The patch titled
Subject: lib/string_helpers: allow to append additional characters to be escaped
has been added to the -mm tree. Its filename is
lib-string_helpers-allow-to-append-additional-characters-to-be-escaped.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/lib-string_helpers-allow-to-append-additional-characters-to-be-escaped.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/lib-string_helpers-allow-to-append-additional-characters-to-be-escaped.patch
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------------------------------------------------------
From: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Subject: 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@xxxxxxxxxxxxxxx
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Chuck Lever <chuck.lever@xxxxxxxxxx>
Cc: "J. Bruce Fields" <bfields@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/string_helpers.h | 1 +
lib/string_helpers.c | 19 +++++++++++++++----
2 files changed, 16 insertions(+), 4 deletions(-)
--- a/include/linux/string_helpers.h~lib-string_helpers-allow-to-append-additional-characters-to-be-escaped
+++ a/include/linux/string_helpers.h
@@ -54,6 +54,7 @@ static inline int string_unescape_any_in
#define ESCAPE_HEX BIT(5)
#define ESCAPE_NA BIT(6)
#define ESCAPE_NAP BIT(7)
+#define ESCAPE_APPEND BIT(8)
int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz,
unsigned int flags, const char *only);
--- a/lib/string_helpers.c~lib-string_helpers-allow-to-append-additional-characters-to-be-escaped
+++ a/lib/string_helpers.c
@@ -493,6 +493,11 @@ static bool escape_hex(unsigned char c,
* 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, s
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, s
* 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;
_
Patches currently in -mm which might be from andriy.shevchenko@xxxxxxxxxxxxxxx are
lib-string_helpers-switch-to-use-bit-macro.patch
lib-string_helpers-move-escape_np-check-inside-else-branch-in-a-loop.patch
lib-string_helpers-drop-indentation-level-in-string_escape_mem.patch
lib-string_helpers-introduce-escape_na-for-escaping-non-ascii.patch
lib-string_helpers-introduce-escape_nap-to-escape-non-ascii-and-non-printable.patch
lib-string_helpers-allow-to-append-additional-characters-to-be-escaped.patch
lib-test-string_helpers-print-flags-in-hexadecimal-format.patch
lib-test-string_helpers-get-rid-of-trailing-comma-in-terminators.patch
lib-test-string_helpers-add-test-cases-for-new-features.patch
maintainers-add-myself-as-designated-reviewer-for-generic-string-library.patch
seq_file-introduce-seq_escape_mem.patch
seq_file-add-seq_escape_str-as-replica-of-string_escape_str.patch
seq_file-convert-seq_escape-to-use-seq_escape_str.patch
nfsd-avoid-non-flexible-api-in-seq_quote_mem.patch
seq_file-drop-unused-_escape_mem_ascii.patch
