/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2012 by Delphix. All rights reserved.
 * Copyright 2019 Joyent, Inc.
 * Copyright 2021 Oxide Computer Company
 */

#include <sys/param.h>
#include <unistd.h>
#include <strings.h>
#include <dlfcn.h>
#include <ctype.h>
#include <link.h>

#include <mdb/mdb_module.h>
#include <mdb/mdb_modapi.h>
#include <mdb/mdb_debug.h>
#include <mdb/mdb_string.h>
#include <mdb/mdb_err.h>
#include <mdb/mdb_io.h>
#include <mdb/mdb_frame.h>
#include <mdb/mdb.h>

int
mdb_module_load(const char *name, int mode)
{
        const char *wformat = "no module '%s' could be found\n";
        const char *fullname = NULL;
        char buf[MAXPATHLEN], *p, *q;
        int i;

        ASSERT(!(mode & MDB_MOD_DEFER));

        if (strchr(name, '/') != NULL) {
                ASSERT(!(mode & MDB_MOD_BUILTIN));

                (void) mdb_iob_snprintf(buf, sizeof (buf), "%s",
                    strbasename(name));

                /*
                 * Remove any .so(.[0-9]+)? suffix
                 */
                if ((p = strrchr(buf, '.')) != NULL) {
                        for (q = p + 1; isdigit(*q); q++)
                                ;

                        if (*q == '\0') {
                                if (q > p + 1) {

                                        /* found digits to remove */
                                        *p = '\0';
                                }
                        }
                        if ((p = strrchr(buf, '.')) != NULL) {
                                if (strcmp(p, ".so") == 0) {
                                        *p = '\0';
                                }
                        }
                }
                fullname = name;
                name = buf;
        }

        if (!mdb_module_validate_name(name, &wformat))
                goto err;

        if (fullname != NULL) {
                if (access(fullname, F_OK) != 0) {
                        name = fullname; /* for warn() below */
                        goto err;
                }
                return (mdb_module_create(name, fullname, mode, NULL));
        }

        /*
         * If a simple name is specified, search for it in the module path.
         * The module path is searched in order, and for each element we
         * look for the following files:
         *
         * 1. If the module name ends in ".so(.[0-9]+)?", search for the literal
         *    name and then search for the name without the [0-9]+ suffix.
         * 2. If the module name ends in ".so", search for the literal name.
         * 3. Search for the module name with ".so" appended.
         *
         * Once a matching file is detected, we attempt to load that module
         * and do not resume our search in the case of an error.
         */
        for (i = 0; mdb.m_lpath[i] != NULL; i++) {
                if ((p = strrchr(name, '.')) != NULL && *++p != '\0') {
                        if (strisnum(p) || strcmp(p, "so") == 0) {
                                (void) mdb_iob_snprintf(buf, sizeof (buf),
                                    "%s/%s", mdb.m_lpath[i], name);
                                mdb_dprintf(MDB_DBG_MODULE,
                                    "checking for %s\n", buf);
                                if (access(buf, F_OK) == 0) {
                                        return (mdb_module_create(name, buf,
                                            mode, NULL));
                                }
                        }

                        while (strisnum(p) && (p = strrchr(buf, '.')) != NULL) {
                                *p = '\0'; /* strip trailing digits */
                                mdb_dprintf(MDB_DBG_MODULE,
                                    "checking for %s\n", buf);
                                if (access(buf, F_OK) == 0) {
                                        return (mdb_module_create(name, buf,
                                            mode, NULL));
                                }
                        }
                }

                (void) mdb_iob_snprintf(buf, sizeof (buf), "%s/%s.so",
                    mdb.m_lpath[i], name);

                mdb_dprintf(MDB_DBG_MODULE, "checking for %s\n", buf);

                if (access(buf, F_OK) == 0)
                        return (mdb_module_create(name, buf, mode, NULL));
        }
err:
        if (!(mode & MDB_MOD_SILENT))
                warn(wformat, name);

        return (-1);
}

typedef struct mdb_modload_data {
        int mld_first;
        int mld_mode;
} mdb_modload_data_t;

/*ARGSUSED*/
static int
module_load(void *fp, const mdb_map_t *map, const char *fullname)
{
        mdb_modload_data_t *mld = fp;
        const char *name = strbasename(fullname);

        if (mdb_module_load(name, mld->mld_mode) == 0 && mdb.m_term != NULL) {
                if (mld->mld_first == TRUE) {
                        mdb_iob_puts(mdb.m_out, "Loading modules: [");
                        mld->mld_first = FALSE;
                }
                mdb_iob_printf(mdb.m_out, " %s", name);
                mdb_iob_flush(mdb.m_out);
        }

        if (strstr(fullname, "/libc/") != NULL) {
                /*
                 * A bit of a kludge:  because we manage alternately capable
                 * libc instances by mounting the appropriately capable
                 * instance over /lib/libc.so.1, we may find that our object
                 * list does not contain libc.so.1, but rather one of its
                 * hwcap variants.  Unfortunately, there is not a way of
                 * getting from this shared object to the object that it is
                 * effectively interposing on -- which means that without
                 * special processing, we will not load any libc.so dmod.  So
                 * if we see that we have a shared object coming out of the
                 * "libc" directory, we assume that we have a "libc-like"
                 * object, and explicitly load the "libc.so" dmod.
                 */
                return (module_load(fp, map, "libc.so.1"));
        }

        if (strstr(fullname, "ld.so") != NULL) {
                /*
                 * This is even more of a kludge. But if we find something has
                 * basically tried to load ld, we will always implicitly load
                 * the list dmod because several binaries and libraries just
                 * build it as a .o and include it in their ELF object.
                 */
                (void) mdb_module_load("list", mld->mld_mode);
        }

        return (0);
}

void
mdb_module_load_all(int mode)
{
        uint_t oflag = mdb_iob_getflags(mdb.m_out) & MDB_IOB_PGENABLE;
        mdb_modload_data_t mld;

        mld.mld_first = TRUE;
        mld.mld_mode = mode | MDB_MOD_LOCAL | MDB_MOD_SILENT;

        mdb_iob_clrflags(mdb.m_out, oflag);

        (void) mdb_tgt_object_iter(mdb.m_target, module_load, &mld);

        if (mdb.m_term != NULL && mld.mld_first == FALSE)
                mdb_iob_puts(mdb.m_out, " ]\n");

        mdb_iob_setflags(mdb.m_out, oflag);
}

/*ARGSUSED*/
int
mdb_module_unload(const char *name, int mode)
{
        ASSERT((mode & ~MDB_MOD_SILENT) == 0);

        return (mdb_module_unload_common(name));
}