| Message ID | 20241112175758.114080-1-pvmohammedanees2003@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | dm: Allow the use of escaped characters in str_field_delimit() | expand |
Dne 12. 11. 24 v 18:57 Mohammed Anees napsal(a): > Escape characters were not handled before, which could lead to > unwanted issues. Some device-mapper names may contain backslashes (`\`) > as valid characters and should not be treated as escape characters. Only > escape characters followed directly by the separator are considered > valid and need to be processed. After handling, the escape characters > are removed to ensure the final string is correctly parsed without > unwanted escape sequences which were used only for escaping. > > Signed-off-by: Mohammed Anees <pvmohammedanees2003@gmail.com> > --- > drivers/md/dm-init.c | 28 ++++++++++++++++++++++++---- > 1 file changed, 24 insertions(+), 4 deletions(-) > > diff --git a/drivers/md/dm-init.c b/drivers/md/dm-init.c > index b37bbe762500..dad9d523f7fb 100644 > --- a/drivers/md/dm-init.c > +++ b/drivers/md/dm-init.c > @@ -88,13 +88,33 @@ static void __init dm_setup_cleanup(struct list_head *devices) > static char __init *str_field_delimit(char **str, char separator) > { > There is libdevmapper project (ATM distirbuted through lvm2 project) which is handling the management of name & uuid with mangling - so they are properly visible on systems with udev. IMHO this escape handling does not belong to kernel and is rather related to the actual user space running on top. Regards Zdenek
On Tue, 12 Nov 2024, Mohammed Anees wrote: > Escape characters were not handled before, which could lead to > unwanted issues. Some device-mapper names may contain backslashes (`\`) > as valid characters and should not be treated as escape characters. Only > escape characters followed directly by the separator are considered > valid and need to be processed. After handling, the escape characters > are removed to ensure the final string is correctly parsed without > unwanted escape sequences which were used only for escaping. > > Signed-off-by: Mohammed Anees <pvmohammedanees2003@gmail.com> Hi Does anyone really need this? Is there some use case for using escape characters in device mapper names? Mikulas > --- > drivers/md/dm-init.c | 28 ++++++++++++++++++++++++---- > 1 file changed, 24 insertions(+), 4 deletions(-) > > diff --git a/drivers/md/dm-init.c b/drivers/md/dm-init.c > index b37bbe762500..dad9d523f7fb 100644 > --- a/drivers/md/dm-init.c > +++ b/drivers/md/dm-init.c > @@ -88,13 +88,33 @@ static void __init dm_setup_cleanup(struct list_head *devices) > static char __init *str_field_delimit(char **str, char separator) > { > char *s; > + /* This variable handles removing escape characters, which are > + * only used to avoid the separator and aren't needed in the > + * final string. > + */ > + char *write; > > - /* TODO: add support for escaped characters */ > *str = skip_spaces(*str); > - s = strchr(*str, separator); > + s = *str; > + write = *str; > + > + /* Find the separator and handle escape character */ > + while (*s) { > + /* If '\' is followed by the separator, skip '\' by > + * incrementing s, write will then overwrite the > + * escape character with the separator. > + */ > + if (*s == '\\' && *(s + 1) != '\0' && *(s + 1) == separator) > + s++; > + else if (*s == separator) > + break; > + > + *write++ = *s++; > + } > + > /* Delimit the field and remove trailing spaces */ > - if (s) > - *s = '\0'; > + if (write) > + *write = '\0'; > *str = strim(*str); > return s ? ++s : NULL; > } > -- > 2.47.0 >
diff --git a/drivers/md/dm-init.c b/drivers/md/dm-init.c index b37bbe762500..dad9d523f7fb 100644 --- a/drivers/md/dm-init.c +++ b/drivers/md/dm-init.c @@ -88,13 +88,33 @@ static void __init dm_setup_cleanup(struct list_head *devices) static char __init *str_field_delimit(char **str, char separator) { char *s; + /* This variable handles removing escape characters, which are + * only used to avoid the separator and aren't needed in the + * final string. + */ + char *write; - /* TODO: add support for escaped characters */ *str = skip_spaces(*str); - s = strchr(*str, separator); + s = *str; + write = *str; + + /* Find the separator and handle escape character */ + while (*s) { + /* If '\' is followed by the separator, skip '\' by + * incrementing s, write will then overwrite the + * escape character with the separator. + */ + if (*s == '\\' && *(s + 1) != '\0' && *(s + 1) == separator) + s++; + else if (*s == separator) + break; + + *write++ = *s++; + } + /* Delimit the field and remove trailing spaces */ - if (s) - *s = '\0'; + if (write) + *write = '\0'; *str = strim(*str); return s ? ++s : NULL; }
Escape characters were not handled before, which could lead to unwanted issues. Some device-mapper names may contain backslashes (`\`) as valid characters and should not be treated as escape characters. Only escape characters followed directly by the separator are considered valid and need to be processed. After handling, the escape characters are removed to ensure the final string is correctly parsed without unwanted escape sequences which were used only for escaping. Signed-off-by: Mohammed Anees <pvmohammedanees2003@gmail.com> --- drivers/md/dm-init.c | 28 ++++++++++++++++++++++++---- 1 file changed, 24 insertions(+), 4 deletions(-)