| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Eric Dumazet | 3054 | 18.22% | 121 | 19.18% |
| David S. Miller | 1861 | 11.10% | 27 | 4.28% |
| Paolo Abeni | 1649 | 9.84% | 35 | 5.55% |
| Linus Torvalds (pre-git) | 1011 | 6.03% | 59 | 9.35% |
| Hideaki Yoshifuji / 吉藤英明 | 979 | 5.84% | 21 | 3.33% |
| Aditi Ghag | 838 | 5.00% | 5 | 0.79% |
| Yonghong Song | 545 | 3.25% | 6 | 0.95% |
| Kuniyuki Iwashima | 537 | 3.20% | 10 | 1.58% |
| Shawn Bohrer | 429 | 2.56% | 4 | 0.63% |
| Willem de Bruijn | 404 | 2.41% | 13 | 2.06% |
| Arnaldo Carvalho de Melo | 383 | 2.29% | 24 | 3.80% |
| Gerrit Renker | 372 | 2.22% | 4 | 0.63% |
| Stefano Brivio | 325 | 1.94% | 3 | 0.48% |
| Tom Herbert | 305 | 1.82% | 13 | 2.06% |
| Herbert Xu | 283 | 1.69% | 10 | 1.58% |
| Pavel Emelyanov | 254 | 1.52% | 19 | 3.01% |
| Craig Gallek | 219 | 1.31% | 4 | 0.63% |
| Alexey Kuznetsov | 188 | 1.12% | 2 | 0.32% |
| David Ahern | 156 | 0.93% | 7 | 1.11% |
| Américo Wang | 150 | 0.89% | 11 | 1.74% |
| Kazunori Miyazawa | 136 | 0.81% | 1 | 0.16% |
| David Held | 120 | 0.72% | 2 | 0.32% |
| Andrey Ignatov | 117 | 0.70% | 3 | 0.48% |
| KOVACS Krisztian | 117 | 0.70% | 3 | 0.48% |
| Steffen Klassert | 104 | 0.62% | 4 | 0.63% |
| Jakub Sitnicki | 90 | 0.54% | 4 | 0.63% |
| Hideo Aoki | 85 | 0.51% | 1 | 0.16% |
| Stephen Hemminger | 85 | 0.51% | 5 | 0.79% |
| Christoph Hellwig | 80 | 0.48% | 4 | 0.63% |
| Martin KaFai Lau | 77 | 0.46% | 5 | 0.79% |
| David Howells | 74 | 0.44% | 3 | 0.48% |
| Menglong Dong | 74 | 0.44% | 5 | 0.79% |
| Tom Parkin | 68 | 0.41% | 1 | 0.16% |
| Vadim Fedorenko | 67 | 0.40% | 1 | 0.16% |
| Vlad Yasevich | 67 | 0.40% | 3 | 0.48% |
| Tonghao Zhang | 65 | 0.39% | 1 | 0.16% |
| Lorenz Bauer | 62 | 0.37% | 4 | 0.63% |
| Joe Perches | 57 | 0.34% | 7 | 1.11% |
| Jason Xing | 53 | 0.32% | 1 | 0.16% |
| Linus Torvalds | 47 | 0.28% | 7 | 1.11% |
| Sabrina Dubroca | 43 | 0.26% | 3 | 0.48% |
| samanthakumar | 41 | 0.24% | 2 | 0.32% |
| Hannes Frederic Sowa | 39 | 0.23% | 6 | 0.95% |
| Eric Garver | 35 | 0.21% | 1 | 0.16% |
| Al Viro | 35 | 0.21% | 6 | 0.95% |
| Richard Gobert | 34 | 0.20% | 2 | 0.32% |
| Wang Chen | 30 | 0.18% | 3 | 0.48% |
| Florian Westphal | 29 | 0.17% | 2 | 0.32% |
| Sean Tranchetti | 28 | 0.17% | 1 | 0.16% |
| Mike Manning | 26 | 0.16% | 3 | 0.48% |
| Denis V. Lunev | 25 | 0.15% | 7 | 1.11% |
| Edward Cree | 25 | 0.15% | 2 | 0.32% |
| Peilin Ye | 25 | 0.15% | 2 | 0.32% |
| Gabriel Krisman Bertazi | 24 | 0.14% | 1 | 0.16% |
| Xin Long | 22 | 0.13% | 2 | 0.32% |
| Joshua Hunt | 22 | 0.13% | 1 | 0.16% |
| Alexey Kodanev | 21 | 0.13% | 1 | 0.16% |
| Guillaume Nault | 21 | 0.13% | 2 | 0.32% |
| James Chapman | 20 | 0.12% | 3 | 0.48% |
| Derek Atkins | 20 | 0.12% | 1 | 0.16% |
| Antoine Tenart | 19 | 0.11% | 1 | 0.16% |
| Erich E. Hoover | 19 | 0.11% | 1 | 0.16% |
| Rusty Russell | 19 | 0.11% | 1 | 0.16% |
| Daniel Lezcano | 19 | 0.11% | 2 | 0.32% |
| Björn Mork | 18 | 0.11% | 1 | 0.16% |
| Pravin B Shelar | 17 | 0.10% | 2 | 0.32% |
| Eric W. Biedermann | 16 | 0.10% | 3 | 0.48% |
| Rick Jones | 16 | 0.10% | 1 | 0.16% |
| Alexander Duyck | 16 | 0.10% | 2 | 0.32% |
| Eldad Zack | 15 | 0.09% | 1 | 0.16% |
| Yan Zhai | 14 | 0.08% | 1 | 0.16% |
| Julian Anastasov | 14 | 0.08% | 1 | 0.16% |
| Robert Shearman | 14 | 0.08% | 2 | 0.32% |
| Breno Leitão | 13 | 0.08% | 1 | 0.16% |
| Anton Arapov | 13 | 0.08% | 1 | 0.16% |
| Balazs Scheidler | 12 | 0.07% | 2 | 0.32% |
| Pavel Begunkov | 12 | 0.07% | 1 | 0.16% |
| Tetsuo Handa | 11 | 0.07% | 1 | 0.16% |
| Vitaly Mayatskikh | 11 | 0.07% | 1 | 0.16% |
| Alexey Dobriyan | 11 | 0.07% | 3 | 0.48% |
| Dmitry Mishin | 11 | 0.07% | 1 | 0.16% |
| Joe Stringer | 10 | 0.06% | 1 | 0.16% |
| Gavrilov Ilia | 10 | 0.06% | 1 | 0.16% |
| Daan De Meyer | 10 | 0.06% | 1 | 0.16% |
| Daniel Borkmann | 10 | 0.06% | 3 | 0.48% |
| Trond Myklebust | 10 | 0.06% | 2 | 0.32% |
| Samuel Thibault | 9 | 0.05% | 1 | 0.16% |
| Jason A. Donenfeld | 9 | 0.05% | 2 | 0.32% |
| Peter Oskolkov | 9 | 0.05% | 2 | 0.32% |
| Jesper Dangaard Brouer | 8 | 0.05% | 2 | 0.32% |
| Steffen Hurrle | 7 | 0.04% | 1 | 0.16% |
| Xufeng Zhang | 7 | 0.04% | 1 | 0.16% |
| Satoru Moriya | 7 | 0.04% | 1 | 0.16% |
| Ben Hutchings | 7 | 0.04% | 1 | 0.16% |
| Wei Dong | 7 | 0.04% | 1 | 0.16% |
| Wei Wang | 7 | 0.04% | 1 | 0.16% |
| Norman Maurer | 7 | 0.04% | 1 | 0.16% |
| Dmitry Kozlov | 6 | 0.04% | 1 | 0.16% |
| Thomas Graf | 6 | 0.04% | 2 | 0.32% |
| Yick Xie | 6 | 0.04% | 1 | 0.16% |
| Octavian Purdila | 6 | 0.04% | 2 | 0.32% |
| Sridhar Samudrala | 6 | 0.04% | 1 | 0.16% |
| Xuemin Su | 6 | 0.04% | 1 | 0.16% |
| Pablo Neira Ayuso | 6 | 0.04% | 1 | 0.16% |
| Jon Grimm | 6 | 0.04% | 1 | 0.16% |
| Harvey Harrison | 6 | 0.04% | 1 | 0.16% |
| Davidlohr Bueso A | 5 | 0.03% | 1 | 0.16% |
| Masahide Nakamura | 5 | 0.03% | 1 | 0.16% |
| Arnd Bergmann | 5 | 0.03% | 2 | 0.32% |
| Lorenzo Colitti | 5 | 0.03% | 2 | 0.32% |
| Thomas Gleixner | 5 | 0.03% | 2 | 0.32% |
| Michal Kubeček | 4 | 0.02% | 1 | 0.16% |
| Venkat Yekkirala | 4 | 0.02% | 1 | 0.16% |
| Benjamin LaHaise | 4 | 0.02% | 1 | 0.16% |
| Francesco Fusco | 4 | 0.02% | 1 | 0.16% |
| Josef Bacik | 4 | 0.02% | 1 | 0.16% |
| Tim Beale | 4 | 0.02% | 1 | 0.16% |
| Randy Dunlap | 3 | 0.02% | 2 | 0.32% |
| Neil Horman | 3 | 0.02% | 1 | 0.16% |
| Jakub Kiciński | 3 | 0.02% | 1 | 0.16% |
| Duan Jiong | 3 | 0.02% | 1 | 0.16% |
| Eliezer Tamir | 3 | 0.02% | 2 | 0.32% |
| Yossi Kuperman | 3 | 0.02% | 1 | 0.16% |
| Jiri Olsa | 3 | 0.02% | 1 | 0.16% |
| Ian Morris | 2 | 0.01% | 1 | 0.16% |
| Nicolas Dichtel | 2 | 0.01% | 1 | 0.16% |
| Tim Bird | 2 | 0.01% | 1 | 0.16% |
| Patrick Ohly | 2 | 0.01% | 1 | 0.16% |
| Mark Rutland | 2 | 0.01% | 1 | 0.16% |
| Andrey Vagin | 2 | 0.01% | 1 | 0.16% |
| Stanislav Fomichev | 2 | 0.01% | 1 | 0.16% |
| Elena Reshetova | 2 | 0.01% | 1 | 0.16% |
| Arjan van de Ven | 2 | 0.01% | 1 | 0.16% |
| Mark Pashmfouroush | 2 | 0.01% | 1 | 0.16% |
| John Fastabend | 1 | 0.01% | 1 | 0.16% |
| Colin Ian King | 1 | 0.01% | 1 | 0.16% |
| yangxingwu | 1 | 0.01% | 1 | 0.16% |
| Jianguo Wu | 1 | 0.01% | 1 | 0.16% |
| Or Gerlitz | 1 | 0.01% | 1 | 0.16% |
| Jiri Kosina | 1 | 0.01% | 1 | 0.16% |
| Andrew Lunn | 1 | 0.01% | 1 | 0.16% |
| Yasuyuki Kozakai | 1 | 0.01% | 1 | 0.16% |
| Jorge Boncompte | 1 | 0.01% | 1 | 0.16% |
| Jerry Chu | 1 | 0.01% | 1 | 0.16% |
| Patrick Talbert | 1 | 0.01% | 1 | 0.16% |
| Cambda Zhu | 1 | 0.01% | 1 | 0.16% |
| Dave Marchevsky | 1 | 0.01% | 1 | 0.16% |
| Paul Moore | 1 | 0.01% | 1 | 0.16% |
| Brian Haley | 1 | 0.01% | 1 | 0.16% |
| Su Yanjun | 1 | 0.01% | 1 | 0.16% |
| Erin MacNeil | 1 | 0.01% | 1 | 0.16% |
| Matteo Croce | 1 | 0.01% | 1 | 0.16% |
| Patrick McHardy | 1 | 0.01% | 1 | 0.16% |
| Oliver Hartkopp | 1 | 0.01% | 1 | 0.16% |
| Mike Rapoport | 1 | 0.01% | 1 | 0.16% |
| Total | 16761 | 631 |
// 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/bpf-cgroup.h> #include <linux/uaccess.h> #include <asm/ioctls.h> #include <linux/memblock.h> #include <linux/highmem.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/gso.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> #include <net/gro.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 ____cacheline_aligned_in_smp; EXPORT_SYMBOL(udp_memory_allocated); DEFINE_PER_CPU(int, udp_memory_per_cpu_fw_alloc); EXPORT_PER_CPU_SYMBOL_GPL(udp_memory_per_cpu_fw_alloc); #define MAX_UDP_PORTS 65536 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN_PERNET) static struct udp_table *udp_get_table_prot(struct sock *sk) { return sk->sk_prot->h.udp_table ? : sock_net(sk)->ipv4.udp_table; } 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_table *udptable = udp_get_table_prot(sk); struct udp_hslot *hslot, *hslot2; struct net *net = sock_net(sk); int error = -EADDRINUSE; if (!snum) { DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN); unsigned short first, last; int low, high, remaining; unsigned int rand; inet_sk_get_local_port_range(sk, &low, &high); remaining = (high - low) + 1; rand = get_random_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; } sock_set_flag(sk, SOCK_RCU_FREE); 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); } 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; } INDIRECT_CALLABLE_SCOPE u32 udp_ehashfn(const struct net *net, const __be32 laddr, const __u16 lport, const __be32 faddr, const __be16 fport) { 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; bool need_rescore; result = NULL; badness = 0; udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { need_rescore = false; rescore: score = compute_score(need_rescore ? result : sk, net, saddr, sport, daddr, hnum, dif, sdif); if (score > badness) { badness = score; if (need_rescore) continue; if (sk->sk_state == TCP_ESTABLISHED) { result = sk; continue; } result = inet_lookup_reuseport(net, sk, skb, sizeof(struct udphdr), saddr, sport, daddr, hnum, udp_ehashfn); 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; /* compute_score is too long of a function to be * inlined, and calling it again here yields * measureable overhead for some * workloads. Work around it by jumping * backwards to rescore 'result'. */ need_rescore = true; goto rescore; } } 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) { 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) && udptable == net->ipv4.udp_table) { sk = inet_lookup_run_sk_lookup(net, IPPROTO_UDP, skb, sizeof(struct udphdr), saddr, sport, daddr, hnum, dif, udp_ehashfn); 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(const struct sk_buff *skb, __be16 sport, __be16 dport) { const u16 offset = NAPI_GRO_CB(skb)->network_offsets[skb->encapsulation]; const struct iphdr *iph = (struct iphdr *)(skb->data + offset); struct net *net = dev_net(skb->dev); int iif, sdif; inet_get_iif_sdif(skb, &iif, &sdif); return __udp4_lib_lookup(net, iph->saddr, sport, iph->daddr, dport, iif, sdif, net->ipv4.udp_table, NULL); } /* 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, net->ipv4.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, const struct sock *sk, __be16 loc_port, __be32 loc_addr, __be16 rmt_port, __be32 rmt_addr, int dif, int sdif, unsigned short hnum) { const 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); EXPORT_SYMBOL(udp_encap_needed_key); #if IS_ENABLED(CONFIG_IPV6) DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key); EXPORT_SYMBOL(udpv6_encap_needed_key); #endif 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 sock *sk, struct sk_buff *skb, u32 info) { int (*lookup)(struct sock *sk, struct sk_buff *skb); int network_offset, transport_offset; struct udp_sock *up; 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); if (sk) { up = udp_sk(sk); lookup = READ_ONCE(up->encap_err_lookup); if (lookup && lookup(sk, skb)) sk = NULL; goto out; } sk = __udp4_lib_lookup(net, iph->daddr, uh->source, iph->saddr, uh->dest, skb->dev->ifindex, 0, udptable, NULL); if (sk) { up = udp_sk(sk); lookup = READ_ONCE(up->encap_err_lookup); if (!lookup || lookup(sk, skb)) sk = NULL; } out: 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 || READ_ONCE(udp_sk(sk)->encap_type)) { /* No socket for error: try tunnels before discarding */ if (static_branch_unlikely(&udp_encap_needed_key)) { sk = __udp4_lib_err_encap(net, iph, uh, udptable, sk, skb, info); if (!sk) return 0; } else sk = ERR_PTR(-ENOENT); 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 (READ_ONCE(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 */ if (udp_sk(sk)->encap_err_rcv) udp_sk(sk)->encap_err_rcv(sk, skb, err, uh->dest, info, (u8 *)(uh+1)); goto out; } if (!inet_test_bit(RECVERR, sk)) { 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_error_report(sk); out: return 0; } int udp_err(struct sk_buff *skb, u32 info) { return __udp4_lib_err(skb, info, dev_net(skb->dev)->ipv4.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; WRITE_ONCE(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; 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 (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_test_bit(RECVERR, sk)) { 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; WRITE_ONCE(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; u8 tos, scope; __be16 dport; int err, is_udplite = IS_UDPLITE(sk); int corkreq = udp_test_bit(CORK, sk) || 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; int uc_index; 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 (READ_ONCE(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); connected = 0; } if (unlikely(err < 0)) { kfree(ipc.opt); return err; } if (ipc.opt) free = 1; } 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(CGROUP_UDP4_SENDMSG) && !connected) { err = BPF_CGROUP_RUN_PROG_UDP4_SENDMSG_LOCK(sk, (struct sockaddr *)usin, &msg->msg_namelen, &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); scope = ip_sendmsg_scope(inet, &ipc, msg); if (scope == RT_SCOPE_LINK) connected = 0; uc_index = READ_ONCE(inet->uc_index); if (ipv4_is_multicast(daddr)) { if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif)) ipc.oif = READ_ONCE(inet->mc_index); if (!saddr) saddr = READ_ONCE(inet->mc_addr); connected = 0; } else if (!ipc.oif) { ipc.oif = uc_index; } else if (ipv4_is_lbcast(daddr) && 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 != uc_index && ipc.oif == l3mdev_master_ifindex_by_index(sock_net(sk), uc_index)) { ipc.oif = uc_index; } } if (connected) rt = dst_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, scope, 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; WRITE_ONCE(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))) WRITE_ONCE(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); void udp_splice_eof(struct socket *sock) { struct sock *sk = sock->sk; struct udp_sock *up = udp_sk(sk); if (!READ_ONCE(up->pending) || udp_test_bit(CORK, sk)) return; lock_sock(sk); if (up->pending && !udp_test_bit(CORK, sk)) udp_push_pending_frames(sk); release_sock(sk); } EXPORT_SYMBOL_GPL(udp_splice_eof); #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 < READ_ONCE(up->forward_threshold) && !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_forward_alloc_add(sk, size); amt = (sk->sk_forward_alloc - partial) & ~(PAGE_SIZE - 1); sk_forward_alloc_add(sk, -amt); if (amt) __sk_mem_reduce_allocated(sk, amt >> PAGE_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); } static int udp_rmem_schedule(struct sock *sk, int size) { int delta; delta = size - sk->sk_forward_alloc; if (delta > 0 && !__sk_mem_schedule(sk, delta, SK_MEM_RECV)) return -ENOBUFS; return 0; } int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb) { struct sk_buff_head *list = &sk->sk_receive_queue; int rmem, err = -ENOMEM; spinlock_t *busy = NULL; bool becomes_readable; int size, rcvbuf; /* Immediately drop when the receive queue is full. * Always allow at least one packet. */ rmem = atomic_read(&sk->sk_rmem_alloc); rcvbuf = READ_ONCE(sk->sk_rcvbuf); if (rmem > 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 > (rcvbuf >> 1)) { skb_condense(skb); busy = busylock_acquire(sk); } size = skb->truesize; udp_set_dev_scratch(skb); atomic_add(size, &sk->sk_rmem_alloc); spin_lock(&list->lock); err = udp_rmem_schedule(sk, size); if (err) { spin_unlock(&list->lock); goto uncharge_drop; } sk_forward_alloc_add(sk, -size); /* no need to setup a destructor, we will explicitly release the * forward allocated memory on dequeue */ sock_skb_set_dropcount(sk, skb); becomes_readable = skb_queue_empty(list); __skb_queue_tail(list, skb); spin_unlock(&list->lock); if (!sock_flag(sk, SOCK_DEAD)) { if (becomes_readable || sk->sk_data_ready != sock_def_readable || READ_ONCE(sk->sk_peek_off) >= 0) INDIRECT_CALL_1(sk->sk_data_ready, sock_def_readable, sk); else sk_wake_async_rcu(sk, SOCK_WAKE_WAITD, POLL_IN); } 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) { udp_lib_init_sock(sk); sk->sk_destruct = udp_destruct_sock; set_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags); return 0; } void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len) { if (unlikely(READ_ONCE(udp_sk(sk)->peeking_with_offset))) sk_peek_offset_bwd(sk, len); 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, int *karg) { switch (cmd) { case SIOCOUTQ: { *karg = sk_wmem_alloc_get(sk); return 0; } case SIOCINQ: { *karg = max_t(int, 0, first_packet_length(sk)); return 0; } default: return -ENOIOCTLCMD; } return 0; } EXPORT_SYMBOL(udp_ioctl); struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags, 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; 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); int udp_read_skb(struct sock *sk, skb_read_actor_t recv_actor) { struct sk_buff *skb; int err; try_again: skb = skb_recv_udp(sk, MSG_DONTWAIT, &err); if (!skb) return err; if (udp_lib_checksum_complete(skb)) { int is_udplite = IS_UDPLITE(sk); struct net *net = sock_net(sk); __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, is_udplite); __UDP_INC_STATS(net, UDP_MIB_INERRORS, is_udplite); atomic_inc(&sk->sk_drops); kfree_skb(skb); goto try_again; } WARN_ON_ONCE(!skb_set_owner_sk_safe(skb, sk)); return recv_actor(sk, skb); } EXPORT_SYMBOL(udp_read_skb); /* * 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 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, &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_cmsgs(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); BPF_CGROUP_RUN_PROG_UDP4_RECVMSG_LOCK(sk, (struct sockaddr *)sin, addr_len); } if (udp_test_bit(GRO_ENABLED, sk)) udp_cmsg_recv(msg, sk, skb); if (inet_cmsg_flags(inet)) 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, &addr_len); } 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 = udp_get_table_prot(sk); 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 = udp_get_table_prot(sk); 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); int drop_reason; /* Note that an ENOMEM error is charged twice */ if (rc == -ENOMEM) { UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS, is_udplite); drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF; } else { UDP_INC_STATS(sock_net(sk), UDP_MIB_MEMERRORS, is_udplite); drop_reason = SKB_DROP_REASON_PROTO_MEM; } UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); trace_udp_fail_queue_rcv_skb(rc, sk, skb); sk_skb_reason_drop(sk, skb, drop_reason); 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) { int drop_reason = SKB_DROP_REASON_NOT_SPECIFIED; 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)) { drop_reason = SKB_DROP_REASON_XFRM_POLICY; goto drop; } nf_reset_ct(skb); if (static_branch_unlikely(&udp_encap_needed_key) && READ_ONCE(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 (udp_test_bit(UDPLITE_RECV_CC, sk) && UDP_SKB_CB(skb)->partial_cov) { u16 pcrlen = READ_ONCE(up->pcrlen); /* * 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 (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 < pcrlen) { net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n", UDP_SKB_CB(skb)->cscov, 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))) { drop_reason = SKB_DROP_REASON_SOCKET_FILTER; goto drop; } udp_csum_pull_header(skb); ipv4_pktinfo_prepare(sk, skb, true); return __udp_queue_rcv_skb(sk, skb); csum_error: drop_reason = SKB_DROP_REASON_UDP_CSUM; __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); sk_skb_reason_drop(sk, skb, drop_reason); 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)); udp_post_segment_fix_csum(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 = unrcu_pointer(xchg(&sk->sk_rx_dst, RCU_INITIALIZER(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 = NULL; struct udphdr *uh; unsigned short ulen; struct rtable *rt = skb_rtable(skb); __be32 saddr, daddr; struct net *net = dev_net(skb->dev); bool refcounted; int drop_reason; drop_reason = SKB_DROP_REASON_NOT_SPECIFIED; /* * 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 = inet_steal_sock(net, skb, sizeof(struct udphdr), saddr, uh->source, daddr, uh->dest, &refcounted, udp_ehashfn); if (IS_ERR(sk)) goto no_sk; 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); no_sk: 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; drop_reason = SKB_DROP_REASON_NO_SOCKET; __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. */ sk_skb_reason_drop(sk, skb, drop_reason); return 0; short_packet: drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL; 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). */ drop_reason = SKB_DROP_REASON_UDP_CSUM; 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); sk_skb_reason_drop(sk, skb, drop_reason); 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 udp_table *udptable = net->ipv4.udp_table; unsigned short hnum = ntohs(loc_port); struct sock *sk, *result; struct udp_hslot *hslot; unsigned int slot; slot = udp_hashfn(net, hnum, udptable->mask); hslot = &udptable->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) { struct udp_table *udptable = net->ipv4.udp_table; INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr); unsigned short hnum = ntohs(loc_port); unsigned int hash2, slot2; struct udp_hslot *hslot2; __portpair ports; struct sock *sk; hash2 = ipv4_portaddr_hash(net, loc_addr, hnum); slot2 = hash2 & udptable->mask; hslot2 = &udptable->hash2[slot2]; ports = INET_COMBINED_PORTS(rmt_port, hnum); 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) return 0; skb->sk = sk; DEBUG_NET_WARN_ON_ONCE(sk_is_refcounted(sk)); skb->destructor = sock_pfree; 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, dev_net(skb->dev)->ipv4.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 (udp_test_bit(ENCAP_ENABLED, sk)) static_branch_dec(&udp_encap_needed_key); } } static void set_xfrm_gro_udp_encap_rcv(__u16 encap_type, unsigned short family, struct sock *sk) { #ifdef CONFIG_XFRM if (udp_test_bit(GRO_ENABLED, sk) && encap_type == UDP_ENCAP_ESPINUDP) { if (family == AF_INET) WRITE_ONCE(udp_sk(sk)->gro_receive, xfrm4_gro_udp_encap_rcv); else if (IS_ENABLED(CONFIG_IPV6) && family == AF_INET6) WRITE_ONCE(udp_sk(sk)->gro_receive, ipv6_stub->xfrm6_gro_udp_encap_rcv); } #endif } /* * 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 (level == SOL_SOCKET) { err = sk_setsockopt(sk, level, optname, optval, optlen); if (optname == SO_RCVBUF || optname == SO_RCVBUFFORCE) { sockopt_lock_sock(sk); /* paired with READ_ONCE in udp_rmem_release() */ WRITE_ONCE(up->forward_threshold, sk->sk_rcvbuf >> 2); sockopt_release_sock(sk); } return err; } 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) { udp_set_bit(CORK, sk); } else { udp_clear_bit(CORK, sk); 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: set_xfrm_gro_udp_encap_rcv(val, sk->sk_family, sk); #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: WRITE_ONCE(up->encap_type, val); udp_tunnel_encap_enable(sk); break; default: err = -ENOPROTOOPT; break; } break; case UDP_NO_CHECK6_TX: udp_set_no_check6_tx(sk, valbool); break; case UDP_NO_CHECK6_RX: udp_set_no_check6_rx(sk, valbool); break; case UDP_SEGMENT: if (val < 0 || val > USHRT_MAX) return -EINVAL; WRITE_ONCE(up->gso_size, val); break; case UDP_GRO: /* when enabling GRO, accept the related GSO packet type */ if (valbool) udp_tunnel_encap_enable(sk); udp_assign_bit(GRO_ENABLED, sk, valbool); udp_assign_bit(ACCEPT_L4, sk, valbool); set_xfrm_gro_udp_encap_rcv(up->encap_type, sk->sk_family, 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; WRITE_ONCE(up->pcslen, val); udp_set_bit(UDPLITE_SEND_CC, sk); 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; WRITE_ONCE(up->pcrlen, val); udp_set_bit(UDPLITE_RECV_CC, sk); 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 || level == SOL_SOCKET) 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; if (len < 0) return -EINVAL; len = min_t(unsigned int, len, sizeof(int)); switch (optname) { case UDP_CORK: val = udp_test_bit(CORK, sk); break; case UDP_ENCAP: val = READ_ONCE(up->encap_type); break; case UDP_NO_CHECK6_TX: val = udp_get_no_check6_tx(sk); break; case UDP_NO_CHECK6_RX: val = udp_get_no_check6_rx(sk); break; case UDP_SEGMENT: val = READ_ONCE(up->gso_size); break; case UDP_GRO: val = udp_test_bit(GRO_ENABLED, sk); 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 = READ_ONCE(up->pcslen); break; case UDPLITE_RECV_CSCOV: val = READ_ONCE(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); /* psock ingress_msg queue should not contain any bad checksum frames */ if (sk_is_readable(sk)) mask |= EPOLLIN | EPOLLRDNORM; return mask; } EXPORT_SYMBOL(udp_poll); int udp_abort(struct sock *sk, int err) { if (!has_current_bpf_ctx()) 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_error_report(sk); __udp_disconnect(sk, 0); out: if (!has_current_bpf_ctx()) 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, .splice_eof = udp_splice_eof, .release_cb = ip4_datagram_release_cb, .hash = udp_lib_hash, .unhash = udp_lib_unhash, .rehash = udp_v4_rehash, .get_port = udp_v4_get_port, .put_port = udp_lib_unhash, #ifdef CONFIG_BPF_SYSCALL .psock_update_sk_prot = udp_bpf_update_proto, #endif .memory_allocated = &udp_memory_allocated, .per_cpu_fw_alloc = &udp_memory_per_cpu_fw_alloc, .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 = NULL, .diag_destroy = udp_abort, }; EXPORT_SYMBOL(udp_prot); /* ------------------------------------------------------------------------ */ #ifdef CONFIG_PROC_FS static unsigned short seq_file_family(const struct seq_file *seq); static bool seq_sk_match(struct seq_file *seq, const struct sock *sk) { unsigned short family = seq_file_family(seq); /* AF_UNSPEC is used as a match all */ return ((family == AF_UNSPEC || family == sk->sk_family) && net_eq(sock_net(sk), seq_file_net(seq))); } #ifdef CONFIG_BPF_SYSCALL static const struct seq_operations bpf_iter_udp_seq_ops; #endif static struct udp_table *udp_get_table_seq(struct seq_file *seq, struct net *net) { const struct udp_seq_afinfo *afinfo; #ifdef CONFIG_BPF_SYSCALL if (seq->op == &bpf_iter_udp_seq_ops) return net->ipv4.udp_table; #endif afinfo = pde_data(file_inode(seq->file)); return afinfo->udp_table ? : net->ipv4.udp_table; } static struct sock *udp_get_first(struct seq_file *seq, int start) { struct udp_iter_state *state = seq->private; struct net *net = seq_file_net(seq); struct udp_table *udptable; struct sock *sk; udptable = udp_get_table_seq(seq, net); for (state->bucket = start; state->bucket <= udptable->mask; ++state->bucket) { struct udp_hslot *hslot = &udptable->hash[state->bucket]; if (hlist_empty(&hslot->head)) continue; spin_lock_bh(&hslot->lock); sk_for_each(sk, &hslot->head) { if (seq_sk_match(seq, sk)) 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_iter_state *state = seq->private; struct net *net = seq_file_net(seq); struct udp_table *udptable; do { sk = sk_next(sk); } while (sk && !seq_sk_match(seq, sk)); if (!sk) { udptable = udp_get_table_seq(seq, net); if (state->bucket <= udptable->mask) spin_unlock_bh(&udptable->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_iter_state *state = seq->private; struct udp_table *udptable; udptable = udp_get_table_seq(seq, seq_file_net(seq)); if (state->bucket <= udptable->mask) spin_unlock_bh(&udptable->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); }; struct bpf_udp_iter_state { struct udp_iter_state state; unsigned int cur_sk; unsigned int end_sk; unsigned int max_sk; int offset; struct sock **batch; bool st_bucket_done; }; static int bpf_iter_udp_realloc_batch(struct bpf_udp_iter_state *iter, unsigned int new_batch_sz); static struct sock *bpf_iter_udp_batch(struct seq_file *seq) { struct bpf_udp_iter_state *iter = seq->private; struct udp_iter_state *state = &iter->state; struct net *net = seq_file_net(seq); int resume_bucket, resume_offset; struct udp_table *udptable; unsigned int batch_sks = 0; bool resized = false; struct sock *sk; resume_bucket = state->bucket; resume_offset = iter->offset; /* The current batch is done, so advance the bucket. */ if (iter->st_bucket_done) state->bucket++; udptable = udp_get_table_seq(seq, net); again: /* New batch for the next bucket. * Iterate over the hash table to find a bucket with sockets matching * the iterator attributes, and return the first matching socket from * the bucket. The remaining matched sockets from the bucket are batched * before releasing the bucket lock. This allows BPF programs that are * called in seq_show to acquire the bucket lock if needed. */ iter->cur_sk = 0; iter->end_sk = 0; iter->st_bucket_done = false; batch_sks = 0; for (; state->bucket <= udptable->mask; state->bucket++) { struct udp_hslot *hslot2 = &udptable->hash2[state->bucket]; if (hlist_empty(&hslot2->head)) continue; iter->offset = 0; spin_lock_bh(&hslot2->lock); udp_portaddr_for_each_entry(sk, &hslot2->head) { if (seq_sk_match(seq, sk)) { /* Resume from the last iterated socket at the * offset in the bucket before iterator was stopped. */ if (state->bucket == resume_bucket && iter->offset < resume_offset) { ++iter->offset; continue; } if (iter->end_sk < iter->max_sk) { sock_hold(sk); iter->batch[iter->end_sk++] = sk; } batch_sks++; } } spin_unlock_bh(&hslot2->lock); if (iter->end_sk) break; } /* All done: no batch made. */ if (!iter->end_sk) return NULL; if (iter->end_sk == batch_sks) { /* Batching is done for the current bucket; return the first * socket to be iterated from the batch. */ iter->st_bucket_done = true; goto done; } if (!resized && !bpf_iter_udp_realloc_batch(iter, batch_sks * 3 / 2)) { resized = true; /* After allocating a larger batch, retry one more time to grab * the whole bucket. */ goto again; } done: return iter->batch[0]; } static void *bpf_iter_udp_seq_next(struct seq_file *seq, void *v, loff_t *pos) { struct bpf_udp_iter_state *iter = seq->private; struct sock *sk; /* Whenever seq_next() is called, the iter->cur_sk is * done with seq_show(), so unref the iter->cur_sk. */ if (iter->cur_sk < iter->end_sk) { sock_put(iter->batch[iter->cur_sk++]); ++iter->offset; } /* After updating iter->cur_sk, check if there are more sockets * available in the current bucket batch. */ if (iter->cur_sk < iter->end_sk) sk = iter->batch[iter->cur_sk]; else /* Prepare a new batch. */ sk = bpf_iter_udp_batch(seq); ++*pos; return sk; } static void *bpf_iter_udp_seq_start(struct seq_file *seq, loff_t *pos) { /* bpf iter does not support lseek, so it always * continue from where it was stop()-ped. */ if (*pos) return bpf_iter_udp_batch(seq); return SEQ_START_TOKEN; } 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; int ret; if (v == SEQ_START_TOKEN) return 0; lock_sock(sk); if (unlikely(sk_unhashed(sk))) { ret = SEQ_SKIP; goto unlock; } uid = from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)); meta.seq = seq; prog = bpf_iter_get_info(&meta, false); ret = udp_prog_seq_show(prog, &meta, v, uid, state->bucket); unlock: release_sock(sk); return ret; } static void bpf_iter_udp_put_batch(struct bpf_udp_iter_state *iter) { while (iter->cur_sk < iter->end_sk) sock_put(iter->batch[iter->cur_sk++]); } static void bpf_iter_udp_seq_stop(struct seq_file *seq, void *v) { struct bpf_udp_iter_state *iter = seq->private; 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); } if (iter->cur_sk < iter->end_sk) { bpf_iter_udp_put_batch(iter); iter->st_bucket_done = false; } } static const struct seq_operations bpf_iter_udp_seq_ops = { .start = bpf_iter_udp_seq_start, .next = bpf_iter_udp_seq_next, .stop = bpf_iter_udp_seq_stop, .show = bpf_iter_udp_seq_show, }; #endif static unsigned short seq_file_family(const struct seq_file *seq) { const struct udp_seq_afinfo *afinfo; #ifdef CONFIG_BPF_SYSCALL /* BPF iterator: bpf programs to filter sockets. */ if (seq->op == &bpf_iter_udp_seq_ops) return AF_UNSPEC; #endif /* Proc fs iterator */ afinfo = pde_data(file_inode(seq->file)); return afinfo->family; } 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 = NULL, }; 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, UDP_HTABLE_SIZE_MAX); 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 __net_init udp_sysctl_init(struct net *net) { net->ipv4.sysctl_udp_rmem_min = PAGE_SIZE; net->ipv4.sysctl_udp_wmem_min = PAGE_SIZE; #ifdef CONFIG_NET_L3_MASTER_DEV net->ipv4.sysctl_udp_l3mdev_accept = 0; #endif } static struct udp_table __net_init *udp_pernet_table_alloc(unsigned int hash_entries) { struct udp_table *udptable; int i; udptable = kmalloc(sizeof(*udptable), GFP_KERNEL); if (!udptable) goto out; udptable->hash = vmalloc_huge(hash_entries * 2 * sizeof(struct udp_hslot), GFP_KERNEL_ACCOUNT); if (!udptable->hash) goto free_table; udptable->hash2 = udptable->hash + hash_entries; udptable->mask = hash_entries - 1; udptable->log = ilog2(hash_entries); for (i = 0; i < hash_entries; i++) { INIT_HLIST_HEAD(&udptable->hash[i].head); udptable->hash[i].count = 0; spin_lock_init(&udptable->hash[i].lock); INIT_HLIST_HEAD(&udptable->hash2[i].head); udptable->hash2[i].count = 0; spin_lock_init(&udptable->hash2[i].lock); } return udptable; free_table: kfree(udptable); out: return NULL; } static void __net_exit udp_pernet_table_free(struct net *net) { struct udp_table *udptable = net->ipv4.udp_table; if (udptable == &udp_table) return; kvfree(udptable->hash); kfree(udptable); } static void __net_init udp_set_table(struct net *net) { struct udp_table *udptable; unsigned int hash_entries; struct net *old_net; if (net_eq(net, &init_net)) goto fallback; old_net = current->nsproxy->net_ns; hash_entries = READ_ONCE(old_net->ipv4.sysctl_udp_child_hash_entries); if (!hash_entries) goto fallback; /* Set min to keep the bitmap on stack in udp_lib_get_port() */ if (hash_entries < UDP_HTABLE_SIZE_MIN_PERNET) hash_entries = UDP_HTABLE_SIZE_MIN_PERNET; else hash_entries = roundup_pow_of_two(hash_entries); udptable = udp_pernet_table_alloc(hash_entries); if (udptable) { net->ipv4.udp_table = udptable; } else { pr_warn("Failed to allocate UDP hash table (entries: %u) " "for a netns, fallback to the global one\n", hash_entries); fallback: net->ipv4.udp_table = &udp_table; } } static int __net_init udp_pernet_init(struct net *net) { udp_sysctl_init(net); udp_set_table(net); return 0; } static void __net_exit udp_pernet_exit(struct net *net) { udp_pernet_table_free(net); } static struct pernet_operations __net_initdata udp_sysctl_ops = { .init = udp_pernet_init, .exit = udp_pernet_exit, }; #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_udp_realloc_batch(struct bpf_udp_iter_state *iter, unsigned int new_batch_sz) { struct sock **new_batch; new_batch = kvmalloc_array(new_batch_sz, sizeof(*new_batch), GFP_USER | __GFP_NOWARN); if (!new_batch) return -ENOMEM; bpf_iter_udp_put_batch(iter); kvfree(iter->batch); iter->batch = new_batch; iter->max_sk = new_batch_sz; return 0; } #define INIT_BATCH_SZ 16 static int bpf_iter_init_udp(void *priv_data, struct bpf_iter_aux_info *aux) { struct bpf_udp_iter_state *iter = priv_data; int ret; ret = bpf_iter_init_seq_net(priv_data, aux); if (ret) return ret; ret = bpf_iter_udp_realloc_batch(iter, INIT_BATCH_SZ); if (ret) bpf_iter_fini_seq_net(priv_data); return ret; } static void bpf_iter_fini_udp(void *priv_data) { struct bpf_udp_iter_state *iter = priv_data; bpf_iter_fini_seq_net(priv_data); kvfree(iter->batch); } 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 bpf_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 | PTR_TRUSTED }, }, .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; /* 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 }
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