From aec0d0966f20d131cc4ff6927b02d448a478a6d4 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Wed, 30 Jun 2021 18:55:20 -0700 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@linux.intel.com Signed-off-by: Andy Shevchenko Cc: Alexander Viro Cc: Chuck Lever Cc: "J. Bruce Fields" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/string_helpers.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) (limited to 'lib') 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; -- cgit v1.2.3-59-g8ed1b