/* * 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). * * Version: $Id: udp.c,v 1.102 2002/02/01 22:01:04 davem Exp $ * * Authors: Ross Biro * Fred N. van Kempen, * Arnt Gulbrandsen, * Alan Cox, * Hirokazu Takahashi, * * 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 : Add Encapulation Support * * * 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. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Snmp MIB for the UDP layer */ DEFINE_SNMP_STAT(struct udp_mib, udp_statistics) __read_mostly; struct hlist_head udp_hash[UDP_HTABLE_SIZE]; DEFINE_RWLOCK(udp_hash_lock); static int udp_port_rover; static inline int udp_lport_inuse(u16 num) { struct sock *sk; struct hlist_node *node; sk_for_each(sk, node, &udp_hash[num & (UDP_HTABLE_SIZE - 1)]) if (inet_sk(sk)->num == num) return 1; return 0; } /** * udp_get_port - common 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 */ int udp_get_port(struct sock *sk, unsigned short snum, int (*saddr_cmp)(const struct sock *sk1, const struct sock *sk2)) { struct hlist_node *node; struct hlist_head *head; struct sock *sk2; int error = 1; write_lock_bh(&udp_hash_lock); if (snum == 0) { int best_size_so_far, best, result, i; if (udp_port_rover > sysctl_local_port_range[1] || udp_port_rover < sysctl_local_port_range[0]) udp_port_rover = sysctl_local_port_range[0]; best_size_so_far = 32767; best = result = udp_port_rover; for (i = 0; i < UDP_HTABLE_SIZE; i++, result++) { int size; head = &udp_hash[result & (UDP_HTABLE_SIZE - 1)]; if (hlist_empty(head)) { if (result > sysctl_local_port_range[1]) result = sysctl_local_port_range[0] + ((result - sysctl_local_port_range[0]) & (UDP_HTABLE_SIZE - 1)); goto gotit; } size = 0; sk_for_each(sk2, node, head) if (++size < best_size_so_far) { best_size_so_far = size; best = result; } } result = best; for(i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++, result += UDP_HTABLE_SIZE) { if (result > sysctl_local_port_range[1]) result = sysctl_local_port_range[0] + ((result - sysctl_local_port_range[0]) & (UDP_HTABLE_SIZE - 1)); if (!udp_lport_inuse(result)) break; } if (i >= (1 << 16) / UDP_HTABLE_SIZE) goto fail; gotit: udp_port_rover = snum = result; } else { head = &udp_hash[snum & (UDP_HTABLE_SIZE - 1)]; sk_for_each(sk2, node, head) if (inet_sk(sk2)->num == snum && sk2 != sk && (!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_cmp)(sk, sk2) ) goto fail; } inet_sk(sk)->num = snum; if (sk_unhashed(sk)) { head = &udp_hash[snum & (UDP_HTABLE_SIZE - 1)]; sk_add_node(sk, head); sock_prot_inc_use(sk->sk_prot); } error = 0; fail: write_unlock_bh(&udp_hash_lock); return error; } static inline 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->rcv_saddr || !inet2->rcv_saddr || inet1->rcv_saddr == inet2->rcv_saddr )); } static inline int udp_v4_get_port(struct sock *sk, unsigned short snum) { return udp_get_port(sk, snum, ipv4_rcv_saddr_equal); } static void udp_v4_hash(struct sock *sk) { BUG(); } static void udp_v4_unhash(struct sock *sk) { write_lock_bh(&udp_hash_lock); if (sk_del_node_init(sk)) { inet_sk(sk)->num = 0; sock_prot_dec_use(sk->sk_prot); } write_unlock_bh(&udp_hash_lock); } /* UDP is nearly always wildcards out the wazoo, it makes no sense to try * harder than this. -DaveM */ static struct sock *udp_v4_lookup_longway(u32 saddr, u16 sport, u32 daddr, u16 dport, int dif) { struct sock *sk, *result = NULL; struct hlist_node *node; unsigned short hnum = ntohs(dport); int badness = -1; sk_for_each(sk, node, &udp_hash[hnum & (UDP_HTABLE_SIZE - 1)]) { struct inet_sock *inet = inet_sk(sk); if (inet->num == hnum && !ipv6_only_sock(sk)) { int score = (sk->sk_family == PF_INET ? 1 : 0); if (inet->rcv_saddr) { if (inet->rcv_saddr != daddr) continue; score+=2; } if (inet->daddr) { if (inet->daddr != saddr) continue; score+=2; } if (inet->dport) { if (inet->dport != sport) continue; score+=2; } if (sk->sk_bound_dev_if) { if (sk->sk_bound_dev_if != dif) continue; score+=2; } if(score == 9) { result = sk; break; } else if(score > badness) { result = sk; badness = score; } } } return result; } static __inline__ struct sock *udp_v4_lookup(u32 saddr, u16 sport, u32 daddr, u16 dport, int dif) { struct sock *sk; read_lock(&udp_hash_lock); sk = udp_v4_lookup_longway(saddr, sport, daddr, dport, dif); if (sk) sock_hold(sk); read_unlock(&udp_hash_lock); return sk; } static inline struct sock *udp_v4_mcast_next(struct sock *sk, u16 loc_port, u32 loc_addr, u16 rmt_port, u32 rmt_addr, int dif) { struct hlist_node *node; struct sock *s = sk; unsigned short hnum = ntohs(loc_port); sk_for_each_from(s, node) { struct inet_sock *inet = inet_sk(s); if (inet->num != hnum || (inet->daddr && inet->daddr != rmt_addr) || (inet->dport != rmt_port && inet->dport) || (inet->rcv_saddr && 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 udp_err(struct sk_buff *skb, u32 info) { struct inet_sock *inet; struct iphdr *iph = (struct iphdr*)skb->data; struct udphdr *uh = (struct udphdr*)(skb->data+(iph->ihl<<2)); int type = skb->h.icmph->type; int code = skb->h.icmph->code; struct sock *sk; int harderr; int err; sk = udp_v4_lookup(iph->daddr, uh->dest, iph->saddr, uh->source, skb->dev->ifindex); if (sk == NULL) { ICMP_INC_STATS_BH(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); } /* * Throw away all pending data and cancel the corking. Socket is locked. */ static 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); } } /* * 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) { struct inet_sock *inet = inet_sk(sk); struct flowi *fl = &inet->cork.fl; struct sk_buff *skb; struct udphdr *uh; int err = 0; /* Grab the skbuff where UDP header space exists. */ if ((skb = skb_peek(&sk->sk_write_queue)) == NULL) goto out; /* * Create a UDP header */ uh = skb->h.uh; uh->source = fl->fl_ip_sport; uh->dest = fl->fl_ip_dport; uh->len = htons(up->len); uh->check = 0; if (sk->sk_no_check == UDP_CSUM_NOXMIT) { skb->ip_summed = CHECKSUM_NONE; goto send; } if (skb_queue_len(&sk->sk_write_queue) == 1) { /* * Only one fragment on the socket. */ if (skb->ip_summed == CHECKSUM_PARTIAL) { skb->csum = offsetof(struct udphdr, check); uh->check = ~csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len, IPPROTO_UDP, 0); } else { skb->csum = csum_partial((char *)uh, sizeof(struct udphdr), skb->csum); uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len, IPPROTO_UDP, skb->csum); if (uh->check == 0) uh->check = -1; } } else { unsigned int csum = 0; /* * 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. */ if (skb->ip_summed == CHECKSUM_PARTIAL) { int offset = (unsigned char *)uh - skb->data; skb->csum = skb_checksum(skb, offset, skb->len - offset, 0); skb->ip_summed = CHECKSUM_NONE; } else { skb->csum = csum_partial((char *)uh, sizeof(struct udphdr), skb->csum); } skb_queue_walk(&sk->sk_write_queue, skb) { csum = csum_add(csum, skb->csum); } uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len, IPPROTO_UDP, csum); if (uh->check == 0) uh->check = -1; } send: err = ip_push_pending_frames(sk); out: up->len = 0; up->pending = 0; return err; } static unsigned short udp_check(struct udphdr *uh, int len, unsigned long saddr, unsigned long daddr, unsigned long base) { return(csum_tcpudp_magic(saddr, daddr, len, IPPROTO_UDP, base)); } 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); int ulen = len; struct ipcm_cookie ipc; struct rtable *rt = NULL; int free = 0; int connected = 0; __be32 daddr, faddr, saddr; u16 dport; u8 tos; int err; int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; if (len > 0xFFFF) return -EMSGSIZE; /* * Check the flags. */ if (msg->msg_flags&MSG_OOB) /* Mirror BSD error message compatibility */ return -EOPNOTSUPP; ipc.opt = NULL; 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->daddr; dport = 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->saddr; ipc.oif = sk->sk_bound_dev_if; if (msg->msg_controllen) { err = ip_cmsg_send(msg, &ipc); if (err) return err; if (ipc.opt) free = 1; connected = 0; } if (!ipc.opt) ipc.opt = inet->opt; saddr = ipc.addr; ipc.addr = faddr = daddr; if (ipc.opt && ipc.opt->srr) { if (!daddr) return -EINVAL; faddr = ipc.opt->faddr; connected = 0; } tos = RT_TOS(inet->tos); if (sock_flag(sk, SOCK_LOCALROUTE) || (msg->msg_flags & MSG_DONTROUTE) || (ipc.opt && ipc.opt->is_strictroute)) { tos |= RTO_ONLINK; connected = 0; } if (MULTICAST(daddr)) { if (!ipc.oif) ipc.oif = inet->mc_index; if (!saddr) saddr = inet->mc_addr; connected = 0; } if (connected) rt = (struct rtable*)sk_dst_check(sk, 0); if (rt == NULL) { struct flowi fl = { .oif = ipc.oif, .nl_u = { .ip4_u = { .daddr = faddr, .saddr = saddr, .tos = tos } }, .proto = IPPROTO_UDP, .uli_u = { .ports = { .sport = inet->sport, .dport = dport } } }; security_sk_classify_flow(sk, &fl); err = ip_route_output_flow(&rt, &fl, sk, !(msg->msg_flags&MSG_DONTWAIT)); if (err) 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->u.dst)); } if (msg->msg_flags&MSG_CONFIRM) goto do_confirm; back_from_confirm: saddr = rt->rt_src; if (!ipc.addr) daddr = ipc.addr = rt->rt_dst; 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 "udp cork app bug 2\n"); err = -EINVAL; goto out; } /* * Now cork the socket to pend data. */ inet->cork.fl.fl4_dst = daddr; inet->cork.fl.fl_ip_dport = dport; inet->cork.fl.fl4_src = saddr; inet->cork.fl.fl_ip_sport = inet->sport; up->pending = AF_INET; do_append_data: up->len += ulen; err = ip_append_data(sk, ip_generic_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, up); release_sock(sk); out: ip_rt_put(rt); if (free) kfree(ipc.opt); if (!err) { UDP_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS); 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(UDP_MIB_SNDBUFERRORS); } return err; do_confirm: dst_confirm(&rt->u.dst); if (!(msg->msg_flags&MSG_PROBE) || len) goto back_from_confirm; err = 0; goto out; } static int udp_sendpage(struct sock *sk, struct page *page, int offset, size_t size, int flags) { 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 "udp cork app bug 3\n"); return -EINVAL; } ret = ip_append_page(sk, 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, up); if (!ret) ret = size; out: release_sock(sk); return ret; } /* * IOCTL requests applicable to the UDP protocol */ int udp_ioctl(struct sock *sk, int cmd, unsigned long arg) { switch(cmd) { case SIOCOUTQ: { int amount = atomic_read(&sk->sk_wmem_alloc); return put_user(amount, (int __user *)arg); } case SIOCINQ: { struct sk_buff *skb; unsigned long amount; amount = 0; spin_lock_bh(&sk->sk_receive_queue.lock); skb = skb_peek(&sk->sk_receive_queue); if (skb != NULL) { /* * We will only return the amount * of this packet since that is all * that will be read. */ amount = skb->len - sizeof(struct udphdr); } spin_unlock_bh(&sk->sk_receive_queue.lock); return put_user(amount, (int __user *)arg); } default: return -ENOIOCTLCMD; } return(0); } static __inline__ int __udp_checksum_complete(struct sk_buff *skb) { return __skb_checksum_complete(skb); } static __inline__ int udp_checksum_complete(struct sk_buff *skb) { return skb->ip_summed != CHECKSUM_UNNECESSARY && __udp_checksum_complete(skb); } /* * This should be easy, if there is something there we * return it, otherwise we block. */ static 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; int copied, err; /* * 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, &err); if (!skb) goto out; copied = skb->len - sizeof(struct udphdr); if (copied > len) { copied = len; msg->msg_flags |= MSG_TRUNC; } if (skb->ip_summed==CHECKSUM_UNNECESSARY) { err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov, copied); } else if (msg->msg_flags&MSG_TRUNC) { if (__udp_checksum_complete(skb)) goto csum_copy_err; 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; sock_recv_timestamp(msg, sk, skb); /* Copy the address. */ if (sin) { sin->sin_family = AF_INET; sin->sin_port = skb->h.uh->source; sin->sin_addr.s_addr = skb->nh.iph->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 = skb->len - sizeof(struct udphdr); out_free: skb_free_datagram(sk, skb); out: return err; csum_copy_err: UDP_INC_STATS_BH(UDP_MIB_INERRORS); skb_kill_datagram(sk, skb, flags); if (noblock) return -EAGAIN; 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->daddr = 0; inet->dport = 0; 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->sport = 0; } sk_dst_reset(sk); return 0; } static void udp_close(struct sock *sk, long timeout) { sk_common_release(sk); } /* return: * 1 if the the UDP system should process it * 0 if we should drop this packet * -1 if it should get processed by xfrm4_rcv_encap */ static int udp_encap_rcv(struct sock * sk, struct sk_buff *skb) { #ifndef CONFIG_XFRM return 1; #else struct udp_sock *up = udp_sk(sk); struct udphdr *uh = skb->h.uh; struct iphdr *iph; int iphlen, len; __u8 *udpdata = (__u8 *)uh + sizeof(struct udphdr); __u32 *udpdata32 = (__u32 *)udpdata; __u16 encap_type = up->encap_type; /* if we're overly short, let UDP handle it */ if (udpdata > skb->tail) return 1; /* if this is not encapsulated socket, then just return now */ if (!encap_type) return 1; len = skb->tail - udpdata; switch (encap_type) { default: case UDP_ENCAP_ESPINUDP: /* Check if this is a keepalive packet. If so, eat it. */ if (len == 1 && udpdata[0] == 0xff) { return 0; } else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0 ) { /* ESP Packet without Non-ESP header */ len = sizeof(struct udphdr); } else /* Must be an IKE packet.. pass it through */ return 1; break; case UDP_ENCAP_ESPINUDP_NON_IKE: /* Check if this is a keepalive packet. If so, eat it. */ if (len == 1 && udpdata[0] == 0xff) { return 0; } else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) && udpdata32[0] == 0 && udpdata32[1] == 0) { /* ESP Packet with Non-IKE marker */ len = sizeof(struct udphdr) + 2 * sizeof(u32); } else /* Must be an IKE packet.. pass it through */ return 1; break; } /* At this point we are sure that this is an ESPinUDP packet, * so we need to remove 'len' bytes from the packet (the UDP * header and optional ESP marker bytes) and then modify the * protocol to ESP, and then call into the transform receiver. */ if (skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) return 0; /* Now we can update and verify the packet length... */ iph = skb->nh.iph; iphlen = iph->ihl << 2; iph->tot_len = htons(ntohs(iph->tot_len) - len); if (skb->len < iphlen + len) { /* packet is too small!?! */ return 0; } /* pull the data buffer up to the ESP header and set the * transport header to point to ESP. Keep UDP on the stack * for later. */ skb->h.raw = skb_pull(skb, len); /* modify the protocol (it's ESP!) */ iph->protocol = IPPROTO_ESP; /* and let the caller know to send this into the ESP processor... */ return -1; #endif } /* returns: * -1: error * 0: success * >0: "udp encap" protocol resubmission * * Note that in the success and error cases, the skb is assumed to * have either been requeued or freed. */ static int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb) { struct udp_sock *up = udp_sk(sk); int rc; /* * Charge it to the socket, dropping if the queue is full. */ if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) { kfree_skb(skb); return -1; } nf_reset(skb); if (up->encap_type) { /* * This is an encapsulation socket, so let's see if this is * an encapsulated packet. * If it's a keepalive packet, then just eat it. * If it's an encapsulateed packet, then pass it to the * IPsec xfrm input and return the response * appropriately. Otherwise, just fall through and * pass this up the UDP socket. */ int ret; ret = udp_encap_rcv(sk, skb); if (ret == 0) { /* Eat the packet .. */ kfree_skb(skb); return 0; } if (ret < 0) { /* process the ESP packet */ ret = xfrm4_rcv_encap(skb, up->encap_type); UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS); return -ret; } /* FALLTHROUGH -- it's a UDP Packet */ } if (sk->sk_filter && skb->ip_summed != CHECKSUM_UNNECESSARY) { if (__udp_checksum_complete(skb)) { UDP_INC_STATS_BH(UDP_MIB_INERRORS); kfree_skb(skb); return -1; } skb->ip_summed = CHECKSUM_UNNECESSARY; } if ((rc = sock_queue_rcv_skb(sk,skb)) < 0) { /* Note that an ENOMEM error is charged twice */ if (rc == -ENOMEM) UDP_INC_STATS_BH(UDP_MIB_RCVBUFERRORS); UDP_INC_STATS_BH(UDP_MIB_INERRORS); kfree_skb(skb); return -1; } UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS); return 0; } /* * Multicasts and broadcasts go to each listener. * * Note: called only from the BH handler context, * so we don't need to lock the hashes. */ static int udp_v4_mcast_deliver(struct sk_buff *skb, struct udphdr *uh, u32 saddr, u32 daddr) { struct sock *sk; int dif; read_lock(&udp_hash_lock); sk = sk_head(&udp_hash[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)]); dif = skb->dev->ifindex; sk = udp_v4_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif); if (sk) { struct sock *sknext = NULL; do { struct sk_buff *skb1 = skb; sknext = udp_v4_mcast_next(sk_next(sk), uh->dest, daddr, uh->source, saddr, dif); if(sknext) skb1 = skb_clone(skb, GFP_ATOMIC); if(skb1) { int ret = udp_queue_rcv_skb(sk, skb1); if (ret > 0) /* we should probably re-process instead * of dropping packets here. */ kfree_skb(skb1); } sk = sknext; } while(sknext); } else kfree_skb(skb); read_unlock(&udp_hash_lock); 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 void udp_checksum_init(struct sk_buff *skb, struct udphdr *uh, unsigned short ulen, u32 saddr, u32 daddr) { if (uh->check == 0) { skb->ip_summed = CHECKSUM_UNNECESSARY; } else if (skb->ip_summed == CHECKSUM_COMPLETE) { if (!udp_check(uh, ulen, saddr, daddr, skb->csum)) skb->ip_summed = CHECKSUM_UNNECESSARY; } if (skb->ip_summed != CHECKSUM_UNNECESSARY) skb->csum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); /* Probably, we should checksum udp header (it should be in cache * in any case) and data in tiny packets (< rx copybreak). */ } /* * All we need to do is get the socket, and then do a checksum. */ int udp_rcv(struct sk_buff *skb) { struct sock *sk; struct udphdr *uh; unsigned short ulen; struct rtable *rt = (struct rtable*)skb->dst; u32 saddr = skb->nh.iph->saddr; u32 daddr = skb->nh.iph->daddr; int len = skb->len; /* * Validate the packet and the UDP length. */ if (!pskb_may_pull(skb, sizeof(struct udphdr))) goto no_header; uh = skb->h.uh; ulen = ntohs(uh->len); if (ulen > len || ulen < sizeof(*uh)) goto short_packet; if (pskb_trim_rcsum(skb, ulen)) goto short_packet; udp_checksum_init(skb, uh, ulen, saddr, daddr); if(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) return udp_v4_mcast_deliver(skb, uh, saddr, daddr); sk = udp_v4_lookup(saddr, uh->source, daddr, uh->dest, skb->dev->ifindex); 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 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_checksum_complete(skb)) goto csum_error; UDP_INC_STATS_BH(UDP_MIB_NOPORTS); 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: short packet: From %u.%u.%u.%u:%u %d/%d to %u.%u.%u.%u:%u\n", NIPQUAD(saddr), ntohs(uh->source), ulen, len, NIPQUAD(daddr), ntohs(uh->dest)); no_header: UDP_INC_STATS_BH(UDP_MIB_INERRORS); kfree_skb(skb); return(0); 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: bad checksum. From %d.%d.%d.%d:%d to %d.%d.%d.%d:%d ulen %d\n", NIPQUAD(saddr), ntohs(uh->source), NIPQUAD(daddr), ntohs(uh->dest), ulen); drop: UDP_INC_STATS_BH(UDP_MIB_INERRORS); kfree_skb(skb); return(0); } static int udp_destroy_sock(struct sock *sk) { lock_sock(sk); udp_flush_pending_frames(sk); release_sock(sk); return 0; } /* * Socket option code for UDP */ static int do_udp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, int optlen) { struct udp_sock *up = udp_sk(sk); int val; int err = 0; if(optlencorkflag = 1; } else { up->corkflag = 0; lock_sock(sk); udp_push_pending_frames(sk, up); release_sock(sk); } break; case UDP_ENCAP: switch (val) { case 0: case UDP_ENCAP_ESPINUDP: case UDP_ENCAP_ESPINUDP_NON_IKE: up->encap_type = val; break; default: err = -ENOPROTOOPT; break; } break; default: err = -ENOPROTOOPT; break; }; return err; } static int udp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, int optlen) { if (level != SOL_UDP) return ip_setsockopt(sk, level, optname, optval, optlen); return do_udp_setsockopt(sk, level, optname, optval, optlen); } #ifdef CONFIG_COMPAT static int compat_udp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, int optlen) { if (level != SOL_UDP) return compat_ip_setsockopt(sk, level, optname, optval, optlen); return do_udp_setsockopt(sk, level, optname, optval, optlen); } #endif static int do_udp_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; default: return -ENOPROTOOPT; }; if(put_user(len, optlen)) return -EFAULT; if(copy_to_user(optval, &val,len)) return -EFAULT; return 0; } static int udp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen) { if (level != SOL_UDP) return ip_getsockopt(sk, level, optname, optval, optlen); return do_udp_getsockopt(sk, level, optname, optval, optlen); } #ifdef CONFIG_COMPAT static int compat_udp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen) { if (level != SOL_UDP) return compat_ip_getsockopt(sk, level, optname, optval, optlen); return do_udp_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)){ struct sk_buff_head *rcvq = &sk->sk_receive_queue; struct sk_buff *skb; spin_lock_bh(&rcvq->lock); while ((skb = skb_peek(rcvq)) != NULL) { if (udp_checksum_complete(skb)) { UDP_INC_STATS_BH(UDP_MIB_INERRORS); __skb_unlink(skb, rcvq); kfree_skb(skb); } else { skb->ip_summed = CHECKSUM_UNNECESSARY; break; } } spin_unlock_bh(&rcvq->lock); /* nothing to see, move along */ if (skb == NULL) mask &= ~(POLLIN | POLLRDNORM); } return mask; } struct proto udp_prot = { .name = "UDP", .owner = THIS_MODULE, .close = udp_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_v4_hash, .unhash = udp_v4_unhash, .get_port = udp_v4_get_port, .obj_size = sizeof(struct udp_sock), #ifdef CONFIG_COMPAT .compat_setsockopt = compat_udp_setsockopt, .compat_getsockopt = compat_udp_getsockopt, #endif }; /* ------------------------------------------------------------------------ */ #ifdef CONFIG_PROC_FS static struct sock *udp_get_first(struct seq_file *seq) { struct sock *sk; struct udp_iter_state *state = seq->private; for (state->bucket = 0; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) { struct hlist_node *node; sk_for_each(sk, node, &udp_hash[state->bucket]) { if (sk->sk_family == state->family) goto found; } } 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; do { sk = sk_next(sk); try_again: ; } while (sk && sk->sk_family != state->family); if (!sk && ++state->bucket < UDP_HTABLE_SIZE) { sk = sk_head(&udp_hash[state->bucket]); goto try_again; } return sk; } static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos) { struct sock *sk = udp_get_first(seq); 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) { read_lock(&udp_hash_lock); return *pos ? udp_get_idx(seq, *pos-1) : (void *)1; } static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos) { struct sock *sk; if (v == (void *)1) 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) { read_unlock(&udp_hash_lock); } static int udp_seq_open(struct inode *inode, struct file *file) { struct udp_seq_afinfo *afinfo = PDE(inode)->data; struct seq_file *seq; int rc = -ENOMEM; struct udp_iter_state *s = kzalloc(sizeof(*s), GFP_KERNEL); if (!s) goto out; s->family = afinfo->family; s->seq_ops.start = udp_seq_start; s->seq_ops.next = udp_seq_next; s->seq_ops.show = afinfo->seq_show; s->seq_ops.stop = udp_seq_stop; rc = seq_open(file, &s->seq_ops); if (rc) goto out_kfree; seq = file->private_data; seq->private = s; out: return rc; out_kfree: kfree(s); goto out; } /* ------------------------------------------------------------------------ */ int udp_proc_register(struct udp_seq_afinfo *afinfo) { struct proc_dir_entry *p; int rc = 0; if (!afinfo) return -EINVAL; afinfo->seq_fops->owner = afinfo->owner; afinfo->seq_fops->open = udp_seq_open; afinfo->seq_fops->read = seq_read; afinfo->seq_fops->llseek = seq_lseek; afinfo->seq_fops->release = seq_release_private; p = proc_net_fops_create(afinfo->name, S_IRUGO, afinfo->seq_fops); if (p) p->data = afinfo; else rc = -ENOMEM; return rc; } void udp_proc_unregister(struct udp_seq_afinfo *afinfo) { if (!afinfo) return; proc_net_remove(afinfo->name); memset(afinfo->seq_fops, 0, sizeof(*afinfo->seq_fops)); } /* ------------------------------------------------------------------------ */ static void udp4_format_sock(struct sock *sp, char *tmpbuf, int bucket) { struct inet_sock *inet = inet_sk(sp); unsigned int dest = inet->daddr; unsigned int src = inet->rcv_saddr; __u16 destp = ntohs(inet->dport); __u16 srcp = ntohs(inet->sport); sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X" " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p", bucket, src, srcp, dest, destp, sp->sk_state, atomic_read(&sp->sk_wmem_alloc), atomic_read(&sp->sk_rmem_alloc), 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp), atomic_read(&sp->sk_refcnt), sp); } static 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"); else { char tmpbuf[129]; struct udp_iter_state *state = seq->private; udp4_format_sock(v, tmpbuf, state->bucket); seq_printf(seq, "%-127s\n", tmpbuf); } return 0; } /* ------------------------------------------------------------------------ */ static struct file_operations udp4_seq_fops; static struct udp_seq_afinfo udp4_seq_afinfo = { .owner = THIS_MODULE, .name = "udp", .family = AF_INET, .seq_show = udp4_seq_show, .seq_fops = &udp4_seq_fops, }; int __init udp4_proc_init(void) { return udp_proc_register(&udp4_seq_afinfo); } void udp4_proc_exit(void) { udp_proc_unregister(&udp4_seq_afinfo); } #endif /* CONFIG_PROC_FS */ EXPORT_SYMBOL(udp_disconnect); EXPORT_SYMBOL(udp_hash); EXPORT_SYMBOL(udp_hash_lock); EXPORT_SYMBOL(udp_ioctl); EXPORT_SYMBOL(udp_get_port); EXPORT_SYMBOL(udp_prot); EXPORT_SYMBOL(udp_sendmsg); EXPORT_SYMBOL(udp_poll); #ifdef CONFIG_PROC_FS EXPORT_SYMBOL(udp_proc_register); EXPORT_SYMBOL(udp_proc_unregister); #endif