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 =============================*/
67using std::string;
68namespace DevdCtl
69{
70
71/*============================= Class Definitions ============================*/
72/*----------------------------- DevdCtl::Consumer ----------------------------*/
73//- Consumer Static Private Data -----------------------------------------------
74const char Consumer::s_devdSockPath[] = "/var/run/devd.seqpacket.pipe";
75
76//- Consumer Public Methods ----------------------------------------------------
77Consumer::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
87Consumer::~Consumer()
88{
89	DisconnectFromDevd();
90}
91
92bool
93Consumer::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
127void
128Consumer::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
137std::string
138Consumer::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
153void
154Consumer::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
176bool
177Consumer::SaveEvent(const Event &event)
178{
179        if (m_replayingEvents)
180                return (false);
181        m_unconsumedEvents.push_back(event.DeepCopy());
182        return (true);
183}
184
185Event *
186Consumer::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. */
208void
209Consumer::ProcessEvents()
210{
211	Event *event;
212	while ((event = NextEvent()) != NULL) {
213		if (event->Process())
214			SaveEvent(*event);
215		delete event;
216	}
217}
218
219void
220Consumer::FlushEvents()
221{
222	std::string s;
223
224	do
225		s = ReadEvent();
226	while (! s.empty()) ;
227}
228
229bool
230Consumer::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