lxc-user-nic: add new {create,delete} subcommands

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

diff --git a/src/lxc/lxc_user_nic.c b/src/lxc/lxc_user_nic.c
index 2afd6b14a24e16b28ce63601000fad79e659485b..d405191364877bf52942136d09dd4c65c30383fd 100644 (file)
--- a/src/lxc/lxc_user_nic.c
+++ b/src/lxc/lxc_user_nic.c
@@ -59,12 +59,17 @@
 
 static void usage(char *me, bool fail)
 {
-       fprintf(stderr, "Usage: %s lxcpath name pid type bridge nicname\n", me);
-       fprintf(stderr, " nicname is the name to use inside the container\n");
-       exit(fail ? 1 : 0);
-}
+       fprintf(stderr, "Usage: %s create {lxcpath} {name} {pid} {type} "
+                       "{bridge} {nicname}\n", me);
+       fprintf(stderr, "Usage: %s delete {lxcpath} {name} {pid} {type} "
+                       "{bridge} {nicname}\n", me);
+       fprintf(stderr, "{nicname} is the name to use inside the container\n");
+
+       if (fail)
+               exit(EXIT_FAILURE);
 
-static char *lxcpath, *lxcname;
+       exit(EXIT_SUCCESS);
+}
 
 static int open_and_lock(char *path)
 {
@@ -921,12 +926,38 @@ static bool may_access_netns(int pid)
        return may_access;
 }
 
+struct user_nic_args {
+       char *cmd;
+       char *lxc_path;
+       char *lxc_name;
+       char *pid;
+       char *type;
+       char *link;
+       char *veth_name;
+};
+
 int main(int argc, char *argv[])
 {
        int fd, n, pid, ret;
        char *me;
        char *cnic = NULL, *nicname = NULL, *vethname = NULL;
        struct alloted_s *alloted = NULL;
+       struct user_nic_args args;
+
+       if (argc < 7 || argc > 8) {
+               usage(argv[0], true);
+               exit(EXIT_FAILURE);
+       }
+
+       memset(&args, 0, sizeof(struct user_nic_args));
+       args.cmd = argv[1];
+       args.lxc_path = argv[2];
+       args.lxc_name = argv[3];
+       args.pid = argv[4];
+       args.type = argv[5];
+       args.link = argv[6];
+       if (argc >= 8)
+               args.veth_name = argv[7];
 
        /* Set a sane env, because we are setuid-root. */
        ret = clearenv();
@@ -947,18 +978,9 @@ int main(int argc, char *argv[])
                exit(EXIT_FAILURE);
        }
 
-       if (argc < 6)
-               usage(argv[0], true);
-
-       if (argc >= 7)
-               vethname = argv[6];
-
-       lxcpath = argv[1];
-       lxcname = argv[2];
-
-       ret = lxc_safe_int(argv[3], &pid);
+       ret = lxc_safe_int(args.pid, &pid);
        if (ret < 0) {
-               usernic_error("Could not read pid: %s\n", argv[1]);
+               usernic_error("Could not read pid: %s\n", args.pid);
                exit(EXIT_FAILURE);
        }
 
@@ -978,10 +1000,10 @@ int main(int argc, char *argv[])
                exit(EXIT_FAILURE);
        }
 
-       n = get_alloted(me, argv[4], argv[5], &alloted);
+       n = get_alloted(me, args.type, args.link, &alloted);
        if (n > 0)
-               nicname = get_nic_if_avail(fd, alloted, pid, argv[4],
-                                          argv[5], n, &cnic);
+               nicname = get_nic_if_avail(fd, alloted, pid, args.type,
+                                          args.link, n, &cnic);
 
        close(fd);
        free_alloted(&alloted);
@@ -991,7 +1013,7 @@ int main(int argc, char *argv[])
        }
 
        /* Now rename the link. */
-       ret = rename_in_ns(pid, cnic, &vethname);
+       ret = rename_in_ns(pid, cnic, &args.veth_name);
        if (ret < 0) {
                usernic_error("%s", "Failed to rename the link\n");
                ret = lxc_netdev_delete_by_name(cnic);
@@ -1002,7 +1024,7 @@ int main(int argc, char *argv[])
        }
 
        /* Write the name of the interface pair to the stdout: eth0:veth9MT2L4 */
-       fprintf(stdout, "%s:%s\n", vethname, nicname);
+       fprintf(stdout, "%s:%s\n", args.veth_name, nicname);
        free(nicname);
        exit(EXIT_SUCCESS);
 }