--- /dev/null
+/* resolv.c
+
+ Parser for /etc/resolv.conf file. */
+
+/*
+ * Copyright (c) 1995, 1996, 1997 The Internet Software Consortium.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of The Internet Software Consortium nor the names
+ * of its contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
+ * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This software has been written for the Internet Software Consortium
+ * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
+ * Enterprises. To learn more about the Internet Software Consortium,
+ * see ``http://www.vix.com/isc''. To learn more about Vixie
+ * Enterprises, see ``http://www.vix.com''.
+ */
+
+#ifndef lint
+static char copyright[] =
+"$Id: resolv.c,v 1.1 1997/06/03 00:25:43 mellon Exp $ Copyright (c) 1995, 1996 The Internet Software Consortium. All rights reserved.\n";
+#endif /* not lint */
+
+#include "dhcpd.h"
+#include "dhctoken.h"
+
+struct name_server *name_servers;
+struct domain_search_list *domains;
+char path_resolv_conf [] = _PATH_RESOLV_CONF;
+
+void read_resolv_conf (parse_time)
+ TIME parse_time;
+{
+ FILE *cfile;
+ char *val;
+ int token;
+ int declaration = 0;
+ struct name_server *sp, *sl, *ns;
+ struct domain_search_list *dp, *dl, *nd;
+ struct iaddr *iaddr;
+
+ new_parse (path_resolv_conf);
+
+ eol_token = 1;
+ if ((cfile = fopen (path_resolv_conf, "r")) == NULL)
+ error ("Can't open %s: %m", path_resolv_conf);
+ do {
+ token = next_token (&val, cfile);
+ if (token == EOF)
+ break;
+ else if (token == EOL)
+ continue;
+ else if (token == DOMAIN || token == SEARCH) {
+ do {
+ struct domain_search_list *nd, **dp;
+ char *dn;
+
+ dn = parse_host_name (cfile);
+ if (!dn)
+ break;
+
+ dp = &domains;
+ for (nd = domains; nd; nd = nd -> next) {
+ dp = &nd -> next;
+ if (!strcmp (nd -> domain, dn))
+ break;
+ }
+ if (!nd) {
+ nd = new_domain_search_list
+ ("read_resolv_conf");
+ if (!nd)
+ error ("No memory for %s", dn);
+ nd -> next =
+ (struct domain_search_list *)0;
+ *dp = nd;
+ nd -> domain = dn;
+ dn = (char *)0;
+ }
+ nd -> rcdate = parse_time;
+ token = next_token (&val, cfile);
+ } while (token == COMMA);
+ if (token != EOL) {
+ parse_warn ("junk after domain declaration");
+ skip_to_semi (cfile);
+ }
+ } else if (token == NAMESERVER) {
+ struct name_server *ns, **sp;
+ struct iaddr iaddr;
+
+ parse_ip_addr (cfile, &iaddr);
+
+ sp = &name_servers;
+ for (ns = name_servers; ns; ns = ns -> next) {
+ sp = &ns -> next;
+ if (!memcmp (&ns -> addr.sin_addr,
+ iaddr.iabuf, iaddr.len))
+ break;
+ }
+ if (!ns) {
+ ns = new_name_server ("read_resolv_conf");
+ if (!ns)
+ error ("No memory for nameserver %s",
+ piaddr (iaddr));
+ ns -> next = (struct name_server *)0;
+ *sp = ns;
+ memcpy (&ns -> addr.sin_addr,
+ iaddr.iabuf, iaddr.len);
+#ifdef HAVE_SA_LEN
+ ns -> addr.sin_len = sizeof ns -> addr;
+#endif
+ ns -> addr.sin_family = AF_INET;
+ ns -> addr.sin_port = htons (53);
+ memset (ns -> addr.sin_zero, 0,
+ sizeof ns -> addr.sin_zero);
+ }
+ ns -> rcdate = parse_time;
+ skip_to_semi (cfile);
+ }
+ } while (1);
+ token = next_token (&val, cfile); /* Clear the peek buffer */
+
+ /* Lose servers that are no longer in /etc/resolv.conf. */
+ sl = (struct name_server *)0;
+ for (sp = name_servers; sp; sp = ns) {
+ ns = sp -> next;
+ if (sp -> rcdate != parse_time) {
+ if (sl)
+ sl -> next = sp -> next;
+ else
+ name_servers = sp -> next;
+ free_name_server (sp, "pick_name_server");
+ } else
+ sl = sp;
+ }
+
+ /* Lose domains that are no longer in /etc/resolv.conf. */
+ dl = (struct domain_search_list *)0;
+ for (dp = domains; dp; dp = nd) {
+ nd = dp -> next;
+ if (dp -> rcdate != parse_time) {
+ if (dl)
+ dl -> next = dp -> next;
+ else
+ domains = dp -> next;
+ free_domain_search_list (dp, "pick_name_server");
+ } else
+ dl = dp;
+ }
+ eol_token = 0;
+}
+
+/* Pick a name server from the /etc/resolv.conf file. */
+
+struct sockaddr_in *pick_name_server ()
+{
+ FILE *rc;
+ static TIME rcdate;
+ struct stat st;
+
+ /* Check /etc/resolv.conf and reload it if it's changed. */
+ if (cur_time > rcdate) {
+ if (stat (path_resolv_conf, &st) < 0)
+ error ("Can't stat %s", path_resolv_conf);
+ if (st.st_mtime > rcdate) {
+ char rcbuf [512];
+ char *s, *t, *u;
+ rcdate = cur_time + 1;
+
+ read_resolv_conf (rcdate);
+ }
+ }
+
+ if (name_servers)
+ return &name_servers -> addr;
+ return (struct sockaddr_in *)0;
+}
projects / thirdparty / dhcp.git / commitdiff
