sd-network: add new library

This is similar to sd-login, but exposes the state of networkd rather than logind.

Include it in libsystemd-dhcp and rename it to libsystemd-network.

src/network/networkd-link.c

@@ -28,6 +28,8 @@
 #include "bus-util.h"
 #include "net-util.h"
 
+#include "dhcp-lease-internal.h"
+
 int link_new(Manager *manager, struct udev_device *device, Link **ret) {
         _cleanup_link_free_ Link *link = NULL;
         const char *mac;
@@ -51,6 +53,11 @@ int link_new(Manager *manager, struct udev_device *device, Link **ret) {
         if (link->ifindex <= 0)
                 return -EINVAL;
 
+        r = asprintf(&link->state_file, "/run/systemd/network/links/%u",
+                     (unsigned) link->ifindex);
+        if (r < 0)
+                return r;
+
         mac = udev_device_get_sysattr_value(device, "address");
         if (mac) {
                 mac_addr = ether_aton(mac);
@@ -83,6 +90,7 @@ void link_free(Link *link) {
         hashmap_remove(link->manager->links, &link->ifindex);
 
         free(link->ifname);
+        free(link->state_file);
 
         free(link);
 }
@@ -139,6 +147,8 @@ static int link_enter_configured(Link *link) {
 
         link->state = LINK_STATE_CONFIGURED;
 
+        link_save(link);
+
         return 0;
 }
 
@@ -148,6 +158,8 @@ static void link_enter_failed(Link *link) {
         log_warning_link(link, "failed");
 
         link->state = LINK_STATE_FAILED;
+
+        link_save(link);
 }
 
 static int route_handler(sd_rtnl *rtnl, sd_rtnl_message *m, void *userdata) {
@@ -900,6 +912,8 @@ static int link_enter_enslave(Link *link) {
 
         link->state = LINK_STATE_ENSLAVING;
 
+        link_save(link);
+
         if (!link->network->bridge && !link->network->bond &&
             hashmap_isempty(link->network->vlans) &&
             hashmap_isempty(link->network->macvlans))
@@ -1066,3 +1080,61 @@ int link_update(Link *link, sd_rtnl_message *m) {
 
         return link_update_flags(link, flags);
 }
+
+int link_save(Link *link) {
+        _cleanup_free_ char *temp_path = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        int r;
+
+        assert(link);
+        assert(link->state_file);
+
+        r = mkdir_safe_label("/run/systemd/network/links", 0755, 0, 0);
+        if (r < 0)
+                goto finish;
+
+        r = fopen_temporary(link->state_file, &f, &temp_path);
+        if (r < 0)
+                goto finish;
+
+        fchmod(fileno(f), 0644);
+
+        fprintf(f,
+                "# This is private data. Do not parse.\n"
+                "STATE=%s\n",
+                link_state_to_string(link->state));
+
+        if (link->dhcp_lease) {
+                const char *lease_file = "/run/systemd/network/leases/test.lease";
+
+                r = dhcp_lease_save(link->dhcp_lease, lease_file);
+                if (r < 0)
+                        goto finish;
+
+                fprintf(f, "DHCP_LEASE=%s\n", lease_file);
+        }
+
+        fflush(f);
+
+        if (ferror(f) || rename(temp_path, link->state_file) < 0) {
+                r = -errno;
+                unlink(link->state_file);
+                unlink(temp_path);
+        }
+
+finish:
+        if (r < 0)
+                log_error("Failed to save link data %s: %s", link->state_file, strerror(-r));
+
+        return r;
+}
+
+static const char* const link_state_table[_LINK_STATE_MAX] = {
+        [LINK_STATE_ENSLAVING] = "configuring",
+        [LINK_STATE_SETTING_ADDRESSES] = "configuring",
+        [LINK_STATE_SETTING_ROUTES] = "configuring",
+        [LINK_STATE_CONFIGURED] = "configured",
+        [LINK_STATE_FAILED] = "failed",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(link_state, LinkState);

src/network/networkd.c

@@ -40,6 +40,11 @@ int main(int argc, char *argv[]) {
                 goto out;
         }
 
+        /* Always create the directories people can create inotify
+         * watches in. */
+        mkdir_label("/run/systemd/network/links", 0755);
+        mkdir_label("/run/systemd/network/leases", 0755);
+
         r = manager_new(&m);
         if (r < 0) {
                 log_error("Could not create manager: %s", strerror(-r));

src/network/networkd.h

@@ -189,6 +189,7 @@ struct Link {
 
         uint64_t ifindex;
         char *ifname;
+        char *state_file;
         struct ether_addr mac;
 
         unsigned flags;
@@ -354,6 +355,11 @@ int link_configure(Link *link);
 
 int link_update(Link *link, sd_rtnl_message *message);
 
+int link_save(Link *link);
+
+const char* link_state_to_string(LinkState s) _const_;
+LinkState link_state_from_string(const char *s) _pure_;
+
 DEFINE_TRIVIAL_CLEANUP_FUNC(Link*, link_free);
 #define _cleanup_link_free_ _cleanup_(link_freep)
 

src/network/sd-network.c

@@ -0,0 +1,237 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2011 Lennart Poettering
+  Copyright 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 <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/inotify.h>
+#include <sys/poll.h>
+
+#include "util.h"
+#include "macro.h"
+#include "strv.h"
+#include "fileio.h"
+#include "sd-network.h"
+#include "dhcp-lease-internal.h"
+
+_public_ int sd_network_get_link_state(unsigned index, char **state) {
+        char *p, *s = NULL;
+        int r;
+
+        assert_return(index, -EINVAL);
+        assert_return(state, -EINVAL);
+
+        if (asprintf(&p, "/run/systemd/network/links/%u", index) < 0)
+                return -ENOMEM;
+
+        r = parse_env_file(p, NEWLINE, "STATE", &s, NULL);
+        free(p);
+
+        if (r == -ENOENT) {
+                free(s);
+                s = strdup("unknown");
+                if (!s)
+                        return -ENOMEM;
+
+                *state = s;
+                return 0;
+        } else if (r < 0) {
+                free(s);
+                return r;
+        } else if (!s)
+                return -EIO;
+
+        *state = s;
+        return 0;
+}
+
+_public_ int sd_network_get_dhcp_lease(unsigned index, sd_dhcp_lease **ret) {
+        sd_dhcp_lease *lease;
+        char *p, *s = NULL;
+        int r;
+
+        assert_return(index, -EINVAL);
+        assert_return(ret, -EINVAL);
+
+        if (asprintf(&p, "/run/systemd/network/links/%u", index) < 0)
+                return -ENOMEM;
+
+        r = parse_env_file(p, NEWLINE, "DHCP_LEASE", &s, NULL);
+        free(p);
+
+        if (r < 0) {
+                free(s);
+                return r;
+        } else if (!s)
+                return -EIO;
+
+        r = dhcp_lease_load(s, &lease);
+        if (r < 0)
+                return r;
+
+        *ret = lease;
+
+        return 0;
+}
+
+_public_ int sd_network_get_ifindices(unsigned **indices) {
+        _cleanup_closedir_ DIR *d;
+        int r = 0;
+        unsigned n = 0;
+        _cleanup_free_ uid_t *l = NULL;
+
+        d = opendir("/run/systemd/network/links/");
+        if (!d)
+                return -errno;
+
+        for (;;) {
+                struct dirent *de;
+                int k;
+                unsigned index;
+
+                errno = 0;
+                de = readdir(d);
+                if (!de && errno != 0)
+                        return -errno;
+
+                if (!de)
+                        break;
+
+                dirent_ensure_type(d, de);
+
+                if (!dirent_is_file(de))
+                        continue;
+
+                k = safe_atou(de->d_name, &index);
+                if (k < 0)
+                        continue;
+
+                if (indices) {
+                        if ((unsigned) r >= n) {
+                                unsigned *t;
+
+                                n = MAX(16, 2*r);
+                                t = realloc(l, sizeof(unsigned) * n);
+                                if (!t)
+                                        return -ENOMEM;
+
+                                l = t;
+                        }
+
+                        assert((unsigned) r < n);
+                        l[r++] = index;
+                } else
+                        r++;
+        }
+
+        if (indices) {
+                *indices = l;
+                l = NULL;
+        }
+
+        return r;
+}
+
+static inline int MONITOR_TO_FD(sd_network_monitor *m) {
+        return (int) (unsigned long) m - 1;
+}
+
+static inline sd_network_monitor* FD_TO_MONITOR(int fd) {
+        return (sd_network_monitor*) (unsigned long) (fd + 1);
+}
+
+_public_ int sd_network_monitor_new(const char *category, sd_network_monitor **m) {
+        int fd, k;
+        bool good = false;
+
+        assert_return(m, -EINVAL);
+
+        fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC);
+        if (fd < 0)
+                return -errno;
+
+        if (!category || streq(category, "netif")) {
+                k = inotify_add_watch(fd, "/run/systemd/network/links/", IN_MOVED_TO|IN_DELETE);
+                if (k < 0) {
+                        close_nointr_nofail(fd);
+                        return -errno;
+                }
+
+                good = true;
+        }
+
+        if (!good) {
+                close_nointr(fd);
+                return -EINVAL;
+        }
+
+        *m = FD_TO_MONITOR(fd);
+        return 0;
+}
+
+_public_ sd_network_monitor* sd_network_monitor_unref(sd_network_monitor *m) {
+        int fd;
+
+        assert_return(m, NULL);
+
+        fd = MONITOR_TO_FD(m);
+        close_nointr(fd);
+
+        return NULL;
+}
+
+_public_ int sd_network_monitor_flush(sd_network_monitor *m) {
+
+        assert_return(m, -EINVAL);
+
+        return flush_fd(MONITOR_TO_FD(m));
+}
+
+_public_ int sd_network_monitor_get_fd(sd_network_monitor *m) {
+
+        assert_return(m, -EINVAL);
+
+        return MONITOR_TO_FD(m);
+}
+
+_public_ int sd_network_monitor_get_events(sd_network_monitor *m) {
+
+        assert_return(m, -EINVAL);
+
+        /* For now we will only return POLLIN here, since we don't
+         * need anything else ever for inotify.  However, let's have
+         * this API to keep our options open should we later on need
+         * it. */
+        return POLLIN;
+}
+
+_public_ int sd_network_monitor_get_timeout(sd_network_monitor *m, uint64_t *timeout_usec) {
+
+        assert_return(m, -EINVAL);
+        assert_return(timeout_usec, -EINVAL);
+
+        /* For now we will only return (uint64_t) -1, since we don't
+         * need any timeout. However, let's have this API to keep our
+         * options open should we later on need it. */
+        *timeout_usec = (uint64_t) -1;
+        return 0;
+}