| /* SPDX-License-Identifier: GPL-2.0-or-later */ |
| /* |
| * INET An implementation of the TCP/IP protocol suite for the LINUX |
| * operating system. INET is implemented using the BSD Socket |
| * interface as the means of communication with the user level. |
| * |
| * Definitions for the UDP module. |
| * |
| * Version: @(#)udp.h 1.0.2 05/07/93 |
| * |
| * Authors: Ross Biro |
| * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> |
| * |
| * Fixes: |
| * Alan Cox : Turned on udp checksums. I don't want to |
| * chase 'memory corruption' bugs that aren't! |
| */ |
| #ifndef _UDP_H |
| #define _UDP_H |
| |
| #include <linux/list.h> |
| #include <linux/bug.h> |
| #include <net/inet_sock.h> |
| #include <net/sock.h> |
| #include <net/snmp.h> |
| #include <net/ip.h> |
| #include <linux/ipv6.h> |
| #include <linux/seq_file.h> |
| #include <linux/poll.h> |
| |
| /** |
| * struct udp_skb_cb - UDP(-Lite) private variables |
| * |
| * @header: private variables used by IPv4/IPv6 |
| * @cscov: checksum coverage length (UDP-Lite only) |
| * @partial_cov: if set indicates partial csum coverage |
| */ |
| struct udp_skb_cb { |
| union { |
| struct inet_skb_parm h4; |
| #if IS_ENABLED(CONFIG_IPV6) |
| struct inet6_skb_parm h6; |
| #endif |
| } header; |
| __u16 cscov; |
| __u8 partial_cov; |
| }; |
| #define UDP_SKB_CB(__skb) ((struct udp_skb_cb *)((__skb)->cb)) |
| |
| /** |
| * struct udp_hslot - UDP hash slot |
| * |
| * @head: head of list of sockets |
| * @count: number of sockets in 'head' list |
| * @lock: spinlock protecting changes to head/count |
| */ |
| struct udp_hslot { |
| struct hlist_head head; |
| int count; |
| spinlock_t lock; |
| } __attribute__((aligned(2 * sizeof(long)))); |
| |
| /** |
| * struct udp_table - UDP table |
| * |
| * @hash: hash table, sockets are hashed on (local port) |
| * @hash2: hash table, sockets are hashed on (local port, local address) |
| * @mask: number of slots in hash tables, minus 1 |
| * @log: log2(number of slots in hash table) |
| */ |
| struct udp_table { |
| struct udp_hslot *hash; |
| struct udp_hslot *hash2; |
| unsigned int mask; |
| unsigned int log; |
| }; |
| extern struct udp_table udp_table; |
| void udp_table_init(struct udp_table *, const char *); |
| static inline struct udp_hslot *udp_hashslot(struct udp_table *table, |
| struct net *net, unsigned int num) |
| { |
| return &table->hash[udp_hashfn(net, num, table->mask)]; |
| } |
| /* |
| * For secondary hash, net_hash_mix() is performed before calling |
| * udp_hashslot2(), this explains difference with udp_hashslot() |
| */ |
| static inline struct udp_hslot *udp_hashslot2(struct udp_table *table, |
| unsigned int hash) |
| { |
| return &table->hash2[hash & table->mask]; |
| } |
| |
| extern struct proto udp_prot; |
| |
| extern atomic_long_t udp_memory_allocated; |
| |
| /* sysctl variables for udp */ |
| extern long sysctl_udp_mem[3]; |
| extern int sysctl_udp_rmem_min; |
| extern int sysctl_udp_wmem_min; |
| |
| struct sk_buff; |
| |
| /* |
| * Generic checksumming routines for UDP(-Lite) v4 and v6 |
| */ |
| static inline __sum16 __udp_lib_checksum_complete(struct sk_buff *skb) |
| { |
| return (UDP_SKB_CB(skb)->cscov == skb->len ? |
| __skb_checksum_complete(skb) : |
| __skb_checksum_complete_head(skb, UDP_SKB_CB(skb)->cscov)); |
| } |
| |
| static inline int udp_lib_checksum_complete(struct sk_buff *skb) |
| { |
| return !skb_csum_unnecessary(skb) && |
| __udp_lib_checksum_complete(skb); |
| } |
| |
| /** |
| * udp_csum_outgoing - compute UDPv4/v6 checksum over fragments |
| * @sk: socket we are writing to |
| * @skb: sk_buff containing the filled-in UDP header |
| * (checksum field must be zeroed out) |
| */ |
| static inline __wsum udp_csum_outgoing(struct sock *sk, struct sk_buff *skb) |
| { |
| __wsum csum = csum_partial(skb_transport_header(skb), |
| sizeof(struct udphdr), 0); |
| skb_queue_walk(&sk->sk_write_queue, skb) { |
| csum = csum_add(csum, skb->csum); |
| } |
| return csum; |
| } |
| |
| static inline __wsum udp_csum(struct sk_buff *skb) |
| { |
| __wsum csum = csum_partial(skb_transport_header(skb), |
| sizeof(struct udphdr), skb->csum); |
| |
| for (skb = skb_shinfo(skb)->frag_list; skb; skb = skb->next) { |
| csum = csum_add(csum, skb->csum); |
| } |
| return csum; |
| } |
| |
| static inline __sum16 udp_v4_check(int len, __be32 saddr, |
| __be32 daddr, __wsum base) |
| { |
| return csum_tcpudp_magic(saddr, daddr, len, IPPROTO_UDP, base); |
| } |
| |
| void udp_set_csum(bool nocheck, struct sk_buff *skb, |
| __be32 saddr, __be32 daddr, int len); |
| |
| static inline void udp_csum_pull_header(struct sk_buff *skb) |
| { |
| if (!skb->csum_valid && skb->ip_summed == CHECKSUM_NONE) |
| skb->csum = csum_partial(skb->data, sizeof(struct udphdr), |
| skb->csum); |
| skb_pull_rcsum(skb, sizeof(struct udphdr)); |
| UDP_SKB_CB(skb)->cscov -= sizeof(struct udphdr); |
| } |
| |
| typedef struct sock *(*udp_lookup_t)(struct sk_buff *skb, __be16 sport, |
| __be16 dport); |
| |
| struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb, |
| struct udphdr *uh, struct sock *sk); |
| int udp_gro_complete(struct sk_buff *skb, int nhoff, udp_lookup_t lookup); |
| |
| struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, |
| netdev_features_t features); |
| |
| static inline struct udphdr *udp_gro_udphdr(struct sk_buff *skb) |
| { |
| struct udphdr *uh; |
| unsigned int hlen, off; |
| |
| off = skb_gro_offset(skb); |
| hlen = off + sizeof(*uh); |
| uh = skb_gro_header_fast(skb, off); |
| if (skb_gro_header_hard(skb, hlen)) |
| uh = skb_gro_header_slow(skb, hlen, off); |
| |
| return uh; |
| } |
| |
| /* hash routines shared between UDPv4/6 and UDP-Litev4/6 */ |
| static inline int udp_lib_hash(struct sock *sk) |
| { |
| BUG(); |
| return 0; |
| } |
| |
| void udp_lib_unhash(struct sock *sk); |
| void udp_lib_rehash(struct sock *sk, u16 new_hash); |
| |
| static inline void udp_lib_close(struct sock *sk, long timeout) |
| { |
| sk_common_release(sk); |
| } |
| |
| int udp_lib_get_port(struct sock *sk, unsigned short snum, |
| unsigned int hash2_nulladdr); |
| |
| u32 udp_flow_hashrnd(void); |
| |
| static inline __be16 udp_flow_src_port(struct net *net, struct sk_buff *skb, |
| int min, int max, bool use_eth) |
| { |
| u32 hash; |
| |
| if (min >= max) { |
| /* Use default range */ |
| inet_get_local_port_range(net, &min, &max); |
| } |
| |
| hash = skb_get_hash(skb); |
| if (unlikely(!hash)) { |
| if (use_eth) { |
| /* Can't find a normal hash, caller has indicated an |
| * Ethernet packet so use that to compute a hash. |
| */ |
| hash = jhash(skb->data, 2 * ETH_ALEN, |
| (__force u32) skb->protocol); |
| } else { |
| /* Can't derive any sort of hash for the packet, set |
| * to some consistent random value. |
| */ |
| hash = udp_flow_hashrnd(); |
| } |
| } |
| |
| /* Since this is being sent on the wire obfuscate hash a bit |
| * to minimize possbility that any useful information to an |
| * attacker is leaked. Only upper 16 bits are relevant in the |
| * computation for 16 bit port value. |
| */ |
| hash ^= hash << 16; |
| |
| return htons((((u64) hash * (max - min)) >> 32) + min); |
| } |
| |
| static inline int udp_rqueue_get(struct sock *sk) |
| { |
| return sk_rmem_alloc_get(sk) - READ_ONCE(udp_sk(sk)->forward_deficit); |
| } |
| |
| static inline bool udp_sk_bound_dev_eq(struct net *net, int bound_dev_if, |
| int dif, int sdif) |
| { |
| #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) |
| return inet_bound_dev_eq(!!net->ipv4.sysctl_udp_l3mdev_accept, |
| bound_dev_if, dif, sdif); |
| #else |
| return inet_bound_dev_eq(true, bound_dev_if, dif, sdif); |
| #endif |
| } |
| |
| /* net/ipv4/udp.c */ |
| void udp_destruct_sock(struct sock *sk); |
| void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len); |
| int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb); |
| void udp_skb_destructor(struct sock *sk, struct sk_buff *skb); |
| struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags, |
| int noblock, int *off, int *err); |
| static inline struct sk_buff *skb_recv_udp(struct sock *sk, unsigned int flags, |
| int noblock, int *err) |
| { |
| int off = 0; |
| |
| return __skb_recv_udp(sk, flags, noblock, &off, err); |
| } |
| |
| int udp_v4_early_demux(struct sk_buff *skb); |
| bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst); |
| int udp_get_port(struct sock *sk, unsigned short snum, |
| int (*saddr_cmp)(const struct sock *, |
| const struct sock *)); |
| int udp_err(struct sk_buff *, u32); |
| int udp_abort(struct sock *sk, int err); |
| int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len); |
| int udp_push_pending_frames(struct sock *sk); |
| void udp_flush_pending_frames(struct sock *sk); |
| int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size); |
| void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst); |
| int udp_rcv(struct sk_buff *skb); |
| int udp_ioctl(struct sock *sk, int cmd, unsigned long arg); |
| int udp_init_sock(struct sock *sk); |
| int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); |
| int __udp_disconnect(struct sock *sk, int flags); |
| int udp_disconnect(struct sock *sk, int flags); |
| __poll_t udp_poll(struct file *file, struct socket *sock, poll_table *wait); |
| struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, |
| netdev_features_t features, |
| bool is_ipv6); |
| int udp_lib_getsockopt(struct sock *sk, int level, int optname, |
| char __user *optval, int __user *optlen); |
| int udp_lib_setsockopt(struct sock *sk, int level, int optname, |
| char __user *optval, unsigned int optlen, |
| int (*push_pending_frames)(struct sock *)); |
| struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, |
| __be32 daddr, __be16 dport, int dif); |
| struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, |
| __be32 daddr, __be16 dport, int dif, int sdif, |
| struct udp_table *tbl, struct sk_buff *skb); |
| struct sock *udp4_lib_lookup_skb(struct sk_buff *skb, |
| __be16 sport, __be16 dport); |
| struct sock *udp6_lib_lookup(struct net *net, |
| const struct in6_addr *saddr, __be16 sport, |
| const struct in6_addr *daddr, __be16 dport, |
| int dif); |
| struct sock *__udp6_lib_lookup(struct net *net, |
| const struct in6_addr *saddr, __be16 sport, |
| const struct in6_addr *daddr, __be16 dport, |
| int dif, int sdif, struct udp_table *tbl, |
| struct sk_buff *skb); |
| struct sock *udp6_lib_lookup_skb(struct sk_buff *skb, |
| __be16 sport, __be16 dport); |
| |
| /* UDP uses skb->dev_scratch to cache as much information as possible and avoid |
| * possibly multiple cache miss on dequeue() |
| */ |
| struct udp_dev_scratch { |
| /* skb->truesize and the stateless bit are embedded in a single field; |
| * do not use a bitfield since the compiler emits better/smaller code |
| * this way |
| */ |
| u32 _tsize_state; |
| |
| #if BITS_PER_LONG == 64 |
| /* len and the bit needed to compute skb_csum_unnecessary |
| * will be on cold cache lines at recvmsg time. |
| * skb->len can be stored on 16 bits since the udp header has been |
| * already validated and pulled. |
| */ |
| u16 len; |
| bool is_linear; |
| bool csum_unnecessary; |
| #endif |
| }; |
| |
| static inline struct udp_dev_scratch *udp_skb_scratch(struct sk_buff *skb) |
| { |
| return (struct udp_dev_scratch *)&skb->dev_scratch; |
| } |
| |
| #if BITS_PER_LONG == 64 |
| static inline unsigned int udp_skb_len(struct sk_buff *skb) |
| { |
| return udp_skb_scratch(skb)->len; |
| } |
| |
| static inline bool udp_skb_csum_unnecessary(struct sk_buff *skb) |
| { |
| return udp_skb_scratch(skb)->csum_unnecessary; |
| } |
| |
| static inline bool udp_skb_is_linear(struct sk_buff *skb) |
| { |
| return udp_skb_scratch(skb)->is_linear; |
| } |
| |
| #else |
| static inline unsigned int udp_skb_len(struct sk_buff *skb) |
| { |
| return skb->len; |
| } |
| |
| static inline bool udp_skb_csum_unnecessary(struct sk_buff *skb) |
| { |
| return skb_csum_unnecessary(skb); |
| } |
| |
| static inline bool udp_skb_is_linear(struct sk_buff *skb) |
| { |
| return !skb_is_nonlinear(skb); |
| } |
| #endif |
| |
| static inline int copy_linear_skb(struct sk_buff *skb, int len, int off, |
| struct iov_iter *to) |
| { |
| int n; |
| |
| n = copy_to_iter(skb->data + off, len, to); |
| if (n == len) |
| return 0; |
| |
| iov_iter_revert(to, n); |
| return -EFAULT; |
| } |
| |
| /* |
| * SNMP statistics for UDP and UDP-Lite |
| */ |
| #define UDP_INC_STATS(net, field, is_udplite) do { \ |
| if (is_udplite) SNMP_INC_STATS((net)->mib.udplite_statistics, field); \ |
| else SNMP_INC_STATS((net)->mib.udp_statistics, field); } while(0) |
| #define __UDP_INC_STATS(net, field, is_udplite) do { \ |
| if (is_udplite) __SNMP_INC_STATS((net)->mib.udplite_statistics, field); \ |
| else __SNMP_INC_STATS((net)->mib.udp_statistics, field); } while(0) |
| |
| #define __UDP6_INC_STATS(net, field, is_udplite) do { \ |
| if (is_udplite) __SNMP_INC_STATS((net)->mib.udplite_stats_in6, field);\ |
| else __SNMP_INC_STATS((net)->mib.udp_stats_in6, field); \ |
| } while(0) |
| #define UDP6_INC_STATS(net, field, __lite) do { \ |
| if (__lite) SNMP_INC_STATS((net)->mib.udplite_stats_in6, field); \ |
| else SNMP_INC_STATS((net)->mib.udp_stats_in6, field); \ |
| } while(0) |
| |
| #if IS_ENABLED(CONFIG_IPV6) |
| #define __UDPX_MIB(sk, ipv4) \ |
| ({ \ |
| ipv4 ? (IS_UDPLITE(sk) ? sock_net(sk)->mib.udplite_statistics : \ |
| sock_net(sk)->mib.udp_statistics) : \ |
| (IS_UDPLITE(sk) ? sock_net(sk)->mib.udplite_stats_in6 : \ |
| sock_net(sk)->mib.udp_stats_in6); \ |
| }) |
| #else |
| #define __UDPX_MIB(sk, ipv4) \ |
| ({ \ |
| IS_UDPLITE(sk) ? sock_net(sk)->mib.udplite_statistics : \ |
| sock_net(sk)->mib.udp_statistics; \ |
| }) |
| #endif |
| |
| #define __UDPX_INC_STATS(sk, field) \ |
| __SNMP_INC_STATS(__UDPX_MIB(sk, (sk)->sk_family == AF_INET), field) |
| |
| #ifdef CONFIG_PROC_FS |
| struct udp_seq_afinfo { |
| sa_family_t family; |
| struct udp_table *udp_table; |
| }; |
| |
| struct udp_iter_state { |
| struct seq_net_private p; |
| int bucket; |
| }; |
| |
| void *udp_seq_start(struct seq_file *seq, loff_t *pos); |
| void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos); |
| void udp_seq_stop(struct seq_file *seq, void *v); |
| |
| extern const struct seq_operations udp_seq_ops; |
| extern const struct seq_operations udp6_seq_ops; |
| |
| int udp4_proc_init(void); |
| void udp4_proc_exit(void); |
| #endif /* CONFIG_PROC_FS */ |
| |
| int udpv4_offload_init(void); |
| |
| void udp_init(void); |
| |
| DECLARE_STATIC_KEY_FALSE(udp_encap_needed_key); |
| void udp_encap_enable(void); |
| #if IS_ENABLED(CONFIG_IPV6) |
| DECLARE_STATIC_KEY_FALSE(udpv6_encap_needed_key); |
| void udpv6_encap_enable(void); |
| #endif |
| |
| static inline struct sk_buff *udp_rcv_segment(struct sock *sk, |
| struct sk_buff *skb, bool ipv4) |
| { |
| netdev_features_t features = NETIF_F_SG; |
| struct sk_buff *segs; |
| |
| /* Avoid csum recalculation by skb_segment unless userspace explicitly |
| * asks for the final checksum values |
| */ |
| if (!inet_get_convert_csum(sk)) |
| features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM; |
| |
| /* UDP segmentation expects packets of type CHECKSUM_PARTIAL or |
| * CHECKSUM_NONE in __udp_gso_segment. UDP GRO indeed builds partial |
| * packets in udp_gro_complete_segment. As does UDP GSO, verified by |
| * udp_send_skb. But when those packets are looped in dev_loopback_xmit |
| * their ip_summed is set to CHECKSUM_UNNECESSARY. Reset in this |
| * specific case, where PARTIAL is both correct and required. |
| */ |
| if (skb->pkt_type == PACKET_LOOPBACK) |
| skb->ip_summed = CHECKSUM_PARTIAL; |
| |
| /* the GSO CB lays after the UDP one, no need to save and restore any |
| * CB fragment |
| */ |
| segs = __skb_gso_segment(skb, features, false); |
| if (IS_ERR_OR_NULL(segs)) { |
| int segs_nr = skb_shinfo(skb)->gso_segs; |
| |
| atomic_add(segs_nr, &sk->sk_drops); |
| SNMP_ADD_STATS(__UDPX_MIB(sk, ipv4), UDP_MIB_INERRORS, segs_nr); |
| kfree_skb(skb); |
| return NULL; |
| } |
| |
| consume_skb(skb); |
| return segs; |
| } |
| |
| #ifdef CONFIG_BPF_STREAM_PARSER |
| struct sk_psock; |
| struct proto *udp_bpf_get_proto(struct sock *sk, struct sk_psock *psock); |
| #endif /* BPF_STREAM_PARSER */ |
| |
| #endif /* _UDP_H */ |
