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authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>2021-07-01 04:55:20 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-07-01 21:06:04 +0300
commitaec0d0966f20d131cc4ff6927b02d448a478a6d4 (patch)
tree751fc1eca537287e2c12147d96dec9b074349881 /lib/string_helpers.c
parent0362c27fb373ea04eace9e7a70e61036ab81f09f (diff)
downloadlinux-aec0d0966f20d131cc4ff6927b02d448a478a6d4.tar.xz
lib/string_helpers: allow to append additional characters to be escaped
Introduce a new flag to append additional characters, passed in 'only' parameter, to be escaped if they fall in the corresponding class. Link: https://lkml.kernel.org/r/20210504180819.73127-7-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/string_helpers.c')
-rw-r--r--lib/string_helpers.c19
1 files changed, 15 insertions, 4 deletions
diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index ceca5fbbd92c..c15aea7a82e9 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -493,6 +493,11 @@ static bool escape_hex(unsigned char c, char **dst, char *end)
* escape only non-ascii characters, checked by isascii()
* %ESCAPE_NAP:
* escape only non-printable or non-ascii characters
+ * %ESCAPE_APPEND:
+ * append characters from @only to be escaped by the given classes
+ *
+ * %ESCAPE_APPEND would help to pass additional characters to the escaped, when
+ * one of %ESCAPE_NP, %ESCAPE_NA, or %ESCAPE_NAP is provided.
*
* One notable caveat, the %ESCAPE_NAP, %ESCAPE_NP and %ESCAPE_NA have the
* higher priority than the rest of the flags (%ESCAPE_NAP is the highest).
@@ -513,9 +518,11 @@ int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz,
char *p = dst;
char *end = p + osz;
bool is_dict = only && *only;
+ bool is_append = flags & ESCAPE_APPEND;
while (isz--) {
unsigned char c = *src++;
+ bool in_dict = is_dict && strchr(only, c);
/*
* Apply rules in the following sequence:
@@ -531,20 +538,24 @@ int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz,
* defined by given @flags
* In these cases we just pass through a character to the
* output buffer.
+ *
+ * When %ESCAPE_APPEND is passed, the characters from @only
+ * have been excluded from the %ESCAPE_NAP, %ESCAPE_NP, and
+ * %ESCAPE_NA cases.
*/
- if (is_dict && !strchr(only, c) &&
+ if (!(is_append || in_dict) && is_dict &&
escape_passthrough(c, &p, end))
continue;
- if (isascii(c) && isprint(c) &&
+ if (!(is_append && in_dict) && isascii(c) && isprint(c) &&
flags & ESCAPE_NAP && escape_passthrough(c, &p, end))
continue;
- if (isprint(c) &&
+ if (!(is_append && in_dict) && isprint(c) &&
flags & ESCAPE_NP && escape_passthrough(c, &p, end))
continue;
- if (isascii(c) &&
+ if (!(is_append && in_dict) && isascii(c) &&
flags & ESCAPE_NA && escape_passthrough(c, &p, end))
continue;