/*
 * Copyright (C) 2001-2003 Fhg Fokus
 *
 * This file is part of Kamailio, a free SIP server.
 *
 * Kamailio 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 2 of the License, or
 * (at your option) any later version
 *
 * Kamailio 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

/** Parser :: Parse To: header.
 * @file
 * @ingroup parser
 */

#include "parse_to.h"
#include <stdlib.h>
#include <string.h>
#include "../dprint.h"
#include "msg_parser.h"
#include "parse_uri.h"
#include "../ut.h"
#include "../mem/mem.h"


enum
{
	START_TO,
	DISPLAY_QUOTED,
	E_DISPLAY_QUOTED,
	DISPLAY_TOKEN,
	DISPLAY_TOKEN_SP,
	S_URI_ENCLOSED,
	URI_ENCLOSED,
	E_URI_ENCLOSED,
	URI_OR_TOKEN,
	MAYBE_URI_END,
	END,
	F_CR,
	F_LF,
	F_CRLF
};


enum
{
	S_PARA_NAME = 20,
	PARA_NAME,
	S_EQUAL,
	S_PARA_VALUE,
	TAG1,
	TAG2,
	TAG3,
	PARA_VALUE_TOKEN,
	PARA_VALUE_QUOTED,
	E_PARA_VALUE
};


#define add_param(_param, _body, _newparam)                                   \
	do {                                                                      \
		LM_DBG("add param: %.*s=%.*s\n", param->name.len, ZSW(param->name.s), \
				param->value.len, ZSW(param->value.s));                       \
		if(!(_body)->param_lst)                                               \
			(_body)->param_lst = (_param);                                    \
		else                                                                  \
			(_body)->last_param->next = (_param);                             \
		(_body)->last_param = (_param);                                       \
		if((_param)->type == TAG_PARAM)                                       \
			memcpy(&((_body)->tag_value), &((_param)->value), sizeof(str));   \
		_newparam = 0;                                                        \
	} while(0);


static char *parse_to_param(char *const buffer, const char *const end,
		struct to_body *const to_b, const int allow_comma_sep,
		int *const returned_status)
{
	struct to_param *param;
	struct to_param *newparam;
	int status;
	int saved_status;
	char *tmp;

	param = 0;
	newparam = 0;
	status = E_PARA_VALUE;
	saved_status = E_PARA_VALUE;
	for(tmp = buffer; tmp < end; tmp++) {
		switch(*tmp) {
			case ' ':
			case '\t':
				switch(status) {
					case TAG3:
						param->type = TAG_PARAM;
					case PARA_NAME:
					case TAG1:
					case TAG2:
						param->name.len = tmp - param->name.s;
						status = S_EQUAL;
						break;
					case PARA_VALUE_TOKEN:
						param->value.len = tmp - param->value.s;
						status = E_PARA_VALUE;
						add_param(param, to_b, newparam);
						break;
					case F_CRLF:
					case F_LF:
					case F_CR:
						/*previous=crlf and now =' '*/
						status = saved_status;
						break;
				}
				break;
			case '\n':
				switch(status) {
					case S_PARA_NAME:
					case S_EQUAL:
					case S_PARA_VALUE:
					case E_PARA_VALUE:
						saved_status = status;
						status = F_LF;
						break;
					case TAG3:
						param->type = TAG_PARAM;
					case PARA_NAME:
					case TAG1:
					case TAG2:
						param->name.len = tmp - param->name.s;
						saved_status = S_EQUAL;
						status = F_LF;
						break;
					case PARA_VALUE_TOKEN:
						param->value.len = tmp - param->value.s;
						saved_status = E_PARA_VALUE;
						status = F_LF;
						add_param(param, to_b, newparam);
						break;
					case F_CR:
						status = F_CRLF;
						break;
					case F_CRLF:
					case F_LF:
						status = saved_status;
						goto endofheader;
					default:
						LM_ERR("unexpected char [%c] in status %d: [%.*s] .\n",
								*tmp, status, (int)(tmp - buffer), ZSW(buffer));
						goto error;
				}
				break;
			case '\r':
				switch(status) {
					case S_PARA_NAME:
					case S_EQUAL:
					case S_PARA_VALUE:
					case E_PARA_VALUE:
						saved_status = status;
						status = F_CR;
						break;
					case TAG3:
						param->type = TAG_PARAM;
					case PARA_NAME:
					case TAG1:
					case TAG2:
						param->name.len = tmp - param->name.s;
						saved_status = S_EQUAL;
						status = F_CR;
						break;
					case PARA_VALUE_TOKEN:
						param->value.len = tmp - param->value.s;
						saved_status = E_PARA_VALUE;
						status = F_CR;
						add_param(param, to_b, newparam);
						break;
					case F_CRLF:
					case F_CR:
					case F_LF:
						status = saved_status;
						goto endofheader;
					default:
						LM_ERR("unexpected char [%c] in status %d: [%.*s] .\n",
								*tmp, status, (int)(tmp - buffer), ZSW(buffer));
						goto error;
				}
				break;
			case 0:
				switch(status) {
					case TAG3:
						param->type = TAG_PARAM;
					case PARA_NAME:
					case TAG1:
					case TAG2:
						param->name.len = tmp - param->name.s;
						status = S_EQUAL;
					case S_EQUAL:
					case S_PARA_VALUE:
						saved_status = status;
						goto endofheader;
					case PARA_VALUE_TOKEN:
						status = E_PARA_VALUE;
						param->value.len = tmp - param->value.s;
						add_param(param, to_b, newparam);
					case E_PARA_VALUE:
						saved_status = status;
						goto endofheader;
						break;
					default:
						LM_ERR("unexpected char [%c] in status %d: [%.*s] .\n",
								*tmp, status, (int)(tmp - buffer), ZSW(buffer));
						goto error;
				}
				break;
			case '\\':
				switch(status) {
					case PARA_VALUE_QUOTED:
						switch(*(tmp + 1)) {
							case '\r':
							case '\n':
								break;
							default:
								tmp++;
						}
					default:
						LM_ERR("unexpected char [%c] in status %d: [%.*s] .\n",
								*tmp, status, (int)(tmp - buffer), ZSW(buffer));
						goto error;
				}
				break;
			case '"':
				switch(status) {
					case S_PARA_VALUE:
						param->value.s = tmp + 1;
						status = PARA_VALUE_QUOTED;
						break;
					case PARA_VALUE_QUOTED:
						param->value.len = tmp - param->value.s;
						add_param(param, to_b, newparam);
						status = E_PARA_VALUE;
						break;
					case F_CRLF:
					case F_LF:
					case F_CR:
						/*previous=crlf and now !=' '*/
						goto endofheader;
					default:
						LM_ERR("unexpected char [%c] in status %d: [%.*s] .\n",
								*tmp, status, (int)(tmp - buffer), ZSW(buffer));
						goto error;
				}
				break;
			case ';':
				switch(status) {
					case PARA_VALUE_QUOTED:
						break;
					case TAG3:
						param->type = TAG_PARAM;
					case PARA_NAME:
					case TAG1:
					case TAG2:
						param->name.len = tmp - param->name.s;
					case S_EQUAL:
						param->value.s = 0;
						param->value.len = 0;
						goto semicolon_add_param;
					case S_PARA_VALUE:
						param->value.s = tmp;
					case PARA_VALUE_TOKEN:
						param->value.len = tmp - param->value.s;
					semicolon_add_param:
						add_param(param, to_b, newparam);
					case E_PARA_VALUE:
						param = (struct to_param *)pkg_malloc(
								sizeof(struct to_param));
						if(!param) {
							LM_ERR("out of memory\n");
							goto error;
						}
						memset(param, 0, sizeof(struct to_param));
						param->type = GENERAL_PARAM;
						status = S_PARA_NAME;
						/* link to free mem if not added in to_body list */
						newparam = param;
						break;
					case F_CRLF:
					case F_LF:
					case F_CR:
						/*previous=crlf and now !=' '*/
						goto endofheader;
					default:
						LM_ERR("unexpected char [%c] in status %d: [%.*s] .\n",
								*tmp, status, (int)(tmp - buffer), ZSW(buffer));
						goto error;
				}
				break;
			case 'T':
			case 't':
				switch(status) {
					case PARA_VALUE_QUOTED:
					case PARA_VALUE_TOKEN:
					case PARA_NAME:
						break;
					case S_PARA_NAME:
						param->name.s = tmp;
						status = TAG1;
						break;
					case S_PARA_VALUE:
						param->value.s = tmp;
						status = PARA_VALUE_TOKEN;
						break;
					case TAG1:
					case TAG2:
					case TAG3:
						status = PARA_NAME;
						break;
					case F_CRLF:
					case F_LF:
					case F_CR:
						/*previous=crlf and now !=' '*/
						goto endofheader;
					default:
						LM_ERR("unexpected char [%c] in status %d: [%.*s] .\n",
								*tmp, status, (int)(tmp - buffer), ZSW(buffer));
						goto error;
				}
				break;
			case 'A':
			case 'a':
				switch(status) {
					case PARA_VALUE_QUOTED:
					case PARA_VALUE_TOKEN:
					case PARA_NAME:
						break;
					case S_PARA_NAME:
						param->name.s = tmp;
						status = PARA_NAME;
						break;
					case S_PARA_VALUE:
						param->value.s = tmp;
						status = PARA_VALUE_TOKEN;
						break;
					case TAG1:
						status = TAG2;
						break;
					case TAG2:
					case TAG3:
						status = PARA_NAME;
						break;
					case F_CRLF:
					case F_LF:
					case F_CR:
						/*previous=crlf and now !=' '*/
						goto endofheader;
					default:
						LM_ERR("unexpected char [%c] in status %d: [%.*s] .\n",
								*tmp, status, (int)(tmp - buffer), ZSW(buffer));
						goto error;
				}
				break;
			case 'G':
			case 'g':
				switch(status) {
					case PARA_VALUE_QUOTED:
					case PARA_VALUE_TOKEN:
					case PARA_NAME:
						break;
					case S_PARA_NAME:
						param->name.s = tmp;
						status = PARA_NAME;
						break;
					case S_PARA_VALUE:
						param->value.s = tmp;
						status = PARA_VALUE_TOKEN;
						break;
					case TAG1:
					case TAG3:
						status = PARA_NAME;
						break;
					case TAG2:
						status = TAG3;
						break;
					case F_CRLF:
					case F_LF:
					case F_CR:
						/*previous=crlf and now !=' '*/
						goto endofheader;
					default:
						LM_ERR("unexpected char [%c] in status %d: [%.*s] .\n",
								*tmp, status, (int)(tmp - buffer), ZSW(buffer));
						goto error;
				}
				break;
			case '=':
				switch(status) {
					case PARA_VALUE_QUOTED:
						break;
					case TAG3:
						param->type = TAG_PARAM;
					case PARA_NAME:
					case TAG1:
					case TAG2:
						param->name.len = tmp - param->name.s;
						status = S_PARA_VALUE;
						break;
					case S_EQUAL:
						status = S_PARA_VALUE;
						break;
					case F_CRLF:
					case F_LF:
					case F_CR:
						/*previous=crlf and now !=' '*/
						goto endofheader;
					default:
						LM_ERR("unexpected char [%c] in status %d: [%.*s] .\n",
								*tmp, status, (int)(tmp - buffer), ZSW(buffer));
						goto error;
				}
				break;
			case ',':
				if(status == PARA_VALUE_QUOTED) {
					/* comma is allowed inside quoted values */
					break;
				}
				if(allow_comma_sep) {
					switch(status) {
						case S_PARA_NAME:
						case S_EQUAL:
						case S_PARA_VALUE:
						case E_PARA_VALUE:
							saved_status = status;
							status = E_PARA_VALUE;
							goto endofheader;
						case TAG3:
							param->type = TAG_PARAM;
						case PARA_NAME:
						case TAG1:
						case TAG2:
							param->name.len = tmp - param->name.s;
							saved_status = S_EQUAL;
							status = E_PARA_VALUE;
							goto endofheader;
						case PARA_VALUE_TOKEN:
							param->value.len = tmp - param->value.s;
							saved_status = E_PARA_VALUE;
							status = E_PARA_VALUE;
							add_param(param, to_b, newparam);
							goto endofheader;
						case F_CRLF:
						case F_CR:
						case F_LF:
							status = saved_status;
							goto endofheader;
						default:
							LM_ERR("unexpected char [%c] in status %d: [%.*s] "
									".\n",
									*tmp, status, (int)(tmp - buffer),
									ZSW(buffer));
							goto error;
					}
					break;
				} else {
					if((status == S_PARA_VALUE || status == PARA_VALUE_TOKEN)
							&& param->type == TAG_PARAM) {
						/* if comma is not separator, allow it as part of value
						 * - some user agents use it */
						break;
					}
					LM_ERR("invalid character ',' in status %d: [%.*s]\n",
							status, (int)(tmp - buffer), ZSW(buffer));
				}
			default:
				switch(status) {
					case TAG1:
					case TAG2:
					case TAG3:
						status = PARA_NAME;
						break;
					case PARA_VALUE_TOKEN:
					case PARA_NAME:
					case PARA_VALUE_QUOTED:
						break;
					case S_PARA_NAME:
						param->name.s = tmp;
						status = PARA_NAME;
						break;
					case S_PARA_VALUE:
						param->value.s = tmp;
						status = PARA_VALUE_TOKEN;
						break;
					case F_CRLF:
					case F_LF:
					case F_CR:
						/*previous=crlf and now !=' '*/
						goto endofheader;
					default:
						LM_ERR("spitting out [%c] in status %d\n", *tmp,
								status);
						goto error;
				}
		} /*switch*/
	}	 /*for*/
	if(!(status == F_CR || status == F_LF || status == F_CRLF))
		saved_status = status;


endofheader:
	switch(saved_status) {
		case TAG3:
			param->type = TAG_PARAM;	/* tag at the end */
										/* no break */
		case PARA_NAME:
		case TAG1:
		case TAG2:
			param->name.len = tmp - param->name.s;
		/* no break */
		case S_EQUAL:
			/* parameter without '=', e.g. foo */
			param->value.s = 0;
			param->value.len = 0;
			add_param(param, to_b, newparam);
			saved_status = E_PARA_VALUE;
			break;
		case S_PARA_VALUE:
			/* parameter with null value, e.g. foo= */
			if(status == F_CRLF)
				param->value.s = tmp - 2;
			else if(status == F_CR || status == F_LF)
				param->value.s = tmp - 1;
			else
				param->value.s = tmp;
			param->value.len = 0;
			add_param(param, to_b, newparam);
			saved_status = E_PARA_VALUE;
			break;
		case PARA_VALUE_TOKEN:
			param->value.len = tmp - param->value.s;
			add_param(param, to_b, newparam);
			saved_status = E_PARA_VALUE;
			break;
		case E_PARA_VALUE:
			break;
		default:
			LM_ERR("unexpected end of header, status %d: [%.*s] .\n",
					saved_status, (int)(tmp - buffer), ZSW(buffer));
			goto error;
	}
	*returned_status = saved_status;
	return tmp;

error:
	if(newparam)
		pkg_free(newparam);
	to_b->error = PARSE_ERROR;
	*returned_status = status;
	return tmp;
}


char *parse_addr_spec(char *const buffer, const char *const end,
		struct to_body *const to_b, const int allow_comma_sep)
{
	int status;
	int saved_status;
	char *tmp, *foo;

	saved_status = START_TO; /* fixes gcc 4.x warning */
	status = START_TO;
	memset(to_b, 0, sizeof(struct to_body));
	to_b->error = PARSE_OK;
	foo = 0;

	for(tmp = buffer; tmp < end; tmp++) {
		switch(*tmp) {
			case ' ':
			case '\t':
				switch(status) {
					case F_CRLF:
					case F_LF:
					case F_CR:
						/*previous=crlf and now =' '*/
						status = saved_status;
						break;
					case URI_ENCLOSED:
						to_b->uri.len = tmp - to_b->uri.s;
						status = E_URI_ENCLOSED;
						break;
					case URI_OR_TOKEN:
						foo = tmp;
						status = MAYBE_URI_END;
						break;
					case DISPLAY_TOKEN:
						foo = tmp;
						status = DISPLAY_TOKEN_SP;
						break;
				}
				break;
			case '\n':
				switch(status) {
					case URI_OR_TOKEN:
						foo = tmp;
						status = MAYBE_URI_END;
					case MAYBE_URI_END:
					case DISPLAY_TOKEN_SP:
					case E_DISPLAY_QUOTED:
					case END:
						saved_status = status;
						status = F_LF;
						break;
					case DISPLAY_TOKEN:
						foo = tmp;
						saved_status = DISPLAY_TOKEN_SP;
						status = F_LF;
						break;
					case F_CR:
						status = F_CRLF;
						break;
					case F_CRLF:
					case F_LF:
						status = saved_status;
						goto endofheader;
					default:
						LM_ERR("unexpected char [%c] in status %d: [%.*s] .\n",
								*tmp, status, (int)(tmp - buffer), ZSW(buffer));
						goto error;
				}
				break;
			case '\r':
				switch(status) {
					case URI_OR_TOKEN:
						foo = tmp;
						status = MAYBE_URI_END;
					case MAYBE_URI_END:
					case DISPLAY_TOKEN_SP:
					case E_DISPLAY_QUOTED:
					case END:
						saved_status = status;
						status = F_CR;
						break;
					case DISPLAY_TOKEN:
						foo = tmp;
						saved_status = DISPLAY_TOKEN_SP;
						status = F_CR;
						break;
					case F_CRLF:
					case F_CR:
					case F_LF:
						status = saved_status;
						goto endofheader;
					default:
						LM_ERR("unexpected char [%c] in status %d: [%.*s] .\n",
								*tmp, status, (int)(tmp - buffer), ZSW(buffer));
						goto error;
				}
				break;
			case 0:
				switch(status) {
					case URI_OR_TOKEN:
					case MAYBE_URI_END:
						to_b->uri.len = tmp - to_b->uri.s;
					case END:
						saved_status = status = END;
						goto endofheader;
					default:
						LM_ERR("unexpected char [%c] in status %d: [%.*s] .\n",
								*tmp, status, (int)(tmp - buffer), ZSW(buffer));
						goto error;
				}
				break;
			case '\\':
				switch(status) {
					case DISPLAY_QUOTED:
						tmp++; /* jump over next char */
						break;
					default:
						LM_ERR("unexpected char [%c] in status %d: [%.*s] .\n",
								*tmp, status, (int)(tmp - buffer), ZSW(buffer));
						goto error;
				}
				break;
			case '<':
				switch(status) {
					case START_TO:
						to_b->body.s = tmp;
						status = S_URI_ENCLOSED;
						break;
					case DISPLAY_QUOTED:
						break;
					case E_DISPLAY_QUOTED:
						status = S_URI_ENCLOSED;
						break;
					case URI_OR_TOKEN:
					case DISPLAY_TOKEN:
						to_b->display.len = tmp - to_b->display.s;
						status = S_URI_ENCLOSED;
						break;
					case DISPLAY_TOKEN_SP:
					case MAYBE_URI_END:
						to_b->display.len = foo - to_b->display.s;
						status = S_URI_ENCLOSED;
						break;
					case F_CRLF:
					case F_LF:
					case F_CR:
						/*previous=crlf and now !=' '*/
						goto endofheader;
					default:
						LM_ERR("unexpected char [%c] in status %d: [%.*s] .\n",
								*tmp, status, (int)(tmp - buffer), ZSW(buffer));
						goto error;
				}
				break;
			case '>':
				switch(status) {
					case DISPLAY_QUOTED:
						break;
					case URI_ENCLOSED:
						to_b->uri.len = tmp - to_b->uri.s;
					case E_URI_ENCLOSED:
						status = END;
						foo = 0;
						break;
					case F_CRLF:
					case F_LF:
					case F_CR:
						/*previous=crlf and now !=' '*/
						goto endofheader;
					default:
						LM_ERR("unexpected char [%c] in status %d: [%.*s] .\n",
								*tmp, status, (int)(tmp - buffer), ZSW(buffer));
						goto error;
				}
				break;
			case '"':
				switch(status) {
					case START_TO:
						to_b->body.s = tmp;
						to_b->display.s = tmp;
						status = DISPLAY_QUOTED;
						break;
					case DISPLAY_QUOTED:
						status = E_DISPLAY_QUOTED;
						to_b->display.len = tmp - to_b->display.s + 1;
						break;
					case F_CRLF:
					case F_LF:
					case F_CR:
						/*previous=crlf and now !=' '*/
						goto endofheader;
					default:
						LM_ERR("unexpected char [%c] in status %d: [%.*s] .\n",
								*tmp, status, (int)(tmp - buffer), buffer);
						goto error;
				}
				break;
			case ';':
				switch(status) {
					case DISPLAY_QUOTED:
					case URI_ENCLOSED:
						break;
					case URI_OR_TOKEN:
						foo = tmp;
					case MAYBE_URI_END:
						to_b->uri.len = foo - to_b->uri.s;
					case END:
						to_b->body.len = tmp - to_b->body.s;
						tmp = parse_to_param(
								tmp, end, to_b, allow_comma_sep, &saved_status);
						goto endofheader;
					case F_CRLF:
					case F_LF:
					case F_CR:
						/*previous=crlf and now !=' '*/
						goto endofheader;
					default:
						LM_ERR("unexpected char [%c] in status %d: [%.*s] .\n",
								*tmp, status, (int)(tmp - buffer), buffer);
						goto error;
				}
				break;
			case ',':
				if(allow_comma_sep) {
					switch(status) {
						case DISPLAY_QUOTED:
						case URI_ENCLOSED:
							break;
						case URI_OR_TOKEN:
							foo = tmp;
						case MAYBE_URI_END:
							to_b->uri.len = foo - to_b->uri.s;
						case END:
							to_b->body.len = tmp - to_b->body.s;
							saved_status = END;
							goto endofheader;
						case F_CRLF:
						case F_LF:
						case F_CR:
							/*previous=crlf and now !=' '*/
							goto endofheader;
						default:
							LM_ERR("unexpected char [%c] in status %d: [%.*s] "
									".\n",
									*tmp, status, (int)(tmp - buffer), buffer);
							goto error;
					}
					break;
				}
			/* If commas not allowed treat as a default character */
			default:
				switch(status) {
					case START_TO:
						to_b->uri.s = to_b->body.s = tmp;
						status = URI_OR_TOKEN;
						to_b->display.s = tmp;
						break;
					case S_URI_ENCLOSED:
						to_b->uri.s = tmp;
						status = URI_ENCLOSED;
						break;
					case MAYBE_URI_END:
					case DISPLAY_TOKEN_SP:
						status = DISPLAY_TOKEN;
					case DISPLAY_QUOTED:
					case DISPLAY_TOKEN:
					case URI_ENCLOSED:
					case URI_OR_TOKEN:
						break;
					case F_CRLF:
					case F_LF:
					case F_CR:
						/*previous=crlf and now !=' '*/
						goto endofheader;
					default:
						LM_DBG("spitting out [%c] in status %d\n", *tmp,
								status);
						goto error;
				}
		} /*char switch*/
	}	 /*for*/

	/* Reached end of buffer */
	switch(status) {
		case URI_OR_TOKEN:
		case MAYBE_URI_END:
		case END:
			saved_status = status;
			foo = tmp;
	}

endofheader:
	if(to_b->display.len == 0)
		to_b->display.s = 0;
	status = saved_status;
	LM_DBG("end of header reached, state=%d\n", status);
	/* check if error*/
	switch(status) {
		case URI_OR_TOKEN:
		case MAYBE_URI_END:
			to_b->uri.len = foo - to_b->uri.s;
		case END:
			to_b->body.len = tmp - to_b->body.s;
		case E_PARA_VALUE:
			break;
		default:
			LM_ERR("invalid To -  unexpected "
					"end of header in state %d\n",
					status);
			goto error;
	}
	return tmp;

error:
	free_to_params(to_b);
	to_b->error = PARSE_ERROR;
	return tmp;
}


void free_to_params(struct to_body *const tb)
{
	struct to_param *tp = tb->param_lst;
	struct to_param *foo;
	while(tp) {
		foo = tp->next;
		pkg_free(tp);
		tp = foo;
	}
	tb->param_lst = NULL;
}


void free_to(struct to_body *const tb)
{
	free_to_params(tb);
	pkg_free(tb);
}