c/r: factor out network dump/restore code

Break the monolithic ->checkpoint and ->restore functions into smaller ones.
This is in preparation for the checkpoint/restore tty work, which has a similar
need to dump information outside of criu.

Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
index 1f1f9ea904a80698b158ce03fd84c62fd3b1bd97..c4cb0ab3c3cf9ead2f3e4fd4f298e736f85adaa0 100644 (file)
--- a/src/lxc/lxccontainer.c
+++ b/src/lxc/lxccontainer.c
@@ -3746,30 +3746,21 @@ static bool criu_ok(struct lxc_container *c)
        return true;
 }
 
-static bool lxcapi_checkpoint(struct lxc_container *c, char *directory, bool stop, bool verbose)
+static bool dump_net_info(struct lxc_container *c, char *directory)
 {
-       int netnr, status;
+       int netnr;
        struct lxc_list *it;
-       bool error = false;
-       pid_t pid;
-
-       if (!criu_ok(c))
-               return false;
-
-       if (mkdir(directory, 0700) < 0 && errno != EEXIST)
-               return false;
 
        netnr = 0;
        lxc_list_for_each(it, &c->lxc_conf->network) {
                char *veth = NULL, *bridge = NULL, veth_path[PATH_MAX], eth[128];
                struct lxc_netdev *n = it->elem;
+               bool has_error = true;
                int pret;
 
                pret = snprintf(veth_path, PATH_MAX, "lxc.network.%d.veth.pair", netnr);
-               if (pret < 0 || pret >= PATH_MAX) {
-                       error = true;
+               if (pret < 0 || pret >= PATH_MAX)
                        goto out;
-               }
 
                veth = lxcapi_get_running_config_item(c, veth_path);
                if (!veth) {
@@ -3781,49 +3772,59 @@ static bool lxcapi_checkpoint(struct lxc_container *c, char *directory, bool sto
                }
 
                pret = snprintf(veth_path, PATH_MAX, "lxc.network.%d.link", netnr);
-               if (pret < 0 || pret >= PATH_MAX) {
-                       error = true;
+               if (pret < 0 || pret >= PATH_MAX)
                        goto out;
-               }
 
                bridge = lxcapi_get_running_config_item(c, veth_path);
-               if (!bridge) {
-                       error = true;
+               if (!bridge)
                        goto out;
-               }
 
                pret = snprintf(veth_path, PATH_MAX, "%s/veth%d", directory, netnr);
-               if (pret < 0 || pret >= PATH_MAX || print_to_file(veth_path, veth) < 0) {
-                       error = true;
+               if (pret < 0 || pret >= PATH_MAX || print_to_file(veth_path, veth) < 0)
                        goto out;
-               }
 
                pret = snprintf(veth_path, PATH_MAX, "%s/bridge%d", directory, netnr);
-               if (pret < 0 || pret >= PATH_MAX || print_to_file(veth_path, bridge) < 0) {
-                       error = true;
+               if (pret < 0 || pret >= PATH_MAX || print_to_file(veth_path, bridge) < 0)
                        goto out;
-               }
 
                if (n->name) {
-                       if (strlen(n->name) >= 128) {
-                               error = true;
+                       if (strlen(n->name) >= 128)
                                goto out;
-                       }
                        strncpy(eth, n->name, 128);
                } else
                        sprintf(eth, "eth%d", netnr);
 
                pret = snprintf(veth_path, PATH_MAX, "%s/eth%d", directory, netnr);
                if (pret < 0 || pret >= PATH_MAX || print_to_file(veth_path, eth) < 0)
-                       error = true;
+                       goto out;
 
+               has_error = false;
 out:
-               free(veth);
-               free(bridge);
-               if (error)
+               if (veth)
+                       free(veth);
+               if (bridge);
+                       free(bridge);
+               if (has_error)
                        return false;
        }
 
+       return true;
+}
+
+static bool lxcapi_checkpoint(struct lxc_container *c, char *directory, bool stop, bool verbose)
+{
+       pid_t pid;
+       int status;
+
+       if (!criu_ok(c))
+               return false;
+
+       if (mkdir(directory, 0700) < 0 && errno != EEXIST)
+               return false;
+
+       if (!dump_net_info(c, directory))
+               return false;
+
        pid = fork();
        if (pid < 0)
                return false;
@@ -3855,10 +3856,42 @@ out:
        }
 }
 
+static bool restore_net_info(struct lxc_container *c, char *directory)
+{
+       struct lxc_list *it;
+       bool has_error = true;
+       int netnr = 0;
+
+       if (container_mem_lock(c))
+               return false;
+
+       lxc_list_for_each(it, &c->lxc_conf->network) {
+               char eth[128], veth[128];
+               struct lxc_netdev *netdev = it->elem;
+
+               if (read_criu_file(directory, "veth", netnr, veth))
+                       goto out_unlock;
+
+               if (read_criu_file(directory, "eth", netnr, eth))
+                       goto out_unlock;
+
+               netdev->priv.veth_attr.pair = strdup(veth);
+               if (!netdev->priv.veth_attr.pair)
+                       goto out_unlock;
+
+               netnr++;
+       }
+
+       has_error = false;
+
+out_unlock:
+       container_mem_unlock(c);
+       return !has_error;
+}
+
 static bool lxcapi_restore(struct lxc_container *c, char *directory, bool verbose)
 {
        pid_t pid;
-       struct lxc_list *it;
        struct lxc_rootfs *rootfs;
        char pidfile[L_tmpnam];
        struct lxc_handler *handler;
@@ -3944,7 +3977,7 @@ static bool lxcapi_restore(struct lxc_container *c, char *directory, bool verbos
                                goto out_fini_handler;
                        }
                        else {
-                               int netnr = 0, ret;
+                               int ret;
                                FILE *f = fopen(pidfile, "r");
                                if (!f) {
                                        perror("reading pidfile");
@@ -3959,34 +3992,11 @@ static bool lxcapi_restore(struct lxc_container *c, char *directory, bool verbos
                                        goto out_fini_handler;
                                }
 
-                               if (container_mem_lock(c))
+                               if (!restore_net_info(c, directory)) {
+                                       ERROR("failed restoring network info");
                                        goto out_fini_handler;
-
-                               lxc_list_for_each(it, &c->lxc_conf->network) {
-                                       char eth[128], veth[128];
-                                       struct lxc_netdev *netdev = it->elem;
-
-                                       if (read_criu_file(directory, "veth", netnr, veth)) {
-                                               container_mem_unlock(c);
-                                               goto out_fini_handler;
-                                       }
-
-                                       if (read_criu_file(directory, "eth", netnr, eth)) {
-                                               container_mem_unlock(c);
-                                               goto out_fini_handler;
-                                       }
-
-                                       netdev->priv.veth_attr.pair = strdup(veth);
-                                       if (!netdev->priv.veth_attr.pair) {
-                                               container_mem_unlock(c);
-                                               goto out_fini_handler;
-                                       }
-
-                                       netnr++;
                                }
 
-                               container_mem_unlock(c);
-
                                if (lxc_set_state(c->name, handler, RUNNING))
                                        goto out_fini_handler;
                        }