/net/ipv4/udp.c
http://github.com/mirrors/linux · C · 3087 lines · 2238 code · 420 blank · 429 comment · 476 complexity · b9e9ebc4d37fda98aee45bb53c4ba105 MD5 · raw file
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- // 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 <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>
- 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;
- 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));
- }
- /* 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;
- 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);
- if (score > badness) {
- if (sk->sk_reuseport &&
- sk->sk_state != TCP_ESTABLISHED) {
- hash = udp_ehashfn(net, daddr, hnum,
- saddr, sport);
- result = reuseport_select_sock(sk, hash, skb,
- sizeof(struct udphdr));
- if (result && !reuseport_has_conns(sk, false))
- 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 *result;
- unsigned short hnum = ntohs(dport);
- unsigned int hash2, slot2;
- struct udp_hslot *hslot2;
- hash2 = ipv4_portaddr_hash(net, daddr, hnum);
- slot2 = hash2 & udptable->mask;
- hslot2 = &udptable->hash2[slot2];
- result = udp4_lib_lookup2(net, saddr, sport,
- daddr, hnum, dif, sdif,
- hslot2, skb);
- if (!result) {
- 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);
- }
- 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);
- /* 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 (skb->len > 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 = 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 || 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
- * 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(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
- /* 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_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 {
- 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_sa…