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-rw-r--r--src/shared/dns-domain.c193
-rw-r--r--src/shared/dns-domain.h3
-rw-r--r--src/test/test-dns-domain.c62
3 files changed, 240 insertions, 18 deletions
diff --git a/src/shared/dns-domain.c b/src/shared/dns-domain.c
index 014e0bd70d..e08143c3be 100644
--- a/src/shared/dns-domain.c
+++ b/src/shared/dns-domain.c
@@ -751,6 +751,34 @@ int dns_name_to_wire_format(const char *domain, uint8_t *buffer, size_t len) {
return out - buffer;
}
+static bool srv_type_label_is_valid(const char *label, size_t n) {
+ size_t k;
+
+ assert(label);
+
+ if (n < 2) /* Label needs to be at least 2 chars long */
+ return false;
+
+ if (label[0] != '_') /* First label char needs to be underscore */
+ return false;
+
+ /* Second char must be a letter */
+ if (!(label[1] >= 'A' && label[1] <= 'Z') &&
+ !(label[1] >= 'a' && label[1] <= 'z'))
+ return false;
+
+ /* Third and further chars must be alphanumeric or a hyphen */
+ for (k = 2; k < n; k++) {
+ if (!(label[k] >= 'A' && label[k] <= 'Z') &&
+ !(label[k] >= 'a' && label[k] <= 'z') &&
+ !(label[k] >= '0' && label[k] <= '9') &&
+ label[k] != '-')
+ return false;
+ }
+
+ return true;
+}
+
int dns_srv_type_verify(const char *name) {
unsigned c = 0;
int r;
@@ -760,7 +788,6 @@ int dns_srv_type_verify(const char *name) {
for (;;) {
char label[DNS_LABEL_MAX];
- int k;
/* This more or less implements RFC 6335, Section 5.1 */
@@ -770,28 +797,18 @@ int dns_srv_type_verify(const char *name) {
if (r < 0)
return r;
if (r == 0)
- return c >= 2; /* At least two labels */
- if (r < 2) /* Label needs to be at least 2 chars long */
- return 0;
- if (label[0] != '_') /* First label char needs to be underscore */
- return 0;
+ break;
- /* Second char must be a letter */
- if (!(label[1] >= 'A' && label[1] <= 'Z') &&
- !(label[1] >= 'a' && label[1] <= 'z'))
+ if (c >= 2)
return 0;
- /* Third and further chars must be alphanumeric or a hyphen */
- for (k = 2; k < r; k++) {
- if (!(label[k] >= 'A' && label[k] <= 'Z') &&
- !(label[k] >= 'a' && label[k] <= 'z') &&
- !(label[k] >= '0' && label[k] <= '9') &&
- label[k] != '-')
- return 0;
- }
+ if (!srv_type_label_is_valid(label, r))
+ return 0;
c++;
}
+
+ return c == 2; /* exactly two labels */
}
bool dns_service_name_is_valid(const char *name) {
@@ -816,3 +833,145 @@ bool dns_service_name_is_valid(const char *name) {
return true;
}
+
+int dns_service_join(const char *name, const char *type, const char *domain, char **ret) {
+ _cleanup_free_ char *escaped = NULL, *n = NULL;
+ int r;
+
+ assert(type);
+ assert(domain);
+ assert(ret);
+
+ if (!dns_srv_type_verify(type))
+ return -EINVAL;
+
+ if (!name)
+ return dns_name_concat(type, domain, ret);
+
+ if (!dns_service_name_is_valid(name))
+ return -EINVAL;
+
+ r = dns_label_escape(name, strlen(name), &escaped);
+ if (r < 0)
+ return r;
+
+ r = dns_name_concat(type, domain, &n);
+ if (r < 0)
+ return r;
+
+ return dns_name_concat(escaped, n, ret);
+}
+
+static bool dns_service_name_label_is_valid(const char *label, size_t n) {
+ char *s;
+
+ assert(label);
+
+ if (memchr(label, 0, n))
+ return false;
+
+ s = strndupa(label, n);
+ return dns_service_name_is_valid(s);
+}
+
+int dns_service_split(const char *joined, char **_name, char **_type, char **_domain) {
+ _cleanup_free_ char *name = NULL, *type = NULL, *domain = NULL;
+ const char *p = joined, *q = NULL, *d = NULL;
+ char a[DNS_LABEL_MAX], b[DNS_LABEL_MAX], c[DNS_LABEL_MAX];
+ int an, bn, cn, r;
+ unsigned x = 0;
+
+ assert(joined);
+
+ /* Get first label from the full name */
+ an = dns_label_unescape(&p, a, sizeof(a));
+ if (an < 0)
+ return an;
+
+ if (an > 0) {
+ x++;
+
+ /* If there was a first label, try to get the second one */
+ bn = dns_label_unescape(&p, b, sizeof(b));
+ if (bn < 0)
+ return bn;
+
+ if (bn > 0) {
+ x++;
+
+ /* If there was a second label, try to get the third one */
+ q = p;
+ cn = dns_label_unescape(&p, c, sizeof(c));
+ if (cn < 0)
+ return cn;
+
+ if (cn > 0)
+ x++;
+ } else
+ cn = 0;
+ } else
+ an = 0;
+
+ if (x >= 2 && srv_type_label_is_valid(b, bn)) {
+
+ if (x >= 3 && srv_type_label_is_valid(c, cn)) {
+
+ if (dns_service_name_label_is_valid(a, an)) {
+
+ /* OK, got <name> . <type> . <type2> . <domain> */
+
+ name = strndup(a, an);
+ if (!name)
+ return -ENOMEM;
+
+ type = new(char, bn+1+cn+1);
+ if (!type)
+ return -ENOMEM;
+ strcpy(stpcpy(stpcpy(type, b), "."), c);
+
+ d = p;
+ goto finish;
+ }
+
+ } else if (srv_type_label_is_valid(a, an)) {
+
+ /* OK, got <type> . <type2> . <domain> */
+
+ name = NULL;
+
+ type = new(char, an+1+bn+1);
+ if (!type)
+ return -ENOMEM;
+ strcpy(stpcpy(stpcpy(type, a), "."), b);
+
+ d = q;
+ goto finish;
+ }
+ }
+
+ name = NULL;
+ type = NULL;
+ d = joined;
+
+finish:
+ r = dns_name_normalize(d, &domain);
+ if (r < 0)
+ return r;
+
+ if (_domain) {
+ *_domain = domain;
+ domain = NULL;
+ }
+
+ if (_type) {
+ *_type = type;
+ type = NULL;
+ }
+
+ if (_name) {
+ *_name = name;
+ name = NULL;
+ }
+
+ return 0;
+}
diff --git a/src/shared/dns-domain.h b/src/shared/dns-domain.h
index 22c394443b..c6d7623e09 100644
--- a/src/shared/dns-domain.h
+++ b/src/shared/dns-domain.h
@@ -73,3 +73,6 @@ int dns_name_to_wire_format(const char *domain, uint8_t *buffer, size_t len);
int dns_srv_type_verify(const char *name);
bool dns_service_name_is_valid(const char *name);
+
+int dns_service_join(const char *name, const char *type, const char *domain, char **ret);
+int dns_service_split(const char *joined, char **name, char **type, char **domain);
diff --git a/src/test/test-dns-domain.c b/src/test/test-dns-domain.c
index a23d5dee05..a664e1c79c 100644
--- a/src/test/test-dns-domain.c
+++ b/src/test/test-dns-domain.c
@@ -332,7 +332,6 @@ static void test_dns_srv_type_verify(void) {
assert_se(dns_srv_type_verify("_http._tcp") > 0);
assert_se(dns_srv_type_verify("_foo-bar._tcp") > 0);
assert_se(dns_srv_type_verify("_w._udp") > 0);
- assert_se(dns_srv_type_verify("_piep._sub._w._udp") > 0);
assert_se(dns_srv_type_verify("_a800._tcp") > 0);
assert_se(dns_srv_type_verify("_a-800._tcp") > 0);
@@ -348,6 +347,65 @@ static void test_dns_srv_type_verify(void) {
assert_se(dns_srv_type_verify("_800._tcp") == 0);
assert_se(dns_srv_type_verify("_-800._tcp") == 0);
assert_se(dns_srv_type_verify("_-foo._tcp") == 0);
+ assert_se(dns_srv_type_verify("_piep._foo._udp") == 0);
+}
+
+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;
+
+ assert_se(dns_service_join(a, b, c, &t) == r);
+ assert_se(streq_ptr(t, d));
+
+ if (r < 0)
+ return;
+
+ assert_se(dns_service_split(t, &x, &y, &z) >= 0);
+ assert_se(streq_ptr(a, x));
+ assert_se(streq_ptr(b, y));
+ assert_se(streq_ptr(c, z));
+}
+
+static void test_dns_service_join(void) {
+ 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);
+ test_dns_service_join_one("foo", "", "foo", -EINVAL, NULL);
+ test_dns_service_join_one("foo", "foo", "foo", -EINVAL, NULL);
+
+ test_dns_service_join_one("foo", "_http._tcp", "", 0, "foo._http._tcp");
+ test_dns_service_join_one(NULL, "_http._tcp", "", 0, "_http._tcp");
+ test_dns_service_join_one("foo", "_http._tcp", "foo", 0, "foo._http._tcp.foo");
+ test_dns_service_join_one(NULL, "_http._tcp", "foo", 0, "_http._tcp.foo");
+ test_dns_service_join_one("Lennart's PC", "_pc._tcp", "foo.bar.com", 0, "Lennart\\039s\\032PC._pc._tcp.foo.bar.com");
+ test_dns_service_join_one(NULL, "_pc._tcp", "foo.bar.com", 0, "_pc._tcp.foo.bar.com");
+}
+
+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;
+
+ assert_se(dns_service_split(joined, &x, &y, &z) == r);
+ assert_se(streq_ptr(x, a));
+ assert_se(streq_ptr(y, b));
+ assert_se(streq_ptr(z, c));
+
+ if (r < 0)
+ return;
+
+ if (y) {
+ assert_se(dns_service_join(x, y, z, &t) == 0);
+ assert_se(streq_ptr(joined, t));
+ } else
+ assert_se(!x && streq_ptr(z, joined));
+}
+
+static void test_dns_service_split(void) {
+ 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);
+ test_dns_service_split_one("_foo.bar", NULL, NULL, "_foo.bar", 0);
+ test_dns_service_split_one("_foo._bar", NULL, "_foo._bar", "", 0);
+ test_dns_service_split_one("_meh._foo._bar", "_meh", "_foo._bar", "", 0);
+ test_dns_service_split_one("Wuff\\032Wuff._foo._bar.waldo.com", "Wuff Wuff", "_foo._bar", "waldo.com", 0);
}
int main(int argc, char *argv[]) {
@@ -367,6 +425,8 @@ int main(int argc, char *argv[]) {
test_dns_name_to_wire_format();
test_dns_service_name_is_valid();
test_dns_srv_type_verify();
+ test_dns_service_join();
+ test_dns_service_split();
return 0;
}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-07-10 08:10:18 +0000