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Diffstat (limited to 'lib/utilunix.c')
| -rw-r--r-- | lib/utilunix.c | 1293 |
1 files changed, 1293 insertions, 0 deletions
diff --git a/lib/utilunix.c b/lib/utilunix.c new file mode 100644 index 0000000..42e0f6d --- /dev/null +++ b/lib/utilunix.c @@ -0,0 +1,1293 @@ +/* + Various utilities - Unix variants + + Copyright (C) 1994-2023 + 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 <aborodin@vmail.ru> 2010-2022 + + 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> +#ifdef HAVE_SYS_PARAM_H +#include <sys/param.h> +#endif +#include <sys/types.h> +#include <sys/stat.h> +#ifdef HAVE_SYS_SELECT_H +#include <sys/select.h> +#endif +#include <sys/wait.h> +#include <pwd.h> +#include <grp.h> + +#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; + +/*** forward declarations (file scope functions) *************************************************/ + +/*** 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 successful, -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 paths 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 successful, -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 successful, -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 successful, -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 + * @parameter 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. + * + * @parameter 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. + * + * @parameter p pipe descriptor + * @parameter 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 + * + * 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; + } + } +} + +/* --------------------------------------------------------------------------------------------- */ + +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; +} + +/* --------------------------------------------------------------------------------------------- */ |