minix/servers/inet/generic/ip_write.c
2009-11-28 13:18:33 +00:00

513 lines
12 KiB
C

/*
ip_write.c
Copyright 1995 Philip Homburg
*/
#include "inet.h"
#include "buf.h"
#include "event.h"
#include "type.h"
#include "arp.h"
#include "assert.h"
#include "clock.h"
#include "eth.h"
#include "icmp_lib.h"
#include "io.h"
#include "ip.h"
#include "ip_int.h"
#include "ipr.h"
THIS_FILE
FORWARD void error_reply ARGS(( ip_fd_t *fd, int error ));
PUBLIC int ip_write (fd, count)
int fd;
size_t count;
{
ip_fd_t *ip_fd;
acc_t *pack;
int r;
ip_fd= &ip_fd_table[fd];
if (count > IP_MAX_PACKSIZE)
{
error_reply (ip_fd, EPACKSIZE);
return NW_OK;
}
pack= (*ip_fd->if_get_userdata)(ip_fd->if_srfd, (size_t)0,
count, FALSE);
if (!pack)
return NW_OK;
r= ip_send(fd, pack, count);
assert(r != NW_WOULDBLOCK);
if (r == NW_OK)
error_reply (ip_fd, count);
else
error_reply (ip_fd, r);
return NW_OK;
}
PUBLIC int ip_send(fd, data, data_len)
int fd;
acc_t *data;
size_t data_len;
{
ip_port_t *ip_port;
ip_fd_t *ip_fd;
ip_hdr_t *ip_hdr, *tmp_hdr;
ipaddr_t dstaddr, nexthop, hostrep_dst, my_ipaddr, netmask;
u8_t *addrInBytes;
acc_t *tmp_pack, *tmp_pack1;
int hdr_len, hdr_opt_len, r;
int type, ttl;
size_t req_mtu;
ev_arg_t arg;
ip_fd= &ip_fd_table[fd];
ip_port= ip_fd->if_port;
if (!(ip_fd->if_flags & IFF_OPTSET))
{
bf_afree(data);
return EBADMODE;
}
if (!(ip_fd->if_port->ip_flags & IPF_IPADDRSET))
{
/* Interface is down. */
bf_afree(data);
return ENETDOWN;
}
data_len= bf_bufsize(data);
if (ip_fd->if_ipopt.nwio_flags & NWIO_RWDATONLY)
{
tmp_pack= bf_memreq(IP_MIN_HDR_SIZE);
tmp_pack->acc_next= data;
data= tmp_pack;
data_len += IP_MIN_HDR_SIZE;
}
if (data_len<IP_MIN_HDR_SIZE)
{
bf_afree(data);
return EPACKSIZE;
}
data= bf_packIffLess(data, IP_MIN_HDR_SIZE);
ip_hdr= (ip_hdr_t *)ptr2acc_data(data);
if (data->acc_linkC != 1 || data->acc_buffer->buf_linkC != 1)
{
tmp_pack= bf_memreq(IP_MIN_HDR_SIZE);
tmp_hdr= (ip_hdr_t *)ptr2acc_data(tmp_pack);
*tmp_hdr= *ip_hdr;
tmp_pack->acc_next= bf_cut(data, IP_MIN_HDR_SIZE,
data_len-IP_MIN_HDR_SIZE);
bf_afree(data);
ip_hdr= tmp_hdr;
data= tmp_pack;
assert (data->acc_length >= IP_MIN_HDR_SIZE);
}
if (ip_fd->if_ipopt.nwio_flags & NWIO_HDR_O_SPEC)
{
hdr_opt_len= ip_fd->if_ipopt.nwio_hdropt.iho_opt_siz;
if (hdr_opt_len)
{
tmp_pack= bf_cut(data, 0, IP_MIN_HDR_SIZE);
tmp_pack1= bf_cut (data, IP_MIN_HDR_SIZE,
data_len-IP_MIN_HDR_SIZE);
bf_afree(data);
data= bf_packIffLess(tmp_pack, IP_MIN_HDR_SIZE);
ip_hdr= (ip_hdr_t *)ptr2acc_data(data);
tmp_pack= bf_memreq (hdr_opt_len);
memcpy (ptr2acc_data(tmp_pack), ip_fd->if_ipopt.
nwio_hdropt.iho_data, hdr_opt_len);
data->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;
ip_hdr->ih_vers_ihl= hdr_len/4;
ip_hdr->ih_tos= ip_fd->if_ipopt.nwio_tos;
ip_hdr->ih_flags_fragoff= 0;
if (ip_fd->if_ipopt.nwio_df)
ip_hdr->ih_flags_fragoff |= HTONS(IH_DONT_FRAG);
ip_hdr->ih_ttl= ip_fd->if_ipopt.nwio_ttl;
ttl= ORTD_UNREACHABLE+1; /* Don't check TTL */
}
else
{
hdr_len= (ip_hdr->ih_vers_ihl & IH_IHL_MASK)*4;
r= NW_OK;
if (hdr_len<IP_MIN_HDR_SIZE)
r= EINVAL;
else if (hdr_len>data_len)
r= EPACKSIZE;
else if (!ip_hdr->ih_ttl)
r= EINVAL;
if (r != NW_OK)
{
bf_afree(data);
return r;
}
data= bf_packIffLess(data, hdr_len);
ip_hdr= (ip_hdr_t *)ptr2acc_data(data);
if (hdr_len != IP_MIN_HDR_SIZE)
{
r= ip_chk_hdropt((u8_t *)(ptr2acc_data(data) +
IP_MIN_HDR_SIZE),
hdr_len-IP_MIN_HDR_SIZE);
if (r != NW_OK)
{
bf_afree(data);
return r;
}
}
ttl= ip_hdr->ih_ttl;
}
ip_hdr->ih_vers_ihl= (ip_hdr->ih_vers_ihl & IH_IHL_MASK) |
(IP_VERSION << 4);
ip_hdr->ih_length= htons(data_len);
ip_hdr->ih_flags_fragoff &= ~HTONS(IH_FRAGOFF_MASK |
IH_FLAGS_UNUSED | IH_MORE_FRAGS);
if (ip_fd->if_ipopt.nwio_flags & NWIO_PROTOSPEC)
ip_hdr->ih_proto= ip_fd->if_ipopt.nwio_proto;
ip_hdr->ih_id= htons(ip_port->ip_frame_id++);
ip_hdr->ih_src= ip_fd->if_port->ip_ipaddr;
if (ip_fd->if_ipopt.nwio_flags & NWIO_REMSPEC)
ip_hdr->ih_dst= ip_fd->if_ipopt.nwio_rem;
netmask= ip_port->ip_subnetmask;
my_ipaddr= ip_port->ip_ipaddr;
dstaddr= ip_hdr->ih_dst;
hostrep_dst= ntohl(dstaddr);
r= 0;
if (hostrep_dst == (ipaddr_t)-1)
; /* OK, local broadcast */
else if ((hostrep_dst & 0xe0000000l) == 0xe0000000l)
; /* OK, Multicast */
else if ((hostrep_dst & 0xf0000000l) == 0xf0000000l)
r= EAFNOSUPPORT; /* Bad class */
else if ((dstaddr ^ my_ipaddr) & netmask)
; /* OK, remote destination */
else if (!(dstaddr & ~netmask) &&
(ip_port->ip_flags & IPF_SUBNET_BCAST))
{
r= EAFNOSUPPORT; /* Zero host part */
}
if (r<0)
{
DIFBLOCK(1, r == EAFNOSUPPORT,
printf("bad destination: ");
writeIpAddr(ip_hdr->ih_dst);
printf("\n"));
bf_afree(data);
return r;
}
ip_hdr_chksum(ip_hdr, hdr_len);
data= bf_packIffLess(data, IP_MIN_HDR_SIZE);
assert (data->acc_length >= IP_MIN_HDR_SIZE);
ip_hdr= (ip_hdr_t *)ptr2acc_data(data);
if (ip_hdr->ih_flags_fragoff & HTONS(IH_DONT_FRAG))
{
req_mtu= bf_bufsize(data);
if (req_mtu > ip_port->ip_mtu)
{
DBLOCK(1, printf(
"packet is larger than link MTU and DF is set\n"));
bf_afree(data);
return EPACKSIZE;
}
}
else
req_mtu= 0;
addrInBytes= (u8_t *)&dstaddr;
if ((addrInBytes[0] & 0xff) == 0x7f) /* local loopback */
{
assert (data->acc_linkC == 1);
dstaddr= ip_hdr->ih_dst; /* swap src and dst
* addresses */
ip_hdr->ih_dst= ip_hdr->ih_src;
ip_hdr->ih_src= dstaddr;
data->acc_ext_link= NULL;
if (ip_port->ip_loopb_head == NULL)
{
ip_port->ip_loopb_head= data;
arg.ev_ptr= ip_port;
ev_enqueue(&ip_port->ip_loopb_event,
ip_process_loopb, arg);
}
else
ip_port->ip_loopb_tail->acc_ext_link= data;
ip_port->ip_loopb_tail= data;
return NW_OK;
}
if ((dstaddr & HTONL(0xe0000000)) == HTONL(0xe0000000))
{
if (dstaddr == (ipaddr_t)-1)
{
r= (*ip_port->ip_dev_send)(ip_port, dstaddr, data,
IP_LT_BROADCAST);
return r;
}
if (ip_nettype(dstaddr) == IPNT_CLASS_D)
{
/* Multicast, what about multicast routing? */
r= (*ip_port->ip_dev_send)(ip_port, dstaddr, data,
IP_LT_MULTICAST);
return r;
}
}
if (dstaddr == my_ipaddr)
{
assert (data->acc_linkC == 1);
data->acc_ext_link= NULL;
if (ip_port->ip_loopb_head == NULL)
{
ip_port->ip_loopb_head= data;
arg.ev_ptr= ip_port;
ev_enqueue(&ip_port->ip_loopb_event,
ip_process_loopb, arg);
}
else
ip_port->ip_loopb_tail->acc_ext_link= data;
ip_port->ip_loopb_tail= data;
return NW_OK;
}
if (((dstaddr ^ my_ipaddr) & netmask) == 0)
{
type= ((dstaddr == (my_ipaddr | ~netmask) &&
(ip_port->ip_flags & IPF_SUBNET_BCAST)) ?
IP_LT_BROADCAST : IP_LT_NORMAL);
r= (*ip_port->ip_dev_send)(ip_port, dstaddr, data, type);
return r;
}
r= oroute_frag (ip_port - ip_port_table, dstaddr, ttl, req_mtu,
&nexthop);
if (r == NW_OK)
{
if (nexthop == ip_port->ip_ipaddr)
{
data->acc_ext_link= NULL;
if (ip_port->ip_loopb_head == NULL)
{
ip_port->ip_loopb_head= data;
arg.ev_ptr= ip_port;
ev_enqueue(&ip_port->ip_loopb_event,
ip_process_loopb, arg);
}
else
ip_port->ip_loopb_tail->acc_ext_link= data;
ip_port->ip_loopb_tail= data;
}
else
{
r= (*ip_port->ip_dev_send)(ip_port,
nexthop, data, IP_LT_NORMAL);
}
}
else
{
DBLOCK(0x10, printf("got error %d\n", r));
bf_afree(data);
}
return r;
}
PUBLIC void ip_hdr_chksum(ip_hdr, ip_hdr_len)
ip_hdr_t *ip_hdr;
int ip_hdr_len;
{
ip_hdr->ih_hdr_chk= 0;
ip_hdr->ih_hdr_chk= ~oneC_sum (0, (u16_t *)ip_hdr, ip_hdr_len);
}
PUBLIC acc_t *ip_split_pack (ip_port, ref_last, mtu)
ip_port_t *ip_port;
acc_t **ref_last;
int mtu;
{
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 data_len, max_data_len, nfrags, new_first_data_len;
int first_opt_size, second_opt_size;
acc_t *first_pack, *second_pack, *tmp_pack;
u8_t *first_optptr, *second_optptr;
int i, optlen;
first_pack= *ref_last;
*ref_last= 0;
second_pack= 0;
first_pack= bf_align(first_pack, IP_MIN_HDR_SIZE, 4);
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);
first_hdr_len= (first_hdr->ih_vers_ihl & IH_IHL_MASK) * 4;
if (first_hdr_len>IP_MIN_HDR_SIZE)
{
first_pack= bf_packIffLess(first_pack, first_hdr_len);
first_hdr= (ip_hdr_t *)ptr2acc_data(first_pack);
}
pack_siz= bf_bufsize(first_pack);
assert(pack_siz > mtu);
assert (!(first_hdr->ih_flags_fragoff & HTONS(IH_DONT_FRAG)));
if (first_pack->acc_linkC != 1 ||
first_pack->acc_buffer->buf_linkC != 1)
{
/* Get a private copy of the IP header */
tmp_pack= bf_memreq(first_hdr_len);
memcpy(ptr2acc_data(tmp_pack), first_hdr, first_hdr_len);
first_pack= bf_delhead(first_pack, first_hdr_len);
tmp_pack->acc_next= first_pack;
first_pack= tmp_pack; tmp_pack= NULL;
first_hdr= (ip_hdr_t *)ptr2acc_data(first_pack);
}
data_len= ntohs(first_hdr->ih_length) - first_hdr_len;
/* Try to split the packet evenly. */
assert(mtu > first_hdr_len);
max_data_len= mtu-first_hdr_len;
nfrags= (data_len/max_data_len)+1;
new_first_data_len= data_len/nfrags;
if (new_first_data_len < 8)
{
/* Special case for extremely small MTUs */
new_first_data_len= 8;
}
new_first_data_len &= ~7; /* data goes in 8 byte chuncks */
assert(new_first_data_len >= 8);
assert(new_first_data_len+first_hdr_len <= mtu);
second_data_len= 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;
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;
assert(first_pack->acc_linkC == 1);
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)));
ip_hdr_chksum(first_hdr, first_hdr_len);
if (second_data_len+second_hdr_len <= mtu)
{
/* second_pack will not be split any further, so we have to
* calculate the header checksum.
*/
ip_hdr_chksum(second_hdr, second_hdr_len);
}
*ref_last= second_pack;
return first_pack;
}
PRIVATE void error_reply (ip_fd, error)
ip_fd_t *ip_fd;
int error;
{
if ((*ip_fd->if_get_userdata)(ip_fd->if_srfd, (size_t)error,
(size_t)0, FALSE))
{
ip_panic(( "can't error_reply" ));
}
}
/*
* $PchId: ip_write.c,v 1.22 2004/08/03 11:11:04 philip Exp $
*/