/* $OpenBSD: manpath.c,v 1.32 2025/06/26 17:21:02 schwarze Exp $ */
/*
 * Copyright (c) 2011,2014,2015,2017-2021 Ingo Schwarze <schwarze@openbsd.org>
 * Copyright (c) 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 *
 * 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 THE AUTHORS DISCLAIM ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS 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 <sys/types.h>
#include <sys/stat.h>

#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "mandoc_aux.h"
#include "mandoc.h"
#include "manconf.h"

#define MAN_CONF_FILE   "/etc/man.conf"
#define MANPATH_BASE    "/usr/share/man:/usr/X11R6/man"
#define MANPATH_DEFAULT "/usr/share/man:/usr/X11R6/man:/usr/local/man"

static  void     manconf_file(struct manconf *, const char *, int);
static  void     manpath_add(struct manpaths *, const char *, char);
static  void     manpath_parseline(struct manpaths *, char *, char);


void
manconf_parse(struct manconf *conf, const char *file, char *pend, char *pbeg)
{
        int use_path_from_file = 1;

        /* Always prepend -m. */
        manpath_parseline(&conf->manpath, pbeg, 'm');

        if (pend != NULL && *pend != '\0') {
                /* If -M is given, it overrides everything else. */
                manpath_parseline(&conf->manpath, pend, 'M');
                use_path_from_file = 0;
                pbeg = pend = NULL;
        } else if ((pbeg = getenv("MANPATH")) == NULL || *pbeg == '\0') {
                /* No MANPATH; use man.conf(5) only. */
                pbeg = pend = NULL;
        } else if (*pbeg == ':') {
                /* Prepend man.conf(5) to MANPATH. */
                pend = pbeg + 1;
                pbeg = NULL;
        } else if ((pend = strstr(pbeg, "::")) != NULL) {
                /* Insert man.conf(5) into MANPATH. */
                *pend = '\0';
                pend += 2;
        } else if (pbeg[strlen(pbeg) - 1] == ':') {
                /* Append man.conf(5) to MANPATH. */
                pend = NULL;
        } else {
                /* MANPATH overrides man.conf(5) completely. */
                use_path_from_file = 0;
                pend = NULL;
        }

        manpath_parseline(&conf->manpath, pbeg, '\0');

        if (file == NULL)
                file = MAN_CONF_FILE;
        manconf_file(conf, file, use_path_from_file);

        manpath_parseline(&conf->manpath, pend, '\0');
}

void
manpath_base(struct manpaths *dirs)
{
        char path_base[] = MANPATH_BASE;
        manpath_parseline(dirs, path_base, '\0');
}

/*
 * Parse a FULL pathname from a colon-separated list of arrays.
 */
static void
manpath_parseline(struct manpaths *dirs, char *path, char option)
{
        char    *dir;

        if (NULL == path)
                return;

        for (dir = strtok(path, ":"); dir; dir = strtok(NULL, ":"))
                manpath_add(dirs, dir, option);
}

/*
 * Add a directory to the array, ignoring bad directories.
 * Grow the array one-by-one for simplicity's sake.
 */
static void
manpath_add(struct manpaths *dirs, const char *dir, char option)
{
        char             buf[PATH_MAX];
        struct stat      sb;
        char            *cp;
        size_t           i;

        if ((cp = realpath(dir, buf)) == NULL)
                goto fail;

        for (i = 0; i < dirs->sz; i++)
                if (strcmp(dirs->paths[i], dir) == 0)
                        return;

        if (stat(cp, &sb) == -1)
                goto fail;

        dirs->paths = mandoc_reallocarray(dirs->paths,
            dirs->sz + 1, sizeof(*dirs->paths));
        dirs->paths[dirs->sz++] = mandoc_strdup(cp);
        return;

fail:
        if (option != '\0')
                mandoc_msg(MANDOCERR_BADARG_BAD, 0, 0,
                    "-%c %s: %s", option, dir, strerror(errno));
}

void
manconf_free(struct manconf *conf)
{
        size_t           i;

        for (i = 0; i < conf->manpath.sz; i++)
                free(conf->manpath.paths[i]);

        free(conf->manpath.paths);
        free(conf->output.includes);
        free(conf->output.man);
        free(conf->output.paper);
        free(conf->output.style);
}

static void
manconf_file(struct manconf *conf, const char *file, int use_path_from_file)
{
        const char *const toks[] = { "manpath", "output" };
        char manpath_default[] = MANPATH_DEFAULT;

        FILE            *stream;
        char            *line, *cp, *ep;
        size_t           linesz, tok, toklen;
        ssize_t          linelen;

        if ((stream = fopen(file, "r")) == NULL)
                goto out;

        line = NULL;
        linesz = 0;

        while ((linelen = getline(&line, &linesz, stream)) != -1) {
                cp = line;
                ep = cp + linelen - 1;
                while (ep > cp && isspace((unsigned char)*ep))
                        *ep-- = '\0';
                while (isspace((unsigned char)*cp))
                        cp++;
                if (cp == ep || *cp == '#')
                        continue;

                for (tok = 0; tok < sizeof(toks)/sizeof(toks[0]); tok++) {
                        toklen = strlen(toks[tok]);
                        if (cp + toklen < ep &&
                            isspace((unsigned char)cp[toklen]) &&
                            strncmp(cp, toks[tok], toklen) == 0) {
                                cp += toklen;
                                while (isspace((unsigned char)*cp))
                                        cp++;
                                break;
                        }
                }

                switch (tok) {
                case 0:  /* manpath */
                        if (use_path_from_file)
                                manpath_add(&conf->manpath, cp, '\0');
                        *manpath_default = '\0';
                        break;
                case 1:  /* output */
                        manconf_output(&conf->output, cp, 1);
                        break;
                default:
                        break;
                }
        }
        free(line);
        fclose(stream);

out:
        if (use_path_from_file && *manpath_default != '\0')
                manpath_parseline(&conf->manpath, manpath_default, '\0');
}

int
manconf_output(struct manoutput *conf, const char *cp, int fromfile)
{
        const char *const toks[] = {
            /* Tokens requiring an argument. */
            "includes", "man", "paper", "style", "indent", "width",
            "outfilename", "tagfilename",
            /* Token taking an optional argument. */
            "tag",
            /* Tokens not taking arguments. */
            "fragment", "noval", "toc"
        };
        const size_t ntoks = sizeof(toks) / sizeof(toks[0]);

        const char      *errstr;
        char            *oldval;
        size_t           len, tok;

        for (tok = 0; tok < ntoks; tok++) {
                len = strlen(toks[tok]);
                if (strncmp(cp, toks[tok], len) == 0 &&
                    strchr(" =  ", cp[len]) != NULL) {
                        cp += len;
                        if (*cp == '=')
                                cp++;
                        while (isspace((unsigned char)*cp))
                                cp++;
                        break;
                }
        }

        if (tok < 8 && *cp == '\0') {
                mandoc_msg(MANDOCERR_BADVAL_MISS, 0, 0, "-O %s=?", toks[tok]);
                return -1;
        }
        if (tok > 8 && tok < ntoks && *cp != '\0') {
                mandoc_msg(MANDOCERR_BADVAL, 0, 0, "-O %s=%s", toks[tok], cp);
                return -1;
        }

        switch (tok) {
        case 0:
                if (conf->includes != NULL) {
                        oldval = mandoc_strdup(conf->includes);
                        break;
                }
                conf->includes = mandoc_strdup(cp);
                return 0;
        case 1:
                if (conf->man != NULL) {
                        oldval = mandoc_strdup(conf->man);
                        break;
                }
                conf->man = mandoc_strdup(cp);
                return 0;
        case 2:
                if (conf->paper != NULL) {
                        oldval = mandoc_strdup(conf->paper);
                        break;
                }
                conf->paper = mandoc_strdup(cp);
                return 0;
        case 3:
                if (conf->style != NULL) {
                        oldval = mandoc_strdup(conf->style);
                        break;
                }
                conf->style = mandoc_strdup(cp);
                return 0;
        case 4:
                if (conf->indent) {
                        mandoc_asprintf(&oldval, "%zu", conf->indent);
                        break;
                }
                conf->indent = strtonum(cp, 0, 1000, &errstr);
                if (errstr == NULL)
                        return 0;
                mandoc_msg(MANDOCERR_BADVAL_BAD, 0, 0,
                    "-O indent=%s is %s", cp, errstr);
                return -1;
        case 5:
                if (conf->width) {
                        mandoc_asprintf(&oldval, "%zu", conf->width);
                        break;
                }
                conf->width = strtonum(cp, 1, 1000, &errstr);
                if (errstr == NULL)
                        return 0;
                mandoc_msg(MANDOCERR_BADVAL_BAD, 0, 0,
                    "-O width=%s is %s", cp, errstr);
                return -1;
        case 6:
                if (conf->outfilename != NULL) {
                        oldval = mandoc_strdup(conf->outfilename);
                        break;
                }
                conf->outfilename = mandoc_strdup(cp);
                return 0;
        case 7:
                if (conf->tagfilename != NULL) {
                        oldval = mandoc_strdup(conf->tagfilename);
                        break;
                }
                conf->tagfilename = mandoc_strdup(cp);
                return 0;
        /*
         * If the index of the following token changes,
         * do not forget to adjust the range check above the switch.
         */
        case 8:
                if (conf->tag != NULL) {
                        oldval = mandoc_strdup(conf->tag);
                        break;
                }
                conf->tag = mandoc_strdup(cp);
                return 0;
        case 9:
                conf->fragment = 1;
                return 0;
        case 10:
                conf->noval = 1;
                return 0;
        case 11:
                conf->toc = 1;
                return 0;
        default:
                mandoc_msg(MANDOCERR_BADARG_BAD, 0, 0, "-O %s", cp);
                return -1;
        }
        if (fromfile) {
                free(oldval);
                return 0;
        } else {
                mandoc_msg(MANDOCERR_BADVAL_DUPE, 0, 0,
                    "-O %s=%s: already set to %s", toks[tok], cp, oldval);
                free(oldval);
                return -1;
        }
}