v4.19.13 snapshot.
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
new file mode 100644
index 0000000..f8183fd
--- /dev/null
+++ b/net/ipv4/udp.c
@@ -0,0 +1,2956 @@
+/*
+ * 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.
+ *
+ * The User Datagram Protocol (UDP).
+ *
+ * Authors: Ross Biro
+ * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
+ * Alan Cox, <alan@lxorguk.ukuu.org.uk>
+ * Hirokazu Takahashi, <taka@valinux.co.jp>
+ *
+ * Fixes:
+ * Alan Cox : verify_area() calls
+ * Alan Cox : stopped close while in use off icmp
+ * messages. Not a fix but a botch that
+ * for udp at least is 'valid'.
+ * Alan Cox : Fixed icmp handling properly
+ * Alan Cox : Correct error for oversized datagrams
+ * Alan Cox : Tidied select() semantics.
+ * Alan Cox : udp_err() fixed properly, also now
+ * select and read wake correctly on errors
+ * Alan Cox : udp_send verify_area moved to avoid mem leak
+ * Alan Cox : UDP can count its memory
+ * Alan Cox : send to an unknown connection causes
+ * an ECONNREFUSED off the icmp, but
+ * does NOT close.
+ * Alan Cox : Switched to new sk_buff handlers. No more backlog!
+ * Alan Cox : Using generic datagram code. Even smaller and the PEEK
+ * bug no longer crashes it.
+ * Fred Van Kempen : Net2e support for sk->broadcast.
+ * Alan Cox : Uses skb_free_datagram
+ * Alan Cox : Added get/set sockopt support.
+ * Alan Cox : Broadcasting without option set returns EACCES.
+ * Alan Cox : No wakeup calls. Instead we now use the callbacks.
+ * Alan Cox : Use ip_tos and ip_ttl
+ * Alan Cox : SNMP Mibs
+ * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support.
+ * Matt Dillon : UDP length checks.
+ * Alan Cox : Smarter af_inet used properly.
+ * Alan Cox : Use new kernel side addressing.
+ * Alan Cox : Incorrect return on truncated datagram receive.
+ * Arnt Gulbrandsen : New udp_send and stuff
+ * Alan Cox : Cache last socket
+ * Alan Cox : Route cache
+ * Jon Peatfield : Minor efficiency fix to sendto().
+ * Mike Shaver : RFC1122 checks.
+ * Alan Cox : Nonblocking error fix.
+ * Willy Konynenberg : Transparent proxying support.
+ * Mike McLagan : Routing by source
+ * David S. Miller : New socket lookup architecture.
+ * Last socket cache retained as it
+ * does have a high hit rate.
+ * Olaf Kirch : Don't linearise iovec on sendmsg.
+ * Andi Kleen : Some cleanups, cache destination entry
+ * for connect.
+ * Vitaly E. Lavrov : Transparent proxy revived after year coma.
+ * Melvin Smith : Check msg_name not msg_namelen in sendto(),
+ * return ENOTCONN for unconnected sockets (POSIX)
+ * Janos Farkas : don't deliver multi/broadcasts to a different
+ * bound-to-device socket
+ * Hirokazu Takahashi : HW checksumming for outgoing UDP
+ * datagrams.
+ * Hirokazu Takahashi : sendfile() on UDP works now.
+ * Arnaldo C. Melo : convert /proc/net/udp to seq_file
+ * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
+ * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind
+ * a single port at the same time.
+ * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support
+ * James Chapman : Add L2TP encapsulation type.
+ *
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) "UDP: " fmt
+
+#include <linux/uaccess.h>
+#include <asm/ioctls.h>
+#include <linux/bootmem.h>
+#include <linux/highmem.h>
+#include <linux/swap.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/module.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/igmp.h>
+#include <linux/inetdevice.h>
+#include <linux/in.h>
+#include <linux/errno.h>
+#include <linux/timer.h>
+#include <linux/mm.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/slab.h>
+#include <net/tcp_states.h>
+#include <linux/skbuff.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <net/net_namespace.h>
+#include <net/icmp.h>
+#include <net/inet_hashtables.h>
+#include <net/route.h>
+#include <net/checksum.h>
+#include <net/xfrm.h>
+#include <trace/events/udp.h>
+#include <linux/static_key.h>
+#include <trace/events/skb.h>
+#include <net/busy_poll.h>
+#include "udp_impl.h"
+#include <net/sock_reuseport.h>
+#include <net/addrconf.h>
+
+struct udp_table udp_table __read_mostly;
+EXPORT_SYMBOL(udp_table);
+
+long sysctl_udp_mem[3] __read_mostly;
+EXPORT_SYMBOL(sysctl_udp_mem);
+
+atomic_long_t udp_memory_allocated;
+EXPORT_SYMBOL(udp_memory_allocated);
+
+#define MAX_UDP_PORTS 65536
+#define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
+
+/* IPCB reference means this can not be used from early demux */
+static bool udp_lib_exact_dif_match(struct net *net, struct sk_buff *skb)
+{
+#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
+ if (!net->ipv4.sysctl_udp_l3mdev_accept &&
+ skb && ipv4_l3mdev_skb(IPCB(skb)->flags))
+ return true;
+#endif
+ return false;
+}
+
+static int udp_lib_lport_inuse(struct net *net, __u16 num,
+ const struct udp_hslot *hslot,
+ unsigned long *bitmap,
+ struct sock *sk, unsigned int log)
+{
+ struct sock *sk2;
+ kuid_t uid = sock_i_uid(sk);
+
+ sk_for_each(sk2, &hslot->head) {
+ if (net_eq(sock_net(sk2), net) &&
+ sk2 != sk &&
+ (bitmap || udp_sk(sk2)->udp_port_hash == num) &&
+ (!sk2->sk_reuse || !sk->sk_reuse) &&
+ (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
+ sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
+ inet_rcv_saddr_equal(sk, sk2, true)) {
+ if (sk2->sk_reuseport && sk->sk_reuseport &&
+ !rcu_access_pointer(sk->sk_reuseport_cb) &&
+ uid_eq(uid, sock_i_uid(sk2))) {
+ if (!bitmap)
+ return 0;
+ } else {
+ if (!bitmap)
+ return 1;
+ __set_bit(udp_sk(sk2)->udp_port_hash >> log,
+ bitmap);
+ }
+ }
+ }
+ return 0;
+}
+
+/*
+ * Note: we still hold spinlock of primary hash chain, so no other writer
+ * can insert/delete a socket with local_port == num
+ */
+static int udp_lib_lport_inuse2(struct net *net, __u16 num,
+ struct udp_hslot *hslot2,
+ struct sock *sk)
+{
+ struct sock *sk2;
+ kuid_t uid = sock_i_uid(sk);
+ int res = 0;
+
+ spin_lock(&hslot2->lock);
+ udp_portaddr_for_each_entry(sk2, &hslot2->head) {
+ if (net_eq(sock_net(sk2), net) &&
+ sk2 != sk &&
+ (udp_sk(sk2)->udp_port_hash == num) &&
+ (!sk2->sk_reuse || !sk->sk_reuse) &&
+ (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
+ sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
+ inet_rcv_saddr_equal(sk, sk2, true)) {
+ if (sk2->sk_reuseport && sk->sk_reuseport &&
+ !rcu_access_pointer(sk->sk_reuseport_cb) &&
+ uid_eq(uid, sock_i_uid(sk2))) {
+ res = 0;
+ } else {
+ res = 1;
+ }
+ break;
+ }
+ }
+ spin_unlock(&hslot2->lock);
+ return res;
+}
+
+static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot)
+{
+ struct net *net = sock_net(sk);
+ kuid_t uid = sock_i_uid(sk);
+ struct sock *sk2;
+
+ sk_for_each(sk2, &hslot->head) {
+ if (net_eq(sock_net(sk2), net) &&
+ sk2 != sk &&
+ sk2->sk_family == sk->sk_family &&
+ ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
+ (udp_sk(sk2)->udp_port_hash == udp_sk(sk)->udp_port_hash) &&
+ (sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
+ sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
+ inet_rcv_saddr_equal(sk, sk2, false)) {
+ return reuseport_add_sock(sk, sk2,
+ inet_rcv_saddr_any(sk));
+ }
+ }
+
+ return reuseport_alloc(sk, inet_rcv_saddr_any(sk));
+}
+
+/**
+ * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
+ *
+ * @sk: socket struct in question
+ * @snum: port number to look up
+ * @hash2_nulladdr: AF-dependent hash value in secondary hash chains,
+ * with NULL address
+ */
+int udp_lib_get_port(struct sock *sk, unsigned short snum,
+ unsigned int hash2_nulladdr)
+{
+ struct udp_hslot *hslot, *hslot2;
+ struct udp_table *udptable = sk->sk_prot->h.udp_table;
+ int error = 1;
+ struct net *net = sock_net(sk);
+
+ if (!snum) {
+ int low, high, remaining;
+ unsigned int rand;
+ unsigned short first, last;
+ DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
+
+ inet_get_local_port_range(net, &low, &high);
+ remaining = (high - low) + 1;
+
+ rand = prandom_u32();
+ first = reciprocal_scale(rand, remaining) + low;
+ /*
+ * force rand to be an odd multiple of UDP_HTABLE_SIZE
+ */
+ rand = (rand | 1) * (udptable->mask + 1);
+ last = first + udptable->mask + 1;
+ do {
+ hslot = udp_hashslot(udptable, net, first);
+ bitmap_zero(bitmap, PORTS_PER_CHAIN);
+ spin_lock_bh(&hslot->lock);
+ udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
+ udptable->log);
+
+ snum = first;
+ /*
+ * Iterate on all possible values of snum for this hash.
+ * Using steps of an odd multiple of UDP_HTABLE_SIZE
+ * give us randomization and full range coverage.
+ */
+ do {
+ if (low <= snum && snum <= high &&
+ !test_bit(snum >> udptable->log, bitmap) &&
+ !inet_is_local_reserved_port(net, snum))
+ goto found;
+ snum += rand;
+ } while (snum != first);
+ spin_unlock_bh(&hslot->lock);
+ cond_resched();
+ } while (++first != last);
+ goto fail;
+ } else {
+ hslot = udp_hashslot(udptable, net, snum);
+ spin_lock_bh(&hslot->lock);
+ if (hslot->count > 10) {
+ int exist;
+ unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum;
+
+ slot2 &= udptable->mask;
+ hash2_nulladdr &= udptable->mask;
+
+ hslot2 = udp_hashslot2(udptable, slot2);
+ if (hslot->count < hslot2->count)
+ goto scan_primary_hash;
+
+ exist = udp_lib_lport_inuse2(net, snum, hslot2, sk);
+ if (!exist && (hash2_nulladdr != slot2)) {
+ hslot2 = udp_hashslot2(udptable, hash2_nulladdr);
+ exist = udp_lib_lport_inuse2(net, snum, hslot2,
+ sk);
+ }
+ if (exist)
+ goto fail_unlock;
+ else
+ goto found;
+ }
+scan_primary_hash:
+ if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 0))
+ goto fail_unlock;
+ }
+found:
+ inet_sk(sk)->inet_num = snum;
+ udp_sk(sk)->udp_port_hash = snum;
+ udp_sk(sk)->udp_portaddr_hash ^= snum;
+ if (sk_unhashed(sk)) {
+ if (sk->sk_reuseport &&
+ udp_reuseport_add_sock(sk, hslot)) {
+ inet_sk(sk)->inet_num = 0;
+ udp_sk(sk)->udp_port_hash = 0;
+ udp_sk(sk)->udp_portaddr_hash ^= snum;
+ goto fail_unlock;
+ }
+
+ sk_add_node_rcu(sk, &hslot->head);
+ hslot->count++;
+ sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
+
+ hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
+ spin_lock(&hslot2->lock);
+ if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
+ sk->sk_family == AF_INET6)
+ hlist_add_tail_rcu(&udp_sk(sk)->udp_portaddr_node,
+ &hslot2->head);
+ else
+ hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
+ &hslot2->head);
+ hslot2->count++;
+ spin_unlock(&hslot2->lock);
+ }
+ sock_set_flag(sk, SOCK_RCU_FREE);
+ error = 0;
+fail_unlock:
+ spin_unlock_bh(&hslot->lock);
+fail:
+ return error;
+}
+EXPORT_SYMBOL(udp_lib_get_port);
+
+int udp_v4_get_port(struct sock *sk, unsigned short snum)
+{
+ unsigned int hash2_nulladdr =
+ ipv4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum);
+ unsigned int hash2_partial =
+ ipv4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0);
+
+ /* precompute partial secondary hash */
+ udp_sk(sk)->udp_portaddr_hash = hash2_partial;
+ return udp_lib_get_port(sk, snum, hash2_nulladdr);
+}
+
+static int compute_score(struct sock *sk, struct net *net,
+ __be32 saddr, __be16 sport,
+ __be32 daddr, unsigned short hnum,
+ int dif, int sdif, bool exact_dif)
+{
+ int score;
+ struct inet_sock *inet;
+
+ if (!net_eq(sock_net(sk), net) ||
+ udp_sk(sk)->udp_port_hash != hnum ||
+ ipv6_only_sock(sk))
+ return -1;
+
+ score = (sk->sk_family == PF_INET) ? 2 : 1;
+ inet = inet_sk(sk);
+
+ if (inet->inet_rcv_saddr) {
+ if (inet->inet_rcv_saddr != daddr)
+ return -1;
+ score += 4;
+ }
+
+ if (inet->inet_daddr) {
+ if (inet->inet_daddr != saddr)
+ return -1;
+ score += 4;
+ }
+
+ if (inet->inet_dport) {
+ if (inet->inet_dport != sport)
+ return -1;
+ score += 4;
+ }
+
+ if (sk->sk_bound_dev_if || exact_dif) {
+ bool dev_match = (sk->sk_bound_dev_if == dif ||
+ sk->sk_bound_dev_if == sdif);
+
+ if (!dev_match)
+ return -1;
+ if (sk->sk_bound_dev_if)
+ score += 4;
+ }
+
+ if (sk->sk_incoming_cpu == raw_smp_processor_id())
+ score++;
+ return score;
+}
+
+static u32 udp_ehashfn(const struct net *net, const __be32 laddr,
+ const __u16 lport, const __be32 faddr,
+ const __be16 fport)
+{
+ static u32 udp_ehash_secret __read_mostly;
+
+ net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret));
+
+ return __inet_ehashfn(laddr, lport, faddr, fport,
+ udp_ehash_secret + net_hash_mix(net));
+}
+
+/* called with rcu_read_lock() */
+static struct sock *udp4_lib_lookup2(struct net *net,
+ __be32 saddr, __be16 sport,
+ __be32 daddr, unsigned int hnum,
+ int dif, int sdif, bool exact_dif,
+ struct udp_hslot *hslot2,
+ struct sk_buff *skb)
+{
+ struct sock *sk, *result;
+ int score, badness;
+ u32 hash = 0;
+
+ result = NULL;
+ badness = 0;
+ udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
+ score = compute_score(sk, net, saddr, sport,
+ daddr, hnum, dif, sdif, exact_dif);
+ if (score > badness) {
+ if (sk->sk_reuseport) {
+ hash = udp_ehashfn(net, daddr, hnum,
+ saddr, sport);
+ result = reuseport_select_sock(sk, hash, skb,
+ sizeof(struct udphdr));
+ if (result)
+ return result;
+ }
+ badness = score;
+ result = sk;
+ }
+ }
+ return result;
+}
+
+/* UDP is nearly always wildcards out the wazoo, it makes no sense to try
+ * harder than this. -DaveM
+ */
+struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
+ __be16 sport, __be32 daddr, __be16 dport, int dif,
+ int sdif, struct udp_table *udptable, struct sk_buff *skb)
+{
+ struct sock *sk, *result;
+ unsigned short hnum = ntohs(dport);
+ unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
+ struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
+ bool exact_dif = udp_lib_exact_dif_match(net, skb);
+ int score, badness;
+ u32 hash = 0;
+
+ if (hslot->count > 10) {
+ hash2 = ipv4_portaddr_hash(net, daddr, hnum);
+ slot2 = hash2 & udptable->mask;
+ hslot2 = &udptable->hash2[slot2];
+ if (hslot->count < hslot2->count)
+ goto begin;
+
+ result = udp4_lib_lookup2(net, saddr, sport,
+ daddr, hnum, dif, sdif,
+ exact_dif, hslot2, skb);
+ if (!result) {
+ unsigned int old_slot2 = slot2;
+ hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
+ slot2 = hash2 & udptable->mask;
+ /* avoid searching the same slot again. */
+ if (unlikely(slot2 == old_slot2))
+ return result;
+
+ hslot2 = &udptable->hash2[slot2];
+ if (hslot->count < hslot2->count)
+ goto begin;
+
+ result = udp4_lib_lookup2(net, saddr, sport,
+ daddr, hnum, dif, sdif,
+ exact_dif, hslot2, skb);
+ }
+ if (unlikely(IS_ERR(result)))
+ return NULL;
+ return result;
+ }
+begin:
+ result = NULL;
+ badness = 0;
+ sk_for_each_rcu(sk, &hslot->head) {
+ score = compute_score(sk, net, saddr, sport,
+ daddr, hnum, dif, sdif, exact_dif);
+ if (score > badness) {
+ if (sk->sk_reuseport) {
+ hash = udp_ehashfn(net, daddr, hnum,
+ saddr, sport);
+ result = reuseport_select_sock(sk, hash, skb,
+ sizeof(struct udphdr));
+ if (unlikely(IS_ERR(result)))
+ return NULL;
+ if (result)
+ return result;
+ }
+ result = sk;
+ badness = score;
+ }
+ }
+ return result;
+}
+EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
+
+static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
+ __be16 sport, __be16 dport,
+ struct udp_table *udptable)
+{
+ const struct iphdr *iph = ip_hdr(skb);
+
+ return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport,
+ iph->daddr, dport, inet_iif(skb),
+ inet_sdif(skb), udptable, skb);
+}
+
+struct sock *udp4_lib_lookup_skb(struct sk_buff *skb,
+ __be16 sport, __be16 dport)
+{
+ return __udp4_lib_lookup_skb(skb, sport, dport, &udp_table);
+}
+EXPORT_SYMBOL_GPL(udp4_lib_lookup_skb);
+
+/* Must be called under rcu_read_lock().
+ * Does increment socket refcount.
+ */
+#if IS_ENABLED(CONFIG_NF_TPROXY_IPV4) || IS_ENABLED(CONFIG_NF_SOCKET_IPV4)
+struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
+ __be32 daddr, __be16 dport, int dif)
+{
+ struct sock *sk;
+
+ sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport,
+ dif, 0, &udp_table, NULL);
+ if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
+ sk = NULL;
+ return sk;
+}
+EXPORT_SYMBOL_GPL(udp4_lib_lookup);
+#endif
+
+static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk,
+ __be16 loc_port, __be32 loc_addr,
+ __be16 rmt_port, __be32 rmt_addr,
+ int dif, int sdif, unsigned short hnum)
+{
+ struct inet_sock *inet = inet_sk(sk);
+
+ if (!net_eq(sock_net(sk), net) ||
+ udp_sk(sk)->udp_port_hash != hnum ||
+ (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
+ (inet->inet_dport != rmt_port && inet->inet_dport) ||
+ (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) ||
+ ipv6_only_sock(sk) ||
+ (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif &&
+ sk->sk_bound_dev_if != sdif))
+ return false;
+ if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif, sdif))
+ return false;
+ return true;
+}
+
+/*
+ * This routine is called by the ICMP module when it gets some
+ * sort of error condition. If err < 0 then the socket should
+ * be closed and the error returned to the user. If err > 0
+ * it's just the icmp type << 8 | icmp code.
+ * Header points to the ip header of the error packet. We move
+ * on past this. Then (as it used to claim before adjustment)
+ * header points to the first 8 bytes of the udp header. We need
+ * to find the appropriate port.
+ */
+
+void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
+{
+ struct inet_sock *inet;
+ const struct iphdr *iph = (const struct iphdr *)skb->data;
+ struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
+ const int type = icmp_hdr(skb)->type;
+ const int code = icmp_hdr(skb)->code;
+ struct sock *sk;
+ int harderr;
+ int err;
+ struct net *net = dev_net(skb->dev);
+
+ sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
+ iph->saddr, uh->source, skb->dev->ifindex, 0,
+ udptable, NULL);
+ if (!sk) {
+ __ICMP_INC_STATS(net, ICMP_MIB_INERRORS);
+ return; /* No socket for error */
+ }
+
+ err = 0;
+ harderr = 0;
+ inet = inet_sk(sk);
+
+ switch (type) {
+ default:
+ case ICMP_TIME_EXCEEDED:
+ err = EHOSTUNREACH;
+ break;
+ case ICMP_SOURCE_QUENCH:
+ goto out;
+ case ICMP_PARAMETERPROB:
+ err = EPROTO;
+ harderr = 1;
+ break;
+ case ICMP_DEST_UNREACH:
+ if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
+ ipv4_sk_update_pmtu(skb, sk, info);
+ if (inet->pmtudisc != IP_PMTUDISC_DONT) {
+ err = EMSGSIZE;
+ harderr = 1;
+ break;
+ }
+ goto out;
+ }
+ err = EHOSTUNREACH;
+ if (code <= NR_ICMP_UNREACH) {
+ harderr = icmp_err_convert[code].fatal;
+ err = icmp_err_convert[code].errno;
+ }
+ break;
+ case ICMP_REDIRECT:
+ ipv4_sk_redirect(skb, sk);
+ goto out;
+ }
+
+ /*
+ * RFC1122: OK. Passes ICMP errors back to application, as per
+ * 4.1.3.3.
+ */
+ if (!inet->recverr) {
+ if (!harderr || sk->sk_state != TCP_ESTABLISHED)
+ goto out;
+ } else
+ ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
+
+ sk->sk_err = err;
+ sk->sk_error_report(sk);
+out:
+ return;
+}
+
+void udp_err(struct sk_buff *skb, u32 info)
+{
+ __udp4_lib_err(skb, info, &udp_table);
+}
+
+/*
+ * Throw away all pending data and cancel the corking. Socket is locked.
+ */
+void udp_flush_pending_frames(struct sock *sk)
+{
+ struct udp_sock *up = udp_sk(sk);
+
+ if (up->pending) {
+ up->len = 0;
+ up->pending = 0;
+ ip_flush_pending_frames(sk);
+ }
+}
+EXPORT_SYMBOL(udp_flush_pending_frames);
+
+/**
+ * udp4_hwcsum - handle outgoing HW checksumming
+ * @skb: sk_buff containing the filled-in UDP header
+ * (checksum field must be zeroed out)
+ * @src: source IP address
+ * @dst: destination IP address
+ */
+void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst)
+{
+ struct udphdr *uh = udp_hdr(skb);
+ int offset = skb_transport_offset(skb);
+ int len = skb->len - offset;
+ int hlen = len;
+ __wsum csum = 0;
+
+ if (!skb_has_frag_list(skb)) {
+ /*
+ * Only one fragment on the socket.
+ */
+ skb->csum_start = skb_transport_header(skb) - skb->head;
+ skb->csum_offset = offsetof(struct udphdr, check);
+ uh->check = ~csum_tcpudp_magic(src, dst, len,
+ IPPROTO_UDP, 0);
+ } else {
+ struct sk_buff *frags;
+
+ /*
+ * HW-checksum won't work as there are two or more
+ * fragments on the socket so that all csums of sk_buffs
+ * should be together
+ */
+ skb_walk_frags(skb, frags) {
+ csum = csum_add(csum, frags->csum);
+ hlen -= frags->len;
+ }
+
+ csum = skb_checksum(skb, offset, hlen, csum);
+ skb->ip_summed = CHECKSUM_NONE;
+
+ uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
+ if (uh->check == 0)
+ uh->check = CSUM_MANGLED_0;
+ }
+}
+EXPORT_SYMBOL_GPL(udp4_hwcsum);
+
+/* Function to set UDP checksum for an IPv4 UDP packet. This is intended
+ * for the simple case like when setting the checksum for a UDP tunnel.
+ */
+void udp_set_csum(bool nocheck, struct sk_buff *skb,
+ __be32 saddr, __be32 daddr, int len)
+{
+ struct udphdr *uh = udp_hdr(skb);
+
+ if (nocheck) {
+ uh->check = 0;
+ } else if (skb_is_gso(skb)) {
+ uh->check = ~udp_v4_check(len, saddr, daddr, 0);
+ } else if (skb->ip_summed == CHECKSUM_PARTIAL) {
+ uh->check = 0;
+ uh->check = udp_v4_check(len, saddr, daddr, lco_csum(skb));
+ if (uh->check == 0)
+ uh->check = CSUM_MANGLED_0;
+ } else {
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ skb->csum_start = skb_transport_header(skb) - skb->head;
+ skb->csum_offset = offsetof(struct udphdr, check);
+ uh->check = ~udp_v4_check(len, saddr, daddr, 0);
+ }
+}
+EXPORT_SYMBOL(udp_set_csum);
+
+static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4,
+ struct inet_cork *cork)
+{
+ struct sock *sk = skb->sk;
+ struct inet_sock *inet = inet_sk(sk);
+ struct udphdr *uh;
+ int err = 0;
+ int is_udplite = IS_UDPLITE(sk);
+ int offset = skb_transport_offset(skb);
+ int len = skb->len - offset;
+ __wsum csum = 0;
+
+ /*
+ * Create a UDP header
+ */
+ uh = udp_hdr(skb);
+ uh->source = inet->inet_sport;
+ uh->dest = fl4->fl4_dport;
+ uh->len = htons(len);
+ uh->check = 0;
+
+ if (cork->gso_size) {
+ const int hlen = skb_network_header_len(skb) +
+ sizeof(struct udphdr);
+
+ if (hlen + cork->gso_size > cork->fragsize)
+ return -EINVAL;
+ if (skb->len > cork->gso_size * UDP_MAX_SEGMENTS)
+ return -EINVAL;
+ if (sk->sk_no_check_tx)
+ return -EINVAL;
+ if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite ||
+ dst_xfrm(skb_dst(skb)))
+ return -EIO;
+
+ skb_shinfo(skb)->gso_size = cork->gso_size;
+ skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
+ skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(len - sizeof(uh),
+ cork->gso_size);
+ goto csum_partial;
+ }
+
+ if (is_udplite) /* UDP-Lite */
+ csum = udplite_csum(skb);
+
+ else if (sk->sk_no_check_tx) { /* UDP csum off */
+
+ skb->ip_summed = CHECKSUM_NONE;
+ goto send;
+
+ } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
+csum_partial:
+
+ udp4_hwcsum(skb, fl4->saddr, fl4->daddr);
+ goto send;
+
+ } else
+ csum = udp_csum(skb);
+
+ /* add protocol-dependent pseudo-header */
+ uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len,
+ sk->sk_protocol, csum);
+ if (uh->check == 0)
+ uh->check = CSUM_MANGLED_0;
+
+send:
+ err = ip_send_skb(sock_net(sk), skb);
+ if (err) {
+ if (err == -ENOBUFS && !inet->recverr) {
+ UDP_INC_STATS(sock_net(sk),
+ UDP_MIB_SNDBUFERRORS, is_udplite);
+ err = 0;
+ }
+ } else
+ UDP_INC_STATS(sock_net(sk),
+ UDP_MIB_OUTDATAGRAMS, is_udplite);
+ return err;
+}
+
+/*
+ * Push out all pending data as one UDP datagram. Socket is locked.
+ */
+int udp_push_pending_frames(struct sock *sk)
+{
+ struct udp_sock *up = udp_sk(sk);
+ struct inet_sock *inet = inet_sk(sk);
+ struct flowi4 *fl4 = &inet->cork.fl.u.ip4;
+ struct sk_buff *skb;
+ int err = 0;
+
+ skb = ip_finish_skb(sk, fl4);
+ if (!skb)
+ goto out;
+
+ err = udp_send_skb(skb, fl4, &inet->cork.base);
+
+out:
+ up->len = 0;
+ up->pending = 0;
+ return err;
+}
+EXPORT_SYMBOL(udp_push_pending_frames);
+
+static int __udp_cmsg_send(struct cmsghdr *cmsg, u16 *gso_size)
+{
+ switch (cmsg->cmsg_type) {
+ case UDP_SEGMENT:
+ if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u16)))
+ return -EINVAL;
+ *gso_size = *(__u16 *)CMSG_DATA(cmsg);
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size)
+{
+ struct cmsghdr *cmsg;
+ bool need_ip = false;
+ int err;
+
+ for_each_cmsghdr(cmsg, msg) {
+ if (!CMSG_OK(msg, cmsg))
+ return -EINVAL;
+
+ if (cmsg->cmsg_level != SOL_UDP) {
+ need_ip = true;
+ continue;
+ }
+
+ err = __udp_cmsg_send(cmsg, gso_size);
+ if (err)
+ return err;
+ }
+
+ return need_ip;
+}
+EXPORT_SYMBOL_GPL(udp_cmsg_send);
+
+int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
+{
+ struct inet_sock *inet = inet_sk(sk);
+ struct udp_sock *up = udp_sk(sk);
+ DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
+ struct flowi4 fl4_stack;
+ struct flowi4 *fl4;
+ int ulen = len;
+ struct ipcm_cookie ipc;
+ struct rtable *rt = NULL;
+ int free = 0;
+ int connected = 0;
+ __be32 daddr, faddr, saddr;
+ __be16 dport;
+ u8 tos;
+ int err, is_udplite = IS_UDPLITE(sk);
+ int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
+ int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
+ struct sk_buff *skb;
+ struct ip_options_data opt_copy;
+
+ if (len > 0xFFFF)
+ return -EMSGSIZE;
+
+ /*
+ * Check the flags.
+ */
+
+ if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
+ return -EOPNOTSUPP;
+
+ getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
+
+ fl4 = &inet->cork.fl.u.ip4;
+ if (up->pending) {
+ /*
+ * There are pending frames.
+ * The socket lock must be held while it's corked.
+ */
+ lock_sock(sk);
+ if (likely(up->pending)) {
+ if (unlikely(up->pending != AF_INET)) {
+ release_sock(sk);
+ return -EINVAL;
+ }
+ goto do_append_data;
+ }
+ release_sock(sk);
+ }
+ ulen += sizeof(struct udphdr);
+
+ /*
+ * Get and verify the address.
+ */
+ if (usin) {
+ if (msg->msg_namelen < sizeof(*usin))
+ return -EINVAL;
+ if (usin->sin_family != AF_INET) {
+ if (usin->sin_family != AF_UNSPEC)
+ return -EAFNOSUPPORT;
+ }
+
+ daddr = usin->sin_addr.s_addr;
+ dport = usin->sin_port;
+ if (dport == 0)
+ return -EINVAL;
+ } else {
+ if (sk->sk_state != TCP_ESTABLISHED)
+ return -EDESTADDRREQ;
+ daddr = inet->inet_daddr;
+ dport = inet->inet_dport;
+ /* Open fast path for connected socket.
+ Route will not be used, if at least one option is set.
+ */
+ connected = 1;
+ }
+
+ ipcm_init_sk(&ipc, inet);
+ ipc.gso_size = up->gso_size;
+
+ if (msg->msg_controllen) {
+ err = udp_cmsg_send(sk, msg, &ipc.gso_size);
+ if (err > 0)
+ err = ip_cmsg_send(sk, msg, &ipc,
+ sk->sk_family == AF_INET6);
+ if (unlikely(err < 0)) {
+ kfree(ipc.opt);
+ return err;
+ }
+ if (ipc.opt)
+ free = 1;
+ connected = 0;
+ }
+ if (!ipc.opt) {
+ struct ip_options_rcu *inet_opt;
+
+ rcu_read_lock();
+ inet_opt = rcu_dereference(inet->inet_opt);
+ if (inet_opt) {
+ memcpy(&opt_copy, inet_opt,
+ sizeof(*inet_opt) + inet_opt->opt.optlen);
+ ipc.opt = &opt_copy.opt;
+ }
+ rcu_read_unlock();
+ }
+
+ if (cgroup_bpf_enabled && !connected) {
+ err = BPF_CGROUP_RUN_PROG_UDP4_SENDMSG_LOCK(sk,
+ (struct sockaddr *)usin, &ipc.addr);
+ if (err)
+ goto out_free;
+ if (usin) {
+ if (usin->sin_port == 0) {
+ /* BPF program set invalid port. Reject it. */
+ err = -EINVAL;
+ goto out_free;
+ }
+ daddr = usin->sin_addr.s_addr;
+ dport = usin->sin_port;
+ }
+ }
+
+ saddr = ipc.addr;
+ ipc.addr = faddr = daddr;
+
+ if (ipc.opt && ipc.opt->opt.srr) {
+ if (!daddr) {
+ err = -EINVAL;
+ goto out_free;
+ }
+ faddr = ipc.opt->opt.faddr;
+ connected = 0;
+ }
+ tos = get_rttos(&ipc, inet);
+ if (sock_flag(sk, SOCK_LOCALROUTE) ||
+ (msg->msg_flags & MSG_DONTROUTE) ||
+ (ipc.opt && ipc.opt->opt.is_strictroute)) {
+ tos |= RTO_ONLINK;
+ connected = 0;
+ }
+
+ if (ipv4_is_multicast(daddr)) {
+ if (!ipc.oif)
+ ipc.oif = inet->mc_index;
+ if (!saddr)
+ saddr = inet->mc_addr;
+ connected = 0;
+ } else if (!ipc.oif) {
+ ipc.oif = inet->uc_index;
+ } else if (ipv4_is_lbcast(daddr) && inet->uc_index) {
+ /* oif is set, packet is to local broadcast and
+ * and uc_index is set. oif is most likely set
+ * by sk_bound_dev_if. If uc_index != oif check if the
+ * oif is an L3 master and uc_index is an L3 slave.
+ * If so, we want to allow the send using the uc_index.
+ */
+ if (ipc.oif != inet->uc_index &&
+ ipc.oif == l3mdev_master_ifindex_by_index(sock_net(sk),
+ inet->uc_index)) {
+ ipc.oif = inet->uc_index;
+ }
+ }
+
+ if (connected)
+ rt = (struct rtable *)sk_dst_check(sk, 0);
+
+ if (!rt) {
+ struct net *net = sock_net(sk);
+ __u8 flow_flags = inet_sk_flowi_flags(sk);
+
+ fl4 = &fl4_stack;
+
+ flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos,
+ RT_SCOPE_UNIVERSE, sk->sk_protocol,
+ flow_flags,
+ faddr, saddr, dport, inet->inet_sport,
+ sk->sk_uid);
+
+ security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
+ rt = ip_route_output_flow(net, fl4, sk);
+ if (IS_ERR(rt)) {
+ err = PTR_ERR(rt);
+ rt = NULL;
+ if (err == -ENETUNREACH)
+ IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
+ goto out;
+ }
+
+ err = -EACCES;
+ if ((rt->rt_flags & RTCF_BROADCAST) &&
+ !sock_flag(sk, SOCK_BROADCAST))
+ goto out;
+ if (connected)
+ sk_dst_set(sk, dst_clone(&rt->dst));
+ }
+
+ if (msg->msg_flags&MSG_CONFIRM)
+ goto do_confirm;
+back_from_confirm:
+
+ saddr = fl4->saddr;
+ if (!ipc.addr)
+ daddr = ipc.addr = fl4->daddr;
+
+ /* Lockless fast path for the non-corking case. */
+ if (!corkreq) {
+ struct inet_cork cork;
+
+ skb = ip_make_skb(sk, fl4, getfrag, msg, ulen,
+ sizeof(struct udphdr), &ipc, &rt,
+ &cork, msg->msg_flags);
+ err = PTR_ERR(skb);
+ if (!IS_ERR_OR_NULL(skb))
+ err = udp_send_skb(skb, fl4, &cork);
+ goto out;
+ }
+
+ lock_sock(sk);
+ if (unlikely(up->pending)) {
+ /* The socket is already corked while preparing it. */
+ /* ... which is an evident application bug. --ANK */
+ release_sock(sk);
+
+ net_dbg_ratelimited("socket already corked\n");
+ err = -EINVAL;
+ goto out;
+ }
+ /*
+ * Now cork the socket to pend data.
+ */
+ fl4 = &inet->cork.fl.u.ip4;
+ fl4->daddr = daddr;
+ fl4->saddr = saddr;
+ fl4->fl4_dport = dport;
+ fl4->fl4_sport = inet->inet_sport;
+ up->pending = AF_INET;
+
+do_append_data:
+ up->len += ulen;
+ err = ip_append_data(sk, fl4, getfrag, msg, ulen,
+ sizeof(struct udphdr), &ipc, &rt,
+ corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
+ if (err)
+ udp_flush_pending_frames(sk);
+ else if (!corkreq)
+ err = udp_push_pending_frames(sk);
+ else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
+ up->pending = 0;
+ release_sock(sk);
+
+out:
+ ip_rt_put(rt);
+out_free:
+ if (free)
+ kfree(ipc.opt);
+ if (!err)
+ return len;
+ /*
+ * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
+ * ENOBUFS might not be good (it's not tunable per se), but otherwise
+ * we don't have a good statistic (IpOutDiscards but it can be too many
+ * things). We could add another new stat but at least for now that
+ * seems like overkill.
+ */
+ if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
+ UDP_INC_STATS(sock_net(sk),
+ UDP_MIB_SNDBUFERRORS, is_udplite);
+ }
+ return err;
+
+do_confirm:
+ if (msg->msg_flags & MSG_PROBE)
+ dst_confirm_neigh(&rt->dst, &fl4->daddr);
+ if (!(msg->msg_flags&MSG_PROBE) || len)
+ goto back_from_confirm;
+ err = 0;
+ goto out;
+}
+EXPORT_SYMBOL(udp_sendmsg);
+
+int udp_sendpage(struct sock *sk, struct page *page, int offset,
+ size_t size, int flags)
+{
+ struct inet_sock *inet = inet_sk(sk);
+ struct udp_sock *up = udp_sk(sk);
+ int ret;
+
+ if (flags & MSG_SENDPAGE_NOTLAST)
+ flags |= MSG_MORE;
+
+ if (!up->pending) {
+ struct msghdr msg = { .msg_flags = flags|MSG_MORE };
+
+ /* Call udp_sendmsg to specify destination address which
+ * sendpage interface can't pass.
+ * This will succeed only when the socket is connected.
+ */
+ ret = udp_sendmsg(sk, &msg, 0);
+ if (ret < 0)
+ return ret;
+ }
+
+ lock_sock(sk);
+
+ if (unlikely(!up->pending)) {
+ release_sock(sk);
+
+ net_dbg_ratelimited("cork failed\n");
+ return -EINVAL;
+ }
+
+ ret = ip_append_page(sk, &inet->cork.fl.u.ip4,
+ page, offset, size, flags);
+ if (ret == -EOPNOTSUPP) {
+ release_sock(sk);
+ return sock_no_sendpage(sk->sk_socket, page, offset,
+ size, flags);
+ }
+ if (ret < 0) {
+ udp_flush_pending_frames(sk);
+ goto out;
+ }
+
+ up->len += size;
+ if (!(up->corkflag || (flags&MSG_MORE)))
+ ret = udp_push_pending_frames(sk);
+ if (!ret)
+ ret = size;
+out:
+ release_sock(sk);
+ return ret;
+}
+
+#define UDP_SKB_IS_STATELESS 0x80000000
+
+static void udp_set_dev_scratch(struct sk_buff *skb)
+{
+ struct udp_dev_scratch *scratch = udp_skb_scratch(skb);
+
+ BUILD_BUG_ON(sizeof(struct udp_dev_scratch) > sizeof(long));
+ scratch->_tsize_state = skb->truesize;
+#if BITS_PER_LONG == 64
+ scratch->len = skb->len;
+ scratch->csum_unnecessary = !!skb_csum_unnecessary(skb);
+ scratch->is_linear = !skb_is_nonlinear(skb);
+#endif
+ /* all head states execept sp (dst, sk, nf) are always cleared by
+ * udp_rcv() and we need to preserve secpath, if present, to eventually
+ * process IP_CMSG_PASSSEC at recvmsg() time
+ */
+ if (likely(!skb_sec_path(skb)))
+ scratch->_tsize_state |= UDP_SKB_IS_STATELESS;
+}
+
+static int udp_skb_truesize(struct sk_buff *skb)
+{
+ return udp_skb_scratch(skb)->_tsize_state & ~UDP_SKB_IS_STATELESS;
+}
+
+static bool udp_skb_has_head_state(struct sk_buff *skb)
+{
+ return !(udp_skb_scratch(skb)->_tsize_state & UDP_SKB_IS_STATELESS);
+}
+
+/* fully reclaim rmem/fwd memory allocated for skb */
+static void udp_rmem_release(struct sock *sk, int size, int partial,
+ bool rx_queue_lock_held)
+{
+ struct udp_sock *up = udp_sk(sk);
+ struct sk_buff_head *sk_queue;
+ int amt;
+
+ if (likely(partial)) {
+ up->forward_deficit += size;
+ size = up->forward_deficit;
+ if (size < (sk->sk_rcvbuf >> 2))
+ return;
+ } else {
+ size += up->forward_deficit;
+ }
+ up->forward_deficit = 0;
+
+ /* acquire the sk_receive_queue for fwd allocated memory scheduling,
+ * if the called don't held it already
+ */
+ sk_queue = &sk->sk_receive_queue;
+ if (!rx_queue_lock_held)
+ spin_lock(&sk_queue->lock);
+
+
+ sk->sk_forward_alloc += size;
+ amt = (sk->sk_forward_alloc - partial) & ~(SK_MEM_QUANTUM - 1);
+ sk->sk_forward_alloc -= amt;
+
+ if (amt)
+ __sk_mem_reduce_allocated(sk, amt >> SK_MEM_QUANTUM_SHIFT);
+
+ atomic_sub(size, &sk->sk_rmem_alloc);
+
+ /* this can save us from acquiring the rx queue lock on next receive */
+ skb_queue_splice_tail_init(sk_queue, &up->reader_queue);
+
+ if (!rx_queue_lock_held)
+ spin_unlock(&sk_queue->lock);
+}
+
+/* Note: called with reader_queue.lock held.
+ * Instead of using skb->truesize here, find a copy of it in skb->dev_scratch
+ * This avoids a cache line miss while receive_queue lock is held.
+ * Look at __udp_enqueue_schedule_skb() to find where this copy is done.
+ */
+void udp_skb_destructor(struct sock *sk, struct sk_buff *skb)
+{
+ prefetch(&skb->data);
+ udp_rmem_release(sk, udp_skb_truesize(skb), 1, false);
+}
+EXPORT_SYMBOL(udp_skb_destructor);
+
+/* as above, but the caller held the rx queue lock, too */
+static void udp_skb_dtor_locked(struct sock *sk, struct sk_buff *skb)
+{
+ prefetch(&skb->data);
+ udp_rmem_release(sk, udp_skb_truesize(skb), 1, true);
+}
+
+/* Idea of busylocks is to let producers grab an extra spinlock
+ * to relieve pressure on the receive_queue spinlock shared by consumer.
+ * Under flood, this means that only one producer can be in line
+ * trying to acquire the receive_queue spinlock.
+ * These busylock can be allocated on a per cpu manner, instead of a
+ * per socket one (that would consume a cache line per socket)
+ */
+static int udp_busylocks_log __read_mostly;
+static spinlock_t *udp_busylocks __read_mostly;
+
+static spinlock_t *busylock_acquire(void *ptr)
+{
+ spinlock_t *busy;
+
+ busy = udp_busylocks + hash_ptr(ptr, udp_busylocks_log);
+ spin_lock(busy);
+ return busy;
+}
+
+static void busylock_release(spinlock_t *busy)
+{
+ if (busy)
+ spin_unlock(busy);
+}
+
+int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb)
+{
+ struct sk_buff_head *list = &sk->sk_receive_queue;
+ int rmem, delta, amt, err = -ENOMEM;
+ spinlock_t *busy = NULL;
+ int size;
+
+ /* try to avoid the costly atomic add/sub pair when the receive
+ * queue is full; always allow at least a packet
+ */
+ rmem = atomic_read(&sk->sk_rmem_alloc);
+ if (rmem > sk->sk_rcvbuf)
+ goto drop;
+
+ /* Under mem pressure, it might be helpful to help udp_recvmsg()
+ * having linear skbs :
+ * - Reduce memory overhead and thus increase receive queue capacity
+ * - Less cache line misses at copyout() time
+ * - Less work at consume_skb() (less alien page frag freeing)
+ */
+ if (rmem > (sk->sk_rcvbuf >> 1)) {
+ skb_condense(skb);
+
+ busy = busylock_acquire(sk);
+ }
+ size = skb->truesize;
+ udp_set_dev_scratch(skb);
+
+ /* we drop only if the receive buf is full and the receive
+ * queue contains some other skb
+ */
+ rmem = atomic_add_return(size, &sk->sk_rmem_alloc);
+ if (rmem > (size + sk->sk_rcvbuf))
+ goto uncharge_drop;
+
+ spin_lock(&list->lock);
+ if (size >= sk->sk_forward_alloc) {
+ amt = sk_mem_pages(size);
+ delta = amt << SK_MEM_QUANTUM_SHIFT;
+ if (!__sk_mem_raise_allocated(sk, delta, amt, SK_MEM_RECV)) {
+ err = -ENOBUFS;
+ spin_unlock(&list->lock);
+ goto uncharge_drop;
+ }
+
+ sk->sk_forward_alloc += delta;
+ }
+
+ sk->sk_forward_alloc -= size;
+
+ /* no need to setup a destructor, we will explicitly release the
+ * forward allocated memory on dequeue
+ */
+ sock_skb_set_dropcount(sk, skb);
+
+ __skb_queue_tail(list, skb);
+ spin_unlock(&list->lock);
+
+ if (!sock_flag(sk, SOCK_DEAD))
+ sk->sk_data_ready(sk);
+
+ busylock_release(busy);
+ return 0;
+
+uncharge_drop:
+ atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
+
+drop:
+ atomic_inc(&sk->sk_drops);
+ busylock_release(busy);
+ return err;
+}
+EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb);
+
+void udp_destruct_sock(struct sock *sk)
+{
+ /* reclaim completely the forward allocated memory */
+ struct udp_sock *up = udp_sk(sk);
+ unsigned int total = 0;
+ struct sk_buff *skb;
+
+ skb_queue_splice_tail_init(&sk->sk_receive_queue, &up->reader_queue);
+ while ((skb = __skb_dequeue(&up->reader_queue)) != NULL) {
+ total += skb->truesize;
+ kfree_skb(skb);
+ }
+ udp_rmem_release(sk, total, 0, true);
+
+ inet_sock_destruct(sk);
+}
+EXPORT_SYMBOL_GPL(udp_destruct_sock);
+
+int udp_init_sock(struct sock *sk)
+{
+ skb_queue_head_init(&udp_sk(sk)->reader_queue);
+ sk->sk_destruct = udp_destruct_sock;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(udp_init_sock);
+
+void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len)
+{
+ if (unlikely(READ_ONCE(sk->sk_peek_off) >= 0)) {
+ bool slow = lock_sock_fast(sk);
+
+ sk_peek_offset_bwd(sk, len);
+ unlock_sock_fast(sk, slow);
+ }
+
+ if (!skb_unref(skb))
+ return;
+
+ /* In the more common cases we cleared the head states previously,
+ * see __udp_queue_rcv_skb().
+ */
+ if (unlikely(udp_skb_has_head_state(skb)))
+ skb_release_head_state(skb);
+ __consume_stateless_skb(skb);
+}
+EXPORT_SYMBOL_GPL(skb_consume_udp);
+
+static struct sk_buff *__first_packet_length(struct sock *sk,
+ struct sk_buff_head *rcvq,
+ int *total)
+{
+ struct sk_buff *skb;
+
+ while ((skb = skb_peek(rcvq)) != NULL) {
+ if (udp_lib_checksum_complete(skb)) {
+ __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS,
+ IS_UDPLITE(sk));
+ __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
+ IS_UDPLITE(sk));
+ atomic_inc(&sk->sk_drops);
+ __skb_unlink(skb, rcvq);
+ *total += skb->truesize;
+ kfree_skb(skb);
+ } else {
+ /* the csum related bits could be changed, refresh
+ * the scratch area
+ */
+ udp_set_dev_scratch(skb);
+ break;
+ }
+ }
+ return skb;
+}
+
+/**
+ * first_packet_length - return length of first packet in receive queue
+ * @sk: socket
+ *
+ * Drops all bad checksum frames, until a valid one is found.
+ * Returns the length of found skb, or -1 if none is found.
+ */
+static int first_packet_length(struct sock *sk)
+{
+ struct sk_buff_head *rcvq = &udp_sk(sk)->reader_queue;
+ struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
+ struct sk_buff *skb;
+ int total = 0;
+ int res;
+
+ spin_lock_bh(&rcvq->lock);
+ skb = __first_packet_length(sk, rcvq, &total);
+ if (!skb && !skb_queue_empty(sk_queue)) {
+ spin_lock(&sk_queue->lock);
+ skb_queue_splice_tail_init(sk_queue, rcvq);
+ spin_unlock(&sk_queue->lock);
+
+ skb = __first_packet_length(sk, rcvq, &total);
+ }
+ res = skb ? skb->len : -1;
+ if (total)
+ udp_rmem_release(sk, total, 1, false);
+ spin_unlock_bh(&rcvq->lock);
+ return res;
+}
+
+/*
+ * IOCTL requests applicable to the UDP protocol
+ */
+
+int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
+{
+ switch (cmd) {
+ case SIOCOUTQ:
+ {
+ int amount = sk_wmem_alloc_get(sk);
+
+ return put_user(amount, (int __user *)arg);
+ }
+
+ case SIOCINQ:
+ {
+ int amount = max_t(int, 0, first_packet_length(sk));
+
+ return put_user(amount, (int __user *)arg);
+ }
+
+ default:
+ return -ENOIOCTLCMD;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(udp_ioctl);
+
+struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags,
+ int noblock, int *peeked, int *off, int *err)
+{
+ struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
+ struct sk_buff_head *queue;
+ struct sk_buff *last;
+ long timeo;
+ int error;
+
+ queue = &udp_sk(sk)->reader_queue;
+ flags |= noblock ? MSG_DONTWAIT : 0;
+ timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
+ do {
+ struct sk_buff *skb;
+
+ error = sock_error(sk);
+ if (error)
+ break;
+
+ error = -EAGAIN;
+ *peeked = 0;
+ do {
+ spin_lock_bh(&queue->lock);
+ skb = __skb_try_recv_from_queue(sk, queue, flags,
+ udp_skb_destructor,
+ peeked, off, err,
+ &last);
+ if (skb) {
+ spin_unlock_bh(&queue->lock);
+ return skb;
+ }
+
+ if (skb_queue_empty(sk_queue)) {
+ spin_unlock_bh(&queue->lock);
+ goto busy_check;
+ }
+
+ /* refill the reader queue and walk it again
+ * keep both queues locked to avoid re-acquiring
+ * the sk_receive_queue lock if fwd memory scheduling
+ * is needed.
+ */
+ spin_lock(&sk_queue->lock);
+ skb_queue_splice_tail_init(sk_queue, queue);
+
+ skb = __skb_try_recv_from_queue(sk, queue, flags,
+ udp_skb_dtor_locked,
+ peeked, off, err,
+ &last);
+ spin_unlock(&sk_queue->lock);
+ spin_unlock_bh(&queue->lock);
+ if (skb)
+ return skb;
+
+busy_check:
+ if (!sk_can_busy_loop(sk))
+ break;
+
+ sk_busy_loop(sk, flags & MSG_DONTWAIT);
+ } while (!skb_queue_empty(sk_queue));
+
+ /* sk_queue is empty, reader_queue may contain peeked packets */
+ } while (timeo &&
+ !__skb_wait_for_more_packets(sk, &error, &timeo,
+ (struct sk_buff *)sk_queue));
+
+ *err = error;
+ return NULL;
+}
+EXPORT_SYMBOL(__skb_recv_udp);
+
+/*
+ * This should be easy, if there is something there we
+ * return it, otherwise we block.
+ */
+
+int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
+ int flags, int *addr_len)
+{
+ struct inet_sock *inet = inet_sk(sk);
+ DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
+ struct sk_buff *skb;
+ unsigned int ulen, copied;
+ int peeked, peeking, off;
+ int err;
+ int is_udplite = IS_UDPLITE(sk);
+ bool checksum_valid = false;
+
+ if (flags & MSG_ERRQUEUE)
+ return ip_recv_error(sk, msg, len, addr_len);
+
+try_again:
+ peeking = flags & MSG_PEEK;
+ off = sk_peek_offset(sk, flags);
+ skb = __skb_recv_udp(sk, flags, noblock, &peeked, &off, &err);
+ if (!skb)
+ return err;
+
+ ulen = udp_skb_len(skb);
+ copied = len;
+ if (copied > ulen - off)
+ copied = ulen - off;
+ else if (copied < ulen)
+ msg->msg_flags |= MSG_TRUNC;
+
+ /*
+ * If checksum is needed at all, try to do it while copying the
+ * data. If the data is truncated, or if we only want a partial
+ * coverage checksum (UDP-Lite), do it before the copy.
+ */
+
+ if (copied < ulen || peeking ||
+ (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
+ checksum_valid = udp_skb_csum_unnecessary(skb) ||
+ !__udp_lib_checksum_complete(skb);
+ if (!checksum_valid)
+ goto csum_copy_err;
+ }
+
+ if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
+ if (udp_skb_is_linear(skb))
+ err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
+ else
+ err = skb_copy_datagram_msg(skb, off, msg, copied);
+ } else {
+ err = skb_copy_and_csum_datagram_msg(skb, off, msg);
+
+ if (err == -EINVAL)
+ goto csum_copy_err;
+ }
+
+ if (unlikely(err)) {
+ if (!peeked) {
+ atomic_inc(&sk->sk_drops);
+ UDP_INC_STATS(sock_net(sk),
+ UDP_MIB_INERRORS, is_udplite);
+ }
+ kfree_skb(skb);
+ return err;
+ }
+
+ if (!peeked)
+ UDP_INC_STATS(sock_net(sk),
+ UDP_MIB_INDATAGRAMS, is_udplite);
+
+ sock_recv_ts_and_drops(msg, sk, skb);
+
+ /* Copy the address. */
+ if (sin) {
+ sin->sin_family = AF_INET;
+ sin->sin_port = udp_hdr(skb)->source;
+ sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
+ memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
+ *addr_len = sizeof(*sin);
+ }
+ if (inet->cmsg_flags)
+ ip_cmsg_recv_offset(msg, sk, skb, sizeof(struct udphdr), off);
+
+ err = copied;
+ if (flags & MSG_TRUNC)
+ err = ulen;
+
+ skb_consume_udp(sk, skb, peeking ? -err : err);
+ return err;
+
+csum_copy_err:
+ if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
+ udp_skb_destructor)) {
+ UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
+ UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
+ }
+ kfree_skb(skb);
+
+ /* starting over for a new packet, but check if we need to yield */
+ cond_resched();
+ msg->msg_flags &= ~MSG_TRUNC;
+ goto try_again;
+}
+
+int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
+{
+ /* This check is replicated from __ip4_datagram_connect() and
+ * intended to prevent BPF program called below from accessing bytes
+ * that are out of the bound specified by user in addr_len.
+ */
+ if (addr_len < sizeof(struct sockaddr_in))
+ return -EINVAL;
+
+ return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr);
+}
+EXPORT_SYMBOL(udp_pre_connect);
+
+int __udp_disconnect(struct sock *sk, int flags)
+{
+ struct inet_sock *inet = inet_sk(sk);
+ /*
+ * 1003.1g - break association.
+ */
+
+ sk->sk_state = TCP_CLOSE;
+ inet->inet_daddr = 0;
+ inet->inet_dport = 0;
+ sock_rps_reset_rxhash(sk);
+ sk->sk_bound_dev_if = 0;
+ if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
+ inet_reset_saddr(sk);
+
+ if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
+ sk->sk_prot->unhash(sk);
+ inet->inet_sport = 0;
+ }
+ sk_dst_reset(sk);
+ return 0;
+}
+EXPORT_SYMBOL(__udp_disconnect);
+
+int udp_disconnect(struct sock *sk, int flags)
+{
+ lock_sock(sk);
+ __udp_disconnect(sk, flags);
+ release_sock(sk);
+ return 0;
+}
+EXPORT_SYMBOL(udp_disconnect);
+
+void udp_lib_unhash(struct sock *sk)
+{
+ if (sk_hashed(sk)) {
+ struct udp_table *udptable = sk->sk_prot->h.udp_table;
+ struct udp_hslot *hslot, *hslot2;
+
+ hslot = udp_hashslot(udptable, sock_net(sk),
+ udp_sk(sk)->udp_port_hash);
+ hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
+
+ spin_lock_bh(&hslot->lock);
+ if (rcu_access_pointer(sk->sk_reuseport_cb))
+ reuseport_detach_sock(sk);
+ if (sk_del_node_init_rcu(sk)) {
+ hslot->count--;
+ inet_sk(sk)->inet_num = 0;
+ sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
+
+ spin_lock(&hslot2->lock);
+ hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
+ hslot2->count--;
+ spin_unlock(&hslot2->lock);
+ }
+ spin_unlock_bh(&hslot->lock);
+ }
+}
+EXPORT_SYMBOL(udp_lib_unhash);
+
+/*
+ * inet_rcv_saddr was changed, we must rehash secondary hash
+ */
+void udp_lib_rehash(struct sock *sk, u16 newhash)
+{
+ if (sk_hashed(sk)) {
+ struct udp_table *udptable = sk->sk_prot->h.udp_table;
+ struct udp_hslot *hslot, *hslot2, *nhslot2;
+
+ hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
+ nhslot2 = udp_hashslot2(udptable, newhash);
+ udp_sk(sk)->udp_portaddr_hash = newhash;
+
+ if (hslot2 != nhslot2 ||
+ rcu_access_pointer(sk->sk_reuseport_cb)) {
+ hslot = udp_hashslot(udptable, sock_net(sk),
+ udp_sk(sk)->udp_port_hash);
+ /* we must lock primary chain too */
+ spin_lock_bh(&hslot->lock);
+ if (rcu_access_pointer(sk->sk_reuseport_cb))
+ reuseport_detach_sock(sk);
+
+ if (hslot2 != nhslot2) {
+ spin_lock(&hslot2->lock);
+ hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
+ hslot2->count--;
+ spin_unlock(&hslot2->lock);
+
+ spin_lock(&nhslot2->lock);
+ hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
+ &nhslot2->head);
+ nhslot2->count++;
+ spin_unlock(&nhslot2->lock);
+ }
+
+ spin_unlock_bh(&hslot->lock);
+ }
+ }
+}
+EXPORT_SYMBOL(udp_lib_rehash);
+
+static void udp_v4_rehash(struct sock *sk)
+{
+ u16 new_hash = ipv4_portaddr_hash(sock_net(sk),
+ inet_sk(sk)->inet_rcv_saddr,
+ inet_sk(sk)->inet_num);
+ udp_lib_rehash(sk, new_hash);
+}
+
+static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+ int rc;
+
+ if (inet_sk(sk)->inet_daddr) {
+ sock_rps_save_rxhash(sk, skb);
+ sk_mark_napi_id(sk, skb);
+ sk_incoming_cpu_update(sk);
+ } else {
+ sk_mark_napi_id_once(sk, skb);
+ }
+
+ rc = __udp_enqueue_schedule_skb(sk, skb);
+ if (rc < 0) {
+ int is_udplite = IS_UDPLITE(sk);
+
+ /* Note that an ENOMEM error is charged twice */
+ if (rc == -ENOMEM)
+ UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS,
+ is_udplite);
+ UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
+ kfree_skb(skb);
+ trace_udp_fail_queue_rcv_skb(rc, sk);
+ return -1;
+ }
+
+ return 0;
+}
+
+static DEFINE_STATIC_KEY_FALSE(udp_encap_needed_key);
+void udp_encap_enable(void)
+{
+ static_branch_enable(&udp_encap_needed_key);
+}
+EXPORT_SYMBOL(udp_encap_enable);
+
+/* returns:
+ * -1: error
+ * 0: success
+ * >0: "udp encap" protocol resubmission
+ *
+ * Note that in the success and error cases, the skb is assumed to
+ * have either been requeued or freed.
+ */
+static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+ struct udp_sock *up = udp_sk(sk);
+ int is_udplite = IS_UDPLITE(sk);
+
+ /*
+ * Charge it to the socket, dropping if the queue is full.
+ */
+ if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
+ goto drop;
+ nf_reset(skb);
+
+ if (static_branch_unlikely(&udp_encap_needed_key) && up->encap_type) {
+ int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
+
+ /*
+ * This is an encapsulation socket so pass the skb to
+ * the socket's udp_encap_rcv() hook. Otherwise, just
+ * fall through and pass this up the UDP socket.
+ * up->encap_rcv() returns the following value:
+ * =0 if skb was successfully passed to the encap
+ * handler or was discarded by it.
+ * >0 if skb should be passed on to UDP.
+ * <0 if skb should be resubmitted as proto -N
+ */
+
+ /* if we're overly short, let UDP handle it */
+ encap_rcv = READ_ONCE(up->encap_rcv);
+ if (encap_rcv) {
+ int ret;
+
+ /* Verify checksum before giving to encap */
+ if (udp_lib_checksum_complete(skb))
+ goto csum_error;
+
+ ret = encap_rcv(sk, skb);
+ if (ret <= 0) {
+ __UDP_INC_STATS(sock_net(sk),
+ UDP_MIB_INDATAGRAMS,
+ is_udplite);
+ return -ret;
+ }
+ }
+
+ /* FALLTHROUGH -- it's a UDP Packet */
+ }
+
+ /*
+ * UDP-Lite specific tests, ignored on UDP sockets
+ */
+ if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
+
+ /*
+ * MIB statistics other than incrementing the error count are
+ * disabled for the following two types of errors: these depend
+ * on the application settings, not on the functioning of the
+ * protocol stack as such.
+ *
+ * RFC 3828 here recommends (sec 3.3): "There should also be a
+ * way ... to ... at least let the receiving application block
+ * delivery of packets with coverage values less than a value
+ * provided by the application."
+ */
+ if (up->pcrlen == 0) { /* full coverage was set */
+ net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n",
+ UDP_SKB_CB(skb)->cscov, skb->len);
+ goto drop;
+ }
+ /* The next case involves violating the min. coverage requested
+ * by the receiver. This is subtle: if receiver wants x and x is
+ * greater than the buffersize/MTU then receiver will complain
+ * that it wants x while sender emits packets of smaller size y.
+ * Therefore the above ...()->partial_cov statement is essential.
+ */
+ if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
+ net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n",
+ UDP_SKB_CB(skb)->cscov, up->pcrlen);
+ goto drop;
+ }
+ }
+
+ prefetch(&sk->sk_rmem_alloc);
+ if (rcu_access_pointer(sk->sk_filter) &&
+ udp_lib_checksum_complete(skb))
+ goto csum_error;
+
+ if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
+ goto drop;
+
+ udp_csum_pull_header(skb);
+
+ ipv4_pktinfo_prepare(sk, skb);
+ return __udp_queue_rcv_skb(sk, skb);
+
+csum_error:
+ __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
+drop:
+ __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
+ atomic_inc(&sk->sk_drops);
+ kfree_skb(skb);
+ return -1;
+}
+
+/* For TCP sockets, sk_rx_dst is protected by socket lock
+ * For UDP, we use xchg() to guard against concurrent changes.
+ */
+bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
+{
+ struct dst_entry *old;
+
+ if (dst_hold_safe(dst)) {
+ old = xchg(&sk->sk_rx_dst, dst);
+ dst_release(old);
+ return old != dst;
+ }
+ return false;
+}
+EXPORT_SYMBOL(udp_sk_rx_dst_set);
+
+/*
+ * Multicasts and broadcasts go to each listener.
+ *
+ * Note: called only from the BH handler context.
+ */
+static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
+ struct udphdr *uh,
+ __be32 saddr, __be32 daddr,
+ struct udp_table *udptable,
+ int proto)
+{
+ struct sock *sk, *first = NULL;
+ unsigned short hnum = ntohs(uh->dest);
+ struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
+ unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
+ unsigned int offset = offsetof(typeof(*sk), sk_node);
+ int dif = skb->dev->ifindex;
+ int sdif = inet_sdif(skb);
+ struct hlist_node *node;
+ struct sk_buff *nskb;
+
+ if (use_hash2) {
+ hash2_any = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum) &
+ udptable->mask;
+ hash2 = ipv4_portaddr_hash(net, daddr, hnum) & udptable->mask;
+start_lookup:
+ hslot = &udptable->hash2[hash2];
+ offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
+ }
+
+ sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
+ if (!__udp_is_mcast_sock(net, sk, uh->dest, daddr,
+ uh->source, saddr, dif, sdif, hnum))
+ continue;
+
+ if (!first) {
+ first = sk;
+ continue;
+ }
+ nskb = skb_clone(skb, GFP_ATOMIC);
+
+ if (unlikely(!nskb)) {
+ atomic_inc(&sk->sk_drops);
+ __UDP_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
+ IS_UDPLITE(sk));
+ __UDP_INC_STATS(net, UDP_MIB_INERRORS,
+ IS_UDPLITE(sk));
+ continue;
+ }
+ if (udp_queue_rcv_skb(sk, nskb) > 0)
+ consume_skb(nskb);
+ }
+
+ /* Also lookup *:port if we are using hash2 and haven't done so yet. */
+ if (use_hash2 && hash2 != hash2_any) {
+ hash2 = hash2_any;
+ goto start_lookup;
+ }
+
+ if (first) {
+ if (udp_queue_rcv_skb(first, skb) > 0)
+ consume_skb(skb);
+ } else {
+ kfree_skb(skb);
+ __UDP_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
+ proto == IPPROTO_UDPLITE);
+ }
+ return 0;
+}
+
+/* Initialize UDP checksum. If exited with zero value (success),
+ * CHECKSUM_UNNECESSARY means, that no more checks are required.
+ * Otherwise, csum completion requires chacksumming packet body,
+ * including udp header and folding it to skb->csum.
+ */
+static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
+ int proto)
+{
+ int err;
+
+ UDP_SKB_CB(skb)->partial_cov = 0;
+ UDP_SKB_CB(skb)->cscov = skb->len;
+
+ if (proto == IPPROTO_UDPLITE) {
+ err = udplite_checksum_init(skb, uh);
+ if (err)
+ return err;
+
+ if (UDP_SKB_CB(skb)->partial_cov) {
+ skb->csum = inet_compute_pseudo(skb, proto);
+ return 0;
+ }
+ }
+
+ /* Note, we are only interested in != 0 or == 0, thus the
+ * force to int.
+ */
+ err = (__force int)skb_checksum_init_zero_check(skb, proto, uh->check,
+ inet_compute_pseudo);
+ if (err)
+ return err;
+
+ if (skb->ip_summed == CHECKSUM_COMPLETE && !skb->csum_valid) {
+ /* If SW calculated the value, we know it's bad */
+ if (skb->csum_complete_sw)
+ return 1;
+
+ /* HW says the value is bad. Let's validate that.
+ * skb->csum is no longer the full packet checksum,
+ * so don't treat it as such.
+ */
+ skb_checksum_complete_unset(skb);
+ }
+
+ return 0;
+}
+
+/* wrapper for udp_queue_rcv_skb tacking care of csum conversion and
+ * return code conversion for ip layer consumption
+ */
+static int udp_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,
+ struct udphdr *uh)
+{
+ int ret;
+
+ if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
+ skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
+ inet_compute_pseudo);
+
+ ret = udp_queue_rcv_skb(sk, skb);
+
+ /* a return value > 0 means to resubmit the input, but
+ * it wants the return to be -protocol, or 0
+ */
+ if (ret > 0)
+ return -ret;
+ return 0;
+}
+
+/*
+ * All we need to do is get the socket, and then do a checksum.
+ */
+
+int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
+ int proto)
+{
+ struct sock *sk;
+ struct udphdr *uh;
+ unsigned short ulen;
+ struct rtable *rt = skb_rtable(skb);
+ __be32 saddr, daddr;
+ struct net *net = dev_net(skb->dev);
+
+ /*
+ * Validate the packet.
+ */
+ if (!pskb_may_pull(skb, sizeof(struct udphdr)))
+ goto drop; /* No space for header. */
+
+ uh = udp_hdr(skb);
+ ulen = ntohs(uh->len);
+ saddr = ip_hdr(skb)->saddr;
+ daddr = ip_hdr(skb)->daddr;
+
+ if (ulen > skb->len)
+ goto short_packet;
+
+ if (proto == IPPROTO_UDP) {
+ /* UDP validates ulen. */
+ if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
+ goto short_packet;
+ uh = udp_hdr(skb);
+ }
+
+ if (udp4_csum_init(skb, uh, proto))
+ goto csum_error;
+
+ sk = skb_steal_sock(skb);
+ if (sk) {
+ struct dst_entry *dst = skb_dst(skb);
+ int ret;
+
+ if (unlikely(sk->sk_rx_dst != dst))
+ udp_sk_rx_dst_set(sk, dst);
+
+ ret = udp_unicast_rcv_skb(sk, skb, uh);
+ sock_put(sk);
+ return ret;
+ }
+
+ if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
+ return __udp4_lib_mcast_deliver(net, skb, uh,
+ saddr, daddr, udptable, proto);
+
+ sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
+ if (sk)
+ return udp_unicast_rcv_skb(sk, skb, uh);
+
+ if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
+ goto drop;
+ nf_reset(skb);
+
+ /* No socket. Drop packet silently, if checksum is wrong */
+ if (udp_lib_checksum_complete(skb))
+ goto csum_error;
+
+ __UDP_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
+ icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
+
+ /*
+ * Hmm. We got an UDP packet to a port to which we
+ * don't wanna listen. Ignore it.
+ */
+ kfree_skb(skb);
+ return 0;
+
+short_packet:
+ net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
+ proto == IPPROTO_UDPLITE ? "Lite" : "",
+ &saddr, ntohs(uh->source),
+ ulen, skb->len,
+ &daddr, ntohs(uh->dest));
+ goto drop;
+
+csum_error:
+ /*
+ * RFC1122: OK. Discards the bad packet silently (as far as
+ * the network is concerned, anyway) as per 4.1.3.4 (MUST).
+ */
+ net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
+ proto == IPPROTO_UDPLITE ? "Lite" : "",
+ &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest),
+ ulen);
+ __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
+drop:
+ __UDP_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
+ kfree_skb(skb);
+ return 0;
+}
+
+/* We can only early demux multicast if there is a single matching socket.
+ * If more than one socket found returns NULL
+ */
+static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net,
+ __be16 loc_port, __be32 loc_addr,
+ __be16 rmt_port, __be32 rmt_addr,
+ int dif, int sdif)
+{
+ struct sock *sk, *result;
+ unsigned short hnum = ntohs(loc_port);
+ unsigned int slot = udp_hashfn(net, hnum, udp_table.mask);
+ struct udp_hslot *hslot = &udp_table.hash[slot];
+
+ /* Do not bother scanning a too big list */
+ if (hslot->count > 10)
+ return NULL;
+
+ result = NULL;
+ sk_for_each_rcu(sk, &hslot->head) {
+ if (__udp_is_mcast_sock(net, sk, loc_port, loc_addr,
+ rmt_port, rmt_addr, dif, sdif, hnum)) {
+ if (result)
+ return NULL;
+ result = sk;
+ }
+ }
+
+ return result;
+}
+
+/* For unicast we should only early demux connected sockets or we can
+ * break forwarding setups. The chains here can be long so only check
+ * if the first socket is an exact match and if not move on.
+ */
+static struct sock *__udp4_lib_demux_lookup(struct net *net,
+ __be16 loc_port, __be32 loc_addr,
+ __be16 rmt_port, __be32 rmt_addr,
+ int dif, int sdif)
+{
+ unsigned short hnum = ntohs(loc_port);
+ unsigned int hash2 = ipv4_portaddr_hash(net, loc_addr, hnum);
+ unsigned int slot2 = hash2 & udp_table.mask;
+ struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
+ INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr);
+ const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
+ struct sock *sk;
+
+ udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
+ if (INET_MATCH(sk, net, acookie, rmt_addr,
+ loc_addr, ports, dif, sdif))
+ return sk;
+ /* Only check first socket in chain */
+ break;
+ }
+ return NULL;
+}
+
+int udp_v4_early_demux(struct sk_buff *skb)
+{
+ struct net *net = dev_net(skb->dev);
+ struct in_device *in_dev = NULL;
+ const struct iphdr *iph;
+ const struct udphdr *uh;
+ struct sock *sk = NULL;
+ struct dst_entry *dst;
+ int dif = skb->dev->ifindex;
+ int sdif = inet_sdif(skb);
+ int ours;
+
+ /* validate the packet */
+ if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr)))
+ return 0;
+
+ iph = ip_hdr(skb);
+ uh = udp_hdr(skb);
+
+ if (skb->pkt_type == PACKET_MULTICAST) {
+ in_dev = __in_dev_get_rcu(skb->dev);
+
+ if (!in_dev)
+ return 0;
+
+ ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr,
+ iph->protocol);
+ if (!ours)
+ return 0;
+
+ sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr,
+ uh->source, iph->saddr,
+ dif, sdif);
+ } else if (skb->pkt_type == PACKET_HOST) {
+ sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr,
+ uh->source, iph->saddr, dif, sdif);
+ }
+
+ if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
+ return 0;
+
+ skb->sk = sk;
+ skb->destructor = sock_efree;
+ dst = READ_ONCE(sk->sk_rx_dst);
+
+ if (dst)
+ dst = dst_check(dst, 0);
+ if (dst) {
+ u32 itag = 0;
+
+ /* set noref for now.
+ * any place which wants to hold dst has to call
+ * dst_hold_safe()
+ */
+ skb_dst_set_noref(skb, dst);
+
+ /* for unconnected multicast sockets we need to validate
+ * the source on each packet
+ */
+ if (!inet_sk(sk)->inet_daddr && in_dev)
+ return ip_mc_validate_source(skb, iph->daddr,
+ iph->saddr, iph->tos,
+ skb->dev, in_dev, &itag);
+ }
+ return 0;
+}
+
+int udp_rcv(struct sk_buff *skb)
+{
+ return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
+}
+
+void udp_destroy_sock(struct sock *sk)
+{
+ struct udp_sock *up = udp_sk(sk);
+ bool slow = lock_sock_fast(sk);
+ udp_flush_pending_frames(sk);
+ unlock_sock_fast(sk, slow);
+ if (static_branch_unlikely(&udp_encap_needed_key) && up->encap_type) {
+ void (*encap_destroy)(struct sock *sk);
+ encap_destroy = READ_ONCE(up->encap_destroy);
+ if (encap_destroy)
+ encap_destroy(sk);
+ }
+}
+
+/*
+ * Socket option code for UDP
+ */
+int udp_lib_setsockopt(struct sock *sk, int level, int optname,
+ char __user *optval, unsigned int optlen,
+ int (*push_pending_frames)(struct sock *))
+{
+ struct udp_sock *up = udp_sk(sk);
+ int val, valbool;
+ int err = 0;
+ int is_udplite = IS_UDPLITE(sk);
+
+ if (optlen < sizeof(int))
+ return -EINVAL;
+
+ if (get_user(val, (int __user *)optval))
+ return -EFAULT;
+
+ valbool = val ? 1 : 0;
+
+ switch (optname) {
+ case UDP_CORK:
+ if (val != 0) {
+ up->corkflag = 1;
+ } else {
+ up->corkflag = 0;
+ lock_sock(sk);
+ push_pending_frames(sk);
+ release_sock(sk);
+ }
+ break;
+
+ case UDP_ENCAP:
+ switch (val) {
+ case 0:
+ case UDP_ENCAP_ESPINUDP:
+ case UDP_ENCAP_ESPINUDP_NON_IKE:
+ up->encap_rcv = xfrm4_udp_encap_rcv;
+ /* FALLTHROUGH */
+ case UDP_ENCAP_L2TPINUDP:
+ up->encap_type = val;
+ udp_encap_enable();
+ break;
+ default:
+ err = -ENOPROTOOPT;
+ break;
+ }
+ break;
+
+ case UDP_NO_CHECK6_TX:
+ up->no_check6_tx = valbool;
+ break;
+
+ case UDP_NO_CHECK6_RX:
+ up->no_check6_rx = valbool;
+ break;
+
+ case UDP_SEGMENT:
+ if (val < 0 || val > USHRT_MAX)
+ return -EINVAL;
+ up->gso_size = val;
+ break;
+
+ /*
+ * UDP-Lite's partial checksum coverage (RFC 3828).
+ */
+ /* The sender sets actual checksum coverage length via this option.
+ * The case coverage > packet length is handled by send module. */
+ case UDPLITE_SEND_CSCOV:
+ if (!is_udplite) /* Disable the option on UDP sockets */
+ return -ENOPROTOOPT;
+ if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
+ val = 8;
+ else if (val > USHRT_MAX)
+ val = USHRT_MAX;
+ up->pcslen = val;
+ up->pcflag |= UDPLITE_SEND_CC;
+ break;
+
+ /* The receiver specifies a minimum checksum coverage value. To make
+ * sense, this should be set to at least 8 (as done below). If zero is
+ * used, this again means full checksum coverage. */
+ case UDPLITE_RECV_CSCOV:
+ if (!is_udplite) /* Disable the option on UDP sockets */
+ return -ENOPROTOOPT;
+ if (val != 0 && val < 8) /* Avoid silly minimal values. */
+ val = 8;
+ else if (val > USHRT_MAX)
+ val = USHRT_MAX;
+ up->pcrlen = val;
+ up->pcflag |= UDPLITE_RECV_CC;
+ break;
+
+ default:
+ err = -ENOPROTOOPT;
+ break;
+ }
+
+ return err;
+}
+EXPORT_SYMBOL(udp_lib_setsockopt);
+
+int udp_setsockopt(struct sock *sk, int level, int optname,
+ char __user *optval, unsigned int optlen)
+{
+ if (level == SOL_UDP || level == SOL_UDPLITE)
+ return udp_lib_setsockopt(sk, level, optname, optval, optlen,
+ udp_push_pending_frames);
+ return ip_setsockopt(sk, level, optname, optval, optlen);
+}
+
+#ifdef CONFIG_COMPAT
+int compat_udp_setsockopt(struct sock *sk, int level, int optname,
+ char __user *optval, unsigned int optlen)
+{
+ if (level == SOL_UDP || level == SOL_UDPLITE)
+ return udp_lib_setsockopt(sk, level, optname, optval, optlen,
+ udp_push_pending_frames);
+ return compat_ip_setsockopt(sk, level, optname, optval, optlen);
+}
+#endif
+
+int udp_lib_getsockopt(struct sock *sk, int level, int optname,
+ char __user *optval, int __user *optlen)
+{
+ struct udp_sock *up = udp_sk(sk);
+ int val, len;
+
+ if (get_user(len, optlen))
+ return -EFAULT;
+
+ len = min_t(unsigned int, len, sizeof(int));
+
+ if (len < 0)
+ return -EINVAL;
+
+ switch (optname) {
+ case UDP_CORK:
+ val = up->corkflag;
+ break;
+
+ case UDP_ENCAP:
+ val = up->encap_type;
+ break;
+
+ case UDP_NO_CHECK6_TX:
+ val = up->no_check6_tx;
+ break;
+
+ case UDP_NO_CHECK6_RX:
+ val = up->no_check6_rx;
+ break;
+
+ case UDP_SEGMENT:
+ val = up->gso_size;
+ break;
+
+ /* The following two cannot be changed on UDP sockets, the return is
+ * always 0 (which corresponds to the full checksum coverage of UDP). */
+ case UDPLITE_SEND_CSCOV:
+ val = up->pcslen;
+ break;
+
+ case UDPLITE_RECV_CSCOV:
+ val = up->pcrlen;
+ break;
+
+ default:
+ return -ENOPROTOOPT;
+ }
+
+ if (put_user(len, optlen))
+ return -EFAULT;
+ if (copy_to_user(optval, &val, len))
+ return -EFAULT;
+ return 0;
+}
+EXPORT_SYMBOL(udp_lib_getsockopt);
+
+int udp_getsockopt(struct sock *sk, int level, int optname,
+ char __user *optval, int __user *optlen)
+{
+ if (level == SOL_UDP || level == SOL_UDPLITE)
+ return udp_lib_getsockopt(sk, level, optname, optval, optlen);
+ return ip_getsockopt(sk, level, optname, optval, optlen);
+}
+
+#ifdef CONFIG_COMPAT
+int compat_udp_getsockopt(struct sock *sk, int level, int optname,
+ char __user *optval, int __user *optlen)
+{
+ if (level == SOL_UDP || level == SOL_UDPLITE)
+ return udp_lib_getsockopt(sk, level, optname, optval, optlen);
+ return compat_ip_getsockopt(sk, level, optname, optval, optlen);
+}
+#endif
+/**
+ * udp_poll - wait for a UDP event.
+ * @file - file struct
+ * @sock - socket
+ * @wait - poll table
+ *
+ * This is same as datagram poll, except for the special case of
+ * blocking sockets. If application is using a blocking fd
+ * and a packet with checksum error is in the queue;
+ * then it could get return from select indicating data available
+ * but then block when reading it. Add special case code
+ * to work around these arguably broken applications.
+ */
+__poll_t udp_poll(struct file *file, struct socket *sock, poll_table *wait)
+{
+ __poll_t mask = datagram_poll(file, sock, wait);
+ struct sock *sk = sock->sk;
+
+ if (!skb_queue_empty(&udp_sk(sk)->reader_queue))
+ mask |= EPOLLIN | EPOLLRDNORM;
+
+ /* Check for false positives due to checksum errors */
+ if ((mask & EPOLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
+ !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1)
+ mask &= ~(EPOLLIN | EPOLLRDNORM);
+
+ return mask;
+
+}
+EXPORT_SYMBOL(udp_poll);
+
+int udp_abort(struct sock *sk, int err)
+{
+ lock_sock(sk);
+
+ sk->sk_err = err;
+ sk->sk_error_report(sk);
+ __udp_disconnect(sk, 0);
+
+ release_sock(sk);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(udp_abort);
+
+struct proto udp_prot = {
+ .name = "UDP",
+ .owner = THIS_MODULE,
+ .close = udp_lib_close,
+ .pre_connect = udp_pre_connect,
+ .connect = ip4_datagram_connect,
+ .disconnect = udp_disconnect,
+ .ioctl = udp_ioctl,
+ .init = udp_init_sock,
+ .destroy = udp_destroy_sock,
+ .setsockopt = udp_setsockopt,
+ .getsockopt = udp_getsockopt,
+ .sendmsg = udp_sendmsg,
+ .recvmsg = udp_recvmsg,
+ .sendpage = udp_sendpage,
+ .release_cb = ip4_datagram_release_cb,
+ .hash = udp_lib_hash,
+ .unhash = udp_lib_unhash,
+ .rehash = udp_v4_rehash,
+ .get_port = udp_v4_get_port,
+ .memory_allocated = &udp_memory_allocated,
+ .sysctl_mem = sysctl_udp_mem,
+ .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
+ .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
+ .obj_size = sizeof(struct udp_sock),
+ .h.udp_table = &udp_table,
+#ifdef CONFIG_COMPAT
+ .compat_setsockopt = compat_udp_setsockopt,
+ .compat_getsockopt = compat_udp_getsockopt,
+#endif
+ .diag_destroy = udp_abort,
+};
+EXPORT_SYMBOL(udp_prot);
+
+/* ------------------------------------------------------------------------ */
+#ifdef CONFIG_PROC_FS
+
+static struct sock *udp_get_first(struct seq_file *seq, int start)
+{
+ struct sock *sk;
+ struct udp_seq_afinfo *afinfo = PDE_DATA(file_inode(seq->file));
+ struct udp_iter_state *state = seq->private;
+ struct net *net = seq_file_net(seq);
+
+ for (state->bucket = start; state->bucket <= afinfo->udp_table->mask;
+ ++state->bucket) {
+ struct udp_hslot *hslot = &afinfo->udp_table->hash[state->bucket];
+
+ if (hlist_empty(&hslot->head))
+ continue;
+
+ spin_lock_bh(&hslot->lock);
+ sk_for_each(sk, &hslot->head) {
+ if (!net_eq(sock_net(sk), net))
+ continue;
+ if (sk->sk_family == afinfo->family)
+ goto found;
+ }
+ spin_unlock_bh(&hslot->lock);
+ }
+ sk = NULL;
+found:
+ return sk;
+}
+
+static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
+{
+ struct udp_seq_afinfo *afinfo = PDE_DATA(file_inode(seq->file));
+ struct udp_iter_state *state = seq->private;
+ struct net *net = seq_file_net(seq);
+
+ do {
+ sk = sk_next(sk);
+ } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != afinfo->family));
+
+ if (!sk) {
+ if (state->bucket <= afinfo->udp_table->mask)
+ spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock);
+ return udp_get_first(seq, state->bucket + 1);
+ }
+ return sk;
+}
+
+static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
+{
+ struct sock *sk = udp_get_first(seq, 0);
+
+ if (sk)
+ while (pos && (sk = udp_get_next(seq, sk)) != NULL)
+ --pos;
+ return pos ? NULL : sk;
+}
+
+void *udp_seq_start(struct seq_file *seq, loff_t *pos)
+{
+ struct udp_iter_state *state = seq->private;
+ state->bucket = MAX_UDP_PORTS;
+
+ return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
+}
+EXPORT_SYMBOL(udp_seq_start);
+
+void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+ struct sock *sk;
+
+ if (v == SEQ_START_TOKEN)
+ sk = udp_get_idx(seq, 0);
+ else
+ sk = udp_get_next(seq, v);
+
+ ++*pos;
+ return sk;
+}
+EXPORT_SYMBOL(udp_seq_next);
+
+void udp_seq_stop(struct seq_file *seq, void *v)
+{
+ struct udp_seq_afinfo *afinfo = PDE_DATA(file_inode(seq->file));
+ struct udp_iter_state *state = seq->private;
+
+ if (state->bucket <= afinfo->udp_table->mask)
+ spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock);
+}
+EXPORT_SYMBOL(udp_seq_stop);
+
+/* ------------------------------------------------------------------------ */
+static void udp4_format_sock(struct sock *sp, struct seq_file *f,
+ int bucket)
+{
+ struct inet_sock *inet = inet_sk(sp);
+ __be32 dest = inet->inet_daddr;
+ __be32 src = inet->inet_rcv_saddr;
+ __u16 destp = ntohs(inet->inet_dport);
+ __u16 srcp = ntohs(inet->inet_sport);
+
+ seq_printf(f, "%5d: %08X:%04X %08X:%04X"
+ " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
+ bucket, src, srcp, dest, destp, sp->sk_state,
+ sk_wmem_alloc_get(sp),
+ udp_rqueue_get(sp),
+ 0, 0L, 0,
+ from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
+ 0, sock_i_ino(sp),
+ refcount_read(&sp->sk_refcnt), sp,
+ atomic_read(&sp->sk_drops));
+}
+
+int udp4_seq_show(struct seq_file *seq, void *v)
+{
+ seq_setwidth(seq, 127);
+ if (v == SEQ_START_TOKEN)
+ seq_puts(seq, " sl local_address rem_address st tx_queue "
+ "rx_queue tr tm->when retrnsmt uid timeout "
+ "inode ref pointer drops");
+ else {
+ struct udp_iter_state *state = seq->private;
+
+ udp4_format_sock(v, seq, state->bucket);
+ }
+ seq_pad(seq, '\n');
+ return 0;
+}
+
+const struct seq_operations udp_seq_ops = {
+ .start = udp_seq_start,
+ .next = udp_seq_next,
+ .stop = udp_seq_stop,
+ .show = udp4_seq_show,
+};
+EXPORT_SYMBOL(udp_seq_ops);
+
+static struct udp_seq_afinfo udp4_seq_afinfo = {
+ .family = AF_INET,
+ .udp_table = &udp_table,
+};
+
+static int __net_init udp4_proc_init_net(struct net *net)
+{
+ if (!proc_create_net_data("udp", 0444, net->proc_net, &udp_seq_ops,
+ sizeof(struct udp_iter_state), &udp4_seq_afinfo))
+ return -ENOMEM;
+ return 0;
+}
+
+static void __net_exit udp4_proc_exit_net(struct net *net)
+{
+ remove_proc_entry("udp", net->proc_net);
+}
+
+static struct pernet_operations udp4_net_ops = {
+ .init = udp4_proc_init_net,
+ .exit = udp4_proc_exit_net,
+};
+
+int __init udp4_proc_init(void)
+{
+ return register_pernet_subsys(&udp4_net_ops);
+}
+
+void udp4_proc_exit(void)
+{
+ unregister_pernet_subsys(&udp4_net_ops);
+}
+#endif /* CONFIG_PROC_FS */
+
+static __initdata unsigned long uhash_entries;
+static int __init set_uhash_entries(char *str)
+{
+ ssize_t ret;
+
+ if (!str)
+ return 0;
+
+ ret = kstrtoul(str, 0, &uhash_entries);
+ if (ret)
+ return 0;
+
+ if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
+ uhash_entries = UDP_HTABLE_SIZE_MIN;
+ return 1;
+}
+__setup("uhash_entries=", set_uhash_entries);
+
+void __init udp_table_init(struct udp_table *table, const char *name)
+{
+ unsigned int i;
+
+ table->hash = alloc_large_system_hash(name,
+ 2 * sizeof(struct udp_hslot),
+ uhash_entries,
+ 21, /* one slot per 2 MB */
+ 0,
+ &table->log,
+ &table->mask,
+ UDP_HTABLE_SIZE_MIN,
+ 64 * 1024);
+
+ table->hash2 = table->hash + (table->mask + 1);
+ for (i = 0; i <= table->mask; i++) {
+ INIT_HLIST_HEAD(&table->hash[i].head);
+ table->hash[i].count = 0;
+ spin_lock_init(&table->hash[i].lock);
+ }
+ for (i = 0; i <= table->mask; i++) {
+ INIT_HLIST_HEAD(&table->hash2[i].head);
+ table->hash2[i].count = 0;
+ spin_lock_init(&table->hash2[i].lock);
+ }
+}
+
+u32 udp_flow_hashrnd(void)
+{
+ static u32 hashrnd __read_mostly;
+
+ net_get_random_once(&hashrnd, sizeof(hashrnd));
+
+ return hashrnd;
+}
+EXPORT_SYMBOL(udp_flow_hashrnd);
+
+static void __udp_sysctl_init(struct net *net)
+{
+ net->ipv4.sysctl_udp_rmem_min = SK_MEM_QUANTUM;
+ net->ipv4.sysctl_udp_wmem_min = SK_MEM_QUANTUM;
+
+#ifdef CONFIG_NET_L3_MASTER_DEV
+ net->ipv4.sysctl_udp_l3mdev_accept = 0;
+#endif
+}
+
+static int __net_init udp_sysctl_init(struct net *net)
+{
+ __udp_sysctl_init(net);
+ return 0;
+}
+
+static struct pernet_operations __net_initdata udp_sysctl_ops = {
+ .init = udp_sysctl_init,
+};
+
+void __init udp_init(void)
+{
+ unsigned long limit;
+ unsigned int i;
+
+ udp_table_init(&udp_table, "UDP");
+ limit = nr_free_buffer_pages() / 8;
+ limit = max(limit, 128UL);
+ sysctl_udp_mem[0] = limit / 4 * 3;
+ sysctl_udp_mem[1] = limit;
+ sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
+
+ __udp_sysctl_init(&init_net);
+
+ /* 16 spinlocks per cpu */
+ udp_busylocks_log = ilog2(nr_cpu_ids) + 4;
+ udp_busylocks = kmalloc(sizeof(spinlock_t) << udp_busylocks_log,
+ GFP_KERNEL);
+ if (!udp_busylocks)
+ panic("UDP: failed to alloc udp_busylocks\n");
+ for (i = 0; i < (1U << udp_busylocks_log); i++)
+ spin_lock_init(udp_busylocks + i);
+
+ if (register_pernet_subsys(&udp_sysctl_ops))
+ panic("UDP: failed to init sysctl parameters.\n");
+}