udp.c

minix3的源代码

/*
udp.c

Copyright 1995 Philip Homburg
*/

#include "inet.h"
#include "type.h"

#include "assert.h"
#include "buf.h"
#include "clock.h"
#include "icmp_lib.h"
#include "io.h"
#include "ip.h"
#include "sr.h"
#include "udp.h"
#include "udp_int.h"

THIS_FILE

FORWARD void read_ip_packets ARGS(( udp_port_t *udp_port ));
FORWARD void udp_buffree ARGS(( int priority ));
#ifdef BUF_CONSISTENCY_CHECK
FORWARD void udp_bufcheck ARGS(( void ));
#endif
FORWARD void udp_main ARGS(( udp_port_t *udp_port ));
FORWARD int udp_select ARGS(( int fd, unsigned operations ));
FORWARD acc_t *udp_get_data ARGS(( int fd, size_t offset, size_t count, 
	int for_ioctl ));
FORWARD int udp_put_data ARGS(( int fd, size_t offset, acc_t *data, 	
	int for_ioctl ));
FORWARD int udp_peek ARGS(( udp_fd_t * ));
FORWARD int udp_sel_read ARGS(( udp_fd_t * ));
FORWARD void udp_restart_write_port ARGS(( udp_port_t *udp_port ));
FORWARD void udp_ip_arrived ARGS(( int port, acc_t *pack, size_t pack_size ));
FORWARD void reply_thr_put ARGS(( udp_fd_t *udp_fd, int reply,
	int for_ioctl ));
FORWARD void reply_thr_get ARGS(( udp_fd_t *udp_fd, int reply,
	int for_ioctl ));
FORWARD int udp_setopt ARGS(( udp_fd_t *udp_fd ));
FORWARD udpport_t find_unused_port ARGS(( int fd ));
FORWARD int is_unused_port ARGS(( Udpport_t port ));
FORWARD int udp_packet2user ARGS(( udp_fd_t *udp_fd ));
FORWARD void restart_write_fd ARGS(( udp_fd_t *udp_fd ));
FORWARD u16_t pack_oneCsum ARGS(( acc_t *pack ));
FORWARD void udp_rd_enqueue ARGS(( udp_fd_t *udp_fd, acc_t *pack,
							clock_t exp_tim ));
FORWARD void hash_fd ARGS(( udp_fd_t *udp_fd ));
FORWARD void unhash_fd ARGS(( udp_fd_t *udp_fd ));

PUBLIC udp_port_t *udp_port_table;
PUBLIC udp_fd_t udp_fd_table[UDP_FD_NR];

PUBLIC void udp_prep()
{
	udp_port_table= alloc(udp_conf_nr * sizeof(udp_port_table[0]));
}

PUBLIC void udp_init()
{
	udp_fd_t *udp_fd;
	udp_port_t *udp_port;
	int i, j, ifno;

	assert (BUF_S >= sizeof(struct nwio_ipopt));
	assert (BUF_S >= sizeof(struct nwio_ipconf));
	assert (BUF_S >= sizeof(struct nwio_udpopt));
	assert (BUF_S >= sizeof(struct udp_io_hdr));
	assert (UDP_HDR_SIZE == sizeof(udp_hdr_t));
	assert (UDP_IO_HDR_SIZE == sizeof(udp_io_hdr_t));

	for (i= 0, udp_fd= udp_fd_table; i<UDP_FD_NR; i++, udp_fd++)
	{
		udp_fd->uf_flags= UFF_EMPTY;
		udp_fd->uf_rdbuf_head= NULL;
	}

#ifndef BUF_CONSISTENCY_CHECK
	bf_logon(udp_buffree);
#else
	bf_logon(udp_buffree, udp_bufcheck);
#endif

	for (i= 0, udp_port= udp_port_table; i<udp_conf_nr; i++, udp_port++)
	{
		udp_port->up_ipdev= udp_conf[i].uc_port;

		udp_port->up_flags= UPF_EMPTY;
		udp_port->up_state= UPS_EMPTY;
		udp_port->up_next_fd= udp_fd_table;
		udp_port->up_write_fd= NULL;
		udp_port->up_wr_pack= NULL;
		udp_port->up_port_any= NULL;
		for (j= 0; j<UDP_PORT_HASH_NR; j++)
			udp_port->up_port_hash[j]= NULL;

		ifno= ip_conf[udp_port->up_ipdev].ic_ifno;
		sr_add_minor(if2minor(ifno, UDP_DEV_OFF),
			i, udp_open, udp_close, udp_read,
			udp_write, udp_ioctl, udp_cancel, udp_select);

		udp_main(udp_port);
	}
}

PUBLIC int udp_open (port, srfd, get_userdata, put_userdata, put_pkt,
	select_res)
int port;
int srfd;
get_userdata_t get_userdata;
put_userdata_t put_userdata;
put_pkt_t put_pkt;
select_res_t select_res;
{
	int i;
	udp_fd_t *udp_fd;

	for (i= 0; i<UDP_FD_NR && (udp_fd_table[i].uf_flags & UFF_INUSE);
		i++);

	if (i>= UDP_FD_NR)
	{
		DBLOCK(1, printf("out of fds\n"));
		return EAGAIN;
	}

	udp_fd= &udp_fd_table[i];

	udp_fd->uf_flags= UFF_INUSE;
	udp_fd->uf_port= &udp_port_table[port];
	udp_fd->uf_srfd= srfd;
	udp_fd->uf_udpopt.nwuo_flags= UDP_DEF_OPT;
	udp_fd->uf_get_userdata= get_userdata;
	udp_fd->uf_put_userdata= put_userdata;
	udp_fd->uf_select_res= select_res;
	assert(udp_fd->uf_rdbuf_head == NULL);
	udp_fd->uf_port_next= NULL;

	return i;

}

PUBLIC int udp_ioctl (fd, req)
int fd;
ioreq_t req;
{
	udp_fd_t *udp_fd;
	udp_port_t *udp_port;
	nwio_udpopt_t *udp_opt;
	acc_t *opt_acc;
	int result;

	udp_fd= &udp_fd_table[fd];

assert (udp_fd->uf_flags & UFF_INUSE);

	udp_port= udp_fd->uf_port;
	udp_fd->uf_flags |= UFF_IOCTL_IP;
	udp_fd->uf_ioreq= req;

	if (udp_port->up_state != UPS_MAIN)
		return NW_SUSPEND;

	switch(req)
	{
	case NWIOSUDPOPT:
		result= udp_setopt(udp_fd);
		break;
	case NWIOGUDPOPT:
		opt_acc= bf_memreq(sizeof(*udp_opt));
assert (opt_acc->acc_length == sizeof(*udp_opt));
		udp_opt= (nwio_udpopt_t *)ptr2acc_data(opt_acc);

		*udp_opt= udp_fd->uf_udpopt;
		udp_opt->nwuo_locaddr= udp_fd->uf_port->up_ipaddr;
		result= (*udp_fd->uf_put_userdata)(udp_fd->uf_srfd, 0, opt_acc,
			TRUE);
		if (result == NW_OK)
			reply_thr_put(udp_fd, NW_OK, TRUE);
		break;
	case NWIOUDPPEEK:
		result= udp_peek(udp_fd);
		break;
	default:
		reply_thr_get(udp_fd, EBADIOCTL, TRUE);
		result= NW_OK;
		break;
	}
	if (result != NW_SUSPEND)
		udp_fd->uf_flags &= ~UFF_IOCTL_IP;
	return result;
}

PUBLIC int udp_read (fd, count)
int fd;
size_t count;
{
	udp_fd_t *udp_fd;
	acc_t *tmp_acc, *next_acc;

	udp_fd= &udp_fd_table[fd];
	if (!(udp_fd->uf_flags & UFF_OPTSET))
	{
		reply_thr_put(udp_fd, EBADMODE, FALSE);
		return NW_OK;
	}

	udp_fd->uf_rd_count= count;

	if (udp_fd->uf_rdbuf_head)
	{
		if (get_time() <= udp_fd->uf_exp_tim)
			return udp_packet2user (udp_fd);
		tmp_acc= udp_fd->uf_rdbuf_head;
		while (tmp_acc)
		{
			next_acc= tmp_acc->acc_ext_link;
			bf_afree(tmp_acc);
			tmp_acc= next_acc;
		}
		udp_fd->uf_rdbuf_head= NULL;
	}
	udp_fd->uf_flags |= UFF_READ_IP;
	return NW_SUSPEND;
}

PRIVATE void udp_main(udp_port)
udp_port_t *udp_port;
{
	udp_fd_t *udp_fd;
	int result, i;

	switch (udp_port->up_state)
	{
	case UPS_EMPTY:
		udp_port->up_state= UPS_SETPROTO;

		udp_port->up_ipfd= ip_open(udp_port->up_ipdev, 
			udp_port->up_ipdev, udp_get_data, udp_put_data,
			udp_ip_arrived, 0 /* no select_res */);
		if (udp_port->up_ipfd < 0)
		{
			udp_port->up_state= UPS_ERROR;
			DBLOCK(1, printf("%s, %d: unable to open ip port\n",
				__FILE__, __LINE__));
			return;
		}

		result= ip_ioctl(udp_port->up_ipfd, NWIOSIPOPT);
		if (result == NW_SUSPEND)
			udp_port->up_flags |= UPF_SUSPEND;
		if (result<0)
		{
			return;
		}
		if (udp_port->up_state != UPS_GETCONF)
			return;
		/* drops through */
	case UPS_GETCONF:
		udp_port->up_flags &= ~UPF_SUSPEND;

		result= ip_ioctl(udp_port->up_ipfd, NWIOGIPCONF);
		if (result == NW_SUSPEND)
			udp_port->up_flags |= UPF_SUSPEND;
		if (result<0)
		{
			return;
		}
		if (udp_port->up_state != UPS_MAIN)
			return;
		/* drops through */
	case UPS_MAIN:
		udp_port->up_flags &= ~UPF_SUSPEND;

		for (i= 0, udp_fd= udp_fd_table; i<UDP_FD_NR; i++, udp_fd++)
		{
			if (!(udp_fd->uf_flags & UFF_INUSE))
				continue;
			if (udp_fd->uf_port != udp_port)
				continue;
			if (udp_fd->uf_flags & UFF_IOCTL_IP)
				udp_ioctl(i, udp_fd->uf_ioreq);
		}
		read_ip_packets(udp_port);
		return;
	default:
		DBLOCK(1, printf("udp_port_table[%d].up_state= %d\n",
			udp_port->up_ipdev, udp_port->up_state));
		ip_panic(( "unknown state" ));
		break;
	}
}

PRIVATE int udp_select(fd, operations)
int fd;
unsigned operations;
{
	int i;
	unsigned resops;
	udp_fd_t *udp_fd;

	udp_fd= &udp_fd_table[fd];
	assert (udp_fd->uf_flags & UFF_INUSE);

	resops= 0;

	if (operations & SR_SELECT_READ)
	{
		if (udp_sel_read(udp_fd))
			resops |= SR_SELECT_READ;
		else if (!(operations & SR_SELECT_POLL))
			udp_fd->uf_flags |= UFF_SEL_READ;
	}
	if (operations & SR_SELECT_WRITE)
	{
		/* Should handle special case when the interface is down */
		resops |= SR_SELECT_WRITE;
	}
	if (operations & SR_SELECT_EXCEPTION)
	{
		printf("udp_select: not implemented for exceptions\n");
	}
	return resops;
}

PRIVATE acc_t *udp_get_data (port, offset, count, for_ioctl)
int port;
size_t offset;
size_t count;
int for_ioctl;
{
	udp_port_t *udp_port;
	udp_fd_t *udp_fd;
	int result;

	udp_port= &udp_port_table[port];

	switch(udp_port->up_state)
	{
	case UPS_SETPROTO:
assert (for_ioctl);
		if (!count)
		{
			result= (int)offset;
			if (result<0)
			{
				udp_port->up_state= UPS_ERROR;
				break;
			}
			udp_port->up_state= UPS_GETCONF;
			if (udp_port->up_flags & UPF_SUSPEND)
				udp_main(udp_port);
			return NULL;
		}
		else
		{
			struct nwio_ipopt *ipopt;
			acc_t *acc;

assert (!offset);
assert (count == sizeof(*ipopt));

			acc= bf_memreq(sizeof(*ipopt));
			ipopt= (struct nwio_ipopt *)ptr2acc_data(acc);
			ipopt->nwio_flags= NWIO_COPY | NWIO_EN_LOC | 
				NWIO_EN_BROAD | NWIO_REMANY | NWIO_PROTOSPEC |
				NWIO_HDR_O_ANY | NWIO_RWDATALL;
			ipopt->nwio_proto= IPPROTO_UDP;
			return acc;
		}
	case UPS_MAIN:
assert (!for_ioctl);
assert (udp_port->up_flags & UPF_WRITE_IP);
		if (!count)
		{
			result= (int)offset;
assert (udp_port->up_wr_pack);
			bf_afree(udp_port->up_wr_pack);
			udp_port->up_wr_pack= 0;
			if (udp_port->up_flags & UPF_WRITE_SP)
			{
				if (udp_port->up_write_fd)
				{
					udp_fd= udp_port->up_write_fd;
					udp_port->up_write_fd= NULL;
					udp_fd->uf_flags &= ~UFF_WRITE_IP;
					reply_thr_get(udp_fd, result, FALSE);
				}
				udp_port->up_flags &= ~(UPF_WRITE_SP | 
					UPF_WRITE_IP);
				if (udp_port->up_flags & UPF_MORE2WRITE)
				{
					udp_restart_write_port(udp_port);
				}
			}
			else
				udp_port->up_flags &= ~UPF_WRITE_IP;
		}
		else
		{
			return bf_cut (udp_port->up_wr_pack, offset, count);
		}
		break;
	default:
		printf("udp_get_data(%d, 0x%x, 0x%x) called but up_state= 0x%x\n",
			port, offset, count, udp_port->up_state);
		break;
	}
	return NULL;
}

PRIVATE int udp_put_data (fd, offset, data, for_ioctl)
int fd;
size_t offset;
acc_t *data;
int for_ioctl;
{
	udp_port_t *udp_port;
	int result;

	udp_port= &udp_port_table[fd];

	switch (udp_port->up_state)
	{
	case UPS_GETCONF:
		if (!data)
		{
			result= (int)offset;
			if (result<0)
			{
				udp_port->up_state= UPS_ERROR;
				return NW_OK;
			}
			udp_port->up_state= UPS_MAIN;
			if (udp_port->up_flags & UPF_SUSPEND)
				udp_main(udp_port);
		}
		else
		{
			struct nwio_ipconf *ipconf;

			data= bf_packIffLess(data, sizeof(*ipconf));
			ipconf= (struct nwio_ipconf *)ptr2acc_data(data);
assert (ipconf->nwic_flags & NWIC_IPADDR_SET);
			udp_port->up_ipaddr= ipconf->nwic_ipaddr;
			bf_afree(data);
		}
		break;
	case UPS_MAIN:
		assert(0);

		assert (udp_port->up_flags & UPF_READ_IP);
		if (!data)
		{
			result= (int)offset;
			compare (result, >=, 0);
			if (udp_port->up_flags & UPF_READ_SP)
			{
				udp_port->up_flags &= ~(UPF_READ_SP|
					UPF_READ_IP);
				read_ip_packets(udp_port);
			}
			else
				udp_port->up_flags &= ~UPF_READ_IP;
		}
		else
		{
assert (!offset);	/* This isn't a valid assertion but ip sends only
			 * whole datagrams up */
			udp_ip_arrived(fd, data, bf_bufsize(data));
		}
		break;
	default:
		ip_panic((
		"udp_put_data(%d, 0x%x, %p) called but up_state= 0x%x\n",
					fd, offset, data, udp_port->up_state ));
	}
	return NW_OK;
}

PRIVATE int udp_setopt(udp_fd)
udp_fd_t *udp_fd;
{
	udp_fd_t *fd_ptr;
	nwio_udpopt_t oldopt, newopt;
	acc_t *data;
	unsigned int new_en_flags, new_di_flags, old_en_flags, old_di_flags,
		all_flags, flags;
	unsigned long new_flags;
	int i;

	data= (*udp_fd->uf_get_userdata)(udp_fd->uf_srfd, 0, 
		sizeof(nwio_udpopt_t), TRUE);

	if (!data)
		return EFAULT;

	data= bf_packIffLess(data, sizeof(nwio_udpopt_t));
assert (data->acc_length == sizeof(nwio_udpopt_t));

	newopt= *(nwio_udpopt_t *)ptr2acc_data(data);
	bf_afree(data);
	oldopt= udp_fd->uf_udpopt;

	old_en_flags= oldopt.nwuo_flags & 0xffff;
	old_di_flags= (oldopt.nwuo_flags >> 16) & 0xffff;

	new_en_flags= newopt.nwuo_flags & 0xffff;
	new_di_flags= (newopt.nwuo_flags >> 16) & 0xffff;

	if (new_en_flags & new_di_flags)
	{
		DBLOCK(1, printf("returning EBADMODE\n"));

		reply_thr_get(udp_fd, EBADMODE, TRUE);
		return NW_OK;
	}

	/* NWUO_ACC_MASK */
	if (new_di_flags & NWUO_ACC_MASK)
	{
		DBLOCK(1, printf("returning EBADMODE\n"));

		reply_thr_get(udp_fd, EBADMODE, TRUE);
		return NW_OK;
		/* access modes can't be disabled */
	}

	if (!(new_en_flags & NWUO_ACC_MASK))
		new_en_flags |= (old_en_flags & NWUO_ACC_MASK);

	/* NWUO_LOCPORT_MASK */
	if (new_di_flags & NWUO_LOCPORT_MASK)
	{
		DBLOCK(1, printf("returning EBADMODE\n"));

		reply_thr_get(udp_fd, EBADMODE, TRUE);
		return NW_OK;
		/* the loc ports can't be disabled */
	}
	if (!(new_en_flags & NWUO_LOCPORT_MASK))
	{
		new_en_flags |= (old_en_flags & NWUO_LOCPORT_MASK);
		newopt.nwuo_locport= oldopt.nwuo_locport;
	}
	else if ((new_en_flags & NWUO_LOCPORT_MASK) == NWUO_LP_SEL)
	{
		newopt.nwuo_locport= find_unused_port(udp_fd-udp_fd_table);
	}
	else if ((new_en_flags & NWUO_LOCPORT_MASK) == NWUO_LP_SET)
	{
		if (!newopt.nwuo_locport)
		{
			DBLOCK(1, printf("returning EBADMODE\n"));

			reply_thr_get(udp_fd, EBADMODE, TRUE);
			return NW_OK;
		}