/usr/share/doc/libsvn1/examples/svnserve-sgid.c is in libsvn-doc 1.9.7-4ubuntu1.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 | /*
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*
*/
/*
* Wrapper to run the svnserve process setgid.
* The idea is to avoid the problem that some interpreters like bash
* invoked by svnserve in hook scripts will reset the effective gid to
* the real gid, nuking the effect of an ordinary setgid svnserve binary.
* Sadly, to set the real gid portably, you need to be root, if only
* for a moment.
* Also smashes the environment to something known, so that games
* can't be played to try to break the security of the hook scripts,
* by setting IFS, PATH, and similar means.
*/
/*
* Written by Perry Metzger, and placed into the public domain.
*/
#include <stdio.h>
#include <unistd.h>
#define REAL_PATH "/usr/bin/svnserve.real"
char *newenv[] = { "PATH=/bin:/usr/bin", "SHELL=/bin/sh", NULL };
int
main(int argc, char **argv)
{
if (setgid(getegid()) == -1) {
perror("setgid(getegid())");
return 1;
}
if (seteuid(getuid()) == -1) {
perror("seteuid(getuid())");
return 1;
}
execve(REAL_PATH, argv, newenv);
perror("attempting to exec " REAL_PATH " failed");
return 1;
}
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