1 /* SPDX-License-Identifier: GPL-2.0-or-later */
15  *		Alan Cox	: Turned on udp checksums. I don't want to
34  *	struct udp_skb_cb  -  UDP(-Lite) private variables
37  *	@cscov:       checksum coverage length (UDP-Lite only)
50 #define UDP_SKB_CB(__skb)	((struct udp_skb_cb *)((__skb)->cb))
53  *	struct udp_hslot - UDP hash slot
66  *	struct udp_table - UDP table
68  *	@hash:	hash table, sockets are hashed on (local port)
69  *	@hash2:	hash table, sockets are hashed on (local port, local address)
85 	return &table->hash[udp_hashfn(net, num, table->mask)];  in udp_hashslot()
94 	return &table->hash2[hash & table->mask];  in udp_hashslot2()
110  *	Generic checksumming routines for UDP(-Lite) v4 and v6
114 	return (UDP_SKB_CB(skb)->cscov == skb->len ?  in __udp_lib_checksum_complete()
116 		__skb_checksum_complete_head(skb, UDP_SKB_CB(skb)->cscov));  in __udp_lib_checksum_complete()
126  * 	udp_csum_outgoing  -  compute UDPv4/v6 checksum over fragments
128  * 	@skb: 	sk_buff containing the filled-in UDP header
135 	skb_queue_walk(&sk->sk_write_queue, skb) {  in udp_csum_outgoing()
136 		csum = csum_add(csum, skb->csum);  in udp_csum_outgoing()
144 				   sizeof(struct udphdr), skb->csum);  in udp_csum()
146 	for (skb = skb_shinfo(skb)->frag_list; skb; skb = skb->next) {  in udp_csum()
147 		csum = csum_add(csum, skb->csum);  in udp_csum()
163 	if (!skb->csum_valid && skb->ip_summed == CHECKSUM_NONE)  in udp_csum_pull_header()
164 		skb->csum = csum_partial(skb->data, sizeof(struct udphdr),  in udp_csum_pull_header()
165 					 skb->csum);  in udp_csum_pull_header()
167 	UDP_SKB_CB(skb)->cscov -= sizeof(struct udphdr);  in udp_csum_pull_header()
183 	skb_queue_head_init(&up->reader_queue);  in udp_lib_init_sock()
184 	up->forward_threshold = sk->sk_rcvbuf >> 2;  in udp_lib_init_sock()
185 	set_bit(SOCK_CUSTOM_SOCKOPT, &sk->sk_socket->flags);  in udp_lib_init_sock()
188 /* hash routines shared between UDPv4/6 and UDP-Litev4/6 */
224 			hash = jhash(skb->data, 2 * ETH_ALEN,  in udp_flow_src_port()
225 				     (__force u32) skb->protocol);  in udp_flow_src_port()
234 	/* Since this is being sent on the wire obfuscate hash a bit  in udp_flow_src_port()
241 	return htons((((u64) hash * (max - min)) >> 32) + min);  in udp_flow_src_port()
246 	return sk_rmem_alloc_get(sk) - READ_ONCE(udp_sk(sk)->forward_deficit);  in udp_rqueue_get()
253 	return inet_bound_dev_eq(!!READ_ONCE(net->ipv4.sysctl_udp_l3mdev_accept),  in udp_sk_bound_dev_eq()
321 /* UDP uses skb->dev_scratch to cache as much information as possible and avoid
322  * possibly multiple cache miss on dequeue()
325 	/* skb->truesize and the stateless bit are embedded in a single field;
333 	 * will be on cold cache lines at recvmsg time.
334 	 * skb->len can be stored on 16 bits since the udp header has been
345 	return (struct udp_dev_scratch *)&skb->dev_scratch;  in udp_skb_scratch()
351 	return udp_skb_scratch(skb)->len;  in udp_skb_len()
356 	return udp_skb_scratch(skb)->csum_unnecessary;  in udp_skb_csum_unnecessary()
361 	return udp_skb_scratch(skb)->is_linear;  in udp_skb_is_linear()
367 	return skb->len;  in udp_skb_len()
384 	return copy_to_iter_full(skb->data + off, len, to) ? 0 : -EFAULT;  in copy_linear_skb()
388  * 	SNMP statistics for UDP and UDP-Lite
391 	if (is_udplite) SNMP_INC_STATS((net)->mib.udplite_statistics, field);       \
392 	else		SNMP_INC_STATS((net)->mib.udp_statistics, field);  }  while(0)
394 	if (is_udplite) __SNMP_INC_STATS((net)->mib.udplite_statistics, field);         \
395 	else		__SNMP_INC_STATS((net)->mib.udp_statistics, field);    }  while(0)
398 	if (is_udplite) __SNMP_INC_STATS((net)->mib.udplite_stats_in6, field);\
399 	else		__SNMP_INC_STATS((net)->mib.udp_stats_in6, field);  \
402 	if (__lite) SNMP_INC_STATS((net)->mib.udplite_stats_in6, field);  \
403 	else	    SNMP_INC_STATS((net)->mib.udp_stats_in6, field);      \
409 	ipv4 ? (IS_UDPLITE(sk) ? sock_net(sk)->mib.udplite_statistics :	\
410 				 sock_net(sk)->mib.udp_statistics) :	\
411 		(IS_UDPLITE(sk) ? sock_net(sk)->mib.udplite_stats_in6 :	\
412 				 sock_net(sk)->mib.udp_stats_in6);	\
417 	IS_UDPLITE(sk) ? sock_net(sk)->mib.udplite_statistics :		\
418 			 sock_net(sk)->mib.udp_statistics;		\
423 	__SNMP_INC_STATS(__UDPX_MIB(sk, (sk)->sk_family == AF_INET), field)
479 	if (skb->pkt_type == PACKET_LOOPBACK)  in udp_rcv_segment()
480 		skb->ip_summed = CHECKSUM_PARTIAL;  in udp_rcv_segment()
487 		int segs_nr = skb_shinfo(skb)->gso_segs;  in udp_rcv_segment()
489 		atomic_add(segs_nr, &sk->sk_drops);  in udp_rcv_segment()
501 	/* UDP-lite can't land here - no GRO */  in udp_post_segment_fix_csum()
502 	WARN_ON_ONCE(UDP_SKB_CB(skb)->partial_cov);  in udp_post_segment_fix_csum()
506 	 * UDP tunnel(xmit) -> veth (segmentation) -> veth (gro) -> UDP tunnel (rx)  in udp_post_segment_fix_csum()
517 	UDP_SKB_CB(skb)->cscov = skb->len;  in udp_post_segment_fix_csum()
518 	if (skb->ip_summed == CHECKSUM_NONE && !skb->csum_valid)  in udp_post_segment_fix_csum()
519 		skb->csum_valid = 1;  in udp_post_segment_fix_csum()