minix3/net/inet/generic/ip_eth.c

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2020-02-21 00:59:27 +05:30
/*
generic/ip_eth.c
Ethernet specific part of the IP implementation
Created: Apr 22, 1993 by Philip Homburg
Copyright 1995 Philip Homburg
*/
#include "inet.h"
#include "type.h"
#include "arp.h"
#include "assert.h"
#include "buf.h"
#include "clock.h"
#include "eth.h"
#include "event.h"
#include "icmp_lib.h"
#include "io.h"
#include "ip.h"
#include "ip_int.h"
THIS_FILE
typedef struct xmit_hdr
{
time_t xh_time;
ipaddr_t xh_ipaddr;
} xmit_hdr_t;
static ether_addr_t broadcast_ethaddr=
{
{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }
};
static ether_addr_t ipmulticast_ethaddr=
{
{ 0x01, 0x00, 0x5e, 0x00, 0x00, 0x00 }
};
static void do_eth_read ARGS(( ip_port_t *port ));
static acc_t *get_eth_data ARGS(( int fd, size_t offset,
size_t count, int for_ioctl ));
static int put_eth_data ARGS(( int fd, size_t offset,
acc_t *data, int for_ioctl ));
static void ipeth_main ARGS(( ip_port_t *port ));
static void ipeth_set_ipaddr ARGS(( ip_port_t *port ));
static void ipeth_restart_send ARGS(( ip_port_t *ip_port ));
static int ipeth_send ARGS(( struct ip_port *ip_port, ipaddr_t dest,
acc_t *pack, int type ));
static void ipeth_arp_reply ARGS(( int ip_port_nr, ipaddr_t ipaddr,
ether_addr_t *dst_ether_ptr ));
static int ipeth_update_ttl ARGS(( time_t enq_time, time_t now,
acc_t *eth_pack ));
static void ip_eth_arrived ARGS(( int port, acc_t *pack,
size_t pack_size ));
int ipeth_init(ip_port)
ip_port_t *ip_port;
{
assert(BUF_S >= sizeof(xmit_hdr_t));
assert(BUF_S >= sizeof(eth_hdr_t));
ip_port->ip_dl.dl_eth.de_fd= eth_open(ip_port->
ip_dl.dl_eth.de_port, ip_port->ip_port,
get_eth_data, put_eth_data, ip_eth_arrived,
0 /* no select_res */);
if (ip_port->ip_dl.dl_eth.de_fd < 0)
{
DBLOCK(1, printf("ip.c: unable to open eth port\n"));
return -1;
}
ip_port->ip_dl.dl_eth.de_state= IES_EMPTY;
ip_port->ip_dl.dl_eth.de_flags= IEF_EMPTY;
ip_port->ip_dl.dl_eth.de_q_head= NULL;
ip_port->ip_dl.dl_eth.de_q_tail= NULL;
ip_port->ip_dl.dl_eth.de_arp_head= NULL;
ip_port->ip_dl.dl_eth.de_arp_tail= NULL;
ip_port->ip_dev_main= ipeth_main;
ip_port->ip_dev_set_ipaddr= ipeth_set_ipaddr;
ip_port->ip_dev_send= ipeth_send;
ip_port->ip_mtu= ETH_MAX_PACK_SIZE-ETH_HDR_SIZE;
ip_port->ip_mtu_max= ip_port->ip_mtu;
return 0;
}
static void ipeth_main(ip_port)
ip_port_t *ip_port;
{
int result;
switch (ip_port->ip_dl.dl_eth.de_state)
{
case IES_EMPTY:
ip_port->ip_dl.dl_eth.de_state= IES_SETPROTO;
result= eth_ioctl(ip_port->ip_dl.dl_eth.de_fd, NWIOSETHOPT);
if (result == NW_SUSPEND)
ip_port->ip_dl.dl_eth.de_flags |= IEF_SUSPEND;
if (result<0)
{
DBLOCK(1, printf("eth_ioctl(..,0x%lx)=%d\n",
(unsigned long)NWIOSETHOPT, result));
return;
}
if (ip_port->ip_dl.dl_eth.de_state != IES_SETPROTO)
return;
/* drops through */
case IES_SETPROTO:
result= arp_set_cb(ip_port->ip_dl.dl_eth.de_port,
ip_port->ip_port,
ipeth_arp_reply);
if (result != NW_OK)
{
printf("ipeth_main: arp_set_cb failed: %d\n",
result);
return;
}
/* Wait until the interface is configured up. */
ip_port->ip_dl.dl_eth.de_state= IES_GETIPADDR;
if (!(ip_port->ip_flags & IPF_IPADDRSET))
{
ip_port->ip_dl.dl_eth.de_flags |= IEF_SUSPEND;
return;
}
/* fall through */
case IES_GETIPADDR:
ip_port->ip_dl.dl_eth.de_state= IES_MAIN;
do_eth_read(ip_port);
return;
default:
ip_panic(( "unknown state: %d",
ip_port->ip_dl.dl_eth.de_state));
}
}
static acc_t *get_eth_data (fd, offset, count, for_ioctl)
int fd;
size_t offset;
size_t count;
int for_ioctl;
{
ip_port_t *ip_port;
acc_t *data;
int result;
ip_port= &ip_port_table[fd];
switch (ip_port->ip_dl.dl_eth.de_state)
{
case IES_SETPROTO:
if (!count)
{
result= (int)offset;
if (result<0)
{
ip_port->ip_dl.dl_eth.de_state= IES_ERROR;
break;
}
if (ip_port->ip_dl.dl_eth.de_flags & IEF_SUSPEND)
ipeth_main(ip_port);
return NW_OK;
}
assert ((!offset) && (count == sizeof(struct nwio_ethopt)));
{
struct nwio_ethopt *ethopt;
acc_t *acc;
acc= bf_memreq(sizeof(*ethopt));
ethopt= (struct nwio_ethopt *)ptr2acc_data(acc);
ethopt->nweo_flags= NWEO_COPY|NWEO_EN_BROAD|
NWEO_EN_MULTI|NWEO_TYPESPEC;
ethopt->nweo_type= HTONS(ETH_IP_PROTO);
return acc;
}
case IES_MAIN:
if (!count)
{
result= (int)offset;
if (result<0)
ip_warning(( "error on write: %d\n", result ));
bf_afree (ip_port->ip_dl.dl_eth.de_frame);
ip_port->ip_dl.dl_eth.de_frame= 0;
if (ip_port->ip_dl.dl_eth.de_flags & IEF_WRITE_SP)
{
ip_port->ip_dl.dl_eth.de_flags &=
~IEF_WRITE_SP;
ipeth_restart_send(ip_port);
}
return NW_OK;
}
data= bf_cut (ip_port->ip_dl.dl_eth.de_frame, offset, count);
assert (data);
return data;
default:
printf(
"get_eth_data(%d, 0x%d, 0x%d) called but ip_state=0x%x\n",
fd, offset, count, ip_port->ip_dl.dl_eth.de_state);
break;
}
return 0;
}
static int put_eth_data (port, offset, data, for_ioctl)
int port;
size_t offset;
acc_t *data;
int for_ioctl;
{
ip_port_t *ip_port;
int result;
ip_port= &ip_port_table[port];
assert(0);
if (ip_port->ip_dl.dl_eth.de_flags & IEF_READ_IP)
{
if (!data)
{
result= (int)offset;
if (result<0)
{
DBLOCK(1, printf(
"ip.c: put_eth_data(..,%d,..)\n", result));
return NW_OK;
}
if (ip_port->ip_dl.dl_eth.de_flags & IEF_READ_SP)
{
ip_port->ip_dl.dl_eth.de_flags &=
~(IEF_READ_IP|IEF_READ_SP);
do_eth_read(ip_port);
}
else
ip_port->ip_dl.dl_eth.de_flags &= ~IEF_READ_IP;
return NW_OK;
}
assert (!offset);
/* Warning: the above assertion is illegal; puts and
gets of data can be brokenup in any piece the server
likes. However we assume that the server is eth.c
and it transfers only whole packets. */
ip_eth_arrived(port, data, bf_bufsize(data));
return NW_OK;
}
printf("ip_port->ip_dl.dl_eth.de_state= 0x%x",
ip_port->ip_dl.dl_eth.de_state);
ip_panic (( "strange status" ));
return -1;
}
static void ipeth_set_ipaddr(ip_port)
ip_port_t *ip_port;
{
arp_set_ipaddr (ip_port->ip_dl.dl_eth.de_port, ip_port->ip_ipaddr);
if (ip_port->ip_dl.dl_eth.de_state == IES_GETIPADDR)
ipeth_main(ip_port);
}
static int ipeth_send(ip_port, dest, pack, type)
struct ip_port *ip_port;
ipaddr_t dest;
acc_t *pack;
int type;
{
int i, r;
acc_t *eth_pack, *tail;
size_t pack_size;
eth_hdr_t *eth_hdr;
xmit_hdr_t *xmit_hdr;
ipaddr_t tmpaddr;
time_t t;
u32_t *p;
/* Start optimistic: the arp will succeed without blocking and the
* ethernet packet can be sent without blocking also. Start with
* the allocation of the ethernet header.
*/
eth_pack= bf_memreq(sizeof(*eth_hdr));
assert(eth_pack->acc_next == NULL);
eth_pack->acc_next= pack;
pack_size= bf_bufsize(eth_pack);
if (pack_size<ETH_MIN_PACK_SIZE)
{
tail= bf_memreq(ETH_MIN_PACK_SIZE-pack_size);
/* Clear padding */
for (i= (ETH_MIN_PACK_SIZE-pack_size)/sizeof(*p),
p= (u32_t *)ptr2acc_data(tail);
i >= 0; i--, p++)
{
*p= 0xdeadbeef;
}
eth_pack= bf_append(eth_pack, tail);
}
eth_hdr= (eth_hdr_t *)ptr2acc_data(eth_pack);
/* Lookup the ethernet address */
if (type != IP_LT_NORMAL)
{
if (type == IP_LT_BROADCAST)
eth_hdr->eh_dst= broadcast_ethaddr;
else
{
tmpaddr= ntohl(dest);
eth_hdr->eh_dst= ipmulticast_ethaddr;
eth_hdr->eh_dst.ea_addr[5]= tmpaddr & 0xff;
eth_hdr->eh_dst.ea_addr[4]= (tmpaddr >> 8) & 0xff;
eth_hdr->eh_dst.ea_addr[3]= (tmpaddr >> 16) & 0x7f;
}
}
else
{
if ((dest ^ ip_port->ip_ipaddr) & ip_port->ip_subnetmask)
{
ip_panic(( "invalid destination" ));
}
assert(dest != ip_port->ip_ipaddr);
r= arp_ip_eth(ip_port->ip_dl.dl_eth.de_port,
dest, &eth_hdr->eh_dst);
if (r == NW_SUSPEND)
{
/* Unfortunately, the arp takes some time, use
* the ethernet header to store the next hop
* ip address and the current time.
*/
xmit_hdr= (xmit_hdr_t *)eth_hdr;
xmit_hdr->xh_time= get_time();
xmit_hdr->xh_ipaddr= dest;
eth_pack->acc_ext_link= NULL;
if (ip_port->ip_dl.dl_eth.de_arp_head == NULL)
ip_port->ip_dl.dl_eth.de_arp_head= eth_pack;
else
{
ip_port->ip_dl.dl_eth.de_arp_tail->
acc_ext_link= eth_pack;
}
ip_port->ip_dl.dl_eth.de_arp_tail= eth_pack;
return NW_OK;
}
if (r == EHOSTUNREACH)
{
bf_afree(eth_pack);
return r;
}
assert(r == NW_OK);
}
/* If we have no write in progress, we can try to send the ethernet
* packet using eth_send. If the IP packet is larger than mtu,
* enqueue the packet and let ipeth_restart_send deal with it.
*/
pack_size= bf_bufsize(eth_pack);
if (ip_port->ip_dl.dl_eth.de_frame == NULL && pack_size <=
ip_port->ip_mtu + sizeof(*eth_hdr))
{
r= eth_send(ip_port->ip_dl.dl_eth.de_fd,
eth_pack, pack_size);
if (r == NW_OK)
return NW_OK;
/* A non-blocking send is not possible, start a regular
* send.
*/
assert(r == NW_WOULDBLOCK);
ip_port->ip_dl.dl_eth.de_frame= eth_pack;
r= eth_write(ip_port->ip_dl.dl_eth.de_fd, pack_size);
if (r == NW_SUSPEND)
{
assert(!(ip_port->ip_dl.dl_eth.de_flags &
IEF_WRITE_SP));
ip_port->ip_dl.dl_eth.de_flags |= IEF_WRITE_SP;
}
assert(r == NW_OK || r == NW_SUSPEND);
return NW_OK;
}
/* Enqueue the packet, and store the current time, in the
* space for the ethernet source address.
*/
t= get_time();
assert(sizeof(t) <= sizeof(eth_hdr->eh_src));
memcpy(&eth_hdr->eh_src, &t, sizeof(t));
eth_pack->acc_ext_link= NULL;
if (ip_port->ip_dl.dl_eth.de_q_head == NULL)
ip_port->ip_dl.dl_eth.de_q_head= eth_pack;
else
{
ip_port->ip_dl.dl_eth.de_q_tail->acc_ext_link= eth_pack;
}
ip_port->ip_dl.dl_eth.de_q_tail= eth_pack;
if (ip_port->ip_dl.dl_eth.de_frame == NULL)
ipeth_restart_send(ip_port);
return NW_OK;
}
static void ipeth_restart_send(ip_port)
ip_port_t *ip_port;
{
time_t now, enq_time;
int i, r;
acc_t *eth_pack, *ip_pack, *next_eth_pack, *next_part, *tail;
size_t pack_size;
eth_hdr_t *eth_hdr, *next_eth_hdr;
u32_t *p;
now= get_time();
while (ip_port->ip_dl.dl_eth.de_q_head != NULL)
{
eth_pack= ip_port->ip_dl.dl_eth.de_q_head;
ip_port->ip_dl.dl_eth.de_q_head= eth_pack->acc_ext_link;
eth_hdr= (eth_hdr_t *)ptr2acc_data(eth_pack);
pack_size= bf_bufsize(eth_pack);
if (pack_size > ip_port->ip_mtu+sizeof(*eth_hdr))
{
/* Split the IP packet */
assert(eth_pack->acc_linkC == 1);
ip_pack= eth_pack->acc_next; eth_pack->acc_next= NULL;
next_part= ip_pack; ip_pack= NULL;
ip_pack= ip_split_pack(ip_port, &next_part,
ip_port->ip_mtu);
if (ip_pack == NULL)
{
bf_afree(eth_pack);
continue;
}
eth_pack->acc_next= ip_pack; ip_pack= NULL;
/* Allocate new ethernet header */
next_eth_pack= bf_memreq(sizeof(*next_eth_hdr));
next_eth_hdr= (eth_hdr_t *)ptr2acc_data(next_eth_pack);
*next_eth_hdr= *eth_hdr;
next_eth_pack->acc_next= next_part;
next_eth_pack->acc_ext_link= NULL;
if (ip_port->ip_dl.dl_eth.de_q_head == NULL)
ip_port->ip_dl.dl_eth.de_q_head= next_eth_pack;
else
{
ip_port->ip_dl.dl_eth.de_q_tail->acc_ext_link=
next_eth_pack;
}
ip_port->ip_dl.dl_eth.de_q_tail= next_eth_pack;
pack_size= bf_bufsize(eth_pack);
}
memcpy(&enq_time, &eth_hdr->eh_src, sizeof(enq_time));
if (enq_time + HZ < now)
{
r= ipeth_update_ttl(enq_time, now, eth_pack);
if (r == ETIMEDOUT)
{
ip_pack= bf_delhead(eth_pack, sizeof(*eth_hdr));
eth_pack= NULL;
icmp_snd_time_exceeded(ip_port->ip_port,
ip_pack, ICMP_TTL_EXC);
continue;
}
assert(r == NW_OK);
}
if (pack_size<ETH_MIN_PACK_SIZE)
{
tail= bf_memreq(ETH_MIN_PACK_SIZE-pack_size);
/* Clear padding */
for (i= (ETH_MIN_PACK_SIZE-pack_size)/sizeof(*p),
p= (u32_t *)ptr2acc_data(tail);
i >= 0; i--, p++)
{
*p= 0xdeadbeef;
}
eth_pack= bf_append(eth_pack, tail);
pack_size= ETH_MIN_PACK_SIZE;
}
assert(ip_port->ip_dl.dl_eth.de_frame == NULL);
r= eth_send(ip_port->ip_dl.dl_eth.de_fd, eth_pack, pack_size);
if (r == NW_OK)
continue;
/* A non-blocking send is not possible, start a regular
* send.
*/
assert(r == NW_WOULDBLOCK);
ip_port->ip_dl.dl_eth.de_frame= eth_pack;
r= eth_write(ip_port->ip_dl.dl_eth.de_fd, pack_size);
if (r == NW_SUSPEND)
{
assert(!(ip_port->ip_dl.dl_eth.de_flags &
IEF_WRITE_SP));
ip_port->ip_dl.dl_eth.de_flags |= IEF_WRITE_SP;
return;
}
assert(r == NW_OK);
}
}
static void ipeth_arp_reply(ip_port_nr, ipaddr, eth_addr)
int ip_port_nr;
ipaddr_t ipaddr;
ether_addr_t *eth_addr;
{
acc_t *prev, *eth_pack;
int r;
xmit_hdr_t *xmit_hdr;
ip_port_t *ip_port;
time_t t;
eth_hdr_t *eth_hdr;
ether_addr_t tmp_eth_addr;
assert (ip_port_nr >= 0 && ip_port_nr < ip_conf_nr);
ip_port= &ip_port_table[ip_port_nr];
for (;;)
{
for (prev= 0, eth_pack= ip_port->ip_dl.dl_eth.de_arp_head;
eth_pack;
prev= eth_pack, eth_pack= eth_pack->acc_ext_link)
{
xmit_hdr= (xmit_hdr_t *)ptr2acc_data(eth_pack);
if (xmit_hdr->xh_ipaddr == ipaddr)
break;
}
if (eth_pack == NULL)
{
/* No packet found. */
break;
}
/* Delete packet from the queue. */
if (prev == NULL)
{
ip_port->ip_dl.dl_eth.de_arp_head=
eth_pack->acc_ext_link;
}
else
{
prev->acc_ext_link= eth_pack->acc_ext_link;
if (prev->acc_ext_link == NULL)
ip_port->ip_dl.dl_eth.de_arp_tail= prev;
}
if (eth_addr == NULL)
{
/* Destination is unreachable, delete packet. */
bf_afree(eth_pack);
continue;
}
/* Fill in the ethernet address and put the packet on the
* transmit queue.
*/
t= xmit_hdr->xh_time;
eth_hdr= (eth_hdr_t *)ptr2acc_data(eth_pack);
eth_hdr->eh_dst= *eth_addr;
memcpy(&eth_hdr->eh_src, &t, sizeof(t));
eth_pack->acc_ext_link= NULL;
if (ip_port->ip_dl.dl_eth.de_q_head == NULL)
ip_port->ip_dl.dl_eth.de_q_head= eth_pack;
else
{
ip_port->ip_dl.dl_eth.de_q_tail->acc_ext_link=
eth_pack;
}
ip_port->ip_dl.dl_eth.de_q_tail= eth_pack;
}
/* Try to get some more ARPs in progress. */
while (ip_port->ip_dl.dl_eth.de_arp_head)
{
eth_pack= ip_port->ip_dl.dl_eth.de_arp_head;
xmit_hdr= (xmit_hdr_t *)ptr2acc_data(eth_pack);
r= arp_ip_eth(ip_port->ip_dl.dl_eth.de_port,
xmit_hdr->xh_ipaddr, &tmp_eth_addr);
if (r == NW_SUSPEND)
break; /* Normal case */
/* Dequeue the packet */
ip_port->ip_dl.dl_eth.de_arp_head= eth_pack->acc_ext_link;
if (r == EHOSTUNREACH)
{
bf_afree(eth_pack);
continue;
}
assert(r == NW_OK);
/* Fill in the ethernet address and put the packet on the
* transmit queue.
*/
t= xmit_hdr->xh_time;
eth_hdr= (eth_hdr_t *)ptr2acc_data(eth_pack);
eth_hdr->eh_dst= tmp_eth_addr;
memcpy(&eth_hdr->eh_src, &t, sizeof(t));
eth_pack->acc_ext_link= NULL;
if (ip_port->ip_dl.dl_eth.de_q_head == NULL)
ip_port->ip_dl.dl_eth.de_q_head= eth_pack;
else
{
ip_port->ip_dl.dl_eth.de_q_tail->acc_ext_link=
eth_pack;
}
ip_port->ip_dl.dl_eth.de_q_tail= eth_pack;
}
/* Restart sending ethernet packets. */
if (ip_port->ip_dl.dl_eth.de_frame == NULL)
ipeth_restart_send(ip_port);
}
static int ipeth_update_ttl(enq_time, now, eth_pack)
time_t enq_time;
time_t now;
acc_t *eth_pack;
{
int ttl_diff;
ip_hdr_t *ip_hdr;
u32_t sum;
u16_t word;
acc_t *ip_pack;
ttl_diff= (now-enq_time)/HZ;
enq_time += ttl_diff*HZ;
assert(enq_time <= now && enq_time + HZ > now);
ip_pack= eth_pack->acc_next;
assert(ip_pack->acc_length >= sizeof(*ip_hdr));
assert(ip_pack->acc_linkC == 1 &&
ip_pack->acc_buffer->buf_linkC == 1);
ip_hdr= (ip_hdr_t *)ptr2acc_data(ip_pack);
if (ip_hdr->ih_ttl <= ttl_diff)
return ETIMEDOUT;
sum= (u16_t)~ip_hdr->ih_hdr_chk;
word= *(u16_t *)&ip_hdr->ih_ttl;
if (word > sum)
sum += 0xffff - word;
else
sum -= word;
ip_hdr->ih_ttl -= ttl_diff;
word= *(u16_t *)&ip_hdr->ih_ttl;
sum += word;
if (sum > 0xffff)
sum -= 0xffff;
assert(!(sum & 0xffff0000));
ip_hdr->ih_hdr_chk= ~sum;
assert(ip_hdr->ih_ttl > 0);
return NW_OK;
}
static void do_eth_read(ip_port)
ip_port_t *ip_port;
{
int result;
assert(!(ip_port->ip_dl.dl_eth.de_flags & IEF_READ_IP));
for (;;)
{
ip_port->ip_dl.dl_eth.de_flags |= IEF_READ_IP;
result= eth_read (ip_port->ip_dl.dl_eth.de_fd,
ETH_MAX_PACK_SIZE);
if (result == NW_SUSPEND)
{
assert(!(ip_port->ip_dl.dl_eth.de_flags &
IEF_READ_SP));
ip_port->ip_dl.dl_eth.de_flags |= IEF_READ_SP;
return;
}
ip_port->ip_dl.dl_eth.de_flags &= ~IEF_READ_IP;
if (result<0)
{
return;
}
}
}
static void ip_eth_arrived(port, pack, pack_size)
int port;
acc_t *pack;
size_t pack_size;
{
int broadcast;
ip_port_t *ip_port;
ip_port= &ip_port_table[port];
broadcast= (*(u8_t *)ptr2acc_data(pack) & 1);
pack= bf_delhead(pack, ETH_HDR_SIZE);
if (broadcast)
ip_arrived_broadcast(ip_port, pack);
else
ip_arrived(ip_port, pack);
}
/*
* $PchId: ip_eth.c,v 1.25 2005/06/28 14:18:10 philip Exp $
*/