commit 0e1aff215dab990f2aa8e179495be96780774131
Author:     Jacob Welsh <jfw>
AuthorDate: Fri Apr 26 21:36:32 2024 +0000
Commit:     Jacob Welsh <jfw>
CommitDate: Fri Apr 26 21:43:41 2024 +0000

    busybox/archival: implement tar --same-owner as default only for root, & related changes.
    
    Now that we properly report failure to chmod, non-root extraction no longer spews permission errors, and as an added bonus no longer hammers on passwd/group database lookups.
    
    Rename related getopt constants for consistency.
    
    Since I had to dig up its meaning anyway, make better use of opt_complementary to set the --same-owner and --same-permissions pairs properly (so later options override earlier ones).

diff --git a/base/busybox/archival/tar.c b/base/busybox/archival/tar.c
index f1cdbc5..62ae895 100644
--- a/base/busybox/archival/tar.c
+++ b/base/busybox/archival/tar.c
@@ -810,6 +810,7 @@ static llist_t *append_file_list_to_list(llist_t *list)
 //usage:	IF_FEATURE_TAR_NOPRESERVE_TIME(
 //usage:     "\n	-m	Don't restore mtime"
 //usage:	)
+//usage:     "\n	--same-owner	Restore owner and group (default for superuser)"
 //usage:     "\n	-o,--no-same-owner	Don't restore owner and group"
 //usage:     "\n	-p,--same-permissions	Restore file permissions (default for superuser)"
 //usage:     "\n	--no-same-permissions	Don't restore file permissions"
@@ -847,10 +848,11 @@ enum {
 	IF_FEATURE_TAR_NOPRESERVE_TIME(OPTBIT_NOPRESERVE_TIME,)
 #if ENABLE_FEATURE_TAR_LONG_OPTIONS
 	OPTBIT_STERILIZE,
+	OPTBIT_SAME_OWNER,
 	OPTBIT_NORECURSION,
 	IF_FEATURE_TAR_TO_COMMAND(OPTBIT_2COMMAND   ,)
 	OPTBIT_NUMERIC_OWNER,
-	OPTBIT_NOPRESERVE_PERM,
+	OPTBIT_NOSAME_PERM,
 	OPTBIT_OVERWRITE,
 #endif
 	OPT_TEST         = 1 << 0, // t
@@ -858,8 +860,8 @@ enum {
 	OPT_BASEDIR      = 1 << 2, // C
 	OPT_TARNAME      = 1 << 3, // f
 	OPT_2STDOUT      = 1 << 4, // O
-	OPT_NOPRESERVE_OWNER = 1 << 5, // o == no-same-owner
-	OPT_P            = 1 << 6, // p
+	OPT_NOSAME_OWNER = 1 << 5, // o == no-same-owner
+	OPT_SAME_PERM    = 1 << 6, // p == same-permissions
 	OPT_VERBOSE      = 1 << 7, // v
 	OPT_KEEP_OLD     = 1 << 8, // k
 	OPT_CREATE       = IF_FEATURE_TAR_CREATE(   (1 << OPTBIT_CREATE      )) + 0, // c
@@ -873,10 +875,11 @@ enum {
 	OPT_COMPRESS     = IF_FEATURE_SEAMLESS_Z(   (1 << OPTBIT_COMPRESS    )) + 0, // Z
 	OPT_NOPRESERVE_TIME = IF_FEATURE_TAR_NOPRESERVE_TIME((1 << OPTBIT_NOPRESERVE_TIME)) + 0, // m
 	OPT_STERILIZE       = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_STERILIZE      )) + 0, // sterilize
+	OPT_SAME_OWNER      = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_SAME_OWNER     )) + 0, // same-owner
 	OPT_NORECURSION     = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_NORECURSION    )) + 0, // no-recursion
 	OPT_2COMMAND        = IF_FEATURE_TAR_TO_COMMAND(  (1 << OPTBIT_2COMMAND       )) + 0, // to-command
 	OPT_NUMERIC_OWNER   = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_NUMERIC_OWNER  )) + 0, // numeric-owner
-	OPT_NOPRESERVE_PERM = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_NOPRESERVE_PERM)) + 0, // no-same-permissions
+	OPT_NOSAME_PERM     = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_NOSAME_PERM    )) + 0, // no-same-permissions
 	OPT_OVERWRITE       = IF_FEATURE_TAR_LONG_OPTIONS((1 << OPTBIT_OVERWRITE      )) + 0, // overwrite
 
 	OPT_ANY_COMPRESS = (OPT_BZIP2 | OPT_LZMA | OPT_GZIP | OPT_XZ | OPT_COMPRESS),
@@ -922,6 +925,7 @@ static const char tar_longopts[] ALIGN1 =
 	"touch\0"               No_argument       "m"
 # endif
 	"sterilize\0"           No_argument       "\x80"
+	"same-owner\0"          No_argument       "\x81"
 	"no-recursion\0"	No_argument       "\xfa"
 # if ENABLE_FEATURE_TAR_TO_COMMAND
 	"to-command\0"		Required_argument "\xfb"
@@ -962,8 +966,12 @@ int tar_main(int argc UNUSED_PARAM, char **argv)
 	opt_complementary = "--:" // first arg is options
 		"tt:vv:" // count -t,-v
 		IF_FEATURE_TAR_FROM("X::T::") // cumulative lists
-#if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
+#if ENABLE_FEATURE_TAR_LONG_OPTIONS
+# if ENABLE_FEATURE_TAR_FROM
 		"\xff::" // cumulative lists for --exclude
+# endif
+		"\x81-o:o-\x81:" // [no-]same-owner mutually override
+		"p-\xfd:\xfd-p:" // [no-]same-permissions mutually override
 #endif
 		IF_FEATURE_TAR_CREATE("c:") "t:x:" // at least one of these is reqd
 		IF_FEATURE_TAR_CREATE("c--tx:t--cx:x--ct") // mutually exclusive
@@ -1044,10 +1052,10 @@ int tar_main(int argc UNUSED_PARAM, char **argv)
 	if (opt & OPT_NUMERIC_OWNER)
 		tar_handle->ah_flags |= ARCHIVE_NUMERIC_OWNER;
 
-	if (opt & OPT_NOPRESERVE_OWNER)
+	if (opt & OPT_NOSAME_OWNER || (!(opt & OPT_SAME_OWNER) && getuid() != 0))
 		tar_handle->ah_flags |= ARCHIVE_DONT_RESTORE_OWNER;
 
-	if (opt & OPT_NOPRESERVE_PERM || (!(opt & OPT_P) && getuid() != 0))
+	if (opt & OPT_NOSAME_PERM || (!(opt & OPT_SAME_PERM) && getuid() != 0))
 		tar_handle->ah_flags |= ARCHIVE_DONT_RESTORE_PERM;
 
 	if (opt & OPT_OVERWRITE) {