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 "log.h"
23 #include "../../libs/zbxcrypto/tls_tcp_active.h"
24
25 #include "checks_agent.h"
26
27 #if !(defined(HAVE_POLARSSL) || defined(HAVE_GNUTLS) || defined(HAVE_OPENSSL))
28 extern unsigned char program_type;
29 #endif
30
31 /******************************************************************************
32 * *
33 * Function: get_value_agent *
34 * *
35 * Purpose: retrieve data from Zabbix agent *
36 * *
37 * Parameters: item - item we are interested in *
38 * *
39 * Return value: SUCCEED - data successfully retrieved and stored in result *
40 * and result_str (as string) *
41 * NETWORK_ERROR - network related error occurred *
42 * NOTSUPPORTED - item not supported by the agent *
43 * AGENT_ERROR - uncritical error on agent side occurred *
44 * FAIL - otherwise *
45 * *
46 * Author: Alexei Vladishev *
47 * *
48 * Comments: error will contain error message *
49 * *
50 ******************************************************************************/
get_value_agent(DC_ITEM * item,AGENT_RESULT * result)51 int get_value_agent(DC_ITEM *item, AGENT_RESULT *result)
52 {
53 const char *__function_name = "get_value_agent";
54 zbx_socket_t s;
55 char *tls_arg1, *tls_arg2;
56 int ret = SUCCEED;
57 ssize_t received_len;
58
59 zabbix_log(LOG_LEVEL_DEBUG, "In %s() host:'%s' addr:'%s' key:'%s' conn:'%s'", __function_name, item->host.host,
60 item->interface.addr, item->key, zbx_tcp_connection_type_name(item->host.tls_connect));
61
62 switch (item->host.tls_connect)
63 {
64 case ZBX_TCP_SEC_UNENCRYPTED:
65 tls_arg1 = NULL;
66 tls_arg2 = NULL;
67 break;
68 #if defined(HAVE_POLARSSL) || defined(HAVE_GNUTLS) || defined(HAVE_OPENSSL)
69 case ZBX_TCP_SEC_TLS_CERT:
70 tls_arg1 = item->host.tls_issuer;
71 tls_arg2 = item->host.tls_subject;
72 break;
73 case ZBX_TCP_SEC_TLS_PSK:
74 tls_arg1 = item->host.tls_psk_identity;
75 tls_arg2 = item->host.tls_psk;
76 break;
77 #else
78 case ZBX_TCP_SEC_TLS_CERT:
79 case ZBX_TCP_SEC_TLS_PSK:
80 SET_MSG_RESULT(result, zbx_dsprintf(NULL, "A TLS connection is configured to be used with agent"
81 " but support for TLS was not compiled into %s.",
82 get_program_type_string(program_type)));
83 ret = CONFIG_ERROR;
84 goto out;
85 #endif
86 default:
87 THIS_SHOULD_NEVER_HAPPEN;
88 SET_MSG_RESULT(result, zbx_strdup(NULL, "Invalid TLS connection parameters."));
89 ret = CONFIG_ERROR;
90 goto out;
91 }
92
93 if (SUCCEED == (ret = zbx_tcp_connect(&s, CONFIG_SOURCE_IP, item->interface.addr, item->interface.port, 0,
94 item->host.tls_connect, tls_arg1, tls_arg2)))
95 {
96 zabbix_log(LOG_LEVEL_DEBUG, "Sending [%s]", item->key);
97
98 if (SUCCEED != zbx_tcp_send(&s, item->key))
99 ret = NETWORK_ERROR;
100 else if (FAIL != (received_len = zbx_tcp_recv_ext(&s, 0)))
101 ret = SUCCEED;
102 else if (SUCCEED == zbx_alarm_timed_out())
103 ret = TIMEOUT_ERROR;
104 else
105 ret = NETWORK_ERROR;
106 }
107 else
108 ret = NETWORK_ERROR;
109
110 if (SUCCEED == ret)
111 {
112 zbx_rtrim(s.buffer, " \r\n");
113 zbx_ltrim(s.buffer, " ");
114
115 zabbix_log(LOG_LEVEL_DEBUG, "get value from agent result: '%s'", s.buffer);
116
117 if (0 == strcmp(s.buffer, ZBX_NOTSUPPORTED))
118 {
119 /* 'ZBX_NOTSUPPORTED\0<error message>' */
120 if (sizeof(ZBX_NOTSUPPORTED) < s.read_bytes)
121 SET_MSG_RESULT(result, zbx_dsprintf(NULL, "%s", s.buffer + sizeof(ZBX_NOTSUPPORTED)));
122 else
123 SET_MSG_RESULT(result, zbx_strdup(NULL, "Not supported by Zabbix Agent"));
124
125 ret = NOTSUPPORTED;
126 }
127 else if (0 == strcmp(s.buffer, ZBX_ERROR))
128 {
129 SET_MSG_RESULT(result, zbx_strdup(NULL, "Zabbix Agent non-critical error"));
130 ret = AGENT_ERROR;
131 }
132 else if (0 == received_len)
133 {
134 SET_MSG_RESULT(result, zbx_dsprintf(NULL, "Received empty response from Zabbix Agent at [%s]."
135 " Assuming that agent dropped connection because of access permissions.",
136 item->interface.addr));
137 ret = NETWORK_ERROR;
138 }
139 else
140 set_result_type(result, ITEM_VALUE_TYPE_TEXT, s.buffer);
141 }
142 else
143 SET_MSG_RESULT(result, zbx_dsprintf(NULL, "Get value from agent failed: %s", zbx_socket_strerror()));
144
145 zbx_tcp_close(&s);
146 out:
147 zabbix_log(LOG_LEVEL_DEBUG, "End of %s():%s", __function_name, zbx_result_string(ret));
148
149 return ret;
150 }
151