/*
 * 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
 */
/*
 *      ns_files.c
 *
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <stdio.h>
#include <stdlib.h>
#include <syslog.h>
#include <string.h>
#include <ctype.h>
#include <nsswitch.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <rpc/rpc.h>
#include <rpcsvc/nfs_prot.h>
#include <thread.h>
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <synch.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <strings.h>
#include "automount.h"

int did_exec_map;
static int read_execout(char *, char **, char *, char *, int);
static int call_read_execout(char *, char *, char *, int);
static FILE *file_open(char *, char *, char **, char ***);

/*
 * Initialize the stack
 */
void
init_files(char **stack, char ***stkptr)
{
        /*
         * The call is bogus for automountd since the stack is
         * is more appropriately initialized in the thread-private
         * routines
         */
        if (stack == NULL && stkptr == NULL)
                return;
        (void) stack_op(INIT, NULL, stack, stkptr);
}

int
getmapent_files(char *key, char *mapname, struct mapline *ml,
    char **stack, char ***stkptr, bool_t *iswildcard, bool_t isrestricted)
{
        int nserr;
        FILE *fp;
        char word[MAXPATHLEN+1], wordq[MAXPATHLEN+1];
        char linebuf[LINESZ], lineqbuf[LINESZ];
        char *lp, *lq;
        struct stat stbuf;
        char fname[MAXFILENAMELEN]; /* /etc prepended to mapname if reqd */
        int syntaxok = 1;

        if (iswildcard)
                *iswildcard = FALSE;
        if ((fp = file_open(mapname, fname, stack, stkptr)) == NULL) {
                nserr = __NSW_UNAVAIL;
                goto done;
        }

        if (stat(fname, &stbuf) < 0) {
                nserr = __NSW_UNAVAIL;
                goto done;
        }

        /*
         * If the file has its execute bit on then
         * assume it's an executable map.
         * Execute it and pass the key as an argument.
         * Expect to get a map entry on the stdout.
         * Ignore the "x" bit on restricted maps.
         */
        if (!isrestricted && (stbuf.st_mode & S_IXUSR)) {
                int rc;

                if (trace > 1) {
                        trace_prt(1, "\tExecutable map: map=%s key=%s\n",
                            fname, key);
                }

                rc = call_read_execout(key, fname, ml->linebuf, LINESZ);

                if (rc != 0) {
                        nserr = __NSW_UNAVAIL;
                        goto done;
                }

                if (strlen(ml->linebuf) == 0) {
                        nserr = __NSW_NOTFOUND;
                        goto done;
                }

                unquote(ml->linebuf, ml->lineqbuf);
                nserr = __NSW_SUCCESS;
                goto done;
        }


        /*
         * It's just a normal map file.
         * Search for the entry with the required key.
         */
        for (;;) {
                lp = get_line(fp, fname, linebuf, sizeof (linebuf));
                if (lp == NULL) {
                        nserr = __NSW_NOTFOUND;
                        goto done;
                }
                if (verbose && syntaxok && isspace(*(uchar_t *)lp)) {
                        syntaxok = 0;
                        syslog(LOG_ERR,
                            "leading space in map entry \"%s\" in %s",
                            lp, mapname);
                }
                lq = lineqbuf;
                unquote(lp, lq);
                if ((getword(word, wordq, &lp, &lq, ' ', sizeof (word))
                    == -1) || (word[0] == '\0'))
                        continue;
                if (strcmp(word, key) == 0)
                        break;
                if (word[0] == '*' && word[1] == '\0') {
                        if (iswildcard)
                                *iswildcard = TRUE;
                        break;
                }
                if (word[0] == '+') {
                        nserr = getmapent(key, word+1, ml, stack, stkptr,
                            iswildcard, isrestricted);
                        if (nserr == __NSW_SUCCESS)
                                goto done;
                        continue;
                }

                /*
                 * sanity check each map entry key against
                 * the lookup key as the map is searched.
                 */
                if (verbose && syntaxok) { /* sanity check entry */
                        if (*key == '/') {
                                if (*word != '/') {
                                        syntaxok = 0;
                                        syslog(LOG_ERR, "bad key \"%s\" in "
                                            "direct map %s\n", word, mapname);
                                }
                        } else {
                                if (strchr(word, '/')) {
                                        syntaxok = 0;
                                        syslog(LOG_ERR, "bad key \"%s\" in "
                                            "indirect map %s\n", word, mapname);
                                }
                        }
                }
        }

        (void) strcpy(ml->linebuf, lp);
        (void) strcpy(ml->lineqbuf, lq);
        nserr = __NSW_SUCCESS;
done:
        if (fp) {
                (void) stack_op(POP, (char *)NULL, stack, stkptr);
                (void) fclose(fp);
        }


        return (nserr);
}

int
getmapkeys_files(char *mapname, struct dir_entry **list, int *error,
    int *cache_time, char **stack, char ***stkptr)
{
        FILE *fp = NULL;
        char word[MAXPATHLEN+1], wordq[MAXPATHLEN+1];
        char linebuf[LINESZ], lineqbuf[LINESZ];
        char *lp, *lq;
        struct stat stbuf;
        char fname[MAXFILENAMELEN]; /* /etc prepended to mapname if reqd */
        int syntaxok = 1;
        int nserr;
        struct dir_entry *last = NULL;

        if (trace > 1)
                trace_prt(1, "getmapkeys_files %s\n", mapname);

        *cache_time = RDDIR_CACHE_TIME;
        if ((fp = file_open(mapname, fname, stack, stkptr)) == NULL) {
                *error = ENOENT;
                nserr = __NSW_UNAVAIL;
                goto done;
        }
        if (fseek(fp, 0L, SEEK_SET) == -1) {
                *error = ENOENT;
                nserr = __NSW_UNAVAIL;
                goto done;
        }

        if (stat(fname, &stbuf) < 0) {
                *error = ENOENT;
                nserr = __NSW_UNAVAIL;
                goto done;
        }

        /*
         * If the file has its execute bit on then
         * assume it's an executable map.
         * I don't know how to list executable maps, return
         * an empty map.
         */
        if (stbuf.st_mode & S_IXUSR) {
                *error = 0;
                nserr = __NSW_SUCCESS;
                goto done;
        }
        /*
         * It's just a normal map file.
         * List entries one line at a time.
         */
        for (;;) {
                lp = get_line(fp, fname, linebuf, sizeof (linebuf));
                if (lp == NULL) {
                        nserr = __NSW_SUCCESS;
                        goto done;
                }
                if (syntaxok && isspace(*(uchar_t *)lp)) {
                        syntaxok = 0;
                        syslog(LOG_ERR,
                            "leading space in map entry \"%s\" in %s",
                            lp, mapname);
                }
                lq = lineqbuf;
                unquote(lp, lq);
                if ((getword(word, wordq, &lp, &lq, ' ', MAXFILENAMELEN)
                    == -1) || (word[0] == '\0'))
                        continue;
                /*
                 * Wildcard entries should be ignored and this should be
                 * the last entry read to corroborate the search through
                 * files, i.e., search for key until a wildcard is reached.
                 */
                if (word[0] == '*' && word[1] == '\0')
                        break;
                if (word[0] == '+') {
                        /*
                         * Name switch here
                         */
                        getmapkeys(word+1, list, error, cache_time,
                            stack, stkptr, 0);
                        /*
                         * the list may have been updated, therefore
                         * our 'last' may no longer be valid
                         */
                        last = NULL;
                        continue;
                }

                if (add_dir_entry(word, list, &last) != 0) {
                        *error = ENOMEM;
                        goto done;
                }
                assert(last != NULL);
        }

        nserr = __NSW_SUCCESS;
done:
        if (fp) {
                (void) stack_op(POP, (char *)NULL, stack, stkptr);
                (void) fclose(fp);
        }

        if (*list != NULL) {
                /*
                 * list of entries found
                 */
                *error = 0;
        }
        return (nserr);
}

int
loadmaster_files(char *mastermap, char *defopts, char **stack, char ***stkptr)
{
        FILE *fp;
        int done = 0;
        char *line, *dir, *map, *opts;
        char linebuf[LINESZ];
        char lineq[LINESZ];
        char fname[MAXFILENAMELEN]; /* /etc prepended to mapname if reqd */


        if ((fp = file_open(mastermap, fname, stack, stkptr)) == NULL)
                return (__NSW_UNAVAIL);

        while ((line = get_line(fp, fname, linebuf,
            sizeof (linebuf))) != NULL) {
                unquote(line, lineq);
                if (macro_expand("", line, lineq, LINESZ)) {
                        syslog(LOG_ERR, "map %s: line too long (max %d chars)",
                            mastermap, LINESZ - 1);
                        continue;
                }
                dir = line;
                while (*dir && isspace(*dir))
                        dir++;
                if (*dir == '\0')
                        continue;
                map = dir;

                while (*map && !isspace(*map)) map++;
                if (*map)
                        *map++ = '\0';

                if (*dir == '+') {
                        opts = map;
                        while (*opts && isspace(*opts))
                                opts++;
                        if (*opts != '-')
                                opts = defopts;
                        else
                                opts++;
                        /*
                         * Check for no embedded blanks.
                         */
                        if (strcspn(opts, " \t") == strlen(opts)) {
                                dir++;
                                (void) loadmaster_map(dir, opts, stack, stkptr);
                        } else {
pr_msg("Warning: invalid entry for %s in %s ignored.\n", dir, fname);
                                continue;
                        }

                } else {
                        while (*map && isspace(*map))
                                map++;
                        if (*map == '\0')
                                continue;
                        opts = map;
                        while (*opts && !isspace(*opts))
                                opts++;
                        if (*opts) {
                                *opts++ = '\0';
                                while (*opts && isspace(*opts))
                                        opts++;
                        }
                        if (*opts != '-')
                                opts = defopts;
                        else
                                opts++;
                        /*
                         * Check for no embedded blanks.
                         */
                        if (strcspn(opts, " \t") == strlen(opts)) {
                                dirinit(dir, map, opts, 0, stack, stkptr);
                        } else {
pr_msg("Warning: invalid entry for %s in %s ignored.\n", dir, fname);
                                continue;
                        }
                }
                done++;
        }

        (void) stack_op(POP, (char *)NULL, stack, stkptr);
        (void) fclose(fp);

        return (done ? __NSW_SUCCESS : __NSW_NOTFOUND);
}

int
loaddirect_files(char *map, char *local_map, char *opts,
    char **stack, char ***stkptr)
{
        FILE *fp;
        int done = 0;
        char *line, *p1, *p2;
        char linebuf[LINESZ];
        char fname[MAXFILENAMELEN]; /* /etc prepended to mapname if reqd */

        if ((fp = file_open(map, fname, stack, stkptr)) == NULL)
                return (__NSW_UNAVAIL);

        while ((line = get_line(fp, fname, linebuf,
            sizeof (linebuf))) != NULL) {
                p1 = line;
                while (*p1 && isspace(*p1))
                        p1++;
                if (*p1 == '\0')
                        continue;
                p2 = p1;
                while (*p2 && !isspace(*p2))
                        p2++;
                *p2 = '\0';
                if (*p1 == '+') {
                        p1++;
                        (void) loaddirect_map(p1, local_map, opts, stack,
                            stkptr);
                } else {
                        dirinit(p1, local_map, opts, 1, stack, stkptr);
                }
                done++;
        }

        (void) stack_op(POP, (char *)NULL, stack, stkptr);
        (void) fclose(fp);

        return (done ? __NSW_SUCCESS : __NSW_NOTFOUND);
}

/*
 * This procedure opens the file and pushes it onto the
 * the stack. Only if a file is opened successfully, is
 * it pushed onto the stack
 */
static FILE *
file_open(char *map, char *fname, char **stack, char ***stkptr)
{
        FILE *fp;

        if (*map != '/') {
                /* prepend an "/etc" */
                (void) strcpy(fname, "/etc/");
                (void) strcat(fname, map);
        } else {
                (void) strcpy(fname, map);
        }

        fp = fopen(fname, "r");

        if (fp != NULL) {
                if (!stack_op(PUSH, fname, stack, stkptr)) {
                        (void) fclose(fp);
                        return (NULL);
                }
        }
        return (fp);
}

/*
 * reimplemnted to be MT-HOT.
 */
int
stack_op(int op, char *name, char **stack, char ***stkptr)
{
        char **ptr = NULL;
        char **stk_top = &stack[STACKSIZ - 1];

        /*
         * the stackptr points to the next empty slot
         * for PUSH: put the element and increment stkptr
         * for POP: decrement stkptr and free
         */

        switch (op) {
        case INIT:
                for (ptr = stack; ptr != stk_top; ptr++)
                        *ptr = (char *)NULL;
                *stkptr = stack;
                return (1);
        case ERASE:
                for (ptr = stack; ptr != stk_top; ptr++)
                        if (*ptr) {
                                if (trace > 1)
                                        trace_prt(1, "  ERASE %s\n", *ptr);
                                free (*ptr);
                                *ptr = (char *)NULL;
                        }
                *stkptr = stack;
                return (1);
        case PUSH:
                if (*stkptr == stk_top)
                        return (0);
                for (ptr = stack; ptr != *stkptr; ptr++)
                        if (*ptr && (strcmp(*ptr, name) == 0)) {
                                return (0);
                        }
                if (trace > 1)
                        trace_prt(1, "  PUSH %s\n", name);
                if ((**stkptr = strdup(name)) == NULL) {
                        syslog(LOG_ERR, "stack_op: Memory alloc failed : %m");
                        return (0);
                }
                (*stkptr)++;
                return (1);
        case POP:
                if (*stkptr != stack)
                        (*stkptr)--;
                else
                        syslog(LOG_ERR, "Attempt to pop empty stack\n");

                if (*stkptr && **stkptr) {
                        if (trace > 1)
                                trace_prt(1, "  POP %s\n", **stkptr);
                        free (**stkptr);
                        **stkptr = (char *)NULL;
                }
                return (1);
        default:
                return (0);
        }
}

#define READ_EXECOUT_ARGS 3

/*
 * read_execout(char *key, char **lp, char *fname, char *line, int linesz)
 * A simpler, multithreaded implementation of popen(). Used due to
 * non multithreaded implementation of popen() (it calls vfork()) and a
 * significant bug in execl().
 * Returns 0 on OK or -1 on error.
 */
static int
read_execout(char *key, char **lp, char *fname, char *line, int linesz)
{
        int p[2];
        int status = 0;
        int child_pid;
        char *args[READ_EXECOUT_ARGS];
        FILE *fp0;

        if (pipe(p) < 0) {
                syslog(LOG_ERR, "read_execout: Cannot create pipe");
                return (-1);
        }

        /* setup args for execv */
        if (((args[0] = strdup(fname)) == NULL) ||
            ((args[1] = strdup(key)) == NULL)) {
                if (args[0] != NULL)
                        free(args[0]);
                syslog(LOG_ERR, "read_execout: Memory allocation failed");
                return (-1);
        }
        args[2] = NULL;

        if (trace > 3)
                trace_prt(1, "\tread_execout: forking .....\n");

        switch ((child_pid = fork1())) {
        case -1:
                syslog(LOG_ERR, "read_execout: Cannot fork");
                return (-1);
        case 0:
                /*
                 * Child
                 */
                close(p[0]);
                close(1);
                if (fcntl(p[1], F_DUPFD, 1) != 1) {
                        syslog(LOG_ERR,
                        "read_execout: dup of stdout failed");
                        _exit(-1);
                }
                close(p[1]);
                execv(fname, &args[0]);
                _exit(-1);
        default:
                /*
                 * Parent
                 */
                close(p[1]);

                /*
                 * wait for child to complete. Note we read after the
                 * child exits to guarantee a full pipe.
                 */
                while (waitpid(child_pid, &status, 0) < 0) {
                        /* if waitpid fails with EINTR, restart */
                        if (errno != EINTR) {
                                status = -1;
                                break;
                        }
                }
                if (status != -1) {
                        if ((fp0 = fdopen(p[0], "r")) != NULL) {
                                *lp = get_line(fp0, fname, line, linesz);
                                fclose(fp0);
                        } else {
                                close(p[0]);
                                status = -1;
                        }
                } else {
                        close(p[0]);
                }

                /* free args */
                free(args[0]);
                free(args[1]);

                if (trace > 3) {
                        trace_prt(1, "\tread_execout: map=%s key=%s line=%s\n",
                            fname, key, line);
                }

                return (status);
        }
}

void
automountd_do_exec_map(void *cookie, char *argp, size_t arg_size,
    door_desc_t *dfd, uint_t n_desc)
{
        command_t       *command;
        char    line[LINESZ];
        char    *lp;
        int     rc;

        command = (command_t *)argp;

        if (sizeof (*command) != arg_size) {
                rc = 0;
                syslog(LOG_ERR, "read_execout: invalid door arguments");
                door_return((char *)&rc, sizeof (rc), NULL, 0);
        }

        rc = read_execout(command->key, &lp, command->file, line, LINESZ);

        if (rc != 0) {
                /*
                 * read_execout returned an error, return 0 to the door_client
                 * to indicate failure
                 */
                rc = 0;
                door_return((char *)&rc, sizeof (rc), NULL, 0);
        } else {
                door_return((char *)line, LINESZ, NULL, 0);
        }
        trace_prt(1, "automountd_do_exec_map, door return failed %s, %s\n",
            command->file, strerror(errno));
        door_return(NULL, 0, NULL, 0);
}

static int
call_read_execout(char *key, char *fname, char *line, int linesz)
{
        command_t command;
        door_arg_t darg;
        int ret;

        bzero(&command, sizeof (command));
        (void) strlcpy(command.file, fname, MAXPATHLEN);
        (void) strlcpy(command.key, key, MAXOPTSLEN);

        if (trace >= 1)
                trace_prt(1, "call_read_execout %s %s\n", fname, key);
        darg.data_ptr = (char *)&command;
        darg.data_size = sizeof (command);
        darg.desc_ptr = NULL;
        darg.desc_num = 0;
        darg.rbuf = line;
        darg.rsize = linesz;

        ret = door_call(did_exec_map, &darg);

        return (ret);
}