raw.c

嵌入式系统设计与实验教材二源码linux内核移植与编译

			csum = (__u16 *) (buff + opt->offset);
			*csum = hdr->cksum;
		} else {
			if (net_ratelimit())
				printk(KERN_DEBUG "icmp: cksum offset too big\n");
			return -EINVAL;
		}
	}	
	return 0; 
}


static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, int len)
{
	struct ipv6_txoptions opt_space;
	struct sockaddr_in6 * sin6 = (struct sockaddr_in6 *) msg->msg_name;
	struct ipv6_pinfo *np = &sk->net_pinfo.af_inet6;
	struct ipv6_txoptions *opt = NULL;
	struct ip6_flowlabel *flowlabel = NULL;
	struct flowi fl;
	int addr_len = msg->msg_namelen;
	struct in6_addr *daddr;
	struct raw6_opt *raw_opt;
	int hlimit = -1;
	u16 proto;
	int err;

	/* Rough check on arithmetic overflow,
	   better check is made in ip6_build_xmit
	 */
	if (len < 0)
		return -EMSGSIZE;

	/* Mirror BSD error message compatibility */
	if (msg->msg_flags & MSG_OOB)		
		return -EOPNOTSUPP;

	/*
	 *	Get and verify the address. 
	 */

	fl.fl6_flowlabel = 0;
	fl.oif = 0;

	if (sin6) {
		if (addr_len < SIN6_LEN_RFC2133) 
			return -EINVAL;

		if (sin6->sin6_family && sin6->sin6_family != AF_INET6) 
			return(-EINVAL);

		/* port is the proto value [0..255] carried in nexthdr */
		proto = ntohs(sin6->sin6_port);

		if (!proto)
			proto = sk->num;

		if (proto > 255)
			return(-EINVAL);

		daddr = &sin6->sin6_addr;
		if (np->sndflow) {
			fl.fl6_flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
			if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
				flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
				if (flowlabel == NULL)
					return -EINVAL;
				daddr = &flowlabel->dst;
			}
		}

		/* Otherwise it will be difficult to maintain sk->dst_cache. */
		if (sk->state == TCP_ESTABLISHED &&
		    !ipv6_addr_cmp(daddr, &sk->net_pinfo.af_inet6.daddr))
			daddr = &sk->net_pinfo.af_inet6.daddr;

		if (addr_len >= sizeof(struct sockaddr_in6) &&
		    sin6->sin6_scope_id &&
		    ipv6_addr_type(daddr)&IPV6_ADDR_LINKLOCAL)
			fl.oif = sin6->sin6_scope_id;
	} else {
		if (sk->state != TCP_ESTABLISHED) 
			return(-EINVAL);
		
		proto = sk->num;
		daddr = &(sk->net_pinfo.af_inet6.daddr);
		fl.fl6_flowlabel = np->flow_label;
	}

	if (ipv6_addr_any(daddr)) {
		/* 
		 * unspecfied destination address 
		 * treated as error... is this correct ?
		 */
		return(-EINVAL);
	}

	if (fl.oif == 0)
		fl.oif = sk->bound_dev_if;
	fl.fl6_src = NULL;

	if (msg->msg_controllen) {
		opt = &opt_space;
		memset(opt, 0, sizeof(struct ipv6_txoptions));

		err = datagram_send_ctl(msg, &fl, opt, &hlimit);
		if (err < 0) {
			fl6_sock_release(flowlabel);
			return err;
		}
		if ((fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
			flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
			if (flowlabel == NULL)
				return -EINVAL;
		}
		if (!(opt->opt_nflen|opt->opt_flen))
			opt = NULL;
	}
	if (opt == NULL)
		opt = np->opt;
	if (flowlabel)
		opt = fl6_merge_options(&opt_space, flowlabel, opt);

	raw_opt = &sk->tp_pinfo.tp_raw;

	fl.proto = proto;
	fl.fl6_dst = daddr;
	if (fl.fl6_src == NULL && !ipv6_addr_any(&np->saddr))
		fl.fl6_src = &np->saddr;
	fl.uli_u.icmpt.type = 0;
	fl.uli_u.icmpt.code = 0;
	
	if (raw_opt->checksum) {
		struct rawv6_fakehdr hdr;
		
		hdr.iov = msg->msg_iov;
		hdr.sk  = sk;
		hdr.len = len;
		hdr.cksum = 0;
		hdr.proto = proto;

		if (opt && opt->srcrt)
			hdr.daddr = daddr;
		else
			hdr.daddr = NULL;

		err = ip6_build_xmit(sk, rawv6_frag_cksum, &hdr, &fl, len,
				     opt, hlimit, msg->msg_flags);
	} else {
		err = ip6_build_xmit(sk, rawv6_getfrag, msg->msg_iov, &fl, len,
				     opt, hlimit, msg->msg_flags);
	}

	fl6_sock_release(flowlabel);

	return err<0?err:len;
}

static int rawv6_seticmpfilter(struct sock *sk, int level, int optname, 
			       char *optval, int optlen)
{
	switch (optname) {
	case ICMPV6_FILTER:
		if (optlen > sizeof(struct icmp6_filter))
			optlen = sizeof(struct icmp6_filter);
		if (copy_from_user(&sk->tp_pinfo.tp_raw.filter, optval, optlen))
			return -EFAULT;
		return 0;
	default:
		return -ENOPROTOOPT;
	};

	return 0;
}

static int rawv6_geticmpfilter(struct sock *sk, int level, int optname, 
			       char *optval, int *optlen)
{
	int len;

	switch (optname) {
	case ICMPV6_FILTER:
		if (get_user(len, optlen))
			return -EFAULT;
		if (len < 0)
			return -EINVAL;
		if (len > sizeof(struct icmp6_filter))
			len = sizeof(struct icmp6_filter);
		if (put_user(len, optlen))
			return -EFAULT;
		if (copy_to_user(optval, &sk->tp_pinfo.tp_raw.filter, len))
			return -EFAULT;
		return 0;
	default:
		return -ENOPROTOOPT;
	};

	return 0;
}


static int rawv6_setsockopt(struct sock *sk, int level, int optname, 
			    char *optval, int optlen)
{
	struct raw6_opt *opt = &sk->tp_pinfo.tp_raw;
	int val;

	switch(level) {
		case SOL_RAW:
			break;

		case SOL_ICMPV6:
			if (sk->num != IPPROTO_ICMPV6)
				return -EOPNOTSUPP;
			return rawv6_seticmpfilter(sk, level, optname, optval,
						   optlen);
		case SOL_IPV6:
			if (optname == IPV6_CHECKSUM)
				break;
		default:
			return ipv6_setsockopt(sk, level, optname, optval,
					       optlen);
	};

  	if (get_user(val, (int *)optval))
		return -EFAULT;

	switch (optname) {
		case IPV6_CHECKSUM:
			if (val < 0) {
				opt->checksum = 0;
			} else {
				opt->checksum = 1;
				opt->offset = val;
			}

			return 0;
			break;

		default:
			return(-ENOPROTOOPT);
	}
}

static int rawv6_getsockopt(struct sock *sk, int level, int optname, 
			    char *optval, int *optlen)
{
	struct raw6_opt *opt = &sk->tp_pinfo.tp_raw;
	int val, len;

	switch(level) {
		case SOL_RAW:
			break;

		case SOL_ICMPV6:
			if (sk->num != IPPROTO_ICMPV6)
				return -EOPNOTSUPP;
			return rawv6_geticmpfilter(sk, level, optname, optval,
						   optlen);
		case SOL_IPV6:
			if (optname == IPV6_CHECKSUM)
				break;
		default:
			return ipv6_getsockopt(sk, level, optname, optval,
					       optlen);
	};

	if (get_user(len,optlen))
		return -EFAULT;

	switch (optname) {
	case IPV6_CHECKSUM:
		if (opt->checksum == 0)
			val = -1;
		else
			val = opt->offset;

	default:
		return -ENOPROTOOPT;
	}

	len = min_t(unsigned int, sizeof(int), len);

	if (put_user(len, optlen))
		return -EFAULT;
	if (copy_to_user(optval,&val,len))
		return -EFAULT;
	return 0;
}

static int rawv6_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->tail - skb->h.raw;
			spin_unlock_irq(&sk->receive_queue.lock);
			return put_user(amount, (int *)arg);
		}

		default:
			return -ENOIOCTLCMD;
	}
}

static void rawv6_close(struct sock *sk, long timeout)
{
	if (sk->num == IPPROTO_RAW)
		ip6_ra_control(sk, -1, NULL);

	inet_sock_release(sk);
}

static int rawv6_init_sk(struct sock *sk)
{
	return(0);
}

#define LINE_LEN 190
#define LINE_FMT "%-190s\n"

static void get_raw6_sock(struct sock *sp, char *tmpbuf, int i)
{
	struct in6_addr *dest, *src;
	__u16 destp, srcp;

	dest  = &sp->net_pinfo.af_inet6.daddr;
	src   = &sp->net_pinfo.af_inet6.rcv_saddr;
	destp = 0;
	srcp  = sp->num;
	sprintf(tmpbuf,
		"%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
		"%02X %08X:%08X %02X:%08lX %08X %5d %8d %ld %d %p",
		i,
		src->s6_addr32[0], src->s6_addr32[1],
		src->s6_addr32[2], src->s6_addr32[3], srcp,
		dest->s6_addr32[0], dest->s6_addr32[1],
		dest->s6_addr32[2], dest->s6_addr32[3], 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 raw6_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[LINE_LEN+2];

	if (offset < LINE_LEN+1)
		len += sprintf(buffer, LINE_FMT,
			       "  sl  "						/* 6 */
			       "local_address                         "		/* 38 */
			       "remote_address                        "		/* 38 */
			       "st tx_queue rx_queue tr tm->when retrnsmt"	/* 41 */
			       "   uid  timeout inode");			/* 21 */
										/*----*/
										/*144 */
	pos = LINE_LEN+1;
	read_lock(&raw_v6_lock);
	for (i = 0; i < RAWV6_HTABLE_SIZE; i++) {
		struct sock *sk;

		for (sk = raw_v6_htable[i]; sk; sk = sk->next, num++) {
			if (sk->family != PF_INET6)
				continue;
			pos += LINE_LEN+1;
			if (pos <= offset)
				continue;
			get_raw6_sock(sk, tmpbuf, i);
			len += sprintf(buffer+len, LINE_FMT, tmpbuf);
			if(len >= length)
				goto out;
		}
	}
out:
	read_unlock(&raw_v6_lock);
	begin = len - (pos - offset);
	*start = buffer + begin;
	len -= begin;
	if(len > length)
		len = length;
	if (len < 0)
		len = 0; 
	return len;
}

struct proto rawv6_prot = {
	name:		"RAW",
	close:		rawv6_close,
	connect:	udpv6_connect,
	disconnect:	udp_disconnect,
	ioctl:		rawv6_ioctl,
	init:		rawv6_init_sk,
	destroy:	inet6_destroy_sock,
	setsockopt:	rawv6_setsockopt,
	getsockopt:	rawv6_getsockopt,
	sendmsg:	rawv6_sendmsg,
	recvmsg:	rawv6_recvmsg,
	bind:		rawv6_bind,
	backlog_rcv:	rawv6_rcv_skb,
	hash:		raw_v6_hash,
	unhash:		raw_v6_unhash,
};