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/*
Various utilities - Unix variants
Copyright (C) 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003,
2004, 2005, 2007, 2011
The Free Software Foundation, Inc.
Written by:
Miguel de Icaza, 1994, 1995, 1996
Janne Kukonlehto, 1994, 1995, 1996
Dugan Porter, 1994, 1995, 1996
Jakub Jelinek, 1994, 1995, 1996
Mauricio Plaza, 1994, 1995, 1996
The mc_realpath routine is mostly from uClibc package, written
by Rick Sladkey <jrs@world.std.com>
This file is part of the Midnight Commander.
The Midnight Commander is free software: you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation, either version 3 of the License,
or (at your option) any later version.
The Midnight Commander 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
/** \file utilunix.c
* \brief Source: various utilities - Unix variant
*/
#include <config.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif
#ifdef HAVE_GET_PROCESS_STATS
#include <sys/procstats.h>
#endif
#include <unistd.h>
#include <pwd.h>
#include <grp.h>
#include "lib/global.h"
#include "lib/vfs/vfs.h" /* VFS_ENCODING_PREFIX */
#include "lib/strutil.h" /* str_move() */
#include "lib/util.h"
#include "lib/widget.h" /* message() */
#include "lib/vfs/xdirentry.h"
#ifdef HAVE_CHARSET
#include "lib/charsets.h"
#endif
#include "utilunix.h"
/*** global variables ****************************************************************************/
struct sigaction startup_handler;
/*** file scope macro definitions ****************************************************************/
#define UID_CACHE_SIZE 200
#define GID_CACHE_SIZE 30
/* Pipes are guaranteed to be able to hold at least 4096 bytes */
/* More than that would be unportable */
#define MAX_PIPE_SIZE 4096
/*** file scope type declarations ****************************************************************/
typedef struct
{
int index;
char *string;
} int_cache;
/*** file scope variables ************************************************************************/
static int_cache uid_cache[UID_CACHE_SIZE];
static int_cache gid_cache[GID_CACHE_SIZE];
static int error_pipe[2]; /* File descriptors of error pipe */
static int old_error; /* File descriptor of old standard error */
/*** file scope functions ************************************************************************/
/* --------------------------------------------------------------------------------------------- */
static char *
i_cache_match (int id, int_cache * cache, int size)
{
int i;
for (i = 0; i < size; i++)
if (cache[i].index == id)
return cache[i].string;
return 0;
}
/* --------------------------------------------------------------------------------------------- */
static void
i_cache_add (int id, int_cache * cache, int size, char *text, int *last)
{
g_free (cache[*last].string);
cache[*last].string = g_strdup (text);
cache[*last].index = id;
*last = ((*last) + 1) % size;
}
/* --------------------------------------------------------------------------------------------- */
/*** public functions ****************************************************************************/
/* --------------------------------------------------------------------------------------------- */
char *
get_owner (int uid)
{
struct passwd *pwd;
static char ibuf[10];
char *name;
static int uid_last;
name = i_cache_match (uid, uid_cache, UID_CACHE_SIZE);
if (name != NULL)
return name;
pwd = getpwuid (uid);
if (pwd != NULL)
{
i_cache_add (uid, uid_cache, UID_CACHE_SIZE, pwd->pw_name, &uid_last);
return pwd->pw_name;
}
else
{
g_snprintf (ibuf, sizeof (ibuf), "%d", uid);
return ibuf;
}
}
/* --------------------------------------------------------------------------------------------- */
char *
get_group (int gid)
{
struct group *grp;
static char gbuf[10];
char *name;
static int gid_last;
name = i_cache_match (gid, gid_cache, GID_CACHE_SIZE);
if (name != NULL)
return name;
grp = getgrgid (gid);
if (grp != NULL)
{
i_cache_add (gid, gid_cache, GID_CACHE_SIZE, grp->gr_name, &gid_last);
return grp->gr_name;
}
else
{
g_snprintf (gbuf, sizeof (gbuf), "%d", gid);
return gbuf;
}
}
/* --------------------------------------------------------------------------------------------- */
/* Since ncurses uses a handler that automatically refreshes the */
/* screen after a SIGCONT, and we don't want this behavior when */
/* spawning a child, we save the original handler here */
void
save_stop_handler (void)
{
sigaction (SIGTSTP, NULL, &startup_handler);
}
/* --------------------------------------------------------------------------------------------- */
int
my_system (int flags, const char *shell, const char *command)
{
struct sigaction ignore, save_intr, save_quit, save_stop;
pid_t pid;
int status = 0;
ignore.sa_handler = SIG_IGN;
sigemptyset (&ignore.sa_mask);
ignore.sa_flags = 0;
sigaction (SIGINT, &ignore, &save_intr);
sigaction (SIGQUIT, &ignore, &save_quit);
/* Restore the original SIGTSTP handler, we don't want ncurses' */
/* handler messing the screen after the SIGCONT */
sigaction (SIGTSTP, &startup_handler, &save_stop);
pid = fork ();
if (pid < 0)
{
fprintf (stderr, "\n\nfork () = -1\n");
status = -1;
}
else if (pid == 0)
{
signal (SIGINT, SIG_DFL);
signal (SIGQUIT, SIG_DFL);
signal (SIGTSTP, SIG_DFL);
signal (SIGCHLD, SIG_DFL);
if (flags & EXECUTE_AS_SHELL)
execl (shell, shell, "-c", command, (char *) NULL);
else
{
gchar **shell_tokens;
const gchar *only_cmd;
shell_tokens = g_strsplit (shell, " ", 2);
if (shell_tokens == NULL)
only_cmd = shell;
else
only_cmd = (*shell_tokens != NULL) ? *shell_tokens : shell;
execlp (only_cmd, shell, command, (char *) NULL);
/*
execlp will replace current process,
therefore no sence in call of g_strfreev().
But this keeped for estetic reason :)
*/
g_strfreev (shell_tokens);
}
_exit (127); /* Exec error */
}
else
{
while (TRUE)
{
if (waitpid (pid, &status, 0) > 0)
{
status = WEXITSTATUS (status);
break;
}
if (errno != EINTR)
{
status = -1;
break;
}
}
}
sigaction (SIGINT, &save_intr, NULL);
sigaction (SIGQUIT, &save_quit, NULL);
sigaction (SIGTSTP, &save_stop, NULL);
return status;
}
/* --------------------------------------------------------------------------------------------- */
/**
* Perform tilde expansion if possible.
* Always return a newly allocated string, even if it's unchanged.
*/
char *
tilde_expand (const char *directory)
{
struct passwd *passwd;
const char *p, *q;
char *name;
if (*directory != '~')
return g_strdup (directory);
p = directory + 1;
/* d = "~" or d = "~/" */
if (!(*p) || (*p == PATH_SEP))
{
passwd = getpwuid (geteuid ());
q = (*p == PATH_SEP) ? p + 1 : "";
}
else
{
q = strchr (p, PATH_SEP);
if (!q)
{
passwd = getpwnam (p);
}
else
{
name = g_strndup (p, q - p);
passwd = getpwnam (name);
q++;
g_free (name);
}
}
/* If we can't figure the user name, leave tilde unexpanded */
if (!passwd)
return g_strdup (directory);
return g_strconcat (passwd->pw_dir, PATH_SEP_STR, q, (char *) NULL);
}
/* --------------------------------------------------------------------------------------------- */
/**
* Creates a pipe to hold standard error for a later analysis.
* The pipe can hold 4096 bytes. Make sure no more is written
* or a deadlock might occur.
*/
void
open_error_pipe (void)
{
if (pipe (error_pipe) < 0)
{
message (D_NORMAL, _("Warning"), _("Pipe failed"));
}
old_error = dup (2);
if (old_error < 0 || close (2) || dup (error_pipe[1]) != 2)
{
message (D_NORMAL, _("Warning"), _("Dup failed"));
close (error_pipe[0]);
error_pipe[0] = -1;
}
else
{
/*
* Settng stderr in nonblocking mode as we close it earlier, than
* program stops. We try to read some error at program startup,
* but we should not block on it.
*
* TODO: make piped stdin/stderr poll()/select()able to get rid
* of following hack.
*/
int fd_flags;
fd_flags = fcntl (error_pipe[0], F_GETFL, NULL);
if (fd_flags != -1)
{
fd_flags |= O_NONBLOCK;
if (fcntl (error_pipe[0], F_SETFL, fd_flags) == -1)
{
/* TODO: handle it somehow */
}
}
}
/* we never write there */
close (error_pipe[1]);
error_pipe[1] = -1;
}
/* --------------------------------------------------------------------------------------------- */
/**
* Returns true if an error was displayed
* error: -1 - ignore errors, 0 - display warning, 1 - display error
* text is prepended to the error message from the pipe
*/
int
close_error_pipe (int error, const char *text)
{
const char *title;
char msg[MAX_PIPE_SIZE];
int len = 0;
/* already closed */
if (error_pipe[0] == -1)
return 0;
if (error < 0 || (error > 0 && (error & D_ERROR) != 0))
title = MSG_ERROR;
else
title = _("Warning");
if (old_error >= 0)
{
if (dup2 (old_error, 2) == -1)
{
if (error < 0)
error = D_ERROR;
message (error, MSG_ERROR, _("Error dup'ing old error pipe"));
return 1;
}
close (old_error);
len = read (error_pipe[0], msg, MAX_PIPE_SIZE - 1);
if (len >= 0)
msg[len] = 0;
close (error_pipe[0]);
error_pipe[0] = -1;
}
if (error < 0)
return 0; /* Just ignore error message */
if (text == NULL)
{
if (len <= 0)
return 0; /* Nothing to show */
/* Show message from pipe */
message (error, title, "%s", msg);
}
else
{
/* Show given text and possible message from pipe */
message (error, title, "%s\n%s", text, msg);
}
return 1;
}
/* --------------------------------------------------------------------------------------------- */
/**
* Canonicalize path, and return a new path. Do everything in place.
* The new path differs from path in:
* Multiple `/'s are collapsed to a single `/'.
* Leading `./'s and trailing `/.'s are removed.
* Trailing `/'s are removed.
* Non-leading `../'s and trailing `..'s are handled by removing
* portions of the path.
* Well formed UNC paths are modified only in the local part.
*/
void
custom_canonicalize_pathname (char *path, CANON_PATH_FLAGS flags)
{
char *p, *s;
size_t len;
char *lpath = path; /* path without leading UNC part */
const size_t url_delim_len = strlen (VFS_PATH_URL_DELIMITER);
/* Detect and preserve UNC paths: //server/... */
if ((flags & CANON_PATH_GUARDUNC) && path[0] == PATH_SEP && path[1] == PATH_SEP)
{
p = path + 2;
while (p[0] && p[0] != '/')
p++;
if (p[0] == '/' && p > path + 2)
lpath = p;
}
if (!lpath[0] || !lpath[1])
return;
if (flags & CANON_PATH_JOINSLASHES)
{
/* Collapse multiple slashes */
p = lpath;
while (*p)
{
if (p[0] == PATH_SEP && p[1] == PATH_SEP && (p == lpath || *(p - 1) != ':'))
{
s = p + 1;
while (*(++s) == PATH_SEP);
str_move (p + 1, s);
}
p++;
}
}
if (flags & CANON_PATH_JOINSLASHES)
{
/* Collapse "/./" -> "/" */
p = lpath;
while (*p)
{
if (p[0] == PATH_SEP && p[1] == '.' && p[2] == PATH_SEP)
str_move (p, p + 2);
else
p++;
}
}
if (flags & CANON_PATH_REMSLASHDOTS)
{
/* Remove trailing slashes */
p = lpath + strlen (lpath) - 1;
while (p > lpath && *p == PATH_SEP)
{
if (p >= lpath - (url_delim_len + 1)
&& strncmp (p - url_delim_len + 1, VFS_PATH_URL_DELIMITER, url_delim_len) == 0)
break;
*p-- = 0;
}
/* Remove leading "./" */
if (lpath[0] == '.' && lpath[1] == PATH_SEP)
{
if (lpath[2] == 0)
{
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
&& (len < url_delim_len
|| strncmp (lpath + len - url_delim_len, VFS_PATH_URL_DELIMITER,
url_delim_len) != 0))
{
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)
{
const size_t enc_prefix_len = strlen (VFS_ENCODING_PREFIX);
/* 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;
if (s >= lpath + url_delim_len - 2
&& strncmp (s - url_delim_len + 2, VFS_PATH_URL_DELIMITER, url_delim_len) == 0)
{
s -= (url_delim_len - 2);
while (s >= lpath && *s-- != PATH_SEP);
}
while (s >= lpath)
{
if (s - url_delim_len > lpath
&& strncmp (s - url_delim_len, VFS_PATH_URL_DELIMITER, url_delim_len) == 0)
{
char *vfs_prefix = s - url_delim_len;
struct vfs_class *vclass;
while (vfs_prefix > lpath && *--vfs_prefix != PATH_SEP);
if (*vfs_prefix == PATH_SEP)
vfs_prefix++;
*(s - url_delim_len) = '\0';
vclass = vfs_prefix_to_class (vfs_prefix);
*(s - url_delim_len) = *VFS_PATH_URL_DELIMITER;
if (vclass != NULL)
{
struct vfs_s_subclass *sub = (struct vfs_s_subclass *) vclass->data;
if (sub != NULL && sub->flags & VFS_S_REMOTE)
{
s = vfs_prefix;
continue;
}
}
}
if (*s == PATH_SEP)
break;
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" */
#ifdef HAVE_CHARSET
if ((strncmp (s, VFS_ENCODING_PREFIX, enc_prefix_len) == 0)
&& (is_supported_encoding (s + enc_prefix_len)))
/* special case: remove encoding */
str_move (s, p + 1);
else
#endif /* HAVE_CHARSET */
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;
#ifdef HAVE_CHARSET
else if ((strncmp (s, VFS_ENCODING_PREFIX, enc_prefix_len) == 0)
&& (is_supported_encoding (s + enc_prefix_len)))
{
/* special case: remove encoding */
s[0] = '.';
s[1] = '.';
s[2] = '\0';
/* search for the previous token */
/* s[-1] == PATH_SEP */
p = s - 1;
while (p >= lpath && *p != PATH_SEP)
p--;
if (p != NULL)
continue;
}
#endif /* HAVE_CHARSET */
else
{
if (s >= lpath + url_delim_len
&& strncmp (s - url_delim_len, VFS_PATH_URL_DELIMITER, url_delim_len) == 0)
*s = '\0';
else
s[-1] = '\0';
}
break;
}
break;
}
}
}
/* --------------------------------------------------------------------------------------------- */
void
canonicalize_pathname (char *path)
{
custom_canonicalize_pathname (path, CANON_PATH_ALL);
}
/* --------------------------------------------------------------------------------------------- */
#ifdef HAVE_GET_PROCESS_STATS
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;
}
/* --------------------------------------------------------------------------------------------- */
/**
* Build filename from arguments.
* Like to g_build_filename(), but respect VFS_PATH_URL_DELIMITER
*/
char *
mc_build_filenamev (const char *first_element, va_list args)
{
gboolean absolute;
const char *element = first_element;
GString *path;
char *ret;
if (element == NULL)
return NULL;
path = g_string_new ("");
absolute = (*first_element != '\0' && *first_element == PATH_SEP);
do
{
if (*element == '\0')
element = va_arg (args, char *);
else
{
char *tmp_element;
size_t len;
const char *start;
tmp_element = g_strdup (element);
element = va_arg (args, char *);
canonicalize_pathname (tmp_element);
len = strlen (tmp_element);
start = (tmp_element[0] == PATH_SEP) ? tmp_element + 1 : tmp_element;
g_string_append (path, start);
if (tmp_element[len - 1] != PATH_SEP && element != NULL)
g_string_append_c (path, PATH_SEP);
g_free (tmp_element);
}
}
while (element != NULL);
if (absolute)
g_string_prepend_c (path, PATH_SEP);
ret = g_string_free (path, FALSE);
canonicalize_pathname (ret);
return ret;
}
/* --------------------------------------------------------------------------------------------- */
/**
* Build filename from arguments.
* Like to g_build_filename(), but respect VFS_PATH_URL_DELIMITER
*/
char *
mc_build_filename (const char *first_element, ...)
{
va_list args;
char *ret;
if (first_element == NULL)
return NULL;
va_start (args, first_element);
ret = mc_build_filenamev (first_element, args);
va_end (args);
return ret;
}
/* --------------------------------------------------------------------------------------------- */
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