block/rbd: Add an escape-aware strchr helper

Sometimes the parser needs to further split a token it has collected
from the token input stream. Right now, it does a cursory check to see
if the relevant characters appear in the token to determine if it should
break it down further.

However, qemu_rbd_next_tok() will escape characters as it removes tokens
from the token stream and plain strchr() won't. This can make the
initial strchr() check slightly misleading since it implies
qemu_rbd_next_tok() will find the token and split on it, except the
reality is that qemu_rbd_next_tok() will pass over it if it is escaped.

Use a custom strchr to avoid mixing escaped and unescaped string
operations. Furthermore, this code is identical to how
qemu_rbd_next_tok() seeks its next token, so incorporate this custom
strchr into the body of that function to reduce duplication.

Reported-by: Han Han <hhan@redhat.com>
Fixes: https://bugzilla.redhat.com/1873913
Signed-off-by: Connor Kuehl <ckuehl@redhat.com>
Message-Id: <20210421212343.85524-3-ckuehl@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Connor Kuehl 2021-04-21 16:23:43 -05:00 committed by Max Reitz
parent f7afa7daa0
commit 2b99cfce08
3 changed files with 28 additions and 11 deletions

View File

@ -113,21 +113,31 @@ static int qemu_rbd_connect(rados_t *cluster, rados_ioctx_t *io_ctx,
const char *keypairs, const char *secretid,
Error **errp);
static char *qemu_rbd_strchr(char *src, char delim)
{
char *p;
for (p = src; *p; ++p) {
if (*p == delim) {
return p;
}
if (*p == '\\' && p[1] != '\0') {
++p;
}
}
return NULL;
}
static char *qemu_rbd_next_tok(char *src, char delim, char **p)
{
char *end;
*p = NULL;
for (end = src; *end; ++end) {
if (*end == delim) {
break;
}
if (*end == '\\' && end[1] != '\0') {
end++;
}
}
if (*end == delim) {
end = qemu_rbd_strchr(src, delim);
if (end) {
*p = end + 1;
*end = '\0';
}
@ -171,7 +181,7 @@ static void qemu_rbd_parse_filename(const char *filename, QDict *options,
qemu_rbd_unescape(found_str);
qdict_put_str(options, "pool", found_str);
if (strchr(p, '@')) {
if (qemu_rbd_strchr(p, '@')) {
image_name = qemu_rbd_next_tok(p, '@', &p);
found_str = qemu_rbd_next_tok(p, ':', &p);
@ -181,7 +191,7 @@ static void qemu_rbd_parse_filename(const char *filename, QDict *options,
image_name = qemu_rbd_next_tok(p, ':', &p);
}
/* Check for namespace in the image_name */
if (strchr(image_name, '/')) {
if (qemu_rbd_strchr(image_name, '/')) {
found_str = qemu_rbd_next_tok(image_name, '/', &image_name);
qemu_rbd_unescape(found_str);
qdict_put_str(options, "namespace", found_str);

View File

@ -55,6 +55,10 @@ _filter_conf()
$QEMU_IMG info "json:{'file.driver':'rbd','file.filename':'rbd:rbd/bogus:conf=${BOGUS_CONF}'}" 2>&1 | _filter_conf
$QEMU_IMG info "json:{'file.driver':'rbd','file.pool':'rbd','file.image':'bogus','file.conf':'${BOGUS_CONF}'}" 2>&1 | _filter_conf
# Regression test: the qemu-img invocation is expected to fail, but it should
# not seg fault the parser.
$QEMU_IMG create "rbd:rbd/aa\/bb:conf=${BOGUS_CONF}" 1M 2>&1 | _filter_conf
# success, all done
echo "*** done"
rm -f $seq.full

View File

@ -4,4 +4,7 @@ unable to get monitor info from DNS SRV with service name: ceph-mon
qemu-img: Could not open 'json:{'file.driver':'rbd','file.filename':'rbd:rbd/bogus:conf=BOGUS_CONF'}': error connecting: No such file or directory
unable to get monitor info from DNS SRV with service name: ceph-mon
qemu-img: Could not open 'json:{'file.driver':'rbd','file.pool':'rbd','file.image':'bogus','file.conf':'BOGUS_CONF'}': error connecting: No such file or directory
Formatting 'rbd:rbd/aa\/bb:conf=BOGUS_CONF', fmt=raw size=1048576
unable to get monitor info from DNS SRV with service name: ceph-mon
qemu-img: rbd:rbd/aa\/bb:conf=BOGUS_CONF: error connecting: No such file or directory
*** done