network: send ifindex for unpriv networks

We use the ifindex as an indicator that liblxc created the network so let's
record it for the unprivileged case as well.

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

diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index c8a05b43cfc646fe9a0aabb35a3345b67db4c1c1..7fe3297eeb4095346866d32028e05f84ec836164 100644 (file)
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -3167,6 +3167,7 @@ bool lxc_delete_network(struct lxc_handler *handler)
 static int unpriv_assign_nic(const char *lxcpath, char *lxcname,
                             struct lxc_netdev *netdev, pid_t pid)
 {
+       int ret;
        pid_t child;
        int bytes, pipefd[2];
        char *token, *saveptr = NULL;
@@ -3280,6 +3281,17 @@ static int unpriv_assign_nic(const char *lxcpath, char *lxcname,
                return -1;
        }
 
+       /* fill netdev->veth_attr.pair field */
+       token = strtok_r(NULL, ":", &saveptr);
+       if (!token)
+               return -1;
+
+       ret = lxc_safe_int(token, &netdev->ifindex);
+       if (ret < 0) {
+               ERROR("Failed to parse ifindex for network device \"%s\"", netdev->name);
+               return -1;
+       }
+
        return 0;
 }
 

diff --git a/src/lxc/lxc_user_nic.c b/src/lxc/lxc_user_nic.c
index a9b37c8e01749050febea400835a28113f7c87e1..70dcd8975dc0086357d862f4c2d9e79c03b7823c 100644 (file)
--- a/src/lxc/lxc_user_nic.c
+++ b/src/lxc/lxc_user_nic.c
@@ -767,7 +767,8 @@ again:
        goto again;
 }
 
-static char *lxc_secure_rename_in_ns(int pid, char *oldname, char *newname)
+static char *lxc_secure_rename_in_ns(int pid, char *oldname, char *newname,
+                                    int *ifidx)
 {
        int ret;
        uid_t ruid, suid, euid;
@@ -849,6 +850,7 @@ static char *lxc_secure_rename_in_ns(int pid, char *oldname, char *newname)
        /* Allocation failure for strdup() is checked below. */
        name = strdup(ifname);
        string_ret = name;
+       *ifidx = ifindex;
 
 do_full_cleanup:
        ret = setresuid(ruid, euid, suid);
@@ -944,7 +946,7 @@ struct user_nic_args {
 
 int main(int argc, char *argv[])
 {
-       int fd, n, pid, ret;
+       int fd, ifindex, n, pid, ret;
        char *me, *newname;
        char *cnic = NULL, *nicname = NULL;
        struct alloted_s *alloted = NULL;
@@ -1019,7 +1021,7 @@ int main(int argc, char *argv[])
        }
 
        /* Now rename the link. */
-       newname = lxc_secure_rename_in_ns(pid, cnic, args.veth_name);
+       newname = lxc_secure_rename_in_ns(pid, cnic, args.veth_name, &ifindex);
        if (!newname) {
                usernic_error("%s", "Failed to rename the link\n");
                ret = lxc_netdev_delete_by_name(cnic);
@@ -1030,7 +1032,7 @@ int main(int argc, char *argv[])
        }
 
        /* Write the name of the interface pair to the stdout: eth0:veth9MT2L4 */
-       fprintf(stdout, "%s:%s\n", newname, nicname);
+       fprintf(stdout, "%s:%s:%d\n", newname, nicname, ifindex);
        free(newname);
        free(nicname);
        exit(EXIT_SUCCESS);