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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /include/net/udp.h | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | include/net/udp.h | 527 |
1 files changed, 527 insertions, 0 deletions
diff --git a/include/net/udp.h b/include/net/udp.h new file mode 100644 index 000000000..fa4cdbe55 --- /dev/null +++ b/include/net/udp.h @@ -0,0 +1,527 @@ +/* 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> +#include <linux/indirect_call_wrapper.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; +DECLARE_PER_CPU(int, udp_memory_per_cpu_fw_alloc); + +/* 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)(const struct sk_buff *skb, __be16 sport, + __be16 dport); + +void udp_v6_early_demux(struct sk_buff *skb); +INDIRECT_CALLABLE_DECLARE(int udpv6_rcv(struct sk_buff *)); + +struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, + netdev_features_t features, bool is_ipv6); + +/* 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(!!READ_ONCE(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_common(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 *off, + int *err); +static inline struct sk_buff *skb_recv_udp(struct sock *sk, unsigned int flags, + int *err) +{ + int off = 0; + + return __skb_recv_udp(sk, flags, &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); +void udp_splice_eof(struct socket *sock); +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, + sockptr_t 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(const 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(const struct sk_buff *skb, + __be16 sport, __be16 dport); +int udp_read_skb(struct sock *sk, skb_read_actor_t recv_actor); + +/* 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; + struct udp_seq_afinfo *bpf_seq_afinfo; +}; + +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); +void udp_encap_disable(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 CHECKSUM_NONE is changed 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; +} + +static inline void udp_post_segment_fix_csum(struct sk_buff *skb) +{ + /* UDP-lite can't land here - no GRO */ + WARN_ON_ONCE(UDP_SKB_CB(skb)->partial_cov); + + /* UDP packets generated with UDP_SEGMENT and traversing: + * + * UDP tunnel(xmit) -> veth (segmentation) -> veth (gro) -> UDP tunnel (rx) + * + * can reach an UDP socket with CHECKSUM_NONE, because + * __iptunnel_pull_header() converts CHECKSUM_PARTIAL into NONE. + * SKB_GSO_UDP_L4 or SKB_GSO_FRAGLIST packets with no UDP tunnel will + * have a valid checksum, as the GRO engine validates the UDP csum + * before the aggregation and nobody strips such info in between. + * Instead of adding another check in the tunnel fastpath, we can force + * a valid csum after the segmentation. + * Additionally fixup the UDP CB. + */ + UDP_SKB_CB(skb)->cscov = skb->len; + if (skb->ip_summed == CHECKSUM_NONE && !skb->csum_valid) + skb->csum_valid = 1; +} + +#ifdef CONFIG_BPF_SYSCALL +struct sk_psock; +struct proto *udp_bpf_get_proto(struct sock *sk, struct sk_psock *psock); +int udp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore); +#endif + +#endif /* _UDP_H */ |