ipv4: coding style: comparison for inequality with NULL

The ipv4 code uses a mixture of coding styles. In some instances check
for non-NULL pointer is done as x != NULL and sometimes as x. x is
preferred according to checkpatch and this patch makes the code
consistent by adopting the latter form.

No changes detected by objdiff.

Signed-off-by: Ian Morris <ipm@chirality.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/af_inet.c

@@ -1269,7 +1269,7 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
 		if (udpfrag) {
 			iph->id = htons(id);
 			iph->frag_off = htons(offset >> 3);
-			if (skb->next != NULL)
+			if (skb->next)
 				iph->frag_off |= htons(IP_MF);
 			offset += skb->len - nhoff - ihl;
 		} else {

net/ipv4/arp.c

@@ -569,7 +569,7 @@ struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,
 		break;
 #endif
 	default:
-		if (target_hw != NULL)
+		if (target_hw)
 			memcpy(arp_ptr, target_hw, dev->addr_len);
 		else
 			memset(arp_ptr, 0, dev->addr_len);

net/ipv4/cipso_ipv4.c

@@ -502,7 +502,7 @@ int cipso_v4_doi_add(struct cipso_v4_doi *doi_def,
 	atomic_set(&doi_def->refcount, 1);
 
 	spin_lock(&cipso_v4_doi_list_lock);
-	if (cipso_v4_doi_search(doi_def->doi) != NULL) {
+	if (cipso_v4_doi_search(doi_def->doi)) {
 		spin_unlock(&cipso_v4_doi_list_lock);
 		ret_val = -EEXIST;
 		goto doi_add_return;
@@ -513,7 +513,7 @@ int cipso_v4_doi_add(struct cipso_v4_doi *doi_def,
 
 doi_add_return:
 	audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_ADD, audit_info);
-	if (audit_buf != NULL) {
+	if (audit_buf) {
 		const char *type_str;
 		switch (doi_type) {
 		case CIPSO_V4_MAP_TRANS:
@@ -617,7 +617,7 @@ int cipso_v4_doi_remove(u32 doi, struct netlbl_audit *audit_info)
 
 doi_remove_return:
 	audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_DEL, audit_info);
-	if (audit_buf != NULL) {
+	if (audit_buf) {
 		audit_log_format(audit_buf,
 				 " cipso_doi=%u res=%u",
 				 doi, ret_val == 0 ? 1 : 0);

net/ipv4/devinet.c

@@ -1290,7 +1290,7 @@ __be32 inet_confirm_addr(struct net *net, struct in_device *in_dev,
 	__be32 addr = 0;
 	struct net_device *dev;
 
-	if (in_dev != NULL)
+	if (in_dev)
 		return confirm_addr_indev(in_dev, dst, local, scope);
 
 	rcu_read_lock();

net/ipv4/fib_trie.c

@@ -391,9 +391,9 @@ static void put_child(struct key_vector *tn, unsigned long i,
 	BUG_ON(i >= child_length(tn));
 
 	/* update emptyChildren, overflow into fullChildren */
-	if (!n && chi != NULL)
+	if (!n && chi)
 		empty_child_inc(tn);
-	if (n != NULL && !chi)
+	if (n && !chi)
 		empty_child_dec(tn);
 
 	/* update fullChildren */

net/ipv4/geneve.c

@@ -230,7 +230,7 @@ static int geneve_gro_complete(struct sk_buff *skb, int nhoff,
 
 	rcu_read_lock();
 	ptype = gro_find_complete_by_type(type);
-	if (ptype != NULL)
+	if (ptype)
 		err = ptype->callbacks.gro_complete(skb, nhoff + gh_len);
 
 	rcu_read_unlock();

net/ipv4/gre_offload.c

@@ -243,7 +243,7 @@ static int gre_gro_complete(struct sk_buff *skb, int nhoff)
 
 	rcu_read_lock();
 	ptype = gro_find_complete_by_type(type);
-	if (ptype != NULL)
+	if (ptype)
 		err = ptype->callbacks.gro_complete(skb, nhoff + grehlen);
 
 	rcu_read_unlock();

net/ipv4/igmp.c

@@ -2370,7 +2370,7 @@ void ip_mc_drop_socket(struct sock *sk)
 		inet->mc_list = iml->next_rcu;
 		in_dev = inetdev_by_index(net, iml->multi.imr_ifindex);
 		(void) ip_mc_leave_src(sk, iml, in_dev);
-		if (in_dev != NULL)
+		if (in_dev)
 			ip_mc_dec_group(in_dev, iml->multi.imr_multiaddr.s_addr);
 		/* decrease mem now to avoid the memleak warning */
 		atomic_sub(sizeof(*iml), &sk->sk_omem_alloc);
@@ -2590,10 +2590,10 @@ static inline struct ip_sf_list *igmp_mcf_get_first(struct seq_file *seq)
 		if (unlikely(!idev))
 			continue;
 		im = rcu_dereference(idev->mc_list);
-		if (likely(im != NULL)) {
+		if (likely(im)) {
 			spin_lock_bh(&im->lock);
 			psf = im->sources;
-			if (likely(psf != NULL)) {
+			if (likely(psf)) {
 				state->im = im;
 				state->idev = idev;
 				break;
@@ -2663,7 +2663,7 @@ static void igmp_mcf_seq_stop(struct seq_file *seq, void *v)
 	__releases(rcu)
 {
 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
-	if (likely(state->im != NULL)) {
+	if (likely(state->im)) {
 		spin_unlock_bh(&state->im->lock);
 		state->im = NULL;
 	}

net/ipv4/inet_connection_sock.c

@@ -673,7 +673,7 @@ struct sock *inet_csk_clone_lock(const struct sock *sk,
 {
 	struct sock *newsk = sk_clone_lock(sk, priority);
 
-	if (newsk != NULL) {
+	if (newsk) {
 		struct inet_connection_sock *newicsk = inet_csk(newsk);
 
 		newsk->sk_state = TCP_SYN_RECV;
@@ -843,7 +843,7 @@ void inet_csk_listen_stop(struct sock *sk)
 		sk_acceptq_removed(sk);
 		reqsk_put(req);
 	}
-	if (queue->fastopenq != NULL) {
+	if (queue->fastopenq) {
 		/* Free all the reqs queued in rskq_rst_head. */
 		spin_lock_bh(&queue->fastopenq->lock);
 		acc_req = queue->fastopenq->rskq_rst_head;
@@ -875,7 +875,7 @@ int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
 {
 	const struct inet_connection_sock *icsk = inet_csk(sk);
 
-	if (icsk->icsk_af_ops->compat_getsockopt != NULL)
+	if (icsk->icsk_af_ops->compat_getsockopt)
 		return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
 							    optval, optlen);
 	return icsk->icsk_af_ops->getsockopt(sk, level, optname,
@@ -888,7 +888,7 @@ int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
 {
 	const struct inet_connection_sock *icsk = inet_csk(sk);
 
-	if (icsk->icsk_af_ops->compat_setsockopt != NULL)
+	if (icsk->icsk_af_ops->compat_setsockopt)
 		return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
 							    optval, optlen);
 	return icsk->icsk_af_ops->setsockopt(sk, level, optname,

net/ipv4/inet_hashtables.c

@@ -64,7 +64,7 @@ struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep,
 {
 	struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC);
 
-	if (tb != NULL) {
+	if (tb) {
 		write_pnet(&tb->ib_net, net);
 		tb->port      = snum;
 		tb->fastreuse = 0;

net/ipv4/inet_timewait_sock.c

@@ -173,7 +173,7 @@ struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, const int stat
 	struct inet_timewait_sock *tw =
 		kmem_cache_alloc(sk->sk_prot_creator->twsk_prot->twsk_slab,
 				 GFP_ATOMIC);
-	if (tw != NULL) {
+	if (tw) {
 		const struct inet_sock *inet = inet_sk(sk);
 
 		kmemcheck_annotate_bitfield(tw, flags);

net/ipv4/ip_fragment.c

@@ -639,7 +639,8 @@ int ip_defrag(struct sk_buff *skb, u32 user)
 	IP_INC_STATS_BH(net, IPSTATS_MIB_REASMREQDS);
 
 	/* Lookup (or create) queue header */
-	if ((qp = ip_find(net, ip_hdr(skb), user)) != NULL) {
+	qp = ip_find(net, ip_hdr(skb), user);
+	if (qp) {
 		int ret;
 
 		spin_lock(&qp->q.lock);

net/ipv4/ip_input.c

@@ -203,7 +203,7 @@ static int ip_local_deliver_finish(struct sk_buff *skb)
 		raw = raw_local_deliver(skb, protocol);
 
 		ipprot = rcu_dereference(inet_protos[protocol]);
-		if (ipprot != NULL) {
+		if (ipprot) {
 			int ret;
 
 			if (!ipprot->no_policy) {

net/ipv4/ip_options.c

@@ -264,7 +264,7 @@ int ip_options_compile(struct net *net,
 	unsigned char *iph;
 	int optlen, l;
 
-	if (skb != NULL) {
+	if (skb) {
 		rt = skb_rtable(skb);
 		optptr = (unsigned char *)&(ip_hdr(skb)[1]);
 	} else

net/ipv4/ip_output.c

@@ -257,7 +257,7 @@ static int ip_finish_output(struct sk_buff *skb)
 {
 #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM)
 	/* Policy lookup after SNAT yielded a new policy */
-	if (skb_dst(skb)->xfrm != NULL) {
+	if (skb_dst(skb)->xfrm) {
 		IPCB(skb)->flags |= IPSKB_REROUTED;
 		return dst_output(skb);
 	}
@@ -376,7 +376,7 @@ int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl)
 	inet_opt = rcu_dereference(inet->inet_opt);
 	fl4 = &fl->u.ip4;
 	rt = skb_rtable(skb);
-	if (rt != NULL)
+	if (rt)
 		goto packet_routed;
 
 	/* Make sure we can route this packet. */
@@ -587,7 +587,7 @@ int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
 					ip_options_fragment(frag);
 				offset += skb->len - hlen;
 				iph->frag_off = htons(offset>>3);
-				if (frag->next != NULL)
+				if (frag->next)
 					iph->frag_off |= htons(IP_MF);
 				/* Ready, complete checksum */
 				ip_send_check(iph);

net/ipv4/ip_sockglue.c

@@ -387,7 +387,7 @@ void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 				   skb_network_header(skb);
 	serr->port = port;
 
-	if (skb_pull(skb, payload - skb->data) != NULL) {
+	if (skb_pull(skb, payload - skb->data)) {
 		skb_reset_transport_header(skb);
 		if (sock_queue_err_skb(sk, skb) == 0)
 			return;

net/ipv4/ip_tunnel.c

@@ -876,7 +876,7 @@ int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)
 			break;
 		}
 		if (dev != itn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
-			if (t != NULL) {
+			if (t) {
 				if (t->dev != dev) {
 					err = -EEXIST;
 					break;

net/ipv4/ip_vti.c

@@ -60,7 +60,7 @@ static int vti_input(struct sk_buff *skb, int nexthdr, __be32 spi,
 
 	tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
 				  iph->saddr, iph->daddr, 0);
-	if (tunnel != NULL) {
+	if (tunnel) {
 		if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
 			goto drop;
 

net/ipv4/ipmr.c

@@ -316,7 +316,7 @@ static struct mr_table *ipmr_new_table(struct net *net, u32 id)
 	unsigned int i;
 
 	mrt = ipmr_get_table(net, id);
-	if (mrt != NULL)
+	if (mrt)
 		return mrt;
 
 	mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);

net/ipv4/ping.c

@@ -971,7 +971,7 @@ bool ping_rcv(struct sk_buff *skb)
 	skb_push(skb, skb->data - (u8 *)icmph);
 
 	sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
-	if (sk != NULL) {
+	if (sk) {
 		struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 
 		pr_debug("rcv on socket %p\n", sk);

net/ipv4/raw.c

@@ -293,7 +293,7 @@ void raw_icmp_error(struct sk_buff *skb, int protocol, u32 info)
 
 	read_lock(&raw_v4_hashinfo.lock);
 	raw_sk = sk_head(&raw_v4_hashinfo.ht[hash]);
-	if (raw_sk != NULL) {
+	if (raw_sk) {
 		iph = (const struct iphdr *)skb->data;
 		net = dev_net(skb->dev);
 
@@ -872,7 +872,7 @@ static int raw_ioctl(struct sock *sk, int cmd, unsigned long arg)
 
 		spin_lock_bh(&sk->sk_receive_queue.lock);
 		skb = skb_peek(&sk->sk_receive_queue);
-		if (skb != NULL)
+		if (skb)
 			amount = skb->len;
 		spin_unlock_bh(&sk->sk_receive_queue.lock);
 		return put_user(amount, (int __user *)arg);

net/ipv4/route.c

@@ -1591,7 +1591,7 @@ static int __mkroute_input(struct sk_buff *skb,
 
 	fnhe = find_exception(&FIB_RES_NH(*res), daddr);
 	if (do_cache) {
-		if (fnhe != NULL)
+		if (fnhe)
 			rth = rcu_dereference(fnhe->fnhe_rth_input);
 		else
 			rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);

net/ipv4/tcp.c

@@ -496,7 +496,7 @@ unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
 
 	/* Connected or passive Fast Open socket? */
 	if (sk->sk_state != TCP_SYN_SENT &&
-	    (sk->sk_state != TCP_SYN_RECV || tp->fastopen_rsk != NULL)) {
+	    (sk->sk_state != TCP_SYN_RECV || tp->fastopen_rsk)) {
 		int target = sock_rcvlowat(sk, 0, INT_MAX);
 
 		if (tp->urg_seq == tp->copied_seq &&
@@ -1028,7 +1028,7 @@ static inline int select_size(const struct sock *sk, bool sg)
 
 void tcp_free_fastopen_req(struct tcp_sock *tp)
 {
-	if (tp->fastopen_req != NULL) {
+	if (tp->fastopen_req) {
 		kfree(tp->fastopen_req);
 		tp->fastopen_req = NULL;
 	}
@@ -1042,7 +1042,7 @@ static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
 
 	if (!(sysctl_tcp_fastopen & TFO_CLIENT_ENABLE))
 		return -EOPNOTSUPP;
-	if (tp->fastopen_req != NULL)
+	if (tp->fastopen_req)
 		return -EALREADY; /* Another Fast Open is in progress */
 
 	tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request),
@@ -2138,7 +2138,7 @@ void tcp_close(struct sock *sk, long timeout)
 		 * aborted (e.g., closed with unread data) before 3WHS
 		 * finishes.
 		 */
-		if (req != NULL)
+		if (req)
 			reqsk_fastopen_remove(sk, req, false);
 		inet_csk_destroy_sock(sk);
 	}
@@ -2776,7 +2776,7 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
 		break;
 
 	case TCP_FASTOPEN:
-		if (icsk->icsk_accept_queue.fastopenq != NULL)
+		if (icsk->icsk_accept_queue.fastopenq)
 			val = icsk->icsk_accept_queue.fastopenq->max_qlen;
 		else
 			val = 0;
@@ -2960,7 +2960,7 @@ void tcp_done(struct sock *sk)
 
 	tcp_set_state(sk, TCP_CLOSE);
 	tcp_clear_xmit_timers(sk);
-	if (req != NULL)
+	if (req)
 		reqsk_fastopen_remove(sk, req, false);
 
 	sk->sk_shutdown = SHUTDOWN_MASK;

net/ipv4/tcp_diag.c

@@ -29,7 +29,7 @@ static void tcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
 		r->idiag_rqueue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
 		r->idiag_wqueue = tp->write_seq - tp->snd_una;
 	}
-	if (info != NULL)
+	if (info)
 		tcp_get_info(sk, info);
 }