src/network/networkd.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <netinet/in.h>
   4 #include <sys/stat.h>
   5 #include <sys/types.h>
   6
   7 #include "sd-daemon.h"
   8 #include "sd-event.h"
   9
  10 #include "capability-util.h"
  11 #include "daemon-util.h"
  12 #include "firewall-util.h"
  13 #include "main-func.h"
  14 #include "mkdir.h"
  15 #include "networkd-conf.h"
  16 #include "networkd-manager.h"
  17 #include "signal-util.h"
  18 #include "user-util.h"
  19
  20 static int run(int argc, char *argv[]) {
  21         _cleanup_(manager_freep) Manager *m = NULL;
  22         _cleanup_(notify_on_cleanup) const char *notify_message = NULL;
  23         int r;
  24
  25         log_setup();
  26
  27         umask(0022);
  28
  29         if (argc != 1)
  30                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "This program takes no arguments.");
  31
  32         /* Drop privileges, but only if we have been started as root. If we are not running as root we assume all
  33          * privileges are already dropped and we can't create our runtime directory. */
  34         if (geteuid() == 0) {
  35                 const char *user = "systemd-network";
  36                 uid_t uid;
  37                 gid_t gid;
  38
  39                 r = get_user_creds(&user, &uid, &gid, NULL, NULL, 0);
  40                 if (r < 0)
  41                         return log_error_errno(r, "Cannot resolve user name %s: %m", user);
  42
  43                 /* Create runtime directory. This is not necessary when networkd is
  44                  * started with "RuntimeDirectory=systemd/netif", or after
  45                  * systemd-tmpfiles-setup.service. */
  46                 r = mkdir_safe_label("/run/systemd/netif", 0755, uid, gid, MKDIR_WARN_MODE);
  47                 if (r < 0)
  48                         log_warning_errno(r, "Could not create runtime directory: %m");
  49
  50                 r = drop_privileges(uid, gid,
  51                                     (1ULL << CAP_NET_ADMIN) |
  52                                     (1ULL << CAP_NET_BIND_SERVICE) |
  53                                     (1ULL << CAP_NET_BROADCAST) |
  54                                     (1ULL << CAP_NET_RAW));
  55                 if (r < 0)
  56                         return log_error_errno(r, "Failed to drop privileges: %m");
  57         }
  58
  59         /* Always create the directories people can create inotify watches in.
  60          * It is necessary to create the following subdirectories after drop_privileges()
  61          * to support old kernels not supporting AmbientCapabilities=. */
  62         r = mkdir_safe_label("/run/systemd/netif/links", 0755, UID_INVALID, GID_INVALID, MKDIR_WARN_MODE);
  63         if (r < 0)
  64                 log_warning_errno(r, "Could not create runtime directory 'links': %m");
  65
  66         r = mkdir_safe_label("/run/systemd/netif/leases", 0755, UID_INVALID, GID_INVALID, MKDIR_WARN_MODE);
  67         if (r < 0)
  68                 log_warning_errno(r, "Could not create runtime directory 'leases': %m");
  69
  70         r = mkdir_safe_label("/run/systemd/netif/lldp", 0755, UID_INVALID, GID_INVALID, MKDIR_WARN_MODE);
  71         if (r < 0)
  72                 log_warning_errno(r, "Could not create runtime directory 'lldp': %m");
  73
  74         assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGTERM, SIGINT, -1) >= 0);
  75
  76         r = manager_new(&m);
  77         if (r < 0)
  78                 return log_error_errno(r, "Could not create manager: %m");
  79
  80         r = manager_connect_bus(m);
  81         if (r < 0)
  82                 return log_error_errno(r, "Could not connect to bus: %m");
  83
  84         r = manager_parse_config_file(m);
  85         if (r < 0)
  86                 log_warning_errno(r, "Failed to parse configuration file: %m");
  87
  88         r = manager_load_config(m);
  89         if (r < 0)
  90                 return log_error_errno(r, "Could not load configuration files: %m");
  91
  92         r = manager_enumerate(m);
  93         if (r < 0)
  94                 return r;
  95
  96         r = manager_start(m);
  97         if (r < 0)
  98                 return log_error_errno(r, "Could not start manager: %m");
  99
 100         log_info("Enumeration completed");
 101
 102         notify_message = notify_start(NOTIFY_READY, NOTIFY_STOPPING);
 103
 104         r = sd_event_loop(m->event);
 105         if (r < 0)
 106                 return log_error_errno(r, "Event loop failed: %m");
 107
 108         return 0;
 109 }
 110
 111 DEFINE_MAIN_FUNCTION(run);