Fixed /proc/self/exe (and /proc/<MY_PID>/exe)

- Implemented a special mapping function for /proc, to be
  able to map the symlink at /proc/self/exe.
- This can be described as a countermeasure to side-effects of
  mapping exec parameters: /proc/self/exe (as well as
  /proc/<MY_PID>/exe, which is the same thing) need special care
  if the binary was started by anything else than direct exec.

Examples:
a) if CPU transparency is used, the real /proc/self/exe points
   to e.g. Qemu. Now SB2 can make it look like the link points
   to the binary which is running under qemu.
b) if "ld.so-start" was used, the real /proc/self/exe points to
   ld.so and not to the binary itself. Again, SB2 maps that
   to a symlink which points to the correct binary.

Other related things:
- all mapping modes use this feature now
- Lua <=> C interface version had to be incremented
- Lua mapping code <=> mapping rules version had to be incremented

8 files changed, 60 insertions, 29 deletions

diff --git a/lua_scripts/create_reverse_rules.lua b/lua_scripts/create_reverse_rules.lua
index fc712dc..abd4421 100644
--- a/lua_scripts/create_reverse_rules.lua
+++ b/lua_scripts/create_reverse_rules.lua
@@ -71,7 +71,7 @@ function reverse_one_rule(output_rules, rule, n)
 			allow_reversing = false
 		end
 
-		local d_path
+		local d_path = nil
 		if (rule.use_orig_path) then
 			new_rule.use_orig_path = true
 			d_path = forward_path
@@ -85,21 +85,27 @@ function reverse_one_rule(output_rules, rule, n)
 		elseif (rule.replace_by) then
 			d_path = rule.replace_by
 			new_rule.replace_by = forward_path
+		elseif (rule.custom_map_funct) then
+			new_rule.error = string.format(
+				"--Notice: custom_map_funct rules can't be reversed, please mark it 'virtual'",
+				new_rule.name)
 		else
 			new_rule.error = string.format(
 				"--ERROR: Rule '%s' does not contain any actions",
 				new_rule.name)
 		end
 
-		local idx
-		if (rule.prefix) then
-			new_rule.prefix = d_path
-			new_rule.orig_prefix = rule.prefix
-			idx = test_rev_rule_position(output_rules, d_path..":")
-		elseif (rule.path) then
-			new_rule.path = d_path
-			new_rule.orig_path = rule.path
-			idx = test_rev_rule_position(output_rules, d_path)
+		local idx = nil
+		if (d_path ~= nil) then
+			if (rule.prefix) then
+				new_rule.prefix = d_path
+				new_rule.orig_prefix = rule.prefix
+				idx = test_rev_rule_position(output_rules, d_path..":")
+			elseif (rule.path) then
+				new_rule.path = d_path
+				new_rule.orig_path = rule.path
+				idx = test_rev_rule_position(output_rules, d_path)
+			end
 		end
 
 		if (idx ~= nil) then
diff --git a/lua_scripts/main.lua b/lua_scripts/main.lua
index 4915486..ef0b8a7 100644
--- a/lua_scripts/main.lua
+++ b/lua_scripts/main.lua
@@ -15,7 +15,7 @@ debug_messages_enabled = sb.debug_messages_enabled()
 --
 -- NOTE: the corresponding identifier for C is in include/sb2.h,
 -- see that file for description about differences
-sb2_lua_c_interface_version = "59,lta-2008-12-04"
+sb2_lua_c_interface_version = "60,2008-12-07"
 
 function do_file(filename)
 	if (debug_messages_enabled) then
diff --git a/lua_scripts/mapping.lua b/lua_scripts/mapping.lua
index 6771339..22a48be 100644
--- a/lua_scripts/mapping.lua
+++ b/lua_scripts/mapping.lua
@@ -50,6 +50,22 @@ end
 --    end
 isprefix = sb.isprefix
 
+function sb2_procfs_mapper(binary_name, func_name, rp, path, rule)
+	local ret_path = path;
+
+	if (debug_messages_enabled) then
+		sb.log("debug", "sb2_procfs_mapper "..path.." : "..rp)
+	end
+
+	local mapped = sb.procfs_mapping_request(path)
+
+	-- Returns exec_policy, path, readonly_flag
+	if (mapped) then
+		ret_path = mapped
+	end
+	return nil, ret_path, false
+end
+
 -- Load mode-specific rules.
 -- A mode file must define three variables:
 --  1. rule_file_interface_version (string) is checked and must match,
@@ -71,6 +87,8 @@ function load_and_check_rules()
 	export_chains = {}
 	exec_policy_chains = {}
 
+	-- Differences between version 17 and 18:
+	-- - added sb2_procfs_mapper()
 	-- Differences between version 16 and 17:
 	-- - Added support for hierarcic rules (i.e. rule
 	--   trees. 16 supports only linear rule lists)
@@ -82,7 +100,7 @@ function load_and_check_rules()
 	--   (previously only one was expected)
 	-- - variables "esc_tools_root" and "esc_target_root"
 	--   were removed
-	local current_rule_interface_version = "17"
+	local current_rule_interface_version = "18"
 
 	do_file(rule_file_path)
 
@@ -400,7 +418,7 @@ function sbox_translate_path(rule, binary_name, func_name, path)
 
 	if (rule.custom_map_funct ~= nil) then
 		exec_policy, ret, readonly_flag = rule.custom_map_funct(
-			binary_name, func_name, rp, path, rules[n])
+			binary_name, func_name, rp, path, rule)
 		if (rule.readonly ~= nil) then
 			readonly_flag = rule.readonly
 		end
@@ -428,7 +446,9 @@ end
 -- path resolution takes place. The primary purpose of this is to
 -- determine where to start resolving symbolic links; shorter paths than
 -- "min_path_len" should not be given to sbox_translate_path()
--- returns "rule", "rule_found", "min_path_len"
+-- returns "rule", "rule_found", "min_path_len", "call_translate_for_all"
+-- ("call_translate_for_all" is a flag which controls optimizations in
+-- the path resolution code)
 function sbox_get_mapping_requirements(binary_name, func_name, full_path)
 	-- loop through the chains, first match is used
 	local min_path_len = 0
@@ -440,17 +460,22 @@ function sbox_get_mapping_requirements(binary_name, func_name, full_path)
 		sb.log("error", string.format("Unable to find chain for: %s(%s)",
 			func_name, full_path))
 
-		return nil, false, 0
+		return nil, false, 0, false
 	end
 
 	rule, min_path_len = find_rule(chain, func_name, full_path)
 	if (not rule) then
 		-- error, not even a default rule found
 		sb.log("error", string.format("Unable to find rule for: %s(%s)", func_name, full_path))
-		return nil, false, 0
+		return nil, false, 0, false
+	end
+
+	local call_translate_for_all = false
+	if (rule.custom_map_funct) then
+		call_translate_for_all = true
 	end
 
-	return rule, true, min_path_len
+	return rule, true, min_path_len, call_translate_for_all
 end
 
 --
diff --git a/lua_scripts/pathmaps/devel/00_default.lua b/lua_scripts/pathmaps/devel/00_default.lua
index 938b708..8c9e53a 100644
--- a/lua_scripts/pathmaps/devel/00_default.lua
+++ b/lua_scripts/pathmaps/devel/00_default.lua
@@ -8,7 +8,7 @@
 
 -- Rule file interface version, mandatory.
 --
-rule_file_interface_version = "17"
+rule_file_interface_version = "18"
 ----------------------------------
 
 tools = tools_root
@@ -461,7 +461,7 @@ simple_chain = {
 		-- -----------------------------------------------
 		-- 90. Top-level directories that must not be mapped:
 		{prefix = "/dev", use_orig_path = true},
-		{prefix = "/proc", use_orig_path = true},
+		{dir = "/proc", custom_map_funct = sb2_procfs_mapper},
 		{prefix = "/sys",
 		 use_orig_path = true, readonly = true},
 
@@ -514,7 +514,7 @@ qemu_chain = {
 		{prefix = "/tmp", map_to = session_dir},
 
 		{prefix = "/dev", use_orig_path = true},
-		{prefix = "/proc", use_orig_path = true},
+		{dir = "/proc", custom_map_funct = sb2_procfs_mapper},
 		{prefix = "/sys", use_orig_path = true},
 
 		{prefix = "/etc/resolv.conf",
diff --git a/lua_scripts/pathmaps/emulate/00_default.lua b/lua_scripts/pathmaps/emulate/00_default.lua
index 052222e..368816d 100644
--- a/lua_scripts/pathmaps/emulate/00_default.lua
+++ b/lua_scripts/pathmaps/emulate/00_default.lua
@@ -3,7 +3,7 @@
 
 -- Rule file interface version, mandatory.
 --
-rule_file_interface_version = "17"
+rule_file_interface_version = "18"
 ----------------------------------
 
 sb1_compat_dir = sbox_target_root .. "/scratchbox1-compat"
@@ -84,7 +84,7 @@ mapall_chain = {
 
 		-- 
 		{prefix = "/dev", use_orig_path = true},
-		{prefix = "/proc", use_orig_path = true},
+		{dir = "/proc", custom_map_funct = sb2_procfs_mapper},
 		{prefix = "/sys", use_orig_path = true},
 
 		{prefix = sbox_dir .. "/share/scratchbox2",
diff --git a/lua_scripts/pathmaps/install/00_default.lua b/lua_scripts/pathmaps/install/00_default.lua
index 9721d5b..bb8a28f 100644
--- a/lua_scripts/pathmaps/install/00_default.lua
+++ b/lua_scripts/pathmaps/install/00_default.lua
@@ -4,7 +4,7 @@
 
 -- Rule file interface version, mandatory.
 --
-rule_file_interface_version = "17"
+rule_file_interface_version = "18"
 ----------------------------------
 
 if (tools_root and tools_root ~= "/") then
@@ -31,7 +31,7 @@ default_chain = {
 		{ prefix = "/usr/local/bin", func_name = ".*exec.*", map_to = tools_target },
 
 		{ prefix = "/dev", func_name = "open.*", use_orig_path = true },
-		{ prefix = "/proc", use_orig_path = true },
+		{ dir = "/proc", custom_map_funct = sb2_procfs_mapper},
 		{ prefix = "/sys", use_orig_path = true },
 
 		{ prefix = session_dir, use_orig_path = true },
diff --git a/lua_scripts/pathmaps/simple/00_default.lua b/lua_scripts/pathmaps/simple/00_default.lua
index 617cf27..b8e3434 100644
--- a/lua_scripts/pathmaps/simple/00_default.lua
+++ b/lua_scripts/pathmaps/simple/00_default.lua
@@ -7,7 +7,7 @@
 
 -- Rule file interface version, mandatory.
 --
-rule_file_interface_version = "17"
+rule_file_interface_version = "18"
 ----------------------------------
 
 tools = tools_root
@@ -61,7 +61,7 @@ simple_chain = {
 		{prefix = "/tmp", map_to = session_dir},
 
 		{prefix = "/dev", use_orig_path = true},
-		{prefix = "/proc", use_orig_path = true},
+		{prefix = "/proc", custom_map_funct = sb2_procfs_mapper},
 		{prefix = "/sys", use_orig_path = true},
 		{prefix = "/etc/resolv.conf", use_orig_path = true},
 		{prefix = "/etc/apt", map_to = target_root},
@@ -83,7 +83,7 @@ qemu_chain = {
 		{prefix = "/tmp", map_to = session_dir},
 
 		{prefix = "/dev", use_orig_path = true},
-		{prefix = "/proc", use_orig_path = true},
+		{dir = "/proc", custom_map_funct = sb2_procfs_mapper},
 		{prefix = "/sys", use_orig_path = true},
 		{prefix = "/etc/resolv.conf", use_orig_path = true},
 		{prefix = tools, use_orig_path = true},
diff --git a/lua_scripts/pathmaps/tools/00_default.lua b/lua_scripts/pathmaps/tools/00_default.lua
index 9320d58..76ecf18 100644
--- a/lua_scripts/pathmaps/tools/00_default.lua
+++ b/lua_scripts/pathmaps/tools/00_default.lua
@@ -6,7 +6,7 @@
 
 -- Rule file interface version, mandatory.
 --
-rule_file_interface_version = "17"
+rule_file_interface_version = "18"
 ----------------------------------
 
 -- If the permission token exists and contains "root", tools_root directories
@@ -54,7 +54,7 @@ mapall_chain = {
 
 		--
 		{prefix = "/dev", use_orig_path = true},
-		{prefix = "/proc", use_orig_path = true},
+		{dir = "/proc", custom_map_funct = sb2_procfs_mapper},
 		{prefix = "/sys", use_orig_path = true},
 
 		{prefix = sbox_user_home_dir .. "/.scratchbox2",