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Diffstat (limited to 'include/net/udp.h')
| -rw-r--r-- | include/net/udp.h | 336 |
1 files changed, 336 insertions, 0 deletions
diff --git a/include/net/udp.h b/include/net/udp.h new file mode 100644 index 000000000..6d4ed18e1 --- /dev/null +++ b/include/net/udp.h @@ -0,0 +1,336 @@ +/* + * 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! + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ +#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_nulls_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); + +struct sk_buff **udp_gro_receive(struct sk_buff **head, struct sk_buff *skb, + struct udphdr *uh); +int udp_gro_complete(struct sk_buff *skb, int nhoff); + +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 void udp_lib_hash(struct sock *sk) +{ + BUG(); +} + +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, + int (*)(const struct sock *, const struct sock *), + 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); +} + +/* net/ipv4/udp.c */ +void udp_v4_early_demux(struct sk_buff *skb); +int udp_get_port(struct sock *sk, unsigned short snum, + int (*saddr_cmp)(const struct sock *, + const struct sock *)); +void udp_err(struct sk_buff *, u32); +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); +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_disconnect(struct sock *sk, int flags); +unsigned int 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, + struct udp_table *tbl); +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, struct udp_table *tbl); + +/* + * SNMP statistics for UDP and UDP-Lite + */ +#define UDP_INC_STATS_USER(net, field, is_udplite) do { \ + if (is_udplite) SNMP_INC_STATS_USER((net)->mib.udplite_statistics, field); \ + else SNMP_INC_STATS_USER((net)->mib.udp_statistics, field); } while(0) +#define UDP_INC_STATS_BH(net, field, is_udplite) do { \ + if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_statistics, field); \ + else SNMP_INC_STATS_BH((net)->mib.udp_statistics, field); } while(0) + +#define UDP6_INC_STATS_BH(net, field, is_udplite) do { \ + if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_stats_in6, field);\ + else SNMP_INC_STATS_BH((net)->mib.udp_stats_in6, field); \ +} while(0) +#define UDP6_INC_STATS_USER(net, field, __lite) do { \ + if (__lite) SNMP_INC_STATS_USER((net)->mib.udplite_stats_in6, field); \ + else SNMP_INC_STATS_USER((net)->mib.udp_stats_in6, field); \ +} while(0) + +#if IS_ENABLED(CONFIG_IPV6) +#define UDPX_INC_STATS_BH(sk, field) \ +do { \ + if ((sk)->sk_family == AF_INET) \ + UDP_INC_STATS_BH(sock_net(sk), field, 0); \ + else \ + UDP6_INC_STATS_BH(sock_net(sk), field, 0); \ +} while (0) +#else +#define UDPX_INC_STATS_BH(sk, field) UDP_INC_STATS_BH(sock_net(sk), field, 0) +#endif + +/* /proc */ +int udp_seq_open(struct inode *inode, struct file *file); + +struct udp_seq_afinfo { + char *name; + sa_family_t family; + struct udp_table *udp_table; + const struct file_operations *seq_fops; + struct seq_operations seq_ops; +}; + +struct udp_iter_state { + struct seq_net_private p; + sa_family_t family; + int bucket; + struct udp_table *udp_table; +}; + +#ifdef CONFIG_PROC_FS +int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo); +void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo); + +int udp4_proc_init(void); +void udp4_proc_exit(void); +#endif + +int udpv4_offload_init(void); + +void udp_init(void); + +void udp_encap_enable(void); +#if IS_ENABLED(CONFIG_IPV6) +void udpv6_encap_enable(void); +#endif +#endif /* _UDP_H */ |