Commit | Line | Data |
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c906108c SS |
1 | /* Serial port emulation using sockets. |
2 | Copyright (C) 1998 Free Software Foundation, Inc. | |
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 | |
7 | the Free Software Foundation; either version 2, or (at your option) | |
8 | any later version. | |
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 | ||
15 | You should have received a copy of the GNU General Public License along | |
16 | with this program; if not, write to the Free Software Foundation, Inc., | |
17 | 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ | |
18 | ||
19 | /* FIXME: will obviously need to evolve. | |
20 | - connectionless sockets might be more appropriate. */ | |
21 | ||
22 | #include "sim-main.h" | |
23 | ||
24 | #ifdef HAVE_STRING_H | |
25 | #include <string.h> | |
26 | #else | |
27 | #ifdef HAVE_STRINGS_H | |
28 | #include <strings.h> | |
29 | #endif | |
30 | #endif | |
31 | #include <signal.h> | |
32 | #ifdef HAVE_STDLIB_H | |
33 | #include <stdlib.h> | |
34 | #endif | |
35 | #ifdef HAVE_FCNTL_H | |
36 | #include <fcntl.h> | |
37 | #endif | |
38 | #ifdef HAVE_UNISTD_H | |
39 | #include <unistd.h> | |
40 | #endif | |
41 | ||
42 | #include <errno.h> | |
43 | #include <sys/types.h> | |
44 | #include <sys/time.h> | |
45 | #include <netinet/in.h> | |
46 | #include <arpa/inet.h> | |
47 | #include <netdb.h> | |
48 | #include <sys/socket.h> | |
49 | ||
50 | #ifndef __CYGWIN32__ | |
51 | #include <netinet/tcp.h> | |
52 | #endif | |
53 | ||
54 | #include "sim-assert.h" | |
55 | #include "sim-options.h" | |
56 | ||
57 | #include "dv-sockser.h" | |
58 | \f | |
59 | /* Get definitions for both O_NONBLOCK and O_NDELAY. */ | |
60 | ||
61 | #ifndef O_NDELAY | |
62 | #ifdef FNDELAY | |
63 | #define O_NDELAY FNDELAY | |
64 | #else /* ! defined (FNDELAY) */ | |
65 | #define O_NDELAY 0 | |
66 | #endif /* ! defined (FNDELAY) */ | |
67 | #endif /* ! defined (O_NDELAY) */ | |
68 | ||
69 | #ifndef O_NONBLOCK | |
70 | #ifdef FNBLOCK | |
71 | #define O_NONBLOCK FNBLOCK | |
72 | #else /* ! defined (FNBLOCK) */ | |
73 | #define O_NONBLOCK 0 | |
74 | #endif /* ! defined (FNBLOCK) */ | |
75 | #endif /* ! defined (O_NONBLOCK) */ | |
76 | \f | |
77 | #define MIN(a,b) ((a) < (b) ? (a) : (b)) | |
78 | ||
79 | /* Compromise between eating cpu and properly busy-waiting. | |
80 | One could have an option to set this but for now that seems | |
81 | like featuritis. */ | |
82 | #define DEFAULT_TIMEOUT 1000 /* microseconds */ | |
83 | ||
84 | /* FIXME: These should allocated at run time and kept with other simulator | |
85 | state (duh...). Later. */ | |
86 | const char * sockser_addr = NULL; | |
87 | /* Timeout in microseconds during status flag computation. | |
88 | Setting this to zero achieves proper busy wait semantics but eats cpu. */ | |
89 | static unsigned int sockser_timeout = DEFAULT_TIMEOUT; | |
90 | static int sockser_listen_fd = -1; | |
91 | static int sockser_fd = -1; | |
92 | \f | |
93 | /* FIXME: use tree properties when they're ready. */ | |
94 | ||
95 | typedef enum { | |
96 | OPTION_ADDR = OPTION_START | |
97 | } SOCKSER_OPTIONS; | |
98 | ||
99 | static DECLARE_OPTION_HANDLER (sockser_option_handler); | |
100 | ||
101 | static const OPTION sockser_options[] = | |
102 | { | |
103 | { { "sockser-addr", required_argument, NULL, OPTION_ADDR }, | |
104 | '\0', "SOCKET ADDRESS", "Set serial emulation socket address", | |
105 | sockser_option_handler }, | |
106 | { { NULL, no_argument, NULL, 0 }, '\0', NULL, NULL, NULL } | |
107 | }; | |
108 | ||
109 | static SIM_RC | |
110 | sockser_option_handler (SIM_DESC sd, sim_cpu *cpu, int opt, | |
111 | char *arg, int is_command) | |
112 | { | |
113 | switch (opt) | |
114 | { | |
115 | case OPTION_ADDR : | |
116 | sockser_addr = arg; | |
117 | break; | |
118 | } | |
119 | ||
120 | return SIM_RC_OK; | |
121 | } | |
122 | ||
123 | static SIM_RC | |
124 | dv_sockser_init (SIM_DESC sd) | |
125 | { | |
126 | struct hostent *hostent; | |
127 | struct sockaddr_in sockaddr; | |
128 | char hostname[100]; | |
129 | const char *port_str; | |
130 | int tmp,port; | |
131 | ||
132 | if (STATE_ENVIRONMENT (sd) != OPERATING_ENVIRONMENT | |
133 | || sockser_addr == NULL) | |
134 | return SIM_RC_OK; | |
135 | ||
136 | if (*sockser_addr == '/') | |
137 | { | |
138 | /* support for these can come later */ | |
139 | sim_io_eprintf (sd, "sockser init: unix domain sockets not supported: `%s'\n", | |
140 | sockser_addr); | |
141 | return SIM_RC_FAIL; | |
142 | } | |
143 | ||
144 | port_str = strchr (sockser_addr, ':'); | |
145 | if (!port_str) | |
146 | { | |
147 | sim_io_eprintf (sd, "sockser init: missing port number: `%s'\n", | |
148 | sockser_addr); | |
149 | return SIM_RC_FAIL; | |
150 | } | |
151 | tmp = MIN (port_str - sockser_addr, (int) sizeof hostname - 1); | |
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); | |
165 | if (sockser_listen_fd < 0) | |
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; | |
173 | sockaddr.sin_port = htons(port); | |
174 | memcpy (&sockaddr.sin_addr.s_addr, hostent->h_addr, | |
175 | sizeof (struct in_addr)); | |
176 | ||
177 | tmp = 1; | |
178 | if (setsockopt (sockser_listen_fd, SOL_SOCKET, SO_REUSEADDR, (void*)& tmp, sizeof(tmp)) < 0) | |
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 | ||
228 | SIM_RC | |
229 | dv_sockser_install (SIM_DESC sd) | |
230 | { | |
231 | SIM_ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER); | |
232 | if (sim_add_option_table (sd, NULL, sockser_options) != SIM_RC_OK) | |
233 | return SIM_RC_FAIL; | |
234 | sim_module_add_init_fn (sd, dv_sockser_init); | |
235 | sim_module_add_uninstall_fn (sd, dv_sockser_uninstall); | |
236 | return SIM_RC_OK; | |
237 | } | |
238 | ||
239 | static int | |
240 | connected_p (SIM_DESC sd) | |
241 | { | |
242 | int numfds,flags; | |
243 | struct timeval tv; | |
244 | fd_set readfds; | |
245 | struct sockaddr sockaddr; | |
246 | int addrlen; | |
247 | ||
248 | if (sockser_listen_fd == -1) | |
249 | return 0; | |
250 | ||
251 | if (sockser_fd >= 0) | |
252 | { | |
253 | /* FIXME: has client gone away? */ | |
254 | return 1; | |
255 | } | |
256 | ||
257 | /* Not connected. Connect with a client if there is one. */ | |
258 | ||
259 | FD_ZERO (&readfds); | |
260 | FD_SET (sockser_listen_fd, &readfds); | |
261 | ||
262 | /* ??? One can certainly argue this should be done differently, | |
263 | but for now this is sufficient. */ | |
264 | tv.tv_sec = 0; | |
265 | tv.tv_usec = sockser_timeout; | |
266 | ||
267 | numfds = select (sockser_listen_fd + 1, &readfds, 0, 0, &tv); | |
268 | if (numfds <= 0) | |
269 | return 0; | |
270 | ||
271 | sockser_fd = accept (sockser_listen_fd, &sockaddr, &addrlen); | |
272 | if (sockser_fd < 0) | |
273 | return 0; | |
274 | ||
275 | /* Set non-blocking i/o. */ | |
276 | flags = fcntl (sockser_fd, F_GETFL); | |
277 | flags |= O_NONBLOCK | O_NDELAY; | |
278 | if (fcntl (sockser_fd, F_SETFL, flags) == -1) | |
279 | { | |
280 | sim_io_eprintf (sd, "unable to set nonblocking i/o"); | |
281 | close (sockser_fd); | |
282 | sockser_fd = -1; | |
283 | return 0; | |
284 | } | |
285 | return 1; | |
286 | } | |
287 | ||
288 | int | |
289 | dv_sockser_status (SIM_DESC sd) | |
290 | { | |
291 | int numrfds,numwfds,status; | |
292 | struct timeval tv; | |
293 | fd_set readfds,writefds; | |
294 | ||
295 | /* status to return if the socket isn't set up, or select fails */ | |
296 | status = DV_SOCKSER_INPUT_EMPTY | DV_SOCKSER_OUTPUT_EMPTY; | |
297 | ||
298 | if (! connected_p (sd)) | |
299 | return status; | |
300 | ||
301 | FD_ZERO (&readfds); | |
302 | FD_ZERO (&writefds); | |
303 | FD_SET (sockser_fd, &readfds); | |
304 | FD_SET (sockser_fd, &writefds); | |
305 | ||
306 | /* ??? One can certainly argue this should be done differently, | |
307 | but for now this is sufficient. The read is done separately | |
308 | from the write to enforce the delay which we heuristically set to | |
309 | once every SOCKSER_TIMEOUT_FREQ tries. | |
310 | No, this isn't great for SMP situations, blah blah blah. */ | |
311 | ||
312 | { | |
313 | static int n; | |
314 | #define SOCKSER_TIMEOUT_FREQ 42 | |
315 | if (++n == SOCKSER_TIMEOUT_FREQ) | |
316 | n = 0; | |
317 | if (n == 0) | |
318 | { | |
319 | tv.tv_sec = 0; | |
320 | tv.tv_usec = sockser_timeout; | |
321 | numrfds = select (sockser_fd + 1, &readfds, 0, 0, &tv); | |
322 | tv.tv_sec = 0; | |
323 | tv.tv_usec = 0; | |
324 | numwfds = select (sockser_fd + 1, 0, &writefds, 0, &tv); | |
325 | } | |
326 | else /* do both selects at once */ | |
327 | { | |
328 | tv.tv_sec = 0; | |
329 | tv.tv_usec = 0; | |
330 | numrfds = numwfds = select (sockser_fd + 1, &readfds, &writefds, 0, &tv); | |
331 | } | |
332 | } | |
333 | ||
334 | status = 0; | |
335 | if (numrfds <= 0 || ! FD_ISSET (sockser_fd, &readfds)) | |
336 | status |= DV_SOCKSER_INPUT_EMPTY; | |
337 | if (numwfds <= 0 || FD_ISSET (sockser_fd, &writefds)) | |
338 | status |= DV_SOCKSER_OUTPUT_EMPTY; | |
339 | return status; | |
340 | } | |
341 | ||
342 | int | |
343 | dv_sockser_write (SIM_DESC sd, unsigned char c) | |
344 | { | |
345 | int n; | |
346 | ||
347 | if (! connected_p (sd)) | |
348 | return -1; | |
349 | n = write (sockser_fd, &c, 1); | |
350 | if (n == -1) | |
351 | { | |
352 | if (errno == EPIPE) | |
353 | { | |
354 | close (sockser_fd); | |
355 | sockser_fd = -1; | |
356 | } | |
357 | return -1; | |
358 | } | |
359 | if (n != 1) | |
360 | return -1; | |
361 | return 1; | |
362 | } | |
363 | ||
364 | int | |
365 | dv_sockser_read (SIM_DESC sd) | |
366 | { | |
367 | unsigned char c; | |
368 | int n; | |
369 | ||
370 | if (! connected_p (sd)) | |
371 | return -1; | |
372 | n = read (sockser_fd, &c, 1); | |
373 | /* ??? We're assuming semantics that may not be correct for all hosts. | |
374 | In particular (from cvssrc/src/server.c), this assumes that we are using | |
375 | BSD or POSIX nonblocking I/O. System V nonblocking I/O returns zero if | |
376 | there is nothing to read. */ | |
377 | if (n == 0) | |
378 | { | |
379 | close (sockser_fd); | |
380 | sockser_fd = -1; | |
381 | return -1; | |
382 | } | |
383 | if (n != 1) | |
384 | return -1; | |
385 | return c; | |
386 | } |