1 /*
2 ** Zabbix
3 ** Copyright (C) 2001-2021 Zabbix SIA
4 **
5 ** This program is free software; you can redistribute it and/or modify
6 ** it under the terms of the GNU General Public License as published by
7 ** the Free Software Foundation; either version 2 of the License, or
8 ** (at your option) any later version.
9 **
10 ** This program is distributed in the hope that it will be useful,
11 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
12 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 ** GNU General Public License for more details.
14 **
15 ** You should have received a copy of the GNU General Public License
16 ** along with this program; if not, write to the Free Software
17 ** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
18 **/
19 
20 #include "common.h"
21 #include "comms.h"
22 #include "zbxjson.h"
23 #include "log.h"
24 
25 /******************************************************************************
26  *                                                                            *
27  * Function: zbx_send_response_ext                                            *
28  *                                                                            *
29  * Purpose: send json SUCCEED or FAIL to socket along with an info message    *
30  *                                                                            *
31  * Parameters: sock    - [IN] socket descriptor                               *
32  *             result  - [IN] SUCCEED or FAIL                                 *
33  *             info    - [IN] info message                                    *
34  *             timeout - [IN] timeout for this operation                      *
35  *                                                                            *
36  * Return value: SUCCEED - data successfully transmited                       *
37  *               NETWORK_ERROR - network related error occurred               *
38  *                                                                            *
39  * Author: Alexander Vladishev, Alexei Vladishev                              *
40  *                                                                            *
41  ******************************************************************************/
zbx_send_response_ext(zbx_socket_t * sock,int result,const char * info,int protocol,int timeout)42 int	zbx_send_response_ext(zbx_socket_t *sock, int result, const char *info, int protocol, int timeout)
43 {
44 	const char	*__function_name = "zbx_send_response_ext";
45 
46 	struct zbx_json	json;
47 	const char	*resp;
48 	int		ret = SUCCEED;
49 
50 	zabbix_log(LOG_LEVEL_DEBUG, "In %s()", __function_name);
51 
52 	zbx_json_init(&json, ZBX_JSON_STAT_BUF_LEN);
53 
54 	resp = SUCCEED == result ? ZBX_PROTO_VALUE_SUCCESS : ZBX_PROTO_VALUE_FAILED;
55 
56 	zbx_json_addstring(&json, ZBX_PROTO_TAG_RESPONSE, resp, ZBX_JSON_TYPE_STRING);
57 
58 	if (NULL != info && '\0' != *info)
59 		zbx_json_addstring(&json, ZBX_PROTO_TAG_INFO, info, ZBX_JSON_TYPE_STRING);
60 
61 	zabbix_log(LOG_LEVEL_DEBUG, "%s() '%s'", __function_name, json.buffer);
62 
63 	if (FAIL == (ret = zbx_tcp_send_ext(sock, json.buffer, strlen(json.buffer), protocol, timeout)))
64 	{
65 		zabbix_log(LOG_LEVEL_DEBUG, "Error sending result back: %s", zbx_socket_strerror());
66 		ret = NETWORK_ERROR;
67 	}
68 
69 	zbx_json_free(&json);
70 
71 	zabbix_log(LOG_LEVEL_DEBUG, "End of %s():%s", __function_name, zbx_result_string(ret));
72 
73 	return ret;
74 }
75 
76 /******************************************************************************
77  *                                                                            *
78  * Function: zbx_recv_response                                                *
79  *                                                                            *
80  * Purpose: read a response message (in JSON format) from socket, optionally  *
81  *          extract "info" value.                                             *
82  *                                                                            *
83  * Parameters: sock    - [IN] socket descriptor                               *
84  *             timeout - [IN] timeout for this operation                      *
85  *             error   - [OUT] pointer to error message                       *
86  *                                                                            *
87  * Return value: SUCCEED - "response":"success" successfully retrieved        *
88  *               FAIL    - otherwise                                          *
89  * Comments:                                                                  *
90  *     Allocates memory.                                                      *
91  *                                                                            *
92  *     If an error occurs, the function allocates dynamic memory for an error *
93  *     message and writes its address into location pointed to by "error"     *
94  *     parameter.                                                             *
95  *                                                                            *
96  *     When the "info" value is present in the response message then function *
97  *     copies the "info" value into the "error" buffer as additional          *
98  *     information                                                            *
99  *                                                                            *
100  *     IMPORTANT: it is a responsibility of the caller to release the         *
101  *                "error" memory !                                            *
102  *                                                                            *
103  ******************************************************************************/
zbx_recv_response(zbx_socket_t * sock,int timeout,char ** error)104 int	zbx_recv_response(zbx_socket_t *sock, int timeout, char **error)
105 {
106 	const char		*__function_name = "zbx_recv_response";
107 
108 	struct zbx_json_parse	jp;
109 	char			value[16];
110 	int			ret = FAIL;
111 
112 	zabbix_log(LOG_LEVEL_DEBUG, "In %s()", __function_name);
113 
114 	if (SUCCEED != zbx_tcp_recv_to(sock, timeout))
115 	{
116 		/* since we have successfully sent data earlier, we assume the other */
117 		/* side is just too busy processing our data if there is no response */
118 		*error = zbx_strdup(*error, zbx_socket_strerror());
119 		goto out;
120 	}
121 
122 	zabbix_log(LOG_LEVEL_DEBUG, "%s() '%s'", __function_name, sock->buffer);
123 
124 	/* deal with empty string here because zbx_json_open() does not produce an error message in this case */
125 	if ('\0' == *sock->buffer)
126 	{
127 		*error = zbx_strdup(*error, "empty string received");
128 		goto out;
129 	}
130 
131 	if (SUCCEED != zbx_json_open(sock->buffer, &jp))
132 	{
133 		*error = zbx_strdup(*error, zbx_json_strerror());
134 		goto out;
135 	}
136 
137 	if (SUCCEED != zbx_json_value_by_name(&jp, ZBX_PROTO_TAG_RESPONSE, value, sizeof(value)))
138 	{
139 		*error = zbx_strdup(*error, "no \"" ZBX_PROTO_TAG_RESPONSE "\" tag");
140 		goto out;
141 	}
142 
143 	if (0 != strcmp(value, ZBX_PROTO_VALUE_SUCCESS))
144 	{
145 		char	*info = NULL;
146 		size_t	info_alloc = 0;
147 
148 		if (SUCCEED == zbx_json_value_by_name_dyn(&jp, ZBX_PROTO_TAG_INFO, &info, &info_alloc))
149 			*error = zbx_strdup(*error, info);
150 		else
151 			*error = zbx_dsprintf(*error, "negative response \"%s\"", value);
152 		zbx_free(info);
153 		goto out;
154 	}
155 
156 	ret = SUCCEED;
157 out:
158 	zabbix_log(LOG_LEVEL_DEBUG, "End of %s():%s", __function_name, zbx_result_string(ret));
159 
160 	return ret;
161 }
162