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Diffstat (limited to 'resolv/ns_name_skip.c')
-rw-r--r--resolv/ns_name_skip.c70
1 files changed, 70 insertions, 0 deletions
diff --git a/resolv/ns_name_skip.c b/resolv/ns_name_skip.c
new file mode 100644
index 0000000000..c26d658a49
--- /dev/null
+++ b/resolv/ns_name_skip.c
@@ -0,0 +1,70 @@
+/* Skip over a (potentially compressed) domain name in wire format.
+ * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
+ * Copyright (c) 1996,1999 by Internet Software Consortium.
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+ * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <arpa/nameser.h>
+#include <errno.h>
+#include <shlib-compat.h>
+
+/* Advances *PTRPTR to skip over the compressed name it points at.
+ Returns 0 on success, -1 (with errno set) on failure. */
+int
+___ns_name_skip (const unsigned char **ptrptr, const unsigned char *eom)
+{
+ const unsigned char *cp;
+ unsigned int n;
+
+ cp = *ptrptr;
+ while (cp < eom)
+ {
+ n = *cp++;
+ if (n == 0)
+ {
+ /* End of domain name without indirection. */
+ *ptrptr = cp;
+ return 0;
+ }
+
+ /* Check for indirection. */
+ switch (n & NS_CMPRSFLGS)
+ {
+ case 0: /* Normal case, n == len. */
+ if (eom - cp < n)
+ goto malformed;
+ cp += n;
+ break;
+ case NS_CMPRSFLGS: /* Indirection. */
+ if (cp == eom)
+ /* No room for second indirection byte. */
+ goto malformed;
+ *ptrptr = cp + 1;
+ return 0;
+ default: /* Illegal type. */
+ goto malformed;
+ }
+ }
+
+ malformed:
+ __set_errno (EMSGSIZE);
+ return -1;
+}
+versioned_symbol (libc, ___ns_name_skip, ns_name_skip, GLIBC_2_34);
+versioned_symbol (libc, ___ns_name_skip, __ns_name_skip, GLIBC_PRIVATE);
+libc_hidden_ver (___ns_name_skip, __ns_name_skip)
+
+#if OTHER_SHLIB_COMPAT (libresolv, GLIBC_2_9, GLIBC_2_34)
+compat_symbol (libresolv, ___ns_name_skip, ns_name_skip, GLIBC_2_9);
+#endif