/* Various utilities - Unix variants Copyright (C) 1994-2022 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 Andrew Borodin 2010-2022 The mc_realpath routine is mostly from uClibc package, written by Rick Sladkey 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 . */ /** \file utilunix.c * \brief Source: various utilities - Unix variant */ #include #include #include #include #include #include #include #include #include #ifdef HAVE_SYS_PARAM_H #include #endif #include #include #ifdef HAVE_SYS_SELECT_H #include #endif #include #include #include #include "lib/global.h" #include "lib/unixcompat.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 /*** file scope type declarations ****************************************************************/ typedef struct { int index; char *string; } int_cache; typedef enum { FORK_ERROR = -1, FORK_CHILD, FORK_PARENT, } my_fork_state_t; typedef struct { struct sigaction intr; struct sigaction quit; struct sigaction stop; } my_system_sigactions_t; /*** file scope variables ************************************************************************/ static int_cache uid_cache[UID_CACHE_SIZE]; static int_cache gid_cache[GID_CACHE_SIZE]; /* --------------------------------------------------------------------------------------------- */ /*** 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; } /* --------------------------------------------------------------------------------------------- */ static my_fork_state_t my_fork (void) { pid_t pid; pid = fork (); if (pid < 0) { fprintf (stderr, "\n\nfork () = -1\n"); return FORK_ERROR; } if (pid == 0) return FORK_CHILD; while (TRUE) { int status = 0; if (waitpid (pid, &status, 0) > 0) return WEXITSTATUS (status) == 0 ? FORK_PARENT : FORK_ERROR; if (errno != EINTR) return FORK_ERROR; } } /* --------------------------------------------------------------------------------------------- */ static void my_system__save_sigaction_handlers (my_system_sigactions_t * sigactions) { struct sigaction ignore; memset (&ignore, 0, sizeof (ignore)); ignore.sa_handler = SIG_IGN; sigemptyset (&ignore.sa_mask); sigaction (SIGINT, &ignore, &sigactions->intr); sigaction (SIGQUIT, &ignore, &sigactions->quit); /* Restore the original SIGTSTP handler, we don't want ncurses' */ /* handler messing the screen after the SIGCONT */ sigaction (SIGTSTP, &startup_handler, &sigactions->stop); } /* --------------------------------------------------------------------------------------------- */ static void my_system__restore_sigaction_handlers (my_system_sigactions_t * sigactions) { sigaction (SIGINT, &sigactions->intr, NULL); sigaction (SIGQUIT, &sigactions->quit, NULL); sigaction (SIGTSTP, &sigactions->stop, NULL); } /* --------------------------------------------------------------------------------------------- */ static GPtrArray * my_system_make_arg_array (int flags, const char *shell, char **execute_name) { GPtrArray *args_array; args_array = g_ptr_array_new (); if ((flags & EXECUTE_AS_SHELL) != 0) { g_ptr_array_add (args_array, (gpointer) shell); g_ptr_array_add (args_array, (gpointer) "-c"); *execute_name = g_strdup (shell); } else { char *shell_token; shell_token = shell != NULL ? strchr (shell, ' ') : NULL; if (shell_token == NULL) *execute_name = g_strdup (shell); else *execute_name = g_strndup (shell, (gsize) (shell_token - shell)); g_ptr_array_add (args_array, (gpointer) shell); } return args_array; } /* --------------------------------------------------------------------------------------------- */ static void mc_pread_stream (mc_pipe_stream_t * ps, const fd_set * fds) { size_t buf_len; ssize_t read_len; if (!FD_ISSET (ps->fd, fds)) { ps->len = MC_PIPE_STREAM_UNREAD; return; } buf_len = (size_t) ps->len; if (buf_len >= MC_PIPE_BUFSIZE) buf_len = ps->null_term ? MC_PIPE_BUFSIZE - 1 : MC_PIPE_BUFSIZE; do { read_len = read (ps->fd, ps->buf, buf_len); } while (read_len < 0 && errno == EINTR); if (read_len < 0) { /* reading error */ ps->len = MC_PIPE_ERROR_READ; ps->error = errno; } else if (read_len == 0) /* EOF */ ps->len = MC_PIPE_STREAM_EOF; else { /* success */ ps->len = read_len; if (ps->null_term) ps->buf[(size_t) ps->len] = '\0'; } ps->pos = 0; } /* --------------------------------------------------------------------------------------------- */ /*** public functions ****************************************************************************/ /* --------------------------------------------------------------------------------------------- */ const char * get_owner (uid_t uid) { struct passwd *pwd; char *name; static uid_t uid_last; name = i_cache_match ((int) uid, uid_cache, UID_CACHE_SIZE); if (name != NULL) return name; pwd = getpwuid (uid); if (pwd != NULL) { i_cache_add ((int) uid, uid_cache, UID_CACHE_SIZE, pwd->pw_name, (int *) &uid_last); return pwd->pw_name; } else { static char ibuf[10]; g_snprintf (ibuf, sizeof (ibuf), "%d", (int) uid); return ibuf; } } /* --------------------------------------------------------------------------------------------- */ const char * get_group (gid_t gid) { struct group *grp; char *name; static gid_t gid_last; name = i_cache_match ((int) gid, gid_cache, GID_CACHE_SIZE); if (name != NULL) return name; grp = getgrgid (gid); if (grp != NULL) { i_cache_add ((int) gid, gid_cache, GID_CACHE_SIZE, grp->gr_name, (int *) &gid_last); return grp->gr_name; } else { static char gbuf[10]; g_snprintf (gbuf, sizeof (gbuf), "%d", (int) 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); } /* --------------------------------------------------------------------------------------------- */ /** * Wrapper for _exit() system call. * The _exit() function has gcc's attribute 'noreturn', and this is reason why we can't * mock the call. * * @param status exit code */ void /* __attribute__ ((noreturn)) */ my_exit (int status) { _exit (status); } /* --------------------------------------------------------------------------------------------- */ /** * Call external programs. * * @parameter flags addition conditions for running external programs. * @parameter shell shell (if flags contain EXECUTE_AS_SHELL), command to run otherwise. * Shell (or command) will be found in paths described in PATH variable * (if shell parameter doesn't begin from path delimiter) * @parameter command Command for shell (or first parameter for command, if flags contain EXECUTE_AS_SHELL) * @return 0 if successfull, -1 otherwise */ int my_system (int flags, const char *shell, const char *command) { return my_systeml (flags, shell, command, NULL); } /* --------------------------------------------------------------------------------------------- */ /** * Call external programs with various parameters number. * * @parameter flags addition conditions for running external programs. * @parameter shell shell (if flags contain EXECUTE_AS_SHELL), command to run otherwise. * Shell (or command) will be found in pathes described in PATH variable * (if shell parameter doesn't begin from path delimiter) * @parameter ... Command for shell with addition parameters for shell * (or parameters for command, if flags contain EXECUTE_AS_SHELL). * Should be NULL terminated. * @return 0 if successfull, -1 otherwise */ int my_systeml (int flags, const char *shell, ...) { GPtrArray *args_array; int status = 0; va_list vargs; char *one_arg; args_array = g_ptr_array_new (); va_start (vargs, shell); while ((one_arg = va_arg (vargs, char *)) != NULL) g_ptr_array_add (args_array, one_arg); va_end (vargs); g_ptr_array_add (args_array, NULL); status = my_systemv_flags (flags, shell, (char *const *) args_array->pdata); g_ptr_array_free (args_array, TRUE); return status; } /* --------------------------------------------------------------------------------------------- */ /** * Call external programs with array of strings as parameters. * * @parameter command command to run. Command will be found in paths described in PATH variable * (if command parameter doesn't begin from path delimiter) * @parameter argv Array of strings (NULL-terminated) with parameters for command * @return 0 if successfull, -1 otherwise */ int my_systemv (const char *command, char *const argv[]) { my_fork_state_t fork_state; int status = 0; my_system_sigactions_t sigactions; my_system__save_sigaction_handlers (&sigactions); fork_state = my_fork (); switch (fork_state) { case FORK_ERROR: status = -1; break; case FORK_CHILD: { signal (SIGINT, SIG_DFL); signal (SIGQUIT, SIG_DFL); signal (SIGTSTP, SIG_DFL); signal (SIGCHLD, SIG_DFL); execvp (command, argv); my_exit (127); /* Exec error */ } MC_FALLTHROUGH; /* no break here, or unreachable-code warning by no returning my_exit() */ default: status = 0; break; } my_system__restore_sigaction_handlers (&sigactions); return status; } /* --------------------------------------------------------------------------------------------- */ /** * Call external programs with flags and with array of strings as parameters. * * @parameter flags addition conditions for running external programs. * @parameter command shell (if flags contain EXECUTE_AS_SHELL), command to run otherwise. * Shell (or command) will be found in paths described in PATH variable * (if shell parameter doesn't begin from path delimiter) * @parameter argv Array of strings (NULL-terminated) with parameters for command * @return 0 if successfull, -1 otherwise */ int my_systemv_flags (int flags, const char *command, char *const argv[]) { char *execute_name = NULL; GPtrArray *args_array; int status = 0; args_array = my_system_make_arg_array (flags, command, &execute_name); for (; argv != NULL && *argv != NULL; argv++) g_ptr_array_add (args_array, *argv); g_ptr_array_add (args_array, NULL); status = my_systemv (execute_name, (char *const *) args_array->pdata); g_free (execute_name); g_ptr_array_free (args_array, TRUE); return status; } /* --------------------------------------------------------------------------------------------- */ /** * Create pipe and run child process. * * @parameter command command line of child process * @parameter read_out do or don't read the stdout of child process * @parameter read_err do or don't read the stderr of child process * @paremeter error contains pointer to object to handle error code and message * * @return newly created object of mc_pipe_t class in success, NULL otherwise */ mc_pipe_t * mc_popen (const char *command, gboolean read_out, gboolean read_err, GError ** error) { mc_pipe_t *p; const char *const argv[] = { "/bin/sh", "sh", "-c", command, NULL }; p = g_try_new (mc_pipe_t, 1); if (p == NULL) { mc_replace_error (error, MC_PIPE_ERROR_CREATE_PIPE, "%s", _("Cannot create pipe descriptor")); goto ret_err; } p->out.fd = -1; p->err.fd = -1; if (!g_spawn_async_with_pipes (NULL, (gchar **) argv, NULL, G_SPAWN_DO_NOT_REAP_CHILD | G_SPAWN_FILE_AND_ARGV_ZERO, NULL, NULL, &p->child_pid, NULL, read_out ? &p->out.fd : NULL, read_err ? &p->err.fd : NULL, error)) { mc_replace_error (error, MC_PIPE_ERROR_CREATE_PIPE_STREAM, "%s", _("Cannot create pipe streams")); goto ret_err; } p->out.buf[0] = '\0'; p->out.len = MC_PIPE_BUFSIZE; p->out.null_term = FALSE; p->err.buf[0] = '\0'; p->err.len = MC_PIPE_BUFSIZE; p->err.null_term = FALSE; return p; ret_err: g_free (p); return NULL; } /* --------------------------------------------------------------------------------------------- */ /** * Read stdout and stderr of pipe asynchronously. * * @parameter p pipe descriptor * * The lengths of read data contain in p->out.len and p->err.len. * * Before read, p->xxx.len is an input. It defines the number of data to read. * Should not be greater than MC_PIPE_BUFSIZE. * * After read, p->xxx.len is an output and contains the following: * p->xxx.len > 0: an actual length of read data stored in p->xxx.buf; * p->xxx.len == MC_PIPE_STREAM_EOF: EOF of stream p->xxx; * p->xxx.len == MC_PIPE_STREAM_UNREAD: stream p->xxx was not read; * p->xxx.len == MC_PIPE_ERROR_READ: reading error, and p->xxx.errno is set appropriately. * * @paremeter error contains pointer to object to handle error code and message */ void mc_pread (mc_pipe_t * p, GError ** error) { gboolean read_out, read_err; fd_set fds; int maxfd = 0; int res; if (error != NULL) *error = NULL; read_out = p->out.fd >= 0; read_err = p->err.fd >= 0; if (!read_out && !read_err) { p->out.len = MC_PIPE_STREAM_UNREAD; p->err.len = MC_PIPE_STREAM_UNREAD; return; } FD_ZERO (&fds); if (read_out) { FD_SET (p->out.fd, &fds); maxfd = p->out.fd; } if (read_err) { FD_SET (p->err.fd, &fds); maxfd = MAX (maxfd, p->err.fd); } /* no timeout */ res = select (maxfd + 1, &fds, NULL, NULL, NULL); if (res < 0 && errno != EINTR) { mc_propagate_error (error, MC_PIPE_ERROR_READ, _ ("Unexpected error in select() reading data from a child process:\n%s"), unix_error_string (errno)); return; } if (read_out) mc_pread_stream (&p->out, &fds); else p->out.len = MC_PIPE_STREAM_UNREAD; if (read_err) mc_pread_stream (&p->err, &fds); else p->err.len = MC_PIPE_STREAM_UNREAD; } /* --------------------------------------------------------------------------------------------- */ /** * Reads a line from @stream. Reading stops after an EOL or a newline. If a newline is read, * it is appended to the line. * * @stream mc_pipe_stream_t object * * @return newly created GString or NULL in case of EOL; */ GString * mc_pstream_get_string (mc_pipe_stream_t * ps) { char *s; size_t size, i; gboolean escape = FALSE; g_return_val_if_fail (ps != NULL, NULL); if (ps->len < 0) return NULL; size = ps->len - ps->pos; if (size == 0) return NULL; s = ps->buf + ps->pos; if (s[0] == '\0') return NULL; /* find '\0' or unescaped '\n' */ for (i = 0; i < size && !(s[i] == '\0' || (s[i] == '\n' && !escape)); i++) escape = s[i] == '\\' ? !escape : FALSE; if (i != size && s[i] == '\n') i++; ps->pos += i; return g_string_new_len (s, i); } /* --------------------------------------------------------------------------------------------- */ /** * Close pipe and destroy pipe descriptor. * * @paremeter p pipe descriptor * @paremeter error contains pointer to object to handle error code and message */ void mc_pclose (mc_pipe_t * p, GError ** error) { int res; if (p == NULL) { mc_replace_error (error, MC_PIPE_ERROR_READ, "%s", _("Cannot close pipe descriptor (p == NULL)")); return; } if (p->out.fd >= 0) res = close (p->out.fd); if (p->err.fd >= 0) res = close (p->err.fd); do { int status; res = waitpid (p->child_pid, &status, 0); } while (res < 0 && errno == EINTR); if (res < 0) mc_replace_error (error, MC_PIPE_ERROR_READ, _("Unexpected error in waitpid():\n%s"), unix_error_string (errno)); g_free (p); } /* --------------------------------------------------------------------------------------------- */ /** * Perform tilde expansion if possible. * * @param directory pointer to the path * * @return newly allocated string, even if it's unchanged. */ char * tilde_expand (const char *directory) { struct passwd *passwd; const char *p, *q; if (*directory != '~') return g_strdup (directory); p = directory + 1; /* d = "~" or d = "~/" */ if (*p == '\0' || IS_PATH_SEP (*p)) { passwd = getpwuid (geteuid ()); q = IS_PATH_SEP (*p) ? p + 1 : ""; } else { q = strchr (p, PATH_SEP); if (q == NULL) passwd = getpwnam (p); else { char *name; 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 == NULL) return g_strdup (directory); return g_strconcat (passwd->pw_dir, PATH_SEP_STR, q, (char *) NULL); } /* --------------------------------------------------------------------------------------------- */ /** * Canonicalize path. * * @param path path to file * @param flags canonicalization flags * * @return a new path * * All modifications of @path are made in place. * Well formed UNC paths are modified only in the local part. */ void canonicalize_pathname_custom (char *path, canon_path_flags_t flags) { char *p, *s; 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) != 0 && IS_PATH_SEP (path[0]) && IS_PATH_SEP (path[1])) { for (p = path + 2; p[0] != '\0' && !IS_PATH_SEP (p[0]); p++) ; if (IS_PATH_SEP (p[0]) && p > path + 2) lpath = p; } if (lpath[0] == '\0' || lpath[1] == '\0') return; if ((flags & CANON_PATH_JOINSLASHES) != 0) { /* Collapse multiple slashes */ for (p = lpath; *p != '\0'; p++) if (IS_PATH_SEP (p[0]) && IS_PATH_SEP (p[1]) && (p == lpath || *(p - 1) != ':')) { s = p + 1; while (IS_PATH_SEP (*(++s))) ; str_move (p + 1, s); } /* Collapse "/./" -> "/" */ for (p = lpath; *p != '\0';) if (IS_PATH_SEP (p[0]) && p[1] == '.' && IS_PATH_SEP (p[2])) str_move (p, p + 2); else p++; } if ((flags & CANON_PATH_REMSLASHDOTS) != 0) { size_t len; /* Remove trailing slashes */ for (p = lpath + strlen (lpath) - 1; p > lpath && IS_PATH_SEP (*p); p--) { 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] == '.' && IS_PATH_SEP (lpath[1])) { if (lpath[2] == '\0') { lpath[1] = '\0'; return; } str_move (lpath, lpath + 2); } /* Remove trailing "/" or "/." */ len = strlen (lpath); if (len < 2) return; if (IS_PATH_SEP (lpath[len - 1]) && (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] == '.' && IS_PATH_SEP (lpath[len - 2])) { if (len == 2) { lpath[1] = '\0'; return; } lpath[len - 2] = '\0'; } } /* Collapse "/.." with the previous part of path */ if ((flags & CANON_PATH_REMDOUBLEDOTS) != 0) { #ifdef HAVE_CHARSET const size_t enc_prefix_len = strlen (VFS_ENCODING_PREFIX); #endif /* HAVE_CHARSET */ for (p = lpath; p[0] != '\0' && p[1] != '\0' && p[2] != '\0';) { if (!IS_PATH_SEP (p[0]) || p[1] != '.' || p[2] != '.' || (!IS_PATH_SEP (p[3]) && 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 && !IS_PATH_SEP (*s--)) ; } 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; vfs_class *vclass; while (vfs_prefix > lpath && !IS_PATH_SEP (*--vfs_prefix)) ; if (IS_PATH_SEP (*vfs_prefix)) 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 && (vclass->flags & VFSF_REMOTE) != 0) { s = vfs_prefix; continue; } } if (IS_PATH_SEP (*s)) 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 && IS_PATH_SEP (*s)) { /* "/../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 (!IS_PATH_SEP (lpath[0])) 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 */ /* IS_PATH_SEP (s[-1]) */ for (p = s - 1; p >= lpath && !IS_PATH_SEP (*p); p--) ; if (p >= lpath) 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; } } } /* --------------------------------------------------------------------------------------------- */ /** * Canonicalize path with CANON_PATH_ALL. * * @param path path to file * @param flags canonicalization flags * * @return a new path * * All modifications of @path are made in place. * Well formed UNC paths are modified only in the local part. */ void canonicalize_pathname (char *path) { canonicalize_pathname_custom (path, CANON_PATH_ALL); } /* --------------------------------------------------------------------------------------------- */ char * mc_realpath (const char *path, char *resolved_path) { #ifdef HAVE_CHARSET const char *p = path; gboolean absolute_path = FALSE; if (IS_PATH_SEP (*p)) { absolute_path = TRUE; p++; } /* ignore encoding: skip "#enc:" */ if (g_str_has_prefix (p, VFS_ENCODING_PREFIX)) { p += strlen (VFS_ENCODING_PREFIX); p = strchr (p, PATH_SEP); if (p != NULL) { if (!absolute_path && p[1] != '\0') p++; path = p; } } #endif /* HAVE_CHARSET */ #ifdef HAVE_REALPATH return realpath (path, resolved_path); #else { char copy_path[PATH_MAX]; char got_path[PATH_MAX]; char *new_path = got_path; char *max_path; #ifdef S_IFLNK char link_path[PATH_MAX]; int readlinks = 0; int n; #endif /* S_IFLNK */ /* 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 (!IS_PATH_SEP (*path)) { new_path = g_get_current_dir (); if (new_path == NULL) strcpy (got_path, ""); else { g_snprintf (got_path, sizeof (got_path), "%s", new_path); g_free (new_path); new_path = got_path; } new_path += strlen (got_path); if (!IS_PATH_SEP (new_path[-1])) *new_path++ = PATH_SEP; } else { *new_path++ = PATH_SEP; path++; } /* Expand each slash-separated pathname component. */ while (*path != '\0') { /* Ignore stray "/". */ if (IS_PATH_SEP (*path)) { path++; continue; } if (*path == '.') { /* Ignore ".". */ if (path[1] == '\0' || IS_PATH_SEP (path[1])) { path++; continue; } if (path[1] == '.') { if (path[2] == '\0' || IS_PATH_SEP (path[2])) { path += 2; /* Ignore ".." at root. */ if (new_path == got_path + 1) continue; /* Handle ".." by backing up. */ while (!IS_PATH_SEP ((--new_path)[-1])) ; continue; } } } /* Safely copy the next pathname component. */ while (*path != '\0' && !IS_PATH_SEP (*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 (IS_PATH_SEP (*link_path)) /* Start over for an absolute symlink. */ new_path = got_path; else /* Otherwise back up over this component. */ while (!IS_PATH_SEP (*(--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++ = PATH_SEP; } /* Delete trailing slash but don't whomp a lone slash. */ if (new_path != got_path + 1 && IS_PATH_SEP (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 = IS_PATH_SEP (*first_element); 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 = IS_PATH_SEP (tmp_element[0]) ? tmp_element + 1 : tmp_element; g_string_append (path, start); if (!IS_PATH_SEP (tmp_element[len - 1]) && 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; } /* --------------------------------------------------------------------------------------------- */