--- /dev/null
+
+/*
+ * server.c Set up and handle communications with a server process.
+ *
+ * Server Handling copyright 1992-1999, 2001 The Free Software Foundation
+ *
+ * Server Handling is free software.
+ * You may redistribute it and/or modify it under the terms of the
+ * GNU General Public License, as published by the Free Software
+ * Foundation; either version 2, or (at your option) any later version.
+ *
+ * Server Handling is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Server Handling. See the file "COPYING". If not,
+ * write to: The Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ *
+ * As a special exception, The Free Software Foundation gives
+ * permission for additional uses of the text contained in his release
+ * of ServerHandler.
+ *
+ * The exception is that, if you link the ServerHandler library with other
+ * files to produce an executable, this does not by itself cause the
+ * resulting executable to be covered by the GNU General Public License.
+ * Your use of that executable is in no way restricted on account of
+ * linking the ServerHandler library code into it.
+ *
+ * This exception does not however invalidate any other reasons why
+ * the executable file might be covered by the GNU General Public License.
+ *
+ * This exception applies only to the code released by The Free
+ * Software Foundation under the name ServerHandler. If you copy code
+ * from other sources under the General Public License into a copy of
+ * ServerHandler, as the General Public License permits, the exception
+ * does not apply to the code that you add in this way. To avoid
+ * misleading anyone as to the status of such modified files, you must
+ * delete this exception notice from them.
+ *
+ * If you write modifications of your own for ServerHandler, it is your
+ * choice whether to permit this exception to apply to your modifications.
+ * If you do not wish that, delete this exception notice.
+ */
+
+#include "fixlib.h"
+#include "server.h"
+
+STATIC volatile enum t_bool read_pipe_timeout;
+STATIC pid_t server_master_pid = NOPROCESS;
+
+tSCC* def_args[] =
+{ (char *) NULL, (char *) NULL };
+STATIC t_pf_pair server_pair =
+{ (FILE *) NULL, (FILE *) NULL };
+STATIC pid_t server_id = NULLPROCESS;
+/*
+ * Arbitrary text that should not be found in the shell output.
+ * It must be a single line and appear verbatim at the start of
+ * the terminating output line.
+ */
+tSCC z_done[] = "ShElL-OuTpUt-HaS-bEeN-cOmPlEtEd";
+tSCC* p_cur_dir = (char *) NULL;
+
+/*
+ * load_data
+ *
+ * Read data from a file pointer (a pipe to a process in this context)
+ * until we either get EOF or we get a marker line back.
+ * The read data are stored in a malloc-ed string that is truncated
+ * to size at the end. Input is assumed to be an ASCII string.
+ */
+static char *
+load_data (FILE* fp)
+{
+ char *pz_text;
+ size_t text_size;
+ char *pz_scan;
+ char z_line[1024];
+ t_bool got_done = BOOL_FALSE;
+
+ text_size = sizeof (z_line) * 2;
+ pz_scan = pz_text = XNEWVEC (char, text_size);
+
+ for (;;)
+ {
+ size_t used_ct;
+
+ alarm (10);
+ read_pipe_timeout = BOOL_FALSE;
+ if (fgets (z_line, sizeof (z_line), fp) == (char *) NULL)
+ break;
+
+ if (strncmp (z_line, z_done, sizeof (z_done) - 1) == 0)
+ {
+ got_done = BOOL_TRUE;
+ break;
+ }
+
+ strcpy (pz_scan, z_line);
+ pz_scan += strlen (z_line);
+ used_ct = (size_t) (pz_scan - pz_text);
+
+ if (text_size - used_ct < sizeof (z_line))
+ {
+ size_t off = (size_t) (pz_scan - pz_text);
+
+ text_size += 4096;
+ pz_text = XRESIZEVEC (char, pz_text, text_size);
+ pz_scan = pz_text + off;
+ }
+ }
+
+ alarm (0);
+ if (read_pipe_timeout || ! got_done)
+ {
+ free ((void *) pz_text);
+ return (char *) NULL;
+ }
+
+ while ((pz_scan > pz_text) && ISSPACE (pz_scan[-1]))
+ pz_scan--;
+ *pz_scan = NUL;
+ return XRESIZEVEC (char, pz_text, strlen (pz_text) + 1);
+}
+
+
+/*
+ * close_server
+ *
+ * Make certain the server process is dead, close the
+ * pipes to it and from it, finally NULL out the file pointers
+ */
+void
+close_server (void)
+{
+ if ( (server_id != NULLPROCESS)
+ && (server_master_pid == getpid ()))
+ {
+ kill ((pid_t) server_id, SIGKILL);
+ server_id = NULLPROCESS;
+ server_master_pid = NOPROCESS;
+ fclose (server_pair.pf_read);
+ fclose (server_pair.pf_write);
+ server_pair.pf_read = server_pair.pf_write = (FILE *) NULL;
+ }
+}
+
+/*
+ * sig_handler really only handles the timeout and pipe signals.
+ * This ensures that we do not wait forever on a request
+ * to our server, and also that if the server dies, we do not
+ * die from a sigpipe problem.
+ */
+static void
+sig_handler (int signo ATTRIBUTE_UNUSED)
+{
+#ifdef DEBUG
+ /* FIXME: this is illegal to do in a signal handler. */
+ fprintf (stderr,
+ "fixincl ERROR: sig_handler: killed pid %ld due to %s\n",
+ (long) server_id, signo == SIGPIPE ? "SIGPIPE" : "SIGALRM");
+#endif
+ close_server ();
+ read_pipe_timeout = BOOL_TRUE;
+}
+
+
+/*
+ * server_setup Establish the signal handler for PIPE and ALARM.
+ * Also establishes the current directory to give to the
+ * server process at the start of every server command.
+ */
+static void
+server_setup (void)
+{
+ static int atexit_done = 0;
+ char buff [MAXPATHLEN + 1];
+
+ if (atexit_done++ == 0)
+ atexit (close_server);
+ else
+ fputs ("NOTE: server restarted\n", stderr);
+
+ server_master_pid = getpid ();
+
+ signal (SIGPIPE, sig_handler);
+ signal (SIGALRM, sig_handler);
+
+ fputs ("trap : 1\n", server_pair.pf_write);
+ fflush (server_pair.pf_write);
+ getcwd (buff, MAXPATHLEN + 1);
+ p_cur_dir = xstrdup (buff);
+}
+
+/*
+ * find_shell
+ *
+ * Locate a shell suitable for use. For various reasons
+ * (like the use of "trap" in server_setup(), it must be a
+ * Bourne-like shell.
+ *
+ * Most of the time, /bin/sh is preferred, but sometimes
+ * it's quite broken (like on Ultrix). autoconf lets you
+ * override with $CONFIG_SHELL, so we do the same.
+ */
+
+static const char *
+find_shell (void)
+{
+ char * shell = getenv ("CONFIG_SHELL");
+ if (shell)
+ return shell;
+
+ return "/bin/sh";
+}
+
+
+/*
+ * run_shell
+ *
+ * Run a shell command on the server. The command string
+ * passed in is wrapped inside the sequence:
+ *
+ * cd <original directory>
+ * <command string>
+ * echo
+ * echo <end-of-command-marker>
+ *
+ * This ensures that all commands start at a known place in
+ * the directory structure, that any incomplete output lines
+ * are completed and that our special marker sequence appears on
+ * a line by itself. We have chosen a marker that is
+ * excessively unlikely to be reproduced in normal output:
+ *
+ * "ShElL-OuTpUt-HaS-bEeN-cOmPlEtEd"
+ */
+char *
+run_shell (const char* pz_cmd)
+{
+ tSCC zNoServer[] = "Server not running, cannot run:\n%s\n\n";
+ t_bool retry = BOOL_TRUE;
+
+ do_retry:
+ /* IF the shell server process is not running yet,
+ THEN try to start it. */
+ if (server_id == NULLPROCESS)
+ {
+ def_args[0] = find_shell ();
+
+ server_id = proc2_fopen (&server_pair, def_args);
+ if (server_id > 0)
+ server_setup ();
+ }
+
+ /* IF it is still not running, THEN return the nil string. */
+ if (server_id <= 0)
+ {
+ fprintf (stderr, zNoServer, pz_cmd);
+ return XCNEW (char);
+ }
+
+ /* Make sure the process will pay attention to us, send the
+ supplied command, and then have it output a special marker that
+ we can find. */
+ fprintf (server_pair.pf_write, "cd %s\n%s\n\necho\necho %s\n",
+ p_cur_dir, pz_cmd, z_done);
+ fflush (server_pair.pf_write);
+
+ /* IF the server died and we received a SIGPIPE,
+ THEN return an empty string. */
+ if (server_id == NULLPROCESS)
+ {
+ fprintf (stderr, zNoServer, pz_cmd);
+ return XCNEW (char);
+ }
+
+ /* Now try to read back all the data. If we fail due to either a
+ sigpipe or sigalrm (timeout), we will return the nil string. */
+ {
+ char *pz = load_data (server_pair.pf_read);
+
+ if (pz == (char *) NULL)
+ {
+ close_server ();
+
+ if (retry)
+ {
+ retry = BOOL_FALSE;
+ goto do_retry;
+ }
+
+ fprintf (stderr, "CLOSING SHELL SERVER - command failure:\n\t%s\n",
+ pz_cmd);
+ pz = XCNEW (char);
+ }
+#ifdef DEBUG
+ fprintf( stderr, "run_shell command success: %s\n", pz );
+#endif
+ return pz;
+ }
+}
projects / msp430-gcc.git / blobdiff