xref: /freebsd/lib/libdevdctl/consumer.cc (revision f7c32ed617858bcd22f8d1b03199099d50125721)
1 /*-
2  * Copyright (c) 2011, 2012, 2013, 2014 Spectra Logic Corporation
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions, and the following disclaimer,
10  *    without modification.
11  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
12  *    substantially similar to the "NO WARRANTY" disclaimer below
13  *    ("Disclaimer") and any redistribution must be conditioned upon
14  *    including a substantially similar Disclaimer requirement for further
15  *    binary redistribution.
16  *
17  * NO WARRANTY
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
26  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
27  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGES.
29  *
30  * Authors: Justin T. Gibbs     (Spectra Logic Corporation)
31  */
32 
33 /**
34  * \file consumer.cc
35  */
36 
37 #include <sys/cdefs.h>
38 #include <sys/poll.h>
39 #include <sys/socket.h>
40 #include <sys/un.h>
41 
42 #include <err.h>
43 #include <errno.h>
44 #include <fcntl.h>
45 #include <syslog.h>
46 #include <unistd.h>
47 
48 #include <cstdarg>
49 #include <cstring>
50 #include <list>
51 #include <map>
52 #include <string>
53 
54 #include "guid.h"
55 #include "event.h"
56 #include "event_factory.h"
57 #include "exception.h"
58 
59 #include "consumer.h"
60 
61 __FBSDID("$FreeBSD$");
62 
63 /*================================== Macros ==================================*/
64 #define NUM_ELEMENTS(x) (sizeof(x) / sizeof(*x))
65 
66 /*============================ Namespace Control =============================*/
67 using std::string;
68 namespace DevdCtl
69 {
70 
71 /*============================= Class Definitions ============================*/
72 /*----------------------------- DevdCtl::Consumer ----------------------------*/
73 //- Consumer Static Private Data -----------------------------------------------
74 const char Consumer::s_devdSockPath[] = "/var/run/devd.seqpacket.pipe";
75 
76 //- Consumer Public Methods ----------------------------------------------------
77 Consumer::Consumer(Event::BuildMethod *defBuilder,
78 		   EventFactory::Record *regEntries,
79 		   size_t numEntries)
80  : m_devdSockFD(-1),
81    m_eventFactory(defBuilder),
82    m_replayingEvents(false)
83 {
84 	m_eventFactory.UpdateRegistry(regEntries, numEntries);
85 }
86 
87 Consumer::~Consumer()
88 {
89 	DisconnectFromDevd();
90 }
91 
92 bool
93 Consumer::ConnectToDevd()
94 {
95 	struct sockaddr_un devdAddr;
96 	int		   sLen;
97 	int		   result;
98 
99 	if (m_devdSockFD != -1) {
100 		/* Already connected. */
101 		syslog(LOG_DEBUG, "%s: Already connected.", __func__);
102 		return (true);
103 	}
104 	syslog(LOG_INFO, "%s: Connecting to devd.", __func__);
105 
106 	memset(&devdAddr, 0, sizeof(devdAddr));
107 	devdAddr.sun_family= AF_UNIX;
108 	strlcpy(devdAddr.sun_path, s_devdSockPath, sizeof(devdAddr.sun_path));
109 	sLen = SUN_LEN(&devdAddr);
110 
111 	m_devdSockFD = socket(AF_UNIX, SOCK_SEQPACKET | SOCK_NONBLOCK, 0);
112 	if (m_devdSockFD == -1)
113 		err(1, "Unable to create socket");
114 	result = connect(m_devdSockFD,
115 			 reinterpret_cast<sockaddr *>(&devdAddr),
116 			 sLen);
117 	if (result == -1) {
118 		syslog(LOG_INFO, "Unable to connect to devd");
119 		DisconnectFromDevd();
120 		return (false);
121 	}
122 
123 	syslog(LOG_INFO, "Connection to devd successful");
124 	return (true);
125 }
126 
127 void
128 Consumer::DisconnectFromDevd()
129 {
130 	if (m_devdSockFD != -1) {
131 		syslog(LOG_INFO, "Disconnecting from devd.");
132 		close(m_devdSockFD);
133 	}
134 	m_devdSockFD = -1;
135 }
136 
137 std::string
138 Consumer::ReadEvent()
139 {
140 	char buf[MAX_EVENT_SIZE + 1];
141 	ssize_t len;
142 
143 	len = ::recv(m_devdSockFD, buf, MAX_EVENT_SIZE, MSG_WAITALL);
144 	if (len == -1)
145 		return (std::string(""));
146 	else {
147 		/* NULL-terminate the result */
148 		buf[len] = '\0';
149 		return (std::string(buf));
150 	}
151 }
152 
153 void
154 Consumer::ReplayUnconsumedEvents(bool discardUnconsumed)
155 {
156 	EventList::iterator event(m_unconsumedEvents.begin());
157 	bool replayed_any = (event != m_unconsumedEvents.end());
158 
159 	m_replayingEvents = true;
160 	if (replayed_any)
161 		syslog(LOG_INFO, "Started replaying unconsumed events");
162 	while (event != m_unconsumedEvents.end()) {
163 		bool consumed((*event)->Process());
164 		if (consumed || discardUnconsumed) {
165 			delete *event;
166 			event = m_unconsumedEvents.erase(event);
167 		} else {
168 			event++;
169 		}
170 	}
171 	if (replayed_any)
172 		syslog(LOG_INFO, "Finished replaying unconsumed events");
173 	m_replayingEvents = false;
174 }
175 
176 bool
177 Consumer::SaveEvent(const Event &event)
178 {
179         if (m_replayingEvents)
180                 return (false);
181         m_unconsumedEvents.push_back(event.DeepCopy());
182         return (true);
183 }
184 
185 Event *
186 Consumer::NextEvent()
187 {
188 	if (!Connected())
189 		return(NULL);
190 
191 	Event *event(NULL);
192 	try {
193 		string evString;
194 
195 		evString = ReadEvent();
196 		if (! evString.empty()) {
197 			Event::TimestampEventString(evString);
198 			event = Event::CreateEvent(m_eventFactory, evString);
199 		}
200 	} catch (const Exception &exp) {
201 		exp.Log();
202 		DisconnectFromDevd();
203 	}
204 	return (event);
205 }
206 
207 /* Capture and process buffered events. */
208 void
209 Consumer::ProcessEvents()
210 {
211 	Event *event;
212 	while ((event = NextEvent()) != NULL) {
213 		if (event->Process())
214 			SaveEvent(*event);
215 		delete event;
216 	}
217 }
218 
219 void
220 Consumer::FlushEvents()
221 {
222 	std::string s;
223 
224 	do
225 		s = ReadEvent();
226 	while (! s.empty()) ;
227 }
228 
229 bool
230 Consumer::EventsPending()
231 {
232 	struct pollfd fds[1];
233 	int	      result;
234 
235 	do {
236 		fds->fd      = m_devdSockFD;
237 		fds->events  = POLLIN;
238 		fds->revents = 0;
239 		result = poll(fds, NUM_ELEMENTS(fds), /*timeout*/0);
240 	} while (result == -1 && errno == EINTR);
241 
242 	if (result == -1)
243 		err(1, "Polling for devd events failed");
244 
245 	if ((fds->revents & POLLERR) != 0)
246 		throw Exception("Consumer::EventsPending(): "
247 				"POLLERR detected on devd socket.");
248 
249 	if ((fds->revents & POLLHUP) != 0)
250 		throw Exception("Consumer::EventsPending(): "
251 				"POLLHUP detected on devd socket.");
252 
253 	return ((fds->revents & POLLIN) != 0);
254 }
255 
256 } // namespace DevdCtl
257