store criu version

- If version != NULL criu_version_ok() stores the detected criu version in
  version. Allocates memory for version which must be freed by caller.
- If version == NULL criu_version_ok() will return true when the version
  matches, false in all other cases.

Signed-off-by: Christian Brauner <cbrauner@suse.de>

diff --git a/src/lxc/criu.c b/src/lxc/criu.c
index a1b7d407bce91a7a0f9506eddceafa6642777415..838432f6fd8db1e523eddafb79c4adbed198e505 100644 (file)
--- a/src/lxc/criu.c
+++ b/src/lxc/criu.c
@@ -402,8 +402,11 @@ err:
  *
  * The intent is that when criu development slows down, we can drop this, but
  * for now we shouldn't attempt to c/r with versions that we know won't work.
+ *
+ * Note: If version != NULL criu_version() stores the detected criu version in
+ * version. Allocates memory for version which must be freed by caller.
  */
-static bool criu_version_ok()
+static bool criu_version_ok(char **version)
 {
        int pipes[2];
        pid_t pid;
@@ -436,7 +439,7 @@ static bool criu_version_ok()
                exit(1);
        } else {
                FILE *f;
-               char version[1024];
+               char *tmp;
                int patch;
 
                close(pipes[1]);
@@ -452,16 +455,22 @@ static bool criu_version_ok()
                        return false;
                }
 
-               if (fscanf(f, "Version: %1023[^\n]s", version) != 1)
+               tmp = malloc(1024);
+               if (!tmp) {
+                       fclose(f);
+                       return false;
+               }
+
+               if (fscanf(f, "Version: %1023[^\n]s", tmp) != 1)
                        goto version_error;
 
                if (fgetc(f) != '\n')
                        goto version_error;
 
-               if (strcmp(version, CRIU_VERSION) >= 0)
+               if (strcmp(tmp, CRIU_VERSION) >= 0)
                        goto version_match;
 
-               if (fscanf(f, "GitID: v%1023[^-]s", version) != 1)
+               if (fscanf(f, "GitID: v%1023[^-]s", tmp) != 1)
                        goto version_error;
 
                if (fgetc(f) != '-')
@@ -470,7 +479,7 @@ static bool criu_version_ok()
                if (fscanf(f, "%d", &patch) != 1)
                        goto version_error;
 
-               if (strcmp(version, CRIU_GITID_VERSION) < 0)
+               if (strcmp(tmp, CRIU_GITID_VERSION) < 0)
                        goto version_error;
 
                if (patch < CRIU_GITID_PATCHLEVEL)
@@ -478,10 +487,15 @@ static bool criu_version_ok()
 
 version_match:
                fclose(f);
+               if (!version)
+                       free(tmp);
+               else
+                       *version = tmp;
                return true;
 
 version_error:
                fclose(f);
+               free(tmp);
                ERROR("must have criu " CRIU_VERSION " or greater to checkpoint/restore\n");
                return false;
        }
@@ -493,7 +507,7 @@ static bool criu_ok(struct lxc_container *c)
 {
        struct lxc_list *it;
 
-       if (!criu_version_ok())
+       if (!criu_version_ok(NULL))
                return false;
 
        if (geteuid()) {