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9f4eb5cc RG |
1 | #include "snmp-agent.hh" |
2 | #include "misc.hh" | |
3 | ||
4 | #ifdef HAVE_NET_SNMP | |
5 | ||
0e663c3b RG |
6 | #ifndef HAVE_SNMP_SELECT_INFO2 |
7 | /* that's terrible, because it means we are going to have trouble with large | |
8 | FD numbers at some point.. */ | |
9 | # define netsnmp_large_fd_set fd_set | |
10 | # define snmp_read2 snmp_read | |
11 | # define snmp_select_info2 snmp_select_info | |
12 | # define netsnmp_large_fd_set_init(...) | |
13 | # define netsnmp_large_fd_set_cleanup(...) | |
14 | # define NETSNMP_LARGE_FD_SET FD_SET | |
15 | # define NETSNMP_LARGE_FD_CLR FD_CLR | |
16 | # define NETSNMP_LARGE_FD_ZERO FD_ZERO | |
17 | # define NETSNMP_LARGE_FD_ISSET FD_ISSET | |
18 | #else | |
19 | # include <net-snmp/library/large_fd_set.h> | |
20 | #endif | |
21 | ||
9f4eb5cc RG |
22 | const oid SNMPAgent::snmpTrapOID[] = { 1, 3, 6, 1, 6, 3, 1, 1, 4, 1, 0 }; |
23 | const size_t SNMPAgent::snmpTrapOIDLen = OID_LENGTH(SNMPAgent::snmpTrapOID); | |
24 | ||
25 | int SNMPAgent::setCounter64Value(netsnmp_request_info* request, | |
26 | uint64_t value) | |
27 | { | |
28 | struct counter64 val64; | |
29 | val64.high = value >> 32; | |
30 | val64.low = value & 0xffffffff; | |
31 | snmp_set_var_typed_value(request->requestvb, | |
32 | ASN_COUNTER64, | |
33 | &val64, | |
34 | sizeof(val64)); | |
35 | return SNMP_ERR_NOERROR; | |
36 | } | |
37 | ||
38 | bool SNMPAgent::sendTrap(int fd, | |
39 | netsnmp_variable_list* varList) | |
40 | { | |
41 | ssize_t written = write(fd, &varList, sizeof(varList)); | |
42 | ||
43 | if (written != sizeof(varList)) { | |
44 | snmp_free_varbind(varList); | |
45 | return false; | |
46 | } | |
47 | return true; | |
48 | } | |
49 | ||
0e663c3b | 50 | void SNMPAgent::handleTrapsEvent() |
9f4eb5cc RG |
51 | { |
52 | netsnmp_variable_list* varList = nullptr; | |
53 | ssize_t got = 0; | |
54 | ||
55 | do { | |
56 | got = read(d_trapPipe[0], &varList, sizeof(varList)); | |
57 | ||
58 | if (got == sizeof(varList)) { | |
59 | send_v2trap(varList); | |
60 | snmp_free_varbind(varList); | |
61 | } | |
62 | } | |
63 | while (got > 0); | |
64 | } | |
0e663c3b RG |
65 | |
66 | void SNMPAgent::handleSNMPQueryEvent(int fd) | |
67 | { | |
68 | netsnmp_large_fd_set fdset; | |
69 | netsnmp_large_fd_set_init(&fdset, FD_SETSIZE); | |
70 | NETSNMP_LARGE_FD_ZERO(&fdset); | |
71 | NETSNMP_LARGE_FD_SET(fd, &fdset); | |
72 | snmp_read2(&fdset); | |
73 | } | |
74 | ||
75 | void SNMPAgent::handleTrapsCB(int fd, FDMultiplexer::funcparam_t& var) | |
76 | { | |
77 | SNMPAgent** agent = boost::any_cast<SNMPAgent*>(&var); | |
78 | if (!agent || !*agent) | |
79 | throw std::runtime_error("Invalid value received in SNMP trap callback"); | |
80 | ||
81 | (*agent)->handleTrapsEvent(); | |
82 | } | |
83 | ||
84 | void SNMPAgent::handleSNMPQueryCB(int fd, FDMultiplexer::funcparam_t& var) | |
85 | { | |
86 | SNMPAgent** agent = boost::any_cast<SNMPAgent*>(&var); | |
87 | if (!agent || !*agent) | |
88 | throw std::runtime_error("Invalid value received in SNMP trap callback"); | |
89 | ||
90 | (*agent)->handleSNMPQueryEvent(fd); | |
91 | } | |
92 | ||
93 | static FDMultiplexer* getMultiplexer() | |
94 | { | |
95 | FDMultiplexer* ret = nullptr; | |
96 | for(const auto& i : FDMultiplexer::getMultiplexerMap()) { | |
97 | try { | |
98 | ret = i.second(); | |
99 | return ret; | |
100 | } | |
101 | catch(const FDMultiplexerException& fe) { | |
102 | } | |
103 | catch(...) { | |
104 | } | |
105 | } | |
106 | return ret; | |
107 | } | |
108 | ||
9f4eb5cc RG |
109 | #endif /* HAVE_NET_SNMP */ |
110 | ||
111 | void SNMPAgent::worker() | |
112 | { | |
113 | #ifdef HAVE_NET_SNMP | |
0e663c3b RG |
114 | FDMultiplexer* mplexer = getMultiplexer(); |
115 | if (mplexer == nullptr) { | |
116 | throw std::runtime_error("No FD multiplexer found for the SNMP agent!"); | |
117 | } | |
118 | ||
119 | int maxfd = 0; | |
9f4eb5cc | 120 | int block = 1; |
0e663c3b | 121 | netsnmp_large_fd_set fdset; |
9f4eb5cc | 122 | struct timeval timeout = { 0, 0 }; |
0e663c3b RG |
123 | struct timeval now; |
124 | ||
125 | /* we want to be notified if a trap is waiting | |
126 | to be sent */ | |
127 | mplexer->addReadFD(d_trapPipe[0], &handleTrapsCB, this); | |
9f4eb5cc RG |
128 | |
129 | while(true) { | |
0e663c3b RG |
130 | netsnmp_large_fd_set_init(&fdset, FD_SETSIZE); |
131 | NETSNMP_LARGE_FD_ZERO(&fdset); | |
9f4eb5cc | 132 | |
0576fe19 RG |
133 | block = 1; |
134 | timeout = { 0, 0 }; | |
0e663c3b | 135 | snmp_select_info2(&maxfd, &fdset, &timeout, &block); |
9f4eb5cc | 136 | |
0e663c3b RG |
137 | for (int fd = 0; fd < maxfd; fd++) { |
138 | if (NETSNMP_LARGE_FD_ISSET(fd, &fdset)) { | |
139 | mplexer->addReadFD(fd, &handleSNMPQueryCB, this); | |
9f4eb5cc RG |
140 | } |
141 | } | |
0e663c3b RG |
142 | |
143 | /* run updates now */ | |
144 | int res = mplexer->run(&now, (timeout.tv_sec * 1000) + (timeout.tv_usec / 1000)); | |
145 | ||
146 | /* we handle timeouts here, the rest has already been handled by callbacks */ | |
147 | if (res == 0) { | |
9f4eb5cc | 148 | snmp_timeout(); |
0576fe19 | 149 | run_alarms(); |
9f4eb5cc | 150 | } |
0e663c3b RG |
151 | |
152 | for (int fd = 0; fd < maxfd; fd++) { | |
153 | if (NETSNMP_LARGE_FD_ISSET(fd, &fdset)) { | |
154 | try { | |
155 | mplexer->removeReadFD(fd); | |
156 | } | |
157 | catch(const FDMultiplexerException& e) { | |
158 | /* we might get an exception when removing a closed file descriptor, | |
159 | just ignore it */ | |
160 | } | |
161 | } | |
162 | } | |
9f4eb5cc RG |
163 | } |
164 | #endif /* HAVE_NET_SNMP */ | |
165 | } | |
166 | ||
167 | SNMPAgent::SNMPAgent(const std::string& name, const std::string& masterSocket) | |
168 | { | |
169 | #ifdef HAVE_NET_SNMP | |
170 | netsnmp_enable_subagent(); | |
171 | snmp_disable_log(); | |
172 | if (!masterSocket.empty()) { | |
173 | netsnmp_ds_set_string(NETSNMP_DS_APPLICATION_ID, | |
174 | NETSNMP_DS_AGENT_X_SOCKET, | |
175 | masterSocket.c_str()); | |
176 | } | |
177 | /* no need to load any MIBS, | |
178 | and it causes import errors if some modules are not present */ | |
179 | setenv("MIBS", "", 1); | |
180 | ||
181 | init_agent(name.c_str()); | |
0576fe19 RG |
182 | |
183 | /* we use select() so don't use SIGALARM to handle alarms. | |
184 | Note that we need to handle alarms for automatic reconnection | |
185 | to the master to work. | |
186 | */ | |
187 | netsnmp_ds_set_boolean(NETSNMP_DS_LIBRARY_ID, | |
188 | NETSNMP_DS_LIB_ALARM_DONT_USE_SIG, | |
189 | 1); | |
190 | ||
9f4eb5cc RG |
191 | init_snmp(name.c_str()); |
192 | ||
193 | if (pipe(d_trapPipe) < 0) | |
194 | unixDie("Creating pipe"); | |
195 | ||
196 | if (!setNonBlocking(d_trapPipe[0])) { | |
197 | close(d_trapPipe[0]); | |
198 | close(d_trapPipe[1]); | |
199 | unixDie("Setting pipe non-blocking"); | |
200 | } | |
201 | ||
202 | if (!setNonBlocking(d_trapPipe[1])) { | |
203 | close(d_trapPipe[0]); | |
204 | close(d_trapPipe[1]); | |
205 | unixDie("Setting pipe non-blocking"); | |
206 | } | |
207 | ||
208 | #endif /* HAVE_NET_SNMP */ | |
209 | } |