Add multiple mapping modes support

Mapping modes can be selected by exporting SBOX2_MAPMODE
environment variable. Currently there are two, default
and emulate.

Signed-off-by: Lauri Leukkunen <lle@rahina.org>

9 files changed, 143 insertions, 118 deletions

diff --git a/Makefile b/Makefile
index ca3439f..df7b21c 100644
--- a/Makefile
+++ b/Makefile
@@ -28,13 +28,16 @@ install: $(targets)
 	install -d -m 755 $(prefix)/lib
 	install -d -m 755 $(prefix)/share/scratchbox2/redir_scripts
 	install -d -m 755 $(prefix)/share/scratchbox2/redir_scripts/preload
+	install -d -m 755 $(prefix)/share/scratchbox2/redir_scripts/preload/default
+	install -d -m 755 $(prefix)/share/scratchbox2/redir_scripts/preload/emulate
 	install -c -m 755 preload/libsb2.so $(prefix)/lib/libsb2.so
 	install -c -m 755 utils/sb2 $(prefix)/bin/sb2
 	install -c -m 755 utils/sb2-build-libtool.sh $(prefix)/bin/sb2-build-libtool
 	install -c -m 755 utils/sb_gcc_wrapper $(prefix)/bin/sb_gcc_wrapper
 	install -c -m 755 scripts/sb2rc $(prefix)/share/scratchbox2/sb2rc
 	install -c -m 644 redir_scripts/main.lua $(prefix)/share/scratchbox2/redir_scripts/main.lua
-	install -c -m 644 redir_scripts/preload/*.lua $(prefix)/share/scratchbox2/redir_scripts/preload/
+	install -c -m 644 redir_scripts/preload/default/*.lua $(prefix)/share/scratchbox2/redir_scripts/preload/default/
+	install -c -m 644 redir_scripts/preload/emulate/*.lua $(prefix)/share/scratchbox2/redir_scripts/preload/emulate/
 	install -c -m 644 etc/sb2.config.sample $(prefix)/share/scratchbox2/sb2.config.sample
 	@for f in $(gcc_bins_expanded); do \
 		ln -sf sb_gcc_wrapper $$f; \
diff --git a/mapping/emumode.c b/mapping/emumode.c
deleted file mode 100644
index 6e9bd37..0000000
--- a/mapping/emumode.c
+++ /dev/null
@@ -1,16 +0,0 @@
-/*
- * Copyright (C) 2007 Lauri Leukkunen <lle@rahina.org>
- *
- * Licensed under LGPL 2.1, see toplevel LICENSE file for details.
- *
- * emumode.c implements target emulation mapping profile.
- * It maps everything except /tmp, /dev, /proc and /sys to
- * $SBOX_TARGET_ROOT. It doesn't use the cache so there's
- * no conflict between emumode and the default mapping mode.
- */
-
-#include <mapping.h>
-
-char *emumode_map(const char *path)
-{
-}
diff --git a/mapping/mapping.c b/mapping/mapping.c
index 6a04c1c..b2bc421 100644
--- a/mapping/mapping.c
+++ b/mapping/mapping.c
@@ -109,7 +109,8 @@ char *decolonize_path(const char *path)
 			return NULL;
 		}
 		unsigned int l = (strlen(cwd) + 1 + strlen(path) + 1);
-		cpath = malloc((strlen(cwd) + 1 + strlen(path) + 1) * sizeof(char));
+		cpath = malloc((strlen(cwd) + 1 
+				+ strlen(path) + 1) * sizeof(char));
 		memset(cpath, '\0', l);
 		strcpy(cpath, cwd);
 		strcat(cpath, "/");
@@ -134,7 +135,8 @@ char *decolonize_path(const char *path)
 		}
 		*index = '\0';
 		if (index == (start)) {
-			goto proceed; /* skip over empty strings resulting from // */
+			goto proceed; /* skip over empty strings 
+					 resulting from // */
 		}
 
 		if (strcmp(start, "..") == 0) {
@@ -178,18 +180,25 @@ proceed:
 
 #ifndef DISABLE_CACHE
 
-static char *create_sb2cache_path(const char *binary_name, const char *func_name, const char *path)
+static char *create_sb2cache_path(const char *mapping_mode, 
+			const char *binary_name, 
+			const char *func_name, 
+			const char *path)
 {
 	char *target_dir = getenv("SBOX_MAPPING_CACHE");
 	char *cache_path;
 	unsigned int length;
 
-	length = strlen(target_dir) + strlen(path) + 1 + strlen(binary_name) + 1 + strlen(func_name) + 4 + 1;
+	length = strlen(mapping_mode) + 1 + strlen(target_dir) + strlen(path) 
+		+ 1 + strlen(binary_name) + 1 + strlen(func_name) + 4 + 1;
+
 	cache_path = malloc(length * sizeof(char));
 	memset(cache_path, '\0', length);
 	strcpy(cache_path, target_dir);
 	strcat(cache_path, path);
 	strcat(cache_path, ".");
+	strcat(cache_path, mapping_mode);
+	strcat(cache_path, ".");
 	strcat(cache_path, binary_name);
 	strcat(cache_path, ".");
 	strcat(cache_path, func_name);
@@ -198,16 +207,20 @@ static char *create_sb2cache_path(const char *binary_name, const char *func_name
 }
 
 /*
- * return NULL if not found from cache, or if the cache is outdated compared to sb2_timestamp
+ * Return NULL if not found from cache, or if the cache is outdated 
+ * compared to sb2_timestamp.
  */
-static char *read_sb2cache(const char *binary_name, const char *func_name, const char *path)
+static char *read_sb2cache(const char *mapping_mode, 
+			const char *binary_name, 
+			const char *func_name, 
+			const char *path)
 {
 	char *link_path = NULL;
 	struct stat64 s;
 
 	if (getenv("SBOX_DISABLE_MAPPING_CACHE")) return NULL;
 
-	char *cache_path = create_sb2cache_path(binary_name, func_name, path);
+	char *cache_path = create_sb2cache_path(mapping_mode, binary_name, func_name, path);
 
 	if (lstat64(cache_path, &s) < 0 ||
 		(s.st_mtime < get_sb2_timestamp())) {
@@ -261,9 +274,13 @@ exit:
 }
 
 /*
- * if the cache dir doesn't exist, this will create it
+ * If the cache dir doesn't exist, this will create it.
  */
-static int insert_sb2cache(const char *binary_name, const char *func_name, const char *path, const char *map_to)
+static int insert_sb2cache(const char *mapping_mode,
+			const char *binary_name, 
+			const char *func_name, 
+			const char *path, 
+			const char *map_to)
 {
 	char *cache_path;
 	char *dcopy;
@@ -287,7 +304,8 @@ static int insert_sb2cache(const char *binary_name, const char *func_name, const
 		}
 	}
 
-	cache_path = create_sb2cache_path(binary_name, func_name, path);
+	cache_path = create_sb2cache_path(mapping_mode, binary_name, 
+					func_name, path);
 
 	dcopy = strdup(cache_path);
 
@@ -417,11 +435,9 @@ static int sb_realpath(lua_State *l)
 
 	path = strdup(lua_tostring(l, 1));
 
-	//printf("sb_realpath: [%s]\n", path);
-
 	/* Here we rely on glibc specific feature of passing NULL as the second
-	 * parameter to realpath, thus forcing it to allocate a sufficient buffer.
-	 * This might not work at all on other systems.
+	 * parameter to realpath, thus forcing it to allocate a sufficient 
+	 * buffer. This might not work at all on other systems.
 	 */
 
 	resolved_path = __sb2_realpath(path, NULL);
@@ -430,8 +446,6 @@ static int sb_realpath(lua_State *l)
 		return 1;
 	}
 
-	//printf("sb_realpath: resolved_path = [%s]\n", resolved_path);
-
 	lua_pushstring(l, resolved_path);
 	return 1;
 }
@@ -461,7 +475,6 @@ static int sb_followsymlink(lua_State *l)
 
 	path = strdup(lua_tostring(l, 1));
 
-	//printf("C thinks path is: %s\n", path);
 #ifdef __x86_64__
 	if (syscall(__NR_lstat, path, &s) < 0) {
 #else
@@ -474,10 +487,9 @@ static int sb_followsymlink(lua_State *l)
 		lua_pushstring(l, path);
 		goto getout;
 	}
-	//printf("about to test for symlink: %i\n", s.st_mode);
+	
 	if (S_ISLNK(s.st_mode)) {
 		/* we have a symlink, read it and return */
-		//printf("WE HAVE A SYMLINK!!!\n");
 		syscall(__NR_readlink, path, link_path, PATH_MAX);
 		lua_pushstring(l, link_path);
 
@@ -485,10 +497,9 @@ static int sb_followsymlink(lua_State *l)
 		//printf("not a symlink! %s\n", path);
 		/* not a symlink, return path */
 		lua_pushstring(l, path);
-		//printf("after pushing\n");
 	}
+
 getout:	
-	//printf("about to free!\n");
 	free(path);
 	return 1;
 }
@@ -497,7 +508,6 @@ getout:
  * This function should ONLY look at things from rsdir
  * any other path leads to loops
  */
-
 static int sb_getdirlisting(lua_State *l)
 {
 	DIR *d;
@@ -552,46 +562,42 @@ char *scratchbox_path(const char *func_name, const char *path)
 	if (tmp) {
 		strcpy(binary_name, tmp);
 	} else {
-		strcpy(binary_name, "DUMMY");
+		strcpy(binary_name, "UNKNOWN");
 	}
 	return scratchbox_path2(binary_name, func_name, path);
 }
 
-char *scratchbox_path2(const char *binary_name, const char *func_name, const char *path)
+char *scratchbox_path2(const char *binary_name,
+		const char *func_name,
+		const char *path)
 {	
 	char work_dir[PATH_MAX + 1];
-	char *tmp = NULL, *decolon_path = NULL;
+	char *tmp = NULL, *decolon_path = NULL, *mapping_mode = NULL;
 	char pidlink[17]; /* /proc/2^8/exe */
-	
+
+	if (!(mapping_mode = getenv("SBOX2_MAPMODE"))) {
+		mapping_mode = "default";
+	}
+
 	if (!path) {
 		WRITE_LOG("ERROR: scratchbox_path2: path == NULL: [%s][%s]\n", binary_name, func_name);
 		return NULL;
 	}
-	//WRITE_LOG("in scratchbox_path2: %s %s (%s)\n", binary_name, func_name, path);
+
 	if (mapping_disabled || getenv("SBOX_DISABLE_MAPPING")) {
 		return strdup(path);
 	}
 
 	disable_mapping();
 	decolon_path = decolonize_path(path);
-	//WRITE_LOG("scratchbox_path2: decolon_path: (%s)\n", decolon_path);
-#if 0
-	if (strstr(decolon_path, getenv("SBOX_TARGET_ROOT"))) {
-		/* short circuit a direct reference to a file inside the sbox 
-		 * target dir */
-		//DBGOUT("about to short circuit: %s\n", func_name);
-		free(decolon_path);
-		enable_mapping();
-		return strdup(path);
-	}
-#endif
-
 
 	/* first try from the cache */
 
 #ifndef DISABLE_CACHE
 	tmp = NULL;
-	if (rsdir && main_lua) tmp = read_sb2cache(binary_name, func_name, decolon_path);
+	if (rsdir && main_lua) tmp = read_sb2cache(mapping_mode,
+						binary_name, 
+						func_name, decolon_path);
 
 	if (tmp) {
 		if (strcmp(tmp, decolon_path) == 0) {
@@ -625,15 +631,11 @@ char *scratchbox_path2(const char *binary_name, const char *func_name, const cha
 	
 	memset(work_dir, '\0', PATH_MAX+1);
 	snprintf(pidlink,16,"/proc/%i/exe",sb_getpid());
-//	if (syscall(__NR_readlink, pidlink, binary_name, PATH_MAX) < 0) {
-//		perror("__NR_readlink() error, check that /proc is mounted!");
-//	}
 	syscall(__NR_getcwd, work_dir, PATH_MAX);
 
 	/* redir_scripts RECURSIVE CALL BREAK */
 	if (strncmp(decolon_path, rsdir, strlen(rsdir)) == 0) {
-		//pthread_mutex_unlock(&lua_lock);
-		//DBGOUT("cutting recursive call\n");
+		pthread_mutex_unlock(&lua_lock);
 		enable_mapping();
 		return (char *)decolon_path;
 	}
@@ -660,23 +662,26 @@ char *scratchbox_path2(const char *binary_name, const char *func_name, const cha
 	}
 
 	lua_getfield(l, LUA_GLOBALSINDEX, "sbox_translate_path");
+	lua_pushstring(l, mapping_mode);
 	lua_pushstring(l, binary_name);
 	lua_pushstring(l, func_name);
 	lua_pushstring(l, work_dir);
 	lua_pushstring(l, decolon_path);
-	lua_call(l, 4, 1); /* four arguments, one result */
+	lua_call(l, 5, 1); /* five arguments, one result */
+
 	tmp = (char *)lua_tostring(l, -1);
 	if (tmp) {
 		tmp = strdup(tmp);
 	}
+
 	lua_pop(l, 1);
 
 	pthread_mutex_unlock(&lua_lock);
 
 #ifndef DISABLE_CACHE
-	insert_sb2cache(binary_name, func_name, decolon_path, tmp);
+	insert_sb2cache(mapping_mode, binary_name, func_name, decolon_path, tmp);
 #endif
-	//DBGOUT("returning path: [%s]\n", tmp);
+	
 	if (strcmp(tmp, decolon_path) == 0) {
 		free(decolon_path);
 		free(tmp);
diff --git a/redir_scripts/main.lua b/redir_scripts/main.lua
index eedeadd..6eaf66e 100644
--- a/redir_scripts/main.lua
+++ b/redir_scripts/main.lua
@@ -2,8 +2,6 @@
 -- Copyright (C) 2006, 2007 Lauri Leukkunen
 -- Licensed under MIT license.
 
---print "hello!\n"
-
 tools_root = os.getenv("SBOX_TOOLS_ROOT")
 if (not tools_root) then
 	tools_root = "/scratchbox/sarge"
@@ -30,54 +28,68 @@ if (rsdir == nil) then
 	rsdir = "/scratchbox/redir_scripts"
 end
 
-chains = {}
+
+function read_mode_part(mode, part)
+	filename = rsdir .. "/preload/" .. mode .. "/" .. part
+	f, err = loadfile(filename)
+	if (f == nil) then
+		error("\nError while loading " .. filename .. ": \n" .. err .. "\n")
+	else
+		f() -- execute the loaded chunk
+		-- export_chains variable contains now the chains
+		-- from the chunk
+		for i = 1,table.maxn(export_chains) do
+			-- fill in the default values
+			if (not export_chains[i].binary) then
+				export_chains[i].binary = ".*"
+			end
+			if (not export_chains[i].rules) then
+				export_chains[i].rules = {}
+			end
+			-- loop through the rules
+			for r = 1, table.maxn(export_chains[i].rules) do
+				if (not export_chains[i].rules[r].func_name) then
+					export_chains[i].rules[r].func_name = ".*"
+				end
+				if (not export_chains[i].rules[r].path) then
+					-- this is an error, report and exit
+					os.exit(1)
+				end
+				export_chains[i].rules[r].lua_script = filename
+				if (export_chains[i].binary) then
+					export_chains[i].rules[r].binary_name = export_chains[i].binary
+				else
+					export_chains[i].rules[r].binary_name = "nil"
+				end
+			end
+			export_chains[i].lua_script = filename
+			table.insert(modes[mode].chains, export_chains[i])
+		end
+	end
+end
+
+-- modes represent the different mapping modes supported.
+-- Each mode contains its own set of chains.
+-- The mode is passed from the libsb2.so to here in the first
+-- argument to sbox_translate_path()
+modes = {}
 
 -- sb.sb_getdirlisting is provided by lua_bindings.c
 -- it returns a table listing all files in a directory
-t = sb.sb_getdirlisting(rsdir .. "/preload")
-
-if (t ~= nil) then
+mm = sb.sb_getdirlisting(rsdir .. "/preload")
+table.sort(mm);
+for m = 1, table.maxn(mm) do
+	local t = sb.sb_getdirlisting(rsdir .. "/preload/" .. mm[m])
 	local i = 0
 	local r = 0
-	table.sort(t)
-	-- load the individual parts ($SBOX_REDIR_SCRIPTS/preload/*.lua)
-	for n = 1,table.maxn(t) do
-		if (string.match(t[n], "%a*%.lua$")) then
-			filename = rsdir .. "/preload/" .. t[n]
-			f, err = loadfile(filename)
-			if (f == nil) then
-				error("\nError while loading " .. filename .. ": \n" .. err .. "\n")
-			else
-				f() -- execute the loaded chunk
-				-- export_chains variable contains now the chains
-				-- from the chunk
-				for i = 1,table.maxn(export_chains) do
-					-- fill in the default values
-					if (not export_chains[i].binary) then
-						export_chains[i].binary = ".*"
-					end
-					if (not export_chains[i].rules) then
-						export_chains[i].rules = {}
-					end
-					-- loop through the rules
-					for r = 1, table.maxn(export_chains[i].rules) do
-						if (not export_chains[i].rules[r].func_name) then
-							export_chains[i].rules[r].func_name = ".*"
-						end
-						if (not export_chains[i].rules[r].path) then
-							-- this is an error, report and exit
-							os.exit(1)
-						end
-						export_chains[i].rules[r].lua_script = filename
-						if (export_chains[i].binary) then
-							export_chains[i].rules[r].binary_name = export_chains[i].binary
-						else
-							export_chains[i].rules[r].binary_name = "nil"
-						end
-					end
-					export_chains[i].lua_script = filename
-					table.insert(chains, export_chains[i])
-				end
+	if (mm[m] ~= "." and mm[m] ~= "..") then
+		table.sort(t)
+		modes[mm[m]] = {}
+		modes[mm[m]].chains = {}
+		-- load the individual parts ($SBOX_REDIR_SCRIPTS/preload/[modename]/*.lua)
+		for n = 1,table.maxn(t) do
+			if (string.match(t[n], "%a*%.lua$")) then
+				read_mode_part(mm[m], t[n])
 			end
 		end
 	end
@@ -215,17 +227,15 @@ end
 -- sbox_translate_path is the function called from libsb2.so
 -- preload library and the FUSE system for each path that needs 
 -- translating
-
-function sbox_translate_path(binary_name, func_name, work_dir, path)
+function sbox_translate_path(mapping_mode, binary_name, func_name, work_dir, path)
 	--sb_debug(string.format("[%s]:", binary_name))
 	--sb_debug(string.format("debug: [%s][%s][%s][%s]", binary_name, func_name, work_dir, path))
 
-	
 	-- loop through the chains, first match is used
-	for n=1,table.maxn(chains) do
-		if (not chains[n].noentry 
-			and string.match(binary_name, chains[n].binary)) then
-			return map_using_chain(chains[n], binary_name, func_name, work_dir, path)
+	for n=1,table.maxn(modes[mapping_mode].chains) do
+		if (not modes[mapping_mode].chains[n].noentry 
+			and string.match(binary_name, modes[mapping_mode].chains[n].binary)) then
+			return map_using_chain(modes[mapping_mode].chains[n], binary_name, func_name, work_dir, path)
 		end
 	end
 
diff --git a/redir_scripts/preload/00_default.lua b/redir_scripts/preload/default/00_default.lua
index 570b85b..570b85b 100644
--- a/redir_scripts/preload/00_default.lua
+++ b/redir_scripts/preload/default/00_default.lua
diff --git a/redir_scripts/preload/10_basic_chains.lua b/redir_scripts/preload/default/10_basic_chains.lua
index 5de2f4a..5de2f4a 100644
--- a/redir_scripts/preload/10_basic_chains.lua
+++ b/redir_scripts/preload/default/10_basic_chains.lua
diff --git a/redir_scripts/preload/XX_catchall.lua b/redir_scripts/preload/default/XX_catchall.lua
index f4ba104..206317f 100644
--- a/redir_scripts/preload/XX_catchall.lua
+++ b/redir_scripts/preload/default/XX_catchall.lua
@@ -1,4 +1,4 @@
--- Copyright (C) 2007 Lauri Leukkunen
+-- Copyright (C) 2007 Lauri Leukkunen <lle@rahina.org>
 -- Licensed under MIT license.
 
 
diff --git a/redir_scripts/preload/emulate/00_default.lua b/redir_scripts/preload/emulate/00_default.lua
new file mode 100644
index 0000000..5ae2aa1
--- /dev/null
+++ b/redir_scripts/preload/emulate/00_default.lua
@@ -0,0 +1,20 @@
+-- Copyright (C) 2007 Lauri Leukkunen <lle@rahina.org>
+-- Licensed under MIT license.
+
+
+mapall_chain = {
+	next_chain = nil,
+	binary = ".*",
+	rules = {
+		{path = ".*qemu.*", map_to = nil},
+		{path = "^/dev", map_to = nil},
+		{path = "^/proc", map_to = nil},
+		{path = "^/tmp", map_to = nil},
+		{path = "^/sys", map_to = nil},
+		{path = ".*", map_to = "="}
+	}
+}
+
+export_chains = {
+	mapall_chain
+}
diff --git a/utils/sb2 b/utils/sb2
index 856cfcd..4299853 100755
--- a/utils/sb2
+++ b/utils/sb2
@@ -70,6 +70,9 @@ if [ "$sb_map_verbose" == "--verbose" ]; then
 	sb_bash_args=$(echo $* | sed 's/^--verbose//')
 fi
 
+# set the initial binary name for the mapping engine
+export __SB2_BINARYNAME="bash"
+
 if [ -z "$sb_bash_args" ]; then
 	exec /bin/bash --noprofile --norc
 else