From 7a5509053a78bf92511626ca06fdb61c2977693f Mon Sep 17 00:00:00 2001

From: Beniamino Galvani <bgalvani@redhat.com>

Date: Sun, 6 Oct 2019 08:27:18 +0200

Subject: [PATCH] dhcp: include conditionals from existing dhclient

 configuration

Since commit 159ff23268b1 ('dhcp/dhclient-utils: skip over

dhclient.conf blocks') we skip blocks enclosed in lines containing '{'

and '}' because NM should ignore 'lease', 'alias' and other

declarations. However, conditional statements seem useful and should

not be skipped.

https://bugzilla.redhat.com/show_bug.cgi?id=1758550

(cherry picked from commit b58e4d311da630ea8d14f60ca3667710877e455d)

(cherry picked from commit 58ffded2d0a317c3a480821272b41780aff0e64e)

(cherry picked from commit 497101fd1e44128496d14a3b8b7496de7febe2f0)

---

 src/dhcp/nm-dhcp-dhclient-utils.c   | 43 +++++++++++++++++++++--------

 src/dhcp/tests/test-dhcp-dhclient.c | 19 ++++++++++++-

 2 files changed, 50 insertions(+), 12 deletions(-)

diff --git a/src/dhcp/nm-dhcp-dhclient-utils.c b/src/dhcp/nm-dhcp-dhclient-utils.c

index 3338fbff2..01d0fc020 100644

--- a/src/dhcp/nm-dhcp-dhclient-utils.c

+++ b/src/dhcp/nm-dhcp-dhclient-utils.c

@@ -275,11 +275,13 @@ nm_dhcp_dhclient_create_config (const char *interface,

 	if (orig_contents) {

 		gs_free const char **lines = NULL;

 		gsize line_i;

-		int nest = 0;

+		nm_auto_free_gstring GString *blocks_stack = NULL;

+		guint blocks_skip = 0;

 		gboolean in_alsoreq = FALSE;

 		gboolean in_req = FALSE;

 		char intf[IFNAMSIZ];

+		blocks_stack = g_string_new (NULL);

 		g_string_append_printf (new_contents, _("# Merged from %s\n\n"), orig_path);

 		intf[0] = '\0';

@@ -297,19 +299,38 @@ nm_dhcp_dhclient_create_config (const char *interface,

 			if (in_req) {

 				/* pass */

 			} else if (strchr (p, '{')) {

-				nest++;

-				if (   !intf[0]

-				    && NM_STR_HAS_PREFIX (p, "interface"))

-					if (read_interface (p, intf, sizeof (intf)))

-						continue;

+				if (   NM_STR_HAS_PREFIX (p, "lease")

+				    || NM_STR_HAS_PREFIX (p, "alias")

+				    || NM_STR_HAS_PREFIX (p, "interface")

+				    || NM_STR_HAS_PREFIX (p, "pseudo")) {

+					/* skip over these blocks, except 'interface' when it

+					 * matches the current interface */

+					blocks_skip++;

+					g_string_append_c (blocks_stack, 'b');

+					if (   !intf[0]

+					    && NM_STR_HAS_PREFIX (p, "interface")) {

+						if (read_interface (p, intf, sizeof (intf)))

+							continue;

+					}

+				} else {

+					/* allow other blocks (conditionals) */

+					if (!strchr (p, '}')) /* '} else {'  */

+						g_string_append_c (blocks_stack, 'c');

+				}

 			} else if (strchr (p, '}')) {

-				if (nest)

-					nest--;

-				intf[0] = '\0';

-				continue;

+				if (blocks_stack->len > 0) {

+					if (blocks_stack->str[blocks_stack->len - 1] == 'b') {

+						g_string_truncate (blocks_stack, blocks_stack->len - 1);

+						nm_assert(blocks_skip > 0);

+						blocks_skip--;

+						intf[0] = '\0';

+						continue;

+					}

+					g_string_truncate (blocks_stack, blocks_stack->len - 1);

+				}

 			}

-			if (nest && !intf[0])

+			if (blocks_skip > 0 && !intf[0])

 				continue;

 			if (intf[0] && !nm_streq (intf, interface))

diff --git a/src/dhcp/tests/test-dhcp-dhclient.c b/src/dhcp/tests/test-dhcp-dhclient.c

index f6267cd28..90480955f 100644

--- a/src/dhcp/tests/test-dhcp-dhclient.c

+++ b/src/dhcp/tests/test-dhcp-dhclient.c

@@ -900,6 +900,11 @@ test_structured (void)

 		"    request subnet-mask, broadcast-address, time-offset, routers,\n"

 		"        domain-search, domain-name, domain-name-servers, host-name;\n"

 		"    require subnet-mask, domain-name-servers;\n"

+		"    if not option domain-name = \"example.org\" {\n"

+		"        prepend domain-name-servers 127.0.0.1;\n"

+		"    } else {\n"

+		"        prepend domain-name-servers 127.0.0.2;\n"

+		"    }  \n"

 		"    }  \n"

 		"\n"

 		"pseudo \"secondary\" \"eth0\"   {  \n"

@@ -926,7 +931,13 @@ test_structured (void)

 		"    interface \"eth0\";\n"

 		"    fixed-address 192.0.2.2;\n"

 		"    option subnet-mask 255.255.255.0;\n"

-		"  }  \n";

+		"  }  \n"

+		"if not option domain-name = \"example.org\" {\n"

+		"  prepend domain-name-servers 127.0.0.1;\n"

+		"  if not option domain-name = \"useless.example.com\" {\n"

+		"    prepend domain-name-servers 127.0.0.2;\n"

+		"  }\n"

+		"}\n";

 	static const char *const expected = \

 		"# Created by NetworkManager\n"

@@ -937,6 +948,12 @@ test_structured (void)

 		"send dhcp-client-identifier \"sad-and-useless\";\n"

 		"send dhcp-lease-time 8086;\n"

 		"require subnet-mask;\n"

+		"if not option domain-name = \"example.org\" {\n"

+		"prepend domain-name-servers 127.0.0.1;\n"

+		"if not option domain-name = \"useless.example.com\" {\n"

+		"prepend domain-name-servers 127.0.0.2;\n"

+		"}\n"

+		"}\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"

-- 

2.21.0