diff options
Diffstat (limited to 'net/ipv4/udp.c')
| -rw-r--r-- | net/ipv4/udp.c | 2288 |
1 files changed, 2288 insertions, 0 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c new file mode 100644 index 00000000..fe141052 --- /dev/null +++ b/net/ipv4/udp.c @@ -0,0 +1,2288 @@ +/* + * 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 <asm/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/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/route.h> +#include <net/checksum.h> +#include <net/xfrm.h> +#include <trace/events/udp.h> +#include "udp_impl.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) + +static int udp_lib_lport_inuse(struct net *net, __u16 num, + const struct udp_hslot *hslot, + unsigned long *bitmap, + struct sock *sk, + int (*saddr_comp)(const struct sock *sk1, + const struct sock *sk2), + unsigned int log) +{ + struct sock *sk2; + struct hlist_nulls_node *node; + + sk_nulls_for_each(sk2, node, &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) && + (*saddr_comp)(sk, sk2)) { + if (bitmap) + __set_bit(udp_sk(sk2)->udp_port_hash >> log, + bitmap); + else + return 1; + } + 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, + int (*saddr_comp)(const struct sock *sk1, + const struct sock *sk2)) +{ + struct sock *sk2; + struct hlist_nulls_node *node; + int res = 0; + + spin_lock(&hslot2->lock); + udp_portaddr_for_each_entry(sk2, node, &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) && + (*saddr_comp)(sk, sk2)) { + res = 1; + break; + } + spin_unlock(&hslot2->lock); + return res; +} + +/** + * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6 + * + * @sk: socket struct in question + * @snum: port number to look up + * @saddr_comp: AF-dependent comparison of bound local IP addresses + * @hash2_nulladdr: AF-dependent hash value in secondary hash chains, + * with NULL address + */ +int udp_lib_get_port(struct sock *sk, unsigned short snum, + int (*saddr_comp)(const struct sock *sk1, + const struct sock *sk2), + 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 rand; + unsigned short first, last; + DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN); + + inet_get_local_port_range(&low, &high); + remaining = (high - low) + 1; + + rand = net_random(); + first = (((u64)rand * remaining) >> 32) + 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, + saddr_comp, 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_reserved_local_port(snum)) + goto found; + snum += rand; + } while (snum != first); + spin_unlock_bh(&hslot->lock); + } 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, saddr_comp); + if (!exist && (hash2_nulladdr != slot2)) { + hslot2 = udp_hashslot2(udptable, hash2_nulladdr); + exist = udp_lib_lport_inuse2(net, snum, hslot2, + sk, saddr_comp); + } + if (exist) + goto fail_unlock; + else + goto found; + } +scan_primary_hash: + if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, + saddr_comp, 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)) { + sk_nulls_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); + hlist_nulls_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); + +static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2) +{ + struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2); + + return (!ipv6_only_sock(sk2) && + (!inet1->inet_rcv_saddr || !inet2->inet_rcv_saddr || + inet1->inet_rcv_saddr == inet2->inet_rcv_saddr)); +} + +static unsigned int udp4_portaddr_hash(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, ipv4_rcv_saddr_equal, hash2_nulladdr); +} + +static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr, + unsigned short hnum, + __be16 sport, __be32 daddr, __be16 dport, int dif) +{ + int score = -1; + + if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum && + !ipv6_only_sock(sk)) { + struct inet_sock *inet = inet_sk(sk); + + score = (sk->sk_family == PF_INET ? 1 : 0); + if (inet->inet_rcv_saddr) { + if (inet->inet_rcv_saddr != daddr) + return -1; + score += 2; + } + if (inet->inet_daddr) { + if (inet->inet_daddr != saddr) + return -1; + score += 2; + } + if (inet->inet_dport) { + if (inet->inet_dport != sport) + return -1; + score += 2; + } + if (sk->sk_bound_dev_if) { + if (sk->sk_bound_dev_if != dif) + return -1; + score += 2; + } + } + return score; +} + +/* + * In this second variant, we check (daddr, dport) matches (inet_rcv_sadd, inet_num) + */ +#define SCORE2_MAX (1 + 2 + 2 + 2) +static inline int compute_score2(struct sock *sk, struct net *net, + __be32 saddr, __be16 sport, + __be32 daddr, unsigned int hnum, int dif) +{ + int score = -1; + + if (net_eq(sock_net(sk), net) && !ipv6_only_sock(sk)) { + struct inet_sock *inet = inet_sk(sk); + + if (inet->inet_rcv_saddr != daddr) + return -1; + if (inet->inet_num != hnum) + return -1; + + score = (sk->sk_family == PF_INET ? 1 : 0); + if (inet->inet_daddr) { + if (inet->inet_daddr != saddr) + return -1; + score += 2; + } + if (inet->inet_dport) { + if (inet->inet_dport != sport) + return -1; + score += 2; + } + if (sk->sk_bound_dev_if) { + if (sk->sk_bound_dev_if != dif) + return -1; + score += 2; + } + } + return score; +} + + +/* called with read_rcu_lock() */ +static struct sock *udp4_lib_lookup2(struct net *net, + __be32 saddr, __be16 sport, + __be32 daddr, unsigned int hnum, int dif, + struct udp_hslot *hslot2, unsigned int slot2) +{ + struct sock *sk, *result; + struct hlist_nulls_node *node; + int score, badness; + +begin: + result = NULL; + badness = -1; + udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) { + score = compute_score2(sk, net, saddr, sport, + daddr, hnum, dif); + if (score > badness) { + result = sk; + badness = score; + if (score == SCORE2_MAX) + goto exact_match; + } + } + /* + * if the nulls value we got at the end of this lookup is + * not the expected one, we must restart lookup. + * We probably met an item that was moved to another chain. + */ + if (get_nulls_value(node) != slot2) + goto begin; + + if (result) { +exact_match: + if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) + result = NULL; + else if (unlikely(compute_score2(result, net, saddr, sport, + daddr, hnum, dif) < badness)) { + sock_put(result); + goto begin; + } + } + 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 sock *sk, *result; + struct hlist_nulls_node *node; + unsigned short hnum = ntohs(dport); + unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask); + struct udp_hslot *hslot2, *hslot = &udptable->hash[slot]; + int score, badness; + + rcu_read_lock(); + 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, + hslot2, slot2); + if (!result) { + hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum); + slot2 = hash2 & udptable->mask; + hslot2 = &udptable->hash2[slot2]; + if (hslot->count < hslot2->count) + goto begin; + + result = udp4_lib_lookup2(net, saddr, sport, + htonl(INADDR_ANY), hnum, dif, + hslot2, slot2); + } + rcu_read_unlock(); + return result; + } +begin: + result = NULL; + badness = -1; + sk_nulls_for_each_rcu(sk, node, &hslot->head) { + score = compute_score(sk, net, saddr, hnum, sport, + daddr, dport, dif); + if (score > badness) { + result = sk; + badness = score; + } + } + /* + * if the nulls value we got at the end of this lookup is + * not the expected one, we must restart lookup. + * We probably met an item that was moved to another chain. + */ + if (get_nulls_value(node) != slot) + goto begin; + + if (result) { + if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) + result = NULL; + else if (unlikely(compute_score(result, net, saddr, hnum, sport, + daddr, dport, dif) < badness)) { + sock_put(result); + goto begin; + } + } + rcu_read_unlock(); + 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) +{ + struct sock *sk; + const struct iphdr *iph = ip_hdr(skb); + + if (unlikely(sk = skb_steal_sock(skb))) + return sk; + else + return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport, + iph->daddr, dport, inet_iif(skb), + udptable); +} + +struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, + __be32 daddr, __be16 dport, int dif) +{ + return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table); +} +EXPORT_SYMBOL_GPL(udp4_lib_lookup); + +static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk, + __be16 loc_port, __be32 loc_addr, + __be16 rmt_port, __be32 rmt_addr, + int dif) +{ + struct hlist_nulls_node *node; + struct sock *s = sk; + unsigned short hnum = ntohs(loc_port); + + sk_nulls_for_each_from(s, node) { + struct inet_sock *inet = inet_sk(s); + + if (!net_eq(sock_net(s), net) || + udp_sk(s)->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(s) || + (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)) + continue; + if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif)) + continue; + goto found; + } + s = NULL; +found: + return s; +} + +/* + * 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); + if (sk == NULL) { + ICMP_INC_STATS_BH(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 */ + 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; + } + + /* + * 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: + sock_put(sk); +} + +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 + */ +static void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst) +{ + struct udphdr *uh = udp_hdr(skb); + struct sk_buff *frags = skb_shinfo(skb)->frag_list; + int offset = skb_transport_offset(skb); + int len = skb->len - offset; + int hlen = len; + __wsum csum = 0; + + if (!frags) { + /* + * 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 { + /* + * 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 + */ + do { + csum = csum_add(csum, frags->csum); + hlen -= frags->len; + } while ((frags = frags->next)); + + 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; + } +} + +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 == UDP_CSUM_NOXMIT) { /* 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(skb); + if (err) { + if (err == -ENOBUFS && !inet->recverr) { + UDP_INC_STATS_USER(sock_net(sk), + UDP_MIB_SNDBUFERRORS, is_udplite); + err = 0; + } + } else + UDP_INC_STATS_USER(sock_net(sk), + UDP_MIB_OUTDATAGRAMS, is_udplite); + return err; +} + +/* + * Push out all pending data as one UDP datagram. Socket is locked. + */ +static 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; +} + +int udp_sendmsg(struct kiocb *iocb, 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; + + 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) { + struct sockaddr_in * usin = (struct sockaddr_in *)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.addr = inet->inet_saddr; + + ipc.oif = sk->sk_bound_dev_if; + err = sock_tx_timestamp(sk, &ipc.tx_flags); + if (err) + return err; + if (msg->msg_controllen) { + err = ip_cmsg_send(sock_net(sk), msg, &ipc); + if (err) + 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; + + if (ipc.opt && ipc.opt->opt.srr) { + if (!daddr) + return -EINVAL; + faddr = ipc.opt->opt.faddr; + connected = 0; + } + tos = RT_TOS(inet->tos); + 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 == NULL) { + struct net *net = sock_net(sk); + + fl4 = &fl4_stack; + flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos, + RT_SCOPE_UNIVERSE, sk->sk_protocol, + inet_sk_flowi_flags(sk)|FLOWI_FLAG_CAN_SLEEP, + faddr, saddr, dport, inet->inet_sport); + + 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_BH(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->msg_iov, ulen, + sizeof(struct udphdr), &ipc, &rt, + msg->msg_flags); + err = PTR_ERR(skb); + if (skb && !IS_ERR(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); + + LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("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->msg_iov, 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_USER(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 (!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(NULL, sk, &msg, 0); + if (ret < 0) + return ret; + } + + lock_sock(sk); + + if (unlikely(!up->pending)) { + release_sock(sk); + + LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("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; +} + + +/** + * 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 0 if none is found. + */ +static unsigned int first_packet_length(struct sock *sk) +{ + struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue; + struct sk_buff *skb; + unsigned int res; + + __skb_queue_head_init(&list_kill); + + spin_lock_bh(&rcvq->lock); + while ((skb = skb_peek(rcvq)) != NULL && + udp_lib_checksum_complete(skb)) { + UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, + IS_UDPLITE(sk)); + atomic_inc(&sk->sk_drops); + __skb_unlink(skb, rcvq); + __skb_queue_tail(&list_kill, skb); + } + res = skb ? skb->len : 0; + spin_unlock_bh(&rcvq->lock); + + if (!skb_queue_empty(&list_kill)) { + bool slow = lock_sock_fast(sk); + + __skb_queue_purge(&list_kill); + sk_mem_reclaim_partial(sk); + unlock_sock_fast(sk, slow); + } + 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: + { + unsigned int amount = first_packet_length(sk); + + if (amount) + /* + * We will only return the amount + * of this packet since that is all + * that will be read. + */ + amount -= sizeof(struct udphdr); + + 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 kiocb *iocb, struct sock *sk, struct msghdr *msg, + size_t len, int noblock, int flags, int *addr_len) +{ + struct inet_sock *inet = inet_sk(sk); + struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; + struct sk_buff *skb; + unsigned int ulen, copied; + int peeked, off = 0; + int err; + int is_udplite = IS_UDPLITE(sk); + bool slow; + + /* + * Check any passed addresses + */ + if (addr_len) + *addr_len = sizeof(*sin); + + if (flags & MSG_ERRQUEUE) + return ip_recv_error(sk, msg, len); + +try_again: + skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0), + &peeked, &off, &err); + if (!skb) + goto out; + + ulen = skb->len - sizeof(struct udphdr); + copied = len; + if (copied > ulen) + copied = ulen; + 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 || UDP_SKB_CB(skb)->partial_cov) { + if (udp_lib_checksum_complete(skb)) + goto csum_copy_err; + } + + if (skb_csum_unnecessary(skb)) + err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), + msg->msg_iov, copied); + else { + err = skb_copy_and_csum_datagram_iovec(skb, + sizeof(struct udphdr), + msg->msg_iov); + + if (err == -EINVAL) + goto csum_copy_err; + } + + if (err) + goto out_free; + + if (!peeked) + UDP_INC_STATS_USER(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)); + } + if (inet->cmsg_flags) + ip_cmsg_recv(msg, skb); + + err = copied; + if (flags & MSG_TRUNC) + err = ulen; + +out_free: + skb_free_datagram_locked(sk, skb); +out: + return err; + +csum_copy_err: + slow = lock_sock_fast(sk); + if (!skb_kill_datagram(sk, skb, flags)) + UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite); + unlock_sock_fast(sk, slow); + + if (noblock) + return -EAGAIN; + + /* starting over for a new packet */ + 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); + +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 (sk_nulls_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_nulls_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) { + hslot = udp_hashslot(udptable, sock_net(sk), + udp_sk(sk)->udp_port_hash); + /* we must lock primary chain too */ + spin_lock_bh(&hslot->lock); + + spin_lock(&hslot2->lock); + hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); + hslot2->count--; + spin_unlock(&hslot2->lock); + + spin_lock(&nhslot2->lock); + hlist_nulls_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); +} + +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); + + rc = sock_queue_rcv_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_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, + is_udplite); + UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite); + kfree_skb(skb); + trace_udp_fail_queue_rcv_skb(rc, sk); + return -1; + } + + return 0; + +} + +/* returns: + * -1: error + * 0: success + * >0: "udp encap" protocol resubmission + * + * Note that in the success and error cases, the skb is assumed to + * have either been requeued or freed. + */ +int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) +{ + struct udp_sock *up = udp_sk(sk); + int rc; + 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 (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 (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) { + int ret; + + ret = encap_rcv(sk, skb); + if (ret <= 0) { + UDP_INC_STATS_BH(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 */ + LIMIT_NETDEBUG(KERN_WARNING "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) { + LIMIT_NETDEBUG(KERN_WARNING "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 drop; + + + if (sk_rcvqueues_full(sk, skb)) + goto drop; + + rc = 0; + + ipv4_pktinfo_prepare(skb); + bh_lock_sock(sk); + if (!sock_owned_by_user(sk)) + rc = __udp_queue_rcv_skb(sk, skb); + else if (sk_add_backlog(sk, skb)) { + bh_unlock_sock(sk); + goto drop; + } + bh_unlock_sock(sk); + + return rc; + +drop: + UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite); + atomic_inc(&sk->sk_drops); + kfree_skb(skb); + return -1; +} + + +static void flush_stack(struct sock **stack, unsigned int count, + struct sk_buff *skb, unsigned int final) +{ + unsigned int i; + struct sk_buff *skb1 = NULL; + struct sock *sk; + + for (i = 0; i < count; i++) { + sk = stack[i]; + if (likely(skb1 == NULL)) + skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC); + + if (!skb1) { + atomic_inc(&sk->sk_drops); + UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, + IS_UDPLITE(sk)); + UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, + IS_UDPLITE(sk)); + } + + if (skb1 && udp_queue_rcv_skb(sk, skb1) <= 0) + skb1 = NULL; + } + if (unlikely(skb1)) + kfree_skb(skb1); +} + +/* + * 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) +{ + struct sock *sk, *stack[256 / sizeof(struct sock *)]; + struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest)); + int dif; + unsigned int i, count = 0; + + spin_lock(&hslot->lock); + sk = sk_nulls_head(&hslot->head); + dif = skb->dev->ifindex; + sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif); + while (sk) { + stack[count++] = sk; + sk = udp_v4_mcast_next(net, sk_nulls_next(sk), uh->dest, + daddr, uh->source, saddr, dif); + if (unlikely(count == ARRAY_SIZE(stack))) { + if (!sk) + break; + flush_stack(stack, count, skb, ~0); + count = 0; + } + } + /* + * before releasing chain lock, we must take a reference on sockets + */ + for (i = 0; i < count; i++) + sock_hold(stack[i]); + + spin_unlock(&hslot->lock); + + /* + * do the slow work with no lock held + */ + if (count) { + flush_stack(stack, count, skb, count - 1); + + for (i = 0; i < count; i++) + sock_put(stack[i]); + } else { + kfree_skb(skb); + } + 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) +{ + const struct iphdr *iph; + 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; + } + + iph = ip_hdr(skb); + if (uh->check == 0) { + skb->ip_summed = CHECKSUM_UNNECESSARY; + } else if (skb->ip_summed == CHECKSUM_COMPLETE) { + if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len, + proto, skb->csum)) + skb->ip_summed = CHECKSUM_UNNECESSARY; + } + if (!skb_csum_unnecessary(skb)) + skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, + skb->len, proto, 0); + /* Probably, we should checksum udp header (it should be in cache + * in any case) and data in tiny packets (< rx copybreak). + */ + + return 0; +} + +/* + * All we need to do is get the socket, and then do a checksum. + */ + +int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, + int proto) +{ + struct sock *sk; + struct udphdr *uh; + unsigned short ulen; + struct rtable *rt = skb_rtable(skb); + __be32 saddr, daddr; + struct net *net = dev_net(skb->dev); + + /* + * Validate the packet. + */ + if (!pskb_may_pull(skb, sizeof(struct udphdr))) + goto drop; /* No space for header. */ + + uh = udp_hdr(skb); + ulen = ntohs(uh->len); + saddr = ip_hdr(skb)->saddr; + daddr = ip_hdr(skb)->daddr; + + if (ulen > skb->len) + goto short_packet; + + if (proto == IPPROTO_UDP) { + /* UDP validates ulen. */ + if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen)) + goto short_packet; + uh = udp_hdr(skb); + } + + if (udp4_csum_init(skb, uh, proto)) + goto csum_error; + + if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) + return __udp4_lib_mcast_deliver(net, skb, uh, + saddr, daddr, udptable); + + sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable); + + if (sk != NULL) { + int 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 (!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_BH(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: + LIMIT_NETDEBUG(KERN_DEBUG "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). + */ + LIMIT_NETDEBUG(KERN_DEBUG "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); +drop: + UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); + kfree_skb(skb); + return 0; +} + +int udp_rcv(struct sk_buff *skb) +{ + return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP); +} + +void udp_destroy_sock(struct sock *sk) +{ + bool slow = lock_sock_fast(sk); + udp_flush_pending_frames(sk); + unlock_sock_fast(sk, slow); +} + +/* + * 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; + int err = 0; + int is_udplite = IS_UDPLITE(sk); + + if (optlen < sizeof(int)) + return -EINVAL; + + if (get_user(val, (int __user *)optval)) + return -EFAULT; + + 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; + break; + default: + err = -ENOPROTOOPT; + break; + } + 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; + + /* 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; + + /* 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)) + mask &= ~(POLLIN | POLLRDNORM); + + return mask; + +} +EXPORT_SYMBOL(udp_poll); + +struct proto udp_prot = { + .name = "UDP", + .owner = THIS_MODULE, + .close = udp_lib_close, + .connect = ip4_datagram_connect, + .disconnect = udp_disconnect, + .ioctl = udp_ioctl, + .destroy = udp_destroy_sock, + .setsockopt = udp_setsockopt, + .getsockopt = udp_getsockopt, + .sendmsg = udp_sendmsg, + .recvmsg = udp_recvmsg, + .sendpage = udp_sendpage, + .backlog_rcv = __udp_queue_rcv_skb, + .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), + .slab_flags = SLAB_DESTROY_BY_RCU, + .h.udp_table = &udp_table, +#ifdef CONFIG_COMPAT + .compat_setsockopt = compat_udp_setsockopt, + .compat_getsockopt = compat_udp_getsockopt, +#endif + .clear_sk = sk_prot_clear_portaddr_nulls, +}; +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 hlist_nulls_node *node; + struct udp_hslot *hslot = &state->udp_table->hash[state->bucket]; + + if (hlist_nulls_empty(&hslot->head)) + continue; + + spin_lock_bh(&hslot->lock); + sk_nulls_for_each(sk, node, &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_nulls_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(inode)->data; + 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) +{ + proc_net_remove(net, afinfo->name); +} +EXPORT_SYMBOL(udp_proc_unregister); + +/* ------------------------------------------------------------------------ */ +static void udp4_format_sock(struct sock *sp, struct seq_file *f, + int bucket, int *len) +{ + 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 %5d %8d %lu %d %pK %d%n", + bucket, src, srcp, dest, destp, sp->sk_state, + sk_wmem_alloc_get(sp), + sk_rmem_alloc_get(sp), + 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp), + atomic_read(&sp->sk_refcnt), sp, + atomic_read(&sp->sk_drops), len); +} + +int udp4_seq_show(struct seq_file *seq, void *v) +{ + if (v == SEQ_START_TOKEN) + seq_printf(seq, "%-127s\n", + " 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; + int len; + + udp4_format_sock(v, seq, state->bucket, &len); + seq_printf(seq, "%*s\n", 127 - len, ""); + } + 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) +{ + if (!str) + return 0; + uhash_entries = simple_strtoul(str, &str, 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; + + if (!CONFIG_BASE_SMALL) + 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, + 64 * 1024); + /* + * Make sure hash table has the minimum size + */ + if (CONFIG_BASE_SMALL || table->mask < UDP_HTABLE_SIZE_MIN - 1) { + table->hash = kmalloc(UDP_HTABLE_SIZE_MIN * + 2 * sizeof(struct udp_hslot), GFP_KERNEL); + if (!table->hash) + panic(name); + table->log = ilog2(UDP_HTABLE_SIZE_MIN); + table->mask = UDP_HTABLE_SIZE_MIN - 1; + } + table->hash2 = table->hash + (table->mask + 1); + for (i = 0; i <= table->mask; i++) { + INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i); + table->hash[i].count = 0; + spin_lock_init(&table->hash[i].lock); + } + for (i = 0; i <= table->mask; i++) { + INIT_HLIST_NULLS_HEAD(&table->hash2[i].head, i); + table->hash2[i].count = 0; + spin_lock_init(&table->hash2[i].lock); + } +} + +void __init udp_init(void) +{ + unsigned long limit; + + 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; +} + +int udp4_ufo_send_check(struct sk_buff *skb) +{ + const struct iphdr *iph; + struct udphdr *uh; + + if (!pskb_may_pull(skb, sizeof(*uh))) + return -EINVAL; + + iph = ip_hdr(skb); + uh = udp_hdr(skb); + + uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len, + IPPROTO_UDP, 0); + skb->csum_start = skb_transport_header(skb) - skb->head; + skb->csum_offset = offsetof(struct udphdr, check); + skb->ip_summed = CHECKSUM_PARTIAL; + return 0; +} + +struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, + netdev_features_t features) +{ + struct sk_buff *segs = ERR_PTR(-EINVAL); + unsigned int mss; + int offset; + __wsum csum; + + mss = skb_shinfo(skb)->gso_size; + if (unlikely(skb->len <= mss)) + goto out; + + if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { + /* Packet is from an untrusted source, reset gso_segs. */ + int type = skb_shinfo(skb)->gso_type; + + if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY) || + !(type & (SKB_GSO_UDP)))) + goto out; + + skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); + + segs = NULL; + goto out; + } + + /* Do software UFO. Complete and fill in the UDP checksum as HW cannot + * do checksum of UDP packets sent as multiple IP fragments. + */ + offset = skb_checksum_start_offset(skb); + csum = skb_checksum(skb, offset, skb->len - offset, 0); + offset += skb->csum_offset; + *(__sum16 *)(skb->data + offset) = csum_fold(csum); + skb->ip_summed = CHECKSUM_NONE; + + /* Fragment the skb. IP headers of the fragments are updated in + * inet_gso_segment() + */ + segs = skb_segment(skb, features); +out: + return segs; +} + |