[NETFILTER]: cleanup nfnetlink_check_attributes()

1) memset return parameter 'cda' (nfattr pointer array) only on success
2) a message without attributes and just a 'struct nfgenmsg' is valid,
   don't return -EINVAL
3) use likely() and unlikely() where apropriate

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Harald Welte 2005-08-09 20:03:54 -07:00 committed by David S. Miller
parent 927ccbcc28
commit a42827b71b

View File

@ -163,17 +163,16 @@ nfnetlink_check_attributes(struct nfnetlink_subsystem *subsys,
cb_id, subsys->cb_count);
return -EINVAL;
}
attr_count = subsys->cb[cb_id].attr_count;
min_len = NLMSG_ALIGN(sizeof(struct nfgenmsg));
if (unlikely(nlh->nlmsg_len < min_len))
return -EINVAL;
attr_count = subsys->cb[cb_id].attr_count;
memset(cda, 0, sizeof(struct nfattr *) * attr_count);
/* check attribute lengths. */
min_len = NLMSG_ALIGN(sizeof(struct nfgenmsg));
if (nlh->nlmsg_len < min_len)
return -EINVAL;
if (nlh->nlmsg_len > min_len) {
if (likely(nlh->nlmsg_len > min_len)) {
struct nfattr *attr = NFM_NFA(NLMSG_DATA(nlh));
int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
@ -186,8 +185,10 @@ nfnetlink_check_attributes(struct nfnetlink_subsystem *subsys,
}
attr = NFA_NEXT(attr, attrlen);
}
} else
return -EINVAL;
}
/* implicit: if nlmsg_len == min_len, we return 0, and an empty
* (zeroed) cda[] array. The message is valid, but empty. */
return 0;
}