diff options
Diffstat (limited to '')
| -rw-r--r-- | net/ipv4/udp.c | 3304 |
1 files changed, 3304 insertions, 0 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c new file mode 100644 index 000000000..476f79f15 --- /dev/null +++ b/net/ipv4/udp.c @@ -0,0 +1,3304 @@ +// 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. + * + * 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. + */ + +#define pr_fmt(fmt) "UDP: " fmt + +#include <linux/uaccess.h> +#include <asm/ioctls.h> +#include <linux/memblock.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/ip_tunnels.h> +#include <net/route.h> +#include <net/checksum.h> +#include <net/xfrm.h> +#include <trace/events/udp.h> +#include <linux/static_key.h> +#include <linux/btf_ids.h> +#include <trace/events/skb.h> +#include <net/busy_poll.h> +#include "udp_impl.h" +#include <net/sock_reuseport.h> +#include <net/addrconf.h> +#include <net/udp_tunnel.h> +#if IS_ENABLED(CONFIG_IPV6) +#include <net/ipv6_stubs.h> +#endif + +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) + +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) +{ + int score; + struct inet_sock *inet; + bool dev_match; + + if (!net_eq(sock_net(sk), net) || + udp_sk(sk)->udp_port_hash != hnum || + ipv6_only_sock(sk)) + return -1; + + if (sk->sk_rcv_saddr != daddr) + return -1; + + score = (sk->sk_family == PF_INET) ? 2 : 1; + + inet = inet_sk(sk); + 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; + } + + dev_match = udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, + dif, sdif); + if (!dev_match) + return -1; + if (sk->sk_bound_dev_if) + score += 4; + + if (READ_ONCE(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)); +} + +static struct sock *lookup_reuseport(struct net *net, struct sock *sk, + struct sk_buff *skb, + __be32 saddr, __be16 sport, + __be32 daddr, unsigned short hnum) +{ + struct sock *reuse_sk = NULL; + u32 hash; + + if (sk->sk_reuseport && sk->sk_state != TCP_ESTABLISHED) { + hash = udp_ehashfn(net, daddr, hnum, saddr, sport); + reuse_sk = reuseport_select_sock(sk, hash, skb, + sizeof(struct udphdr)); + } + return reuse_sk; +} + +/* 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, + struct udp_hslot *hslot2, + struct sk_buff *skb) +{ + struct sock *sk, *result; + int score, badness; + + result = NULL; + badness = 0; + udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { + score = compute_score(sk, net, saddr, sport, + daddr, hnum, dif, sdif); + if (score > badness) { + badness = score; + result = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum); + if (!result) { + result = sk; + continue; + } + + /* Fall back to scoring if group has connections */ + if (!reuseport_has_conns(sk)) + return result; + + /* Reuseport logic returned an error, keep original score. */ + if (IS_ERR(result)) + continue; + + badness = compute_score(result, net, saddr, sport, + daddr, hnum, dif, sdif); + + } + } + return result; +} + +static struct sock *udp4_lookup_run_bpf(struct net *net, + struct udp_table *udptable, + struct sk_buff *skb, + __be32 saddr, __be16 sport, + __be32 daddr, u16 hnum) +{ + struct sock *sk, *reuse_sk; + bool no_reuseport; + + if (udptable != &udp_table) + return NULL; /* only UDP is supported */ + + no_reuseport = bpf_sk_lookup_run_v4(net, IPPROTO_UDP, + saddr, sport, daddr, hnum, &sk); + if (no_reuseport || IS_ERR_OR_NULL(sk)) + return sk; + + reuse_sk = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum); + if (reuse_sk) + sk = reuse_sk; + return sk; +} + +/* 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) +{ + unsigned short hnum = ntohs(dport); + unsigned int hash2, slot2; + struct udp_hslot *hslot2; + struct sock *result, *sk; + + hash2 = ipv4_portaddr_hash(net, daddr, hnum); + slot2 = hash2 & udptable->mask; + hslot2 = &udptable->hash2[slot2]; + + /* Lookup connected or non-wildcard socket */ + result = udp4_lib_lookup2(net, saddr, sport, + daddr, hnum, dif, sdif, + hslot2, skb); + if (!IS_ERR_OR_NULL(result) && result->sk_state == TCP_ESTABLISHED) + goto done; + + /* Lookup redirect from BPF */ + if (static_branch_unlikely(&bpf_sk_lookup_enabled)) { + sk = udp4_lookup_run_bpf(net, udptable, skb, + saddr, sport, daddr, hnum); + if (sk) { + result = sk; + goto done; + } + } + + /* Got non-wildcard socket or error on first lookup */ + if (result) + goto done; + + /* Lookup wildcard sockets */ + hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum); + slot2 = hash2 & udptable->mask; + hslot2 = &udptable->hash2[slot2]; + + result = udp4_lib_lookup2(net, saddr, sport, + htonl(INADDR_ANY), hnum, dif, sdif, + hslot2, skb); +done: + if (IS_ERR(result)) + return NULL; + 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) +{ + 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), &udp_table, NULL); +} +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) || + !udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif)) + return false; + if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif, sdif)) + return false; + return true; +} + +DEFINE_STATIC_KEY_FALSE(udp_encap_needed_key); +void udp_encap_enable(void) +{ + static_branch_inc(&udp_encap_needed_key); +} +EXPORT_SYMBOL(udp_encap_enable); + +void udp_encap_disable(void) +{ + static_branch_dec(&udp_encap_needed_key); +} +EXPORT_SYMBOL(udp_encap_disable); + +/* Handler for tunnels with arbitrary destination ports: no socket lookup, go + * through error handlers in encapsulations looking for a match. + */ +static int __udp4_lib_err_encap_no_sk(struct sk_buff *skb, u32 info) +{ + int i; + + for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) { + int (*handler)(struct sk_buff *skb, u32 info); + const struct ip_tunnel_encap_ops *encap; + + encap = rcu_dereference(iptun_encaps[i]); + if (!encap) + continue; + handler = encap->err_handler; + if (handler && !handler(skb, info)) + return 0; + } + + return -ENOENT; +} + +/* Try to match ICMP errors to UDP tunnels by looking up a socket without + * reversing source and destination port: this will match tunnels that force the + * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that + * lwtunnels might actually break this assumption by being configured with + * different destination ports on endpoints, in this case we won't be able to + * trace ICMP messages back to them. + * + * If this doesn't match any socket, probe tunnels with arbitrary destination + * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port + * we've sent packets to won't necessarily match the local destination port. + * + * Then ask the tunnel implementation to match the error against a valid + * association. + * + * Return an error if we can't find a match, the socket if we need further + * processing, zero otherwise. + */ +static struct sock *__udp4_lib_err_encap(struct net *net, + const struct iphdr *iph, + struct udphdr *uh, + struct udp_table *udptable, + struct sk_buff *skb, u32 info) +{ + int network_offset, transport_offset; + struct sock *sk; + + network_offset = skb_network_offset(skb); + transport_offset = skb_transport_offset(skb); + + /* Network header needs to point to the outer IPv4 header inside ICMP */ + skb_reset_network_header(skb); + + /* Transport header needs to point to the UDP header */ + skb_set_transport_header(skb, iph->ihl << 2); + + sk = __udp4_lib_lookup(net, iph->daddr, uh->source, + iph->saddr, uh->dest, skb->dev->ifindex, 0, + udptable, NULL); + if (sk) { + int (*lookup)(struct sock *sk, struct sk_buff *skb); + struct udp_sock *up = udp_sk(sk); + + lookup = READ_ONCE(up->encap_err_lookup); + if (!lookup || lookup(sk, skb)) + sk = NULL; + } + + if (!sk) + sk = ERR_PTR(__udp4_lib_err_encap_no_sk(skb, info)); + + skb_set_transport_header(skb, transport_offset); + skb_set_network_header(skb, network_offset); + + return sk; +} + +/* + * 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. + */ + +int __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; + bool tunnel = false; + 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, + inet_sdif(skb), udptable, NULL); + if (!sk) { + /* No socket for error: try tunnels before discarding */ + sk = ERR_PTR(-ENOENT); + if (static_branch_unlikely(&udp_encap_needed_key)) { + sk = __udp4_lib_err_encap(net, iph, uh, udptable, skb, + info); + if (!sk) + return 0; + } + + if (IS_ERR(sk)) { + __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); + return PTR_ERR(sk); + } + + tunnel = true; + } + + 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 (tunnel) { + /* ...not for tunnels though: we don't have a sending socket */ + goto out; + } + 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 0; +} + +int udp_err(struct sk_buff *skb, u32 info) +{ + return __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; + int datalen = len - sizeof(*uh); + __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) { + kfree_skb(skb); + return -EINVAL; + } + if (datalen > cork->gso_size * UDP_MAX_SEGMENTS) { + kfree_skb(skb); + return -EINVAL; + } + if (sk->sk_no_check_tx) { + kfree_skb(skb); + return -EINVAL; + } + if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite || + dst_xfrm(skb_dst(skb))) { + kfree_skb(skb); + return -EIO; + } + + if (datalen > cork->gso_size) { + 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(datalen, + 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 = READ_ONCE(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 = READ_ONCE(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 || netif_index_is_l3_master(sock_net(sk), 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 + * 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, ipc.sockc.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_common(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 (!(READ_ONCE(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 + +/* all head states (dst, sk, nf conntrack) except skb extensions are + * cleared by udp_rcv(). + * + * We need to preserve secpath, if present, to eventually process + * IP_CMSG_PASSSEC at recvmsg() time. + * + * Other extensions can be cleared. + */ +static bool udp_try_make_stateless(struct sk_buff *skb) +{ + if (!skb_has_extensions(skb)) + return true; + + if (!secpath_exists(skb)) { + skb_ext_reset(skb); + return true; + } + + return false; +} + +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 + if (udp_try_make_stateless(skb)) + scratch->_tsize_state |= UDP_SKB_IS_STATELESS; +} + +static void udp_skb_csum_unnecessary_set(struct sk_buff *skb) +{ + /* We come here after udp_lib_checksum_complete() returned 0. + * This means that __skb_checksum_complete() might have + * set skb->csum_valid to 1. + * On 64bit platforms, we can set csum_unnecessary + * to true, but only if the skb is not shared. + */ +#if BITS_PER_LONG == 64 + if (!skb_shared(skb)) + udp_skb_scratch(skb)->csum_unnecessary = true; +#endif +} + +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) && + !skb_queue_empty(&up->reader_queue)) + 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 + (unsigned int)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_common(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); +} +EXPORT_SYMBOL_GPL(udp_destruct_common); + +static void udp_destruct_sock(struct sock *sk) +{ + udp_destruct_common(sk); + inet_sock_destruct(sk); +} + +int udp_init_sock(struct sock *sk) +{ + skb_queue_head_init(&udp_sk(sk)->reader_queue); + sk->sk_destruct = udp_destruct_sock; + return 0; +} + +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 { + udp_skb_csum_unnecessary_set(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_lockless(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 *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; + do { + spin_lock_bh(&queue->lock); + skb = __skb_try_recv_from_queue(sk, queue, flags, off, + err, &last); + if (skb) { + if (!(flags & MSG_PEEK)) + udp_skb_destructor(sk, skb); + spin_unlock_bh(&queue->lock); + return skb; + } + + if (skb_queue_empty_lockless(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, off, + err, &last); + if (skb && !(flags & MSG_PEEK)) + udp_skb_dtor_locked(sk, skb); + 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_lockless(sk_queue)); + + /* sk_queue is empty, reader_queue may contain peeked packets */ + } while (timeo && + !__skb_wait_for_more_packets(sk, &sk->sk_receive_queue, + &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 off, err, peeking = flags & MSG_PEEK; + 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: + off = sk_peek_offset(sk, flags); + skb = __skb_recv_udp(sk, flags, noblock, &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 (!peeking) { + atomic_inc(&sk->sk_drops); + UDP_INC_STATS(sock_net(sk), + UDP_MIB_INERRORS, is_udplite); + } + kfree_skb(skb); + return err; + } + + if (!peeking) + 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 (cgroup_bpf_enabled) + BPF_CGROUP_RUN_PROG_UDP4_RECVMSG_LOCK(sk, + (struct sockaddr *)sin); + } + + if (udp_sk(sk)->gro_enabled) + udp_cmsg_recv(msg, sk, skb); + + 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_prot->rehash && + (sk->sk_userlocks & SOCK_BINDPORT_LOCK)) + sk->sk_prot->rehash(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); + +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; +} + +/* 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_one_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_ct(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 ((up->pcflag & 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; +} + +static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) +{ + struct sk_buff *next, *segs; + int ret; + + if (likely(!udp_unexpected_gso(sk, skb))) + return udp_queue_rcv_one_skb(sk, skb); + + BUILD_BUG_ON(sizeof(struct udp_skb_cb) > SKB_GSO_CB_OFFSET); + __skb_push(skb, -skb_mac_offset(skb)); + segs = udp_rcv_segment(sk, skb, true); + skb_list_walk_safe(segs, skb, next) { + __skb_pull(skb, skb_transport_offset(skb)); + ret = udp_queue_rcv_one_skb(sk, skb); + if (ret > 0) + ip_protocol_deliver_rcu(dev_net(skb->dev), skb, ret); + } + return 0; +} + +/* 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((__force struct dst_entry **)&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 checksumming 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, 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); + bool refcounted; + + /* + * 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, &refcounted); + if (sk) { + struct dst_entry *dst = skb_dst(skb); + int ret; + + if (unlikely(rcu_dereference(sk->sk_rx_dst) != dst)) + udp_sk_rx_dst_set(sk, dst); + + ret = udp_unicast_rcv_skb(sk, skb, uh); + if (refcounted) + 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_ct(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(net, sk, acookie, 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 = rcu_dereference(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 & IPTOS_RT_MASK, + 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); + + /* protects from races with udp_abort() */ + sock_set_flag(sk, SOCK_DEAD); + udp_flush_pending_frames(sk); + unlock_sock_fast(sk, slow); + if (static_branch_unlikely(&udp_encap_needed_key)) { + if (up->encap_type) { + void (*encap_destroy)(struct sock *sk); + encap_destroy = READ_ONCE(up->encap_destroy); + if (encap_destroy) + encap_destroy(sk); + } + if (up->encap_enabled) + static_branch_dec(&udp_encap_needed_key); + } +} + +/* + * Socket option code for UDP + */ +int udp_lib_setsockopt(struct sock *sk, int level, int optname, + sockptr_t 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 (copy_from_sockptr(&val, optval, sizeof(val))) + return -EFAULT; + + valbool = val ? 1 : 0; + + switch (optname) { + case UDP_CORK: + if (val != 0) { + WRITE_ONCE(up->corkflag, 1); + } else { + WRITE_ONCE(up->corkflag, 0); + lock_sock(sk); + push_pending_frames(sk); + release_sock(sk); + } + break; + + case UDP_ENCAP: + switch (val) { + case 0: +#ifdef CONFIG_XFRM + case UDP_ENCAP_ESPINUDP: + case UDP_ENCAP_ESPINUDP_NON_IKE: +#if IS_ENABLED(CONFIG_IPV6) + if (sk->sk_family == AF_INET6) + WRITE_ONCE(up->encap_rcv, + ipv6_stub->xfrm6_udp_encap_rcv); + else +#endif + WRITE_ONCE(up->encap_rcv, + xfrm4_udp_encap_rcv); +#endif + fallthrough; + case UDP_ENCAP_L2TPINUDP: + up->encap_type = val; + lock_sock(sk); + udp_tunnel_encap_enable(sk->sk_socket); + release_sock(sk); + 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; + WRITE_ONCE(up->gso_size, val); + break; + + case UDP_GRO: + lock_sock(sk); + + /* when enabling GRO, accept the related GSO packet type */ + if (valbool) + udp_tunnel_encap_enable(sk->sk_socket); + up->gro_enabled = valbool; + up->accept_udp_l4 = valbool; + release_sock(sk); + 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, sockptr_t 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); +} + +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 = READ_ONCE(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 = READ_ONCE(up->gso_size); + break; + + case UDP_GRO: + val = up->gro_enabled; + 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); +} + +/** + * 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_lockless(&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); + + /* udp{v6}_destroy_sock() sets it under the sk lock, avoid racing + * with close() + */ + if (sock_flag(sk, SOCK_DEAD)) + goto out; + + sk->sk_err = err; + sk->sk_error_report(sk); + __udp_disconnect(sk, 0); + +out: + 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, + .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; + struct udp_iter_state *state = seq->private; + struct net *net = seq_file_net(seq); + + if (state->bpf_seq_afinfo) + afinfo = state->bpf_seq_afinfo; + else + afinfo = PDE_DATA(file_inode(seq->file)); + + 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 (afinfo->family == AF_UNSPEC || + 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; + struct udp_iter_state *state = seq->private; + struct net *net = seq_file_net(seq); + + if (state->bpf_seq_afinfo) + afinfo = state->bpf_seq_afinfo; + else + afinfo = PDE_DATA(file_inode(seq->file)); + + do { + sk = sk_next(sk); + } while (sk && (!net_eq(sock_net(sk), net) || + (afinfo->family != AF_UNSPEC && + 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; + struct udp_iter_state *state = seq->private; + + if (state->bpf_seq_afinfo) + afinfo = state->bpf_seq_afinfo; + else + afinfo = PDE_DATA(file_inode(seq->file)); + + 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 %u", + 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; +} + +#ifdef CONFIG_BPF_SYSCALL +struct bpf_iter__udp { + __bpf_md_ptr(struct bpf_iter_meta *, meta); + __bpf_md_ptr(struct udp_sock *, udp_sk); + uid_t uid __aligned(8); + int bucket __aligned(8); +}; + +static int udp_prog_seq_show(struct bpf_prog *prog, struct bpf_iter_meta *meta, + struct udp_sock *udp_sk, uid_t uid, int bucket) +{ + struct bpf_iter__udp ctx; + + meta->seq_num--; /* skip SEQ_START_TOKEN */ + ctx.meta = meta; + ctx.udp_sk = udp_sk; + ctx.uid = uid; + ctx.bucket = bucket; + return bpf_iter_run_prog(prog, &ctx); +} + +static int bpf_iter_udp_seq_show(struct seq_file *seq, void *v) +{ + struct udp_iter_state *state = seq->private; + struct bpf_iter_meta meta; + struct bpf_prog *prog; + struct sock *sk = v; + uid_t uid; + + if (v == SEQ_START_TOKEN) + return 0; + + uid = from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)); + meta.seq = seq; + prog = bpf_iter_get_info(&meta, false); + return udp_prog_seq_show(prog, &meta, v, uid, state->bucket); +} + +static void bpf_iter_udp_seq_stop(struct seq_file *seq, void *v) +{ + struct bpf_iter_meta meta; + struct bpf_prog *prog; + + if (!v) { + meta.seq = seq; + prog = bpf_iter_get_info(&meta, true); + if (prog) + (void)udp_prog_seq_show(prog, &meta, v, 0, 0); + } + + udp_seq_stop(seq, v); +} + +static const struct seq_operations bpf_iter_udp_seq_ops = { + .start = udp_seq_start, + .next = udp_seq_next, + .stop = bpf_iter_udp_seq_stop, + .show = bpf_iter_udp_seq_show, +}; +#endif + +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, +}; + +#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) +DEFINE_BPF_ITER_FUNC(udp, struct bpf_iter_meta *meta, + struct udp_sock *udp_sk, uid_t uid, int bucket) + +static int bpf_iter_init_udp(void *priv_data, struct bpf_iter_aux_info *aux) +{ + struct udp_iter_state *st = priv_data; + struct udp_seq_afinfo *afinfo; + int ret; + + afinfo = kmalloc(sizeof(*afinfo), GFP_USER | __GFP_NOWARN); + if (!afinfo) + return -ENOMEM; + + afinfo->family = AF_UNSPEC; + afinfo->udp_table = &udp_table; + st->bpf_seq_afinfo = afinfo; + ret = bpf_iter_init_seq_net(priv_data, aux); + if (ret) + kfree(afinfo); + return ret; +} + +static void bpf_iter_fini_udp(void *priv_data) +{ + struct udp_iter_state *st = priv_data; + + kfree(st->bpf_seq_afinfo); + bpf_iter_fini_seq_net(priv_data); +} + +static const struct bpf_iter_seq_info udp_seq_info = { + .seq_ops = &bpf_iter_udp_seq_ops, + .init_seq_private = bpf_iter_init_udp, + .fini_seq_private = bpf_iter_fini_udp, + .seq_priv_size = sizeof(struct udp_iter_state), +}; + +static struct bpf_iter_reg udp_reg_info = { + .target = "udp", + .ctx_arg_info_size = 1, + .ctx_arg_info = { + { offsetof(struct bpf_iter__udp, udp_sk), + PTR_TO_BTF_ID_OR_NULL }, + }, + .seq_info = &udp_seq_info, +}; + +static void __init bpf_iter_register(void) +{ + udp_reg_info.ctx_arg_info[0].btf_id = btf_sock_ids[BTF_SOCK_TYPE_UDP]; + if (bpf_iter_reg_target(&udp_reg_info)) + pr_warn("Warning: could not register bpf iterator udp\n"); +} +#endif + +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"); + +#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) + bpf_iter_register(); +#endif +} |