Add --conf-script

CHANGELOG

@@ -47,6 +47,8 @@ version 2.87
 	always allocates a fresh index, they are not reused). We now
 	take this behaviour into account and keep up with changing indexes.
 
+	Add --conf-script configuration option.
+
 	
 version 2.86
 	Handle DHCPREBIND requests in the DHCPv6 server code.

man/dnsmasq.8

@@ -2141,6 +2141,23 @@ A special case of
 which differs in two respects. Firstly, only \fB--server\fP and \fB--rev-server\fP are allowed
 in the configuration file included. Secondly, the file is re-read and the configuration
 therein is updated when dnsmasq receives SIGHUP.
+.TP
+.B \--conf-script=<file>[ <arg]
+Execute <file>, and treat what it emits to stdout as the contents of a configuration file.
+If the script exits with a non-zero exit code, dnsmasq treats this as a fatal error.
+The script can be passed arguments, space seperated from the filename and each other so, for instance
+.B --conf-dir="/etc/dnsmasq-uncompress-ads /share/ads-domains.gz"
+
+with /etc/dnsmasq-uncompress-ads containing 
+
+set -e
+
+zcat ${1} | sed -e "s:^:address=/:" -e "s:$:/:" 
+
+exit 0
+
+and /share/ads-domains.gz containing a compressed
+list of ad server domains will save disk space with large ad-server blocklists.
 .SH CONFIG FILE
 At startup, dnsmasq reads
 .I /etc/dnsmasq.conf,
@@ -2537,7 +2554,9 @@ file/directory, permissions).
 5 - Other miscellaneous problem.
 .PP
 11 or greater - a non zero return code was received from the
-lease-script process "init" call. The exit code from dnsmasq is the
+lease-script process "init" call or a
+.B \--conf-script
+file. The exit code from dnsmasq is the
 script's exit code with 10 added. 
 
 .SH LIMITS

src/option.c

@@ -179,6 +179,8 @@ struct myoption {
 #define LOPT_FILTER_AAAA   370
 #define LOPT_STRIP_SBNET   371
 #define LOPT_STRIP_MAC     372
+#define LOPT_CONF_OPT      373
+#define LOPT_CONF_SCRIPT   374
 
 #ifdef HAVE_GETOPT_LONG
 static const struct option opts[] =  
@@ -225,6 +227,7 @@ static const struct myoption opts[] =
     { "local", 1, 0, LOPT_LOCAL },
     { "address", 1, 0, 'A' },
     { "conf-file", 2, 0, 'C' },
+    { "conf-script", 1, 0, LOPT_CONF_SCRIPT },
     { "no-resolv", 0, 0, 'R' },
     { "expand-hosts", 0, 0, 'E' },
     { "localmx", 0, 0, 'L' },
@@ -467,6 +470,7 @@ static struct {
   { LOPT_SCRIPTUSR, ARG_ONE, "<username>", gettext_noop("Run lease-change scripts as this user."), NULL },
   { LOPT_SCRIPT_ARP, OPT_SCRIPT_ARP, NULL, gettext_noop("Call dhcp-script with changes to local ARP table."), NULL },
   { '7', ARG_DUP, "<path>", gettext_noop("Read configuration from all the files in this directory."), NULL },
+  { LOPT_CONF_SCRIPT, ARG_DUP, "<path>", gettext_noop("Execute file and read configuration from stdin."), NULL },
   { '8', ARG_ONE, "<facility>|<file>", gettext_noop("Log to this syslog facility or file. (defaults to DAEMON)"), NULL },
   { '9', OPT_LEASE_RO, NULL, gettext_noop("Do not use leasefile."), NULL },
   { '0', ARG_ONE, "<integer>", gettext_noop("Maximum number of concurrent DNS queries. (defaults to %s)"), "!" }, 
@@ -1810,6 +1814,17 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 	break;
       }
 
+    case LOPT_CONF_SCRIPT: /* --conf-script */
+      {
+	char *file = opt_string_alloc(arg);
+	if (file)
+	  {
+	    one_file(file, LOPT_CONF_SCRIPT);
+	    free(file);
+	  }
+	break;
+      }
+
     case '7': /* --conf-dir */	      
       {
 	DIR *dir_stream;
@@ -4966,11 +4981,19 @@ static void read_file(char *file, FILE *f, int hard_opt)
   
   while (fgets(buff, MAXDNAME, f))
     {
-      int white, i;
-      volatile int option = (hard_opt == LOPT_REV_SERV) ? 0 : hard_opt;
+      int white, i, script = 0;
+      volatile int option;
       char *errmess, *p, *arg, *start;
       size_t len;
 
+      if (hard_opt == LOPT_CONF_SCRIPT)
+	{
+	  hard_opt = 0;
+	  script = 1;
+	}
+      
+      option = (hard_opt == LOPT_REV_SERV) ? 0 : hard_opt;
+ 
       /* Memory allocation failure longjmps here if mem_recover == 1 */ 
       if (option != 0 || hard_opt == LOPT_REV_SERV)
 	{
@@ -5084,7 +5107,11 @@ static void read_file(char *file, FILE *f, int hard_opt)
 	  
       if (errmess || !one_opt(option, arg, daemon->namebuff, _("error"), 0, hard_opt == LOPT_REV_SERV))
 	{
-	  sprintf(daemon->namebuff + strlen(daemon->namebuff), _(" at line %d of %s"), lineno, file);
+	  if (script)
+	    sprintf(daemon->namebuff + strlen(daemon->namebuff), _(" in output from %s"), file);
+	  else
+	    sprintf(daemon->namebuff + strlen(daemon->namebuff), _(" at line %d of %s"), lineno, file);
+	  
 	  if (hard_opt != 0)
 	    my_syslog(LOG_ERR, "%s", daemon->namebuff);
 	  else
@@ -5093,7 +5120,6 @@ static void read_file(char *file, FILE *f, int hard_opt)
     }
 
   mem_recover = 0;
-  fclose(f);
 }
 
 #if defined(HAVE_DHCP) && defined(HAVE_INOTIFY)
@@ -5113,7 +5139,7 @@ int option_read_dynfile(char *file, int flags)
 static int one_file(char *file, int hard_opt)
 {
   FILE *f;
-  int nofile_ok = 0;
+  int nofile_ok = 0, do_popen = 0;
   static int read_stdin = 0;
   static struct fileread {
     dev_t dev;
@@ -5121,13 +5147,13 @@ static int one_file(char *file, int hard_opt)
     struct fileread *next;
   } *filesread = NULL;
   
-  if (hard_opt == '7')
+  if (hard_opt == LOPT_CONF_OPT)
     {
       /* default conf-file reading */
       hard_opt = 0;
       nofile_ok = 1;
     }
-
+  
   if (hard_opt == 0 && strcmp(file, "-") == 0)
     {
       if (read_stdin == 1)
@@ -5141,6 +5167,12 @@ static int one_file(char *file, int hard_opt)
       /* ignore repeated files. */
       struct stat statbuf;
     
+      if (hard_opt == LOPT_CONF_SCRIPT)
+	{
+	  hard_opt = 0;
+	  do_popen = 1;
+	}
+      
       if (hard_opt == 0 && stat(file, &statbuf) == 0)
 	{
 	  struct fileread *r;
@@ -5155,8 +5187,13 @@ static int one_file(char *file, int hard_opt)
 	  r->dev = statbuf.st_dev;
 	  r->ino = statbuf.st_ino;
 	}
-      
-      if (!(f = fopen(file, "r")))
+
+      if (do_popen)
+	{
+	  if (!(f = popen(file, "r")))
+	    die(_("cannot execute %s: %s"), file, EC_FILE);
+	}
+      else if (!(f = fopen(file, "r")))
 	{   
 	  if (errno == ENOENT && nofile_ok)
 	    return 1; /* No conffile, all done. */
@@ -5174,7 +5211,21 @@ static int one_file(char *file, int hard_opt)
 	} 
     }
   
-  read_file(file, f, hard_opt);
+  read_file(file, f, do_popen ? LOPT_CONF_SCRIPT : hard_opt);
+
+  if (do_popen)
+    {
+      int rc;
+
+      if ((rc = pclose(f)) == -1)
+	die(_("error executing %s: %s"), file, EC_MISC);
+
+      if (rc != 0)
+	die(_("%s returns non-zero error code"), file, rc+10);
+    }
+  else
+    fclose(f);
+	
   return 1;
 }
 
@@ -5315,6 +5366,7 @@ void read_servers_file(void)
   
   mark_servers(SERV_FROM_FILE);
   read_file(daemon->servers_file, f, LOPT_REV_SERV);
+  fclose(f);
   cleanup_servers();
   check_servers(0);
 }
@@ -5540,7 +5592,7 @@ void read_opts(int argc, char **argv, char *compile_opts)
       free(conffile);
     }
   else
-    one_file(CONFFILE, '7');
+    one_file(CONFFILE, LOPT_CONF_OPT);
 
   /* port might not be known when the address is parsed - fill in here */
   if (daemon->servers)