1//===-- RNBSocket.cpp -------------------------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Created by Greg Clayton on 12/12/07.
10//
11//===----------------------------------------------------------------------===//
12
13#include "RNBSocket.h"
14#include "DNBError.h"
15#include "DNBLog.h"
16#include <arpa/inet.h>
17#include <cerrno>
18#include <fcntl.h>
19#include <map>
20#include <netdb.h>
21#include <netinet/in.h>
22#include <netinet/tcp.h>
23#include <sys/event.h>
24#include <termios.h>
25#include <vector>
26
27#include "lldb/Host/SocketAddress.h"
28
29#ifdef WITH_LOCKDOWN
30#include "lockdown.h"
31#endif
32
33rnb_err_t RNBSocket::Listen(const char *listen_host, uint16_t port,
34 PortBoundCallback callback,
35 const void *callback_baton) {
36 // DNBLogThreadedIf(LOG_RNB_COMM, "%8u RNBSocket::%s called",
37 // (uint32_t)m_timer.ElapsedMicroSeconds(true), __FUNCTION__);
38 // Disconnect without saving errno
39 Disconnect(save_errno: false);
40
41 DNBError err;
42 int queue_id = kqueue();
43 if (queue_id < 0) {
44 err.SetError(errno, flavor: DNBError::MachKernel);
45 err.LogThreaded(format: "error: failed to create kqueue.");
46 return rnb_err;
47 }
48
49 bool any_addr = (strcmp(listen_host, "*") == 0);
50
51 // If the user wants to allow connections from any address we should create
52 // sockets on all families that can resolve localhost. This will allow us to
53 // listen for IPv6 and IPv4 connections from all addresses if those interfaces
54 // are available.
55 const char *local_addr = any_addr ? "localhost" : listen_host;
56
57 std::map<int, lldb_private::SocketAddress> sockets;
58 auto addresses = lldb_private::SocketAddress::GetAddressInfo(
59 hostname: local_addr, NULL, AF_UNSPEC, SOCK_STREAM, IPPROTO_TCP);
60
61 for (auto address : addresses) {
62 int sock_fd = ::socket(address.GetFamily(), SOCK_STREAM, IPPROTO_TCP);
63 if (sock_fd == -1)
64 continue;
65
66 SetSocketOption(sock_fd, SOL_SOCKET, SO_REUSEADDR, 1);
67
68 lldb_private::SocketAddress bind_address = address;
69
70 if(any_addr || !bind_address.IsLocalhost())
71 bind_address.SetToAnyAddress(bind_address.GetFamily(), port);
72 else
73 bind_address.SetPort(port);
74
75 int error =
76 ::bind(sock_fd, &bind_address.sockaddr(), bind_address.GetLength());
77 if (error == -1) {
78 ClosePort(sock_fd, false);
79 continue;
80 }
81
82 error = ::listen(sock_fd, 5);
83 if (error == -1) {
84 ClosePort(sock_fd, false);
85 continue;
86 }
87
88 // We were asked to listen on port zero which means we must now read the
89 // actual port that was given to us as port zero is a special code for "find
90 // an open port for me". This will only execute on the first socket created,
91 // subesquent sockets will reuse this port number.
92 if (port == 0) {
93 socklen_t sa_len = address.GetLength();
94 if (getsockname(sock_fd, &address.sockaddr(), &sa_len) == 0)
95 port = address.GetPort();
96 }
97
98 sockets[sock_fd] = address;
99 }
100
101 if (sockets.size() == 0) {
102 err.SetError(errno, flavor: DNBError::POSIX);
103 err.LogThreaded(format: "::listen or ::bind failed");
104 return rnb_err;
105 }
106
107 if (callback)
108 callback(callback_baton, port);
109
110 std::vector<struct kevent> events;
111 events.resize(new_size: sockets.size());
112 int i = 0;
113 for (auto socket : sockets) {
114 EV_SET(&events[i++], socket.first, EVFILT_READ, EV_ADD, 0, 0, 0);
115 }
116
117 bool accept_connection = false;
118
119 // Loop until we are happy with our connection
120 while (!accept_connection) {
121
122 struct kevent event_list[4];
123 int num_events;
124 do {
125 errno = 0;
126 num_events =
127 kevent(queue_id, events.data(), events.size(), event_list, 4, NULL);
128 } while (num_events == -1 &&
129 (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR));
130
131 if (num_events < 0) {
132 err.SetError(errno, flavor: DNBError::MachKernel);
133 err.LogThreaded(format: "error: kevent() failed.");
134 }
135
136 for (int i = 0; i < num_events; ++i) {
137 auto sock_fd = event_list[i].ident;
138 auto socket_pair = sockets.find(sock_fd);
139 if (socket_pair == sockets.end())
140 continue;
141
142 lldb_private::SocketAddress &addr_in = socket_pair->second;
143 lldb_private::SocketAddress accept_addr;
144 socklen_t sa_len = accept_addr.GetMaxLength();
145 m_fd = ::accept(fd: sock_fd, addr: &accept_addr.sockaddr(), addr_len: &sa_len);
146
147 if (m_fd == -1) {
148 err.SetError(errno, flavor: DNBError::POSIX);
149 err.LogThreaded(format: "error: Socket accept failed.");
150 }
151
152 if (addr_in.IsAnyAddr())
153 accept_connection = true;
154 else {
155 if (accept_addr == addr_in)
156 accept_connection = true;
157 else {
158 ::close(fd: m_fd);
159 m_fd = -1;
160 ::fprintf(
161 stderr,
162 format: "error: rejecting incoming connection from %s (expecting %s)\n",
163 accept_addr.GetIPAddress().c_str(),
164 addr_in.GetIPAddress().c_str());
165 DNBLogThreaded("error: rejecting connection from %s (expecting %s)\n",
166 accept_addr.GetIPAddress().c_str(),
167 addr_in.GetIPAddress().c_str());
168 err.Clear();
169 }
170 }
171 }
172 if (err.Fail())
173 break;
174 }
175 for (auto socket : sockets) {
176 int ListenFd = socket.first;
177 ClosePort(fd&: ListenFd, save_errno: false);
178 }
179
180 if (err.Fail())
181 return rnb_err;
182
183 // Keep our TCP packets coming without any delays.
184 SetSocketOption(fd: m_fd, IPPROTO_TCP, TCP_NODELAY, option_value: 1);
185
186 return rnb_success;
187}
188
189rnb_err_t RNBSocket::Connect(const char *host, uint16_t port) {
190 auto result = rnb_err;
191 Disconnect(save_errno: false);
192
193 auto addresses = lldb_private::SocketAddress::GetAddressInfo(
194 hostname: host, NULL, AF_UNSPEC, SOCK_STREAM, IPPROTO_TCP);
195
196 for (auto address : addresses) {
197 m_fd = ::socket(domain: address.GetFamily(), SOCK_STREAM, IPPROTO_TCP);
198 if (m_fd == -1)
199 continue;
200
201 // Enable local address reuse
202 SetSocketOption(fd: m_fd, SOL_SOCKET, SO_REUSEADDR, option_value: 1);
203
204 address.SetPort(port);
205
206 if (-1 == ::connect(fd: m_fd, addr: &address.sockaddr(), len: address.GetLength())) {
207 Disconnect(save_errno: false);
208 continue;
209 }
210 SetSocketOption(fd: m_fd, IPPROTO_TCP, TCP_NODELAY, option_value: 1);
211
212 result = rnb_success;
213 break;
214 }
215 return result;
216}
217
218rnb_err_t RNBSocket::useFD(int fd) {
219 if (fd < 0) {
220 DNBLogThreadedIf(LOG_RNB_COMM, "Bad file descriptor passed in.");
221 return rnb_err;
222 }
223
224 m_fd = fd;
225 return rnb_success;
226}
227
228#ifdef WITH_LOCKDOWN
229rnb_err_t RNBSocket::ConnectToService() {
230 DNBLog("Connecting to com.apple.%s service...", DEBUGSERVER_PROGRAM_NAME);
231 // Disconnect from any previous connections
232 Disconnect(false);
233 if (::secure_lockdown_checkin(&m_ld_conn, NULL, NULL) != kLDESuccess) {
234 DNBLogThreadedIf(LOG_RNB_COMM,
235 "::secure_lockdown_checkin(&m_fd, NULL, NULL) failed");
236 m_fd = -1;
237 return rnb_not_connected;
238 }
239 m_fd = ::lockdown_get_socket(m_ld_conn);
240 if (m_fd == -1) {
241 DNBLogThreadedIf(LOG_RNB_COMM, "::lockdown_get_socket() failed");
242 return rnb_not_connected;
243 }
244 m_fd_from_lockdown = true;
245 return rnb_success;
246}
247#endif
248
249rnb_err_t RNBSocket::OpenFile(const char *path) {
250 DNBError err;
251 m_fd = open(file: path, O_RDWR);
252 if (m_fd == -1) {
253 err.SetError(errno, flavor: DNBError::POSIX);
254 err.LogThreaded(format: "can't open file '%s'", path);
255 return rnb_not_connected;
256 } else {
257 struct termios stdin_termios;
258
259 if (::tcgetattr(fd: m_fd, termios_p: &stdin_termios) == 0) {
260 stdin_termios.c_lflag &= ~ECHO; // Turn off echoing
261 stdin_termios.c_lflag &= ~ICANON; // Get one char at a time
262 ::tcsetattr(fd: m_fd, TCSANOW, termios_p: &stdin_termios);
263 }
264 }
265 return rnb_success;
266}
267
268int RNBSocket::SetSocketOption(int fd, int level, int option_name,
269 int option_value) {
270 return ::setsockopt(fd: fd, level: level, optname: option_name, optval: &option_value,
271 optlen: sizeof(option_value));
272}
273
274rnb_err_t RNBSocket::Disconnect(bool save_errno) {
275#ifdef WITH_LOCKDOWN
276 if (m_fd_from_lockdown) {
277 m_fd_from_lockdown = false;
278 m_fd = -1;
279 lockdown_disconnect(m_ld_conn);
280 return rnb_success;
281 }
282#endif
283 return ClosePort(fd&: m_fd, save_errno);
284}
285
286rnb_err_t RNBSocket::Read(std::string &p) {
287 char buf[1024];
288 p.clear();
289
290 // Note that BUF is on the stack so we must be careful to keep any
291 // writes to BUF from overflowing or we'll have security issues.
292
293 if (m_fd == -1)
294 return rnb_err;
295
296 // DNBLogThreadedIf(LOG_RNB_COMM, "%8u RNBSocket::%s calling read()",
297 // (uint32_t)m_timer.ElapsedMicroSeconds(true), __FUNCTION__);
298 DNBError err;
299 ssize_t bytesread;
300 do {
301 errno = 0;
302 bytesread = read(fd: m_fd, buf: buf, nbytes: sizeof(buf));
303 } while (bytesread == -1 &&
304 (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR));
305 if (bytesread <= 0)
306 err.SetError(errno, flavor: DNBError::POSIX);
307 else
308 p.append(s: buf, n: bytesread);
309
310 if (err.Fail() || DNBLogCheckLogBit(LOG_RNB_COMM))
311 err.LogThreaded(format: "::read ( %i, %p, %llu ) => %i", m_fd, buf, sizeof(buf),
312 (uint64_t)bytesread);
313
314 // Our port went away - we have to mark this so IsConnected will return the
315 // truth.
316 if (bytesread == 0) {
317 m_fd = -1;
318 return rnb_not_connected;
319 } else if (bytesread == -1) {
320 m_fd = -1;
321 return rnb_err;
322 }
323 // Strip spaces from the end of the buffer
324 while (!p.empty() && isspace(p[p.size() - 1]))
325 p.erase(pos: p.size() - 1);
326
327 // Most data in the debugserver packets valid printable characters...
328 DNBLogThreadedIf(LOG_RNB_COMM, "read: %s", p.c_str());
329 return rnb_success;
330}
331
332rnb_err_t RNBSocket::Write(const void *buffer, size_t length) {
333 if (m_fd == -1)
334 return rnb_err;
335
336 DNBError err;
337 ssize_t bytessent = write(fd: m_fd, buf: buffer, n: length);
338 if (bytessent < 0)
339 err.SetError(errno, flavor: DNBError::POSIX);
340
341 if (err.Fail() || DNBLogCheckLogBit(LOG_RNB_COMM))
342 err.LogThreaded(format: "::write ( socket = %i, buffer = %p, length = %llu) => %i",
343 m_fd, buffer, length, (uint64_t)bytessent);
344
345 if (bytessent < 0)
346 return rnb_err;
347
348 if ((size_t)bytessent != length)
349 return rnb_err;
350
351 DNBLogThreadedIf(
352 LOG_RNB_PACKETS, "putpkt: %*s", (int)length,
353 (const char *)
354 buffer); // All data is string based in debugserver, so this is safe
355 DNBLogThreadedIf(LOG_RNB_COMM, "sent: %*s", (int)length,
356 (const char *)buffer);
357
358 return rnb_success;
359}
360
361rnb_err_t RNBSocket::ClosePort(int &fd, bool save_errno) {
362 int close_err = 0;
363 if (fd > 0) {
364 errno = 0;
365 close_err = close(fd: fd);
366 fd = -1;
367 }
368 return close_err != 0 ? rnb_err : rnb_success;
369}
370

source code of lldb/tools/debugserver/source/RNBSocket.cpp