/*      $OpenBSD: firmload.c,v 1.16 2018/08/13 23:12:39 deraadt Exp $   */

/*
 * Copyright (c) 2004 Theo de Raadt <deraadt@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/syslimits.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/errno.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/device.h>
#include <sys/pledge.h>

int
loadfirmware(const char *name, u_char **bufp, size_t *buflen)
{
        struct proc *p = curproc;
        struct nameidata nid;
        char *path, *ptr;
        struct iovec iov;
        struct uio uio;
        struct vattr va;
        int error;

        if (!rootvp || !vcount(rootvp))
                return (EIO);

        path = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT);
        if (path == NULL)
                return (ENOMEM);

        if (snprintf(path, MAXPATHLEN, "/etc/firmware/%s", name) >=
            MAXPATHLEN) {
                error = ENAMETOOLONG;
                goto err;
        }

        NDINIT(&nid, LOOKUP, NOFOLLOW|LOCKLEAF|KERNELPATH,
            UIO_SYSSPACE, path, p);
        nid.ni_pledge = PLEDGE_RPATH;
        error = namei(&nid);
#ifdef RAMDISK_HOOKS
        /* try again with mounted disk */
        if (error) {
                if (snprintf(path, MAXPATHLEN, "/mnt/etc/firmware/%s", name) >=
                    MAXPATHLEN) {
                        error = ENAMETOOLONG;
                        goto err;
                }

                NDINIT(&nid, LOOKUP, NOFOLLOW|LOCKLEAF|KERNELPATH,
                    UIO_SYSSPACE, path, p);
                nid.ni_pledge = PLEDGE_RPATH;
                error = namei(&nid);
        }
#endif
        if (error)
                goto err;
        error = VOP_GETATTR(nid.ni_vp, &va, p->p_ucred, p);
        if (error)
                goto fail;
        if (nid.ni_vp->v_type != VREG || va.va_size == 0) {
                error = EINVAL;
                goto fail;
        }
        if (va.va_size > FIRMWARE_MAX) {
                error = E2BIG;
                goto fail;
        }
        ptr = malloc(va.va_size, M_DEVBUF, M_NOWAIT);
        if (ptr == NULL) {
                error = ENOMEM;
                goto fail;
        }

        iov.iov_base = ptr;
        iov.iov_len = va.va_size;
        uio.uio_iov = &iov;
        uio.uio_iovcnt = 1;
        uio.uio_offset = 0;
        uio.uio_resid = va.va_size;
        uio.uio_segflg = UIO_SYSSPACE;
        uio.uio_rw = UIO_READ;
        uio.uio_procp = p;

        error = VOP_READ(nid.ni_vp, &uio, 0, p->p_ucred);

        if (error == 0) {
                *bufp = ptr;
                *buflen = va.va_size;
        } else
                free(ptr, M_DEVBUF, va.va_size);

fail:
        vput(nid.ni_vp);
err:
        free(path, M_TEMP, MAXPATHLEN);
        return (error);
}