pinger.cc
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1/*
2 * Copyright (C) 1996-2022 The Squid Software Foundation and contributors
3 *
4 * Squid software is distributed under GPLv2+ license and includes
5 * contributions from numerous individuals and organizations.
6 * Please see the COPYING and CONTRIBUTORS files for details.
7 */
8
9/* DEBUG: section 42 ICMP Pinger program */
10
11#define SQUID_HELPER 1
12
42#include "squid.h"
43#include "debug/Stream.h"
44
45#if USE_ICMP
46
47#include "Icmp4.h"
48#include "Icmp6.h"
49#include "IcmpPinger.h"
50#include "ip/tools.h"
51#include "time/gadgets.h"
52
53#if _SQUID_WINDOWS_
54
55#if HAVE_WINSOCK2_H
56#include <winsock2.h>
57#elif HAVE_WINSOCK_H
58#include <winsock.h>
59#endif
60#include <process.h>
61#include "fde.h"
62
63#define PINGER_TIMEOUT 5
64
65/* windows uses the control socket for feedback to squid */
66#define LINK_TO_SQUID squid_link
67
68// windows still requires WSAFD but there are too many dependency problems
69// to just link to win32.cc where it is normally defined.
70
71int
72Win32__WSAFDIsSet(int fd, fd_set FAR * set)
73{
74 fde *F = &fd_table[fd];
75 SOCKET s = F->win32.handle;
76
77 return __WSAFDIsSet(s, set);
78}
79
80#else
81
82#define PINGER_TIMEOUT 10
83
84/* non-windows use STDOUT for feedback to squid */
85#define LINK_TO_SQUID 1
86
87#endif /* _SQUID_WINDOWS_ */
88
89// ICMP Engines are declared global here so they can call each other easily.
93
95
100int
101main(int, char **)
102{
103 fd_set R;
104 int x;
105 int max_fd = 0;
106
107 struct timeval tv;
108 time_t last_check_time = 0;
109
110 /*
111 * cevans - do this first. It grabs a raw socket. After this we can
112 * drop privs
113 */
114 int icmp4_worker = -1;
115 int icmp6_worker = -1;
116 int squid_link = -1;
117
118 Debug::NameThisHelper("pinger");
119
121
122 // determine IPv4 or IPv6 capabilities before using sockets.
124
125 debugs(42, DBG_CRITICAL, "Initialising ICMP pinger ...");
126
127 icmp4_worker = icmp4.Open();
128 if (icmp4_worker < 0) {
129 debugs(42, DBG_CRITICAL, "ERROR: Unable to start ICMP pinger.");
130 }
131 max_fd = max(max_fd, icmp4_worker);
132
133#if USE_IPV6
134 icmp6_worker = icmp6.Open();
135 if (icmp6_worker <0 ) {
136 debugs(42, DBG_CRITICAL, "ERROR: Unable to start ICMPv6 pinger.");
137 }
138 max_fd = max(max_fd, icmp6_worker);
139#endif
140
142 if (icmp4_worker < 0 && icmp6_worker < 0) {
143 debugs(42, DBG_CRITICAL, "FATAL: Unable to open any ICMP sockets.");
144 exit(EXIT_FAILURE);
145 }
146
147 if ( (squid_link = control.Open()) < 0) {
148 debugs(42, DBG_CRITICAL, "FATAL: Unable to setup Pinger control sockets.");
149 icmp4.Close();
150 icmp6.Close();
151 exit(EXIT_FAILURE); // fatal error if the control channel fails.
152 }
153 max_fd = max(max_fd, squid_link);
154
155 if (setgid(getgid()) < 0) {
156 int xerrno = errno;
157 debugs(42, DBG_CRITICAL, "FATAL: setgid(" << getgid() << ") failed: " << xstrerr(xerrno));
158 icmp4.Close();
159 icmp6.Close();
160 exit(EXIT_FAILURE);
161 }
162 if (setuid(getuid()) < 0) {
163 int xerrno = errno;
164 debugs(42, DBG_CRITICAL, "FATAL: setuid(" << getuid() << ") failed: " << xstrerr(xerrno));
165 icmp4.Close();
166 icmp6.Close();
167 exit(EXIT_FAILURE);
168 }
169
170#if USE_LIBCAP
171 // Drop remaining capabilities (if installed as non-setuid setcap cap_net_raw=ep).
172 // If pinger binary was installed setuid root, setuid() above already dropped all
173 // capabilities, and this is no-op.
174 cap_t caps;
175 caps = cap_init();
176 if (!caps) {
177 int xerrno = errno;
178 debugs(42, DBG_CRITICAL, "FATAL: cap_init() failed: " << xstrerr(xerrno));
179 icmp4.Close();
180 icmp6.Close();
181 exit(EXIT_FAILURE);
182 } else {
183 if (cap_set_proc(caps) != 0) {
184 int xerrno = errno;
185 // cap_set_proc(cap_init()) is expected to never fail
186 debugs(42, DBG_CRITICAL, "FATAL: cap_set_proc(none) failed: " << xstrerr(xerrno));
187 cap_free(caps);
188 icmp4.Close();
189 icmp6.Close();
190 exit(EXIT_FAILURE);
191 }
192 cap_free(caps);
193 }
194#endif
195
196 last_check_time = squid_curtime;
197
198 for (;;) {
199 tv.tv_sec = PINGER_TIMEOUT;
200 tv.tv_usec = 0;
201 FD_ZERO(&R);
202 if (icmp4_worker >= 0) {
203 FD_SET(icmp4_worker, &R);
204 }
205 if (icmp6_worker >= 0) {
206 FD_SET(icmp6_worker, &R);
207 }
208
209 FD_SET(squid_link, &R);
210 x = select(max_fd+1, &R, nullptr, nullptr, &tv);
212
213 if (x < 0) {
214 int xerrno = errno;
215 debugs(42, DBG_CRITICAL, "FATAL: select()==" << x << ", ERR: " << xstrerr(xerrno));
216 control.Close();
217 exit(EXIT_FAILURE);
218 }
219
220 if (FD_ISSET(squid_link, &R)) {
221 control.Recv();
222 }
223
224 if (icmp6_worker >= 0 && FD_ISSET(icmp6_worker, &R)) {
225 icmp6.Recv();
226 }
227 if (icmp4_worker >= 0 && FD_ISSET(icmp4_worker, &R)) {
228 icmp4.Recv();
229 }
230
231 if (PINGER_TIMEOUT + last_check_time < squid_curtime) {
232 if (send(LINK_TO_SQUID, &tv, 0, 0) < 0) {
233 debugs(42, DBG_CRITICAL, "Closing. No requests in last " << PINGER_TIMEOUT << " seconds.");
234 control.Close();
235 exit(EXIT_FAILURE);
236 }
237
238 last_check_time = squid_curtime;
239 }
240 }
241
242 /* NOTREACHED */
243 return EXIT_SUCCESS;
244}
245
246#else /* !USE_ICMP */
247
248#include <ostream>
249int
250main(int argc, char *argv[])
251{
252 std::cerr << argv[0] << ": ICMP support not compiled in." << std::endl;
253 return EXIT_FAILURE;
254}
255
256#endif /* USE_ICMP */
257
time_t squid_curtime
Definition: stub_libtime.cc:20
static void NameThisHelper(const char *name)
Definition: debug.cc:382
Definition: Icmp4.h:134
virtual void Recv(void)
Handle ICMP responses.
Definition: Icmp4.cc:156
virtual int Open()
Start pinger helper and initiate control channel.
Definition: Icmp4.cc:66
Definition: Icmp6.h:46
virtual void Recv(void)
Definition: Icmp6.cc:196
virtual int Open()
Start pinger helper and initiate control channel.
Definition: Icmp6.cc:98
virtual void Close()
Shutdown pinger helper and control channel.
Definition: IcmpPinger.cc:150
virtual void Recv(void)
Handle ICMP requests from squid, passing to helpers.
Definition: IcmpPinger.cc:165
virtual int Open()
Start and initiate control channel to squid.
Definition: IcmpPinger.cc:46
virtual void Close()
Shutdown pinger helper and control channel.
Definition: Icmp.cc:25
Definition: fde.h:52
A const & max(A const &lhs, A const &rhs)
#define debugs(SECTION, LEVEL, CONTENT)
Definition: Stream.h:196
#define DBG_CRITICAL
Definition: Stream.h:40
#define fd_table
Definition: fde.h:189
int main(int, char **)
Definition: pinger.cc:101
static uint32 F(uint32 X, uint32 Y, uint32 Z)
Definition: md4.c:46
void ProbeTransport(void)
Probe to discover IPv6 capabilities.
IcmpPinger control
pinger helper contains one of these as a global object.
Definition: pinger.cc:90
int icmp_pkts_sent
Definition: pinger.cc:94
#define PINGER_TIMEOUT
Definition: pinger.cc:82
#define LINK_TO_SQUID
Definition: pinger.cc:85
Icmp6 icmp6
pinger helper contains one of these as a global object.
Definition: pinger.cc:92
Icmp4 icmp4
pinger helper contains one of these as a global object.
Definition: pinger.cc:91
time_t getCurrentTime() STUB_RETVAL(0) int tvSubUsec(struct timeval
const char * xstrerr(int error)
Definition: xstrerror.cc:83

 

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