mirror of https://github.com/MidnightCommander/mc
864 lines
22 KiB
C
864 lines
22 KiB
C
/* Various utilities - Unix variants
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Copyright (C) 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003,
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2004, 2005, 2007 Free Software Foundation, Inc.
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Written 1994, 1995, 1996 by:
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Miguel de Icaza, Janne Kukonlehto, Dugan Porter,
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Jakub Jelinek, Mauricio Plaza.
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The mc_realpath routine is mostly from uClibc package, written
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by Rick Sladkey <jrs@world.std.com>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
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/** \file utilunix.c
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* \brief Source: various utilities - Unix variant
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*/
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#include <config.h>
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#include <ctype.h>
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#include <errno.h>
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#include <limits.h>
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#include <signal.h>
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#include <stdarg.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <fcntl.h>
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#include <sys/param.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <sys/wait.h>
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#ifdef HAVE_SYS_IOCTL_H
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# include <sys/ioctl.h>
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#endif
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#include <unistd.h>
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#include <pwd.h>
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#include <grp.h>
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#include "lib/global.h"
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#include "src/execute.h"
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#include "src/wtools.h" /* message() */
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struct sigaction startup_handler;
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#define UID_CACHE_SIZE 200
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#define GID_CACHE_SIZE 30
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typedef struct
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{
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int index;
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char *string;
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} int_cache;
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static int_cache uid_cache[UID_CACHE_SIZE];
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static int_cache gid_cache[GID_CACHE_SIZE];
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static char *
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i_cache_match (int id, int_cache * cache, int size)
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{
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int i;
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for (i = 0; i < size; i++)
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if (cache[i].index == id)
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return cache[i].string;
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return 0;
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}
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static void
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i_cache_add (int id, int_cache * cache, int size, char *text, int *last)
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{
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g_free (cache[*last].string);
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cache[*last].string = g_strdup (text);
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cache[*last].index = id;
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*last = ((*last) + 1) % size;
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}
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char *
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get_owner (int uid)
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{
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struct passwd *pwd;
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static char ibuf[10];
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char *name;
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static int uid_last;
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name = i_cache_match (uid, uid_cache, UID_CACHE_SIZE);
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if (name != NULL)
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return name;
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pwd = getpwuid (uid);
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if (pwd != NULL)
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{
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i_cache_add (uid, uid_cache, UID_CACHE_SIZE, pwd->pw_name, &uid_last);
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return pwd->pw_name;
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}
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else
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{
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g_snprintf (ibuf, sizeof (ibuf), "%d", uid);
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return ibuf;
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}
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}
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char *
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get_group (int gid)
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{
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struct group *grp;
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static char gbuf[10];
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char *name;
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static int gid_last;
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name = i_cache_match (gid, gid_cache, GID_CACHE_SIZE);
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if (name != NULL)
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return name;
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grp = getgrgid (gid);
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if (grp != NULL)
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{
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i_cache_add (gid, gid_cache, GID_CACHE_SIZE, grp->gr_name, &gid_last);
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return grp->gr_name;
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}
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else
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{
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g_snprintf (gbuf, sizeof (gbuf), "%d", gid);
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return gbuf;
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}
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}
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/* Since ncurses uses a handler that automatically refreshes the */
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/* screen after a SIGCONT, and we don't want this behavior when */
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/* spawning a child, we save the original handler here */
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void
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save_stop_handler (void)
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{
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sigaction (SIGTSTP, NULL, &startup_handler);
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}
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int
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my_system (int flags, const char *shell, const char *command)
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{
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struct sigaction ignore, save_intr, save_quit, save_stop;
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pid_t pid;
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int status = 0;
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ignore.sa_handler = SIG_IGN;
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sigemptyset (&ignore.sa_mask);
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ignore.sa_flags = 0;
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sigaction (SIGINT, &ignore, &save_intr);
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sigaction (SIGQUIT, &ignore, &save_quit);
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/* Restore the original SIGTSTP handler, we don't want ncurses' */
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/* handler messing the screen after the SIGCONT */
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sigaction (SIGTSTP, &startup_handler, &save_stop);
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pid = fork ();
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if (pid < 0)
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{
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fprintf (stderr, "\n\nfork () = -1\n");
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status = -1;
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}
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else if (pid == 0)
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{
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signal (SIGINT, SIG_DFL);
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signal (SIGQUIT, SIG_DFL);
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signal (SIGTSTP, SIG_DFL);
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signal (SIGCHLD, SIG_DFL);
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if (flags & EXECUTE_AS_SHELL)
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execl (shell, shell, "-c", command, (char *) NULL);
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else
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{
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gchar **shell_tokens;
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const gchar *only_cmd;
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shell_tokens = g_strsplit (shell, " ", 2);
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if (shell_tokens == NULL)
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only_cmd = shell;
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else
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only_cmd = (*shell_tokens != NULL) ? *shell_tokens : shell;
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execlp (only_cmd, shell, command, (char *) NULL);
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/*
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execlp will replace current process,
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therefore no sence in call of g_strfreev().
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But this keeped for estetic reason :)
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*/
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g_strfreev (shell_tokens);
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}
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_exit (127); /* Exec error */
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}
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else
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{
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while (TRUE)
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{
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if (waitpid (pid, &status, 0) > 0)
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{
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status = WEXITSTATUS(status);
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break;
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}
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if (errno != EINTR)
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{
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status = -1;
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break;
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}
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}
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}
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sigaction (SIGINT, &save_intr, NULL);
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sigaction (SIGQUIT, &save_quit, NULL);
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sigaction (SIGTSTP, &save_stop, NULL);
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return status;
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}
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/*
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* Perform tilde expansion if possible.
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* Always return a newly allocated string, even if it's unchanged.
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*/
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char *
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tilde_expand (const char *directory)
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{
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struct passwd *passwd;
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const char *p, *q;
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char *name;
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if (*directory != '~')
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return g_strdup (directory);
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p = directory + 1;
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/* d = "~" or d = "~/" */
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if (!(*p) || (*p == PATH_SEP))
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{
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passwd = getpwuid (geteuid ());
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q = (*p == PATH_SEP) ? p + 1 : "";
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}
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else
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{
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q = strchr (p, PATH_SEP);
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if (!q)
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{
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passwd = getpwnam (p);
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}
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else
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{
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name = g_strndup (p, q - p);
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passwd = getpwnam (name);
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q++;
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g_free (name);
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}
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}
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/* If we can't figure the user name, leave tilde unexpanded */
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if (!passwd)
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return g_strdup (directory);
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return g_strconcat (passwd->pw_dir, PATH_SEP_STR, q, (char *) NULL);
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}
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/*
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* Return the directory where mc should keep its temporary files.
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* This directory is (in Bourne shell terms) "${TMPDIR=/tmp}/mc-$USER"
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* When called the first time, the directory is created if needed.
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* The first call should be done early, since we are using fprintf()
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* and not message() to report possible problems.
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*/
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const char *
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mc_tmpdir (void)
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{
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static char buffer[64];
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static const char *tmpdir;
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const char *sys_tmp;
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struct passwd *pwd;
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struct stat st;
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const char *error = NULL;
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/* Check if already correctly initialized */
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if (tmpdir && lstat (tmpdir, &st) == 0 && S_ISDIR (st.st_mode) &&
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st.st_uid == getuid () && (st.st_mode & 0777) == 0700)
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return tmpdir;
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sys_tmp = getenv ("TMPDIR");
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if (!sys_tmp || sys_tmp[0] != '/')
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{
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sys_tmp = TMPDIR_DEFAULT;
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}
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pwd = getpwuid (getuid ());
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if (pwd)
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g_snprintf (buffer, sizeof (buffer), "%s/mc-%s", sys_tmp, pwd->pw_name);
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else
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g_snprintf (buffer, sizeof (buffer), "%s/mc-%lu", sys_tmp, (unsigned long) getuid ());
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canonicalize_pathname (buffer);
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if (lstat (buffer, &st) == 0)
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{
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/* Sanity check for existing directory */
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if (!S_ISDIR (st.st_mode))
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error = _("%s is not a directory\n");
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else if (st.st_uid != getuid ())
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error = _("Directory %s is not owned by you\n");
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else if (((st.st_mode & 0777) != 0700) && (chmod (buffer, 0700) != 0))
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error = _("Cannot set correct permissions for directory %s\n");
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}
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else
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{
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/* Need to create directory */
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if (mkdir (buffer, S_IRWXU) != 0)
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{
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fprintf (stderr,
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_("Cannot create temporary directory %s: %s\n"),
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buffer, unix_error_string (errno));
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error = "";
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}
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}
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if (error != NULL)
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{
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int test_fd;
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char *test_fn, *fallback_prefix;
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int fallback_ok = 0;
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if (*error)
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fprintf (stderr, error, buffer);
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/* Test if sys_tmp is suitable for temporary files */
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fallback_prefix = g_strdup_printf ("%s/mctest", sys_tmp);
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test_fd = mc_mkstemps (&test_fn, fallback_prefix, NULL);
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g_free (fallback_prefix);
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if (test_fd != -1)
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{
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close (test_fd);
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test_fd = open (test_fn, O_RDONLY);
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if (test_fd != -1)
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{
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close (test_fd);
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unlink (test_fn);
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fallback_ok = 1;
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}
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}
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if (fallback_ok)
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{
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fprintf (stderr, _("Temporary files will be created in %s\n"), sys_tmp);
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g_snprintf (buffer, sizeof (buffer), "%s", sys_tmp);
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error = NULL;
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}
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else
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{
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fprintf (stderr, _("Temporary files will not be created\n"));
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g_snprintf (buffer, sizeof (buffer), "%s", "/dev/null/");
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}
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fprintf (stderr, "%s\n", _("Press any key to continue..."));
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getc (stdin);
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}
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tmpdir = buffer;
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if (!error)
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g_setenv ("MC_TMPDIR", tmpdir, TRUE);
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return tmpdir;
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}
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/* Pipes are guaranteed to be able to hold at least 4096 bytes */
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/* More than that would be unportable */
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#define MAX_PIPE_SIZE 4096
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static int error_pipe[2]; /* File descriptors of error pipe */
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static int old_error; /* File descriptor of old standard error */
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/* Creates a pipe to hold standard error for a later analysis. */
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/* The pipe can hold 4096 bytes. Make sure no more is written */
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/* or a deadlock might occur. */
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void
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open_error_pipe (void)
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{
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if (pipe (error_pipe) < 0)
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{
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message (D_NORMAL, _("Warning"), _("Pipe failed"));
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}
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old_error = dup (2);
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if (old_error < 0 || close (2) || dup (error_pipe[1]) != 2)
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{
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message (D_NORMAL, _("Warning"), _("Dup failed"));
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close (error_pipe[0]);
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error_pipe[0] = -1;
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}
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else
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{
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/*
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* Settng stderr in nonblocking mode as we close it earlier, than
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* program stops. We try to read some error at program startup,
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* but we should not block on it.
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*
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* TODO: make piped stdin/stderr poll()/select()able to get rid
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* of following hack.
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*/
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int fd_flags;
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fd_flags = fcntl (error_pipe[0], F_GETFL, NULL);
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if (fd_flags != -1)
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{
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fd_flags |= O_NONBLOCK;
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if (fcntl (error_pipe[0], F_SETFL, fd_flags) == -1)
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{
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/* TODO: handle it somehow */
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}
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}
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}
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/* we never write there */
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close (error_pipe[1]);
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error_pipe[1] = -1;
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}
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/*
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* Returns true if an error was displayed
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* error: -1 - ignore errors, 0 - display warning, 1 - display error
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* text is prepended to the error message from the pipe
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*/
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int
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close_error_pipe (int error, const char *text)
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{
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const char *title;
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char msg[MAX_PIPE_SIZE];
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int len = 0;
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/* already closed */
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if (error_pipe[0] == -1)
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return 0;
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if (error)
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title = MSG_ERROR;
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else
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title = _("Warning");
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if (old_error >= 0)
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{
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if (dup2 (old_error, 2) == -1)
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{
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message (error, MSG_ERROR, _("Error dup'ing old error pipe"));
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return 1;
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}
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close (old_error);
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len = read (error_pipe[0], msg, MAX_PIPE_SIZE - 1);
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if (len >= 0)
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msg[len] = 0;
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close (error_pipe[0]);
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error_pipe[0] = -1;
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}
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if (error < 0)
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return 0; /* Just ignore error message */
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if (text == NULL)
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{
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if (len <= 0)
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return 0; /* Nothing to show */
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/* Show message from pipe */
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message (error, title, "%s", msg);
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}
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else
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{
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/* Show given text and possible message from pipe */
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message (error, title, "%s\n%s", text, msg);
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}
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return 1;
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}
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/*
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* Canonicalize path, and return a new path. Do everything in place.
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* The new path differs from path in:
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* Multiple `/'s are collapsed to a single `/'.
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* Leading `./'s and trailing `/.'s are removed.
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* Trailing `/'s are removed.
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* Non-leading `../'s and trailing `..'s are handled by removing
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* portions of the path.
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* Well formed UNC paths are modified only in the local part.
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*/
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void
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custom_canonicalize_pathname (char *path, CANON_PATH_FLAGS flags)
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{
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char *p, *s;
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int len;
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char *lpath = path; /* path without leading UNC part */
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/* Detect and preserve UNC paths: //server/... */
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if ((flags & CANON_PATH_GUARDUNC) && path[0] == PATH_SEP && path[1] == PATH_SEP)
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{
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p = path + 2;
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while (p[0] && p[0] != '/')
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p++;
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if (p[0] == '/' && p > path + 2)
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lpath = p;
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}
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if (!lpath[0] || !lpath[1])
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return;
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if (flags & CANON_PATH_JOINSLASHES)
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{
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/* Collapse multiple slashes */
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p = lpath;
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while (*p)
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{
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if (p[0] == PATH_SEP && p[1] == PATH_SEP)
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{
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s = p + 1;
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while (*(++s) == PATH_SEP);
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str_move (p + 1, s);
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}
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p++;
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}
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}
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if (flags & CANON_PATH_JOINSLASHES)
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{
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/* Collapse "/./" -> "/" */
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p = lpath;
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while (*p)
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{
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if (p[0] == PATH_SEP && p[1] == '.' && p[2] == PATH_SEP)
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str_move (p, p + 2);
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else
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p++;
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}
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}
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if (flags & CANON_PATH_REMSLASHDOTS)
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{
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/* Remove trailing slashes */
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p = lpath + strlen (lpath) - 1;
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while (p > lpath && *p == PATH_SEP)
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*p-- = 0;
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/* Remove leading "./" */
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if (lpath[0] == '.' && lpath[1] == PATH_SEP)
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{
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if (lpath[2] == 0)
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{
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lpath[1] = 0;
|
|
return;
|
|
}
|
|
else
|
|
{
|
|
str_move (lpath, lpath + 2);
|
|
}
|
|
}
|
|
|
|
/* Remove trailing "/" or "/." */
|
|
len = strlen (lpath);
|
|
if (len < 2)
|
|
return;
|
|
if (lpath[len - 1] == PATH_SEP)
|
|
{
|
|
lpath[len - 1] = 0;
|
|
}
|
|
else
|
|
{
|
|
if (lpath[len - 1] == '.' && lpath[len - 2] == PATH_SEP)
|
|
{
|
|
if (len == 2)
|
|
{
|
|
lpath[1] = 0;
|
|
return;
|
|
}
|
|
else
|
|
{
|
|
lpath[len - 2] = 0;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (flags & CANON_PATH_REMDOUBLEDOTS)
|
|
{
|
|
/* Collapse "/.." with the previous part of path */
|
|
p = lpath;
|
|
while (p[0] && p[1] && p[2])
|
|
{
|
|
if ((p[0] != PATH_SEP || p[1] != '.' || p[2] != '.') || (p[3] != PATH_SEP && p[3] != 0))
|
|
{
|
|
p++;
|
|
continue;
|
|
}
|
|
|
|
/* search for the previous token */
|
|
s = p - 1;
|
|
while (s >= lpath && *s != PATH_SEP)
|
|
s--;
|
|
|
|
s++;
|
|
|
|
/* If the previous token is "..", we cannot collapse it */
|
|
if (s[0] == '.' && s[1] == '.' && s + 2 == p)
|
|
{
|
|
p += 3;
|
|
continue;
|
|
}
|
|
|
|
if (p[3] != 0)
|
|
{
|
|
if (s == lpath && *s == PATH_SEP)
|
|
{
|
|
/* "/../foo" -> "/foo" */
|
|
str_move (s + 1, p + 4);
|
|
}
|
|
else
|
|
{
|
|
/* "token/../foo" -> "foo" */
|
|
str_move (s, p + 4);
|
|
}
|
|
p = (s > lpath) ? s - 1 : s;
|
|
continue;
|
|
}
|
|
|
|
/* trailing ".." */
|
|
if (s == lpath)
|
|
{
|
|
/* "token/.." -> "." */
|
|
if (lpath[0] != PATH_SEP)
|
|
{
|
|
lpath[0] = '.';
|
|
}
|
|
lpath[1] = 0;
|
|
}
|
|
else
|
|
{
|
|
/* "foo/token/.." -> "foo" */
|
|
if (s == lpath + 1)
|
|
s[0] = 0;
|
|
else
|
|
s[-1] = 0;
|
|
break;
|
|
}
|
|
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
void
|
|
canonicalize_pathname (char *path)
|
|
{
|
|
custom_canonicalize_pathname (path, CANON_PATH_ALL);
|
|
}
|
|
|
|
#ifdef HAVE_GET_PROCESS_STATS
|
|
# include <sys/procstats.h>
|
|
|
|
int
|
|
gettimeofday (struct timeval *tp, void *tzp)
|
|
{
|
|
return get_process_stats (tp, PS_SELF, 0, 0);
|
|
}
|
|
#endif /* HAVE_GET_PROCESS_STATS */
|
|
|
|
#ifndef HAVE_REALPATH
|
|
char *
|
|
mc_realpath (const char *path, char *resolved_path)
|
|
{
|
|
char copy_path[PATH_MAX];
|
|
char link_path[PATH_MAX];
|
|
char got_path[PATH_MAX];
|
|
char *new_path = got_path;
|
|
char *max_path;
|
|
int readlinks = 0;
|
|
int n;
|
|
|
|
/* Make a copy of the source path since we may need to modify it. */
|
|
if (strlen (path) >= PATH_MAX - 2)
|
|
{
|
|
errno = ENAMETOOLONG;
|
|
return NULL;
|
|
}
|
|
strcpy (copy_path, path);
|
|
path = copy_path;
|
|
max_path = copy_path + PATH_MAX - 2;
|
|
/* If it's a relative pathname use getwd for starters. */
|
|
if (*path != '/')
|
|
{
|
|
|
|
new_path = g_get_current_dir ();
|
|
if (new_path == NULL)
|
|
{
|
|
strcpy (got_path, "");
|
|
}
|
|
else
|
|
{
|
|
g_snprintf (got_path, PATH_MAX, "%s", new_path);
|
|
g_free (new_path);
|
|
new_path = got_path;
|
|
}
|
|
|
|
new_path += strlen (got_path);
|
|
if (new_path[-1] != '/')
|
|
*new_path++ = '/';
|
|
}
|
|
else
|
|
{
|
|
*new_path++ = '/';
|
|
path++;
|
|
}
|
|
/* Expand each slash-separated pathname component. */
|
|
while (*path != '\0')
|
|
{
|
|
/* Ignore stray "/". */
|
|
if (*path == '/')
|
|
{
|
|
path++;
|
|
continue;
|
|
}
|
|
if (*path == '.')
|
|
{
|
|
/* Ignore ".". */
|
|
if (path[1] == '\0' || path[1] == '/')
|
|
{
|
|
path++;
|
|
continue;
|
|
}
|
|
if (path[1] == '.')
|
|
{
|
|
if (path[2] == '\0' || path[2] == '/')
|
|
{
|
|
path += 2;
|
|
/* Ignore ".." at root. */
|
|
if (new_path == got_path + 1)
|
|
continue;
|
|
/* Handle ".." by backing up. */
|
|
while ((--new_path)[-1] != '/');
|
|
continue;
|
|
}
|
|
}
|
|
}
|
|
/* Safely copy the next pathname component. */
|
|
while (*path != '\0' && *path != '/')
|
|
{
|
|
if (path > max_path)
|
|
{
|
|
errno = ENAMETOOLONG;
|
|
return NULL;
|
|
}
|
|
*new_path++ = *path++;
|
|
}
|
|
#ifdef S_IFLNK
|
|
/* Protect against infinite loops. */
|
|
if (readlinks++ > MAXSYMLINKS)
|
|
{
|
|
errno = ELOOP;
|
|
return NULL;
|
|
}
|
|
/* See if latest pathname component is a symlink. */
|
|
*new_path = '\0';
|
|
n = readlink (got_path, link_path, PATH_MAX - 1);
|
|
if (n < 0)
|
|
{
|
|
/* EINVAL means the file exists but isn't a symlink. */
|
|
if (errno != EINVAL)
|
|
{
|
|
/* Make sure it's null terminated. */
|
|
*new_path = '\0';
|
|
strcpy (resolved_path, got_path);
|
|
return NULL;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Note: readlink doesn't add the null byte. */
|
|
link_path[n] = '\0';
|
|
if (*link_path == '/')
|
|
/* Start over for an absolute symlink. */
|
|
new_path = got_path;
|
|
else
|
|
/* Otherwise back up over this component. */
|
|
while (*(--new_path) != '/');
|
|
/* Safe sex check. */
|
|
if (strlen (path) + n >= PATH_MAX - 2)
|
|
{
|
|
errno = ENAMETOOLONG;
|
|
return NULL;
|
|
}
|
|
/* Insert symlink contents into path. */
|
|
strcat (link_path, path);
|
|
strcpy (copy_path, link_path);
|
|
path = copy_path;
|
|
}
|
|
#endif /* S_IFLNK */
|
|
*new_path++ = '/';
|
|
}
|
|
/* Delete trailing slash but don't whomp a lone slash. */
|
|
if (new_path != got_path + 1 && new_path[-1] == '/')
|
|
new_path--;
|
|
/* Make sure it's null terminated. */
|
|
*new_path = '\0';
|
|
strcpy (resolved_path, got_path);
|
|
return resolved_path;
|
|
}
|
|
#endif /* HAVE_REALPATH */
|
|
|
|
/* Return the index of the permissions triplet */
|
|
int
|
|
get_user_permissions (struct stat *st)
|
|
{
|
|
static gboolean initialized = FALSE;
|
|
static gid_t *groups;
|
|
static int ngroups;
|
|
static uid_t uid;
|
|
int i;
|
|
|
|
if (!initialized)
|
|
{
|
|
uid = geteuid ();
|
|
|
|
ngroups = getgroups (0, NULL);
|
|
if (ngroups == -1)
|
|
ngroups = 0; /* ignore errors */
|
|
|
|
/* allocate space for one element in addition to what
|
|
* will be filled by getgroups(). */
|
|
groups = g_new (gid_t, ngroups + 1);
|
|
|
|
if (ngroups != 0)
|
|
{
|
|
ngroups = getgroups (ngroups, groups);
|
|
if (ngroups == -1)
|
|
ngroups = 0; /* ignore errors */
|
|
}
|
|
|
|
/* getgroups() may or may not return the effective group ID,
|
|
* so we always include it at the end of the list. */
|
|
groups[ngroups++] = getegid ();
|
|
|
|
initialized = TRUE;
|
|
}
|
|
|
|
if (st->st_uid == uid || uid == 0)
|
|
return 0;
|
|
|
|
for (i = 0; i < ngroups; i++)
|
|
{
|
|
if (st->st_gid == groups[i])
|
|
return 1;
|
|
}
|
|
|
|
return 2;
|
|
}
|