src/patches/dnsmasq/0010-Teach-the-new-inotify-code-about-symlinks.patch

   1 From 857973e6f7e0a3d03535a9df7f9373fd7a0b65cc Mon Sep 17 00:00:00 2001
   2 From: Simon Kelley <simon@thekelleys.org.uk>
   3 Date: Mon, 15 Dec 2014 15:58:13 +0000
   4 Subject: [PATCH 10/71] Teach the new inotify code about symlinks.
   5
   6 ---
   7  src/inotify.c | 43 +++++++++++++++++++++++++++----------------
   8  1 file changed, 27 insertions(+), 16 deletions(-)
   9
  10 diff --git a/src/inotify.c b/src/inotify.c
  11 index a0223443d6b6..960bf5efb41f 100644
  12 --- a/src/inotify.c
  13 +++ b/src/inotify.c
  14 @@ -41,29 +41,40 @@ void inotify_dnsmasq_init()
  15
  16    inotify_buffer = safe_malloc(INOTIFY_SZ);
  17
  18 -  daemon->inotifyfd = inotify_init1(IN_NONBLOCK | IN_CLOEXEC);
  19
  20 +  daemon->inotifyfd = inotify_init1(IN_NONBLOCK | IN_CLOEXEC);
  21 +
  22    if (daemon->inotifyfd == -1)
  23      die(_("failed to create inotify: %s"), NULL, EC_MISC);
  24 -
  25 +
  26    for (res = daemon->resolv_files; res; res = res->next)
  27      {
  28 -      char *d = strrchr(res->name, '/');
  29 -
  30 -      if (!d)
  31 -       die(_("resolv-file %s not an absolute path"), res->name, EC_MISC);
  32 -
  33 -      *d = 0; /* make ->name just directory */
  34 -      res->wd = inotify_add_watch(daemon->inotifyfd, res->name, IN_CLOSE_WRITE | IN_MOVED_TO);
  35 -      res->file = d+1; /* pointer to filename */
  36 -
  37 -      if (res->wd == -1 && errno == ENOENT)
  38 -       die(_("directory %s for resolv-file is missing, cannot poll"), res->name, EC_MISC);
  39 +      char *d = NULL, *path;
  40
  41 -      *d = '/'; /* restore name */
  42 +      if (!(path = realpath(res->name, NULL)))
  43 +       {
  44 +         /* realpath will fail if the file doesn't exist, but
  45 +            dnsmasq copes with missing files, so fall back
  46 +            and assume that symlinks are not in use in that case. */
  47 +         if (errno == ENOENT)
  48 +           path = res->name;
  49 +         else
  50 +           die(_("cannot cannonicalise resolv-file %s: %s"), res->name, EC_MISC);
  51 +       }
  52
  53 -      if (res->wd == -1)
  54 -       die(_("failed to create inotify for %s: %s"), res->name, EC_MISC);
  55 +      if ((d = strrchr(path, '/')))
  56 +       {
  57 +         *d = 0; /* make path just directory */
  58 +         res->wd = inotify_add_watch(daemon->inotifyfd, path, IN_CLOSE_WRITE | IN_MOVED_TO);
  59 +         res->file = d+1; /* pointer to filename */
  60 +         *d = '/';
  61 +
  62 +         if (res->wd == -1 && errno == ENOENT)
  63 +           die(_("directory %s for resolv-file is missing, cannot poll"), res->name, EC_MISC);
  64 +
  65 +         if (res->wd == -1)
  66 +           die(_("failed to create inotify for %s: %s"), res->name, EC_MISC);
  67 +       }
  68      }
  69  }
  70
  71 --
  72 2.1.0
  73