,
+       false,
+       set_config_unsupported_key,
+       get_config_unsupported_key,
+       clr_config_unsupported_key,
+};
+
 struct lxc_config_t *lxc_get_config_exact(const char *key)
 {
        size_t i;
@@ -327,13 +362,13 @@ struct lxc_config_t *lxc_get_config(const char *key)
                case 0:
                        continue;
                case -E2BIG:
-                       return NULL;
+                       return &unsupported_config_key;
                }
 
                return cur;
        }
 
-       return NULL;
+       return &unsupported_config_key;
 }
 
 static inline bool match_config_net_item(const struct lxc_config_net_t *entry,
@@ -355,7 +390,7 @@ static struct lxc_config_net_t *lxc_get_config_net(const char *key)
                return cur;
        }
 
-       return NULL;
+       return &unsupported_config_net_key;
 }
 
 static int set_config_net(const char *key, const char *value,
@@ -3037,9 +3072,6 @@ static int parse_line(char *buffer, void *data)
        }
 
        config = lxc_get_config(key);
-       if (!config)
-               return log_error_errno(-EINVAL, EINVAL, "Unknown configuration key \"%s\"", key);
-
        return config->set(key, value, plc->conf, NULL);
 }
 
@@ -5363,7 +5395,7 @@ static int get_network_config_ops(const char *key, struct lxc_conf *lxc_conf,
 
        /* lxc.net.<idx>.<subkey> */
        info->ops = lxc_get_config_net(info->subkey);
-       if (!info->ops)
+       if (info->ops == &unsupported_config_net_key)
                return syserror_set(-ENOENT, "Unknown network configuration key \"%s\"", key);
 
        return 0;

diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
index ec54a96eb03061fc8698e3d1f901acb79cdf9bd0..58c24d3934142e51e7602ef31aef7008d3ac89d6 100644 (file)
--- a/src/lxc/lxccontainer.c
+++ b/src/lxc/lxccontainer.c
@@ -2230,12 +2230,8 @@ static bool do_lxcapi_clear_config_item(struct lxc_container *c,
                return false;
 
        config = lxc_get_config(key);
-       /* Verify that the config key exists and that it has a callback
-        * implemented.
-        */
-       if (config && config->clr)
-               ret = config->clr(key, c->lxc_conf, NULL);
 
+       ret = config->clr(key, c->lxc_conf, NULL);
        if (!ret)
                do_clear_unexp_config_line(c->lxc_conf, key);
 
@@ -2571,11 +2567,8 @@ static int do_lxcapi_get_config_item(struct lxc_container *c, const char *key, c
                return -1;
 
        config = lxc_get_config(key);
-       /* Verify that the config key exists and that it has a callback
-        * implemented.
-        */
-       if (config && config->get)
-               ret = config->get(key, retv, inlen, c->lxc_conf, NULL);
+
+       ret = config->get(key, retv, inlen, c->lxc_conf, NULL);
 
        container_mem_unlock(c);
        return ret;
@@ -3138,8 +3131,6 @@ int lxc_set_config_item_locked(struct lxc_conf *conf, const char *key,
        bool bret = true;
 
        config = lxc_get_config(key);
-       if (!config)
-               return -EINVAL;
 
        ret = config->set(key, v, conf, NULL);
        if (ret < 0)