mirror of
https://github.com/rd235/cado
synced 2024-12-27 06:24:11 +01:00
76 lines
1.9 KiB
C
76 lines
1.9 KiB
C
/*
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* cado: execute a command in a capability ambient
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* Copyright (C) 2016 Renzo Davoli, University of Bologna
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*
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* This file is part of cado.
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*
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* Cado is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#include <stdio.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#undef __linux__
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#ifdef __linux__
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#include <sys/sendfile.h>
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#define MAXSENDFILE 0x7ffff000
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#else
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#define BUFSIZE 1024
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#endif
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/* copy a file: when possible use a fast system call */
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ssize_t copyfile(int infd, int outfd) {
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ssize_t rv=0;
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ssize_t n;
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#ifdef __linux__
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do
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rv += n = sendfile(outfd, infd, NULL, MAXSENDFILE);
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while (n == MAXSENDFILE);
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#else
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static int pagesize;
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if (__builtin_expect((pagesize == 0),0)) pagesize=sysconf(_SC_PAGESIZE);
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char buf[BUFSIZE];
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while ((n = read(infd, buf, BUFSIZE)) > 0)
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rv += write(outfd, buf, n);
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#endif
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return (n < 0) ? n : rv;
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}
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/* create a temporary copy of a file (using copyfile) */
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/* outtemplate is a template for temporary files as explained in mkstemp(3) */
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ssize_t copytemp(char *inpath, char *outtemplate) {
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int infd=open(inpath, O_RDONLY);
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int outfd;
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mode_t oldmask;
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ssize_t rv;
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if (infd < 0)
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return -1;
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oldmask = umask(077);
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outfd = mkstemp(outtemplate);
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umask(oldmask);
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if (outfd < 0) {
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close(infd);
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return -1;
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}
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rv = copyfile(infd, outfd);
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close(infd);
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close(outfd);
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return rv;
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}
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