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-rw-r--r--include/net/udp.h532
1 files changed, 532 insertions, 0 deletions
diff --git a/include/net/udp.h b/include/net/udp.h
new file mode 100644
index 0000000000..488a6d2bab
--- /dev/null
+++ b/include/net/udp.h
@@ -0,0 +1,532 @@
+/* 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/gso.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);
+
+static inline void udp_lib_init_sock(struct sock *sk)
+{
+ struct udp_sock *up = udp_sk(sk);
+
+ skb_queue_head_init(&up->reader_queue);
+ up->forward_threshold = sk->sk_rcvbuf >> 2;
+ set_bit(SOCK_CUSTOM_SOCKOPT, &sk->sk_socket->flags);
+}
+
+/* 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_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, int *karg);
+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;
+};
+
+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;
+int udp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore);
+#endif
+
+#endif /* _UDP_H */
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