uIRC/src/uirc.c

/*
 *  This file is part of uIRC. (https://git.redxen.eu/caskd/uIRC)
 *  Copyright (c) 2019, 2020 Alex-David Denes
 *
 *  uIRC is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  any later version.
 *
 *  uIRC is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with uIRC.  If not, see <https://www.gnu.org/licenses/>.
*/
#include "uirc.h"

const char* uirc_ircmd[] = {
    [PASS] = "PASS",
    [NICK] = "NICK",
    [USER] = "USER",
    [SERVER] = "SERVER",
    [OPER] = "OPER",
    [QUIT] = "QUIT",
    [SQUIT] = "SQUIT",
    [JOIN] = "JOIN",
    [PART] = "PART",
    [MODE] = "MODE",
    [TOPIC] = "TOPIC",
    [NAMES] = "NAMES",
    [LIST] = "LIST",
    [INVITE] = "INVITE",
    [KICK] = "KICK",
    [VERSION] = "VERSION",
    [STATS] = "STATS",
    [LINKS] = "LINKS",
    [TIME] = "TIME",
    [CONNECT] = "CONNECT",
    [TRACE] = "TRACE",
    [ADMIN] = "ADMIN",
    [INFO] = "INFO",
    [PRIVMSG] = "PRIVMSG",
    [NOTICE] = "NOTICE",
    [WHO] = "WHO",
    [WHOIS] = "WHOIS",
    [WHOWAS] = "WHOWAS",
    [KILL] = "KILL",
    [PING] = "PING",
    [PONG] = "PONG",
    [ERROR] = "ERROR",
    [AWAY] = "AWAY",
    [REHASH] = "REHASH",
    [RESTART] = "RESTART",
    [SUMMON] = "SUMMON",
    [USERS] = "USERS",
    [WALLOPS] = "WALLOPS",
    [USERHOST] = "USERHOST",
    [ISON] = "ISON"};

struct tagmapping {
	char* name;
	IRC_Tag* assg;
};

int uirc_tokenize_message(IRC_Message* irc_msg, char** line)
{
	char *progr = *line, *command;

	if (*progr == '@') {
		char* tags;
		if ((tags = tokspace(progr, &progr)) != NULL) {
			if (!tagmgr(&tags, irc_msg, true))
				return -1;
		} else
			return 0;
	}
	if (*progr == ':') {
		char* prefix;
		if ((prefix = tokspace(progr, &progr)) != NULL) {
			if (!tok_prefix(prefix, &irc_msg->name))
				return 0;
		} else
			return 0;
	}

	command = tokspace(progr, &progr);
	if (isalpha(*command)) {
		if (!(irc_msg->cmd = uirc_ircmd_stoi(command)))
			return 0;
	} else if (isdigit(*command)) {
		if ((irc_msg->cmd = atoi(command)) == 0)
			return 0;
	} else {
		return 0;
	}
	if (progr == NULL)
		return 1;

	int i;
	for (i = 0; *progr != ':' && i < 14; i++) {
		if ((irc_msg->args[i] = strtok_r(NULL, " :", &progr)) == NULL)
			return 0;
	}
	irc_msg->args[i] = NULL;
	if (*progr == ':')
		++progr;
	irc_msg->trailing = progr;
	return 1;
}
unsigned int uirc_ircmd_stoi(char* str)
{
	for (unsigned short i = PASS; i <= ISON; i++) {
		if (strcmp(uirc_ircmd[i], str) == 0)
			return i;
	}
	return 0;
}
int uirc_assm_mesg(char* buf, IRC_Message* mesg)
{
	if (buf == NULL)
		return -2;
	char* pos = buf;
	int cnt;

	if (!tagmgr(&pos, mesg, false))
		return -1;
	if (mesg->name.nick || mesg->name.host) {
		if (!assm_prefix(&pos, &mesg->name))
			return 0;
	}
	if ((uirc_ircmd[mesg->cmd] != NULL) && ((cnt = sprintf(pos, "%s", uirc_ircmd[mesg->cmd])) > 0))
		pos += cnt;
	else
		return -1;
	for (unsigned int i = 0; i < 14 && mesg->args[i] != NULL; i++) {
		if ((cnt = sprintf(pos, " %s", mesg->args[i])) > 0)
			pos += cnt;
		else
			return -1;
	}
	if (mesg->trailing != NULL) {
		if ((cnt = sprintf(pos, " :%s", mesg->trailing)) > 0)
			pos += cnt;
		else
			return -1;
	}
	if ((cnt = sprintf(pos, "\r\n")) != 2)
		return -1;
	return 1;
}
bool tagmgr(char** pos, IRC_Message* mesg, bool tagged)
{
	const char* origpos = *pos;
	char *cval, *cpos = *pos;
	int cnt;
	bool clientbound;
	const struct tagmapping tags[] = {
	    {.name = "time", .assg = &mesg->tags.time},
	    {.name = "account", .assg = &mesg->tags.account},
	    {.name = "batch", .assg = &mesg->tags.batch},
	    {.name = "label", .assg = &mesg->tags.label},
	    {.name = "msgid", .assg = &mesg->tags.msgid},
	    {.name = "multiline-concat", .assg = &mesg->tags.multiline_concat},
	    {.name = "typing", .assg = &mesg->tags.typing},
	    {.name = "react", .assg = &mesg->tags.react},
	    {.name = "reply", .assg = &mesg->tags.reply}};
	if (tagged) {
		if (*cpos == '@')
			cpos++;
		do {
			clientbound = false;
			if (*cpos == '+') {
				cpos++;
				clientbound = true;
			}
			if ((cval = strchr(cpos, '=')) != NULL) {
				*(cval++) = '\0';
				for (unsigned int i = 0; i < sizeof(tags) / sizeof(struct tagmapping); i++) {
					if (!strcmp(cpos, tags[i].name)) {
						(*tags[i].assg).value = cval;
						(*tags[i].assg).clientbound = clientbound;
					}
				}
				if ((cpos = strchr(cval, ';')) != NULL)
					*(cpos++) = '\0';
			} else
				return false;
		} while (cpos != NULL);
	} else {
		for (unsigned int i = 0; i < sizeof(tags) / sizeof(struct tagmapping); i++) {
			if ((*tags[i].assg).value != NULL) {
				if (cpos == origpos) {
					if (sprintf(cpos++, "@") != 1)
						return false;
				} else {
					if (sprintf(cpos++, ";") != 1)
						return false;
				}
				if ((*tags[i].assg).clientbound) {
					if (sprintf(cpos++, "+") != 1)
						return false;
				}
				if ((cnt = sprintf(cpos, "%s=%s", tags[i].name, (*tags[i].assg).value)) > 0)
					cpos += cnt;
				else
					return false;
			}
		}
		if (*origpos == '@') {
			if (sprintf(cpos++, " ") != 1)
				return false;
		}
		*pos = cpos;
	}
	return true;
}
char* tokspace(char* pos, char** save)
{
	char* delimpos = NULL;
	if (pos == NULL || (delimpos = strchr(pos, ' ')) == NULL)
		return NULL;
	while (*delimpos == ' ') {
		*(delimpos++) = '\0';
	}
	*save = delimpos;
	return pos;
}
bool assm_prefix(char** str, IRC_User* usr)
{
	int cnt;
	char* pos = *str;
	*(pos++) = ':';
	if (!usr->nick && !usr->user) {
		if ((cnt = sprintf(pos, "%s", usr->host)) > 0)
			pos += cnt;
		else
			return false;
	} else {
		if ((cnt = sprintf(pos, "%s", usr->nick)) > 0)
			pos += cnt;
		else
			return false;
		if (usr->user) {
			if ((cnt = sprintf(pos, "!%s", usr->user)) > 0)
				pos += cnt;
			else
				return false;
		}
		if (usr->host) {
			if ((cnt = sprintf(pos, "@%s", usr->host)) > 0)
				pos += cnt;
			else
				return false;
		}
	}
	*(pos++) = ' ';
	*str = pos;
	return true;
}
bool tok_prefix(char* prefix, IRC_User* user)
{
	char* pos = (*prefix == ':') ? prefix + 1 : prefix;
	if ((user->host = strchr(prefix, '@')) != NULL)
		*(user->host++) = '\0';
	if ((user->user = strchr(prefix, '!')) != NULL) /* RFC2812 says this cannot be here without the host but RFC1459 says it can, we accept both options */
		*(user->user++) = '\0';
	if (*(user->nick = prefix) == '\0') /* NOTE: This may be the server instead of a nick according to RFC2812, it is left to the library user to decide how to interpret this based on the context. */
		return false;
	return true;
}