raw.c
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上传日期:2013-04-10
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文件大小:16k
- /*
- * 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.
- *
- * RAW - implementation of IP "raw" sockets.
- *
- * Version: $Id: raw.c,v 1.63.2.1 2002/03/05 12:47:34 davem Exp $
- *
- * Authors: Ross Biro, <bir7@leland.Stanford.Edu>
- * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
- *
- * Fixes:
- * Alan Cox : verify_area() fixed up
- * Alan Cox : ICMP error handling
- * Alan Cox : EMSGSIZE if you send too big a packet
- * Alan Cox : Now uses generic datagrams and shared
- * skbuff library. No more peek crashes,
- * no more backlogs
- * Alan Cox : Checks sk->broadcast.
- * Alan Cox : Uses skb_free_datagram/skb_copy_datagram
- * Alan Cox : Raw passes ip options too
- * Alan Cox : Setsocketopt added
- * Alan Cox : Fixed error return for broadcasts
- * Alan Cox : Removed wake_up calls
- * Alan Cox : Use ttl/tos
- * Alan Cox : Cleaned up old debugging
- * Alan Cox : Use new kernel side addresses
- * Arnt Gulbrandsen : Fixed MSG_DONTROUTE in raw sockets.
- * Alan Cox : BSD style RAW socket demultiplexing.
- * Alan Cox : Beginnings of mrouted support.
- * Alan Cox : Added IP_HDRINCL option.
- * Alan Cox : Skip broadcast check if BSDism set.
- * David S. Miller : New socket lookup architecture.
- *
- * 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 <linux/config.h>
- #include <asm/system.h>
- #include <asm/uaccess.h>
- #include <asm/ioctls.h>
- #include <linux/types.h>
- #include <linux/sched.h>
- #include <linux/errno.h>
- #include <linux/timer.h>
- #include <linux/mm.h>
- #include <linux/kernel.h>
- #include <linux/fcntl.h>
- #include <linux/socket.h>
- #include <linux/in.h>
- #include <linux/inet.h>
- #include <linux/netdevice.h>
- #include <linux/mroute.h>
- #include <net/ip.h>
- #include <net/protocol.h>
- #include <linux/skbuff.h>
- #include <net/sock.h>
- #include <net/icmp.h>
- #include <net/udp.h>
- #include <net/raw.h>
- #include <net/inet_common.h>
- #include <net/checksum.h>
- struct sock *raw_v4_htable[RAWV4_HTABLE_SIZE];
- rwlock_t raw_v4_lock = RW_LOCK_UNLOCKED;
- static void raw_v4_hash(struct sock *sk)
- {
- struct sock **skp = &raw_v4_htable[sk->num & (RAWV4_HTABLE_SIZE - 1)];
- write_lock_bh(&raw_v4_lock);
- 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(&raw_v4_lock);
- }
- static void raw_v4_unhash(struct sock *sk)
- {
- write_lock_bh(&raw_v4_lock);
- if (sk->pprev) {
- if (sk->next)
- sk->next->pprev = sk->pprev;
- *sk->pprev = sk->next;
- sk->pprev = NULL;
- sock_prot_dec_use(sk->prot);
- __sock_put(sk);
- }
- write_unlock_bh(&raw_v4_lock);
- }
- struct sock *__raw_v4_lookup(struct sock *sk, unsigned short num,
- unsigned long raddr, unsigned long laddr,
- int dif)
- {
- struct sock *s = sk;
- for (s = sk; s; s = s->next) {
- if (s->num == num &&
- !(s->daddr && s->daddr != raddr) &&
- !(s->rcv_saddr && s->rcv_saddr != laddr) &&
- !(s->bound_dev_if && s->bound_dev_if != dif))
- break; /* gotcha */
- }
- return s;
- }
- /*
- * 0 - deliver
- * 1 - block
- */
- static __inline__ int icmp_filter(struct sock *sk, struct sk_buff *skb)
- {
- int type;
- type = skb->h.icmph->type;
- if (type < 32) {
- __u32 data = sk->tp_pinfo.tp_raw4.filter.data;
- return ((1 << type) & data) != 0;
- }
- /* Do not block unknown ICMP types */
- return 0;
- }
- /* IP input processing comes here for RAW socket delivery.
- * This is fun as to avoid copies we want to make no surplus
- * copies.
- *
- * RFC 1122: SHOULD pass TOS value up to the transport layer.
- * -> It does. And not only TOS, but all IP header.
- */
- struct sock *raw_v4_input(struct sk_buff *skb, struct iphdr *iph, int hash)
- {
- struct sock *sk;
- read_lock(&raw_v4_lock);
- if ((sk = raw_v4_htable[hash]) == NULL)
- goto out;
- sk = __raw_v4_lookup(sk, iph->protocol,
- iph->saddr, iph->daddr,
- skb->dev->ifindex);
- while (sk) {
- struct sock *sknext = __raw_v4_lookup(sk->next, iph->protocol,
- iph->saddr, iph->daddr,
- skb->dev->ifindex);
- if (iph->protocol != IPPROTO_ICMP ||
- !icmp_filter(sk, skb)) {
- struct sk_buff *clone;
- if (!sknext)
- break;
- clone = skb_clone(skb, GFP_ATOMIC);
- /* Not releasing hash table! */
- if (clone)
- raw_rcv(sk, clone);
- }
- sk = sknext;
- }
- out:
- if (sk)
- sock_hold(sk);
- read_unlock(&raw_v4_lock);
- return sk;
- }
- void raw_err (struct sock *sk, struct sk_buff *skb, u32 info)
- {
- int type = skb->h.icmph->type;
- int code = skb->h.icmph->code;
- int err = 0;
- int harderr = 0;
- /* Report error on raw socket, if:
- 1. User requested ip_recverr.
- 2. Socket is connected (otherwise the error indication
- is useless without ip_recverr and error is hard.
- */
- if (!sk->protinfo.af_inet.recverr && sk->state != TCP_ESTABLISHED)
- return;
- switch (type) {
- default:
- case ICMP_TIME_EXCEEDED:
- err = EHOSTUNREACH;
- break;
- case ICMP_SOURCE_QUENCH:
- return;
- case ICMP_PARAMETERPROB:
- err = EPROTO;
- harderr = 1;
- break;
- case ICMP_DEST_UNREACH:
- err = EHOSTUNREACH;
- if (code > NR_ICMP_UNREACH)
- break;
- err = icmp_err_convert[code].errno;
- harderr = icmp_err_convert[code].fatal;
- if (code == ICMP_FRAG_NEEDED) {
- harderr = sk->protinfo.af_inet.pmtudisc !=
- IP_PMTUDISC_DONT;
- err = EMSGSIZE;
- }
- }
- if (sk->protinfo.af_inet.recverr) {
- struct iphdr *iph = (struct iphdr*)skb->data;
- u8 *payload = skb->data + (iph->ihl << 2);
- if (sk->protinfo.af_inet.hdrincl)
- payload = skb->data;
- ip_icmp_error(sk, skb, err, 0, info, payload);
- }
- if (sk->protinfo.af_inet.recverr || harderr) {
- sk->err = err;
- sk->error_report(sk);
- }
- }
- static int raw_rcv_skb(struct sock * sk, struct sk_buff * skb)
- {
- /* Charge it to the socket. */
-
- if (sock_queue_rcv_skb(sk, skb) < 0) {
- IP_INC_STATS(IpInDiscards);
- kfree_skb(skb);
- return NET_RX_DROP;
- }
- IP_INC_STATS(IpInDelivers);
- return NET_RX_SUCCESS;
- }
- int raw_rcv(struct sock *sk, struct sk_buff *skb)
- {
- skb_push(skb, skb->data - skb->nh.raw);
- raw_rcv_skb(sk, skb);
- return 0;
- }
- struct rawfakehdr
- {
- struct iovec *iov;
- u32 saddr;
- struct dst_entry *dst;
- };
- /*
- * Send a RAW IP packet.
- */
- /*
- * Callback support is trivial for SOCK_RAW
- */
-
- static int raw_getfrag(const void *p, char *to, unsigned int offset,
- unsigned int fraglen)
- {
- struct rawfakehdr *rfh = (struct rawfakehdr *) p;
- return memcpy_fromiovecend(to, rfh->iov, offset, fraglen);
- }
- /*
- * IPPROTO_RAW needs extra work.
- */
-
- static int raw_getrawfrag(const void *p, char *to, unsigned int offset,
- unsigned int fraglen)
- {
- struct rawfakehdr *rfh = (struct rawfakehdr *) p;
- if (memcpy_fromiovecend(to, rfh->iov, offset, fraglen))
- return -EFAULT;
- if (!offset) {
- struct iphdr *iph = (struct iphdr *)to;
- if (!iph->saddr)
- iph->saddr = rfh->saddr;
- iph->check = 0;
- iph->tot_len = htons(fraglen); /* This is right as you can't
- frag RAW packets */
- /*
- * Deliberate breach of modularity to keep
- * ip_build_xmit clean (well less messy).
- */
- if (!iph->id)
- ip_select_ident(iph, rfh->dst, NULL);
- iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
- }
- return 0;
- }
- static int raw_sendmsg(struct sock *sk, struct msghdr *msg, int len)
- {
- struct ipcm_cookie ipc;
- struct rawfakehdr rfh;
- struct rtable *rt = NULL;
- int free = 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
- */
- err = -EMSGSIZE;
- if (len < 0 || len > 0xFFFF)
- goto out;
- /*
- * Check the flags.
- */
- err = -EOPNOTSUPP;
- if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message */
- goto out; /* compatibility */
-
- /*
- * Get and verify the address.
- */
- if (msg->msg_namelen) {
- struct sockaddr_in *usin = (struct sockaddr_in*)msg->msg_name;
- err = -EINVAL;
- if (msg->msg_namelen < sizeof(*usin))
- goto out;
- if (usin->sin_family != AF_INET) {
- static int complained;
- if (!complained++)
- printk(KERN_INFO "%s forgot to set AF_INET in "
- "raw sendmsg. Fix it!n",
- current->comm);
- err = -EINVAL;
- if (usin->sin_family)
- goto out;
- }
- daddr = usin->sin_addr.s_addr;
- /* ANK: I did not forget to get protocol from port field.
- * I just do not know, who uses this weirdness.
- * IP_HDRINCL is much more convenient.
- */
- } else {
- err = -EINVAL;
- if (sk->state != TCP_ESTABLISHED)
- goto out;
- daddr = sk->daddr;
- }
- ipc.addr = sk->saddr;
- ipc.opt = NULL;
- ipc.oif = sk->bound_dev_if;
- if (msg->msg_controllen) {
- err = ip_cmsg_send(msg, &ipc);
- if (err)
- goto out;
- if (ipc.opt)
- free = 1;
- }
- rfh.saddr = ipc.addr;
- ipc.addr = daddr;
- if (!ipc.opt)
- ipc.opt = sk->protinfo.af_inet.opt;
- if (ipc.opt) {
- err = -EINVAL;
- /* Linux does not mangle headers on raw sockets,
- * so that IP options + IP_HDRINCL is non-sense.
- */
- if (sk->protinfo.af_inet.hdrincl)
- goto done;
- if (ipc.opt->srr) {
- if (!daddr)
- goto done;
- daddr = ipc.opt->faddr;
- }
- }
- tos = RT_TOS(sk->protinfo.af_inet.tos) | sk->localroute;
- if (msg->msg_flags & MSG_DONTROUTE)
- tos |= RTO_ONLINK;
- if (MULTICAST(daddr)) {
- if (!ipc.oif)
- ipc.oif = sk->protinfo.af_inet.mc_index;
- if (!rfh.saddr)
- rfh.saddr = sk->protinfo.af_inet.mc_addr;
- }
- err = ip_route_output(&rt, daddr, rfh.saddr, tos, ipc.oif);
- if (err)
- goto done;
- err = -EACCES;
- if (rt->rt_flags & RTCF_BROADCAST && !sk->broadcast)
- goto done;
- if (msg->msg_flags & MSG_CONFIRM)
- goto do_confirm;
- back_from_confirm:
- rfh.iov = msg->msg_iov;
- rfh.saddr = rt->rt_src;
- rfh.dst = &rt->u.dst;
- if (!ipc.addr)
- ipc.addr = rt->rt_dst;
- err = ip_build_xmit(sk, sk->protinfo.af_inet.hdrincl ? raw_getrawfrag :
- raw_getfrag, &rfh, len, &ipc, rt, msg->msg_flags);
- done:
- if (free)
- kfree(ipc.opt);
- ip_rt_put(rt);
- out: return err < 0 ? err : len;
- do_confirm:
- dst_confirm(&rt->u.dst);
- if (!(msg->msg_flags & MSG_PROBE) || len)
- goto back_from_confirm;
- err = 0;
- goto done;
- }
- static void raw_close(struct sock *sk, long timeout)
- {
- /*
- * Raw sockets may have direct kernel refereneces. Kill them.
- */
- ip_ra_control(sk, 0, NULL);
- inet_sock_release(sk);
- }
- /* This gets rid of all the nasties in af_inet. -DaveM */
- static int raw_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
- {
- struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
- int ret = -EINVAL;
- int chk_addr_ret;
- if (sk->state != TCP_CLOSE || addr_len < sizeof(struct sockaddr_in))
- goto out;
- chk_addr_ret = inet_addr_type(addr->sin_addr.s_addr);
- ret = -EADDRNOTAVAIL;
- if (addr->sin_addr.s_addr && chk_addr_ret != RTN_LOCAL &&
- chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST)
- goto out;
- sk->rcv_saddr = sk->saddr = addr->sin_addr.s_addr;
- if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
- sk->saddr = 0; /* Use device */
- sk_dst_reset(sk);
- ret = 0;
- out: return ret;
- }
- /*
- * This should be easy, if there is something there
- * we return it, otherwise we block.
- */
- int raw_recvmsg(struct sock *sk, struct msghdr *msg, int len,
- int noblock, int flags, int *addr_len)
- {
- int copied = 0;
- int err = -EOPNOTSUPP;
- struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
- struct sk_buff *skb;
- if (flags & MSG_OOB)
- goto out;
- if (addr_len)
- *addr_len = sizeof(*sin);
- if (flags & MSG_ERRQUEUE) {
- err = ip_recv_error(sk, msg, len);
- goto out;
- }
- skb = skb_recv_datagram(sk, flags, noblock, &err);
- if (!skb)
- goto out;
- copied = skb->len;
- if (len < copied) {
- msg->msg_flags |= MSG_TRUNC;
- copied = len;
- }
- err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
- if (err)
- goto done;
- sock_recv_timestamp(msg, sk, skb);
- /* Copy the address. */
- if (sin) {
- sin->sin_family = AF_INET;
- 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);
- done:
- skb_free_datagram(sk, skb);
- out: return err ? : copied;
- }
- static int raw_init(struct sock *sk)
- {
- struct raw_opt *tp = &(sk->tp_pinfo.tp_raw4);
- if (sk->num == IPPROTO_ICMP)
- memset(&tp->filter, 0, sizeof(tp->filter));
- return 0;
- }
- static int raw_seticmpfilter(struct sock *sk, char *optval, int optlen)
- {
- if (optlen > sizeof(struct icmp_filter))
- optlen = sizeof(struct icmp_filter);
- if (copy_from_user(&sk->tp_pinfo.tp_raw4.filter, optval, optlen))
- return -EFAULT;
- return 0;
- }
- static int raw_geticmpfilter(struct sock *sk, char *optval, int *optlen)
- {
- int len, ret = -EFAULT;
- if (get_user(len, optlen))
- goto out;
- ret = -EINVAL;
- if (len < 0)
- goto out;
- if (len > sizeof(struct icmp_filter))
- len = sizeof(struct icmp_filter);
- ret = -EFAULT;
- if (put_user(len, optlen) ||
- copy_to_user(optval, &sk->tp_pinfo.tp_raw4.filter, len))
- goto out;
- ret = 0;
- out: return ret;
- }
- static int raw_setsockopt(struct sock *sk, int level, int optname,
- char *optval, int optlen)
- {
- if (level != SOL_RAW)
- return ip_setsockopt(sk, level, optname, optval, optlen);
- if (optname == ICMP_FILTER) {
- if (sk->num != IPPROTO_ICMP)
- return -EOPNOTSUPP;
- else
- return raw_seticmpfilter(sk, optval, optlen);
- }
- return -ENOPROTOOPT;
- }
- static int raw_getsockopt(struct sock *sk, int level, int optname,
- char *optval, int *optlen)
- {
- if (level != SOL_RAW)
- return ip_getsockopt(sk, level, optname, optval, optlen);
- if (optname == ICMP_FILTER) {
- if (sk->num != IPPROTO_ICMP)
- return -EOPNOTSUPP;
- else
- return raw_geticmpfilter(sk, optval, optlen);
- }
- return -ENOPROTOOPT;
- }
- static int raw_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;
- int amount = 0;
- spin_lock_irq(&sk->receive_queue.lock);
- skb = skb_peek(&sk->receive_queue);
- if (skb != NULL)
- amount = skb->len;
- spin_unlock_irq(&sk->receive_queue.lock);
- return put_user(amount, (int *)arg);
- }
- default:
- #ifdef CONFIG_IP_MROUTE
- return ipmr_ioctl(sk, cmd, arg);
- #else
- return -ENOIOCTLCMD;
- #endif
- }
- }
- static void get_raw_sock(struct sock *sp, char *tmpbuf, int i)
- {
- unsigned int dest = sp->daddr,
- src = sp->rcv_saddr;
- __u16 destp = 0,
- srcp = sp->num;
- sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X"
- " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %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 raw_get_info(char *buffer, char **start, off_t offset, int length)
- {
- int len = 0, num = 0, i;
- off_t pos = 128;
- off_t begin;
- char tmpbuf[129];
- if (offset < 128)
- len += sprintf(buffer, "%-127sn",
- " sl local_address rem_address st tx_queue "
- "rx_queue tr tm->when retrnsmt uid timeout "
- "inode");
- read_lock(&raw_v4_lock);
- for (i = 0; i < RAWV4_HTABLE_SIZE; i++) {
- struct sock *sk;
- for (sk = raw_v4_htable[i]; sk; sk = sk->next, num++) {
- if (sk->family != PF_INET)
- continue;
- pos += 128;
- if (pos <= offset)
- continue;
- get_raw_sock(sk, tmpbuf, i);
- len += sprintf(buffer + len, "%-127sn", tmpbuf);
- if (len >= length)
- goto out;
- }
- }
- out:
- read_unlock(&raw_v4_lock);
- begin = len - (pos - offset);
- *start = buffer + begin;
- len -= begin;
- if (len > length)
- len = length;
- if (len < 0)
- len = 0;
- return len;
- }
- struct proto raw_prot = {
- name: "RAW",
- close: raw_close,
- connect: udp_connect,
- disconnect: udp_disconnect,
- ioctl: raw_ioctl,
- init: raw_init,
- setsockopt: raw_setsockopt,
- getsockopt: raw_getsockopt,
- sendmsg: raw_sendmsg,
- recvmsg: raw_recvmsg,
- bind: raw_bind,
- backlog_rcv: raw_rcv_skb,
- hash: raw_v4_hash,
- unhash: raw_v4_unhash,
- };