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/*================================== Macros ==================================*/
61#define NUM_ELEMENTS(x) (sizeof(x) / sizeof(*x))
62
63/*============================ Namespace Control =============================*/
64using std::string;
65namespace DevdCtl
66{
67
68/*============================= Class Definitions ============================*/
69/*----------------------------- DevdCtl::Consumer ----------------------------*/
70//- Consumer Static Private Data -----------------------------------------------
71const char Consumer::s_devdSockPath[] = "/var/run/devd.seqpacket.pipe";
72
73//- Consumer Public Methods ----------------------------------------------------
74Consumer::Consumer(Event::BuildMethod *defBuilder,
75		   EventFactory::Record *regEntries,
76		   size_t numEntries)
77 : m_devdSockFD(-1),
78   m_eventFactory(defBuilder),
79   m_replayingEvents(false)
80{
81	m_eventFactory.UpdateRegistry(regEntries, numEntries);
82}
83
84Consumer::~Consumer()
85{
86	DisconnectFromDevd();
87}
88
89bool
90Consumer::ConnectToDevd()
91{
92	struct sockaddr_un devdAddr;
93	int		   sLen;
94	int		   result;
95
96	if (m_devdSockFD != -1) {
97		/* Already connected. */
98		syslog(LOG_DEBUG, "%s: Already connected.", __func__);
99		return (true);
100	}
101	syslog(LOG_INFO, "%s: Connecting to devd.", __func__);
102
103	memset(&devdAddr, 0, sizeof(devdAddr));
104	devdAddr.sun_family= AF_UNIX;
105	strlcpy(devdAddr.sun_path, s_devdSockPath, sizeof(devdAddr.sun_path));
106	sLen = SUN_LEN(&devdAddr);
107
108	m_devdSockFD = socket(AF_UNIX, SOCK_SEQPACKET | SOCK_NONBLOCK, 0);
109	if (m_devdSockFD == -1)
110		err(1, "Unable to create socket");
111	result = connect(m_devdSockFD,
112			 reinterpret_cast<sockaddr *>(&devdAddr),
113			 sLen);
114	if (result == -1) {
115		syslog(LOG_INFO, "Unable to connect to devd");
116		DisconnectFromDevd();
117		return (false);
118	}
119
120	syslog(LOG_INFO, "Connection to devd successful");
121	return (true);
122}
123
124void
125Consumer::DisconnectFromDevd()
126{
127	if (m_devdSockFD != -1) {
128		syslog(LOG_INFO, "Disconnecting from devd.");
129		close(m_devdSockFD);
130	}
131	m_devdSockFD = -1;
132}
133
134std::string
135Consumer::ReadEvent()
136{
137	char buf[MAX_EVENT_SIZE + 1];
138	ssize_t len;
139
140	len = ::recv(m_devdSockFD, buf, MAX_EVENT_SIZE, MSG_WAITALL);
141	if (len == -1)
142		return (std::string(""));
143	else {
144		/* NULL-terminate the result */
145		buf[len] = '\0';
146		return (std::string(buf));
147	}
148}
149
150void
151Consumer::ReplayUnconsumedEvents(bool discardUnconsumed)
152{
153	EventList::iterator event(m_unconsumedEvents.begin());
154	bool replayed_any = (event != m_unconsumedEvents.end());
155
156	m_replayingEvents = true;
157	if (replayed_any)
158		syslog(LOG_INFO, "Started replaying unconsumed events");
159	while (event != m_unconsumedEvents.end()) {
160		bool consumed((*event)->Process());
161		if (consumed || discardUnconsumed) {
162			delete *event;
163			event = m_unconsumedEvents.erase(event);
164		} else {
165			event++;
166		}
167	}
168	if (replayed_any)
169		syslog(LOG_INFO, "Finished replaying unconsumed events");
170	m_replayingEvents = false;
171}
172
173bool
174Consumer::SaveEvent(const Event &event)
175{
176        if (m_replayingEvents)
177                return (false);
178        m_unconsumedEvents.push_back(event.DeepCopy());
179        return (true);
180}
181
182Event *
183Consumer::NextEvent()
184{
185	if (!Connected())
186		return(NULL);
187
188	Event *event(NULL);
189	try {
190		string evString;
191
192		evString = ReadEvent();
193		if (! evString.empty()) {
194			Event::TimestampEventString(evString);
195			event = Event::CreateEvent(m_eventFactory, evString);
196		}
197	} catch (const Exception &exp) {
198		exp.Log();
199		DisconnectFromDevd();
200	}
201	return (event);
202}
203
204/* Capture and process buffered events. */
205void
206Consumer::ProcessEvents()
207{
208	Event *event;
209	while ((event = NextEvent()) != NULL) {
210		if (event->Process())
211			SaveEvent(*event);
212		delete event;
213	}
214}
215
216void
217Consumer::FlushEvents()
218{
219	std::string s;
220
221	do
222		s = ReadEvent();
223	while (! s.empty()) ;
224}
225
226bool
227Consumer::EventsPending()
228{
229	struct pollfd fds[1];
230	int	      result;
231
232	do {
233		fds->fd      = m_devdSockFD;
234		fds->events  = POLLIN;
235		fds->revents = 0;
236		result = poll(fds, NUM_ELEMENTS(fds), /*timeout*/0);
237	} while (result == -1 && errno == EINTR);
238
239	if (result == -1)
240		err(1, "Polling for devd events failed");
241
242	if ((fds->revents & POLLERR) != 0)
243		throw Exception("Consumer::EventsPending(): "
244				"POLLERR detected on devd socket.");
245
246	if ((fds->revents & POLLHUP) != 0)
247		throw Exception("Consumer::EventsPending(): "
248				"POLLHUP detected on devd socket.");
249
250	return ((fds->revents & POLLIN) != 0);
251}
252
253} // namespace DevdCtl
254