ip_write.c

MINIX系统源码

#if DEBUG & 256
 { where(); printf("processing arp_pack\n"); }
#endif
		assert (ip_port->ip_dl.dl_eth.de_arp_pack);
		ip_port->ip_dl.dl_eth.de_wr_ipaddr= (ipaddr_t)0;
		ip_port->ip_dl.dl_eth.de_wr_ethaddr= ip_port->ip_dl.
			dl_eth.de_arp_ethaddr;
		ip_port->ip_dl.dl_eth.de_wr_frag= ip_port->ip_dl.dl_eth.
			de_arp_pack;
		ip_port->ip_dl.dl_eth.de_flags &= ~IEF_ARP_MASK;
		return;
	}
	for (i=0, ip_fd= ip_fd_table; i<IP_FD_NR; i++, ip_fd++)
	{
		if (!(ip_fd->if_flags & IFF_INUSE))
			continue;
		if (!(ip_fd->if_flags & IFF_DLL_WR_IP))
			continue;
		if (ip_fd->if_wr_port != ip_port)
			continue;
#if DEBUG & 256
 { where(); printf("calling restart_fd_write\n"); }
#endif
		restart_fd_write(ip_fd);
		if (ip_port->ip_dl.dl_eth.de_wr_frag)
			return;
	}
}


PRIVATE void restart_netbroad_fd(ip_fd)
ip_fd_t *ip_fd;
{
	assert (!(netbroad_flags & NF_INUSE));
	assert (ip_fd->if_flags & IFF_NETBROAD_IP);
	ip_fd->if_flags &= ~IFF_NETBROAD_IP;
	netbroad_flags |= NF_INUSE;
	netbroad_dst= ip_fd->if_wr_dstaddr;
	netbroad_netmask= ip_get_netmask(netbroad_dst);
	netbroad_pack= get_packet(ip_fd, (int)get_time());
	if (!netbroad_pack)
	{
		netbroad_flags &= ~NF_INUSE;
		return;
	}
	netbroad_port= ip_port_table;
	restart_netbroadcast();

	error_reply(ip_fd, ip_fd->if_wr_count);
}

PRIVATE void restart_fd_write(ip_fd)
ip_fd_t *ip_fd;
{
	ip_port_t *ip_port;
	ipaddr_t dstaddr;
	acc_t *pack;
	int result;

	assert (ip_fd->if_flags & IFF_DLL_WR_IP);

	ip_port= ip_fd->if_wr_port;
	dstaddr= ip_fd->if_wr_dstaddr;
	result= dll_ready(ip_port, dstaddr);
	if (result == NW_SUSPEND)
	{
		return;
	}
	if (result == EDSTNOTRCH)
	{
#if DEBUG
 { where(); printf("dll_ready returned EDSTNOTRCH, gateway= ");
	writeIpAddr(ip_fd->if_wr_dstaddr); printf(", the packet was %s\n",
	(ip_fd->if_flags & IFF_ROUTED) ? "routed" : "not routed"); }
#endif
		if (!(ip_fd->if_flags & IFF_ROUTED))
		{
			error_reply (ip_fd, result);
			return;
		}
		else
		{
			ipr_gateway_down (ip_fd->if_wr_dstaddr,
				IPR_GW_DOWN_TIMEOUT);
			error_reply(ip_fd, NW_OK);
			return;
		}
	}
assert (result == NW_OK);

	ip_fd->if_flags &= ~IFF_DLL_WR_IP;

	ip_port->ip_frame_id++;
	pack= get_packet(ip_fd, ip_port->ip_frame_id);
	if (!pack)
	{
		return;
	}
	dll_write(ip_port, dstaddr, pack);
	error_reply(ip_fd, ip_fd->if_wr_count);
}

PRIVATE void ip_remroute_addr(ip_fd, ttl)
ip_fd_t *ip_fd;
u8_t ttl;
{
	ipaddr_t dstaddr, nexthop;
	ip_port_t *ip_port;
	int result, port;

	dstaddr= ip_fd->if_wr_dstaddr;
	result= iproute_frag (dstaddr, ttl, &nexthop, &port);
#if DEBUG & 256
 { where(); printf("ip_remroute_addr("); writeIpAddr(dstaddr); 
	printf(", %d)= %d\n", ttl, result); }
#endif
	if (result>0)
	{
		ip_port= &ip_port_table[port];
		ip_fd->if_flags |= IFF_DLL_WR_IP|IFF_ROUTED;
		ip_fd->if_wr_dstaddr= nexthop;
		ip_fd->if_wr_port= ip_port;
#if DEBUG & 256
 { where(); printf("calling restart_fd_write\n"); }
#endif
		restart_fd_write(ip_fd);
		return;
	}
	if (result<0)
	{
		error_reply (ip_fd, result);
		return;
	}
#if IP_ROUTER
	ip_panic(( "not implemented" ));
#else
	ip_panic(( "shouldn't be here" ));
#endif
}

PRIVATE acc_t *ip_split_pack (ref_last, first_size)
acc_t **ref_last;
int first_size;
{
	int pack_siz;
	ip_hdr_t *first_hdr, *second_hdr;
	int first_hdr_len, second_hdr_len;
	int first_data_len, second_data_len;
	int new_first_data_len;
	int first_opt_size, second_opt_size;
	acc_t *first_pack, *second_pack, *tmp_pack, *tmp_pack1;
	u8_t *first_optptr, *second_optptr;
	int i, optlen;

	first_pack= *ref_last;
	*ref_last= 0;
	second_pack= 0;

	first_pack= bf_packIffLess(first_pack, IP_MIN_HDR_SIZE);
	assert (first_pack->acc_length >= IP_MIN_HDR_SIZE);

	first_hdr= (ip_hdr_t *)ptr2acc_data(first_pack);
#if DEBUG & 256
 { where(); writeIpAddr(first_hdr->ih_dst); printf("\n"); }
#endif
	first_hdr_len= (first_hdr->ih_vers_ihl & IH_IHL_MASK) * 4;
#if DEBUG & 256
 { where(); printf("fist_hdr_len= %d\n", first_hdr_len); }
#endif
	pack_siz= bf_bufsize(first_pack);
	if (pack_siz > first_size)
	{
#if DEBUG & 256
 { where(); printf("splitting pack\n"); }
#endif
		if (first_hdr->ih_flags_fragoff & HTONS(IH_DONT_FRAG))
		{
assert (!(first_hdr->ih_flags_fragoff) & HTONS(IH_FRAGOFF_MASK));
			icmp_dont_frag(first_pack);
			return 0;
		}
		first_data_len= ntohs(first_hdr->ih_length) - first_hdr_len;
		new_first_data_len= (first_size- first_hdr_len) & ~7;
			/* data goes in 8 byte chuncks */
		second_data_len= first_data_len-new_first_data_len;
		second_pack= bf_cut(first_pack, first_hdr_len+
			new_first_data_len, second_data_len);
		tmp_pack= first_pack;
		first_data_len= new_first_data_len;
		first_pack= bf_cut (tmp_pack, 0, first_hdr_len+first_data_len);
		bf_afree(tmp_pack);
		tmp_pack= bf_memreq(first_hdr_len);
		tmp_pack->acc_next= second_pack;
		second_pack= tmp_pack;
		second_hdr= (ip_hdr_t *)ptr2acc_data(second_pack);
		*second_hdr= *first_hdr;
		second_hdr->ih_flags_fragoff= htons(
			ntohs(first_hdr->ih_flags_fragoff)+(first_data_len/8));

		first_opt_size= first_hdr_len-IP_MIN_HDR_SIZE;
		second_opt_size= 0;
		if (first_opt_size)
		{
			first_pack= bf_packIffLess (first_pack,
				first_hdr_len);
			first_hdr= (ip_hdr_t *)ptr2acc_data(first_pack);
			assert (first_pack->acc_length>=first_hdr_len);
			first_optptr= (u8_t *)ptr2acc_data(first_pack)+
				IP_MIN_HDR_SIZE;
			second_optptr= (u8_t *)ptr2acc_data(
				second_pack)+IP_MIN_HDR_SIZE;
			i= 0;
			while (i<first_opt_size)
			{
				switch (*first_optptr & IP_OPT_NUMBER)
				{
				case 0:
				case 1:
					optlen= 1;
					break;
				default:
					optlen= first_optptr[1];
					break;
				}
				assert (i + optlen <= first_opt_size);
				i += optlen;
				if (*first_optptr & IP_OPT_COPIED)
				{
					second_opt_size += optlen;
					while (optlen--)
						*second_optptr++=
							*first_optptr++;
				}
				else
					first_optptr += optlen;
			}
			while (second_opt_size & 3)
			{
				*second_optptr++= 0;
				second_opt_size++;
			}
		}
		second_hdr_len= IP_MIN_HDR_SIZE + second_opt_size;
#if DEBUG & 256
 { where(); printf("second_opt_size= %d, second_hdr_len= %d\n",
	second_opt_size, second_hdr_len); }
#endif
		second_hdr->ih_vers_ihl= second_hdr->ih_vers_ihl & 0xf0
			+ (second_hdr_len/4);
		second_hdr->ih_length= htons(second_data_len+
			second_hdr_len);
		second_pack->acc_length= second_hdr_len;
		if (first_pack->acc_buffer->buf_linkC>1)
		{
			tmp_pack= bf_cut(first_pack, 0,
				IP_MIN_HDR_SIZE);
			tmp_pack1= bf_cut(first_pack, IP_MIN_HDR_SIZE,
				bf_bufsize(first_pack)-
				IP_MIN_HDR_SIZE);
			bf_afree(first_pack);
#if DEBUG
 { where(); printf("calling bf_pack\n"); }
#endif
			first_pack= bf_pack(tmp_pack);
			first_pack->acc_next= tmp_pack1;
			first_hdr= (ip_hdr_t *)ptr2acc_data(
				first_pack);
		}
		assert (first_pack->acc_buffer->buf_linkC == 1);
		first_hdr->ih_flags_fragoff |= HTONS(IH_MORE_FRAGS);
		first_hdr->ih_length= htons(first_data_len+
			first_hdr_len);
assert (!(second_hdr->ih_flags_fragoff & HTONS(IH_DONT_FRAG)));
	}
	if (first_pack->acc_buffer->buf_linkC>1)
	{
		tmp_pack= bf_cut(first_pack, 0,	IP_MIN_HDR_SIZE);
		tmp_pack1= bf_cut(first_pack, IP_MIN_HDR_SIZE,
			bf_bufsize(first_pack)-IP_MIN_HDR_SIZE);
		bf_afree(first_pack);
#if DEBUG
 { where(); printf("calling bf_pack\n"); }
#endif
		first_pack= bf_pack(tmp_pack);
		first_pack->acc_next= tmp_pack1;
		first_hdr= (ip_hdr_t *)ptr2acc_data(first_pack);
	}
	assert (first_hdr->ih_ttl);
#if DEBUG & 256
 { where(); printf("ip_write.c: ip_split_pack: first_hdr_len= %d\n",
	first_hdr_len); }
#endif
	first_hdr->ih_hdr_chk= 0;
	first_hdr->ih_hdr_chk= ~oneC_sum (0, (u16_t *)first_hdr,
		first_hdr_len);
	*ref_last= second_pack;
	return first_pack;
}

PRIVATE void restart_netbroadcast()
{
	int was_suspended, result, i;
	ip_port_t *ip_port, *hi_port;
	ip_fd_t *ip_fd;

	assert (netbroad_flags & NF_INUSE);
	was_suspended= !!(netbroad_flags & NF_SUSPENDED);
	hi_port= &ip_port_table[IP_PORT_NR];

	for (; netbroad_port < hi_port; netbroad_port++)
	{
		if (!(netbroad_port->ip_flags & IPF_IPADDRSET))
			continue;
		if (!((netbroad_dst ^ netbroad_port->ip_ipaddr) &
			netbroad_netmask))
			continue;
		result= dll_ready (netbroad_port, (ipaddr_t)-1);
		if (result == NW_SUSPEND)
		{
			netbroad_flags |= NF_SUSPENDED;
			return;
		}
assert (result >= 0);

		netbroad_pack->acc_linkC++;
#if DEBUG
 { where(); printf("calling dll_write\n"); }
#endif
		dll_write (netbroad_port, (ipaddr_t)(-1),
			netbroad_pack);
	}
	netbroad_flags &= ~NF_INUSE;
	bf_afree(netbroad_pack);
	netbroad_pack= 0;
	if (!was_suspended)
		return;

	for (i=0, ip_fd= ip_fd_table; i<IP_FD_NR; i++, ip_fd++)
	{
		if (!(ip_fd->if_flags & IFF_INUSE) ||
			!(ip_fd->if_flags & IFF_NETBROAD_IP))
			continue;
		restart_netbroad_fd(ip_fd);
		if (netbroad_flags & NF_INUSE)
			return;
	}
}

PRIVATE void error_reply (ip_fd, error)
ip_fd_t *ip_fd;
int error;
{
	ip_fd->if_flags &= ~IFF_WRITE_MASK;
	if ((*ip_fd->if_get_userdata)(ip_fd->if_srfd, (size_t)error,
		(size_t)0, FALSE))
		ip_panic(( "can't error_reply" ));
}

PRIVATE acc_t *get_packet (ip_fd, id)
ip_fd_t *ip_fd;
u16_t id;
{
	acc_t *pack, *tmp_pack, *tmp_pack1;
	ip_hdr_t *hdr, *tmp_hdr;
	int pack_len, hdr_len, hdr_opt_len, error;

	pack_len= ip_fd->if_wr_count;
	pack= (*ip_fd->if_get_userdata)(ip_fd->if_srfd, (size_t)0,
		pack_len, FALSE);
	if (!pack)
		return pack;
assert(pack_len == bf_bufsize(pack));
	if (ip_fd->if_ipopt.nwio_flags & NWIO_RWDATONLY)
	{
		tmp_pack= bf_memreq (IP_MIN_HDR_SIZE);
		tmp_pack->acc_next= pack;
		pack= tmp_pack;
		pack_len += IP_MIN_HDR_SIZE;
	}
	if (pack_len<IP_MIN_HDR_SIZE)
	{
		bf_afree(pack);
		error_reply(ip_fd, EPACKSIZE);
		return 0;
	}
	pack= bf_packIffLess(pack, IP_MIN_HDR_SIZE);
assert (pack->acc_length >= IP_MIN_HDR_SIZE);
	hdr= (ip_hdr_t *)ptr2acc_data(pack);
	if (pack->acc_linkC != 1 || pack->acc_buffer->buf_linkC != 1)
	{
		tmp_pack= bf_memreq(IP_MIN_HDR_SIZE);
		tmp_hdr= (ip_hdr_t *)ptr2acc_data(tmp_pack);
		*tmp_hdr= *hdr;
		tmp_pack->acc_next= bf_cut(pack, IP_MIN_HDR_SIZE,
			pack_len-IP_MIN_HDR_SIZE);
		bf_afree(pack);
		hdr= tmp_hdr;
#if DEBUG & 256
 { where(); printf("ih_vers_ihl= 0x%x\n", hdr->ih_vers_ihl); }
#endif
		pack= tmp_pack;
assert (pack->acc_length >= IP_MIN_HDR_SIZE);
	}
assert (pack->acc_linkC == 1 && pack->acc_buffer->buf_linkC == 1);

	if (ip_fd->if_ipopt.nwio_flags & NWIO_HDR_O_SPEC)
	{
#if DEBUG & 256
 { where(); printf("ih_vers_ihl= 0x%x\n", hdr->ih_vers_ihl); }
#endif
		hdr_opt_len= ip_fd->if_ipopt.nwio_hdropt.iho_opt_siz;
		if (hdr_opt_len)
		{
			tmp_pack= bf_cut(pack, 0, IP_MIN_HDR_SIZE);
			tmp_pack1= bf_cut (pack, IP_MIN_HDR_SIZE,
				pack_len-IP_MIN_HDR_SIZE);
			bf_afree(pack);
			pack= bf_packIffLess(tmp_pack, IP_MIN_HDR_SIZE);
			hdr= (ip_hdr_t *)ptr2acc_data(pack);
 { where(); printf("ih_vers_ihl= 0x%x\n", hdr->ih_vers_ihl); }
			tmp_pack= bf_memreq (hdr_opt_len);
			memcpy (ptr2acc_data(tmp_pack), ip_fd->if_ipopt.
				nwio_hdropt.iho_data, hdr_opt_len);
 { where(); printf("ih_vers_ihl= 0x%x\n", hdr->ih_vers_ihl); }
			pack->acc_next= tmp_pack;
			tmp_pack->acc_next= tmp_pack1;
			hdr_len= IP_MIN_HDR_SIZE+hdr_opt_len;
		}
		else
			hdr_len= IP_MIN_HDR_SIZE;
		hdr->ih_vers_ihl= hdr_len/4;
#if DEBUG & 256
 { where(); printf("ih_vers_ihl= 0x%x\n", hdr->ih_vers_ihl); }
#endif
		hdr->ih_tos= ip_fd->if_ipopt.nwio_tos;
		hdr->ih_flags_fragoff= 0;
		if (ip_fd->if_ipopt.nwio_df)
			hdr->ih_flags_fragoff |= HTONS(IH_DONT_FRAG);
		hdr->ih_ttl= ip_fd->if_ipopt.nwio_ttl;
#if DEBUG & 256
 { where(); printf("ih_vers_ihl= 0x%x\n", hdr->ih_vers_ihl); }
#endif
	}
	else
	{
assert (ip_fd->if_ipopt.nwio_flags & NWIO_HDR_O_ANY);
		hdr_len= (hdr->ih_vers_ihl & IH_IHL_MASK)*4;
#if DEBUG & 256
 { where(); printf("ih_vers_ihl= 0x%x\n", hdr->ih_vers_ihl); }
#endif
		error= NW_OK;
		if (hdr_len<IP_MIN_HDR_SIZE)
			error= EINVAL;
		else if (hdr_len>pack_len)
			error= EPACKSIZE;
		else if (!hdr->ih_ttl)
			error= EINVAL;
		if (error<0)
		{
			bf_afree(pack);
			error_reply (ip_fd, error);
			return 0;
		}
		pack= bf_packIffLess(pack, hdr_len);
		hdr= (ip_hdr_t *)ptr2acc_data(pack);
#if DEBUG & 256
 { where(); printf("ih_vers_ihl= 0x%x\n", hdr->ih_vers_ihl); }
#endif
		if (hdr_len != IP_MIN_HDR_SIZE)
		{
			error= ip_chk_hdropt((u8_t *)(ptr2acc_data(pack) +
				IP_MIN_HDR_SIZE),
				hdr_len-IP_MIN_HDR_SIZE);
			if (error<0)
			{
				bf_afree(pack);
				error_reply (ip_fd, error);
				return 0;
			}
		}
#if DEBUG & 256
 { where(); printf("ih_vers_ihl= 0x%x\n", hdr->ih_vers_ihl); }
#endif
	}
#if DEBUG & 256
 if (hdr->ih_flags_fragoff & HTONS(IH_DONT_FRAG))
 { where(); printf("proto= %d\n", hdr->ih_proto); }
#endif
assert (!(hdr->ih_flags_fragoff & HTONS(IH_DONT_FRAG)));
#if DEBUG & 256
 { where(); printf("ih_vers_ihl= 0x%x\n", hdr->ih_vers_ihl); }
#endif
	hdr->ih_vers_ihl= (hdr->ih_vers_ihl & IH_IHL_MASK) |
		(IP_VERSION << 4);
#if DEBUG & 256
 { where(); printf("ih_vers_ihl= 0x%x\n", hdr->ih_vers_ihl); }
#endif
	hdr->ih_length= htons(pack_len);
	hdr->ih_flags_fragoff &= ~HTONS(IH_FRAGOFF_MASK |
		IH_FLAGS_UNUSED | IH_MORE_FRAGS);
	if (ip_fd->if_ipopt.nwio_flags & NWIO_PROTOSPEC)
		hdr->ih_proto= ip_fd->if_ipopt.nwio_proto;
	hdr->ih_id= htons(id);
	hdr->ih_src= ip_fd->if_port->ip_ipaddr;
	if (ip_fd->if_ipopt.nwio_flags & NWIO_REMSPEC)
		hdr->ih_dst= ip_fd->if_ipopt.nwio_rem;
	else
	{
assert (ip_fd->if_ipopt.nwio_flags & NWIO_REMANY);
		error= chk_dstaddr(hdr->ih_dst);
		if (error<0)
		{
			bf_afree(pack);
			error_reply(ip_fd, error);
			return 0;
		}
	}
	return pack;
}

PRIVATE chk_dstaddr (dst)
ipaddr_t dst;
{
	ipaddr_t hostrep_dst, netmask;

	hostrep_dst= ntohl(dst);
	if (hostrep_dst == (ipaddr_t)-1)
		return NW_OK;
	if ((hostrep_dst & 0xe0000000l) == 0xe0000000l)
		return EBADDEST;
	netmask= ip_get_netmask(dst);
	if (!(dst & ~netmask))
		return EBADDEST;
	return NW_OK;
}