| 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 | } |