Line data    Source code

       1              : /* SPDX-License-Identifier: GPL-2.0-only */
       2              : /*
       3              :  * Copyright (c) 2023 Meta Platforms, Inc. and affiliates.
       4              :  */
       5              : 
       6              : // clang-format off
       7              : // Include net/if.h before any kernel header to avoid conflicts.
       8              : #include <net/if.h>
       9              : // clang-format on
      10              : 
      11              : #include "core/if.h"
      12              : 
      13              : #include <errno.h>
      14              : #include <limits.h>
      15              : #include <stdlib.h>
      16              : #include <string.h>
      17              : #include <sys/types.h>
      18              : 
      19              : #include "core/helper.h"
      20              : #include "core/logger.h"
      21              : 
      22              : static char _bf_if_name[IFNAMSIZ];
      23              : 
      24            0 : int bf_if_index_from_name(const char *name)
      25              : {
      26              :     unsigned int r;
      27              : 
      28            0 :     bf_assert(name);
      29              : 
      30            0 :     r = if_nametoindex(name);
      31            0 :     if (r == 0) {
      32            0 :         return bf_err_r(errno, "failed to get ifindex for interface '%s'",
      33              :                         name);
      34              :     }
      35              : 
      36            0 :     if (r > INT_MAX)
      37            0 :         return bf_err_r(-E2BIG, "ifindex is too big: %d", r);
      38              : 
      39              :     return (int)r;
      40              : }
      41              : 
      42            0 : const char *bf_if_name_from_index(int index)
      43              : {
      44            0 :     if (!if_indextoname(index, _bf_if_name)) {
      45            0 :         bf_warn_r(errno, "failed to get ifname for interface '%d'", index);
      46            0 :         strncpy(_bf_if_name, "<unknown>", IFNAMSIZ);
      47              :     }
      48              : 
      49            0 :     return _bf_if_name;
      50              : }
      51              : 
      52            0 : ssize_t bf_if_get_ifaces(struct bf_if_iface **ifaces)
      53              : {
      54              :     _cleanup_free_ struct bf_if_iface *_ifaces = NULL;
      55              :     struct if_nameindex *if_ni, *it;
      56              :     ssize_t n_ifaces = 0;
      57              :     size_t i = 0;
      58              : 
      59            0 :     bf_assert(ifaces);
      60              : 
      61            0 :     if_ni = if_nameindex();
      62            0 :     if (!if_ni)
      63            0 :         return bf_err_r(errno, "failed to fetch interfaces details");
      64              : 
      65              :     // Gather the number of interfaces to allocate the memory.
      66            0 :     for (it = if_ni; it->if_index != 0 || it->if_name != NULL; ++it)
      67            0 :         ++n_ifaces;
      68              : 
      69            0 :     if (n_ifaces == 0)
      70              :         return 0;
      71              : 
      72            0 :     _ifaces = malloc(n_ifaces * sizeof(*_ifaces));
      73            0 :     if (!_ifaces) {
      74            0 :         if_freenameindex(if_ni);
      75            0 :         return bf_err_r(-ENOMEM,
      76              :                         "failed to allocate memory for interfaces buffer");
      77              :     }
      78              : 
      79            0 :     for (it = if_ni; it->if_index != 0 || it->if_name != NULL; ++it) {
      80            0 :         _ifaces[i].index = it->if_index;
      81              : 
      82            0 :         if (it->if_index)
      83            0 :             strncpy(_ifaces[i].name, it->if_name, IF_NAMESIZE);
      84              :         else
      85            0 :             bf_warn("interface %d has no name", it->if_index);
      86              : 
      87            0 :         ++i;
      88              :     }
      89              : 
      90            0 :     *ifaces = TAKE_PTR(_ifaces);
      91              : 
      92            0 :     if_freenameindex(if_ni);
      93              : 
      94            0 :     return n_ifaces;
      95              : }