[INET_DIAG]: Introduce inet_twsk_diag_dump & inet_twsk_diag_fill

To properly dump TIME_WAIT sockets and to reduce complexity a bit by
having per socket class accessor routines.

Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: Arnaldo Carvalho de Melo

net/ipv4/inet_diag.c

@@ -70,20 +70,22 @@ static int inet_diag_fill(struct sk_buff *skb, struct sock *sk,
 	nlh->nlmsg_flags = nlmsg_flags;
 
 	r = NLMSG_DATA(nlh);
-	if (sk->sk_state != TCP_TIME_WAIT) {
-		if (ext & (1 << (INET_DIAG_MEMINFO - 1)))
-			minfo = INET_DIAG_PUT(skb, INET_DIAG_MEMINFO,
-					      sizeof(*minfo));
-		if (ext & (1 << (INET_DIAG_INFO - 1)))
-			info = INET_DIAG_PUT(skb, INET_DIAG_INFO,
-					   handler->idiag_info_size);
-
-		if ((ext & (1 << (INET_DIAG_CONG - 1))) && icsk->icsk_ca_ops) {
-			size_t len = strlen(icsk->icsk_ca_ops->name);
-			strcpy(INET_DIAG_PUT(skb, INET_DIAG_CONG, len + 1),
-			       icsk->icsk_ca_ops->name);
-		}
+	BUG_ON(sk->sk_state == TCP_TIME_WAIT);
+
+	if (ext & (1 << (INET_DIAG_MEMINFO - 1)))
+		minfo = INET_DIAG_PUT(skb, INET_DIAG_MEMINFO, sizeof(*minfo));
+
+	if (ext & (1 << (INET_DIAG_INFO - 1)))
+		info = INET_DIAG_PUT(skb, INET_DIAG_INFO,
+				     handler->idiag_info_size);
+
+	if ((ext & (1 << (INET_DIAG_CONG - 1))) && icsk->icsk_ca_ops) {
+		const size_t len = strlen(icsk->icsk_ca_ops->name);
+
+		strcpy(INET_DIAG_PUT(skb, INET_DIAG_CONG, len + 1),
+		       icsk->icsk_ca_ops->name);
 	}
+
 	r->idiag_family = sk->sk_family;
 	r->idiag_state = sk->sk_state;
 	r->idiag_timer = 0;
@@ -93,37 +95,6 @@ static int inet_diag_fill(struct sk_buff *skb, struct sock *sk,
 	r->id.idiag_cookie[0] = (u32)(unsigned long)sk;
 	r->id.idiag_cookie[1] = (u32)(((unsigned long)sk >> 31) >> 1);
 
-	if (r->idiag_state == TCP_TIME_WAIT) {
-		const struct inet_timewait_sock *tw = inet_twsk(sk);
-		long tmo = tw->tw_ttd - jiffies;
-		if (tmo < 0)
-			tmo = 0;
-
-		r->id.idiag_sport = tw->tw_sport;
-		r->id.idiag_dport = tw->tw_dport;
-		r->id.idiag_src[0] = tw->tw_rcv_saddr;
-		r->id.idiag_dst[0] = tw->tw_daddr;
-		r->idiag_state = tw->tw_substate;
-		r->idiag_timer = 3;
-		r->idiag_expires = (tmo * 1000 + HZ - 1) / HZ;
-		r->idiag_rqueue = 0;
-		r->idiag_wqueue = 0;
-		r->idiag_uid = 0;
-		r->idiag_inode = 0;
-#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
-		if (r->idiag_family == AF_INET6) {
-			const struct inet6_timewait_sock *tw6 = inet6_twsk(sk);
-
-			ipv6_addr_copy((struct in6_addr *)r->id.idiag_src,
-				       &tw6->tw_v6_rcv_saddr);
-			ipv6_addr_copy((struct in6_addr *)r->id.idiag_dst,
-				       &tw6->tw_v6_daddr);
-		}
-#endif
-		nlh->nlmsg_len = skb->tail - b;
-		return skb->len;
-	}
-
 	r->id.idiag_sport = inet->sport;
 	r->id.idiag_dport = inet->dport;
 	r->id.idiag_src[0] = inet->rcv_saddr;
@@ -185,6 +156,62 @@ static int inet_diag_fill(struct sk_buff *skb, struct sock *sk,
 	return -1;
 }
 
+static int inet_twsk_diag_fill(struct inet_timewait_sock *tw,
+			       struct sk_buff *skb, int ext, u32 pid,
+			       u32 seq, u16 nlmsg_flags,
+			       const struct nlmsghdr *unlh)
+{
+	long tmo;
+	struct inet_diag_msg *r;
+	const unsigned char *previous_tail = skb->tail;
+	struct nlmsghdr *nlh = NLMSG_PUT(skb, pid, seq,
+					 unlh->nlmsg_type, sizeof(*r));
+
+	r = NLMSG_DATA(nlh);
+	BUG_ON(tw->tw_state != TCP_TIME_WAIT);
+
+	nlh->nlmsg_flags = nlmsg_flags;
+
+	tmo = tw->tw_ttd - jiffies;
+	if (tmo < 0)
+		tmo = 0;
+
+	r->idiag_family	      = tw->tw_family;
+	r->idiag_state	      = tw->tw_state;
+	r->idiag_timer	      = 0;
+	r->idiag_retrans      = 0;
+	r->id.idiag_if	      = tw->tw_bound_dev_if;
+	r->id.idiag_cookie[0] = (u32)(unsigned long)tw;
+	r->id.idiag_cookie[1] = (u32)(((unsigned long)tw >> 31) >> 1);
+	r->id.idiag_sport     = tw->tw_sport;
+	r->id.idiag_dport     = tw->tw_dport;
+	r->id.idiag_src[0]    = tw->tw_rcv_saddr;
+	r->id.idiag_dst[0]    = tw->tw_daddr;
+	r->idiag_state	      = tw->tw_substate;
+	r->idiag_timer	      = 3;
+	r->idiag_expires      = (tmo * 1000 + HZ - 1) / HZ;
+	r->idiag_rqueue	      = 0;
+	r->idiag_wqueue	      = 0;
+	r->idiag_uid	      = 0;
+	r->idiag_inode	      = 0;
+#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+	if (tw->tw_family == AF_INET6) {
+		const struct inet6_timewait_sock *tw6 =
+						inet6_twsk((struct sock *)tw);
+
+		ipv6_addr_copy((struct in6_addr *)r->id.idiag_src,
+			       &tw6->tw_v6_rcv_saddr);
+		ipv6_addr_copy((struct in6_addr *)r->id.idiag_dst,
+			       &tw6->tw_v6_daddr);
+	}
+#endif
+	nlh->nlmsg_len = skb->tail - previous_tail;
+	return skb->len;
+nlmsg_failure:
+	skb_trim(skb, previous_tail - skb->data);
+	return -1;
+}
+
 static int inet_diag_get_exact(struct sk_buff *in_skb,
 			       const struct nlmsghdr *nlh)
 {
@@ -450,6 +477,42 @@ static int inet_diag_dump_sock(struct sk_buff *skb, struct sock *sk,
 			      cb->nlh->nlmsg_seq, NLM_F_MULTI, cb->nlh);
 }
 
+static int inet_twsk_diag_dump(struct inet_timewait_sock *tw,
+			       struct sk_buff *skb,
+			       struct netlink_callback *cb)
+{
+	struct inet_diag_req *r = NLMSG_DATA(cb->nlh);
+
+	if (cb->nlh->nlmsg_len > 4 + NLMSG_SPACE(sizeof(*r))) {
+		struct inet_diag_entry entry;
+		struct rtattr *bc = (struct rtattr *)(r + 1);
+
+		entry.family = tw->tw_family;
+#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+		if (tw->tw_family == AF_INET6) {
+			struct inet6_timewait_sock *tw6 =
+						inet6_twsk((struct sock *)tw);
+			entry.saddr = tw6->tw_v6_rcv_saddr.s6_addr32;
+			entry.daddr = tw6->tw_v6_daddr.s6_addr32;
+		} else
+#endif
+		{
+			entry.saddr = &tw->tw_rcv_saddr;
+			entry.daddr = &tw->tw_daddr;
+		}
+		entry.sport = tw->tw_num;
+		entry.dport = ntohs(tw->tw_dport);
+		entry.userlocks = 0; 
+
+		if (!inet_diag_bc_run(RTA_DATA(bc), RTA_PAYLOAD(bc), &entry))
+			return 0;
+	}
+
+	return inet_twsk_diag_fill(tw, skb, r->idiag_ext,
+				   NETLINK_CB(cb->skb).pid,
+				   cb->nlh->nlmsg_seq, NLM_F_MULTI, cb->nlh);
+}
+
 static int inet_diag_fill_req(struct sk_buff *skb, struct sock *sk,
 			      struct request_sock *req, u32 pid, u32 seq,
 			      const struct nlmsghdr *unlh)
@@ -696,9 +759,10 @@ static int inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
 		}
 
 		if (r->idiag_states & TCPF_TIME_WAIT) {
-			sk_for_each(sk, node,
+			struct inet_timewait_sock *tw;
+
+			inet_twsk_for_each(tw, node,
 				    &hashinfo->ehash[i + hashinfo->ehash_size].chain) {
-				const struct inet_timewait_sock *tw = inet_twsk(sk);
 
 				if (num < s_num)
 					goto next_dying;
@@ -708,7 +772,7 @@ static int inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
 				if (r->id.idiag_dport != tw->tw_dport &&
 				    r->id.idiag_dport)
 					goto next_dying;
-				if (inet_diag_dump_sock(skb, sk, cb) < 0) {
+				if (inet_twsk_diag_dump(tw, skb, cb) < 0) {
 					read_unlock_bh(&head->lock);
 					goto done;
 				}