diff options
| -rw-r--r-- | include/arpa/nameser.h | 6 | ||||
| -rw-r--r-- | resolv/Makefile | 5 | ||||
| -rw-r--r-- | resolv/ns_samebinaryname.c | 55 | ||||
| -rw-r--r-- | resolv/tst-ns_samebinaryname.c | 62 |
4 files changed, 128 insertions, 0 deletions
diff --git a/include/arpa/nameser.h b/include/arpa/nameser.h index 53f1dbc7c3..bb1dede187 100644 --- a/include/arpa/nameser.h +++ b/include/arpa/nameser.h @@ -55,6 +55,12 @@ int __ns_name_ntop (const unsigned char *, char *, size_t) __THROW; int __ns_name_unpack (const unsigned char *, const unsigned char *, const unsigned char *, unsigned char *, size_t) __THROW; +/* Like ns_samename, but for uncompressed binary names. Return true + if the two arguments compare are equal as case-insensitive domain + names. */ +_Bool __ns_samebinaryname (const unsigned char *, const unsigned char *) + attribute_hidden; + #define ns_msg_getflag(handle, flag) \ (((handle)._flags & _ns_flagdata[flag].mask) >> _ns_flagdata[flag].shift) diff --git a/resolv/Makefile b/resolv/Makefile index 0038bb7028..ec61ad07bd 100644 --- a/resolv/Makefile +++ b/resolv/Makefile @@ -46,6 +46,7 @@ routines := \ ns_name_skip \ ns_name_uncompress \ ns_name_unpack \ + ns_samebinaryname \ ns_samename \ nsap_addr \ nss_dns_functions \ @@ -106,6 +107,10 @@ tests += \ tests-internal += tst-resolv-txnid-collision tests-static += tst-resolv-txnid-collision +# Likewise for __ns_samebinaryname. +tests-internal += tst-ns_samebinaryname +tests-static += tst-ns_samebinaryname + # These tests need libdl. ifeq (yes,$(build-shared)) tests += \ diff --git a/resolv/ns_samebinaryname.c b/resolv/ns_samebinaryname.c new file mode 100644 index 0000000000..9a47d8e97a --- /dev/null +++ b/resolv/ns_samebinaryname.c @@ -0,0 +1,55 @@ +/* Compare two binary domain names for quality. + Copyright (C) 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <arpa/nameser.h> +#include <stdbool.h> + +/* Convert ASCII letters to upper case. */ +static inline int +ascii_toupper (unsigned char ch) +{ + if (ch >= 'a' && ch <= 'z') + return ch - 'a' + 'A'; + else + return ch; +} + +bool +__ns_samebinaryname (const unsigned char *a, const unsigned char *b) +{ + while (*a != 0 && *b != 0) + { + if (*a != *b) + /* Different label length. */ + return false; + int labellen = *a; + ++a; + ++b; + for (int i = 0; i < labellen; ++i) + { + if (*a != *b && ascii_toupper (*a) != ascii_toupper (*b)) + /* Different character in label. */ + return false; + ++a; + ++b; + } + } + + /* Match if both names are at the root label. */ + return *a == 0 && *b == 0; +} diff --git a/resolv/tst-ns_samebinaryname.c b/resolv/tst-ns_samebinaryname.c new file mode 100644 index 0000000000..b06ac610b4 --- /dev/null +++ b/resolv/tst-ns_samebinaryname.c @@ -0,0 +1,62 @@ +/* Test the __ns_samebinaryname function. + Copyright (C) 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <arpa/nameser.h> +#include <array_length.h> +#include <stdbool.h> +#include <stdio.h> +#include <support/check.h> + +/* First character denotes the comparison group: All names with the + same first character are expected to compare equal. */ +static const char *const cases[] = + { + " ", + "1\001a", "1\001A", + "2\002ab", "2\002aB", "2\002Ab", "2\002AB", + "3\001a\002ab", "3\001A\002ab", + "w\003www\007example\003com", "w\003Www\007Example\003Com", + "w\003WWW\007EXAMPLE\003COM", + "W\003WWW", "W\003www", + }; + +static int +do_test (void) +{ + for (int i = 0; i < array_length (cases); ++i) + for (int j = 0; j < array_length (cases); ++j) + { + unsigned char *a = (unsigned char *) &cases[i][1]; + unsigned char *b = (unsigned char *) &cases[j][1]; + bool actual = __ns_samebinaryname (a, b); + bool expected = cases[i][0] == cases[j][0]; + if (actual != expected) + { + char a1[NS_MAXDNAME]; + TEST_VERIFY (ns_name_ntop (a, a1, sizeof (a1)) > 0); + char b1[NS_MAXDNAME]; + TEST_VERIFY (ns_name_ntop (b, b1, sizeof (b1)) > 0); + printf ("error: \"%s\" \"%s\": expected %s\n", + a1, b1, expected ? "equal" : "unqueal"); + support_record_failure (); + } + } + return 0; +} + +#include <support/test-driver.c> |