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-rw-r--r--src/shared/dns-domain.c95
-rw-r--r--src/shared/dns-domain.h2
-rw-r--r--src/test/test-dns-domain.c74
3 files changed, 167 insertions, 4 deletions
diff --git a/src/shared/dns-domain.c b/src/shared/dns-domain.c
index 20a44ce4e1..8a0dec1540 100644
--- a/src/shared/dns-domain.c
+++ b/src/shared/dns-domain.c
@@ -114,6 +114,68 @@ int dns_label_unescape(const char **name, char *dest, size_t sz) {
return r;
}
+/* @label_terminal: terminal character of a label, updated to point to the terminal character of
+ * the previous label (always skipping one dot) or to NULL if there are no more
+ * labels. */
+int dns_label_unescape_suffix(const char *name, const char **label_terminal, char *dest, size_t sz) {
+ const char *terminal;
+ int r;
+
+ assert(name);
+ assert(label_terminal);
+ assert(dest);
+
+ /* no more labels */
+ if (!*label_terminal) {
+ if (sz >= 1)
+ *dest = 0;
+
+ return 0;
+ }
+
+ assert(**label_terminal == '.' || **label_terminal == 0);
+
+ /* skip current terminal character */
+ terminal = *label_terminal - 1;
+
+ /* point name to the last label, and terminal to the preceding terminal symbol (or make it a NULL pointer) */
+ for (;;) {
+ if (terminal < name) {
+ /* reached the first label, so indicate that there are no more */
+ terminal = NULL;
+ break;
+ }
+
+ /* find the start of the last label */
+ if (*terminal == '.') {
+ const char *y;
+ unsigned slashes = 0;
+
+ for (y = terminal - 1; y >= name && *y == '\\'; y--)
+ slashes ++;
+
+ if (slashes % 2 == 0) {
+ /* the '.' was not escaped */
+ name = terminal + 1;
+ break;
+ } else {
+ terminal = y;
+ continue;
+ }
+ }
+
+ terminal --;
+ }
+
+ r = dns_label_unescape(&name, dest, sz);
+ if (r < 0)
+ return r;
+
+ *label_terminal = terminal;
+
+ return r;
+}
+
int dns_label_escape(const char *p, size_t l, char **ret) {
_cleanup_free_ char *s = NULL;
char *q;
@@ -338,20 +400,23 @@ unsigned long dns_name_hash_func(const void *s, const uint8_t hash_key[HASH_KEY_
}
int dns_name_compare_func(const void *a, const void *b) {
- const char *x = a, *y = b;
+ const char *x, *y;
int r, q, k, w;
assert(a);
assert(b);
+ x = (const char *) a + strlen(a);
+ y = (const char *) b + strlen(b);
+
for (;;) {
char la[DNS_LABEL_MAX+1], lb[DNS_LABEL_MAX+1];
- if (*x == 0 && *y == 0)
+ if (x == NULL && y == NULL)
return 0;
- r = dns_label_unescape(&x, la, sizeof(la));
- q = dns_label_unescape(&y, lb, sizeof(lb));
+ r = dns_label_unescape_suffix(a, &x, la, sizeof(la));
+ q = dns_label_unescape_suffix(b, &y, lb, sizeof(lb));
if (r < 0 || q < 0)
return r - q;
@@ -464,6 +529,28 @@ int dns_name_endswith(const char *name, const char *suffix) {
}
}
+int dns_name_between(const char *a, const char *b, const char *c) {
+ int n;
+
+ /* Determine if b is strictly greater than a and strictly smaller than c.
+ We consider the order of names to be circular, so that if a is
+ strictly greater than c, we consider b to be between them if it is
+ either greater than a or smaller than c. This is how the canonical
+ DNS name order used in NSEC records work. */
+
+ n = dns_name_compare_func(a, c);
+ if (n == 0)
+ return -EINVAL;
+ else if (n < 0)
+ /* a<---b--->c */
+ return dns_name_compare_func(a, b) < 0 &&
+ dns_name_compare_func(b, c) < 0;
+ else
+ /* <--b--c a--b--> */
+ return dns_name_compare_func(b, c) < 0 ||
+ dns_name_compare_func(a, b) < 0;
+}
+
int dns_name_reverse(int family, const union in_addr_union *a, char **ret) {
const uint8_t *p;
int r;
diff --git a/src/shared/dns-domain.h b/src/shared/dns-domain.h
index 00caf5d700..bd50ad3e6d 100644
--- a/src/shared/dns-domain.h
+++ b/src/shared/dns-domain.h
@@ -29,6 +29,7 @@
#define DNS_NAME_MAX 255
int dns_label_unescape(const char **name, char *dest, size_t sz);
+int dns_label_unescape_suffix(const char *name, const char **label_end, char *dest, size_t sz);
int dns_label_escape(const char *p, size_t l, char **ret);
int dns_label_apply_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max);
@@ -49,6 +50,7 @@ unsigned long dns_name_hash_func(const void *s, const uint8_t hash_key[HASH_KEY_
int dns_name_compare_func(const void *a, const void *b);
extern const struct hash_ops dns_name_hash_ops;
+int dns_name_between(const char *a, const char *b, const char *c);
int dns_name_equal(const char *x, const char *y);
int dns_name_endswith(const char *name, const char *suffix);
diff --git a/src/test/test-dns-domain.c b/src/test/test-dns-domain.c
index 527cdd3b54..31e110cf0d 100644
--- a/src/test/test-dns-domain.c
+++ b/src/test/test-dns-domain.c
@@ -50,6 +50,46 @@ static void test_dns_label_unescape(void) {
test_dns_label_unescape_one("foobar.", "foobar", 20, 6);
}
+static void test_dns_label_unescape_suffix_one(const char *what, const char *expect1, const char *expect2, size_t buffer_sz, int ret1, int ret2) {
+ char buffer[buffer_sz];
+ const char *label;
+ int r;
+
+ label = what + strlen(what);
+
+ r = dns_label_unescape_suffix(what, &label, buffer, buffer_sz);
+ assert_se(r == ret1);
+ if (r >= 0)
+ assert_se(streq(buffer, expect1));
+
+ r = dns_label_unescape_suffix(what, &label, buffer, buffer_sz);
+ assert_se(r == ret2);
+ if (r >= 0)
+ assert_se(streq(buffer, expect2));
+}
+
+static void test_dns_label_unescape_suffix(void) {
+ test_dns_label_unescape_suffix_one("hallo", "hallo", "", 6, 5, 0);
+ test_dns_label_unescape_suffix_one("hallo", "hallo", "", 4, -ENOSPC, -ENOSPC);
+ test_dns_label_unescape_suffix_one("", "", "", 10, 0, 0);
+ test_dns_label_unescape_suffix_one("hallo\\.foobar", "hallo.foobar", "", 20, 12, 0);
+ test_dns_label_unescape_suffix_one("hallo.foobar", "foobar", "hallo", 10, 6, 5);
+ test_dns_label_unescape_suffix_one("hallo.foobar\n", "foobar", "foobar", 20, -EINVAL, -EINVAL);
+ test_dns_label_unescape_suffix_one("hallo\\", "hallo", "hallo", 20, -EINVAL, -EINVAL);
+ test_dns_label_unescape_suffix_one("hallo\\032 ", "hallo ", "", 20, 7, 0);
+ test_dns_label_unescape_suffix_one(".", "", "", 20, 0, 0);
+ test_dns_label_unescape_suffix_one("..", "", "", 20, 0, 0);
+ test_dns_label_unescape_suffix_one(".foobar", "foobar", "", 20, 6, -EINVAL);
+ test_dns_label_unescape_suffix_one("foobar.", "", "foobar", 20, 0, 6);
+ test_dns_label_unescape_suffix_one("foo\\\\bar", "foo\\bar", "", 20, 7, 0);
+ test_dns_label_unescape_suffix_one("foo.bar", "bar", "foo", 20, 3, 3);
+ test_dns_label_unescape_suffix_one("foo..bar", "bar", "", 20, 3, -EINVAL);
+ test_dns_label_unescape_suffix_one("foo...bar", "bar", "", 20, 3, -EINVAL);
+ test_dns_label_unescape_suffix_one("foo\\.bar", "foo.bar", "", 20, 7, 0);
+ test_dns_label_unescape_suffix_one("foo\\\\.bar", "bar", "foo\\", 20, 3, 4);
+ test_dns_label_unescape_suffix_one("foo\\\\\\.bar", "foo\\.bar", "", 20, 8, 0);
+}
+
static void test_dns_label_escape_one(const char *what, size_t l, const char *expect, int ret) {
_cleanup_free_ char *t = NULL;
int r;
@@ -120,6 +160,38 @@ static void test_dns_name_equal(void) {
test_dns_name_equal_one("..", "..", -EINVAL);
}
+static void test_dns_name_between_one(const char *a, const char *b, const char *c, int ret) {
+ int r;
+
+ r = dns_name_between(a, b, c);
+ assert_se(r == ret);
+
+ r = dns_name_between(c, b, a);
+ if (ret >= 0)
+ assert_se(r == 0);
+ else
+ assert_se(r == ret);
+}
+
+static void test_dns_name_between(void) {
+ /* see https://tools.ietf.org/html/rfc4034#section-6.1
+ Note that we use "\033.z.example" in stead of "\001.z.example" as we
+ consider the latter invalid */
+ test_dns_name_between_one("example", "a.example", "yljkjljk.a.example", true);
+ test_dns_name_between_one("a.example", "yljkjljk.a.example", "Z.a.example", true);
+ test_dns_name_between_one("yljkjljk.a.example", "Z.a.example", "zABC.a.EXAMPLE", true);
+ test_dns_name_between_one("Z.a.example", "zABC.a.EXAMPLE", "z.example", true);
+ test_dns_name_between_one("zABC.a.EXAMPLE", "z.example", "\\033.z.example", true);
+ test_dns_name_between_one("z.example", "\\033.z.example", "*.z.example", true);
+ test_dns_name_between_one("\\033.z.example", "*.z.example", "\\200.z.example", true);
+ test_dns_name_between_one("*.z.example", "\\200.z.example", "example", true);
+ test_dns_name_between_one("\\200.z.example", "example", "a.example", true);
+
+ test_dns_name_between_one("example", "a.example", "example", -EINVAL);
+ test_dns_name_between_one("example", "example", "yljkjljk.a.example", false);
+ test_dns_name_between_one("example", "yljkjljk.a.example", "yljkjljk.a.example", false);
+}
+
static void test_dns_name_endswith_one(const char *a, const char *b, int ret) {
assert_se(dns_name_endswith(a, b) == ret);
}
@@ -180,10 +252,12 @@ static void test_dns_name_reverse(void) {
int main(int argc, char *argv[]) {
test_dns_label_unescape();
+ test_dns_label_unescape_suffix();
test_dns_label_escape();
test_dns_name_normalize();
test_dns_name_equal();
test_dns_name_endswith();
+ test_dns_name_between();
test_dns_name_root();
test_dns_name_single_label();
test_dns_name_reverse();
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-12-19 16:51:02 +0000