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/*
* manconv_client.c: use manconv in a pipeline
*
* Copyright (C) 2007, 2008, 2010 Colin Watson.
*
* This file is part of man-db.
*
* man-db 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 2 of the License, or
* (at your option) any later version.
*
* man-db 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 man-db; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif /* HAVE_CONFIG_H */
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include "gl_array_list.h"
#include "gl_xlist.h"
#include "xalloc.h"
#include "xvasprintf.h"
#include "manconfig.h"
#include "pipeline.h"
#include "appendstr.h"
#include "glcontainers.h"
#include "sandbox.h"
#include "security.h"
#include "decompress.h"
#include "manconv.h"
#include "manconv_client.h"
#include "utf8.h"
extern man_sandbox *sandbox;
struct manconv_codes {
gl_list_t from;
char *to;
};
static void manconv_stdin (void *data)
{
struct manconv_codes *codes = data;
decompress *decomp;
decomp = decompress_fdopen (dup (STDIN_FILENO));
decompress_start (decomp);
if (manconv (decomp, codes->from, codes->to, NULL) != 0)
/* manconv already wrote an error message to stderr. Just
* exit non-zero.
*/
exit (FATAL);
decompress_wait (decomp);
decompress_free (decomp);
}
static void manconv_pre_exec (void *data)
{
/* We must drop privileges before loading the sandbox, since our
* seccomp filter doesn't allow setresuid and friends.
*/
drop_privs (NULL);
sandbox_load (data);
}
static void free_manconv_codes (void *data)
{
struct manconv_codes *codes = data;
gl_list_free (codes->from);
free (codes->to);
free (codes);
}
void add_manconv (pipeline *p,
const char *source_encoding, const char *target_encoding)
{
struct manconv_codes *codes;
char *name;
pipecmd *cmd;
if (STREQ (source_encoding, target_encoding))
return;
codes = xmalloc (sizeof *codes);
/* informational only; no shell quoting concerns */
name = xasprintf ("%s -f ", MANCONV);
codes->from = new_string_list (GL_ARRAY_LIST, true);
if (STREQ (source_encoding, "UTF-8")) {
gl_list_add_last (codes->from, xstrdup (source_encoding));
name = appendstr (name, source_encoding, (void *) 0);
} else {
gl_list_add_last (codes->from, xstrdup ("UTF-8"));
gl_list_add_last (codes->from, xstrdup (source_encoding));
name = appendstr (name, "UTF-8:", source_encoding, (void *) 0);
}
codes->to = xasprintf ("%s//IGNORE", target_encoding);
/* informational only; no shell quoting concerns */
name = appendstr (name, " -t ", codes->to, (void *) 0);
if (quiet >= 2)
name = appendstr (name, " -q", (void *) 0);
/* iconv_open may not work correctly in setuid processes; in GNU
* libc, gconv modules may be linked against other gconv modules and
* rely on RPATH $ORIGIN to load those modules from the correct
* path, but $ORIGIN is disabled in setuid processes. It is
* impossible to reset libc's idea of setuidness without creating a
* whole new process image. Therefore, if the calling process is
* setuid, we must drop privileges and execute manconv.
*/
if (running_setuid ()) {
gl_list_t from = codes->from;
const char *from_code;
char *sources = NULL;
cmd = pipecmd_new_args (MANCONV, "-f", (void *) 0);
GL_LIST_FOREACH (from, from_code) {
sources = appendstr (sources, from_code, (void *) 0);
if (gl_list_next_node (from, from_node))
sources = appendstr (sources, ":", (void *) 0);
}
pipecmd_arg (cmd, sources);
free (sources);
pipecmd_args (cmd, "-t", codes->to, (void *) 0);
if (quiet >= 2)
pipecmd_arg (cmd, "-q");
pipecmd_pre_exec (cmd, manconv_pre_exec, sandbox_free,
sandbox);
free_manconv_codes (codes);
} else {
cmd = pipecmd_new_function (name, &manconv_stdin,
&free_manconv_codes, codes);
pipecmd_pre_exec (cmd, sandbox_load, sandbox_free, sandbox);
}
free (name);
pipeline_command (p, cmd);
}
/* Convert the result of in-process decompression to a target encoding.
*
* This converts the buffered result of decompression to a new buffer, then
* replaces the decompress object's buffer with the converted one for use by
* later stages of processing.
*
* Returns zero on success or non-zero on failure.
*/
int manconv_inprocess (decompress *d,
const char *source_encoding,
const char *target_encoding)
{
gl_list_t from;
char *to;
struct manconv_outbuf outbuf;
int ret = 0;
if (STREQ (source_encoding, target_encoding))
return 0;
from = new_string_list (GL_ARRAY_LIST, true);
if (STREQ (source_encoding, "UTF-8"))
gl_list_add_last (from, xstrdup (source_encoding));
else {
if (STREQ (target_encoding, "UTF-8")) {
/* If the target encoding is UTF-8, then instead of
* starting with trial conversion from UTF-8 to
* UTF-8, we can start by simply performing UTF-8
* validation, avoiding a copy. (The source
* encoding cannot be UTF-8 in this case, since we
* already checked that the source and target
* encodings are different.)
*/
if (utf8_validate_len (decompress_inprocess_buf (d),
decompress_inprocess_len (d)))
goto out;
} else
gl_list_add_last (from, xstrdup ("UTF-8"));
gl_list_add_last (from, xstrdup (source_encoding));
}
to = xasprintf ("%s//IGNORE", target_encoding);
outbuf.len = 0;
/* UTF-8 uses at most four bytes per Unicode code point. We assume
* that this conversion will be no worse than 1:4.
*/
outbuf.max = decompress_inprocess_len (d) * 4;
outbuf.buf = xmalloc (outbuf.max);
if (manconv (d, from, to, &outbuf) == 0)
decompress_inprocess_replace (d, outbuf.buf, outbuf.len);
else {
/* manconv already wrote an error message to stderr. Just
* return non-zero.
*/
free (outbuf.buf);
ret = -1;
}
free (to);
out:
gl_list_free (from);
return ret;
}
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