| Message ID | 20180307232620.15746-4-mwilck@suse.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | christophe varoqui |
| Headers | show |
On 03/08/2018 12:26 AM, Martin Wilck wrote: > We have seen model strings lile '2.5" SSD' which can't be parsed > by the current config parser. This patch fixes this by allowing > '""' to represent a double quote character inside a a string. > The above model string could now be entered in the config file like this: > > blacklist { > vendor SomeCorp > product "2.5"" SSD" > } Could this work in the first place? product "2.5\" SSD" -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel
On Fr, 2018-03-23 at 17:59 +0100, Xose Vazquez Perez wrote: > On 03/08/2018 12:26 AM, Martin Wilck wrote: > > > We have seen model strings lile '2.5" SSD' which can't be parsed > > by the current config parser. This patch fixes this by allowing > > '""' to represent a double quote character inside a a string. > > The above model string could now be entered in the config file like > > this: > > > > blacklist { > > vendor SomeCorp > > product "2.5"" SSD" > > } > > > Could this work in the first place? > > product "2.5\" SSD" I'm not sure what you mean. For the current code, the answer is "no". The parser doesn't treat '\' special in any way. For the parser, the result of the above is the tuple ['product', '2.5\', 'SSD']. The config file parser would discard the last tuple element (the cli command parser takes more than 2 tuple elements, but not the config file parser). The regexp parser would bail out on the lone backslash in '2.5\'. If you meant to say that, instead of using '""', I could have changed the parser to use '\"' to represent a single double-quote character, yes, that would have been possible, at the cost of a much bigger and more error-prone rewrite of the parsing code. Moreover, I think using '\"' has an addtional disadvantage compared to '""'. As you know, the values for many options are regular expressions, and the backslash has special meaning in regexps. Figuring out the correct number of backslashes for complex regexps is hard anyway, and if we give '\' special meaning in the option parser, too, we'd treat it specially on two separate layers, making it even harder for users. The double-quote character, OTOH, has no special meaning in regexps, so that the two quoting mechanisms on the two layers are orthogonal. Regards Martin
diff --git a/libmultipath/parser.c b/libmultipath/parser.c index 3d9656f47945..21151a16ad74 100644 --- a/libmultipath/parser.c +++ b/libmultipath/parser.c @@ -219,11 +219,13 @@ alloc_strvec(char *string) in_string = 0; while (1) { + int two_quotes = 0; + if (!vector_alloc_slot(strvec)) goto out; start = cp; - if (*cp == '"') { + if (*cp == '"' && !(in_string && *(cp + 1) == '"')) { cp++; token = MALLOC(2); @@ -246,11 +248,23 @@ alloc_strvec(char *string) *(token + 1) = '\0'; cp++; } else { + + move_on: while ((in_string || (!isspace((int) *cp) && isascii((int) *cp) && *cp != '!' && *cp != '#' && *cp != '{' && *cp != '}')) && *cp != '\0' && *cp != '"') cp++; + + /* Two consecutive double quotes - don't end string */ + if (in_string && *cp == '"') { + if (*(cp + 1) == '"') { + two_quotes = 1; + cp += 2; + goto move_on; + } + } + strlen = cp - start; token = MALLOC(strlen + 1); @@ -259,6 +273,16 @@ alloc_strvec(char *string) memcpy(token, start, strlen); *(token + strlen) = '\0'; + + /* Replace "" by " */ + if (two_quotes) { + char *qq = strstr(token, "\"\""); + while (qq != NULL) { + memmove(qq + 1, qq + 2, + strlen + 1 - (qq + 2 - token)); + qq = strstr(qq + 1, "\"\""); + } + } } vector_set_slot(strvec, token);
We have seen model strings lile '2.5" SSD' which can't be parsed by the current config parser. This patch fixes this by allowing '""' to represent a double quote character inside a a string. The above model string could now be entered in the config file like this: blacklist { vendor SomeCorp product "2.5"" SSD" } Signed-off-by: Martin Wilck <mwilck@suse.com> --- libmultipath/parser.c | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-)