/* * 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 1.91 2000/11/28 13:38:38 davem Exp $ * * Authors: Ross Biro, * Fred N. van Kempen, * Arnt Gulbrandsen, * Alan Cox, * * 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 * * * 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 /* * Snmp MIB for the UDP layer */ struct udp_mib udp_statistics[NR_CPUS*2]; struct sock *udp_hash[UDP_HTABLE_SIZE]; rwlock_t udp_hash_lock = RW_LOCK_UNLOCKED; /* Shared by v4/v6 udp. */ int udp_port_rover; static int udp_v4_get_port(struct sock *sk, unsigned short snum) { 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++) { struct sock *sk; int size; sk = udp_hash[result & (UDP_HTABLE_SIZE - 1)]; if (!sk) { 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; do { if (++size >= best_size_so_far) goto next; } while ((sk = sk->next) != NULL); best_size_so_far = size; best = result; next:; } 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 { struct sock *sk2; for (sk2 = udp_hash[snum & (UDP_HTABLE_SIZE - 1)]; sk2 != NULL; sk2 = sk2->next) { if (sk2->num == snum && sk2 != sk && sk2->bound_dev_if == sk->bound_dev_if && (!sk2->rcv_saddr || !sk->rcv_saddr || sk2->rcv_saddr == sk->rcv_saddr) && (!sk2->reuse || !sk->reuse)) goto fail; } } sk->num = snum; if (sk->pprev == NULL) { struct sock **skp = &udp_hash[snum & (UDP_HTABLE_SIZE - 1)]; if ((sk->next = *skp) != NULL) (*skp)->pprev = &sk->next; *skp = sk; sk->pprev = skp; sock_prot_inc_use(sk->prot); sock_hold(sk); } write_unlock_bh(&udp_hash_lock); return 0; fail: write_unlock_bh(&udp_hash_lock); return 1; } 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->pprev) { if (sk->next) sk->next->pprev = sk->pprev; *sk->pprev = sk->next; sk->pprev = NULL; sk->num = 0; sock_prot_dec_use(sk->prot); __sock_put(sk); } write_unlock_bh(&udp_hash_lock); } /* UDP is nearly always wildcards out the wazoo, it makes no sense to try * harder than this. -DaveM */ struct sock *udp_v4_lookup_longway(u32 saddr, u16 sport, u32 daddr, u16 dport, int dif) { struct sock *sk, *result = NULL; unsigned short hnum = ntohs(dport); int badness = -1; for(sk = udp_hash[hnum & (UDP_HTABLE_SIZE - 1)]; sk != NULL; sk = sk->next) { if(sk->num == hnum) { int score = 0; if(sk->rcv_saddr) { if(sk->rcv_saddr != daddr) continue; score++; } if(sk->daddr) { if(sk->daddr != saddr) continue; score++; } if(sk->dport) { if(sk->dport != sport) continue; score++; } if(sk->bound_dev_if) { if(sk->bound_dev_if != dif) continue; score++; } if(score == 4) { result = sk; break; } else if(score > badness) { result = sk; badness = score; } } } return result; } __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 sock *s = sk; unsigned short hnum = ntohs(loc_port); for(; s; s = s->next) { if ((s->num != hnum) || (s->daddr && s->daddr!=rmt_addr) || (s->dport != rmt_port && s->dport != 0) || (s->rcv_saddr && s->rcv_saddr != loc_addr) || (s->bound_dev_if && s->bound_dev_if != dif)) continue; break; } 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, unsigned char *dp, int len) { struct iphdr *iph = (struct iphdr*)dp; struct udphdr *uh = (struct udphdr*)(dp+(iph->ihl<<2)); int type = skb->h.icmph->type; int code = skb->h.icmph->code; struct sock *sk; int harderr; u32 info; int err; if (len < (iph->ihl<<2)+sizeof(struct udphdr)) { ICMP_INC_STATS_BH(IcmpInErrors); return; } sk = udp_v4_lookup(iph->daddr, uh->dest, iph->saddr, uh->source, skb->dev->ifindex); if (sk == NULL) { ICMP_INC_STATS_BH(IcmpInErrors); return; /* No socket for error */ } err = 0; info = 0; harderr = 0; switch (type) { default: case ICMP_TIME_EXCEEDED: err = EHOSTUNREACH; break; case ICMP_SOURCE_QUENCH: goto out; case ICMP_PARAMETERPROB: err = EPROTO; info = ntohl(skb->h.icmph->un.gateway)>>24; harderr = 1; break; case ICMP_DEST_UNREACH: if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ if (sk->protinfo.af_inet.pmtudisc != IP_PMTUDISC_DONT) { err = EMSGSIZE; info = ntohs(skb->h.icmph->un.frag.mtu); 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 (!sk->protinfo.af_inet.recverr) { if (!harderr || sk->state != TCP_ESTABLISHED) goto out; } else { ip_icmp_error(sk, skb, err, uh->dest, info, (u8*)(uh+1)); } sk->err = err; sk->error_report(sk); out: sock_put(sk); } 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)); } struct udpfakehdr { struct udphdr uh; u32 saddr; u32 daddr; struct iovec *iov; u32 wcheck; }; /* * Copy and checksum a UDP packet from user space into a buffer. We still have * to do the planning to get ip_build_xmit to spot direct transfer to network * card and provide an additional callback mode for direct user->board I/O * transfers. That one will be fun. */ static int udp_getfrag(const void *p, char * to, unsigned int offset, unsigned int fraglen) { struct udpfakehdr *ufh = (struct udpfakehdr *)p; if (offset==0) { if (csum_partial_copy_fromiovecend(to+sizeof(struct udphdr), ufh->iov, offset, fraglen-sizeof(struct udphdr), &ufh->wcheck)) return -EFAULT; ufh->wcheck = csum_partial((char *)ufh, sizeof(struct udphdr), ufh->wcheck); ufh->uh.check = csum_tcpudp_magic(ufh->saddr, ufh->daddr, ntohs(ufh->uh.len), IPPROTO_UDP, ufh->wcheck); if (ufh->uh.check == 0) ufh->uh.check = -1; memcpy(to, ufh, sizeof(struct udphdr)); return 0; } if (csum_partial_copy_fromiovecend(to, ufh->iov, offset-sizeof(struct udphdr), fraglen, &ufh->wcheck)) return -EFAULT; return 0; } /* * Unchecksummed UDP is sufficiently critical to stuff like ATM video conferencing * that we use two routines for this for speed. Probably we ought to have a * CONFIG_FAST_NET set for >10Mb/second boards to activate this sort of coding. * Timing needed to verify if this is a valid decision. */ static int udp_getfrag_nosum(const void *p, char * to, unsigned int offset, unsigned int fraglen) { struct udpfakehdr *ufh = (struct udpfakehdr *)p; if (offset==0) { memcpy(to, ufh, sizeof(struct udphdr)); return memcpy_fromiovecend(to+sizeof(struct udphdr), ufh->iov, offset, fraglen-sizeof(struct udphdr)); } return memcpy_fromiovecend(to, ufh->iov, offset-sizeof(struct udphdr), fraglen); } int udp_sendmsg(struct sock *sk, struct msghdr *msg, int len) { int ulen = len + sizeof(struct udphdr); struct ipcm_cookie ipc; struct udpfakehdr ufh; struct rtable *rt = NULL; int free = 0; int connected = 0; u32 daddr; u8 tos; int err; /* This check is ONLY to check for arithmetic overflow on integer(!) len. Not more! Real check will be made in ip_build_xmit --ANK BTW socket.c -> af_*.c -> ... make multiple invalid conversions size_t -> int. We MUST repair it f.e. by replacing all of them with size_t and revise all the places sort of len += sizeof(struct iphdr) If len was ULONG_MAX-10 it would be cathastrophe --ANK */ if (len < 0 || len > 0xFFFF) return -EMSGSIZE; /* * Check the flags. */ if (msg->msg_flags&MSG_OOB) /* Mirror BSD error message compatibility */ return -EOPNOTSUPP; /* * 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 -EINVAL; } ufh.daddr = usin->sin_addr.s_addr; ufh.uh.dest = usin->sin_port; if (ufh.uh.dest == 0) return -EINVAL; } else { if (sk->state != TCP_ESTABLISHED) return -ENOTCONN; ufh.daddr = sk->daddr; ufh.uh.dest = sk->dport; /* Open fast path for connected socket. Route will not be used, if at least one option is set. */ connected = 1; } ipc.addr = sk->saddr; ufh.uh.source = sk->sport; ipc.opt = NULL; ipc.oif = 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 = sk->protinfo.af_inet.opt; ufh.saddr = ipc.addr; ipc.addr = daddr = ufh.daddr; if (ipc.opt && ipc.opt->srr) { if (!daddr) return -EINVAL; daddr = ipc.opt->faddr; connected = 0; } tos = RT_TOS(sk->protinfo.af_inet.tos); if (sk->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 = sk->protinfo.af_inet.mc_index; if (!ufh.saddr) ufh.saddr = sk->protinfo.af_inet.mc_addr; connected = 0; } if (connected) rt = (struct rtable*)sk_dst_check(sk, 0); if (rt == NULL) { err = ip_route_output(&rt, daddr, ufh.saddr, tos, ipc.oif); if (err) goto out; err = -EACCES; if (rt->rt_flags&RTCF_BROADCAST && !sk->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: ufh.saddr = rt->rt_src; if (!ipc.addr) ufh.daddr = ipc.addr = rt->rt_dst; ufh.uh.len = htons(ulen); ufh.uh.check = 0; ufh.iov = msg->msg_iov; ufh.wcheck = 0; /* RFC1122: OK. Provides the checksumming facility (MUST) as per */ /* 4.1.3.4. It's configurable by the application via setsockopt() */ /* (MAY) and it defaults to on (MUST). */ err = ip_build_xmit(sk, (sk->no_check == UDP_CSUM_NOXMIT ? udp_getfrag_nosum : udp_getfrag), &ufh, ulen, &ipc, rt, msg->msg_flags); out: ip_rt_put(rt); if (free) kfree(ipc.opt); if (!err) { UDP_INC_STATS_USER(UdpOutDatagrams); return len; } return err; do_confirm: dst_confirm(&rt->u.dst); if (!(msg->msg_flags&MSG_PROBE) || len) goto back_from_confirm; err = 0; goto out; } /* * 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->wmem_alloc); return put_user(amount, (int *)arg); } case SIOCINQ: { struct sk_buff *skb; unsigned long amount; amount = 0; spin_lock_irq(&sk->receive_queue.lock); skb = skb_peek(&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_irq(&sk->receive_queue.lock); return put_user(amount, (int *)arg); } default: return -ENOIOCTLCMD; } return(0); } static __inline__ int __udp_checksum_complete(struct sk_buff *skb) { return (unsigned short)csum_fold(csum_partial(skb->h.raw, skb->len, skb->csum)); } 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. */ int udp_recvmsg(struct sock *sk, struct msghdr *msg, int len, int noblock, int flags, int *addr_len) { 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); /* * From here the generic datagram does a lot of the work. Come * the finished NET3, it will do _ALL_ the work! */ 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 = copy_and_csum_toiovec(msg->msg_iov, skb, sizeof(struct udphdr)); if (err) 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 (sk->protinfo.af_inet.cmsg_flags) ip_cmsg_recv(msg, skb); err = copied; out_free: skb_free_datagram(sk, skb); out: return err; csum_copy_err: UDP_INC_STATS_BH(UdpInErrors); /* Clear queue. */ if (flags&MSG_PEEK) { int clear = 0; spin_lock_irq(&sk->receive_queue.lock); if (skb == skb_peek(&sk->receive_queue)) { __skb_unlink(skb, &sk->receive_queue); clear = 1; } spin_unlock_irq(&sk->receive_queue.lock); if (clear) kfree_skb(skb); } skb_free_datagram(sk, skb); return -EAGAIN; } int udp_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) { struct sockaddr_in *usin = (struct sockaddr_in *) uaddr; struct rtable *rt; int err; if (addr_len < sizeof(*usin)) return -EINVAL; if (usin->sin_family != AF_INET) return -EAFNOSUPPORT; sk_dst_reset(sk); err = ip_route_connect(&rt, usin->sin_addr.s_addr, sk->saddr, sk->protinfo.af_inet.tos|sk->localroute, sk->bound_dev_if); if (err) return err; if ((rt->rt_flags&RTCF_BROADCAST) && !sk->broadcast) { ip_rt_put(rt); return -EACCES; } if(!sk->saddr) sk->saddr = rt->rt_src; /* Update source address */ if(!sk->rcv_saddr) sk->rcv_saddr = rt->rt_src; sk->daddr = rt->rt_dst; sk->dport = usin->sin_port; sk->state = TCP_ESTABLISHED; sk_dst_set(sk, &rt->u.dst); return(0); } int udp_disconnect(struct sock *sk, int flags) { /* * 1003.1g - break association. */ sk->state = TCP_CLOSE; sk->daddr = 0; sk->dport = 0; sk->bound_dev_if = 0; if (!(sk->userlocks&SOCK_BINDADDR_LOCK)) { sk->rcv_saddr = 0; sk->saddr = 0; #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) memset(&sk->net_pinfo.af_inet6.saddr, 0, 16); memset(&sk->net_pinfo.af_inet6.rcv_saddr, 0, 16); #endif } if (!(sk->userlocks&SOCK_BINDPORT_LOCK)) { sk->prot->unhash(sk); sk->sport = 0; } sk_dst_reset(sk); return 0; } static void udp_close(struct sock *sk, long timeout) { inet_sock_release(sk); } static int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb) { /* * Charge it to the socket, dropping if the queue is full. */ #if defined(CONFIG_FILTER) if (sk->filter && skb->ip_summed != CHECKSUM_UNNECESSARY) { if (__udp_checksum_complete(skb)) { UDP_INC_STATS_BH(UdpInErrors); IP_INC_STATS_BH(IpInDiscards); ip_statistics[smp_processor_id()*2].IpInDelivers--; kfree_skb(skb); return -1; } skb->ip_summed = CHECKSUM_UNNECESSARY; } #endif if (sock_queue_rcv_skb(sk,skb)<0) { UDP_INC_STATS_BH(UdpInErrors); IP_INC_STATS_BH(IpInDiscards); ip_statistics[smp_processor_id()*2].IpInDelivers--; kfree_skb(skb); return -1; } UDP_INC_STATS_BH(UdpInDatagrams); 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 = 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, uh->dest, daddr, uh->source, saddr, dif); if(sknext) skb1 = skb_clone(skb, GFP_ATOMIC); if(skb1) udp_queue_rcv_skb(sk, 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 int 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_HW) { if (udp_check(uh, ulen, saddr, daddr, skb->csum)) return -1; skb->ip_summed = CHECKSUM_UNNECESSARY; } else 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). */ return 0; } /* * All we need to do is get the socket, and then do a checksum. */ int udp_rcv(struct sk_buff *skb, unsigned short len) { 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; /* * Get the header. */ uh = skb->h.uh; __skb_pull(skb, skb->h.raw - skb->data); IP_INC_STATS_BH(IpInDelivers); /* * Validate the packet and the UDP length. */ ulen = ntohs(uh->len); if (ulen > len || ulen < sizeof(*uh)) { NETDEBUG(printk(KERN_DEBUG "UDP: short packet: %d/%d\n", ulen, len)); UDP_INC_STATS_BH(UdpInErrors); kfree_skb(skb); return(0); } skb_trim(skb, ulen); if (udp_checksum_init(skb, uh, ulen, saddr, daddr) < 0) goto csum_error; 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) { udp_queue_rcv_skb(sk, skb); sock_put(sk); return 0; } /* No socket. Drop packet silently, if checksum is wrong */ if (udp_checksum_complete(skb)) goto csum_error; UDP_INC_STATS_BH(UdpNoPorts); 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); csum_error: /* * RFC1122: OK. Discards the bad packet silently (as far as * the network is concerned, anyway) as per 4.1.3.4 (MUST). */ NETDEBUG(printk(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)); UDP_INC_STATS_BH(UdpInErrors); kfree_skb(skb); return(0); } static void get_udp_sock(struct sock *sp, char *tmpbuf, int i) { unsigned int dest, src; __u16 destp, srcp; dest = sp->daddr; src = sp->rcv_saddr; destp = ntohs(sp->dport); srcp = ntohs(sp->sport); sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X" " %02X %08X:%08X %02X:%08lX %08X %5d %8d %ld %d %p", i, src, srcp, dest, destp, sp->state, atomic_read(&sp->wmem_alloc), atomic_read(&sp->rmem_alloc), 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp), atomic_read(&sp->refcnt), sp); } int udp_get_info(char *buffer, char **start, off_t offset, int length) { int len = 0, num = 0, i; off_t pos = 0; off_t begin; char tmpbuf[129]; if (offset < 128) len += sprintf(buffer, "%-127s\n", " sl local_address rem_address st tx_queue " "rx_queue tr tm->when retrnsmt uid timeout inode"); pos = 128; read_lock(&udp_hash_lock); for (i = 0; i < UDP_HTABLE_SIZE; i++) { struct sock *sk; for (sk = udp_hash[i]; sk; sk = sk->next, num++) { if (sk->family != PF_INET) continue; pos += 128; if (pos <= offset) continue; get_udp_sock(sk, tmpbuf, i); len += sprintf(buffer+len, "%-127s\n", tmpbuf); if(len >= length) goto out; } } out: read_unlock(&udp_hash_lock); begin = len - (pos - offset); *start = buffer + begin; len -= begin; if(len > length) len = length; if (len < 0) len = 0; return len; } struct proto udp_prot = { name: "UDP", close: udp_close, connect: udp_connect, disconnect: udp_disconnect, ioctl: udp_ioctl, setsockopt: ip_setsockopt, getsockopt: ip_getsockopt, sendmsg: udp_sendmsg, recvmsg: udp_recvmsg, backlog_rcv: udp_queue_rcv_skb, hash: udp_v4_hash, unhash: udp_v4_unhash, get_port: udp_v4_get_port, };