/*
 * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Matthias Schmidt <matthias@dragonflybsd.org>, University of Marburg,
 * Germany.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name of The DragonFly Project nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific, prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <stdarg.h>

#include "dma.h"

#define DP      ": \t"
#define EQS     " \t"


/*
 * Remove trailing \n's
 */
void
trim_line(char *line)
{
        size_t linelen;
        char *p;

        if ((p = strchr(line, '\n')))
                *p = (char)0;

        /* Escape leading dot in every case */
        linelen = strlen(line);
        if (line[0] == '.') {
                if ((linelen + 2) > 1000) {
                        syslog(LOG_CRIT, "Cannot escape leading dot.  Buffer overflow");
                        exit(EX_DATAERR);
                }
                memmove((line + 1), line, (linelen + 1));
                line[0] = '.';
        }
}

static void
chomp(char *str)
{
        size_t len = strlen(str);

        if (len == 0)
                return;
        if (str[len - 1] == '\n')
                str[len - 1] = 0;
}

/*
 * Read the SMTP authentication config file
 *
 * file format is:
 * user|host:password
 *
 * A line starting with # is treated as comment and ignored.
 */
void
parse_authfile(const char *path)
{
        char line[2048];
        struct authuser *au;
        FILE *a;
        char *data;
        int lineno = 0;

        a = fopen(path, "r");
        if (a == NULL) {
                errlog(EX_NOINPUT, "can not open auth file `%s'", path);
                /* NOTREACHED */
        }

        while (!feof(a)) {
                if (fgets(line, sizeof(line), a) == NULL)
                        break;
                lineno++;

                chomp(line);

                /* We hit a comment */
                if (*line == '#')
                        continue;
                /* Ignore empty lines */
                if (*line == 0)
                        continue;

                au = calloc(1, sizeof(*au));
                if (au == NULL)
                        errlog(EX_OSERR, NULL);

                data = strdup(line);
                au->login = strsep(&data, "|");
                au->host = strsep(&data, DP);
                au->password = data;

                if (au->login == NULL ||
                    au->host == NULL ||
                    au->password == NULL) {
                        errlogx(EX_CONFIG, "syntax error in authfile %s:%d", path, lineno);
                        /* NOTREACHED */
                }

                SLIST_INSERT_HEAD(&authusers, au, next);
        }

        fclose(a);
}

/*
 * XXX TODO
 * Check for bad things[TM]
 */
void
parse_conf(const char *config_path)
{
        char *word;
        char *data;
        FILE *conf;
        char line[2048];
        int lineno = 0;

        conf = fopen(config_path, "r");
        if (conf == NULL) {
                /* Don't treat a non-existing config file as error */
                if (errno == ENOENT)
                        return;
                errlog(EX_NOINPUT, "can not open config `%s'", config_path);
                /* NOTREACHED */
        }

        while (!feof(conf)) {
                if (fgets(line, sizeof(line), conf) == NULL)
                        break;
                lineno++;

                chomp(line);

                /* We hit a comment */
                if (strchr(line, '#'))
                        *strchr(line, '#') = 0;

                data = line;
                word = strsep(&data, EQS);

                /* Ignore empty lines */
                if (word == NULL || *word == 0)
                        continue;

                if (data != NULL && *data != 0)
                        data = strdup(data);
                else
                        data = NULL;

                if (strcmp(word, "SMARTHOST") == 0 && data != NULL)
                        config.smarthost = data;
                else if (strcmp(word, "PORT") == 0 && data != NULL)
                        config.port = atoi(data);
                else if (strcmp(word, "ALIASES") == 0 && data != NULL)
                        config.aliases = data;
                else if (strcmp(word, "SPOOLDIR") == 0 && data != NULL)
                        config.spooldir = data;
                else if (strcmp(word, "AUTHPATH") == 0 && data != NULL)
                        config.authpath= data;
                else if (strcmp(word, "CERTFILE") == 0 && data != NULL)
                        config.certfile = data;
                else if (strcmp(word, "MAILNAME") == 0 && data != NULL)
                        config.mailname = data;
                else if (strcmp(word, "MASQUERADE") == 0 && data != NULL) {
                        char *user = NULL, *host = NULL;
                        if (strrchr(data, '@')) {
                                host = strrchr(data, '@');
                                *host = 0;
                                host++;
                                user = data;
                        } else {
                                host = data;
                        }
                        if (host && *host == 0)
                                host = NULL;
                        if (user && *user == 0)
                                user = NULL;
                        config.masquerade_host = host;
                        config.masquerade_user = user;
                } else if (strcmp(word, "STARTTLS") == 0 && data == NULL)
                        config.features |= STARTTLS;
                else if (strcmp(word, "FINGERPRINT") == 0) {
                        if (strlen(data) != SHA256_DIGEST_LENGTH * 2) {
                                errlogx(EX_CONFIG, "invalid sha256 fingerprint length");
                        }
                        unsigned char *fingerprint = malloc(SHA256_DIGEST_LENGTH);
                        if (fingerprint == NULL) {
                                errlogx(EX_CONFIG, "fingerprint allocation failed");
                        }
                        for (unsigned int i = 0; i < SHA256_DIGEST_LENGTH; i++) {
                                if(sscanf(data + 2 * i, "%02hhx", &fingerprint[i]) != 1) {
                                        errlogx(EX_CONFIG, "failed to read fingerprint");
                                }
                        }
                        free(data);
                        config.fingerprint = fingerprint;
                } else if (strcmp(word, "OPPORTUNISTIC_TLS") == 0 && data == NULL)
                        config.features |= TLS_OPP;
                else if (strcmp(word, "SECURETRANSFER") == 0 && data == NULL)
                        config.features |= SECURETRANSFER;
                else if (strcmp(word, "DEFER") == 0 && data == NULL)
                        config.features |= DEFER;
                else if (strcmp(word, "INSECURE") == 0 && data == NULL)
                        config.features |= INSECURE;
                else if (strcmp(word, "FULLBOUNCE") == 0 && data == NULL)
                        config.features |= FULLBOUNCE;
                else if (strcmp(word, "NULLCLIENT") == 0 && data == NULL)
                        config.features |= NULLCLIENT;
                else {
                        errlogx(EX_CONFIG, "syntax error in %s:%d", config_path, lineno);
                        /* NOTREACHED */
                }
        }

        if ((config.features & NULLCLIENT) && config.smarthost == NULL) {
                errlogx(EX_CONFIG, "%s: NULLCLIENT requires SMARTHOST", config_path);
                /* NOTREACHED */
        }

        fclose(conf);
}