root/ext/standard/exec.c

/* [<][>][^][v][top][bottom][index][help] */

DEFINITIONS

This source file includes following definitions.
  1. php_exec
  2. php_exec_ex
  3. PHP_FUNCTION
  4. PHP_FUNCTION
  5. PHP_FUNCTION
  6. php_escape_shell_cmd
  7. php_escape_shell_arg
  8. PHP_FUNCTION
  9. PHP_FUNCTION
  10. PHP_FUNCTION
  11. PHP_FUNCTION

/*
   +----------------------------------------------------------------------+
   | PHP Version 5                                                        |
   +----------------------------------------------------------------------+
   | Copyright (c) 1997-2015 The PHP Group                                |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | http://www.php.net/license/3_01.txt                                  |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
   | Author: Rasmus Lerdorf <rasmus@php.net>                              |
   |         Ilia Alshanetsky <iliaa@php.net>                             |
   +----------------------------------------------------------------------+
 */
/* $Id$ */

#include <stdio.h>
#include "php.h"
#include <ctype.h>
#include "php_string.h"
#include "ext/standard/head.h"
#include "ext/standard/file.h"
#include "basic_functions.h"
#include "exec.h"
#include "php_globals.h"
#include "SAPI.h"

#if HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif
#if HAVE_SIGNAL_H
#include <signal.h>
#endif

#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#if HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#if HAVE_FCNTL_H
#include <fcntl.h>
#endif

#if HAVE_NICE && HAVE_UNISTD_H
#include <unistd.h>
#endif

/* {{{ php_exec
 * If type==0, only last line of output is returned (exec)
 * If type==1, all lines will be printed and last lined returned (system)
 * If type==2, all lines will be saved to given array (exec with &$array)
 * If type==3, output will be printed binary, no lines will be saved or returned (passthru)
 *
 */
PHPAPI int php_exec(int type, char *cmd, zval *array, zval *return_value TSRMLS_DC)
{
        FILE *fp;
        char *buf;
        int l = 0, pclose_return;
        char *b, *d=NULL;
        php_stream *stream;
        size_t buflen, bufl = 0;
#if PHP_SIGCHILD
        void (*sig_handler)() = NULL;
#endif

#if PHP_SIGCHILD
        sig_handler = signal (SIGCHLD, SIG_DFL);
#endif

#ifdef PHP_WIN32
        fp = VCWD_POPEN(cmd, "rb");
#else
        fp = VCWD_POPEN(cmd, "r");
#endif
        if (!fp) {
                php_error_docref(NULL TSRMLS_CC, E_WARNING, "Unable to fork [%s]", cmd);
                goto err;
        }

        stream = php_stream_fopen_from_pipe(fp, "rb");

        buf = (char *) emalloc(EXEC_INPUT_BUF);
        buflen = EXEC_INPUT_BUF;

        if (type != 3) {
                b = buf;
                
                while (php_stream_get_line(stream, b, EXEC_INPUT_BUF, &bufl)) {
                        /* no new line found, let's read some more */
                        if (b[bufl - 1] != '\n' && !php_stream_eof(stream)) {
                                if (buflen < (bufl + (b - buf) + EXEC_INPUT_BUF)) {
                                        bufl += b - buf;
                                        buflen = bufl + EXEC_INPUT_BUF;
                                        buf = erealloc(buf, buflen);
                                        b = buf + bufl;
                                } else {
                                        b += bufl;
                                }
                                continue;
                        } else if (b != buf) {
                                bufl += b - buf;
                        }

                        if (type == 1) {
                                PHPWRITE(buf, bufl);
                                if (php_output_get_level(TSRMLS_C) < 1) {
                                        sapi_flush(TSRMLS_C);
                                }
                        } else if (type == 2) {
                                /* strip trailing whitespaces */
                                l = bufl;
                                while (l-- && isspace(((unsigned char *)buf)[l]));
                                if (l != (int)(bufl - 1)) {
                                        bufl = l + 1;
                                        buf[bufl] = '\0';
                                }
                                add_next_index_stringl(array, buf, bufl, 1);
                        }
                        b = buf;
                }
                if (bufl) {
                        /* strip trailing whitespaces if we have not done so already */
                        if ((type == 2 && buf != b) || type != 2) {
                                l = bufl;
                                while (l-- && isspace(((unsigned char *)buf)[l]));
                                if (l != (int)(bufl - 1)) {
                                        bufl = l + 1;
                                        buf[bufl] = '\0';
                                }
                                if (type == 2) {
                                        add_next_index_stringl(array, buf, bufl, 1);
                                }
                        }

                        /* Return last line from the shell command */
                        RETVAL_STRINGL(buf, bufl, 1);
                } else { /* should return NULL, but for BC we return "" */
                        RETVAL_EMPTY_STRING();
                }
        } else {
                while((bufl = php_stream_read(stream, buf, EXEC_INPUT_BUF)) > 0) {
                        PHPWRITE(buf, bufl);
                }
        }

        pclose_return = php_stream_close(stream);
        efree(buf);

done:
#if PHP_SIGCHILD
        if (sig_handler) {
                signal(SIGCHLD, sig_handler);
        }
#endif
        if (d) {
                efree(d);
        }
        return pclose_return;
err:
        pclose_return = -1;
        goto done;
}
/* }}} */

static void php_exec_ex(INTERNAL_FUNCTION_PARAMETERS, int mode) /* {{{ */
{
        char *cmd;
        int cmd_len;
        zval *ret_code=NULL, *ret_array=NULL;
        int ret;

        if (mode) {
                if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s|z/", &cmd, &cmd_len, &ret_code) == FAILURE) {
                        RETURN_FALSE;
                }
        } else {
                if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s|z/z/", &cmd, &cmd_len, &ret_array, &ret_code) == FAILURE) {
                        RETURN_FALSE;
                }
        }
        if (!cmd_len) {
                php_error_docref(NULL TSRMLS_CC, E_WARNING, "Cannot execute a blank command");
                RETURN_FALSE;
        }
        if (strlen(cmd) != cmd_len) {
                php_error_docref(NULL TSRMLS_CC, E_WARNING, "NULL byte detected. Possible attack");
                RETURN_FALSE;
        }

        if (!ret_array) {
                ret = php_exec(mode, cmd, NULL, return_value TSRMLS_CC);
        } else {
                if (Z_TYPE_P(ret_array) != IS_ARRAY) {
                        zval_dtor(ret_array);
                        array_init(ret_array);
                }
                ret = php_exec(2, cmd, ret_array, return_value TSRMLS_CC);
        }
        if (ret_code) {
                zval_dtor(ret_code);
                ZVAL_LONG(ret_code, ret);
        }
}
/* }}} */

/* {{{ proto string exec(string command [, array &output [, int &return_value]])
   Execute an external program */
PHP_FUNCTION(exec)
{
        php_exec_ex(INTERNAL_FUNCTION_PARAM_PASSTHRU, 0);
}
/* }}} */

/* {{{ proto int system(string command [, int &return_value])
   Execute an external program and display output */
PHP_FUNCTION(system)
{
        php_exec_ex(INTERNAL_FUNCTION_PARAM_PASSTHRU, 1);
}
/* }}} */

/* {{{ proto void passthru(string command [, int &return_value])
   Execute an external program and display raw output */
PHP_FUNCTION(passthru)
{
        php_exec_ex(INTERNAL_FUNCTION_PARAM_PASSTHRU, 3);
}
/* }}} */

/* {{{ php_escape_shell_cmd
   Escape all chars that could possibly be used to
   break out of a shell command

   This function emalloc's a string and returns the pointer.
   Remember to efree it when done with it.

   *NOT* safe for binary strings
*/
PHPAPI char *php_escape_shell_cmd(char *str)
{
        register int x, y, l = strlen(str);
        char *cmd;
        char *p = NULL;
        size_t estimate = (2 * l) + 1;

        TSRMLS_FETCH();

        cmd = safe_emalloc(2, l, 1);

        for (x = 0, y = 0; x < l; x++) {
                int mb_len = php_mblen(str + x, (l - x));

                /* skip non-valid multibyte characters */
                if (mb_len < 0) {
                        continue;
                } else if (mb_len > 1) {
                        memcpy(cmd + y, str + x, mb_len);
                        y += mb_len;
                        x += mb_len - 1;
                        continue;
                }

                switch (str[x]) {
#ifndef PHP_WIN32
                        case '"':
                        case '\'':
                                if (!p && (p = memchr(str + x + 1, str[x], l - x - 1))) {
                                        /* noop */
                                } else if (p && *p == str[x]) {
                                        p = NULL;
                                } else {
                                        cmd[y++] = '\\';
                                }
                                cmd[y++] = str[x];
                                break;
#else
                        /* % is Windows specific for enviromental variables, ^%PATH% will 
                                output PATH while ^%PATH^% will not. escapeshellcmd will escape all % and !.
                        */
                        case '%':
                        case '!':
                        case '"':
                        case '\'':
#endif
                        case '#': /* This is character-set independent */
                        case '&':
                        case ';':
                        case '`':
                        case '|':
                        case '*':
                        case '?':
                        case '~':
                        case '<':
                        case '>':
                        case '^':
                        case '(':
                        case ')':
                        case '[':
                        case ']':
                        case '{':
                        case '}':
                        case '$':
                        case '\\':
                        case '\x0A': /* excluding these two */
                        case '\xFF':
#ifdef PHP_WIN32
                                cmd[y++] = '^';
#else
                                cmd[y++] = '\\';
#endif
                                /* fall-through */
                        default:
                                cmd[y++] = str[x];

                }
        }
        cmd[y] = '\0';

        if ((estimate - y) > 4096) {
                /* realloc if the estimate was way overill
                 * Arbitrary cutoff point of 4096 */
                cmd = erealloc(cmd, y + 1);
        }

        return cmd;
}
/* }}} */

/* {{{ php_escape_shell_arg
 */
PHPAPI char *php_escape_shell_arg(char *str)
{
        int x, y = 0, l = strlen(str);
        char *cmd;
        size_t estimate = (4 * l) + 3;

        TSRMLS_FETCH();

        cmd = safe_emalloc(4, l, 3); /* worst case */

#ifdef PHP_WIN32
        cmd[y++] = '"';
#else
        cmd[y++] = '\'';
#endif

        for (x = 0; x < l; x++) {
                int mb_len = php_mblen(str + x, (l - x));

                /* skip non-valid multibyte characters */
                if (mb_len < 0) {
                        continue;
                } else if (mb_len > 1) {
                        memcpy(cmd + y, str + x, mb_len);
                        y += mb_len;
                        x += mb_len - 1;
                        continue;
                }

                switch (str[x]) {
#ifdef PHP_WIN32
                case '"':
                case '%':
                case '!':
                        cmd[y++] = ' ';
                        break;
#else
                case '\'':
                        cmd[y++] = '\'';
                        cmd[y++] = '\\';
                        cmd[y++] = '\'';
#endif
                        /* fall-through */
                default:
                        cmd[y++] = str[x];
                }
        }
#ifdef PHP_WIN32
        if (y > 0 && '\\' == cmd[y - 1]) {
                int k = 0, n = y - 1;
                for (; n >= 0 && '\\' == cmd[n]; n--, k++);
                if (k % 2) {
                        cmd[y++] = '\\';
                }
        }

        cmd[y++] = '"';
#else
        cmd[y++] = '\'';
#endif
        cmd[y] = '\0';

        if ((estimate - y) > 4096) {
                /* realloc if the estimate was way overill
                 * Arbitrary cutoff point of 4096 */
                cmd = erealloc(cmd, y + 1);
        }
        return cmd;
}
/* }}} */

/* {{{ proto string escapeshellcmd(string command)
   Escape shell metacharacters */
PHP_FUNCTION(escapeshellcmd)
{
        char *command;
        int command_len;
        char *cmd = NULL;

        if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s", &command, &command_len) == FAILURE) {
                return;
        }

        if (command_len) {
                cmd = php_escape_shell_cmd(command);
                RETVAL_STRING(cmd, 0);
        } else {
                RETVAL_EMPTY_STRING();
        }
}
/* }}} */

/* {{{ proto string escapeshellarg(string arg)
   Quote and escape an argument for use in a shell command */
PHP_FUNCTION(escapeshellarg)
{
        char *argument;
        int argument_len;
        char *cmd = NULL;

        if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s", &argument, &argument_len) == FAILURE) {
                return;
        }

        if (argument) {
                cmd = php_escape_shell_arg(argument);
                RETVAL_STRING(cmd, 0);
        }
}
/* }}} */

/* {{{ proto string shell_exec(string cmd)
   Execute command via shell and return complete output as string */
PHP_FUNCTION(shell_exec)
{
        FILE *in;
        size_t total_readbytes;
        char *command;
        int command_len;
        char *ret;
        php_stream *stream;

        if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s", &command, &command_len) == FAILURE) {
                return;
        }

#ifdef PHP_WIN32
        if ((in=VCWD_POPEN(command, "rt"))==NULL) {
#else
        if ((in=VCWD_POPEN(command, "r"))==NULL) {
#endif
                php_error_docref(NULL TSRMLS_CC, E_WARNING, "Unable to execute '%s'", command);
                RETURN_FALSE;
        }

        stream = php_stream_fopen_from_pipe(in, "rb");
        total_readbytes = php_stream_copy_to_mem(stream, &ret, PHP_STREAM_COPY_ALL, 0);
        php_stream_close(stream);

        if (total_readbytes > 0) {
                RETVAL_STRINGL(ret, total_readbytes, 0);
        }
}
/* }}} */

#ifdef HAVE_NICE
/* {{{ proto bool proc_nice(int priority)
   Change the priority of the current process */
PHP_FUNCTION(proc_nice)
{
        long pri;

        if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "l", &pri) == FAILURE) {
                RETURN_FALSE;
        }

        errno = 0;
        php_ignore_value(nice(pri));
        if (errno) {
                php_error_docref(NULL TSRMLS_CC, E_WARNING, "Only a super user may attempt to increase the priority of a process");
                RETURN_FALSE;
        }

        RETURN_TRUE;
}
/* }}} */
#endif

/*
 * Local variables:
 * tab-width: 4
 * c-basic-offset: 4
 * End:
 * vim600: sw=4 ts=4 fdm=marker
 * vim<600: sw=4 ts=4
 */

/* [<][>][^][v][top][bottom][index][help] */