root/usr/src/cmd/fs.d/autofs/auto_subr.c
/*
 * 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) 2010, Oracle and/or its affiliates. All rights reserved.
 */


#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <locale.h>
#include <syslog.h>
#include <errno.h>
#include <string.h>
#include <stdarg.h>
#include <dirent.h>
#include <limits.h>
#include <thread.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/vfs.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mnttab.h>
#include <sys/mntent.h>
#include <sys/mount.h>
#include <sys/signal.h>
#include <sys/utsname.h>
#include <sys/systeminfo.h>
#include <sys/tiuser.h>
#include <sys/utsname.h>
#include <rpc/rpc.h>
#include <rpcsvc/nfs_prot.h>
#include <rpcsvc/daemon_utils.h>
#include <assert.h>
#include "automount.h"
#include <deflt.h>
#include <zone.h>
#include <priv.h>
#include <fcntl.h>
#include <libshare.h>
#include <libscf.h>
#include "smfcfg.h"

static char *check_hier(char *);
static int arch(char *, size_t, bool_t);
static int cpu(char *, size_t);
static int natisa(char *, size_t);
static int platform(char *, size_t);

struct mntlist *current_mounts;

static bool_t nodirect_map = FALSE;

/*
 * If the system is labeled then we need to
 * have a uniquely-named auto_home map for each zone.
 * The maps are made unique by appending the zonename.
 * The home directory is made unique by prepending /zone/<zonename>
 * for each zone that is dominated by the current zone.
 * The current zone's home directory mount point is not changed.
 *
 * For each auto_home_<zonename> a default template map is created
 * only if it doesn't exist yet. The default entry is used to declare
 * local home directories created within each zone. For example:
 *
 *      +auto_home_public
 *      * -fstype=lofs :/zone/public/export/home/&
 */
static void
loadzone_maps(char *mntpnt, char *map, char *opts, char **stack, char ***stkptr)
{
        zoneid_t *zids = NULL;
        zoneid_t my_zoneid;
        uint_t nzents_saved;
        uint_t nzents;
        int i;

        if (!priv_ineffect(PRIV_SYS_MOUNT))
                return;

        if (zone_list(NULL, &nzents) != 0) {
                return;
        }
        my_zoneid = getzoneid();
again:
        if (nzents == 0)
                return;

        zids = malloc(nzents * sizeof (zoneid_t));
        nzents_saved = nzents;

        if (zone_list(zids, &nzents) != 0) {
                free(zids);
                return;
        }
        if (nzents != nzents_saved) {
                /* list changed, try again */
                free(zids);
                goto again;
        }

        for (i = 0; i < nzents; i++) {
                char zonename[ZONENAME_MAX];
                char zoneroot[MAXPATHLEN];

                if (getzonenamebyid(zids[i], zonename, ZONENAME_MAX) != -1) {
                        char appended_map[MAXPATHLEN];
                        char prepended_mntpnt[MAXPATHLEN];
                        char map_path[MAXPATHLEN];
                        int fd;

                        (void) snprintf(appended_map, sizeof (appended_map),
                            "%s_%s", map, zonename);

                        /* for current zone, leave mntpnt alone */
                        if (zids[i] != my_zoneid) {
                                (void) snprintf(prepended_mntpnt,
                                    sizeof (prepended_mntpnt),
                                    "/zone/%s%s", zonename, mntpnt);
                                if (zone_getattr(zids[i], ZONE_ATTR_ROOT,
                                    zoneroot, sizeof (zoneroot)) == -1)
                                        continue;
                        } else {
                                (void) strcpy(prepended_mntpnt, mntpnt);
                                zoneroot[0] = '\0';
                        }

                        dirinit(prepended_mntpnt, appended_map, opts, 0, stack,
                            stkptr);
                        /*
                         * Next create auto_home_<zone> maps for each zone
                         */

                        (void) snprintf(map_path, sizeof (map_path),
                            "/etc/%s", appended_map);
                        /*
                         * If the map file doesn't exist create a template
                         */
                        if ((fd = open(map_path, O_RDWR | O_CREAT | O_EXCL,
                            S_IRUSR | S_IWUSR | S_IRGRP| S_IROTH)) != -1) {
                                int len;
                                char map_rec[MAXPATHLEN];

                                len = snprintf(map_rec, sizeof (map_rec),
                                    "+%s\n*\t-fstype=lofs\t:%s/export/home/&\n",
                                    appended_map, zoneroot);
                                if (len <= sizeof (map_rec))
                                        (void) write(fd, map_rec, len);
                                (void) close(fd);
                        }
                }
        }
        free(zids);
}

void
dirinit(char *mntpnt, char *map, char *opts, int direct, char **stack,
    char ***stkptr)
{
        struct autodir *dir;
        char *p;

        if (strcmp(map, "-null") == 0) {
                if (strcmp(mntpnt, "/-") == 0)
                        nodirect_map = TRUE;
                goto enter;
        }

        p = mntpnt + (strlen(mntpnt) - 1);
        if (*p == '/')
                *p = '\0';      /* trim trailing / */
        if (*mntpnt != '/') {
                pr_msg("dir %s must start with '/'", mntpnt);
                return;
        }
        if (p = check_hier(mntpnt)) {
                pr_msg("hierarchical mountpoint: %s and %s",
                    p, mntpnt);
                return;
        }

        /*
         * If it's a direct map then call dirinit
         * for every map entry.
         */
        if ((strcmp(mntpnt, "/-") == 0) && !(nodirect_map)) {
                (void) loaddirect_map(map, map, opts, stack, stkptr);
                return;
        }

        /*
         * Home directories are polyinstantiated on
         * labeled systems.
         */
        if (is_system_labeled() &&
            (strcmp(mntpnt, "/home") == 0) &&
            (strcmp(map, "auto_home") == 0)) {
                (void) loadzone_maps(mntpnt, map, opts, stack, stkptr);
                return;
        }
enter:
        dir = (struct autodir *)malloc(sizeof (*dir));
        if (dir == NULL)
                goto alloc_failed;
        dir->dir_name = strdup(mntpnt);
        if (dir->dir_name == NULL)
                goto alloc_failed;
        dir->dir_map = strdup(map);
        if (dir->dir_map == NULL)
                goto alloc_failed;
        dir->dir_opts = strdup(opts);
        if (dir->dir_opts == NULL)
                goto alloc_failed;
        dir->dir_direct = direct;
        dir->dir_remount = 0;
        dir->dir_next = NULL;

        /*
         * Append to dir chain
         */
        if (dir_head == NULL)
                dir_head = dir;
        else
                dir_tail->dir_next = dir;

        dir->dir_prev = dir_tail;
        dir_tail = dir;

        return;

alloc_failed:
        if (dir != NULL) {
                if (dir->dir_opts)
                        free(dir->dir_opts);
                if (dir->dir_map)
                        free(dir->dir_map);
                if (dir->dir_name)
                        free(dir->dir_name);
                free(dir);
        }
        pr_msg("dirinit: memory allocation failed");
}

/*
 *  Check whether the mount point is a
 *  subdirectory or a parent directory
 *  of any previously mounted automount
 *  mount point.
 */
static char *
check_hier(mntpnt)
        char *mntpnt;
{
        register struct autodir *dir;
        register char *p, *q;

        for (dir = dir_head; dir; dir = dir->dir_next) {
                p = dir->dir_name;
                q = mntpnt;
                for (; *p == *q; p++, q++)
                        if (*p == '\0')
                                break;
                if (*p == '/' && *q == '\0')
                        return (dir->dir_name);
                if (*p == '\0' && *q == '/')
                        return (dir->dir_name);
                if (*p == '\0' && *q == '\0')
                        return (NULL);
        }
        return (NULL);  /* it's not a subdir or parent */
}

/*
 * Gets the next token from the string "p" and copies it into "w".  The "wq" is
 * a quote vector for "w" and is derived from "pq", which is a quote vector for
 * "p". Delim is the character to be used as a delimiter for the scan.  A space
 * means "whitespace". The call to getword must provide buffers w and wq of size
 * at least wordsz. getword() will pass strings of maximum length (wordsz-1),
 * since it needs to null terminate the string.
 * Returns 0 on ok and -1 on error.
 */
int
getword(char *w, char *wq, char **p, char **pq, char delim, int wordsz)
{
        char *tmp = w;
        char *tmpq = wq;
        int count = wordsz;

        if (wordsz <= 0) {
                if (verbose)
                        syslog(LOG_ERR,
                        "getword: input word size %d must be > 0", wordsz);
                return (-1);
        }

        while ((delim == ' ' ? isspace(**p) : **p == delim) && **pq == ' ')
                (*p)++, (*pq)++;

        while (**p &&
            !((delim == ' ' ? isspace(**p) : **p == delim) &&
            **pq == ' ')) {
                if (--count <= 0) {
                        *tmp = '\0';
                        *tmpq = '\0';
                        syslog(LOG_ERR,
                        "maximum word length (%d) exceeded", wordsz);
                        return (-1);
                }
                *w++  = *(*p)++;
                *wq++ = *(*pq)++;
        }
        *w  = '\0';
        *wq = '\0';

        return (0);
}

/*
 * get_line attempts to get a line from the map, upto LINESZ. A line in
 * the map is a concatenation of lines if the continuation symbol '\'
 * is used at the end of the line. Returns line on success, a NULL on
 * EOF, and an empty string on lines > linesz.
 */
char *
get_line(FILE *fp, char *map, char *line, int linesz)
{
        register char *p = line;
        register int len;
        int excess = 0;

        *p = '\0';

        for (;;) {
                if (fgets(p, linesz - (p-line), fp) == NULL) {
                        return (*line ? line : NULL);   /* EOF */
                }

                len = strlen(line);
                if (len <= 0) {
                        p = line;
                        continue;
                }
                p = &line[len - 1];

                /*
                 * Is input line too long?
                 */
                if (*p != '\n') {
                        excess = 1;
                        /*
                         * Perhaps last char read was '\'. Reinsert it
                         * into the stream to ease the parsing when we
                         * read the rest of the line to discard.
                         */
                        (void) ungetc(*p, fp);
                        break;
                }
trim:
                /* trim trailing white space */
                while (p >= line && isspace(*(uchar_t *)p))
                        *p-- = '\0';
                if (p < line) {                 /* empty line */
                        p = line;
                        continue;
                }

                if (*p == '\\') {               /* continuation */
                        *p = '\0';
                        continue;
                }

                /*
                 * Ignore comments. Comments start with '#'
                 * which must be preceded by a whitespace, unless
                 * if '#' is the first character in the line.
                 */
                p = line;
                while (p = strchr(p, '#')) {
                        if (p == line || isspace(*(p-1))) {
                                *p-- = '\0';
                                goto trim;
                        }
                        p++;
                }
                break;
        }
        if (excess) {
                int c;

                /*
                 * discard rest of line and return an empty string.
                 * done to set the stream to the correct place when
                 * we are done with this line.
                 */
                while ((c = getc(fp)) != EOF) {
                        *p = c;
                        if (*p == '\n')         /* end of the long line */
                                break;
                        else if (*p == '\\') {          /* continuation */
                                if (getc(fp) == EOF)    /* ignore next char */
                                        break;
                        }
                }
                syslog(LOG_ERR,
                    "map %s: line too long (max %d chars)",
                    map, linesz-1);
                *line = '\0';
        }

        return (line);
}

/*
 * Gets the retry=n entry from opts.
 * Returns 0 if retry=n is not present in option string,
 * retry=n is invalid, or when option string is NULL.
 */
int
get_retry(char *opts)
{
        int retry = 0;
        char buf[MAXOPTSLEN];
        char *p, *pb, *lasts;

        if (opts == NULL)
                return (retry);

        (void) strcpy(buf, opts);
        pb = buf;
        while (p = (char *)strtok_r(pb, ",", &lasts)) {
                pb = NULL;
                if (strncmp(p, "retry=", 6) == 0)
                        retry = atoi(p+6);
        }
        return (retry > 0 ? retry : 0);
}

/*
 * Returns zero if "opt" is found in mnt->mnt_opts, setting
 * *sval to whatever follows the equal sign after "opt".
 * str_opt allocates a string long enough to store the value of
 * "opt" plus a terminating null character and returns it as *sval.
 * It is the responsability of the caller to deallocate *sval.
 * *sval will be equal to NULL upon return if either "opt=" is not found,
 * or "opt=" has no value associated with it.
 *
 * stropt will return -1 on error.
 */
int
str_opt(struct mnttab *mnt, char *opt, char **sval)
{
        char *str, *comma;

        /*
         * is "opt" in the options field?
         */
        if (str = hasmntopt(mnt, opt)) {
                str += strlen(opt);
                if (*str++ != '=' ||
                    (*str == ',' || *str == '\0')) {
                        syslog(LOG_ERR, "Bad option field");
                        return (-1);
                }
                comma = strchr(str, ',');
                if (comma != NULL)
                        *comma = '\0';
                *sval = strdup(str);
                if (comma != NULL)
                        *comma = ',';
                if (*sval == NULL)
                        return (-1);
        } else
                *sval = NULL;

        return (0);
}

/*
 * Performs text expansions in the string "pline".
 * "plineq" is the quote vector for "pline".
 * An identifier prefixed by "$" is replaced by the
 * corresponding environment variable string.  A "&"
 * is replaced by the key string for the map entry.
 *
 * This routine will return an error (non-zero) if *size* would be
 * exceeded after expansion, indicating that the macro_expand failed.
 * This is to prevent writing past the end of pline and plineq.
 * Both pline and plineq are left untouched in such error case.
 */
int
macro_expand(key, pline, plineq, size)
        char *key, *pline, *plineq;
        int size;
{
        register char *p,  *q;
        register char *bp, *bq;
        register char *s;
        char buffp[LINESZ], buffq[LINESZ];
        char namebuf[64], *pn;
        int expand = 0;
        struct utsname name;
        char procbuf[SYS_NMLN];
        char isaname[64];

        p = pline;  q = plineq;
        bp = buffp; bq = buffq;

        while (*p) {
                if (*p == '&' && *q == ' ') {   /* insert key */
                        /*
                         * make sure we don't overflow buffer
                         */
                        if ((int)((bp - buffp) + strlen(key)) < size) {
                                for (s = key; *s; s++) {
                                        *bp++ = *s;
                                        *bq++ = ' ';
                                }
                                expand++;
                                p++; q++;
                                continue;
                        } else {
                                /*
                                 * line too long...
                                 */
                                return (1);
                        }
                }

                if (*p == '$' && *q == ' ') {   /* insert env var */
                        p++; q++;
                        pn = namebuf;
                        if (*p == '{') {
                                p++; q++;
                                while (*p && *p != '}') {
                                        *pn++ = *p++;
                                        q++;
                                }
                                if (*p) {
                                        p++; q++;
                                }
                        } else {
                                while (*p && (*p == '_' || isalnum(*p))) {
                                        *pn++ = *p++;
                                        q++;
                                }
                        }
                        *pn = '\0';

                        s = getenv(namebuf);
                        if (!s) {
                                /* not found in env */
                                if (strcmp(namebuf, "ARCH") == 0) {
                                        if (arch(procbuf, sizeof (procbuf),
                                            FALSE))
                                                s = procbuf;
                                } else if (strcmp(namebuf, "CPU") == 0) {
                                        if (cpu(procbuf, sizeof (procbuf)))
                                                s = procbuf;
                                } else if (strcmp(namebuf, "HOST") == 0) {
                                        (void) uname(&name);
                                        s = name.nodename;
                                } else if (strcmp(namebuf, "KARCH") == 0) {
                                        if (arch(procbuf, sizeof (procbuf),
                                            TRUE))
                                                s = procbuf;
                                } else if (strcmp(namebuf, "OSREL") == 0) {
                                        (void) uname(&name);
                                        s = name.release;
                                } else if (strcmp(namebuf, "OSNAME") == 0) {
                                        (void) uname(&name);
                                        s = name.sysname;
                                } else if (strcmp(namebuf, "OSVERS") == 0) {
                                        (void) uname(&name);
                                        s = name.version;
                                } else if (strcmp(namebuf, "NATISA") == 0) {
                                        if (natisa(isaname, sizeof (isaname)))
                                                s = isaname;
                                } else if (strcmp(namebuf, "PLATFORM") == 0) {
                                        if (platform(procbuf, sizeof (procbuf)))
                                                s = procbuf;
                                }
                        }

                        if (s) {
                                if ((int)((bp - buffp) + strlen(s)) < size) {
                                        while (*s) {
                                                *bp++ = *s++;
                                                *bq++ = ' ';
                                        }
                                } else {
                                        /*
                                         * line too long...
                                         */
                                        return (1);
                                }
                        }
                        expand++;
                        continue;
                }
                /*
                 * Since buffp needs to be null terminated, we need to
                 * check that there's still room in the buffer to
                 * place at least two more characters, *p and the
                 * terminating null.
                 */
                if (bp - buffp == size - 1) {
                        /*
                         * There was not enough room for at least two more
                         * characters, return with an error.
                         */
                        return (1);
                }
                /*
                 * The total number of characters so far better be less
                 * than the size of buffer passed in.
                 */
                *bp++ = *p++;
                *bq++ = *q++;

        }
        if (!expand)
                return (0);
        *bp = '\0';
        *bq = '\0';
        /*
         * We know buffp/buffq will fit in pline/plineq since we
         * processed at most size characters.
         */
        (void) strcpy(pline, buffp);
        (void) strcpy(plineq, buffq);

        return (0);
}

/*
 * Removes backslashes, quotes and brackets from the string "str"
 * and returns the quoting information in "qbuf". Character is
 * considered escaped when it is
 *
 *      preceded with '\'       e.g. \a
 *      within quotes           e.g. "string"
 *      a ':' in brackets       e.g. [an:ip:6::ad::d:re:s:s]
 *
 * original str: 'the "brown" f\ox said: [fe80::20a:e4ff:fe35:8b0d]'
 * unquoted str: 'the brown fox said: [fe80::20a:e4ff:fe35:8b0d]'
 * and the qbuf: '    ^^^^^  ^             ^^   ^    ^    ^     '
 */
void
unquote(str, qbuf)
        char *str, *qbuf;
{
        register int escaped, inquote, inbracket, quoted;
        register char *ip, *bp, *qp;
        char buf[LINESZ];

        escaped = inquote = inbracket = quoted = 0;

        for (ip = str, bp = buf, qp = qbuf; *ip; ip++) {
                if (!escaped) {
                        if (*ip == '\\') {
                                escaped = 1;
                                quoted++;
                                continue;
                        } else
                        if (*ip == '"') {
                                inquote = !inquote;
                                quoted++;
                                continue;
                        } else
                        if (*ip == '[') {
                                inbracket++;
                                quoted++;
                        } else
                        if (*ip == ']') {
                                if (inbracket > 0) inbracket--;
                        }
                }

                *bp++ = *ip;
                *qp++ = (inquote || escaped) ? '^'
                                : ((inbracket && (*ip == ':')) ? '^' : ' ');
                escaped = 0;
        }

        *bp = '\0';
        *qp = '\0';

        if (quoted)
                (void) strcpy(str, buf);
}

/*
 * If str is enclosed in [brackets], trim them off.
 */
void
unbracket(s)
        char **s;
{
        char *b = *s + strlen(*s) - 1;

        if (*b == ']')
                *b = '\0';
        if (**s == '[')
                (*s)++;
}

/*
 * Removes trailing spaces from string "s".
 */
void
trim(s)
        char *s;
{
        char *p = &s[strlen(s) - 1];

        while (p >= s && isspace(*(uchar_t *)p))
                *p-- = '\0';
}

/*
 * try to allocate memory using malloc, if malloc fails, then flush the
 * rddir caches, and retry. If the second allocation after the readdir
 * caches have been flushed fails too, then return NULL to indicate
 * memory could not be allocated.
 */
char *
auto_rddir_malloc(unsigned nbytes)
{
        char *p;
        int again = 0;

        if ((p = malloc(nbytes)) == NULL) {
                /*
                 * No memory, free rddir caches and try again
                 */
                mutex_lock(&cleanup_lock);
                cond_signal(&cleanup_start_cv);
                if (cond_wait(&cleanup_done_cv, &cleanup_lock)) {
                        mutex_unlock(&cleanup_lock);
                        syslog(LOG_ERR, "auto_rddir_malloc interrupted\n");
                } else {
                        mutex_unlock(&cleanup_lock);
                        again = 1;
                }
        }

        if (again)
                p = malloc(nbytes);

        return (p);
}

/*
 * try to strdup a string, if it fails, then flush the rddir caches,
 * and retry. If the second strdup fails, return NULL to indicate failure.
 */
char *
auto_rddir_strdup(const char *s1)
{
        char *s2;
        int again = 0;

        if ((s2 = strdup(s1)) == NULL) {
                /*
                 * No memory, free rddir caches and try again
                 */
                mutex_lock(&cleanup_lock);
                cond_signal(&cleanup_start_cv);
                if (cond_wait(&cleanup_done_cv, &cleanup_lock)) {
                        mutex_unlock(&cleanup_lock);
                        syslog(LOG_ERR, "auto_rddir_strdup interrupted\n");
                } else {
                        mutex_unlock(&cleanup_lock);
                        again = 1;
                }
        }

        if (again)
                s2 = strdup(s1);

        return (s2);
}

/*
 * Returns a pointer to the entry corresponding to 'name' if found,
 * otherwise it returns NULL.
 */
struct dir_entry *
btree_lookup(struct dir_entry *head, char *name)
{
        register struct dir_entry *p;
        register int direction;

        for (p = head; p != NULL; ) {
                direction = strcmp(name, p->name);
                if (direction == 0)
                        return (p);
                if (direction > 0)
                        p = p->right;
                else p = p->left;
        }
        return (NULL);
}

/*
 * Add entry to binary tree
 * Duplicate entries are not added
 */
void
btree_enter(struct dir_entry **head, struct dir_entry *ent)
{
        register struct dir_entry *p, *prev = NULL;
        register int direction;

        ent->right = ent->left = NULL;
        if (*head == NULL) {
                *head = ent;
                return;
        }

        for (p = *head; p != NULL; ) {
                prev = p;
                direction = strcmp(ent->name, p->name);
                if (direction == 0) {
                        /*
                         * entry already in btree
                         */
                        return;
                }
                if (direction > 0)
                        p = p->right;
                else p = p->left;
        }
        assert(prev != NULL);
        if (direction > 0)
                prev->right = ent;
        else prev->left = ent;
}

/*
 * If entry doesn't exist already, add it to the linear list
 * after '*last' and to the binary tree list.
 * If '*last == NULL' then the list is walked till the end.
 * *last is always set to the new element after successful completion.
 * if entry already exists '*last' is only updated if not previously
 * provided.
 */
int
add_dir_entry(char *name, struct dir_entry **list, struct dir_entry **last)
{
        struct dir_entry *e, *l;

        if ((*list != NULL) && (*last == NULL)) {
                /*
                 * walk the list to find last element
                 */
                for (l = *list; l != NULL; l = l->next)
                        *last = l;
        }

        if (btree_lookup(*list, name) == NULL) {
                /*
                 * not a duplicate, add it to list
                 */
                /* LINTED pointer alignment */
                e = (struct dir_entry *)
                    auto_rddir_malloc(sizeof (struct dir_entry));
                if (e == NULL)
                        return (ENOMEM);
                (void) memset((char *)e, 0, sizeof (*e));
                e->name = auto_rddir_strdup(name);
                if (e->name == NULL) {
                        free(e);
                        return (ENOMEM);
                }
                e->next = NULL;
                if (*list == NULL) {
                        /*
                         * list is empty
                         */
                        *list = *last = e;
                } else {
                        /*
                         * append to end of list
                         */
                        assert(*last != NULL);
                        (*last)->next = e;
                        *last = e;
                }
                /*
                 * add to binary tree
                 */
                btree_enter(list, e);
        }
        return (0);
}

/*
 * Print trace output.
 * Like fprintf(stderr, fmt, ...) except that if "id" is nonzero, the output
 * is preceeded by the ID of the calling thread.
 */
#define FMT_BUFSIZ 1024

void
trace_prt(int id, char *fmt, ...)
{
        va_list args;

        char buf[FMT_BUFSIZ];

        if (id) {
                (void) sprintf(buf, "t%u\t%s", thr_self(), fmt);
                fmt = buf;
        }
        va_start(args, fmt);
        (void) vfprintf(stderr, fmt, args);
        va_end(args);
}

/*
 * Extract the isalist(7) for userland from the kernel.
 */
static char *
isalist(void)
{
        char *buf;
        size_t bufsize = BUFSIZ;        /* wild guess */
        long ret;

        buf = malloc(bufsize);
        do {
                ret = sysinfo(SI_ISALIST, buf, bufsize);
                if (ret == -1l)
                        return (NULL);
                if (ret > bufsize) {
                        bufsize = ret;
                        buf = realloc(buf, bufsize);
                } else
                        break;
        } while (buf != NULL);

        return (buf);
}

/*
 * Classify isa's as to bitness of the corresponding ABIs.
 * isa's which have no "official" system ABI are returned
 * unrecognised i.e. zero bits.
 */
static int
bitness(char *isaname)
{
        if (strcmp(isaname, "sparc") == 0 ||
            strcmp(isaname, "i386") == 0)
                return (32);

        if (strcmp(isaname, "sparcv9") == 0 ||
            strcmp(isaname, "amd64") == 0)
                return (64);

        return (0);
}

/*
 * Determine the application architecture (derived from uname -m) to expand
 * the $ARCH and $KARCH macros.
 *
 * Like arch(1), we need to substitute "sun4" for "sun4u", "sun4v", ... for
 * backward compatibility. When kflag is set (like arch -k), the unmodifed
 * value is returned instead.
 */
static int
arch(char *buf, size_t bufsize, bool_t karch)
{
        long ret;

        ret = sysinfo(SI_MACHINE, buf, bufsize);
        if (ret == -1L)
                return (0);
        if (!karch && strncmp(buf, "sun4", 4) == 0)
                (void) strlcpy(buf, "sun4", bufsize);
        return (1);
}

/*
 * Determine the basic ISA (uname -p) to expand the $CPU macro.
 */
static int
cpu(char *buf, size_t bufsize)
{
        long ret;

        ret = sysinfo(SI_ARCHITECTURE, buf, bufsize);
        if (ret == -1L)
                return (0);
        else
                return (1);
}

/*
 * Find the left-most element in the isalist that matches our idea of a
 * system ABI.
 *
 * On machines with only one ABI, this is usually the same as uname -p.
 */
static int
natisa(char *buf, size_t bufsize)
{
        int bits;
        char *isa, *list;
        char *lasts;

        if ((list = isalist()) == NULL)
                return (0);

        for (isa = strtok_r(list, " ", &lasts);
            isa; isa = strtok_r(0, " ", &lasts))
                if ((bits = bitness(isa)) != 0)
                        break;  /* ignore "extension" architectures */

        if (isa == 0 || bits == 0) {
                free(list);
                return (0);     /* can't figure it out :( */
        }

        (void) strncpy(buf, isa, bufsize);
        free(list);

        return (1);
}

/*
 * Determine the platform (uname -i) to expand the $PLATFORM macro.
 */
static int
platform(char *buf, size_t bufsize)
{
        long ret;

        ret = sysinfo(SI_PLATFORM, buf, bufsize);
        if (ret == -1L)
                return (0);
        else
                return (1);
}

/*
 * Set environment variables
 */
void
put_automountd_env(void)
{
        char defval[PATH_MAX], *p, *a, *c;
        int ret = 0, bufsz = PATH_MAX;

        ret = autofs_smf_get_prop("environment", defval, DEFAULT_INSTANCE,
            SCF_TYPE_ASTRING, AUTOMOUNTD, &bufsz);
        if (ret == SA_OK) {
                a = c = defval;
                if (*a == '\0')
                        return;
                /*
                 * Environment variables can have more than one value
                 * seperated by a comma and there can be multiple
                 * environment variables. * a=b\,c,d=e. For multiple
                 * valued environment variable, values are seperated
                 * with an escape character.
                 */
                while ((p = strchr(c, ',')) != NULL) {
                        if (*(p - 1) == '\\') {
                                c = p + 1;
                                continue;
                        }
                        *p = '\0';
                        if ((c = strchr(a, '=')) != NULL)
                                putenv(strdup(a));
                        a = c = p + 1;
                }
                if (*a != '\0') {
                        if ((c = strchr(a, '=')) != NULL)
                                putenv(strdup(a));
                }
        }
}