libnm: add NMSockAddrEndpoint API

NMSockAddrEndpoint is an immutable structure that contains the endpoint
string of a service. It also includes the (naive) parsing of the host and
port/service parts.

This will be used for the endpoint of WireGuard's peers. But since endpoints
are not something specific to WireGuard, give it a general name (and
purpose) independent from WireGuard.

Essentially, this structure takes a string in a manner that libnm
understands, and uses it for node and service arguments for
getaddrinfo().

NMSockAddrEndpoint allows to have endpoints that are not parsable into
a host and port part. That is useful because our settings need to be
able to hold invalid values. That is for forward compatibility (server
sends a new endpoint format) and for better error handling (have
invalid settings that can be constructed without loss, but fail later
during the NMSetting:verify() step).

libnm-core/nm-core-internal.h

@@ -614,6 +614,25 @@ gboolean _nm_setting_sriov_sort_vfs (NMSettingSriov *setting);
 
 /*****************************************************************************/
 
+typedef struct _NMSockAddrEndpoint NMSockAddrEndpoint;
+
+NMSockAddrEndpoint *nm_sock_addr_endpoint_new (const char *endpoint);
+
+NMSockAddrEndpoint *nm_sock_addr_endpoint_ref (NMSockAddrEndpoint *self);
+void nm_sock_addr_endpoint_unref (NMSockAddrEndpoint *self);
+
+const char *nm_sock_addr_endpoint_get_endpoint (NMSockAddrEndpoint *self);
+const char *nm_sock_addr_endpoint_get_host (NMSockAddrEndpoint *self);
+gint32 nm_sock_addr_endpoint_get_port (NMSockAddrEndpoint *self);
+
+gboolean nm_sock_addr_endpoint_get_fixed_sockaddr (NMSockAddrEndpoint *self,
+                                                   gpointer sockaddr);
+
+#define nm_auto_unref_sockaddrendpoint nm_auto(_nm_auto_unref_sockaddrendpoint)
+NM_AUTO_DEFINE_FCN_VOID0 (NMSockAddrEndpoint *, _nm_auto_unref_sockaddrendpoint, nm_sock_addr_endpoint_unref)
+
+/*****************************************************************************/
+
 typedef struct _NMSettInfoSetting  NMSettInfoSetting;
 typedef struct _NMSettInfoProperty NMSettInfoProperty;
 

libnm-core/nm-utils.c

@@ -59,6 +59,277 @@
  * access points and devices, among other things.
  */
 
+/*****************************************************************************/
+
+struct _NMSockAddrEndpoint {
+	const char *host;
+	guint16 port;
+	guint refcount;
+	char endpoint[];
+};
+
+static gboolean
+NM_IS_SOCK_ADDR_ENDPOINT (const NMSockAddrEndpoint *self)
+{
+	return self && self->refcount > 0;
+}
+
+static const char *
+_parse_endpoint (char *str,
+                 guint16 *out_port)
+{
+	char *s;
+	const char *s_port;
+	gint16 port;
+
+	/* Like
+	 * - https://git.zx2c4.com/WireGuard/tree/src/tools/config.c?id=5e99a6d43fe2351adf36c786f5ea2086a8fe7ab8#n192
+	 * - https://github.com/systemd/systemd/blob/911649fdd43f3a9158b847947724a772a5a45c34/src/network/netdev/wireguard.c#L614
+	 */
+
+	g_strstrip (str);
+
+	if (!str[0])
+		return NULL;
+
+	if (str[0] == '[') {
+		str++;
+		s = strchr (str, ']');
+		if (!s)
+			return NULL;
+		if (s == str)
+			return NULL;
+		if (s[1] != ':')
+			return NULL;
+		if (!s[2])
+			return NULL;
+		*s = '\0';
+		s_port = &s[2];
+	} else {
+		s = strrchr (str, ':');
+		if (!s)
+			return NULL;
+		if (s == str)
+			return NULL;
+		if (!s[1])
+			return NULL;
+		*s = '\0';
+		s_port = &s[1];
+	}
+
+	if (!NM_STRCHAR_ALL (s_port, ch, (ch >= '0' && ch <= '9')))
+		return NULL;
+
+	port = _nm_utils_ascii_str_to_int64 (s_port, 10, 1, G_MAXUINT16, 0);
+	if (port == 0)
+		return NULL;
+
+	*out_port = port;
+	return str;
+}
+
+/**
+ * nm_sock_addr_endpoint_new:
+ * @endpoint: the endpoint string.
+ *
+ * This function cannot fail, even if the @endpoint is invalid.
+ * The reason is to allow NMSockAddrEndpoint also to be used
+ * for tracking invalid endpoints. Use nm_sock_addr_endpoint_get_host()
+ * to determine whether the endpoint is valid.
+ *
+ * Returns: (transfer full): the new #NMSockAddrEndpoint endpoint.
+ */
+NMSockAddrEndpoint *
+nm_sock_addr_endpoint_new (const char *endpoint)
+{
+	NMSockAddrEndpoint *ep;
+	gsize l_endpoint;
+	gsize l_host = 0;
+	gsize i;
+	gs_free char *host_clone = NULL;
+	const char *host;
+	guint16 port;
+
+	g_return_val_if_fail (endpoint, NULL);
+
+	l_endpoint = strlen (endpoint) + 1;
+
+	host = _parse_endpoint (nm_strndup_a (200, endpoint, l_endpoint - 1, &host_clone),
+	                        &port);
+
+	if (host)
+		l_host = strlen (host) + 1;
+
+	ep = g_malloc (sizeof (NMSockAddrEndpoint) + l_endpoint + l_host);
+	ep->refcount = 1;
+	memcpy (ep->endpoint, endpoint, l_endpoint);
+	if (host) {
+		i = l_endpoint;
+		memcpy (&ep->endpoint[i], host, l_host);
+		ep->host = &ep->endpoint[i];
+		ep->port = port;
+	} else {
+		ep->host = NULL;
+		ep->port = 0;
+	}
+	return ep;
+}
+
+/**
+ * nm_sock_addr_endpoint_ref:
+ * @self: (allow-none): the #NMSockAddrEndpoint
+ */
+NMSockAddrEndpoint *
+nm_sock_addr_endpoint_ref (NMSockAddrEndpoint *self)
+{
+	if (!self)
+		return NULL;
+
+	g_return_val_if_fail (NM_IS_SOCK_ADDR_ENDPOINT (self), NULL);
+
+	nm_assert (self->refcount < G_MAXUINT);
+
+	self->refcount++;
+	return self;
+}
+
+/**
+ * nm_sock_addr_endpoint_unref:
+ * @self: (allow-none): the #NMSockAddrEndpoint
+ */
+void
+nm_sock_addr_endpoint_unref (NMSockAddrEndpoint *self)
+{
+	if (!self)
+		return;
+
+	g_return_if_fail (NM_IS_SOCK_ADDR_ENDPOINT (self));
+
+	if (--self->refcount == 0)
+		g_free (self);
+}
+
+/**
+ * nm_sock_addr_endpoint_get_endpoint:
+ * @self: the #NMSockAddrEndpoint
+ *
+ * Gives the endpoint string. Since #NMSockAddrEndpoint's only
+ * information is the endpoint string, this can be used for comparing
+ * to instances for equality and order them lexically.
+ *
+ * Returns: (transfer none): the endpoint.
+ */
+const char *
+nm_sock_addr_endpoint_get_endpoint (NMSockAddrEndpoint *self)
+{
+	g_return_val_if_fail (NM_IS_SOCK_ADDR_ENDPOINT (self), NULL);
+
+	return self->endpoint;
+}
+
+/**
+ * nm_sock_addr_endpoint_get_host:
+ * @self: the #NMSockAddrEndpoint
+ *
+ * Returns: (transfer none): the parsed host part of the endpoint.
+ *   If the endpoint is invalid, %NULL will be returned.
+ */
+const char *
+nm_sock_addr_endpoint_get_host (NMSockAddrEndpoint *self)
+{
+	g_return_val_if_fail (NM_IS_SOCK_ADDR_ENDPOINT (self), NULL);
+
+	return self->host;
+}
+
+/**
+ * nm_sock_addr_endpoint_get_port:
+ * @self: the #NMSockAddrEndpoint
+ *
+ * Returns: the parsed port part of the endpoint (the service).
+ *   If the endpoint is invalid, -1 will be returned.
+ */
+gint32
+nm_sock_addr_endpoint_get_port (NMSockAddrEndpoint *self)
+{
+	g_return_val_if_fail (NM_IS_SOCK_ADDR_ENDPOINT (self), -1);
+
+	return self->host ? (int) self->port : -1;
+}
+
+gboolean
+nm_sock_addr_endpoint_get_fixed_sockaddr (NMSockAddrEndpoint *self,
+                                          gpointer sockaddr)
+{
+	int addr_family;
+	NMIPAddr addrbin;
+	const char *s;
+	guint scope_id = 0;
+
+	g_return_val_if_fail (NM_IS_SOCK_ADDR_ENDPOINT (self), FALSE);
+	g_return_val_if_fail (sockaddr, FALSE);
+
+	if (!self->host)
+		return FALSE;
+
+	if (nm_utils_parse_inaddr_bin (AF_UNSPEC, self->host, &addr_family, &addrbin))
+		goto good;
+
+	/* See if there is an IPv6 scope-id...
+	 *
+	 * Note that it does not make sense to persist connection profiles to disk,
+	 * that refenrence a scope-id (because the interface's ifindex changes on
+	 * reboot). However, we also support runtime only changes like `nmcli device modify`
+	 * where nothing is persisted to disk. At least in that case, passing a scope-id
+	 * might be reasonable. So, parse that too. */
+	s = strchr (self->host, '%');
+	if (!s)
+		return FALSE;
+
+	if (   s[1] == '\0'
+	    || !NM_STRCHAR_ALL (&s[1], ch, (ch >= '0' && ch <= '9')))
+		return FALSE;
+
+	scope_id = _nm_utils_ascii_str_to_int64 (&s[1], 10, 0, G_MAXINT32, G_MAXUINT);
+	if (scope_id == G_MAXUINT && errno)
+		return FALSE;
+
+	{
+		gs_free char *tmp_str = NULL;
+		const char *host_part;
+
+		host_part = nm_strndup_a (200, self->host, s - self->host, &tmp_str);
+		if (nm_utils_parse_inaddr_bin (AF_INET6, host_part, &addr_family, &addrbin))
+			goto good;
+	}
+
+	return FALSE;
+
+good:
+	switch (addr_family) {
+	case AF_INET:
+		*((struct sockaddr_in *) sockaddr) = (struct sockaddr_in) {
+			.sin_family = AF_INET,
+			.sin_addr   = addrbin.addr4_struct,
+			.sin_port   = htons (self->port),
+		};
+		return TRUE;
+	case AF_INET6:
+		*((struct sockaddr_in6 *) sockaddr) = (struct sockaddr_in6) {
+			.sin6_family   = AF_INET6,
+			.sin6_addr     = addrbin.addr6,
+			.sin6_port     = htons (self->port),
+			.sin6_scope_id = scope_id,
+			.sin6_flowinfo = 0,
+		};
+		return TRUE;
+	}
+
+	return FALSE;
+}
+
+/*****************************************************************************/
+
 struct IsoLangToEncodings
 {
 	const char *lang;

libnm-core/nm-utils.h

@@ -40,6 +40,8 @@
 
 G_BEGIN_DECLS
 
+/*****************************************************************************/
+
 typedef struct _NMVariantAttributeSpec NMVariantAttributeSpec;
 
 /* SSID helpers */

libnm-core/tests/test-general.c

@@ -5522,6 +5522,158 @@ test_setting_user_data (void)
 
 /*****************************************************************************/
 
+typedef union {
+	struct sockaddr     sa;
+	struct sockaddr_in  in;
+	struct sockaddr_in6 in6;
+} SockAddrUnion;
+
+static void
+_sock_addr_endpoint (const char *endpoint,
+                     const char *host,
+                     gint32 port)
+{
+	nm_auto_unref_sockaddrendpoint NMSockAddrEndpoint *ep = NULL;
+	const char *s_endpoint;
+	const char *s_host;
+	gint32 s_port;
+	SockAddrUnion sockaddr = { };
+
+	g_assert (endpoint);
+	g_assert (!host == (port == -1));
+	g_assert (port >= -1 && port <= G_MAXUINT16);
+
+	ep = nm_sock_addr_endpoint_new (endpoint);
+	g_assert (ep);
+
+	s_endpoint = nm_sock_addr_endpoint_get_endpoint (ep);
+	s_host = nm_sock_addr_endpoint_get_host (ep);
+	s_port = nm_sock_addr_endpoint_get_port (ep);
+	g_assert_cmpstr (endpoint, ==, s_endpoint);
+	g_assert_cmpstr (host,     ==, s_host);
+	g_assert_cmpint (port,     ==, s_port);
+
+	g_assert (!nm_sock_addr_endpoint_get_fixed_sockaddr (ep, &sockaddr));
+
+	if (endpoint[0] != ' ') {
+		gs_free char *endpoint2 = NULL;
+
+		/* also test with a leading space */
+		endpoint2 = g_strdup_printf (" %s", endpoint);
+		_sock_addr_endpoint (endpoint2, host, port);
+	}
+
+	if (endpoint[0] && endpoint[strlen (endpoint) - 1] != ' ') {
+		gs_free char *endpoint2 = NULL;
+
+		/* also test with a trailing space */
+		endpoint2 = g_strdup_printf ("%s ", endpoint);
+		_sock_addr_endpoint (endpoint2, host, port);
+	}
+}
+
+static void
+_sock_addr_endpoint_fixed (const char *endpoint,
+                           const char *host,
+                           guint16 port,
+                           guint scope_id)
+{
+	nm_auto_unref_sockaddrendpoint NMSockAddrEndpoint *ep = NULL;
+	const char *s_endpoint;
+	const char *s_host;
+	gint32 s_port;
+	int addr_family;
+	NMIPAddr addrbin;
+	SockAddrUnion sockaddr = { };
+
+	g_assert (endpoint);
+	g_assert (host);
+	g_assert (port > 0);
+
+	if (!nm_utils_parse_inaddr_bin (AF_UNSPEC, host, &addr_family, &addrbin))
+		g_assert_not_reached ();
+
+	ep = nm_sock_addr_endpoint_new (endpoint);
+	g_assert (ep);
+
+	s_endpoint = nm_sock_addr_endpoint_get_endpoint (ep);
+	s_host = nm_sock_addr_endpoint_get_host (ep);
+	s_port = nm_sock_addr_endpoint_get_port (ep);
+	g_assert_cmpstr (endpoint, ==, s_endpoint);
+	g_assert_cmpstr (NULL,     !=, s_host);
+	g_assert_cmpint (port,     ==, s_port);
+
+	if (!nm_sock_addr_endpoint_get_fixed_sockaddr (ep, &sockaddr))
+		g_assert_not_reached ();
+
+	g_assert_cmpint (sockaddr.sa.sa_family, ==, addr_family);
+	if (addr_family == AF_INET) {
+		const SockAddrUnion s = {
+			.in = {
+				.sin_family = AF_INET,
+				.sin_addr   = addrbin.addr4_struct,
+				.sin_port   = htons (port),
+			},
+		};
+
+		g_assert_cmpint (sockaddr.in.sin_addr.s_addr, ==, addrbin.addr4);
+		g_assert_cmpint (sockaddr.in.sin_port, ==, htons (port));
+		g_assert (memcmp (&s, &sockaddr, sizeof (s.in)) == 0);
+	} else if (addr_family == AF_INET6) {
+		const SockAddrUnion s = {
+			.in6 = {
+				.sin6_family   = AF_INET6,
+				.sin6_addr     = addrbin.addr6,
+				.sin6_scope_id = scope_id,
+				.sin6_port     = htons (port),
+			},
+		};
+
+		g_assert (memcmp (&sockaddr.in6.sin6_addr, &addrbin, sizeof (addrbin.addr6)) == 0);
+		g_assert_cmpint (sockaddr.in6.sin6_port, ==, htons (port));
+		g_assert_cmpint (sockaddr.in6.sin6_scope_id, ==, scope_id);
+		g_assert_cmpint (sockaddr.in6.sin6_flowinfo, ==, 0);
+		g_assert (memcmp (&s, &sockaddr, sizeof (s.in6)) == 0);
+	} else
+		g_assert_not_reached ();
+}
+
+static void
+test_sock_addr_endpoint (void)
+{
+	_sock_addr_endpoint ("",                NULL, -1);
+	_sock_addr_endpoint (":",               NULL, -1);
+	_sock_addr_endpoint ("a",               NULL, -1);
+	_sock_addr_endpoint ("a:",              NULL, -1);
+	_sock_addr_endpoint (":a",              NULL, -1);
+	_sock_addr_endpoint ("[]:a",            NULL, -1);
+	_sock_addr_endpoint ("[]a",             NULL, -1);
+	_sock_addr_endpoint ("[]:",             NULL, -1);
+	_sock_addr_endpoint ("[a]b",            NULL, -1);
+	_sock_addr_endpoint ("[a:b",            NULL, -1);
+	_sock_addr_endpoint ("[a[:b",           NULL, -1);
+	_sock_addr_endpoint ("a:6",             "a",  6);
+	_sock_addr_endpoint ("a:6",             "a",  6);
+	_sock_addr_endpoint ("[a]:6",           "a",  6);
+	_sock_addr_endpoint ("[a]:6",           "a",  6);
+	_sock_addr_endpoint ("[a]:655",         "a",  655);
+	_sock_addr_endpoint ("[ab]:][6",        NULL, -1);
+	_sock_addr_endpoint ("[ab]:]:[6",       NULL, -1);
+	_sock_addr_endpoint ("[a[]:b",          NULL, -1);
+	_sock_addr_endpoint ("[192.169.6.x]:6", "192.169.6.x", 6);
+	_sock_addr_endpoint ("[192.169.6.x]:0", NULL, -1);
+	_sock_addr_endpoint ("192.169.6.7:0",   NULL, -1);
+
+	_sock_addr_endpoint_fixed ("192.169.6.7:6",   "192.169.6.7", 6, 0);
+	_sock_addr_endpoint_fixed ("[192.169.6.7]:6", "192.169.6.7", 6, 0);
+	_sock_addr_endpoint_fixed ("[a:b::]:6", "a:b::", 6, 0);
+	_sock_addr_endpoint_fixed ("[a:b::%7]:6", "a:b::", 6, 7);
+	_sock_addr_endpoint_fixed ("a:b::1%75:6", "a:b::1", 6, 75);
+	_sock_addr_endpoint_fixed ("a:b::1%0:64", "a:b::1", 64, 0);
+}
+
+/*****************************************************************************/
+
 static void
 test_hexstr2bin (void)
 {
@@ -7735,6 +7887,8 @@ int main (int argc, char **argv)
 	g_test_add_func ("/core/general/test_setting_compare_default_strv", test_setting_compare_default_strv);
 	g_test_add_func ("/core/general/test_setting_user_data", test_setting_user_data);
 
+	g_test_add_func ("/core/general/test_sock_addr_endpoint", test_sock_addr_endpoint);
+
 	g_test_add_func ("/core/general/hexstr2bin", test_hexstr2bin);
 	g_test_add_func ("/core/general/nm_strquote", test_nm_strquote);
 	g_test_add_func ("/core/general/test_nm_utils_uuid_generate_from_string", test_nm_utils_uuid_generate_from_string);