UdsOp.cc
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1 /*
2  * Copyright (C) 1996-2020 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 54 Interprocess Communication */
10 
11 #include "squid.h"
12 #include "base/TextException.h"
13 #include "comm.h"
14 #include "comm/Connection.h"
15 #include "comm/Write.h"
16 #include "CommCalls.h"
17 #include "ipc/UdsOp.h"
18 
19 Ipc::UdsOp::UdsOp(const String& pathAddr):
20  AsyncJob("Ipc::UdsOp"),
21  address(PathToAddress(pathAddr)),
22  options(COMM_NONBLOCKING)
23 {
24  debugs(54, 5, HERE << '[' << this << "] pathAddr=" << pathAddr);
25 }
26 
28 {
29  debugs(54, 5, HERE << '[' << this << ']');
30  if (Comm::IsConnOpen(conn_))
31  conn_->close();
32  conn_ = NULL;
33 }
34 
35 void Ipc::UdsOp::setOptions(int newOptions)
36 {
37  options = newOptions;
38 }
39 
42 {
43  if (!Comm::IsConnOpen(conn_)) {
44  if (options & COMM_DOBIND)
45  unlink(address.sun_path);
46  if (conn_ == NULL)
47  conn_ = new Comm::Connection;
48  conn_->fd = comm_open_uds(SOCK_DGRAM, 0, &address, options);
49  Must(Comm::IsConnOpen(conn_));
50  }
51  return conn_;
52 }
53 
54 void Ipc::UdsOp::setTimeout(int seconds, const char *handlerName)
55 {
57  AsyncCall::Pointer handler = asyncCall(54,5, handlerName,
58  Dialer(CbcPointer<UdsOp>(this), &UdsOp::noteTimeout));
59  commSetConnTimeout(conn(), seconds, handler);
60 }
61 
63 {
65 }
66 
68 {
69  timedout(); // our kid handles communication timeout
70 }
71 
72 struct sockaddr_un
73 Ipc::PathToAddress(const String& pathAddr) {
74  assert(pathAddr.size() != 0);
75  struct sockaddr_un unixAddr;
76  memset(&unixAddr, 0, sizeof(unixAddr));
77  unixAddr.sun_family = AF_LOCAL;
78  xstrncpy(unixAddr.sun_path, pathAddr.termedBuf(), sizeof(unixAddr.sun_path));
79  return unixAddr;
80 }
81 
83 
84 Ipc::UdsSender::UdsSender(const String& pathAddr, const TypedMsgHdr& aMessage):
85  UdsOp(pathAddr),
86  codeContext(CodeContext::Current()),
87  message(aMessage),
88  retries(10), // TODO: make configurable?
89  timeout(10), // TODO: make configurable?
90  sleeping(false),
91  writing(false)
92 {
94 }
95 
97 {
98  // did we abort while waiting between retries?
99  if (sleeping)
100  cancelSleep();
101 
102  UdsOp::swanSong();
103 }
104 
106 {
107  UdsOp::start();
108  write();
109  if (timeout > 0)
110  setTimeout(timeout, "Ipc::UdsSender::noteTimeout");
111 }
112 
114 {
115  return !writing && !sleeping && UdsOp::doneAll();
116 }
117 
119 {
120  debugs(54, 5, HERE);
122  AsyncCall::Pointer writeHandler = JobCallback(54, 5,
123  Dialer, this, UdsSender::wrote);
124  Comm::Write(conn(), message.raw(), message.size(), writeHandler, NULL);
125  writing = true;
126 }
127 
129 {
130  debugs(54, 5, HERE << params.conn << " flag " << params.flag << " retries " << retries << " [" << this << ']');
131  writing = false;
132  if (params.flag != Comm::OK && retries-- > 0) {
133  // perhaps a fresh connection and more time will help?
134  conn()->close();
135  startSleep();
136  }
137 }
138 
141 {
142  Must(!sleeping);
143  sleeping = true;
144  eventAdd("Ipc::UdsSender::DelayedRetry",
146  new Pointer(this), 1, 0, false); // TODO: Use Fibonacci increments
147 }
148 
151 {
152  if (sleeping) {
153  // Why not delete the event? See Comm::ConnOpener::cancelSleep().
154  sleeping = false;
155  debugs(54, 9, "stops sleeping");
156  }
157 }
158 
161 {
162  Pointer *ptr = static_cast<Pointer*>(data);
163  assert(ptr);
164  if (UdsSender *us = dynamic_cast<UdsSender*>(ptr->valid())) {
165  CallBack(us->codeContext, [&us] {
166  CallJobHere(54, 4, us, UdsSender, delayedRetry);
167  });
168  }
169  delete ptr;
170 }
171 
174 {
175  debugs(54, 5, HERE << sleeping);
176  if (sleeping) {
177  sleeping = false;
178  write(); // reopens the connection if needed
179  }
180 }
181 
183 {
184  debugs(54, 5, HERE);
185  mustStop("timedout");
186 }
187 
188 void Ipc::SendMessage(const String& toAddress, const TypedMsgHdr &message)
189 {
190  AsyncJob::Start(new UdsSender(toAddress, message));
191 }
192 
194 Ipc::ImportFdIntoComm(const Comm::ConnectionPointer &conn, int socktype, int protocol, Ipc::FdNoteId noteId)
195 {
196  struct sockaddr_storage addr;
197  socklen_t len = sizeof(addr);
198  if (getsockname(conn->fd, reinterpret_cast<sockaddr*>(&addr), &len) == 0) {
199  conn->remote = addr;
200  struct addrinfo* addr_info = NULL;
201  conn->remote.getAddrInfo(addr_info);
202  addr_info->ai_socktype = socktype;
203  addr_info->ai_protocol = protocol;
204  comm_import_opened(conn, Ipc::FdNote(noteId), addr_info);
205  Ip::Address::FreeAddr(addr_info);
206  } else {
207  int xerrno = errno;
208  debugs(54, DBG_CRITICAL, "ERROR: Ipc::ImportFdIntoComm: " << conn << ' ' << xstrerr(xerrno));
209  conn->close();
210  }
211  return conn;
212 }
213 
const char * xstrerr(int error)
Definition: xstrerror.cc:83
void write()
schedule writing
Definition: UdsOp.cc:118
void delayedRetry()
make another sending attempt after a pause
Definition: UdsOp.cc:173
struct sockaddr_un address
UDS address from path; treat as read-only.
Definition: UdsOp.h:37
#define AF_LOCAL
Definition: cmsg.h:128
void setOptions(int newOptions)
changes socket options
Definition: UdsOp.cc:35
virtual void swanSong()
Definition: AsyncJob.h:54
virtual void timedout()
Definition: UdsOp.cc:182
virtual void start()
called by AsyncStart; do not call directly
Definition: UdsOp.cc:105
int commSetConnTimeout(const Comm::ConnectionPointer &conn, int timeout, AsyncCall::Pointer &callback)
Definition: comm.cc:567
virtual bool doneAll() const
whether positive goal has been reached
Definition: UdsOp.cc:113
static void FreeAddr(struct addrinfo *&ai)
Definition: Address.cc:686
void comm_import_opened(const Comm::ConnectionPointer &conn, const char *note, struct addrinfo *AI)
update Comm state after getting a comm_open() FD from another process
Definition: comm.cc:514
char * xstrncpy(char *dst, const char *src, size_t n)
Definition: xstring.cc:37
bool IsConnOpen(const Comm::ConnectionPointer &conn)
Definition: Connection.cc:26
@ OK
Definition: Flag.h:16
#define DBG_CRITICAL
Definition: Debug.h:45
void CallBack(const CodeContext::Pointer &callbackContext, Fun &&callback)
Definition: CodeContext.h:81
char sun_family
Definition: cmsg.h:107
const char * FdNote(int fdNodeId)
converts FdNoteId into a string
Definition: FdNotes.cc:16
int socklen_t
Definition: types.h:158
#define COMM_NONBLOCKING
Definition: Connection.h:46
CBDATA_NAMESPACED_CLASS_INIT(Ipc, UdsSender)
char sun_path[256]
Definition: cmsg.h:108
void noteTimeout(const CommTimeoutCbParams &p)
Comm timeout callback; calls timedout()
Definition: UdsOp.cc:67
#define NULL
Definition: types.h:166
virtual bool doneAll() const
whether positive goal has been reached
Definition: AsyncJob.cc:96
#define debugs(SECTION, LEVEL, CONTENT)
Definition: Debug.h:128
attempts to send an IPC message a few times, with a timeout
Definition: UdsOp.h:68
TypedMsgHdr message
what to send
Definition: UdsOp.h:93
static Pointer Start(AsyncJob *job)
starts a freshly created job (i.e., makes the job asynchronous)
Definition: AsyncJob.cc:23
std::ostream & HERE(std::ostream &s)
Definition: Debug.h:157
void wrote(const CommIoCbParams &params)
done writing or error
Definition: UdsOp.cc:128
void setTimeout(int seconds, const char *handlerName)
call timedout() if no UDS messages in a given number of seconds
Definition: UdsOp.cc:54
FdNoteId
We cannot send char* FD notes to other processes. Pass int IDs and convert.
Definition: FdNotes.h:20
void const char HLPCB void * data
Definition: stub_helper.cc:16
Comm::ConnectionPointer conn
Definition: CommCalls.h:85
void SendMessage(const String &toAddress, const TypedMsgHdr &message)
Definition: UdsOp.cc:188
int conn
the current server connection FD
Definition: Transport.cc:26
#define assert(EX)
Definition: assert.h:19
Comm::Flag flag
comm layer result status.
Definition: CommCalls.h:87
#define JobCallback(dbgSection, dbgLevel, Dialer, job, method)
Convenience macro to create a Dialer-based job callback.
Definition: AsyncJobCalls.h:69
void startSleep()
pause for a while before resending the message
Definition: UdsOp.cc:140
virtual ~UdsOp()
Definition: UdsOp.cc:27
void Write(const Comm::ConnectionPointer &conn, const char *buf, int size, AsyncCall::Pointer &callback, FREE *free_func)
Definition: Write.cc:35
int commUnsetConnTimeout(const Comm::ConnectionPointer &conn)
Definition: comm.cc:593
void clearTimeout()
remove previously set timeout, if any
Definition: UdsOp.cc:62
UdsSender(const String &pathAddr, const TypedMsgHdr &aMessage)
Definition: UdsOp.cc:84
virtual void swanSong()
Definition: UdsOp.cc:96
void cancelSleep()
stop sleeping (or do nothing if we were not)
Definition: UdsOp.cc:150
#define COMM_DOBIND
Definition: Connection.h:49
static int retries
virtual void start()
called by AsyncStart; do not call directly
Definition: AsyncJob.cc:43
#define Must(condition)
Like assert() but throws an exception instead of aborting the process.
Definition: TextException.h:69
void IPH * handler
Definition: stub_ipcache.cc:16
AsyncCall * asyncCall(int aDebugSection, int aDebugLevel, const char *aName, const Dialer &aDialer)
Definition: AsyncCall.h:156
struct msghdr with a known type, fixed-size I/O and control buffers
Definition: TypedMsgHdr.h:31
int unsigned int const char *desc STUB void int len
Definition: stub_fd.cc:20
const Comm::ConnectionPointer & ImportFdIntoComm(const Comm::ConnectionPointer &conn, int socktype, int protocol, FdNoteId noteId)
import socket fd from another strand into our Comm state
Definition: UdsOp.cc:194
struct sockaddr_un PathToAddress(const String &pathAddr)
converts human-readable filename path into UDS address
Definition: UdsOp.cc:73
int comm_open_uds(int sock_type, int proto, struct sockaddr_un *addr, int flags)
Create a unix-domain socket (UDS) that only supports FD_MSGHDR I/O.
Definition: comm.cc:1911
#define false
Definition: GnuRegex.c:233
UdsOp(const String &pathAddr)
Definition: UdsOp.cc:19
static void DelayedRetry(void *data)
legacy wrapper for Ipc::UdsSender::delayedRetry()
Definition: UdsOp.cc:160
void address(const struct sockaddr_un &addr)
sets [dest.] address
Definition: TypedMsgHdr.cc:92
void eventAdd(const char *name, EVH *func, void *arg, double when, int weight, bool cbdata)
Definition: event.cc:109
Definition: IpcIoFile.h:23
Comm::ConnectionPointer & conn()
creates if needed and returns raw UDS socket descriptor
Definition: UdsOp.cc:41

 

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