src/patches/dnsmasq/0034-Add-dhcp-hostsdir-config-option.patch

   1 From 5f4dc5c6ca50655ab14f572c7e30815ed74cd51a Mon Sep 17 00:00:00 2001
   2 From: Simon Kelley <simon@thekelleys.org.uk>
   3 Date: Tue, 20 Jan 2015 20:51:02 +0000
   4 Subject: [PATCH 34/78] Add --dhcp-hostsdir config option.
   5
   6 ---
   7  CHANGELOG     |   5 +++
   8  man/dnsmasq.8 |   9 +++++
   9  src/dnsmasq.c |  28 ++++++++++----
  10  src/dnsmasq.h |  15 ++++++--
  11  src/inotify.c | 119 +++++++++++++++++++++++++++++++++++++++++++++++++++++++---
  12  src/option.c  |  22 +++++++++--
  13  6 files changed, 177 insertions(+), 21 deletions(-)
  14
  15 diff --git a/CHANGELOG b/CHANGELOG
  16 index bbd7e6619689..0076b557e95e 100644
  17 --- a/CHANGELOG
  18 +++ b/CHANGELOG
  19 @@ -53,6 +53,11 @@ version 2.73
  20             Cope with multiple interfaces with the same link-local
  21             address. (IPv6 addresses are scoped, so this is allowed.)
  22             Thanks to Cory Benfield for help with this.
  23 +
  24 +           Add --dhcp-hostsdir. This allows addition of new host
  25 +           configurations to a running dnsmasq instance much more
  26 +           cheaply than having dnsmasq re-read all its existing
  27 +           configuration each time.
  28
  29
  30  version 2.72
  31 diff --git a/man/dnsmasq.8 b/man/dnsmasq.8
  32 index 5cfa355dea4a..005b5cca8d1f 100644
  33 --- a/man/dnsmasq.8
  34 +++ b/man/dnsmasq.8
  35 @@ -977,6 +977,15 @@ is given, then read all the files contained in that directory. The advantage of
  36  using this option is the same as for --dhcp-hostsfile: the
  37  dhcp-optsfile will be re-read when dnsmasq receives SIGHUP. Note that
  38  it is possible to encode the information in a
  39 +.TP
  40 +.B --dhcp-hostsdir=<path>
  41 +This is exactly equivalent to dhcp-hostfile, except for the following. The path MUST be a
  42 +directory, and not an individual file. Changed or new files within
  43 +the directory are read automatically, without the need to send SIGHUP.
  44 +If a file is deleted for changed after it has been read by dnsmasq, then the
  45 +host record it contained will remain until dnsmasq recieves a SIGHUP, or
  46 +is restarted; ie host records are only added dynamically.
  47 +.TP
  48  .B --dhcp-boot
  49  flag as DHCP options, using the options names bootfile-name,
  50  server-ip-address and tftp-server. This allows these to be included
  51 diff --git a/src/dnsmasq.c b/src/dnsmasq.c
  52 index c0c0589d4ce1..04cc98278f62 100644
  53 --- a/src/dnsmasq.c
  54 +++ b/src/dnsmasq.c
  55 @@ -142,6 +142,9 @@ int main (int argc, char **argv)
  56        set_option_bool(OPT_NOWILD);
  57        reset_option_bool(OPT_CLEVERBIND);
  58      }
  59 +
  60 +  if (daemon->inotify_hosts)
  61 +    die(_("dhcp-hostsdir not supported on this platform"), NULL, EC_BADCONF);
  62  #endif
  63
  64    if (option_bool(OPT_DNSSEC_VALID))
  65 @@ -316,13 +319,16 @@ int main (int argc, char **argv)
  66  #ifdef HAVE_DNSSEC
  67        blockdata_init();
  68  #endif
  69 +    }
  70
  71  #ifdef HAVE_LINUX_NETWORK
  72 -      if (!option_bool(OPT_NO_POLL))
  73 -       inotify_dnsmasq_init();
  74 +  if ((!option_bool(OPT_NO_POLL) && daemon->port != 0) ||
  75 +      daemon->dhcp || daemon->doing_dhcp6)
  76 +    inotify_dnsmasq_init();
  77 +  else
  78 +    daemon->inotifyfd = -1;
  79  #endif
  80 -    }
  81 -
  82 +
  83    if (option_bool(OPT_DBUS))
  84  #ifdef HAVE_DBUS
  85      {
  86 @@ -745,7 +751,7 @@ int main (int argc, char **argv)
  87  #endif
  88
  89  #ifdef HAVE_TFTP
  90 -       if (option_bool(OPT_TFTP))
  91 +  if (option_bool(OPT_TFTP))
  92      {
  93  #ifdef FD_SETSIZE
  94        if (FD_SETSIZE < (unsigned)max_fd)
  95 @@ -870,7 +876,7 @@ int main (int argc, char **argv)
  96  #if defined(HAVE_LINUX_NETWORK)
  97        FD_SET(daemon->netlinkfd, &rset);
  98        bump_maxfd(daemon->netlinkfd, &maxfd);
  99 -      if (daemon->port != 0 && !option_bool(OPT_NO_POLL))
 100 +      if (daemon->inotifyfd != -1)
 101         {
 102           FD_SET(daemon->inotifyfd, &rset);
 103           bump_maxfd(daemon->inotifyfd, &maxfd);
 104 @@ -943,8 +949,11 @@ int main (int argc, char **argv)
 105  #endif
 106
 107  #ifdef HAVE_LINUX_NETWORK
 108 -      if (daemon->port != 0 && !option_bool(OPT_NO_POLL) && FD_ISSET(daemon->inotifyfd, &rset) && inotify_check())
 109 -       poll_resolv(1, 1, now);
 110 +      if  (daemon->inotifyfd != -1 && FD_ISSET(daemon->inotifyfd, &rset) && inotify_check(now))
 111 +       {
 112 +         if (daemon->port != 0 && !option_bool(OPT_NO_POLL))
 113 +           poll_resolv(1, 1, now);
 114 +       }
 115  #else
 116        /* Check for changes to resolv files once per second max. */
 117        /* Don't go silent for long periods if the clock goes backwards. */
 118 @@ -1385,6 +1394,9 @@ void clear_cache_and_reload(time_t now)
 119        if (option_bool(OPT_ETHERS))
 120         dhcp_read_ethers();
 121        reread_dhcp();
 122 +#ifdef HAVE_LINUX_NETWORK
 123 +      set_dhcp_inotify();
 124 +#endif
 125        dhcp_update_configs(daemon->dhcp_conf);
 126        lease_update_from_configs();
 127        lease_update_file(now);
 128 diff --git a/src/dnsmasq.h b/src/dnsmasq.h
 129 index f8275e3ac479..d841fdc064ad 100644
 130 --- a/src/dnsmasq.h
 131 +++ b/src/dnsmasq.h
 132 @@ -550,13 +550,17 @@ struct resolvc {
 133  #endif
 134  };
 135
 136 -/* adn-hosts parms from command-line (also dhcp-hostsfile and dhcp-optsfile */
 137 +/* adn-hosts parms from command-line (also dhcp-hostsfile and dhcp-optsfile and dhcp-hostsdir*/
 138  #define AH_DIR      1
 139  #define AH_INACTIVE 2
 140 +#define AH_WD_DONE  4
 141  struct hostsfile {
 142    struct hostsfile *next;
 143    int flags;
 144    char *fname;
 145 +#ifdef HAVE_LINUX_NETWORK
 146 +  int wd; /* inotify watch descriptor */
 147 +#endif
 148    unsigned int index; /* matches to cache entries for logging */
 149  };
 150
 151 @@ -961,7 +965,7 @@ extern struct daemon {
 152    int doing_ra, doing_dhcp6;
 153    struct dhcp_netid_list *dhcp_ignore, *dhcp_ignore_names, *dhcp_gen_names;
 154    struct dhcp_netid_list *force_broadcast, *bootp_dynamic;
 155 -  struct hostsfile *dhcp_hosts_file, *dhcp_opts_file;
 156 +  struct hostsfile *dhcp_hosts_file, *dhcp_opts_file, *inotify_hosts;
 157    int dhcp_max, tftp_max;
 158    int dhcp_server_port, dhcp_client_port;
 159    int start_tftp_port, end_tftp_port;
 160 @@ -1197,7 +1201,7 @@ void reset_option_bool(unsigned int opt);
 161  struct hostsfile *expand_filelist(struct hostsfile *list);
 162  char *parse_server(char *arg, union mysockaddr *addr,
 163                    union mysockaddr *source_addr, char *interface, int *flags);
 164 -
 165 +int option_read_hostsfile(char *file);
 166  /* forward.c */
 167  void reply_query(int fd, int family, time_t now);
 168  void receive_query(struct listener *listen, time_t now);
 169 @@ -1486,5 +1490,8 @@ int detect_loop(char *query, int type);
 170  /* inotify.c */
 171  #ifdef HAVE_LINUX_NETWORK
 172  void inotify_dnsmasq_init();
 173 -int inotify_check(void);
 174 +int inotify_check(time_t now);
 175 +#  ifdef HAVE_DHCP
 176 +void set_dhcp_inotify(void);
 177 +#  endif
 178  #endif
 179 diff --git a/src/inotify.c b/src/inotify.c
 180 index 83730008c11b..52a30d7f44db 100644
 181 --- a/src/inotify.c
 182 +++ b/src/inotify.c
 183 @@ -19,6 +19,11 @@
 184
 185  #include <sys/inotify.h>
 186
 187 +#ifdef HAVE_DHCP
 188 +static void check_for_dhcp_inotify(struct inotify_event *in, time_t now);
 189 +#endif
 190 +
 191 +
 192  /* the strategy is to set a inotify on the directories containing
 193     resolv files, for any files in the directory which are close-write
 194     or moved into the directory.
 195 @@ -40,8 +45,6 @@ void inotify_dnsmasq_init()
 196    struct resolvc *res;
 197
 198    inotify_buffer = safe_malloc(INOTIFY_SZ);
 199 -
 200 -
 201    daemon->inotifyfd = inotify_init1(IN_NONBLOCK | IN_CLOEXEC);
 202
 203    if (daemon->inotifyfd == -1)
 204 @@ -66,6 +69,7 @@ void inotify_dnsmasq_init()
 205         {
 206           *d = 0; /* make path just directory */
 207           res->wd = inotify_add_watch(daemon->inotifyfd, path, IN_CLOSE_WRITE | IN_MOVED_TO);
 208 +
 209           res->file = d+1; /* pointer to filename */
 210           *d = '/';
 211
 212 @@ -78,7 +82,7 @@ void inotify_dnsmasq_init()
 213      }
 214  }
 215
 216 -int inotify_check(void)
 217 +int inotify_check(time_t now)
 218  {
 219    int hit = 0;
 220
 221 @@ -101,13 +105,116 @@ int inotify_check(void)
 222           for (res = daemon->resolv_files; res; res = res->next)
 223             if (res->wd == in->wd && in->len != 0 && strcmp(res->file, in->name) == 0)
 224               hit = 1;
 225 +
 226 +#ifdef HAVE_DHCP
 227 +         if (daemon->dhcp || daemon->doing_dhcp6)
 228 +           check_for_dhcp_inotify(in, now);
 229 +#endif
 230         }
 231      }
 232 -
 233    return hit;
 234  }
 235
 236 -#endif
 237 +#ifdef HAVE_DHCP
 238 +/* initialisation for dhcp-hostdir. Set inotify watch for each directory, and read pre-existing files */
 239 +void set_dhcp_inotify(void)
 240 +{
 241 +  struct hostsfile *ah;
 242
 243 -
 244 +  for (ah = daemon->inotify_hosts; ah; ah = ah->next)
 245 +    {
 246 +       DIR *dir_stream = NULL;
 247 +       struct dirent *ent;
 248 +       struct stat buf;
 249 +
 250 +       if (stat(ah->fname, &buf) == -1 || !(S_ISDIR(buf.st_mode)))
 251 +        {
 252 +          my_syslog(LOG_ERR, _("bad directory in dhcp-hostsdir %s"), ah->fname);
 253 +          continue;
 254 +        }
 255 +
 256 +       if (!(ah->flags & AH_WD_DONE))
 257 +        {
 258 +          ah->wd = inotify_add_watch(daemon->inotifyfd, ah->fname, IN_CLOSE_WRITE | IN_MOVED_TO);
 259 +          ah->flags |= AH_WD_DONE;
 260 +        }
 261 +       /* Read contents of dir _after_ calling add_watch, in the ho[e of avoiding
 262 +         a race which misses files being added as we start */
 263 +       if (ah->wd == -1 || !(dir_stream = opendir(ah->fname)))
 264 +        {
 265 +          my_syslog(LOG_ERR, _("failed to create inotify for %s"), ah->fname);
 266 +          continue;
 267 +        }
 268 +
 269 +       while ((ent = readdir(dir_stream)))
 270 +        {
 271 +          size_t lendir = strlen(ah->fname);
 272 +          size_t lenfile = strlen(ent->d_name);
 273 +          char *path;
 274 +
 275 +          /* ignore emacs backups and dotfiles */
 276 +          if (lenfile == 0 ||
 277 +              ent->d_name[lenfile - 1] == '~' ||
 278 +              (ent->d_name[0] == '#' && ent->d_name[lenfile - 1] == '#') ||
 279 +              ent->d_name[0] == '.')
 280 +            continue;
 281 +
 282 +          if ((path = whine_malloc(lendir + lenfile + 2)))
 283 +            {
 284 +              strcpy(path, ah->fname);
 285 +              strcat(path, "/");
 286 +              strcat(path, ent->d_name);
 287 +
 288 +              /* ignore non-regular files */
 289 +              if (stat(path, &buf) != -1 && S_ISREG(buf.st_mode))
 290 +                option_read_hostsfile(path);
 291 +
 292 +              free(path);
 293 +            }
 294 +        }
 295 +    }
 296 +}
 297 +
 298 +static void check_for_dhcp_inotify(struct inotify_event *in, time_t now)
 299 +{
 300 +  struct hostsfile *ah;
 301 +
 302 +  /* ignore emacs backups and dotfiles */
 303 +  if (in->len == 0 ||
 304 +      in->name[in->len - 1] == '~' ||
 305 +      (in->name[0] == '#' && in->name[in->len - 1] == '#') ||
 306 +      in->name[0] == '.')
 307 +    return;
 308 +
 309 +  for (ah = daemon->inotify_hosts; ah; ah = ah->next)
 310 +    if (ah->wd == in->wd)
 311 +      {
 312 +       size_t lendir = strlen(ah->fname);
 313 +       char *path;
 314 +
 315 +       if ((path = whine_malloc(lendir + in->len + 2)))
 316 +         {
 317 +           strcpy(path, ah->fname);
 318 +           strcat(path, "/");
 319 +           strcat(path, in->name);
 320 +
 321 +           if (option_read_hostsfile(path))
 322 +             {
 323 +               /* Propogate the consequences of loading a new dhcp-host */
 324 +               dhcp_update_configs(daemon->dhcp_conf);
 325 +               lease_update_from_configs();
 326 +               lease_update_file(now);
 327 +               lease_update_dns(1);
 328 +             }
 329 +
 330 +           free(path);
 331 +         }
 332 +
 333 +       return;
 334 +      }
 335 +}
 336 +
 337 +#endif /* DHCP */
 338 +
 339 +#endif  /* LINUX_NETWORK */
 340
 341 diff --git a/src/option.c b/src/option.c
 342 index 8b994098cc9f..22e11c37d374 100644
 343 --- a/src/option.c
 344 +++ b/src/option.c
 345 @@ -149,7 +149,7 @@ struct myoption {
 346  #define LOPT_LOOP_DETECT   337
 347  #define LOPT_IGNORE_ADDR   338
 348  #define LOPT_MINCTTL       339
 349 -
 350 +#define LOPT_DHCP_INOTIFY  340
 351
 352  #ifdef HAVE_GETOPT_LONG
 353  static const struct option opts[] =
 354 @@ -248,6 +248,7 @@ static const struct myoption opts[] =
 355      { "interface-name", 1, 0, LOPT_INTNAME },
 356      { "dhcp-hostsfile", 1, 0, LOPT_DHCP_HOST },
 357      { "dhcp-optsfile", 1, 0, LOPT_DHCP_OPTS },
 358 +    { "dhcp-hostsdir", 1, 0, LOPT_DHCP_INOTIFY },
 359      { "dhcp-no-override", 0, 0, LOPT_OVERRIDE },
 360      { "tftp-port-range", 1, 0, LOPT_TFTPPORTS },
 361      { "stop-dns-rebind", 0, 0, LOPT_REBIND },
 362 @@ -336,6 +337,7 @@ static struct {
 363    { 'G', ARG_DUP, "<hostspec>", gettext_noop("Set address or hostname for a specified machine."), NULL },
 364    { LOPT_DHCP_HOST, ARG_DUP, "<path>", gettext_noop("Read DHCP host specs from file."), NULL },
 365    { LOPT_DHCP_OPTS, ARG_DUP, "<path>", gettext_noop("Read DHCP option specs from file."), NULL },
 366 +  { LOPT_DHCP_INOTIFY, ARG_DUP, "<path>", gettext_noop("Read DHCP host specs from a directory."), NULL },
 367    { LOPT_TAG_IF, ARG_DUP, "tag-expression", gettext_noop("Evaluate conditional tag expression."), NULL },
 368    { 'h', OPT_NO_HOSTS, NULL, gettext_noop("Do NOT load %s file."), HOSTSFILE },
 369    { 'H', ARG_DUP, "<path>", gettext_noop("Specify a hosts file to be read in addition to %s."), HOSTSFILE },
 370 @@ -1710,8 +1712,9 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 371        break;
 372  #endif /* HAVE_DHCP */
 373
 374 -    case LOPT_DHCP_HOST: /* --dhcp-hostfile */
 375 +    case LOPT_DHCP_HOST: /* --dhcp-hostsfile */
 376      case LOPT_DHCP_OPTS: /* --dhcp-optsfile */
 377 +    case LOPT_DHCP_INOTIFY: /* dhcp-hostsdir */
 378      case 'H': /* --addn-hosts */
 379        {
 380         struct hostsfile *new = opt_malloc(sizeof(struct hostsfile));
 381 @@ -1734,6 +1737,12 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 382             new->next = daemon->dhcp_opts_file;
 383             daemon->dhcp_opts_file = new;
 384           }
 385 +       else if (option == LOPT_DHCP_INOTIFY)
 386 +         {
 387 +           new->next = daemon->inotify_hosts;
 388 +           daemon->inotify_hosts = new;
 389 +         }
 390 +
 391         break;
 392        }
 393
 394 @@ -4042,6 +4051,13 @@ static void read_file(char *file, FILE *f, int hard_opt)
 395    fclose(f);
 396  }
 397
 398 +#ifdef HAVE_DHCP
 399 +int option_read_hostsfile(char *file)
 400 +{
 401 +  return one_file(file, LOPT_BANK);
 402 +}
 403 +#endif
 404 +
 405  static int one_file(char *file, int hard_opt)
 406  {
 407    FILE *f;
 408 @@ -4139,7 +4155,7 @@ struct hostsfile *expand_filelist(struct hostsfile *list)
 409
 410             /* don't read this as a file */
 411             ah->flags |= AH_INACTIVE;
 412 -
 413 +
 414             if (!(dir_stream = opendir(ah->fname)))
 415               my_syslog(LOG_ERR, _("cannot access directory %s: %s"),
 416                         ah->fname, strerror(errno));
 417 --
 418 2.1.0
 419