/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2002 Poul-Henning Kamp
 * Copyright (c) 2002 Networks Associates Technology, Inc.
 * All rights reserved.
 * Copyright (c) 2022 Alexander Motin <mav@FreeBSD.org>
 *
 * This software was developed for the FreeBSD Project by Poul-Henning Kamp
 * and NAI Labs, the Security Research Division of Network Associates, Inc.
 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
 * DARPA CHATS research program.
 *
 * 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.
 * 3. The names of the authors may not be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/malloc.h>
#include <sys/sbuf.h>
#include <sys/stdarg.h>

#include <vm/vm.h>
#include <vm/vm_extern.h>

#include <geom/geom.h>
#include <geom/geom_int.h>
#define GCTL_TABLE 1
#include <geom/geom_ctl.h>

static d_ioctl_t g_ctl_ioctl;

static struct cdevsw g_ctl_cdevsw = {
        .d_version =    D_VERSION,
        .d_flags =      0,
        .d_ioctl =      g_ctl_ioctl,
        .d_name =       "g_ctl",
};

CTASSERT(GCTL_PARAM_RD == VM_PROT_READ);
CTASSERT(GCTL_PARAM_WR == VM_PROT_WRITE);

void
g_ctl_init(void)
{

        make_dev_credf(MAKEDEV_ETERNAL, &g_ctl_cdevsw, 0, NULL,
            UID_ROOT, GID_OPERATOR, 0640, PATH_GEOM_CTL);
}

/*
 * Report an error back to the user in ascii format.  Return nerror
 * or EINVAL if nerror isn't specified.
 */
int
gctl_error(struct gctl_req *req, const char *fmt, ...)
{
        va_list ap;

        if (req == NULL)
                return (EINVAL);

        /* We only record the first error */
        if (sbuf_done(req->serror)) {
                if (!req->nerror)
                        req->nerror = EEXIST;
#ifdef DIAGNOSTIC
                printf("gctl_error: buffer closed, message discarded.\n");
#endif
                return (req->nerror);
        }
        if (!req->nerror)
                req->nerror = EINVAL;

        /* If this is the last of several messages, indent it on a new line */
        if (sbuf_len(req->serror) > 0)
                sbuf_cat(req->serror, "\n\t");
        va_start(ap, fmt);
        sbuf_vprintf(req->serror, fmt, ap);
        va_end(ap);
        gctl_post_messages(req);
        return (req->nerror);
}

/*
 * The gctl_error() function will only report a single message.
 * Commands that handle multiple devices may want to report a
 * message for each of the devices. The gctl_msg() function
 * can be called multiple times to post messages. When done
 * the application must either call gctl_post_messages() or
 * call gctl_error() to cause the messages to be reported to
 * the calling process.
 *
 * The errno argument should be zero if it is an informational
 * message or an errno value (EINVAL, EBUSY, etc) if it is an error.
 * If any of the messages has a non-zero errno, the utility will
 * EXIT_FAILURE. If only informational messages (with zero errno)
 * are posted, the utility will EXIT_SUCCESS.
 */
void
gctl_msg(struct gctl_req *req, int errno, const char *fmt, ...)
{
        va_list ap;

        if (req == NULL)
                return;
        if (sbuf_done(req->serror)) {
#ifdef DIAGNOSTIC
                printf("gctl_msg: buffer closed, message discarded.\n");
#endif
                return;
        }
        if (req->nerror == 0)
                req->nerror = errno;
        /* Put second and later messages indented on a new line */
        if (sbuf_len(req->serror) > 0)
                sbuf_cat(req->serror, "\n\t");
        va_start(ap, fmt);
        sbuf_vprintf(req->serror, fmt, ap);
        va_end(ap);
}

/*
 * Post the messages to the user.
 */
void
gctl_post_messages(struct gctl_req *req)
{

        if (sbuf_done(req->serror)) {
#ifdef DIAGNOSTIC
                printf("gctl_post_messages: message buffer already closed.\n");
#endif
                return;
        }
        sbuf_finish(req->serror);
        if (g_debugflags & G_F_CTLDUMP)
                printf("gctl %p message(s) \"%s\"\n", req,
                    sbuf_data(req->serror));
}

/*
 * Allocate space and copyin() something.
 * XXX: this should really be a standard function in the kernel.
 */
static void *
geom_alloc_copyin(struct gctl_req *req, void *uaddr, size_t len)
{
        void *ptr;

        ptr = g_malloc(len, M_WAITOK);
        req->nerror = copyin(uaddr, ptr, len);
        if (!req->nerror)
                return (ptr);
        g_free(ptr);
        return (NULL);
}

static void
gctl_copyin(struct gctl_req *req)
{
        struct gctl_req_arg *ap;
        char *p;
        u_int i;

        if (req->narg > GEOM_CTL_ARG_MAX) {
                gctl_error(req, "too many arguments");
                req->arg = NULL;
                return;
        }

        ap = geom_alloc_copyin(req, req->arg, req->narg * sizeof(*ap));
        if (ap == NULL) {
                gctl_error(req, "bad control request");
                req->arg = NULL;
                return;
        }

        /* Nothing have been copyin()'ed yet */
        for (i = 0; i < req->narg; i++) {
                ap[i].flag &= ~(GCTL_PARAM_NAMEKERNEL|GCTL_PARAM_VALUEKERNEL);
                ap[i].flag &= ~GCTL_PARAM_CHANGED;
                ap[i].kvalue = NULL;
        }

        for (i = 0; i < req->narg; i++) {
                if (ap[i].nlen < 1 || ap[i].nlen > SPECNAMELEN) {
                        gctl_error(req,
                            "wrong param name length %d: %d", i, ap[i].nlen);
                        break;
                }
                p = geom_alloc_copyin(req, ap[i].name, ap[i].nlen);
                if (p == NULL)
                        break;
                if (p[ap[i].nlen - 1] != '\0') {
                        gctl_error(req, "unterminated param name");
                        g_free(p);
                        break;
                }
                ap[i].name = p;
                ap[i].flag |= GCTL_PARAM_NAMEKERNEL;
                if (ap[i].len <= 0) {
                        gctl_error(req, "negative param length");
                        break;
                }
                if (ap[i].flag & GCTL_PARAM_RD) {
                        p = geom_alloc_copyin(req, ap[i].value, ap[i].len);
                        if (p == NULL)
                                break;
                        if ((ap[i].flag & GCTL_PARAM_ASCII) &&
                            p[ap[i].len - 1] != '\0') {
                                gctl_error(req, "unterminated param value");
                                g_free(p);
                                break;
                        }
                } else {
                        p = g_malloc(ap[i].len, M_WAITOK | M_ZERO);
                }
                ap[i].kvalue = p;
                ap[i].flag |= GCTL_PARAM_VALUEKERNEL;
        }
        req->arg = ap;
        return;
}

static void
gctl_copyout(struct gctl_req *req)
{
        int error, i;
        struct gctl_req_arg *ap;

        if (req->nerror)
                return;
        error = 0;
        ap = req->arg;
        for (i = 0; i < req->narg; i++, ap++) {
                if (!(ap->flag & GCTL_PARAM_CHANGED))
                        continue;
                error = copyout(ap->kvalue, ap->value, ap->len);
                if (!error)
                        continue;
                req->nerror = error;
                return;
        }
        return;
}

static void
gctl_free(struct gctl_req *req)
{
        u_int i;

        sbuf_delete(req->serror);
        if (req->arg == NULL)
                return;
        for (i = 0; i < req->narg; i++) {
                if (req->arg[i].flag & GCTL_PARAM_NAMEKERNEL)
                        g_free(req->arg[i].name);
                if ((req->arg[i].flag & GCTL_PARAM_VALUEKERNEL) &&
                    req->arg[i].len > 0)
                        g_free(req->arg[i].kvalue);
        }
        g_free(req->arg);
}

static void
gctl_dump(struct gctl_req *req, const char *what)
{
        struct gctl_req_arg *ap;
        u_int i;
        int j;

        printf("Dump of gctl %s at %p:\n", what, req);
        if (req->nerror > 0) {
                printf("  nerror:\t%d\n", req->nerror);
                if (sbuf_len(req->serror) > 0)
                        printf("  error:\t\"%s\"\n", sbuf_data(req->serror));
        }
        if (req->arg == NULL)
                return;
        for (i = 0; i < req->narg; i++) {
                ap = &req->arg[i];
                if (!(ap->flag & GCTL_PARAM_NAMEKERNEL))
                        printf("  param:\t%d@%p", ap->nlen, ap->name);
                else
                        printf("  param:\t\"%s\"", ap->name);
                printf(" [%s%s%d] = ",
                    ap->flag & GCTL_PARAM_RD ? "R" : "",
                    ap->flag & GCTL_PARAM_WR ? "W" : "",
                    ap->len);
                if (!(ap->flag & GCTL_PARAM_VALUEKERNEL)) {
                        printf(" =@ %p", ap->value);
                } else if (ap->flag & GCTL_PARAM_ASCII) {
                        printf("\"%s\"", (char *)ap->kvalue);
                } else if (ap->len > 0) {
                        for (j = 0; j < ap->len && j < 512; j++)
                                printf(" %02x", ((u_char *)ap->kvalue)[j]);
                } else {
                        printf(" = %p", ap->kvalue);
                }
                printf("\n");
        }
}

int
gctl_set_param(struct gctl_req *req, const char *param, void const *ptr,
    int len)
{
        u_int i;
        struct gctl_req_arg *ap;

        for (i = 0; i < req->narg; i++) {
                ap = &req->arg[i];
                if (strcmp(param, ap->name))
                        continue;
                if (!(ap->flag & GCTL_PARAM_WR))
                        return (EPERM);
                ap->flag |= GCTL_PARAM_CHANGED;
                if (ap->len < len) {
                        bcopy(ptr, ap->kvalue, ap->len);
                        return (ENOSPC);
                }
                bcopy(ptr, ap->kvalue, len);
                return (0);
        }
        return (EINVAL);
}

void
gctl_set_param_err(struct gctl_req *req, const char *param, void const *ptr,
    int len)
{

        switch (gctl_set_param(req, param, ptr, len)) {
        case EPERM:
                gctl_error(req, "No write access %s argument", param);
                break;
        case ENOSPC:
                gctl_error(req, "Wrong length %s argument", param);
                break;
        case EINVAL:
                gctl_error(req, "Missing %s argument", param);
                break;
        }
}

void *
gctl_get_param_flags(struct gctl_req *req, const char *param, int flags, int *len)
{
        u_int i;
        void *p;
        struct gctl_req_arg *ap;

        for (i = 0; i < req->narg; i++) {
                ap = &req->arg[i];
                if (strcmp(param, ap->name))
                        continue;
                if ((ap->flag & flags) != flags)
                        continue;
                p = ap->kvalue;
                if (len != NULL)
                        *len = ap->len;
                return (p);
        }
        return (NULL);
}

void *
gctl_get_param(struct gctl_req *req, const char *param, int *len)
{

        return (gctl_get_param_flags(req, param, GCTL_PARAM_RD, len));
}

char const *
gctl_get_asciiparam(struct gctl_req *req, const char *param)
{
        char const *p;
        int len;

        p = gctl_get_param_flags(req, param, GCTL_PARAM_RD, &len);
        if (p == NULL)
                return (NULL);
        if (len < 1) {
                gctl_error(req, "Argument without length (%s)", param);
                return (NULL);
        }
        if (p[len - 1] != '\0') {
                gctl_error(req, "Unterminated argument (%s)", param);
                return (NULL);
        }
        return (p);
}

void *
gctl_get_paraml_opt(struct gctl_req *req, const char *param, int len)
{
        int i;
        void *p;

        p = gctl_get_param(req, param, &i);
        if (i != len) {
                p = NULL;
                gctl_error(req, "Wrong length %s argument", param);
        }
        return (p);
}

void *
gctl_get_paraml(struct gctl_req *req, const char *param, int len)
{
        void *p;

        p = gctl_get_paraml_opt(req, param, len);
        if (p == NULL)
                gctl_error(req, "Missing %s argument", param);
        return (p);
}

struct g_class *
gctl_get_class(struct gctl_req *req, char const *arg)
{
        char const *p;
        struct g_class *cp;

        p = gctl_get_asciiparam(req, arg);
        if (p == NULL) {
                gctl_error(req, "Missing %s argument", arg);
                return (NULL);
        }
        LIST_FOREACH(cp, &g_classes, class) {
                if (!strcmp(p, cp->name))
                        return (cp);
        }
        gctl_error(req, "Class not found: \"%s\"", p);
        return (NULL);
}

struct g_geom *
gctl_get_geom(struct gctl_req *req, struct g_class *mp, char const *arg)
{
        char const *p;
        struct g_geom *gp;

        MPASS(mp != NULL);
        p = gctl_get_asciiparam(req, arg);
        if (p == NULL) {
                gctl_error(req, "Missing %s argument", arg);
                return (NULL);
        }
        LIST_FOREACH(gp, &mp->geom, geom)
                if (!strcmp(p, gp->name))
                        return (gp);
        gctl_error(req, "Geom not found: \"%s\"", p);
        return (NULL);
}

struct g_provider *
gctl_get_provider(struct gctl_req *req, char const *arg)
{
        char const *p;
        struct g_provider *pp;

        p = gctl_get_asciiparam(req, arg);
        if (p == NULL) {
                gctl_error(req, "Missing '%s' argument", arg);
                return (NULL);
        }
        pp = g_provider_by_name(p);
        if (pp != NULL)
                return (pp);
        gctl_error(req, "Provider not found: \"%s\"", p);
        return (NULL);
}

static void
g_ctl_getxml(struct gctl_req *req, struct g_class *mp)
{
        const char *name;
        char *buf;
        struct sbuf *sb;
        int len, i = 0, n = 0, *parents;
        struct g_geom *gp, **gps;
        struct g_consumer *cp;

        parents = gctl_get_paraml(req, "parents", sizeof(*parents));
        if (parents == NULL)
                return;
        name = gctl_get_asciiparam(req, "arg0");
        n = 0;
        LIST_FOREACH(gp, &mp->geom, geom) {
                if (name && strcmp(gp->name, name) != 0)
                        continue;
                n++;
                if (*parents) {
                        LIST_FOREACH(cp, &gp->consumer, consumer)
                                n++;
                }
        }
        gps = g_malloc((n + 1) * sizeof(*gps), M_WAITOK);
        i = 0;
        LIST_FOREACH(gp, &mp->geom, geom) {
                if (name && strcmp(gp->name, name) != 0)
                        continue;
                gps[i++] = gp;
                if (*parents) {
                        LIST_FOREACH(cp, &gp->consumer, consumer) {
                                if (cp->provider != NULL)
                                        gps[i++] = cp->provider->geom;
                        }
                }
        }
        KASSERT(i == n, ("different number of geoms found (%d != %d)",
            i, n));
        gps[i] = 0;

        buf = gctl_get_param_flags(req, "output", GCTL_PARAM_WR, &len);
        if (buf == NULL) {
                gctl_error(req, "output parameter missing");
                g_free(gps);
                return;
        }
        sb = sbuf_new(NULL, buf, len, SBUF_FIXEDLEN | SBUF_INCLUDENUL);
        g_conf_specific(sb, gps);
        gctl_set_param(req, "output", buf, 0);
        if (sbuf_error(sb))
                gctl_error(req, "output buffer overflow");
        sbuf_delete(sb);
        g_free(gps);
}

static void
g_ctl_req(void *arg, int flag __unused)
{
        struct g_class *mp;
        struct gctl_req *req;
        char const *verb;

        g_topology_assert();
        req = arg;
        mp = gctl_get_class(req, "class");
        if (mp == NULL)
                return;
        verb = gctl_get_param(req, "verb", NULL);
        if (verb == NULL) {
                gctl_error(req, "Verb missing");
                return;
        }
        if (strcmp(verb, "getxml") == 0) {
                g_ctl_getxml(req, mp);
        } else if (mp->ctlreq == NULL) {
                gctl_error(req, "Class takes no requests");
        } else {
                mp->ctlreq(req, mp, verb);
        }
        g_topology_assert();
}

static int
g_ctl_ioctl_ctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
{
        struct gctl_req *req;
        int nerror;

        req = (void *)data;
        req->nerror = 0;
        /* It is an error if we cannot return an error text */
        if (req->lerror < 2)
                return (EINVAL);
        if (!useracc(req->error, req->lerror, VM_PROT_WRITE))
                return (EINVAL);

        req->serror = sbuf_new_auto();
        /* Check the version */
        if (req->version != GCTL_VERSION) {
                gctl_error(req, "kernel and libgeom version mismatch.");
                req->arg = NULL;
        } else {
                /* Get things on board */
                gctl_copyin(req);

                if (g_debugflags & G_F_CTLDUMP)
                        gctl_dump(req, "request");

                if (!req->nerror) {
                        g_waitfor_event(g_ctl_req, req, M_WAITOK, NULL);

                        if (g_debugflags & G_F_CTLDUMP)
                                gctl_dump(req, "result");

                        gctl_copyout(req);
                }
        }
        if (sbuf_done(req->serror)) {
                nerror = copyout(sbuf_data(req->serror), req->error,
                    imin(req->lerror, sbuf_len(req->serror) + 1));
                if (nerror != 0 && req->nerror == 0)
                        req->nerror = nerror;
        }

        nerror = req->nerror;
        gctl_free(req);
        return (nerror);
}

static int
g_ctl_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
{
        int error;

        switch(cmd) {
        case GEOM_CTL:
                error = g_ctl_ioctl_ctl(dev, cmd, data, fflag, td);
                break;
        default:
                error = ENOIOCTL;
                break;
        }
        return (error);

}