/*
 * Copyright (c) 1997 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Gordon W. Ross.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Copyright 2018 OmniOS Community Edition (OmniOSce) Association.
 */

#include <sys/cdefs.h>

/*
 * This module implements a "raw device" interface suitable for
 * use by the stand-alone I/O library NFS code.  This interface
 * does not support any "block" access, and exists only for the
 * purpose of initializing the network interface, getting boot
 * parameters, and performing the NFS mount.
 *
 * At open time, this does:
 *
 * find interface      - netif_open()
 * RARP for IP address - rarp_getipaddress()
 * RPC/bootparams      - callrpc(d, RPC_BOOTPARAMS, ...)
 * RPC/mountd          - nfs_mount(sock, ip, path)
 *
 * the root file handle from mountd is saved in a global
 * for use by the NFS open code (NFS/lookup).
 */

#include <machine/stdarg.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>

#include <stand.h>
#include <stddef.h>
#include <string.h>
#include <net.h>
#include <netif.h>
#include <bootp.h>
#include <bootparam.h>

#include "dev_net.h"
#include "bootstrap.h"

#ifdef  NETIF_DEBUG
int debug = 0;
#endif

static char *netdev_name;
static int netdev_sock = -1;
static int netdev_opens;

static int      net_init(void);
static int      net_open(struct open_file *, ...);
static int      net_close(struct open_file *);
static void     net_cleanup(void);
static int      net_strategy(void *, int, daddr_t, size_t, char *, size_t *);
static int      net_print(int);

static int net_getparams(int sock);

struct devsw netdev = {
        "net",
        DEVT_NET,
        net_init,
        net_strategy,
        net_open,
        net_close,
        noioctl,
        net_print,
        net_cleanup
};

static struct uri_scheme {
        const char *scheme;
        int proto;
} uri_schemes[] = {
        { "tftp:/", NET_TFTP },
        { "nfs:/", NET_NFS },
};

static int
net_init(void)
{

        return (0);
}

/*
 * Called by devopen after it sets f->f_dev to our devsw entry.
 * This opens the low-level device and sets dev->d_opendata.
 * This is declared with variable arguments...
 */
static int
net_open(struct open_file *f, ...)
{
        struct iodesc *d;
        va_list args;
        struct devdesc *dev;
        const char *devname;    /* Device part of file name (or NULL). */
        int error = 0;

        va_start(args, f);
        dev = va_arg(args, struct devdesc *);
        va_end(args);

        devname = dev->d_dev->dv_name;
        /* Before opening another interface, close the previous one first. */
        if (netdev_sock >= 0 && strcmp(devname, netdev_name) != 0)
                net_cleanup();

        /* On first open, do netif open, mount, etc. */
        if (netdev_opens == 0) {
                /* Find network interface. */
                if (netdev_sock < 0) {
                        netdev_sock = netif_open(dev);
                        if (netdev_sock < 0) {
                                printf("%s: netif_open() failed\n", __func__);
                                return (ENXIO);
                        }
                        netdev_name = strdup(devname);
#ifdef  NETIF_DEBUG
                        if (debug)
                                printf("%s: netif_open() succeeded\n",
                                    __func__);
#endif
                }
                /*
                 * If network params were not set by netif_open(), try to get
                 * them via bootp, rarp, etc.
                 */
                if (rootip.s_addr == 0) {
                        /* Get root IP address, and path, etc. */
                        error = net_getparams(netdev_sock);
                        if (error) {
                                /* getparams makes its own noise */
                                free(netdev_name);
                                netif_close(netdev_sock);
                                netdev_sock = -1;
                                return (error);
                        }
                }
                /*
                 * Set the variables required by the kernel's nfs_diskless
                 * mechanism.  This is the minimum set of variables required to
                 * mount a root filesystem without needing to obtain additional
                 * info from bootp or other sources.
                 */
                d = socktodesc(netdev_sock);
                setenv("boot.netif.hwaddr", ether_sprintf(d->myea), 1);
                setenv("boot.netif.ip", inet_ntoa(myip), 1);
                setenv("boot.netif.netmask", intoa(netmask), 1);
                setenv("boot.netif.gateway", inet_ntoa(gateip), 1);
                setenv("boot.netif.server", inet_ntoa(rootip), 1);
                if (netproto == NET_TFTP) {
                        setenv("boot.tftproot.server", inet_ntoa(rootip), 1);
                        setenv("boot.tftproot.path", rootpath, 1);
                } else {
                        setenv("boot.nfsroot.server", inet_ntoa(rootip), 1);
                        setenv("boot.nfsroot.path", rootpath, 1);
                }
                if (intf_mtu != 0) {
                        char mtu[16];
                        snprintf(mtu, sizeof (mtu), "%u", intf_mtu);
                        setenv("boot.netif.mtu", mtu, 1);
                }
        }
        netdev_opens++;
        dev->d_opendata = &netdev_sock;
        return (error);
}

static int
net_close(struct open_file *f)
{
        struct devdesc *dev;

#ifdef  NETIF_DEBUG
        if (debug)
                printf("%s: opens=%d\n", __func__, netdev_opens);
#endif

        dev = f->f_devdata;
        dev->d_opendata = NULL;

        return (0);
}

static void
net_cleanup(void)
{

        if (netdev_sock >= 0) {
#ifdef  NETIF_DEBUG
                if (debug)
                        printf("%s: calling netif_close()\n", __func__);
#endif
                rootip.s_addr = 0;
                free(netdev_name);
                netif_close(netdev_sock);
                netdev_sock = -1;
        }
}

static int
net_strategy(void *devdata __unused, int rw __unused, daddr_t blk __unused,
    size_t size __unused, char *buf __unused, size_t *rsize __unused)
{

        return (EIO);
}

/*
 * Get info for NFS boot: our IP address, our hostname,
 * server IP address, and our root path on the server.
 * There are two ways to do this:  The old, Sun way,
 * and the more modern, BOOTP/DHCP way. (RFC951, RFC1048)
 */

extern n_long ip_convertaddr(char *p);

static int
net_getparams(int sock)
{
        char buf[MAXHOSTNAMELEN];
        n_long rootaddr, smask;

        /*
         * Try to get boot info using BOOTP/DHCP.  If we succeed, then
         * the server IP address, gateway, and root path will all
         * be initialized.  If any remain uninitialized, we will
         * use RARP and RPC/bootparam (the Sun way) to get them.
         */
        bootp(sock);
        if (myip.s_addr != 0)
                goto exit;
#ifdef  NETIF_DEBUG
        if (debug)
                printf("%s: BOOTP failed, trying RARP/RPC...\n", __func__);
#endif

        /*
         * Use RARP to get our IP address.  This also sets our
         * netmask to the "natural" default for our address.
         */
        if (rarp_getipaddress(sock)) {
                printf("%s: RARP failed\n", __func__);
                return (EIO);
        }
        printf("%s: client addr: %s\n", __func__, inet_ntoa(myip));

        /* Get our hostname, server IP address, gateway. */
        if (bp_whoami(sock)) {
                printf("%s: bootparam/whoami RPC failed\n", __func__);
                return (EIO);
        }
#ifdef  NETIF_DEBUG
        if (debug)
                printf("%s: client name: %s\n", __func__, hostname);
#endif

        /*
         * Ignore the gateway from whoami (unreliable).
         * Use the "gateway" parameter instead.
         */
        smask = 0;
        gateip.s_addr = 0;
        if (bp_getfile(sock, "gateway", &gateip, buf) == 0) {
                /* Got it!  Parse the netmask. */
                smask = ip_convertaddr(buf);
        }
        if (smask) {
                netmask = smask;
#ifdef  NETIF_DEBUG
                if (debug)
                        printf("%s: subnet mask: %s\n", __func__,
                            intoa(netmask));
#endif
        }
#ifdef  NETIF_DEBUG
        if (gateip.s_addr && debug)
                printf("%s: net gateway: %s\n", __func__, inet_ntoa(gateip));
#endif

        /* Get the root server and pathname. */
        if (bp_getfile(sock, "root", &rootip, rootpath)) {
                printf("%s: bootparam/getfile RPC failed\n", __func__);
                return (EIO);
        }
exit:
        if ((rootaddr = net_parse_rootpath()) != INADDR_NONE)
                rootip.s_addr = rootaddr;

#ifdef  NETIF_DEBUG
        if (debug) {
                printf("%s: server addr: %s\n", __func__,
                    inet_ntoa(rootip));
                printf("%s: server path: %s\n", __func__, rootpath);
        }
#endif

        return (0);
}

static int
net_print(int verbose)
{
        struct netif_driver *drv;
        int i, d, cnt;
        int ret = 0;

        if (netif_drivers[0] == NULL)
                return (ret);

        printf("%s devices:", netdev.dv_name);
        if ((ret = pager_output("\n")) != 0)
                return (ret);

        cnt = 0;
        for (d = 0; netif_drivers[d]; d++) {
                drv = netif_drivers[d];
                for (i = 0; i < drv->netif_nifs; i++) {
                        printf("\t%s%d:", netdev.dv_name, cnt++);
                        if (verbose) {
                                printf(" (%s%d)", drv->netif_bname,
                                    drv->netif_ifs[i].dif_unit);
                        }
                        if ((ret = pager_output("\n")) != 0)
                                return (ret);
                }
        }
        return (ret);
}

/*
 * Parses the rootpath if present
 *
 * The rootpath format can be in the form
 * <scheme>://IPv4/path
 * <scheme>:/path
 *
 * For compatibility with previous behaviour it also accepts as an NFS scheme
 * IPv4:/path
 * /path
 *
 * If an IPv4 address has been specified, it will be stripped out and passed
 * out as the return value of this function in network byte order.
 *
 * If no rootpath is present then we will default to TFTP.
 *
 * If no global default scheme has been specified and no scheme has been
 * specified, we will assume that this is an NFS URL.
 *
 * The pathname will be stored in the global variable rootpath.
 */
uint32_t
net_parse_rootpath(void)
{
        n_long addr = htonl(INADDR_NONE);
        size_t i;
        char ip[FNAME_SIZE];
        char *ptr, *val;

        netproto = NET_NONE;

        for (i = 0; i < nitems(uri_schemes); i++) {
                if (strncmp(rootpath, uri_schemes[i].scheme,
                    strlen(uri_schemes[i].scheme)) != 0)
                        continue;

                netproto = uri_schemes[i].proto;
                break;
        }
        ptr = rootpath;
        /* Fallback for compatibility mode */
        if (netproto == NET_NONE) {
                if (strcmp(rootpath, "/") == 0) {
                        netproto = NET_TFTP;
                } else {
                        netproto = NET_NFS;
                        (void) strsep(&ptr, ":");
                        if (ptr != NULL) {
                                addr = inet_addr(rootpath);
                                bcopy(ptr, rootpath, strlen(ptr) + 1);
                        }
                }
        } else {
                ptr += strlen(uri_schemes[i].scheme);
                if (*ptr == '/') {
                        /*
                         * We are in the form <scheme>://, we do expect an ip.
                         */
                        ptr++;
                        /*
                         * XXX when http will be there we will need to check for
                         * a port, but right now we do not need it yet.
                         * Also will need rework for IPv6.
                         */
                        val = strchr(ptr, '/');
                        if (val == NULL) {
                                /* If no pathname component, default to / */
                                strlcat(rootpath, "/", sizeof (rootpath));
                                val = strchr(ptr, '/');
                        }
                        if (val != NULL) {
                                snprintf(ip, sizeof (ip), "%.*s",
                                    (int)((uintptr_t)val - (uintptr_t)ptr),
                                    ptr);
                                addr = inet_addr(ip);
                                if (addr == htonl(INADDR_NONE)) {
                                        printf("Bad IP address: %s\n", ip);
                                }
                                bcopy(val, rootpath, strlen(val) + 1);
                        }
                } else {
                        ptr--;
                        bcopy(ptr, rootpath, strlen(ptr) + 1);
                }
        }

        return (addr);
}