net: support owning interfaces with libnl too

diff --git a/cmdline.cc b/cmdline.cc
index 6a03185..b08521b 100644 (file)
--- a/cmdline.cc
+++ b/cmdline.cc
@@ -145,7 +145,7 @@ struct custom_option custom_opts[] = {
     { { "cgroup_cpu_mount", required_argument, NULL, 0x0822 }, "Location of cpu cgroup FS (default: '/sys/fs/cgroup/net_cls')" },
     { { "cgroup_cpu_parent", required_argument, NULL, 0x0833 }, "Which pre-existing cpu cgroup to use as a parent (default: 'NSJAIL')" },
     { { "iface_no_lo", no_argument, NULL, 0x700 }, "Don't bring the 'lo' interface up" },
-    { { "iface_own", required_argument, NULL, 0x704 }, "Move this existing network interface into the new NET namespace" },
+    { { "iface_own", required_argument, NULL, 0x704 }, "Move this existing network interface into the new NET namespace. Can be specified multiple times" },
     { { "macvlan_iface", required_argument, NULL, 'I' }, "Interface which will be cloned (MACVLAN) and put inside the subprocess' namespace as 'vs'" },
     { { "macvlan_vs_ip", required_argument, NULL, 0x701 }, "IP of the 'vs' interface (e.g. \"192.168.0.1\")" },
     { { "macvlan_vs_nm", required_argument, NULL, 0x702 }, "Netmask of the 'vs' interface (e.g. \"255.255.255.0\")" },

diff --git a/net.cc b/net.cc
index 6a0c4b8..4799119 100644 (file)
--- a/net.cc
+++ b/net.cc
@@ -54,19 +54,75 @@ namespace net {
 #include <netlink/route/link.h>
 #include <netlink/route/link/macvlan.h>
 
-bool initNsFromParent(nsjconf_t* nsjconf, int pid) {
-       if (!nsjconf->clone_newnet) {
-               return true;
+static bool cloneIface(
+    nsjconf_t* nsjconf, struct nl_sock* sk, struct nl_cache* link_cache, int pid) {
+       struct rtnl_link* rmv = rtnl_link_macvlan_alloc();
+       if (rmv == NULL) {
+               LOG_E("rtnl_link_macvlan_alloc()");
+               return false;
        }
-       if (nsjconf->iface_vs.empty()) {
-               return true;
+
+       int err;
+       int master_index = rtnl_link_name2i(link_cache, nsjconf->iface_vs.c_str());
+       if (!master_index) {
+               LOG_E("rtnl_link_name2i(): Did not find '%s' interface", nsjconf->iface_vs.c_str());
+               rtnl_link_put(rmv);
+               return false;
        }
 
-       LOG_D("Putting iface:'%s' into namespace of PID:%d (with libnl3)",
-           nsjconf->iface_vs.c_str(), pid);
+       rtnl_link_set_name(rmv, IFACE_NAME);
+       rtnl_link_set_link(rmv, master_index);
+       rtnl_link_set_ns_pid(rmv, pid);
+
+       if ((err = rtnl_link_add(sk, rmv, NLM_F_CREATE)) < 0) {
+               LOG_E("rtnl_link_add(name:'%s' link:'%s'): %s", IFACE_NAME,
+                   nsjconf->iface_vs.c_str(), nl_geterror(err));
+               rtnl_link_put(rmv);
+               return false;
+       }
+
+       rtnl_link_put(rmv);
+       return true;
+}
+
+static bool moveToNs(
+    const std::string& iface, struct nl_sock* sk, struct nl_cache* link_cache, pid_t pid) {
+       LOG_D("Moving interface '%s' into netns=%d", iface.c_str(), (int)pid);
+
+       struct rtnl_link* orig_link = rtnl_link_get_by_name(link_cache, iface.c_str());
+       if (!orig_link) {
+               LOG_E("Couldn't find interface '%s'", iface.c_str());
+               return false;
+       }
+       struct rtnl_link* new_link = rtnl_link_alloc();
+       if (!new_link) {
+               LOG_E("Couldn't allocate new link");
+               rtnl_link_put(orig_link);
+               return false;
+       }
+
+       rtnl_link_set_ns_pid(new_link, pid);
 
+       int err = rtnl_link_change(sk, orig_link, new_link, RTM_SETLINK);
+       if (err < 0) {
+               LOG_E("rtnl_link_change(): set NS of interface '%s' to PID=%d: %s", iface.c_str(),
+                   (int)pid, nl_geterror(err));
+               rtnl_link_put(new_link);
+               rtnl_link_put(orig_link);
+               return false;
+       }
+
+       rtnl_link_put(new_link);
+       rtnl_link_put(orig_link);
+       return true;
+}
+
+bool initNsFromParent(nsjconf_t* nsjconf, int pid) {
+       if (!nsjconf->clone_newnet) {
+               return true;
+       }
        struct nl_sock* sk = nl_socket_alloc();
-       if (sk == NULL) {
+       if (!sk) {
                LOG_E("Could not allocate socket with nl_socket_alloc()");
                return false;
        }
@@ -78,51 +134,33 @@ bool initNsFromParent(nsjconf_t* nsjconf, int pid) {
                return false;
        }
 
-       struct rtnl_link* rmv = rtnl_link_macvlan_alloc();
-       if (rmv == NULL) {
-               LOG_E("rtnl_link_macvlan_alloc(): %s", nl_geterror(err));
-               nl_socket_free(sk);
-               return false;
-       }
-
        struct nl_cache* link_cache;
        if ((err = rtnl_link_alloc_cache(sk, AF_UNSPEC, &link_cache)) < 0) {
                LOG_E("rtnl_link_alloc_cache(): %s", nl_geterror(err));
-               rtnl_link_put(rmv);
                nl_socket_free(sk);
                return false;
        }
 
-       int master_index = rtnl_link_name2i(link_cache, nsjconf->iface_vs.c_str());
-       if (master_index == 0) {
-               LOG_E("rtnl_link_name2i(): Did not find '%s' interface", nsjconf->iface_vs.c_str());
-               nl_cache_free(link_cache);
-               rtnl_link_put(rmv);
-               nl_socket_free(sk);
-               return false;
+       for (const auto& iface : nsjconf->ifaces) {
+               if (!moveToNs(iface, sk, link_cache, pid)) {
+                       nl_cache_free(link_cache);
+                       nl_socket_free(sk);
+                       return false;
+               }
        }
-
-       rtnl_link_set_name(rmv, IFACE_NAME);
-       rtnl_link_set_link(rmv, master_index);
-       rtnl_link_set_ns_pid(rmv, pid);
-
-       if ((err = rtnl_link_add(sk, rmv, NLM_F_CREATE)) < 0) {
-               LOG_E("rtnl_link_add(name:'%s' link:'%s'): %s", IFACE_NAME,
-                   nsjconf->iface_vs.c_str(), nl_geterror(err));
+       if (!nsjconf->iface_vs.empty() && !cloneIface(nsjconf, sk, link_cache, pid)) {
                nl_cache_free(link_cache);
-               rtnl_link_put(rmv);
                nl_socket_free(sk);
                return false;
        }
 
        nl_cache_free(link_cache);
-       rtnl_link_put(rmv);
        nl_socket_free(sk);
        return true;
 }
 #else   // defined(NSJAIL_NL3_WITH_MACVLAN)
 
-bool moveToNs(const std::string& iface, pid_t pid) {
+static bool moveToNs(const std::string& iface, pid_t pid) {
        const std::vector<std::string> argv{
            "/sbin/ip", "link", "set", iface, "netns", std::to_string(pid)};
        if (subproc::systemExe(argv, environ) != 0) {