control.c

实现linux平台下零拷贝技术的软件包。

/*
 * 	control.c
 * 
 * 2006 Copyright (c) Evgeniy Polyakov <[e-mail]>
 * All rights reserved.
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <sys/poll.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/ioctl.h>

#include <fcntl.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <ctype.h>

#include "include/linux/types.h"
#include "net/core/alloc/avl.h"

#include "control.h"

static int zc_mmap(struct zc_control *ctl, struct zc_status *st)
{
	struct zc_data *e;
	unsigned int entry_num = st->entry_num;
	int i;

	for (i=0; i<ZC_MAX_ENTRY_NUM; ++i) {
		struct zc_entry_status *ent = &st->entry[i];

		e = &ctl->e[i];

		if (e->data.ptr || !ent->node_num)
			continue;

		e->data.ptr = mmap(NULL, PAGE_SIZE*(1<<ent->node_order)*ent->node_num, PROT_READ|PROT_WRITE, MAP_SHARED, ctl->fd, ctl->offset*PAGE_SIZE);
		if (e->data.ptr == MAP_FAILED) {
			fprintf(stderr, "Failed to mmap: number: %u, order: %u, offset: %u, errno: %d - %s.\n", 
					ent->node_num, ent->node_order, ctl->offset, errno, strerror(errno));
			e->data.ptr = NULL;
			return -1;
		}

		printf("mmap: %2d.%2d: cpu: %d, ptr: %p, number: %u, order: %u, offset: %u.\n", 
				i, st->entry_num, ctl->cpu, e->data.ptr, ent->node_num, ent->node_order, ctl->offset);
		ctl->offset += (1<<ent->node_order)*ent->node_num;
		e->entry = i;

		if (--entry_num == 0)
			break;
	}

	return 0;
}

int zc_prepare(struct zc_control *ctl, unsigned int entry_num)
{
	struct zc_data *e;
	void *ptr;

	e = &ctl->e[entry_num]; 
	ptr = e->data.ptr;

	if (!ptr) {
		int err;
		struct zc_status st;

		memset(&st, 0, sizeof(struct zc_status));
		st.entry_num = 0;
		err = ioctl(ctl->fd, ZC_STATUS, &st);
		if (err) {
			fprintf(stderr, "Failed to get status for CPU%d: %s [%d].\n", 
					ctl->cpu, strerror(errno), errno);
			return err;
		}

		err = zc_mmap(ctl,  &st);
		if (err)
			return err;
	}

	return 0;
}

struct zc_control *zc_ctl_init(int nr_cpus, char *ctl_file)
{
	int i, err;
	struct zc_control *zc_ctl, *ctl;

	zc_ctl = malloc(nr_cpus * sizeof(struct zc_control));
	if (!zc_ctl) {
		fprintf(stderr, "Failed to allocate control structures for %d cpus.\n", nr_cpus);
		return NULL;
	}
	memset(zc_ctl, 0, nr_cpus * sizeof(struct zc_control));

	for (i=0; i<nr_cpus; ++i) {
		ctl = &zc_ctl[i];

		ctl->cpu = i;
		ctl->fd = open(ctl_file, O_RDWR);
		if (!ctl->fd) {
			fprintf(stderr, "Failed to open control file %s: %s [%d].\n", ctl_file, strerror(errno), errno);
			return NULL;
		}

		err = ioctl(ctl->fd, ZC_SET_CPU, &ctl->cpu);
		if (err) {
			close(ctl->fd);
			fprintf(stderr, "Failed to setup CPU%d.\n", ctl->cpu);
			return NULL;
		}
	}

	return zc_ctl;
}