mirror of https://github.com/rd235/cado
76 lines
1.9 KiB
C
76 lines
1.9 KiB
C
/*
|
|
* cado: execute a command in a capability ambient
|
|
* Copyright (C) 2016 Renzo Davoli, University of Bologna
|
|
*
|
|
* This file is part of cado.
|
|
*
|
|
* Cado 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.
|
|
*
|
|
* This program 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/>.
|
|
*
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <fcntl.h>
|
|
#include <unistd.h>
|
|
#include <stdlib.h>
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
|
|
#undef __linux__
|
|
#ifdef __linux__
|
|
#include <sys/sendfile.h>
|
|
#define MAXSENDFILE 0x7ffff000
|
|
#else
|
|
#define BUFSIZE 1024
|
|
#endif
|
|
|
|
/* copy a file: when possible use a fast system call */
|
|
ssize_t copyfile(int infd, int outfd) {
|
|
ssize_t rv=0;
|
|
ssize_t n;
|
|
#ifdef __linux__
|
|
do
|
|
rv += n = sendfile(outfd, infd, NULL, MAXSENDFILE);
|
|
while (n == MAXSENDFILE);
|
|
#else
|
|
static int pagesize;
|
|
if (__builtin_expect((pagesize == 0),0)) pagesize=sysconf(_SC_PAGESIZE);
|
|
char buf[BUFSIZE];
|
|
while ((n = read(infd, buf, BUFSIZE)) > 0)
|
|
rv += write(outfd, buf, n);
|
|
#endif
|
|
return (n < 0) ? n : rv;
|
|
}
|
|
|
|
/* create a temporary copy of a file (using copyfile) */
|
|
/* outtemplate is a template for temporary files as explained in mkstemp(3) */
|
|
ssize_t copytemp(char *inpath, char *outtemplate) {
|
|
int infd=open(inpath, O_RDONLY);
|
|
int outfd;
|
|
mode_t oldmask;
|
|
ssize_t rv;
|
|
if (infd < 0)
|
|
return -1;
|
|
oldmask = umask(077);
|
|
outfd = mkstemp(outtemplate);
|
|
umask(oldmask);
|
|
if (outfd < 0) {
|
|
close(infd);
|
|
return -1;
|
|
}
|
|
rv = copyfile(infd, outfd);
|
|
close(infd);
|
|
close(outfd);
|
|
return rv;
|
|
}
|