libsystemd-networkd: introduce sd-pppoe library

This library negotiates a PPPoE channel. It handles the discovery stage and
leaves the session stage to the kernel. A further PPP library is needed to
actually set up a PPP unit (negotatie LCP, IPCP and do authentication), so in
isolation this is not yet very useful.

The test program has two modes:

  # ./test-pppoe

will create a veth tunnel in a new network namespace, start pppoe-server on one
end and this client library on the other. The pppd server will time out as no
LCP is performed, and the client will then shut down gracefully.

  # ./test-pppoe eth0

will run the client on eth0 (or any other netdev), and requires a PPPoE server
to be reachable on the local link.

.gitignore

@@ -168,6 +168,7 @@
 /test-dhcp-option
 /test-dhcp-server
 /test-dhcp6-client
+/test-pppoe
 /test-dns-domain
 /test-icmp6-rs
 /test-ellipsize

Makefile.am

@@ -2958,6 +2958,7 @@ libsystemd_network_la_SOURCES = \
 	src/systemd/sd-icmp6-nd.h \
 	src/systemd/sd-dhcp6-client.h \
 	src/systemd/sd-dhcp6-lease.h \
+	src/systemd/sd-pppoe.h \
 	src/libsystemd-network/sd-dhcp-client.c \
 	src/libsystemd-network/sd-dhcp-server.c \
 	src/libsystemd-network/dhcp-network.c \
@@ -2972,6 +2973,7 @@ libsystemd_network_la_SOURCES = \
 	src/libsystemd-network/ipv4ll-network.c \
 	src/libsystemd-network/ipv4ll-packet.c \
 	src/libsystemd-network/ipv4ll-internal.h \
+	src/libsystemd-network/sd-pppoe.c \
 	src/libsystemd-network/network-internal.c \
 	src/libsystemd-network/network-internal.h \
 	src/libsystemd-network/sd-icmp6-nd.c \
@@ -3031,6 +3033,14 @@ test_ipv4ll_LDADD = \
 	libsystemd-internal.la \
 	libsystemd-shared.la
 
+test_pppoe_SOURCES = \
+	src/systemd/sd-pppoe.h \
+	src/libsystemd-network/test-pppoe.c
+
+test_pppoe_LDADD = \
+	libsystemd-network.la \
+	libsystemd-shared.la
+
 test_icmp6_rs_SOURCES = \
 	src/systemd/sd-dhcp6-client.h \
 	src/systemd/sd-icmp6-nd.h \
@@ -3060,6 +3070,9 @@ tests += \
 	test-icmp6-rs \
 	test-dhcp6-client
 
+manual_tests += \
+	test-pppoe
+
 # ------------------------------------------------------------------------------
 if ENABLE_TERMINAL
 noinst_LTLIBRARIES += \

src/libsystemd-network/test-pppoe.c

@@ -0,0 +1,181 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright (C) 2014 Tom Gundersen <teg@jklm.no>
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <stdlib.h>
+#include <assert.h>
+#include <errno.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+#include <linux/veth.h>
+#include <net/if.h>
+
+#include "util.h"
+#include "socket-util.h"
+#include "sd-event.h"
+#include "event-util.h"
+#include "sd-rtnl.h"
+#include "rtnl-util.h"
+#include "sd-pppoe.h"
+
+static void pppoe_handler(sd_pppoe *ppp, int event, void *userdata) {
+        static int pppoe_state = -1;
+        sd_event *e = userdata;
+
+        assert_se(ppp);
+        assert_se(e);
+
+        switch (event) {
+        case PPPOE_EVENT_RUNNING:
+                assert_se(pppoe_state == -1);
+                log_info("running");
+                break;
+        case PPPOE_EVENT_STOPPED:
+                assert_se(pppoe_state == PPPOE_EVENT_RUNNING);
+                log_info("stopped");
+                assert_se(sd_event_exit(e, 0) >= 0);
+                break;
+        default:
+                assert_not_reached("invalid pppoe event");
+        }
+
+        pppoe_state = event;
+}
+
+static int client_run(const char *client_name, sd_event *e) {
+        sd_pppoe *pppoe;
+        int client_ifindex;
+
+        client_ifindex = (int) if_nametoindex(client_name);
+        assert_se(client_ifindex > 0);
+
+        assert_se(sd_pppoe_new(&pppoe) >= 0);
+        assert_se(sd_pppoe_attach_event(pppoe, e, 0) >= 0);
+
+        assert_se(sd_pppoe_set_ifname(pppoe, "pppoe-client") >= 0);
+        assert_se(sd_pppoe_set_ifindex(pppoe, client_ifindex) >= 0);
+        assert_se(sd_pppoe_set_callback(pppoe, pppoe_handler, e) >= 0);
+
+        log_info("starting PPPoE client, it will exit when the server times out and sends PADT");
+
+        assert_se(sd_pppoe_start(pppoe) >= 0);
+
+        assert_se(sd_event_loop(e) >= 0);
+
+        assert_se(!sd_pppoe_unref(pppoe));
+
+        return EXIT_SUCCESS;
+}
+
+static int test_pppoe_server(sd_event *e) {
+        sd_rtnl *rtnl;
+        sd_rtnl_message *m;
+        pid_t pid;
+        int r, client_ifindex, server_ifindex;
+
+        r = unshare(CLONE_NEWNET);
+        if (r < 0 && errno == EPERM)
+                return EXIT_TEST_SKIP;
+
+        assert_se(r >= 0);
+
+        assert_se(sd_rtnl_open(&rtnl, 0) >= 0);
+        assert_se(sd_rtnl_attach_event(rtnl, e, 0) >= 0);
+
+        assert_se(sd_rtnl_message_new_link(rtnl, &m, RTM_NEWLINK, 0) >= 0);
+        assert_se(sd_rtnl_message_append_string(m, IFLA_IFNAME, "pppoe-server") >= 0);
+        assert_se(sd_rtnl_message_open_container(m, IFLA_LINKINFO) >= 0);
+        assert_se(sd_rtnl_message_open_container_union(m, IFLA_INFO_DATA, "veth") >= 0);
+        assert_se(sd_rtnl_message_open_container(m, VETH_INFO_PEER) >= 0);
+        assert_se(sd_rtnl_message_append_string(m, IFLA_IFNAME, "pppoe-client") >= 0);
+        assert_se(sd_rtnl_message_close_container(m) >= 0);
+        assert_se(sd_rtnl_message_close_container(m) >= 0);
+        assert_se(sd_rtnl_message_close_container(m) >= 0);
+        assert_se(sd_rtnl_call(rtnl, m, 0, NULL) >= 0);
+
+        client_ifindex = (int) if_nametoindex("pppoe-client");
+        assert_se(client_ifindex > 0);
+        server_ifindex = (int) if_nametoindex("pppoe-server");
+        assert_se(server_ifindex > 0);
+
+        m = sd_rtnl_message_unref(m);
+        assert_se(sd_rtnl_message_new_link(rtnl, &m, RTM_SETLINK, client_ifindex) >= 0);
+        assert_se(sd_rtnl_message_link_set_flags(m, IFF_UP, IFF_UP) >= 0);
+        assert_se(sd_rtnl_call(rtnl, m, 0, NULL) >= 0);
+
+        m = sd_rtnl_message_unref(m);
+        assert_se(sd_rtnl_message_new_link(rtnl, &m, RTM_SETLINK, server_ifindex) >= 0);
+        assert_se(sd_rtnl_message_link_set_flags(m, IFF_UP, IFF_UP) >= 0);
+        assert_se(sd_rtnl_call(rtnl, m, 0, NULL) >= 0);
+
+        pid = fork();
+        assert_se(pid >= 0);
+        if (pid == 0) {
+                /* let the client send some discover messages before the server is started */
+                sleep(2);
+
+                /* TODO: manage pppoe-server-options */
+                execlp("pppoe-server", "pppoe-server", "-F",
+                       "-I", "pppoe-server",
+                       "-C", "Test-AC",
+                       "-S", "Service-Default",
+                       "-S", "Service-First-Auxillary",
+                       "-S", "Service-Second-Auxillary",
+                       NULL);
+                assert_not_reached("failed to execute pppoe-server. not installed?");
+        }
+
+        client_run("pppoe-client", e);
+
+        assert_se(kill(pid, SIGTERM) >= 0);
+        assert_se(wait_for_terminate(pid, NULL) >= 0);
+
+        assert_se(!sd_rtnl_message_unref(m));
+        assert_se(!sd_rtnl_unref(rtnl));
+
+        return EXIT_SUCCESS;
+}
+
+int main(int argc, char *argv[]) {
+        _cleanup_event_unref_ sd_event *e = NULL;
+
+        log_set_max_level(LOG_DEBUG);
+        log_parse_environment();
+        log_open();
+
+        assert_se(sd_event_new(&e) >= 0);
+
+        if (argc == 1) {
+                log_info("running PPPoE client against local server");
+
+                return test_pppoe_server(e);
+        } else if (argc == 2) {
+                log_info("running PPPoE client over '%s'", argv[1]);
+
+                return client_run(argv[1], e);
+        } else {
+                log_error("This program takes one or no arguments.\n"
+                          "\t %s [<ifname>]", program_invocation_short_name);
+                return EXIT_FAILURE;
+        }
+}

src/systemd/sd-pppoe.h

@@ -0,0 +1,53 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#ifndef foosdpppoefoo
+#define foosdpppoefoo
+
+/***
+  This file is part of systemd.
+
+  Copyright (C) 2014 Tom Gundersen
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <stdbool.h>
+#include <net/ethernet.h>
+
+#include "sd-event.h"
+
+#include "sparse-endian.h"
+
+enum {
+        PPPOE_EVENT_RUNNING                     = 0,
+        PPPOE_EVENT_STOPPED                     = 1,
+};
+
+typedef struct sd_pppoe sd_pppoe;
+typedef void (*sd_pppoe_cb_t)(sd_pppoe *ppp, int event, void *userdata);
+
+int sd_pppoe_detach_event(sd_pppoe *ppp);
+int sd_pppoe_attach_event(sd_pppoe *ppp, sd_event *event, int priority);
+int sd_pppoe_get_channel(sd_pppoe *ppp, int *channel);
+int sd_pppoe_set_callback(sd_pppoe *ppp, sd_pppoe_cb_t cb, void *userdata);
+int sd_pppoe_set_ifindex(sd_pppoe *ppp, int ifindex);
+int sd_pppoe_set_ifname(sd_pppoe *ppp, const char *ifname);
+int sd_pppoe_set_service_name(sd_pppoe *ppp, const char *service_name);
+int sd_pppoe_start(sd_pppoe *ppp);
+int sd_pppoe_stop(sd_pppoe *ppp);
+sd_pppoe *sd_pppoe_ref(sd_pppoe *ppp);
+sd_pppoe *sd_pppoe_unref(sd_pppoe *ppp);
+int sd_pppoe_new (sd_pppoe **ret);
+
+#endif