src/network/networkd-lldp-rx.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <net/if.h>
   4 #include <net/if_arp.h>
   5 #include <unistd.h>
   6
   7 #include "fd-util.h"
   8 #include "fileio.h"
   9 #include "fs-util.h"
  10 #include "networkd-link.h"
  11 #include "networkd-lldp-rx.h"
  12 #include "networkd-lldp-tx.h"
  13 #include "networkd-manager.h"
  14 #include "networkd-network.h"
  15 #include "string-table.h"
  16 #include "string-util.h"
  17 #include "strv.h"
  18 #include "tmpfile-util.h"
  19
  20 DEFINE_CONFIG_PARSE_ENUM(config_parse_lldp_mode, lldp_mode, LLDPMode, "Failed to parse LLDP= setting.");
  21
  22 static const char* const lldp_mode_table[_LLDP_MODE_MAX] = {
  23         [LLDP_MODE_NO] = "no",
  24         [LLDP_MODE_YES] = "yes",
  25         [LLDP_MODE_ROUTERS_ONLY] = "routers-only",
  26 };
  27
  28 DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(lldp_mode, LLDPMode, LLDP_MODE_YES);
  29
  30 static bool link_lldp_rx_enabled(Link *link) {
  31         assert(link);
  32
  33         if (link->flags & IFF_LOOPBACK)
  34                 return false;
  35
  36         if (link->iftype != ARPHRD_ETHER)
  37                 return false;
  38
  39         if (!link->network)
  40                 return false;
  41
  42         /* LLDP should be handled on bridge and bond slaves as those have a direct connection to their peers,
  43          * not on the bridge/bond master. Linux doesn't even (by default) forward lldp packets to the bridge
  44          * master. */
  45         if (link->kind && STR_IN_SET(link->kind, "bridge", "bond"))
  46                 return false;
  47
  48         return link->network->lldp_mode != LLDP_MODE_NO;
  49 }
  50
  51 static void lldp_rx_handler(sd_lldp_rx *lldp_rx, sd_lldp_rx_event_t event, sd_lldp_neighbor *n, void *userdata) {
  52         Link *link = ASSERT_PTR(userdata);
  53         int r;
  54
  55         if (link->lldp_tx && event == SD_LLDP_RX_EVENT_ADDED) {
  56                 /* If we received information about a new neighbor, restart the LLDP "fast" logic */
  57
  58                 log_link_debug(link, "Received LLDP datagram from previously unknown neighbor, restarting 'fast' LLDP transmission.");
  59
  60                 (void) sd_lldp_tx_stop(link->lldp_tx);
  61                 r = sd_lldp_tx_start(link->lldp_tx);
  62                 if (r < 0)
  63                         log_link_warning_errno(link, r, "Failed to restart LLDP transmission: %m");
  64         }
  65 }
  66
  67 int link_lldp_rx_configure(Link *link) {
  68         int r;
  69
  70         if (!link_lldp_rx_enabled(link))
  71                 return 0;
  72
  73         if (link->lldp_rx)
  74                 return -EBUSY;
  75
  76         r = sd_lldp_rx_new(&link->lldp_rx);
  77         if (r < 0)
  78                 return r;
  79
  80         r = sd_lldp_rx_attach_event(link->lldp_rx, link->manager->event, 0);
  81         if (r < 0)
  82                 return r;
  83
  84         r = sd_lldp_rx_set_ifindex(link->lldp_rx, link->ifindex);
  85         if (r < 0)
  86                 return r;
  87
  88         r = sd_lldp_rx_match_capabilities(link->lldp_rx,
  89                                           link->network->lldp_mode == LLDP_MODE_ROUTERS_ONLY ?
  90                                           SD_LLDP_SYSTEM_CAPABILITIES_ALL_ROUTERS :
  91                                           SD_LLDP_SYSTEM_CAPABILITIES_ALL);
  92         if (r < 0)
  93                 return r;
  94
  95         r = sd_lldp_rx_set_filter_address(link->lldp_rx, &link->hw_addr.ether);
  96         if (r < 0)
  97                 return r;
  98
  99         r = sd_lldp_rx_set_callback(link->lldp_rx, lldp_rx_handler, link);
 100         if (r < 0)
 101                 return r;
 102
 103         return 0;
 104 }