Add SPDX license identifiers to source files under the LGPL

[thirdparty/systemd.git] / src / shared / dns-domain.c

diff --git a/src/shared/dns-domain.c b/src/shared/dns-domain.c
index 40aec3a1ea77cfbc5169b6203d6ddc0607284c29..670aa48800104faea3689f2285e05468b3bcb1e7 100644 (file)
--- a/src/shared/dns-domain.c
+++ b/src/shared/dns-domain.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
 /***
   This file is part of systemd.
 
@@ -17,9 +18,9 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  ***/
 
-#if defined(HAVE_LIBIDN2)
+#if HAVE_LIBIDN2
 #  include <idn2.h>
-#elif defined(HAVE_LIBIDN)
+#elif HAVE_LIBIDN
 #  include <idna.h>
 #  include <stringprep.h>
 #endif
@@ -76,7 +77,7 @@ int dns_label_unescape(const char **name, char *dest, size_t sz) {
                                 /* Ending NUL */
                                 return -EINVAL;
 
-                        else if (*n == '\\' || *n == '.') {
+                        else if (IN_SET(*n, '\\', '.')) {
                                 /* Escaped backslash or dot */
 
                                 if (d)
@@ -164,7 +165,7 @@ int dns_label_unescape_suffix(const char *name, const char **label_terminal, cha
         }
 
         terminal = *label_terminal;
-        assert(*terminal == '.' || *terminal == 0);
+        assert(IN_SET(*terminal, 0, '.'));
 
         /* Skip current terminal character (and accept domain names ending it ".") */
         if (*terminal == 0)
@@ -228,7 +229,7 @@ int dns_label_escape(const char *p, size_t l, char *dest, size_t sz) {
         q = dest;
         while (l > 0) {
 
-                if (*p == '.' || *p == '\\') {
+                if (IN_SET(*p, '.', '\\')) {
 
                         /* Dot or backslash */
 
@@ -240,8 +241,7 @@ int dns_label_escape(const char *p, size_t l, char *dest, size_t sz) {
 
                         sz -= 2;
 
-                } else if (*p == '_' ||
-                           *p == '-' ||
+                } else if (IN_SET(*p, '_', '-') ||
                            (*p >= '0' && *p <= '9') ||
                            (*p >= 'a' && *p <= 'z') ||
                            (*p >= 'A' && *p <= 'Z')) {
@@ -301,7 +301,7 @@ int dns_label_escape_new(const char *p, size_t l, char **ret) {
         return r;
 }
 
-#ifdef HAVE_LIBIDN
+#if HAVE_LIBIDN
 int dns_label_apply_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max) {
         _cleanup_free_ uint32_t *input = NULL;
         size_t input_size, l;
@@ -1272,21 +1272,47 @@ int dns_name_common_suffix(const char *a, const char *b, const char **ret) {
 int dns_name_apply_idna(const char *name, char **ret) {
         /* Return negative on error, 0 if not implemented, positive on success. */
 
-#if defined(HAVE_LIBIDN2)
+#if HAVE_LIBIDN2
         int r;
+        _cleanup_free_ char *t = NULL;
 
         assert(name);
         assert(ret);
 
-        r = idn2_lookup_u8((uint8_t*) name, (uint8_t**) ret,
+        r = idn2_lookup_u8((uint8_t*) name, (uint8_t**) &t,
                            IDN2_NFC_INPUT | IDN2_NONTRANSITIONAL);
-        if (r == IDN2_OK)
+        log_debug("idn2_lookup_u8: %s → %s", name, t);
+        if (r == IDN2_OK) {
+                if (!startswith(name, "xn--")) {
+                        _cleanup_free_ char *s = NULL;
+
+                        r = idn2_to_unicode_8z8z(t, &s, 0);
+                        if (r != IDN2_OK) {
+                                log_debug("idn2_to_unicode_8z8z(\"%s\") failed: %d/%s",
+                                          t, r, idn2_strerror(r));
+                                return 0;
+                        }
+
+                        if (!streq_ptr(name, s)) {
+                                log_debug("idn2 roundtrip failed: \"%s\" → \"%s\" → \"%s\", ignoring.",
+                                          name, t, s);
+                                return 0;
+                        }
+                }
+
+                *ret = t;
+                t = NULL;
                 return 1; /* *ret has been written */
-        else if (IN_SET(r, IDN2_TOO_BIG_DOMAIN, IDN2_TOO_BIG_LABEL))
+        }
+
+        log_debug("idn2_lookup_u8(\"%s\") failed: %d/%s", name, r, idn2_strerror(r));
+        if (r == IDN2_2HYPHEN)
+                /* The name has two hypens — forbidden by IDNA2008 in some cases */
+                return 0;
+        if (IN_SET(r, IDN2_TOO_BIG_DOMAIN, IDN2_TOO_BIG_LABEL))
                 return -ENOSPC;
-        else
-                return -EINVAL;
-#elif defined(HAVE_LIBIDN)
+        return -EINVAL;
+#elif HAVE_LIBIDN
         _cleanup_free_ char *buf = NULL;
         size_t n = 0, allocated = 0;
         bool first = true;
@@ -1322,7 +1348,7 @@ int dns_name_apply_idna(const char *name, char **ret) {
                 else
                         buf[n++] = '.';
 
-                n +=r;
+                n += r;
         }
 
         if (n > DNS_HOSTNAME_MAX)
@@ -1335,7 +1361,7 @@ int dns_name_apply_idna(const char *name, char **ret) {
         *ret = buf;
         buf = NULL;
 
-        return (int) n;
+        return 1;
 #else
         return 0;
 #endif