batctl/patches/0005-batctl-Prefer-netlink-hardif-status-retrieval-over-s.patch

   1 From: Sven Eckelmann <sven@narfation.org>
   2 Date: Wed, 19 Jun 2019 09:37:50 +0200
   3 Subject: batctl: Prefer netlink hardif status retrieval over sysfs
   4
   5 The sysfs code in batman-adv was changed to print a deprecated warning when
   6 sysfs files are accessed. The `batctl if` call would therefore cause
   7 warnings like this in the kernel log:
   8
   9   batman_adv: [Deprecated]: batctl (pid 18540) Use of sysfs file "iface_status".
  10   Use batadv genl family instead
  11
  12 It is now appropriate to try the generic netlink BATADV_CMD_GET_HARDIF
  13 request first to get the status of the interface before falling back to
  14 sysfs.
  15
  16 Reported-by: Linus Lüssing <linus.luessing@c0d3.blue>
  17 Signed-off-by: Sven Eckelmann <sven@narfation.org>
  18
  19 Origin: upstream, https://git.open-mesh.org/batctl.git/commit/ce5f0efb35bff8a80992df63876bcac1d4a94867
  20
  21 diff --git a/interface.c b/interface.c
  22 index 5ff25a7b790d68aa69155f0cc7661080145ac86e..0a694c9f41f71a3dd72ae87b79b28434f7e8918f 100644
  23 --- a/interface.c
  24 +++ b/interface.c
  25 @@ -67,18 +67,18 @@ static int get_iface_status_netlink_parse(struct nl_msg *msg, void *arg)
  26  static char *get_iface_status_netlink(unsigned int meshif, unsigned int hardif,
  27                                       char *iface_status)
  28  {
  29 +       char *ret_status = NULL;
  30         struct nl_sock *sock;
  31         struct nl_msg *msg;
  32         int batadv_family;
  33         struct nl_cb *cb;
  34         int ret;
  35
  36 -       strncpy(iface_status, "<error reading status>\n", IFACE_STATUS_LEN);
  37 -       iface_status[IFACE_STATUS_LEN - 1] = '\0';
  38 +       iface_status[0] = '\0';
  39
  40         sock = nl_socket_alloc();
  41         if (!sock)
  42 -               return iface_status;
  43 +               return NULL;
  44
  45         ret = genl_connect(sock);
  46         if (ret < 0)
  47 @@ -111,6 +111,9 @@ static char *get_iface_status_netlink(unsigned int meshif, unsigned int hardif,
  48
  49         nl_recvmsgs(sock, cb);
  50
  51 +       if (strlen(iface_status) > 0)
  52 +               ret_status = iface_status;
  53 +
  54  err_free_msg:
  55         nlmsg_free(msg);
  56  err_free_cb:
  57 @@ -118,7 +121,7 @@ static char *get_iface_status_netlink(unsigned int meshif, unsigned int hardif,
  58  err_free_sock:
  59         nl_socket_free(sock);
  60
  61 -       return iface_status;
  62 +       return ret_status;
  63  }
  64
  65  static struct nla_policy link_policy[IFLA_MAX + 1] = {
  66 @@ -161,13 +164,17 @@ static int print_interfaces_rtnl_parse(struct nl_msg *msg, void *arg)
  67         if (master != print_arg->ifindex)
  68                 goto err;
  69
  70 -       snprintf(path_buff, sizeof(path_buff), SYS_IFACE_STATUS_FMT, ifname);
  71 -       ret = read_file("", path_buff, USE_READ_BUFF | SILENCE_ERRORS, 0, 0, 0);
  72 -       if (ret != EXIT_SUCCESS)
  73 -               status = get_iface_status_netlink(master, ifm->ifi_index,
  74 -                                                 iface_status);
  75 -       else
  76 -               status = line_ptr;
  77 +       status = get_iface_status_netlink(master, ifm->ifi_index, iface_status);
  78 +       if (!status) {
  79 +               snprintf(path_buff, sizeof(path_buff), SYS_IFACE_STATUS_FMT,
  80 +                        ifname);
  81 +               ret = read_file("", path_buff, USE_READ_BUFF | SILENCE_ERRORS,
  82 +                               0, 0, 0);
  83 +               if (ret != EXIT_SUCCESS)
  84 +                       status = "<error reading status>\n";
  85 +               else
  86 +                       status = line_ptr;
  87 +       }
  88
  89         printf("%s: %s", ifname, status);
  90