Merge pull request #2515 from brauner/2018-02-06/network_netns_id

netns: allocate network namespace id

.travis.yml

@@ -18,7 +18,7 @@ before_install:
  - echo -n | openssl s_client -connect scan.coverity.com:443 | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' | sudo tee -a /etc/ssl/certs/ca-
  - sudo add-apt-repository ppa:ubuntu-lxc/daily -y
  - sudo apt-get update -qq
- - sudo apt-get install -qq libapparmor-dev libcap-dev libseccomp-dev python3-dev python3-setuptools docbook2x libgnutls-dev libselinux1-dev
+ - sudo apt-get install -qq libapparmor-dev libcap-dev libseccomp-dev python3-dev python3-setuptools docbook2x libgnutls-dev libselinux1-dev linux-libc-dev
 script:
  - ./autogen.sh
  - rm -Rf build

src/lxc/macro.h

@@ -142,4 +142,49 @@ extern int __build_bug_on_failed;
 
 #define prctl_arg(x) ((unsigned long)x)
 
+/* networking */
+#ifndef IFLA_LINKMODE
+#define IFLA_LINKMODE 17
+#endif
+
+#ifndef IFLA_LINKINFO
+#define IFLA_LINKINFO 18
+#endif
+
+#ifndef IFLA_NET_NS_PID
+#define IFLA_NET_NS_PID 19
+#endif
+
+#ifndef IFLA_INFO_KIND
+#define IFLA_INFO_KIND 1
+#endif
+
+#ifndef IFLA_VLAN_ID
+#define IFLA_VLAN_ID 1
+#endif
+
+#ifndef IFLA_INFO_DATA
+#define IFLA_INFO_DATA 2
+#endif
+
+#ifndef VETH_INFO_PEER
+#define VETH_INFO_PEER 1
+#endif
+
+#ifndef IFLA_MACVLAN_MODE
+#define IFLA_MACVLAN_MODE 1
+#endif
+
+#ifndef IFLA_NEW_NETNSID
+#define IFLA_NEW_NETNSID 45
+#endif
+
+#ifndef IFLA_IF_NETNSID
+#define IFLA_IF_NETNSID 46
+#endif
+
+#ifndef RTM_NEWNSID
+#define RTM_NEWNSID 88
+#endif
+
 #endif /* __LXC_MACRO_H */

src/lxc/network.c

@@ -63,38 +63,6 @@
 #include "include/strlcpy.h"
 #endif
 
-#ifndef IFLA_LINKMODE
-#define IFLA_LINKMODE 17
-#endif
-
-#ifndef IFLA_LINKINFO
-#define IFLA_LINKINFO 18
-#endif
-
-#ifndef IFLA_NET_NS_PID
-#define IFLA_NET_NS_PID 19
-#endif
-
-#ifndef IFLA_INFO_KIND
-#define IFLA_INFO_KIND 1
-#endif
-
-#ifndef IFLA_VLAN_ID
-#define IFLA_VLAN_ID 1
-#endif
-
-#ifndef IFLA_INFO_DATA
-#define IFLA_INFO_DATA 2
-#endif
-
-#ifndef VETH_INFO_PEER
-#define VETH_INFO_PEER 1
-#endif
-
-#ifndef IFLA_MACVLAN_MODE
-#define IFLA_MACVLAN_MODE 1
-#endif
-
 lxc_log_define(network, lxc);
 
 typedef int (*instantiate_cb)(struct lxc_handler *, struct lxc_netdev *);
@@ -3195,3 +3163,73 @@ void lxc_delete_network(struct lxc_handler *handler)
 	else
 		DEBUG("Deleted network devices");
 }
+
+int addattr(struct nlmsghdr *n, int maxlen, int type, const void *data, int alen)
+{
+	int len = RTA_LENGTH(alen);
+	struct rtattr *rta;
+
+	if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen)
+		return -1;
+
+	rta = NLMSG_TAIL(n);
+	rta->rta_type = type;
+	rta->rta_len = len;
+	if (alen)
+		memcpy(RTA_DATA(rta), data, alen);
+	n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
+
+	return 0;
+}
+
+/* Attributes of RTM_NEWNSID/RTM_GETNSID messages */
+enum {
+	LXC_NETNSA_NONE,
+#define LXC_NETNSA_NSID_NOT_ASSIGNED -1
+	LXC_NETNSA_NSID,
+	LXC_NETNSA_PID,
+	LXC_NETNSA_FD,
+	__LXC_NETNSA_MAX,
+};
+
+int lxc_netns_set_nsid(int fd)
+{
+	ssize_t ret;
+	char l_buffer[NLMSG_ALIGN(sizeof(struct nlmsghdr)) +
+		      NLMSG_ALIGN(sizeof(struct rtgenmsg)) +
+		      NLMSG_ALIGN(1024)];
+	struct nl_handler nlh;
+	struct nlmsghdr *l_hdr;
+	struct rtgenmsg *l_msg;
+	struct sockaddr_nl l_addr;
+	int nsid = -1;
+
+	ret = netlink_open(&nlh, NETLINK_ROUTE);
+	if (ret < 0)
+		return ret;
+
+	memset(l_buffer, 0, sizeof(l_buffer));
+	l_hdr = (struct nlmsghdr *)l_buffer;
+	l_msg = (struct rtgenmsg *)NLMSG_DATA(l_hdr);
+
+	l_hdr->nlmsg_len = NLMSG_LENGTH(sizeof(*l_msg));
+	l_hdr->nlmsg_type = RTM_NEWNSID;
+	l_hdr->nlmsg_flags = NLM_F_REQUEST;
+	l_hdr->nlmsg_pid = 0;
+	l_hdr->nlmsg_seq = RTM_NEWNSID;
+	l_msg->rtgen_family = AF_UNSPEC;
+
+	addattr(l_hdr, 1024, LXC_NETNSA_FD, &fd, sizeof(__u32));
+	addattr(l_hdr, 1024, LXC_NETNSA_NSID, &nsid, sizeof(__u32));
+
+	memset(&l_addr, 0, sizeof(l_addr));
+	l_addr.nl_family = AF_NETLINK;
+
+	ret = sendto(nlh.fd, l_hdr, l_hdr->nlmsg_len, 0,
+		     (struct sockaddr *)&l_addr, sizeof(l_addr));
+	netlink_close(&nlh);
+	if (ret < 0)
+		return -1;
+
+	return 0;
+}

src/lxc/network.h

@@ -272,5 +272,6 @@ extern int lxc_network_send_veth_names_to_child(struct lxc_handler *handler);
 extern int lxc_network_recv_veth_names_from_parent(struct lxc_handler *handler);
 extern int lxc_network_send_name_and_ifindex_to_parent(struct lxc_handler *handler);
 extern int lxc_network_recv_name_and_ifindex_from_child(struct lxc_handler *handler);
+extern int lxc_netns_set_nsid(int netns_fd);
 
 #endif /* __LXC_NETWORK_H */

src/lxc/start.c

@@ -1818,6 +1818,13 @@ static int lxc_spawn(struct lxc_handler *handler)
 	} else {
 		handler->nsfd[LXC_NS_NET] = ret;
 		DEBUG("Preserved net namespace via fd %d", ret);
+
+		ret = lxc_netns_set_nsid(handler->nsfd[LXC_NS_NET]);
+		if (ret < 0) {
+			ERROR("Failed to allocate new network namespace id: %d", ret);
+			goto out_delete_net;
+		}
+		TRACE("Allocated new network namespace id");
 	}
 
 	/* Create the network configuration. */