src/network/networkd.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   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 "main-func.h"
  13 #include "mkdir.h"
  14 #include "networkd-conf.h"
  15 #include "networkd-manager.h"
  16 #include "signal-util.h"
  17 #include "user-util.h"
  18
  19 static int run(int argc, char *argv[]) {
  20         _cleanup_(manager_freep) Manager *m = NULL;
  21         _cleanup_(notify_on_cleanup) const char *notify_message = NULL;
  22         int r;
  23
  24         log_setup_service();
  25
  26         umask(0022);
  27
  28         if (argc != 1)
  29                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "This program takes no arguments.");
  30
  31         /* Drop privileges, but only if we have been started as root. If we are not running as root we assume all
  32          * privileges are already dropped and we can't create our runtime directory. */
  33         if (geteuid() == 0) {
  34                 const char *user = "systemd-network";
  35                 uid_t uid;
  36                 gid_t gid;
  37
  38                 r = get_user_creds(&user, &uid, &gid, NULL, NULL, 0);
  39                 if (r < 0)
  40                         return log_error_errno(r, "Cannot resolve user name %s: %m", user);
  41
  42                 /* Create runtime directory. This is not necessary when networkd is
  43                  * started with "RuntimeDirectory=systemd/netif", or after
  44                  * systemd-tmpfiles-setup.service. */
  45                 r = mkdir_safe_label("/run/systemd/netif", 0755, uid, gid, MKDIR_WARN_MODE);
  46                 if (r < 0)
  47                         log_warning_errno(r, "Could not create runtime directory: %m");
  48
  49                 r = drop_privileges(uid, gid,
  50                                     (1ULL << CAP_NET_ADMIN) |
  51                                     (1ULL << CAP_NET_BIND_SERVICE) |
  52                                     (1ULL << CAP_NET_BROADCAST) |
  53                                     (1ULL << CAP_NET_RAW));
  54                 if (r < 0)
  55                         return log_error_errno(r, "Failed to drop privileges: %m");
  56         }
  57
  58         /* Always create the directories people can create inotify watches in.
  59          * It is necessary to create the following subdirectories after drop_privileges()
  60          * to support old kernels not supporting AmbientCapabilities=. */
  61         r = mkdir_safe_label("/run/systemd/netif/links", 0755, UID_INVALID, GID_INVALID, MKDIR_WARN_MODE);
  62         if (r < 0)
  63                 log_warning_errno(r, "Could not create runtime directory 'links': %m");
  64
  65         r = mkdir_safe_label("/run/systemd/netif/leases", 0755, UID_INVALID, GID_INVALID, MKDIR_WARN_MODE);
  66         if (r < 0)
  67                 log_warning_errno(r, "Could not create runtime directory 'leases': %m");
  68
  69         r = mkdir_safe_label("/run/systemd/netif/lldp", 0755, UID_INVALID, GID_INVALID, MKDIR_WARN_MODE);
  70         if (r < 0)
  71                 log_warning_errno(r, "Could not create runtime directory 'lldp': %m");
  72
  73         assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGTERM, SIGINT, -1) >= 0);
  74
  75         r = manager_new(&m);
  76         if (r < 0)
  77                 return log_error_errno(r, "Could not create manager: %m");
  78
  79         r = manager_connect_bus(m);
  80         if (r < 0)
  81                 return log_error_errno(r, "Could not connect to bus: %m");
  82
  83         r = manager_parse_config_file(m);
  84         if (r < 0)
  85                 log_warning_errno(r, "Failed to parse configuration file: %m");
  86
  87         r = manager_load_config(m);
  88         if (r < 0)
  89                 return log_error_errno(r, "Could not load configuration files: %m");
  90
  91         r = manager_rtnl_enumerate_links(m);
  92         if (r < 0)
  93                 return log_error_errno(r, "Could not enumerate links: %m");
  94
  95         r = manager_rtnl_enumerate_addresses(m);
  96         if (r < 0)
  97                 return log_error_errno(r, "Could not enumerate addresses: %m");
  98
  99         r = manager_rtnl_enumerate_neighbors(m);
 100         if (r < 0)
 101                 return log_error_errno(r, "Could not enumerate neighbors: %m");
 102
 103         r = manager_rtnl_enumerate_routes(m);
 104         if (r < 0)
 105                 return log_error_errno(r, "Could not enumerate routes: %m");
 106
 107         r = manager_rtnl_enumerate_rules(m);
 108         if (r < 0)
 109                 return log_error_errno(r, "Could not enumerate rules: %m");
 110
 111         r = manager_rtnl_enumerate_nexthop(m);
 112         if (r < 0)
 113                 return log_error_errno(r, "Could not enumerate nexthop: %m");
 114
 115         r = manager_start(m);
 116         if (r < 0)
 117                 return log_error_errno(r, "Could not start manager: %m");
 118
 119         log_info("Enumeration completed");
 120
 121         notify_message = notify_start(NOTIFY_READY, NOTIFY_STOPPING);
 122
 123         r = sd_event_loop(m->event);
 124         if (r < 0)
 125                 return log_error_errno(r, "Event loop failed: %m");
 126
 127         return 0;
 128 }
 129
 130 DEFINE_MAIN_FUNCTION(run);