[NETFILTER]: nfnetlink: parse attributes with nfattr_parse in nfnetlink_check_attribute

Use nfattr_parse to parse attributes, this patch also modifies the default
behaviour since unknown attributes will be ignored instead of returning
EINVAL. This ensure backward compatibility: new libraries with new
attributes and old kernels can work.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Pablo Neira Ayuso 2007-03-14 16:45:39 -07:00 committed by David S. Miller
parent c8e2078cfe
commit ac6d141dc7

View File

@ -151,26 +151,14 @@ nfnetlink_check_attributes(struct nfnetlink_subsystem *subsys,
struct nlmsghdr *nlh, struct nfattr *cda[])
{
int min_len = NLMSG_SPACE(sizeof(struct nfgenmsg));
u_int16_t attr_count;
u_int8_t cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type);
attr_count = subsys->cb[cb_id].attr_count;
memset(cda, 0, sizeof(struct nfattr *) * attr_count);
u_int16_t attr_count = subsys->cb[cb_id].attr_count;
/* check attribute lengths. */
if (likely(nlh->nlmsg_len > min_len)) {
struct nfattr *attr = NFM_NFA(NLMSG_DATA(nlh));
int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
while (NFA_OK(attr, attrlen)) {
unsigned flavor = NFA_TYPE(attr);
if (flavor) {
if (flavor > attr_count)
return -EINVAL;
cda[flavor - 1] = attr;
}
attr = NFA_NEXT(attr, attrlen);
}
nfattr_parse(cda, attr_count, attr, attrlen);
}
/* implicit: if nlmsg_len == min_len, we return 0, and an empty