Merge pull request #2521 from brauner/2018-08-11/fix_netnsid_allocation

src/lxc/network.c

@@ -3192,93 +3192,6 @@ enum {
 	__LXC_NETNSA_MAX,
 };
 
-static int nl_send(struct nl_handler *handler, struct nlmsghdr *nlmsghdr)
-{
-	struct sockaddr_nl nladdr;
-	struct iovec iov = {
-		.iov_base = nlmsghdr,
-		.iov_len = nlmsghdr->nlmsg_len,
-	};
-	struct msghdr msg = {
-		.msg_name = &nladdr,
-		.msg_namelen = sizeof(nladdr),
-		.msg_iov = &iov,
-		.msg_iovlen = 1,
-	};
-	int ret;
-
-	memset(&nladdr, 0, sizeof(nladdr));
-	nladdr.nl_family = AF_NETLINK;
-	nladdr.nl_pid = 0;
-	nladdr.nl_groups = 0;
-
-	ret = sendmsg(handler->fd, &msg, MSG_NOSIGNAL);
-	if (ret < 0)
-		return -errno;
-
-	return ret;
-}
-
-static int nl_recv(struct nl_handler *handler, struct nlmsghdr *nlmsghdr)
-{
-	int ret;
-	struct sockaddr_nl nladdr;
-	struct iovec iov = {
-	    .iov_base = nlmsghdr,
-	    .iov_len = nlmsghdr->nlmsg_len,
-	};
-
-	struct msghdr msg = {
-		.msg_name = &nladdr,
-		.msg_namelen = sizeof(nladdr),
-		.msg_iov = &iov,
-		.msg_iovlen = 1,
-	};
-
-	memset(&nladdr, 0, sizeof(nladdr));
-	nladdr.nl_family = AF_NETLINK;
-	nladdr.nl_pid = 0;
-	nladdr.nl_groups = 0;
-
-again:
-	ret = recvmsg(handler->fd, &msg, 0);
-	if (ret < 0) {
-		if (errno == EINTR)
-			goto again;
-
-		return -1;
-	}
-
-	if (!ret)
-		return 0;
-
-	if (msg.msg_flags & MSG_TRUNC && (ret == nlmsghdr->nlmsg_len))
-		return -EMSGSIZE;
-
-	return ret;
-}
-
-extern int nl_transaction(struct nl_handler *handler, struct nlmsghdr *request,
-			  struct nlmsghdr *answer)
-{
-	int ret;
-
-	ret = nl_send(handler, request);
-	if (ret < 0)
-		return ret;
-
-	ret = nl_recv(handler, answer);
-	if (ret < 0)
-		return ret;
-
-	if (answer->nlmsg_type == NLMSG_ERROR) {
-		struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(answer);
-		return err->error;
-	}
-
-	return 0;
-}
-
 int lxc_netns_set_nsid(int fd)
 {
 	ssize_t ret;
@@ -3309,7 +3222,7 @@ int lxc_netns_set_nsid(int fd)
 	addattr(hdr, 1024, __LXC_NETNSA_FD, &netns_fd, sizeof(netns_fd));
 	addattr(hdr, 1024, __LXC_NETNSA_NSID, &ns_id, sizeof(ns_id));
 
-	ret = nl_transaction(&nlh, hdr, hdr);
+	ret = __netlink_transaction(&nlh, hdr, hdr);
 	netlink_close(&nlh);
 	if (ret < 0)
 		return -1;

src/lxc/nl.c

@@ -171,13 +171,13 @@ extern void nlmsg_free(struct nlmsg *nlmsg)
 	free(nlmsg);
 }
 
-extern int netlink_rcv(struct nl_handler *handler, struct nlmsg *answer)
+extern int __netlink_recv(struct nl_handler *handler, struct nlmsghdr *nlmsghdr)
 {
 	int ret;
 	struct sockaddr_nl nladdr;
 	struct iovec iov = {
-		.iov_base = answer->nlmsghdr,
-		.iov_len = answer->nlmsghdr->nlmsg_len,
+	    .iov_base = nlmsghdr,
+	    .iov_len = nlmsghdr->nlmsg_len,
 	};
 
 	struct msghdr msg = {
@@ -197,25 +197,31 @@ again:
 	if (ret < 0) {
 		if (errno == EINTR)
 			goto again;
-		return -errno;
+
+		return -1;
 	}
 
 	if (!ret)
 		return 0;
 
-	if (msg.msg_flags & MSG_TRUNC &&
-	    ret == answer->nlmsghdr->nlmsg_len)
+	if (msg.msg_flags & MSG_TRUNC && (ret == nlmsghdr->nlmsg_len))
 		return -EMSGSIZE;
 
 	return ret;
 }
 
-extern int netlink_send(struct nl_handler *handler, struct nlmsg *nlmsg)
+extern int netlink_rcv(struct nl_handler *handler, struct nlmsg *answer)
 {
+	return __netlink_recv(handler, answer->nlmsghdr);
+}
+
+extern int __netlink_send(struct nl_handler *handler, struct nlmsghdr *nlmsghdr)
+{
+	int ret;
 	struct sockaddr_nl nladdr;
 	struct iovec iov = {
-		.iov_base = nlmsg->nlmsghdr,
-		.iov_len = nlmsg->nlmsghdr->nlmsg_len,
+	    .iov_base = nlmsghdr,
+	    .iov_len = nlmsghdr->nlmsg_len,
 	};
 	struct msghdr msg = {
 	    .msg_name = &nladdr,
@@ -223,7 +229,6 @@ extern int netlink_send(struct nl_handler *handler, struct nlmsg *nlmsg)
 	    .msg_iov = &iov,
 	    .msg_iovlen = 1,
 	};
-	int ret;
 
 	memset(&nladdr, 0, sizeof(nladdr));
 	nladdr.nl_family = AF_NETLINK;
@@ -232,32 +237,45 @@ extern int netlink_send(struct nl_handler *handler, struct nlmsg *nlmsg)
 
 	ret = sendmsg(handler->fd, &msg, MSG_NOSIGNAL);
 	if (ret < 0)
-		return -errno;
+		return -1;
 
 	return ret;
 }
 
-extern int netlink_transaction(struct nl_handler *handler,
-			       struct nlmsg *request, struct nlmsg *answer)
+extern int netlink_send(struct nl_handler *handler, struct nlmsg *nlmsg)
+{
+	return __netlink_send(handler, nlmsg->nlmsghdr);
+}
+
+extern int __netlink_transaction(struct nl_handler *handler,
+				 struct nlmsghdr *request,
+				 struct nlmsghdr *answer)
 {
 	int ret;
 
-	ret = netlink_send(handler, request);
+	ret = __netlink_send(handler, request);
 	if (ret < 0)
 		return ret;
 
-	ret = netlink_rcv(handler, answer);
+	ret = __netlink_recv(handler, answer);
 	if (ret < 0)
 		return ret;
 
-	if (answer->nlmsghdr->nlmsg_type == NLMSG_ERROR) {
-		struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(answer->nlmsghdr);
+	if (answer->nlmsg_type == NLMSG_ERROR) {
+		struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(answer);
 		return err->error;
 	}
 
 	return 0;
 }
 
+extern int netlink_transaction(struct nl_handler *handler,
+			       struct nlmsg *request, struct nlmsg *answer)
+{
+	return __netlink_transaction(handler, request->nlmsghdr,
+				     answer->nlmsghdr);
+}
+
 extern int netlink_open(struct nl_handler *handler, int protocol)
 {
 	socklen_t socklen;

src/lxc/nl.h

@@ -98,6 +98,7 @@ int netlink_close(struct nl_handler *handler);
  * Returns 0 on success, < 0 otherwise
  */
 int netlink_rcv(struct nl_handler *handler, struct nlmsg *nlmsg);
+int __netlink_recv(struct nl_handler *handler, struct nlmsghdr *nlmsg);
 
 /*
  * netlink_send: send a netlink message to the kernel. It is up
@@ -109,6 +110,7 @@ int netlink_rcv(struct nl_handler *handler, struct nlmsg *nlmsg);
  * Returns 0 on success, < 0 otherwise
  */
 int netlink_send(struct nl_handler *handler, struct nlmsg *nlmsg);
+int __netlink_send(struct nl_handler *handler, struct nlmsghdr *nlmsg);
 
 /*
  * netlink_transaction: send a request to the kernel and read the response.
@@ -123,6 +125,8 @@ int netlink_send(struct nl_handler *handler, struct nlmsg *nlmsg);
  */
 int netlink_transaction(struct nl_handler *handler,
 			struct nlmsg *request, struct nlmsg *anwser);
+int __netlink_transaction(struct nl_handler *handler, struct nlmsghdr *request,
+			  struct nlmsghdr *anwser);
 
 /*
  * nla_put_string: copy a null terminated string to a netlink message