1 /* 2 * Run programs residing in the filesystem. 3 * 4 * Copyright (C) 2022, 2023, 2024 Paul Boddie <paul@boddie.org.uk> 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License as 8 * published by the Free Software Foundation; either version 2 of 9 * the License, or (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, 19 * Boston, MA 02110-1301, USA 20 */ 21 22 #include <l4/sys/err.h> 23 24 #include <fsclient/client.h> 25 #include <fsclient/process.h> 26 #include <systypes/fcntl.h> 27 #include <systypes/format.h> 28 29 #include <stdio.h> 30 #include <stdlib.h> 31 #include <string.h> 32 33 #include "ops.h" 34 35 36 37 /* Transfer size for communication. */ 38 39 static const offset_t TO_TRANSFER = 1024; 40 41 42 43 /* Initiated programs (jobs). 44 NOTE: Arbitrary limit. */ 45 46 #define NUMBER_OF_JOBS 32 47 48 static file_t *readers[NUMBER_OF_JOBS] = {NULL}; 49 static process_t *processes[NUMBER_OF_JOBS] = {NULL}; 50 static char *programs[NUMBER_OF_JOBS] = {NULL}; 51 static int next_job = 0; 52 53 54 55 /* Find the given program in the job list. */ 56 57 static int _find_program(process_t *process) 58 { 59 int job_number; 60 61 for (job_number = 0; job_number < NUMBER_OF_JOBS; job_number++) 62 { 63 if (processes[job_number] == process) 64 return job_number; 65 } 66 67 return -1; 68 } 69 70 /* Remove the details of a program from the job list. */ 71 72 static void _remove_program(int job_number) 73 { 74 readers[job_number] = NULL; 75 processes[job_number] = NULL; 76 77 free(programs[job_number]); 78 programs[job_number] = NULL; 79 } 80 81 /* Show the details of a running program. */ 82 83 static void _show_program(int job_number) 84 { 85 /* Employ the Unix convention of a "+" for the default job to be restored upon 86 the appropriate command. */ 87 88 printf("[%d]%s %s%s\n", job_number, job_number == next_job ? "+" : " ", 89 programs[job_number], readers[job_number] != NULL ? " [!]" : ""); 90 } 91 92 93 94 /* Show output from a program. */ 95 96 static void _show_output(file_t *reader) 97 { 98 char buffer[TO_TRANSFER]; 99 offset_t nread; 100 101 while ((nread = client_read(reader, buffer, TO_TRANSFER))) 102 fwrite(buffer, sizeof(char), nread, stdout); 103 } 104 105 /* Show the exit status of a program. */ 106 107 static void _show_status(notifiable_t *notifiable) 108 { 109 int job_number = _find_program((process_t *) notifiable->base); 110 111 if (job_number == -1) 112 return; 113 114 printf("[%d] Completed with", job_number); 115 116 if (notifiable->notifications & NOTIFY_TASK_ERROR) 117 printf(" error"); 118 119 if (notifiable->notifications & NOTIFY_TASK_SIGNAL) 120 printf(" signal %ld", notifiable->values.sig); 121 122 printf(" value %ld\n", notifiable->values.val); 123 } 124 125 /* Wait for a program to finish, showing its output. */ 126 127 static int _wait_program(file_t *reader, process_t *process) 128 { 129 notifier_t *notifier = client_notifier_task(); 130 notifiable_t *notifiable; 131 int exitcode; 132 long err; 133 134 /* Subscribe to reader and process notifications. */ 135 136 if (reader != NULL) 137 { 138 err = client_subscribe(reader, NOTIFY_CONTENT_AVAILABLE | NOTIFY_PEER_CLOSED, notifier); 139 140 if (err) 141 { 142 printf("Could not subscribe to pipe notifications: %s\n", l4sys_errtostr(err)); 143 return -1; 144 } 145 } 146 147 err = notify_subscribe(process_notifiable(process), NOTIFY_TASK_ALL, notifier); 148 149 if (err) 150 { 151 printf("Could not subscribe to process notifications: %s\n", l4sys_errtostr(err)); 152 client_unsubscribe(reader, notifier); 153 return -1; 154 } 155 156 /* Read from and write to pipes until the program terminates. */ 157 158 while (1) 159 { 160 err = notify_wait_many(¬ifiable, notifier); 161 162 if (err) 163 { 164 printf("Notification error: %s\n", l4sys_errtostr(err)); 165 166 if (reader != NULL) 167 client_unsubscribe(reader, notifier); 168 169 notify_unsubscribe(process_notifiable(process), notifier); 170 return -1; 171 } 172 173 /* Handle input from the reader. */ 174 175 if ((reader != NULL) && (file_notifications(reader) & (NOTIFY_CONTENT_AVAILABLE | NOTIFY_PEER_CLOSED))) 176 _show_output(reader); 177 178 /* Handle process termination, obtaining the process state. */ 179 180 if (process_terminated(notifiable)) 181 { 182 if ((reader != NULL) && ((process_t *) notifiable->base == process)) 183 _show_output(reader); 184 185 _show_status(notifiable); 186 187 /* If explicitly waiting for this process, remove it from the job list and 188 return. Otherwise, just remove it from the job list and keep waiting 189 for the indicated process. */ 190 191 _remove_program(_find_program((process_t *) notifiable->base)); 192 193 if ((process_t *) notifiable->base == process) 194 break; 195 } 196 } 197 198 exitcode = notifiable->values.val; 199 200 if (reader != NULL) 201 client_unsubscribe(reader, notifier); 202 203 notify_unsubscribe(process_notifiable(process), notifier); 204 205 /* Close the process and pipe. */ 206 207 process_free(process); 208 209 if (reader != NULL) 210 client_close(reader); 211 212 return exitcode; 213 } 214 215 /* Run the given program. */ 216 217 static int _run_program(int argc, char *argv[], file_t *input_reader) 218 { 219 process_t *process; 220 file_t *output_reader, *output_writer; 221 int last_job; 222 long err; 223 224 /* Create a pipe for process output. */ 225 226 err = client_pipe(&output_reader, &output_writer, O_NONBLOCK); 227 228 if (err) 229 { 230 printf("Could not obtain pipe for output: %s\n", l4sys_errtostr(err)); 231 return -1; 232 } 233 234 /* Start the process. */ 235 236 err = process_spawn(argc, (const char **) argv, input_reader, output_writer, &process); 237 238 if (err) 239 { 240 printf("Could not start process: %s\n", l4sys_errtostr(err)); 241 return -1; 242 } 243 244 /* Release the relinquished end of the pipe. */ 245 246 client_close(output_writer); 247 248 /* Record the output stream. */ 249 250 last_job = next_job; 251 252 while (processes[next_job] != NULL) 253 { 254 next_job++; 255 256 if (next_job >= NUMBER_OF_JOBS) 257 next_job = 0; 258 259 /* Return an error if no more job slots are available. */ 260 261 if (next_job == last_job) 262 { 263 printf("No job slots available.\n"); 264 return -1; 265 } 266 } 267 268 readers[next_job] = output_reader; 269 processes[next_job] = process; 270 programs[next_job] = strdup(argv[0]); 271 272 return 0; 273 } 274 275 276 277 /* Run the given program, providing input from a file. */ 278 279 int file_to_program(int argc, char *argv[]) 280 { 281 file_t *reader; 282 283 /* Obtain a file reader and run the program with this as its input reader. */ 284 285 if (argc < 1) 286 return -1; 287 288 reader = client_open(argv[0], O_RDONLY); 289 290 if (!client_opened(reader)) 291 { 292 printf("Could not open file: %s\n", argv[0]); 293 return -1; 294 } 295 296 return _run_program(argc - 1, &argv[1], reader); 297 } 298 299 /* Run the given program, connecting input from another program. */ 300 301 int pipe_to_program(int argc, char *argv[]) 302 { 303 int job_number; 304 int exitcode; 305 306 /* Obtain the job number for the output writer and run the program with this 307 as its input reader. */ 308 309 if (argc < 1) 310 return -1; 311 312 if (!strcmp(argv[0], "+")) 313 job_number = next_job; 314 else 315 job_number = atoi(argv[0]); 316 317 if (readers[job_number] == NULL) 318 { 319 printf("No output available for this job: %s\n", argv[0]); 320 return -1; 321 } 322 323 exitcode = _run_program(argc - 1, &argv[1], readers[job_number]); 324 325 /* Remove the job's reader to prevent direct access to it and to allow it to 326 be closed by the receiving program. */ 327 328 client_close(readers[job_number]); 329 readers[job_number] = NULL; 330 331 /* Subscribe to signals from the process. */ 332 333 notify_subscribe(process_notifiable(processes[job_number]), NOTIFY_TASK_ALL, client_notifier_task()); 334 335 return exitcode; 336 } 337 338 /* Run the given program and wait for it to finish. */ 339 340 int run_program(int argc, char *argv[]) 341 { 342 int exitcode = _run_program(argc, argv, NULL); 343 344 if (exitcode) 345 return exitcode; 346 347 return _wait_program(readers[next_job], processes[next_job]); 348 } 349 350 /* Show initiated programs. */ 351 352 int show_programs(int argc, char *argv[]) 353 { 354 (void) argc; (void) argv; 355 356 int job_number; 357 358 for (job_number = 0; job_number < NUMBER_OF_JOBS; job_number++) 359 { 360 if (processes[job_number] != NULL) 361 _show_program(job_number); 362 } 363 364 return 0; 365 } 366 367 /* Run the given program but do not wait for it to finish, instead allowing the 368 program to produce output and potentially block until an operation to wait 369 for its completion is performed. */ 370 371 int spawn_program(int argc, char *argv[]) 372 { 373 int exitcode = _run_program(argc, argv, NULL); 374 375 if (!exitcode) 376 _show_program(next_job); 377 378 return exitcode; 379 } 380 381 /* Wait for the indicated program (or the last program to be spawned) to finish, 382 showing its output. */ 383 384 int wait_program(int argc, char *argv[]) 385 { 386 int job_number; 387 388 if ((argc < 1) || !strcmp(argv[0], "+")) 389 job_number = next_job; 390 else 391 job_number = atoi(argv[0]); 392 393 if (processes[job_number] == NULL) 394 { 395 printf("No such job: %s\n", argv[0]); 396 return -1; 397 } 398 399 return _wait_program(readers[job_number], processes[job_number]); 400 } 401 402 /* vim: tabstop=2 expandtab shiftwidth=2 403 */