inet: Add function that checks if the hostname is valid

diff --git a/include/inet.h b/include/inet.h
index 2048de1..aa67573 100644 (file)
--- a/include/inet.h
+++ b/include/inet.h
@@ -80,6 +80,7 @@ int connman_inet_setup_tunnel(char *tunnel, int mtu);
 int connman_inet_create_tunnel(char **iface);
 int connman_inet_get_dest_addr(int index, char **dest);
 int connman_inet_ipv6_get_dest_addr(int index, char **dest);
+connman_bool_t connman_inet_check_hostname(const char *ptr, size_t len);
 
 #ifdef __cplusplus
 }

diff --git a/src/inet.c b/src/inet.c
index e01bfb3..effa68c 100644 (file)
--- a/src/inet.c
+++ b/src/inet.c
@@ -44,6 +44,7 @@
 #include <netinet/icmp6.h>
 #include <fcntl.h>
 #include <linux/if_tun.h>
+#include <ctype.h>
 
 #include "connman.h"
 
@@ -2172,3 +2173,50 @@ int __connman_inet_rtnl_addattr32(struct nlmsghdr *n, size_t maxlen, int type,
 
        return 0;
 }
+
+/* Check routine modified from ics-dhcp 4.2.3-P2 */
+connman_bool_t connman_inet_check_hostname(const char *ptr, size_t len)
+{
+       const char *p;
+
+       /*
+        * Not empty or complete length not over 255 characters.
+        */
+       if ((len == 0) || (len > 256))
+               return FALSE;
+
+       /*
+        * Consists of [[:alnum:]-]+ labels separated by [.]
+        * a [_] is against RFC but seems to be "widely used"
+        */
+       for (p = ptr; (*p != 0) && (len-- > 0); p++) {
+
+               if ((*p == '-') || (*p == '_')) {
+                       /*
+                        * Not allowed at begin or end of a label.
+                        */
+                       if (((p - ptr) == 0) || (len == 0) || (p[1] == '.'))
+                               return FALSE;
+
+               } else if (*p == '.') {
+                       /*
+                        * Each label has to be 1-63 characters;
+                        * we allow [.] at the end ('foo.bar.')
+                        */
+                       size_t d = p - ptr;
+
+                       if ((d <= 0) || (d >= 64))
+                               return FALSE;
+
+                       ptr = p + 1; /* Jump to the next label */
+
+               } else if (isalnum((unsigned char)*p) == 0) {
+                       /*
+                        * Also numbers at the begin are fine
+                        */
+                       return FALSE;
+               }
+       }
+
+       return TRUE;
+}