Commit 8ffa22d1 authored by Beniamino Galvani's avatar Beniamino Galvani

dhcp: dhclient: set type 0 for printable client IDs

The documentation for the ipv4.dhcp-client-id property says:

 If the property is not a hex string it is considered as a
 non-hardware-address client ID and the 'type' field is set to 0.

However, currently we set the client-id without the leading zero byte
in the dhclient configuration and thus dhclient sends the first string
character as type and the remainder as client-id content. Looking
through git history, the dhclient plugin has always behaved this way
even if the intent was clearly that string client-id had to be zero
padded (this is evident by looking at
nm_dhcp_utils_client_id_string_to_bytes()). The internal plugin
instead sends the correct client-id with zero type.

Change the dhclient plugin to honor the documented behavior and add
the leading zero byte when the client-id is a string.

This commit introduces a change in behavior for users that have
dhcp=dhclient and have a plain string (not hexadecimal) set in
ipv4.dhcp-client-id, as NM will send a different client-id possibly
changing the IP address returned by the server.

https://bugzilla.gnome.org/show_bug.cgi?id=793957
parent b6059158
=============================================
NetworkManager-1.?? (not released yet)
Overview of changes since NetworkManager-1.10
=============================================
* A non-hexadecimal DHCPv4 client-id is now properly passed to
dhclient with the first byte (type) set to zero, as stated in the
documentation. This represents a change in behavior since previous
versions where the first character of the string was used as
type. The internal client is not affected by the change.
============================================
NetworkManager-1.10
Overview of changes since NetworkManager-1.8
......
......@@ -138,8 +138,9 @@ add_ip4_config (GString *str, GBytes *client_id, const char *hostname, gboolean
g_string_append_printf (str, "%02x", (guint8) p[i]);
}
} else {
/* Printable; just add to the line minus the 'type' */
/* Printable; just add to the line with type 0 */
g_string_append_c (str, '"');
g_string_append (str, "\\x00");
g_string_append_len (str, p + 1, l - 1);
g_string_append_c (str, '"');
}
......@@ -177,31 +178,60 @@ read_client_id (const char *str)
{
gs_free char *s = NULL;
char *p;
int i = 0, j = 0;
nm_assert (!strncmp (str, CLIENTID_TAG, NM_STRLEN (CLIENTID_TAG)));
str += NM_STRLEN (CLIENTID_TAG);
if (!g_ascii_isspace (*str))
return NULL;
while (g_ascii_isspace (*str))
str++;
if (*str == '"') {
/* Parse string literal with escape sequences */
s = g_strdup (str + 1);
p = strrchr (s, '"');
if (p)
*p = '\0';
else
return NULL;
} else
s = g_strdup (str);
if (!s[0])
return NULL;
while (s[i]) {
if ( s[i] == '\\'
&& s[i + 1] == 'x'
&& g_ascii_isxdigit (s[i + 2])
&& g_ascii_isxdigit (s[i + 3])) {
s[j++] = (g_ascii_xdigit_value (s[i + 2]) << 4)
+ g_ascii_xdigit_value (s[i + 3]);
i += 4;
continue;
}
if ( s[i] == '\\'
&& s[i + 1] >= '0' && s[i + 1] <= '7'
&& s[1 + 2] >= '0' && s[i + 2] <= '7'
&& s[1 + 3] >= '0' && s[i + 3] <= '7') {
s[j++] = ((s[i + 1] - '0') << 6)
+ ((s[i + 2] - '0') << 3)
+ ( s[i + 3] - '0');
i += 4;
continue;
}
s[j++] = s[i++];
}
return g_bytes_new_take (g_steal_pointer (&s), j);
}
/* Otherwise, try to read a hexadecimal sequence */
s = g_strdup (str);
g_strchomp (s);
if (s[strlen (s) - 1] == ';')
s[strlen (s) - 1] = '\0';
if (!s[0])
return NULL;
return nm_dhcp_utils_client_id_string_to_bytes (s);
return nm_utils_hexstr2bin (s);
}
GBytes *
......
......@@ -154,7 +154,7 @@ test_override_client_id (void)
static const char *quote_client_id_expected = \
"# Created by NetworkManager\n"
"\n"
"send dhcp-client-identifier \"1234\"; # added by NetworkManager\n"
"send dhcp-client-identifier \"\\x00abcd\"; # added by NetworkManager\n"
"\n"
"option rfc3442-classless-static-routes code 121 = array of unsigned integer 8;\n"
"option ms-classless-static-routes code 249 = array of unsigned integer 8;\n"
......@@ -172,7 +172,36 @@ test_quote_client_id (void)
{
test_config (NULL, quote_client_id_expected,
AF_INET, NULL, 0, FALSE,
"1234",
"abcd",
NULL,
"eth0",
NULL);
}
/*****************************************************************************/
static const char *hex_zero_client_id_expected = \
"# Created by NetworkManager\n"
"\n"
"send dhcp-client-identifier 00:11:22:33; # added by NetworkManager\n"
"\n"
"option rfc3442-classless-static-routes code 121 = array of unsigned integer 8;\n"
"option ms-classless-static-routes code 249 = array of unsigned integer 8;\n"
"option wpad code 252 = string;\n"
"\n"
"also request rfc3442-classless-static-routes;\n"
"also request ms-classless-static-routes;\n"
"also request static-routes;\n"
"also request wpad;\n"
"also request ntp-servers;\n"
"\n";
static void
test_hex_zero_client_id (void)
{
test_config (NULL, hex_zero_client_id_expected,
AF_INET, NULL, 0, FALSE,
"00:11:22:33",
NULL,
"eth0",
NULL);
......@@ -183,7 +212,7 @@ test_quote_client_id (void)
static const char *ascii_client_id_expected = \
"# Created by NetworkManager\n"
"\n"
"send dhcp-client-identifier \"qb:cd:ef:12:34:56\"; # added by NetworkManager\n"
"send dhcp-client-identifier \"\\x00qb:cd:ef:12:34:56\"; # added by NetworkManager\n"
"\n"
"option rfc3442-classless-static-routes code 121 = array of unsigned integer 8;\n"
"option ms-classless-static-routes code 249 = array of unsigned integer 8;\n"
......@@ -239,13 +268,13 @@ test_hex_single_client_id (void)
/*****************************************************************************/
static const char *existing_hex_client_id_orig = \
"send dhcp-client-identifier 00:30:04:20:7A:08;\n";
"send dhcp-client-identifier 10:30:04:20:7A:08;\n";
static const char *existing_hex_client_id_expected = \
"# Created by NetworkManager\n"
"# Merged from /path/to/dhclient.conf\n"
"\n"
"send dhcp-client-identifier 00:30:04:20:7A:08;\n"
"send dhcp-client-identifier 10:30:04:20:7A:08;\n"
"\n"
"option rfc3442-classless-static-routes code 121 = array of unsigned integer 8;\n"
"option ms-classless-static-routes code 249 = array of unsigned integer 8;\n"
......@@ -262,7 +291,7 @@ static void
test_existing_hex_client_id (void)
{
gs_unref_bytes GBytes *new_client_id = NULL;
const guint8 bytes[] = { 0x00, 0x30, 0x04,0x20, 0x7A, 0x08 };
const guint8 bytes[] = { 0x10, 0x30, 0x04, 0x20, 0x7A, 0x08 };
new_client_id = g_bytes_new (bytes, sizeof (bytes));
test_config (existing_hex_client_id_orig, existing_hex_client_id_expected,
......@@ -275,16 +304,52 @@ test_existing_hex_client_id (void)
/*****************************************************************************/
static const char *existing_escaped_client_id_orig = \
"send dhcp-client-identifier \"\\044test\\xfe\";\n";
static const char *existing_escaped_client_id_expected = \
"# Created by NetworkManager\n"
"# Merged from /path/to/dhclient.conf\n"
"\n"
"send dhcp-client-identifier \"\\044test\\xfe\";\n"
"\n"
"option rfc3442-classless-static-routes code 121 = array of unsigned integer 8;\n"
"option ms-classless-static-routes code 249 = array of unsigned integer 8;\n"
"option wpad code 252 = string;\n"
"\n"
"also request rfc3442-classless-static-routes;\n"
"also request ms-classless-static-routes;\n"
"also request static-routes;\n"
"also request wpad;\n"
"also request ntp-servers;\n"
"\n";
static void
test_existing_escaped_client_id (void)
{
gs_unref_bytes GBytes *new_client_id = NULL;
new_client_id = g_bytes_new ("$test\xfe", 6);
test_config (existing_escaped_client_id_orig, existing_escaped_client_id_expected,
AF_INET, NULL, 0, FALSE,
NULL,
new_client_id,
"eth0",
NULL);
}
/*****************************************************************************/
#define EACID "qb:cd:ef:12:34:56"
static const char *existing_ascii_client_id_orig = \
"send dhcp-client-identifier \"" EACID "\";\n";
"send dhcp-client-identifier \"\\x00" EACID "\";\n";
static const char *existing_ascii_client_id_expected = \
"# Created by NetworkManager\n"
"# Merged from /path/to/dhclient.conf\n"
"\n"
"send dhcp-client-identifier \"" EACID "\";\n"
"send dhcp-client-identifier \"\\x00" EACID "\";\n"
"\n"
"option rfc3442-classless-static-routes code 121 = array of unsigned integer 8;\n"
"option ms-classless-static-routes code 249 = array of unsigned integer 8;\n"
......@@ -1036,9 +1101,11 @@ main (int argc, char **argv)
g_test_add_func ("/dhcp/dhclient/orig_missing", test_orig_missing);
g_test_add_func ("/dhcp/dhclient/override_client_id", test_override_client_id);
g_test_add_func ("/dhcp/dhclient/quote_client_id", test_quote_client_id);
g_test_add_func ("/dhcp/dhclient/hex_zero_client_id", test_hex_zero_client_id);
g_test_add_func ("/dhcp/dhclient/ascii_client_id", test_ascii_client_id);
g_test_add_func ("/dhcp/dhclient/hex_single_client_id", test_hex_single_client_id);
g_test_add_func ("/dhcp/dhclient/existing-hex-client-id", test_existing_hex_client_id);
g_test_add_func ("/dhcp/dhclient/existing-client-id", test_existing_escaped_client_id);
g_test_add_func ("/dhcp/dhclient/existing-ascii-client-id", test_existing_ascii_client_id);
g_test_add_func ("/dhcp/dhclient/fqdn", test_fqdn);
g_test_add_func ("/dhcp/dhclient/fqdn_options_override", test_fqdn_options_override);
......
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