inet: Use fallthrough;

Convert the various uses of fallthrough comments to fallthrough;

Done via script
Link: https://lore.kernel.org/lkml/b56602fcf79f849e733e7b521bb0e17895d390fa.1582230379.git.joe@perches.com/

And by hand:

net/ipv6/ip6_fib.c has a fallthrough comment outside of an #ifdef block
that causes gcc to emit a warning if converted in-place.

So move the new fallthrough; inside the containing #ifdef/#endif too.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/af_inet.c

@@ -872,7 +872,7 @@ int inet_shutdown(struct socket *sock, int how)
 		err = -ENOTCONN;
 		/* Hack to wake up other listeners, who can poll for
 		   EPOLLHUP, even on eg. unconnected UDP sockets -- RR */
-		/* fall through */
+		fallthrough;
 	default:
 		sk->sk_shutdown |= how;
 		if (sk->sk_prot->shutdown)
@@ -886,7 +886,7 @@ int inet_shutdown(struct socket *sock, int how)
 	case TCP_LISTEN:
 		if (!(how & RCV_SHUTDOWN))
 			break;
-		/* fall through */
+		fallthrough;
 	case TCP_SYN_SENT:
 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;

net/ipv4/ah4.c

@@ -107,7 +107,7 @@ static int ip_clear_mutable_options(const struct iphdr *iph, __be32 *daddr)
 			if (optlen < 6)
 				return -EINVAL;
 			memcpy(daddr, optptr+optlen-4, 4);
-			/* Fall through */
+			fallthrough;
 		default:
 			memset(optptr, 0, optlen);
 		}

net/ipv4/arp.c

@@ -1181,7 +1181,7 @@ int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg)
 	case SIOCSARP:
 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 			return -EPERM;
-		/* fall through */
+		fallthrough;
 	case SIOCGARP:
 		err = copy_from_user(&r, arg, sizeof(struct arpreq));
 		if (err)

net/ipv4/devinet.c

@@ -1566,11 +1566,11 @@ static int inetdev_event(struct notifier_block *this, unsigned long event,
 			}
 		}
 		ip_mc_up(in_dev);
-		/* fall through */
+		fallthrough;
 	case NETDEV_CHANGEADDR:
 		if (!IN_DEV_ARP_NOTIFY(in_dev))
 			break;
-		/* fall through */
+		fallthrough;
 	case NETDEV_NOTIFY_PEERS:
 		/* Send gratuitous ARP to notify of link change */
 		inetdev_send_gratuitous_arp(dev, in_dev);
@@ -1588,7 +1588,7 @@ static int inetdev_event(struct notifier_block *this, unsigned long event,
 		if (inetdev_valid_mtu(dev->mtu))
 			break;
 		/* disable IP when MTU is not enough */
-		/* fall through */
+		fallthrough;
 	case NETDEV_UNREGISTER:
 		inetdev_destroy(in_dev);
 		break;

net/ipv4/fib_semantics.c

@@ -1962,7 +1962,7 @@ int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force)
 				case NETDEV_DOWN:
 				case NETDEV_UNREGISTER:
 					nexthop_nh->fib_nh_flags |= RTNH_F_DEAD;
-					/* fall through */
+					fallthrough;
 				case NETDEV_CHANGE:
 					nexthop_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
 					break;
@@ -1984,7 +1984,7 @@ int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force)
 			case NETDEV_DOWN:
 			case NETDEV_UNREGISTER:
 				fi->fib_flags |= RTNH_F_DEAD;
-				/* fall through */
+				fallthrough;
 			case NETDEV_CHANGE:
 				fi->fib_flags |= RTNH_F_LINKDOWN;
 				break;

net/ipv4/icmp.c

@@ -865,7 +865,7 @@ static bool icmp_unreach(struct sk_buff *skb)
 			case 3:
 				if (!icmp_tag_validation(iph->protocol))
 					goto out;
-				/* fall through */
+				fallthrough;
 			case 0:
 				info = ntohs(icmph->un.frag.mtu);
 			}

net/ipv4/ip_output.c

@@ -333,7 +333,7 @@ static int ip_mc_finish_output(struct net *net, struct sock *sk,
 	switch (ret) {
 	case NET_XMIT_CN:
 		do_cn = true;
-		/* fall through */
+		fallthrough;
 	case NET_XMIT_SUCCESS:
 		break;
 	default:

net/ipv4/ipmr.c

@@ -1465,7 +1465,7 @@ int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval,
 	case MRT_ADD_MFC:
 	case MRT_DEL_MFC:
 		parent = -1;
-		/* fall through */
+		fallthrough;
 	case MRT_ADD_MFC_PROXY:
 	case MRT_DEL_MFC_PROXY:
 		if (optlen != sizeof(mfc)) {

net/ipv4/netfilter/nf_log_ipv4.c

@@ -173,7 +173,7 @@ static void dump_ipv4_packet(struct net *net, struct nf_log_buf *m,
 		case ICMP_REDIRECT:
 			/* Max length: 24 "GATEWAY=255.255.255.255 " */
 			nf_log_buf_add(m, "GATEWAY=%pI4 ", &ich->un.gateway);
-			/* Fall through */
+			fallthrough;
 		case ICMP_DEST_UNREACH:
 		case ICMP_SOURCE_QUENCH:
 		case ICMP_TIME_EXCEEDED:

net/ipv4/netfilter/nf_nat_pptp.c

@@ -168,7 +168,7 @@ pptp_outbound_pkt(struct sk_buff *skb,
 		pr_debug("unknown outbound packet 0x%04x:%s\n", msg,
 			 msg <= PPTP_MSG_MAX ? pptp_msg_name[msg] :
 					       pptp_msg_name[0]);
-		/* fall through */
+		fallthrough;
 	case PPTP_SET_LINK_INFO:
 		/* only need to NAT in case PAC is behind NAT box */
 	case PPTP_START_SESSION_REQUEST:
@@ -271,7 +271,7 @@ pptp_inbound_pkt(struct sk_buff *skb,
 		pr_debug("unknown inbound packet %s\n",
 			 msg <= PPTP_MSG_MAX ? pptp_msg_name[msg] :
 					       pptp_msg_name[0]);
-		/* fall through */
+		fallthrough;
 	case PPTP_START_SESSION_REQUEST:
 	case PPTP_START_SESSION_REPLY:
 	case PPTP_STOP_SESSION_REQUEST:

net/ipv4/nexthop.c

@@ -1327,7 +1327,7 @@ static int rtm_to_nh_config(struct net *net, struct sk_buff *skb,
 	case AF_UNSPEC:
 		if (tb[NHA_GROUP])
 			break;
-		/* fallthrough */
+		fallthrough;
 	default:
 		NL_SET_ERR_MSG(extack, "Invalid address family");
 		goto out;

net/ipv4/tcp.c

@@ -2251,7 +2251,7 @@ void tcp_set_state(struct sock *sk, int state)
 		if (inet_csk(sk)->icsk_bind_hash &&
 		    !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
 			inet_put_port(sk);
-		/* fall through */
+		fallthrough;
 	default:
 		if (oldstate == TCP_ESTABLISHED)
 			TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);

net/ipv4/tcp_input.c

@@ -2865,7 +2865,7 @@ static void tcp_fastretrans_alert(struct sock *sk, const u32 prior_snd_una,
 		      (*ack_flag & FLAG_LOST_RETRANS)))
 			return;
 		/* Change state if cwnd is undone or retransmits are lost */
-		/* fall through */
+		fallthrough;
 	default:
 		if (tcp_is_reno(tp)) {
 			if (flag & FLAG_SND_UNA_ADVANCED)
@@ -6367,7 +6367,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
 				mptcp_incoming_options(sk, skb, &tp->rx_opt);
 			break;
 		}
-		/* fall through */
+		fallthrough;
 	case TCP_FIN_WAIT1:
 	case TCP_FIN_WAIT2:
 		/* RFC 793 says to queue data in these states,
@@ -6382,7 +6382,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
 				return 1;
 			}
 		}
-		/* Fall through */
+		fallthrough;
 	case TCP_ESTABLISHED:
 		tcp_data_queue(sk, skb);
 		queued = 1;

net/ipv4/tcp_ipv4.c

@@ -2072,7 +2072,7 @@ int tcp_v4_rcv(struct sk_buff *skb)
 		}
 	}
 		/* to ACK */
-		/* fall through */
+		fallthrough;
 	case TCP_TW_ACK:
 		tcp_v4_timewait_ack(sk, skb);
 		break;
@@ -2368,7 +2368,7 @@ static void *tcp_seek_last_pos(struct seq_file *seq)
 			break;
 		st->bucket = 0;
 		st->state = TCP_SEQ_STATE_ESTABLISHED;
-		/* Fallthrough */
+		fallthrough;
 	case TCP_SEQ_STATE_ESTABLISHED:
 		if (st->bucket > tcp_hashinfo.ehash_mask)
 			break;

net/ipv4/udp.c

@@ -2563,7 +2563,7 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
 		case UDP_ENCAP_ESPINUDP_NON_IKE:
 			up->encap_rcv = xfrm4_udp_encap_rcv;
 #endif
-			/* FALLTHROUGH */
+			fallthrough;
 		case UDP_ENCAP_L2TPINUDP:
 			up->encap_type = val;
 			lock_sock(sk);

net/ipv6/addrconf.c

@@ -3299,7 +3299,7 @@ static void addrconf_addr_gen(struct inet6_dev *idev, bool prefix_route)
 	switch (idev->cnf.addr_gen_mode) {
 	case IN6_ADDR_GEN_MODE_RANDOM:
 		ipv6_gen_mode_random_init(idev);
-		/* fallthrough */
+		fallthrough;
 	case IN6_ADDR_GEN_MODE_STABLE_PRIVACY:
 		if (!ipv6_generate_stable_address(&addr, 0, idev))
 			addrconf_add_linklocal(idev, &addr,
@@ -3517,9 +3517,7 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event,
 			break;
 
 		run_pending = 1;
-
-		/* fall through */
-
+		fallthrough;
 	case NETDEV_UP:
 	case NETDEV_CHANGE:
 		if (dev->flags & IFF_SLAVE)

net/ipv6/ah6.c

@@ -259,7 +259,7 @@ static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir)
 		case NEXTHDR_DEST:
 			if (dir == XFRM_POLICY_OUT)
 				ipv6_rearrange_destopt(iph, exthdr.opth);
-			/* fall through */
+			fallthrough;
 		case NEXTHDR_HOP:
 			if (!zero_out_mutable_opts(exthdr.opth)) {
 				net_dbg_ratelimited("overrun %sopts\n",

net/ipv6/exthdrs.c

@@ -97,7 +97,7 @@ static bool ip6_tlvopt_unknown(struct sk_buff *skb, int optoff,
 		 */
 		if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr))
 			break;
-		/* fall through */
+		fallthrough;
 	case 2: /* send ICMP PARM PROB regardless and drop packet */
 		icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff);
 		return false;

net/ipv6/icmp.c

@@ -898,7 +898,7 @@ static int icmpv6_rcv(struct sk_buff *skb)
 		hdr = icmp6_hdr(skb);
 
 		/* to notify */
-		/* fall through */
+		fallthrough;
 	case ICMPV6_DEST_UNREACH:
 	case ICMPV6_TIME_EXCEED:
 	case ICMPV6_PARAMPROB:

net/ipv6/ip6_fib.c

@@ -2068,8 +2068,8 @@ static int fib6_walk_continue(struct fib6_walker *w)
 				continue;
 			}
 			w->state = FWS_L;
+			fallthrough;
 #endif
-			/* fall through */
 		case FWS_L:
 			left = rcu_dereference_protected(fn->left, 1);
 			if (left) {
@@ -2078,7 +2078,7 @@ static int fib6_walk_continue(struct fib6_walker *w)
 				continue;
 			}
 			w->state = FWS_R;
-			/* fall through */
+			fallthrough;
 		case FWS_R:
 			right = rcu_dereference_protected(fn->right, 1);
 			if (right) {
@@ -2088,7 +2088,7 @@ static int fib6_walk_continue(struct fib6_walker *w)
 			}
 			w->state = FWS_C;
 			w->leaf = rcu_dereference_protected(fn->leaf, 1);
-			/* fall through */
+			fallthrough;
 		case FWS_C:
 			if (w->leaf && fn->fn_flags & RTN_RTINFO) {
 				int err;
@@ -2107,7 +2107,7 @@ static int fib6_walk_continue(struct fib6_walker *w)
 			}
 skip:
 			w->state = FWS_U;
-			/* fall through */
+			fallthrough;
 		case FWS_U:
 			if (fn == w->root)
 				return 0;

net/ipv6/ip6mr.c

@@ -1691,7 +1691,7 @@ int ip6_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, uns
 	case MRT6_ADD_MFC:
 	case MRT6_DEL_MFC:
 		parent = -1;
-		/* fall through */
+		fallthrough;
 	case MRT6_ADD_MFC_PROXY:
 	case MRT6_DEL_MFC_PROXY:
 		if (optlen < sizeof(mfc))

net/ipv6/ndisc.c

@@ -1782,7 +1782,7 @@ static int ndisc_netdev_event(struct notifier_block *this, unsigned long event,
 	case NETDEV_CHANGEADDR:
 		neigh_changeaddr(&nd_tbl, dev);
 		fib6_run_gc(0, net, false);
-		/* fallthrough */
+		fallthrough;
 	case NETDEV_UP:
 		idev = in6_dev_get(dev);
 		if (!idev)

net/ipv6/netfilter/nf_log_ipv6.c

@@ -248,7 +248,7 @@ static void dump_ipv6_packet(struct net *net, struct nf_log_buf *m,
 			/* Max length: 17 "POINTER=ffffffff " */
 			nf_log_buf_add(m, "POINTER=%08x ",
 				       ntohl(ic->icmp6_pointer));
-			/* Fall through */
+			fallthrough;
 		case ICMPV6_DEST_UNREACH:
 		case ICMPV6_PKT_TOOBIG:
 		case ICMPV6_TIME_EXCEED:

net/ipv6/raw.c

@@ -1076,7 +1076,7 @@ static int rawv6_setsockopt(struct sock *sk, int level, int optname,
 		if (optname == IPV6_CHECKSUM ||
 		    optname == IPV6_HDRINCL)
 			break;
-		/* fall through */
+		fallthrough;
 	default:
 		return ipv6_setsockopt(sk, level, optname, optval, optlen);
 	}
@@ -1099,7 +1099,7 @@ static int compat_rawv6_setsockopt(struct sock *sk, int level, int optname,
 		if (optname == IPV6_CHECKSUM ||
 		    optname == IPV6_HDRINCL)
 			break;
-		/* fall through */
+		fallthrough;
 	default:
 		return compat_ipv6_setsockopt(sk, level, optname,
 					      optval, optlen);
@@ -1161,7 +1161,7 @@ static int rawv6_getsockopt(struct sock *sk, int level, int optname,
 		if (optname == IPV6_CHECKSUM ||
 		    optname == IPV6_HDRINCL)
 			break;
-		/* fall through */
+		fallthrough;
 	default:
 		return ipv6_getsockopt(sk, level, optname, optval, optlen);
 	}
@@ -1184,7 +1184,7 @@ static int compat_rawv6_getsockopt(struct sock *sk, int level, int optname,
 		if (optname == IPV6_CHECKSUM ||
 		    optname == IPV6_HDRINCL)
 			break;
-		/* fall through */
+		fallthrough;
 	default:
 		return compat_ipv6_getsockopt(sk, level, optname,
 					      optval, optlen);

net/ipv6/route.c

@@ -4370,7 +4370,7 @@ static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes)
 			IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
 			break;
 		}
-		/* FALLTHROUGH */
+		fallthrough;
 	case IPSTATS_MIB_OUTNOROUTES:
 		IP6_INC_STATS(net, idev, ipstats_mib_noroutes);
 		break;

net/ipv6/tcp_ipv6.c

@@ -1742,7 +1742,7 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
 		}
 	}
 		/* to ACK */
-		/* fall through */
+		fallthrough;
 	case TCP_TW_ACK:
 		tcp_v6_timewait_ack(sk, skb);
 		break;