[NETLINK]: Introduce NLMSG_NEW macro to better handle netlink flags
Introduces a new macro NLMSG_NEW which extends NLMSG_PUT but takes
a flags argument. NLMSG_PUT stays there for compatibility but now
calls NLMSG_NEW with flags == 0. NLMSG_PUT_ANSWER is renamed to
NLMSG_NEW_ANSWER which now also takes a flags argument.
Also converts the users of NLMSG_PUT_ANSWER to use NLMSG_NEW_ANSWER
and fixes the two direct users of __nlmsg_put to either provide
the flags or use NLMSG_NEW(_ANSWER).
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 8d1cb419..e38407a 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -156,7 +156,7 @@
};
static __inline__ struct nlmsghdr *
-__nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, int type, int len)
+__nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, int type, int len, int flags)
{
struct nlmsghdr *nlh;
int size = NLMSG_LENGTH(len);
@@ -164,20 +164,23 @@
nlh = (struct nlmsghdr*)skb_put(skb, NLMSG_ALIGN(size));
nlh->nlmsg_type = type;
nlh->nlmsg_len = size;
- nlh->nlmsg_flags = 0;
+ nlh->nlmsg_flags = flags;
nlh->nlmsg_pid = pid;
nlh->nlmsg_seq = seq;
return nlh;
}
-#define NLMSG_PUT(skb, pid, seq, type, len) \
+#define NLMSG_NEW(skb, pid, seq, type, len, flags) \
({ if (skb_tailroom(skb) < (int)NLMSG_SPACE(len)) \
goto nlmsg_failure; \
- __nlmsg_put(skb, pid, seq, type, len); })
+ __nlmsg_put(skb, pid, seq, type, len, flags); })
-#define NLMSG_PUT_ANSWER(skb, cb, type, len) \
- NLMSG_PUT(skb, NETLINK_CB((cb)->skb).pid, \
- (cb)->nlh->nlmsg_seq, type, len)
+#define NLMSG_PUT(skb, pid, seq, type, len) \
+ NLMSG_NEW(skb, pid, seq, type, len, 0)
+
+#define NLMSG_NEW_ANSWER(skb, cb, type, len, flags) \
+ NLMSG_NEW(skb, NETLINK_CB((cb)->skb).pid, \
+ (cb)->nlh->nlmsg_seq, type, len, flags)
#define NLMSG_END(skb, nlh) \
({ (nlh)->nlmsg_len = (skb)->tail - (unsigned char *) (nlh); \
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 2296a14..0fb742e 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1590,8 +1590,8 @@
struct nlmsghdr *nlh;
struct ndtmsg *ndtmsg;
- nlh = NLMSG_PUT_ANSWER(skb, cb, RTM_NEWNEIGHTBL, sizeof(struct ndtmsg));
- nlh->nlmsg_flags |= NLM_F_MULTI;
+ nlh = NLMSG_NEW_ANSWER(skb, cb, RTM_NEWNEIGHTBL, sizeof(struct ndtmsg),
+ NLM_F_MULTI);
ndtmsg = NLMSG_DATA(nlh);
@@ -1675,8 +1675,8 @@
struct ndtmsg *ndtmsg;
struct nlmsghdr *nlh;
- nlh = NLMSG_PUT_ANSWER(skb, cb, RTM_NEWNEIGHTBL, sizeof(struct ndtmsg));
- nlh->nlmsg_flags |= NLM_F_MULTI;
+ nlh = NLMSG_NEW_ANSWER(skb, cb, RTM_NEWNEIGHTBL, sizeof(struct ndtmsg),
+ NLM_F_MULTI);
ndtmsg = NLMSG_DATA(nlh);
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index e41ce45..70bcd47 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1095,8 +1095,7 @@
return 0;
}
- nlh = __nlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq, NLMSG_DONE, sizeof(int));
- nlh->nlmsg_flags |= NLM_F_MULTI;
+ nlh = NLMSG_NEW_ANSWER(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI);
memcpy(NLMSG_DATA(nlh), &len, sizeof(len));
skb_queue_tail(&sk->sk_receive_queue, skb);
sk->sk_data_ready(sk, skb->len);
@@ -1107,6 +1106,9 @@
netlink_destroy_callback(cb);
return 0;
+
+nlmsg_failure:
+ return -ENOBUFS;
}
int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
@@ -1178,7 +1180,7 @@
}
rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
- NLMSG_ERROR, sizeof(struct nlmsgerr));
+ NLMSG_ERROR, sizeof(struct nlmsgerr), 0);
errmsg = NLMSG_DATA(rep);
errmsg->error = err;
memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(struct nlmsghdr));
