Merge pull request #10897 from keszybz/etc-fstab-parsing

Forbid dashes in hostnames and /etc/fstab parsing improvements

src/basic/hostname-util.c

@@ -69,12 +69,12 @@ int gethostname_strict(char **ret) {
         return 0;
 }
 
-static bool hostname_valid_char(char c) {
+bool valid_ldh_char(char c) {
         return
                 (c >= 'a' && c <= 'z') ||
                 (c >= 'A' && c <= 'Z') ||
                 (c >= '0' && c <= '9') ||
-                IN_SET(c, '-', '_', '.');
+                c == '-';
 }
 
 /**
@@ -90,7 +90,7 @@ static bool hostname_valid_char(char c) {
 bool hostname_is_valid(const char *s, bool allow_trailing_dot) {
         unsigned n_dots = 0;
         const char *p;
-        bool dot;
+        bool dot, hyphen;
 
         if (isempty(s))
                 return false;
@@ -100,23 +100,34 @@ bool hostname_is_valid(const char *s, bool allow_trailing_dot) {
          * sequence. Also ensures that the length stays below
          * HOST_NAME_MAX. */
 
-        for (p = s, dot = true; *p; p++) {
+        for (p = s, dot = hyphen = true; *p; p++)
                 if (*p == '.') {
-                        if (dot)
+                        if (dot || hyphen)
                                 return false;
 
                         dot = true;
+                        hyphen = false;
                         n_dots++;
-                } else {
-                        if (!hostname_valid_char(*p))
+
+                } else if (*p == '-') {
+                        if (dot)
                                 return false;
 
                         dot = false;
+                        hyphen = true;
+
+                } else {
+                        if (!valid_ldh_char(*p))
+                                return false;
+
+                        dot = false;
+                        hyphen = false;
                 }
-        }
 
         if (dot && (n_dots < 2 || !allow_trailing_dot))
                 return false;
+        if (hyphen)
+                return false;
 
         if (p-s > HOST_NAME_MAX) /* Note that HOST_NAME_MAX is 64 on
                                   * Linux, but DNS allows domain names
@@ -128,29 +139,38 @@ bool hostname_is_valid(const char *s, bool allow_trailing_dot) {
 
 char* hostname_cleanup(char *s) {
         char *p, *d;
-        bool dot;
+        bool dot, hyphen;
 
         assert(s);
 
-        strshorten(s, HOST_NAME_MAX);
-
-        for (p = s, d = s, dot = true; *p; p++) {
+        for (p = s, d = s, dot = hyphen = true; *p && d - s < HOST_NAME_MAX; p++)
                 if (*p == '.') {
-                        if (dot)
+                        if (dot || hyphen)
                                 continue;
 
                         *(d++) = '.';
                         dot = true;
-                } else if (hostname_valid_char(*p)) {
+                        hyphen = false;
+
+                } else if (*p == '-') {
+                        if (dot)
+                                continue;
+
+                        *(d++) = '-';
+                        dot = false;
+                        hyphen = true;
+
+                } else if (valid_ldh_char(*p)) {
                         *(d++) = *p;
                         dot = false;
+                        hyphen = false;
                 }
-        }
 
-        if (dot && d > s)
-                d[-1] = 0;
-        else
-                *d = 0;
+        if (d > s && IN_SET(d[-1], '-', '.'))
+                /* The dot can occur at most once, but we might have multiple
+                 * hyphens, hence the loop */
+                d--;
+        *d = 0;
 
         return s;
 }

src/basic/hostname-util.h

@@ -11,6 +11,7 @@ bool hostname_is_set(void);
 char* gethostname_malloc(void);
 int gethostname_strict(char **ret);
 
+bool valid_ldh_char(char c) _const_;
 bool hostname_is_valid(const char *s, bool allow_trailing_dot) _pure_;
 char* hostname_cleanup(char *s);
 

src/libsystemd-network/ndisc-router.c

@@ -676,7 +676,7 @@ _public_ int sd_ndisc_router_dnssl_get_domains(sd_ndisc_router *rt, char ***ret)
                                 _cleanup_free_ char *normalized = NULL;
 
                                 e[n] = 0;
-                                r = dns_name_normalize(e, &normalized);
+                                r = dns_name_normalize(e, 0, &normalized);
                                 if (r < 0)
                                         return r;
 

src/libsystemd-network/sd-dhcp-lease.c

@@ -355,7 +355,7 @@ static int lease_parse_domain(const uint8_t *option, size_t len, char **ret) {
                 return 0;
         }
 
-        r = dns_name_normalize(name, &normalized);
+        r = dns_name_normalize(name, 0, &normalized);
         if (r < 0)
                 return r;
 

src/network/networkd-network.c

@@ -659,7 +659,7 @@ int config_parse_domains(
                         domain = "."; /* make sure we don't allow empty strings, thus write the root domain as "." */
 
                 } else {
-                        r = dns_name_normalize(domain, &normalized);
+                        r = dns_name_normalize(domain, 0, &normalized);
                         if (r < 0) {
                                 log_syntax(unit, LOG_ERR, filename, line, r, "'%s' is not a valid domain name, ignoring.", domain);
                                 continue;

src/resolve/resolved-bus.c

@@ -192,7 +192,7 @@ static void bus_method_resolve_hostname_complete(DnsQuery *q) {
 
         /* The key names are not necessarily normalized, make sure that they are when we return them to our bus
          * clients. */
-        r = dns_name_normalize(dns_resource_key_name(canonical->key), &normalized);
+        r = dns_name_normalize(dns_resource_key_name(canonical->key), 0, &normalized);
         if (r < 0)
                 goto finish;
 
@@ -405,7 +405,7 @@ static void bus_method_resolve_address_complete(DnsQuery *q) {
                 if (r == 0)
                         continue;
 
-                r = dns_name_normalize(rr->ptr.name, &normalized);
+                r = dns_name_normalize(rr->ptr.name, 0, &normalized);
                 if (r < 0)
                         goto finish;
 
@@ -743,7 +743,7 @@ static int append_srv(DnsQuery *q, sd_bus_message *reply, DnsResourceRecord *rr)
         if (r < 0)
                 return r;
 
-        r = dns_name_normalize(rr->srv.name, &normalized);
+        r = dns_name_normalize(rr->srv.name, 0, &normalized);
         if (r < 0)
                 return r;
 
@@ -799,7 +799,7 @@ static int append_srv(DnsQuery *q, sd_bus_message *reply, DnsResourceRecord *rr)
         if (canonical) {
                 normalized = mfree(normalized);
 
-                r = dns_name_normalize(dns_resource_key_name(canonical->key), &normalized);
+                r = dns_name_normalize(dns_resource_key_name(canonical->key), 0, &normalized);
                 if (r < 0)
                         return r;
         }

src/resolve/resolved-dns-dnssec.c

@@ -74,7 +74,7 @@ int dnssec_canonicalize(const char *n, char *buffer, size_t buffer_max) {
                 return -ENOBUFS;
 
         for (;;) {
-                r = dns_label_unescape(&n, buffer, buffer_max);
+                r = dns_label_unescape(&n, buffer, buffer_max, 0);
                 if (r < 0)
                         return r;
                 if (r == 0)
@@ -1705,7 +1705,7 @@ static int dnssec_nsec_wildcard_equal(DnsResourceRecord *rr, const char *name) {
                 return 0;
 
         n = dns_resource_key_name(rr->key);
-        r = dns_label_unescape(&n, label, sizeof(label));
+        r = dns_label_unescape(&n, label, sizeof label, 0);
         if (r <= 0)
                 return r;
         if (r != 1 || label[0] != '*')
@@ -1827,13 +1827,13 @@ static int dnssec_nsec_covers_wildcard(DnsResourceRecord *rr, const char *name)
                 return r;
         if (r > 0)  /* If the name we are interested in is a child of the NSEC RR, then append the asterisk to the NSEC
                      * RR's name. */
-                r = dns_name_concat("*", dns_resource_key_name(rr->key), &wc);
+                r = dns_name_concat("*", dns_resource_key_name(rr->key), 0, &wc);
         else {
                 r = dns_name_common_suffix(dns_resource_key_name(rr->key), rr->nsec.next_domain_name, &common_suffix);
                 if (r < 0)
                         return r;
 
-                r = dns_name_concat("*", common_suffix, &wc);
+                r = dns_name_concat("*", common_suffix, 0, &wc);
         }
         if (r < 0)
                 return r;

src/resolve/resolved-dns-packet.c

@@ -535,7 +535,7 @@ int dns_packet_append_name(
                         }
                 }
 
-                r = dns_label_unescape(&name, label, sizeof(label));
+                r = dns_label_unescape(&name, label, sizeof label, 0);
                 if (r < 0)
                         goto fail;
 

src/resolve/resolved-dns-rr.c

@@ -77,7 +77,7 @@ int dns_resource_key_new_append_suffix(DnsResourceKey **ret, DnsResourceKey *key
                 return 0;
         }
 
-        r = dns_name_concat(dns_resource_key_name(key), name, &joined);
+        r = dns_name_concat(dns_resource_key_name(key), name, 0, &joined);
         if (r < 0)
                 return r;
 
@@ -222,7 +222,7 @@ int dns_resource_key_match_rr(const DnsResourceKey *key, DnsResourceRecord *rr,
         if (search_domain) {
                 _cleanup_free_ char *joined = NULL;
 
-                r = dns_name_concat(dns_resource_key_name(key), search_domain, &joined);
+                r = dns_name_concat(dns_resource_key_name(key), search_domain, 0, &joined);
                 if (r < 0)
                         return r;
 
@@ -254,7 +254,7 @@ int dns_resource_key_match_cname_or_dname(const DnsResourceKey *key, const DnsRe
         if (search_domain) {
                 _cleanup_free_ char *joined = NULL;
 
-                r = dns_name_concat(dns_resource_key_name(key), search_domain, &joined);
+                r = dns_name_concat(dns_resource_key_name(key), search_domain, 0, &joined);
                 if (r < 0)
                         return r;
 

src/resolve/resolved-dns-search-domain.c

@@ -19,7 +19,7 @@ int dns_search_domain_new(
         assert((type == DNS_SEARCH_DOMAIN_LINK) == !!l);
         assert(name);
 
-        r = dns_name_normalize(name, &normalized);
+        r = dns_name_normalize(name, 0, &normalized);
         if (r < 0)
                 return r;
 

src/resolve/resolved-dnssd.c

@@ -228,10 +228,10 @@ int dnssd_update_rrs(DnssdService *s) {
         if (r < 0)
                 return r;
 
-        r = dns_name_concat(s->type, "local", &service_name);
+        r = dns_name_concat(s->type, "local", 0, &service_name);
         if (r < 0)
                 return r;
-        r = dns_name_concat(n, service_name, &full_name);
+        r = dns_name_concat(n, service_name, 0, &full_name);
         if (r < 0)
                 return r;
 

src/resolve/resolved-etc-hosts.c

@@ -46,19 +46,20 @@ static int parse_line(EtcHosts *hosts, unsigned nr, const char *line) {
 
         r = extract_first_word(&line, &address_str, NULL, EXTRACT_RELAX);
         if (r < 0)
-                return log_error_errno(r, "Couldn't extract address, in line /etc/hosts:%u.", nr);
-        if (r == 0)
-                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
-                                       "Premature end of line, in line /etc/hosts:%u.",
-                                       nr);
+                return log_error_errno(r, "/etc/hosts:%u: failed to extract address: %m", nr);
+        assert(r > 0); /* We already checked that the line is not empty, so it should contain *something* */
 
         r = in_addr_ifindex_from_string_auto(address_str, &address.family, &address.address, NULL);
-        if (r < 0)
-                return log_error_errno(r, "Address '%s' is invalid, in line /etc/hosts:%u.", address_str, nr);
+        if (r < 0) {
+                log_warning_errno(r, "/etc/hosts:%u: address '%s' is invalid, ignoring: %m", nr, address_str);
+                return 0;
+        }
 
         r = in_addr_is_null(address.family, &address.address);
-        if (r < 0)
-                return r;
+        if (r < 0) {
+                log_warning_errno(r, "/etc/hosts:%u: address '%s' is invalid, ignoring: %m", nr, address_str);
+                return 0;
+        }
         if (r > 0)
                 /* This is an 0.0.0.0 or :: item, which we assume means that we shall map the specified hostname to
                  * nothing. */
@@ -92,16 +93,18 @@ static int parse_line(EtcHosts *hosts, unsigned nr, const char *line) {
 
                 r = extract_first_word(&line, &name, NULL, EXTRACT_RELAX);
                 if (r < 0)
-                        return log_error_errno(r, "Couldn't extract host name, in line /etc/hosts:%u.", nr);
+                        return log_error_errno(r, "/etc/hosts:%u: couldn't extract host name: %m", nr);
                 if (r == 0)
                         break;
 
-                r = dns_name_is_valid(name);
-                if (r <= 0)
-                        return log_error_errno(r, "Hostname %s is not valid, ignoring, in line /etc/hosts:%u.", name, nr);
-
                 found = true;
 
+                r = dns_name_is_valid_ldh(name);
+                if (r <= 0) {
+                        log_warning_errno(r, "/etc/hosts:%u: hostname \"%s\" is not valid, ignoring.", nr, name);
+                        continue;
+                }
+
                 if (is_localhost(name))
                         /* Suppress the "localhost" line that is often seen */
                         continue;
@@ -152,9 +155,7 @@ static int parse_line(EtcHosts *hosts, unsigned nr, const char *line) {
         }
 
         if (!found)
-                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
-                                       "Line is missing any host names, in line /etc/hosts:%u.",
-                                       nr);
+                log_warning("/etc/hosts:%u: line is missing any host names", nr);
 
         return 0;
 }
@@ -176,11 +177,13 @@ int etc_hosts_parse(EtcHosts *hosts, FILE *f) {
 
                 nr++;
 
+                l = strchr(line, '#');
+                if (l)
+                        *l = '\0';
+
                 l = strstrip(line);
                 if (isempty(l))
                         continue;
-                if (l[0] == '#')
-                        continue;
 
                 r = parse_line(&t, nr, l);
                 if (r < 0)

src/resolve/resolved-manager.c

@@ -334,7 +334,7 @@ static int determine_hostname(char **full_hostname, char **llmnr_hostname, char
                 return log_debug_errno(r, "Can't determine system hostname: %m");
 
         p = h;
-        r = dns_label_unescape(&p, label, sizeof label);
+        r = dns_label_unescape(&p, label, sizeof label, 0);
         if (r < 0)
                 return log_error_errno(r, "Failed to unescape host name: %m");
         if (r == 0)
@@ -372,7 +372,7 @@ static int determine_hostname(char **full_hostname, char **llmnr_hostname, char
                 return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
                                        "System hostname is 'localhost', ignoring.");
 
-        r = dns_name_concat(n, "local", mdns_hostname);
+        r = dns_name_concat(n, "local", 0, mdns_hostname);
         if (r < 0)
                 return log_error_errno(r, "Failed to determine mDNS hostname: %m");
 
@@ -404,7 +404,7 @@ static int make_fallback_hostnames(char **full_hostname, char **llmnr_hostname,
         assert(mdns_hostname);
 
         p = fallback_hostname();
-        r = dns_label_unescape(&p, label, sizeof(label));
+        r = dns_label_unescape(&p, label, sizeof label, 0);
         if (r < 0)
                 return log_error_errno(r, "Failed to unescape fallback host name: %m");
 
@@ -414,7 +414,7 @@ static int make_fallback_hostnames(char **full_hostname, char **llmnr_hostname,
         if (r < 0)
                 return log_error_errno(r, "Failed to escape fallback hostname: %m");
 
-        r = dns_name_concat(n, "local", &m);
+        r = dns_name_concat(n, "local", 0, &m);
         if (r < 0)
                 return log_error_errno(r, "Failed to concatenate mDNS hostname: %m");
 
@@ -1148,7 +1148,7 @@ int manager_next_hostname(Manager *m) {
         if (r < 0)
                 return r;
 
-        r = dns_name_concat(h, "local", &k);
+        r = dns_name_concat(h, "local", 0, &k);
         if (r < 0)
                 return r;
 

src/resolve/test-resolved-etc-hosts.c

@@ -1,14 +1,22 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
 
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+
 #include "fd-util.h"
+#include "fileio.h"
 #include "fs-util.h"
 #include "log.h"
 #include "resolved-etc-hosts.h"
+#include "strv.h"
 #include "tmpfile-util.h"
 
 static void test_parse_etc_hosts_system(void) {
         _cleanup_fclose_ FILE *f = NULL;
 
+        log_info("/* %s */", __func__);
+
         f = fopen("/etc/hosts", "re");
         if (!f) {
                 assert_se(errno == ENOENT);
@@ -19,59 +27,98 @@ static void test_parse_etc_hosts_system(void) {
         assert_se(etc_hosts_parse(&hosts, f) == 0);
 }
 
-static void test_parse_etc_hosts(const char *fname) {
+#define address_equal_4(_addr, _address)                                \
+        ((_addr)->family == AF_INET &&                                  \
+         !memcmp(&(_addr)->address.in, &(struct in_addr) { .s_addr = (_address) }, 4))
+
+#define address_equal_6(_addr, ...)                                     \
+        ((_addr)->family == AF_INET6 &&                                 \
+         !memcmp(&(_addr)->address.in6, &(struct in6_addr) { .s6_addr = __VA_ARGS__}, 16) )
+
+static void test_parse_etc_hosts(void) {
         _cleanup_(unlink_tempfilep) char
                 t[] = "/tmp/test-resolved-etc-hosts.XXXXXX";
 
+        log_info("/* %s */", __func__);
+
         int fd;
         _cleanup_fclose_ FILE *f;
+        const char *s;
 
-        if (fname) {
-                f = fopen(fname, "re");
-                assert_se(f);
-        } else {
-                fd = mkostemp_safe(t);
-                assert_se(fd >= 0);
+        fd = mkostemp_safe(t);
+        assert_se(fd >= 0);
 
-                f = fdopen(fd, "r+");
-                assert_se(f);
-                fputs("1.2.3.4 some.where\n", f);
-                fputs("1.2.3.5 some.where\n", f);
-                fputs("::0 some.where some.other\n", f);
-                fputs("0.0.0.0 black.listed\n", f);
-                fputs("::5 some.where some.other foobar.foo.foo\n", f);
-                fputs("        \n", f);
-                fflush(f);
-                rewind(f);
-        }
+        f = fdopen(fd, "r+");
+        assert_se(f);
+        fputs("1.2.3.4 some.where\n"
+              "1.2.3.5 some.where\n"
+              "1.2.3.6 dash dash-dash.where-dash\n"
+              "1.2.3.7 bad-dash- -bad-dash -bad-dash.bad-\n"
+              "1.2.3.8\n"
+              "1.2.3.9 before.comment # within.comment\n"
+              "1.2.3.10 before.comment#within.comment2\n"
+              "1.2.3.11 before.comment# within.comment3\n"
+              "1.2.3.12 before.comment#\n"
+              "1.2.3 short.address\n"
+              "1.2.3.4.5 long.address\n"
+              "1::2::3 multi.colon\n"
+
+              "::0 some.where some.other\n"
+              "0.0.0.0 black.listed\n"
+              "::5\t\t\t \tsome.where\tsome.other foobar.foo.foo\t\t\t\n"
+              "        \n", f);
+        assert_se(fflush_and_check(f) >= 0);
+        rewind(f);
 
         _cleanup_(etc_hosts_free) EtcHosts hosts = {};
         assert_se(etc_hosts_parse(&hosts, f) == 0);
 
-        if (fname)
-                return;
-
         EtcHostsItemByName *bn;
         assert_se(bn = hashmap_get(hosts.by_name, "some.where"));
         assert_se(bn->n_addresses == 3);
         assert_se(bn->n_allocated >= 3);
+        assert_se(address_equal_4(bn->addresses[0], inet_addr("1.2.3.4")));
+        assert_se(address_equal_4(bn->addresses[1], inet_addr("1.2.3.5")));
+        assert_se(address_equal_6(bn->addresses[2], {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5}));
 
-        assert_se(bn->addresses[0]->family == AF_INET);
-        assert_se(memcmp(&bn->addresses[0]->address.in,
-                         &(struct in_addr) { .s_addr = htobe32(0x01020304) }, 4) == 0);
-        assert_se(bn->addresses[1]->family == AF_INET);
-        assert_se(memcmp(&bn->addresses[1]->address.in,
-                         &(struct in_addr) { .s_addr = htobe32(0x01020305) }, 4) == 0);
-        assert_se(bn->addresses[2]->family == AF_INET6);
-        assert_se(memcmp(&bn->addresses[2]->address.in6,
-                         &(struct in6_addr) { .s6_addr = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5} }, 16 ) == 0);
+        assert_se(bn = hashmap_get(hosts.by_name, "dash"));
+        assert_se(bn->n_addresses == 1);
+        assert_se(bn->n_allocated >= 1);
+        assert_se(address_equal_4(bn->addresses[0], inet_addr("1.2.3.6")));
+
+        assert_se(bn = hashmap_get(hosts.by_name, "dash-dash.where-dash"));
+        assert_se(bn->n_addresses == 1);
+        assert_se(bn->n_allocated >= 1);
+        assert_se(address_equal_4(bn->addresses[0], inet_addr("1.2.3.6")));
+
+        /* See https://tools.ietf.org/html/rfc1035#section-2.3.1 */
+        FOREACH_STRING(s, "bad-dash-", "-bad-dash", "-bad-dash.bad-")
+                assert_se(!hashmap_get(hosts.by_name, s));
+
+        assert_se(bn = hashmap_get(hosts.by_name, "before.comment"));
+        assert_se(bn->n_addresses == 4);
+        assert_se(bn->n_allocated >= 4);
+        assert_se(address_equal_4(bn->addresses[0], inet_addr("1.2.3.9")));
+        assert_se(address_equal_4(bn->addresses[1], inet_addr("1.2.3.10")));
+        assert_se(address_equal_4(bn->addresses[2], inet_addr("1.2.3.11")));
+        assert_se(address_equal_4(bn->addresses[3], inet_addr("1.2.3.12")));
+
+        assert(!hashmap_get(hosts.by_name, "within.comment"));
+        assert(!hashmap_get(hosts.by_name, "within.comment2"));
+        assert(!hashmap_get(hosts.by_name, "within.comment3"));
+        assert(!hashmap_get(hosts.by_name, "#"));
+
+        assert(!hashmap_get(hosts.by_name, "short.address"));
+        assert(!hashmap_get(hosts.by_name, "long.address"));
+        assert(!hashmap_get(hosts.by_name, "multi.colon"));
+        assert_se(!set_contains(hosts.no_address, "short.address"));
+        assert_se(!set_contains(hosts.no_address, "long.address"));
+        assert_se(!set_contains(hosts.no_address, "multi.colon"));
 
         assert_se(bn = hashmap_get(hosts.by_name, "some.other"));
         assert_se(bn->n_addresses == 1);
         assert_se(bn->n_allocated >= 1);
-        assert_se(bn->addresses[0]->family == AF_INET6);
-        assert_se(memcmp(&bn->addresses[0]->address.in6,
-                         &(struct in6_addr) { .s6_addr = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5} }, 16 ) == 0);
+        assert_se(address_equal_6(bn->addresses[0], {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5}));
 
         assert_se( set_contains(hosts.no_address, "some.where"));
         assert_se( set_contains(hosts.no_address, "some.other"));
@@ -79,14 +126,26 @@ static void test_parse_etc_hosts(const char *fname) {
         assert_se(!set_contains(hosts.no_address, "foobar.foo.foo"));
 }
 
+static void test_parse_file(const char *fname) {
+        _cleanup_(etc_hosts_free) EtcHosts hosts = {};
+        _cleanup_fclose_ FILE *f;
+
+        log_info("/* %s(\"%s\") */", __func__, fname);
+
+        assert_se(f = fopen(fname, "re"));
+        assert_se(etc_hosts_parse(&hosts, f) == 0);
+}
+
 int main(int argc, char **argv) {
         log_set_max_level(LOG_DEBUG);
         log_parse_environment();
         log_open();
 
-        if (argc == 1)
+        if (argc == 1) {
                 test_parse_etc_hosts_system();
-        test_parse_etc_hosts(argv[1]);
+                test_parse_etc_hosts();
+        } else
+                test_parse_file(argv[1]);
 
         return 0;
 }

src/shared/dns-domain.c

@@ -17,6 +17,7 @@
 #include "dns-domain.h"
 #include "hashmap.h"
 #include "hexdecoct.h"
+#include "hostname-util.h"
 #include "in-addr-util.h"
 #include "macro.h"
 #include "parse-util.h"
@@ -24,9 +25,9 @@
 #include "strv.h"
 #include "utf8.h"
 
-int dns_label_unescape(const char **name, char *dest, size_t sz) {
+int dns_label_unescape(const char **name, char *dest, size_t sz, DNSLabelFlags flags) {
         const char *n;
-        char *d;
+        char *d, last_char = 0;
         int r = 0;
 
         assert(name);
@@ -36,14 +37,16 @@ int dns_label_unescape(const char **name, char *dest, size_t sz) {
         d = dest;
 
         for (;;) {
-                if (*n == '.') {
-                        n++;
+                if (*n == 0 || *n == '.') {
+                        if (FLAGS_SET(flags, DNS_LABEL_LDH) && last_char == '-')
+                                /* Trailing dash */
+                                return -EINVAL;
+
+                        if (*n == '.')
+                                n++;
                         break;
                 }
 
-                if (*n == 0)
-                        break;
-
                 if (r >= DNS_LABEL_MAX)
                         return -EINVAL;
 
@@ -52,6 +55,8 @@ int dns_label_unescape(const char **name, char *dest, size_t sz) {
 
                 if (*n == '\\') {
                         /* Escaped character */
+                        if (FLAGS_SET(flags, DNS_LABEL_NO_ESCAPES))
+                                return -EINVAL;
 
                         n++;
 
@@ -62,6 +67,10 @@ int dns_label_unescape(const char **name, char *dest, size_t sz) {
                         else if (IN_SET(*n, '\\', '.')) {
                                 /* Escaped backslash or dot */
 
+                                if (FLAGS_SET(flags, DNS_LABEL_LDH))
+                                        return -EINVAL;
+
+                                last_char = *n;
                                 if (d)
                                         *(d++) = *n;
                                 sz--;
@@ -90,6 +99,11 @@ int dns_label_unescape(const char **name, char *dest, size_t sz) {
                                 if (k > 255)
                                         return -EINVAL;
 
+                                if (FLAGS_SET(flags, DNS_LABEL_LDH) &&
+                                    !valid_ldh_char((char) k))
+                                        return -EINVAL;
+
+                                last_char = (char) k;
                                 if (d)
                                         *(d++) = (char) k;
                                 sz--;
@@ -103,6 +117,15 @@ int dns_label_unescape(const char **name, char *dest, size_t sz) {
 
                         /* Normal character */
 
+                        if (FLAGS_SET(flags, DNS_LABEL_LDH)) {
+                                if (!valid_ldh_char(*n))
+                                        return -EINVAL;
+                                if (r == 0 && *n == '-')
+                                        /* Leading dash */
+                                        return -EINVAL;
+                        }
+
+                        last_char = *n;
                         if (d)
                                 *(d++) = *n;
                         sz--;
@@ -184,7 +207,7 @@ int dns_label_unescape_suffix(const char *name, const char **label_terminal, cha
                 terminal--;
         }
 
-        r = dns_label_unescape(&name, dest, sz);
+        r = dns_label_unescape(&name, dest, sz, 0);
         if (r < 0)
                 return r;
 
@@ -378,7 +401,7 @@ int dns_label_undo_idna(const char *encoded, size_t encoded_size, char *decoded,
 }
 #endif
 
-int dns_name_concat(const char *a, const char *b, char **_ret) {
+int dns_name_concat(const char *a, const char *b, DNSLabelFlags flags, char **_ret) {
         _cleanup_free_ char *ret = NULL;
         size_t n = 0, allocated = 0;
         const char *p;
@@ -395,7 +418,7 @@ int dns_name_concat(const char *a, const char *b, char **_ret) {
         for (;;) {
                 char label[DNS_LABEL_MAX];
 
-                r = dns_label_unescape(&p, label, sizeof(label));
+                r = dns_label_unescape(&p, label, sizeof label, flags);
                 if (r < 0)
                         return r;
                 if (r == 0) {
@@ -468,7 +491,7 @@ void dns_name_hash_func(const char *p, struct siphash *state) {
         for (;;) {
                 char label[DNS_LABEL_MAX+1];
 
-                r = dns_label_unescape(&p, label, sizeof(label));
+                r = dns_label_unescape(&p, label, sizeof label, 0);
                 if (r < 0)
                         break;
                 if (r == 0)
@@ -521,11 +544,11 @@ int dns_name_equal(const char *x, const char *y) {
         for (;;) {
                 char la[DNS_LABEL_MAX], lb[DNS_LABEL_MAX];
 
-                r = dns_label_unescape(&x, la, sizeof(la));
+                r = dns_label_unescape(&x, la, sizeof la, 0);
                 if (r < 0)
                         return r;
 
-                q = dns_label_unescape(&y, lb, sizeof(lb));
+                q = dns_label_unescape(&y, lb, sizeof lb, 0);
                 if (q < 0)
                         return q;
 
@@ -552,14 +575,14 @@ int dns_name_endswith(const char *name, const char *suffix) {
         for (;;) {
                 char ln[DNS_LABEL_MAX], ls[DNS_LABEL_MAX];
 
-                r = dns_label_unescape(&n, ln, sizeof(ln));
+                r = dns_label_unescape(&n, ln, sizeof ln, 0);
                 if (r < 0)
                         return r;
 
                 if (!saved_n)
                         saved_n = n;
 
-                q = dns_label_unescape(&s, ls, sizeof(ls));
+                q = dns_label_unescape(&s, ls, sizeof ls, 0);
                 if (q < 0)
                         return q;
 
@@ -590,13 +613,13 @@ int dns_name_startswith(const char *name, const char *prefix) {
         for (;;) {
                 char ln[DNS_LABEL_MAX], lp[DNS_LABEL_MAX];
 
-                r = dns_label_unescape(&p, lp, sizeof(lp));
+                r = dns_label_unescape(&p, lp, sizeof lp, 0);
                 if (r < 0)
                         return r;
                 if (r == 0)
                         return true;
 
-                q = dns_label_unescape(&n, ln, sizeof(ln));
+                q = dns_label_unescape(&n, ln, sizeof ln, 0);
                 if (q < 0)
                         return q;
 
@@ -625,14 +648,14 @@ int dns_name_change_suffix(const char *name, const char *old_suffix, const char
                 if (!saved_before)
                         saved_before = n;
 
-                r = dns_label_unescape(&n, ln, sizeof(ln));
+                r = dns_label_unescape(&n, ln, sizeof ln, 0);
                 if (r < 0)
                         return r;
 
                 if (!saved_after)
                         saved_after = n;
 
-                q = dns_label_unescape(&s, ls, sizeof(ls));
+                q = dns_label_unescape(&s, ls, sizeof ls, 0);
                 if (q < 0)
                         return q;
 
@@ -655,7 +678,7 @@ int dns_name_change_suffix(const char *name, const char *old_suffix, const char
         /* Found it! Now generate the new name */
         prefix = strndupa(name, saved_before - name);
 
-        r = dns_name_concat(prefix, new_suffix, ret);
+        r = dns_name_concat(prefix, new_suffix, 0, ret);
         if (r < 0)
                 return r;
 
@@ -733,7 +756,7 @@ int dns_name_address(const char *p, int *family, union in_addr_union *address) {
                 for (i = 0; i < ELEMENTSOF(a); i++) {
                         char label[DNS_LABEL_MAX+1];
 
-                        r = dns_label_unescape(&p, label, sizeof(label));
+                        r = dns_label_unescape(&p, label, sizeof label, 0);
                         if (r < 0)
                                 return r;
                         if (r == 0)
@@ -770,7 +793,7 @@ int dns_name_address(const char *p, int *family, union in_addr_union *address) {
                         char label[DNS_LABEL_MAX+1];
                         int x, y;
 
-                        r = dns_label_unescape(&p, label, sizeof(label));
+                        r = dns_label_unescape(&p, label, sizeof label, 0);
                         if (r <= 0)
                                 return r;
                         if (r != 1)
@@ -779,7 +802,7 @@ int dns_name_address(const char *p, int *family, union in_addr_union *address) {
                         if (x < 0)
                                 return -EINVAL;
 
-                        r = dns_label_unescape(&p, label, sizeof(label));
+                        r = dns_label_unescape(&p, label, sizeof label, 0);
                         if (r <= 0)
                                 return r;
                         if (r != 1)
@@ -847,7 +870,7 @@ int dns_name_to_wire_format(const char *domain, uint8_t *buffer, size_t len, boo
                  * dns_label_unescape() returns 0 when it hits the end
                  * of the domain name, which we rely on here to encode
                  * the trailing NUL byte. */
-                r = dns_label_unescape(&domain, (char *) out, len);
+                r = dns_label_unescape(&domain, (char *) out, len, 0);
                 if (r < 0)
                         return r;
 
@@ -914,7 +937,7 @@ bool dns_srv_type_is_valid(const char *name) {
 
                 /* This more or less implements RFC 6335, Section 5.1 */
 
-                r = dns_label_unescape(&name, label, sizeof(label));
+                r = dns_label_unescape(&name, label, sizeof label, 0);
                 if (r < 0)
                         return false;
                 if (r == 0)
@@ -974,7 +997,7 @@ int dns_service_join(const char *name, const char *type, const char *domain, cha
                 return -EINVAL;
 
         if (!name)
-                return dns_name_concat(type, domain, ret);
+                return dns_name_concat(type, domain, 0, ret);
 
         if (!dns_service_name_is_valid(name))
                 return -EINVAL;
@@ -983,11 +1006,11 @@ int dns_service_join(const char *name, const char *type, const char *domain, cha
         if (r < 0)
                 return r;
 
-        r = dns_name_concat(type, domain, &n);
+        r = dns_name_concat(type, domain, 0, &n);
         if (r < 0)
                 return r;
 
-        return dns_name_concat(escaped, n, ret);
+        return dns_name_concat(escaped, n, 0, ret);
 }
 
 static bool dns_service_name_label_is_valid(const char *label, size_t n) {
@@ -1012,7 +1035,7 @@ int dns_service_split(const char *joined, char **_name, char **_type, char **_do
         assert(joined);
 
         /* Get first label from the full name */
-        an = dns_label_unescape(&p, a, sizeof(a));
+        an = dns_label_unescape(&p, a, sizeof(a), 0);
         if (an < 0)
                 return an;
 
@@ -1020,7 +1043,7 @@ int dns_service_split(const char *joined, char **_name, char **_type, char **_do
                 x++;
 
                 /* If there was a first label, try to get the second one */
-                bn = dns_label_unescape(&p, b, sizeof(b));
+                bn = dns_label_unescape(&p, b, sizeof(b), 0);
                 if (bn < 0)
                         return bn;
 
@@ -1029,7 +1052,7 @@ int dns_service_split(const char *joined, char **_name, char **_type, char **_do
 
                         /* If there was a second label, try to get the third one */
                         q = p;
-                        cn = dns_label_unescape(&p, c, sizeof(c));
+                        cn = dns_label_unescape(&p, c, sizeof(c), 0);
                         if (cn < 0)
                                 return cn;
 
@@ -1079,7 +1102,7 @@ int dns_service_split(const char *joined, char **_name, char **_type, char **_do
         d = joined;
 
 finish:
-        r = dns_name_normalize(d, &domain);
+        r = dns_name_normalize(d, 0, &domain);
         if (r < 0)
                 return r;
 
@@ -1224,12 +1247,12 @@ int dns_name_common_suffix(const char *a, const char *b, const char **ret) {
                 }
 
                 x = a_labels[n - 1 - k];
-                r = dns_label_unescape(&x, la, sizeof(la));
+                r = dns_label_unescape(&x, la, sizeof la, 0);
                 if (r < 0)
                         return r;
 
                 y = b_labels[m - 1 - k];
-                q = dns_label_unescape(&y, lb, sizeof(lb));
+                q = dns_label_unescape(&y, lb, sizeof lb, 0);
                 if (q < 0)
                         return q;
 
@@ -1297,13 +1320,13 @@ int dns_name_apply_idna(const char *name, char **ret) {
         for (;;) {
                 char label[DNS_LABEL_MAX];
 
-                r = dns_label_unescape(&name, label, sizeof(label));
+                r = dns_label_unescape(&name, label, sizeof label, 0);
                 if (r < 0)
                         return r;
                 if (r == 0)
                         break;
 
-                q = dns_label_apply_idna(label, r, label, sizeof(label));
+                q = dns_label_apply_idna(label, r, label, sizeof label);
                 if (q < 0)
                         return q;
                 if (q > 0)

src/shared/dns-domain.h

@@ -24,13 +24,18 @@
 /* Maximum number of labels per valid hostname */
 #define DNS_N_LABELS_MAX 127
 
-int dns_label_unescape(const char **name, char *dest, size_t sz);
+typedef enum DNSLabelFlags {
+        DNS_LABEL_LDH        = 1 << 0, /* Follow the "LDH" rule — only letters, digits, and internal hyphens. */
+        DNS_LABEL_NO_ESCAPES = 1 << 1, /* Do not treat backslashes specially */
+} DNSLabelFlags;
+
+int dns_label_unescape(const char **name, char *dest, size_t sz, DNSLabelFlags flags);
 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 *dest, size_t sz);
 int dns_label_escape_new(const char *p, size_t l, char **ret);
 
 static inline int dns_name_parent(const char **name) {
-        return dns_label_unescape(name, NULL, DNS_LABEL_MAX);
+        return dns_label_unescape(name, NULL, DNS_LABEL_MAX, 0);
 }
 
 #if HAVE_LIBIDN
@@ -38,18 +43,29 @@ int dns_label_apply_idna(const char *encoded, size_t encoded_size, char *decoded
 int dns_label_undo_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max);
 #endif
 
-int dns_name_concat(const char *a, const char *b, char **ret);
+int dns_name_concat(const char *a, const char *b, DNSLabelFlags flags, char **ret);
 
-static inline int dns_name_normalize(const char *s, char **ret) {
+static inline int dns_name_normalize(const char *s, DNSLabelFlags flags, char **ret) {
         /* dns_name_concat() normalizes as a side-effect */
-        return dns_name_concat(s, NULL, ret);
+        return dns_name_concat(s, NULL, flags, ret);
 }
 
 static inline int dns_name_is_valid(const char *s) {
         int r;
 
         /* dns_name_normalize() verifies as a side effect */
-        r = dns_name_normalize(s, NULL);
+        r = dns_name_normalize(s, 0, NULL);
+        if (r == -EINVAL)
+                return 0;
+        if (r < 0)
+                return r;
+        return 1;
+}
+
+static inline int dns_name_is_valid_ldh(const char *s) {
+        int r;
+
+        r = dns_name_concat(s, NULL, DNS_LABEL_LDH|DNS_LABEL_NO_ESCAPES, NULL);
         if (r == -EINVAL)
                 return 0;
         if (r < 0)

src/test/test-dns-domain.c

@@ -6,39 +6,65 @@
 #include "string-util.h"
 #include "tests.h"
 
-static void test_dns_label_unescape_one(const char *what, const char *expect, size_t buffer_sz, int ret) {
+static void test_dns_label_unescape_one(const char *what, const char *expect, size_t buffer_sz, int ret, int ret_ldh) {
         char buffer[buffer_sz];
         int r;
+        const char *w = what;
 
-        r = dns_label_unescape(&what, buffer, buffer_sz);
+        log_info("%s, %s, %zu, →%d/%d", what, expect, buffer_sz, ret, ret_ldh);
+
+        r = dns_label_unescape(&w, buffer, buffer_sz, 0);
         assert_se(r == ret);
+        if (r >= 0)
+                assert_se(streq(buffer, expect));
 
-        if (r < 0)
-                return;
+        w = what;
+        r = dns_label_unescape(&w, buffer, buffer_sz, DNS_LABEL_LDH);
+        assert_se(r == ret_ldh);
+        if (r >= 0)
+                assert_se(streq(buffer, expect));
 
-        assert_se(streq(buffer, expect));
+        w = what;
+        r = dns_label_unescape(&w, buffer, buffer_sz, DNS_LABEL_NO_ESCAPES);
+        const int ret_noe = strchr(what, '\\') ? -EINVAL : ret;
+        assert_se(r == ret_noe);
+        if (r >= 0)
+                assert_se(streq(buffer, expect));
 }
 
 static void test_dns_label_unescape(void) {
-        test_dns_label_unescape_one("hallo", "hallo", 6, 5);
-        test_dns_label_unescape_one("hallo", "hallo", 4, -ENOBUFS);
-        test_dns_label_unescape_one("", "", 10, 0);
-        test_dns_label_unescape_one("hallo\\.foobar", "hallo.foobar", 20, 12);
-        test_dns_label_unescape_one("hallo.foobar", "hallo", 10, 5);
-        test_dns_label_unescape_one("hallo\n.foobar", "hallo", 20, -EINVAL);
-        test_dns_label_unescape_one("hallo\\", "hallo", 20, -EINVAL);
-        test_dns_label_unescape_one("hallo\\032 ", "hallo  ", 20, 7);
-        test_dns_label_unescape_one(".", "", 20, 0);
-        test_dns_label_unescape_one("..", "", 20, -EINVAL);
-        test_dns_label_unescape_one(".foobar", "", 20, -EINVAL);
-        test_dns_label_unescape_one("foobar.", "foobar", 20, 6);
-        test_dns_label_unescape_one("foobar..", "foobar", 20, -EINVAL);
+        log_info("/* %s */", __func__);
+
+        test_dns_label_unescape_one("hallo", "hallo", 6, 5, 5);
+        test_dns_label_unescape_one("hallo", "hallo", 4, -ENOBUFS, -ENOBUFS);
+        test_dns_label_unescape_one("", "", 10, 0, 0);
+        test_dns_label_unescape_one("hallo\\.foobar", "hallo.foobar", 20, 12, -EINVAL);
+        test_dns_label_unescape_one("hallo.foobar", "hallo", 10, 5, 5);
+        test_dns_label_unescape_one("hallo\n.foobar", "hallo", 20, -EINVAL, -EINVAL);
+        test_dns_label_unescape_one("hallo\\", "hallo", 20, -EINVAL, -EINVAL);
+        test_dns_label_unescape_one("hallo\\032 ", "hallo  ", 20, 7, -EINVAL);
+        test_dns_label_unescape_one(".", "", 20, 0, 0);
+        test_dns_label_unescape_one("..", "", 20, -EINVAL, -EINVAL);
+        test_dns_label_unescape_one(".foobar", "", 20, -EINVAL, -EINVAL);
+        test_dns_label_unescape_one("foobar.", "foobar", 20, 6, 6);
+        test_dns_label_unescape_one("foobar..", "foobar", 20, -EINVAL, -EINVAL);
+        test_dns_label_unescape_one("foo-bar", "foo-bar", 20, 7, 7);
+        test_dns_label_unescape_one("foo-", "foo-", 20, 4, -EINVAL);
+        test_dns_label_unescape_one("-foo", "-foo", 20, 4, -EINVAL);
+        test_dns_label_unescape_one("-foo-", "-foo-", 20, 5, -EINVAL);
+        test_dns_label_unescape_one("foo-.", "foo-", 20, 4, -EINVAL);
+        test_dns_label_unescape_one("foo.-", "foo", 20, 3, 3);
+        test_dns_label_unescape_one("foo\\032", "foo ", 20, 4, -EINVAL);
+        test_dns_label_unescape_one("foo\\045", "foo-", 20, 4, -EINVAL);
+        test_dns_label_unescape_one("głąb", "głąb", 20, 6, -EINVAL);
 }
 
 static void test_dns_name_to_wire_format_one(const char *what, const char *expect, size_t buffer_sz, int ret) {
         uint8_t buffer[buffer_sz];
         int r;
 
+        log_info("%s, %s, %zu, →%d", what, expect, buffer_sz, ret);
+
         r = dns_name_to_wire_format(what, buffer, buffer_sz, false);
         assert_se(r == ret);
 
@@ -80,6 +106,8 @@ static void test_dns_name_to_wire_format(void) {
                                      9, 'a', '1', '2', '3', '4', '5', '6', '7', '8',
                                      3, 'a', '1', '2', 0 };
 
+        log_info("/* %s */", __func__);
+
         test_dns_name_to_wire_format_one("", out0, sizeof(out0), sizeof(out0));
 
         test_dns_name_to_wire_format_one("foo", out1, sizeof(out1), sizeof(out1));
@@ -100,6 +128,8 @@ static void test_dns_label_unescape_suffix_one(const char *what, const char *exp
         const char *label;
         int r;
 
+        log_info("%s, %s, %s, %zu, %d, %d", what, expect1, expect2, buffer_sz, ret1, ret2);
+
         label = what + strlen(what);
 
         r = dns_label_unescape_suffix(what, &label, buffer, buffer_sz);
@@ -114,6 +144,8 @@ static void test_dns_label_unescape_suffix_one(const char *what, const char *exp
 }
 
 static void test_dns_label_unescape_suffix(void) {
+        log_info("/* %s */", __func__);
+
         test_dns_label_unescape_suffix_one("hallo", "hallo", "", 6, 5, 0);
         test_dns_label_unescape_suffix_one("hallo", "hallo", "", 4, -ENOBUFS, -ENOBUFS);
         test_dns_label_unescape_suffix_one("", "", "", 10, 0, 0);
@@ -139,6 +171,8 @@ static void test_dns_label_escape_one(const char *what, size_t l, const char *ex
         _cleanup_free_ char *t = NULL;
         int r;
 
+        log_info("%s, %zu, %s, →%d", what, l, expect, ret);
+
         r = dns_label_escape_new(what, l, &t);
         assert_se(r == ret);
 
@@ -149,6 +183,8 @@ static void test_dns_label_escape_one(const char *what, size_t l, const char *ex
 }
 
 static void test_dns_label_escape(void) {
+        log_info("/* %s */", __func__);
+
         test_dns_label_escape_one("", 0, NULL, -EINVAL);
         test_dns_label_escape_one("hallo", 5, "hallo", 5);
         test_dns_label_escape_one("hallo", 6, "hallo\\000", 9);
@@ -159,7 +195,7 @@ static void test_dns_name_normalize_one(const char *what, const char *expect, in
         _cleanup_free_ char *t = NULL;
         int r;
 
-        r = dns_name_normalize(what, &t);
+        r = dns_name_normalize(what, 0, &t);
         assert_se(r == ret);
 
         if (r < 0)
@@ -320,7 +356,7 @@ static void test_dns_name_reverse(void) {
 static void test_dns_name_concat_one(const char *a, const char *b, int r, const char *result) {
         _cleanup_free_ char *p = NULL;
 
-        assert_se(dns_name_concat(a, b, &p) == r);
+        assert_se(dns_name_concat(a, b, 0, &p) == r);
         assert_se(streq_ptr(p, result));
 }
 
@@ -339,46 +375,68 @@ static void test_dns_name_concat(void) {
         test_dns_name_concat_one(NULL, "foo", 0, "foo");
 }
 
-static void test_dns_name_is_valid_one(const char *s, int ret) {
+static void test_dns_name_is_valid_one(const char *s, int ret, int ret_ldh) {
+        log_info("%s, →%d", s, ret);
+
         assert_se(dns_name_is_valid(s) == ret);
+        assert_se(dns_name_is_valid_ldh(s) == ret_ldh);
 }
 
 static void test_dns_name_is_valid(void) {
-        test_dns_name_is_valid_one("foo", 1);
-        test_dns_name_is_valid_one("foo.", 1);
-        test_dns_name_is_valid_one("foo..", 0);
-        test_dns_name_is_valid_one("Foo", 1);
-        test_dns_name_is_valid_one("foo.bar", 1);
-        test_dns_name_is_valid_one("foo.bar.baz", 1);
-        test_dns_name_is_valid_one("", 1);
-        test_dns_name_is_valid_one("foo..bar", 0);
-        test_dns_name_is_valid_one(".foo.bar", 0);
-        test_dns_name_is_valid_one("foo.bar.", 1);
-        test_dns_name_is_valid_one("foo.bar..", 0);
-        test_dns_name_is_valid_one("\\zbar", 0);
-        test_dns_name_is_valid_one("ä", 1);
-        test_dns_name_is_valid_one("\n", 0);
+        log_info("/* %s */", __func__);
+
+        test_dns_name_is_valid_one("foo",               1, 1);
+        test_dns_name_is_valid_one("foo.",              1, 1);
+        test_dns_name_is_valid_one("foo..",             0, 0);
+        test_dns_name_is_valid_one("Foo",               1, 1);
+        test_dns_name_is_valid_one("foo.bar",           1, 1);
+        test_dns_name_is_valid_one("foo.bar.baz",       1, 1);
+        test_dns_name_is_valid_one("",                  1, 1);
+        test_dns_name_is_valid_one("foo..bar",          0, 0);
+        test_dns_name_is_valid_one(".foo.bar",          0, 0);
+        test_dns_name_is_valid_one("foo.bar.",          1, 1);
+        test_dns_name_is_valid_one("foo.bar..",         0, 0);
+        test_dns_name_is_valid_one("\\zbar",            0, 0);
+        test_dns_name_is_valid_one("ä",                 1, 0);
+        test_dns_name_is_valid_one("\n",                0, 0);
+
+        test_dns_name_is_valid_one("dash-",             1, 0);
+        test_dns_name_is_valid_one("-dash",             1, 0);
+        test_dns_name_is_valid_one("dash-dash",         1, 1);
+        test_dns_name_is_valid_one("foo.dash-",         1, 0);
+        test_dns_name_is_valid_one("foo.-dash",         1, 0);
+        test_dns_name_is_valid_one("foo.dash-dash",     1, 1);
+        test_dns_name_is_valid_one("foo.dash-.bar",     1, 0);
+        test_dns_name_is_valid_one("foo.-dash.bar",     1, 0);
+        test_dns_name_is_valid_one("foo.dash-dash.bar", 1, 1);
+        test_dns_name_is_valid_one("dash-.bar",         1, 0);
+        test_dns_name_is_valid_one("-dash.bar",         1, 0);
+        test_dns_name_is_valid_one("dash-dash.bar",     1, 1);
+        test_dns_name_is_valid_one("-.bar",             1, 0);
+        test_dns_name_is_valid_one("foo.-",             1, 0);
 
         /* 256 characters */
-        test_dns_name_is_valid_one("a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345", 0);
+        test_dns_name_is_valid_one("a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345", 0, 0);
 
         /* 255 characters */
-        test_dns_name_is_valid_one("a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a1234", 0);
+        test_dns_name_is_valid_one("a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a1234", 0, 0);
 
         /* 254 characters */
-        test_dns_name_is_valid_one("a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a123", 0);
+        test_dns_name_is_valid_one("a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a123", 0, 0);
 
         /* 253 characters */
-        test_dns_name_is_valid_one("a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12", 1);
+        test_dns_name_is_valid_one("a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12345678.a12", 1, 1);
 
         /* label of 64 chars length */
-        test_dns_name_is_valid_one("a123456789a123456789a123456789a123456789a123456789a123456789a123", 0);
+        test_dns_name_is_valid_one("a123456789a123456789a123456789a123456789a123456789a123456789a123", 0, 0);
 
         /* label of 63 chars length */
-        test_dns_name_is_valid_one("a123456789a123456789a123456789a123456789a123456789a123456789a12", 1);
+        test_dns_name_is_valid_one("a123456789a123456789a123456789a123456789a123456789a123456789a12", 1, 1);
 }
 
 static void test_dns_service_name_is_valid(void) {
+        log_info("/* %s */", __func__);
+
         assert_se(dns_service_name_is_valid("Lennart's Compüter"));
         assert_se(dns_service_name_is_valid("piff.paff"));
 
@@ -390,6 +448,7 @@ static void test_dns_service_name_is_valid(void) {
 }
 
 static void test_dns_srv_type_is_valid(void) {
+        log_info("/* %s */", __func__);
 
         assert_se(dns_srv_type_is_valid("_http._tcp"));
         assert_se(dns_srv_type_is_valid("_foo-bar._tcp"));
@@ -413,6 +472,7 @@ static void test_dns_srv_type_is_valid(void) {
 }
 
 static void test_dnssd_srv_type_is_valid(void) {
+        log_info("/* %s */", __func__);
 
         assert_se(dnssd_srv_type_is_valid("_http._tcp"));
         assert_se(dnssd_srv_type_is_valid("_foo-bar._tcp"));
@@ -439,6 +499,8 @@ static void test_dnssd_srv_type_is_valid(void) {
 static void test_dns_service_join_one(const char *a, const char *b, const char *c, int r, const char *d) {
         _cleanup_free_ char *x = NULL, *y = NULL, *z = NULL, *t = NULL;
 
+        log_info("%s, %s, %s, →%d, %s", a, b, c, r, d);
+
         assert_se(dns_service_join(a, b, c, &t) == r);
         assert_se(streq_ptr(t, d));
 
@@ -452,6 +514,8 @@ static void test_dns_service_join_one(const char *a, const char *b, const char *
 }
 
 static void test_dns_service_join(void) {
+        log_info("/* %s */", __func__);
+
         test_dns_service_join_one("", "", "", -EINVAL, NULL);
         test_dns_service_join_one("", "_http._tcp", "", -EINVAL, NULL);
         test_dns_service_join_one("", "_http._tcp", "foo", -EINVAL, NULL);
@@ -469,6 +533,8 @@ static void test_dns_service_join(void) {
 static void test_dns_service_split_one(const char *joined, const char *a, const char *b, const char *c, int r) {
         _cleanup_free_ char *x = NULL, *y = NULL, *z = NULL, *t = NULL;
 
+        log_info("%s, %s, %s, %s, →%d", joined, a, b, c, r);
+
         assert_se(dns_service_split(joined, &x, &y, &z) == r);
         assert_se(streq_ptr(x, a));
         assert_se(streq_ptr(y, b));
@@ -485,6 +551,8 @@ static void test_dns_service_split_one(const char *joined, const char *a, const
 }
 
 static void test_dns_service_split(void) {
+        log_info("/* %s */", __func__);
+
         test_dns_service_split_one("", NULL, NULL, ".", 0);
         test_dns_service_split_one("foo", NULL, NULL, "foo", 0);
         test_dns_service_split_one("foo.bar", NULL, NULL, "foo.bar", 0);
@@ -497,11 +565,15 @@ static void test_dns_service_split(void) {
 static void test_dns_name_change_suffix_one(const char *name, const char *old_suffix, const char *new_suffix, int r, const char *result) {
         _cleanup_free_ char *s = NULL;
 
+        log_info("%s, %s, %s, →%s", name, old_suffix, new_suffix, result);
+
         assert_se(dns_name_change_suffix(name, old_suffix, new_suffix, &s) == r);
         assert_se(streq_ptr(s, result));
 }
 
 static void test_dns_name_change_suffix(void) {
+        log_info("/* %s */", __func__);
+
         test_dns_name_change_suffix_one("foo.bar", "bar", "waldo", 1, "foo.waldo");
         test_dns_name_change_suffix_one("foo.bar.waldi.quux", "foo.bar.waldi.quux", "piff.paff", 1, "piff.paff");
         test_dns_name_change_suffix_one("foo.bar.waldi.quux", "bar.waldi.quux", "piff.paff", 1, "foo.piff.paff");
@@ -516,11 +588,15 @@ static void test_dns_name_change_suffix(void) {
 static void test_dns_name_suffix_one(const char *name, unsigned n_labels, const char *result, int ret) {
         const char *p = NULL;
 
+        log_info("%s, %d, →%s, %d", name, n_labels, result, ret);
+
         assert_se(ret == dns_name_suffix(name, n_labels, &p));
         assert_se(streq_ptr(p, result));
 }
 
 static void test_dns_name_suffix(void) {
+        log_info("/* %s */", __func__);
+
         test_dns_name_suffix_one("foo.bar", 2, "foo.bar", 0);
         test_dns_name_suffix_one("foo.bar", 1, "bar", 1);
         test_dns_name_suffix_one("foo.bar", 0, "", 2);
@@ -538,10 +614,14 @@ static void test_dns_name_suffix(void) {
 }
 
 static void test_dns_name_count_labels_one(const char *name, int n) {
+        log_info("%s, →%d", name, n);
+
         assert_se(dns_name_count_labels(name) == n);
 }
 
 static void test_dns_name_count_labels(void) {
+        log_info("/* %s */", __func__);
+
         test_dns_name_count_labels_one("foo.bar.quux.", 3);
         test_dns_name_count_labels_one("foo.bar.quux", 3);
         test_dns_name_count_labels_one("foo.bar.", 2);
@@ -554,10 +634,14 @@ static void test_dns_name_count_labels(void) {
 }
 
 static void test_dns_name_equal_skip_one(const char *a, unsigned n_labels, const char *b, int ret) {
+        log_info("%s, %u, %s, →%d", a, n_labels, b, ret);
+
         assert_se(dns_name_equal_skip(a, n_labels, b) == ret);
 }
 
 static void test_dns_name_equal_skip(void) {
+        log_info("/* %s */", __func__);
+
         test_dns_name_equal_skip_one("foo", 0, "bar", 0);
         test_dns_name_equal_skip_one("foo", 0, "foo", 1);
         test_dns_name_equal_skip_one("foo", 1, "foo", 0);
@@ -585,6 +669,8 @@ static void test_dns_name_equal_skip(void) {
 }
 
 static void test_dns_name_compare_func(void) {
+        log_info("/* %s */", __func__);
+
         assert_se(dns_name_compare_func("", "") == 0);
         assert_se(dns_name_compare_func("", ".") == 0);
         assert_se(dns_name_compare_func(".", "") == 0);
@@ -600,11 +686,15 @@ static void test_dns_name_compare_func(void) {
 static void test_dns_name_common_suffix_one(const char *a, const char *b, const char *result) {
         const char *c;
 
+        log_info("%s, %s, →%s", a, b, result);
+
         assert_se(dns_name_common_suffix(a, b, &c) >= 0);
         assert_se(streq(c, result));
 }
 
 static void test_dns_name_common_suffix(void) {
+        log_info("/* %s */", __func__);
+
         test_dns_name_common_suffix_one("", "", "");
         test_dns_name_common_suffix_one("foo", "", "");
         test_dns_name_common_suffix_one("", "foo", "");
@@ -639,6 +729,7 @@ static void test_dns_name_apply_idna(void) {
 #else
         const int ret = 0;
 #endif
+        log_info("/* %s */", __func__);
 
         /* IDNA2008 forbids names with hyphens in third and fourth positions
          * (https://tools.ietf.org/html/rfc5891#section-4.2.3.1).
@@ -676,6 +767,8 @@ static void test_dns_name_apply_idna(void) {
 }
 
 static void test_dns_name_is_valid_or_address(void) {
+        log_info("/* %s */", __func__);
+
         assert_se(dns_name_is_valid_or_address(NULL) == 0);
         assert_se(dns_name_is_valid_or_address("") == 0);
         assert_se(dns_name_is_valid_or_address("foobar") > 0);

src/test/test-hostname-util.c

@@ -53,6 +53,12 @@ static void test_hostname_cleanup(void) {
         assert_se(streq(hostname_cleanup(s), "foobar.com"));
         s = strdupa("foobar.com.");
         assert_se(streq(hostname_cleanup(s), "foobar.com"));
+        s = strdupa("foo-bar.-com-.");
+        assert_se(streq(hostname_cleanup(s), "foo-bar.com"));
+        s = strdupa("foo-bar-.-com-.");
+        assert_se(streq(hostname_cleanup(s), "foo-bar--com"));
+        s = strdupa("--foo-bar.-com");
+        assert_se(streq(hostname_cleanup(s), "foo-bar.com"));
         s = strdupa("fooBAR");
         assert_se(streq(hostname_cleanup(s), "fooBAR"));
         s = strdupa("fooBAR.com");
@@ -79,6 +85,8 @@ static void test_hostname_cleanup(void) {
         assert_se(streq(hostname_cleanup(s), "foo.bar"));
         s = strdupa("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
         assert_se(streq(hostname_cleanup(s), "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"));
+        s = strdupa("xxxx........xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
+        assert_se(streq(hostname_cleanup(s), "xxxx.xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"));
 }
 
 static void test_read_etc_hostname(void) {