daemon_user.c

Go to the documentation of this file.

/*
 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
 * Copyright (C) 2001 Lennert Buytenhek ([email protected]) and
 * James Leu ([email protected]).
 * Copyright (C) 2001 by various other people who didn't put their name here.
 * Licensed under the GPL.
 */

#include <stdint.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/un.h>
#include "daemon.h"
#include <net_user.h>
#include <os.h>
#include <um_malloc.h>

enum request_type { REQ_NEW_CONTROL };

#define SWITCH_MAGIC 0xfeedface

struct request_v3 {
    uint32_t magic;
    uint32_t version;
    enum request_type type;
    struct sockaddr_un sock;
};

static struct sockaddr_un *new_addr(void *name, int len)
{
    struct sockaddr_un *sun;

    sun = uml_kmalloc(sizeof(struct sockaddr_un), UM_GFP_KERNEL);
    if (sun == NULL) {
        printk(UM_KERN_ERR "new_addr: allocation of sockaddr_un "
               "failed\n");
        return NULL;
    }
    sun->sun_family = AF_UNIX;
    memcpy(sun->sun_path, name, len);
    return sun;
}

static int connect_to_switch(struct daemon_data *pri)
{
    struct sockaddr_un *ctl_addr = pri->ctl_addr;
    struct sockaddr_un *local_addr = pri->local_addr;
    struct sockaddr_un *sun;
    struct request_v3 req;
    int fd, n, err;

    pri->control = socket(AF_UNIX, SOCK_STREAM, 0);
    if (pri->control < 0) {
        err = -errno;
        printk(UM_KERN_ERR "daemon_open : control socket failed, "
               "errno = %d\n", -err);
        return err;
    }

    if (connect(pri->control, (struct sockaddr *) ctl_addr,
           sizeof(*ctl_addr)) < 0) {
        err = -errno;
        printk(UM_KERN_ERR "daemon_open : control connect failed, "
               "errno = %d\n", -err);
        goto out;
    }

    fd = socket(AF_UNIX, SOCK_DGRAM, 0);
    if (fd < 0) {
        err = -errno;
        printk(UM_KERN_ERR "daemon_open : data socket failed, "
               "errno = %d\n", -err);
        goto out;
    }
    if (bind(fd, (struct sockaddr *) local_addr, sizeof(*local_addr)) < 0) {
        err = -errno;
        printk(UM_KERN_ERR "daemon_open : data bind failed, "
               "errno = %d\n", -err);
        goto out_close;
    }

    sun = uml_kmalloc(sizeof(struct sockaddr_un), UM_GFP_KERNEL);
    if (sun == NULL) {
        printk(UM_KERN_ERR "new_addr: allocation of sockaddr_un "
               "failed\n");
        err = -ENOMEM;
        goto out_close;
    }

    req.magic = SWITCH_MAGIC;
    req.version = SWITCH_VERSION;
    req.type = REQ_NEW_CONTROL;
    req.sock = *local_addr;
    n = write(pri->control, &req, sizeof(req));
    if (n != sizeof(req)) {
        printk(UM_KERN_ERR "daemon_open : control setup request "
               "failed, err = %d\n", -errno);
        err = -ENOTCONN;
        goto out_free;
    }

    n = read(pri->control, sun, sizeof(*sun));
    if (n != sizeof(*sun)) {
        printk(UM_KERN_ERR "daemon_open : read of data socket failed, "
               "err = %d\n", -errno);
        err = -ENOTCONN;
        goto out_free;
    }

    pri->data_addr = sun;
    return fd;

 out_free:
    kfree(sun);
 out_close:
    close(fd);
 out:
    close(pri->control);
    return err;
}

static int daemon_user_init(void *data, void *dev)
{
    struct daemon_data *pri = data;
    struct timeval tv;
    struct {
        char zero;
        int pid;
        int usecs;
    } name;

    if (!strcmp(pri->sock_type, "unix"))
        pri->ctl_addr = new_addr(pri->ctl_sock,
                     strlen(pri->ctl_sock) + 1);
    name.zero = 0;
    name.pid = os_getpid();
    gettimeofday(&tv, NULL);
    name.usecs = tv.tv_usec;
    pri->local_addr = new_addr(&name, sizeof(name));
    pri->dev = dev;
    pri->fd = connect_to_switch(pri);
    if (pri->fd < 0) {
        kfree(pri->local_addr);
        pri->local_addr = NULL;
        return pri->fd;
    }

    return 0;
}

static int daemon_open(void *data)
{
    struct daemon_data *pri = data;
    return pri->fd;
}

static void daemon_remove(void *data)
{
    struct daemon_data *pri = data;

    close(pri->fd);
    pri->fd = -1;
    close(pri->control);
    pri->control = -1;

    kfree(pri->data_addr);
    pri->data_addr = NULL;
    kfree(pri->ctl_addr);
    pri->ctl_addr = NULL;
    kfree(pri->local_addr);
    pri->local_addr = NULL;
}

int daemon_user_write(int fd, void *buf, int len, struct daemon_data *pri)
{
    struct sockaddr_un *data_addr = pri->data_addr;

    return net_sendto(fd, buf, len, data_addr, sizeof(*data_addr));
}

const struct net_user_info daemon_user_info = {
    .init       = daemon_user_init,
    .open       = daemon_open,
    .close      = NULL,
    .remove     = daemon_remove,
    .add_address    = NULL,
    .delete_address = NULL,
    .mtu        = ETH_MAX_PACKET,
    .max_packet = ETH_MAX_PACKET + ETH_HEADER_OTHER,
};