| /* |
| * INET An implementation of the TCP/IP protocol suite for the LINUX |
| * operating system. INET is implemented using the BSD Socket |
| * interface as the means of communication with the user level. |
| * |
| * The User Datagram Protocol (UDP). |
| * |
| * Authors: Ross Biro |
| * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> |
| * Arnt Gulbrandsen, <agulbra@nvg.unit.no> |
| * Alan Cox, <alan@lxorguk.ukuu.org.uk> |
| * Hirokazu Takahashi, <taka@valinux.co.jp> |
| * |
| * Fixes: |
| * Alan Cox : verify_area() calls |
| * Alan Cox : stopped close while in use off icmp |
| * messages. Not a fix but a botch that |
| * for udp at least is 'valid'. |
| * Alan Cox : Fixed icmp handling properly |
| * Alan Cox : Correct error for oversized datagrams |
| * Alan Cox : Tidied select() semantics. |
| * Alan Cox : udp_err() fixed properly, also now |
| * select and read wake correctly on errors |
| * Alan Cox : udp_send verify_area moved to avoid mem leak |
| * Alan Cox : UDP can count its memory |
| * Alan Cox : send to an unknown connection causes |
| * an ECONNREFUSED off the icmp, but |
| * does NOT close. |
| * Alan Cox : Switched to new sk_buff handlers. No more backlog! |
| * Alan Cox : Using generic datagram code. Even smaller and the PEEK |
| * bug no longer crashes it. |
| * Fred Van Kempen : Net2e support for sk->broadcast. |
| * Alan Cox : Uses skb_free_datagram |
| * Alan Cox : Added get/set sockopt support. |
| * Alan Cox : Broadcasting without option set returns EACCES. |
| * Alan Cox : No wakeup calls. Instead we now use the callbacks. |
| * Alan Cox : Use ip_tos and ip_ttl |
| * Alan Cox : SNMP Mibs |
| * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support. |
| * Matt Dillon : UDP length checks. |
| * Alan Cox : Smarter af_inet used properly. |
| * Alan Cox : Use new kernel side addressing. |
| * Alan Cox : Incorrect return on truncated datagram receive. |
| * Arnt Gulbrandsen : New udp_send and stuff |
| * Alan Cox : Cache last socket |
| * Alan Cox : Route cache |
| * Jon Peatfield : Minor efficiency fix to sendto(). |
| * Mike Shaver : RFC1122 checks. |
| * Alan Cox : Nonblocking error fix. |
| * Willy Konynenberg : Transparent proxying support. |
| * Mike McLagan : Routing by source |
| * David S. Miller : New socket lookup architecture. |
| * Last socket cache retained as it |
| * does have a high hit rate. |
| * Olaf Kirch : Don't linearise iovec on sendmsg. |
| * Andi Kleen : Some cleanups, cache destination entry |
| * for connect. |
| * Vitaly E. Lavrov : Transparent proxy revived after year coma. |
| * Melvin Smith : Check msg_name not msg_namelen in sendto(), |
| * return ENOTCONN for unconnected sockets (POSIX) |
| * Janos Farkas : don't deliver multi/broadcasts to a different |
| * bound-to-device socket |
| * Hirokazu Takahashi : HW checksumming for outgoing UDP |
| * datagrams. |
| * Hirokazu Takahashi : sendfile() on UDP works now. |
| * Arnaldo C. Melo : convert /proc/net/udp to seq_file |
| * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which |
| * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind |
| * a single port at the same time. |
| * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support |
| * James Chapman : Add L2TP encapsulation type. |
| * |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| |
| #define pr_fmt(fmt) "UDP: " fmt |
| |
| #include <linux/uaccess.h> |
| #include <asm/ioctls.h> |
| #include <linux/bootmem.h> |
| #include <linux/highmem.h> |
| #include <linux/swap.h> |
| #include <linux/types.h> |
| #include <linux/fcntl.h> |
| #include <linux/module.h> |
| #include <linux/socket.h> |
| #include <linux/sockios.h> |
| #include <linux/igmp.h> |
| #include <linux/inetdevice.h> |
| #include <linux/in.h> |
| #include <linux/errno.h> |
| #include <linux/timer.h> |
| #include <linux/mm.h> |
| #include <linux/inet.h> |
| #include <linux/netdevice.h> |
| #include <linux/slab.h> |
| #include <net/tcp_states.h> |
| #include <linux/skbuff.h> |
| #include <linux/proc_fs.h> |
| #include <linux/seq_file.h> |
| #include <net/net_namespace.h> |
| #include <net/icmp.h> |
| #include <net/inet_hashtables.h> |
| #include <net/route.h> |
| #include <net/checksum.h> |
| #include <net/xfrm.h> |
| #include <trace/events/udp.h> |
| #include <linux/static_key.h> |
| #include <trace/events/skb.h> |
| #include <net/busy_poll.h> |
| #include "udp_impl.h" |
| #include <net/sock_reuseport.h> |
| #include <net/addrconf.h> |
| |
| struct udp_table udp_table __read_mostly; |
| EXPORT_SYMBOL(udp_table); |
| |
| long sysctl_udp_mem[3] __read_mostly; |
| EXPORT_SYMBOL(sysctl_udp_mem); |
| |
| int sysctl_udp_rmem_min __read_mostly; |
| EXPORT_SYMBOL(sysctl_udp_rmem_min); |
| |
| int sysctl_udp_wmem_min __read_mostly; |
| EXPORT_SYMBOL(sysctl_udp_wmem_min); |
| |
| atomic_long_t udp_memory_allocated; |
| EXPORT_SYMBOL(udp_memory_allocated); |
| |
| #define MAX_UDP_PORTS 65536 |
| #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN) |
| |
| /* IPCB reference means this can not be used from early demux */ |
| static bool udp_lib_exact_dif_match(struct net *net, struct sk_buff *skb) |
| { |
| #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) |
| if (!net->ipv4.sysctl_udp_l3mdev_accept && |
| skb && ipv4_l3mdev_skb(IPCB(skb)->flags)) |
| return true; |
| #endif |
| return false; |
| } |
| |
| static int udp_lib_lport_inuse(struct net *net, __u16 num, |
| const struct udp_hslot *hslot, |
| unsigned long *bitmap, |
| struct sock *sk, unsigned int log) |
| { |
| struct sock *sk2; |
| kuid_t uid = sock_i_uid(sk); |
| |
| sk_for_each(sk2, &hslot->head) { |
| if (net_eq(sock_net(sk2), net) && |
| sk2 != sk && |
| (bitmap || udp_sk(sk2)->udp_port_hash == num) && |
| (!sk2->sk_reuse || !sk->sk_reuse) && |
| (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || |
| sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && |
| inet_rcv_saddr_equal(sk, sk2, true)) { |
| if (sk2->sk_reuseport && sk->sk_reuseport && |
| !rcu_access_pointer(sk->sk_reuseport_cb) && |
| uid_eq(uid, sock_i_uid(sk2))) { |
| if (!bitmap) |
| return 0; |
| } else { |
| if (!bitmap) |
| return 1; |
| __set_bit(udp_sk(sk2)->udp_port_hash >> log, |
| bitmap); |
| } |
| } |
| } |
| return 0; |
| } |
| |
| /* |
| * Note: we still hold spinlock of primary hash chain, so no other writer |
| * can insert/delete a socket with local_port == num |
| */ |
| static int udp_lib_lport_inuse2(struct net *net, __u16 num, |
| struct udp_hslot *hslot2, |
| struct sock *sk) |
| { |
| struct sock *sk2; |
| kuid_t uid = sock_i_uid(sk); |
| int res = 0; |
| |
| spin_lock(&hslot2->lock); |
| udp_portaddr_for_each_entry(sk2, &hslot2->head) { |
| if (net_eq(sock_net(sk2), net) && |
| sk2 != sk && |
| (udp_sk(sk2)->udp_port_hash == num) && |
| (!sk2->sk_reuse || !sk->sk_reuse) && |
| (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || |
| sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && |
| inet_rcv_saddr_equal(sk, sk2, true)) { |
| if (sk2->sk_reuseport && sk->sk_reuseport && |
| !rcu_access_pointer(sk->sk_reuseport_cb) && |
| uid_eq(uid, sock_i_uid(sk2))) { |
| res = 0; |
| } else { |
| res = 1; |
| } |
| break; |
| } |
| } |
| spin_unlock(&hslot2->lock); |
| return res; |
| } |
| |
| static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot) |
| { |
| struct net *net = sock_net(sk); |
| kuid_t uid = sock_i_uid(sk); |
| struct sock *sk2; |
| |
| sk_for_each(sk2, &hslot->head) { |
| if (net_eq(sock_net(sk2), net) && |
| sk2 != sk && |
| sk2->sk_family == sk->sk_family && |
| ipv6_only_sock(sk2) == ipv6_only_sock(sk) && |
| (udp_sk(sk2)->udp_port_hash == udp_sk(sk)->udp_port_hash) && |
| (sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && |
| sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) && |
| inet_rcv_saddr_equal(sk, sk2, false)) { |
| return reuseport_add_sock(sk, sk2); |
| } |
| } |
| |
| /* Initial allocation may have already happened via setsockopt */ |
| if (!rcu_access_pointer(sk->sk_reuseport_cb)) |
| return reuseport_alloc(sk); |
| return 0; |
| } |
| |
| /** |
| * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6 |
| * |
| * @sk: socket struct in question |
| * @snum: port number to look up |
| * @hash2_nulladdr: AF-dependent hash value in secondary hash chains, |
| * with NULL address |
| */ |
| int udp_lib_get_port(struct sock *sk, unsigned short snum, |
| unsigned int hash2_nulladdr) |
| { |
| struct udp_hslot *hslot, *hslot2; |
| struct udp_table *udptable = sk->sk_prot->h.udp_table; |
| int error = 1; |
| struct net *net = sock_net(sk); |
| |
| if (!snum) { |
| int low, high, remaining; |
| unsigned int rand; |
| unsigned short first, last; |
| DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN); |
| |
| inet_get_local_port_range(net, &low, &high); |
| remaining = (high - low) + 1; |
| |
| rand = prandom_u32(); |
| first = reciprocal_scale(rand, remaining) + low; |
| /* |
| * force rand to be an odd multiple of UDP_HTABLE_SIZE |
| */ |
| rand = (rand | 1) * (udptable->mask + 1); |
| last = first + udptable->mask + 1; |
| do { |
| hslot = udp_hashslot(udptable, net, first); |
| bitmap_zero(bitmap, PORTS_PER_CHAIN); |
| spin_lock_bh(&hslot->lock); |
| udp_lib_lport_inuse(net, snum, hslot, bitmap, sk, |
| udptable->log); |
| |
| snum = first; |
| /* |
| * Iterate on all possible values of snum for this hash. |
| * Using steps of an odd multiple of UDP_HTABLE_SIZE |
| * give us randomization and full range coverage. |
| */ |
| do { |
| if (low <= snum && snum <= high && |
| !test_bit(snum >> udptable->log, bitmap) && |
| !inet_is_local_reserved_port(net, snum)) |
| goto found; |
| snum += rand; |
| } while (snum != first); |
| spin_unlock_bh(&hslot->lock); |
| cond_resched(); |
| } while (++first != last); |
| goto fail; |
| } else { |
| hslot = udp_hashslot(udptable, net, snum); |
| spin_lock_bh(&hslot->lock); |
| if (hslot->count > 10) { |
| int exist; |
| unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum; |
| |
| slot2 &= udptable->mask; |
| hash2_nulladdr &= udptable->mask; |
| |
| hslot2 = udp_hashslot2(udptable, slot2); |
| if (hslot->count < hslot2->count) |
| goto scan_primary_hash; |
| |
| exist = udp_lib_lport_inuse2(net, snum, hslot2, sk); |
| if (!exist && (hash2_nulladdr != slot2)) { |
| hslot2 = udp_hashslot2(udptable, hash2_nulladdr); |
| exist = udp_lib_lport_inuse2(net, snum, hslot2, |
| sk); |
| } |
| if (exist) |
| goto fail_unlock; |
| else |
| goto found; |
| } |
| scan_primary_hash: |
| if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 0)) |
| goto fail_unlock; |
| } |
| found: |
| inet_sk(sk)->inet_num = snum; |
| udp_sk(sk)->udp_port_hash = snum; |
| udp_sk(sk)->udp_portaddr_hash ^= snum; |
| if (sk_unhashed(sk)) { |
| if (sk->sk_reuseport && |
| udp_reuseport_add_sock(sk, hslot)) { |
| inet_sk(sk)->inet_num = 0; |
| udp_sk(sk)->udp_port_hash = 0; |
| udp_sk(sk)->udp_portaddr_hash ^= snum; |
| goto fail_unlock; |
| } |
| |
| sk_add_node_rcu(sk, &hslot->head); |
| hslot->count++; |
| sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); |
| |
| hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); |
| spin_lock(&hslot2->lock); |
| if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport && |
| sk->sk_family == AF_INET6) |
| hlist_add_tail_rcu(&udp_sk(sk)->udp_portaddr_node, |
| &hslot2->head); |
| else |
| hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, |
| &hslot2->head); |
| hslot2->count++; |
| spin_unlock(&hslot2->lock); |
| } |
| sock_set_flag(sk, SOCK_RCU_FREE); |
| error = 0; |
| fail_unlock: |
| spin_unlock_bh(&hslot->lock); |
| fail: |
| return error; |
| } |
| EXPORT_SYMBOL(udp_lib_get_port); |
| |
| static u32 udp4_portaddr_hash(const struct net *net, __be32 saddr, |
| unsigned int port) |
| { |
| return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port; |
| } |
| |
| int udp_v4_get_port(struct sock *sk, unsigned short snum) |
| { |
| unsigned int hash2_nulladdr = |
| udp4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum); |
| unsigned int hash2_partial = |
| udp4_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, |
| bool exact_dif) |
| { |
| int score; |
| struct inet_sock *inet; |
| |
| if (!net_eq(sock_net(sk), net) || |
| udp_sk(sk)->udp_port_hash != hnum || |
| ipv6_only_sock(sk)) |
| return -1; |
| |
| score = (sk->sk_family == PF_INET) ? 2 : 1; |
| inet = inet_sk(sk); |
| |
| if (inet->inet_rcv_saddr) { |
| if (inet->inet_rcv_saddr != daddr) |
| return -1; |
| score += 4; |
| } |
| |
| if (inet->inet_daddr) { |
| if (inet->inet_daddr != saddr) |
| return -1; |
| score += 4; |
| } |
| |
| if (inet->inet_dport) { |
| if (inet->inet_dport != sport) |
| return -1; |
| score += 4; |
| } |
| |
| if (sk->sk_bound_dev_if || exact_dif) { |
| if (sk->sk_bound_dev_if != dif) |
| return -1; |
| score += 4; |
| } |
| if (sk->sk_incoming_cpu == raw_smp_processor_id()) |
| score++; |
| return score; |
| } |
| |
| static u32 udp_ehashfn(const struct net *net, const __be32 laddr, |
| const __u16 lport, const __be32 faddr, |
| const __be16 fport) |
| { |
| static u32 udp_ehash_secret __read_mostly; |
| |
| net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret)); |
| |
| return __inet_ehashfn(laddr, lport, faddr, fport, |
| udp_ehash_secret + net_hash_mix(net)); |
| } |
| |
| /* called with rcu_read_lock() */ |
| static struct sock *udp4_lib_lookup2(struct net *net, |
| __be32 saddr, __be16 sport, |
| __be32 daddr, unsigned int hnum, int dif, bool exact_dif, |
| struct udp_hslot *hslot2, |
| struct sk_buff *skb) |
| { |
| struct sock *sk, *result; |
| int score, badness, matches = 0, reuseport = 0; |
| u32 hash = 0; |
| |
| result = NULL; |
| badness = 0; |
| udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { |
| score = compute_score(sk, net, saddr, sport, |
| daddr, hnum, dif, exact_dif); |
| if (score > badness) { |
| reuseport = sk->sk_reuseport; |
| if (reuseport) { |
| hash = udp_ehashfn(net, daddr, hnum, |
| saddr, sport); |
| result = reuseport_select_sock(sk, hash, skb, |
| sizeof(struct udphdr)); |
| if (result) |
| return result; |
| matches = 1; |
| } |
| badness = score; |
| result = sk; |
| } else if (score == badness && reuseport) { |
| matches++; |
| if (reciprocal_scale(hash, matches) == 0) |
| result = sk; |
| hash = next_pseudo_random32(hash); |
| } |
| } |
| 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, struct udp_table *udptable, struct sk_buff *skb) |
| { |
| struct sock *sk, *result; |
| unsigned short hnum = ntohs(dport); |
| unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask); |
| struct udp_hslot *hslot2, *hslot = &udptable->hash[slot]; |
| bool exact_dif = udp_lib_exact_dif_match(net, skb); |
| int score, badness, matches = 0, reuseport = 0; |
| u32 hash = 0; |
| |
| if (hslot->count > 10) { |
| hash2 = udp4_portaddr_hash(net, daddr, hnum); |
| slot2 = hash2 & udptable->mask; |
| hslot2 = &udptable->hash2[slot2]; |
| if (hslot->count < hslot2->count) |
| goto begin; |
| |
| result = udp4_lib_lookup2(net, saddr, sport, |
| daddr, hnum, dif, |
| exact_dif, hslot2, skb); |
| if (!result) { |
| unsigned int old_slot2 = slot2; |
| hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum); |
| slot2 = hash2 & udptable->mask; |
| /* avoid searching the same slot again. */ |
| if (unlikely(slot2 == old_slot2)) |
| return result; |
| |
| hslot2 = &udptable->hash2[slot2]; |
| if (hslot->count < hslot2->count) |
| goto begin; |
| |
| result = udp4_lib_lookup2(net, saddr, sport, |
| daddr, hnum, dif, |
| exact_dif, hslot2, skb); |
| } |
| return result; |
| } |
| begin: |
| result = NULL; |
| badness = 0; |
| sk_for_each_rcu(sk, &hslot->head) { |
| score = compute_score(sk, net, saddr, sport, |
| daddr, hnum, dif, exact_dif); |
| if (score > badness) { |
| reuseport = sk->sk_reuseport; |
| if (reuseport) { |
| hash = udp_ehashfn(net, daddr, hnum, |
| saddr, sport); |
| result = reuseport_select_sock(sk, hash, skb, |
| sizeof(struct udphdr)); |
| if (result) |
| return result; |
| matches = 1; |
| } |
| result = sk; |
| badness = score; |
| } else if (score == badness && reuseport) { |
| matches++; |
| if (reciprocal_scale(hash, matches) == 0) |
| result = sk; |
| hash = next_pseudo_random32(hash); |
| } |
| } |
| 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), |
| udptable, skb); |
| } |
| |
| struct sock *udp4_lib_lookup_skb(struct sk_buff *skb, |
| __be16 sport, __be16 dport) |
| { |
| return __udp4_lib_lookup_skb(skb, sport, dport, &udp_table); |
| } |
| EXPORT_SYMBOL_GPL(udp4_lib_lookup_skb); |
| |
| /* Must be called under rcu_read_lock(). |
| * Does increment socket refcount. |
| */ |
| #if IS_ENABLED(CONFIG_NETFILTER_XT_MATCH_SOCKET) || \ |
| IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TPROXY) || \ |
| 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, &udp_table, NULL); |
| if (sk && !atomic_inc_not_zero(&sk->sk_refcnt)) |
| sk = NULL; |
| return sk; |
| } |
| EXPORT_SYMBOL_GPL(udp4_lib_lookup); |
| #endif |
| |
| static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk, |
| __be16 loc_port, __be32 loc_addr, |
| __be16 rmt_port, __be32 rmt_addr, |
| int dif, unsigned short hnum) |
| { |
| struct inet_sock *inet = inet_sk(sk); |
| |
| if (!net_eq(sock_net(sk), net) || |
| udp_sk(sk)->udp_port_hash != hnum || |
| (inet->inet_daddr && inet->inet_daddr != rmt_addr) || |
| (inet->inet_dport != rmt_port && inet->inet_dport) || |
| (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) || |
| ipv6_only_sock(sk) || |
| (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)) |
| return false; |
| if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif)) |
| return false; |
| return true; |
| } |
| |
| /* |
| * This routine is called by the ICMP module when it gets some |
| * sort of error condition. If err < 0 then the socket should |
| * be closed and the error returned to the user. If err > 0 |
| * it's just the icmp type << 8 | icmp code. |
| * Header points to the ip header of the error packet. We move |
| * on past this. Then (as it used to claim before adjustment) |
| * header points to the first 8 bytes of the udp header. We need |
| * to find the appropriate port. |
| */ |
| |
| void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable) |
| { |
| struct inet_sock *inet; |
| const struct iphdr *iph = (const struct iphdr *)skb->data; |
| struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2)); |
| const int type = icmp_hdr(skb)->type; |
| const int code = icmp_hdr(skb)->code; |
| struct sock *sk; |
| int harderr; |
| int err; |
| struct net *net = dev_net(skb->dev); |
| |
| sk = __udp4_lib_lookup(net, iph->daddr, uh->dest, |
| iph->saddr, uh->source, skb->dev->ifindex, udptable, |
| NULL); |
| if (!sk) { |
| __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); |
| return; /* No socket for error */ |
| } |
| |
| err = 0; |
| harderr = 0; |
| inet = inet_sk(sk); |
| |
| switch (type) { |
| default: |
| case ICMP_TIME_EXCEEDED: |
| err = EHOSTUNREACH; |
| break; |
| case ICMP_SOURCE_QUENCH: |
| goto out; |
| case ICMP_PARAMETERPROB: |
| err = EPROTO; |
| harderr = 1; |
| break; |
| case ICMP_DEST_UNREACH: |
| if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ |
| ipv4_sk_update_pmtu(skb, sk, info); |
| if (inet->pmtudisc != IP_PMTUDISC_DONT) { |
| err = EMSGSIZE; |
| harderr = 1; |
| break; |
| } |
| goto out; |
| } |
| err = EHOSTUNREACH; |
| if (code <= NR_ICMP_UNREACH) { |
| harderr = icmp_err_convert[code].fatal; |
| err = icmp_err_convert[code].errno; |
| } |
| break; |
| case ICMP_REDIRECT: |
| ipv4_sk_redirect(skb, sk); |
| goto out; |
| } |
| |
| /* |
| * RFC1122: OK. Passes ICMP errors back to application, as per |
| * 4.1.3.3. |
| */ |
| if (!inet->recverr) { |
| if (!harderr || sk->sk_state != TCP_ESTABLISHED) |
| goto out; |
| } else |
| ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1)); |
| |
| sk->sk_err = err; |
| sk->sk_error_report(sk); |
| out: |
| return; |
| } |
| |
| void udp_err(struct sk_buff *skb, u32 info) |
| { |
| __udp4_lib_err(skb, info, &udp_table); |
| } |
| |
| /* |
| * Throw away all pending data and cancel the corking. Socket is locked. |
| */ |
| void udp_flush_pending_frames(struct sock *sk) |
| { |
| struct udp_sock *up = udp_sk(sk); |
| |
| if (up->pending) { |
| up->len = 0; |
| up->pending = 0; |
| ip_flush_pending_frames(sk); |
| } |
| } |
| EXPORT_SYMBOL(udp_flush_pending_frames); |
| |
| /** |
| * udp4_hwcsum - handle outgoing HW checksumming |
| * @skb: sk_buff containing the filled-in UDP header |
| * (checksum field must be zeroed out) |
| * @src: source IP address |
| * @dst: destination IP address |
| */ |
| void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst) |
| { |
| struct udphdr *uh = udp_hdr(skb); |
| int offset = skb_transport_offset(skb); |
| int len = skb->len - offset; |
| int hlen = len; |
| __wsum csum = 0; |
| |
| if (!skb_has_frag_list(skb)) { |
| /* |
| * Only one fragment on the socket. |
| */ |
| skb->csum_start = skb_transport_header(skb) - skb->head; |
| skb->csum_offset = offsetof(struct udphdr, check); |
| uh->check = ~csum_tcpudp_magic(src, dst, len, |
| IPPROTO_UDP, 0); |
| } else { |
| struct sk_buff *frags; |
| |
| /* |
| * HW-checksum won't work as there are two or more |
| * fragments on the socket so that all csums of sk_buffs |
| * should be together |
| */ |
| skb_walk_frags(skb, frags) { |
| csum = csum_add(csum, frags->csum); |
| hlen -= frags->len; |
| } |
| |
| csum = skb_checksum(skb, offset, hlen, csum); |
| skb->ip_summed = CHECKSUM_NONE; |
| |
| uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum); |
| if (uh->check == 0) |
| uh->check = CSUM_MANGLED_0; |
| } |
| } |
| EXPORT_SYMBOL_GPL(udp4_hwcsum); |
| |
| /* Function to set UDP checksum for an IPv4 UDP packet. This is intended |
| * for the simple case like when setting the checksum for a UDP tunnel. |
| */ |
| void udp_set_csum(bool nocheck, struct sk_buff *skb, |
| __be32 saddr, __be32 daddr, int len) |
| { |
| struct udphdr *uh = udp_hdr(skb); |
| |
| if (nocheck) { |
| uh->check = 0; |
| } else if (skb_is_gso(skb)) { |
| uh->check = ~udp_v4_check(len, saddr, daddr, 0); |
| } else if (skb->ip_summed == CHECKSUM_PARTIAL) { |
| uh->check = 0; |
| uh->check = udp_v4_check(len, saddr, daddr, lco_csum(skb)); |
| if (uh->check == 0) |
| uh->check = CSUM_MANGLED_0; |
| } else { |
| skb->ip_summed = CHECKSUM_PARTIAL; |
| skb->csum_start = skb_transport_header(skb) - skb->head; |
| skb->csum_offset = offsetof(struct udphdr, check); |
| uh->check = ~udp_v4_check(len, saddr, daddr, 0); |
| } |
| } |
| EXPORT_SYMBOL(udp_set_csum); |
| |
| static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4) |
| { |
| struct sock *sk = skb->sk; |
| struct inet_sock *inet = inet_sk(sk); |
| struct udphdr *uh; |
| int err = 0; |
| int is_udplite = IS_UDPLITE(sk); |
| int offset = skb_transport_offset(skb); |
| int len = skb->len - offset; |
| __wsum csum = 0; |
| |
| /* |
| * Create a UDP header |
| */ |
| uh = udp_hdr(skb); |
| uh->source = inet->inet_sport; |
| uh->dest = fl4->fl4_dport; |
| uh->len = htons(len); |
| uh->check = 0; |
| |
| if (is_udplite) /* UDP-Lite */ |
| csum = udplite_csum(skb); |
| |
| else if (sk->sk_no_check_tx) { /* UDP csum disabled */ |
| |
| skb->ip_summed = CHECKSUM_NONE; |
| goto send; |
| |
| } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ |
| |
| udp4_hwcsum(skb, fl4->saddr, fl4->daddr); |
| goto send; |
| |
| } else |
| csum = udp_csum(skb); |
| |
| /* add protocol-dependent pseudo-header */ |
| uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len, |
| sk->sk_protocol, csum); |
| if (uh->check == 0) |
| uh->check = CSUM_MANGLED_0; |
| |
| send: |
| err = ip_send_skb(sock_net(sk), skb); |
| if (err) { |
| if (err == -ENOBUFS && !inet->recverr) { |
| UDP_INC_STATS(sock_net(sk), |
| UDP_MIB_SNDBUFERRORS, is_udplite); |
| err = 0; |
| } |
| } else |
| UDP_INC_STATS(sock_net(sk), |
| UDP_MIB_OUTDATAGRAMS, is_udplite); |
| return err; |
| } |
| |
| /* |
| * Push out all pending data as one UDP datagram. Socket is locked. |
| */ |
| int udp_push_pending_frames(struct sock *sk) |
| { |
| struct udp_sock *up = udp_sk(sk); |
| struct inet_sock *inet = inet_sk(sk); |
| struct flowi4 *fl4 = &inet->cork.fl.u.ip4; |
| struct sk_buff *skb; |
| int err = 0; |
| |
| skb = ip_finish_skb(sk, fl4); |
| if (!skb) |
| goto out; |
| |
| err = udp_send_skb(skb, fl4); |
| |
| out: |
| up->len = 0; |
| up->pending = 0; |
| return err; |
| } |
| EXPORT_SYMBOL(udp_push_pending_frames); |
| |
| 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); |
| struct flowi4 fl4_stack; |
| struct flowi4 *fl4; |
| int ulen = len; |
| struct ipcm_cookie ipc; |
| struct rtable *rt = NULL; |
| int free = 0; |
| int connected = 0; |
| __be32 daddr, faddr, saddr; |
| __be16 dport; |
| u8 tos; |
| int err, is_udplite = IS_UDPLITE(sk); |
| int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; |
| int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); |
| struct sk_buff *skb; |
| struct ip_options_data opt_copy; |
| |
| if (len > 0xFFFF) |
| return -EMSGSIZE; |
| |
| /* |
| * Check the flags. |
| */ |
| |
| if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */ |
| return -EOPNOTSUPP; |
| |
| ipc.opt = NULL; |
| ipc.tx_flags = 0; |
| ipc.ttl = 0; |
| ipc.tos = -1; |
| |
| getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; |
| |
| fl4 = &inet->cork.fl.u.ip4; |
| if (up->pending) { |
| /* |
| * There are pending frames. |
| * The socket lock must be held while it's corked. |
| */ |
| lock_sock(sk); |
| if (likely(up->pending)) { |
| if (unlikely(up->pending != AF_INET)) { |
| release_sock(sk); |
| return -EINVAL; |
| } |
| goto do_append_data; |
| } |
| release_sock(sk); |
| } |
| ulen += sizeof(struct udphdr); |
| |
| /* |
| * Get and verify the address. |
| */ |
| if (msg->msg_name) { |
| DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); |
| 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; |
| } |
| |
| ipc.sockc.tsflags = sk->sk_tsflags; |
| ipc.addr = inet->inet_saddr; |
| ipc.oif = sk->sk_bound_dev_if; |
| |
| if (msg->msg_controllen) { |
| err = ip_cmsg_send(sk, msg, &ipc, sk->sk_family == AF_INET6); |
| if (unlikely(err)) { |
| kfree(ipc.opt); |
| return err; |
| } |
| if (ipc.opt) |
| free = 1; |
| connected = 0; |
| } |
| if (!ipc.opt) { |
| struct ip_options_rcu *inet_opt; |
| |
| rcu_read_lock(); |
| inet_opt = rcu_dereference(inet->inet_opt); |
| if (inet_opt) { |
| memcpy(&opt_copy, inet_opt, |
| sizeof(*inet_opt) + inet_opt->opt.optlen); |
| ipc.opt = &opt_copy.opt; |
| } |
| rcu_read_unlock(); |
| } |
| |
| saddr = ipc.addr; |
| ipc.addr = faddr = daddr; |
| |
| sock_tx_timestamp(sk, ipc.sockc.tsflags, &ipc.tx_flags); |
| |
| if (ipc.opt && ipc.opt->opt.srr) { |
| if (!daddr) |
| return -EINVAL; |
| faddr = ipc.opt->opt.faddr; |
| connected = 0; |
| } |
| tos = get_rttos(&ipc, inet); |
| if (sock_flag(sk, SOCK_LOCALROUTE) || |
| (msg->msg_flags & MSG_DONTROUTE) || |
| (ipc.opt && ipc.opt->opt.is_strictroute)) { |
| tos |= RTO_ONLINK; |
| connected = 0; |
| } |
| |
| if (ipv4_is_multicast(daddr)) { |
| if (!ipc.oif) |
| ipc.oif = inet->mc_index; |
| if (!saddr) |
| saddr = inet->mc_addr; |
| connected = 0; |
| } else if (!ipc.oif) |
| ipc.oif = inet->uc_index; |
| |
| if (connected) |
| rt = (struct rtable *)sk_dst_check(sk, 0); |
| |
| if (!rt) { |
| struct net *net = sock_net(sk); |
| __u8 flow_flags = inet_sk_flowi_flags(sk); |
| |
| fl4 = &fl4_stack; |
| |
| flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos, |
| RT_SCOPE_UNIVERSE, sk->sk_protocol, |
| flow_flags, |
| faddr, saddr, dport, inet->inet_sport, |
| sk->sk_uid); |
| |
| security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); |
| rt = ip_route_output_flow(net, fl4, sk); |
| if (IS_ERR(rt)) { |
| err = PTR_ERR(rt); |
| rt = NULL; |
| if (err == -ENETUNREACH) |
| IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); |
| goto out; |
| } |
| |
| err = -EACCES; |
| if ((rt->rt_flags & RTCF_BROADCAST) && |
| !sock_flag(sk, SOCK_BROADCAST)) |
| goto out; |
| if (connected) |
| sk_dst_set(sk, dst_clone(&rt->dst)); |
| } |
| |
| if (msg->msg_flags&MSG_CONFIRM) |
| goto do_confirm; |
| back_from_confirm: |
| |
| saddr = fl4->saddr; |
| if (!ipc.addr) |
| daddr = ipc.addr = fl4->daddr; |
| |
| /* Lockless fast path for the non-corking case. */ |
| if (!corkreq) { |
| skb = ip_make_skb(sk, fl4, getfrag, msg, ulen, |
| sizeof(struct udphdr), &ipc, &rt, |
| msg->msg_flags); |
| err = PTR_ERR(skb); |
| if (!IS_ERR_OR_NULL(skb)) |
| err = udp_send_skb(skb, fl4); |
| 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("cork app bug 2\n"); |
| err = -EINVAL; |
| goto out; |
| } |
| /* |
| * Now cork the socket to pend data. |
| */ |
| fl4 = &inet->cork.fl.u.ip4; |
| fl4->daddr = daddr; |
| fl4->saddr = saddr; |
| fl4->fl4_dport = dport; |
| fl4->fl4_sport = inet->inet_sport; |
| up->pending = AF_INET; |
| |
| do_append_data: |
| up->len += ulen; |
| err = ip_append_data(sk, fl4, getfrag, msg, ulen, |
| sizeof(struct udphdr), &ipc, &rt, |
| corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); |
| if (err) |
| udp_flush_pending_frames(sk); |
| else if (!corkreq) |
| err = udp_push_pending_frames(sk); |
| else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) |
| up->pending = 0; |
| release_sock(sk); |
| |
| out: |
| ip_rt_put(rt); |
| 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: |
| dst_confirm(&rt->dst); |
| if (!(msg->msg_flags&MSG_PROBE) || len) |
| goto back_from_confirm; |
| err = 0; |
| goto out; |
| } |
| EXPORT_SYMBOL(udp_sendmsg); |
| |
| int udp_sendpage(struct sock *sk, struct page *page, int offset, |
| size_t size, int flags) |
| { |
| struct inet_sock *inet = inet_sk(sk); |
| struct udp_sock *up = udp_sk(sk); |
| int ret; |
| |
| if (flags & MSG_SENDPAGE_NOTLAST) |
| flags |= MSG_MORE; |
| |
| if (!up->pending) { |
| struct msghdr msg = { .msg_flags = flags|MSG_MORE }; |
| |
| /* Call udp_sendmsg to specify destination address which |
| * sendpage interface can't pass. |
| * This will succeed only when the socket is connected. |
| */ |
| ret = udp_sendmsg(sk, &msg, 0); |
| if (ret < 0) |
| return ret; |
| } |
| |
| lock_sock(sk); |
| |
| if (unlikely(!up->pending)) { |
| release_sock(sk); |
| |
| net_dbg_ratelimited("udp cork app bug 3\n"); |
| return -EINVAL; |
| } |
| |
| ret = ip_append_page(sk, &inet->cork.fl.u.ip4, |
| page, offset, size, flags); |
| if (ret == -EOPNOTSUPP) { |
| release_sock(sk); |
| return sock_no_sendpage(sk->sk_socket, page, offset, |
| size, flags); |
| } |
| if (ret < 0) { |
| udp_flush_pending_frames(sk); |
| goto out; |
| } |
| |
| up->len += size; |
| if (!(up->corkflag || (flags&MSG_MORE))) |
| ret = udp_push_pending_frames(sk); |
| if (!ret) |
| ret = size; |
| out: |
| release_sock(sk); |
| return ret; |
| } |
| |
| /* fully reclaim rmem/fwd memory allocated for skb */ |
| static void udp_rmem_release(struct sock *sk, int size, int partial) |
| { |
| struct udp_sock *up = udp_sk(sk); |
| int amt; |
| |
| if (likely(partial)) { |
| up->forward_deficit += size; |
| size = up->forward_deficit; |
| if (size < (sk->sk_rcvbuf >> 2) && |
| !skb_queue_empty(&sk->sk_receive_queue)) |
| return; |
| } else { |
| size += up->forward_deficit; |
| } |
| up->forward_deficit = 0; |
| |
| sk->sk_forward_alloc += size; |
| amt = (sk->sk_forward_alloc - partial) & ~(SK_MEM_QUANTUM - 1); |
| sk->sk_forward_alloc -= amt; |
| |
| if (amt) |
| __sk_mem_reduce_allocated(sk, amt >> SK_MEM_QUANTUM_SHIFT); |
| |
| atomic_sub(size, &sk->sk_rmem_alloc); |
| } |
| |
| /* Note: called with sk_receive_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) |
| { |
| udp_rmem_release(sk, skb->dev_scratch, 1); |
| } |
| EXPORT_SYMBOL(udp_skb_destructor); |
| |
| /* Idea of busylocks is to let producers grab an extra spinlock |
| * to relieve pressure on the receive_queue spinlock shared by consumer. |
| * Under flood, this means that only one producer can be in line |
| * trying to acquire the receive_queue spinlock. |
| * These busylock can be allocated on a per cpu manner, instead of a |
| * per socket one (that would consume a cache line per socket) |
| */ |
| static int udp_busylocks_log __read_mostly; |
| static spinlock_t *udp_busylocks __read_mostly; |
| |
| static spinlock_t *busylock_acquire(void *ptr) |
| { |
| spinlock_t *busy; |
| |
| busy = udp_busylocks + hash_ptr(ptr, udp_busylocks_log); |
| spin_lock(busy); |
| return busy; |
| } |
| |
| static void busylock_release(spinlock_t *busy) |
| { |
| if (busy) |
| spin_unlock(busy); |
| } |
| |
| int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb) |
| { |
| struct sk_buff_head *list = &sk->sk_receive_queue; |
| int rmem, delta, amt, err = -ENOMEM; |
| spinlock_t *busy = NULL; |
| int size; |
| |
| /* try to avoid the costly atomic add/sub pair when the receive |
| * queue is full; always allow at least a packet |
| */ |
| rmem = atomic_read(&sk->sk_rmem_alloc); |
| if (rmem > sk->sk_rcvbuf) |
| goto drop; |
| |
| /* Under mem pressure, it might be helpful to help udp_recvmsg() |
| * having linear skbs : |
| * - Reduce memory overhead and thus increase receive queue capacity |
| * - Less cache line misses at copyout() time |
| * - Less work at consume_skb() (less alien page frag freeing) |
| */ |
| if (rmem > (sk->sk_rcvbuf >> 1)) { |
| skb_condense(skb); |
| |
| busy = busylock_acquire(sk); |
| } |
| size = skb->truesize; |
| /* Copy skb->truesize into skb->dev_scratch to avoid a cache line miss |
| * in udp_skb_destructor() |
| */ |
| skb->dev_scratch = size; |
| |
| /* we drop only if the receive buf is full and the receive |
| * queue contains some other skb |
| */ |
| rmem = atomic_add_return(size, &sk->sk_rmem_alloc); |
| if (rmem > (size + sk->sk_rcvbuf)) |
| goto uncharge_drop; |
| |
| spin_lock(&list->lock); |
| if (size >= sk->sk_forward_alloc) { |
| amt = sk_mem_pages(size); |
| delta = amt << SK_MEM_QUANTUM_SHIFT; |
| if (!__sk_mem_raise_allocated(sk, delta, amt, SK_MEM_RECV)) { |
| err = -ENOBUFS; |
| spin_unlock(&list->lock); |
| goto uncharge_drop; |
| } |
| |
| sk->sk_forward_alloc += delta; |
| } |
| |
| sk->sk_forward_alloc -= size; |
| |
| /* no need to setup a destructor, we will explicitly release the |
| * forward allocated memory on dequeue |
| */ |
| sock_skb_set_dropcount(sk, skb); |
| |
| __skb_queue_tail(list, skb); |
| spin_unlock(&list->lock); |
| |
| if (!sock_flag(sk, SOCK_DEAD)) |
| sk->sk_data_ready(sk); |
| |
| busylock_release(busy); |
| return 0; |
| |
| uncharge_drop: |
| atomic_sub(skb->truesize, &sk->sk_rmem_alloc); |
| |
| drop: |
| atomic_inc(&sk->sk_drops); |
| busylock_release(busy); |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb); |
| |
| void udp_destruct_sock(struct sock *sk) |
| { |
| /* reclaim completely the forward allocated memory */ |
| unsigned int total = 0; |
| struct sk_buff *skb; |
| |
| while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { |
| total += skb->truesize; |
| kfree_skb(skb); |
| } |
| udp_rmem_release(sk, total, 0); |
| |
| inet_sock_destruct(sk); |
| } |
| EXPORT_SYMBOL_GPL(udp_destruct_sock); |
| |
| int udp_init_sock(struct sock *sk) |
| { |
| sk->sk_destruct = udp_destruct_sock; |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(udp_init_sock); |
| |
| void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len) |
| { |
| if (unlikely(READ_ONCE(sk->sk_peek_off) >= 0)) { |
| bool slow = lock_sock_fast(sk); |
| |
| sk_peek_offset_bwd(sk, len); |
| unlock_sock_fast(sk, slow); |
| } |
| consume_skb(skb); |
| } |
| EXPORT_SYMBOL_GPL(skb_consume_udp); |
| |
| /** |
| * 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 = &sk->sk_receive_queue; |
| struct sk_buff *skb; |
| int total = 0; |
| int res; |
| |
| spin_lock_bh(&rcvq->lock); |
| while ((skb = skb_peek(rcvq)) != NULL && |
| 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); |
| } |
| res = skb ? skb->len : -1; |
| if (total) |
| udp_rmem_release(sk, total, 1); |
| spin_unlock_bh(&rcvq->lock); |
| return res; |
| } |
| |
| /* |
| * IOCTL requests applicable to the UDP protocol |
| */ |
| |
| int udp_ioctl(struct sock *sk, int cmd, unsigned long arg) |
| { |
| switch (cmd) { |
| case SIOCOUTQ: |
| { |
| int amount = sk_wmem_alloc_get(sk); |
| |
| return put_user(amount, (int __user *)arg); |
| } |
| |
| case SIOCINQ: |
| { |
| int amount = max_t(int, 0, first_packet_length(sk)); |
| |
| return put_user(amount, (int __user *)arg); |
| } |
| |
| default: |
| return -ENOIOCTLCMD; |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(udp_ioctl); |
| |
| /* |
| * This should be easy, if there is something there we |
| * return it, otherwise we block. |
| */ |
| |
| int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, |
| int flags, int *addr_len) |
| { |
| struct inet_sock *inet = inet_sk(sk); |
| DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); |
| struct sk_buff *skb; |
| unsigned int ulen, copied; |
| int peeked, peeking, off; |
| int err; |
| int is_udplite = IS_UDPLITE(sk); |
| bool checksum_valid = false; |
| |
| if (flags & MSG_ERRQUEUE) |
| return ip_recv_error(sk, msg, len, addr_len); |
| |
| try_again: |
| peeking = off = sk_peek_offset(sk, flags); |
| skb = __skb_recv_udp(sk, flags, noblock, &peeked, &off, &err); |
| if (!skb) |
| return err; |
| |
| ulen = skb->len; |
| 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_lib_checksum_complete(skb); |
| if (!checksum_valid) |
| goto csum_copy_err; |
| } |
| |
| if (checksum_valid || skb_csum_unnecessary(skb)) |
| err = skb_copy_datagram_msg(skb, off, msg, copied); |
| else { |
| err = skb_copy_and_csum_datagram_msg(skb, off, msg); |
| |
| if (err == -EINVAL) |
| goto csum_copy_err; |
| } |
| |
| if (unlikely(err)) { |
| if (!peeked) { |
| atomic_inc(&sk->sk_drops); |
| UDP_INC_STATS(sock_net(sk), |
| UDP_MIB_INERRORS, is_udplite); |
| } |
| kfree_skb(skb); |
| return err; |
| } |
| |
| if (!peeked) |
| UDP_INC_STATS(sock_net(sk), |
| UDP_MIB_INDATAGRAMS, is_udplite); |
| |
| sock_recv_ts_and_drops(msg, sk, skb); |
| |
| /* Copy the address. */ |
| if (sin) { |
| sin->sin_family = AF_INET; |
| sin->sin_port = udp_hdr(skb)->source; |
| sin->sin_addr.s_addr = ip_hdr(skb)->saddr; |
| memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); |
| *addr_len = sizeof(*sin); |
| } |
| if (inet->cmsg_flags) |
| ip_cmsg_recv_offset(msg, sk, skb, sizeof(struct udphdr), off); |
| |
| err = copied; |
| if (flags & MSG_TRUNC) |
| err = ulen; |
| |
| skb_consume_udp(sk, skb, peeking ? -err : err); |
| return err; |
| |
| csum_copy_err: |
| if (!__sk_queue_drop_skb(sk, skb, flags)) { |
| 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_disconnect(struct sock *sk, int flags) |
| { |
| struct inet_sock *inet = inet_sk(sk); |
| /* |
| * 1003.1g - break association. |
| */ |
| |
| sk->sk_state = TCP_CLOSE; |
| inet->inet_daddr = 0; |
| inet->inet_dport = 0; |
| sock_rps_reset_rxhash(sk); |
| sk->sk_bound_dev_if = 0; |
| if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) |
| inet_reset_saddr(sk); |
| |
| if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) { |
| sk->sk_prot->unhash(sk); |
| inet->inet_sport = 0; |
| } |
| sk_dst_reset(sk); |
| return 0; |
| } |
| EXPORT_SYMBOL(__udp_disconnect); |
| |
| int udp_disconnect(struct sock *sk, int flags) |
| { |
| lock_sock(sk); |
| __udp_disconnect(sk, flags); |
| release_sock(sk); |
| return 0; |
| } |
| EXPORT_SYMBOL(udp_disconnect); |
| |
| void udp_lib_unhash(struct sock *sk) |
| { |
| if (sk_hashed(sk)) { |
| struct udp_table *udptable = sk->sk_prot->h.udp_table; |
| struct udp_hslot *hslot, *hslot2; |
| |
| hslot = udp_hashslot(udptable, sock_net(sk), |
| udp_sk(sk)->udp_port_hash); |
| hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); |
| |
| spin_lock_bh(&hslot->lock); |
| if (rcu_access_pointer(sk->sk_reuseport_cb)) |
| reuseport_detach_sock(sk); |
| if (sk_del_node_init_rcu(sk)) { |
| hslot->count--; |
| inet_sk(sk)->inet_num = 0; |
| sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); |
| |
| spin_lock(&hslot2->lock); |
| hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); |
| hslot2->count--; |
| spin_unlock(&hslot2->lock); |
| } |
| spin_unlock_bh(&hslot->lock); |
| } |
| } |
| EXPORT_SYMBOL(udp_lib_unhash); |
| |
| /* |
| * inet_rcv_saddr was changed, we must rehash secondary hash |
| */ |
| void udp_lib_rehash(struct sock *sk, u16 newhash) |
| { |
| if (sk_hashed(sk)) { |
| struct udp_table *udptable = sk->sk_prot->h.udp_table; |
| struct udp_hslot *hslot, *hslot2, *nhslot2; |
| |
| hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); |
| nhslot2 = udp_hashslot2(udptable, newhash); |
| udp_sk(sk)->udp_portaddr_hash = newhash; |
| |
| if (hslot2 != nhslot2 || |
| rcu_access_pointer(sk->sk_reuseport_cb)) { |
| hslot = udp_hashslot(udptable, sock_net(sk), |
| udp_sk(sk)->udp_port_hash); |
| /* we must lock primary chain too */ |
| spin_lock_bh(&hslot->lock); |
| if (rcu_access_pointer(sk->sk_reuseport_cb)) |
| reuseport_detach_sock(sk); |
| |
| if (hslot2 != nhslot2) { |
| spin_lock(&hslot2->lock); |
| hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); |
| hslot2->count--; |
| spin_unlock(&hslot2->lock); |
| |
| spin_lock(&nhslot2->lock); |
| hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, |
| &nhslot2->head); |
| nhslot2->count++; |
| spin_unlock(&nhslot2->lock); |
| } |
| |
| spin_unlock_bh(&hslot->lock); |
| } |
| } |
| } |
| EXPORT_SYMBOL(udp_lib_rehash); |
| |
| static void udp_v4_rehash(struct sock *sk) |
| { |
| u16 new_hash = udp4_portaddr_hash(sock_net(sk), |
| inet_sk(sk)->inet_rcv_saddr, |
| inet_sk(sk)->inet_num); |
| udp_lib_rehash(sk, new_hash); |
| } |
| |
| int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) |
| { |
| int rc; |
| |
| if (inet_sk(sk)->inet_daddr) { |
| sock_rps_save_rxhash(sk, skb); |
| sk_mark_napi_id(sk, skb); |
| sk_incoming_cpu_update(sk); |
| } else { |
| sk_mark_napi_id_once(sk, skb); |
| } |
| |
| rc = __udp_enqueue_schedule_skb(sk, skb); |
| if (rc < 0) { |
| int is_udplite = IS_UDPLITE(sk); |
| |
| /* Note that an ENOMEM error is charged twice */ |
| if (rc == -ENOMEM) |
| UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS, |
| is_udplite); |
| UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); |
| kfree_skb(skb); |
| trace_udp_fail_queue_rcv_skb(rc, sk); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| static struct static_key udp_encap_needed __read_mostly; |
| void udp_encap_enable(void) |
| { |
| if (!static_key_enabled(&udp_encap_needed)) |
| static_key_slow_inc(&udp_encap_needed); |
| } |
| EXPORT_SYMBOL(udp_encap_enable); |
| |
| /* returns: |
| * -1: error |
| * 0: success |
| * >0: "udp encap" protocol resubmission |
| * |
| * Note that in the success and error cases, the skb is assumed to |
| * have either been requeued or freed. |
| */ |
| int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) |
| { |
| struct udp_sock *up = udp_sk(sk); |
| int is_udplite = IS_UDPLITE(sk); |
| |
| /* |
| * Charge it to the socket, dropping if the queue is full. |
| */ |
| if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) |
| goto drop; |
| nf_reset(skb); |
| |
| if (static_key_false(&udp_encap_needed) && 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 = ACCESS_ONCE(up->encap_rcv); |
| if (encap_rcv) { |
| int ret; |
| |
| /* Verify checksum before giving to encap */ |
| if (udp_lib_checksum_complete(skb)) |
| goto csum_error; |
| |
| ret = encap_rcv(sk, skb); |
| if (ret <= 0) { |
| __UDP_INC_STATS(sock_net(sk), |
| UDP_MIB_INDATAGRAMS, |
| is_udplite); |
| return -ret; |
| } |
| } |
| |
| /* FALLTHROUGH -- it's a UDP Packet */ |
| } |
| |
| /* |
| * UDP-Lite specific tests, ignored on UDP sockets |
| */ |
| if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { |
| |
| /* |
| * MIB statistics other than incrementing the error count are |
| * disabled for the following two types of errors: these depend |
| * on the application settings, not on the functioning of the |
| * protocol stack as such. |
| * |
| * RFC 3828 here recommends (sec 3.3): "There should also be a |
| * way ... to ... at least let the receiving application block |
| * delivery of packets with coverage values less than a value |
| * provided by the application." |
| */ |
| if (up->pcrlen == 0) { /* full coverage was set */ |
| net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n", |
| UDP_SKB_CB(skb)->cscov, skb->len); |
| goto drop; |
| } |
| /* The next case involves violating the min. coverage requested |
| * by the receiver. This is subtle: if receiver wants x and x is |
| * greater than the buffersize/MTU then receiver will complain |
| * that it wants x while sender emits packets of smaller size y. |
| * Therefore the above ...()->partial_cov statement is essential. |
| */ |
| if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { |
| net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n", |
| UDP_SKB_CB(skb)->cscov, up->pcrlen); |
| goto drop; |
| } |
| } |
| |
| if (rcu_access_pointer(sk->sk_filter) && |
| udp_lib_checksum_complete(skb)) |
| goto csum_error; |
| |
| if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) |
| goto drop; |
| |
| udp_csum_pull_header(skb); |
| |
| ipv4_pktinfo_prepare(sk, skb); |
| return __udp_queue_rcv_skb(sk, skb); |
| |
| csum_error: |
| __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); |
| drop: |
| __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); |
| atomic_inc(&sk->sk_drops); |
| kfree_skb(skb); |
| return -1; |
| } |
| |
| /* For TCP sockets, sk_rx_dst is protected by socket lock |
| * For UDP, we use xchg() to guard against concurrent changes. |
| */ |
| static void udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst) |
| { |
| struct dst_entry *old; |
| |
| dst_hold(dst); |
| old = xchg(&sk->sk_rx_dst, dst); |
| dst_release(old); |
| } |
| |
| /* |
| * 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; |
| struct hlist_node *node; |
| struct sk_buff *nskb; |
| |
| if (use_hash2) { |
| hash2_any = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum) & |
| udptable->mask; |
| hash2 = udp4_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, hnum)) |
| continue; |
| |
| if (!first) { |
| first = sk; |
| continue; |
| } |
| nskb = skb_clone(skb, GFP_ATOMIC); |
| |
| if (unlikely(!nskb)) { |
| atomic_inc(&sk->sk_drops); |
| __UDP_INC_STATS(net, UDP_MIB_RCVBUFERRORS, |
| IS_UDPLITE(sk)); |
| __UDP_INC_STATS(net, UDP_MIB_INERRORS, |
| IS_UDPLITE(sk)); |
| continue; |
| } |
| if (udp_queue_rcv_skb(sk, nskb) > 0) |
| consume_skb(nskb); |
| } |
| |
| /* Also lookup *:port if we are using hash2 and haven't done so yet. */ |
| if (use_hash2 && hash2 != hash2_any) { |
| hash2 = hash2_any; |
| goto start_lookup; |
| } |
| |
| if (first) { |
| if (udp_queue_rcv_skb(first, skb) > 0) |
| consume_skb(skb); |
| } else { |
| kfree_skb(skb); |
| __UDP_INC_STATS(net, UDP_MIB_IGNOREDMULTI, |
| proto == IPPROTO_UDPLITE); |
| } |
| return 0; |
| } |
| |
| /* Initialize UDP checksum. If exited with zero value (success), |
| * CHECKSUM_UNNECESSARY means, that no more checks are required. |
| * Otherwise, csum completion requires chacksumming packet body, |
| * including udp header and folding it to skb->csum. |
| */ |
| static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh, |
| int proto) |
| { |
| int err; |
| |
| UDP_SKB_CB(skb)->partial_cov = 0; |
| UDP_SKB_CB(skb)->cscov = skb->len; |
| |
| if (proto == IPPROTO_UDPLITE) { |
| err = udplite_checksum_init(skb, uh); |
| if (err) |
| return err; |
| } |
| |
| /* Note, we are only interested in != 0 or == 0, thus the |
| * force to int. |
| */ |
| return (__force int)skb_checksum_init_zero_check(skb, proto, uh->check, |
| inet_compute_pseudo); |
| } |
| |
| /* |
| * All we need to do is get the socket, and then do a checksum. |
| */ |
| |
| int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, |
| int proto) |
| { |
| struct sock *sk; |
| struct udphdr *uh; |
| unsigned short ulen; |
| struct rtable *rt = skb_rtable(skb); |
| __be32 saddr, daddr; |
| struct net *net = dev_net(skb->dev); |
| |
| /* |
| * Validate the packet. |
| */ |
| if (!pskb_may_pull(skb, sizeof(struct udphdr))) |
| goto drop; /* No space for header. */ |
| |
| uh = udp_hdr(skb); |
| ulen = ntohs(uh->len); |
| saddr = ip_hdr(skb)->saddr; |
| daddr = ip_hdr(skb)->daddr; |
| |
| if (ulen > skb->len) |
| goto short_packet; |
| |
| if (proto == IPPROTO_UDP) { |
| /* UDP validates ulen. */ |
| if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen)) |
| goto short_packet; |
| uh = udp_hdr(skb); |
| } |
| |
| if (udp4_csum_init(skb, uh, proto)) |
| goto csum_error; |
| |
| sk = skb_steal_sock(skb); |
| if (sk) { |
| struct dst_entry *dst = skb_dst(skb); |
| int ret; |
| |
| if (unlikely(sk->sk_rx_dst != dst)) |
| udp_sk_rx_dst_set(sk, dst); |
| |
| ret = udp_queue_rcv_skb(sk, skb); |
| sock_put(sk); |
| /* 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; |
| } |
| |
| 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) { |
| int ret; |
| |
| if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk)) |
| skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check, |
| inet_compute_pseudo); |
| |
| ret = udp_queue_rcv_skb(sk, skb); |
| |
| /* a return value > 0 means to resubmit the input, but |
| * it wants the return to be -protocol, or 0 |
| */ |
| if (ret > 0) |
| return -ret; |
| return 0; |
| } |
| |
| if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) |
| goto drop; |
| nf_reset(skb); |
| |
| /* No socket. Drop packet silently, if checksum is wrong */ |
| if (udp_lib_checksum_complete(skb)) |
| goto csum_error; |
| |
| __UDP_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); |
| icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); |
| |
| /* |
| * Hmm. We got an UDP packet to a port to which we |
| * don't wanna listen. Ignore it. |
| */ |
| kfree_skb(skb); |
| return 0; |
| |
| short_packet: |
| net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n", |
| proto == IPPROTO_UDPLITE ? "Lite" : "", |
| &saddr, ntohs(uh->source), |
| ulen, skb->len, |
| &daddr, ntohs(uh->dest)); |
| goto drop; |
| |
| csum_error: |
| /* |
| * RFC1122: OK. Discards the bad packet silently (as far as |
| * the network is concerned, anyway) as per 4.1.3.4 (MUST). |
| */ |
| net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n", |
| proto == IPPROTO_UDPLITE ? "Lite" : "", |
| &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest), |
| ulen); |
| __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE); |
| drop: |
| __UDP_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); |
| kfree_skb(skb); |
| return 0; |
| } |
| |
| /* We can only early demux multicast if there is a single matching socket. |
| * If more than one socket found returns NULL |
| */ |
| static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net, |
| __be16 loc_port, __be32 loc_addr, |
| __be16 rmt_port, __be32 rmt_addr, |
| int dif) |
| { |
| struct sock *sk, *result; |
| unsigned short hnum = ntohs(loc_port); |
| unsigned int slot = udp_hashfn(net, hnum, udp_table.mask); |
| struct udp_hslot *hslot = &udp_table.hash[slot]; |
| |
| /* Do not bother scanning a too big list */ |
| if (hslot->count > 10) |
| return NULL; |
| |
| result = NULL; |
| sk_for_each_rcu(sk, &hslot->head) { |
| if (__udp_is_mcast_sock(net, sk, loc_port, loc_addr, |
| rmt_port, rmt_addr, dif, 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) |
| { |
| unsigned short hnum = ntohs(loc_port); |
| unsigned int hash2 = udp4_portaddr_hash(net, loc_addr, hnum); |
| unsigned int slot2 = hash2 & udp_table.mask; |
| struct udp_hslot *hslot2 = &udp_table.hash2[slot2]; |
| INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr); |
| const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum); |
| struct sock *sk; |
| |
| udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { |
| if (INET_MATCH(sk, net, acookie, rmt_addr, |
| loc_addr, ports, dif)) |
| return sk; |
| /* Only check first socket in chain */ |
| break; |
| } |
| return NULL; |
| } |
| |
| void udp_v4_early_demux(struct sk_buff *skb) |
| { |
| struct net *net = dev_net(skb->dev); |
| const struct iphdr *iph; |
| const struct udphdr *uh; |
| struct sock *sk = NULL; |
| struct dst_entry *dst; |
| int dif = skb->dev->ifindex; |
| int ours; |
| |
| /* validate the packet */ |
| if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr))) |
| return; |
| |
| iph = ip_hdr(skb); |
| uh = udp_hdr(skb); |
| |
| if (skb->pkt_type == PACKET_BROADCAST || |
| skb->pkt_type == PACKET_MULTICAST) { |
| struct in_device *in_dev = __in_dev_get_rcu(skb->dev); |
| |
| if (!in_dev) |
| return; |
| |
| /* we are supposed to accept bcast packets */ |
| if (skb->pkt_type == PACKET_MULTICAST) { |
| ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr, |
| iph->protocol); |
| if (!ours) |
| return; |
| } |
| |
| sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr, |
| uh->source, iph->saddr, dif); |
| } else if (skb->pkt_type == PACKET_HOST) { |
| sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr, |
| uh->source, iph->saddr, dif); |
| } |
| |
| if (!sk || !atomic_inc_not_zero_hint(&sk->sk_refcnt, 2)) |
| return; |
| |
| skb->sk = sk; |
| skb->destructor = sock_efree; |
| dst = READ_ONCE(sk->sk_rx_dst); |
| |
| if (dst) |
| dst = dst_check(dst, 0); |
| if (dst) { |
| /* DST_NOCACHE can not be used without taking a reference */ |
| if (dst->flags & DST_NOCACHE) { |
| if (likely(atomic_inc_not_zero(&dst->__refcnt))) |
| skb_dst_set(skb, dst); |
| } else { |
| skb_dst_set_noref(skb, dst); |
| } |
| } |
| } |
| |
| int udp_rcv(struct sk_buff *skb) |
| { |
| return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP); |
| } |
| |
| void udp_destroy_sock(struct sock *sk) |
| { |
| struct udp_sock *up = udp_sk(sk); |
| bool slow = lock_sock_fast(sk); |
| udp_flush_pending_frames(sk); |
| unlock_sock_fast(sk, slow); |
| if (static_key_false(&udp_encap_needed) && up->encap_type) { |
| void (*encap_destroy)(struct sock *sk); |
| encap_destroy = ACCESS_ONCE(up->encap_destroy); |
| if (encap_destroy) |
| encap_destroy(sk); |
| } |
| } |
| |
| /* |
| * Socket option code for UDP |
| */ |
| int udp_lib_setsockopt(struct sock *sk, int level, int optname, |
| char __user *optval, unsigned int optlen, |
| int (*push_pending_frames)(struct sock *)) |
| { |
| struct udp_sock *up = udp_sk(sk); |
| int val, valbool; |
| int err = 0; |
| int is_udplite = IS_UDPLITE(sk); |
| |
| if (optlen < sizeof(int)) |
| return -EINVAL; |
| |
| if (get_user(val, (int __user *)optval)) |
| return -EFAULT; |
| |
| valbool = val ? 1 : 0; |
| |
| switch (optname) { |
| case UDP_CORK: |
| if (val != 0) { |
| up->corkflag = 1; |
| } else { |
| up->corkflag = 0; |
| lock_sock(sk); |
| push_pending_frames(sk); |
| release_sock(sk); |
| } |
| break; |
| |
| case UDP_ENCAP: |
| switch (val) { |
| case 0: |
| case UDP_ENCAP_ESPINUDP: |
| case UDP_ENCAP_ESPINUDP_NON_IKE: |
| up->encap_rcv = xfrm4_udp_encap_rcv; |
| /* FALLTHROUGH */ |
| case UDP_ENCAP_L2TPINUDP: |
| up->encap_type = val; |
| udp_encap_enable(); |
| break; |
| default: |
| err = -ENOPROTOOPT; |
| break; |
| } |
| break; |
| |
| case UDP_NO_CHECK6_TX: |
| up->no_check6_tx = valbool; |
| break; |
| |
| case UDP_NO_CHECK6_RX: |
| up->no_check6_rx = valbool; |
| break; |
| |
| /* |
| * UDP-Lite's partial checksum coverage (RFC 3828). |
| */ |
| /* The sender sets actual checksum coverage length via this option. |
| * The case coverage > packet length is handled by send module. */ |
| case UDPLITE_SEND_CSCOV: |
| if (!is_udplite) /* Disable the option on UDP sockets */ |
| return -ENOPROTOOPT; |
| if (val != 0 && val < 8) /* Illegal coverage: use default (8) */ |
| val = 8; |
| else if (val > USHRT_MAX) |
| val = USHRT_MAX; |
| up->pcslen = val; |
| up->pcflag |= UDPLITE_SEND_CC; |
| break; |
| |
| /* The receiver specifies a minimum checksum coverage value. To make |
| * sense, this should be set to at least 8 (as done below). If zero is |
| * used, this again means full checksum coverage. */ |
| case UDPLITE_RECV_CSCOV: |
| if (!is_udplite) /* Disable the option on UDP sockets */ |
| return -ENOPROTOOPT; |
| if (val != 0 && val < 8) /* Avoid silly minimal values. */ |
| val = 8; |
| else if (val > USHRT_MAX) |
| val = USHRT_MAX; |
| up->pcrlen = val; |
| up->pcflag |= UDPLITE_RECV_CC; |
| break; |
| |
| default: |
| err = -ENOPROTOOPT; |
| break; |
| } |
| |
| return err; |
| } |
| EXPORT_SYMBOL(udp_lib_setsockopt); |
| |
| int udp_setsockopt(struct sock *sk, int level, int optname, |
| char __user *optval, unsigned int optlen) |
| { |
| if (level == SOL_UDP || level == SOL_UDPLITE) |
| return udp_lib_setsockopt(sk, level, optname, optval, optlen, |
| udp_push_pending_frames); |
| return ip_setsockopt(sk, level, optname, optval, optlen); |
| } |
| |
| #ifdef CONFIG_COMPAT |
| int compat_udp_setsockopt(struct sock *sk, int level, int optname, |
| char __user *optval, unsigned int optlen) |
| { |
| if (level == SOL_UDP || level == SOL_UDPLITE) |
| return udp_lib_setsockopt(sk, level, optname, optval, optlen, |
| udp_push_pending_frames); |
| return compat_ip_setsockopt(sk, level, optname, optval, optlen); |
| } |
| #endif |
| |
| int udp_lib_getsockopt(struct sock *sk, int level, int optname, |
| char __user *optval, int __user *optlen) |
| { |
| struct udp_sock *up = udp_sk(sk); |
| int val, len; |
| |
| if (get_user(len, optlen)) |
| return -EFAULT; |
| |
| len = min_t(unsigned int, len, sizeof(int)); |
| |
| if (len < 0) |
| return -EINVAL; |
| |
| switch (optname) { |
| case UDP_CORK: |
| val = up->corkflag; |
| break; |
| |
| case UDP_ENCAP: |
| val = up->encap_type; |
| break; |
| |
| case UDP_NO_CHECK6_TX: |
| val = up->no_check6_tx; |
| break; |
| |
| case UDP_NO_CHECK6_RX: |
| val = up->no_check6_rx; |
| break; |
| |
| /* The following two cannot be changed on UDP sockets, the return is |
| * always 0 (which corresponds to the full checksum coverage of UDP). */ |
| case UDPLITE_SEND_CSCOV: |
| val = up->pcslen; |
| break; |
| |
| case UDPLITE_RECV_CSCOV: |
| val = up->pcrlen; |
| break; |
| |
| default: |
| return -ENOPROTOOPT; |
| } |
| |
| if (put_user(len, optlen)) |
| return -EFAULT; |
| if (copy_to_user(optval, &val, len)) |
| return -EFAULT; |
| return 0; |
| } |
| EXPORT_SYMBOL(udp_lib_getsockopt); |
| |
| int udp_getsockopt(struct sock *sk, int level, int optname, |
| char __user *optval, int __user *optlen) |
| { |
| if (level == SOL_UDP || level == SOL_UDPLITE) |
| return udp_lib_getsockopt(sk, level, optname, optval, optlen); |
| return ip_getsockopt(sk, level, optname, optval, optlen); |
| } |
| |
| #ifdef CONFIG_COMPAT |
| int compat_udp_getsockopt(struct sock *sk, int level, int optname, |
| char __user *optval, int __user *optlen) |
| { |
| if (level == SOL_UDP || level == SOL_UDPLITE) |
| return udp_lib_getsockopt(sk, level, optname, optval, optlen); |
| return compat_ip_getsockopt(sk, level, optname, optval, optlen); |
| } |
| #endif |
| /** |
| * udp_poll - wait for a UDP event. |
| * @file - file struct |
| * @sock - socket |
| * @wait - poll table |
| * |
| * This is same as datagram poll, except for the special case of |
| * blocking sockets. If application is using a blocking fd |
| * and a packet with checksum error is in the queue; |
| * then it could get return from select indicating data available |
| * but then block when reading it. Add special case code |
| * to work around these arguably broken applications. |
| */ |
| unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait) |
| { |
| unsigned int mask = datagram_poll(file, sock, wait); |
| struct sock *sk = sock->sk; |
| |
| sock_rps_record_flow(sk); |
| |
| /* Check for false positives due to checksum errors */ |
| if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) && |
| !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1) |
| mask &= ~(POLLIN | POLLRDNORM); |
| |
| return mask; |
| |
| } |
| EXPORT_SYMBOL(udp_poll); |
| |
| int udp_abort(struct sock *sk, int err) |
| { |
| lock_sock(sk); |
| |
| sk->sk_err = err; |
| sk->sk_error_report(sk); |
| __udp_disconnect(sk, 0); |
| |
| release_sock(sk); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(udp_abort); |
| |
| struct proto udp_prot = { |
| .name = "UDP", |
| .owner = THIS_MODULE, |
| .close = udp_lib_close, |
| .connect = ip4_datagram_connect, |
| .disconnect = udp_disconnect, |
| .ioctl = udp_ioctl, |
| .init = udp_init_sock, |
| .destroy = udp_destroy_sock, |
| .setsockopt = udp_setsockopt, |
| .getsockopt = udp_getsockopt, |
| .sendmsg = udp_sendmsg, |
| .recvmsg = udp_recvmsg, |
| .sendpage = udp_sendpage, |
| .release_cb = ip4_datagram_release_cb, |
| .hash = udp_lib_hash, |
| .unhash = udp_lib_unhash, |
| .rehash = udp_v4_rehash, |
| .get_port = udp_v4_get_port, |
| .memory_allocated = &udp_memory_allocated, |
| .sysctl_mem = sysctl_udp_mem, |
| .sysctl_wmem = &sysctl_udp_wmem_min, |
| .sysctl_rmem = &sysctl_udp_rmem_min, |
| .obj_size = sizeof(struct udp_sock), |
| .h.udp_table = &udp_table, |
| #ifdef CONFIG_COMPAT |
| .compat_setsockopt = compat_udp_setsockopt, |
| .compat_getsockopt = compat_udp_getsockopt, |
| #endif |
| .diag_destroy = udp_abort, |
| }; |
| EXPORT_SYMBOL(udp_prot); |
| |
| /* ------------------------------------------------------------------------ */ |
| #ifdef CONFIG_PROC_FS |
| |
| static struct sock *udp_get_first(struct seq_file *seq, int start) |
| { |
| struct sock *sk; |
| struct udp_iter_state *state = seq->private; |
| struct net *net = seq_file_net(seq); |
| |
| for (state->bucket = start; state->bucket <= state->udp_table->mask; |
| ++state->bucket) { |
| struct udp_hslot *hslot = &state->udp_table->hash[state->bucket]; |
| |
| if (hlist_empty(&hslot->head)) |
| continue; |
| |
| spin_lock_bh(&hslot->lock); |
| sk_for_each(sk, &hslot->head) { |
| if (!net_eq(sock_net(sk), net)) |
| continue; |
| if (sk->sk_family == state->family) |
| goto found; |
| } |
| spin_unlock_bh(&hslot->lock); |
| } |
| sk = NULL; |
| found: |
| return sk; |
| } |
| |
| static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk) |
| { |
| struct udp_iter_state *state = seq->private; |
| struct net *net = seq_file_net(seq); |
| |
| do { |
| sk = sk_next(sk); |
| } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family)); |
| |
| if (!sk) { |
| if (state->bucket <= state->udp_table->mask) |
| spin_unlock_bh(&state->udp_table->hash[state->bucket].lock); |
| return udp_get_first(seq, state->bucket + 1); |
| } |
| return sk; |
| } |
| |
| static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos) |
| { |
| struct sock *sk = udp_get_first(seq, 0); |
| |
| if (sk) |
| while (pos && (sk = udp_get_next(seq, sk)) != NULL) |
| --pos; |
| return pos ? NULL : sk; |
| } |
| |
| static 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; |
| } |
| |
| static 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; |
| } |
| |
| static void udp_seq_stop(struct seq_file *seq, void *v) |
| { |
| struct udp_iter_state *state = seq->private; |
| |
| if (state->bucket <= state->udp_table->mask) |
| spin_unlock_bh(&state->udp_table->hash[state->bucket].lock); |
| } |
| |
| int udp_seq_open(struct inode *inode, struct file *file) |
| { |
| struct udp_seq_afinfo *afinfo = PDE_DATA(inode); |
| struct udp_iter_state *s; |
| int err; |
| |
| err = seq_open_net(inode, file, &afinfo->seq_ops, |
| sizeof(struct udp_iter_state)); |
| if (err < 0) |
| return err; |
| |
| s = ((struct seq_file *)file->private_data)->private; |
| s->family = afinfo->family; |
| s->udp_table = afinfo->udp_table; |
| return err; |
| } |
| EXPORT_SYMBOL(udp_seq_open); |
| |
| /* ------------------------------------------------------------------------ */ |
| int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo) |
| { |
| struct proc_dir_entry *p; |
| int rc = 0; |
| |
| afinfo->seq_ops.start = udp_seq_start; |
| afinfo->seq_ops.next = udp_seq_next; |
| afinfo->seq_ops.stop = udp_seq_stop; |
| |
| p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, |
| afinfo->seq_fops, afinfo); |
| if (!p) |
| rc = -ENOMEM; |
| return rc; |
| } |
| EXPORT_SYMBOL(udp_proc_register); |
| |
| void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo) |
| { |
| remove_proc_entry(afinfo->name, net->proc_net); |
| } |
| EXPORT_SYMBOL(udp_proc_unregister); |
| |
| /* ------------------------------------------------------------------------ */ |
| static void udp4_format_sock(struct sock *sp, struct seq_file *f, |
| int bucket) |
| { |
| struct inet_sock *inet = inet_sk(sp); |
| __be32 dest = inet->inet_daddr; |
| __be32 src = inet->inet_rcv_saddr; |
| __u16 destp = ntohs(inet->inet_dport); |
| __u16 srcp = ntohs(inet->inet_sport); |
| |
| seq_printf(f, "%5d: %08X:%04X %08X:%04X" |
| " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d", |
| bucket, src, srcp, dest, destp, sp->sk_state, |
| sk_wmem_alloc_get(sp), |
| sk_rmem_alloc_get(sp), |
| 0, 0L, 0, |
| from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), |
| 0, sock_i_ino(sp), |
| atomic_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; |
| } |
| |
| static const struct file_operations udp_afinfo_seq_fops = { |
| .owner = THIS_MODULE, |
| .open = udp_seq_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release_net |
| }; |
| |
| /* ------------------------------------------------------------------------ */ |
| static struct udp_seq_afinfo udp4_seq_afinfo = { |
| .name = "udp", |
| .family = AF_INET, |
| .udp_table = &udp_table, |
| .seq_fops = &udp_afinfo_seq_fops, |
| .seq_ops = { |
| .show = udp4_seq_show, |
| }, |
| }; |
| |
| static int __net_init udp4_proc_init_net(struct net *net) |
| { |
| return udp_proc_register(net, &udp4_seq_afinfo); |
| } |
| |
| static void __net_exit udp4_proc_exit_net(struct net *net) |
| { |
| udp_proc_unregister(net, &udp4_seq_afinfo); |
| } |
| |
| static struct pernet_operations udp4_net_ops = { |
| .init = udp4_proc_init_net, |
| .exit = udp4_proc_exit_net, |
| }; |
| |
| int __init udp4_proc_init(void) |
| { |
| return register_pernet_subsys(&udp4_net_ops); |
| } |
| |
| void udp4_proc_exit(void) |
| { |
| unregister_pernet_subsys(&udp4_net_ops); |
| } |
| #endif /* CONFIG_PROC_FS */ |
| |
| static __initdata unsigned long uhash_entries; |
| static int __init set_uhash_entries(char *str) |
| { |
| ssize_t ret; |
| |
| if (!str) |
| return 0; |
| |
| ret = kstrtoul(str, 0, &uhash_entries); |
| if (ret) |
| return 0; |
| |
| if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN) |
| uhash_entries = UDP_HTABLE_SIZE_MIN; |
| return 1; |
| } |
| __setup("uhash_entries=", set_uhash_entries); |
| |
| void __init udp_table_init(struct udp_table *table, const char *name) |
| { |
| unsigned int i; |
| |
| table->hash = alloc_large_system_hash(name, |
| 2 * sizeof(struct udp_hslot), |
| uhash_entries, |
| 21, /* one slot per 2 MB */ |
| 0, |
| &table->log, |
| &table->mask, |
| UDP_HTABLE_SIZE_MIN, |
| 64 * 1024); |
| |
| table->hash2 = table->hash + (table->mask + 1); |
| for (i = 0; i <= table->mask; i++) { |
| INIT_HLIST_HEAD(&table->hash[i].head); |
| table->hash[i].count = 0; |
| spin_lock_init(&table->hash[i].lock); |
| } |
| for (i = 0; i <= table->mask; i++) { |
| INIT_HLIST_HEAD(&table->hash2[i].head); |
| table->hash2[i].count = 0; |
| spin_lock_init(&table->hash2[i].lock); |
| } |
| } |
| |
| u32 udp_flow_hashrnd(void) |
| { |
| static u32 hashrnd __read_mostly; |
| |
| net_get_random_once(&hashrnd, sizeof(hashrnd)); |
| |
| return hashrnd; |
| } |
| EXPORT_SYMBOL(udp_flow_hashrnd); |
| |
| 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; |
| |
| sysctl_udp_rmem_min = SK_MEM_QUANTUM; |
| sysctl_udp_wmem_min = SK_MEM_QUANTUM; |
| |
| /* 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); |
| } |