diff options
Diffstat (limited to 'include/net/netlink.h')
| -rw-r--r-- | include/net/netlink.h | 35 |
1 files changed, 33 insertions, 2 deletions
diff --git a/include/net/netlink.h b/include/net/netlink.h index 02740a94f108..cb1f3504687f 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -192,8 +192,15 @@ enum { * NLA_NUL_STRING Maximum length of string (excluding NUL) * NLA_FLAG Unused * NLA_BINARY Maximum length of attribute payload - * NLA_NESTED_COMPAT Exact length of structure payload - * All other Exact length of attribute payload + * NLA_NESTED Don't use `len' field -- length verification is + * done by checking len of nested header (or empty) + * NLA_NESTED_COMPAT Minimum length of structure payload + * NLA_U8, NLA_U16, + * NLA_U32, NLA_U64, + * NLA_MSECS Leaving the length field zero will verify the + * given type fits, using it verifies minimum length + * just like "All other" + * All other Minimum length of attribute payload * * Example: * static const struct nla_policy my_policy[ATTR_MAX+1] = { @@ -638,6 +645,30 @@ static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 pid) nlmsg_ok(pos, rem); \ pos = nlmsg_next(pos, &(rem))) +/** + * nl_dump_check_consistent - check if sequence is consistent and advertise if not + * @cb: netlink callback structure that stores the sequence number + * @nlh: netlink message header to write the flag to + * + * This function checks if the sequence (generation) number changed during dump + * and if it did, advertises it in the netlink message header. + * + * The correct way to use it is to set cb->seq to the generation counter when + * all locks for dumping have been acquired, and then call this function for + * each message that is generated. + * + * Note that due to initialisation concerns, 0 is an invalid sequence number + * and must not be used by code that uses this functionality. + */ +static inline void +nl_dump_check_consistent(struct netlink_callback *cb, + struct nlmsghdr *nlh) +{ + if (cb->prev_seq && cb->seq != cb->prev_seq) + nlh->nlmsg_flags |= NLM_F_DUMP_INTR; + cb->prev_seq = cb->seq; +} + /************************************************************************** * Netlink Attributes **************************************************************************/ |