/* Copyright 1988,1990,1993,1994 by Paul Vixie
 * All rights reserved
 */

/*
 * Copyright (c) 1997 by Internet Software Consortium
 *
 * 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 INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM 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 "cron.h"


char **
env_init(void)
{
        char    **p = (char **) malloc(sizeof(char **));

        if (p)
                p[0] = NULL;
        return (p);
}


void
env_free(char **envp)
{
        char    **p;

        if ((p = envp))
            for (;  *p;  p++)
                free(*p);
        free(envp);
}


char **
env_copy(char **envp)
{
        int     count, i;
        char    **p;

        for (count = 0;  envp[count] != NULL;  count++)
                ;
        p = (char **) reallocarray(NULL, count+1, sizeof(char *)); /* 1 for the NULL */
        if (p == NULL) {
                errno = ENOMEM;
                return NULL;
        }
        for (i = 0;  i < count;  i++)
                if ((p[i] = strdup(envp[i])) == NULL) {
                        while (--i >= 0)
                                (void) free(p[i]);
                        free(p);
                        errno = ENOMEM;
                        return NULL;
                }
        p[count] = NULL;
        return (p);
}


char **
env_set(char **envp, char *envstr)
{
        int     count, found;
        char    **p;
        char    *q;

        /*
         * count the number of elements, including the null pointer;
         * also set 'found' to -1 or index of entry if already in here.
         */
        found = -1;
        for (count = 0;  envp[count] != NULL;  count++) {
                if (!strcmp_until(envp[count], envstr, '='))
                        found = count;
        }
        count++;        /* for the NULL */

        if (found != -1) {
                /*
                 * it exists already, so just free the existing setting,
                 * save our new one there, and return the existing array.
                 */
                q = envp[found];
                if ((envp[found] = strdup(envstr)) == NULL) {
                        envp[found] = q;
                        /* XXX env_free(envp); */
                        errno = ENOMEM;
                        return NULL;
                }
                free(q);
                return (envp);
        }

        /*
         * it doesn't exist yet, so resize the array, move null pointer over
         * one, save our string over the old null pointer, and return resized
         * array.
         */
        p = (char **) reallocarray(envp, count+1, sizeof(char *));
        if (p == NULL)  {
                /* XXX env_free(envp); */
                errno = ENOMEM;
                return NULL;
        }
        p[count] = p[count-1];
        if ((p[count-1] = strdup(envstr)) == NULL) {
                env_free(p);
                errno = ENOMEM;
                return NULL;
        }
        return (p);
}


/* return       ERR = end of file
 *              FALSE = not an env setting (file was repositioned)
 *              TRUE = was an env setting
 */
int
load_env(char *envstr, FILE *f)
{
        long    filepos;
        int     fileline;
        char    name[MAX_ENVSTR], val[MAX_ENVSTR];
        char    quotechar, *c, *str;
        int     state;

        /* The following states are traversed in order: */
#define NAMEI   0       /* First char of NAME, may be quote */
#define NAME    1       /* Subsequent chars of NAME */
#define EQ1     2       /* After end of name, looking for '=' sign */
#define EQ2     3       /* After '=', skipping whitespace */
#define VALUEI  4       /* First char of VALUE, may be quote */
#define VALUE   5       /* Subsequent chars of VALUE */
#define FINI    6       /* All done, skipping trailing whitespace */
#define ERROR   7       /* Error */

        filepos = ftell(f);
        fileline = LineNumber;
        skip_comments(f);
        if (EOF == get_string(envstr, MAX_ENVSTR, f, "\n"))
                return (ERR);

        Debug(DPARS, ("load_env, read <%s>\n", envstr));

        bzero (name, sizeof name);
        bzero (val, sizeof val);
        str = name;
        state = NAMEI;
        quotechar = '\0';
        c = envstr;
        while (state != ERROR && *c) {
                switch (state) {
                case NAMEI:
                case VALUEI:
                        if (*c == '\'' || *c == '"')
                                quotechar = *c++;
                        ++state;
                        /* FALLTHROUGH */
                case NAME:
                case VALUE:
                        if (quotechar) {
                                if (*c == quotechar) {
                                        state++;
                                        c++;
                                        break;
                                }
                                if (state == NAME && *c == '=') {
                                        state = ERROR;
                                        break;
                                }
                        } else {
                                if (state == NAME) {
                                        if (isspace (*c)) {
                                                c++;
                                                state++;
                                                break;
                                        }
                                        if (*c == '=') {
                                                state++;
                                                break;
                                        }
                                }
                        }
                        *str++ = *c++;
                        break;

                case EQ1:
                        if (*c == '=') {
                                state++;
                                str = val;
                                quotechar = '\0';
                        } else {
                                if (!isspace (*c))
                                        state = ERROR;
                        }
                        c++;
                        break;
                case EQ2:
                case FINI:
                        if (isspace (*c))
                                c++;
                        else
                                state++;
                        break;
                }
        }
        if (state != FINI && !(state == VALUE && !quotechar)) {
                Debug(DPARS, ("load_env, parse error, state = %d\n", state))
                fseek(f, filepos, 0);
                Set_LineNum(fileline);
                return (FALSE);
        }
        if (state == VALUE) {
                /* End of unquoted value: trim trailing whitespace */
                c = val + strlen (val);
                while (c > val && isspace (*(c - 1)))
                        *(--c) = '\0';
        }

        /* 2 fields from parser; looks like an env setting */

        if (snprintf(envstr, MAX_ENVSTR, "%s=%s", name, val) >= MAX_ENVSTR)
                return (FALSE);
        Debug(DPARS, ("load_env, <%s> <%s> -> <%s>\n", name, val, envstr))
        return (TRUE);
}


char *
env_get(char *name, char **envp)
{
        int     len = strlen(name);
        char    *p, *q;

        while ((p = *envp++) != NULL) {
                if (!(q = strchr(p, '=')))
                        continue;
                if ((q - p) == len && !strncmp(p, name, len))
                        return (q+1);
        }
        return (NULL);
}