/*
 * 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 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include        <sys/types.h>
#include        <stdio.h>
#include        <errno.h>
#include        <unistd.h>
#include        <string.h>
#include        <wait.h>
#include        <limits.h>
#include        <gelf.h>
#include        "machdep.h"
#include        "sgs.h"
#include        "conv.h"
#include        "_crle.h"
#include        "msg.h"

/*
 * Establish an association between a filter and filtee.  Both the filter and
 * filtee already exist in the internal hash table, since auditing registers
 * objects (la_objopen()) before it registers filters (la_objfilter()).
 */
static int
filter(Crle_desc *crle, const char *filter, const char *str, const char *filtee)
{
        Hash_ent        *fltrent, *flteent;
        Flt_desc        *flt;
        Aliste          idx;

        /*
         * Locate the filter.  Mark the underlying object as the filter to
         * reflect that no matter how it is referenced, it's a filter.
         */
        if ((fltrent = get_hash(crle->c_strtbl, (Addr)filter, 0,
            HASH_FND_ENT)) == NULL)
                return (1);
        if ((fltrent = get_hash(crle->c_strtbl, (Addr)fltrent->e_obj->o_path, 0,
            HASH_FND_ENT)) == NULL)
                return (1);
        fltrent->e_obj->o_flags |= RTC_OBJ_FILTER;

        /*
         * Locate the filtee.  Mark the referencing object as the filtee, as
         * this is the object referenced by the filter.
         */
        if ((flteent = get_hash(crle->c_strtbl, (Addr)filtee, 0,
            HASH_FND_ENT)) == NULL)
                return (1);
        flteent->e_flags |= RTC_OBJ_FILTEE;

        /*
         * Traverse the filter list using the filters real name.  If ld.so.1
         * inspects the resulting configuration file for filters, it's the
         * objects real name that will be used (PATHNAME()).
         */
        for (APLIST_TRAVERSE(crle->c_flt, idx, flt)) {
                /*
                 * Determine whether this filter and filtee string pair already
                 * exist.
                 */
                if ((strcmp(flt->f_fent->e_obj->o_path,
                    fltrent->e_obj->o_path) != 0) &&
                    (strcmp(flt->f_str, str) != 0))
                        continue;

                /*
                 * Add this filtee additional association.
                 */
                if (aplist_append(&(flt->f_filtee), flteent,
                    AL_CNT_CRLE) == NULL)
                        return (1);

                crle->c_fltenum++;
                return (0);
        }

        /*
         * This is a new filter descriptor.  Add this new filtee association.
         */
        if (((flt = malloc(sizeof (Flt_desc))) == NULL) ||
            ((flt->f_strsz = strlen(str) + 1) == 0) ||
            ((flt->f_str = malloc(flt->f_strsz)) == NULL)) {
                int err = errno;
                (void) fprintf(stderr, MSG_INTL(MSG_SYS_MALLOC),
                    crle->c_name, strerror(err));
                free(flt);
                return (1);
        }
        if ((aplist_append(&(crle->c_flt), flt, AL_CNT_CRLE) == NULL) ||
            (aplist_append(&(flt->f_filtee), flteent, AL_CNT_CRLE) == NULL))
                return (1);

        flt->f_fent = fltrent;
        (void) memcpy((void *)flt->f_str, (void *)str, flt->f_strsz);
        crle->c_strsize += flt->f_strsz;
        crle->c_fltrnum += 1;
        crle->c_fltenum += 2;           /* Account for null filtee desc. */

        return (0);
}

/*
 * Establish the dependencies of an ELF object and add them to the internal
 * configuration information. This information is gathered by using libcrle.so.1
 * as an audit library - this is akin to using ldd(1) only simpler.
 */
int
depend(Crle_desc *crle, const char *name, Half flags, GElf_Ehdr *ehdr)
{
        const char      *exename;
        const char      *preload;
        int             fildes[2], pid;

        /*
         * If we're dealing with a dynamic executable we'll execute it,
         * otherwise we'll preload the shared object with one of the lddstub's.
         */
        if (ehdr->e_type == ET_EXEC) {
                exename = name;
                preload = NULL;
        } else {
                exename = conv_lddstub(M_CLASS);
                preload = name;
        }

        /*
         * Set up a pipe through which the audit library will write the
         * dependencies.
         */
        if (pipe(fildes) == -1) {
                int err = errno;
                (void) fprintf(stderr, MSG_INTL(MSG_SYS_PIPE),
                    crle->c_name, strerror(err));
                return (1);
        }

        /*
         * Fork ourselves to run our executable and collect its dependencies.
         */
        if ((pid = fork()) == -1) {
                int err = errno;
                (void) fprintf(stderr, MSG_INTL(MSG_SYS_FORK),
                    crle->c_name, strerror(err));
                return (1);
        }

        if (pid) {
                /*
                 * Parent. Read each dependency from the audit library. The read
                 * side of the pipe is attached to stdio to make obtaining the
                 * individual dependencies easier.
                 */
                int     error = 0, status;
                FILE    *fd;
                char    buffer[PATH_MAX];

                (void) close(fildes[1]);
                if ((fd = fdopen(fildes[0], MSG_ORIG(MSG_STR_READ))) != NULL) {
                        char    *str;

                        while (fgets(buffer, PATH_MAX, fd) != NULL) {
                                /*
                                 * Make sure we recognize the message, remove
                                 * the newline (which allowed fgets() use) and
                                 * register the name;
                                 */
                                if (strncmp(MSG_ORIG(MSG_AUD_PRF), buffer,
                                    MSG_AUD_PRF_SIZE))
                                        continue;

                                str = strrchr(buffer, '\n');
                                *str = '\0';
                                str = buffer + MSG_AUD_PRF_SIZE;

                                if (strncmp(MSG_ORIG(MSG_AUD_DEPEND),
                                    str, MSG_AUD_DEPEND_SIZE) == 0) {
                                        /*
                                         * Process any dependencies.
                                         */
                                        str += MSG_AUD_DEPEND_SIZE;

                                        if ((error = inspect(crle, str,
                                            (flags & ~RTC_OBJ_GROUP))) != 0)
                                                break;

                                } else if (strncmp(MSG_ORIG(MSG_AUD_FILTER),
                                    str, MSG_AUD_FILTER_SIZE) == 0) {
                                        char    *_flt, *_str;

                                        /*
                                         * Process any filters.
                                         */
                                        _flt = str += MSG_AUD_FILTER_SIZE;
                                        _str = strchr(str, ':');
                                        *_str++ = '\0'; str = _str++;
                                        str = strrchr(str, ')');
                                        *str++ = '\0'; str++;
                                        if ((error = filter(crle, _flt, _str,
                                            str)) != 0)
                                                break;
                                }
                        }
                } else
                        error = errno;

                while (wait(&status) != pid)
                        ;
                if (status) {
                        if (WIFSIGNALED(status)) {
                                (void) fprintf(stderr,
                                    MSG_INTL(MSG_SYS_EXEC), crle->c_name,
                                    exename, (WSIGMASK & status),
                                    ((status & WCOREFLG) ?
                                    MSG_INTL(MSG_SYS_CORE) :
                                    MSG_ORIG(MSG_STR_EMPTY)));
                        }
                        error = status;
                }
                (void) fclose(fd);

                return (error);
        } else {
                char    efds[MSG_ENV_AUD_FD_SIZE + 10];
                char    epld[PATH_MAX];
                char    eldf[PATH_MAX];

                (void) close(fildes[0]);

                /*
                 * Child. Set up environment variables to enable and identify
                 * auditing.  Initialize CRLE_FD and LD_FLAGS strings.
                 */
                (void) snprintf(efds, (MSG_ENV_AUD_FD_SIZE + 10),
                    MSG_ORIG(MSG_ENV_AUD_FD), fildes[1]);
                (void) snprintf(eldf, PATH_MAX, MSG_ORIG(MSG_ENV_LD_FLAGS));

                /*
                 * If asked to dump a group of dependencies make sure any
                 * lazily-loaded objects get processed - (append loadavail to
                 * LD_FLAGS=confgen).
                 */
                if (flags & RTC_OBJ_GROUP)
                        (void) strcat(eldf, MSG_ORIG(MSG_LDFLG_LOADAVAIL));

                /*
                 * Put LD_PRELOAD= in the environment if necessary.
                 */
                if (preload) {
                        (void) snprintf(epld, PATH_MAX,
                            MSG_ORIG(MSG_ENV_LD_PRELOAD), preload);
                }

                /*
                 * Put strings in the environment for exec().
                 * NOTE, use of automatic variables for construction of the
                 * environment variables is legitimate here, as they are local
                 * to the child process and are established solely for exec().
                 */
                if ((putenv(efds) != 0) || (putenv(crle->c_audit) != 0) ||
                    (putenv(eldf) != 0) || (preload && (putenv(epld) != 0))) {
                        int err = errno;
                        (void) fprintf(stderr, MSG_INTL(MSG_SYS_PUTENV),
                            crle->c_name, strerror(err));
                        return (1);
                }

                if (execlp(exename, exename, 0) == -1) {
                        _exit(errno);
                        /* NOTREACHED */
                }
        }
        return (0);
}