Commit | Line | Data |
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c906108c | 1 | /* Serial port emulation using sockets. |
88b9d363 | 2 | Copyright (C) 1998-2022 Free Software Foundation, Inc. |
c906108c SS |
3 | Contributed by Cygnus Solutions. |
4 | ||
5 | This program is free software; you can redistribute it and/or modify | |
6 | it under the terms of the GNU General Public License as published by | |
4744ac1b JB |
7 | the Free Software Foundation; either version 3 of the License, or |
8 | (at your option) any later version. | |
c906108c SS |
9 | |
10 | This program is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | GNU General Public License for more details. | |
14 | ||
4744ac1b JB |
15 | You should have received a copy of the GNU General Public License |
16 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
c906108c SS |
17 | |
18 | /* FIXME: will obviously need to evolve. | |
19 | - connectionless sockets might be more appropriate. */ | |
20 | ||
6df01ab8 MF |
21 | /* This must come before any other includes. */ |
22 | #include "defs.h" | |
23 | ||
c906108c SS |
24 | #include "sim-main.h" |
25 | ||
c906108c | 26 | #include <string.h> |
c906108c | 27 | #include <signal.h> |
c906108c | 28 | #include <stdlib.h> |
c906108c SS |
29 | #ifdef HAVE_FCNTL_H |
30 | #include <fcntl.h> | |
31 | #endif | |
32 | #ifdef HAVE_UNISTD_H | |
33 | #include <unistd.h> | |
34 | #endif | |
35 | ||
36 | #include <errno.h> | |
37 | #include <sys/types.h> | |
38 | #include <sys/time.h> | |
39 | #include <netinet/in.h> | |
40 | #include <arpa/inet.h> | |
41 | #include <netdb.h> | |
2726bbc3 | 42 | #include <sys/select.h> |
c906108c SS |
43 | #include <sys/socket.h> |
44 | ||
45 | #ifndef __CYGWIN32__ | |
46 | #include <netinet/tcp.h> | |
47 | #endif | |
48 | ||
49 | #include "sim-assert.h" | |
50 | #include "sim-options.h" | |
51 | ||
52 | #include "dv-sockser.h" | |
53 | \f | |
75005b3a MF |
54 | #ifndef HAVE_SOCKLEN_T |
55 | typedef int socklen_t; | |
56 | #endif | |
57 | ||
c906108c SS |
58 | /* Get definitions for both O_NONBLOCK and O_NDELAY. */ |
59 | ||
60 | #ifndef O_NDELAY | |
61 | #ifdef FNDELAY | |
62 | #define O_NDELAY FNDELAY | |
63 | #else /* ! defined (FNDELAY) */ | |
64 | #define O_NDELAY 0 | |
65 | #endif /* ! defined (FNDELAY) */ | |
66 | #endif /* ! defined (O_NDELAY) */ | |
67 | ||
68 | #ifndef O_NONBLOCK | |
69 | #ifdef FNBLOCK | |
70 | #define O_NONBLOCK FNBLOCK | |
71 | #else /* ! defined (FNBLOCK) */ | |
72 | #define O_NONBLOCK 0 | |
73 | #endif /* ! defined (FNBLOCK) */ | |
74 | #endif /* ! defined (O_NONBLOCK) */ | |
75 | \f | |
c906108c SS |
76 | |
77 | /* Compromise between eating cpu and properly busy-waiting. | |
78 | One could have an option to set this but for now that seems | |
79 | like featuritis. */ | |
80 | #define DEFAULT_TIMEOUT 1000 /* microseconds */ | |
81 | ||
82 | /* FIXME: These should allocated at run time and kept with other simulator | |
83 | state (duh...). Later. */ | |
84 | const char * sockser_addr = NULL; | |
85 | /* Timeout in microseconds during status flag computation. | |
86 | Setting this to zero achieves proper busy wait semantics but eats cpu. */ | |
87 | static unsigned int sockser_timeout = DEFAULT_TIMEOUT; | |
88 | static int sockser_listen_fd = -1; | |
89 | static int sockser_fd = -1; | |
90 | \f | |
91 | /* FIXME: use tree properties when they're ready. */ | |
92 | ||
93 | typedef enum { | |
94 | OPTION_ADDR = OPTION_START | |
95 | } SOCKSER_OPTIONS; | |
96 | ||
97 | static DECLARE_OPTION_HANDLER (sockser_option_handler); | |
98 | ||
99 | static const OPTION sockser_options[] = | |
100 | { | |
101 | { { "sockser-addr", required_argument, NULL, OPTION_ADDR }, | |
102 | '\0', "SOCKET ADDRESS", "Set serial emulation socket address", | |
21cf617c MF |
103 | sockser_option_handler, NULL }, |
104 | { { NULL, no_argument, NULL, 0 }, '\0', NULL, NULL, NULL, NULL } | |
c906108c SS |
105 | }; |
106 | ||
107 | static SIM_RC | |
108 | sockser_option_handler (SIM_DESC sd, sim_cpu *cpu, int opt, | |
109 | char *arg, int is_command) | |
110 | { | |
111 | switch (opt) | |
112 | { | |
113 | case OPTION_ADDR : | |
114 | sockser_addr = arg; | |
115 | break; | |
116 | } | |
117 | ||
118 | return SIM_RC_OK; | |
119 | } | |
120 | ||
121 | static SIM_RC | |
122 | dv_sockser_init (SIM_DESC sd) | |
123 | { | |
124 | struct hostent *hostent; | |
125 | struct sockaddr_in sockaddr; | |
126 | char hostname[100]; | |
127 | const char *port_str; | |
128 | int tmp,port; | |
129 | ||
130 | if (STATE_ENVIRONMENT (sd) != OPERATING_ENVIRONMENT | |
131 | || sockser_addr == NULL) | |
132 | return SIM_RC_OK; | |
133 | ||
134 | if (*sockser_addr == '/') | |
135 | { | |
136 | /* support for these can come later */ | |
137 | sim_io_eprintf (sd, "sockser init: unix domain sockets not supported: `%s'\n", | |
138 | sockser_addr); | |
139 | return SIM_RC_FAIL; | |
140 | } | |
141 | ||
142 | port_str = strchr (sockser_addr, ':'); | |
143 | if (!port_str) | |
144 | { | |
145 | sim_io_eprintf (sd, "sockser init: missing port number: `%s'\n", | |
146 | sockser_addr); | |
147 | return SIM_RC_FAIL; | |
148 | } | |
548a3e15 AC |
149 | tmp = port_str - sockser_addr; |
150 | if (tmp >= sizeof hostname) | |
151 | tmp = sizeof (hostname) - 1; | |
c906108c SS |
152 | strncpy (hostname, sockser_addr, tmp); |
153 | hostname[tmp] = '\000'; | |
154 | port = atoi (port_str + 1); | |
155 | ||
156 | hostent = gethostbyname (hostname); | |
157 | if (! hostent) | |
158 | { | |
159 | sim_io_eprintf (sd, "sockser init: unknown host: %s\n", | |
160 | hostname); | |
161 | return SIM_RC_FAIL; | |
162 | } | |
163 | ||
164 | sockser_listen_fd = socket (PF_INET, SOCK_STREAM, 0); | |
363a6e9f | 165 | if (sockser_listen_fd == -1) |
c906108c SS |
166 | { |
167 | sim_io_eprintf (sd, "sockser init: unable to get socket: %s\n", | |
168 | strerror (errno)); | |
169 | return SIM_RC_FAIL; | |
170 | } | |
171 | ||
172 | sockaddr.sin_family = PF_INET; | |
34b47c38 | 173 | sockaddr.sin_port = htons (port); |
c906108c SS |
174 | memcpy (&sockaddr.sin_addr.s_addr, hostent->h_addr, |
175 | sizeof (struct in_addr)); | |
176 | ||
177 | tmp = 1; | |
34b47c38 | 178 | if (setsockopt (sockser_listen_fd, SOL_SOCKET, SO_REUSEADDR, (void*)& tmp, sizeof (tmp)) < 0) |
c906108c SS |
179 | { |
180 | sim_io_eprintf (sd, "sockser init: unable to set SO_REUSEADDR: %s\n", | |
181 | strerror (errno)); | |
182 | } | |
183 | if (bind (sockser_listen_fd, (struct sockaddr *) &sockaddr, sizeof (sockaddr)) < 0) | |
184 | { | |
185 | sim_io_eprintf (sd, "sockser init: unable to bind socket address: %s\n", | |
186 | strerror (errno)); | |
187 | close (sockser_listen_fd); | |
188 | sockser_listen_fd = -1; | |
189 | return SIM_RC_FAIL; | |
190 | } | |
191 | if (listen (sockser_listen_fd, 1) < 0) | |
192 | { | |
193 | sim_io_eprintf (sd, "sockser init: unable to set up listener: %s\n", | |
194 | strerror (errno)); | |
195 | close (sockser_listen_fd); | |
196 | sockser_listen_fd = -1; | |
197 | return SIM_RC_OK; | |
198 | } | |
199 | ||
200 | /* Handle writes to missing client -> SIGPIPE. | |
201 | ??? Need a central signal management module. */ | |
202 | { | |
203 | RETSIGTYPE (*orig) (); | |
204 | orig = signal (SIGPIPE, SIG_IGN); | |
205 | /* If a handler is already set up, don't mess with it. */ | |
206 | if (orig != SIG_DFL && orig != SIG_IGN) | |
207 | signal (SIGPIPE, orig); | |
208 | } | |
209 | ||
210 | return SIM_RC_OK; | |
211 | } | |
212 | ||
213 | static void | |
214 | dv_sockser_uninstall (SIM_DESC sd) | |
215 | { | |
216 | if (sockser_listen_fd != -1) | |
217 | { | |
218 | close (sockser_listen_fd); | |
219 | sockser_listen_fd = -1; | |
220 | } | |
221 | if (sockser_fd != -1) | |
222 | { | |
223 | close (sockser_fd); | |
224 | sockser_fd = -1; | |
225 | } | |
226 | } | |
227 | ||
328e805b MF |
228 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
229 | extern MODULE_INIT_FN sim_install_dv_sockser; | |
230 | ||
c906108c | 231 | SIM_RC |
328e805b | 232 | sim_install_dv_sockser (SIM_DESC sd) |
c906108c SS |
233 | { |
234 | SIM_ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER); | |
235 | if (sim_add_option_table (sd, NULL, sockser_options) != SIM_RC_OK) | |
236 | return SIM_RC_FAIL; | |
237 | sim_module_add_init_fn (sd, dv_sockser_init); | |
238 | sim_module_add_uninstall_fn (sd, dv_sockser_uninstall); | |
239 | return SIM_RC_OK; | |
240 | } | |
241 | ||
242 | static int | |
243 | connected_p (SIM_DESC sd) | |
244 | { | |
245 | int numfds,flags; | |
246 | struct timeval tv; | |
247 | fd_set readfds; | |
248 | struct sockaddr sockaddr; | |
75005b3a | 249 | socklen_t addrlen; |
c906108c SS |
250 | |
251 | if (sockser_listen_fd == -1) | |
252 | return 0; | |
253 | ||
254 | if (sockser_fd >= 0) | |
255 | { | |
256 | /* FIXME: has client gone away? */ | |
257 | return 1; | |
258 | } | |
259 | ||
260 | /* Not connected. Connect with a client if there is one. */ | |
261 | ||
262 | FD_ZERO (&readfds); | |
263 | FD_SET (sockser_listen_fd, &readfds); | |
264 | ||
265 | /* ??? One can certainly argue this should be done differently, | |
266 | but for now this is sufficient. */ | |
267 | tv.tv_sec = 0; | |
268 | tv.tv_usec = sockser_timeout; | |
269 | ||
270 | numfds = select (sockser_listen_fd + 1, &readfds, 0, 0, &tv); | |
271 | if (numfds <= 0) | |
272 | return 0; | |
273 | ||
9846de1b | 274 | addrlen = sizeof (sockaddr); |
c906108c | 275 | sockser_fd = accept (sockser_listen_fd, &sockaddr, &addrlen); |
363a6e9f | 276 | if (sockser_fd == -1) |
c906108c SS |
277 | return 0; |
278 | ||
279 | /* Set non-blocking i/o. */ | |
280 | flags = fcntl (sockser_fd, F_GETFL); | |
281 | flags |= O_NONBLOCK | O_NDELAY; | |
282 | if (fcntl (sockser_fd, F_SETFL, flags) == -1) | |
283 | { | |
284 | sim_io_eprintf (sd, "unable to set nonblocking i/o"); | |
285 | close (sockser_fd); | |
286 | sockser_fd = -1; | |
287 | return 0; | |
288 | } | |
289 | return 1; | |
290 | } | |
291 | ||
292 | int | |
293 | dv_sockser_status (SIM_DESC sd) | |
294 | { | |
295 | int numrfds,numwfds,status; | |
296 | struct timeval tv; | |
297 | fd_set readfds,writefds; | |
298 | ||
299 | /* status to return if the socket isn't set up, or select fails */ | |
e8a76151 MF |
300 | status = DV_SOCKSER_INPUT_EMPTY | DV_SOCKSER_OUTPUT_EMPTY | |
301 | DV_SOCKSER_DISCONNECTED; | |
c906108c SS |
302 | |
303 | if (! connected_p (sd)) | |
304 | return status; | |
305 | ||
306 | FD_ZERO (&readfds); | |
307 | FD_ZERO (&writefds); | |
308 | FD_SET (sockser_fd, &readfds); | |
309 | FD_SET (sockser_fd, &writefds); | |
310 | ||
311 | /* ??? One can certainly argue this should be done differently, | |
312 | but for now this is sufficient. The read is done separately | |
313 | from the write to enforce the delay which we heuristically set to | |
314 | once every SOCKSER_TIMEOUT_FREQ tries. | |
315 | No, this isn't great for SMP situations, blah blah blah. */ | |
316 | ||
317 | { | |
318 | static int n; | |
319 | #define SOCKSER_TIMEOUT_FREQ 42 | |
320 | if (++n == SOCKSER_TIMEOUT_FREQ) | |
321 | n = 0; | |
322 | if (n == 0) | |
323 | { | |
324 | tv.tv_sec = 0; | |
325 | tv.tv_usec = sockser_timeout; | |
326 | numrfds = select (sockser_fd + 1, &readfds, 0, 0, &tv); | |
327 | tv.tv_sec = 0; | |
328 | tv.tv_usec = 0; | |
329 | numwfds = select (sockser_fd + 1, 0, &writefds, 0, &tv); | |
330 | } | |
331 | else /* do both selects at once */ | |
332 | { | |
333 | tv.tv_sec = 0; | |
334 | tv.tv_usec = 0; | |
335 | numrfds = numwfds = select (sockser_fd + 1, &readfds, &writefds, 0, &tv); | |
336 | } | |
337 | } | |
338 | ||
339 | status = 0; | |
340 | if (numrfds <= 0 || ! FD_ISSET (sockser_fd, &readfds)) | |
341 | status |= DV_SOCKSER_INPUT_EMPTY; | |
342 | if (numwfds <= 0 || FD_ISSET (sockser_fd, &writefds)) | |
343 | status |= DV_SOCKSER_OUTPUT_EMPTY; | |
344 | return status; | |
345 | } | |
346 | ||
347 | int | |
6ab5626b MF |
348 | dv_sockser_write_buffer (SIM_DESC sd, const unsigned char *buffer, |
349 | unsigned nr_bytes) | |
c906108c SS |
350 | { |
351 | int n; | |
352 | ||
353 | if (! connected_p (sd)) | |
354 | return -1; | |
6ab5626b | 355 | n = write (sockser_fd, buffer, nr_bytes); |
c906108c SS |
356 | if (n == -1) |
357 | { | |
358 | if (errno == EPIPE) | |
359 | { | |
360 | close (sockser_fd); | |
361 | sockser_fd = -1; | |
362 | } | |
363 | return -1; | |
364 | } | |
6ab5626b | 365 | if (n != nr_bytes) |
c906108c | 366 | return -1; |
6ab5626b MF |
367 | return nr_bytes; |
368 | } | |
369 | ||
370 | int | |
371 | dv_sockser_write (SIM_DESC sd, unsigned char c) | |
372 | { | |
373 | return dv_sockser_write_buffer (sd, &c, 1); | |
c906108c SS |
374 | } |
375 | ||
376 | int | |
377 | dv_sockser_read (SIM_DESC sd) | |
378 | { | |
379 | unsigned char c; | |
380 | int n; | |
381 | ||
382 | if (! connected_p (sd)) | |
383 | return -1; | |
384 | n = read (sockser_fd, &c, 1); | |
385 | /* ??? We're assuming semantics that may not be correct for all hosts. | |
386 | In particular (from cvssrc/src/server.c), this assumes that we are using | |
387 | BSD or POSIX nonblocking I/O. System V nonblocking I/O returns zero if | |
388 | there is nothing to read. */ | |
389 | if (n == 0) | |
390 | { | |
391 | close (sockser_fd); | |
392 | sockser_fd = -1; | |
393 | return -1; | |
394 | } | |
395 | if (n != 1) | |
396 | return -1; | |
397 | return c; | |
398 | } |